用激光微细加工制作平面型InGaAs/InP PIN 光探测器

 采用激光微细加工技术来制作单片集成光接收机的探测器，在制作过程中，用固态杂质源10.6 μm激光诱导Zn扩散工艺来进行探测器的p-区掺杂。制作出平面型顶部入射的InGaAs/InP PIN 光探测器，响应度为0.21 A/W。分析了激光诱导扩散中影响探测器性能的因素，因此提出了扩散温度自动控制、扩散区温度分布均匀化及激光焦斑与扩散区精确对准等相应的改进方法。

Fabrication of Planar InGaAs/InP PIN photodiodes using laser assisted microprocessing

As the fundamentals of the fabrication of monolithically integrated optical receiver, a photodiode has been fabricated using laser assisted microprocessing. Laser induced local zinc diffusion has been used to form the p-n junction of the photodiode. The diffusion process was implemented by using the focused laser spot to heat the diffusion window. A spin-on film doped by Zn was used as the diffusion source. Lithography, passivation, electrodes fabrication and packaging are conventional, as the wafers don't endure high temperature in these steps. The responsivity of the fabricated Planar InGaAs/InP PIN photodiodes arrived 0.21 A/W. It was found that some factors in the laser induced diffusion process caused the low performance of the photodiodes. Then improvements including the automatic controlling of the diffusion temperature, the flatting of temperature distribution in the small diffusion region, and the aligning of the invisible laser focus spot and the diffusion region are proposed.