The long-period surface reconstruction of GaAs(001) in which a delta-doping Si and Be layer were placed less than 10nm underneath the surface was studied by reflection high-energy electron diffraction. The reversible phase transition between the long-period and (2 x 4) reconstructions with changes of the surface temperature was observed. The modulation period varies as a function of the net donor concentration and the depth of the delta-doping layer from the surface. There were two different factors which determine the periods: the concentration of the conduction electrons trapped in the surface and a structural restriction on periods shorter than 15 times the (1 x 1) lattice constant.

Continuous Variation in Modulation Period of Charge-Induced Reconstruction of GaAs(001) Surface. A.Sugawara, K.Fujieda, N.Otsuka: Surface Science, 1998, 416[1-2], L1079-84