WO2014168437A1

WO2014168437A1 - Group iii nitride semiconductor stacked body

Info

Publication number: WO2014168437A1
Application number: PCT/KR2014/003123
Authority: WO
Inventors: 황성민; 조인성; 임원택; 김두수
Original assignee: 주식회사 소프트에피
Priority date: 2013-04-10
Filing date: 2014-04-10
Publication date: 2014-10-16
Also published as: KR101548610B1; KR20140122554A

Abstract

The present invention relates to a group III nitride semiconductor stacked body characterized by comprising: a substrate provided with a first surface and a second surface facing the first surface, wherein a group III nitride semiconductor layer is grown on the side of the first surface; any one from among a convex or a concave portion having a side surface on which the group III nitride semiconductor layer is grown, the convex or concave part being formed on the first surface; and the group III nitride semiconductor layer grown on a side surface.

Description

Group III nitride semiconductor laminate

This disclosure relates generally to Group III nitride semiconductor laminates, and more particularly to Group III nitride semiconductor laminates grown using protrusions and / or recesses.

Here, the group III nitride semiconductor means a compound semiconductor layer made of Al (x) Ga (y) In (1-xy) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). The light emitting device may be used for manufacturing a light emitting device such as a light emitting diode and a light receiving device such as a photodiode. In addition to the optical device, the light emitting device may be applied to various fields such as the manufacture of electrical devices such as diodes and transistors.

This section provides background information related to the present disclosure which is not necessarily prior art.

1 is a view illustrating an example of a method of growing a group III nitride semiconductor layer disclosed in US Patent Publication No. 2003-0057444, in which a group III nitride semiconductor layer 310 is formed on a substrate 100 on which protrusions 110 are formed. It explains the process of growth. The group III nitride semiconductor layer 310 is first grown on the bottom surface of the substrate 100 and the top surface of the protrusion 110, and then the group III nitride semiconductor layers 310 on both sides meet to fill the side, and finally planarize. It can be seen that the growth of the group III nitride semiconductor layer 310 does not occur on the side surface of the protrusion 110. The protrusion 110 may improve the crystalline quality (Growth Quality) of the group III nitride semiconductor layer 310 grown on the substrate 100 and may function as a light scattering surface.

FIG. 2 is a diagram illustrating an example of a method of growing a group III nitride semiconductor layer disclosed in US Patent Publication No. 2005-0082546, wherein the group III nitride semiconductor layer (not shown) is formed on a substrate 100 having a rounded protrusion 110. 310 shows the process of growth. The group III nitride semiconductor layer 310 is not grown on the protrusions 110, but is grown on the bottom surface of the substrate 100 to be filled and finally planarized.

From these examples, it can be seen that the crystal surface of the growth substrate 100 used for the growth of the group III nitride semiconductor layer 310 is affected, and in the case of the prior art, the group III nitride semiconductor layer on the side of the protrusion 110 is known. There is not much interest in the growth of 310.

This is described later in the section titled 'Details of the Invention.'

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all, provided that this is a summary of the disclosure. of its features).

According to one aspect of the present disclosure, there is provided an according to one aspect of the present disclosure, which includes a first side and a second side opposite to the first side, wherein the growth of the group III nitride semiconductor layer on the first side A substrate; At least one of the protrusions and the recesses formed on the first surface, wherein at least one of the protrusions and the recesses has a side surface at which the group III nitride semiconductor layer is grown; In addition, a group III nitride semiconductor laminate is provided.

This is described later in the section titled 'Details of the Invention.'

1 is a view showing an example of a method of growing a group III nitride semiconductor layer disclosed in US Patent Publication No. 2003-0057444;

2 is a view showing an example of a method of growing a group III nitride semiconductor layer shown in US Patent Publication No. 2005-0082546,

3 is a view illustrating an example of a substrate on which protrusions are formed according to the present disclosure;

4 is a photograph showing an example of a group III nitride semiconductor layer formed on a substrate on which protrusions as in FIG. 3 are formed;

FIG. 5 is a diagram for specifically describing growth of a group III nitride semiconductor layer illustrated in FIG. 4;

