CONFOCAL RAMAN-SPECTROSCOPIC STUDY OF THE HETEROEPITAXIAL DIAMOND GROWTH ON PT(111)

We have characterized heteroepitaxial diamond on Pt(111) using the non -destructive technique of confocal Raman spectroscopy to investigate t he variation in structure and strain with depth. The spectral depth pr ofiles of isolated heteroepitaxial diamond crystal showed the sharp di amond peak at 1332 cm(-1), while those of nonepitaxial diamond crystal showed the diamond peak, as well as three bands centered at 1400, 150 0 and 1530-1580 cm(-1). Various nondiamond phases were present in the nonepitaxial diamond crystals from the initial stage of diamond growth . The spectral depth profiles of heteroepitaxial diamond film showed t he diamond peak at 1332-1335 cm(-1) and four bands centered at 1230, 1 470-1490, 1530-1580 and 1640 cm(-1) near the surface. The diamond peak shifted to the single crystal peak position at 1332 cm(-1) as the lin ewidth was broadened with free surface proximity. The compressive stra in in the heteroepitaxial diamond crystal decreased and turned into th e random strain. At the same time, the Raman band at 1470-1490 cm(-1) grew in intensity. The constituents of nondiamond phase in the heteroe pitaxial growth regions are different from those formed in the randoml y oriented regions. (C) 1998 Elsevier Science S.A.