JP3471687B2 - Semiconductor substrate and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate and a method for manufacturing the same, and more particularly to a structure and method useful when a semiconductor material which is prone to dislocation defects is used.

[0002]

2. Description of the Related Art Ga is used for crystal growth of GaN-based materials.
Sapphire, because N-based materials do not have a lattice-matched substrate,
Substrates that are not lattice-matched, such as SiC, spinel, and recently Si, are used. However, as many as 10 ¹⁰ dislocations / cm ² are present in the GaN film produced due to the lack of lattice matching. High brightness light emitting diode in recent years,
Although semiconductor lasers and the like have been realized, it is desired to reduce the dislocation density in order to improve the characteristics.

[0003]

As a method for reducing the dislocation density, for example, a GaN-based semiconductor crystal or the like is grown on a sapphire substrate to form a buffer layer and a GaN layer, which is used as an underlying substrate, and is partially formed on the substrate. A method has been proposed in which a high-quality crystal with a reduced dislocation density is obtained by performing crystal growth in the lateral direction by providing a selective mask and performing selective growth (for example, JP-A-10-312971).

However, according to the above method, there is a problem that the c-axis is tilted in the lateral growth direction with a small amount in the portion laterally grown on the mask layer, which causes deterioration of crystal quality. It turned out to be a problem (MSR 1998 Fall, Meeti
ng Proceedings G3.1). This measures the incident azimuth dependence of X-ray rocking curve measurement (XRC) (¢ scan)
You can also check by doing. That is, the full width at half maximum (F of the X-ray rocking curve due to the incident X-ray from the lateral growth direction (F
WHM) is larger than the FWHM value of X-rays from the stripe direction of the mask layer, which shows that the minute tilt (tilting) of the C axis has azimuth dependence.
This suggests that many new defects may be induced in the merged portion of the lateral growth on the mask.

As an attempt to solve such a problem, S
A substrate in which a buffer layer and a GaN layer are provided on an iC base substrate is subjected to stripe groove processing up to the SiC layer to form a convex portion, and the GaN layer to be located above the convex portion. Has proposed a method for crystal growth (MRS 1998 Fall Meeting Proceedings G3.38).
According to this method, selective growth can be performed without the SiO ² mask layer, and various problems caused by using the above-mentioned SiO ² mask can be solved.

In the above method, a sapphire substrate can be used as a base substrate, and a method thereof is also disclosed (for example, Japanese Patent Laid-Open No. 11-191659). However, the above method requires the steps of crystal growth of the buffer layer material and the GaN-based material on the sapphire base substrate, once taking out from the growth furnace, performing groove processing, and then performing crystal growth again. There is a problem that a new inconvenience occurs, the number of working steps increases, and the cost increases.

Also (Autumn of Applied Physics 99 Autumn Proceedings 2P-W
In -8), an attempt to obtain a low dislocation density region by forming a step on a GaN substrate and performing buried growth is also disclosed. Here, a low dislocation density region is formed in a part of the buried layer. However, in the above method, in order to obtain a low dislocation density region, it is necessary to widen the interval between the convex portions or deepen the depth of the concave portions. In order to do so, it is necessary to spend a lot of time for burying and to grow thickly, which causes various problems such as generation of cracks due to thickening of the film and cost because it takes time.

Attempts have also been made to grow a GaN-based material on a Si substrate, but when a GaN-based crystal is grown, there arises a problem that warpage or cracks are generated due to a difference in thermal expansion coefficient, and good quality crystal growth cannot be performed. there were.

Therefore, in view of the above problems, it is an object of the present invention to avoid various problems caused by ELO growth using a normal mask layer and to simplify the manufacturing process. It is also intended to solve the problem caused by the embedded growth of the step structure having no mask. Furthermore Si
The purpose is to suppress the occurrence of warpage and cracks when a substrate or the like is used.

[0010]

The semiconductor substrate of the present invention comprises:
A semiconductor substrate comprising a substrate and a semiconductor crystal vapor-deposited on the substrate, wherein the crystal growth surface of the substrate is an uneven surface, and the recess has substantially no crystal growth from the layer. The semiconductor crystal is characterized by being exclusively crystal-grown from the upper portion of the convex portion on the uneven surface. In this case, the semiconductor crystal is Al
_x Ga _1-xy In _y N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1)
It is desirable that it is a crystal made of a semiconductor determined by the above .

