Improved low temperature characteristics of p-channel MOSFETs with Si1-xGex raised source and drain

Abstract

P-channel metal-oxide-semiconductor field-effect transistors with Si1-xGex raised source and drain (RSD) have been fabricated and further studied for low temperature applications. The Si1-xGex RSD layer was selectively grown by ANELVA. SRE-612 ultra-high vacuum chemical vapor deposition (UHVCVD) system, Compared to devices with conventional Si RSD, improved transconductance and specific contact resistance were obtained, and these improvements become even more dramatic with reducing channel length, Well-behaved short channel characteristics with reduced drain-induced barrier lowering (DIBL) and off-state leakage current are demonstrated on devices with 100 nm Si1-xGex RSD, due to the resultant shallow junction and less implantation damage. Moreover, temperature measurements reveal that Si1-xGex RSD devices show more dramatic improvement in device performance at low temperature (-50 degreesC) operation, which can be ascribed to the higher temperature sensitivity of the Si1-xGex sheet resistance.