Epitaxial silicon growth and usage of epitaxial gate insulator for low power, high performance devices

摘要

A method for reducing off-state leakage current of a MOSFET while promoting the formation of an epitaxial gate insulator layer between the substrate and gate stack includes implanting source/drain dopant into the substrate, and then forming a very thin epitaxial Silicon layer on the substrate by, e.g., molecular beam epitaxy. The high-k gate insulator layer is then deposited on the epitaxial layer, without an interfering native oxide or interfacial oxide being formed between the insulator layer and substrate, while establishing a very steep retrograde dopant profile and hence reducing off-state leakage current through the channel region.