WO2010004964A1 - Gan crystal substrate, gan crystal substrate manufacturing method, gan crystal substrate provided with semiconductor epitaxial layer, semiconductor device and semiconductor device manufacturing method - Google Patents

Gan crystal substrate, gan crystal substrate manufacturing method, gan crystal substrate provided with semiconductor epitaxial layer, semiconductor device and semiconductor device manufacturing method Download PDF

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WO2010004964A1
WO2010004964A1 PCT/JP2009/062310 JP2009062310W WO2010004964A1 WO 2010004964 A1 WO2010004964 A1 WO 2010004964A1 JP 2009062310 W JP2009062310 W JP 2009062310W WO 2010004964 A1 WO2010004964 A1 WO 2010004964A1
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crystal
dislocation density
region
gan
substrate
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PCT/JP2009/062310
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French (fr)
Japanese (ja)
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英樹 長田
成二 中畑
木山 誠
拓 堀井
和英 住吉
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住友電気工業株式会社
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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104Forming layers
    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02612Formation types
    • H01L21/02617Deposition types
    • H01L21/02636Selective deposition, e.g. simultaneous growth of mono- and non-monocrystalline semiconductor materials
    • H01L21/02639Preparation of substrate for selective deposition
    • CCHEMISTRY; METALLURGY
    • C30CRYSTAL GROWTH
    • C30BSINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B25/00Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
    • C30B25/02Epitaxial-layer growth
    • CCHEMISTRY; METALLURGY
    • C30CRYSTAL GROWTH
    • C30BSINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10Inorganic compounds or compositions
    • C30B29/40AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
    • C30B29/403AIII-nitrides
    • C30B29/406Gallium nitride
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    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104Forming layers
    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02367Substrates
    • H01L21/0237Materials
    • H01L21/02387Group 13/15 materials
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    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104Forming layers
    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02367Substrates
    • H01L21/0237Materials
    • H01L21/02387Group 13/15 materials
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    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104Forming layers
    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02367Substrates
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    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
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    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02436Intermediate layers between substrates and deposited layers
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    • H01L21/00Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/02104Forming layers
    • H01L21/02365Forming inorganic semiconducting materials on a substrate
    • H01L21/02518Deposited layers
    • H01L21/02521Materials
    • H01L21/02538Group 13/15 materials
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    • H01L2924/30Technical effects
    • H01L2924/301Electrical effects
    • H01L2924/30105Capacitance

Abstract

A GaN crystal substrate (20p) has a main surface (20m) having an off angle of 0° or more but not more than 30° to a (0001) plane, and includes a low dislocation density crystal region (20k) and a high dislocation density crystal region (20h).  The high dislocation density crystal region (20h) on the main surface (20m) has a shape of a lattice which includes a plurality of first stripe crystal regions (20hs) extending in a [1-100] direction, and a plurality of second stripe crystal regions (20ht) extending in a[11-20] direction.  Thus, the GaN crystal substrate, which has large effects of collecting displacements and low dislocation density in a low dislocation density crystal region even with a large pitch of the high dislocation density crystal region and has a small warpage, is provided.

Description

GaN crystal substrate and a manufacturing method thereof, GaN crystal substrate with a semiconductor epitaxial layer and a semiconductor device and a manufacturing method thereof,

The present invention relates to a light emitting device, to suitably GaN crystal substrate and a manufacturing method thereof, for use in the manufacture of semiconductor devices such as electronic devices. More particularly, to a GaN crystal substrate and a manufacturing method thereof including low dislocation density crystal region.

GaN crystal substrate, a light emitting device, are widely used in a semiconductor device such as an electronic device. To enhance the physical properties of semiconductor devices, development of low dislocation density GaN crystal substrate has been advanced.

For example, JP 2003-165799 (Patent Document 1), by the facet growing GaN crystal by placing a dot-like seed crystal on the starting substrate, attracting dislocations on dot-shaped seed crystal dot forming a Jo of high dislocation density crystal region, discloses a method of manufacturing a GaN crystal substrate having a low dislocation density crystal region thereby formed.

Further, JP 2003-183100 (Patent Document 2), by the facet growing GaN crystal by placing a mask in the shape of a stripe on an underlying substrate, a stripe-shaped attracting dislocations on the stripe-shaped mask forming a high dislocation density crystal region, discloses a method of manufacturing a GaN crystal substrate having a low dislocation density crystal region thereby formed.

JP 2003-165799 JP JP 2003-183100 JP

However, in the method of the JP-2003-165799 (Patent Document 1), a high dislocation density crystal region of the dot-shaped dislocations concentrated at a high dislocation density is very small compared to the whole crystalline region, dots Jo of high dislocation density crystal region to lower the effect of gathering dislocations, effect of reducing the dislocation density of the low dislocation density crystal region is low. Further, in order to widen the low dislocation density crystal region, the dislocation to increase the pitch of the dot-like high dislocation density crystal region concentrated at a high dislocation density, the effect of collecting dislocations in dots of high dislocation density crystal region further decreases, the effect of reducing the dislocation density of the low dislocation density crystal region is further reduced.

Also in the method of JP 2003-183100 (Patent Document 2), in order to widen the low dislocation density crystal region, the pitch of the stripe-shaped high dislocation density crystal region dislocations becomes high dislocation density is concentrated When the larger, reduced the effect of gathering dislocations in dots or stripes of high dislocation density crystal region, the effect of reducing the dislocation density of the low dislocation density crystal region is reduced.

Also, GaN crystal, by the internal stress tends crystals warp caused by propagation of dislocations and dislocation generated when the GaN crystal and the chemical composition is grown on the underlying substrate different heterologous. Therefore, the deviation of the plane orientation occurs between the central portion and the peripheral portion of the main surface of the GaN crystal substrate. In contrast, by forming a stripe-shaped high dislocation density crystal region, the plane orientation of the central portion and the peripheral portion of the main surface of GaN crystal substrate by suppressing the propagation of dislocations for the direction parallel to the stripe direction it can be alleviated deviation. However, to form a stripe-shaped high dislocation density crystal region, the direction perpendicular to the stripe direction was not possible to alleviate the displacement of the plane orientation of the central portion and the peripheral portion of the main surface of GaN crystal substrate .

The interval of the stripe high dislocation density crystal region is also to prepare a Schottky barrier diode is a semiconductor device using the above GaN crystal substrate 400 [mu] m, reverse withstand voltage is disadvantageously lowered. Observation of the low dislocation density crystal region over the width 400μm of GaN crystal substrate by CL (cathode luminescence), low dislocation density high-dislocation-density dislocations in the portion near the crystal region locally 1 × 10 7 in the crystalline regions cm -2 dislocation concentrated region centered was more observed as dark portions above. Such dislocation-concentrated region, the larger the distance between the high dislocation density crystal region, i.e. the width of the low dislocation density crystal region increases, was larger number observed. Furthermore, dislocation-concentrated region in the GaN crystal substrate in a semiconductor device, causing a reduction of the withstand voltage of the semiconductor device.

The present invention is to solve the above problems, a high dislocation density crystals be larger pitch area low dislocation density effect is large low dislocation density crystal region gathering dislocations uniformly small warpage GaN crystal substrate and its manufacturing method, and an object thereof is to provide a semiconductor device and a manufacturing method thereof including GaN crystal substrate with an epitaxial layer including a GaN crystal substrate, as well as a GaN crystal substrate.

The present invention, (0001) plane having a main surface having an off angle of 0 ° or 30 ° or less with respect to, and a low dislocation density crystal region and the high dislocation density crystal region, the high dislocation density crystals along the principal face shape of the region is a GaN crystal substrate is a lattice shape and a plurality of second stripe-crystal region extending in the [1-100] plurality of first stripe-crystal region extending in the direction [11-20] direction. Here, the off-angle of the primary surface, means an off angle at the center point of the main surface.

In GaN crystal substrate according to the present invention, the first stripe crystal region can pitch a width of 5μm or 120μm or less and 200μm or more 10000μm less, second stripe crystal region pitch width of 5μm or 120μm or less 200μm it can be equal to or greater than 10000μm below. The high dislocation density crystal region may be a polarity reversed crystal region in which the polarity of the [0001] direction is inverted with respect to low dislocation density crystals region. Further, low dislocation density crystals region, the ratio of the area of ​​(0001) plane growth and a crystalline region and facet growth crystal region, (0001) to the area of ​​facet growth crystal region in the main surface plane growth crystal region 0.7 it can be less than or equal to. Moreover, the off-angle and the center of the first deviation angle and the center of the main surface is the difference between the off-angle at the end of the [1-100] direction from the off-angle and the center at the center of the main surface [11-20 ] direction of the second deviation angle is the difference between the off-angle at the ends and respectively 0 ℃ 0.30 ° or less, and the first displacement angle difference between the second displacement angle 0 ℃ 0.30 ° can be less than or equal to. Further, the first stripe-crystalline region or the second stripe crystal region can be discontinuous at at least one location. Further, the carrier concentration can be 1 × 10 18 cm -3 or more 1.2 × 10 19 cm -3 or less. Further, low dislocation density crystal region can have a 0.1 / region than 5.5 pieces / area less dislocation concentrated region per region surrounded by high dislocation density crystal region.

Further, the present invention is a manufacturing method of the GaN crystal substrate, the main surface having an off angle of 0 ° or 30 ° or less with respect to the plane orientation of the base substrate corresponding to the (0001) plane of the GaN crystal substrate preparing a base substrate having a plurality of first stripe mask extending in a first direction corresponding to the [1-100] direction of GaN crystal substrate on the principal surface of the base substrate, the GaN crystal substrate [11- 20] forming a mask having a lattice-like pattern comprising a plurality of second stripe mask extending in a second direction, the corresponding direction, a GaN crystal is grown on the main surface of the base substrate on which the mask is formed and a step, obtaining a GaN crystal substrate by forming a main surface parallel to the GaN crystal on the main surface of the base substrate. The step of growing a GaN crystal, the GaN crystal on the masked growth (000-1) plane, the GaN crystal in the central portion of the opening portion of the mask of the underlying substrate to grow (0001) plane, the periphery of the opening of the mask GaN crystal is grown facets in part. Thus, (0001) and a low dislocation density crystal region formed by the surface growth and facet growth, GaN crystal grows including a high dislocation density crystal region formed by the (000-1) plane growth. The manufacturing method of a GaN crystal substrate according to the present invention, the first stripe mask or the second stripe masks may be discontinuous at at least one location.

Further, the present invention comprises at least one layer III nitride semiconductor epitaxial layer is formed on the GaN crystal substrate and the GaN crystal substrate, the group III nitride semiconductor epitaxial layer of GaN crystal substrate low GaN crystal substrate with a semiconductor epitaxial layer including the high dislocation density epitaxial crystal region formed right above the high dislocation density crystal region of low dislocation density epitaxial crystal region and the GaN crystal substrate is formed right above the dislocation density crystal region it is.

Further, the present invention includes the above GaN crystal substrate, at least one layer III nitride semiconductor epitaxial layer is formed on one main surface of GaN crystal substrate, the principal plane of the Group III nitride semiconductor epitaxial layer and a electrode formed on at least one of the upper and the other main surface of the GaN crystal substrate, GaN crystal substrate, in at least 400μm square size, the dislocation density of less than 1 × 10 7 cm -2 it is a semiconductor device. In the semiconductor device according to the present invention, the GaN crystal substrate (0001) plane growth and a crystalline region and facet growth crystal region, (0001) to the area of ​​facet growth crystal region in one main surface of GaN crystal substrate surface growth the ratio of the area of ​​the crystal region can be 0.2 to 0.7.

Further, the present invention includes the steps of preparing the GaN crystal substrate, and growing a group III nitride semiconductor epitaxial layer at least one layer of the GaN crystal substrate, a straight of low dislocation density crystal region of GaN crystal substrate and forming an electrode on at least one of upper and directly below in a a in group III nitride semiconductor epitaxial layer region and a GaN crystal substrate, a method of manufacturing a semiconductor device comprising a.

According to the present invention, a large effect of pitch of the high dislocation density crystal region is large even collect dislocation, the dislocation density of the low dislocation density crystal region is low, small warpage GaN crystal substrate and a manufacturing method thereof, a GaN crystal substrate according semiconductor device and manufacturing method thereof comprising GaN crystal substrate with an epitaxial layer, as well as a GaN crystal substrate including a can be provided.

Is a schematic diagram showing an example of a GaN crystal substrate according to the present invention. Here, (a) is a schematic plan view, (b) a simplified cross-sectional view along the IB-IB of (a), a schematic cross-sectional view of IC-IC of (c) is (a). Is a schematic diagram showing an example of the underlying substrate and the mask formed is used in the manufacture of a GaN crystal substrate according to the present invention. Here, (a) is a schematic plan view, (b) is a schematic cross-sectional view taken along IIB-IIB of (a), a schematic cross-sectional view in the IIC-IIC of (c) is (a). It is a schematic sectional view showing an example of a manufacturing method of a GaN crystal substrate according to the present invention. Here, (a) is a schematic cross-sectional view of (1-100) plane of the GaN crystal substrate, (b) is a schematic sectional view of a GaN crystal substrate (11-20) plane. Typical is a schematic diagram showing an example of a GaN crystal substrate. Here, (a) is a schematic plan view and a schematic cross-sectional view taken along IVB-IVB of (b) is (a). It is a schematic diagram showing an example of a typical base substrate and a mask formed used in the manufacture of a GaN crystal substrate. Here, (a) is a schematic plan view and a schematic sectional view taken along VB-VB of (b) is (a). Showing an example of a manufacturing method of a GaN crystal substrate according to the present invention, is a schematic cross-sectional view of (1-100) plane of the GaN crystal substrate. Is a schematic plan view showing an example of a hexagonal lattice additional mask having a micro-opening of the plurality of hexagonal in part A of FIG. 2 (a). Here, (a) shows an example of the arrangement of the micro-opening, showing another example of the arrangement of (b) is micro-apertures. Is a schematic plan view showing a stripe-shaped additional mask having a micro-opening of the plurality of stripe-shaped in the part A of FIG. 2 (a). Here, (a) shows an example of the arrangement of the micro-opening, showing another example of the arrangement of (b) is micro-apertures. Is a schematic plan view showing an example of a hexagonal lattice additional mask having a micro-opening of the plurality of hexagonal in part B of FIG. 5 (a). It is a schematic diagram showing another example of a GaN crystal substrate according to the present invention. Here, (a) is a schematic plan view, (b) is a schematic cross-sectional view taken along XB-XB of (a), a schematic cross-sectional view in the XC-XC of (c) is (a). Another example of the base substrate and the mask formed is used in the manufacture of a GaN crystal substrate according to the present invention is a schematic diagram showing. Here, (a) is a schematic plan view, (b) a simplified cross-sectional view along the XIB-XIB of (a), a schematic cross-sectional view taken along XIC-XIC in (c) is (a). Is a schematic diagram showing an example of a GaN crystal substrate with a semiconductor epitaxial layer according to the present invention. Here, (a) is a schematic plan view, (b) a simplified cross-sectional view along the XIIB-XIIB of (a), a schematic cross-sectional view in the XIIC-XIIC of (c) is (a). The first stripe crystal region and the 2 GaN crystal substrate with a semiconductor epitaxial layer a stripe crystal region continuously take the main surface of the substrate is another example of a GaN crystal substrate with a semiconductor epitaxial layer has an off-angle in the present invention it is a schematic plan view showing. Semiconductor epitaxial further first stripe crystal region or the second stripe crystal region major surface of the substrate has an off angle which is another example of a semiconductor epitaxial GaN crystal substrate with layers according to the present invention are discontinuous at least one point it is a schematic plan view showing a GaN crystal substrate with a layer. It is a schematic diagram showing an example of a method of manufacturing a semiconductor device according to the present invention. Here, (a) is a schematic plan view, (b) a simplified cross-sectional view along the XVB-XVB of (a), a schematic cross-sectional view in the XVC-XVC in (c) is (a). An example of the obtained semiconductor devices by the method of manufacturing a semiconductor device according to the present invention is a schematic diagram showing. Here, (a) is a schematic plan view and a schematic sectional view of XVIB-XVIB of (b) is (a). Another example of a method of manufacturing a semiconductor device according to the present invention is a schematic diagram showing. Here, (a) is a schematic plan view, (b) a simplified cross-sectional view along the XVIIB-XVIIB of (a), a schematic cross-sectional view taken along XVIIC-XVIIC of (c) is (a). Another example of the obtained semiconductor devices by the method of manufacturing a semiconductor device according to the present invention is a schematic diagram showing. Here, (a) is a schematic plan view and a schematic sectional view of XVIIIB-XVIIIB of (b) is (a). It is a schematic sectional view showing a C portion and D portion in Figure 17. Here, (a) shows the C portion in FIG. 17 (2) shows a D portion of (b) is 17 (3).

(Embodiment 1)
Referring to FIG. 1, one embodiment of a GaN crystal substrate according to the present invention has a main surface 20m having an off-angle of 0 ° or 30 ° or less with respect to the (0001) plane, low dislocation density crystal region and a and high-dislocation-density crystal region 20h 20k, the shape of the high dislocation density crystal region 20h of the main surface 20m is [1-100] and a plurality of first stripe-crystal region 20hs extending in the direction [11-20] direction a lattice shape and a plurality of second stripe-crystal region 20ht extending.

Major surface 20m of the GaN crystal substrate 20p of this embodiment has an off-angle of 0 ° or 30 ° or less with respect to the (0001) plane. Here, the off-angle of the primary surface 20 m, which means an off angle at the center point of the main surface 20 m. Therefore, it is possible on the main surface 20m of the GaN crystal substrate 20p, the III nitride crystal layer (0001) by growing surface as a crystal growth surface to produce various semiconductor devices. III nitride crystal (0001) plane in view of facilitating the growth of the crystal growth surface, the off angle of the primary surface 20m with respect to the (0001) plane of the GaN crystal substrate 20p is preferably 0 ° or more 25 ° or less , more preferably at most 10 ° 0 ° or more.

On the other hand, referring to FIG. 12, the off angle is 0 ° in the major surface 20m of the GaN crystal substrate 20p If (i.e. major surface 20m is (0001) plane) of, III-group on a main surface 20m nitride semiconductor epitaxial layer When growing, to grow parallel to the main surface 20 m (i.e. (0001) plane) as a crystal growth plane, since the step flow growth is inhibited, the impurities into III nitride semiconductor epitaxial layer 30 uptake There becomes uneven, the breakdown voltage yield of the resulting semiconductor device is reduced.

Further, with reference to FIGS. 12 and 13, with respect to for example [1-100] direction (which is the main surface 20m of the GaN crystal substrate 20p is (0001) plane, is in the extending direction of the first stripe-crystal region 20hs If.) in on the main surface 20m of the GaN crystal substrate 20p having a small off angle from 1 ° greater than 0.05 ° for growing the group III nitride semiconductor epitaxial layer 30, the GaN crystal substrate 20p [1-100] perpendicular [11-20] from the area in contact with the second stripe crystal region 20ht extending in a direction in low dislocation density crystals regions 20k [1-100] direction slightly enters the area of ​​the right above the area in the direction (such regions flat but the equivalent.) to be described later epitaxial abnormal growth region 30ei, (0001) grown surface as a crystal growth plane, in other regions, on the main surface Line plane (which is (0001) is a surface having a small off-angle of the relative surface) grows as a crystal growth surface. In group III nitride semiconductor epitaxial layer 30 grown on the major surface 20m of the GaN crystal substrate 20p having a small off angle as described above with respect to the main surface 20m is (0001) plane, crystal growth (0001) region growing as a surface is referred to as an epitaxial abnormal growth region 30Ei, it reduces the withstand voltage of the semiconductor device including such regions.

