阅读说明：本技术 一种柔性垂直腔面发射激光器芯片及其制作方法 (Flexible vertical cavity surface emitting laser chip and manufacturing method thereof ) 是由 杨文奕 何键华 黄嘉敬 杜伟 胡丹 于 2020-06-11 设计创作，主要内容包括：本发明公开了一种高性能的柔性垂直腔面发射激光器芯片及其制作方法,包括下电极、下电极接触层、下布拉格反射镜层、有源区、氧化限制层、上布拉格反射镜层、上电极接触层、上电极和反射绝缘层；其中,所述下电极、下电极接触层、下布拉格反射镜层、有源区、氧化限制层、上布拉格反射镜层、上电极接触层、上电极按照从下往上的顺序依次叠加,构成一个激光器芯片主体,所述反射绝缘层制作在该激光器芯片主体的侧面,在起绝缘作用的同时兼具反射作用,以减少光的侧向发散。本发明在提高激光器芯片性能的同时,减小了激光器芯片的厚度进而提升芯片的封装密度,同时芯片具有一定的柔性,能满足一些特定应用环境的形变要求。(The invention discloses a high-performance flexible vertical cavity surface emitting laser chip and a manufacturing method thereof, wherein the high-performance flexible vertical cavity surface emitting laser chip comprises a lower electrode, a lower electrode contact layer, a lower Bragg reflector layer, an active region, an oxidation limiting layer, an upper Bragg reflector layer, an upper electrode contact layer, an upper electrode and a reflection insulating layer; the laser chip comprises a lower electrode, a lower electrode contact layer, a lower Bragg reflector layer, an active region, an oxidation limiting layer, an upper Bragg reflector layer, an upper electrode contact layer and an upper electrode, wherein the lower electrode, the lower electrode contact layer, the lower Bragg reflector layer, the active region, the oxidation limiting layer, the upper Bragg reflector layer, the upper electrode contact layer and the upper electrode are sequentially overlapped from bottom to top to form a laser chip main body, and a reflection insulating layer is manufactured on the side face of the laser chip main body, plays a role in insulation and reflection, and reduces lateral divergence of light. The invention improves the performance of the laser chip, reduces the thickness of the laser chip and further improves the packaging density of the chip, and meanwhile, the chip has certain flexibility and can meet the deformation requirements of certain specific application environments.)

1. A flexible vertical cavity surface emitting laser chip characterized in that: the device comprises a lower electrode (8), a lower electrode contact layer (7), a lower Bragg reflector layer (6), an active region (5), an oxidation limiting layer (4), an upper Bragg reflector layer (3), an upper electrode contact layer (2), an upper electrode (1) and a reflection insulating layer (9); the laser chip comprises a lower electrode (8), a lower electrode contact layer (7), a lower Bragg reflector layer (6), an active region (5), an oxidation limiting layer (4), an upper Bragg reflector layer (3), an upper electrode contact layer (2) and an upper electrode (1) which are sequentially stacked from bottom to top to form a laser chip main body, wherein a reflection insulating layer (9) is manufactured on the side face of the laser chip main body, and has a reflection effect while playing an insulating effect so as to reduce lateral divergence of light.

2. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the lower electrode (8) comprises a flexible conductive material layer.

3. A flexible vertical cavity surface emitting laser chip according to claim 2, wherein: the flexible conductive material layer is a graphene silver nano material layer or a boron-alkene film, the thickness of the flexible conductive material layer is 1-10um, and the surface of the flexible conductive material layer is in a folded state and used for increasing the direction of reflected light and improving the overall reflectivity of the lower Bragg reflector layer (6).

4. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the doping concentration of the upper electrode contact layer (2) and the lower electrode contact layer (7) is more than 1E18cm³The thickness is 5-10 nm.

5. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the lower Bragg reflector layer (6) and the upper Bragg reflector layer (3) adopt high-refractive-index material layers and low-refractive-index material layers which are alternately arranged, wherein the material layers are of superlattice GaAs/AlAs structures or AlGaAs/AlGaAs structures, and the number of periodic pairs is 5-30 pairs.

6. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the active region (5) comprises an InGaAs/AlGaAs, InGaAs/GaAs, or GaAsP/AlGaAsP quantum well structure.

7. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the material of the oxidation limiting layer (4) is AlAs or AlGaAs.

