The surface structures of InP (001) are completely different from their counterpart on GaAs (001).  Several STM images published in PRL and PRB are shown below.

     Slightly annealing the c(2x2)/p(2x2) surface in vacuum at 300 ^oC results desorption of the P, CHx, and H adsorbates.  The surface becomes (2x1), which is covered with a complete layer of P dimers.  Electron counting reveals that there are only three dangling electrons associated with each dimer.  The honeycomb structure highlighted in the image is a higher ordered c(4x2) reconstructions 

    Further annealing of (2x1) surface at 400 ^oC for 30 min leads to desorption of phosphorous from the surface.  The surface becomes an indium-rich s-(2x4). For each (2x4) unit cell, there is one phosphorous dimer in the top layer and four indium dimer in the second layers

   s (2x4) surface can be further converted to d (2x4) by replacing the P-P dimer with a In-P mixing dimer.  This surface shown on the left was obtained by annealing the InP crystal at 500 ^oC.  The triangular spots highlighted in the image is corresponding to one P dangling bond and two In-In backbonds.

© Copyright 1996-2007, R. F. Hicks, Semiconductor Material Chemistry and Plasma Processing Laboratory, University of California, Los Angeles.