Single crystal aluminum nitride layers, useful as high frequency SAW filters and buffer layers for electronic and optoelectronics component deposition, are grown on silicon using silicon surface construction and reconstruction steps

摘要

Single crystal aluminum nitride layer molecular beam epitaxial growth on silicon comprises silicon surface construction and reconstruction steps. Single crystal aluminum nitride layers are produced on silicon by: (a) placing a single crystal silicon wafer (2) with a clean Si(111) surface (3), an Al molecular beam source (4), an activated nitrogen source (5) and a RHEED electron diffraction unit (6) in an MBE growth chamber (1); (b) forming a Si(111)-(7x7) surface construction on the wafer surface at elevated temperature under ultrahigh vacuum conditions; (c) heating the wafer to the nucleation temperature of 600-800 deg C; (d) either directing an atomic nitrogen flow onto the wafer surface for rapid achievement of a 3x3 surface reconstruction and then initiating a similar size flow of Al or directing an Al flow onto the wafer surface for rapid achievement of a 43x43 surface reconstruction and then initiating a similar size flow of atomic nitrogen; and (e) gradually heating the wafer to 850-950 deg C while directing a constant flow of atomic nitrogen onto the wafer and adjusting the Al flow so that a 32x32, 1x1 or 2x6 reconstruction is observed in the electron diffraction image.