Structure, optical properties and resistance to laser radiation of thin barium disilicide films grown on silicon

Abstract

Polycrystalline and oriented films of barium disilicide (BaSi2) with a thickness of up to 100 nm were formed on silicon (111) substrates by high-temperature (800 ° C) solid-phase (single-stage and two-stage) annealing. The single phase of barium disilicide films and their semiconductor nature have been proven to be below 1.25 eV according to X-ray and optical spectroscopic methods. Two preferential orientations of the BaSi2 crystallites were detected and their orientation was determined in the films formed by two-stage annealing. According to the calculations of the parameters of the crystal structure of BaSi2 films, a compression of the unit cell volume from 2.7% to 5.13% was found, depending on the cooling time to room temperature. The stability of the films to laser radiation was studied by registering the Raman spectra with a variable power of laser radiation. The maximum power density of the laser beam (3⋅109 W/m2), which does not lead to the beginning of the destruction of these films, was determined.