Device for semiconductor laser unit Zn impurity source diffusion and application thereof

Abstract

The invention relates to a device for semiconductor laser unit Zn impurity source diffusion. The device comprises a first diffusion heating furnace and a second diffusion heating furnace which are arranged on a track in sequence. The first diffusion heating furnace is in the shape of a groove with one end sealed. The second diffusion heating furnace is in the shape of a hollow-out ring. The position, at one end of the track, behind the second diffusion heating furnace is provided with a support. The support is provided with a quartz tube with one end sealed and the other end open. A first thermocouple and a second thermocouple are sequentially arranged in the quartz tube in the longitudinal direction. The front-half portion of a quartz boat is arranged on the first thermocouple. The rear-half portion of the quartz boat is arranged on the second thermocouple. According to the device, the separation of a diffusion source and a chip is adopted, a double-temperature area is adopted to control the temperature of the diffusion source and the temperature of the chip, and during the diffusion process, the temperature of the diffusion source and the temperature of the chip are controlled so that the stability of a furnace temperature can be guaranteed; GaAs on the surface layer of the chip of a laser unit is prevented from decomposing in large quantity under the diffusion temperature, so that a high-concentration surface layer which has the advantages of being bright in surface, even in distribution of the Zn concentration, good in repeatability, and free of damage is obtained.

Description

technical field [0001] The patent of the invention relates to a device for diffusing a Zn impurity source of a semiconductor laser and its application, which belongs to the technical field of semiconductor technology. Background technique [0002] In the fields of optical communication, data storage, DVD / VCD and barcode readers, laser printing, laser display, gas monitoring and medical equipment, lasers (LD) have a wide range of applications, of which 650nm lasers are mainly used in optical storage systems for Manufactures laser heads for DVD, DVD-R / RW. For DVD-R / RW, the recording speed is proportional to the square of the LD output power. To obtain a fast recording speed, the output power of the LD must be increased, and the maximum output power is limited by the optical disaster (COD) of the laser end face. The expansion of application fields puts forward higher requirements for laser output power, which requires further optimization and improvement of laser material sele...

AI Technical Summary

Problems solved by technology

In the method of the present invention, the distance between the diffusion source and the chip is placed in the same furnace tube, and the separate temperature control of the diffusion source and the diffusion chip cannot be realized. Agglomeration is very easy to occur on the surface of the chip when cooling after diffusion, causing the surface after diffusion to be not smooth. Quartz The other end of the tube is located outside the furnace of the heating furnace and is not isolated. The diffusion source is easily condensed at the furnace mouth, resulting in insufficient diffusion source and insufficient diffusion depth.

[0006] Chinese patent CN101950775A records "A Method of Using Epitaxy Equipment to Make Double Diffusion Type Backlight Illuminated Optical Avalanche Tube", which uses the double diffusion method of MOCVD epitaxy equipment to control the flow rate of the diffusion source to achieve gradual doping in different regions and different concentrations. Doping by forming an abrupt junction during diffusion, this method is relatively expensive and has the disadvantage that the process is not easy to control

[0009] To sum up the current conventional Zn diffusion method has the following disadvantages: poor process repeatability; agglomeration phenomenon is easy to appear at the strip window on the surface of the laser chip and the furnace mouth during diffusion; the surface is not smooth after Zn diffusion; It is very easy to oxidize and prevent further diffusion. These deficiencies are very unfavorable to the manufacture of devices, and may even completely destroy the four-layer structure of the epitaxial wafer. It cannot meet the needs of devices with complex structures and high requirements on parameters such as junction depth.

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