Surface structures of phosphorus and indium on Si(111)

The interaction of vapor phase P-2 with the Si(111)-(root 7 x root 3)-In monolayer surface at room temperature and elevated temperature has been monitored by scanning tunneling microscopy (STM) and spectroscopy (STS) in conjunction with Auger electron spectroscopy and low-energy electron diffaction (LEED). The surface reaction can be readily followed by STM because of the very different contrast of the reacted areas in the STM images. The reaction develops around overlayer defects at room temperature and appears to be diffusion-limited, whereas at 300 degrees C the reaction is initiated at the step edges, from which the reaction front progresses onto the lower terrace areas. At elevated temperature several. ordered surface reconstructions, showing different STS fingerprints, are detected on the P-In/Si(111) surfaces, which are associated tentatively with P-and Si-terminated structures and an ordered InP phase.