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

parameters controlling the removal rate of chemical vapor deposition (CVD) diamond films thermochemically polished on transition metals in a mixed arg on-hydrogen atmosphere were investigated. The ambient temperature, the pres sure exerted on the diamond film, the angular velocity of the polishing pla te, the frequency and the amplitude of the transverse vibrations were among the parameters used in the experiments. Temperature measurements showed th at the removal rare was increased exponentially with increasing magnitude o f the parameter. An exponential increase in the removal rate was also obser ved with increasing pressure and hence with increasing contact between the diamond film and the polishing plate. However. an exponential decrease in t he removal rate was observed with increasing angular velocity of the polish ing plate. The removal rate obtained with the application of transverse vib rations was more than three times that obtained without transverse vibratio ns. Moreover, the removal rate was seen to be higher at resonant frequencie s. An increase in the removal rate with increasing amplitude of the transve rse vibrations was also observed. Raman measurements carried out on the fil ms to determine the presence of the non-diamond carbon layer after thermoch emical polishing revealed non-diamond Raman lines only for films polished a t 1000 degreesC and 1050 degreesC for the temperature range 750-1050 degree sC.