6 and 7 are photographs showing an example in which the seed layer grown in the hydrogen (H ₂ ) atmosphere and the seed layer grown in the nitrogen (N ₂ ) atmosphere are compared;

8 is a view showing an example of a group III nitride semiconductor laminate manufactured according to the present disclosure;

9 shows examples of a combination of a surface substrate and protrusions and / or recesses according to the present disclosure;

10 is a view showing examples of a combination of a c-plane substrate and a protrusion and / or a recess according to the present disclosure;

11 illustrates examples of a combination of an n-plane substrate and a protrusion and / or a recess according to the present disclosure;

12 shows examples of a combination of an m-plane substrate and a projection and / or a recess according to the present disclosure;

13 shows examples of a combination of an r-plane substrate and a projection and / or a recess according to the present disclosure;

14 shows examples of combinations of protrusions and / or recesses in accordance with the present disclosure.

The present disclosure will now be described in detail with reference to the accompanying drawing (s).

3 is a view illustrating an example of a substrate on which protrusions are formed according to the present disclosure. An upper surface 13 includes a c surface substrate 10 (for example, a c surface sapphire substrate) and an opposite surface of r surface and r surface as a side surface. As an example, the projection 11 having the c surface is formed. The direction penetrating the ground is a surface, and the projection 11 extends in a stripe shape toward the a surface, and the surface of the substrate 10 exposed by etching is the bottom surface 12. That is, according to the present disclosure, the side surface 15 of the protrusion 11 is made of a surface on which a group III nitride semiconductor can be grown. The protrusion 11 may be formed through an etching process of forming a conventional patterned sapphire substrate (PSS) as shown in FIGS. 1 and 2. If necessary, the side surface of the protrusion 11 may be formed as a vertical surface or an inclined surface.

FIG. 4 is a photograph showing an example of a group III nitride semiconductor layer formed on a substrate having protrusions as shown in FIG. 3, wherein the group III nitride semiconductor layer 31 is uneven or sawtooth on the substrate 10 on which the protrusions 11 are formed. You can see that it is formed into a shape. For example, the group III nitride semiconductor layer 31 can be formed under the following conditions. The substrate 10 on which the protrusions 11 were formed was placed in a MOCVD reactor, the atmosphere gas was N ₂ , and then injected into the reactor with a NH ₃ flow rate of 8000 sccm (Standard Cubic Cm per Min.) From 450 ° C. to 1050 ° C. It heated up. This was for the nitriding treatment of the substrate 10. GaN nuclei were grown at a rate of 0.5 nm / sec using TMGa at 1050 ° C. At this time, the pressure of the reactor was 100 mbar. After growing the seed layer, the atmosphere gas is changed to hydrogen. NH ₃ is 4000 sccm, pressure is 100 mbar, temperature is 1050 ℃, and growth rate is about 500nm ~ 1300nm at the speed of 0.6nm / sec. Thereafter, after the temperature was lowered to 920 ° C., the pressure was 250 mbar and NH ₃ was 12,000 sccm, thereby growing the group III nitride semiconductor layer 31.

FIG. 5 is a diagram illustrating the growth of the group III nitride semiconductor layer illustrated in FIG. 4 in detail, in which growth of the group III nitride semiconductor layers (a, b) does not occur on the c plane of the substrate 10, as is generally expected. It can be seen that it occurred on the side of the projection (11) without. This will be described below.

In general, when a group III nitride semiconductor layer is grown on a growth substrate, a buffer layer is first formed as a seed layer, and then a group III nitride semiconductor layer is formed. The seed layer may be formed by growing GaN at a temperature of about 550 ° C. under a hydrogen (H ₂ ) atmosphere. The seed layer thus formed is well grown on the c-plane substrate and is generally used to form a group III nitride semiconductor layer as shown in FIGS. 1 and 2.

However, when forming the seed layer, using a nitrogen (N ₂ ) atmosphere rather than a hydrogen (H ₂ ) atmosphere, the growth pattern is completely different. As shown in FIGS. 4 and 5, the growth of the group III nitride semiconductor layers 31, a, and b does not occur well at the c surface, and the growth is at the opposite surface of the r surface and the r surface of the protrusion 11. Is actively happening in.

