JPH11163404A - Gan-based semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce lattice defects of a GaN-based semiconductor, without having the GaN-based semiconductor grown in two stages, that is, to provide a GaN-based semiconductor of highest possible quality with a minimum possible number of steps. SOLUTION: On a substrate 2 made of a metal or on a multilayered body consisting of a conductive semiconductor and a buffer layer made of a metal, a pattern layer 3 of SiO2 is formed so as to partly expose the substrate 2 or the buffer layer. A GaN-based semiconductor layer 4 is selectively grown from the exposed surface and is grown laterally on the pattern layer 3, and the surface of GaN-semiconductor layer 4 becomes flat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a GaN-based semiconductor.

[0002]

2. Description of the Related Art It is known that a GaN-based semiconductor can be used, for example, as a blue light emitting device. In such a light emitting device, sapphire is generally used as a substrate material,
For example, a GaN-based semiconductor layer is stacked via an AlN layer to form a light-emitting element structure. Here, it is considered that the AlN layer plays a role of providing nucleation when growing a GaN-based semiconductor layer.

[0003] A good crystal can be produced through an AlN layer, and a high-brightness light emitting diode (L
ED), but the G on the AlN layer
A lattice defect of about 10 ⁸ / cm ² still exists in the aN-based semiconductor layer, and reducing this defect is indispensable for improving the performance and reliability of the device.

[0004] Conventionally, the following measures have been known to reduce lattice defects in the GaN layer. A first GaN layer is grown on a sapphire substrate, and a SiO ₂ mask pattern is formed thereon. After that, the first GaN
A second GaN layer is grown on the layer and the mask pattern. In the second GaN layer, the lattice defect (EPD: 1
0 ⁶ / cm ² ) is the lattice defect (EPD: 1) of the first GaN layer.
0 ⁸ / cm ² ). This is because GaN does not grow on the mask pattern made of SiO ₂ , so that the second GaN layer grown from the surface of the first GaN layer that is not covered with the mask pattern has a lateral direction on the mask pattern. It is considered that threading dislocations in the vertical direction are suppressed in the second GaN layer as a result. The lateral growth of GaN using a mask pattern is described in the second International Conference on Nitride Semiconductors (The S
econd InternationalConfer
once on nitride semicondu
ctors) pp. 52-53 Jaime
A. Freitas et al. "Optical
and Structural Property
sof Lateral Epitaxial Ove
rgrow GaN Layers ".

In such an element, it is desired to replace the sapphire substrate with another material. This is because the sapphire substrate is expensive. Furthermore, since the sapphire substrate is an insulator, it is necessary to form an electrode on the same side, and a part of the semiconductor layer must be etched.
Accordingly, the number of bonding steps is doubled. Also,
Since both n and p electrodes are formed on the same surface side, there is also a limitation in miniaturizing the element size. In addition, there was a problem of charge-up.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an element having a GaN-based semiconductor layer having a novel structure. According to the present invention, the GaN-based semiconductor layer
An object is to reduce lattice defects of the GaN-based semiconductor layer without growing the GaN-based semiconductor layer in stages. That is, it is an object of the present invention to provide a GaN-based semiconductor having as high a quality as possible with as few steps as possible. An object of the present invention is to provide a GaN-based semiconductor in which a material other than sapphire can be used as a material for a substrate. Another object of the present invention is to provide a buffer layer having a new configuration. here,
The buffer layer refers to a layer provided between the substrate and the GaN-based semiconductor layer.

[0007] According to another aspect of the present invention, it is an object of the present invention to provide a laminate having a novel structure, which serves as an intermediate when a device including a GaN-based semiconductor layer is formed.

[0008]

The present invention achieves at least one of the above objects. The configuration is as follows. A substrate made of metal, a pattern layer formed so that the substrate is partially exposed, and a GaN-based semiconductor layer formed so as to cover the pattern layer on the exposed substrate. Characteristic GaN-based semiconductor. Alternatively, a laminate of a conductive semiconductor substrate and a buffer layer made of a metal, a pattern layer formed so that the buffer layer is partially exposed, and the pattern layer may be covered on the exposed buffer layer. A GaN-based semiconductor layer formed on the GaN-based semiconductor layer.

According to such a configuration, the GaN-based semiconductor layer grown on the substrate or the buffer layer grows laterally on the pattern layer, so that lattice defects are reduced. As a result, a high-quality GaN-based semiconductor can be provided. Therefore, for example, when a structure of a light emitting element is formed of such a GaN-based semiconductor, the light emitting efficiency can be improved and the life of the element can be extended.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the above, Al is generally the GaN-based semiconductor _X Ga _Y an In _{1-X over} Y N (0 ≦ X ≦ 1,0
≦ Y ≦ 1, X + Y ≦ 1). As is well known, a light-emitting element has a configuration in which a light-emitting layer made of a GaN-based semiconductor is sandwiched between GaN-based semiconductor layers (cladding layers) of different conductivity types, such as a superlattice structure (quantum well structure) and a double hetero structure. Has been adopted. G electronic devices with FET structure
It can also be formed of an aN-based semiconductor.

(Regarding the substrate exposed from between the pattern layers) The substrate exposed from between the pattern layers satisfies at least two of the following requirements. Good adhesion between the GaN-based semiconductor and the substrate The thermal expansion coefficient of the GaN-based semiconductor is close to that of the substrate The elastic modulus of the substrate is low The crystal structure of the substrate is the same as that of the GaN-based semiconductor | Lattice constant of substrate-Lattice constant of GaN-based semiconductor | /
The lattice constant of the GaN-based semiconductor is ≦ 0.05 (that is, the difference between the lattice constant of the substrate and the lattice constant of the GaN-based semiconductor layer is within ± 5%). At least three, more preferably at least four, and most preferably all five of the above requirements are satisfied.

In the above, the substrate only needs to satisfy the above requirements at least on its surface, that is, the surface in contact with the GaN-based semiconductor layer. Therefore, the base portion of the substrate can be formed of any material, and the surface portion of the substrate can be formed of a material satisfying the above requirements.

The substrate is preferably formed of a conductive material (specifically, a metal material). Even in that case,
The base portion of the substrate may be formed of a low-purity or impurity-containing material, and the surface portion of the base may be formed of a high-purity material satisfying the above requirements. As a method of forming the surface portion of the substrate with a high-purity metal, plasma CVD, thermal C
VD, CVD (Chemical Vap, etc.)
(Physical Vapor Deposition) including sputtering, evaporation, etc.
on)) and the like. The thickness of the surface portion is appropriately designed so that the material of the base portion does not affect the GaN-based semiconductor layer.