[0011] protrusion of the crystal growth surface of the substrate, it is preferable that the convex portion made of parallel stripes. Furthermore, the width of the concave portion is made wider than that of the convex portion,
In the case of a sapphire substrate, the longitudinal direction is <1 of that substrate.
1-20> direction of a substrate made of a material other than sapphire
In some cases, <1-100 of the semiconductor crystal grown on the substrate.
It is more preferable that the direction> .

A more specific semiconductor base material according to the present invention is a semiconductor base material comprising a substrate and a semiconductor crystal vapor-grown on the substrate, wherein the crystal growth surface of the substrate is an uneven surface. , The concave portion is covered with a mask in which crystal growth is substantially impossible from the layer, and the semiconductor crystal is grown on the semiconductor substrate exclusively from above the convex portion on the uneven surface, and the uneven surface is grown. The semiconductor crystal layer is covered with a semiconductor crystal, and a cavity is formed between the semiconductor crystal layer and the recess in the uneven surface.

In the semiconductor base material, the crystal growth surface of the substrate is formed into an uneven surface, and the concave portion is covered with a mask which cannot substantially grow crystals from the layer, and the convex portion on the uneven surface is formed by the vapor phase growth method. Of the first semiconductor crystal formed by crystal growth exclusively from the upper part of the, and the surface of the first semiconductor crystal is an uneven surface, and similarly, the recess cannot substantially grow from the layer. Alternatively, the mask may be covered with a second semiconductor crystal formed by growing crystals exclusively from the upper portion of the convex portion.

Further, the surface of the second semiconductor crystal in the above semiconductor substrate is formed into an uneven surface, and the concave portion is covered with a mask from which the crystal growth is substantially impossible. The formed third semiconductor layer or the same steps may be repeated to provide a plurality of semiconductor layers formed in multiple layers.

According to the method for producing a semiconductor substrate of the present invention, when a semiconductor crystal is vapor-phase grown on a substrate, the surface of the substrate is previously prepared.
With a groove having a concave portion and a ridge having a convex portion.
Use a tripe-shaped concavo-convex surface so that the width of the recess is wider than the width of the protrusion.
Comb , the recesses on the uneven surface are covered with a mask that does not allow crystal growth substantially from the layer, and then a source gas is supplied to the substrate to grow crystals exclusively from the upper part of the projections on the uneven surface. The uneven surface of the substrate is covered with a semiconductor crystal. Also, the longitudinal direction of the stripe
In the case of a sapphire substrate, <11-20
＞ direction, when the substrate is made of material excluding sapphire
Is the <1-100> direction of the semiconductor crystal grown on the substrate.
And

[0016]

According to the present invention, by providing an uneven surface on a substrate in which no buffer layer or the like is formed, and covering the concave portion with a mask which cannot grow substantially from the layer, the crystal is grown substantially from the beginning. The feature is that a ground plane that causes lateral growth capable of forming a low dislocation density region is provided in advance.
That is, in the case of vapor phase growth, the raw material diffuses over the entire surface of the substrate in the initial stage of growth, but crystal growth does not easily occur on the concave mask, so growth at the convex portion becomes dominant, and by extension the layer grown from the convex portion. It is covered by.

In the growth of the convex portion, so-called lateral growth in the direction perpendicular to the C-axis occurs, and a low dislocation density region is formed. As described above, the growth of the crystal base material having the low dislocation density region can be performed only once, and the subsequent growth steps can be continuously performed. Further, since the growth in the recess can be suppressed, the efficiency of lateral growth is improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1A to 1C are cross-sectional views for explaining a crystal growth state of a semiconductor substrate according to the present invention. In the figure, 1 is a substrate, and 2 is a semiconductor crystal vapor-deposited on the substrate 1, respectively. A convex portion 11 and a concave portion 12 are formed on the crystal growth surface of the substrate 1, and the crystal growth is performed exclusively from above the convex portion 11. Also, the recess 12 is covered by a mask 3 which cannot grow substantially from that layer.

The substrate referred to in the present invention is a substrate that serves as a base for growing various semiconductor crystal layers, and is in a state in which a buffer layer for lattice matching has not yet been formed. Examples of such a substrate include sapphire (C surface, A surface, R surface), SiC (6H, 4H, 3C),
GaN, Si, spinel, ZnO, GaAs, NGO, etc. can be used, but other materials may be used as long as they meet the purpose of the invention. Moreover, you may use what turned off from these substrates.