8. A flexible vertical cavity surface emitting laser chip according to claim 1, wherein: the insulation layerThe material of the injection layer (9) is SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂Two or more of them are alternately constituted in high and low refractive indexes.

9. A method of fabricating a flexible vertical cavity surface emitting laser chip according to any of claims 1 to 8, comprising the steps of:

1) selecting a substrate;

2) the method comprises the following steps that a sacrificial layer, an upper electrode contact layer (2), an upper Bragg reflector layer (3), an oxidation limiting layer (4), an active region (5), a lower Bragg reflector layer (6) and a lower electrode contact layer (7) are epitaxially grown on a substrate in sequence, wherein a laser chip main body is provided with high-aluminum component AlGaAs and AlAs series materials, and in order to improve the selective corrosion effective degree in an epitaxial lift-off process, the sacrificial layer is preferably made of InAlP materials;

3) manufacturing a metal contact layer on a lower electrode contact layer (7) on the surface of the product after epitaxial growth, and depositing metal by adopting an electron beam evaporation or sputtering process, wherein the material is one or a combination of more of Ag, Au, Ni and AuGeNi, and the thickness is 0.5-1 um;

manufacturing a flexible conductive material on the surface of a metal contact layer of a product, specifically coating a graphene silver nano material layer, or evaporating boron atoms by using PVD and CVD vacuum deposition equipment to deposit a boron-olefin film with the thickness of 1-10um on the metal contact layer, thereby preparing a lower electrode (8); the lower electrode (8) is made of a graphene silver nanowire material or a boron thin film, so that the flexibility and the strength of the electrode can be improved, the tearing damage to the epitaxial thin film due to large stress warping of a metal contact layer in an epitaxial stripping process is avoided, the direction of reflected light can be increased through folds on the surface of the graphene silver nanowire material layer or the surface of the boron thin film, and the overall reflectivity of the lower Bragg reflector layer (6) is improved;

before the product is subjected to an epitaxial stripping process, a corrosion-resistant protective coating needs to be coated on the surface of the lower electrode (8) so as to ensure the reliability and appearance of the lower electrode (8) after the stripping process; the corrosion-resistant protective coating adopts UV glue or black wax, and the surface of the lower electrode (8) is uniformly covered by the corrosion-resistant protective coating in a spin coating mode;

4) the sacrificial layer is corroded by stripping corrosive liquid, the lower electrode (8) can drive the epitaxial layer to curl in the direction back to the substrate due to the action of internal stress in the process of stripping the epitaxial layer from the sacrificial layer, an effective corrosion channel is formed, the stripping rate is increased, and after the epitaxial layer is completely separated from the substrate, the epitaxial film is prevented from cracking due to the supporting action of the flexible conductive material of the lower electrode (8);

the stripping corrosive liquid adopts hydrochloric acid solution, the concentration of the hydrochloric acid is controlled to be 25% -35%, the hydrochloric acid can react on InAlP materials of the sacrificial layer, and does not carry out corrosion reaction on AlGaAs and AlAs series materials, so that the substrate and the epitaxial film are effectively separated, and a complete epitaxial film is obtained, and the integrity and the effectiveness of the epitaxial film are ensured to the maximum extent;

removing the corrosion-resistant protective coating coated on the lower electrode (8) from the stripped epitaxial film through a corresponding cleaning agent, removing the corrosion-resistant protective coating by using acetone or a photoresist removing liquid if the corrosion-resistant protective coating is protected by using UV (ultraviolet) glue, and cleaning the corrosion-resistant protective coating by using a de-waxing liquid or toluene if the corrosion-resistant protective coating is black wax;

5) bonding the temporary substrate with an adhesive to perform a laser chip process, wherein the adhesive is compatible with a subsequent chip process, is not dissolved by various solutions used in a cleaning process, and can endure various thermal processes without property change;

cleaning the surface of the product after temporary bonding, and carrying out ultrasonic cleaning by sequentially using acetone, isopropanol, hydrochloric acid and BOE buffer solution to remove organic matters, metal particles and oxide impurities on the surface of the product;

performing spin coating of photoresist, exposure and development by adopting a photoetching method, protecting an electrode contact layer of an upper electrode area to be manufactured by using the photoresist, and exposing oxidation limiting layers (4) on two sides by wet etching or ICP etching;

