Structure of GaAs(001) (2×4)-c(2×8) determined by scanning tunneling microscopy

Abstract

The scanning tunneling microscope (STM) has been used to study the (2×4)-c(2×8) reconstruction on the arsenic-rich surface of GaAs(001). The STM images show that the 4× periodicity is due to a regular array of missing arsenic dimers. The (2×4) units are arranged so as to give small domains of either (2×4) or c(2×8) reconstructions. These images are the first high-resolution STM images obtained from a surface grown by molecular-beam epitaxy. Features are seen which may be important in the mechanism of growth. © 1988 The American Physical Society.