LAYER-BY-LAYER REMOVAL OF GAAS(110) BY BROMINE

Scanning tunneling microscopy results show that heating a nearly satur ated Br-GaAs(110) 2 x 1/c(2 x 2) surface to 600 K leads to a random di stribution of single-layer deep vacancy islands. These islands expand via continued etching upon heating to 700 K. Subsequent exposure to Br -2 at 625 K results in complete removal of the first layer via step re treat. Accordingly, monolayer etching can be achieved. The different e tching pathways of the exposure-annealing treatment and that of contin uous etching are discussed. (C) 1996 American Vacuum Society.