carrying out an oxidation process on an AlGaAs or AlAs material in the oxidation limiting layer (4) by adopting a wet oxidation process to form an injection current limiting aperture, and determining temperature and time parameters of the oxidation process according to the size of a light-emitting aperture designed by a laser so as to achieve the required oxidation depth;

depositing a reflective insulation layer (9) by PECVD or electron beam evaporation, selecting SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂Two or more materials in the composition are alternately arranged according to high and low refractive indexes, and the thickness is 100nm-300 nm;

windowing by using a photoetching method to manufacture an upper electrode pattern, adopting BOE etching solution to corrode the deposited reflection insulating layer (9), evaporating upper electrode metal, soaking the evaporated metal product in acetone or photoetching stripping solution by using one or more of Au, Al, Ni, Pd, Ag and Ti as the upper electrode metal material, and removing the photoresist and the metal on the surface of the photoresist to obtain the required electrode metal pattern;

photoetching a light outlet by adopting a photoetching method, corroding an electrode contact layer by adopting citric acid or ammonia water solution after corroding a reflection insulation layer (9) of the light outlet by using BOE etching solution, exposing a part of the light outlet, soaking the product in acetone or photoresist removing solution, and removing photoresist;

dissolving the adhesive using a solution capable of removing the adhesive to separate the temporary substrate from the laser chip;

annealing and alloying the separated laser chip to form good ohmic contact of the electrode, so that the laser chip is manufactured; wherein, the low-temperature alloy process is adopted in consideration of the flexible stress bending of the product.

10. The method of claim 9, wherein the step of forming the flexible vertical cavity surface emitting laser chip comprises: in step 1), a GaAs substrate of 300-; in the step 5), the adhesive is made of high-melting-point wax, and toluene is selected to remove the adhesive when the adhesive is dissolved.

Technical Field

The invention relates to the technical field of semiconductors, in particular to a flexible vertical cavity surface emitting laser chip and a manufacturing method thereof.

Background

A Vertical Cavity Surface Emitting Laser (VCSEL) is a novel semiconductor Laser manufactured based on GaAs semiconductor material, has the advantages of small volume, low threshold current, high efficiency, low power consumption, small light divergence angle, easy integration into large-area arrays, and the like, and can be widely applied to the fields of optical information processing, optical interconnection, optical calculation, and the like.

A general VSCEL mainly includes a substrate, a lower bragg reflector (DBR) layer, an active region, an oxide confinement layer, an upper DBR layer, an upper metal electrode, and a lower metal electrode.

The thickness of the GaAs substrate used for the growth of the VSCEL epitaxial structure is generally different from 300-. Firstly, the GaAs substrate is removed in the later preparation process, but after the substrate is removed, the thickness of a device layer is about 10-15 μm, which is not beneficial to chip preparation. And secondly, the substrate is reserved firstly, the substrate is thinned to 50-100 mu m after the VSCEL chip process is carried out and before the VSCEL chip process is welded on the heat sink, but the polishing and thinning of the substrate also has certain hidden cracking risk and increased cost, and meanwhile, the whole chip still has certain thickness to influence the heat dissipation and subsequent packaging density. At present, some technologies adopt an epitaxial layer stripping process to manufacture thin film type VSCEL, metal reflector layers with certain thickness such as Cu, Ag, Au and the like are basically adopted as electrode layers, the metal layers generally have large internal stress and are easy to warp and deform, and the epitaxial thin film layer is subjected to tensile stress in the stripping process to generate crack damage so as to influence the performance of subsequent chips.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a high-performance flexible vertical cavity surface emitting laser chip and a manufacturing method thereof, which can reduce the thickness of the laser chip and further improve the packaging density of the chip while improving the performance of the laser chip, and meanwhile, the chip has certain flexibility, can meet the deformation requirements of certain specific application environments, and has high adaptability.

In order to achieve the purpose, the technical scheme provided by the invention is as follows: a flexible vertical cavity surface emitting laser chip comprises a lower electrode, a lower electrode contact layer, a lower Bragg reflector layer, an active region, an oxidation limiting layer, an upper Bragg reflector layer, an upper electrode contact layer, an upper electrode and a reflecting insulating layer; the laser chip comprises a lower electrode, a lower electrode contact layer, a lower Bragg reflector layer, an active region, an oxidation limiting layer, an upper Bragg reflector layer, an upper electrode contact layer and an upper electrode, wherein the lower electrode, the lower electrode contact layer, the lower Bragg reflector layer, the active region, the oxidation limiting layer, the upper Bragg reflector layer, the upper electrode contact layer and the upper electrode are sequentially overlapped from bottom to top to form a laser chip main body, and a reflection insulating layer is manufactured on the side face of the laser chip main body, plays a role in insulation and reflection, and reduces lateral divergence of light.

