KR101504272B1 - Compound semiconductor and method of producing the same - Google Patents

Abstract

The present invention relates to a compound semiconductor and to a method for manufacturing the same. According to the present invention, the compound semiconductor includes: a substrate; a semiconductor layer which is disposed on the substrate; and a bending prevention layer which is formed on the upper side of the semiconductor layer. When the thermal expansion coefficient of the semiconductor layer formed on the substrate is less than the thermal expansion coefficient of the substrate, the thermal expansion coefficient of the bending prevention layer is greater than or the same as the thermal expansion coefficient of the substrate. When the thermal expansion coefficient of the semiconductor layer formed on the substrate is greater than the thermal expansion coefficient of the substrate, the thermal expansion coefficient of the bending prevention layer is less than or the same as the thermal expansion coefficient of the substrate. According to an embodiment of the present invention, the present invention alleviates stress due to thermal expansion coefficient difference between the substrate and the semiconductor layer at room temperatures by forming the bending prevention layer on the upper side of the semiconductor layer in materials having a thermal expansion coefficient greater than or the same as, or less than or the same as the substrate. The present invention manufactures the compound semiconductor which does not generate or reduces bending deformation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compound semiconductor,

The present invention relates to a compound semiconductor and a method of manufacturing the same, and more particularly, to a compound semiconductor that prevents warpage due to a difference in thermal expansion coefficient between a substrate and a semiconductor layer and a method for manufacturing the same.

Gallium nitride (GaN) -based semiconductors have a wide band gap and are used in a variety of photoelectric devices ranging from visible light to ultraviolet light. Among photoelectric elements, a light emitting diode (LED) is a compound semiconductor layer of a nitride compound (III-N) type on a sapphire (Al ₂ O ₃ ) wafer substrate, that is, undoped GaN, n-doped n -GaN, an active layer of a quantum well structure, and a p-type doped p-GaN layer.

In forming a compound semiconductor layer on a wafer, a metal organic chemical vapor deposition (MOCVD) method, which is a kind of chemical vapor deposition method, is used.

Typical MOCVD growth equipment includes a chamber, a susceptor mounted rotatably within the chamber to seat the wafer, a heater disposed below the susceptor to heat the susceptor, a source for forming a semiconductor layer into the chamber, And a gas introduction port for introducing the V source.

A method of growing a nitride compound (III-N) on a substrate in the III-V group compound in the MOCVD growth apparatus will be briefly described below.

After the sapphire (Al ₂ O ₃ ) wafer is placed on the susceptor, the wafer is heated to a high temperature by operating the heater. When trimethyl-gallium (TMGa), which is a Group III source gas, and ammonia (NH ₃ ), which is a Group V source, are introduced into the chamber through the gas inlet, the gallium (Ga) and nitrogen N) source are mutually reacted to form a gallium nitride (GaN) thin film on the deposition surface of the wafer heated to a high temperature.

On the other hand, the growth of the compound semiconductor layer is performed at a high temperature of about 1100 DEG C, and when the growth of the compound semiconductor layer is finished, the temperature is lowered to room temperature and then the compound semiconductor layer is taken out from the chamber. However, due to the difference in thermal expansion coefficient between the wafer and the compound semiconductor layer, the wafer is bent. Because, for example, sapphire (Al ₂ O ₃₎ When growing a gallium nitride (GaN) thin film on a wafer, a sapphire (Al ₂ O ₃₎ size of the thermal expansion coefficient of the wafer as compared to the thermal expansion coefficient of gallium nitride (GaN), The sapphire (Al ₂ O ₃ ) wafer shrinks sharply when compared to a gallium nitride (GaN) thin film when the temperature is lowered to room temperature after growing the thin film at a high temperature. Thus, convex bowing deformation occurs on the upper surface of the sapphire (Al ₂ O ₃ ) wafer. Such bending deformation causes defects such as dislocations in the compound semiconductor layer, which acts as a factor to deteriorate the characteristics or quality of the compound semiconductor layer.