In terms of preferred conditions for the growth of the group III nitride semiconductor layer 31 illustrated in FIG. 4, in the case of a seed layer (eg, GaN) using a nitrogen (N ₂ ) atmosphere, a conventional 500 ° C. vicinity (eg, 550) Unlike the GaN buffer layer formed at < RTI ID = 0.0 > C), < / RTI > It is possible to form a better seed layer 20 at a temperature above 750 ° C., but to grow at a temperature above 800 ° C. for rapid transfer to growth conditions for the Group III nitride semiconductor layer 31 grown at a higher temperature. In this regard, it is desirable to grow at a temperature of 800 ℃ or more.

6 and 7 are photographs showing an example of comparing a seed layer grown in a hydrogen (H ₂ ) atmosphere with a seed layer grown in a nitrogen (N ₂ ) atmosphere. On the m surface sapphire substrate, a growth prevention film 15 was formed of stripe-shaped SiO ₂ , and a seed layer was formed under a hydrogen (H ₂ ) atmosphere. When grown in a hydrogen (H ₂ ) atmosphere at high temperature, as shown in (b), the growth is not good, and some very large nuclei 20 are formed, and when grown at low temperature, ( As shown in a), the polycrystals cover even the growth prevention film. When grown in a nitrogen (N ₂ ) atmosphere, as shown in FIG. 7, it can be seen that the seed layer 20 is formed only on the m-plane substrate 10 exposed between the growth preventing films 15. At this time, the following conditions may be used. After m-sapphire substrates were organically cleaned, SiO ₂ was deposited by PECVD, and then grown using MOCVD. The atmosphere gas in the MOCVD reactor was changed to N ₂ , and then injected into the reactor with a NH ₃ flow rate of 8000 sccm (Standard Cubic Cm per Min.) From 450 ° C., and the temperature was increased to 1050 ° C. This was for the nitriding treatment of the sapphire surface. GaN nuclei were grown at a rate of 0.5 nm / sec using TMGa at 1050 ° C. At this time, the pressure of the reactor was 100 mbar.

From the results of FIGS. 4, 6 and 7, (1) the Group III nitride semiconductor layer may or may not grow well depending on the surface orientation exposed on the growth substrate and (2) the Group III nitride semiconductor layer. It can be seen that the Group III nitride semiconductor layer may or may not grow well depending on the growth conditions of the seed layer applied to the growth substrate prior to the growth. For example, in the case of the c-plane substrate, when the seed layer is formed in the hydrogen (H ₂ ) atmosphere, the group III nitride semiconductor layer grows well thereon, but the seed layer is formed in the nitrogen (N ₂ ) atmosphere. In this case, the group III nitride semiconductor layer is hardly grown thereon. It is already known that in the case where the seed layer is formed in hydrogen (H ₂ ) atmosphere, the group III nitride semiconductor layer is well grown thereon, and the present inventors know that when the seed layer is formed in nitrogen (N ₂ ) atmosphere, It was further found that the Group III nitride semiconductor layer grows well on the r plane, the symmetry plane of r, and the plane of m, and the Group III nitride semiconductor layer does not grow well on the c plane, the a plane, and the n plane. Face orientation was based on sapphire of HCP (Hexagonal Closed Packed) structure. The present disclosure relates to group III nitride semiconductor laminates that utilize the growth of group III nitride semiconductor layers in terms of projections, based on these existing knowledge and new insights. On the other hand, although it is common to form protrusions on a substrate, the same principle can be applied to forming recesses on the substrate. Since the projections and the recesses are relative concepts, the bottom surface 12 and the top surface 13 in FIG. 3 may be applied to the recesses as they are.

