Strained-Si-strained-SiGe dual-channel layer structure as CMOS substrate for single workfunction metal-gate technology

The strained-Si-strained-SiGe dual-channel layer substrate is known for its mobility advantage. This letter investigates its potential as a CMOS substrate that would enable single workfunction metal-gate electrode technology. Simulation shows that a single metal electrode with workfunction of 4.5 eV produces near-ideal CMOS performance on a dual-channel layer substrate that consists sequentially of a silicon wafer, an epitaxially grown 30% Ge relaxed SiGe layer, a compressively strained 60% Ge layer, and a tensile-strained-Si cap layer. Measured threshold voltages in experimental TiN gate n- and p-MOSFETs built on such dual-channel layer substrates support the simulation analysis.