In order to solve the above-mentioned problems, US Pat. No. 7,198,671 discloses a technique for depositing a different material having a different thermal expansion coefficient from a compound semiconductor layer to be grown on the lower surface of the wafer to prevent warpage. However, if a thin film for preventing warpage of the wafer is formed on the lower surface of the wafer, the temperature distribution of the upper surface of the wafer at that time, and the temperature distribution of the wafer when the thin film for preventing warpage is not formed on the lower surface of the wafer, When the thin film is grown on the wafer under the same conditions as the upper surface temperature distribution is different, the thin film characteristics can be different from the conventional one. Particularly, in the case of a light emitting diode (LED) using such a compound semiconductor substrate, the quantum well growth temperature is affected and the optical characteristics are deteriorated. Further, in order to solve the temperature difference problem, it is troublesome to change the growth condition of the conventional MOCVD thin film.

In the case of a light emitting diode (LED), a compound semiconductor layer is formed on the upper surface of a sapphire (Al ₂ O ₃ ) wafer as described above. In order to manufacture a vertical LED, a sapphire (Al ₂ O ₃ ) Must be removed through a Laser Lift Off (LLO) process.

However, when a heterogeneous material is deposited on the lower surface of the wafer to prevent bowing as in US Pat. No. 7,198,671, a deposition film formed on the lower surface of the wafer for a laser lift off (LLO) There is a problem that the process to be removed must be preceded.

Japanese Laid-Open Patent Application No. 1995-249573 discloses a technique for preventing bowing by processing the lower surface of the wafer so as to have a convex or concave curvature. However, since the wafer has a predetermined hardness, it is very difficult to process the entire lower surface of the wafer in a convex or concave manner, and it is difficult to produce a wafer having the same curvature, the bowing phenomenon can not be completely eliminated.

US registered patent 7,198,671 Japanese Patent Application Laid-Open No. 1995-249573

The present invention provides a compound semiconductor that prevents warpage deformation due to a difference in thermal expansion coefficient between a substrate and a semiconductor layer, and a method of manufacturing the same.

The compound semiconductor according to the present invention includes a substrate, a semiconductor layer formed on an upper surface of the substrate, and a bending prevention layer formed on an upper surface of the semiconductor layer. When the thermal expansion coefficient of the semiconductor layer formed on the substrate is smaller than the thermal expansion coefficient of the substrate, Wherein the coefficient of thermal expansion of the bending prevention layer is greater than or equal to the coefficient of thermal expansion of the substrate when the coefficient of thermal expansion of the semiconductor layer formed on the substrate is larger than the coefficient of thermal expansion of the substrate, It is less than or equal to the coefficient.

Wherein the substrate is one of a sapphire (Al ₂ O ₃ ) wafer and a silicon (Si) wafer, and the semiconductor layer is made of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), gold (Au), and silicon (Si), wherein the bending prevention layer is made of one of indium ). ≪ / RTI >

The substrate is a sapphire (Al ₂ O ₃ ) wafer, and the semiconductor layer is made of any one of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride And the bending prevention layer is formed of at least one of aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au).

Wherein the substrate is a silicon wafer and the semiconductor layer is any one of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride (InGaN) The bending prevention layer is formed of silicon (Si).

The semiconductor layer includes an n-type semiconductor layer formed on a substrate, an active layer having a quantum well structure formed on the n-type semiconductor layer, and a p-type semiconductor layer formed on the active layer, As shown in FIG.

The semiconductor layer includes an n-type semiconductor layer formed on a substrate, an active layer of a quantum well structure formed on the n-type semiconductor layer, a p-type semiconductor layer formed on the active layer, and an ohmic contact layer ), And the bending prevention layer is formed on the ohmic contact layer.

