Growth of diamond films with high surface smoothness

摘要

Diamond films with highly smooth backside surface have been deposited by positively biasing the substrate during diamond growth in a hot-filament chemical vapor deposition (HFCVD) system. By bonding the diamond film on the glass and wet etching to remove silicon, the highly smooth diamond surface can be exposed and used directly for the fabrication of diamond devices. Silicon substrate was first treated by diamond powder of 625 nm in an ultrasonic bath. By positively biasing the substrate, electron bombardment during diamond growth increases the nucleation density from 10~8 ~ 10~9 cm~(-2) to 4 X 10~(11) cm~(-2) The surface smoothness on the backside of diamond film has thus been improved significantly, inducing root-mean-square roughness of 5 run. Owing to the extremely high surface smoothness and the high crystalline quality on the backside of diamond film and the high diamond growth rate, the backside surface of the diamond firm grown under electron bombardment is particularly suitable for device fabrication.