From the viewpoint of reducing the epitaxial abnormal growth region 30Ei, off angle of the primary surface 20m of the GaN crystal substrate 20p is preferably 0 ° or more 0.05 ° or less, or 1 ° or 25 ° or less. Here, the off angle of the primary surface 20m is formed 1 ° smaller than the epitaxial abnormal growth region greater than 0.05 °, the uptake of the carrier in that region are different. In such a case, as described later, by discontinuous stripe crystal region extending in a direction perpendicular to the off direction of the off angle, it is possible to suppress the formation of an epitaxial abnormal growth region. In such a case, when growing a group III nitride semiconductor epitaxial layer on GaN crystal substrate, for good step flow is made, the carrier density can be obtained a uniform epitaxial layer. The off angle by the 0 ° or 0.05 ° or less, the epitaxial growth is improved, it is possible to suppress the formation of an epitaxial abnormal growth region. Further, even when the off angle in the 1 ° or more can suppress the formation of an epitaxial abnormal growth region. However, when the off-angle is greater than 25 °, when growing the GaN crystal by using a GaAs substrate as the base substrate, GaAs (111) GaN crystal grown on the off-angle is large GaAs substrate on the principal surface with respect to surface A, epitaxial growth is not made, the multi-crystallization. Such epitaxial abnormal growth region 30ei is determined from the measurement of the height distribution of the crystal growth surface of the epitaxial layer by using a laser microscope.

Further, in GaN crystal substrate 20p of this embodiment, the first deviation angle and the main surface center of which is the difference between the off-angle at the end of the [1-100] direction from the off-angle and the center at the center of the main surface the difference is that the second deviation angle is preferably less 0.30 ° 0 ° or more, respectively, the first deviation angle and the second offset between the off-angle at the end of the [11-20] direction from the off-angle and the center of the difference between the angle is preferably 0 ° or more 0.30 ° or less. The first deviation angle and the second deviation angle, it is preferable from the viewpoint of reducing the maximum on-resistance of the device obtained by reducing the variation of carrier concentration on the main surface 20 m, small, for example 0 ° or 0.30 ° preferably less, more preferably 0.10 ° or less 0 ° or more. On the other hand, considering the workability of the production from the current production technology of a GaN crystal substrate 20p, the first deviation angle and the second deviation angle, preferably at least about 0.01 °. Further, the first deviation angle is the difference between the second deviation angle, it will cause variations in the carrier concentration of group III nitride semiconductor epitaxial layer grown on the GaN crystal substrate, the smaller is preferable, for example, 0 ° or 0 preferably .30 ° or less, more preferably 0.10 ° or less 0 ° or more.

Here, the first displacement angle, the ω- rocking curve (0002) plane of the GaN crystal by the respective X-ray diffraction a plane orientation of the plane orientation and center at the center of the main surface [1-100] direction of the end portion measured, determined by calculating the difference between them. Further, the first deviation angle, measured by ω- rocking curve (0002) plane of the GaN crystal by the respective X-ray diffraction from the surface orientation and center [1-100] direction of the plane orientation of the end portion at the center of the main surface was obtained by calculating the difference between them. The second deviation angle, measured by ω- rocking curve (0002) plane of the GaN crystal from the plane orientation and center at the center of the main surface [11-20] direction of the plane orientation in the end portion by X-ray diffraction, respectively, determined by calculating the difference between them.

GaN crystal substrate 20p of this embodiment includes a low dislocation density crystal region 20k and the high dislocation density crystal region 20h. GaN crystal substrate 20p is, by forming the high-dislocation-density crystal region 20h dislocations in the crystal collected in a predetermined area during the crystal growth, thereby reducing the dislocation density in regions other than high dislocation density crystal region 20h it is obtained by forming a low dislocation density crystal region 20k. GaN crystal substrate 20p can be by growing one or more layers of group III nitride crystal layer on the low dislocation density crystal region 20k, to produce a variety of semiconductor devices with good characteristics.

Multiple GaN crystal substrate 20p of this embodiment, the shape of the high dislocation density crystal region 20h of the main surface 20m is extending in a [1-100] and a plurality of first stripe-crystal region 20hs extending in the direction [11-20] direction a grid-like and a second stripe crystal region 20ht of. GaN crystal substrate 20p of this embodiment, since by having a high dislocation density crystal region 20h of such a shape, the dislocation is collected in the high dislocation density crystal region 20h surrounding the four sides of the low dislocation density crystal region 20k, the high dislocation density also it increases the pitch P 1 and the pitch P 2 of the second stripe-crystal region 20ht the first stripe crystal region 20hs crystal regions 20h, the dislocation density of low dislocation density crystal region 20k can be sufficiently reduced.

In contrast, since with reference to FIG. 4, a typical GaN crystal substrate 20p is, high dislocation density crystal region 20h is [1-100] is a plurality of first stripe-crystal region extending in a stripe shape in a direction, When the pitch P 1 of the first stripe-crystal region increases, the effect of collecting dislocations at a high dislocation density crystal region 20h is reduced, it is impossible to sufficiently lower the dislocation density of the low-dislocation-density crystal region 20k.

Also, GaN crystal substrate 20p of this embodiment, high dislocation density crystal region 20h to mitigate warpage in the crystal occurring during crystal growth [1-100] and a plurality of first stripe-crystal region 20hs extending in a direction [11 -20] for containing a plurality of second stripe-crystal region 20ht extending in a direction, the [1-100] in the direction parallel to the parallel direction and the [11-20] direction toward the central portion of the GaN crystal substrate and the peripheral displacement of the plane orientation of the parts can be reduced.

In contrast, since with reference to FIG. 4, a typical GaN crystal substrate 20p is, high dislocation density crystal region 20h is [1-100] is a plurality of first stripe-crystal region extending in a stripe shape in a direction, [1-100] but in a direction parallel to the direction it is possible to reduce the deviation of the plane orientation of the central portion and the peripheral portion of the GaN crystal substrate, [1-100] direction perpendicular to the direction (i.e., [11- 20] in the direction) parallel to the direction can not be reduced deviation of the plane orientation of the central portion and the peripheral portion of the GaN crystal substrate.

In GaN crystal substrate 20p of this embodiment, the width W 1 of the first stripe-crystal region 20hs high dislocation density crystal region 20h is preferably 5μm or 120μm or less, more preferably 10μm or more 100μm or less. The width W 1 of the first stripe-crystal region 20hs is, reduces the effect of collecting 5μm becomes smaller than a dislocation, low dislocation density crystal region 20k is reduced greater becomes than 120 [mu] m. High dislocation density pitch P 1 of the first stripe-crystal region 20hs crystal regions 20h is preferably 200μm or more 10000μm or less, more preferably 400μm or more 9500Myuemu. Pitch P 1 of the first stripe-crystal region 20hs is, 200 [mu] m smaller than each of the low dislocation density crystal region 20k is reduced, the effect is reduced to collect 10000μm greater dislocation.

The width W 2 of the second stripe-crystal region 20ht high dislocation density crystal region 20h is preferably 5μm or 120μm or less, more preferably 10μm or more 100μm or less. The width W 2 of the second stripe-crystal region 20ht is, reduces the effect of collecting 5μm becomes smaller than a dislocation, low dislocation density crystal region 20k is reduced greater becomes than 120 [mu] m. Pitch P 2 of the second stripe-crystal region 20ht high dislocation density crystal region 20h is preferably 200μm or more 10000μm or less, more preferably 400μm or more 9500Myuemu. Pitch P 2 of the second stripe-crystal region 20ht is, 200 [mu] m smaller than each of the low dislocation density crystal region 20k is reduced, the effect is reduced to collect 10000μm greater dislocation.

Further, with reference to FIGS. 11 to 14, in GaN crystal substrate 20p of this embodiment, the main surface 20m is (0001) a small off angle (e.g. 1.0 ° less than greater than 0.05 ° with respect to surface may have an off-angle), from the viewpoint of growing a group III nitride semiconductor epitaxial layer 30 without forming an epitaxial abnormal growth region 30ei on the primary surface 20 m, the first striped crystalline region 20hs or second stripe crystal region 20ht is preferably discontinuous in at least one location.

Here, the stripe crystal region discontinuous at least one location, as long as one of the first stripe crystal region 20hs or second stripe crystal region 20Ht, extending in a direction perpendicular to the direction in which the off angle is greater it is preferably a stripe crystalline region. Further, even if also has an off angle of comparable in any direction of the extending direction of the direction and the second stripe-crystal region 20ht extension of the first stripe crystal region 20HS, second stripe crystal region 20ht and first stripe by both crystalline regions 20hs discontinuous at at least one location, it is possible to suppress the formation of an epitaxial abnormal growth region 30ei for growing the group III nitride semiconductor epitaxial layer 30.

Referring to FIG. 13, for example, to the main surface 20m is (0001) plane [1-100] direction (which is the extending direction of the first stripe-crystal region 20HS.) Small off-angle (e.g., 0. 05 when growing the group III nitride semiconductor epitaxial layer 30 on the major surface 20m of the GaN crystal substrate 20p having a larger than 1.0 ° smaller than the off angle) °, the GaN crystal substrate 20p of low dislocation density crystal region 20k in right above the area, [1-100] direction perpendicular [11-20] off-angle of the two regions in contact with the second stripe crystal region 20ht extending in the direction of a region of a larger second stripe crystal region side epitaxial abnormal growth region 30ei grown directly above the (0001) plane as a crystal growth surface is formed, parallel to the main surface 20m directly above the other region A surface grown region is formed as a crystal growth plane (this (small with respect to 0001) plane is a plane having an off angle). Semiconductor devices comprising such epitaxial abnormal growth region 30ei withstand voltage is lowered.

Referring to FIG. 14, with respect to for example [1-100] direction (which is the extending direction of the first stripe-crystal region 20HS.) Major surface 20m is (0001) plane smaller off angle (e.g. 0 ° even GaN crystal substrate 20p having a larger 0.7 ° smaller than the off-angle), that growing the group III nitride semiconductor epitaxial layer 30 without forming an epitaxial abnormal growth region 30ei on the main surface 20m it can.

Referring to FIG. 10, the length L W of the first stripe-crystal region 20hs or discontinuous portions of the second stripe-crystal region 20ht of GaN crystal substrate 20p is not particularly limited but is preferably 1μm or more 200μm or less, 2 [mu] m above 100μm or less is more preferable. The length L W of the discontinuous portions, 1 [mu] m smaller than not the epitaxial abnormal growth region connected to cause epitaxial growth abnormalities relaxation, reduction of dislocation density of 200μm larger than the GaN crystal substrate and the epitaxial layer is not sufficient. The length L of the continuous portion of the first stripe-crystal region 20hs or second stripe crystal region 20ht is not particularly limited, preferably 5μm or 140μm or less, more preferably 10μm or more 40μm or less. The length L of the discontinuous portion, 5 [mu] m smaller than the high dislocation density dislocations not fall crystal region leaks from the high dislocation density crystal region to a low dislocation density crystal region, 140 .mu.m larger than the respective low dislocation density crystal region the size is reduced, the size of each resulting device is reduced.

Carrier concentration of the GaN crystal substrate 20p of this embodiment is not particularly limited, from the viewpoint of lowering the specific resistance of the semiconductor device including the GaN crystal substrate 20p, preferably 1.00 × 10 18 cm -3 or more, 4 .0 × 10 18 cm -3 or more is more preferable. Further, by using the GaN crystal substrate 20p, from the viewpoint of preventing the occurrence of cracks when manufacturing the GaN crystal substrate or a semiconductor device with a semiconductor epitaxial layer, the carrier concentration of the GaN crystal substrate 20p is, 1.2 × 10 19 cm -3 or less, and more preferably 1.0 × 10 19 cm -3 or less. Here, the carrier concentration of the GaN crystal substrate can be measured by hole measurement.

Further, in GaN crystal substrate 20p of this embodiment, high dislocation density crystal region 20h is preferably a polar reversed crystal region in which the polarity of the [0001] direction is inverted with respect to low dislocation density crystals regions 20k. High-dislocation-density crystal region 20h dislocations in high-dislocation-density crystal region 20h to be polarity reversed crystal region are collected more easily, are more reduced dislocation density of the low dislocation density crystal region 20k. Here, the inversion domains in which the polarity of the [0001] direction is inverted in the GaN crystal substrate 20p can be measured by etching of the differences when the crystal surface is etched. That is, (000-1) plane is a surface that is reversed in polarity in the [0001] direction with respect to the (0001) plane, is easily etched than the (0001) plane. For example, when dipping the GaN crystal substrate in aqueous NaOH or KOH solution, it appeared on the surface of the substrate (000-1) plane is appeared on the surface of the substrate (0001) compared the plane is more deeply etched.

Further, in GaN crystal substrate 20p of this embodiment, the low-dislocation-density crystal region 20k is to the area of ​​the (0001) plane growth includes a crystalline region 20kc and the facet growth crystal region 20Kf, facet growth crystal region 20Kf in the main surface 20m (0001) plane growth ratio of the area of ​​crystalline regions 20KC (the ratio of C / F ratio, hereinafter the same.) is preferably 0.7 or less, more preferably 0.5 or less, more preferably 0.4 or less .

Here, (0001) plane growth crystal region 20kc facet growth crystal region 20kf compared to the, O (oxygen) easily incorporated impurities such as, for the carrier concentration increases, the low specific resistance. Accordingly, in the semiconductor device obtained by growing one or more layers of group III nitride crystal layer on the GaN crystal substrate 20p, as C / F ratio is low, the specific resistance greater (0001) plane growth crystal region is reduced , reduction in the on-resistance of the semiconductor device, can apply a large current by the semiconductor device.

GaN crystal substrate 20p of this embodiment, [1-100] and a plurality of first stripe-crystal region 20hs extending in the direction [11-20] high dislocation density crystals and a plurality of second stripe-crystal region 20ht extending in a direction because having a region 20h, the low dislocation density crystal region 20k is surrounded on all sides by the high-dislocation-density crystal region 20h. Therefore, the low dislocation density crystal region in a central portion of 20k (0001) plane growth crystal region 20kc is formed, facet growth crystal region 20kf is formed in the periphery of the square, C / F ratio becomes smaller.

Here, the (0001) plane and the growth crystal region 20kc refers to the crystalline regions the growth of the (0001) plane as a crystal growth plane, refers to a crystal region the growth of the facet as a crystal growth plane is a facet growth crystal region 20kf. The high dislocation density crystal region 20h is [0001] polarity of the direction is inverted with respect to low dislocation density crystals regions 20k, a crystal region grown (000-1) plane as a crystal growth plane.

In contrast, with reference to FIG. 4, a typical GaN crystal substrate 20p is, since it has a high dislocation density crystal region 20h composed of a plurality of first stripe-crystal region extending in the 1-100] direction, the high dislocation each low dislocation density crystal region 20k is sandwiched the two-way by density crystal region 20h. Therefore, each of the central portion of low dislocation density crystal region 20k (0001) plane growth crystal region 20kc is formed, in the peripheral portion of the two-way facet growth crystal region 20kf is formed. That is, while the facet growth crystal region on the periphery of four sides of each low dislocation density crystal region in GaN crystal substrate of the present embodiment is formed, typically the low dislocation density crystal region in GaN crystal substrate facet growth crystal region only on the periphery of the two-way in is not formed. Thus, typical GaN crystal substrate, it is impossible to reduce the GaN crystal substrate as the C / F ratio in this embodiment.

Above (0001) plane growth crystal region 20KC, facet growth crystal region 20kf and high-dislocation-density crystal region 20h may be the major surface 20m of the GaN crystal substrate 20p was observed with a fluorescence microscope, distinguished by their brightness. That is, when observing the major surface 20m of the GaN crystal substrate 20p by fluorescence microscopy, it appears as a (0001) plane growth crystal region 20kc is seen as the brightest first bright region, the darkest dark region facet growth crystal region 20Kf, high dislocation density crystal regions 20h appears as followed bright second bright region (0001) plane growth crystal region.

Referring to FIG. 1, GaN crystal substrate 20p of this embodiment is not particularly limited, 0.1 or low dislocation density crystal region 20k is a per region surrounded by the high dislocation density crystal region 20h / it is preferred to have a 5.5 pieces / area less dislocation concentrated region 20kd or more regions. Density of dislocation-concentrated region 20kd per region of low dislocation density crystal region 20k of the GaN crystal substrate 20p is, the withstand voltage characteristics of the semiconductor devices fabricated employing 5.5 pieces / area greater than its GaN crystal substrate 20p There decreased the yield of the semiconductor device to reduce, 0.1 / region smaller than the low-dislocation-density crystals (0001) to the area of ​​facet growth crystal region 20kf in the region 20k plane growth ratio of the area of ​​crystalline regions 20KC (C / F ratio) is increased on-resistance of the semiconductor devices fabricated employing the GaN crystal substrate 20p becomes high.

Referring to FIG. 4, GaN crystal substrate 20p having a stripe-shaped high-dislocation-density crystal region 20h is dislocation concentrated region 20kd were observed large number portion near the high-dislocation-density crystal region 20h in low dislocation density crystal region 20k . In particular, when the distance P 1 -W 1 between striped high dislocation density crystal region is not less than 400 [mu] m, that is, when the width of the stripe-shaped low dislocation density crystal region 20k is not less than 400 [mu] m, the density of dislocation concentrated region 20kd is increased did.

In contrast, with reference to FIG. 1, GaN crystal substrate 20p having a grid-like high-dislocation-density crystal region 20h including the first stripe crystal region 20hs and second striped crystalline region 20ht, the lattice-like high dislocation density distance P 1 -W 1 between crystal regions 20h, even P 2 -W 2 is 400μm or more, that the high dislocation density the size of a region of low dislocation density crystal region 20k surrounded by the crystalline region 20h is even 400 [mu] m square (400μm × 400μm) above, the density of dislocation concentrated region 20kd observed in low dislocation density crystal region is small, for example, per one region of low dislocation density crystal region 20k, the following six / area preferably be 5.5 particles / area less than 0.1 / region.

(Embodiment 2)
Referring to FIGS. 1 to 3, one embodiment of a method of manufacturing a GaN crystal substrate according to the present invention is a method of manufacturing a GaN crystal substrate of Embodiment 1 comprises the following steps.

Referring to FIG. 2, the manufacturing method of the GaN crystal substrate of the present embodiment, first, the off angle of 0 ° or 30 ° or less with respect to the plane orientation of the base substrate 10 corresponding to the (0001) plane of the GaN crystal substrate comprising the step of providing a base substrate 10 having a principal face 10m having.

Base substrate 10 is not particularly limited as long as it can be epitaxially growing a GaN crystal on the main surface 10 m, is not particularly limited, from the viewpoint mismatch of the crystal lattice is small, GaAs substrate, a sapphire substrate, a SiC substrate is preferably used.

Here, the plane orientation of the base substrate 10 corresponding to the (0001) plane of the GaN crystal substrate, means a plane orientation of the base substrate 10 that is capable of growing a GaN crystal to crystal growth surface of (0001) plane , it depends on the type of underlying substrate 10. For example, the plane orientation in the case of GaAs substrate underlying substrate 10 has a cubic crystal structure of zinc blende type is (111) A plane, corundum base substrate 10 is hexagonal or rhombohedral the plane orientation in the case of a sapphire substrate having a crystal structure of the type (0001) plane, the plane orientation if the underlying substrate 10 is a SiC substrate having a crystal structure of wurtzite hexagonal (0001) it is a surface. Further, the main surface 10m of the base substrate 10, because it has less than 30 ° off-angle of 0 ° or more with respect to the plane orientation, growing a GaN crystal to on (0001) plane crystal growth surface thereof it can be.

Referring to FIGS. 2 and 3, the manufacturing method of the GaN crystal substrate of the present embodiment, then, on the main surface 10m of the base substrate 10, the first corresponding to the [1-100] direction of GaN crystal substrate 20p forming a mask 11 having a first striped mask 11s plurality extending in a direction, a grid-like pattern comprising a plurality of second stripe mask 11t that [11-20] extending in a second direction corresponding to the direction of GaN crystal substrate 20p comprising the step of.

