PtSi contact metallurgy: Comparison of different annealing sequences, annealing time and ambients, and deposition techniques of Pt

Abstract

PtSi films formed by different processes are compared, including different annealing sequences, annealing time, and annealing ambients, using either sputtered Pt or electron-beam evaporated Pt onto heated and unheated substrates. The structures and compositions, surface passivating oxide and its resistance to aqua regia, and electrical characteristics of Schottky diodes fabricated are compared. It is shown that for the Pt films deposited onto unheated Si wafers using either sputtering or evaporation, the three-temperature sequences at 200-300-500 °C using forming gas with different annealing times are superior to the various two-temperature ones, which, in turn, are better than the one-temperature one at 550 °C. Application to device fabrication and concerns of throughput using the recommended three-temperature or two-temperature processes are discussed.