If the substrate is made conductive, it becomes possible to connect electrodes to the substrate and to supply electricity to the GaN-based semiconductor layer from the substrate side. Therefore, complicated etching for the semiconductor layer, which is required when forming a light emitting element or a light receiving element with the GaN-based semiconductor layer, becomes unnecessary. In the example of FIG. 1, n
The clad layer can be electrically connected to the outside via the substrate. On the other hand, in the case of a sapphire substrate, since it was insulative, it was necessary to etch the light emitting layer and the p-cladding layer to expose the n-cladding layer and electrically connect it to the outside.

Since it is possible to conduct electricity from the substrate to the semiconductor layer, bonding to an external power supply becomes easy. Furthermore, the problem of charge-up can be easily solved by grounding.

As a matter of course, the material of the substrate must have a higher melting point than the temperature applied during the manufacturing process of the GaN-based semiconductor layer and the semiconductor device after the formation thereof. Therefore, the material of the substrate needs to have a melting point exceeding 1000 ° C.

In order to improve the adhesion between the GaN-based semiconductor and the substrate, the substrate must be formed from a material having a negative free energy of nitride formation, or the substrate must contain such a material. Is preferred.

By making the thermal expansion coefficients of the GaN-based semiconductor and the substrate close to each other, the warpage of the GaN-based semiconductor element can be suppressed. The occurrence of warpage causes distortion to remain in the semiconductor film in the form of internal stress. Preferably, the thermal expansion coefficients of the two are made substantially equal. Thereby, the problem of warpage is completely solved.
Since the linear expansion coefficient of GaN is a 5.59 X 10 ^-6 / K, it is preferable to make it of the substrate than 10X 10 ^-6 / K. The linear expansion coefficient of most metallic materials is 4 × 1
0 ⁻⁶ / K or more.

By lowering the modulus of elasticity of the substrate of the above requirements, that is, by forming the substrate with a soft material, even if the crystal structure and the lattice constant of the substrate and the GaN-based semiconductor are different, the difference is larger on the substrate side. Absorption is alleviated. The elastic modulus of the substrate is preferably set to 20 × 10 ¹⁰ N / m ² or less. More preferably, the elastic modulus of the substrate is 15X.
It shall be 10 ¹⁰ N / m ² or less.

By making the crystal structure of the substrate satisfying the above requirements the same as that of the GaN-based semiconductor, the GaN-based semiconductor layer can be easily epitaxially grown on the substrate. Ga
The crystal structure of the N-based semiconductor layer is hexagonal (hexagona).
l).

The above requirement | lattice constant of substrate-lattice constant of GaN-based semiconductor | / lattice constant of GaN-based semiconductor ≤ 0.
05 is also intended to alleviate the lattice distortion between the substrate and the GaN-based semiconductor. For example, since the lattice constant of GaN is 3.189 angstroms, the lattice constant of the substrate is 3.030 to 3.348 angstroms.
More preferably, | lattice constant of substrate-lattice constant of GaN-based semiconductor | / lattice constant of GaN-based semiconductor ≤ 0.0
Let it be 2.

To reiterate, each of the above requirements 1 to 5 may be sufficient if the surface of the substrate, that is, the surface in contact with the GaN-based semiconductor layer is provided.

When the substrate is formed of a metal and the GaN-based semiconductor layer has a light emitting element structure or a light receiving element structure, the substrate itself functions as a reflection layer. Therefore, it is not necessary to form a separate reflective layer, which is required for the light emitting element and the light receiving element using the transparent sapphire substrate of the conventional example. G
When the substrate is formed of a material that absorbs light such as aAs, the operation of removing the substrate becomes unnecessary.

According to the study of the present inventor, the following materials were found to be the surface materials of the substrate satisfying many of the above conditions.
The fact that the melting point is 1000 ° C. or higher is a condition naturally required for forming an element, and all the metals listed below satisfy this condition.

Cr: The nitride formation energy is negative and the coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less. Hf: The coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less, and the elastic modulus is 15 × 10 ¹⁰ N / m ² or less. Nb: The coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less, and the elastic modulus is 15 × 10 ¹⁰ N / m ² or less. Re: The coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less, and the crystal structure is hexagonal. Ta: The nitride formation energy is negative, and the coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less. Ti: Nitride formation energy is negative, linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15
X 10 ¹⁰ N / m ² or less, and the crystal structure is hexagonal. V: Nitride formation energy is negative, linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15
X 10 ¹⁰ N / m ² or less. Zr: Nitride formation energy is negative, linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15
X 10 ¹⁰ N / m ² or less, the crystal structure is hexagonal, and the difference in lattice constant with GaN is within 2%. Y: the elastic modulus is 15 × 10 ¹⁰ N / m ² or less;
The crystal structure is hexagonal.

From the above description, the metal forming the surface of the substrate is preferably one or more metals selected from Cr, Hf, Nb, Re, Ta, Ti, V, Zr and Y. Among them, those satisfying three or more requirements are V, Ti and Zr, those satisfying four or more requirements are Ti and Zr, and those satisfying five requirements are Zr.

Therefore, more preferably, V, Ti and Z
The substrate surface is formed of one or more metals selected from r. Still more preferably, the substrate surface is formed of one or more metals selected from Ti and Zr. Most preferably, the substrate surface is formed of Zr.

Further, such a metal substrate can be easily removed by treating it with an acid or alkali solution, so that it is suitable for preparing a substrate for homoepitaxial growth.

(Regarding Buffer Layer Exposed from Between Pattern Layers) A case where a buffer layer made of metal is laminated on a conductive semiconductor substrate and the buffer layer is exposed from between the pattern layers will be described. One embodiment of the combination of the substrate and the buffer layer will be described below. According to this combination of embodiments, as shown in FIG.
Since the stress generated due to the difference in the thermal expansion coefficient between the system semiconductor layer 24 and the substrate 21 is reduced, the tensile stress in the GaN semiconductor layer 24 decreases. Therefore, cracks hardly occur there, and lattice distortion is reduced. Therefore, the GaN-based semiconductor layer 24 can exhibit its original function as designed. Reference numeral 23 in the figure is a pattern layer.

