High-performance low-cost DFB laser epitaxial wafer and manufacturing method thereof

Abstract

A high-performance low-cost DFB laser epitaxial wafer comprises a substrate, a lower buffer layer, a lower limiting layer, a lower waveguide layer, a quantum well, an upper waveguide layer, an upper limiting layer, an upper buffer layer, a corrosion barrier layer, a cladding, a grating manufacturing layer, a secondary epitaxial layer, a barrier gradient layer and an ohmic contact layer which are sequentially stacked from bottom to top. The grating manufacturing layer is divided into a grating area and a non-grating area. The invention provides a high-performance low-cost DFB laser epitaxial wafer and a manufacturing method thereof. The high-performance low-cost DFB laser epitaxial wafer can effectively restrain the space hole burning effect of a laser, improve the side mode rejection ratio of the DFB laser, optimize the spectral mode of the DFB laser, reduce the manufacturing requirement of a grating photoetching plate, improve the product yield of the DFB laser, and is low in manufacturing cost.

Description

technical field [0001] The invention relates to a laser epitaxial wafer and a manufacturing method thereof, in particular to a high-performance and low-cost DFB laser epitaxial wafer and a manufacturing method thereof. Background technique [0002] The optical communication network uses light as the carrier of signal transmission. Compared with the electrical communication network using copper cables as the transmission medium, the speed, capacity and anti-interference ability of information interconnection have been significantly improved, so it has been widely used. Semiconductor lasers are the main light sources for optical communication networks, including Fabry-Perot lasers (FP lasers), distributed feedback lasers (DFB) and vertical cavity surface emitting lasers (VCSEL). Among them, the DFB laser establishes a Bragg grating inside the semiconductor, and relies on the distribution feedback of light to realize the selection of a single longitudinal mode. In the current ...

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Problems solved by technology

[0004] The traditional grating is distributed in the whole resonant cavity, so there will be two modes randomly distributed, the double peak effect is obvious, and the wavelength stability is poor

[0005] Invention patent CN201710632079.3, using double exposure method to prepare asymmetric grating, first use holographic coherent exposure method to expose with ultraviolet lithography machine, after the two exposures are completed, use developer to develop, and then use corrosion solution to grating area Etching is carried out simultaneously with the non-grating area, and then the photoresist mask is removed; however, the area in contact with the solution between the grating area and the non-grating area is quite different, and the etching rate of the two positions is significantly different during etching, and the two areas cannot be reached at the same time. Just in the state of complete etching, the non-grating area has the problem of too deep etching. After the second epitaxy, it will affect the reliability of the device. The uniformity of holographic exposure is greatly affected by the optical path, and it is difficult to achieve a large-scale uniform grating. Great impact on DFB laser yield

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