用刻蚀坑方法抑制平面型InGaAs/InP盖革模式APD的边缘击穿

Using Etch Well to Suppress Edge Breakdown of Planar-type InGaAs/InP Geiger Mode Avalanche Photodiodes

通过测量平面型InGaAs/InP雪崩光电二极管闭管扩散器件帽层InP中Zn杂质的分布,拟合出掺杂浓度随扩散深度的变化函数,并且利用离化积分研究不同倍增层厚度下的最佳刻蚀坑深度和最佳刻蚀方法.结果表明在帽层深度不变的情况下,最佳刻蚀坑深度会随着倍增层厚度而变化,当倍增层厚度为1μm左右时刻蚀坑深度在0.1~0.3μm之间.采取反应离子刻蚀可以获得良好的刻蚀坑形貌,有利于边缘击穿的抑制.

By measuring the distribution of impurity Zn in InP of planar-type InGaAs/InP Geiger mode Avalanche Photodiodes,the function of doping concentration with diffusion depth was fitted,and the optimum depth of etch well at different multiplication layer thickness as well as the best etching method were studied using ionization integral.The results show that the optimum etch well depth is varied with multiplication layer thickness when the thickness of top InP is constant.And when the multiplication layer thickness is about 1μm,the well depth should be between 0.1μm and 0.3μm.Reactive ion etching can obtain a good etch well morphology,which is beneficial to the suppression of edge breakdown.