Effects of ramp-up rates on the salicide process

Increases in the sheet resistance of TiSi2 with a decreasing linewidth has been attributed to incomplete transformation from high resistance C49-TiSi2 phase to the desired low resistance C54-TiSi2 phase. In this article, we i nvestigate the effects of increasing the ramp up rate of the first rapid th ermal anneal (RTA1) in the salicide process. Electrical testing and micro-R aman spectroscopy were used to investigate the C49-to-C54 phase transformat ion on poly lines with different linewidths. Samples were annealed with two different ramp-up rates in RTA1. From micro-Raman spectra, it is observed that increased ramp-up rate during RTA1 results in more C54-TiSi2 formed du ring the second rapid thermal anneal (RTA2). It is also shown that higher r amp-up rates result in lower sheet resistance for deep submicron poly lines . (C) 1999 American Vacuum Society. [[S0734-211X(99)06205-8].