As the semiconductor crystal grown on the substrate 1, various semiconductor materials can be used. Al _x Ga _1-xy
For In _y N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1), GaN, AlGaN , InGaN, and the like having different composition ratios of x and y can be exemplified.

Protrusions 11 formed on the crystal growth surface of the substrate 1
Is effective when the crystal is grown exclusively from the upper part. "The crystal growth is performed exclusively from the upper part" means a state in which the crystal growth can be predominantly performed at the apex or the top surface of the convex portion 11 and in the vicinity thereof, even if the growth in the concave portion occurs at the initial stage of the growth. Good, but finally indicates that the crystal growth of the convex portion 11 becomes dominant.

The mask 3 formed on the recess 12 is
It suffices that the layer has such a function that substantially no crystal growth is possible. The phrase “substantially unable to grow from that layer” means a state in which crystal growth is unlikely to occur, and growth may occur on the concave mask at the initial stage of growth, but finally the convex part 11 is formed. It means that crystal growth becomes dominant. That is, if the low dislocation density region is formed by the lateral growth starting from the upper portion, the same effect as that of the conventional ELO requiring a mask can be obtained. This is a feature of the present invention in that the low dislocation density region can be formed by one crystal growth only by processing the substrate. Hereinafter, this point will be described with reference to FIGS. 1 and 2.

FIGS. 1 and 2 are cross-sectional views of the projections formed in stripes. First, FIG. 1 illustrates a case where a substrate 1 having a deep groove depth (height of convex portion) h with respect to a groove width B is used as shown in FIG. In this case, the raw material gas does not sufficiently reach the concave portion 12 and its vicinity, and the concave portion 12 is provided with the mask 3, so that the crystal growth occurs only from the upper portion of the convex portion 11. In FIG. 1 (b), 20
Indicates the crystal unit at the start of this crystal growth. Under such a circumstance, if the crystal growth continues, the films grown in the lateral direction are connected from the upper part of the convex portion 11 as a starting point, and eventually the film shown in FIG.
As described above, the concave-convex surface of the substrate 1 is covered while leaving the hollow portion 13 in the concave portion. In this case, a low dislocation region is formed in the laterally grown portion, that is, in the upper portion of the recess 12, so that the quality of the produced film is improved.

FIG. 2 shows the groove depth (height of the protrusion) with respect to the groove width B.
The case where h is very shallow, or the case where the substrate 1 whose groove width B is extremely wider than the width A of the convex portion 11 is used is illustrated (see FIG. 2A). In this case, since the source gas can reach the mask 3 of the recess 12 and its vicinity, the growth of the recess 12 may occur. However, the growth rate is much slower than the growth on the top of the protrusion. This is because the raw material reaching the mask 3 is often desorbed into the gas again. Thus, lateral crystal growth occurs from the upper portion of the convex portion 11, and as shown in FIG. 2B, the crystal unit 20 is generated on the upper portion of the convex portion 11 and the surface of the concave portion 12. . Under such a circumstance, if the crystal growth continues, the films grown in the lateral direction from the upper portion of the convex portion 11 as a starting point are connected to each other, and eventually the film shown in FIG.
As shown in (c), the uneven surface of the substrate 1 is covered. In this case, since the number of laterally grown portions starting from the convex portion 11 is larger than that in the example of FIG. 1, the proportion of low dislocation regions is large, and the quality of the entire fabricated film is higher than that in the case of FIG. Will be achieved.

In the present invention, there is no particular limitation as long as it is such a convex portion 11, and various shapes can be adopted. Specifically, when the groove depth (height of protrusion) h is deeper than the groove width B as described above, and when the groove depth (height of protrusion) h is shallower than the groove width B, the groove width is further increased. Various combinations can be performed, such as when the groove depth (height of the convex portion) h is extremely shallow with respect to B, or when the groove width B is very large relative to the width A of the convex portion 11. In particular, when the groove width B is wider than the width A of the convex portion 11, the number of laterally grown portions starting from the upper portion of the convex portion 11 is increased and the low dislocation region is formed wide, which is preferable.