A method for fabricating a compound semiconductor according to the present invention includes: preparing a substrate; Forming a semiconductor layer on the substrate; And forming a bending prevention layer on the semiconductor layer by using a material having a thermal expansion coefficient different from that of the substrate. In the process of forming the bending prevention layer on the semiconductor layer, the thermal expansion coefficient of the semiconductor layer A bending prevention layer is formed on the semiconductor layer by using a material having a thermal expansion coefficient larger than or equal to the thermal expansion coefficient of the substrate when the thermal expansion coefficient of the semiconductor layer is smaller than a thermal expansion coefficient of the substrate, A bending prevention layer is formed on the semiconductor layer by using a material having a thermal expansion coefficient smaller than or equal to the thermal expansion coefficient of the substrate.

Wherein the substrate is one of a sapphire (Al ₂ O ₃ ) wafer and a silicon (Si) wafer, and the semiconductor layer is made of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), gold (Au), and indium gallium nitride (InGaN) , And silicon (Si).

(GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) or indium gallium nitride (InGaN) on the sapphire (Al ₂ O ₃ ) Wherein the semiconductor layer is formed by using any one of aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au) .

A semiconductor layer is formed on the silicon (Si) wafer substrate by any one of the series of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride (InGaN) And a bending prevention layer is formed on the semiconductor layer using silicon (Si).

The bending prevention layer is formed continuously in the equipment for growing the semiconductor layer after the formation of the semiconductor layer.

The semiconductor layer and the bending prevention layer are successively grown in the same MOCVD growth equipment.

Forming an n-type semiconductor layer on the substrate to form the semiconductor layer; Forming an active layer having a quantum well structure on the n-type semiconductor layer; And forming a p-type semiconductor layer on the active layer, wherein the bending prevention layer is formed on the p-type semiconductor layer.

Forming an n-type semiconductor layer on the substrate to form the semiconductor layer; Forming an active layer having a quantum well structure on the n-type semiconductor layer; Forming a p-type semiconductor layer on the active layer; And forming an ohmic contact on the p-type semiconductor layer, wherein the bending prevention layer is formed on the ohmic contact layer.

According to the embodiments of the present invention, the bending prevention layer is formed on the upper surface of the semiconductor layer with a material having a thermal expansion coefficient larger than, equal to, or smaller than that of the substrate, thereby buffering stress caused by the difference in thermal expansion coefficient between the substrate and the semiconductor layer . Thus, a compound semiconductor in which bowing deformation does not occur at room temperature or can be reduced can be produced.

Further, after the completion of the growth of the semiconductor layer, the bending prevention layer is continuously formed in the growth equipment in which the semiconductor layer is grown without the step of processing the substrate as in the prior art. Accordingly, the process time for producing the compound semiconductor is shortened, and there is no need to provide a separate growth equipment for the growth of the anti-flexural layer.

1 is a cross-sectional view showing a compound semiconductor according to an embodiment of the present invention
2A to 2C are views sequentially showing a method of manufacturing a compound semiconductor according to an embodiment of the present invention
3 is a cross-sectional view of an MOCVD growth apparatus forming a semiconductor layer and a bending prevention layer of a compound semiconductor according to an embodiment of the present invention

Hereinafter, embodiments of the present invention will be described in detail. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely.

The present invention relates to a compound semiconductor in which a semiconductor layer 200 is formed on a substrate 100 and a compound semiconductor in which a bowing deformation due to a difference in thermal expansion coefficient between the substrate 100 and the semiconductor layer 200 is prevented, And a manufacturing method thereof. In order to prevent bowing deformation, a thin film (hereinafter referred to as a bending prevention layer 300) is formed on the top surface of the compound semiconductor layer 200 with a material having a thermal expansion coefficient different from that of the substrate 100, And buffer or buffer the stress due to the difference in thermal expansion coefficient between the compound semiconductor layers 200. The material of the bending prevention layer 300 when the semiconductor layer 200 is formed on the substrate 100 is different from that of the substrate 100 when the coefficient of thermal expansion of the semiconductor layer 200 is smaller than that of the substrate 100. More specifically, when the coefficient of thermal expansion of the semiconductor layer 200 is smaller than that of the substrate 100, the bending prevention layer 300 is grown or formed of a material having a thermal expansion coefficient greater than or equal to that of the substrate 100. Conversely, when the coefficient of thermal expansion of the semiconductor layer 200 is larger than that of the substrate 100, the bending prevention layer 300 is grown or formed of a material having a thermal expansion coefficient smaller or equal to that of the substrate 100.

