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

Thin films of metastable SiCAlN solid solution were deposited on Si(111) su bstrates at 550-750 degreesC, considerably below the miscibility gap of SiC and AlN phases at 1900 degreesC. 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. Char acterization of deposited films by spectroscopic and microscopic techniques yielded near-stoichiometric composition throughout the columnar wurtzite s tructure with lattice parameters very close to those of 2H-SiC and hexagona l AlN. An average hardness of 25 GPa was measured for the SiCAlN films, com parable to that measured for sapphire. (C) 2001 American Institute of Physi cs.