Influence of Si-C bond density on the properties of a-Si_(1-x)C_x thin films

摘要

Amorphous silicon carbide (a-Si_(1_x)C_x) films were deposited on silicon (100) and quartz substrates by pulsed DC reactive magnetron sputtering of silicon in methane (CH_4)-Argon (Ar) atmosphere. The influence of substrate temperature and target power on the composition, carbon bonding configuration, band gap, refractive index and hardness of a-SiC films has been investigated. Increase in substrate temperature results in slightly decreasing the carbon concentration in the films but favors silicon-carbon (Si-C) bonding. Also lower target powers were favorable towards Si-C bonding. X-ray photoelectron spectroscopy (XPS) results agree with the Fourier Transform Infrared (FTIR), UV-vis spectroscopy results. Increase in substrate temperature resulted in increased hardness of the thin films from 13 to 17GPa and the corresponding bandgap varied from 2.1 to 1.8 eV.