High mobility Si-Ge channels and novel high-k materials for nanomosfets

The implementation of more powerful materials into leading edge CMOS devices allows performance improvements without scaling and without changing the circuit design libraries. This highly motivates the research on novel materials. In this paper we present various transistor fabrication processes like “gate first” and “replacement gate” for different channel stack configurations like strained Si, strained SiGe alloy layers and Ge channels with HfO2 and novel high-k dielectrics and metal gates. We discuss HfO2 as a reference material and various ternary rare earth oxides with k ≈ 30 desired for the next technology nodes in order to ensure optimum gate control and minimum short channel effects.