Here, the first direction corresponding to the [1-100] direction of GaN crystal substrate 20p is, depends on the type of the base substrate 10, when the base substrate 10 is a GaAs substrate is [11-2] direction, the base substrate If 10 of the sapphire substrate is [11-20] direction, if the underlying substrate 10 is a SiC substrate is [1-100] direction. The second direction corresponding to the [11-20] direction of GaN crystal substrate 20p is, depends on the type of the base substrate 10, when the base substrate 10 is a GaAs substrate is [110] direction, the base substrate 10 If it is a sapphire substrate is [1-100] direction, if the underlying substrate 10 is a SiC substrate is [11-20] direction. Further, the mask 11 is not particularly limited as long as the material inhibiting the growth of GaN crystals, such as SiO 2, Si 3 N 4 is used. Further, the method of forming the mask 11 is not particularly limited, for example, after forming a mask layer by a sputtering method, it is possible to form a mask 11 of the grid-shaped pattern by photolithography.

The width W M1 of the first stripe mask 11s in the mask 11 is preferably 5μm or 120μm or less, more preferably 10μm or more 100μm or less. Width W M1 of the first stripe mask 11s is, becomes smaller than 5μm possibly first stripe crystal region 20hs high dislocation density crystal region 20h disappears is there during growth of GaN crystal 20 is grown to be larger than 120μm low dislocation density crystal region 20k of the GaN crystal 20 is reduced. Pitch P M1 of the first stripe mask 11s in the mask 11 is preferably 200μm or more 10000μm or less, more preferably 400μm or more 9500Myuemu. Pitch P M1 of the first stripe mask 11s is, low dislocation density crystal region 20k of each of the GaN crystal 20 is grown and 200μm smaller decreases, the effect is reduced to collect dislocations of the GaN crystal 20 is grown with 10000μm larger .

The width W M2 of the second stripe mask 11t in the mask 11 is preferably 5μm or 120μm or less, more preferably 10μm or more 100μm or less. Width W M2 of the second stripe mask 11t is, becomes smaller than 5μm possibly second stripe crystal region 20ht high dislocation density crystal region 20h disappears is there during growth of GaN crystal 20 is grown to be larger than 120μm low dislocation density crystal region 20k of the GaN crystal 20 is reduced. Pitch P M2 of the second stripe mask 11t in the mask 11 is preferably 200μm or more 10000μm or less, more preferably 400μm or more 9500Myuemu. Pitch P M2 of the second stripe mask 11t is, low dislocation density crystal region 20k of each of the GaN crystal 20 is grown and 200μm smaller decreases, the effect is reduced to collect dislocations of the GaN crystal 20 is grown with 10000μm larger .

Referring to FIGS. 2 and 3, the manufacturing method of the GaN crystal substrate of the present embodiment, then, comprises the step of growing GaN crystal 20 on the main surface 10m of the base substrate 10 on which the mask 11 is formed. The method of growing GaN crystal 20 is not particularly limited, but from the viewpoint of increasing the crystal growth rate, HVPE (hydride vapor phase epitaxy) method, the vapor-phase method such as MOCVD (metal organic chemical vapor deposition) method preferably used.

In the step of growing GaN crystal 20, the GaN crystal 20 on the mask 11 is formed polarity reversed crystal region grown (000-1) plane, GaN on a central portion of the opening 11w of the mask 11 of the base substrate 10 crystals 20 (0001) plane growing (0001) plane growth crystal region 20kc is formed, the GaN crystal 20 on the periphery of the opening 11w of the mask 11 facet growth crystal region 20kf are formed by facet growth .

Here, (000-1) plane to say that the growth of the (000-1) plane 20d as a crystal growth surface and growth, the (0001) plane and the growth that the growth of the (0001) plane 20c as crystal growth surface refers to, it says that the growth of the facet 20f as a crystal growth plane is a facet growth. Further, the facet 20f refers to a surface having an inclination with respect to the (0001) plane 20c.

Here, the facet 20f is formed on the peripheral portion of the opening 11w of the mask 11, the mask 11 is to inhibit the growth of GaN crystal 20, the growth of GaN crystal 20 on main surface 10m of the base substrate 10 begins the opening 11w of the mask 11, also the growth of the GaN crystal on the mask 11 is slower than the growth of the GaN crystal on the opening 11w, considered.

In addition, the opening 11w of the mask 11, the major surface 10m of the at least underlying substrate 10 has only to be exposed. For example, may also be the entire surface exposed major surface of the base substrate of the opening of the mask 11, a portion of the main surface of the base substrate on a surface of the opening portion of the mask may be exposed.

The method for exposing a part of the main surface of the base substrate on a surface of the opening portion of the mask is not particularly limited, for example, with reference to FIGS. 7 and 8, a plurality of micro-openings in the opening 11w of the mask a method of forming an additional mask 12 having a 12w. According to this method, the main surface of the underlying substrate is exposed to the micro-openings 12w. Here additional mask 12 to be formed is intended to promote the facet growth during the growth of GaN crystal, but the present invention is to form a polarity reversed crystal region on additional mask 12. The formation of such additional mask 12, the dislocation density of the GaN crystal grown on the opening 11w of the mask can be further reduced.

Specifically, with reference to FIG. 7, as an example of the additional mask 12, the shape of a hexagonal lattice of the additional mask 12 having a plurality of hexagonal micro window 12w and the like. No particular limitation on the arrangement of the hexagonal lattice micro opening 12w, but from the viewpoint of uniform crystal growth, it is preferable to arrange such that the dimensionally hexagonal close-packed. Particularly where the width W N of the additional mask 12 is preferably less than 5μm or 0.5 [mu] m. Width W N of the additional mask 12, there is a fear that reduces the effect of promoting 0.5μm smaller than the facet growth, forming a polarity reversed crystal region as being 5μm or more additional masks 12. The pitch P N of the micro opening 12w is preferably 2.0μm or more 10μm or less. Pitch P N of the micro opening 12w, since the greater the crystal nuclei formed in the early 2.0μm smaller crystal growth, a number of defects will occur than when those crystal nuclei are bonded to each other, 10 [mu] m since the crystal nuclei formed at the initial larger crystal growth is increased, the stress therein occurs in each crystal nuclei, the deviation of the plane orientation in the central portion and the end portion tends to occur in each crystal nucleus, their respective crystal nucleus grows easily cracked upon binding to each other.

Here, no particular limitation on the direction of the arrangement of hexagonal micro window 12w, for example, with reference to FIG. 7 (a), the micro-window 12w adjacent to each other, the first direction and the first it can be placed side by side in a direction having an angle of 60 ° relative to the direction. Further, with reference to FIG. 7 (b), the micro-window 12w adjacent to each other, can be arranged side by side in a direction having an angle of 60 ° with respect to the second direction and the second direction. Arrangement of micro window 12w as shown in FIG. 7 (a), for each of the micro-apertures of the two sides are parallel to the second direction of the base substrate, further reduce the dislocation density to promote the facet growth of GaN crystal from the viewpoint of, preferably.

Further, with reference to FIG. 8, as another example of an additional mask, stripe-shaped additional mask 12 having a plurality of stripe-shaped micro window 12w and the like. Not particularly limited to the arrangement of the stripe-shaped micro opening 12w, but from the viewpoint of uniform crystal growth, it is preferably periodically arranged. Here, the width W N of the additional mask 12 is preferably less than 5μm or 0.5 [mu] m. Width W N of the additional mask 12, there is a fear that reduces the effect of promoting 0.5μm smaller than the facet growth, forming a polarity reversed crystal region as being 5μm or more additional masks 12. The pitch P N of the micro opening 12w is preferably 2.0μm or more 10μm or less. Pitch P N of the micro opening 12w, since the greater the crystal nuclei formed in the early 2.0μm smaller crystal growth, a number of defects will occur than when those crystal nuclei are bonded to each other, 10 [mu] m since the crystal nuclei formed at the initial larger crystal growth is increased, the stress therein occurs in each crystal nuclei, the deviation of the plane orientation in the central portion and the end portion tends to occur in each crystal nucleus, their respective crystal nucleus grows easily cracked upon binding to each other.

Here, it is possible with reference to FIG. 8 (a), placing the adjacent stripe-shaped micro window 12w extending in a second direction side by side in the first direction. Further, it is possible with reference to FIG. 8 (b), placing the adjacent stripe-shaped micro window 12w extending in a first direction side by side in the second direction.

In FIG 7 and FIG 8, the additional mask 12 is not particularly limited as long as the material inhibiting the growth of GaN crystals, such as SiO 2, Si 3 N 4 is used. Further, the method of forming the additional mask 12 is not particularly limited, for example, after forming a mask layer by a sputtering method, to form an additional mask 12 having a hexagonal lattice or stripe pattern by photolithography it can.

The facet growth as described above, GaN crystal grown on the opening 11w of the mask, dislocations propagate toward the periphery from the center of the opening 11w of the mask 11. Therefore, the dislocation density of the facet growth crystal region 20kf which grows on the periphery of the opening 11w of the opening portion grows on the central part of 11w (0001) plane growth crystal region 20kc and the mask 11 of the mask 11 is reduced low dislocation density crystal region 20k is formed. On the other hand, high dislocation density crystal region 20h dislocation of GaN crystal 20 is collected on the mask 11 is formed.

Referring to FIG. 3, in the step of growing the GaN crystal 20, the on the first stripe mask 11s of the mask 11 is first striped crystalline region 20hs high dislocation density crystal region 20h growth, the second stripe mask 11 the mask 11t second stripe crystal region 20ht high dislocation density crystal region 20h is grown. Here, the crystal growth rate of the high-dislocation-density crystal region 20h is smaller than the crystal growth rate of the low dislocation density crystal region 20k, the larger the crystal growth thickness, width W 1 of the first stripe-crystal region first smaller than the width W M1 of one stripe mask width W 2 of the second stripe-crystal region is smaller than the width W M2 of the second stripe mask. Also, in certain crystal growth thickness, width W 2 of the reduction rate 100 × the second stripe crystal region to the width W M2 of the second stripe mask (W M2 -W 2) / W M2 (%) is the first stripe smaller than the first stripe reduction rate 100 × width W 1 of the crystalline region to the width W M1 of the mask (W M1 -W 1) / W M1 (%).

Referring to FIG. 3, method for manufacturing the GaN crystal substrate of the present embodiment, then, in parallel with the main surface 10m of the base substrate 10, comprising the step of forming a major surface 20m of the GaN crystal 20. Such process, GaN crystal substrate 20p embodiment 1 of GaN crystal 20 is obtained. Here, in GaN crystal 20 in a method of forming a parallel main surfaces 20m to the main surface 10m of the base substrate 10 is not particularly limited, the GaN crystal 20 in a plurality of planes parallel to the principal face 10m of the base substrate 10 excised, a method of forming a major surface 20m of the cut surface grinding and / or polishing to, or a method of forming a major surface 20m of the crystal growth surface of the GaN crystal 20 grinding and / or polishing to the like.

In the method for manufacturing a GaN crystal substrate of the present embodiment, the first striped mask 11s or the second stripe mask 11t formed on the main surface 10m of the base substrate 10 may be discontinuous at at least one location. By the first striped mask 11s discontinuous first stripe crystal region 20hs discontinuous GaN crystal substrate 20p is obtained (not shown). Further, (see Figure 11) by the second stripe masks 11t discontinuous second stripe crystal region 20ht discontinuous GaN crystal substrate 20p is obtained (see Figure 10).

The case of producing a GaN crystal substrate having the main surface 20m is a (0001) small off-angle with respect to plane (e.g. 0 ° or 0.7 ° or less off-angle), the epitaxial abnormal grown region 30ei on the main surface 20m from the viewpoint of GaN crystal substrate 20p which can be grown without a group III nitride semiconductor epitaxial layer can be formed is obtained, the first striped mask 11s or the second stripe mask 11t formed on the main surface 10m of the base substrate 10 is , it is preferable that the discontinuous in at least one place.

Here, the mask 11 to the discontinuity at least one location, as long as one of the first stripe mask 11s or the second stripe mask 11t, is not particularly limited, the off angle of the GaN crystal substrate 20p to produce the it is preferably a stripe mask that extends in a direction corresponding to a direction perpendicular to the larger becomes the direction.

Referring to FIG. 11, the length L MW of the first stripe mask 11s or discontinuous portions of the second stripe mask 11t formed on the principal face 10m of the base substrate 10 is not particularly limited, 1 [mu] m or more 200μm or less and more preferably 2μm or 100μm or less. The length L MW discontinuities may not be 1μm smaller than the epitaxial abnormal growth region will be connected epitaxial growth abnormalities relaxed formed group III nitride semiconductor epitaxial layer is grown GaN crystal substrate, 200 [mu] m reduction of dislocation density of larger than GaN crystal substrate and the epitaxial layer is not sufficient. The length L M of the continuous portion of the first stripe mask 11s or the second stripe mask 11t is not particularly limited, preferably 5μm or 140μm or less, more preferably 10μm or more 40μm or less. The length L M of the discontinuous portion, 5 [mu] m smaller than GaN dislocations not fall high dislocation density crystal region of the crystalline substrate leaks from the high dislocation density crystal region to a low dislocation density crystal region, 140 .mu.m larger than the low the size is reduced dislocation density crystal region, the size of each resulting device is reduced.

Incidentally, in the growth of GaN crystal 20, the high dislocation density crystal region 20h which grows in the first stripe crystal region 20hs and on the second stripe mask 11t of high-dislocation-density crystal region 20h grown on first stripe mask 11s first 2 crystal growth rate of the stripe crystal region 20ht is smaller than the crystal growth rate of the low dislocation density crystal region 20k grown on underlying substrate 10. Therefore, the length L W of the first stripe-crystal region 20hs or discontinuous portions of the second stripe-crystal region 20ht of GaN crystal substrate 20p is generally discontinuous first stripe mask 11s or the second stripe mask 11t or less length L MW portions. The length of successive portions of the length L of the continuous portion of the first stripe-crystal region 20hs or second stripe crystal region 20ht of GaN crystal substrate 20p is generally first striped mask 11s or the second stripe mask 11t L M is less than or equal to.

(Embodiment 3)
Referring to FIG. 12, one embodiment of a semiconductor epitaxial GaN crystal substrate with layers according to the present invention, III-nitride of at least one layer that is formed on the GaN crystal substrate 20p and GaN crystal substrate 20p embodiments 1 and a goods semiconductor epitaxial layer 30, III nitride semiconductor epitaxial layer 30 has a low dislocation density epitaxial crystal region 30k formed immediately above the low dislocation density crystal region 20k of the GaN crystal substrate 20p, GaN crystal substrate 20p It is the formation immediately above the high-dislocation-density crystal region 20h includes a high dislocation density epitaxial crystal region 30h.

Semiconductor epitaxial layer with GaN crystal substrate 33 of the present embodiment, III-nitride semiconductor epitaxial layer 30 of at least one layer grown directly above the GaN crystal substrate 20p (substantially upward direction perpendicular to the main surface of the substrate) is, to take over the dislocation of GaN crystal substrate 20p, although directly above the high-dislocation-density crystal region 20h of the GaN crystal substrate 20p dislocation density is high high dislocation density epitaxial crystal region 30h is formed, the low dislocation GaN crystal substrate 20p right above the density crystal region 20k is low dislocation density low dislocation density epitaxial crystal region 30k is formed.

The method of forming a group III nitride semiconductor epitaxial layer 30 of at least one layer on GaN crystal substrate 20p, is not particularly limited, from the viewpoint of excellent crystallinity epitaxial layer of device applications can be obtained relatively easily, such as MOCVD method is preferable.

(Embodiment 4)
With reference to FIGS. 16 and 18, an embodiment of a semiconductor device according to the present invention, a GaN crystal substrate 20p of the first embodiment, at least one being formed on one main surface 20m of the GaN crystal substrate 20p a III nitride semiconductor epitaxial layer 30 and 70 of the layer, the main surface 30m of group III nitride semiconductor epitaxial layer 30 and 70, is formed on at least one of the other main surface 20n of 70m and on GaN crystal substrate 20p and a and has electrodes 41,42,81,82, GaN crystal substrate 20p is, in more than 400μm square size, the dislocation density is less than 1 × 10 7 cm -2. The method of group III nitride semiconductor epitaxial layer 30, 70 formed of at least one layer on one main surface 20m of the GaN crystal substrate 20p, is not particularly limited, good crystallinity epitaxial layer of device applications is relatively from the viewpoint of easily obtained, such as the MOCVD method is preferably used. Further, the method of forming the electrodes 41,42,81,82, usually, EB (electron beam) evaporation, resistance heating evaporation method, a sputtering deposition method and the like are used.

Chip semiconductor device 40c of the present embodiment, 80c is GaN crystal substrate 20p contained as the substrate, in at least 400μm square size, CL (cathode luminescence) dislocation even if the observation is 1 × 10 7 cm dislocation concentrated region 20kd localized to concentrate to -2 or not observed, the dislocation density is formed only at a low dislocation density crystal region 20k of less than 1 × 10 7 cm -2. Thus, chip semiconductor device 40c, the withstand voltage characteristics of 80c is high.

With reference to FIGS. 16 and 18, the semiconductor device 40c of the present embodiment, in 80c, the GaN crystal substrate 20p is (0001) plane growth includes a crystalline region 20kc and the facet growth crystal region 20Kf, the GaN crystal substrate 20p in one main surface 20 m, the ratio of the area of ​​the (0001) plane growth crystal region 20kc to the area of ​​the facet growth crystal region 20Kf (hereinafter, also referred to as a C / F ratio.) is a 0.2 to 0.7 it is preferable, more preferably 0.2 to 0.5.

Facet growth crystal region 20kf compared to (0001) plane growth crystal region 20kc is, O (oxygen) easily incorporated impurities such as, for the carrier concentration increases, the low specific resistance. Therefore, as the C / F ratio is low, reduction in the on-resistance of the semiconductor device, can apply a large current by the semiconductor device. On the other hand, when the C / F is too low, it becomes difficult to extrude the dislocation of low dislocation density crystal region 20k in high-dislocation-density crystal region 20h, it is difficult to reduce the dislocation density of the low dislocation density crystal region 20k.

Semiconductor devices 40c, 80c of the present embodiment includes the following two examples. Referring to FIG. 16, which is an example semiconductor device 40c of this embodiment is a SBD (Schottky Barrier Diode). The semiconductor device 40c is in magnitude on one main surface 20m of the GaN crystal substrate 20p dislocation density is less than 1 × 10 7 cm -2 or more 400μm square, III group of at least one layer of nitride semiconductor epitaxial layer 30 GaN layer is formed as a. Such GaN crystal substrate 20p is dislocation density is formed only at a low dislocation density crystal region 20k of less than 1 × 10 7 cm -2. Therefore, the dislocation density of the low dislocation density epitaxial crystal region 30k of the group III nitride semiconductor epitaxial layer 30 formed on such a low dislocation density crystal region 20k is less than 1 × 10 7 cm -2. The dislocation density of the low dislocation density crystal region 20k and low dislocation density epitaxial crystal region 30k, the more low Preferably, for example, 1 × 10 6 cm -2 or less. Further, on the GaN layer (III-nitride semiconductor epitaxial layer 30), as a Schottky electrode 41, the first layer 41a and second layer 41b are formed. Further, the ohmic electrode 42 is formed on the other main surface 20n on the GaN crystal substrate 20p.

Incidentally, in FIG. 16, the Schottky electrode 41 has been formed extends directly above the region of the second region of the (0001) plane growth crystal region 20kc and facet growth crystal region 20Kf, (0001) plane grown crystal it may be formed in the region of the straight upper region of the region 20KC.

Referring to FIG. 18, another example serving semiconductor device 80c of the present embodiment is a LED (light emitting diode). The semiconductor device 80c is in magnitude on one main surface 20m of the GaN crystal substrate 20p dislocation density is less than 1 × 10 7 cm -2 or more 400μm square, III group of at least one layer of nitride semiconductor epitaxial layer 70 as, n-type GaN layer 71, n-type Al 0.1 Ga 0.9 n layer 72, the light emitting layer 73, p-type Al 0.1 Ga 0.9 n layer 74, p-type GaN layer 75 are sequentially formed. Such GaN crystal substrate 20p is dislocation density is formed only at a low dislocation density crystal region 20k of less than 1 × 10 7 cm -2.

