Development of a low temperature SiC protection layer for post-CMOS MEMS fabrication utilizing vapour release technologies

In post-CMOS processing a sufficient protection of the underlying CMOS structures, while applying sacrificial layer release technologies to realize free standing MEMS, is required. In this work, a low temperature Silicon Carbide (SiC) process at 300 C by Inductively Coupled Plasma Chemical Vapour Deposition (ICPCVD) has been developed. It has been demonstrated, that SiC provides an excellent protection character in HF=H2O vapour mixtures. For proof of principle, perforated free-standing SiC-structures with a layer thickness of less than 200 nm and 80 mm in diameter have successfully been released in a vapour etch process.