CN103594593B - There is the manufacture method of the inverted light-emitting diode (LED) of alligatoring transparency electrode - Google Patents

Abstract

The invention discloses a method for manufacturing a flip-chip light-emitting diode with a roughened transparent electrode, comprising: providing a growth substrate on which an n-type semiconductor layer (6), an active layer (5), and a p-type semiconductor layer are sequentially formed layer (4) and p-type reflective electrode (2); forming a stepped structure; forming a transparent insulating layer (3); forming a transparent electrode layer (7); forming a through groove (8), and the through groove (8) has an inner side wall ( 8b) and the outer sidewall (8a); filling the through groove (8) with a transparent conductive material for the transparent electrode layer (7); cutting the flip-chip light-emitting diode, so that the four sides of the entire flip-chip light-emitting diode and A transparent electrode layer (7) is formed on the top surface; the surface of the transparent electrode layer (7) is roughened, thereby forming a roughened structure (9) on the entire surface of the transparent electrode layer (7). The light-emitting diode with transparent electrodes prepared by the method proposed by the invention can improve the integration degree, simplify the process, and eliminate the need for a lead structure, thereby reducing the manufacturing cost, and can improve the light extraction efficiency, thereby improving the overall luminous efficiency.

Description

Manufacturing method of flip-chip light-emitting diode with roughened transparent electrode

technical field

The invention belongs to the technical field of semiconductors, in particular to a method for manufacturing a flip-chip light-emitting diode with a roughened transparent electrode.

Background technique

The advantages of semiconductor light-emitting diodes are high luminous intensity, strong light directivity, low energy consumption, low manufacturing cost, etc., so their applications are becoming more and more extensive, especially in the trend of replacing incandescent and fluorescent lamps in lighting. The advantages of flip-chip light emitting diodes are excellent heat dissipation characteristics and high luminous efficiency. And in recent years, in order to improve the brightness of light-emitting diodes, light-emitting diodes with a vertical structure have been developed. Compared with light-emitting diodes with a front-mounted structure, that is, a mesa structure, the light-emitting diodes with a vertical structure have many advantages. The two electrodes of the vertical light-emitting diode are located on both sides of the light-emitting diode. Almost all the current flows vertically through the semiconductor epitaxial layer, and there is no current flowing laterally. Therefore, the current distribution is uniform and the heat generated is relatively small. And because the two electrodes of the vertical structure are on both sides, the light extraction process will not be blocked by the electrodes on the same side, and the light extraction efficiency is higher.

However, the above-mentioned light-emitting diode with a vertical structure has problems that the two electrodes are respectively located on both sides of the light-emitting diode, resulting in low integration, complex process, and the need for a lead structure, and low light extraction efficiency.

Contents of the invention

In view of this, the present invention aims at the problems of the prior art, and proposes a method for manufacturing a flip-chip light-emitting diode with a roughened transparent electrode. By improving the structure and arrangement of the n-type electrode and the p-type electrode of the light-emitting diode, the degree of integration can be increased, the process can be simplified, and no lead structure is required, thereby reducing the manufacturing cost. Moreover, the flip-chip light-emitting diode with transparent electrodes of the present invention can improve the light extraction efficiency, thereby improving the overall luminous efficiency.

The manufacturing method of the flip-chip light-emitting diode with roughened transparent electrodes proposed by the present invention includes:

(1) Provide a growth substrate, on which an n-type semiconductor layer (6), an active layer (5), a p-type semiconductor layer (4) and a p-type reflective electrode (2) are sequentially formed;

(2) Etching part of the p-type semiconductor layer (4) and the p-type reflective electrode (2) to expose part of the active layer (5), thereby forming a stepped structure;

(3) Filling the transparent insulating material into the stepped structure to form a transparent insulating layer (3);

(4) Inverting the obtained structure, placing it on the carrier substrate (1), and peeling off the growth substrate, thereby exposing the n-type semiconductor layer (6);

(5) forming a transparent electrode layer (7) on the exposed n-type semiconductor layer (6);

(6) Forming a through groove (8), which penetrates the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer (3), and the through groove (8) has an inner wall (8b) and outer side wall (8a);

(7) Fill the through groove (8) with a transparent conductive material for the transparent electrode layer (7), such as one or more of ITO, ZnO, AZO, ATO, FTO, _SnO2 , etc. or a combination of the above materials film;

(8) Using the outer wall (8a) as a cutting boundary, cut the flip-chip light-emitting diode, thereby removing part of the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer ( 3), so that a transparent electrode layer (7) is formed on the four sides and the top surface of the entire flip-chip light-emitting diode;

(9) Spin-coat the titanium-containing nanoparticle dispersion on the entire surface of the transparent electrode layer (7) to form a single-layer titanium nanoparticle film; dry the single-layer titanium nanoparticle film to form the ICP etching required A mask layer of a single layer of titanium nanoparticles; using the mask layer of a single layer of titanium nanoparticles to perform ICP etching on the transparent electrode layer (7), thereby forming a roughened structure (9) on the entire surface of the transparent electrode layer (7) ); remove the mask layer of monolayer titanium nanoparticles