The material of the substrate is not particularly limited. Preferably, the substrate is conductive. Si as a conductive material,
GaAs, GaP, ZnO, ZnSe and the like can be mentioned.

The material of the buffer layer is not particularly limited as long as it acts to relieve the stress between the GaN-based semiconductor layer and the substrate. Further, the buffer layer may be composed of two or more layers. The conditions for achieving the above effects are as follows. (A) The coefficient of thermal expansion of the material of the buffer layer is the larger of the three coefficients of thermal expansion of the material of the semiconductor layer and the material of the substrate.
Less than twice. (A) The elastic modulus of the material of the buffer layer is 20 × 10 ¹⁰ N /
m ² or less. That is, the coefficient of thermal expansion of the material of the buffer layer is made to be close to that of GaN or silicon to some extent, and the buffer layer is softened by making the elastic modulus relatively small, thereby relaxing the internal stress of the device with this buffer layer. In addition,
More preferably, the elastic modulus of the material of the buffer layer is 15 × 10 ¹⁰ N / m ² or less.

From a different point of view, (c) in the above, it is preferable that the thermal expansion coefficient of the material of the buffer layer be between the respective thermal expansion coefficients of the GaN-based semiconductor and the material of the substrate. More preferably, the coefficient of thermal expansion of the material of the buffer layer is set substantially at the center of the respective coefficients of thermal expansion of the GaN-based semiconductor and the material of the substrate. Further, specifically, (d) the thermal expansion coefficient of the material of the buffer layer is set to 10 × 10 ⁻⁶ / K or less.

In order to increase the adhesion between the buffer layer and the GaN-based semiconductor layer, the buffer layer must be formed from a material having a negative free energy of nitride formation, or the buffer layer must include such a material. Is preferred.

Further, in order to improve the conformity between the buffer layer and the GaN-based semiconductor layer and to reduce the lattice distortion of the GaN-based semiconductor layer, it is preferable that the crystal structure of the buffer layer be hexagonal, which is the same as GaN. In addition, from the same viewpoint, the buffer layer has the following requirements | lattice constant of buffer layer−lattice constant of GaN | / GaN
It is preferable to satisfy the following condition: lattice constant ≦ 0.05. Buffer layer has the following requirements | Lattice constant of buffer layer−Lattice constant of GaN | / GaN
It is more preferable that the following formula is satisfied.

It is preferable that the material of the buffer layer be conductive and the material of the substrate be conductive. Thus, it becomes possible to connect the electrode to the substrate and to supply electricity to the GaN-based semiconductor layer from the substrate side. Therefore, complicated etching for the semiconductor layer, which is required when an element is formed using the GaN-based semiconductor layer, becomes unnecessary. In the example of FIG. 6, the n-cladding layer can be electrically connected to the outside via the buffer layer and the substrate. On the other hand, in the case of a sapphire substrate, since it was insulative, it was necessary to etch the light emitting layer and the p-cladding layer to expose the n-cladding layer and electrically connect it to the outside. Since it becomes possible to conduct electricity to the semiconductor layer via the substrate and the buffer layer, bonding to an external power supply is also facilitated. Further, since electrodes can be formed above and below the semiconductor layer, the size of the element can be reduced.
Furthermore, the problem of charge-up can be easily solved by grounding.

When the material of the substrate is silicon, from the viewpoint of adhesion, the buffer layer is preferably made of a metal material which reacts with the silicon to form silicide, or contains such a material.

As a matter of course, the material of the buffer layer must have a melting point higher than the temperature applied in the process of manufacturing the GaN-based semiconductor layer and the semiconductor device after forming the buffer layer. Therefore, the material of the buffer layer is 10
It must have a melting point above 00 ° C.

When the buffer layer is formed of a metal and the GaN-based semiconductor layer has a light emitting element structure or a light receiving element structure, the buffer layer itself functions as a reflection layer. Therefore, it is not necessary to form a separate reflective layer, which is required for the light emitting element and the light receiving element using the transparent sapphire substrate of the conventional example. Further, when the substrate is formed of a material that absorbs light, such as GaAs, the operation of removing the substrate becomes unnecessary.

According to the studies made by the present inventors, the following materials have been found as materials for the buffer layer satisfying many of the above conditions. Cr: has a melting point of 1000 ° C. or more, a linear expansion coefficient of 10 × 10 ⁻⁶ / K or less, a negative energy of nitride formation, a difference in lattice constant from GaN of 2% or less, and a silicide Can be formed. Hf: melting point is 1000 ° C. or more, coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15 × 10 6
¹⁰ N / m ² or less, and the difference in lattice constant with GaN is 2
% Or less, and silicide can be formed. Nb: melting point is 1000 ° C. or more, linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15 × 10
¹⁰ N / m ² or less, and the difference in lattice constant with GaN is 2
% Or less, and silicide can be formed. Ta: the melting point is 1000 ° C. or more, the linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, the energy of nitride formation is negative, the difference in lattice constant with GaN is 2% or less, Can be formed. V: The melting point is 1000 ° C. or more, the linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and the elastic modulus is 15 × 10 6
¹⁰ N / m ² or less, the nitride formation energy is negative, the difference in lattice constant with GaN is 2% or less,
Silicide can be formed. Ti: melting point is 1000 ° C. or more, coefficient of linear expansion is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15 × 10 6
¹⁰ N / m ² or less, the nitride formation energy is negative, the difference in lattice constant with GaN is 2% or less,
Silicide can be formed. The crystal structure is hcp. Zr: melting point is 1000 ° C. or more, linear expansion coefficient is 10 × 10 ⁻⁶ / K or less, and elastic modulus is 15 × 10
¹⁰ N / m ² or less, the nitride formation energy is negative, the difference in lattice constant with GaN is 2% or less,
Silicide can be formed. The crystal structure is hcp.

As described above, the metal forming the buffer layer is C
1 selected from r, Hf, Nb, Ta, V, Ti, and Zr
It is preferable to use one or more metals. More preferably, the buffer layer is formed of one or more metals selected from Ti, V, and Zr. Most preferably, Zr
To form a buffer layer.

