Growth of Polycrystalline Diamond Films Including Diborane and Oxygen in the Source Gas

Abstract

Boron‐doped polycrystalline diamond with both (100) and (111) facets were grown by microwave plasma chemical vapor deposition with and without oxygen to study effects of on surface morphology, crystal quality, and boron‐doping concentration of the films. It was found by Raman spectroscopy that the addition of improved the film quality as evidenced by the decrease of both the full width at half‐maximum of the diamond peak and the background level. By the addition of , the boron concentrations in the diamond decreased to the same extent by two orders of magnitude for both (100) and (111) facets, indicating that the oxygen is playing a role in the gas phase in suppressing the involvement of diborane. It was also observed by scanning electron microscopy that the (100) facets of the diamond grown with appeared darker than the (111) facets, while the opposite is the case for the films grown without . This is because the secondary electron emission was suppressed by a higher concentration of terminating species on the (100) facets as compared to the (111) planes, indicating the added oxygen is also affecting the chemistry of the diamond surface. © 1999 The Electrochemical Society. All rights reserved.