Preparation process of ridge waveguide DFB laser based on double-glue-layer structure

Abstract

The invention discloses a preparation process of a ridge-type waveguide DFB laser based on a double-glue-layer structure. Windowing of a ridge-type region current channelcomprises the steps: depositing a SiO2 insulating layer in a plasma enhanced chemical vapor deposition mode; coating a first layer of photoresist on the surface of the SiO2 insulating layer, and baking the first layer of photoresist to prevent the first layer of photoresist from being corroded by a wet method; coating a second layer of photoresist on the first layer of photoresist; baking the second layer of photoresist, wherein the baking temperature and time are both lower than those of the first layer of photoresist; performing exposure and development on the second layer of photoresist by using the photomask; corrodingthe second layer of photoresist subjected to exposure and development by adopting a wet etching process; etching the first layer of photoresist by adopting an RIE dry etching process; and etching theSiO2 insulating layer by adopting an RIE dry etching process, and removing the SiO2 insulating layer on the ridge strips to form a current channel. According to the method, the ridge-shaped structurewith a complete vertical shape on the side surface can be prepared.

Description

technical field [0001] The invention belongs to the technical field of semiconductor laser preparation technology, and relates to a preparation technology of a ridge waveguide DFB laser based on a double glue layer structure. Background technique [0002] In optical fiber communication, semiconductor lasers have become the core signal transmission source in the field of optical communication due to their small size, high efficiency, low power consumption, and easy integration. With the rapid development of optical fiber communication, long-wavelength DFB (Distributed Feedback Laser) lasers are widely used in high-speed transmission systems due to their stable dynamic single longitudinal mode characteristics. Especially in recent years, the rapid development of FTTH has greatly promoted the development of DFB laser epitaxy. Development of materials and process preparation processes. [0003] At present, there are two structures of DFB lasers, ridge waveguide structure (RWG) ...

AI Technical Summary

Problems solved by technology

[0013] The following problems exist in the traditional process steps: the substrate to be coated with photoresist is a ridge waveguide structure with a certain depth, which makes it difficult for the photoresist to meet the requirements for flatness of the back surface of the waveguide structure. Resist requirements and overlay exposure technology requirements are relatively high

When using solution wet etching to develop and expose the photoresist layer, there is a certain relationship between the solution etching speed and the concentration, uniformity, and etching time of the etching solution, so it is difficult to accurately control the depth of etching, resulting in corroded photolithography. It is difficult to keep the depth of glue consistent, and then dry etch SiO 2 insulating layer, it is difficult to avoid SiO on the ridge sidewall 2 Etching, resulting in an increase in leakage current, making it difficult to guarantee the consistency of chip production, and the device may be broken down under working conditions

The insufficiency of the traditional process method leads to the instability of the laser manufacturing process, which seriously affects the performance, reliability and product yield of the DFB laser

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