Description of drawings

1 is a cross-sectional view of a flip-chip light-emitting diode with a roughened transparent electrode of the present invention;

Fig. 2 is the sectional view in the manufacture of the flip-chip light-emitting diode with roughened transparent electrode of the present invention;

FIG. 3 is a top view of the flip-chip LED with roughened transparent electrodes in the fabrication of FIG. 2 .

detailed description

The flip-chip light-emitting diode with roughened transparent electrodes and its manufacturing method of the present invention will be described in detail below with reference to FIGS. 1-3 . For clarity, the various structures shown in the figures are not drawn to scale, and the present invention is not limited to the structures shown in the figures.

Referring first to Figure 1, the flip-chip light-emitting diode with roughened transparent electrodes includes a carrier substrate (1); a p-type reflective electrode (2) on the carrier substrate (1); a p-type semiconductor layer on the p-type reflective electrode (2) (4); the active layer (5) on the p-type semiconductor layer (4); the n-type semiconductor layer (6) on the active layer (5); and the transparent electrode layer ( 7), wherein the transparent electrode layer (7) covers the top and side surfaces of the entire flip-chip light emitting diode, and the entire surface of the transparent electrode layer (7) has a roughened structure (9).

The carrier substrate (1) can be a metal material with high reflectivity, such as Al, Au, Ag, Pt, Ni, Cu, Ti or a combination of the above metal materials.

The p-type reflective electrode ( 2 ) is a multilayer electrode made of a metal material with high reflectivity, such as Al, Au, Ag, Pt, Ni, Cu, Ti or a combination of the above metal materials.

Materials of the p-type semiconductor layer ( 4 ), active layer ( 5 ) and n-type semiconductor layer ( 6 ) are, for example, III-V group semiconductor materials, such as GaN, AlN, InGaN, AlGaN and so on.

The transparent electrode layer (7) is a transparent conductive oxide (TCO), specifically one or more of indium tin oxide (ITO), ZnO, AZO, ATO, FTO, _SnO2 , etc. or a composite film of the above materials.

Moreover, as shown in Figures 1 and 3, the area of the p-type reflective electrode (2) and the p-type semiconductor layer (4) in plan view is smaller than the area of the active layer (5) and the n-type semiconductor layer (6), that is, through Etching and etching away part of the p-type reflective electrode (2) and the p-type semiconductor layer (4), thereby exposing part of the active layer (5), thereby forming a stepped structure, and filling the transparent insulating layer (3) in the stepped structure, For example Al ₂ O ₃ . And the transparent electrode layer (7) covers the top and side surfaces of the entire flip-chip light-emitting diode, see Figure 3 for details, the transparent electrode layer (7) covers the top surface of the flip-chip light-emitting diode, that is, covers the entire n-type semiconductor layer (6) , and cover the entire side of the flip-chip light-emitting diode, that is, cover the four sides of the flip-chip light-emitting diode. Moreover, the transparent electrode layer (7) is used as the n-electrode of the flip-chip light-emitting diode, and in order to insulate the transparent electrode layer (7) used as the n-electrode of the flip-chip light-emitting diode from the p-type reflective electrode (2), to To prevent short circuit, the above-mentioned transparent insulating layer (3) is provided between the transparent electrode layer (7) covering the four sides of the flip-chip light-emitting diode and the p-type reflective electrode (2).

Moreover, the entire surface of the transparent electrode layer (7) has a roughened structure (9), and the roughened structure (9) is formed as follows: spin-coating a titanium nanoparticle-containing dispersion on the entire surface of the transparent electrode layer (7), thereby forming A single-layer titanium nanoparticle film; drying the single-layer titanium nanoparticle film to form a mask layer of a single-layer titanium nanoparticle required for ICP etching; using a single-layer titanium nanoparticle mask layer to mask the transparent electrode layer ( 7) performing ICP etching to form a roughened structure (9) on the entire surface of the transparent electrode layer (7); removing the mask layer of the single layer of titanium nanoparticles. And the roughness Ra of the roughened structure (9) is 1nm-10nm, preferably 2.5nm, 3.5nm, 4.5nm, 6.5nm, 8.5nm, 9.5nm.

The method of manufacturing the flip-chip light-emitting diode with roughened transparent electrodes of the present invention will be described below. Refer to Figure 1-2 for details.