The method of forming the buffer layer is not particularly limited, and is appropriately selected according to the characteristics of the material of the substrate and the material of the buffer layer itself. For example, when the buffer layer is formed of the above-described metal, a CVD (Chemical Vapor Depos) such as a plasma CVD, a thermal CVD, and an optical CVD is used.
(physical), sputtering, vapor deposition, etc.
(Vapour Deposition) or the like.

(Pattern Layer) Next, the pattern layer will be described. The material of the pattern layer is not particularly limited as long as the GaN-based semiconductor layer is grown thereon (lateral growth). Thereby, threading dislocations in the vertical direction are suppressed. Therefore, the GaN-based semiconductor layer is not grown on the pattern layer. In the example, the pattern layer was formed of SiO ₂ . G on SiO ₂
It is known that aN does not grow. In addition, AlGa
N grows on SiO ₂ . That is, the material for forming the pattern layer is appropriately selected according to the selected GaN-based semiconductor layer. Therefore, the formation method is also appropriately selected. For example, CVD such as plasma CVD, thermal CVD, and optical CVD
(Chemical Vapor Depositi
on), sputtering, evaporation, etc. (Physical Va)
After a film is formed by a method such as pour deposition, the film is formed into a desired shape by a photolithography technique.

The pattern shape and film thickness of the pattern layer are G
There is no particular limitation as long as the upper surface of the aN-based semiconductor layer becomes flat. As the pattern shape, an arbitrary shape such as a stripe shape, a lattice shape, an island shape, or the like can be used.

After forming the pattern layer, the GaN-based semiconductor layer is selectively grown from the surface of the first layer that is not covered with the pattern layer.

[0045]

An embodiment of the present invention will be described below.

(Embodiment 1) This embodiment is a light emitting diode 10, the structure of which is shown in FIG. The specifications of each semiconductor layer are as follows. Layer: Composition: Dopant (thickness) P cladding layer 6: p-GaN: Mg (0.3 μm) Light emitting layer 5: Superlattice structure Quantum well layer: Ga _0.85 In _0.15 N (3.5 nm) Barrier layer: GaN (3.5 nm) Number of repetitions of quantum well layer and barrier layer: 1 to 10 n clad layer 4: n-GaN: Si (4 μm) Pattern layer 3: SiO ₂ (0.1 to 0.5 μm) Substrate 2: Zr (300 μm)

In the above, the substrate 2 is composed of the base part 2a and the surface part 2b. The base portion 2a is made of a commercially available bulk of Zr, and the surface portion 2b is formed on the base portion 2a by CVD.
The reaction product may be changed in the reaction.

The pattern layer 3 has a plurality of stripe shapes continuous in the direction perpendicular to the paper surface. The width of each stripe is about 10
μm, and the width between stripes is about 10 μm.

The pattern layer 3 is formed by uniformly forming a SiO ₂ film on the substrate 2 by a thermal CVD method,
As shown in (1), the film is etched into a stripe shape using photolithography. Thereafter, a GaN layer 4a is epitaxially grown as shown in FIG. GaN is S
Since it does not grow on iO ₂ , this GaN layer 4 a grows selectively from the surface of the substrate 2 not covered with the pattern layer 3. Then, it grows in the lateral direction beyond the pattern layer 3, and finally its upper surface becomes flat and becomes the n-cladding layer 4 as shown in FIG.

The n-clad layer 4 thus formed
EPD (Etch Pit Density) is 10
⁶ / cm ² , and the number of lattice defects is reduced by two orders of magnitude as compared with the case where there is no pattern layer.

The n-cladding layer 4 can have a two-layer structure including a low electron concentration n layer on the light emitting layer 5 side and a high electron concentration n ⁺ layer on the substrate 2 side. The element structure is not limited to the superlattice structure, but may be a single hetero structure, a double hetero structure, a homojunction structure, or the like. Light emitting layer 5 and p
Wide Al _X Ga bandgap doped with an acceptor of magnesium or the like between the cladding layer 6 _Y an In _{1-X over Y} N
(0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, X + Y ≦ 1) layers can be interposed. This is to prevent the electrons injected into the light emitting layer 5 from diffusing into the p clad layer 6. p
The cladding layer 6 is formed of the low hole concentration p layer on the light emitting layer 5 side and the electrode 7
And a high hole concentration p ⁺ layer on the side.

Each GaN-based semiconductor layer is formed by a well-known metalorganic compound vapor deposition method (hereinafter, referred to as “MOVPE method”). In this growth method, ammonia gas and an alkyl compound gas of a group III element such as trimethylgallium (TMG) and trimethylaluminum (TM
A) and trimethylindium (TMI) are supplied onto a substrate heated to an appropriate temperature to cause a thermal decomposition reaction, thereby growing a desired crystal on the substrate.

Zr has the same crystal structure (hexagonal) as GaN and has a lattice constant similar to that of GaN. Therefore, MOVPE
As shown in FIG. 3, it is expected that the substrate surface 2b and the n-cladding layer 4 fuse with each other due to the heat generated when the method is performed, and a ZrN layer is formed at the junction between the two.

The translucent electrode 7 is a thin film containing gold, and is laminated so as to cover substantially the entire upper surface of the p-cladding layer 6.
The p-electrode 8 is also made of a material containing gold, and is formed on the translucent electrode 7 by vapor deposition. The substrate can be used as it is as an n-electrode.

Further, as shown in FIG.
The light emitting device 10 can also be configured by sequentially growing the cladding layer 14, the light emitting layer 15, and the n cladding layer 16. In the case of the element 10, the n-layer having a low resistance is the uppermost surface, so that the translucent electrode (see reference numeral 7 in FIG. 1) can be omitted.

(Second Embodiment) Hereinafter, a second embodiment will be described with reference to FIG.
This will be described with reference to FIG. The device of the embodiment is the light emitting diode 20, and the specifications of each layer are as follows. Layer: Composition: Dopant (thickness) P-cladding layer 26: p-GaN: Mg (0.3 μm) Light-emitting layer 25: Superlattice structure Quantum well layer: Ga _0.85 In _0.15 N (3.5 nm) Barrier layer: GaN (3.5 nm) Number of repetitions of quantum well layer and barrier layer: 1 to 10 n cladding layer 24: n-GaN: Si (4 μm) pattern layer 23: SiO ₂ (0.1 to 0.5 μm) buffer layer 22: Zr (50 nm) substrate 21: Si (300μm)

In the above, the buffer layer 22 is laminated on the substrate 21 by CVD. The translucent electrode 27 is a thin film containing gold, and is laminated so as to cover substantially the entire upper surface of the p-cladding layer 26. The p-electrode 29 is also made of a material containing gold, and is formed on the translucent electrode 27 by vapor deposition.
The n-electrode 28 is attached to the substrate 21 by vapor deposition.

