The effect of diluent gases on the growth of β-SiC films by laser CVD with HMDS

β-SiC films have been fabricated on (100) Si substrates by laser chemical vapour deposition using hexamethyldisilane ( (CH3)3-Si-Si-(CH3)3) as a source precursor while argon or hydrogen as a diluent gas, respectively. The effects of different diluent gases species on the microstructure and deposition rate have been investigated by varying the flow rate of hexamethyldisilane (fHMDS). The results showed that pyramid, flower and needle-like morphologies were obtained using argon as diluent gas, whereas only pyramid with little flower structure appeared in the case of hydrogen. The deposition rate (Rdep) was in proportion to the fHMDS irrespective of diluent gases. Rdep was nearly 50% higher for hydrogen as diluent gas.