Diamond deposition from fluorinated precursors using microwave-plasma chemical vapor deposition

Abstract

Diamond thin films were grown using fluorinated precursors by microwave plasma-assisted chemical vapor deposition. Using CH4/H2, CH3F/H2, and CF4/H2 gas mixtures, films were grown at surface temperatures in the range 600–900 °C at constant microwave power, carbon mole fraction, and pressure. Growth activation energies for the CH4/H2, CH3F/H2, and CF4/H2 mixtures were 12.6±1.8, 13.7±1.2, and 12.4±1.1 kcal/mole, respectively. Argon ion etching in conjunction with x-ray photoelectron spectroscopy indicated negligible fluorine incorporation into the films. These results are consistent with the hypothesis that diamond is grown from the same intermediates, namely methyl radicals and atomic hydrogen, for all of these mixtures.