Atomic resolution structure of growth and etching patterns at the surface of microwave plasma chemical vapor deposited diamond films

Abstract

Scanning tunneling microscopy and spectroscopy of microwave chemical vapor deposited diamond films prepared using a methane/hydrogen gas mixture indicates that the predominant diamond surface structure is (001) 1×1: 2H with a wide variety of facet shapes and orientations, and that the film surface is diamond-like and semiconductive but with a surface band gap (∼1.1 eV) that is smaller than the band gap of normal bulk diamond. Significant differences are observed in the electronic properties, resolution, and contrast between newly deposited surface carbon atoms and those bound in the underlying lattice. The composition of the deposition gas mixture is important in determining both the crystal structure and the type of bond termination at the surface.