GaAs(001)c(4×4) surfaces were obtained in the 380–450 °C temperature range by thermal desorption of As cap layers from substrates prepared by molecular beam epitaxy. Although reflection high‐energy electron diffraction patterns showed little change in the temperature range explored,insituscanning tunneling microscopy and Auger spectroscopy, complemented byexsituatomic force microscopy, indicate that in the lower‐temperature range examined up to 11%–12% of the surface may still be occupied by adsorbed As in the form of wires and particles preferentially oriented along 〈100〉 directions.