1 is a cross-sectional view showing a compound semiconductor according to an embodiment of the present invention, for example, a vertical type light emitting diode (LED).

Hereinafter, a compound semiconductor according to an embodiment of the present invention will be described with reference to FIG. The substrate according to the embodiment described hereinafter is a wafer, more specifically a 2 inch wafer.

1, a compound semiconductor according to an embodiment of the present invention includes a substrate 100, a semiconductor layer 200 formed on the upper surface of the substrate 100, a semiconductor layer 200 formed on the upper surface of the semiconductor layer 200, And a bending prevention layer (300) for preventing bowing deformation due to a difference in thermal expansion coefficient between the semiconductor layer (200) and the semiconductor layer (200).

Here, the substrate 100 may be any one of a sapphire (Al ₂ O ₃ ) wafer and a silicon (Si) wafer. Of course, the substrate 100 is not limited to this, and wafers of various materials can be used.

The semiconductor layer 200 includes first to third semiconductor layers 210, 220 and 230 formed on the upper surface of the substrate 100 and a first semiconductor layer 210 and a second semiconductor layer 220 And a third semiconductor layer 230 are sequentially stacked. Here, the first semiconductor layer 210 is an n-type semiconductor layer, the second semiconductor layer 220 is a quantum well structure active layer, and the third semiconductor layer 230 is a p-type semiconductor layer. That is, in the semiconductor layer 200 according to the embodiment, the n-type semiconductor layer, the active layer, and the p-type semiconductor layer are sequentially formed on the substrate 100. The semiconductor layer 200 includes a semiconductor layer (hereinafter referred to as a fourth semiconductor layer 240) formed between the substrate 100 and the first semiconductor layer 210 (n-type semiconductor layer) And an electron blocking layer (hereinafter, referred to as a fifth semiconductor layer 250) formed between the semiconductor layer 230 (p-type semiconductor layer) and blocking the movement of electrons. An ohmic contact layer (not shown) is formed on the p-type semiconductor layer (that is, the third semiconductor layer 230) in order to reduce the contact resistance of the semiconductor layer 200 or to improve the ohmic contact. Can be formed.

For example, the first semiconductor layer 210 is made of n-GaN, the second semiconductor layer 220 is made of InGaN / GaN, and the second semiconductor layer 220 is made of InGaN / GaN. The third semiconductor layer 230 is made of p-GaN, the fourth semiconductor layer 240 is made of GaN, and the fifth semiconductor layer 250 is made of AlGaN. That is, the semiconductor layer 200 according to the embodiment has a structure in which GaN, n-GaN, InGaN / GaN, AlGaN, and p-GaN are stacked in this order on the substrate 100. In addition, an ohmic contact layer made of InGaN may be formed on the third semiconductor layer 230 made of p-GaN.

(AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride (GaN), for example, but the present invention is not limited thereto. InGaN) -based compound semiconductor layer 200 may be used.

The growth equipment in which the semiconductor layer 200 according to the embodiment is grown may be, for example, MOCVD.

