Cost effective and robust nickel silicidation process qualification and chamber matching in rapid thermal processing tools

Abstract

A new technique in qualification of low temperature nickel silicide process is studied. Bare silicon wafers are first oxidized to form a thick film of thermal oxide, followed by nickel and titanium film stack deposition. The samples are then annealed at low temperature using a rapid thermal processing tool. It is shown that the nickel and titanium film stack forms an alloy above the thermal oxide layer. This alloy's sheet resistance depends on the nickel/titanium film thickness, nickel to titanium thickness ratio, annealing temperature and time. Using the high temperature sensitivity compared to that in conventional technique, this new technique offers an accurate, reliable, and cost effective approach for process qualification, rapid thermal annealing chamber matching and daily monitoring.. Keywords-nickel silicide; low temperature; nickel and titanium film stack; process qualification; chamber matching Figure 1 Schematic flow chart for the conventional approach