Selective SiGe epitaxy by rtcvd for new device architectures

Abstract

CMOS technologies and devices are approaching their theoretical limits such as optical lithography, gate oxide thickness, etc. Consequently, new efforts are made in order to improve or modify device architecture. New epitaxial films grown at low temperature have potential of improving both electrical performances and integration of advanced devices. Firstly, we investigate the selective SiGe epitaxy with high Ge content based on the DCS/GeH 4/HCl/H 2 chemistry using an industrial 200 mm single wafer chemical vapour deposition at reduced pressure (<40 Torr) and low temperature (600–750 °C). We present new results about global loading effects in terms of growth and Ge content (15–40%) of perfectly strained SiGe films used for their selective etch properties in new device architectures. Secondly, we report on morphological results of the novel CMOS device architecture called silicon-on-nothing (SON). They allow extremely thin (a few nanometers) buried dielectric and silicon films to be fabricated with high resolution and uniformity guaranteed by SiGe and Si selective epitaxial processes. It is a very permissive structure as first approach of ultra thin SOI films.