FIG. 8 is a view showing an example of a group III nitride semiconductor laminate manufactured according to the present disclosure, wherein the group III nitride semiconductor laminate is an n-type group III nitride on the group III nitride semiconductor layer 31 shown in FIG. 4. Semiconductor layer 30 (eg Si-doped GaN), switching layer 40 (InGaN / GaN multi-quantum well structure), p-type group III nitride semiconductor layer 50 (eg Mg-doped GaN), etched and exposed n The n-side electrode 80 formed on the type-III group nitride semiconductor layer 30 and the p-side electrode 90 on the p-type Group III nitride semiconductor layer 30 are included. When the group III nitride semiconductor laminate is a light emitting device, the switching layer 40 generates light through the combination of electrons and holes. When the group III nitride semiconductor laminate is a light receiving device, the switching layer 40 is light. Is converted to current. If necessary, a current diffusion electrode (eg, ITO, Ag, Al) may be further provided between the p-type group III nitride semiconductor layer 50 and the p-side electrode 90. Positions of the n-type III-nitride semiconductor layer 30 and the p-type III-nitride semiconductor layer 50 may be changed. Forming the n-type III-nitride semiconductor layer 30 and the switching layer 40 The p-type III-nitride semiconductor layer 50 forms dopants such as Mg and Si in the process of growing the III-nitride semiconductor layer 30. Or by injecting other Group 5 elements such as In and Al. Each of the n-type III-nitride semiconductor layer 30 and the p-type III-nitride semiconductor layer 50 may be formed in multiple layers. The application of the group III nitride semiconductor laminate is not limited to light emitting devices and light receiving devices, and may be applied to various fields, such as the manufacture of electrical devices such as diodes and transistors, in addition to optical devices. In addition, the group III nitride semiconductor laminate prepared according to the present disclosure can be used as a growth substrate for growth of other group III nitride semiconductors or other semiconductors.

First, by forming the projection 11 as shown in FIG. 3 on the substrate 10, the projection 11 can be used as a light scattering surface. In addition, as shown in FIG. 8, if the group III nitride semiconductor layer 31 is not planarized, and then the group III nitride semiconductor layers 30, 40, and 50 are formed, the group III nitride semiconductor layers as compared to the planarized ones are formed. Since the area of (30, 40, 50) can be enlarged, in the case of a light emitting device, the switching layer 40 can be enlarged, and in the case of a light receiving device, a p-type group III nitride semiconductor layer that absorbs light ( 50) can have various advantages such as to enlarge the area. In addition, in Fig. 6, SiO ₂ was used as the growth prevention film 15, but instead, it is also possible to form projections with faces that do not grow well and use them as growth prevention films.

9 is a diagram showing examples of a combination of a surface substrate and protrusions and / or recesses according to the present disclosure. A recess is formed instead of the protrusion, and the same principle as the side of the protrusion may be applied to the side of the recess. In the case of the left side and the right side, the wedge-shaped recessed part is formed by the inclined surface, and the recessed part which has a vertical surface side surface is formed in the center case. The growth of the group III nitride semiconductor layer may be on an inclined surface or a vertical surface.

10 is a diagram showing examples of a combination of a c-plane substrate and a projection and / or a recess according to the present disclosure. A recess is formed instead of the protrusion, and the same principle as the side of the protrusion may be applied to the side of the recess.

11 is a diagram illustrating examples of a combination of an n-plane substrate and a protrusion and / or a recess according to the present disclosure. A recess is formed instead of the protrusion, and the same principle as the side of the protrusion may be applied to the side of the recess.

12 is a diagram showing examples of a combination of an m-plane substrate and protrusions and / or recesses according to the present disclosure. Unlike the substrates shown in FIGS. 9 to 11, an m surface substrate capable of growing a group III nitride semiconductor layer is used. However, in forming projections or recesses in the m surface substrate, one side is formed on the r surface or the m surface. And the side surface 14 which follows this is formed in the surface by which the growth of a group III nitride semiconductor layer is suppressed, and the same effect as the board | substrate shown in FIGS. 9-11 can be acquired. From the disclosure shown in FIGS. 9 to 12, the lamination of the group III nitride semiconductor layer according to the present disclosure includes a side from which the group III nitride semiconductor layer can be grown, and a surface on which the lamination of the group III nitride semiconductor layer is suppressed (top, bottom). , Side)). The surface on which the growth of the group III nitride semiconductor layer is suppressed is not necessarily the c surface, the a surface, or the n surface. For example, the c plane, the a plane, the plane of which the angle is off from the n plane, the m plane, the plane that is much off from the r plane, and the like may be included.

