DIAMOND FILMS HETEROEPITAXIALLY GROWN ON PLATINUM(111)

Diamond films were grown by microwave plasma chemical vapor deposition on as-received platinum (Pt) foils, specially processed Pt foils with (111) domains, bulk single-crystal Pt with a (111) surface, and singl e-crystal Pt(111) films deposited on strontium titanate (111). In all cases, the substrate surfaces had been significantly roughened by scra tching to enhance diamond nucleation. Nevertheless, it was found by sc anning electron microscopy that diamond films grown on the (111) areas of the above substrates had azimuthally aligned (111) faces, where a significant spontaneous coalescence developed between neighboring face s. An observation of the diamond-Pt interface region by transmission e lectron microscopy indicated that diamond crystals had an epitaxial re lationship with Pt, and a (111) crystal at a diamond film surface cont ained an extremely low density of dislocations on the order of 10(8)/c m(2). Effects of H-2 and CH4/H-2 plasma on a Pt surface, as well as th e nucleation and growth process, were investigated in detail. [S0163-1 829(97)01047-3].