METALLOGRAPHIC ETCHING OF POLYCRYSTALLINE DIAMOND FILMS BY REACTION WITH METAL

It has been shown for the first time that the high-temperature anneali ng of a diamond film in contact with Mn and Fe can reveal the microstr uctural features within the film. The diamond film was annealed in con tact with Mn and Fe at 900-1000 degrees C for 0.5-20 h. After annealin g the sample was cleaned by acid and was rinsed in acetone. The cleane d surface was observed by scanning electron microscopy under a seconda ry electron mode. A clear image of the etch pattern appeared on the fl attened diamond him surface from the reaction with the metals. The det ailed microstructural features in the etch patterns were correlated to those on the as-grown surface. The image contrast in the etch pattern was related to the local defect density: the more defective region ap peared darker. The origin of image contrast on the etched surface was discussed.