Further, the lower electrode comprises a flexible conductive material layer.

Furthermore, the flexible conductive material layer is a graphene silver nano material layer or a boron-graphene film, the thickness of the flexible conductive material layer is 1-10um, and the surface of the flexible conductive material layer is in a folded state and is used for increasing the direction of reflected light and improving the overall reflectivity of the lower Bragg reflector layer.

Further, the doping concentration of the upper electrode contact layer and the lower electrode contact layer is more than 1E18cm³The thickness is 5-10 nm.

Furthermore, the lower Bragg reflector layer and the upper Bragg reflector layer adopt high-refractive-index material layers and low-refractive-index material layers which are alternately arranged, wherein the material layers are of a superlattice GaAs/AlAs structure or an AlGaAs/AlGaAs structure, and the number of periodic logarithm is 5-30 pairs.

Further, the active region includes InGaAs/AlGaAs, InGaAs/GaAs, or GaAsP/AlGaAsP quantum well structures.

Further, the material of the oxidation limiting layer is AlAs or AlGaAs.

Further, the insulating reflecting layer is made of SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂Two or more of them are alternately constituted in high and low refractive indexes.

The invention also provides a manufacturing method of the flexible vertical cavity surface emitting laser chip, which comprises the following steps:

1) selecting a substrate;

2) epitaxially growing a sacrificial layer, an upper electrode contact layer, an upper Bragg reflector layer, an oxidation limiting layer, an active region, a lower Bragg reflector layer and a lower electrode contact layer on a substrate in sequence, wherein the main body of the laser chip is provided with high-aluminum component AlGaAs and AlAs series materials, and the sacrificial layer is preferably made of InAlP materials in order to improve the effective degree of selective corrosion in the epitaxial lift-off process;

3) manufacturing a metal contact layer on a lower electrode contact layer on the surface of the product after epitaxial growth, and depositing metal by adopting an electron beam evaporation or sputtering process, wherein the material is one or a combination of more of Ag, Au, Ni and AuGeNi, and the thickness is 0.5-1 um;

manufacturing a flexible conductive material on the surface of a metal contact layer of a product, specifically coating a graphene silver nano material layer, or evaporating boron atoms by using PVD and CVD vacuum deposition equipment to deposit on the metal contact layer to form a boron-olefin film with the thickness of 1-10um, thereby preparing a lower electrode; the lower electrode is made of a graphene silver nanowire material or a boron thin film, so that the flexibility and the strength of the electrode can be improved, the tearing damage of the epitaxial thin film due to large stress warping of a metal contact layer in an epitaxial stripping process is avoided, the direction of reflected light can be increased through folds on the surface of the graphene silver nanowire material layer or the surface of the boron thin film, and the overall reflectivity of the lower Bragg reflector layer is improved;

before the product is subjected to an epitaxial stripping process, a corrosion-resistant protective coating needs to be coated on the surface of the lower electrode so as to ensure the reliability and appearance of the lower electrode after the stripping process; the corrosion-resistant protective coating adopts UV glue or black wax, and the surface of the lower electrode is uniformly covered by the corrosion-resistant protective coating in a spin coating mode;

4) the stripping corrosive liquid is adopted to corrode the sacrificial layer, the lower electrode can drive the epitaxial layer to curl in the direction away from the substrate due to the internal stress action in the process of carrying out the epitaxial layer stripping process on the sacrificial layer, an effective corrosion channel is formed, the stripping rate is increased, and after the epitaxial layer is completely separated from the substrate, the epitaxial film is prevented from cracking due to the supporting action of the flexible conductive material of the lower electrode;

the stripping corrosive liquid adopts hydrochloric acid solution, the concentration of the hydrochloric acid is controlled to be 25% -35%, the hydrochloric acid can react on InAlP materials of the sacrificial layer, and does not carry out corrosion reaction on AlGaAs and AlAs series materials, so that the substrate and the epitaxial film are effectively separated, and a complete epitaxial film is obtained, and the integrity and the effectiveness of the epitaxial film are ensured to the maximum extent;

removing the corrosion-resistant protective coating coated on the lower electrode from the stripped epitaxial film through a corresponding cleaning agent, removing the corrosion-resistant protective coating by using acetone or a photoresist removing liquid if the corrosion-resistant protective coating is protected by using UV (ultraviolet) glue, and cleaning the corrosion-resistant protective coating by using a de-waxing liquid or toluene if the corrosion-resistant protective coating is protected by using black wax;