As a mode of forming such an uneven surface,
Examples thereof include island-shaped scattered convex portions, convex portions formed of stripe-shaped convex stripes, lattice-shaped convex portions, and convex portions in which the lines forming these are curved lines. Among these aspects of the protrusions, the aspect in which the stripe-shaped protrusions are provided is preferable because the production process can be simplified and a regular pattern can be easily produced. The longitudinal direction of the stripe may be arbitrary, but when the material to be grown on the substrate is GaN,
The <11-20> direction and <1-100> direction of the GaN-based material are preferable. Especially in the <1-100> direction,
Since it is difficult to form oblique facets such as {1-101} planes, lateral growth (lateral growth) becomes faster. As a result, it is particularly preferable in that the uneven surface can be covered more quickly.

As the mask 3 formed on the recess 12,
It suffices that the layer does not substantially grow, and SiO ₂ , SiNx, TiO ₂ , ZrO ₂ or the like can be used. It is also possible to have a laminated structure of these materials.

As in the embodiment shown in FIG. 1, when the uneven portion of the substrate 1 is buried with the hollow portion 13 left, and then the light emitting portion is grown thereon to manufacture a light emitting element, the hollow portion and the semiconductor are formed. A large difference in refractive index at the interface can be obtained. As a result, the proportion of light traveling downward from the light emitting portion is reflected at this interface.
For example, when the LED is die-bonded with the surface of the sapphire substrate facing downward, the amount of light that can be extracted upward is increased, which is preferable.

Further, since the contact area between the substrate 1 and the semiconductor layer grown on the substrate 1 can be made small by embedding the hollow portion 13 while leaving it, it is possible to reduce the difference in lattice constant and difference in thermal expansion coefficient in the semiconductor. It is preferable in that the distortion caused can be reduced. This reduction in strain has the effect of reducing the warpage that occurs when a GaN-based material is grown thick on sapphire.
In particular, in the conventional method, there was a problem that warpage or cracks occurred due to the difference in thermal expansion coefficient during crystal growth of a GaN-based material on a Si substrate, and high quality crystal growth could not be performed. You can solve the problem.

Further, taking advantage of the fact that the contact area between the substrate 1 and the semiconductor layer 2 grown thereon can be reduced, when the semiconductor layer 2 is grown thick, stress concentrates on this small contact portion, The substrate 1 and the semiconductor layer 2 can be separated from the portion. By applying this, a substrate such as GaN can be manufactured.

Although the case where only one semiconductor layer 2 is grown on the substrate 1 has been described above, the same steps may be repeated twice in order to reduce dislocation defects. That is, as shown in FIG. 4, after the crystal growth of the first semiconductor layer 2a is performed so as to cover the uneven surface of the substrate 1 by the same method as described above, the surface of the first semiconductor layer 2a is uneven. It is also possible to form a second semiconductor crystal 2b by providing a mask 3a so that the surface of the first semiconductor layer 2a is exclusively crystallized from above the convex portion 11a of the first semiconductor layer 2a by vapor phase growth. . In this case, in particular, if the protrusion 11 of the substrate 1 and the position of the protrusion 11a formed on the first semiconductor layer 2a are vertically displaced, the second semiconductor layer 2 can be formed.
Many dislocations on the convex portion 11a of the first semiconductor layer 2a do not propagate to b. That is, with such a configuration, the entire second semiconductor layer 2b can be made to have a low dislocation region, and a higher quality semiconductor layer can be obtained.

Further, the surface of the second semiconductor crystal 2b may be made uneven, and a third semiconductor layer similarly formed by vapor phase epitaxy may be formed thereon. Alternatively, the same steps may be repeated to form a plurality of semiconductor layers in multiple layers. With such a configuration, it is possible to gradually reduce the dislocation propagating each time the layers are stacked, without intentionally adjusting the positions of the upper and lower convex portions as described above.

The protrusions are formed by patterning according to the shape of the protrusions using, for example, an ordinary photolithography technique, and R
It can be manufactured by etching using IE technology or the like.

As a method of growing a crystal of a semiconductor layer on a substrate, HVPE, MOCVD, MBE method or the like is preferable. The HVPE method is preferable when forming a thick film, but the MOCVD method is preferable when forming a thin film.

The growth conditions (gas species, growth pressure, growth temperature, etc.) for crystal growth of the semiconductor layer on the substrate may be selected according to the purpose as long as the effects of the present invention can be obtained. .

