Controllable material removal behavior of 6H-SiC wafer in nanoscale polishing

Abstract

Controlling material removal uniformity in nanoscale is of importance for the nano-manufacturing process. The interaction between diamond abrasives and 6H-SiC wafer surface during ultra-precision polishing had been analyzed in this study by employing the relevant experiments and molecular dynamics (MD) simulations. The material removal behavior of 6H-SiC wafer through the semi-fixed abrasive polishing pad was obviously controllable. Both the brittle removal and plastic removal were existed during the processing when the cutting depth was uniform with a size of tens of nanometers, while that was the brittle removal when the cutting depth was uneven in this case. The abrasive cutting depth with approximately 4 nm was proved as the critical value of plastic-brittle transition of SiC material. A smooth, scratch-free and nearly damage-free wafer surface could be achieved by controlling material removal uniformly and restricting the abrasive cutting depth in the level of tens of nanometers or less.