5) bonding the temporary substrate with an adhesive to perform a laser chip process, wherein the adhesive is compatible with a subsequent chip process, is not dissolved by various solutions used in a cleaning process, and can endure various thermal processes without property change;

cleaning the surface of the product after temporary bonding, and carrying out ultrasonic cleaning by sequentially using acetone, isopropanol, hydrochloric acid and BOE buffer solution to remove organic matters, metal particles and oxide impurities on the surface of the product;

performing spin coating of photoresist, exposure and development by adopting a photoetching method, protecting an electrode contact layer of an upper electrode area to be manufactured by using the photoresist, and etching by using a wet etching method or ICP (inductively coupled plasma) to expose oxidation limiting layers on two sides;

carrying out an oxidation process on the AlGaAs or AlAs material in the oxidation limiting layer by adopting a wet oxidation process to form an injection current limiting aperture, and determining the temperature and time parameters of the oxidation process according to the size of a light-emitting aperture designed by the laser so as to achieve the required oxidation depth;

depositing a reflecting insulating layer by PECVD or electron beam evaporation, and selecting SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂Two or more materials in the composition are alternately arranged according to high and low refractive indexes, and the thickness is 100nm-300 nm;

windowing by using a photoetching method to manufacture an upper electrode pattern, evaporating upper electrode metal after corroding the deposited reflecting insulating layer by using BOE etching solution, soaking the evaporated metal product in acetone or photoetching stripping solution by using one or more of Au, Al, Ni, Pd, Ag and Ti as an upper electrode metal material, and removing the photoresist and the metal on the surface of the photoresist to obtain the required electrode metal pattern;

photoetching a light outlet by adopting a photoetching method, corroding an electrode contact layer by adopting citric acid or ammonia water solution after corroding a reflection insulation layer of the light outlet by using BOE etching solution, exposing a part of the light outlet, soaking the product in acetone or photoresist removing solution, and removing photoresist;

dissolving the adhesive using a solution capable of removing the adhesive to separate the temporary substrate from the laser chip;

annealing and alloying the separated laser chip to form good ohmic contact of the electrode, so that the laser chip is manufactured; wherein, the low-temperature alloy process is adopted in consideration of the flexible stress bending of the product.

Further, in step 1), a GaAs substrate of 300- & 600um is used.

Further, in the step 5), the adhesive is made of high-melting wax, and toluene is selected to remove the adhesive when the adhesive is dissolved.

Compared with the prior art, the invention has the following advantages and beneficial effects:

1. by manufacturing conductive materials such as graphene silver nanowire materials or boron alkene on the back of the lower Bragg reflector layer and arranging the insulating reflecting layer on the side face of the chip device, the reflection efficiency can be increased, the gain is improved, better thermal stability is obtained, and the threshold current density is reduced.

2. The damage rate of the epitaxial thin film in the epitaxial stripping process can be reduced, the yield of the chip is improved, the obtained flexible vertical cavity surface emitting laser chip can meet the deformation requirements of certain specific application environments, the thickness of the chip is reduced, and the packaging density of the chip is improved.

Drawings

Fig. 1 is a schematic structural diagram of a flexible vertical cavity surface emitting laser chip according to the present invention.

FIG. 2 is a flow chart of the fabrication of a flexible VCSEL chip in accordance with the present invention.

FIG. 3 is a schematic diagram of a flexible VCSEL chip fabrication process according to the present invention.

FIG. 4 is another schematic diagram of a flexible VCSEL chip fabrication process according to the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples.

Referring to fig. 1, the present embodiment provides a flexible vcsel chip, which includes a lower electrode 8, a lower electrode contact layer 7, a lower bragg mirror layer 6, an active region 5, an oxide confinement layer 4, an upper bragg mirror layer 3, an upper electrode contact layer 2, an upper electrode 1, and a reflective insulation layer 9.