[0036]

EXAMPLES Example 1 Photoresist patterning (width: 2 μm, period: 6 μm, stripe orientation: stripe extending direction is <11-20> direction of sapphire substrate) on a c-plane sapphire substrate, and RIE ( Reactive Ion E
Etching was performed in a rectangular shape with a tching device to a depth of 2 μm. Subsequently, a SiO ₂ film was deposited to a thickness of 0.1 μm on the entire surface of the substrate, and then the photoresist and the SiO ₂ film deposited thereon were removed by a lift-off process. In this way, the mask layer was applied to the concave portion of the substrate. After that, attach the substrate to the MOVPE device and raise the temperature to 1100 ° C in a hydrogen atmosphere,
Thermal etching was performed. After that, the temperature is lowered to 500 ° C., and trimethylgallium (hereinafter TM
G) was used as N raw material and ammonia was caused to flow to grow a GaN low temperature buffer layer. Subsequently, the temperature was raised to 1000 ° C. and TMG / ammonia as a raw material and silane as a dopant were flown to grow an n-type GaN layer on the substrate. At that time, the growth time is Ga when the normal unevenness is not applied.
The time corresponding to 4 μm in N growth was set.

When the cross section after the growth is observed, although there are some traces of the growth on the substrate recess mask, as shown in FIG. 2 (c), the recesses and protrusions are covered and the recesses and cavities 13 are left flat. The obtained GaN film was obtained.

For comparison, a GaN layer formed on a normal c-plane sapphire substrate under the same growth conditions and a GaN film grown by ELO using the SiO ₂ mask of the same pattern were prepared. The evaluation was InGaN (InN mixed crystal ratio = 0.2, 10
The pits (corresponding to dislocations) appearing after continuous growth of 0 nm thickness were counted and used as the dislocation density. The evaluation results are shown in Table 1.

[0039]

[Table 1]

It can be seen that in the sample of the embodiment, the dislocation density can be reduced to the same extent as in the conventional ELO. The FWHM of XRC is 170 sec, which is the smallest, and it can be said that it is a high quality film as a whole.

[Example 2] An n-type AlGaN clad layer, an InGaN light emitting layer, a p-type layer were formed in succession to the film obtained in Example 1.
-Type AlGaN clad layer and p-type GaN contact layer were sequentially formed to produce an ultraviolet LED wafer having an emission wavelength of 370 nm. After that, electrodes were formed and elements were separated to obtain LED elements. The average value of the output of the LED chips collected on the entire wafer and the reverse current characteristics were evaluated. For comparison, an ultraviolet LED chip with the above structure manufactured using conventional ELO technology and an ultraviolet LED with the above structure manufactured using a normal sapphire substrate.
It is an LED chip. The results of these evaluations are shown in Table 2.

[0042]

[Table 2]

As shown in Table 2, it was found that the sample manufactured by using the present invention can manufacture a high-quality LED with higher output and less leakage current than the conventional example.

[Embodiment 3] Next, an example using GaN as a substrate will be described. Patterning of photoresist on GaN substrate (width: 2 μm, period: 6 μm, stripe orientation: G
<1-100>) of aN substrate and perform RIE (Reactive Ion Et
Etching was performed in a rectangular cross section to a depth of 2 μm. Subsequently, a SiO ₂ film having a thickness of 0.1 μm was deposited on the entire surface of the substrate, and then the photoresist and the SiO ₂ film deposited thereon were removed by a lift-off process. The GaN substrate processed in this way was mounted on a MOVPE device, and nitrogen,
The temperature was raised to 1000 ° C. under a mixed atmosphere of hydrogen and ammonia. After that, TMG / ammonia as a raw material and silane as a dopant were flown to grow an n-type GaN layer. The growth time at that time is GaN in the case where the usual unevenness is not applied.
The time corresponding to 4 μm in growth was set.

When the cross section after the growth is observed, a slight trace of the growth and the growth on the side surface of the convex portion can be seen on the substrate concave mask, but as shown in FIG. The obtained GaN film was obtained. Subsequently, the pits of the obtained film were evaluated. GaN used as a substrate
Had a pit density of 2 × 10 ⁵ cm ⁻³ , but when the growth of this example was performed, the number of pits decreased to 1 × 10 ⁵ cm ^{−3 at} the upper portion of the convex portion and 5 × 10 ³ cm ⁻³ at the upper portion of the concave portion. I knew that I was doing it. Thus, it was confirmed that the dislocation density can be further reduced even on a substrate having few dislocations.

