Fabrication of poly 3C-SiC thin film diodes for extreme environment applications

Abstract

Polycrystalline (poly) 3C-SiC thin films were deposited onto oxidized Si wafers by APCVD using HMDS as a precursor. In this work, the optimized growth temperature and HMDS flow rate were 1,100degC and 8 sccm, respectively. A Schottky diode with a Au/poly 3C-SiC/Si(n-type) structure was fabricated and its threshold voltage (Vd), breakdown voltage, thickness of depletion layer, and doping concentration (ND) values were measured as 0.84 V, over 140 V, 61 nm, and 2.7 times 1019 cm3, respectively. To produce good ohmic contact, Al/3C-SiC were annealed at 300, 400, and 500degC for 30 min under a vacuum of 5.0 times 10-6 Torr. The obtained p-n junction diode fabricated by poly 3C-SiC had similar characteristics to a single 3C-SiC p-n junction diode.