Therefore, according to the low dislocation density crystal region low dislocation density of 20k III group is formed on the nitride semiconductor epitaxial layer 70 epitaxially crystal regions 70k (details, with reference to FIG. 19, n-type GaN layer 71, n type the Al 0.1 Ga 0.9 N layer, 72, luminescent layer 73, p-type Al 0.1 Ga 0.9 N layer 74 and the p-type respectively low dislocation density epitaxial crystal region 71k of the GaN layer 75, 72k, 73k, 74k, the dislocation density of the 75k) It is less than 1 × 10 7 cm -2. The dislocation density of the low dislocation density crystal region 20k and low dislocation density epitaxial crystal region 70k, the more low Preferably, for example, 1 × 10 6 cm -2 or less.

Further, p-side electrode 81 is formed on the p-type GaN layer 75. Further, n-side electrode 82 is formed on the other main surface 20n on the GaN crystal substrate 20p. The light-emitting layer 73 may be, for example, a MQW (multiple quantum well) structure of triple well structure formed by laminating and In 0.15 Ga 0.85 N well layers of GaN barrier layer and the thickness of 3nm thickness 15nm alternately.

Incidentally, in FIG. 18, p-side electrode 81 and the n-side electrode 82, respectively (0001) plane grown crystal of 2 regions in the region 20kc and facet growth crystal region 20kf formed extends in the region of the straight upper and immediately under it is, or may be formed in each of the (0001) plane grown crystal immediately above and immediately below in the region of the area of ​​region 20KC.

(Embodiment 5)
Referring to FIGS. 15 to 19, an embodiment of a method of manufacturing a semiconductor device according to the present invention includes the steps of preparing a GaN crystal substrate 20p embodiment 1, III of at least one layer on GaN crystal substrate 20p growing a nitride semiconductor epitaxial layer 30 and 70, the main group III nitride semiconductor epitaxial layer 30, 70 be in the region of the straight upper and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p face comprising 30 m, forming an electrode 41,42,81,82 to at least one of the other main surface 20n of 70m and on GaN crystal substrate 20p, the.

By providing such a step, the resulting semiconductor device 40,40c, 80,80c (wafer-shaped semiconductor devices 40, 80 and chip semiconductor device 40c, 80c) includes a GaN crystal substrate 20p of the first embodiment, comprising a group III nitride semiconductor epitaxial layer 30, 70 of at least one layer formed on the GaN crystal substrate 20p. The low dislocation density crystal region 20k of the GaN crystal substrate 20p of the first embodiment, 0.1 / region than 5.5 pieces / region following the per region surrounded by the high dislocation density crystal region 20h having a dislocation concentrated area. Furthermore, III nitride semiconductor epitaxial layer 30, 70 of at least one layer formed on a GaN crystal substrate 20p is formed immediately above the high-dislocation-density crystal region 20h of the GaN crystal substrate 20p embodiments 1 the dislocation density is high high dislocation density epitaxial crystal region 30h which are, with a 70h, a low dislocation density are formed on the low dislocation density crystal region 20k of the GaN crystal substrate 20p low dislocation density epitaxial crystal region 30k, and 70k. The region of the straight upper and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p 40k, acting in the 80k. Therefore, the manufacturing method of this embodiment, a semiconductor device having excellent device characteristics such as withstand voltage is high is obtained in high yield.

The method of manufacturing a semiconductor device of the present embodiment, a wafer-shaped semiconductor devices 40, 80, GaN crystal substrate 20p constituting the respective semiconductor devices, III nitride semiconductor epitaxial layer 30, 70 and electrodes 41,42,81, 82 immediately above and immediately below the region 40k of the low dislocation density crystal region 20k of all GaN crystal substrate 20p, to fit into 80k, by dividing the wafer-shaped semiconductor devices 40, 80 dividing line 40b, at 80b chip of semiconductor devices 40c, 80c is obtained.

Semiconductor devices 40,40c of this embodiment, a manufacturing method of 80,80c includes the following two examples. Referring to FIGS. 15 and 16, the manufacturing method of which is an example semiconductor device 40,40c of the present embodiment is a method of manufacturing SBD. It will be specifically described below.

First, the manufacturing method of Embodiment 2, to prepare a GaN crystal substrate 20p embodiment 1 (GaN crystal substrate preparation step). Such GaN crystal substrate 20p is preferably as the dislocation density of the low dislocation density crystal region 20k is low, for example 1
× preferably 10 8 cm -2 or less, more preferably 1 × 10 6 cm -2.

Then, on one main surface 20m of the GaN crystal substrate 20p, growing as a group III nitride semiconductor epitaxial layer 30 at least one layer of e.g. GaN layer (semiconductor epitaxial layer growth step). Growth method is not particularly limited, from the viewpoint of excellent crystallinity epitaxial layer of device applications can be obtained relatively easily, MOCVD, etc. (metal organic chemical vapor deposition) method is preferred. The dislocation density of the thus obtained GaN layer (III-nitride semiconductor epitaxial layer 30), in the low dislocation density epitaxial crystal region 30k formed on the low dislocation density crystal region 20k of the GaN crystal substrate 20p, preferably 1 × 10 a is no dislocation-concentrated regions less than 7 cm -2, more preferably 1 × 10 6 cm -2.

GaN layer formed on the GaN crystal substrate 20p thus obtained (III-nitride semiconductor epitaxial layer 30) has a higher high dislocation density is formed directly above the high-dislocation-density crystal region 20h of the GaN crystal substrate 20p has a dislocation density epitaxial crystal region 30h, a low dislocation density dislocation density are formed on the low dislocation density crystal region 20k of the GaN crystal substrate 20p is lower epitaxial crystal regions 30k.

Next, the other main surface 20n on the GaN crystal substrate 20p, the ohmic electrode 42 (ohmic electrode formation step). Specifically, to implement for example the following steps. First, wash the major surface 20n of GaN crystal substrate 20p by organic cleaning and hydrochloric acid. Then, for example, EB (electron beam) evaporation method, or a resistance heating evaporation method, Ti, Al, a layer of a metal material such as Au is formed on the entire main surface 20n. Then, for example, by heat treatment at about 2 minutes 600 ° C. under a nitrogen atmosphere, subjected to alloying of the metal material layer, an ohmic electrode 42.

Then, on the GaN layer a region 40k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p (III nitride semiconductor epitaxial layer 30), it is formed by Ni or Ni alloy forming a Schottky electrode 41 that includes a first layer 41a (Schottky electrode formation step). Here, in FIG. 15, the Schottky electrode 41 has been formed extends directly above the region of the second region of the (0001) plane growth crystal region 20kc and facet growth crystal region 20Kf, (0001) plane growth it may be formed immediately above the region in the region of crystalline regions 20KC. Specifically, to implement for example the following steps. By photolithography, on a main surface 30m of the GaN layer (III-nitride semiconductor epitaxial layer 30), a circular aperture positioned within the region 40k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p forming a resist having a section (not shown). Thereafter, the surface treatment of GaN layer with hydrochloric acid washed (III-nitride semiconductor epitaxial layer 30), carried out at room temperature for 3 minutes. Then, a metal layer to serve as the Schottky electrode 41. First, a first metal layer formed of Ni or Ni alloy to be the first layer 41a of the Schottky electrode 41, the such first metal layer, are formed by Au to be the second layer 41b it is preferable to form the second metal layer. The metal layer may be formed in any manner, for example, the first metal layer was formed by EB method, forming a second metal layer by a resistance heating evaporation method. Then, when removing the resist, the resist metal layer deposited on are simultaneously removed (lift-off), a metal layer to serve as Schottky electrode 41 is formed. The metal layer may be a plane shape formed to be circular.

Thereafter, by heat-treating the metal layer, the Schottky electrode 41 comprising a first layer 41a is obtained. At this time, it is possible to increase the barrier height of first layer 41a which is formed from Ni or Ni alloy, the barrier height of the Schottky electrode 41 is high. Heat treatment of such a metal layer, from the viewpoint of increasing the barrier height of first layer 41a in a short time, preferably 300 ° C. or higher 600 ° C. or less, and more preferably at a 400 ° C. or higher 550 ° C. or less. Incidentally, the above heat treatment, material such as gold and the like as a second metal layer that can increase the barrier height of the Schottky electrode 41. Further, the heat treatment is preferably performed in an atmosphere containing nitrogen. Since N atoms easy transitions at low energy, the heat is applied to the GaN layer (III-nitride semiconductor epitaxial layer 30), a region exposed to an atmosphere of the heat treatment on the main surface 30m of the GaN layer N atom is likely to come out. However, the inclusion of nitrogen in the atmosphere to heat treatment, hardly N atoms escape from GaN layer, also can be compensated N atom missing from GaN layer. Therefore, it is possible to suppress the N atom to escape from the GaN layer. Therefore, it is possible to prevent the defects such be subjected to heat treatment due to the N atom passing it to the GaN layer dislocations are formed. Therefore, it is possible to suppress the increase in the reverse leakage current. In the heat treatment, it is preferable that heat treatment of the metal layer in an atmosphere of atmospheric pressure. It is also possible to heat treatment of the metal layer in a pressurized atmosphere.

Further, in the step of forming the Schottky electrode 41, it can be performed in parallel with the formation of the metal layer, and a heat treatment. Specifically, for example, a metal layer is formed on the main surface 30m of the GaN layer (III-nitride semiconductor epitaxial layer 30) is heated from the other main surface 20n side of the GaN crystal substrate 20p. This makes it possible to heat treatment of the metal layer formed on the main surface 30m of the GaN layer from the main surface 20n of GaN crystal substrate 20p. A method of heating from the main surface 20n side of the GaN crystal substrate 20p is not particularly limited, for example, a method of heating by laser light or the like, by placing the main surface 20n side of the GaN crystal substrate 20p on the susceptor was mounted on the susceptor and a method of heating by the heating member such as a thermocouple and the like. Incidentally, the heat treatment and formation of the metal layer is not limited provided that it can perform at least some of the steps concurrently. Thus, the wafer-shaped SBD (semiconductor device 40 wafer-like) acting in the area 40k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p can be obtained.

Then, the wafer-shaped SBD (wafer-shaped semiconductor device 40) a, GaN crystal substrate 20p constituting each SBD, III nitride semiconductor epitaxial layer 30, the Schottky electrode 41 and ohmic electrode 42 are all GaN crystal substrate 20p of to fit low dislocation density crystals within just above and just below the region 40k of the region 20k, the wafer-shaped SBD (semiconductor device 40 of the wafer-shaped) is divided by the division line 40b chipped SBD (chip of semiconductor devices 40c) is obtained.

Referring to FIGS. 17 to 19, the manufacturing method of which is an example semiconductor device 80,80c of the present embodiment is a method of manufacturing an LED. It will be specifically described below.

First, the manufacturing method of Embodiment 2, to prepare a GaN crystal substrate 20p embodiment 1 (GaN crystal substrate preparation step). Such GaN crystal substrate 20p is preferably as the dislocation density of the low dislocation density crystal region 20k is low, for example preferably less than 1 × 10 7 cm -2, more preferably 1 × 10 6 cm -2.

Then, on one main surface 20m of the GaN crystal substrate 20p, as a group III nitride semiconductor epitaxial layer 70 of at least one layer, n-type GaN layer 71, n-type Al 0.1 Ga 0.9 N layer 72, the light emitting layer 73, sequentially growing a p-type Al 0.1 Ga 0.9 N layer 74, p-type GaN layer 75 (semiconductor epitaxial layer growth step). Growth method is not particularly limited, from the viewpoint of excellent crystallinity epitaxial layer of device applications can be obtained relatively easily, MOCVD, etc. (metal organic chemical vapor deposition) method is preferred.

At least one layer of group III nitride semiconductor epitaxial layer 70 formed on the GaN crystal substrate 20p thus obtained has a higher high dislocation density is formed directly above the high-dislocation-density crystal region 20h of the GaN crystal substrate 20p the dislocation density epitaxial crystal region 70h (details, with reference to FIG. 19, n-type GaN layer 71, n-type Al 0.1 Ga 0.9 n layer 72, the light emitting layer 73, p-type Al 0.1 Ga 0.9 n layer 74 and the p-type each high dislocation density epitaxial crystal region 71h of the GaN layer 75, 72h, 73h, 74h, 75h) and, GaN low dislocation density crystal region dislocation density are formed on the 20k low low dislocation density epitaxial crystal of the crystal substrate 20p region 70k (specifically, with reference to FIG. 19, n-type GaN layer 71, n-type Al 0.1 Ga 0.9 n layer 72, the light emitting layer 73, p-type with l 0.1 Ga 0.9 N layer 74 and the p-type GaN layer 75 of each of the low dislocation density epitaxial crystal regions 71k, 72k, 73k, 74k, and 75k), the.

Then, p-side electrode on the (top layer of the group III nitride semiconductor epitaxial layer 70) p-type GaN layer 75 a region 80k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p 81 to form (p-side electrode formation step). Next, an n-side electrode on the other main surface 20n of GaN crystal substrate 20p a region 80k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p (n-side electrode formation step ). Here, in FIG. 17, p-side electrode 81 and the n-side electrode 82 is formed spreading in a region of the straight upper and just below the second region, respectively (0001) plane growth crystal region 20kc and facet growth crystal region 20kf and are, or may be formed in each of the (0001) plane grown crystal immediately above and immediately below in the region of the area of ​​region 20KC. Thus, the region of the straight upper and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p 40k, a wafer-shaped LED (semiconductor device 80 wafer-like) acting in the 80k is obtained.

Then, the wafer-shaped LED (semiconductor device 80 of the wafer-shaped), GaN crystal substrate 20p constituting each LED, III nitride semiconductor epitaxial layer 70, p-side electrode 81 and the n-side electrode 82, all GaN to fit the straight upper and right under the region 80k of the low dislocation density crystal region 20k of the crystal substrate 20p, a wafer-shaped LED (semiconductor device 80 shaped wafer) is divided by the division line 80b LED separated into chips (chip semiconductor device 80c) is obtained.

[Example A]
First, as Example A, Example will be described of producing a GaN crystal substrate 20p using GaAs substrate or sapphire substrate as the base substrate 10. Example A, the following examples are included A1 ~ A19 and Comparative Examples RA1 ~ RA3.

(Example A1)
1. Referring to prepare diagram 2 of the base substrate, the major surface 10m as an underlying substrate 10 (111) was prepared GaAs substrate with a thickness of 500μm in diameter of 2 inches is A-plane (50.8 mm).

2. Referring to form Figure 2 of the mask, then, on the main surface 10m of the GaAs substrate (underlying substrate 10), after forming a SiO 2 mask layer with a thickness of 0.1μm by sputtering, by photolithography, forming a SiO 2 mask 11 having a grid-like pattern. Multiple The SiO 2 mask 11, extending in the [11-2] direction a plurality of first stripe mask 11s and the [1-10] extending (first direction) direction (second direction) of GaSa substrate (underlying substrate 10) and a second stripe mask 11t of the pitch P M1 in the first stripe mask 11s width W M1 is 40 [mu] m is 400 [mu] m, the pitch P M2 in the second stripe mask 11t has width W M2 40 [mu] m was 400 [mu] m .

Further, simultaneously with the formation of the SiO 2 mask 11, the opening 11w of the mask 11, [11-2] of the micro opening 12w is GaAs substrate adjacent to each other as shown in FIG. 7 (a) (base substrate 10) direction (first direction) and a first hexagonal lattice additional mask 12 of SiO 2 having a plurality of hexagonal micro window 12w arranged side by side in a direction having an angle of 60 ° to the direction the formed. Width W N of the additional mask 12 is 2 [mu] m, the pitch P N of the micro window 12w was 5 [mu] m.

3. Referring to growth Figure 2 and Figure 3 of the GaN crystal, then, the GaAs substrate (underlying substrate 10) of the SiO 2 mask 11 and the SiO 2 of the additional mask 12 is formed on the main surface 10 m, thickness by HVPE It was grown GaN buffer layer of 60nm is. Growth conditions of the buffer layer, the growth temperature 490 ° C., the partial pressure of HCl gas for generating the Ga chloride gas is brought into contact with the Ga melt 2 × 10 -3 atm (0.2026kPa) , Ga chloride gas the partial pressure of NH 3 gas to produce a GaN reacts with was 0.2atm (20.26kPa). Then, the GaN buffer layer was grown GaN crystal having a thickness of 6mm by HVPE. Growth conditions for the GaN crystal, 1030 ° C. The growth temperature, the partial pressure of HCl gas for generating the Ga chloride gas is brought into contact with the Ga melt 2 × 10 -2 atm (2.026kPa) , Ga chloride gas the partial pressure of NH 3 gas to produce a GaN reacts with was 0.3atm (30.39kPa). Also, the partial pressure of O 2 gas for doping O (oxygen) in the crystals was 0.0065atm (659Pa).

4. Obtained by reference to the fabrication Figure 3 of the GaN crystal substrate, then, a plurality of GaN crystal substrate 20p slices with a thickness of 500μm the obtained GaN crystal 20 in a plurality of planes parallel to the major surface 10m of GaAs substrate It was.

The obtained dislocation density in any low dislocation density crystal region measured at a plurality of GaN crystal substrate, such dislocation density was good substrate things than 1 × 10 6 cm -2, good substrate from the GaN crystal is a balanced number was five. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.02 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained. Measurement of such dislocation density, SEM using the CL mounted on (scanning electron microscope) (cathodoluminescence), 50 [mu] m × 50 [mu] m for any low dislocation density regions (F) and high dislocation density crystal region in the main surface of GaN crystal substrate the density was calculated by measuring the number of dislocations in the observed as dark points in each region.

Further, in the main surface of the GaN crystal substrate, and its center point, [1-100] point away 20mm in the direction from the center point, and the plane orientation at a point spaced 20mm in [11-20] direction from the center point, It was measured by ω- rocking curve measurements on (0002) plane of the GaN crystal by X-ray diffraction. Plane orientation at the center point of the main surface is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) 0. is 03 °, the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation on the [11-20] direction at a center point (second displacement angle) is 0.06 °, the plane of the main surface orientation deviation angle was very small.

The carrier concentration of the GaN crystal substrate, according to Hall measurement was 6.80 × 10 18 cm -3.

Further, by observing the main surface of the GaN crystal substrate in a fluorescence microscope, (0001) plane growth crystal region of the main surface, the facet growth crystal region and the high dislocation density crystal region was identified. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region calculated from the observation by such fluorescence microscopy (C / F ratio) is 0.48, was lower resistivity of the entire substrate .

Further, with reference to FIG. 3, the first striped crystalline region 20hs high dislocation density crystal region 20h of the GaN crystal 20 was observed by fluorescence microscopy, the pitch P 1 is 400 [mu] m, 1 mm from the crystal growth start surface 20b (referred grown to a thickness of 1mm surface, hereinafter the same) grown surface (referred to growth thickness 5.5mm surface, the same below) and 5.5mm grown surface width W 1 in were respectively 35.8μm and 13.0μm . The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20 was observed by fluorescence microscopy, the pitch P 2 is 400 [mu] m, in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface width W 2 were respectively 39.0μm and 26.0μm. The results are summarized in Table 1.

(Example A2)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 800 [mu] m, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was five. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 2.00 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.04 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.07 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.40 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.44, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 800 [mu] m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 800 [mu] m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A3)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks respectively and 1500 .mu.m, and a substrate is prepared in the same manner as in Example A1, the mask formed, by growing GaN crystals, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 6.75 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.06 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.11 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.55 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.41, the area of ​​the (0001) plane growth crystal region the area of ​​the facet growth crystal region than was large.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 1500 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 1500 .mu.m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A4)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 2000 .mu.m, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.60 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.06 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.12 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.11 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.39, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A5)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 3000 .mu.m, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was three. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 3.50 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.07 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.12 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.90 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.35, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 3000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the width W 2 is the pitch P 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm face a 3000 .mu.m, respectively 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A6)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 4000 .mu.m, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was three. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 5.50 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.07 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.13 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.43 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.32, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 4000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 4000 .mu.m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A7)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 5000 .mu.m, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was two. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 6.50 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.07 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.13 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.15 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.29, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 5000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 5000 .mu.m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A8)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 9500Myuemu, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was one. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 8.30 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.09 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.19 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.00 × 10 18 cm -3. The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.20, the area of ​​the (0001) plane growth crystal region the area of ​​the facet growth crystal region than was large.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 9500Myuemu, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 9500Myuemu, width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Example A9)
Prepare the same underlying substrate as in Example A1, except that the pitch P M1 and P M2 of the first and second stripe masks were respectively 10000, forming a mask in the same manner as in Example A1, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was one. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 8.80 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.10 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.20 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 5.25 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.18, the area of ​​the (0001) plane growth crystal region the area of ​​the facet growth crystal region than was large.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 10000, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 10000, the width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 1.

