Properties of epitaxial Si films grown on yttria-stabilized cubic zirconia substrates by chemical vapor deposition

Abstract

Epitaxial growth of single-crystal Si films on monocrystalline yttria-stabilized cubic zirconia, (Y₂O₃)_m (ZrO₂)_(1-m) substrates with m=0.09 - 0.33 has been realized for the first time by the pyrolysis of SiH₄ in H₂ carrier gas. Films and substrates were characterized by means of Nomarski optical and scanning electron microscopies, reflection electron diffraction, MeV₄He₊ Rutherford backscattering and channeling, X-ray diffraction, transmission electron microscopy (TEM), secondary ion mass spectrometry, and electrical measurements. Single-crystal film growth was achieved on the three principal substrate cubic planes (100), (110), and (111) in the temperature range 975-1077°C at deposition rates of 0.08 - 1.2µm/ min. The orientations of the Si films were found to be the same as those of the substrates. The nearsurface crystal quality of several 0.4µm thick, (100) oriented Si films on yttria - stabilized zirconia was found by MeV He⁺ channeling and TEM to be superior to that of commercial (100) Si on sapphire films of similar thickness. The electrical properties of nominally undoped films were found to depend critically on the pre-deposition, in-situ substrate preparation. The effect of the ionic superconduction properties of the substrate material on the structure of the deposited Si films will also be discussed.