FIG. 13 is a view showing examples of a combination of an r-plane substrate and protrusions and / or recesses according to the present disclosure. Projections or recesses are formed using the m surface as the side surface 15 on which the group III nitride semiconductor layer can be grown, and the c surface 14 as the side surface 14 on which the growth of the Group 3 nitride semiconductor layer is suppressed. The

sides

14 and 15 may have the same length or different lengths. The length of the sides 15 may also vary as needed.

14 is a diagram showing examples of combinations of protrusions and / or recesses according to the present disclosure. In the case of the left side, the side surface 15 (vertical surface) which can grow a group III nitride semiconductor layer in the m surface is formed in the a surface substrate, and the unevenness | corrugation 16 is formed in the upper surface of the a surface substrate, and the group 3 nitride semiconductor is formed. Growth of the layer was inhibited. Growth may be suppressed on both sides of the unevenness 16, and growth may be suppressed only on one side. In the case of the right side, the side surface 14 (an inclined surface) in which the growth of the group III nitride semiconductor layer is suppressed to the c surface is formed on the n surface, and the irregularities are formed on the upper surface of the n surface substrate, but the side surface 15 of the irregularities is formed. Was formed into a surface capable of growth. It can be seen from the examples presented in FIGS. 9-14 that (1) the present disclosure can be applied to substrates having various orientations prior to the formation of protrusions and / or recesses, and (2) the formation of a group III nitride semiconductor layer on any substrate. It can be seen that it is possible to form projections and / or recesses on the surface where growth is possible, and (3) the projections and / or recesses are formed in various lengths, widths, inclinations, spacings, and sizes using vertical or inclined surfaces. (4) The present disclosure can be made with a combination of a side (top, bottom, side) where growth of the group 3 nitride semiconductor layer is possible and growth of the group 3 nitride semiconductor layer is suppressed. It can be seen that.

Hereinafter, various embodiments of the present disclosure will be described.

(1) a substrate having a first surface and a second surface opposite to the first surface, on which the group III nitride semiconductor layer is grown; At least one of the protrusions and the recesses formed on the first surface, wherein at least one of the protrusions and the recesses has a side surface at which the group III nitride semiconductor layer is grown; And a group III nitride semiconductor layer grown on the side surface. The present disclosure includes both protrusions, recesses, or both provided on the substrate. The projections or recesses may be of any shape as long as the principles of the present disclosure can be applied, such as trapezoidal longitudinal sections, inverted trapezoidal profiles, triangular longitudinal sections, rectangular longitudinal sections, and rounded cones of the top.

(2) A group III nitride semiconductor laminate, wherein the side surface is a vertical surface or an inclined surface.

(3) A group III nitride semiconductor laminate, wherein the first surface before at least one of the protrusions and the recesses is formed is a surface on which growth of the group III nitride semiconductor layer is suppressed.

(4) A group III nitride semiconductor laminate, wherein a bottom surface on which the growth of the group III nitride semiconductor layer, which extends from the side surface, is suppressed is provided.

(5) The group III nitride semiconductor laminate according to claim 1, wherein an upper surface of which the growth of the group III nitride semiconductor layer, which extends from the side surface, is suppressed is provided.

(6) At least one of the projections and the concave portion has a side surface connected with the growth of the group 3 nitride semiconductor layer and a side surface from which the growth of the group 3 nitride semiconductor layer is suppressed.

(7) A group III nitride semiconductor layer comprising a seed layer grown in a nitrogen (N ₂ ) atmosphere.

(8) A group III nitride semiconductor laminate, wherein the first surface before at least one of the protrusions and the recesses is formed is at least one of c surface, a surface, and n surface.

(9) A group III nitride semiconductor laminate, wherein the side surface includes at least one of an r surface, an opposing surface of r, and an m surface.

(10) A group III nitride semiconductor laminate, wherein the substrate is a sapphire substrate. In addition to sapphire, any substrate can be used as long as it can grow group III nitride semiconductors (eg, GaN, InGaN, AlGaN, InN, AlN, InGaAlN).

(11) A group III nitride semiconductor laminate, characterized in that at least one of the projections and the concave portion has a stripe shape having an r surface and an opposing surface of r as a side surface. Although the stripe-like protrusions and recesses were tested, there is a possibility of application to the independent island-like protrusions and recesses.