(Comparative Example RA1)
1. Preparation Referring to prepare Figure 5 of the starting substrate, in the same manner as in Example A1, the main surface 10m as an underlying substrate 10 is a GaAs substrate with a thickness of 500μm at (111) diameter of 2 inches is A-plane (50.8 mm) did.

2. Referring to formation Figure 5 of the mask, then, on the main surface 10m of the GaAs substrate (underlying substrate 10), after forming a SiO 2 mask layer with a thickness of 0.1μm by sputtering, by photolithography, forming a SiO 2 mask 11 having a striped pattern. The SiO 2 mask 11 is a plurality of first stripe mask extending in the [11-2] direction (first direction) of GaSa substrate (underlying substrate 10), the pitch P in the first stripe mask width W M1 40 [mu] m M1 was 400μm.

Further, simultaneously with the formation of the SiO 2 mask 11, the opening 11w of the mask 11, the micro openings 12w is GaSa substrate adjacent to each other as shown in FIG. 9 (underlying substrate 10) [11-2] direction (a to form a first direction) and the shape of a hexagonal lattice of additional mask 12 of SiO 2 having a plurality of hexagonal micro window 12w arranged side by side in a direction having an angle of 60 ° with respect to the first direction. Width W N of the additional mask 12 is 2 [mu] m, the pitch P N of the micro window 12w was 5 [mu] m.

3. Referring to growth Figure 5 and 6 of the GaN crystal, then, in the same manner as in Example A1, the main surface 10m of SiO 2 additional mask 12 of the mask 11 and the SiO 2 is formed of a GaAs substrate (underlying substrate 10) above, by HVPE, grown GaN buffer layer having a thickness of 60 nm, then, it was grown with a thickness of 6 mm GaN crystal.

4. Referring to Preparation 6 of the GaN crystal substrate, then, similarly, resulting plurality of thickness 500μm by slicing a plurality of planes parallel to the principal face 10m of the GaN crystal 20 GaAs substrate as in Example A1 It was obtained of GaN crystal substrate 20p.

Take the number of good substrate from the GaN crystal was five. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 3.15 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.04 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is 0.14, deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.28 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 1.33, the resistivity of the entire substrate was high.

The first stripe crystal region is a high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 400 [mu] m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The results are summarized in Table 1.

(Comparative Example RA2)
Prepare the same base substrate as in Comparative Example RA1, except that the pitch P M12 of the first stripe masks and 5000 .mu.m, forming a mask in the same manner as in Comparative Example RA1, by growing GaN crystal, GaN crystal substrates It was produced.

Take the number of good substrate from the GaN crystal was 0 sheets. For the fabricated GaN crystal substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 2.11 × 10 7 cm -2 and 8.50 × 10 8 cm -2, low dislocation density in the dislocation density crystal region is increased.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.11 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.34 ° , [11-20] deviation angle of the plane orientation in the direction is increased. The carrier concentration of the GaN crystal substrate was 6.30 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.80, the resistivity of the entire substrate was high.

The first stripe crystal region is a high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 5000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The results are summarized in Table 1.

(Comparative Example RA3)
Prepare the same base substrate as in Comparative Example RA1, except that the pitch P M12 of the first stripe masks and 10000, to form a mask in the same manner as in Comparative Example RA1, by growing GaN crystal, GaN crystal substrates It was produced.

Take the number of good substrate from the GaN crystal was 0 sheets. For the fabricated GaN crystal substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 7.89 × 10 7 cm -2 and 8.50 × 10 8 cm -2, low dislocation density in the dislocation density crystal region is increased.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.20 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.38 ° , [11-20] deviation angle of the plane orientation in the direction is increased. The carrier concentration of the GaN crystal substrate was 6.10 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.55, was lower resistivity of the entire substrate.

The first stripe crystal region is a high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 10000, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The results are summarized in Table 1.

Figure JPOXMLDOC01-appb-T000001

Referring to Table 1, the results of Comparative Examples RA1 ~ RA3 and Examples A1 ~ A9, the following was found. Typical GaN crystal substrate including a [1-100] stripe shape extending in the direction of the high dislocation density crystal region (first stripe-crystal region) in the main surface, the pitch P 1 of the first stripe-crystal region 400 [mu] m, 5000 .mu.m, according as large as 10000, high dislocation density concentration of dislocations in the crystal region is significantly reduced, low dislocation density crystal region of the dislocation density are 3.15 × 10 4 cm -2, 2.11 × 10 7 cm -2, as high as 7.89 × 10 7 cm -2, 5 sheets take the number of good substrates, respectively, 0 sheets became 0 Like (Comparative example RA1 ~ RA3). In contrast, the present invention comprising a grid of the high dislocation density crystal region including a [1-100] first stripe crystal region extending in the direction [11-20] second stripe crystal region extending in a direction in the main surface the GaN crystal substrate, the first and second stripe pitch P 1 and P 2 are 400μm each crystal, 5000 .mu.m, even as large as 10000, the concentration of dislocations into high-dislocation-density crystal region is hardly reduced, respectively five, two, 0.00 one good substrates, low dislocation density crystals dislocation density of each 1.02 × regions 10 4 cm -2 in good substrate, 6.50 × 10 5 cm -2, 8.80 × was as small as 10 5 cm -2 (example A1, A7 and A9).

Moreover, typical GaN crystal substrate having a [1-100] striped high dislocation density crystal region extending in the direction (the width W 1 of the first stripe 40 [mu] m, the pitch P 1 is 5000 .mu.m) in the main surface is, [1 100] Although the deviation angle of the primary surface in the direction (first displacement angle) as small as 0.11 °, [11-20] deviation angle of the primary surface in the direction (second displacement angle) and 0.34 ° It was large (comparative example RA2). In contrast, [1-100] direction and a [11-20] extending in a direction grid high dislocation density crystal region (first and second stripe width W 1 and W 2 40μm each in the main surface, the pitch GaN crystal substrate P 1 and P 2 according to the present invention each having 5000 .mu.m) is as small as [1-100] and [11-20] directions definitive deviation angle respectively 0.07 and 0.13 of the main surface and (example A7).

Moreover, typical GaN crystal substrate having a [1-100] striped high dislocation density crystal region extending in the direction (the width W 1 of the first stripe 40 [mu] m, the pitch P 1 is 5000 .mu.m) in the main surface, the main surface the ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region (C / F ratio) is large and 0.80 in. In contrast, [1-100] direction and a [11-20] extending in a direction grid high dislocation density crystal region (first and second stripe width W 1 and W 2 40μm each in the main surface, the pitch GaN crystal substrate according to the present invention which P 1 and P 2 each have a 5000 .mu.m) were able to reduce 0.29 the C / F ratio (example A7). Thus, a semiconductor device using a GaN crystal substrate according to the present invention, it is expected that the ON resistance becomes low.

Further, in the case of each of Examples A1 ~ A9 also first stripe crystal region 35.8μm in width W 1 (growth 1mm thick of ([1-100] high dislocation density crystal region extending in a direction), the growth thickness is 13.0) in 5.5mm is smaller than the width W M1 of the first stripe mask ([1-100] mask extending direction) (40 [mu] m), the second stripe crystal region ([11-20] direction the width W 2 of the high dislocation density crystal region) extending in the (39.0Myuemu in the growth thickness 1mm, 26.0μm in the growth thickness 5.5 mm) is a mask extending in the second stripe mask ([11-20] direction) It was smaller than the width W M2 (40μm).

Further, in the growth thickness of 1mm of the GaN crystal, the reduction rate of 2.5% of the width W 2 (39.0μm) of a second stripe crystal region to the width W M2 (40 [mu] m) of the second stripe mask of the first stripe mask It becomes smaller than the reduction rate of 10.5% of the width W 1 of the first stripe-crystal region to the width W M1 (40μm) (35.8μm) . Further, in the growth thickness 5.5mm GaN crystal, reduction rate 35.0% of the width W 2 (26.0μm) of a second stripe crystal region to the width W M2 (40 [mu] m) of the second stripe mask is first stripe It becomes smaller than the reduction rate 67.5% of the width of the first stripe-crystal region to the width W M1 of the mask (40μm) W 1 (13.0μm) .

(Example A10)
Prepare the same underlying substrate as in Example A4, except that the width W M1 and W M2 of the first and second stripe masks was 10μm respectively, forming a mask in the same manner as in Example A4, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 2.00 × 10 5 cm -2 and 8.35 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.06 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.12 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.19 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.36, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 9. It was 0μm and 3.3μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, the width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 9. It was 8μm and 6.5μm. The results are summarized in Table 2.

(Example A11)
Prepare the same underlying substrate as in Example A4, except that the width W M1 and W M2 of the first and second stripe masks was 100μm respectively, forming a mask in the same manner as in Example A4, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.20 × 10 5 cm -2 and 7.90 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.05 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.10 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.01 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.37, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 89. It was 5μm and 32.5μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, the width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 97. It was 5μm and 65.0μm. The results are summarized in Table 2.

(Example A12)
Except having an off angle of the primary surface (111) from the A plane [1-10] direction in 10 °, it was prepared the same underlying substrate as in Example A4, to form a mask in the same manner as in Example A4 , by growing GaN crystals, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.88 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate had a surface orientation has an off angle of 10 ° to the [11-20] direction from the (0001), from the center point with respect to the plane orientation in the central point [1- 100] direction deviation angle of plane orientation (first deviation angle) at a point spaced 20mm in is 0.03 °, the surface at a point away 20mm from the center point with respect to the plane orientation on the [11-20] direction at a center point deviation angle of orientation (second displacement angle) is 0.05 °, the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.50 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) of 0.50, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 34. It was 5μm and 11.8μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, the width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 37. It was 1μm and 25.6μm. The results are summarized in Table 2.

(Example A13)
Except that it has an off angle of 25 ° from the major surface (111) A plane [1-10] directions to the same underlying substrate as in Example A4, to form a mask in the same manner as in Example A4 , by growing GaN crystals, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each located at 2.10 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate had a surface orientation has an off angle of 25 ° to the [11-20] direction from the (0001), from the center point with respect to the plane orientation in the central point [1- 100] direction deviation angle of plane orientation (first deviation angle) at a point spaced 20mm in is 0.07 °, the surface at a point away 20mm from the center point with respect to the plane orientation on the [11-20] direction at a center point deviation angle of orientation (second displacement angle) is 0.10 °, the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.23 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.23, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 33. It was 2μm and 10.9μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, 35 width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 2μm and 23.2μm. The results are summarized in Table 2.

(Example A14)
Except having an off angle of the primary surface (111) from the A plane [11-2] direction 10 °, it was prepared the same underlying substrate as in Example A4, to form a mask in the same manner as in Example A4 , by growing GaN crystals, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.98 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate had a surface orientation has an off angle of 10 ° to the [11-20] direction from the (0001), from the center point with respect to the plane orientation in the central point [1- 100] direction deviation angle of plane orientation (first deviation angle) at a point spaced 20mm in is 0.03 °, the surface at a point away 20mm from the center point with respect to the plane orientation on the [11-20] direction at a center point deviation angle of orientation (second displacement angle) is 0.05 °, the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.30 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.48, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm face each 34.5μm and was 11.8μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, the width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces, respectively 37 It was .1μm and 25.6μm. The results are summarized in Table 2.

(Example A15)
Except that it has an off angle of 25 ° from the major surface (111) A plane in the 11-2] directions to the same underlying substrate as in Example A4, to form a mask in the same manner as in Example A4 , by growing GaN crystals, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was four. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 2.30 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate had a surface orientation has an off angle of 25 ° to the [11-20] direction from the (0001), from the center point with respect to the plane orientation in the central point [1- 100] direction deviation angle of plane orientation (first deviation angle) at a point spaced 20mm in is 0.07 °, the surface at a point away 20mm from the center point with respect to the plane orientation on the [11-20] direction at a center point deviation angle of orientation (second displacement angle) is 0.10 °, the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.03 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.20, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 2000 .mu.m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively 33. It was 2μm and 10.9μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 2000 .mu.m, 35 width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 2μm and 23.2μm. The results are summarized in Table 2.

(Example A16)
1. Referring to prepare diagram 2 of the base substrate was prepared sapphire substrate having a thickness of 500μm at the main surface 10m as the base substrate 10 (0001) 2 inches in diameter is surface (50.8 mm).

2. Referring to form Figure 2 of the mask, then, on the main surface 10m of the sapphire substrate (underlying substrate 10), after forming a SiO 2 mask layer with a thickness of 0.1μm by sputtering, by photolithography, forming a SiO 2 mask 11 having a grid-like pattern. Multiple The SiO 2 mask 11, extending in the sapphire substrate (underlying substrate 10) of the [11-20] direction and a plurality of first stripe mask 11s extending (first direction) [1-100] direction (second direction) and a second stripe mask 11t of the pitch P M1 in the first stripe mask 11s width W M1 is 40 [mu] m is 400 [mu] m, the pitch P M2 in the second stripe mask 11t has width W M2 40 [mu] m was 400 [mu] m .

Further, simultaneously with the formation of the SiO 2 mask 11, the opening 11w of the mask 11, the micro openings 12w adjacent to each other as shown in FIG. 9 is a sapphire substrate (underlying substrate 10) [11-20] direction (a to form a first direction) and the shape of a hexagonal lattice of additional mask 12 of SiO 2 having a plurality of hexagonal micro window 12w arranged side by side in a direction having an angle of 60 ° with respect to the first direction. Width W N of the additional mask 12 is 2 [mu] m, the pitch P N of the micro window 12w was 5 [mu] m.

3. Referring to growth Figure 2 and Figure 3 of the GaN crystal, then, on the main surface 10m of the SiO 2 mask 11 is formed of the sapphire substrate (underlying substrate 10), in the same manner as in Example A1, by HVPE, growing a GaN buffer layer having a thickness of 60 nm, then, it was grown with a thickness of 6 mm GaN crystal.

4. Referring to prepare diagram 3 of the GaN crystal substrate, then, similarly, resulting plurality of thickness 500μm by slicing a plurality of planes parallel to the principal face 10m of the GaN crystal 20 GaAs substrate as in Example A1 It was obtained of GaN crystal substrate 20p.

Take the number of good substrate from the GaN crystal was five. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.01 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.03 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.05 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.99 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.52, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 400 [mu] m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 400 [mu] m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 2.

(Example A17)
Prepare the same underlying substrate as in Example A16, except that the pitch P M1 and P M2 of the first and second stripe masks respectively and 5000 .mu.m, forming a mask in the same manner as in Example A16, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was two. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 4.50 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.07 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.10 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.25 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.25, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 5000 .mu.m, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 2 is 5000 .mu.m, a width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 2.

(Example A18)
Prepare the same underlying substrate as in Example A16, except that the pitch P M1 and P M2 of the first and second stripe masks respectively and 10000, to form a mask in the same manner as in Example A16, the GaN crystal grown, to produce GaN crystal substrate.

Take the number of good substrate from the GaN crystal was one. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 8.20 × 10 5 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.08 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.15 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.25 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.25, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 10000, 35 width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surfaces respectively. It was 8μm and 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal 20, the pitch P 1 is 10000, the width in the growth thickness of 1mm surface and grown to a thickness of 5.5mm surface W 2 each 39. It was 0μm and 26.0μm. The results are summarized in Table 2.

(Example A19)
Except that diameter of 4 inches (101.6 mm), to prepare the same underlying substrate as in Example A1, a mask is formed in the same manner as in Example A1, by growing GaN crystal, the GaN crystal substrate It was produced.

Take the number of good substrate from the GaN crystal was five. For GaN crystal substrate which is a good substrate, the dislocation density of the average of the low dislocation density regions (F) and high dislocation density crystal region are each 1.02 × 10 4 cm -2 and 8.50 × 10 8 cm -2 , the GaN crystal substrate having a crystal region of very low dislocation density was obtained.

Plane orientation at the center point of the main surface of the GaN crystal substrate is (0001), the deviation angle of the plane orientation in a point away 20mm from the center point with respect to the plane orientation in a [1-100] direction at a center point (first deviation angle) is 0.03 °, the deviation angle of the plane orientation at a point spaced 20mm in [11-20] direction from the center point with respect to the plane orientation in the center point (second displacement angle) is at 0.05 ° , the deviation angle of the plane orientation of the main surface was very small. The carrier concentration of the GaN crystal substrate was 6.80 × 10 18 cm -3.

The ratio of the area of ​​the (0001) plane growth crystal region to an area of ​​the facet growth crystal region in the main surface of the GaN crystal substrate (C / F ratio) is 0.51, was lower resistivity of the entire substrate.

The first stripe crystal region 20hs high dislocation density crystal region 20h of the GaN crystal, the pitch P 1 is 400 [mu] m, a width W 1 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm face each 35.8μm and was 13.0μm. The second stripe crystal region 20ht high dislocation density crystal region 20h of the GaN crystal, the pitch P 2 is 400 [mu] m, the width W 2 in the growth thickness of 1mm surface and grown to a thickness of 5.5mm face each 39.0μm and was 26.0μm. The results are summarized in Table 2.

Figure JPOXMLDOC01-appb-T000002

Referring to Table 2, the results of Examples A10 ~ A19, the following was found. Both the width of the first and second stripe masks of the grid-shaped mask W M1 and W M2 formed on the main surface of the underlying substrate, even 10μm or 100 [mu] m, the dislocation density of the low dislocation density crystals regions 2 GaN crystal substrate .00 × 10 5 cm -2 or 1.20 × 10 5 cm -2 and less present invention was obtained (example A10, A11).

Further, (if the underlying substrate is a GaAs substrate, (111) A) plane orientation of the base substrate corresponding to the (0001) plane of the GaN crystal substrate for producing relative, mainly having an off angle of 10 ° or 25 ° using the underlying substrate having a surface, the GaN crystal substrate major surface (0001) having a low dislocation density present invention having a low dislocation density crystal region having an off angle of 10 ° or 25 ° respectively surface obtained and (example A12 ~ A15).

Further, even when using a sapphire substrate as the base substrate, GaN crystal substrate of the dislocation density of the low dislocation density crystal region is low the present invention was obtained (Example A16 ~ A18). Moreover, even with the diameter as the underlying substrate is a GaAs substrate 4-inch (101.6 mm), GaN crystal substrate of low dislocation density low dislocation density present invention crystal regions were obtained (Example A19).

[Example B]
Next, as an example B, and 15 and 16, it is grown a group III nitride semiconductor epitaxial layer 30 to form a GaN crystal substrate with a semiconductor epitaxial layer on the major surface 20m of the GaN crystal substrate 20p further forming a Schottky electrode 41 on the main surface 30m on the group III nitride semiconductor epitaxial layer 30, of manufacturing a semiconductor device 40,40c serving SBD to form the ohmic electrode 42 on the main surface 20n of GaN crystal substrate 20p It will be described embodiments. Example B includes examples B1 ~ B24 and Comparative Examples RB1 ~ RB3 follows.

(Example B1)
1. The GaN crystal obtained by preparing growth of GaN crystal substrate from (0001) plane [1-100] except that sliced ​​along a plane parallel to 0.4 ° off the plane in direction, in the same manner as in Example A4, GaN to obtain a crystal substrate.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.4 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively was 1.60 × 10 5 cm -2 and 8.50 × 10 8 cm -2. Here, the measurement of the dislocation density was performed in the same manner as in Example A1. The number is fourteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 14 cells / area. Here, the measurement of the number of dislocation concentrated region was carried out by measuring the number of CL (cathodoluminescence) scotoma appearing in low dislocation density region which appears as a bright portion in the observation set region. The carrier concentration is 5.11 × 10 18 cm -3, C / F ratio was 0.39. Carrier concentration and C / F ratio was measured in the same manner as in Example A1.

