High-power 808nm DFB LD built-in grating preparation method

Abstract

The invention aims to prepare a distributed feedback Bragg grating suitable for a high-power 808nm semiconductor laser by using holographic lithography and wet etching process, and relates to the technical field of semiconductor device manufacture. The invention is characterized by comprising the steps of carrying out one-time epitaxial growth on a GaAs substrate by using metal organic chemical vapor deposition (MOCVD) technology; exposing the prepared epitaxial wafer by using a holographic exposure system with an exposure source being a 325nmHe-Cd laser; carrying out developing and hardening; and finally, etching an InGaP grating layer by using an etching solution with a volume ratio of HCl:C2H6O2=3:2 and obtaining a grating. The beneficial effects of the invention are that a second-order grating with better morphology is prepared on the InGaP grating layer and the duty cycle, groove depth and other parameters enables the laser to have narrow linewidth and small wavelength shift. Meanwhile, the process can be used for high-power compound semiconductor laser of other wavelength and has a wide range of application.

Description

technical field [0001] A method for preparing a built-in grating of a high-power 808nm DFB distributed feedback semiconductor laser, especially a method for preparing a second-order distributed feedback Bragg grating on the InGaP grating layer. The invention belongs to the technical field of semiconductor device manufacturing, including holographic exposure and wet etching processes. Background technique [0002] The technique of using built-in gratings to lock the wavelength of semiconductor lasers has been studied for nearly half a century. Distributed feedback laser is the product of this technology. With the progress of optical fiber communication in the 1980s and 1990s, it developed most rapidly in the 1.3μm and 1.55μm bands. Compared with distributed feedback semiconductor lasers in this band, the development of GaAs-based short-wave distributed feedback lasers seems to lag behind. The main reason for this phenomenon is that these short-wavelength lasers are not wide...

AI Technical Summary

Problems solved by technology

The grating layer of the 808nm distributed feedback laser is developing towards Al-free materials such as InGaP, which solves the problem that Al-containing materials are easy to oxidize, but InGaP brings difficulties to the traditional preparation process

As far as the existing technology is concerned, it is difficult to guarantee a narrow linewidth and a small wavelength drift for the prepared distributed feedback laser.

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