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CN-117767109-B - Manufacturing method of flip-chip ridge waveguide semiconductor laser and semiconductor laser

CN117767109BCN 117767109 BCN117767109 BCN 117767109BCN-117767109-B

Abstract

The invention discloses a manufacturing method of a flip-chip ridge waveguide semiconductor laser and the semiconductor laser, the manufacturing method comprises providing a substrate, forming a mask layer on the surface of the substrate; etching the mask layer to prepare a strip-shaped window on the mask layer, sequentially growing an n-type covering layer and an n-type limiting layer in the strip-shaped window to form an n-type ridge waveguide, growing an epitaxial structure on the surface of the n-type limiting layer, forming a current expansion layer on the epitaxial structure and forming a p-type electrode on the surface of the current expansion layer, removing the substrate and forming an n-type electrode on the surface of the n-type covering layer. According to the manufacturing method of the flip-chip ridge waveguide semiconductor laser and the semiconductor laser, the preparation of the ridge waveguide of the n-type region can be completed without etching the n-type region, the luminous performance of the laser is improved, meanwhile, the flip-chip process of the semiconductor laser is greatly simplified, the ohmic contact area of the p-type contact layer is increased, and the heat dissipation of the whole device is facilitated.

Inventors

  • GONG YI
  • ZHU JIANJUN
  • YANG WENXIAN
  • LU SHULONG
  • Hua Haowen
  • ZHANG PENG
  • GU YING
  • HUANG MENGYANG

Assignees

  • 中国科学院苏州纳米技术与纳米仿生研究所

Dates

Publication Date
20260508
Application Date
20231226

Claims (10)

  1. 1. A method of fabricating a flip-chip ridge waveguide semiconductor laser, comprising: providing a substrate, and forming a mask layer on the surface of the substrate; Etching the mask layer to prepare a strip-shaped window on the mask layer; sequentially growing an n-type covering layer and an n-type limiting layer in the strip-shaped window to form an n-type ridge waveguide; Growing an epitaxial structure on the surface of the n-type limiting layer; forming a current expansion layer on the epitaxial structure, and forming a p-type electrode on the surface of the current expansion layer; and removing the substrate, and forming an n-type electrode on the surface of the n-type covering layer to obtain the semiconductor laser epitaxial wafer.
  2. 2. The method of fabricating a flip-chip ridge waveguide semiconductor laser of claim 1, wherein juxtaposed stripe-shaped windows are fabricated on the mask layer by photolithography, wet etching, dry etching processes, the stripe-shaped windows exposing a portion of the substrate.
  3. 3. The method of fabricating a flip-chip ridge waveguide semiconductor laser according to claim 2, wherein the mask layer has a thickness of 1 μm to 2 μm, and/or, The distance between the adjacent strip-shaped windows is 1.5-3 mu m.
  4. 4. The method of fabricating a flip-chip ridge waveguide semiconductor laser of claim 1, wherein epitaxial growth of the n-type cladding layer and the n-type confinement layer is performed within the stripe-shaped window using a lateral epitaxial overgrowth technique, and/or, The thickness of the n-type covering layer is smaller than that of the mask layer, and the sum of the thicknesses of the n-type covering layer and the n-type limiting layer is larger than or equal to that of the mask layer.
  5. 5. The method of claim 1, wherein the epitaxial structure comprises a lower waveguide layer, an active layer, an upper waveguide layer, a p-type electron blocking layer, a p-type confinement layer, a p-type cladding layer, and a p-type contact layer sequentially grown on the surface of the n-type confinement layer.
  6. 6. The manufacturing method of the flip-chip ridge waveguide semiconductor laser device according to claim 1, wherein the p-type electrode comprises contact metal and contact electrode which are arranged in a stacked mode, the thickness of the contact metal is 1-300 nm, the material of the contact metal comprises one or more of Pd, ni, pt, al, ti, the thickness of the contact electrode is greater than or equal to 30nm, and the material of the contact electrode comprises Au.
  7. 7. The method of fabricating a flip-chip ridge waveguide semiconductor laser of claim 1, further comprising, after the step of forming the p-type electrode on the surface of the current spreading layer: Bonding heat deposition on the surface of the p-type electrode; The material of the heat sink comprises diamond and SiC.
  8. 8. The method of fabricating a flip-chip ridge waveguide semiconductor laser of claim 1, wherein removing the substrate comprises: removing the substrate by grinding, thinning, polishing, or The substrate is stripped by a laser.
  9. 9. The method of manufacturing a flip-chip ridge waveguide semiconductor laser according to claim 1, further comprising dicing, cleaving and facet coating the semiconductor laser epitaxial wafer to obtain a flip-chip ridge waveguide semiconductor laser.
  10. 10. A flip-chip ridge waveguide semiconductor laser, comprising: An n-type electrode having a first surface; A mask layer formed on the first surface, wherein a strip-shaped window is formed in the mask layer, and the strip-shaped window exposes part of the first surface; An n-type ridge waveguide formed in the strip-shaped window, wherein the n-type ridge waveguide comprises an n-type covering layer formed on the first surface and an n-type limiting layer formed on one side surface of the n-type covering layer, which is away from the n-type electrode; the epitaxial structure is formed on the surface of one side of the n-type limiting layer, which is away from the n-type electrode; the current expansion layer is formed on the surface of one side of the epitaxial structure, which is away from the n-type electrode; the p-type electrode is formed on the surface of one side of the current expansion layer, which is away from the n-type electrode; And the heat sink is formed on the surface of one side of the p-type electrode, which is away from the n-type electrode.