The shape of the pattern layer 22 and the method of forming the same are the same as in the first embodiment. The method of forming the GaN-based semiconductor layer is the same as that of the first embodiment.

The heat of growing the GaN-based semiconductor layer causes the material (Zr) of the buffer layer 22 to react with the material (Si) of the substrate 21 to form silicide (ZrSi ₂ ). Zr has the same crystal structure (hexagonal) as GaN and has a lattice constant close to that of GaN. Therefore, the two layers are fused between the n-cladding layer 24 and the buffer layer 22 so that Z
It is expected that an rN layer is formed.

The present invention is not limited to the description of the above-described embodiments and examples, but includes various modifications that can be made by those skilled in the art without departing from the scope of the claims.

Hereinafter, the following items will be disclosed. (1) An element including a GaN-based semiconductor layer, wherein the G
a first layer composed of a substrate on which an aN-based semiconductor layer can be grown or a laminate of a substrate and a buffer layer (excluding a layer composed of a GaN-based semiconductor), and a pattern layer formed on the surface of the first layer An element comprising the GaN-based semiconductor layer, wherein the pattern layer comprises a pattern layer on which the lateral growth of the GaN-based semiconductor layer is allowed. (2) The device according to (1), wherein the pattern layer includes a material that inhibits the growth of the GaN-based semiconductor layer thereon. (3) The pattern layer is made of SiO ₂ , and the Ga
The N-based semiconductor layer is made of GaN (1).
An element according to claim 1. (4) The element according to any one of (1) to (3), wherein the pattern layer is formed in a stripe shape.

(10) When the first layer is composed of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer satisfies at least two of the following requirements. Including a material having a coefficient of linear expansion of 10 × 10 ⁻⁶ / K or less, including a material having an elastic modulus of 15 × 10 ¹⁰ N / m ² or less, and a material having a hexagonal crystal structure. The device according to any one of (1) to (4), further comprising a material having a difference between its lattice constant and the lattice constant of the GaN-based semiconductor layer being ± 5% or less. (11) When the first layer is formed of the substrate, a surface of the substrate that contacts a layer formed when the GaN-based semiconductor layer is formed satisfies at least two of the following requirements: Including a material having a negative free energy of formation, including a material having a linear expansion coefficient of 10 × 10 ⁻⁶ / K or less, including a material having an elastic modulus of 15 × 10 ¹⁰ N / m ² or less, Any one of (1) to (4), including a material having a hexagonal crystal, and a material having a difference between its lattice constant and the lattice constant of the GaN-based semiconductor layer being ± 5% or less. An element according to claim 1. (12) The device according to (10) or (11), wherein the melting point of the substrate is 1000 ° C. or higher. (13) The melting point of the substrate is higher than the temperature at which the GaN-based semiconductor layer is formed (10).
Or the element as described in (11). (14) The device according to any one of (10) to (13), wherein a thermal expansion coefficient of a material of the substrate and a thermal expansion coefficient of a material of the GaN-based semiconductor layer are substantially equal. (15) The substrate includes the surface made of a material satisfying the conditions defined in (10) to (14), and a base made of the same or similar material having a lower purity than the material of the surface. The device according to any one of (10) to (14), wherein (16) The semiconductor device according to any one of (10) to (15), wherein the substrate is entirely conductive.

(20) When the first layer is made of the substrate, the surface of the substrate in contact with the GaN-based semiconductor layer is one of Zr, Ti, V, Cr, Nb, Re, Ta, and Y. Alternatively, the device according to any one of (1) to (4), comprising at least two materials. (21) When the first layer is composed of the substrate, the surface of the substrate that contacts the GaN-based semiconductor layer is V, Ti
The device according to any one of (1) to (4), comprising one or more materials selected from Zr and Zr. (22) When the first layer is made of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is made of Ti and / or Zr. (1) to (4)
An element according to any one of the above. (23) The device according to any one of (1) to (4), wherein, when the first layer is formed of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is formed of Zr. . (24) The substrate includes the surface made of a material satisfying the conditions defined in (20) to (23), and a base made of the same or similar material having a lower purity than the material on the surface. The device according to any one of (20) to (23), wherein (25) When the first layer is formed of the substrate, a surface of the substrate that contacts a layer formed at the time of forming the GaN-based semiconductor layer is Zr, Ti, V, Cr, Nb, Re, or T.
a, consisting of one or more materials selected from Y,
The device according to any one of (1) to (4), wherein (26) When the first layer is composed of the substrate, a surface of the substrate that contacts a layer formed during the formation of the GaN-based semiconductor layer is one or more selected from V, Ti, and Zr. (1)
The element according to any one of (4). (27) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is formed of Ti and / or Zr. The device according to any one of (1) to (4). (28) When the first layer is made of the substrate, a surface of the substrate which is in contact with a layer formed at the time of forming the GaN-based semiconductor layer is made of Zr.
The device according to any one of (1) to (4). (29) The substrate includes the surface made of a material satisfying the conditions defined in (25) to (28), and a base made of the same or similar material having a lower purity than the material of the surface. The device according to any one of (25) to (28), wherein (30) The semiconductor device is a light emitting device, a light receiving device or an electronic device.
The element according to any one of 9).

