STM study of the TerSi 100/interface

The structure of TerSi 100.- 2=1.has been studied by scanning tunnelling microscopy STM.. The samples were prepared as follows: first, Te was deposited at elevated temperature, then a CdTe 111.B film was grown by molecular beam epitaxy. The structural quality of the CdTe film was checked by double-crystal X-ray diffraction. Finally, the CdTe film was desorbed at 5008C in ultra-high vacuum. Auger electron spectroscopy confirms previous photoelectron spectroscopy data showing that this procedure results in a Te coverage of about one monolayer. In addition to the well-known 2=1. reconstruction of the TerSi 100.surface, STM reveals areas of a 3=1.-like reconstruction which are probably related to defects on the Si surface. We propose a model in which the STM images from both these reconstructions can be explained in terms of buckled or non-buckled Te dimers. q1999 Elsevier Science B.V. All rights reserved.