MOSCAP and MOSFET characteristics using ZrO/sub 2/ gate dielectric deposited directly on Si

Abstract

MOSCAP and MOSFET characteristics using ZrO/sub 2/ gate dielectric deposited directly on Si have been investigated. Thin equivalent oxide thickness (EOT), low leakage, negligible frequency dispersion, interface density less than 10/sup 11/ cm/sup -2/ eV/sup -1/, small hysteresis, excellent reliability characteristics have been demonstrated. The ZrO/sub 2/ film has been shown to be amorphous. A thin interfacial Zr-silicate layer (k>8) exists and is beneficial in maintaining good interfacial quality. This Zr-silicate layer grows after annealing and can be minimized through process optimization. Well-behaved p-channel MOS transistor characteristics with a subthreshold swing of 80 mV/decade have also been achieved.