Low-stress PECVD SiC thin films for IC-compatible microstructures

A low-temperature, IC-compatible, deposition process for SiC thin films with low mechanical stress and good passivating properties has been developed. SIC films with excellent etch resistance to various electrolytes have been deposited using a commercial-type PECVD reactor and patterned by dry etching in a fluorine-based chemistry. Deposition rates up to 100 nm min(-1) and good uniformity have been measured. A low compressive stress (350 MPa) has been obtained for as-deposited films by adjusting the deposition parameters. The stress can be further reduced (20 MPa) and even shifted into the low tensile region by a post-deposition anneal at 600 degrees C. Due to their excellent properties, these SiC thin films can be used as masking layers in various etch processes, particularly for deep etching of glass or silicon, and to realize IC-compatible SiC membranes. (C) 1998 Elsevier Science S.A. Ali rights reserved.