Plasma etching phenomena in heavily boron-doped diamond growth

摘要

Heavily boron-doped diamond growth turned into etching when boron-to-carbon molar ratios in the feed gas exceeded 1% and the carbon fraction was below 0.7%, under the constant microwave power density and gas pressure. Doping efficiency, diamond surface morphology, and plasma optical emissions have been investigated. Bright BH (A(1)Pi-X-1 Sigma) emission, at ca. 433 nm, has been correlated with etching features observed on the diamond surface. The analysis of the boron concentration by cathodoluminescence has revealed no diamond film growth under the bright BH emission conditions. The study of plasma optical emissions put forward the contribution of boron species in the chemical etching process.