Kinetics of silicon stacking fault growth/shrinkage in an oxidizing ambient containing a chlorine compound

Abstract

A kinetic model for the growth and shrinkage of oxidation-induced stacking faults (OSF) in silicon in an oxidizing ambient containing a chlorine compound is developed. The main assumption used in the model is that the vacancy injection rate due to Si-Cl compound formation is essentially independent of the silicon self-interstitial injection rate due to SiO2 growth. That is, the process of Si-Cl compound formation is not correlated with the process of SiO2 growth. This permits us to calculate the OSF size from RClSF = 1640t0.75 exp(−2.5/kT) −(4.86×109t/ kT) exp(−5.02/kT)−RCl , where RClSF is one half the OSF length (in chlorine oxidation) in cm, t in sec, kT in eV, and RCl = btm with b and m determined from experimental data. RCl represents the further shrinkage of OSF size due to the action of chlorine in addition to that due to stacking fault energy. The agreement between this model and available experimental results is satisfactory. We have found that m adopted values between 0.5 and 1, indicating that Si-Cl formation changes from diffusion limited processes to interface reaction limited processes, and this is sensitive to chlorine content in the ambient and to oxidation temperatures. A limited number of data are useful for arriving at the activation energy for vacancy injection due to Si-Cl compound formation of 2–2.5 eV, and for concluding that the most likely Si-Cl compound formed is SiCl.