Epitaxial relationship in the AlN/Si(001) heterosystem

The epitaxial growth of crystalline wurtzite AlN thin films on (001) Si sub strates by plasma-assisted molecular-beam epitaxy is reported. The nucleati on and the growth dynamics have been studied in situ by reflection high-ene rgy electron diffraction. Cross-sectional transmission electron microscopy and x-ray diffraction investigations revealed a two-domain film structure ( AlN1 and AlN2) with a 30 degrees rotation between neighboring domain orient ations and an epitaxial orientation relationship of [0001]AlN parallel to[0 01]Si and [01(1) over bar 0]AlN(1)parallel to[(2) over bar 110]AlN(2)parall el to[110]Si. A model for the nucleation and growth mechanism of 2H-AlN lay ers on Si(001) is proposed. (C) 2000 American Institute of Physics. [S0003- 6951(00)03915-2].