KR20120106227A - Substrate for semiconductor light emitting device and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A substrate for a semiconductor light emitting device and a manufacturing method thereof are provided to have various scattering faces by including a protrusion with a convex side and a concave side. CONSTITUTION: An etching mask(A) is formed on a substrate(10) using a photolithography process. A cone type protrusion(11a) is formed on the substrate by etching. The substrate is a sapphire substrate and used for the growth of a semiconductor layer(20). A protrusion(11) is formed by wet etching.

Description

SUBSTRATE FOR SEMICONDUCTOR LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING THE SAME

The present disclosure relates generally to a substrate for a semiconductor light emitting device and a method for manufacturing the same, and more particularly, to a substrate for a semiconductor light emitting device having irregularities and a method for manufacturing the same.

Here, the light emitting device refers to an optical device that generates light through recombination of electrons and holes, for example, a group III nitride semiconductor light emitting device. The group III nitride semiconductor consists of a compound of Al (x) Ga (y) In (1-x-y) N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). A GaAs-based semiconductor light-emitting element used for red light emission, and the like.

Herein, the background art relating to the present disclosure is provided, and these are not necessarily meant to be known arts.

1 is a view illustrating an example of a conventional Group III nitride semiconductor light emitting device, wherein the Group III nitride semiconductor light emitting device is grown on the substrate 100, the buffer layer 200 grown on the substrate 100, and the buffer layer 200. n-type group III nitride semiconductor layer 300, an active layer 400 grown on the n-type group III nitride semiconductor layer 300, p-type group III nitride semiconductor layer 500, p-type 3 grown on the active layer 400 The p-side electrode 600 formed on the group nitride semiconductor layer 500, the p-side bonding pad 700 formed on the p-side electrode 600, and the p-type group III nitride semiconductor layer 500 and the active layer 400. The n-side electrode 800 is formed on the n-type III-nitride semiconductor layer 300 exposed by the mesa etching.

2 is a view showing an example of the semiconductor light emitting device shown in US Patent Publication No. 2003/0057444 and US Patent Publication No. 2006/0226431, in addition to the light emitting device of FIG. Alternatively, stripe-shaped protrusions 110 are formed. The projection 110 functions to increase light extraction efficiency by scattering light emitted from the active layer 400 and extracting the light emitted to the outside of the light emitting device. Description of the same reference numerals will be omitted.

3 and 4 are diagrams showing examples of conventional protrusions, and FIG. 3 shows a projection 110 having a hexagonal cross section, and FIG. 4 shows a projection 110 having a hemispherical shape as a whole. As described above, the protrusion 110 may have various shapes, but may affect the quality of the semiconductor layer that is grown, and thus may not be implemented without limit.

This will be described later in the Specification for Implementation of the Invention.

SUMMARY OF THE INVENTION Herein, a general summary of the present disclosure is provided, which should not be construed as limiting the scope of the present disclosure. of its features).

According to one aspect of the present disclosure, there is provided an according to one aspect of the present disclosure, comprising: an upper surface on which a semiconductor layer is grown; And, provided on the upper surface, there is provided a substrate for a semiconductor light emitting device comprising a; projections having a recessed side and a projecting side.

According to another aspect of the present disclosure, there is provided a method of manufacturing a substrate for a semiconductor light emitting device, the method comprising: preparing a substrate having protrusions; And, wet etching the substrate; wet etching so that the projections have a recessed side and the protruding side; there is provided a method for manufacturing a substrate for a semiconductor light emitting device comprising a.

According to still another aspect of the present disclosure, there is provided a substrate for a semiconductor light emitting device having a protrusion having a multi-sided first dry etching and then wet etching, and a method of manufacturing the same.

This will be described later in the Specification for Implementation of the Invention.

1 is a view showing an example of a conventional group III nitride semiconductor light emitting device,
2 is a view showing an example of a group III nitride semiconductor light emitting device shown in US Patent Publication No. 2003/0057444 and US Patent Publication No. 2006/0226431;
3 and 4 are views showing examples of the conventional projections,
5 is a view illustrating an example of a protrusion according to the present disclosure;
6 illustrates an example of a method of forming a protrusion according to the present disclosure.