The bending prevention layer 300 is formed on the upper surface of the semiconductor layer 200 and more specifically the third semiconductor layer 230 is formed on the upper surface of the p-type semiconductor layer and between the substrate 100 and the semiconductor layer 200 The material to be formed is different depending on the thermal expansion coefficient relationship. That is, when the coefficient of thermal expansion of the semiconductor layer 200 is smaller than that of the substrate 100, the bending prevention layer 300 is formed of a material having a thermal expansion coefficient greater than or equal to that of the substrate 100. Conversely, when the coefficient of thermal expansion of the semiconductor layer 200 is larger than that of the substrate 100, the bending prevention layer 300 is formed of a material having a thermal expansion coefficient smaller than or equal to that of the substrate 100. More specifically, for example, the substrate 100 may be a sapphire (Al ₂ O ₃ ) wafer, and may be gallium nitride (GaN), aluminum nitride (GaN), or the like, which is a nitride compound having a thermal expansion coefficient lower than that of the sapphire (Al ₂ O ₃ ) In the case where the semiconductor layer 200 is grown using any one of AlN, AlGaN, InN, and InGaN, the bending prevention layer 300 may be formed of sapphire (Al ₂ O ₃ ) (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au). As another example, the substrate 100 may be a silicon (Si) wafer and may be formed of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) And the indium gallium nitride (InGaN) series, the bending prevention layer 300 is formed of a material having a thermal expansion coefficient smaller or equal to that of silicon (Si), for example, silicon (Si) .

The bending prevention layer 300 is formed on the third semiconductor layer 230 of the semiconductor layer 200, that is, the p-type semiconductor layer. However, the present invention is not limited thereto. When the ohmic contact layer is formed on the p-type semiconductor layer to improve the ohmic contact, the bending prevention layer 300 may be formed on the ohmic contact layer.

When the coefficient of thermal expansion of the semiconductor layer 200 is smaller than that of the substrate 100, the material of the bending prevention layer 300 may be aluminum (Al), nickel (Ni), chromium (Cr) (Si) is used as a material for forming the bending prevention layer 300 when the coefficient of thermal expansion of the semiconductor layer 200 is larger than that of the substrate 100. On the other hand, The use of the above-mentioned example has been described. However, the present invention is not limited to the above-described materials, and various materials having a thermal expansion coefficient greater than or equal to that of the substrate 100 and a material having a thermal expansion larger than that of the substrate 100 can be used. It is more preferable to use materials that can be formed in the same growth equipment as the equipment to be used, for example, MOCVD equipment.

The semiconductor layer 200 is grown at a high temperature in the MOCVD growth equipment. When the temperature of the semiconductor layer 200 is lowered to room temperature after the semiconductor layer 200 is grown, the thermal expansion between the substrate 100 and the semiconductor layer 200 The substrate 100 on which the semiconductor layer 200 is formed due to the difference in coefficient is deformed. For example, when the semiconductor layer 200 having a smaller thermal expansion coefficient than that of the substrate 100 is formed, convex bowing occurs to the upper side where the semiconductor layer 200 is located, and conversely, When a large semiconductor layer 200 is formed, a convex warpage occurs to the lower side where the substrate 100 is located.

For example, a GaN semiconductor layer 200 having a thermal expansion coefficient smaller than that of the substrate 100 is formed on a 2-inch sapphire (Al ₂ O ₃ ) substrate 100 having a thickness of 430 탆 in a growth equipment at a temperature of 1100 캜 to a thickness of 5 탆 . When the substrate 100 on which the semiconductor layer 200 is grown is taken out to a normal temperature, convex bowing deformation is generated in the direction in which the semiconductor layer 200 is formed. This is due to the difference in thermal expansion coefficient between the sapphire (Al ₂ O ₃ ) wafer and the GaN semiconductor layer, when the sapphire (Al ₂ O ₃ ) wafer shrinks to a gallium nitride (GaN) Is larger than a thin film. Accordingly, convex bowing deformation occurs on the upper surface of the sapphire (Al ₂ O ₃ ) wafer.

Here, the degree of warpage of 55 占 퐉 means that the height difference between the convex portion (the uppermost height position) of the upper surface of the substrate 100 or the semiconductor layer 200 and the both ends of the substrate 100 or the semiconductor layer 200 is 55 ㎛.

