Super critical thickness SiGe-channel heterostructure p -type metal-oxide-semiconductor field-effect transistors using laser spike annealing

Strained Si/strained Si 0.3 Ge 0.7 /relaxed Si 0.7 Ge 0.3 heterostructure p -type metal-oxide-semiconductor field-effect transistors (MOSFETs) with high mobility and low leakage are demonstrated using laser spike annealing, despite a strained Si 0.3 Ge 0.7 channel thickness that is two times the equilibrium critical thickness. Measured hole mobility is enhanced four times for Si 0.3 Ge 0.7 channel MOSFETs relative to Si control devices, at an inversion charge density of 10 13 cm − 2 . For supercritical thickness strained SiGe channel films, the use of laser spike annealing allows source/drain annealing at significantly higher temperatures than is possible with rapid thermal annealing (e.g., 975 versus 800 ° C ), while achieving superior leakage characteristics. For laser spike annealing temperatures above 1000 ° C , mobility is found to degrade due to partial relaxation and dislocation formation in the Si 0.3 Ge 0.7 channel.