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

FIG. 5 is a diagram illustrating an example of the protrusion according to the present disclosure. In FIG. 5A, the protrusion 11a is formed on the single crystal substrate 10 by etching (eg, inductively coupled plasma (ICP) etching). Roughly conical protrusions 11a are formed, and in addition to the crystal surfaces (for example, the C surface of the sapphire substrate) formed by the top surface of the single crystal substrate 10 through this etching, various materials of the single crystal substrate 10 (for example, sapphire) are formed. The face is exposed. (b), (c) and (d) show a form in which the protrusions 11a change as the wet etching is performed. Since the surface of the conical projection 11a is not a single crystal surface, the degree of each etching is different with respect to the wet etching. In the initial stage (b) of wet etching, a plurality of faces begin to appear while maintaining the basic cone shape. As the wet etching proceeds, as in (c), the indentation (wet etching) side 12 and the protruding (wet etching) side 13 appear alternately (where the protrusion height is 1.03 um and the width is 2.27). um). As the wet etching proceeds further, as in (d), the bottom side of the protrusion 11 generally comes close to a triangular shape, that is, a hexagonal shape in which each side protrudes, and the sides of the protrusion 11 are conical. It gets sharper out of it. A lot of wet etching proceeds, and the upper surface of the substrate 10 around the protrusion 11 is also etched (where the height of the protrusion is 0.92 um and the width is 2.15 um).

According to the present disclosure, by providing a projection 11 having a concave (wet etch) side 12 and a protruding (wet etch) side 13, it is possible to make various scanning surfaces in comparison with the conical protrusion 11a. The cross section of the side surface of the protrusion 11a may be in the form of a polygon or a circle. The upper surface of the projection 11a does not necessarily need to be pointed. In the case where the projection 11a has a flat top surface of sufficient area, the semiconductor layer can be grown on this top surface. However, when the projection 11a has a middle area, it may adversely affect the crystallinity, so it is preferable to have a pointed shape rather than this. .

FIG. 6 is a diagram illustrating an example of a method of forming a protrusion according to the present disclosure. First, as in (a), an etching mask A is formed on a substrate 10 through a photolithography process to be etched (example : ICP etching). Through this process, as shown in (b), the projection (11a) is formed on the substrate 10. At this time, even if the disk-shaped etching mask (A) is used, since the etching occurs first in the corner portion of the etching mask (A) during the etching process, the shape of the projection 11 according to the conditions of etching is conical, hemispherical, etc. Can be formed. Next, as in (d), wet etching is performed to form the protrusions 11. The substrate 10 having the protrusions 11 according to the present disclosure thus formed may be used for growth of the semiconductor layer 20, as in (e). As illustrated in FIG. 1, the semiconductor layer 20 may include a buffer layer 200, an n-type semiconductor layer 300, an active layer 400, and a p-type semiconductor layer 500.

For example, the etchant was used by adding sodium hydroxide (NaOH) to the antifreeze at a rate of 20-30%, and when the antifreeze is used, a boiling point higher than that of the sodium hydroxide (NaOH) solution can be obtained, and the boiling point of the antifreeze solution is higher than the boiling point of water. Higher temperatures allow etching at higher temperatures. The etching was performed at 180 ° C to 220 ° C. If the ratio of sodium hydroxide (NaOH) is too small, the etching is slow to progress, in too many cases it may be difficult to control the process due to the rapid etching.

Meanwhile, as in (c), the substrate 10 having the protrusions 11a may be used for the growth of the semiconductor layer 20a, and the substrate 10 having the protrusions 11 may be formed of the semiconductor layer 20a. It may be formed by wet etching the grown substrate 10. This means that the substrate 10 having the protrusion 11 according to the present disclosure can be used for regeneration of the semiconductor wafer. In this case, by first removing part or all of the semiconductor layer 20a through dry etching, wet etching may be performed to increase the efficiency of the process. It is also possible to maintain the original shape of the protrusion 11a by changing the etching conditions such as using 20% or less sodium hydroxide (NaOH) as the etching solution.

Various embodiments of the present disclosure will be described below.

(1) A substrate for semiconductor light emitting element, wherein the substrate is a sapphire substrate. The sapphire substrate is particularly suitable for growth of group III nitride semiconductor layers. In addition, the SiC substrate is an example of a substrate for growing a semiconductor layer.

(2) A substrate for semiconductor light emitting element, wherein the upper surface is the C surface of the sapphire substrate. Currently, in the case of a commercial Group III nitride semiconductor light emitting device, almost C surface sapphire substrate is used. In addition, it can be used by cutting a few degrees obliquely from the C side or the A side. It is possible to define the crystal orientation of the projections on the C plane, of which certain orientations are particularly vulnerable to wet etching, forming recessed sides.

(3) A substrate for semiconductor light emitting element, characterized in that the side surfaces of the projections are alternately formed with a plurality of recessed side surfaces and a plurality of projecting side surfaces. This is a result of the periodic characteristics due to the substrate is a single crystal, which is the result of the wet etching.

(4) A substrate for semiconductor light emitting element, characterized in that the width of the side surface of the vessel narrows from the upper surface of the substrate toward the projection.

(5) A substrate for semiconductor light emitting element, characterized in that the upper end of the projection is sharp. In the case of this type of projection, the planarization of the semiconductor layer occurs faster than the projection in which growth occurs on its upper surface. The present disclosure does not exclude projections having a flat top surface.

