Single Crystalline Silicide Formation

Abstract

Formation conditions of single crystalline silicide films on Si substrates by solid phase reactions were investigated using MeV He+ Rutherford backscattering and channeling techniques and transmission electron microscopy. It was shown that single crystalline silicide films (NiSi2, CoSi2 and Pd2Si) can be formed on (111)Si when metals are deposited onto clean surfaces and they are annealed without exposure to air. Channeling minimum yields in the backscattering analysis were 0.03–0.04 in NiSi2 and CoSi2 films thinner than 150 nm and 0.06 in Pd2Si films thinner than 100 nm. In the transmission electron microscopy measurement, grain boundaries were not observed at least in an area of 100×100 µm2, but several defects like twins and dislocations were observed in some silicide films. The resistivity of silicide films was also measured by the four-point probe method, and the resistivities of CoSi2, Pd2Si and NiSi2 were about 15 µΩ-cm, 25 µΩ-cm and 35 µΩ-cm, respectively.