Therefore, in the present invention, as described above, the bending prevention layer 300 is formed on the upper surface of the semiconductor layer 200 with the same or smaller thermal expansion coefficient than that of the substrate 100, After the completion of the growth, it is formed before the temperature falls to room temperature. The bending prevention layer 300 functions to buffer or relax the stress due to the difference in thermal expansion coefficient between the substrate 100 and the semiconductor layer 200 by mutually canceling each other. Accordingly, after the bending prevention layer 300 is formed on the semiconductor layer 200, when the temperature is lowered to room temperature, the bending prevention layer 300 prevents the bending deformation due to the difference in thermal expansion coefficient.

For example, a GaN semiconductor layer 200 having a thermal expansion coefficient smaller than that of the substrate 100 is formed on a 2-inch sapphire (Al ₂ O ₃ ) substrate 100 having a thickness of 430 탆 in a growth equipment at a temperature of 1100 캜 to a thickness of 5 탆 . When the bending prevention layer 300 made of copper (Cu) is formed on the semiconductor layer 200 and then the bending prevention layer 300 is taken out to a room temperature, bowing hardly occurs in the substrate 100.

The semiconductor layer 200 is formed using the MOCVD growth equipment. In the embodiment, the material that can be grown by the MOCVD growth equipment, that is, aluminum (Al), nickel (Ni), chromium (Cr), copper (Si) is used to form the bending prevention layer (300). Thus, the bending prevention layer 300 can be continuously formed in the MOCVD growth equipment in which the semiconductor layer 200 is grown, without moving the substrate 100 to other equipment after the completion of the growth of the semiconductor layer 200. Therefore, the process time for forming the bending prevention layer 300 can be shortened.

On the other hand, when a material having a thermal expansion coefficient different from that of the semiconductor layer is deposited on the entire lower surface of the substrate, there is a problem that a temperature difference occurs on the upper surface of the substrate, that is, the deposition surface, due to the deposition film formed on the lower surface of the substrate.

Since the bending prevention layer 300 is formed on the upper surface of the semiconductor layer 200 in the embodiment of the present invention, the deposition surface (that is, the upper surface) of the substrate 100, There is no change in the process conditions due to the temperature difference. In addition, the semiconductor layer 200 and the bending prevention layer 300 can be grown on the upper surface of the substrate 100 without changing the conventional MOCVD growth conditions.

Hereinafter, a method for manufacturing the compound semiconductor 1000 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. Here, the compound semiconductor is a vertical type light emitting diode (LED), and a compound semiconductor manufacturing method in which a gallium nitride (GaN) semiconductor layer having a thermal expansion coefficient smaller than that of the substrate is formed on a sapphire (Al ₂ O ₃ ) For example,

2A to 2C are views sequentially illustrating a method of manufacturing a compound semiconductor according to an embodiment of the present invention. 3 is a cross-sectional view of an MOCVD growth apparatus for forming a semiconductor layer and a bending prevention layer of a compound semiconductor according to an embodiment of the present invention.

First, a substrate 100 is provided (FIG. 2A) and charged into an MOCVD growth apparatus to form a GaN-based semiconductor layer 200 on the substrate 100 (FIG. 2B). 3, the substrate 100 is placed on the susceptor 20 installed in the chamber 10, and the heater 40 is operated to move the susceptor 20 and the susceptor 20 ) Is heated to a growth temperature of the semiconductor layer, for example, 500 to 1500 ° C. When the substrate 100 is heated to the growth temperature of the semiconductor layer 200, a plurality of sources of gallium nitride (GaN) are injected through the gas injection part 50 to form the semiconductor layer 200, An n-GaN layer which is an n-type semiconductor layer (one semiconductor layer 200), an InGaN / GaN layer which is an active layer (second semiconductor layer 220), a p-type semiconductor layer )) P-GaN layer are successively grown. At this time, before forming the n-GaN layer on the substrate 100, a GaN layer which is an undoped semiconductor layer (the fourth semiconductor layer 240) is formed, and an InGaN / GaN layer An AlGaN layer which is an electron blocking layer (fifth semiconductor layer 250) can be formed.

