Published online by Cambridge University Press: 22 February 2011
Sputtered deposited titanium films on silicon substrates were used to study the effects of first rapid thermal anneal temperature, duration of anneal time and thickness of the titanium films for TiSi2 formation. A central composite, coupled with a cross design was used to analyze response surface. Empirical models were developed and contour plots were generated to describe the outcome of the first anneal. A window of operation to control the process of titanium silicide formation was recommended. Response surface analysis of data revealed an operating window of ±10° C for RTA1 for stable TiSi2 formation. Within this window of operation, the within wafer uniformity was found to be at its minimum. Anneal time was found to have minimum effect on the variability although sheet resistance decreases monotonically with increasing anneal time. Thickness of titanium films were found to be very critical in determining final TiSi2 thickness as determined by RBS and/or XRF techniques.