(40) The buffer layer satisfies the following requirements. (A) The thermal expansion coefficient of the buffer layer material is three times or less of the larger of the respective thermal expansion coefficients of the semiconductor material and the substrate material. (A) The device according to any one of (1) to (4), wherein the buffer layer material has an elastic modulus of 20 × 10 ¹⁰ N / m ² or less. (41) The elastic modulus of the buffer layer material is 15 × 10
(40) The element according to (40), which is ¹⁰ N / m ² or less. (42) The buffer layer satisfies the following requirements:
(C) the coefficient of thermal expansion of the buffer layer material is between the respective coefficients of thermal expansion of the semiconductor layer and the substrate; (b) the elastic modulus of the buffer layer material is not more than 20 × 10 ¹⁰ N / m ² The device according to any one of (1) to (4), wherein (43) The device according to (42), wherein the coefficient of thermal expansion of the buffer layer material is substantially at the center of each of the coefficients of thermal expansion of the semiconductor material and the substrate material. (44) The elastic modulus of the buffer layer material is 15 × 10
The element according to (42) or (43), wherein the element is ¹⁰ N / m ² or less. (45) The buffer layer satisfies the following requirements:
(D) The thermal expansion coefficient of the buffer layer material is 10 X 10 ^-6 /
K or less. (A) The buffer layer material has an elastic modulus of 20
X 10 ¹⁰ N / m ² or less (1)
The device according to any one of (1) to (4). (46) The elastic modulus of the buffer layer material is 15 × 10
The element according to (45), wherein the element is ¹⁰ N / m ² or less. (47) The buffer layer includes a material having a negative free energy of nitride formation that is negative.
The device according to any one of (0) to (46). (48) The buffer layer has the following requirements | lattice constant of buffer layer−lattice constant of GaN | / lattice constant of GaN ≦
0.05 (40) to (4)
The element according to any one of 7). (49) The buffer layer has the following requirements: | lattice constant of buffer layer−lattice constant of GaN | / lattice constant of GaN ≦
The device according to (48), which satisfies 0.02. (50) The device according to any one of (40) to (49), wherein the buffer layer has a hexagonal crystal structure. (51) The device according to any one of (40) to (50), wherein the substrate material and the buffer layer material are conductive. (52) The device according to (51), wherein the material of the substrate is silicon. (53) The device according to (52), wherein the buffer layer contains a material that reacts with the silicon. (54) The buffer layer is made of Cr, Hf, Nb, T
The device according to any one of (1) to (4), comprising one or more metals selected from a, Ti, V, and Zr. (55) The device according to any one of (1) to (4), wherein the buffer layer includes one or more metals selected from Ti, V, and Zr. (56) The device according to any one of (1) to (4), wherein the buffer layer contains Zr. (57) The device according to any one of (54) to (56), wherein the material of the substrate is silicon.

(60) The material according to any one of (1) to (4) and (40) to (57), wherein the material of the buffer layer has a melting point higher than the temperature applied during the manufacturing process of the device. Element. (61) The element according to any one of (1) to (4) and (40) to (57), wherein the element is a light emitting element, a light receiving element, or an electronic device. (70) A substrate on which a GaN-based semiconductor layer can be grown or a substrate and a buffer layer (excluding those composed of a GaN-based semiconductor)
Forming a pattern layer allowing lateral growth of the GaN-based semiconductor layer on the first layer made of a laminate of
Wherein said GaN-based semiconductor layer is selectively grown from a surface of said layer that is not covered with a pattern layer.

(101) A first layer composed of a substrate or a laminate of a substrate and a buffer layer (excluding those composed of a GaN-based semiconductor), and a pattern layer formed on the surface of the first layer. A pattern layer that allows lateral growth of the GaN-based semiconductor layer thereon and a GaN-based semiconductor layer that is formed on the first layer, and covers the pattern layer. The top surface is substantially flat Ga
And a N-type semiconductor layer. (102) The laminate according to (101), wherein the pattern layer includes a material that inhibits the growth of the GaN-based semiconductor layer thereon. (103) The laminate according to (101), wherein the pattern layer is made of SiO ₂ , and the GaN-based semiconductor layer is made of GaN. (104) The laminate according to any one of (101) to (103), wherein the pattern layer is formed in a stripe shape.

(111) When the first layer is formed of the substrate, a surface of the substrate which contacts a layer formed at the time of forming the GaN-based semiconductor layer satisfies at least two of the following requirements: Including a material having a negative free energy of formation of nitrides, including a material having a linear expansion coefficient of 10 × 10 ⁻⁶ / K or less, including a material having a modulus of elasticity of 15 × 10 ¹⁰ N / m ² or less, (101) to (104), including a material having a hexagonal crystal structure, and including a material having a difference between its lattice constant and the lattice constant of the GaN-based semiconductor layer of ± 5% or less. The laminate according to any one of the above. (112) The laminate according to (110) or (111), wherein the melting point of the substrate is 1000 ° C. or higher. (113) The melting point of the substrate is higher than the temperature at which the GaN-based semiconductor layer is formed (11).
0) or the laminated body according to (111). (114) The coefficient of thermal expansion of the material of the substrate and the GaN
The laminate according to any one of (110) to (113), wherein the thermal expansion coefficient of the material of the system semiconductor layer is substantially equal. (115) The substrate includes the surface made of a material satisfying the conditions defined in (110) to (114), and a base made of the same or similar material having a lower purity than the material on the surface. (110)-(114)
The laminate according to any one of the above. (116) The laminate according to any one of (110) to (115), wherein the substrate is entirely conductive.

(120) When the first layer is composed of the substrate, the surface of the substrate in contact with the GaN-based semiconductor layer is one of Zr, Ti, V, Cr, Nb, Re, Ta, and Y. Alternatively, the laminate according to any one of (101) to (104), comprising two or more materials. (121) When the first layer is formed of the substrate, the surface of the substrate in contact with the GaN-based semiconductor layer has V, T
The laminate according to any one of (101) to (104), comprising one or more materials selected from i and Zr. (122) Any of (101) to (104), wherein when the first layer is made of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is made of Ti and / or Zr. The laminate according to item 1. (123) The laminate according to any one of (101) to (104), wherein when the first layer is formed of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is formed of Zr. body. (124) The substrate includes the surface made of a material satisfying the conditions defined in (120) to (123), and a base made of the same or similar material having a lower purity than the material on the surface. (120)-(123)
The laminate according to any one of the above. (125) When the first layer is formed of the substrate, a surface of the substrate that contacts a layer formed at the time of forming the GaN-based semiconductor layer is Zr, Ti, V, Cr, Nb, Re,
The laminate according to any one of (101) to (104), comprising one or more materials selected from Ta and Y. (126) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer formed at the time of forming the GaN-based semiconductor layer is at least one selected from V, Ti, and Zr. (10)
The laminate according to any one of 1) to (104). (127) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is formed of Ti and / or Zr. ) The laminate according to any one of (104) to (104). (128) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is formed of Zr.
(01) The laminate according to any one of (104) to (104). (129) The substrate includes the surface made of a material satisfying the conditions defined in (125) to (128), and a base made of the same or similar material having a lower purity than the material on the surface. (125)-(128)
The laminate according to any one of the above. (130) The laminate is for a light emitting element, a light receiving element or an electronic device (11).
0) to (129).

