Heteroepitaxial growth of {111}-oriented diamond films on platinum {111}/sapphire{0001} substrates

By microwave enhanced chemical vapor deposition, {1 1 1}-oriented diamond f ilms were heteroepitaxially grown on platinum{1 1 1} films of 4 mu m thickn ess which were sputter-deposited at 600 degrees C on sapphire{0 0 0 1}. It was found that X-ray diffraction rocking curve of diamond{1 1 1} has a full -width at half-maximum value of 2.0 degrees. The films have an intensively coalesced smooth surface consisting of azimuthally aligned diamond{1 1 1}. It was also found using Raman spectroscopy that the diamond films have unex pectedly small residual stress, which is considered to be a major reason wh y the diamonds are successfully grown without crack or delamination over th e entire surface of substrates. While the sample area in this study is only 5 x 10 mm(2), the present achievements opened a path towards fabrication o f large-area single crystal diamond films as sapphire substrates are commer cially available in several inches of diameter (C) 1999 Elsevier Science B. V. All rights reserved.