No abstract

No abstract

Thin films of GaAs and InAs were deposited on GaAs(0 0 1) substrates by metalorganic vapor-phase epitaxy (MOVPE), and their surfaces were characterized by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and low-energy electron diffraction (LEED). Gallium arsenide surfaces produced in the MOVPE reactor at 570°C and a V/III ratio of 50 exhibit a (1;2) reconstruction, and are covered with weakly bound alkyl groups. Heating this material in flowing hydrogen in the reactor produces a variety of surface phases, depending on the sample temperature. These phases include (2;4) and (4;2) reconstructions, all of which are terminated with As or Ga dimers. The surfaces of InAs films grown by MOVPE exhibit these same phases. This study demonstrates that compound semiconductor surfaces formed in the MOVPE environment are nearly the same as those produced by molecular-beam epitaxy under ultrahigh vacuum conditions.