Effect of A1 Doping on Properties of SiC Films

摘要

Undoped and Al-doped 3C-SiC films are deposited on Si(lO0) substrates by low-pressure chemical vapour deposition. Effects of aluminium incorporation on crystaJlinity, strain stress, surface morphology and growth rate of SiC films have been investigated. The x-ray diffraction patterns and rocking curves indicate that the crystallinity is improved with aluminium doping. Raman scatting patterns also demonstrate that the strain stress in SiC films is released due to the incorporation of A1 ions and the increase of film thickness. Furthermore, due to the catalysis of surface reaction which is induced by trimethylaluminium, the growth rate is increased greatly and the growth process varies from three-dimensional island-growth mode to step-flow growth mode.