Fabrication and characterization of metal-oxide-semiconductor field-effect transistors and gated diodes using Ta/sub 2/O/sub 5/ gate oxide

Abstract

N-channel metal oxide semiconductor field effect transistors (MOSFETs) using Ta/sub 2/O/sub 5/, gate oxide were fabricated. The Ta/sub 2/O/sub 5/ films were deposited by plasma enhanced chemical vapor deposition. The I/sub DS/-V/sub DS/ and I/sub DS/-V/sub GS/ characteristics mere measured. The electron mobility was 333 cm/sup 2//V/spl middot/s. The subthreshold swing was 73 mV/dec. The interface trapped charge density, the surface recombination velocity, and the minority carrier lifetime in the field-induced depletion region measured from gated diodes were 9.5/spl times/10/sup 12/ cm/sup -2/ eV/sup -1/, 780 cm/s and 3/spl times/10/sup -6/ sec, respectively. A comparison with conventional MOSFETs using SiO/sub 2/ gate oxide was made.