The project is aimed towards exploration of high-performance field-effect structures in strained Si/SiGe. An important topic is to master single-wafer vapour-phase epitaxy (VPE) in synthesising the Si/SiGe structures, up to date not previously reported. The project presents great challenges in advanced epitaxial growth techniques of strained layers and in-depth material characterisation has been required for proper fabrication of the desired heterostructures with different compositions and doping. The growth conditions for strained and relaxed layer growth are being optimised for maximum mobility and saturation velocity for field-effect devices. During 1998 simple modulation doped multilayer MOSFET structures have been fabricated to characterise the growth process. The first devices are p-channel, but both n- and p-type channel types will be considered in the future. The main emphasis will thereafter be put on preparing a high-speed heterostructure FET (HFET) in integrated MOS structures using a planar geometry. Promising devices will be further processed in test circuits. The proposed activities will provide new insights into artificially created Si/SiGe semiconductor structures utilising strain engineering concepts. Our main goal is the preparation of a high-performance heterostructure CMOS device (HCMOS) utilising the enhanced mobility of charge carriers in buried SiGe channels under strain. Hence the project constitutes a mix of fundamental and applied topics.
Vapour-phase epitaxy, Heterostructure FET, High frequency MOSFET, SiGe strained layer