Scanning tunneling microscopy results show that heating a nearly saturated Br–GaAs(110) 2×1/c(2×2) surface to 600 K leads to a random distribution of single‐layer deep vacancy islands. These islands expand via continued etching upon heating to 700 K. Subsequent exposure to Br2at 625 K results in complete removal of the first layer via step retreat. Accordingly, monolayer etching can be achieved. The different etching pathways of the exposure‐annealing treatment and that of continuous etching are discussed.