The lower electrode 8 is provided with a flexible conductive material layer which is directly connected with the lower Bragg reflector layer 6 through the lower electrode contact layer 7 and has the functions of reflector layer, device flexible support and heat dissipation, and the flexible conductive material layer can be a graphene silver nano material layer or a boron alkene thin film layer with the thickness of 1-10 um. Compared with the prior art that metal layers such as Cu, Ag and Au are used as lower electrode materials, the graphene silver nano material or the boron thin film is adopted, so that the flexibility and the strength of the electrode materials can be improved, the tearing damage to the epitaxial thin film caused by the large stress warping of the metal layer in the epitaxial stripping process is avoided, meanwhile, the graphene silver nano material layer or the boron thin film can present a certain fold state on the surface, the directions of reflected light rays can be increased, the overall reflectivity of the lower Bragg reflector layer 6 is improved, and the light emitting efficiency of the VCSEL is further improved.

The doping concentration of the upper electrode contact layer 2 and the lower electrode contact layer 7 is more than 1E18cm³The thickness is 5-10 nm.

The upper Bragg reflector layer 3 and the lower Bragg reflector layer 6 adopt high refractive index material layers and low refractive index material layers which are alternately arranged, the material layers are of superlattice GaAs/AlAs structures or AlGaAs/AlGaAs structures, and the cycle logarithm is 5-30 pairs.

The quantum well structure in the active region 5 may be InGaAs/AlGaAs, InGaAs/GaAs, GaAsP/AlGaAsP, etc., and the material system and quantum well structure of the active layer may be specifically selected according to the target wavelength of the VCSEL device.

The oxidation limiting layer 4 is selected from a material that readily achieves oxidation and controls the rate of oxidation, such as AlAs or AlGaAs.

The insulating reflecting layer 9 on the side surface of the laser chip main body is SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂Are alternately formed with high and low refractive indices so that the device side oxide layer has a reflective effect while insulating to reduce light escape from the device side.

The upper electrode 1 can be made of one or more of Au, Al, Ni, Pd, Ag and Ti, and is deposited by evaporation, sputtering and the like.

Referring to fig. 2, the present embodiment provides a method for manufacturing the flexible vertical cavity surface emitting laser chip, including the following steps:

in step P1, a substrate is selected, and a GaAs substrate of 300-.

Step P2, referring to fig. 3, sequentially stacking epitaxial growth sacrificial layers 10, upper electrode contact layers 2, upper bragg mirror layers 3, oxidation limiting layers 4, active regions 5, lower bragg mirror layers 6, lower electrode contact layers 7, and other laser epitaxial structures on a substrate 11; the main body of the laser chip is provided with high-aluminum component AlGaAs, AlAs and other series materials, and in order to improve the effective degree of selective corrosion in the epitaxial lift-off process, InAlP material is preferably selected as the sacrificial layer 10.

And step P3, manufacturing a metal contact layer on the lower electrode contact layer 7 on the surface of the product after epitaxial growth, and depositing metal by adopting processes such as electron beam evaporation, sputtering and the like, wherein the material can be one or a combination of more of Ag, Au, Ni and AuGeNi, and the thickness is 0.5-1 um.

And manufacturing a flexible conductive material on the surface of the metal contact layer of the product, specifically coating a graphene silver nano material layer, or evaporating boron atoms by using vacuum deposition equipment such as PVD, CVD and the like to deposit on the metal contact layer to form a boron-olefin film with the thickness of 1-10um, thereby manufacturing the lower electrode 8.

Before the product is subjected to an epitaxial stripping process, a corrosion-resistant protective coating needs to be coated on the surface of the lower electrode 8 so as to ensure the reliability and good appearance of the lower electrode 8 after the stripping process; the corrosion-resistant protective coating can adopt UV glue or black wax, and the surface of the lower electrode 8 is uniformly covered by the corrosion-resistant protective coating in a spin coating mode.

And step P4, corroding the sacrificial layer 10 by using a stripping corrosive liquid, wherein in the process of peeling the epitaxial layer by corroding the sacrificial layer 10, the lower electrode 8 can drive the epitaxial layer to curl in the direction away from the substrate due to the action of internal stress, so that an effective corrosion channel is formed, the stripping rate is increased, and after the epitaxial layer is completely separated from the substrate, the epitaxial film is prevented from cracking due to the supporting action of the flexible conductive material of the lower electrode 8.

