Yuan (David) Zhang
SiGe/Si HIP Separate Absorption Multiplication Avalanche Middle Wavelength Infrared PhotoDiode
Separate-absorption-and-multiplication (SAM) Avalanche PhotoDiode (APD) is widely accepted in optical communication systems due to the presence of large photocurrent gain. In this thesis, a designed SAM middle wavelength infrared avalanche photo detector operating at room temperature is presented. The designed photo detector is based on SiGe/Si heterojunction internal photoemission (HIP) and it is compatible with CMOS technology. The detection mechanism of the SiGe/Si HIP detector is infrared absorption in the degenerately doped p+-SiGe layer followed by internal photoemission of photoexcited holes over the heterojunction barrier. Silvaco TCAD tool is utilized to implement the simulation of this designed SiGe/Si HIP SAM APD. The structure of the designed APD is evaluated by simulation tools, the simulation results of the dark current, the current under illumination, photogenetation rate, recombination rate, and electrical field are shown in this thesis. The relation between dark current and generation recombination is discussed at the end of this thesis.