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CN-115133401-B - Flip VCSEL chip structure and manufacturing method thereof

CN115133401BCN 115133401 BCN115133401 BCN 115133401BCN-115133401-B

Abstract

The invention discloses a flip VCSEL chip structure and a manufacturing method thereof, the structure comprises a substrate, a first Bragg reflector layer, a quantum well layer, a second Bragg reflector layer and a dielectric film layer. The substrate is provided with a first surface and a second surface which are oppositely arranged, a micro-lens structure with a focusing function is formed on the first surface, the first Bragg reflector layer is arranged on the second surface of the substrate, the quantum well layer is arranged on one side of the first Bragg reflector layer, which is away from the substrate, the second Bragg reflector layer is arranged on one side of the quantum well layer, which is away from the first Bragg reflector layer, the dielectric film layer covers the second Bragg reflector layer, the quantum well layer and the side wall of the first Bragg reflector layer and the surface extending to the second surface of the substrate, and the dielectric film layer partially covers the surface of the second Bragg reflector layer, which is away from the quantum well layer. The flip VCSEL chip structure provided by the invention has a micro lens structure with a focusing function, and simplifies the packaging process of the VCSEL chip.

Inventors

  • ZHU JINTIAN

Assignees

  • 杰创半导体(苏州)有限公司

Dates

Publication Date
20260512
Application Date
20220628

Claims (6)

  1. 1. A flip-chip VCSEL chip structure, comprising: the substrate is provided with a first surface and a second surface which are oppositely arranged, wherein a micro-lens structure with a focusing function is formed on the first surface; a first Bragg reflector layer disposed on the second surface of the substrate; the quantum well layer is arranged on one side of the first Bragg reflector layer, which is away from the substrate; The second Bragg reflector layer is arranged on one side, away from the first Bragg reflector layer, of the quantum well layer, and the logarithm of the second Bragg reflector layer is larger than that of the first Bragg reflector layer; A dielectric film layer covering the sidewalls of the second Bragg reflector layer, the quantum well layer and the first Bragg reflector layer and extending to the second surface of the substrate, and the dielectric film layer partially covering the surface of the second Bragg reflector layer facing away from the side of the quantum well layer; the first electrode is arranged on the surface of the second Bragg reflector layer, which is away from the quantum well layer; A second electrode disposed on the second surface of the substrate and extending from the second surface of the substrate to a surface of the dielectric film layer facing away from the second bragg reflector layer, wherein the second electrode is electrically isolated from the first electrode, and the second electrode and the first electrode are located on the same plane; and a high-aluminum oxide layer is arranged on the surface of one side of the first Bragg reflector layer, which is away from the substrate, and a window area corresponding to the micro-lens structure is formed on the high-aluminum oxide layer in a penetrating manner.
  2. 2. The flip-chip VCSEL chip structure of claim 1, wherein the first electrode covers the exposed surface of the second bragg reflector layer.
  3. 3. The flip-chip VCSEL chip structure in accordance with claim 1, wherein the microlens structure is integrally formed with the substrate.
  4. 4. A method of fabricating a flip-chip VCSEL chip, characterized in that the flip-chip VCSEL chip has a flip-chip VCSEL chip structure according to any of claims 1 to 3; The manufacturing method of the flip VCSEL chip comprises the following steps: providing a substrate, wherein the substrate is provided with a first surface and a second surface which are oppositely arranged; forming a first Bragg reflector layer on a second surface of the substrate; Forming a high-alumina oxide layer on the surface of the first Bragg reflector layer, which is away from the substrate, wherein a window area capable of flowing electricity is formed on the high-alumina oxide layer; forming a quantum well layer on one side of the high aluminum oxide layer away from the first Bragg reflector layer; a second Bragg reflector layer is formed on one side, away from the high-alumina oxide layer, of the quantum well layer, wherein the logarithm of the second Bragg reflector layer is larger than that of the first Bragg reflector layer; Forming a dielectric film layer covering the second Bragg reflector layer, the quantum well layer, and the side wall of the first Bragg reflector layer and extending to the second surface of the substrate, an The dielectric film layer partially covers the surface of one side of the second Bragg reflector layer, which is away from the quantum well layer; forming a first electrode and a second electrode, wherein the first electrode is positioned on the surface of the second Bragg reflector layer, which faces away from the quantum well layer, and covers the exposed surface of the second Bragg reflector layer, the second electrode is positioned on the second surface of the substrate and extends from the second surface of the substrate to the surface of the dielectric film layer, which faces away from the second Bragg reflector layer, the second electrode is electrically isolated from the first electrode, and the second electrode and the first electrode are positioned on the same plane; thinning the substrate, forming a micro-lens structure corresponding to a window area on the high-alumina oxide layer on the first surface of the substrate, and evaporating an AR antireflection film on the surface of the micro-lens structure.
  5. 5. The method of fabricating a flip-chip VCSEL chip of claim 4, wherein a high aluminum oxide layer is formed on a surface of the first bragg reflector layer facing away from the substrate, the high aluminum oxide layer having a window region through which a current can flow, comprising: And forming a high-aluminum AlGaAs layer on the surface of the first Bragg reflector layer, which is away from the substrate, and keeping the position, corresponding to the micro lens structure, of the high-aluminum AlGaAs layer unchanged to form the window region, wherein the rest high-aluminum AlGaAs layers form the high-aluminum oxide layer through wet oxygen oxidation.
  6. 6. The method of fabricating a flip-chip VCSEL chip as claimed in claim 4 wherein the substrate is thinned by grinding and polishing processes and the microlens structure is fabricated by photolithography and ICP etching processes.