The stripping corrosive liquid adopts hydrochloric acid solution with a certain concentration, the hydrochloric acid concentration is controlled to be 25% -35%, the hydrochloric acid can react on InAlP materials of the sacrificial layer, and does not carry out corrosion reaction on AlGaAs, AlAs and other series materials, so that the substrate and the epitaxial thin film are effectively separated, the integrity and the effectiveness of the epitaxial thin film are ensured to the maximum extent, and the complete epitaxial thin film is obtained as shown in figure 4.

And removing the corrosion-resistant protective coating coated on the lower electrode 8 from the stripped epitaxial film by using a corresponding cleaning agent, wherein acetone or a photoresist removing liquid can be used for removing if UV (ultraviolet) glue protection is adopted, and the wax removing liquid or toluene can be used for cleaning and removing if black wax is adopted.

And P5, bonding the substrate on the temporary substrate by using an adhesive to perform a laser chip process. The adhesive may be a high melting wax or other type of adhesive that is compatible with subsequent chip processing, will not dissolve in the various solutions used in the cleaning process, and will also withstand the various thermal processes without property changes.

And cleaning the surface of the product after temporary bonding, and carrying out ultrasonic cleaning by sequentially using acetone, isopropanol, hydrochloric acid and BOE buffer solution to remove impurities such as organic matters, metal particles, oxides and the like on the surface of the product.

And (3) performing spin coating of photoresist, exposure and development by adopting a photoetching method, protecting an electrode contact layer of an upper electrode area to be manufactured by using the photoresist, and exposing the oxidation limiting layers 4 on two sides by wet etching or ICP etching.

And (3) carrying out an oxidation process on the AlGaAs or AlAs material in the oxidation limiting layer 4 by adopting a wet oxidation process to form an injection current limiting aperture, and determining the temperature and time parameters of the oxidation process according to the size of a light-emitting aperture designed by the laser so as to achieve the required oxidation depth.

The reflective insulating layer 9 is deposited by PECVD or electron beam evaporation, optionally using SiO₂、Al₂O₃、TiO₂、ZrO₂、Si₃N₄、ZnS、CaF₂、MgF₂In a combination of two or more materials, the thickness is approximately 100nm to 300nm, depending on the alternating arrangement of the high and low refractive index.

And (2) windowing by using a photoetching method to manufacture an upper electrode pattern, corroding the deposited reflecting insulating layer 9 by using BOE etching solution, evaporating upper electrode metal, soaking the evaporated metal product in acetone or photoetching stripping solution by using one or more of Au, Al, Ni, Pd, Ag and Ti as an upper electrode metal material, removing the photoresist and the metal on the surface of the photoresist to obtain the required electrode metal pattern, and finishing the manufacture of the upper electrode 1.

And (3) photoetching a light outlet, corroding the electrode contact layer by using citric acid or ammonia water solution after corroding the reflection insulation layer 9 of the light outlet by using BOE etching solution, exposing the light outlet, soaking the product in acetone or photoresist removing solution, removing the photoresist, cleaning the surface by using pure water, and drying to obtain the laser chip structure shown in the figure 1.

The temporary substrate is separated from the laser chip by dissolving the adhesive using a solution that removes the adhesive, which may be toluene.

Annealing and alloying the separated laser chip to form good ohmic contact of the electrode, so that the laser chip is manufactured; wherein, the flexible stress bending of the product is considered, a low-temperature alloy process is adopted, the temperature is 200 ℃, and the time is 90-120 minutes.

In summary, the graphene silver nano material layer or the boron-alkene conductive material layer is manufactured on the back surface of the lower Bragg reflector layer (namely the lower DBR), so that the structure of the device is simplified, and the reflection insulating layer is arranged on the side surface of the chip device, so that the reflection efficiency can be improved integrally, and the gain performance can be improved; meanwhile, the epitaxial transfer can be effectively realized by adopting an epitaxial stripping process, so that the substrate can be recycled, and the production cost is reduced. In addition, the thickness of the laser chip is greatly reduced, the subsequent packaging density of the chip is improved, and the chip device has certain flexibility and can meet the deformation requirements of certain specific application environments; meanwhile, the manufacturing and integration of the large-scale chip can be realized by combining the temporary bonding process, and the method has practical application value and is worthy of popularization.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, so that the changes in the shape and principle of the present invention should be covered within the protection scope of the present invention.