Gallium arsenide and indium arsenide surfaces produced by metalorganic vapor-phase epitaxy

Thin films of GaAs and InAs were deposited on GaAs(001) substrates by metal organic vapor-phase epitaxy (MOVPE), and their surfaces were characterized by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (X PS), and low-energy electron diffraction (LEED). Gallium arsenide surfaces produced in the MOVPE reactor at 570 degrees C and a V/III ratio of 50 exhi bit a (1 x 2) reconstruction, and are covered with weakly bound alkyl group s. Heating this material in flowing hydrogen in the reactor produces a vari ety of surface phases, depending on the sample temperature. These phases in clude (2 x 4) and (4 x 2) reconstructions, all of which are terminated with As or Ga dimers. The surfaces of InAs films grown by MOVPE exhibit these s ame phases. This study demonstrates that compound semiconductor surfaces fo rmed in the MOVPE environment are nearly the same as those produced by mole cular-beam epitaxy under ultrahigh vacuum conditions. (C) 1998 Published by Elsevier Science B.V. All rights reserved.