Low-temperature growth of SiCAlN films of high hardness on Si(111) substrates

Abstract

Thin films of metastable SiCAlN solid solution were deposited on Si(111) substrates at 550–750 °C, considerably below the miscibility gap of SiC and AlN phases at 1900 °C. Our low-temperature growth was based upon thermally activated reactions between a unimolecular precursor H3SiCN and Al atoms from an evaporative cell in a molecular-beam-epitaxy chamber. Characterization of deposited films by spectroscopic and microscopic techniques yielded near-stoichiometric composition throughout the columnar wurtzite structure with lattice parameters very close to those of 2H–SiC and hexagonal AlN. An average hardness of 25 GPa was measured for the SiCAlN films, comparable to that measured for sapphire.