CN112701563B

CN112701563B - Preparation method of BH laser MESA table top

Info

Publication number: CN112701563B
Application number: CN202011591704.2A
Authority: CN
Inventors: 张鹏; 张永; 单智发; 陈阳华
Original assignee: Epihouse Optoelectronic Co ltd
Current assignee: Epihouse Optoelectronic Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2022-08-05
Anticipated expiration: 2040-12-29
Also published as: CN112701563A

Abstract

The invention discloses a preparation method of a BH laser MESA table top, which comprises the following steps: 1) growing a SIO2 masking layer, and growing a SIO2 masking film by using PEALD; 2) MESA photoetching; 3) SIO2 mask etch; 4) MESA corrosion; 5) and (5) secondary epitaxy. According to the preparation method of the MESA table top of the BH laser, the SIO2 film layer grown by PEALD (plasma enhanced atomic layer deposition) is adopted, the deposition is carried out on the atomic layer, the film layer is more compact and does not have a pinhole compared with PECVD growth, the adhesion between the film layer and the surface of a substrate is extremely strong, the requirement of secondary epitaxy can be met by the film thickness of 50-100 nm, the stress is small during the growth, and the buried layer grown by the secondary epitaxy is more uniform.

Description

Preparation method of BH laser MESA table top

Technical Field

The invention relates to the technical field of lasers, in particular to a preparation method of a BH laser MESA table top.

Background

The structure of the edge-emitting laser is mainly divided into a ridge waveguide structure (RWG) and a buried heterojunction structure (BH), and the RWG structure laser chip has the advantages of simple structural design, large power consumption and low elliptical light spot coupling efficiency; the BH structure laser chip has the advantages of low power consumption, high light-emitting power and high circular light spot coupling efficiency, and has the defect of complex structural design. The current market is mainly moving towards low power and high coupling efficiency products, and BH lasers are currently the major research direction.

The preparation of the MESA of MESA is one of the most important processes in the manufacturing process of BH laser, and how to ensure the uniformity of the MESA height and the MESA width is the key and difficult point of research. The preparation of the MESA MESA is mainly divided into the steps of SIO2 covering layer growth, MESA photoetching, SIO2 covering layer etching, MESA corrosion and secondary epitaxy. In the prior art, a PECVE is adopted for growing a SIO2 in the growth of a SIO2 covering layer, a PECVE is adopted for growing a SIO2 film layer, the compactness and the stress and the adhesion are poor, the film needs to be a thick SIO2 film as an MESA covering layer, the film thickness is usually 150 nm-300 nm, meanwhile, the thermal expansion coefficient of the film grown by PECVD is high, the high-temperature epitaxial growth process is easy to fall off, and the uniformity is influenced. The method has the advantages that the MESA etching solution is etched in a ratio of the existing MESA etching solution, the uniformity of etching the whole MESA is 20-30%, the uniformity of the whole MESA is poor, the MESA stress of the Mesa is large, and the secondary epitaxial growth is influenced. There is therefore a need to develop a method that can improve the MESA uniformity of BH lasers.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to design a preparation method of a BH laser MESA MESA for improving the uniformity of the BH laser MESA, which comprises the following steps:

a preparation method of a BH laser MESA table-board comprises the following steps:

1) growing a SIO2 masking layer, and growing a SIO2 masking film by using PEALD;

2) MESA photoetching;

3) SIO2 mask etch;

4) MESA corrosion;

5) and (5) secondary epitaxy.

Preferably, in the step 1), the growth temperature of the SIO2 masking film is 300 ℃, and the growth rate is 0.2 nm/s.

Preferably, the thickness of the growing SIO2 masking film is 50 nm-100 nm.

Preferably, in the step 4), the etching solution used for the MESA etching comprises BR, saturated bromine water, HBR and H2O, wherein the volume ratio of BR, saturated bromine water, HBR and H2O is 0.5-1: 1-2: 60-80: 100-200.