(12) A group III nitride semiconductor laminate, wherein at least one of the protrusions and the recesses includes protrusions, and the shape of the group III nitride semiconductor layer formed on the protrusions is sawtooth-shaped.

(13) In the present disclosure, an m-plane substrate is preferably an accurate m-plane substrate, but those skilled in the art should bear in mind that a substrate cut at an angle slightly off from the m-plane may be used.

(14) A group III nitride semiconductor laminate, wherein one of the m plane, the r plane, and the (11-22) plane is used as a growth plane of the Group III nitride semiconductor layer. Although not directly tested, the growth mode of FIG. 5 is expected to allow growth even in the (11-22) plane.

(15) A substrate having a first surface and a second surface opposite to the first surface, wherein the group III nitride semiconductor layer is grown on the first surface side, wherein the group III nitride semiconductor layer is grown on the first surface. A substrate having a surface (top surface, bottom surface, side surface) formed thereon and a surface (top surface, bottom surface, side surface) on which growth of the group III nitride semiconductor layer is suppressed; A seed layer formed on the first surface side and grown in a nitrogen (N ₂ ) atmosphere; And a group III nitride semiconductor layer grown on the surface of the group III nitride semiconductor layer grown through the seed layer.

According to one group III nitride semiconductor laminate according to the present disclosure, the side surface of the substrate can be used for growth of the group III nitride semiconductor layer.

According to another group III nitride semiconductor laminate according to the present disclosure, it is possible to grow a group III nitride semiconductor layer by using a seed layer grown in a nitrogen (N ₂ ) atmosphere.

Claims

A substrate having a first surface and a second surface opposite to the first surface, wherein the group III nitride semiconductor layer is grown on the first surface side;

At least one of the protrusions and the recesses formed on the first surface, wherein at least one of the protrusions and the recesses has a side surface at which the group III nitride semiconductor layer is grown; And,

A group III nitride semiconductor laminate comprising a; group III nitride semiconductor layer grown in the side.
The method according to claim 1,

The side face is a group III nitride semiconductor laminate, characterized in that the vertical surface or inclined surface.
The method according to claim 1,

A group III nitride semiconductor laminate, wherein the first surface before at least one of the protrusions and the recesses is formed is a surface on which growth of the group III nitride semiconductor layer is suppressed.
The method according to claim 1,

The group III nitride semiconductor laminate according to claim 1, wherein a bottom surface on which the growth of the group III nitride semiconductor layer, which extends from the side surface, is suppressed is provided.
The method according to claim 1,

An upper surface on which the growth of the group III nitride semiconductor layer, which extends from the side surface, is suppressed is provided on the first surface.
The method according to claim 4,

An upper surface on which the growth of the group III nitride semiconductor layer, which extends from the side surface, is suppressed is provided on the first surface.
The method according to claim 1,

At least one of the protrusions and the concave portion has a side surface in which the growth of the group III nitride semiconductor layer is formed, and a side surface in which the growth of the group III nitride semiconductor layer is suppressed.
The method according to claim 1,

A group III nitride semiconductor layer comprising a seed layer grown in a nitrogen (N 2 ) atmosphere.
The method according to claim 1,

A group III nitride semiconductor laminate, wherein the first surface before at least one of the protrusions and the recesses is formed is at least one of a c surface, a surface, and an n surface.
The method according to claim 1,

The side surface includes at least one of r surface, opposing surface of r, and m surface.
The method according to claim 1,

The substrate is a group III nitride semiconductor laminate, wherein the substrate is a sapphire substrate.
The method according to claim 1,

The sides are vertical or inclined,

The group III nitride semiconductor layer includes a seed layer grown in a nitrogen (N 2 ) atmosphere,

The substrate is a group III nitride semiconductor laminate, wherein the substrate is a sapphire substrate.
The method according to claim 14,

The side surface includes at least one of r surface, opposing surface of r, and m surface.
The method according to claim 1,

At least one of the projections and the concave portion has a stripe shape having an r surface and an opposing surface of r as a side surface.
The method according to claim 1,

At least one of the protrusion and the recess includes a protrusion,

A group III nitride semiconductor laminate, wherein the group III nitride semiconductor layer formed on the projection has a sawtooth shape.