Further, in GaN crystal substrate, the radius of curvature at the [1-100] direction of the main surface is 18.5 m, the off-angle and the center at the center of the main surface [1-100] in the off angle in the direction of the end portion the first deviation angle is the difference between (hereinafter referred to as a first deviation angle in the [1-100] direction of the main surface.) was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.7 m, is the difference between the off-angle at the end of the [11-20] direction from the off-angle and the center at the center of the main surface second displacement angle (hereinafter, referred to as a second deviation angle in the [11-20] direction of the main surface.) was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.06 °. Here, the first deviation angle and the second deviation angle was measured in the same manner as in Example A1. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.3. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.3Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.4μm × 1986.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
Referring to FIGS. 12 and 15, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, by the MOCVD method, GaN layer having a thickness of 5μm as a Group III nitride semiconductor epitaxial layer 30 of at least one layer grown to produce GaN crystal substrate with a semiconductor epitaxial layer. Growth conditions for the GaN layer (III-nitride semiconductor epitaxial layer 30), the growth temperature 1050 ° C., TMG (trimethyl gallium) feed molar ratio of the gas and NH 3 gas ([V] / [III] ) is 1250 to it is desirable that the 10000. By using a high feed mole ratio, it can be reduced the amount of carbon occupying the group-V site. When the supply molar ratio ([V] / [III]) is too high, the growth interface of the crystal will be covered with N, Ga hardly reached, defects Ga missing increases.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), the width W ei, as shown in FIG. 13 has been formed is 400μm epitaxial abnormal growth region 30Ei. Normal epitaxial growth regions other than the epitaxial abnormal growth region 30ei of GaN layer takes over the off angle of the GaN crystal substrate 20p, the GaN layer (0001) plane from the [1-100] in 0.4 ° off the plane in a direction Although crystal growth, epitaxial abnormal growth region 30ei are grown in the (0001) plane. And such epitaxial abnormal growth region 30Ei, the boundary between the other regions are observed in the microscope. The epitaxial abnormal growth region 30ei, when compared with other areas, the carrier concentration contained in epi layer is reduced CV - be confirmed by (capacitance-voltage) measurement. The can also be confirmed from the height of the distribution of crystal growth surface observed using a laser microscope.

GaN layer (III-nitride semiconductor epitaxial layer 30), low dislocation density epitaxial dislocation density of the crystal regions 30k and high dislocation density epitaxial crystal region 30h are respectively 1.60 × 10 5 cm -2 and 8.50 × 10 8 is cm -2, it was respectively equal to the dislocation density of the low dislocation density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 m -3.

3. Referring to Preparation 15 of the semiconductor device, grown GaN crystal substrate with a semiconductor epitaxial layer obtained above (GaN layer on the main surface 20m of the GaN crystal substrate 20p (III nitride semiconductor epitaxial layer 30) to form an ohmic electrode 42 on the other main surface 20n of GaN crystal substrate 20p of things). Specifically, first, washing the main surface 20n of GaN crystal substrate 20p by organic cleaning and hydrochloric acid. Thereafter, the EB (electron beam) evaporation method, Ti, Al, 20nm respectively in the order of Ti and Au, 100 nm, a layer of 20nm and 200nm for the metal material is formed on the entire main surface 20n. Then heat treated at about 2 minutes 600 ° C. under a nitrogen atmosphere, subjected to alloying of the metal material layer to form an ohmic electrode 42.

Then, on the main surface 30m of the GaN layer a region 40k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p (III nitride semiconductor epitaxial layer 30), a Ni-Au It is evaporated to form a Schottky electrode 41 having a thickness of 350nm in diameter 1600 .mu.m. Specifically, by photolithography, on a main surface 30m of the GaN layer (III-nitride semiconductor epitaxial layer 30), in the region 40k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p to form a resist having a circular opening located (not shown). Thereafter, the surface treatment of GaN layer with hydrochloric acid washed (III-nitride semiconductor epitaxial layer 30) was carried out for 3 minutes at room temperature. Then, to form the N layer having a thickness of 50nm by an EB evaporation method as the first metal layer to the first layer 41a of the Schottky electrode 41. In such first metal layer was formed on the Au layer having a thickness of 300nm by resistance heating deposition as the second metal layer serving as the second layer 41b. Then, when removing the resist, the resist metal layer deposited on are simultaneously removed (lift-off), a metal layer to serve as Schottky electrode 41 is formed. The metal layer has a plane shape is formed to have a circular shape.

Then, the wafer-shaped SBD, GaN crystal substrate 20p constituting each SBD, III nitride semiconductor epitaxial layer 30, the low dislocation density crystal region of the Schottky electrode 41 and ohmic electrode 42 are all GaN crystal substrate 20p 20k to fit directly above and directly below the area 40k of, and, as the main surface of the chip SBD after splitting the area is maximized in substantially square, the wafer-shaped SBD (wafer-shaped semiconductor device 40 ) is divided by the division line 40b to obtain a chipped SBD (chip semiconductor device 40c) to a size of 1993.4μm × 1986.9μm.

The resulting chipped SBD (chip semiconductor device 40c) is a C / F ratio is 0.39, the breakdown voltage yield is 0.50, the average on-resistance in 0.90mΩ · cm 2 There, the maximum on-resistance is 1.20mΩ · cm 2, the maximum operating current (referred to the maximum current is calculated as flown electrode area 1 cm 2 per 500A during operation. hereinafter the same.) was 10A.

Here, the withstand voltage yield, good products SBD the reverse voltage reaches 600V without current leakage when the current density is 0.001 A · cm -2, the current without reverse breakdown voltage reaches 600V leak as the defective ones, was calculated the yield rate (number of non-defective) / (conforming items + defectives). Further, the average on-resistance and maximum on-resistance for all SBD separated into chips obtained from one wafer-shaped SBD, the change in current flowing when a voltage is applied by changing from 0V to 3V, respectively the measured parameter analyzer calculates the change in voltage with respect to the change in current as the on-resistance, and the average value thereof and the average oN-resistance, and their maximum value and maximum on-resistance. The maximum operating current is calculated as flown electrode area 1 cm 2 per 500A, was confirmed flowed actually the size of the current. The results are summarized in Table 3. Incidentally, chipped SBD withstand voltage yield, average on-resistance and voltage for calculating the maximum on-resistance, measurement of the current and resistance, in the examples and comparative examples, the chipped SBD, implementation only package, an ohmic electrode 42 side of the SBD and die bonding, the Schottky electrode 41 side of the SBD by wire bonding was performed by mounting of.

(Example B2)
1. The pitch P M1 and P M2 of the first and second stripe masks formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal of the GaN crystal substrate was respectively 800 [mu] m, and were grown except that sliced ​​along a plane parallel to the GaN crystal GaAs substrate main surface of the (base substrate) ((111) a plane), the same procedure as in example B1, to obtain a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density is respectively 2.00 × 10 4 cm -2 and 8.50 × crystal regions It was 10 8 cm -2. Further, eight number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 625, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 01 cells / area. The carrier concentration is 5.40 × 10 18 cm -3, C / F ratio was 0.70. The curvature radius of [1-100] direction of the main surface is 28.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.04 °. The curvature radius of [11-20] direction of the main surface is 15.6 m, the second deviation angle in the [11-20] direction of the main surface was 0.07 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.03 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 800 [mu] m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 800 [mu] m, a width W 2 was 26.4Myuemu. Therefore, the size of one of low dislocation density crystal region was 793.3μm × 786.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.00 × 10 4 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode 41 of the semiconductor device and 600μm, the same procedure as in Example B1, 793.3μm × 786.8μm of magnitude chipped SBD (chip semiconductor device 40c ) was obtained. The resulting chipped SBD is C / F ratio is 0.70, the breakdown voltage yield is 0.92, the average on-resistance is 1.10mΩ · cm 2, the maximum on-resistance 1.39mΩ · cm 2, and the maximum operating current was 1.5A. The results are summarized in Table 3.

(Example B3)
1. Except that the first and second stripes, respectively 1500μm pitch P M1 and P M2 of the mask to be formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, Example in the same manner as B2, to obtain a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density is respectively 6.75 × 10 4 cm -2 and 8.50 × crystal regions It was 10 8 cm -2. Also, 12 is the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 178, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 07 cells / area. The carrier concentration is 5.55 × 10 18 cm -3, C / F ratio was 0.41. The curvature radius of [1-100] direction of the main surface is 20.1M, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 10.8 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 1500 .mu.m, a width W 1 was 13.3. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 1500 .mu.m, a width W 2 was 26.5. Therefore, the size of one of low dislocation density crystal region was 1493.4μm × 1486.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 6.75 × 10 4 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode 41 of the semiconductor device and 1200μm, the same procedure as in Example B1, 1493.4μm × 1486.8μm of magnitude chipped SBD (chip semiconductor device 40c ) was obtained. The resulting chipped SBD is C / F ratio is 0.41, the breakdown voltage yield is 0.88, the average on-resistance is 0.96mΩ · cm 2, the maximum on-resistance 1.38mΩ · cm 2, and the maximum operating current was 6A. The results are summarized in Table 3.

(Example B4)
1. The GaN crystal obtained by preparing growth of GaN crystal substrate (0001) except that the sliced ​​along a plane parallel to the surface, in the same manner as in Example B1, to obtain a GaN crystal substrate. Incidentally, how to prepare a GaN crystal substrate in the present embodiment B4 is the pitch P M1 and P M2 of the first and second stripe masks formed on the main surface of the GaAs substrate (underlying substrate) during growth of the GaN crystal except that each and 2000 .mu.m, the same as in example B2.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.60 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is fourteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 14 cells / area. The carrier concentration is 5.11 × 10 18 cm -3, C / F ratio was 0.39. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.7 m, the second deviation angle in the [11-20] direction of the main surface was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.06 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.0. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.0Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.5μm × 1987.0μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.60 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a diameter of the Schottky electrode 41 is chipped to a size of 1993.5μm × 1987.0μm in 1600 .mu.m SBD (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.39, the breakdown voltage yield is 0.80, the average on-resistance is 0.98mΩ · cm 2, the maximum on-resistance 1.39mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 3.

(Comparative Example RB1)
1. It was prepared in the same manner GaN crystal substrate as prepared in Comparative Example RA1 of GaN crystal substrate.

Prepared GaN crystal substrate is a surface orientation of the major surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 3.15 × 10 4 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number fifty dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 50, the density of dislocation-concentrated region per one dislocation density crystal region of 1. It was 00 cells / area. However, in this comparative example, a low dislocation density crystal region since a stripe shape, the semiconductor device of one low dislocation density crystal region from a plurality of square is taken. In the embodiment, taking a single semiconductor device from a single low dislocation density crystal region. From this point of view, one of low dislocation density crystal region of this comparative example, in the embodiment corresponds to the 50 low-dislocation-density crystal region. That is, the number of examples corresponding low dislocation density crystal region per 20mm angle because it is 2500, a density of one embodiment corresponding dislocation density crystal region per dislocation concentrated region was 0.02 / region .

The carrier concentration is 4.28 × 10 18 cm -3, C / F ratio was 0.80. The curvature radius of [1-100] direction of the main surface is 32.4M, the first deviation angle in the [1-100] direction of the main surface was 0.04 °. The curvature radius of [11-20] direction of the main surface is 6.8 m, the second deviation angle in the [11-20] direction of the main surface was 0.16 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.12 °. The first stripe crystal region of high dislocation density regions in the main surface, with a pitch P 1 is 400 [mu] m, the width W 1 was 13.1Myuemu. Therefore, the size of one low dislocation density crystal region in 20mm square was 395.5μm × 20000μm (20mm).

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 3.15 × 10 4 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode 41 of the semiconductor device and 200μm, the same procedure as in Example B1, the ohmic electrode 42 and the Schottky electrode 41 was formed wafer-shaped SBD (semiconductor device 40 of the wafer-shaped) It was obtained. Then, the wafer-shaped SBD, GaN crystal substrate constituting each SBD, III nitride semiconductor epitaxial layer, a Schottky electrode and an ohmic electrode is directly above and directly below the low dislocation density crystal region all GaN crystal substrate to fit within the region (not shown), and, as the main surface of the chip SBD after splitting the area is maximized in substantially square, and dividing the wafer-shaped SBD (wafer-shaped semiconductor devices) Te to obtain SBD that is chipped to a size of 395.5μm × 400.0μm (the chipped semiconductor device 40c).

The resulting chipped SBD is C / F ratio is 0.80, the breakdown voltage yield is 0.95, the average on-resistance is 1.38mΩ · cm 2, the maximum on-resistance 2.34mΩ · cm 2, and the maximum operating current was 0.15A. The results are summarized in Table 3.

(Comparative Example RB2)
1. Except that a 2000μm pitch P M1 of the first stripe mask formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, in the same manner as in Comparative Example RB1, GaN to obtain a crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density is respectively 8.00 × 10 6 cm -2 and 8.50 × crystal regions It was 10 8 cm -2. The number is 700 pieces of dislocation-concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 10, the density of dislocation-concentrated region per one dislocation density crystal region 70. It was 0 / region. Here, from the same viewpoint as in Comparative Example RB1, 1 single low dislocation density crystal region of this comparative example, in the embodiment corresponds to the 10 low-dislocation-density crystal region. That is, the number of examples corresponding low dislocation density crystal region per 20mm angle since it is 100, the density of one embodiment corresponding dislocation density crystal region per dislocation concentrated region was 7.00 pieces / area .

The carrier concentration is 5.18 × 10 18 cm -3, C / F ratio was 0.55. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 5.7 m, the second deviation angle in the [11-20] direction of the main surface was 0.20 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.14 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.5 .mu.m. Therefore, the size of one low dislocation density crystal region in 20mm square was 1993.3μm × 20000μm (20mm).

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 8.00 × 10 6 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode of the semiconductor device and 1600μm, the same procedure as Comparative Example RB1, SBD that is chipped to a size of 1993.3μm × 2000.0μm (chip semiconductor device 40c) It was obtained. The resulting chipped SBD is C / F ratio is 0.55, the breakdown voltage yield is 0.02, the average on-resistance is 1.09mΩ · cm 2, the maximum on-resistance 2.28mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 3.

(Comparative Example RB3)
1. Except that a 5000μm pitch P M1 of the first stripe mask formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, in the same manner as in Comparative Example RB1, GaN to obtain a crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 2.05 × 10 7 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is 2200 amino dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm square is four, the density of dislocation-concentrated region per one dislocation density crystal region 550. It was 0 / region. Here, from the same viewpoint as in Comparative Example RB1, 1 single low dislocation density crystal region of this comparative example, in the embodiment corresponds to the four low dislocation density crystal region. That is, since the number of examples corresponding low dislocation density crystal region per 20mm angle is 16, the density of one embodiment corresponding dislocation density crystal region per dislocation concentrated region was 137.5 cells / area .

The carrier concentration is 5.20 × 10 18 cm -3, C / F ratio was 0.36. The curvature radius of [1-100] direction of the main surface is 9.2 m, the first deviation angle in the [1-100] direction of the main surface was 0.12 °. The curvature radius of [11-20] direction of the main surface is 2.4 m, the second deviation angle in the [11-20] direction of the main surface was 0.48 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.36 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 5000 .mu.m, a width W 1 was 13.8Myuemu. Therefore, the size of one low dislocation density crystal region in 20mm square was 4993.1μm × 20000μm (20mm).

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.05 × 10 7 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode of the semiconductor device and 4500μm, the same procedure as Comparative Example RB1, SBD that is chipped to a size of 4993.1μm × 5000.0μm (chip semiconductor device 40c) It was obtained. The resulting chipped SBD is, C / F ratio is 0.36, the breakdown voltage yield was 0.00. That is, good SBD was not obtained. The results are summarized in Table 3.

Figure JPOXMLDOC01-appb-T000003

(Example B5)
1. Except that the first and second stripes, respectively 9500μm pitch P M1 and P M2 of the mask to be formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, Example in the same manner as B2, to obtain a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density is respectively 8.30 × 10 5 cm -2 and 8.50 × crystal regions It was 10 8 cm -2. The number is 20 dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 4.2 pieces, the density of dislocation-concentrated region per one dislocation density crystal region It was 4.76 cells / area. Further, a carrier concentration of 5.00 × 10 18 cm -3, C / F ratio was 0.20. The curvature radius of [1-100] direction of the main surface is 13.0m, the first deviation angle in the [1-100] direction of the main surface was 0.09 °. The curvature radius of [11-20] direction of the main surface is 9.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.03 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is in 9500Myuemu, width W 1 was 13.2Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 9500Myuemu, the width W 2 was 26.5. Therefore, the size of one of low dislocation density crystal region was 9493.4μm × 9486.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 8.30 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode of the semiconductor device and 9000μm, the same procedure as in Example B1, SBD that is chipped to a size of 9493.4μm × 9486.8μm (chip semiconductor device 40c) It was obtained. The resulting chipped SBD is C / F ratio of 0.20, the breakdown voltage yield is 0.45, the average on-resistance is 0.86mΩ · cm 2, the maximum on-resistance 1.37mΩ · cm 2, and the maximum operating current was 300A. The results are summarized in Table 4.

(Example B6)
1. Except that the first and second stripes, respectively 10000μm pitch P M1 and P M2 of the mask to be formed on the main surface of the GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, Example in the same manner as B2, to obtain a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density is respectively 8.80 × 10 5 cm -2 and 8.50 × crystal regions It was 10 8 cm -2. The number is 22 amino dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm square is four, the density of dislocation-concentrated region per one dislocation density crystal region 5. It was 50 cells / area. The carrier concentration is 5.25 × 10 18 cm -3, C / F ratio was 0.18. The curvature radius of [1-100] direction of the main surface is 11.6 m, the first deviation angle in the [1-100] direction of the main surface was 0.10 °. The curvature radius of [11-20] direction of the main surface is 9.0 m, the second deviation angle in the [11-20] direction of the main surface was 0.13 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.03 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 10000, the width W 1 was 13.0. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 10000, the width W 2 was 26.3Myuemu. Therefore, the size of one of low dislocation density crystal region was 9993.5μm × 9986.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 8.80 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. Except that the diameter of making Schottky electrode of the semiconductor device and 9500μm, the same procedure as in Example B1, SBD that is chipped to a size of 9993.5μm × 9986.9μm (chip semiconductor device 40c) It was obtained. The resulting chipped SBD is C / F ratio is 0.18, the breakdown voltage yield is 0.40, the average on-resistance is 0.83mΩ · cm 2, the maximum on-resistance 1.40mΩ · cm 2, and the maximum operating current was 350A. The results are summarized in Table 4.

(Example B7)
1. Except that the O partial pressure of O 2 gas for doping (oxygen) to 6 × 10 -7 atm (0.06Pa) to the crystal during growth of the GaN crystal by preparing HVPE method of GaN crystal substrate, in the same manner as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.80 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. The carrier concentration is 8.21 × 10 18 cm -3, C / F ratio was 0.38. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 10.8 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.3. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.4Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.4μm × 1986.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.80 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, the diameter of the Schottky electrode is in 1600 .mu.m, to obtain a chipped SBD (chip semiconductor device 40c) to a size of 1993.4μm × 1986.8μm. The resulting chipped SBD is C / F ratio is 0.38, the breakdown voltage yield is 0.78, the average on-resistance is 0.82mΩ · cm 2, the maximum on-resistance 1.19mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 4.

(Example B8)
1. Except that the partial pressure of O 2 gas for doping O (oxygen) to the crystal during growth of the GaN crystal and 1.2 × 10 -6 atm (0.12Pa) by preparing HVPE method of GaN crystal substrate , the same procedure as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.70 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. The carrier concentration is 1.20 × 10 19 cm -3, C / F ratio was 0.35. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 10.8 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.2Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1986.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.70 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1986.9μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.35, the breakdown voltage yield is 0.77, the average on-resistance is 0.72mΩ · cm 2, the maximum on-resistance 1.05mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 4.

