Silicon Nitride Coatings Formed using the Selective Area Laser Deposition (SALD) Technique

Abstract

AbstractIn this paper, the Selective Area Laser Deposition (SALD) technique was used to deposit silicon nitride material from the gas phase. Tetramethylsilane (TMS) and ammonia were chosen as precursors for silicon and nitrogen respectively. Effects of processing temperatures and gas ratios of TMS to total pressure (PTMS+ PNH3) on the relative amounts of silicon nitride and the growth kinetics were studied. Further, surface morphology and electrical properties of the deposits were also examined. It is found that the as-deposited materials are mainly composed of amorphous phases and the heat-treated samples (at 1500°C for 8hrs) consist of α-Si 3N4, α-SiC and β-SiC. The amount of αz-Si3N4decreases with the increase of the TMS pressure. The volume growth rate of deposits also increases with the TMS pressure. The apparent activation energy for these processes is estimated as 1 OOkJ/mol.