(140) The buffer layer satisfies the following requirements. (A) The thermal expansion coefficient of the buffer layer material is three times or less of the larger of the respective thermal expansion coefficients of the semiconductor material and the substrate material. (A) The laminate according to any one of (101) to (104), wherein the buffer layer material has an elastic modulus of 20 × 10 ¹⁰ N / m ² or less. (141) The elastic modulus of the buffer layer material is 15 X 1
0 ¹⁰ N / m ² or less (140)
The laminate according to item 1. (142) The buffer layer satisfies the following requirements:
(C) the coefficient of thermal expansion of the buffer layer material is between the respective coefficients of thermal expansion of the semiconductor layer and the substrate; (b) the elastic modulus of the buffer layer material is not more than 20 × 10 ¹⁰ N / m ² The laminate according to any one of (101) to (104), characterized in that: (143) The laminate according to (142), wherein a thermal expansion coefficient of the buffer layer material is substantially at a center of each of thermal expansion coefficients of the semiconductor material and the substrate material. (144) The elastic modulus of the buffer layer material is 15 X 1
0 ¹⁰ N / m ² or less (142)
Or the laminate according to (143). (145) The buffer layer satisfies the following requirements:
(D) The thermal expansion coefficient of the buffer layer material is 10 X 10 ^-6 /
K or less. (A) The buffer layer material has an elastic modulus of 20
X 10 ¹⁰ N / m ² or less (10
The laminate according to any one of 1) to (104). (146) The elastic modulus of the buffer layer material is 15 X 1
0 is ¹⁰ N / m ² or less, wherein the (145)
The laminate according to item 1. (147) The laminate according to any one of (140) to (146), wherein the buffer layer includes a material having a negative free energy of nitride formation. (148) The buffer layer has the following requirements | lattice constant of buffer layer−lattice constant of GaN | / lattice constant of GaN ≦
0.05 (140) to (1)
47) The laminate according to any one of the above items. (149) The buffer layer has the following requirements: | lattice constant of buffer layer−lattice constant of GaN | / lattice constant of GaN ≦
0.02 is satisfied, The laminated body as described in (148) characterized by the above-mentioned. (150) The laminate according to any one of (140) to (149), wherein the buffer layer has a hexagonal crystal structure. (151) The laminate according to any one of (140) to (150), wherein the substrate material and the buffer layer material are conductive. (152) The laminate according to (151), wherein the material of the substrate is silicon. (153) The laminate according to (152), wherein the buffer layer includes a material that reacts with the silicon. (154) The buffer layer is made of Cr, Hf, Nb, T
(101) to (10), comprising one or more metals selected from a, Ti, V, and Zr.
The laminate according to any one of 4). (155) The laminated body according to any one of (101) to (104), wherein the buffer layer contains one or more metals selected from Ti, V, and Zr. (156) The laminate according to any one of (101) to (104), wherein the buffer layer contains Zr. (157) The laminate according to any one of (154) to (156), wherein the material of the substrate is silicon.

(160) The material of the buffer layer has a melting point higher than the temperature applied during the manufacturing process of the device, (101) to (104) and (140) to (140).
(157) The laminate according to any of (157). (161) The laminate according to any one of (101) to (104) and (140) to (157), wherein the laminate is used for a light emitting element, a light receiving element, or an electronic device.

(201) A first layer composed of a substrate on which a GaN-based semiconductor layer can be grown or a laminate of a substrate and a buffer layer (excluding a GaN-based semiconductor layer), and a surface of the first layer A pattern layer formed on the GaN-based semiconductor layer, wherein the pattern layer comprises a pattern layer that allows lateral growth of the GaN-based semiconductor layer thereon. body. (202) The laminate according to (201), wherein the pattern layer includes a material that inhibits the growth of the GaN-based semiconductor layer thereon. (203) The laminate according to (201), wherein the pattern layer is made of SiO ₂ , and the GaN-based semiconductor layer is made of GaN. (204) The laminate according to any one of (201) to (203), wherein the pattern layer is formed in a stripe shape.

(211) When the first layer is made of the substrate, a surface of the substrate that contacts a layer formed when the GaN-based semiconductor layer is formed satisfies at least two of the following requirements Including a material having a negative free energy of formation of nitrides, including a material having a linear expansion coefficient of 10 × 10 ⁻⁶ / K or less, including a material having a modulus of elasticity of 15 × 10 ¹⁰ N / m ² or less, (201) to (204), including a material having a hexagonal crystal structure, and including a material having a difference between its lattice constant and the lattice constant of the GaN-based semiconductor layer of ± 5% or less. The laminate according to any one of the above. (212) The laminate according to (210) or (211), wherein the melting point of the substrate is 1000 ° C. or higher. (213) The melting point of the substrate is higher than the temperature at which the GaN-based semiconductor layer is formed (21).
0) or the laminate according to (211). (214) The coefficient of thermal expansion of the material of the substrate and the GaN
The laminate according to any one of (210) to (213), wherein a thermal expansion coefficient of a material of the system semiconductor layer is substantially equal. (215) The substrate includes the surface made of a material satisfying the conditions defined in (210) to (214), and a base made of the same or similar material having a lower purity than the material on the surface. (210)-(214)
The laminate according to any one of the above. (216) The laminate according to any one of (210) to (215), wherein the substrate is entirely conductive.

(220) When the first layer is composed of the substrate, the surface of the substrate in contact with the GaN-based semiconductor layer is one of Zr, Ti, V, Cr, Nb, Re, Ta, and Y. Alternatively, the laminate according to any one of (201) to (204), comprising two or more materials. (221) When the first layer is made of the substrate, the surface of the substrate in contact with the GaN-based semiconductor layer has V, T
The laminate according to any one of (201) to (204), comprising one or more materials selected from i and Zr. (222) Any of (201) to (204), wherein when the first layer is made of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is made of Ti and / or Zr. The laminate according to item 1. (223) The laminate according to any one of (201) to (204), wherein when the first layer is formed of the substrate, a surface of the substrate in contact with the GaN-based semiconductor layer is formed of Zr. body. (224) The substrate includes the surface made of a material satisfying the conditions defined in (220) to (223), and a base made of the same or similar material having a lower purity than the material on the surface. (220) to (223)
The laminate according to any one of the above. (225) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is Zr, Ti, V, Cr, Nb, Re,
The laminate according to any one of (201) to (204), comprising one or more materials selected from Ta and Y. (226) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is at least one selected from V, Ti, and Zr. (20)
The laminate according to any one of 1) to (204). (227) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is formed of Ti and / or Zr. (201) ) To (204). (228) When the first layer is formed of the substrate, a surface of the substrate that is in contact with a layer generated at the time of forming the GaN-based semiconductor layer is formed of Zr.
01) to the laminate according to any one of (204). (229) The substrate includes the surface made of a material satisfying the conditions defined in (225) to (228), and a base made of the same or similar material having a lower purity than the material on the surface. (225) to (228)
The laminate according to any one of the above. (230) The laminate is for a light emitting element, a light receiving element or an electronic device (11).
0) to (229).