Preferably, the MESA corrosion in the step 4) is carried out in a constant temperature bath, and the temperature is controlled to be-15 ℃ to-5 ℃.

The technical scheme has the following beneficial effects: the preparation method of the MESA table top of the BH laser adopts the SIO2 film layer grown by PEALD (plasma enhanced atomic layer deposition), the deposition is carried out on the atomic layer surface, the film layer is more compact and has no pin holes compared with the PECVD growth, the adhesion between the film layer and the surface of a substrate is strong, and the requirement of secondary epitaxy can be met by the film thickness of 50-100 nm; compared with the traditional process, the thickness of SiO2 grown by PECVD is required to exceed 200nm, the thickness of SiO2 grown by PEALD is less than 100nm, the stress is small during growth, and a buried layer grown by secondary epitaxy is more uniform; the volume ratio of BR, saturated bromine water, HBR and H2O in the MESA corrosive solution is 0.5-1: 1-2: 60-80: 100-200, and the corrosive solution is easy to control; the MESA corrosion temperature is-15 to-5 ℃, and the corrosion uniformity can be less than 5 percent.

Drawings

FIG. 1 is a flow chart of an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Example embodiments will now be described more fully. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, devices, steps, and so forth. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the invention.

As shown in fig. 1, the present patent discloses a method for preparing a MESA of a BH laser MESA, which includes the following steps:

1) growing a SIO2 masking layer, and growing a SIO2 masking film by PEALD (plasma enhanced chemical vapor deposition), wherein the growth temperature of the SIO2 masking film is 300 ℃, the growth rate is 0.2nm/s, and the thickness of the grown SIO2 masking film is 50 nm-100 nm;

2) MESA photoetching;

3) SIO2 mask etch;

4) MESA corrosion, wherein a corrosion solution used in the MESA corrosion comprises BR, saturated bromine water, HBR and H2O, the volume ratio of the BR to the saturated bromine water to the HBR to the H2O is 0.5-1: 1-2: 60-80: 100-200, the MESA corrosion is carried out in a constant temperature tank, and the temperature is controlled at-15 ℃ to-5 ℃;

5) and (5) secondary epitaxy.

The preparation method of the MESA table top of the BH laser adopts the SIO2 film layer grown by PEALD (plasma enhanced atomic layer deposition), the deposition is carried out on the atomic layer surface, the film layer is more compact and has no pin holes compared with the PECVD growth, the adhesion between the film layer and the surface of a substrate is strong, and the requirement of secondary epitaxy can be met by the film thickness of 50-100 nm; compared with the traditional process, the thickness of SiO2 grown by PECVD is required to exceed 200nm, the thickness of SiO2 grown by PEALD is less than 100nm, the stress is small during growth, and a buried layer grown by secondary epitaxy is more uniform; the volume ratio of BR, saturated bromine water, HBR and H2O in the MESA corrosive solution is 0.5-1: 1-2: 60-80: 100-200, and the corrosive solution is easy to control; the MESA corrosion temperature is-15 to-5 ℃, and the corrosion uniformity can be less than 5 percent.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A preparation method of a BH laser MESA table-board is characterized by comprising the following steps:

1）SiO ₂ growing mask layer, and growing SiO by PEALD pulse deposition ₂ Mask layer of the grown SiO ₂ The thickness of the mask layer is 50 nm-100 nm;

2) MESA photoetching;

3）SiO ₂ etching the mask layer;

4) MESA corrosion;

5) secondary epitaxy;

SiO ₂ the growth temperature of the masking film is 300 ℃, and the growth rate is 0.2 nm/s;

in the step 4), an etching solution used for MESA etching comprises BR, saturated bromine water, HBR and H ₂ O, the BR, saturated bromine water, HBR, H ₂ The volume ratio of O is 0.5-1: 1-2: 60-80: 100-200.

2. The method for preparing the MESA MESA of the BH laser of claim 1, characterized in that the MESA corrosion in step 4) is carried out in a thermostatic bath, the temperature is controlled to be-15 ℃ to-5 ℃.