Kinetics of Au induced faceting of vicinal Si(111) R. Hild a,1 , C. Seifert a,1 , M. Kammler a,2 , F.-J. Meyer zu Heringdorf a,2 , M. Horn-von-Hoegen a, * ,1 , R.A. Zhachuk b , B.Z. Olshanetsky b a Institut f€ ur Festk€ orperphysik, Universit€ at Hannover, Appelstraße 2, D-30167 Hannover, Germany b Institute of Semiconductor Physics, Russian Academy of Sciences, Siberian Branch, Novosibirsk 630090, Russia Received 1 February 2001; accepted for publication 5 March 2002 Abstract Au induced faceting of vicinal Si(1 1 1) has been studied during adsorption at elevated temperature by spot profile analyzing of low energy electron diffraction and after quenching to room temperature by scanning tunneling micro- scopy. On the surfaces inclined towards ½11  2 five different types of facets form with increasing Au coverage at ad- sorption temperatures T ads below 800 °C. They are (4 4 3), (7 7 5), (5 5 3), a stepped (2 2 1), and the (3 3 1) facets. Atomic models for the (5 5 3) and (7 7 5) facet planes are proposed on the basis of high resolution STM images. At T ads ¼ 800 °C we found the formation of an ordered step train which covers the entire surface. With further increasing Au coverage the stepped surface decomposes again into (1 1 1) terraces and step bunches. Driving force is the formation of the Si(111)-(5  2)–Au reconstruction. Ó 2002 Elsevier Science B.V. All rights reserved. Keywords: Low energy electron diffraction (LEED); Scanning tunneling microscopy; Silicon; Gold; Faceting; Adsorption kinetics; Step formation and bunching 1. Introduction The interaction of metal atoms with silicon vicinal surfaces is of high interest due to their potential of the formation of self-assembled quantum size objects. Metal adsorption at elevated temperatures causes step bunching and the for- mation of a ‘‘hill-and-valley’’ structure of flat areas and facets. Au adsorption on vicinal Si(1 0 0) and Si(1 1 1) planes has been most intensively studied among other metals [1–8]. It was found that on vicinal Si(001) surfaces gold adsorption at T > 750 °C causes the formation of macroscopic facets with (1 0 0) and (1 1 9) orientations and di- mensions up to 2000 nm [1,2]. On Si(1 1 1) there are two types of atomic steps depending on the miscut direction. Au adsorption has been studied on vicinal planes of both types. Yagi et al. found in an extensive reflection electron microscopy (REM) and in a reflection high energy electron diffraction (RHEED) study a variety of stable facets. Depending on the miscut orientation Surface Science 512 (2002) 117–127 www.elsevier.com/locate/susc * Corresponding author. Tel.: +49-201-183-4338/4323; fax: +49-201-183-4359. E-mail address: horn-von-hoegen@uni-essen.de (M. Horn- von-Hoegen). 1 Present address: Institut f€ ur Laser- und Plasmaphysik, Universit€ at––Essen, Universit€ atsstrasse 5, 45117 Essen, Ger- many. 2 Present address: IBM T.J. Watson Research Center, P.O. Box 218, Yorktown Heights, NY 10598, USA. 0039-6028/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0039-6028(02)01666-7