Experimental investigation of the parameter dependency of the removal rate of thermochemically polished CVD diamond films

摘要

Parameters controlling the removal rate of chemical vapor deposition (CVD) diamond films ther-mochemically polished on transition metals in a mixed argon-hydrogen atmosphere were investigated. The ambient temperature, the pressure exerted on the dia-mond film, the angular velocity of the polishing plate, the frequency and the amplitude of the transverse vi-brations were among the parameters used in the exper-iments. Temperature measurements showed that the removal rate was increased exponentially with increasing magnitude of the parameter. An exponential increase in the removal rate was also observed with increasing pressure and hence with increasing contact between the diamond film and the polishing plate. However, an ex-ponential decrease in the removal rate was observed with increasing angular velocity of the polishing plate. The removal rate obtained with the application of transverse vibrations was more than three times that obtained without transverse vibrations. Moreover, the removal rate was seen to be higher at resonant frequencies. An increase in the removal rate with increasing amplitude of the transverse vibrations was also observed. Raman measurements carried out on the films to determine the presence of the non-diamond carbon layer after ther-mochemical polishing revealed non-diamond Raman lines only for films polished at 1000 0C and 1050 0C for the temperature range 750—1050 deg C.