(Example B9)
1. The GaN crystal obtained by preparing growth of GaN crystal substrate from (0001) plane [1-100] except that sliced ​​along a plane parallel to 0.7 ° off the plane direction, the same procedure as in Example B4, GaN to obtain a crystal substrate.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.7 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively was 1.60 × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is fourteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 14 cells / area. The carrier concentration is 5.11 × 10 18 cm -3, C / F ratio was 0.39. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.7 m, the second deviation angle in the [11-20] direction of the main surface was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.06 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.1Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.5. Therefore, the size of one of low dislocation density crystal region was 1993.5μm × 1986.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), the width W ei, as shown in FIG. 13 has been formed is 200μm epitaxial abnormal growth region 30Ei. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.60 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.5μm × 1986.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.39, the breakdown voltage yield is 0.80, the average on-resistance is 0.90mΩ · cm 2, the maximum on-resistance 1.20mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 4.

Figure JPOXMLDOC01-appb-T000004

See Table 3 and Table 4 above the following was found. SBD containing GaN crystal substrate having a stripe-shaped high dislocation density crystal region, since C / F ratio is high high none average on-resistance and maximum on-resistance, is the distance between the high dislocation density crystal region increases the breakdown voltage yield greatly decreased (Comparative example RB1, RB2, RB3). In contrast, SBD containing GaN crystal substrate having a lattice-like high dislocation density crystal region, both the average ON-resistance and maximum on-resistance for C / F ratio is low is low, the interval of the high dislocation density crystal region breakdown voltage yield is increased remained high (examples B1 ~ B9). This, by forming a high dislocation density of the GaN crystal substrate in a grid pattern, the low dislocation density, C / F ratio is reduced, presumably because the formation of the dislocation concentrated region is suppressed. The average on-resistance and the maximum on-resistance is low, the resistance of the GaN crystal substrate is considered to reduce (Example B4, B7, B8) of the SBD including carrier concentration is higher GaN crystal substrate. That is, lowering the C / F ratio, and / or by increasing the carrier concentration of the GaN crystal substrate, it is considered possible to lower the average on-resistance and maximum on-resistance. Moreover, the improvement in the breakdown voltage yield of the SBD including carrier concentration is higher GaN crystal substrate, it is considered that reduction of the dislocation density and the dislocation-concentrated regions of the GaN crystal substrate greatly contributes.

(Example B10)
1. A first stripe mask formed on the main surface a continuous GaAs substrate (underlying substrate) during growth of the preparation GaN crystal GaN crystal substrate, except that the second stripe masks were discontinuous, as in Example B1 Similarly, yielding a GaN crystal substrate. The second stripe mask discontinuities repeated continuous portion at constant intervals, the length L MW discontinuities is 2 [mu] m, the length L M of the continuous portion was 40 [mu] m.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.4 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively 2.00 was × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. The carrier concentration is 6.01 × 10 18 cm -3, C / F ratio was 0.30. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.5Myuemu. The second stripe crystal region, discontinuous portion a repeating and continuous part at regular intervals, the length L W of the discontinuous portion 17.5 .mu.m, a length L of the continuous portion was 24.5Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1987.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

The obtained GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei as in Example B1 was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.00 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1987.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.30, the breakdown voltage yield is 0.85, the average on-resistance is 0.86mΩ · cm 2, the maximum on-resistance 1.25mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B11)
1. Prepare second stripe mask GaN crystal substrate, repeated at discontinuous portions and continuous portions is constant intervals, 100 [mu] m length L MW of discontinuities, except that the length L M of the continuous portion is set to 40 [mu] m, performed in the same manner as in example B12, yielding a GaN crystal substrate.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.4 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively 5.00 was × 10 5 cm -2 and 8.50 × 10 8 cm -2. Also, 18 is the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 18 cells / area. The carrier concentration is 6.01 × 10 18 cm -3, C / F ratio was 0.30. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.2Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.0Myuemu. The second stripe crystal region, discontinuous portion a repeating and continuous part at regular intervals, the length L W of the discontinuous portion 116Myuemu, the length L of the continuous portion was 24.0Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.4μm × 1988.0μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

The obtained GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei as in Example B1 was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 5.00 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.4μm × 1988.0μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.30, the breakdown voltage yield is 0.77, the average on-resistance is 0.86mΩ · cm 2, the maximum on-resistance 1.25mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B12)
1. When preparing the GaN crystal growth of the GaN crystal substrate, except that the plane orientation of the principal surface as a base substrate (111) using a GaAs substrate was 10 ° off [1-10] direction from A is Example B4 in the same manner as to obtain a GaN crystal substrate.

The obtained GaN crystal substrate, the plane orientation of main surface has 10 ° off [11-20] direction from the (0001), the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region, each 1. was 88 × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is fourteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 14 cells / area. Further, a carrier concentration of 6.50 × 10 18 cm -3, C / F ratio was 0.50. The curvature radius of [1-100] direction of the main surface is 36.5M, the first deviation angle in the [1-100] direction of the main surface was 0.03 °. The curvature radius of [11-20] direction of the main surface is 4.50 m, the second deviation angle in the [11-20] direction of the main surface was 0.25 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.22 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.5 .mu.m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.3Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1987.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.88 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1987.9μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.50, the breakdown voltage yield is 0.78, the average on-resistance is 0.96mΩ · cm 2, the maximum on-resistance 1.36mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B13)
1. When preparing the GaN crystal growth of the GaN crystal substrate, except that the plane orientation of the principal surface as a base substrate (111) using a GaAs substrate was 25 ° off [1-10] direction from A is Example B4 in the same manner as to obtain a GaN crystal substrate.

The obtained GaN crystal substrate, the surface orientation of the major surface from (0001) [11-20] direction has 25 ° off, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. was 10 × 10 5 cm -2 and 8.50 × 10 8 cm -2. Also, 18 is the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 18 cells / area. The carrier concentration is 6.23 × 10 18 cm -3, C / F ratio was 0.23. The curvature radius of [1-100] direction of the main surface is 17.6M, the first deviation angle in the [1-100] direction of the main surface was 0.07 °. The curvature radius of [11-20] direction of the main surface is 3.12M, the second deviation angle in the [11-20] direction of the main surface was 0.37 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.30 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 9.5 .mu.m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 23.2Myuemu. Therefore, the size of one of low dislocation density crystal region was 1995.3μm × 1988.4μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.10 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1995.3μm × 1988.4μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.23, the breakdown voltage yield is 0.61, the average on-resistance is 0.80mΩ · cm 2, the maximum on-resistance 1.40mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B14)
1. When preparing the GaN crystal growth of the GaN crystal substrate, except that the plane orientation of the principal surface as a base substrate (111) using a GaAs substrate was 10 ° off [11-2] direction from A is Example B4 in the same manner as to obtain a GaN crystal substrate.

The obtained GaN crystal substrate, the plane orientation of main surface has 10 ° off [1-100] direction from the (0001), the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region, each 1. was 98 × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. The carrier concentration is 6.30 × 10 18 cm -3, C / F ratio was 0.48. The curvature radius of [1-100] direction of the main surface is 4.40M, the first deviation angle in the [1-100] direction of the main surface was 0.26 °. The curvature radius of [11-20] direction of the main surface is 22.1 m, the second deviation angle in the [11-20] direction of the main surface was 0.05 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.21 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 12.5 .mu.m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.5Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.8μm × 1987.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.98 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.8μm × 1987.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.48, the breakdown voltage yield is 0.82, the average on-resistance is 0.96mΩ · cm 2, the maximum on-resistance 1.38mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B15)
1. When preparing the GaN crystal growth of the GaN crystal substrate, except that the plane orientation of the principal surface as a base substrate (111) using a GaAs substrate was 25 ° off [11-2] direction from A is Example B4 in the same manner as to obtain a GaN crystal substrate.

The obtained GaN crystal substrate, the surface orientation of the major surface from (0001) has 25 ° off [1-100] direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. was 30 × 10 5 cm -2 and 8.50 × 10 8 cm -2. Also, 19 is the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 19 cells / area. The carrier concentration is 6.03 × 10 18 cm -3, C / F ratio was 0.20. The curvature radius of [1-100] direction of the main surface is 2.95M, the first deviation angle in the [1-100] direction of the main surface was 0.40 °. The curvature radius of [11-20] direction of the main surface is 11.0 m, the second deviation angle in the [11-20] direction of the main surface was 0.10 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.30 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 10.3. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 22.5. Therefore, the size of one of low dislocation density crystal region was 1994.9μm × 1988.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.30 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1994.9μm × 1988.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio of 0.20, the breakdown voltage yield is 0.63, the average on-resistance is 0.79mΩ · cm 2, the maximum on-resistance 1.42mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

Figure JPOXMLDOC01-appb-T000005

Example B1, B4 of Table 3, as is apparent with reference to Examples B10 ~ B15 Example B9 and Table 5 Table 4, the main surface is (0001) plane from a little off-angle (e.g., 0.4 While ° or epitaxial abnormal growth region in the group III nitride semiconductor epitaxial layer grown on the main surface of the GaN crystal substrate (example B1, B9) with a 0.7 °) is formed, the high dislocation density crystals first and second either GaN crystal substrate (example B10, B11) is discontinuous stripe crystal region area or off angle of the primary surface of the GaN crystal substrate (0001) 0 ° from the plane, 10 ° epitaxial abnormal growth region in the group III nitride semiconductor epitaxial layer grown on the main surface of the GaN crystal substrate (example B4, B12 ~ B15) or 25 ° was formed.

In the following Examples B16 ~ B21, and B24 are examples of the case where the diameter is to produce GaN crystal substrate using a GaAs substrate (underlying substrate) 4 inch (10.16 cm). In these embodiments, major surface [1-100] second deviation angle in the [11-20] direction of the first displacement angle and the main surface in the direction, the off angle and the center point at the center point of each main surface from 1-100 from off-angle and the center point at the center point of the difference and the principal surface between the off-angle at the point of end remote 4cm in the direction [11-20] point end remote 4cm direction It was calculated from the difference between the off-angle in. Here, the off angle of the primary surface at each point, is calculated from the plane orientation of the point being measured by ω- rocking curve associated (0002) plane by X-ray diffraction at that point.

(Example B16)
1. During growth of the preparation GaN crystal GaN crystal substrate, and the first stripe mask formed on the main surface of the GaAs substrate with a diameter of 4 inches (10.16 cm) (base substrate) and continuous, the second stripe mask not except that a continuous, in the same manner as in example B4, yielding a GaN crystal substrate. The second stripe mask discontinuities repeated continuous portion at constant intervals, the length L MW discontinuities is 2 [mu] m, the length L M of the continuous portion was 40 [mu] m.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.4 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively was 1.90 × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number fifteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 15 cells / area. The carrier concentration is 6.23 × 10 18 cm -3, C / F ratio was 0.29. The curvature radius of [1-100] direction of the main surface is 37.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 25.3 m, the second deviation angle in the [11-20] direction of the main surface was 0.10 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.04 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.5Myuemu. The second stripe crystal region, discontinuous portion a repeating and continuous part at regular intervals, the length L W of the discontinuous portion 17.5 .mu.m, a length L of the continuous portion was 24.5Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1987.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

The obtained GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei as in Example B1 was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.90 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1987.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.29, the breakdown voltage yield is 0.84, the average on-resistance is 0.81mΩ · cm 2, the maximum on-resistance 1.30mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 6.

(Example B17)
1. Prepare second stripe mask GaN crystal substrate, repeated at discontinuous portions and continuous portions is constant intervals, 100 [mu] m length L MW of discontinuities, except that the length L M of the continuous portion is set to 40 [mu] m, performed in the same manner as in example B16, yielding a GaN crystal substrate. .

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) has 0.4 ° off the direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region respectively 4.50 was × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is 20 dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 20 cells / area. The carrier concentration is 6.30 × 10 18 cm -3, C / F ratio was 0.28. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.12 °. The curvature radius of [11-20] direction of the main surface is 9.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.22 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.10 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.5 .mu.m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.0Myuemu. The second stripe crystal region, discontinuous portion a repeating and continuous part at regular intervals, the length L W of the discontinuous portion 116Myuemu, the length L of the continuous portion was 24.0Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1988.0μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

The obtained GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei as in Example B1 was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 4.50 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1988.0μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.28, the breakdown voltage yield is 0.72, the average on-resistance is 0.88mΩ · cm 2, the maximum on-resistance 1.30mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 6.

(Example B18)
1. During growth of the preparation GaN crystal GaN crystal substrate, GaAs substrate diameter as a base substrate is 10 ° off the [1-10] direction the plane orientation of the main from (111) A with 4 inches (10.16 cm) except for the use of, the same procedure as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate, the plane orientation of main surface has 10 ° off [11-20] direction from the (0001), the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. 00 was × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is 16 dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 16 cells / area. The carrier concentration is 6.03 × 10 18 cm -3, C / F ratio was 0.48. The curvature radius of [1-100] direction of the main surface is 36.5M, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 3.72M, the second deviation angle in the [11-20] direction of the main surface was 0.31 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.25 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.8Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.4Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.1μm × 1987.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.00 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.1μm × 1987.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.48, the breakdown voltage yield is 0.76, the average on-resistance is 1.00mΩ · cm 2, the maximum on-resistance 1.33mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 5.

(Example B19)
1. During growth of the preparation GaN crystal GaN crystal substrate, GaAs substrate was 25 ° off [1-10] direction the diameter as an underlying substrate is the plane orientation of main surface with 4 inches (10.16cm) (111) from A except for the use of, the same procedure as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate, the surface orientation of the major surface from (0001) [11-20] direction has 25 ° off, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. was 30 × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number is 20 dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 20 cells / area. Further, a carrier concentration of 6.80 × 10 18 cm -3, C / F ratio was 0.35. The curvature radius of [1-100] direction of the main surface is 35.6M, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 3.10M, the second deviation angle in the [11-20] direction of the main surface was 0.36 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.30 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.3. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 23.8Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.4μm × 1988.1μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.30 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.4μm × 1988.1μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.35, the breakdown voltage yield is 0.60, the average on-resistance is 0.91mΩ · cm 2, the maximum on-resistance 1.42mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 6.

(Example B20)
1. During growth of the preparation GaN crystal GaN crystal substrate, GaAs substrate diameter as a base substrate was 10 ° off [11-2] direction plane orientation of the main surface from (111) A with 4 inches (10.16 cm) except for the use of, the same procedure as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate, [1-100] plane orientation of the main surface from (0001) direction has 10 ° off, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. 00 was × 10 5 cm -2 and 8.50 × 10 8 cm -2. The number fifteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 15 cells / area. Further, a carrier concentration of 6.40 × 10 18 cm -3, C / F ratio was 0.42. The curvature radius of [1-100] direction of the main surface is 3.85 m, the first deviation angle in the [1-100] direction of the main surface was 0.29 °. The curvature radius of [11-20] direction of the main surface is 19.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.17 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 12.9. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.9Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.6μm × 1987.6μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.00 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.6μm × 1987.6μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.42, the breakdown voltage yield is 0.80, the average on-resistance is 0.95mΩ · cm 2, the maximum on-resistance 1.34mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 6.

(Example B21)
1. During growth of the preparation GaN crystal GaN crystal substrate, GaAs substrate was 25 ° off [11-2] direction diameter as an underlying substrate is the plane orientation of main surface with 4 inches (10.16cm) (111) from A except for the use of, the same procedure as in example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate, the surface orientation of the major surface from (0001) has 25 ° off [1-100] direction, the dislocation density of the low dislocation density regions (F) and high dislocation density crystal region are respectively 2. was 80 × 10 5 cm -2 and 8.50 × 10 8 cm -2. Also, number 21 of dislocation-concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 21 cells / area. Further, a carrier concentration of 6.00 × 10 18 cm -3, C / F ratio was 0.29. The curvature radius of [1-100] direction of the main surface is 2.91M, the first deviation angle in the [1-100] direction of the main surface was 0.39 °. The curvature radius of [11-20] direction of the main surface is 29.1M, the second deviation angle in the [11-20] direction of the main surface was 0.31 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.02 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.1Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 23.0Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.5μm × 1988.5μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the, GaN layer having a thickness of 5 [mu] m (III nitride semiconductor epitaxial layer 30) is formed GaN crystal with a semiconductor epitaxial layer to obtain a substrate.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 2.80 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 7.0 × 10 15 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.5μm × 1988.5μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.29, a withstand voltage yield 0.69, average on-resistance is 0.80mΩ · cm 2, the maximum on-resistance 1.41mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 6.

Figure JPOXMLDOC01-appb-T000006

Examples in Table 6 B16 to ~ B21 and below As is clear with reference to examples B24 in Table 7, even when the diameter of the GaN crystal substrate is as large as 4 inches slightly from the main surface is (0001) plane off angle of (for example, 0.4 °) GaN crystal substrate or is discontinuous in the first and second stripe crystal region of high dislocation density crystal region have a (example B16, B17) or off angle of the primary surface of the GaN crystal substrate (0001) 0 ° from the plane, 10 ° or 25 ° GaN crystal substrate (example B24, B18 ~ B21) III nitride grown on the main surface of the epitaxial abnormal growth region in the semiconductor epitaxial layer was not formed.

(Example B22)
1. In the same manner as Preparative Example B4 of the GaN crystal substrate, yielding a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.70 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. The carrier concentration is 5.90 × 10 18 cm -3, C / F ratio was 0.43. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 9.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.11 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.05 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.1Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 23.0Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.5μm × 1988.5μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In order to lower the carrier concentration of the epitaxial layer, except that constitutes the chamber with a material that does not contain quartz, in the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the above, give thickness GaN layer of 5μm to (III-nitride semiconductor epitaxial layer 30) semiconductor epitaxial GaN crystal substrate with layers which are formed.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.70 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 5.00 × 10 14 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.5μm × 1988.5μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.43, a withstand voltage yield 0.81, average on-resistance is 0.99mΩ · cm 2, the maximum on-resistance 1.54mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 7.

(Example B23)
1. In the same manner as Preparative Example B4 of the GaN crystal substrate, yielding a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.80 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. The number is fourteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 14 cells / area. Further, a carrier concentration of 5.50 × 10 18 cm -3, C / F ratio was 0.38. The curvature radius of [1-100] direction of the main surface is 18.5 m, the first deviation angle in the [1-100] direction of the main surface was 0.05 °. The curvature radius of [11-20] direction of the main surface is 22.0M, the second deviation angle in the [11-20] direction of the main surface was 0.05 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.00 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.2Myuemu. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 24.4Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.4μm × 1987.8μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In order to increase the carrier concentration of the epitaxial layer, except that intentionally doped with Si epitaxial layer, in the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the above, the thickness to give the 5 [mu] m GaN layer of (III-nitride semiconductor epitaxial layer 30) GaN crystal substrate with a semiconductor epitaxial layer is formed.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.80 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 1.00 × 10 17 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.4μm × 1987.8μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.38, the breakdown voltage yield is 0.82, the average on-resistance is 1.02mΩ · cm 2, the maximum on-resistance 1.48mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 7.

(Example B24)
1. When preparing the GaN crystal growth of the GaN crystal substrate, except that the diameter using GaAs substrate 4-inch (10.16 cm), in the same manner as in Example B4, yielding a GaN crystal substrate.

The obtained GaN crystal substrate is a plane orientation of main surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of 1.55 × 10 5 cm -2 and 8.50 × respective crystal regions It was 10 8 cm -2. Also, 12 is the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 12 cells / area. The carrier concentration is 6.10 × 10 18 cm -3, C / F ratio was 0.36. The curvature radius of [1-100] direction of the main surface is 19.0M, the first deviation angle in the [1-100] direction of the main surface was 0.10 °. The curvature radius of [11-20] direction of the main surface is 18.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.12 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.02 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.2Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1986.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In order to increase the carrier concentration of the epitaxial layer, except that intentionally doped with Si epitaxial layer, in the same manner as in Example B1, on the main surface 20m of the GaN crystal substrates 20p, which is prepared by the above, the thickness to give the 5 [mu] m GaN layer of (III-nitride semiconductor epitaxial layer 30) GaN crystal substrate with a semiconductor epitaxial layer is formed.

