Coating method for cavity surface of semiconductor laser chip

Abstract

The invention belongs to the technical field of semiconductor laser end surface coating, and particularly relates to a coating method for a cavity surface of a semiconductor laser chip. The coating method comprises the following steps of 1) performing Bar strip cleavage and strip clamping on a chip to be coated, quickly putting the chip into evaporation coating equipment, and vacuumizing; 2) carrying out ion source pre-cleaning treatment on the light emitting cavity surface of the chip; 3) plating a high anti-reflection film system on the light emitting cavity surface of the chip, wherein the high anti-reflection film system at least comprises a first Al layer and a first AlOX layer; firstly plating an Al layer, and then introducing O2 by using an ion source to carry out oxidation treatment; 4) carrying out ion source pre-cleaning treatment on the backlight cavity surface of the chip; and 5) plating a high-reflective film system on the backlight cavity surface of the chip, the high-reflective film system at least comprising a second Al layer and a second AlOX layer, firstly plating the Al layers, and then introducing O2 by using an ion source for oxidation treatment. According to the method, the Al layers are plated on the front cavity surface and the rear cavity surface of the chip, and partial oxidation is performed, so that the effect of protecting the laser semiconductor cavity surface is achieved, and the reliability problem caused by oxidation of the cavity surface is further avoided.

Description

technical field [0001] The invention belongs to the technical field of film coating on the end face of a semiconductor laser, and in particular relates to a film coating method for a cavity face of a semiconductor laser chip. Background technique [0002] In order to improve the service life of the semiconductor laser chip and improve the reliability of the product, it is necessary to coat the front and rear cavity surfaces of the chip to protect the cavity surface and realize the reduction of the laser threshold and the power of the laser through different film characteristics of the cavity surface. Especially as the current high-speed chips generally adopt the InGaAlAs structure when doping, Al is easily oxidized in the air, and the cavity surface formed by cleavage is easily oxidized to form oxide defects, resulting in It is easy to form heat accumulation at the defect, which will affect the quality of the film layer on the cavity surface, increase the risk of film failur...

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Problems solved by technology

[0002] In order to improve the service life of the semiconductor laser chip and improve the reliability of the product, it is necessary to coat the front and rear cavity surfaces of the chip to protect the cavity surface and realize the reduction of the laser threshold and the power of the laser through different film characteristics of the cavity surface. Especially as the current high-speed chips generally use the InGaAlAs structure when doping, Al is easily oxidized in the air, and the cavity surface formed by cleavage is easily oxidized to form oxide defects. It is easy to form heat accumulation at the defect, which will affect the quality of the film layer on the cavity surface, increase the risk of film failure, directly lead to unstable laser performance, poor product reliability, and directly affect the service life of the product; at the same time, for For chips with Al structure, the structure of the cavity film system, the shape of the film layer, and its stable optical performance are all important factors that directly affect the laser chip, which can make the performance and reliability of the chip more stable. Stronger impact resistance, more stable light output and longer life

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