Raman and IR Spectrum Analysis of CrSi2 Thin Films Formed in Direct Current and Variable Frequency Modes of a Magnetron Sputtering Device
Abstract
CrSi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> thin films were deposited using direct current and variable frequency magnetron sputtering. The formation of nanofilms by solid-phase ion-plasma method in high vacuum using a magnetron sputtering device in different modes is currently the most effective method. Chromium disilicide thin films were formed on SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> substrates and n-type Si(111) single crystals via magnetron sputtering in different modes, and performed spectroscopic analyses to determine their optical parameters. Before the deposition, the substrates were cleaned with acetone and ethanol in an ultrasonic bath for 5 min and dried under nitrogen (N<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>). Thermal treatment of thin films was carried out in a dynamic vacuum (10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> mbar) at a temperature of 750 K for 1 hour with a heating rate of 450 K·h<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> and natural cooling. The temperature was controlled by a K-type thermocouple next to the sample.Raman spectroscopy performed on polycrystalline thin films revealed the presence of a Raman-active mode at 508 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>. This confirms the density-functional theory calculations predicting a mode at 297 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, which has so far been difficult to observe in polycrystalline CrSi<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>. Combinatorial vibrations, one of the broad features centered at 1322 and 1563 cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup>, were also observed.