Obtained the GaN layer (III-nitride semiconductor epitaxial layer 30), an epitaxial abnormal growth region 30ei was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 30k and the high dislocation density epitaxial crystal region 30h are each 1.55 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p. The carrier concentration was 2.20 × 10 16 cm -3.

3. In the same manner as in Production Example B1 a semiconductor device, to obtain a SBD the diameter of the Schottky electrode is chipped to a size of 1993.3μm × 1986.9μm in 1600 .mu.m (chip semiconductor device 40c). The resulting chipped SBD is C / F ratio is 0.36, the breakdown voltage yield is 0.79, the average on-resistance is 0.89mΩ · cm 2, the maximum on-resistance 1.39mΩ · cm 2, the maximum operating current was 10A. The results are summarized in Table 7.

Figure JPOXMLDOC01-appb-T000007

Referring to Table 7, in the semiconductor device (SBD), time of changing the carrier concentration of the GaN layer (III-nitride semiconductor epitaxial layer 30), low carrier concentration (e.g. 5.00 × 10 14 cm -3 or less ) becomes the average for the resistance of the epitaxial layer is high on-resistance and the maximum on-resistance is increased, the carrier concentration is high (e.g. 1.00 × 10 17 cm -3 or more) becomes the average for the resistance of the epitaxial layer is increased on-resistance and maximum on-resistance is higher.

[Example C]
Next, as an example C, and with reference to FIGS. 17 to 19, by growing the Group III nitride semiconductor epitaxial layer 70 to form a GaN crystal substrate with a semiconductor epitaxial layer on the major surface 20m of the GaN crystal substrate 20p further a p-side electrode 81 is formed on the main surface 70m of group III nitride semiconductor epitaxial layer 70, the semiconductor device 80,80c serving LED to form the n-side electrode 82 on a main surface 20n of GaN crystal substrate 20p for example manufactured will be described. Example C includes the following examples Comparative Example RC1.

(Example C1)
1. It was prepared in the same manner GaN crystal substrate as prepared in Example B4 of the GaN crystal substrate.

The prepared GaN crystal substrate is a surface orientation of the major surface (0001), low dislocation density regions (F) and high dislocation density dislocation density of the crystal region is respectively 2.10 × 10 5 cm -2 and 8.50 × 10 It was 8 cm -2. The number is thirteen dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 100, the density of dislocation-concentrated region per one dislocation density crystal region is 0. It was 13 cells / area. Further, a carrier concentration of 5.00 × 10 18 cm -3, C / F ratio was 0.38. The curvature radius of [1-100] direction of the main surface is 18.4, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 17.5 m, the second deviation angle in the [11-20] direction of the main surface was 0.06 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.00 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was a 13.4 m. The second stripe crystal region of high dislocation density crystal region in the main surface, the pitch P 2 is at 2000 .mu.m, a width W 2 was 26.2Myuemu. Therefore, the size of one of low dislocation density crystal region was 1993.3μm × 1986.9μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
Referring to FIGS. 17 to 19, on the main surface 20m of the prepared GaN crystal substrate 20p, as a group III nitride semiconductor epitaxial layer 70 of at least one layer, by MOCVD, n-type GaN layer having a thickness of 2μm 71, triple wells laminated n-type Al 0.1 Ga 0.9 n layer 72 having a thickness of 0.01 [mu] m, and in 0.15 Ga 0.85 n well layers of GaN barrier layer and the thickness of 3nm thickness 15nm as the light emitting layer 73 alternately MQW (multiple quantum well) structure layer structure, and the p-type GaN layer 75 of p-type Al 0.1 Ga 0.9 N layer 74 and the thickness of 0.1μm thickness 0.01μm are sequentially grown. Thus, on the major surface 20m of the GaN crystal substrate 20p, the GaN crystal substrate with the group III nitride semiconductor epitaxial layer semiconductor epitaxial layer 70 is formed is obtained.

The obtained group III nitride semiconductor epitaxial layer 70, the epitaxial abnormal growth region was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 70k and the high dislocation density epitaxial crystal region 70h are each 2.10 × 10 5 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p.

3. Manufacturing a semiconductor device Next, p-type GaN layer 75 a region 80k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p of (the uppermost layer of the group III nitride semiconductor epitaxial layer 70) on the main surface 70m, to form a p-side electrode 81 as follows. The transparent electrode 81a which is a part of the p-side electrode 81, the resistance heating method, by depositing a thick nickel layer 5 nm, a thickness of 10nm and a gold layer were lifted off of such metal layers. Thereafter, the terminal electrodes 81b which is a part of the p-side electrode 81, the resistance heating method, and an Au layer with a thickness of 300nm in diameter 100 [mu] m, was subjected to wire bonding. Then, a region 80k straight above and just below the low dislocation density crystal region 20k of the GaN crystal substrate 20p on the other main surface 20n of GaN crystal substrate 20p, as the n-side electrode 82, a vacuum deposition method (more Specifically by EB method), to form the Al layer of the Ti layer and the thickness of 300nm thickness 20nm on the main surface 20n entire surface to obtain the above wafer-shaped LED (semiconductor device 80 of the wafer-shaped).

Then, the wafer-shaped LED (semiconductor device 80 of the wafer-shaped), GaN crystal substrate 20p constituting each LED, III nitride semiconductor epitaxial layer 70, p-side electrode 81 and the n-side electrode 82, all GaN to fit directly above and directly below the area 80k of low dislocation density crystal region 20k of the crystal substrate 20p, and as the main surface of the chip SBD after splitting the area is maximized in substantially square, the wafer Jo of an LED (semiconductor device 80 of the wafer-shaped) is divided by the dividing line 80b, to obtain a LED (chip semiconductor device 80c) which is chipped to a size of 1993.3μm × 1986.9μm.

The resulting chipped LED is C / F ratio is 0.38, the emission wavelength distribution yield as high as 0.97, the voltage increase during operation is as small as 0.04 V. Here, the emission wavelength distribution yield, was calculated as follows. In the wafer-shaped LED, and measuring the light output at the time of passing current of 75A / cm 2 in the LED integrating sphere the emission wavelength of which is located within a radius of 20mm from the center of the GaN crystal substrate with a multichannel spectrometer, As the average value was calculated Av and standard deviation sigma. Then, by measuring the emission wavelength of all the LED separated into chips from the wafer-shaped LED, the measured value A, | A-Av | nondefective LED satisfying ≦ sigma, | a> sigma | A-Av as a defective product to LED satisfying was calculated that the yield rate (good) / (good + bad products). Further, the voltage increase during operation, was calculated as follows. The resulting chipped LED, the voltage during operation necessary for conducting a current of 100mA at ambient temperature 80 ° C., measured at the working operation start time and 1000 hours, during operation by operation 1000 hours It was calculated increment of voltage. The results are summarized in Table 8.

(Comparative Example RC1)
1. It was prepared in the same manner GaN crystal substrate as prepared in Comparative Example RB2 of GaN crystal substrate.

The prepared GaN crystal substrate is a surface orientation of the major surface (0001), low dislocation density regions (F) and high dislocation density crystal region dislocation density respectively 8.20 × 10 of 6 cm -2 and 8.50 × 10 It was 8 cm -2. Also, 705 pieces in the number of dislocation concentrated region per 20mm square, since the number of low dislocation density crystal region per 20mm angle is 10, the density of dislocation-concentrated region per one dislocation density crystal region 70. It was 5 cells / area. Here, from the same viewpoint as in Comparative Example RB1, 1 single low dislocation density crystal region of this comparative example, in the embodiment corresponds to the 10 low-dislocation-density crystal region. That is, the number of examples corresponding low dislocation density crystal region per 20mm angle since it is 100, the density of one embodiment corresponding dislocation density crystal region per dislocation concentrated region was 7.05 pieces / area . The carrier concentration is 5.20 × 10 18 cm -3, C / F ratio was 0.61. The curvature radius of [1-100] direction of the main surface is 18.9 m, the first deviation angle in the [1-100] direction of the main surface was 0.06 °. The curvature radius of [11-20] direction of the main surface is 5.1 m, the second deviation angle in the [11-20] direction of the main surface was 0.20 °. Accordingly, a first displacement angle difference between the second displacement angle was 0.14 °. The first stripe crystal region of high dislocation density regions in the main surface, the pitch P 1 is at 2000 .mu.m, a width W 1 was 13.2Myuemu. Therefore, the size of one of low dislocation density crystal region in 20mm angle was 1993.4μm × 20000μm.

2. Growth of the group III nitride semiconductor epitaxial layer (Preparation of GaN crystal substrate with semiconductor epitaxial layer)
In the same way as in Example 1C, on the main surface 20m of the GaN crystal substrate 20p, to obtain a GaN crystal substrate with the group III nitride semiconductor epitaxial layer semiconductor epitaxial layer 70 is formed.

The obtained group III nitride semiconductor epitaxial layer 70, the epitaxial abnormal growth region was not formed. Further, GaN layer, the dislocation density of the low dislocation density epitaxial crystal region 70k and the high dislocation density epitaxial crystal region 70h are each 8.20 × 10 6 cm -2 and 8.50 × 10 8 cm -2, respectively It was equivalent to the dislocation density of the low-dislocation-density crystal region 20k and the high dislocation density crystal region 20h of the GaN crystal substrate 20p.

3. Manufacturing a semiconductor device Next, in the same manner as in Example C1, to prepare a wafer-shaped LED, to obtain a chipped LED. The resulting chipped LED is C / F ratio is 0.61, the emission wavelength distribution yield is 0.75, the voltage increase during operation was 1.09V. The results are summarized in Table 8.

Figure JPOXMLDOC01-appb-T000008

Referring to Table 8, the LED obtained in Example C1, as compared with the LED obtained in Comparative Example RC1, emission wavelength distribution yield is high, the voltage increase during operation is lowered. This is because the first deviation angle and the second deviation angle of the GaN crystal substrate of the former LED is smaller than the first deviation angle and the second deviation angle of the GaN crystal substrate of the latter LED, respectively, III-nitride carrier uptake during growth of the semiconductor epitaxial layer 70 becomes uniform, the carrier concentration is considered to be because a uniform group III nitride semiconductor epitaxial layer 70 is formed.

Incidentally, when the description of the present examples and comparative examples, after summarized in First Table 1-8 experimental data was performed with reference to the values ​​in Table 1-8. That is, numerical values ​​of the experimental data listed in Table 1-8 and specification, numerical values ​​of the experimental data listed in the table is original.

Embodiments and examples disclosed herein are carried out are to be considered and not restrictive in all respects as illustrative. The scope of the invention is defined by claims rather than the above description, it is intended to include any modifications within the meaning and range of equivalency of the claims.

10 base substrate, 10m, 20m, 20n, 30m, 70m main surface, 11 a mask, 11s first striped mask, 11t second stripe mask, 11 w opening 12 additional mask, 12w micro openings, 20 GaN crystals, 20b crystals growth start surface, 20c (0001) plane, 20d (000-1) plane, 20f facets, 20h high dislocation density crystal region, 20HS first stripe crystal region, 20Ht second stripe crystal region, 20k low dislocation density crystal region, 20KC (0001) plane growth crystal region, 20 kd dislocation concentrated region, 20Kf facet growth crystal region, 20p GaN crystal substrate, 30, 70 III nitride semiconductor epitaxial layer, 30Ei epitaxial abnormal growth region, 30h, 70h, 71h, 72h, 73h , 74h, 75h high dislocation Degrees epitaxial crystal region, 30k, 70k, 71k, 72k, 73k, 74k, 75k low dislocation density epitaxial crystal region, GaN crystal substrate with 33 semiconductor epitaxial layer, 40,40c, 80,80c semiconductor devices, 40b, 80b dividing line, 40k, just above and just below the region of 80k low dislocation density crystal region, 41 Schottky electrode, 41a first layer, 41b second layer, 42 ohmic electrode, 71 n-type GaN layer, 72 n-type Al 0.1 Ga 0.9 n layer, 73 light-emitting layer, 74 p-type Al 0.1 Ga 0.9 n layer, 75 p-type GaN layer, 81 p-side electrode, 81a transparent electrode, 81b terminal electrodes, 82 n-side electrode.

Claims (14)

  1. (0001) has a main surface (20 m) having an off-angle of 30 ° or less 0 ° or more to the surface,
    And a low dislocation density crystal region (20k) high dislocation density crystal region (20h),
    Shape of said high dislocation density crystal region in said main surface (20m) (20h) includes a plurality of extending [11-20] direction and [1-100] of the plurality extending in a direction first stripe crystal region (20HS) first GaN crystal substrate a lattice shape which includes a 2 stripe crystal regions (20ht).
  2. The first stripe crystal region (20HS) has a width of at 5μm above 120μm or less, the pitch is at 200μm or more 10000μm less,
    It said second stripe crystal region (20ht) has a width of at 5μm above 120μm or less, GaN crystal substrate according to claim 1, wherein the pitch is 200μm or 10000μm less.
  3. It said high dislocation density crystal region (20h) is described in the scope first of claims polar reversed crystal region are inverted relative to the [0001] direction of polarity is the low dislocation density crystal region (20k) GaN crystal substrate.
  4. The low dislocation density crystal region (20k) includes a (0001) plane growth crystal region (20KC) facet growth crystal region (20Kf),
    In the main surface (20 m), according to claim 1, wherein the ratio of the areas is 0.7 or less of the (0001) plane growth crystal region (20KC) to the area of ​​the facet growth crystal region (20Kf) GaN crystal substrate.
  5. Off-angle at the center of the first deviation angle and the main surface is the difference between the off-angle at the end of the [1-100] direction from the center and off-angle at the center of the main surface (20m) (20m) the central from 11-20] second deviation angle is the difference between the off-angle in the direction of the end portion is not more than 0.30 ° 0 ° or more, respectively, the second shift and the first deviation angle and GaN crystal substrate according to claim 1 the difference between the corners is 0.30 ° or less 0 ° or more.
  6. The first stripe crystal region (20HS) or the second stripe region (20ht) is, GaN crystal substrate according to claim 1 is discontinuous at at least one location.
  7. GaN crystal substrate according to claim 1, wherein the carrier concentration is 1.2 × 10 19 cm -3 or less than 1 × 10 18 cm -3.
  8. The low dislocation density crystal region (20k), the high dislocation density crystal region 0.1 or per a region surrounded by (20h) / region than 5.5 pieces / area less dislocation concentrated region (20 kd) GaN crystal substrate according to claim 1 having a.
  9. A method of manufacturing a GaN crystal substrate of claim 1, wherein,
    The base substrate having a main surface (10 m) having an off-angle of 0 ° or 30 ° or less with respect to the plane orientation of (0001) underlying substrate (10) corresponding to the surface of the GaN crystal substrate (20p) (10) a step of preparing a,
    Wherein the upper major surface (10 m) of the base substrate (10), and the GaN crystal substrate (20p) of [1-100] plurality of first stripe mask extending in a first direction corresponding to the direction (11s), the GaN forming a mask (11) having a grid-like pattern comprising a plurality of second stripe mask extending in a second direction corresponding to the [11-20] direction of the crystal substrate and (11t), a
    Growing a GaN crystal (20) on the main surface (10 m) of the mask the underlying substrate (11) is formed (10),
    And a step of obtaining a main surface the GaN crystal in parallel to (10 m) (20) to form a main surface (20 m) the GaN crystal substrate (20p) of said underlying substrate (10),
    In the step of growing said GaN crystal (20), the GaN crystals in the upper mask (11) (20) (000-1) plane grows, the said opening of the mask (11) of the base substrate (10) the GaN crystal at the center of the (11 w) (20) is grown (0001) plane, the GaN crystal in the vicinity of the opening (11 w) of the mask (11) (20) is facet growth,
    Including the a (0001) the low dislocation density crystal region formed by the surface growth and the facet growth (20k), wherein said high dislocation density crystal region formed by the (000-1) plane growth (20h), the method of manufacturing a GaN crystal substrate to grow the GaN crystal (20).
  10. The first stripe mask (11s) or the second stripe mask (11t), the method of manufacturing a GaN crystal substrate according to Claim 9 is discontinuous in at least one location.
  11. A GaN crystal substrate of Claims first term (20p), the GaN crystal substrate (20p) at least one layer of group III nitride semiconductor epitaxial layer of the formed on the main surface (20 m) and (30) It includes,
    The III nitride semiconductor epitaxial layer (30) includes a low dislocation density epitaxial crystal region (30k) of the formed immediately above the low dislocation density crystal region (20k) of the GaN crystal substrate (20p), said GaN It said high dislocation density crystal region (20h) of the high dislocation density epitaxial crystal region (30h) which is formed directly above, GaN crystal substrate with a semiconductor epitaxial layer comprising a crystal substrate (20p).
  12. A GaN crystal substrate of Claims first term (20p), the GaN crystal substrate (20p) at least one layer of group III nitride semiconductor epitaxial layer of one of the formed on the main surface (20 m) of (30 , 70) and, formed on at least one of the said III-nitride main surface (30m of the semiconductor epitaxial layers (30, 70), 70m) and on the other main surface of the GaN crystal substrate (20p) (20n) anda electrode being,
    Semiconductor devices the GaN crystal substrate (20p) is a more than 400μm square size, the dislocation density is less than 1 × 10 7 cm -2.
  13. The GaN crystal substrate (20p) includes a (0001) plane growth crystal region (20KC) facet growth crystal region (20Kf),
    In one of the main surface of the GaN crystal substrate (20p) (20m), the facet growth crystal the relative area of ​​the region (20kf) (0001) plane growth ratio of the area of ​​crystalline regions (20KC) of 0.2 or more 0 the semiconductor device according to claim 12 is .7 below.
  14. A step of preparing a GaN crystal substrate of Claims first term (20p),
    A step of growing at least one layer III nitride semiconductor epitaxial layer (30, 70) on one of the main surface of the GaN crystal substrate (20p) (20 m), the lower of the GaN crystal substrate (20p) the main surface (30m, 70m) of the dislocation density crystal region immediately above and immediately below the III nitride semiconductor epitaxial layer lie in the region of the (20k) (30,70) and on the GaN crystal substrate (20p) the method of manufacturing a semiconductor device comprising the steps of: forming at least the electrode on one on the other main surface (20n), a.
PCT/JP2009/062310 2008-07-07 2009-07-06 Gan crystal substrate, gan crystal substrate manufacturing method, gan crystal substrate provided with semiconductor epitaxial layer, semiconductor device and semiconductor device manufacturing method WO2010004964A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2469581A1 (en) * 2009-08-20 2012-06-27 Powdec K.k. Semiconductor element and production method thereof

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5685035B2 (en) * 2010-09-24 2015-03-18 住友電気工業株式会社 The method of manufacturing a semiconductor light emitting element

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003165799A (en) * 2001-09-19 2003-06-10 Sumitomo Electric Ind Ltd Gallium nitride single crystal substrate, method for growing the same and method for producing the same
JP2003183100A (en) * 2001-10-09 2003-07-03 Sumitomo Electric Ind Ltd Single crystal gallium nitride substrate, crystal growth method for single crystal gallium nitride, and production method for single crystal gallium nitride substrate
JP2005191530A (en) * 2003-12-03 2005-07-14 Sumitomo Electric Ind Ltd Light emitting device
JP2008022032A (en) * 2007-09-27 2008-01-31 Sumitomo Electric Ind Ltd Nitride semiconductor device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003165799A (en) * 2001-09-19 2003-06-10 Sumitomo Electric Ind Ltd Gallium nitride single crystal substrate, method for growing the same and method for producing the same
JP2003183100A (en) * 2001-10-09 2003-07-03 Sumitomo Electric Ind Ltd Single crystal gallium nitride substrate, crystal growth method for single crystal gallium nitride, and production method for single crystal gallium nitride substrate
JP2005191530A (en) * 2003-12-03 2005-07-14 Sumitomo Electric Ind Ltd Light emitting device
JP2008022032A (en) * 2007-09-27 2008-01-31 Sumitomo Electric Ind Ltd Nitride semiconductor device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2469581A1 (en) * 2009-08-20 2012-06-27 Powdec K.k. Semiconductor element and production method thereof
EP2469581A4 (en) * 2009-08-20 2013-10-23 Powdec Kk Semiconductor element and production method thereof

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