Sb adsorption on Si(111)-In(4 x 1) surface phase

We studied the formation of first InSb molecular layer on the Si(111) subst rate by depositing about 1 ml of Sb on In(4 x 1) reconstruction in the temp erature range 170-350 degreesC, using reflection high-energy electron diffr action (RHEED) and auger electron spectroscopy (AES). The element Sb deposi tion at 210 degreesC resulted in the formation of an epitaxial InSb molecul ar layer (not psudomorphic). This surface showed a weak I x 1 RHEED pattern with a 'dramatic rotation' of the surface layer with respect to the Si sub strate. Ar this temperature, the deposited Sb atoms do not replace the Si-I n bonds. However, Sb deposition above 250 degreesC resulted in the replacem ent of In-layer by Sb atoms. Subsequently Sb formed various well-ordered re constructions. which are highly sensitive to the deposition conditions. 1 m l Sb deposition on In(4 x l)reconstruction at 260, 300 and 350 degreesC for med 2 x 1, 2 x 2 and root3 x root3 structures, respectively. All these surf ace phases produced very sharp RHEED patterns indicating the long-range ord er. For Sb depositions above 300 degreesC, AES results showed negligible In presence on the Si surface, suggesting the coalescence of In reconstructio n by the adsorbed Sb. This replacement reaction drastically changes the bon ding nature of the Si surface, which explains the role played by the In(4 x 1)reconstruction for the InSb growth on Si(111) substrate. (C) 2001 Elsevi er Science B.V. All rights reserved.