[Example 4] The GaN crystal produced in Example 1 was used as a first crystal, and a second crystal was grown thereon. First, patterning a photoresist on the GaN first crystal (width: 2 μm, period: 6 μm, stripe orientation: GaN
<1-100>) of the substrate was performed, and a RIE device was used to etch a rectangular cross section to a depth of 2 μm. The patterning at this time was arranged so that the concave portion of the first crystal was located on the convex portion of the substrate. Subsequently, a SiO ₂ film having a thickness of 0.1 μm was deposited on the entire surface of the substrate, and then the photoresist and the SiO ₂ film deposited thereon were removed by a lift-off process. After such processing, the substrate was mounted on the MOVPE apparatus and heated to 1000 ° C. in a mixed atmosphere of nitrogen, hydrogen and ammonia. After that, TMG / ammonia as a raw material and silane as a dopant were flown to grow an n-type GaN layer. The growth time at that time was set to a time corresponding to 4 μm in GaN growth in the case where no regular unevenness was applied.

When the cross section after the growth is observed, a slight trace of growth and growth on the side surface of the convex portion can be seen on the concave mask of the substrate, but as shown in FIG. The obtained GaN film was obtained. When the pits of the obtained film were evaluated subsequently, it was found that the pits were reduced to 8 × 10 ⁵ cm ^-3 . Thus, it was confirmed that the effect of further reducing the dislocation density was obtained by repeating this example.

[0048]

As described above, according to the semiconductor substrate and the method for manufacturing the same of the present invention, the convex portion is provided on the substrate,
By covering the concave portion with a mask that cannot substantially grow from the layer, lateral growth capable of forming a substantially low dislocation density region from the beginning of crystal growth can be preferentially performed. Therefore, it is possible to solve the problem of the generation of a new defect in the merged portion of the lateral growth portion and the problem of autodoping, which are the problems caused by the ELO growth for forming a normal mask layer, due to the minute axis tilting. Further, since the growth of the buffer layer and the growth of the semiconductor crystal layer such as the light emitting portion can be continuously performed by one-time growth only by subjecting the substrate to the above processing, there is an advantage that the manufacturing process can be simplified. In particular, since it is possible to suppress the growth in the concave portion, there is an advantage that the efficiency of lateral growth is improved. Further, it is an extremely valuable invention from the viewpoint of improving the characteristics and reducing the cost because it has the effect of improving the reflectance and suppressing the residual strain by using the cavity.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining a crystal growth state of a semiconductor substrate according to the present invention.

FIG. 2 is a cross-sectional view for explaining a crystal growth state of a semiconductor substrate according to the present invention.

FIG. 3 is a cross-sectional view for explaining a crystal growth state of a semiconductor substrate according to the present invention.

FIG. 4 is a cross-sectional view for explaining a crystal growth state of a semiconductor substrate according to the present invention.

[Explanation of symbols]

1 substrate 11 convex 12 recess 13 Cavity 2 semiconductor layers 3 masks

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Koto 4-3 Ikejiri, Itami-shi, Hyogo Prefecture Itami Works, Mitsubishi Electric Wire & Cable Co., Ltd. (56) References 2003-511871 (JP, A) Special table 2003 -514392 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/205

Claims (8)

