Deposition of epitaxial silicon carbide films using high vacuum MOCVD method for MEMS applications

摘要

Silicon carbide (SiC) thin film have been prepared on both Si(100) and SiO_2 patterned Si(100) substrates by the high vacuum metal-organic chemical vapor deposition (MOCVD) method using a single source precursor at various growth temperatures in the range of 700-1000 ℃. Diethylmethylsilane(DEMS) was used as precursor without carrier gas. The effects of substrate temperature as well as deposition time on the crystal growth and hardness were mainly investigated in this study. The optimum temperature for the formation of the epitaxial SiC thin films were found to 900 ℃ on the basis of XRD results. However, the XPS result shows that the SiC film grown at 900 ℃ have carbon rich (Si:C= 1:1.2 composition) surface due to surface reaction of the precursor itself. From the SEM images, substrate temperature has influence on the grain size and crystallinity of the SiC films. Especially, the major crystal form of these deposited films was rectangular in shape on the substrates at 900 ℃. We also obtain a high hardness SiC thin film with 32 GPa.