STRUCTURAL AND DOPING PROPERTIES OF MOLECULAR-BEAM EPITAXY-GROWN SI-DOPED GAAS(001) SURFACES

Scanning funneling microscopy was used to study surface structures and doping properties of molecular beam epitaxy (MBE)-grown Si-doped. GaA s(001)-(2 x 4) and GaAs(001)-c(4 x 4) surfaces on the atomic scale. It was found that on the Si-doped (2 x 4) surface, arsenic dimers formed severer energetically different configurations besides the most stabl e two-dimer configuration. The doping properties of the c(4 x 4) surfa ce vr ere found to be significantly different from the (2 x 4) case. T he Si dopants tended to segregate on top of the c(4 x 4) surface and f ormed small asymmetric clusters oriented along the [110] direction.