STRUCTURE AND COMPOSITION OF THE C(4X4) RECONSTRUCTION FORMED DURING GALLIUM-ARSENIDE METALORGANIC VAPOR-PHASE EPITAXY

Surfaces of GaAs (001) were prepared by metalorganic vapor-phase epita xy and characterized by scanning tunneling microscopy, x-ray photoelec tron spectroscopy, infrared spectroscopy, and low-energy electron diff raction. Upon removal from the reactor, the gallium arsenide surface e xhibits a (1 x 2) reconstruction, which is a disordered variant of the c(4 x 4). The disorder arises from the presence of adsorbed alkyl gro ups. Heating the sample to 350 degrees C desorbs the hydrocarbons and produces a well-ordered c(4x4) structure. A model is proposed for the alkyl-terminated (1 x 2) reconstruction. (C) 1998 American Institute o f Physics. [S0003-6951(98)04125-4].