Laser light-emitting device structure and preparation method thereof

Abstract

The invention relates to a laser light-emitting device structure and a preparation method thereof. The laser light-emitting device structure is a light-emitting device composed of a first semiconductor layer, a second semiconductor layer and an active layer. The active layer is located between the first semiconductor layer and the second semiconductor layer, and the first semiconductor layer is arranged on the substrate; the first conducting layer is in ohmic contact with the second semiconductor layer; the second conducting layer is electrically connected with the first conducting layer; the positive electrode is electrically connected with the second conducting layer; the first conductive layer, the second conductive layer and the positive electrode jointly form a first electric connection layer; the first insulating layer covers part of the surface of the second semiconductor layer; the first insulating layer wraps the side walls of the first conductive layer and the second conductive layer in the process of etching the ridge. In the process of etching the ridge, the first conductive layer and the second conductive layer are isolated, and the etching gas is prevented from reacting with the first conductive layer and the second conductive layer, so that the stability of the device is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor lasers, and particularly to a laser emitting device structure and a preparation method thereof. Background Art

[0002] For an edge-emitting laser diode, the P-type semiconductor contact layer is mainly a transparent conductive layer, one or more of palladium, platinum, nickel, and titanium, and a metal oxide layer or a metal layer can act as a mask and an ohmic contact for the ridge; an optical insulating layer is covered on the side of the ridge to form optical confinement, allowing current to be injected from the ridge to form a high current density and reach the laser threshold.

[0003] For an edge-emitting laser diode, the P-type semiconductor contact layer is mainly a transparent conductive layer or a metal layer, such as indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), aluminum-gallium co-doped zinc oxide (AGZO), indium gallium zinc oxide (IGZO), a palladium metal layer, a platinum metal layer, a nickel metal layer, a titanium metal layer, etc., and a metal oxide layer or a metal layer can act as a mask and an ohmic contact for the ridge; during the process of fabricating the ridge, dry etching of the epitaxial layer is required, and the conductive layer exposed on the sidewall will react with the etching gas during the dry etching process, thereby generating corresponding plasma (In 3+ , Sn 3 + , O 2- etc.), and these ions attaching to the sidewall of the ridge will cause instability of the entire device, and the residues on the sidewall increase the harmfulness of leakage current. Summary of the Invention

[0004] Based on the technical problems existing in the background art, the present invention proposes a laser emitting device structure and a preparation method thereof. During the process of etching the ridge, the conductive layer is isolated to avoid the reaction between the etching gas and the conductive layer, thereby improving the stability of the device.

[0005] A laser emitting device structure proposed by the present invention is a light-emitting device composed of a first semiconductor layer, a second semiconductor layer, and an active layer; the active layer is located between the first semiconductor layer and the second semiconductor layer, and the first semiconductor layer is disposed on a substrate;

[0006] A first conductive layer forming an ohmic contact with the second semiconductor layer, a second conductive layer electrically connected to the first conductive layer, and a positive electrode electrically connected to the second conductive layer; the first conductive layer, the second conductive layer, and the positive electrode together form a first electrical connection layer;

[0007] A first insulating layer covering a part of the surface of the second semiconductor layer; the first insulating layer covers the sidewalls of the first conductive layer and the second conductive layer during the process of etching the ridge;

[0008] A second insulating layer covering the surface of the first insulating layer and a part of the surface of the second semiconductor layer and partially exposed to the outside of the device;

[0009] A negative electrode covering the surface of the other side of the substrate, placed on both sides of the substrate with the first semiconductor layer, and forming an electrical connection with the first semiconductor layer. The negative electrode and the substrate form a second electrical connection layer.

[0010] Preferably, the first conductive layer is a transparent conductive layer structure such as indium tin oxide, and the second conductive layer, the positive electrode, and the negative electrode are multi-layer metal structures. The first insulating layer and the second insulating layer are made of insulating materials.

[0011] Preferably, during the fabrication of the positive electrode, the first insulating layer on the sidewall of the ridge is removed.

[0012] A method for preparing a laser light-emitting device structure, comprising the following steps;

[0013] S1. Grow a first semiconductor layer, an active layer, and a second semiconductor layer on the substrate in sequence;

[0014] S2. Using ultraviolet photomask patterning and sputtering methods, using the first conductive layer and the second conductive layer, such as indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), aluminum-gallium co-doped zinc oxide (AGZO), indium gallium zinc oxide (IGZO), palladium, platinum, nickel, titanium, or a combination of several metals or metal oxides as a mask and ohmic contact for the ridge, fabricate a mask with a width of 0.5 - 3 μm;

[0015] S3. Using ultraviolet photomask patterning and plasma etching methods, fabricate a ridge with a width of 0.5 - 3 μm for the first time, and the ridge depth is 0.1 - 0.5 μm;

[0016] S4. Using chemical vapor deposition, grow a first insulating layer, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc. The first insulating layer covers a part of the surface of the second semiconductor layer, and coats the sidewalls and surfaces of the first conductive layer and the second conductive layer;

