In-situ investigation of the formation of nickel silicides during interaction of single-crystalline and amorphous silicon with nickel

Abstract

In situ investigations showed that the sequence of phase formation during interaction of nickel particles with single crystalline (100) silicon and amorphous silicon corresponds to the following sequence of stages during the annealing of thin-film systems: (a) within a temperature range up to 500°C, the first and prevailing phase formed is Ni 2Si; and (b) annealing at temperatures above 600°C is accompanied by the formation and epitaxial growth of the NiSi 2 phase. The growth of the nickel disilicide crystalline phase is accompanied by the formation of dislocations both in the nickel disilicide phase and in the silicon phase. The interaction of the amorphous silicon film with nickel particles at temperatures above 600°C leads to the crystallization of several silicide phases: NiSi 2, NiSi, Ni 3Si 2. The formation of silicide phases due to the interaction of nickel particles with silicon during annealing did not confirm the formation of an intermediate amorphous silicide that was observed earlier in thin-film nickel–silicon systems. Irradiation with a beam of accelerated electrons in a microscope leads to an increase of the rate of silicide phase formation and to a decrease of the temperature at which the nickel disilicide phase is formed epitaxially, at least to 400°C. In our opinion, the observed effect can be due to the formation of defects in the structure of single crystalline silicon.