AVS 45th International Symposium
    Surface Science Division Monday Sessions
       Session SS-MoP

Paper SS-MoP26
Sites for Arsine Adsorption on GaAs(001)-(4x2)

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Surface Science Division Poster Session
Presenter: Q. Fu, University of California, Los Angeles
Authors: Q. Fu, University of California, Los Angeles
L. Li, University of California, Los Angeles
M.J. Begarney, University of California, Los Angeles
B.-K. Han, University of California, Los Angeles
R.F. Hicks, University of California, Los Angeles
Correspondent: Click to Email
Arsine adsorption on GaAs(001)-c(8x2) at 298K-693K has been studied by internal-reflectance infrared spectroscopy and x-ray photoelectron spectroscopy. At 298K, AsH@sub 3@ dissociatively adsorbs on terminal Ga sites on step edges and transfers hydrogen to terminal As sites. No gallium hydride was observed during the dosing of AsH@sub 3@ at room temperature. c(8x2) reconstruction was well maintained when GaAs(001) surface was under extended exposure of AsH@sub 3@ between 298K and 573K. Upon dosing AsH@sub 3@ with a dosage of 9600L at 650K, surface reconstruction was converted from c(8x2) to a mixture of c(6x4) and (4x2) domains as illustrated by LEED. XPS also revealed a small increase of As/Ga area ratio after dosing at 650K. Further adsorption of arsine at 650K transformed surface to As rich (2x4) reconstruction. We found that it is necessary to have enough adsorption sites( terminal As) to accomodate hydrogen from arsine in order to incorporate As efficiently during epitaxy growth.