(57) [Claims] 1. A semiconductor substrate comprising a sapphire substrate and a semiconductor crystal vapor-deposited on the substrate, wherein the semiconductor crystal is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
There, the crystal growth surface of the substrate, and grooves as concave, a convex portion
It is a stripe-shaped uneven surface of which has a ridge of Te, recesses
The width of the stripe is wider than the width of the protrusion, and the length of the stripe
Direction is <11-20> direction of the sapphire substrate, the recess from the layer covered by the mask not substantially crystal growth, wherein the semiconductor crystal exclusively from an upper part of the convex portion in the concavo convex crystals A semiconductor substrate characterized by being grown. 2. Between the semiconductor crystal and the recess,
The semiconductor substrate according to claim 1, wherein a cavity is formed . 3. A substrate made of a material other than sapphire,
Semiconductor consisting of semiconductor crystal vapor-deposited on the substrate
The base material, which is a semiconductor crystal, is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
There, the crystal growth surface of the substrate, and grooves as concave, a convex portion
Stripe-shaped uneven surface having all the ridges
The width of the stripe is wider than the width of the protrusion, and the length of the stripe
The direction is the <1-100> direction of the semiconductor crystal that grows on the substrate.
The recess is substantially free from crystal growth from that layer.
The semiconductor crystal from above the convex portion on the uneven surface.
Semiconductors characterized by being exclusively crystal-grown
Base material. 4. A sapphire substrate and vapor phase growth on the substrate
And a semiconductor crystal, wherein the semiconductor crystal is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
There, the crystal growth surface of the substrate, and grooves as concave, a convex portion
Stripe-shaped uneven surface having all the ridges
The width wider than the width of the convex portion, and the longitudinal of the stripe
Direction is <11-20> direction of the sapphire substrate, the recesses We covered with a mask not substantially crystal growth from the layer, said semiconductor crystal exclusively from an upper part of the convex portion of the concavo-convex surface of the substrate The first semiconductor crystal formed by crystal growth, and the surface of this first semiconductor crystal as an uneven surface, and the concave portion is covered with a mask from which crystal growth is practically impossible from the layer, and the convex portion second semiconductor crystal and a semiconductor substrate characterized by comprising the exclusively formed by being grown from the upper part of. 5. A substrate made of a material other than sapphire,
Semiconductor consisting of semiconductor crystal vapor-deposited on the substrate
The base material, which is a semiconductor crystal, is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
There, the crystal growth surface of the substrate, and grooves as concave, a convex portion
Stripe-shaped uneven surface having all the ridges
The width of the stripe is wider than the width of the protrusion, and the length of the stripe
The direction is the <1-100> direction of the semiconductor crystal that grows on the substrate.
The recess is substantially free from crystal growth from that layer.
Covered with a mask, the semiconductor crystal grows exclusively from above the protrusions on the uneven surface of the substrate.
And the surface of the first semiconductor crystal formed by the
Cover the layer with a mask that does not allow substantial crystal growth,
Formed by growing crystals exclusively from the upper part of the protrusion
A semiconductor substrate comprising a second semiconductor crystal . 6. The surface of the second semiconductor crystal in the semiconductor substrate according to claim 4 or 5 is formed into an uneven surface, and the concave portion is covered with a mask from which crystal growth is substantially impossible, and the same is applied on top of it. A semiconductor substrate having a third semiconductor layer formed by a vapor phase epitaxy method or a plurality of semiconductor layers formed in multiple layers by repeating the same steps. 7. A sapphire substrate and vapor phase growth on the substrate
For producing a semiconductor substrate composed of the formed semiconductor crystal
And the semiconductor crystal is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
Yes, the crystal growth surface of the substrate has a groove as a concave and a convex
Stripe-shaped uneven surface having
The width is wider than the width of the convex part and the longitudinal direction of the stripe
The direction is the <11-20> direction of the sapphire substrate, and when vapor-depositing a semiconductor crystal on the substrate , the recesses on the uneven surface of the substrate are covered with a mask that cannot substantially grow crystals from the layer, and then the raw material gas was supplied to the substrate, the manufacturing method of the semiconductor body, characterized in that covering the front Ki凹 convex in semiconductor crystals which are exclusively grown from the upper part of the convex parts of the uneven surface. 8. A substrate made of a material other than sapphire,
Semiconductor consisting of semiconductor crystal vapor-deposited on the substrate
A method for manufacturing a base material, wherein the semiconductor crystal is Al _x Ga _1-xy In _y N (0 ≦ x ≦ 1,
A crystal made of a semiconductor determined by 0 ≦ y ≦ 1)
Yes, the crystal growth surface of the substrate has a groove as a concave and a convex
Stripe-shaped uneven surface having
The width is wider than the width of the convex part and the longitudinal direction of the stripe
The direction is the <1-100> direction of the semiconductor crystal growing on the substrate.
When vapor-depositing a semiconductor crystal on a substrate,
The recesses on the uneven surface of the plate are essentially crystallized from that layer.
Cover with a long-lasting mask, then source gas against the substrate
Is supplied from the upper part of the convex part on the uneven surface.
It is a special feature to cover the uneven surface with a semiconductor crystal grown by crystal growth.
A method for manufacturing a semiconductor substrate.