(240) The buffer layer satisfies the following requirements. (A) The coefficient of thermal expansion of the buffer layer material is three times or less of the larger of the respective thermal expansion coefficients of the semiconductor material and the substrate material. (A) The laminate according to any one of (201) to (204), wherein the buffer layer material has an elastic modulus of 20 × 10 ¹⁰ N / m ² or less. (241) The elastic modulus of the buffer layer material is 15 X 1
0 ¹⁰ N / m ² or less (240)
The laminate according to item 1. (242) The buffer layer satisfies the following requirements:
(C) the coefficient of thermal expansion of the buffer layer material is between the respective coefficients of thermal expansion of the semiconductor layer and the substrate; (b) the elastic modulus of the buffer layer material is not more than 20 × 10 ¹⁰ N / m ² The laminate according to any one of (201) to (204), characterized in that: (243) The laminate according to (242), wherein the coefficient of thermal expansion of the buffer layer material is substantially at the center of the respective coefficients of thermal expansion of the semiconductor material and the substrate material. (244) The elastic modulus of the buffer layer material is 15 X 1
0 is ¹⁰ N / m ² or less, wherein the (242)
Or the laminate according to (243). (245) The buffer layer satisfies the following requirements:
(D) The thermal expansion coefficient of the buffer layer material is 10 X 10 ^-6 /
K or less. (A) The buffer layer material has an elastic modulus of 20
X 10 ¹⁰ N / m ² or less (20
The laminate according to any one of 1) to (204). (246) The buffer layer material has an elastic modulus of 15 × 1
0 is ¹⁰ N / m ² or less, wherein the (245)
The laminate according to item 1. (247) The laminate according to any one of (240) to (246), wherein the buffer layer includes a material having a negative free energy of nitride formation. (248) The buffer layer has the following requirements: | lattice constant of buffer layer−lattice constant of GaN | / GaN
The laminate according to any one of (240) to (247), which satisfies the following lattice constant: ≦ 0.05. (249) The buffer layer has the following requirements: | lattice constant of buffer layer−lattice constant of GaN | / GaN
248. The laminate according to (248), wherein a lattice constant of 0.02 is satisfied. (250) The laminate according to any one of (240) to (249), wherein the crystal structure of the buffer layer is hexagonal. (251) The laminate according to any one of (240) to (250), wherein the substrate material and the buffer layer material are conductive. (252) The laminate according to (251), wherein the material of the substrate is silicon. (253) The laminate according to (252), wherein the buffer layer contains a material that reacts with the silicon. (254) The buffer layer is made of Cr, Hf, Nb, T
(201) to (20), comprising one or more metals selected from a, Ti, V, and Zr.
The laminate according to any one of 4). (255) The laminate according to any one of (201) to (204), wherein the buffer layer includes one or more metals selected from Ti, V, and Zr. (256) The laminate according to any one of (201) to (204), wherein the buffer layer contains Zr. (257) The laminate according to any one of (254) to (256), wherein the material of the substrate is silicon.

(260) The material of the buffer layer has a melting point higher than the temperature applied in the manufacturing process of the device, and is characterized in that (201) to (204) and (240) to
The laminate according to any one of (257). (261) The laminate according to any one of (201) to (204) and (240) to (257), wherein the laminate is used for a light emitting element, a light receiving element, or an electronic device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a light emitting diode according to a first embodiment of the present invention.

FIG. 2 is a view showing a method of forming an n-clad layer composed of a pattern layer and a GaN-based semiconductor layer.

FIG. 3 is a partially enlarged view of the light emitting diode of FIG. 1;

FIG. 4 is a diagram showing a light emitting diode of another mode in the first embodiment.

FIG. 5 is a diagram showing stress relaxation by a buffer layer 22.

FIG. 6 is a view showing a light emitting diode according to a second embodiment of the present invention.

[Explanation of symbols]

1, 10, 20 Light-emitting diode 2, 21 Substrate 3, 23 Pattern layer 22 Buffer layer 4, 14, 24 GaN-based semiconductor layer 4, 6, 14, 16, 24, 26 GaN-based semiconductor layer (cladding layer) 5, 15 , 25 GaN-based semiconductor layer (light-emitting layer)

Claims (6)

[Claims] A substrate formed of metal, a pattern layer formed so that the substrate is partially exposed, and a GaN-based semiconductor layer formed on the exposed substrate so as to cover the pattern layer. A GaN-based semiconductor, comprising: 2. A laminate of a conductive semiconductor substrate and a buffer layer made of a metal, a pattern layer formed so that the buffer layer is partially exposed, and a pattern layer formed on the exposed buffer layer. A GaN-based semiconductor layer formed so as to cover the GaN-based semiconductor. 3. The substrate comprises chromium (Cr), hafnium (Hf), niobium (Nb), tantalum (Ta), rhenium (Re), yttrium (Y), vanadium (V),
2. The GaN-based semiconductor according to claim 1, comprising at least one metal selected from titanium (Ti) and zirconium (Zr). 4. The buffer layer is made of chromium (Cr), hafnium (Hf), niobium (Nb), tantalum (Ta),
Vanadium (V), titanium (Ti), zirconium (Z
The GaN-based semiconductor according to claim 2, comprising at least one metal selected from r). 5. The GaN-based semiconductor according to claim 1, wherein the pattern layer is made of a material that prevents a GaN-based semiconductor layer from directly growing thereon. 6. The GaN according to claim 1, wherein said pattern layer is made of SiO ₂ , and said GaN-based semiconductor is made of GaN.
System semiconductor.