(1) Provide a growth substrate, on which an n-type semiconductor layer (6), an active layer (5), a p-type semiconductor layer (4) and a p-type reflective electrode (2) are sequentially formed;

(2) Etching part of the p-type semiconductor layer (4) and the p-type reflective electrode (2) to expose part of the active layer (5), thereby forming a stepped structure;

(3) Filling the transparent insulating material into the stepped structure to form a transparent insulating layer (3);

(4) Inverting the obtained structure, placing it on the carrier substrate (1), and peeling off the growth substrate, thereby exposing the n-type semiconductor layer (6);

(5) forming a transparent electrode layer (7) on the exposed n-type semiconductor layer (6);

(6) Forming a through groove (8), which penetrates the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer (3), and the through groove (8) has an inner wall (8b) and outer side wall (8a);

(7) Fill the through groove (8) with a transparent conductive material for the transparent electrode layer (7), such as one or more of ITO, ZnO, AZO, ATO, FTO, _SnO2 , etc. or a combination of the above materials film;

(8) Using the outer wall (8a) as a cutting boundary, cut the flip-chip light-emitting diode, thereby removing part of the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer ( 3), so that a transparent electrode layer (7) is formed on the four sides and the top surface of the entire flip-chip light-emitting diode;

(9) Spin-coat the titanium-containing nanoparticle dispersion on the entire surface of the transparent electrode layer (7) to form a single-layer titanium nanoparticle film; dry the single-layer titanium nanoparticle film to form the ICP etching required A mask layer of a single layer of titanium nanoparticles; using the mask layer of a single layer of titanium nanoparticles to perform ICP etching on the transparent electrode layer (7), thereby forming a roughened structure (9) on the entire surface of the transparent electrode layer (7) ); remove the masking layer of the monolayer of Ti nanoparticles. Thus, the flip-chip light-emitting diode with roughened transparent electrodes of the present invention is formed.

So far, the above description has explained in detail the flip-chip light-emitting diode with transparent electrodes of the present invention and its manufacturing method. Compared with the light-emitting diodes produced by the existing methods, the light-emitting diodes produced by the method proposed by the present invention can improve the integration , Simplify the process, no lead structure is required, thereby reducing the manufacturing cost. Moreover, the flip-chip light-emitting diode with transparent electrodes of the present invention can improve the light extraction efficiency, thereby improving the overall luminous efficiency. The embodiments described above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Those skilled in the art can make any modifications to the present invention without departing from the spirit of the present invention, and the protection scope of the present invention is defined by the appended claims.

Claims (5)

1. A method of manufacturing a flip-chip light-emitting diode with a roughened transparent electrode, comprising: (1) A growth substrate is provided, on which an n-type semiconductor layer (6), an active layer (5), a p-type semiconductor layer (4) and a p-type reflective electrode (2) are sequentially formed; (2) Etching part of the p-type semiconductor layer (4) and the p-type reflective electrode (2) to expose part of the active layer (5), thereby forming a stepped structure; (3) filling the step structure with a transparent insulating material, thereby forming a transparent insulating layer (3); (4) Inverting the obtained structure, placing it on the carrier substrate (1), and peeling off the growth substrate, thereby exposing the n-type semiconductor layer (6); (5) forming a transparent electrode layer (7) on the exposed n-type semiconductor layer (6); (6) form a through groove (8), which penetrates the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer (3), and the through groove (8) has an inner side wall (8b) and outer side wall (8a); (7) filling the transparent conductive material for the transparent electrode layer (7) in the through groove (8); (8) Using the outer wall (8a) as a cutting boundary, the flip-chip light-emitting diode is cut, thereby removing part of the transparent electrode layer (7), n-type semiconductor layer (6), active layer (5), transparent insulating layer ( 3), so that a transparent electrode layer is formed on the four sides and the top surface of the entire flip-chip light-emitting diode; (9) Roughening the surface of the transparent electrode layer (7), thereby forming a roughened structure (9) on the entire surface of the transparent electrode layer (7). 2. The method for manufacturing a flip-chip light-emitting diode according to claim 1, wherein the method for forming the roughened structure (9) comprises the following steps: Spin-coating the titanium-containing nanoparticle dispersion on the entire surface of the transparent electrode layer (7) to form a single-layer titanium nanoparticle film; drying the single-layer titanium nanoparticle film to form the single-layer titanium nanoparticle film required for ICP etching. masking layer for nanoparticles; performing ICP etching on the transparent electrode layer (7) by using a mask layer of a single layer of titanium nanoparticles, thereby forming a roughened structure (9) on the entire surface of the transparent electrode layer (7); Remove the masking layer of the monolayer of titanium nanoparticles. 3. The manufacturing method of flip-chip light-emitting diode according to claim 2, wherein the transparent insulating layer (3) is sandwiched between the transparent electrode layer (7) covering the side of the flip-chip light-emitting diode and the p on the carrier substrate (1). between the p-type reflective electrodes (2), so that the transparent electrode layer (7) and the p-type reflective electrode (2) are insulated from each other, and the transparent insulating layer (3) is Al ₂ O ₃ . 4. The manufacturing method of flip-chip light emitting diode according to claim 3, wherein the transparent electrode layer (7) is one of ITO, ZnO, AZO, ATO, FTO, SnO ₂ or a composite film of the above materials. 5. The method for manufacturing a flip-chip light-emitting diode according to claim 4, wherein the roughness Ra of the roughened structure (9) is 1 nm-10 nm.