[0017] S5. Using ultraviolet photomask patterning and plasma etching methods, fabricate a ridge with a width of 0.5 - 3 μm for the second time, and the ridge depth is 0.5 - 2 μm; During this process, the first insulating layer covers the sidewalls of the first conductive layer and the second conductive layer, avoiding reaction with the conductive layer during the plasma etching process;

[0018] S6. Using chemical vapor deposition, grow a second insulating layer, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc. The second insulating layer covers the entire surface of the ridge, the first conductive layer, and the second conductive layer;

[0019] S7. Use ultraviolet photomask patterning to clean the photoresist on the ridge, and use plasma etching to etch the insulating layer in the photoresist-free area;

[0020] S8. Fabricate the positive electrode and the negative electrode by ultraviolet photomask patterning and sputtering;

[0021] S9. Split into bars, deposit the cavity film, and form a laser diode.

[0022] The beneficial effects of the present invention are as follows: During the process of etching the ridge, the conductive layer is isolated, avoiding the reaction between the etching gas and the conductive layer, thereby improving the stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a laser light-emitting device structure proposed by the present invention;

[0024] Figure 2 is an enlarged schematic diagram of the ridge of the present invention;

[0025] Figure 3 is a schematic structural diagram of the first step of the manufacturing process of the present invention;

[0026] Figure 4 is a schematic structural diagram of the second step of the manufacturing process of the present invention;

[0027] Figure 5 is a schematic structural diagram of the third step of the manufacturing process of the present invention;

[0028] Figure 6 is a schematic structural diagram of the fourth step of the manufacturing process of the present invention;

[0029] Figure 7 is a schematic structural diagram of the fifth step of the manufacturing process of the present invention;

[0030] Figure 8 is a schematic structural diagram of the sixth step of the manufacturing process of the present invention;

[0031] Figure 9 is a schematic structural diagram of the seventh step of the manufacturing process of the present invention;

[0032] Figure 10 is a schematic structural diagram of the eighth step of the manufacturing process of the present invention.

[0033] In the figure: 1. First semiconductor layer, 2. Second semiconductor layer, 3. Active layer, 4. Substrate, 5. First conductive layer, 6. Second conductive layer, 7. Positive electrode, 8. First insulating layer, 9. Second insulating layer, 10. Negative electrode. DETAILED DESCRIPTION OF THE INVENTION

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0035] Referring to Figure 1-2 , a laser light-emitting device structure includes a light-emitting device composed of a first semiconductor layer 1, a second semiconductor layer 2, and an active layer 3; the active layer 3 is located between the first semiconductor layer 1 and the second semiconductor layer 2; the first semiconductor layer 1 is disposed on a substrate 4, and is characterized in that

[0036] a first conductive layer 5 that forms an ohmic contact with the second semiconductor layer 2, the first conductive layer 5 is a transparent conductive structure such as indium tin oxide, a second conductive layer 6 that is electrically connected to the first conductive layer 5, the second conductive layer 6 is a multi-layer metal structure, a positive electrode 7 that is electrically connected to the second conductive layer 6, the positive electrode 7 is a multi-layer metal structure, and the first conductive layer 5, the second conductive layer 6, and the positive electrode 7 together form a first electrical connection layer;

[0037] a first insulating layer 8 covering a part of the surface of the second semiconductor layer 2, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide, and the first insulating layer 8 covers the side walls of the first conductive layer 5 and the second conductive layer 6 during the process of etching the ridge, referring to Figure 2 as shown; during the process of fabricating the positive electrode 7, the first insulating layer 8 on the side wall of the ridge is removed;

[0038] a second insulating layer 9 covering the surface of the first insulating layer 8 and a part of the surface of the second semiconductor layer 2 and partially exposed to the outside of the device, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide;

[0039] a negative electrode 10 covering the other surface of the substrate 4, disposed on both sides of the substrate 4 with the first semiconductor layer 1, and electrically connected to the first semiconductor layer 1, the negative electrode 10 is a multi-layer metal structure, and the negative electrode 10 and the substrate 4 form a second electrical connection layer.

[0040] Referring to Figures 3-10 , a preparation method of a laser light-emitting device structure includes the following steps;

[0041] S1. The first semiconductor layer 1, the active layer 3, and the second semiconductor layer 2 are sequentially grown on the substrate 4;

[0042] S2. Using ultraviolet photomask patterning and sputtering methods, with the first conductive layer 5 and the second conductive layer 6, such as indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), aluminum-gallium co-doped zinc oxide (AGZO), indium gallium zinc oxide (IGZO), palladium, platinum, nickel, titanium, or several of these metals or metal oxides, as the mask and ohmic contact for the ridge, fabricate a mask with a width of 0.5 - 3 μm.

[0043] S3. Using ultraviolet photomask patterning and plasma etching methods, fabricate the ridge with a width of 0.5 - 3 μm for the first time, and the ridge depth is 0.1 - 0.5 μm.

