A kind of preparation method of bh laser mesa mesa

Abstract

The invention discloses a preparation method of a BH laser MESA mesa, which comprises the following steps: 1) SIO2 masking layer growth, using PEALD to grow the SIO2 masking film; 2) MESA lithography; 3) SIO2 masking layer etching; 4) MESA etching ; 5) Secondary epitaxy. The preparation method of the BH laser MESA mesa adopts the SIO2 film layer grown by PEALD (plasma enhanced atomic layer deposition), which is deposited at the atomic level. Compared with PECVD growth, the film layer is denser and has no pinholes. The adhesion is very strong, and the film thickness of 50~100nm can meet the needs of secondary epitaxy, and the stress during growth is small, and the buried layer of secondary epitaxy growth is more uniform.

Description

technical field [0001] The invention relates to the technical field of lasers, in particular to a preparation method of a BH laser MESA table. Background technique [0002] The structure of edge-emitting lasers is mainly divided into two types: ridge waveguide structure (RWG) and buried heterojunction structure (BH). The advantages of RWG structure laser chips are simple in structure design, but the disadvantages are large power consumption and low elliptical spot coupling efficiency; BH structure laser chips The advantages are low power consumption, high light output power, and high coupling efficiency of circular light spots. The disadvantage is that the structure design is complicated. At present, the market mainly tends to products with low power and high coupling efficiency, so BH laser is the main research direction at present. [0003] MESA table preparation is one of the most important processes in the BH laser manufacturing process. How to ensure the uniformity of ...

AI Technical Summary

Problems solved by technology

In the prior art, the growth of SIO2 cover layer uses PECVE to grow SIO2, and the growth of SIO2 film layer by PECVE is dense, stress and adhesion are not good. As a MESA mask layer, a thick SIO2 film is required, and the film thickness is usually 150nm~300nm. , at the same time, the thermal expansion coefficient of the film layer grown by PECVD is high, and it is easy to fall off during the high-temperature epitaxial growth process, which affects the uniformity

Because the existing MESA etching solution is etched in proportion, the uniformity of etching the entire MESA is 20%~30%, which makes the uniformity of the entire sheet poor, making the Mesa table stress large, and will also affect the secondary epitaxial growth.

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