Diamond films grown by a 60-kW microwave plasma chemical vapor deposition system

In order to use chemical vapor deposition (CVD) diamond films for electroni c devices, it is necessary to establish technologies for producing diamond wafers with controlled quality. Most of existing diamond CVD systems are, h owever, designed primarily for laboratory use. To cross the technological g ap between the commercial production and the laboratory experiments, the cu rrent CVD technologies of diamond must be scaled up and upgraded. Developme nt of large-scale diamond deposition processes was undertaken by using a mi crowave plasma CVD system, equipped with a 915-MHz, 60-kW generator for gen erating a large-size plasma. Polycrystalline diamond films were deposited f rom a hydrogen/methane gas mixture with typical gas pressures and substrate temperatures of 80-120 torr and 800-1050 degreesC, respectively. It was fo und that depending on the growth conditions, the deposited films have vario us surface morphologies. Some of the samples have well-defined {111} and {1 00} facets of up to tens of micrometers in size. The Raman spectra had an i ntense main peak due to diamond at 1333 cm(-1) without a trace of non-diamo nd carbon. The film quality in terms of Raman spectra was relatively unifor m across the samples of 100 mm in diameter. Both < 111 > and < 001 > textur ed diamond films were obtained by selected growth conditions. (C) 2001 Else vier Science B.V. All rights reserved.