Properties of silicon nitride film and its application to open-tube zinc diffusion

Silicon nitride(SiNx) films were deposited by PECVD using a SiH4 and NH3 gas mixture,and the properties of SiNx films were characterized by using infrared spectroscopic ellipsometer,FTIR and AES.The refractive indexes of SiNx films were observed to increase with increasing SiH4/NH3 gas ratios.FTIR experimental results indicated that SiNx films contain Si—N,Si—H,N—H,Si—O and Si—C bonds,and the concentration minimum of hydrogen bonds with silicon and nitrogen corresponds to the gas ratio of 38/8.The SiNx film with optimal deposition conditions and depth was applied to the open-tube zinc diffusion,and the planar InP/InGaAs PIN detectors were fabricated successfully.