Next, the bending prevention layer 300 is formed on the upper surface of the semiconductor layer 200, that is, on the p-GaN layer (the third semiconductor layer 230). Since the GaN-based semiconductor layer 200 formed first has a smaller thermal expansion coefficient than a sapphire (Al ₂ O ₃ ) wafer that is the substrate 100, it is preferable to use a material having a thermal expansion coefficient greater than or equal to that of sapphire (Al ₂ O ₃ ) A source including any one of aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au) A bending prevention layer 300 is grown on the first semiconductor layer (third semiconductor layer). At this time, it is more preferable to form the bending prevention layer 300 by using a material such as aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu) Therefore, the anti-bending layer 300 can be formed directly on the p-GaN layer (the third semiconductor layer 230) in the MOCVD growth apparatus in which the semiconductor layer 200 is grown. That is, after the semiconductor layer 200 is grown in the MOCVD equipment, the bending prevention layer 300 is continuously formed in the MOCVD equipment in which the semiconductor layer 200 is formed, without moving the substrate 100 to another growth equipment .

As another example, the substrate 100 on which the gallium nitride (GaN) semiconductor layer 200 is formed may be a silicon (Si) wafer having a thermal expansion coefficient larger than that of gallium nitride (GaN). In this case, a gallium nitride (GaN) semiconductor layer is grown on the silicon (Si) wafer substrate 100, and then a material having a thermal expansion coefficient smaller than that of silicon (Si), such as Si, is grown on the p- The anti-bending layer 300 is formed.

As described above, in the present invention, the bending prevention layer 300 is formed on the upper surface of the semiconductor layer 200 with a material having the same or smaller thermal expansion coefficient than that of the substrate 100, ) And the semiconductor layer (200). Accordingly, it is possible to prevent or reduce the bending of the compound semiconductor at room temperature.

The semiconductor layer 200 is formed using the MOCVD growth equipment. In the embodiment, the material that can be grown by the MOCVD growth equipment, that is, aluminum (Al), nickel (Ni), chromium (Cr), copper (Si) is used to form the bending prevention layer (300). Thus, the bending prevention layer 300 can be continuously formed in the MOCVD growth apparatus in which the semiconductor layer 200 is grown, without moving the substrate 100 to other equipment after the completion of the growth of the semiconductor layer 200. Therefore, the process time for forming the bending prevention layer 300 can be shortened.

100: substrate 200: semiconductor layer
300: bending prevention layer

Claims (14)

