Formation of ytterbium silicide thin films by solid-phase crystallization

Abstract

Ytterbium silicide (YbSi1.7 thin films were prepared on single-crystal Si (111) wafers and fused silica plates by solid-phase crystallization. The structure and phase transformations of the films were analysed by X-ray diffraction and Rutherford backscattering spectroscopy (RBS). The electrical properties of these silicides were studied by Hall mobility measurements and four-point probe measurements of sheet resistance. Solid-phase crystallization was carried out by irradiating the samples with infrared radiation in a vacuum, the process being monitored by in situ sheet resistance measurements to obtain the phase transformation temperature. The crystallization of YbSi1.7 phase occurs at a temperature as low as 260 °C on Si substrate, and at about 400 °C on fused silica. The results of 2.5 MeV +Li7 RBS showed that the atomic ratio of Si to Yb in the irradiated films is close to 1.7, and the Yb atomic density is almost constant through the depth of the films.