Description

Flip VCSEL chip structure and manufacturing method thereof Technical Field The invention relates to the technical field of semiconductor laser chips, in particular to a flip VCSEL chip structure and a manufacturing method thereof. Background VCSEL (vertical cavity Surface emitting Laser) (VERTICAL CAVITY Surface EMITTING LASER) is developed based on gallium arsenide semiconductor materials, is different from other light sources such as LEDs (light emitting diodes) and LDs (Laser Diode), has the advantages of small volume, round output light spots, single longitudinal mode output, small threshold current, low price, easy integration into a large-area array and the like, and is widely applied to the fields of optical communication, optical interconnection, optical storage and the like. Currently, in the packaging process of a VCSEL chip, a lens is usually added between the light-emitting end of the chip and the optical fiber to focus the light emitted from the VCSEL chip and then couple the focused light into the optical fiber to improve the coupling efficiency of the light. This process adds a packaging step to the VCSEL chip, complicating the packaging process of the VCSEL chip. 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 flip VCSEL chip structure and a manufacturing method thereof, which are provided with micro-lens structures, simplify the packaging process of the VCSEL chip and improve the heat dissipation effect of the VCSEL chip. To achieve the above object, an embodiment of the present invention provides a flip-chip VCSEL chip structure, including a substrate, a first bragg reflector layer, a quantum well layer, a second bragg reflector layer, and a dielectric film layer. The substrate is provided with a first surface and a second surface which are oppositely arranged, a micro-lens structure is formed on the first surface, a first Bragg reflector layer is arranged on the second surface of the substrate and partially covers the second surface, a quantum well layer is arranged on one side of the first Bragg reflector layer, which is away from the substrate, a second Bragg reflector layer is arranged on one side of the quantum well layer, which is away from the first Bragg reflector layer, a dielectric film layer covers the second Bragg reflector layer, the quantum well layer, the side wall of the first Bragg reflector layer and the second surface extending to the substrate, and the dielectric film layer partially covers the surface of the second Bragg reflector layer, which is away from one side of the quantum well layer. In one or more embodiments of the present invention, a high aluminum oxide layer is disposed on a surface of the first bragg reflector layer facing away from the substrate, and a window region corresponding to the microlens structure is formed on the high aluminum oxide layer. In one or more embodiments of the invention, the flip-chip VCSEL chip structure further comprises a first electrode and a second electrode. The first electrode is arranged on the surface of the second Bragg reflector layer, which is away from the quantum well layer, and covers the exposed surface of the second Bragg reflector layer, the second electrode is arranged on the second surface of the substrate, extends from the second surface of the substrate to the surface of the dielectric film layer, which is away from the second Bragg reflector layer, the second electrode is electrically isolated from the first electrode, and the second electrode and the first electrode are positioned on the same plane. In one or more embodiments of the invention, the second bragg mirror layer has a larger logarithm than the first bragg mirror layer. In one or more embodiments of the invention, the microlens structure is integrally formed with the substrate. In one or more embodiments of the present invention, the microlens structure is a hemispherical structure disposed in a convex manner with respect to the first surface of the substrate. In one or more embodiments of the present invention, the surface of the microlens structure is vapor-deposited with an AR antireflection film. In one or more embodiments of the present invention, the material of the substrate is GaAs, and the material of the microlens structure is GaAs. In one or more embodiments of the invention, the first Bragg reflector layer is an N-DBR, the second Bragg reflector layer is a P-DBR, the first electrode is a P-pole metal electrode, and the second electrode is an N-pole metal electrode. The invention also provides a manufacturing method of the flip VCSEL chip, which comprises the following steps: providing a substrate, wherein the substrate is provi