A comparison of mechanical lapping versus chemical-assisted mechanical polishing and planarization of chemical vapor deposited (CVD) diamond

Polishing and planarization of CVD diamond substrates are essential steps in the processing of synthetic diamond for applications in the semiconductor industry. Using the methods of mechanical lapping and chemical-assisted mechanical polishing (CAMP), CVD diamond samples were polished against a cast-iron scaife and an alumina plate, respectively, using the same pressure on the samples. A diamond slurry was used in the mechanical lapping process, and a heated liquid chemical was used in a patented chemical-assisted mechanical polishing and planarization (CAMPP) process. The diamond samples were analyzed at several time intervals during the lapping and polishing processes, and during a combination of the two processes in which mechanical lapping preceded CAMPP. The polishing rate and surface characteristics of the diamond samples were the primary analytical measurements made, and the data were used to compare the relative lapping/polishing efficiencies of the two processes in an effort to develop an optimized process for producing highly polished CVD diamond substrates. (C) 1999 Elsevier Science S.A. All rights reserved.