Description

Manufacturing method of flip-chip ridge waveguide semiconductor laser and semiconductor laser Technical Field The invention belongs to the technical field of semiconductors, and particularly relates to a manufacturing method of a flip-chip ridge waveguide semiconductor laser and the flip-chip ridge waveguide semiconductor laser. Background With the development of the age, gaN-based semiconductor Laser Diodes (LD) are increasingly used in the fields of laser display, automotive headlamp lighting, visible light communication, industrial processing, biomedical treatment, and the like. In order to enhance the lateral optical field confinement and current confinement of the laser, ridge waveguide structures are widely used. At present, the main technical scheme for preparing the ridge waveguide of the laser at home and abroad is to carry out photoetching and etching processes on the p-type upper limiting layer and the p-type contact layer, however, the preparation method can cause side wall damage and is difficult to repair, thereby increasing light absorption loss and easily introducing a leakage channel. In addition, the heat dissipation problem also restricts the development of the high-power LD. The peak power of LD is very high when working, can produce a large amount of heat and lead to the active region temperature to rise rapidly to cause the optics catastrophe of LD, even burn out, seriously influence the reliability and the life-span of LD. Therefore, the exploration of a novel method for preparing the ridge waveguide of the laser and solving the heat dissipation problem are of great significance to the development of the LD. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide a manufacturing method of a flip-chip ridge waveguide semiconductor laser and the flip-chip ridge waveguide semiconductor laser, which can finish the preparation of a ridge waveguide of an n-type region without etching the n-type region (an n-type covering layer and an n-type limiting layer), improve the luminous performance of the laser, greatly simplify the flip-chip process of the semiconductor laser, increase the ohmic contact area of a p-type contact layer and facilitate the heat dissipation of an integral device. In order to achieve the above object, a specific embodiment of the present invention provides the following technical solution: A manufacturing method of a flip-chip ridge waveguide semiconductor laser comprises the following steps: providing a substrate, and forming a mask layer on the surface of the substrate; Etching the mask layer to prepare a strip-shaped window on the mask layer; sequentially growing an n-type covering layer and an n-type limiting layer in the strip-shaped window to form an n-type ridge waveguide; Growing an epitaxial structure on the surface of the n-type limiting layer; forming a current expansion layer on the epitaxial structure, and forming a p-type electrode on the surface of the current expansion layer; and removing the substrate, and forming an n-type electrode on the surface of the n-type covering layer to obtain the semiconductor laser epitaxial wafer. In one or more embodiments of the invention, the n-type confinement layer covers the mask layer or a surface of the n-type confinement layer facing away from the n-type confinement layer is flush with a surface of the mask layer facing away from the substrate. In one or more embodiments of the present invention, strip-shaped windows are prepared on the mask layer in parallel by photolithography, wet etching, and dry etching processes, wherein a portion of the substrate is exposed by the strip-shaped windows. In one or more embodiments of the present invention, the thickness of the mask layer is 1 μm to 2 μm. In one or more embodiments of the present invention, a distance between adjacent strip-shaped windows is 1.5 μm to 3 μm. In one or more embodiments of the invention, epitaxial growth of the n-type cladding layer and the n-type confinement layer is performed within the stripe-shaped window using a lateral epitaxial overgrowth technique. In one or more embodiments of the invention, the thickness of the n-type cladding layer is less than the thickness of the mask layer, and the sum of the thicknesses of the n-type cladding layer and the n-type confinement layer is greater than or equal to the thickness of the mask layer. In one or more embodiments of the present invention, the epitaxial structure includes a lower waveguide layer, an active layer, an upper waveguide layer, a p-type electron blocking layer, a p-type confinement layer, a p-type cladding layer, and a p-type contact layer sequentially grown on the surface of the n-type