Process control of titanium silicide formation using rapid thermal processing

Abstract

Rapid thermal processing has been used to precisely control and study the reaction rate for the formation of titanium silicide. Samples were prepared by first depositing an 80 nm thick layer of Ti on n-type Si wafers. Half of the wafers were then coated with 100 nm of reactively sputtered TiN. The wafers were then subjected to a matrix of rapid time-temperature profiles under argon, nitrogen and forming gas ambients to precisely control the silicide formation kinetics. Reacted films were characterized by four point probe conductivity measurements and Auger Electron Spectroscopy. Results show that the rate of silicide formation is fastest for films annealed in argon, slowest for films annealed in forming gas and that the TiN encapsulating layer retards the reaction rate in both cases.