Dependence of the Crystallization Kinetics of Cr_0.26Si_0.74 Thin Films on Their Thickness

Abstract

The thermoelectric properties and crystallization kinetics of Cr_0.26Si_0.74 thin films with the thicknesses 11, 14, 21, 31, 56, 74, and 115 nm are studied. The films are produced by magnetron-assisted sputtering onto a cold substrate and, in the initial state, are amorphous in structure. During thermal annealing, the amorphous mixture transforms into a two-phase nanocrystalline composite consisting of chromium disilicide and silicon. In-situ measurements of the thermoelectric properties of the films during annealing show that the temperature of the onset of crystallization decreases, as the film thickness is decreased, whereas the crystallization rate increases. The thermopower of the nanocrystalline films decreases, as the film thickness is increased, and the thermoelectric-power factor reaches its maximum in films with a thickness of 31 nm.