[0044] S4. Using chemical vapor deposition, grow the first insulating layer 8, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc. The first insulating layer 8 covers part of the surface of the second semiconductor layer 2, and coats the sidewalls and surfaces of the first conductive layer 5 and the second conductive layer 6.

[0045] S5. Using ultraviolet photomask patterning and plasma etching methods, fabricate the ridge with a width of 0.5 - 3 μm for the second time, and the ridge depth is 0.5 - 2 μm. During this process, the first insulating layer 8 covers the sidewalls of the first conductive layer 5 and the second conductive layer 6, preventing reaction with the first conductive layer 5 and the second conductive layer 6 during the plasma etching process.

[0046] S6. Using chemical vapor deposition, grow the second insulating layer 9, including insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc. The second insulating layer entirely covers the ridge, the first conductive layer 5, and the second conductive layer 6.

[0047] S7. Using ultraviolet photomask patterning to clean the photoresist on the ridge, and using plasma etching to etch the insulating layer in the area without photoresist.

[0048] S8. Using ultraviolet photomask patterning and sputtering methods, fabricate the positive electrode 7 and the negative electrode 10.

[0049] S9. Split into bars, deposit the cavity film, and form a laser diode.

[0050] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A laser light-emitting device structure and a preparation method thereof, comprising a light-emitting device composed of a first semiconductor layer (1), a second semiconductor layer (2) and an active layer (3); The active layer (3) is located between the first semiconductor layer (1) and the second semiconductor layer (2); the first semiconductor layer (1) is disposed on the substrate (4), characterized in that, A first conductive layer (5) forming an ohmic contact with the second semiconductor layer (2), a second conductive layer (6) electrically connected to the first conductive layer (5), and a positive electrode (7) electrically connected to the second conductive layer (6); the first conductive layer (5), the second conductive layer (6), and the positive electrode (7) together form a first electrical connection layer; A first insulating layer (8) covering a part of the surface of the second semiconductor layer (2); the first insulating layer (8) covers the sidewalls of the first conductive layer (5) and the second conductive layer (6) during the etching of the ridge. A second insulating layer (9) covering the surface of the first insulating layer (8) and a part of the surface of the second semiconductor layer (2) and partially exposed to the outside of the device; A negative electrode (10) covering the other surface of the substrate (4), disposed on both sides of the substrate (4) with the first semiconductor layer (1), and electrically connected to the first semiconductor layer (1), the negative electrode (10) and the substrate (4) form a second electrical connection layer.

2. The structure of a laser emitting device and its manufacturing method according to claim 1, characterized in that The first conductive layer (5) is a transparent conductive layer structure, the second conductive layer (6), the positive electrode (7), and the negative electrode (10) are multi-layer metal structures, and the first insulating layer (8) and the second insulating layer (9) are insulating materials.

3. A laser light-emitting device structure and a manufacturing method thereof according to claim 1, characterized in that, During the fabrication of the positive electrode (7), the first insulating layer (8) on the sidewall of the ridge is removed.

4. A method for preparing a laser light-emitting device structure, characterized in that, Comprising the following steps; S1. The first semiconductor layer (1), the active layer (3), and the second semiconductor layer (2) are sequentially grown on the substrate (4); S2. Using ultraviolet photomask patterning and sputtering methods, using the first conductive layer (5) and the second conductive layer (6), such as indium tin oxide ITO, aluminum-doped zinc oxide AZO, gallium-doped zinc oxide GZO, aluminum-gallium co-doped zinc oxide AGZO, indium gallium zinc oxide IGZO, palladium, platinum, nickel, titanium, or one or several metals or metal oxides thereof are used as the mask and ohmic contact of the ridge to fabricate a mask with a width of 0.5 - 3 um; S3. Using ultraviolet photomask patterning and plasma etching methods, the first ridge with a width of 0.5 - 3 um is fabricated for the first time, and the ridge depth is 0.1 - 0.5 um; S4. Using chemical vapor deposition method, the first insulating layer (8) is grown, and the first insulating layer (8) includes insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, etc. The first insulating layer (8) covers a part of the surface of the second semiconductor layer (2), and covers the sidewalls and the surface of the first conductive layer (5) and the second conductive layer (6); S5. Using ultraviolet photomask patterning and plasma etching methods, the second ridge with a width of 0.5 - 3 um is fabricated for the second time, and the ridge depth is 0.5 - 2 um; during this process, the first insulating layer (8) covers the sidewalls of the first conductive layer (5) and the second conductive layer (6) to avoid reaction with the first conductive layer (5) and the second conductive layer (6) during the plasma etching process; S6. Using chemical vapor deposition method, the second insulating layer (9) is grown, and the second insulating layer (9) includes insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide; The second insulating layer (9) entirely covers the ridge, the first conductive layer (5), and the second conductive layer (6); S7. Use an ultraviolet photomask to pattern and clean the photoresist on the ridge, and etch the insulating layer in the area without photoresist by means of plasma etching; S8. Fabricate the positive electrode (7) and the negative electrode (10) by means of ultraviolet photomask patterning and sputtering; S9. Split into bars, coat the cavity film, and form a laser diode.

Images