Board;
A semiconductor layer formed on the upper surface of the substrate;
A bending prevention layer formed on an upper surface of the semiconductor layer;
/ RTI >
The coefficient of thermal expansion of the bending prevention layer is smaller or larger than the coefficient of thermal expansion of the substrate as the coefficient of thermal expansion of the semiconductor layer is larger or smaller than the coefficient of thermal expansion of the substrate,
Wherein when the thermal expansion coefficient of the semiconductor layer formed on the substrate is smaller than the thermal expansion coefficient of the substrate, a material having a thermal expansion coefficient greater than or equal to that of the substrate is deposited on the semiconductor layer to form a thin film, The coefficient is equal to or greater than the thermal expansion coefficient of the substrate,
When a thermal expansion coefficient of the semiconductor layer formed on the substrate is larger than a thermal expansion coefficient of the substrate, a material having a thermal expansion coefficient smaller than or equal to that of the substrate is deposited on the semiconductor layer to form a thin film, Wherein the coefficient is less than or equal to the thermal expansion coefficient of the substrate. The method according to claim 1,
Wherein the substrate is one of a sapphire (Al ₂ O ₃ ) wafer and a silicon (Si) wafer, and the semiconductor layer is made of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), gold (Au), and silicon (Si), wherein the bending prevention layer is made of one of indium ). ≪ / RTI > The method of claim 2,
The substrate is a sapphire (Al ₂ O ₃ ) wafer, and the semiconductor layer is made of any one of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride One,
Wherein the bending prevention layer is formed of at least one of aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au). The method of claim 2,
Wherein the substrate is a silicon wafer and the semiconductor layer is any one of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride (InGaN)
Wherein the bending prevention layer is formed of silicon (Si). The method according to any one of claims 1 to 4,
The semiconductor layer includes an n-type semiconductor layer formed on a substrate, an active layer having a quantum well structure formed on the n-type semiconductor layer, and a p-type semiconductor layer formed on the active layer, Lt; / RTI > The method according to any one of claims 1 to 4,
The semiconductor layer includes an n-type semiconductor layer formed on a substrate, an active layer of a quantum well structure formed on the n-type semiconductor layer, a p-type semiconductor layer formed on the active layer, and an ohmic contact layer formed on the p- And the bending prevention layer is formed on the ohmic contact layer. A process of preparing a substrate;
Depositing a semiconductor layer on the substrate;
A material having a coefficient of thermal expansion greater or smaller than a coefficient of thermal expansion of the substrate is deposited on the semiconductor layer in accordance with the coefficient of thermal expansion of the semiconductor layer formed on the substrate is larger or smaller than the coefficient of thermal expansion of the substrate, ;
/ RTI >
In the process of forming the bending prevention layer on the semiconductor layer,
Forming a semiconductor layer in the same growth equipment as a growth equipment for depositing a semiconductor layer on the substrate, and growing a bending prevention layer continuously on the semiconductor layer,
A bending prevention layer is formed on the semiconductor layer using a material having a thermal expansion coefficient greater than or equal to a thermal expansion coefficient of the substrate when the thermal expansion coefficient of the semiconductor layer is smaller than a thermal expansion coefficient of the substrate,
Wherein the bending prevention layer is formed on the semiconductor layer by using a material having a thermal expansion coefficient smaller than or equal to the thermal expansion coefficient of the substrate when the thermal expansion coefficient of the semiconductor layer is larger than the thermal expansion coefficient of the substrate. The method of claim 7,
Wherein the substrate is one of a sapphire (Al ₂ O ₃ ) wafer and a silicon (Si) wafer, and the semiconductor layer is made of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), gold (Au), and indium gallium nitride (InGaN) , And silicon (Si). The method of claim 8,
(GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN) or indium gallium nitride (InGaN) on the sapphire (Al ₂ O ₃ ) Wherein the semiconductor layer is formed by using any one of aluminum (Al), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), and gold (Au) Wherein the compound semiconductor is a compound semiconductor. The method of claim 8,
A semiconductor layer is formed on the silicon (Si) wafer substrate by any one of the series of gallium nitride (GaN), aluminum nitride (AlN), aluminum gallium nitride (AlGaN), indium nitride (InN), and indium gallium nitride (InGaN) And forming a bending prevention layer using silicon (Si) on the semiconductor layer. delete The method of claim 8,
Wherein the semiconductor layer and the bending prevention layer are continuously grown in the same MOCVD growth equipment. The method of claim 8,
In forming the semiconductor layer,
Forming an n-type semiconductor layer on the substrate;
Forming an active layer having a quantum well structure on the n-type semiconductor layer; And
Forming a p-type semiconductor layer on the active layer;
/ RTI >
And the bending prevention layer is formed on the p-type semiconductor layer. The method of claim 8,
In forming the semiconductor layer,
Forming an n-type semiconductor layer on the substrate;
Forming an active layer having a quantum well structure on the n-type semiconductor layer;
Forming a p-type semiconductor layer on the active layer; And
Forming an ohmic contact layer on the p-type semiconductor layer;
/ RTI >
And the bending prevention layer is formed on the ohmic contact layer.

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