Passivation of LPCVD nitride silicon stacks by atomic H

Abstract

In this paper, H introduction into low pressure chemical vapor deposited silicon nitride (LPCVD SiN) films using molecular and atomic hydrogen is discussed and compared. Infra-red Multiple Internal Reflection (MIR) measurements were taken to analyse the hydrogen bond content in the nitride films. Quasi-steady state photoconductivity decay (QSSPCD) measurements on phosphorus diffused samples were used to determine the effective lifetime and the emitter saturation current Joe. Long process times and high temperatures are required for molecular hydrogen introduction whereas shorter times and low temperatures are sufficient for atomic hydrogen introduction. Hydrogen introduced into the nitride layer in this way can passivate the Si-SiO2 interface of oxide/nitride stacks on silicon. An annealing following atomic H re-introduction at elevated temperatures in N2 further improves the properties of the Si-SiO2 interface.