(6) A method of manufacturing a substrate for semiconductor light emitting element, wherein in the step of preparing a substrate having protrusions, a semiconductor layer is formed on the substrate having protrusions. Through this method, it is possible to manufacture a substrate according to the present disclosure using a recycled wafer.

(7) A method of manufacturing a substrate for semiconductor light emitting element, wherein in the step of preparing the substrate having the projections, the projections are formed by dry etching.

(8) A method of manufacturing a substrate for a semiconductor light emitting element, characterized in that in the wet etching step of the projections, the width of the concave side is narrowed from the upper surface of the substrate toward the projections.

(9) A substrate for a semiconductor light emitting device having projections formed by dry etching and additionally wet etching as a whole, and a method of manufacturing the same. The face of the dry etched protrusion and the face of the wet etched protrusion not only differ in the manufacturing method thereof, but also in the characteristics of the resultant side. The dry etched face is formed by an etching mask and a method of dry etching. This is because the final shape and surface roughness are defined, while the wet-etched surface is defined by the crystal face exposed to the etching.

(10) A substrate for a semiconductor light emitting device having a projection having a multi-sided first dry etching and then wet etching, and a method of manufacturing the same. With this configuration and method, the present disclosure can be extended to wet etched projections prior to the indentation side formation as in FIG. 5B.

(11) A method of manufacturing a substrate for semiconductor light emitting device, in which a portion of the semiconductor layer is removed by dry etching, and then the conditions of wet etching are adjusted to maintain the shape of the circular protrusion.

According to one substrate for semiconductor light emitting elements according to the present disclosure, it is possible to provide a substrate having protrusions having various scattering surfaces.

In addition, according to the method for manufacturing a substrate for a semiconductor light emitting device according to the present disclosure, it is possible to manufacture a substrate having projections having various scattering surfaces.

In addition, according to another method for manufacturing a substrate for semiconductor light emitting elements according to the present disclosure, it is possible to manufacture a substrate for semiconductor light emitting elements from a recycled wafer.

Substrate: 10 Protrusion: 11a

Claims (20)

In the substrate for semiconductor light emitting device,
An upper surface on which the semiconductor layer is grown; And,
A substrate for a semiconductor light emitting device, comprising: a projection formed on the upper surface, the projection having a concave side and a protruding side. The method according to claim 1,
The substrate is a semiconductor light emitting device substrate, characterized in that the sapphire substrate. The method according to claim 1,
The upper surface is a substrate for a semiconductor light emitting device, characterized in that the C surface of the sapphire substrate. The method according to claim 1,
The side surface of the projection is a substrate for a semiconductor light emitting device, characterized in that the plurality of recessed side and the plurality of protruding side alternate. The method according to claim 1,
A substrate for semiconductor light emitting element, characterized in that the width of the side surface of the vessel narrows from the upper surface of the substrate toward the projection. The method according to claim 1,
A substrate for a semiconductor light emitting device, characterized in that the upper end of the projection is pointed. The method according to claim 5,
The side surface of the projection is a substrate for a semiconductor light emitting device, characterized in that the plurality of recessed side and the plurality of protruding side alternate. The method of claim 7,
The substrate is a semiconductor light emitting device substrate, characterized in that the sapphire substrate. The method according to claim 8,
The upper surface is a substrate for a semiconductor light emitting device, characterized in that the C surface of the sapphire substrate. The method according to claim 9,
A substrate for a semiconductor light emitting device, characterized in that the upper end of the projection is pointed. In the manufacturing method of the substrate for semiconductor light emitting elements,
Preparing a substrate having protrusions; And,
Wet etching the substrate; Wet etching so that the projection has a recessed side and a protruding side; manufacturing method for a substrate for a semiconductor light emitting device comprising a. The method of claim 11,
In the preparing step, a semiconductor layer is formed on a substrate having protrusions. The method of claim 11,
In the preparation step, the projection is formed by a dry etching method of manufacturing a substrate for a semiconductor light emitting device. The method of claim 11,
In the wet etching step, the impregnated side surface is formed such that the width of the impregnated side is narrowed from the upper surface of the substrate to the projection upwards. The method of claim 12,
In the wet etching step, the impregnated side surface is formed such that the width of the impregnated side is narrowed from the upper surface of the substrate to the projection upwards. The method according to claim 14,
In the preparation step, the projection is formed by a dry etching method of manufacturing a substrate for a semiconductor light emitting device. 18. The method of claim 16,
The substrate is a method for manufacturing a substrate for semiconductor light emitting elements, characterized in that the sapphire substrate. 18. The method of claim 17,
A projection is formed on a C surface sapphire substrate. The method according to claim 15,
The substrate is a method for manufacturing a substrate for semiconductor light emitting elements, characterized in that the sapphire substrate. The method of claim 19,
In the preparation step, the projection is formed by a dry etching method of manufacturing a substrate for a semiconductor light emitting device.

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