Abstract
Crowth of GaAs by molecular beam epitaxy and electrical characterization of grown layers are described. Six kinds of electron traps with thermal activation energies ranging from 0.08 to 0.55 eV were detected in undoped GaAs by DLTS. The concentration of these traps, which is in the range of 2.0×1014-3.3×1015cm-3, is reduced by a factor 10-50 by Pb flux incident on the crystal surface during growth. The reduction of trap concentration seems to be due to the modification of the surface processes during MBE growth.
