Growth of 2-mercaptobenzoxazole on Cu(100) surface: chemisorbed and physisorbed phases Valeria Di Castro a, * , Francesco Allegretti b , Chiara Baldacchini c , Maria Grazia Betti c , Giorgio Contini d , Valdis Corradini b , Francesca Lamastra a , Carlo Mariani b a Dipartimento di Chimica and INFM, Universit  a di Roma ‘‘La Sapienza’’, Piazzale Aldo Moro 2, I-00185 Roma, Italy b Dipartimento di Fisica and INFM, Universit  a di Modena e Reggio Emilia, Via G. Campi 213/A, I-41100 Modena, Italy c Dipartimento di Fisica and INFM, Universit  a ‘‘La Sapienza’’, Piazzale Aldo Moro 2, I-00185 Roma, Italy d CNR-ITM, Via Bolognola 7, I-00138 Roma, Italy Abstract Wepresentahigh-resolutionUVphotoelectronspectroscopystudyof2-mercaptobenzoxazole(MBO)adsorbedon clean Cu(100), by sublimation in controlled ultra-high-vacuum conditions, at room temperature and at 100 K. The photoemissiondatashowtheformationofanMBOlayerchemicallyinteractingwiththecoppersubstrate.Saturation coverageisachievedatroomtemperaturewiththechemisorbedphase,whileaphysisorbedmultilayerisformedatlow temperatures on top of the chemisorbed interfacial layer. Ó 2002 Elsevier Science B.V. All rights reserved. Keywords: Self-assembly; Chemisorption; Copper; Photoelectron spectroscopy 1. Introduction Self-organization on a solid surface is a prom- isingtoolforgrowinguniformnanostructureswith regular size and spacing. Organic materials are interestingcandidatesbecauseoftheirlowintrinsic conductivity and their possibility to form mono- layers and multilayers of nanometric thickness. Organic thiols constitute an interesting class of self-assemblingmoleculesonmetalsurfaces.Their technological interest is due to their potential ap- plication as biosensors and corrosion inhibitors [1]. These interfacial structures are spontaneously formed by the adsorption of molecules with a functional reactive head group which bind chemi- cally to the metal surface, and an organic part (saturated alkyl chain or aromatic ring) which gives rise to the lateral van der Waals interac- tion between the molecules, driving the molecular packing on the surface. The quality and kind of interaction, the ad-molecule to substrate interac- tion and eventually the ad-molecule to ad-mole- cule interaction and the role of the substrate to formultra-thinorderedlayers,arestillopenques- tions. A comprehensive range of data has been collected and interpreted for self-assembling of akanethiolsonvarioussubstrate[1–3].Incontrast, theliteratureontheadsorptionandself-assembling Surface Science 507–510 (2002) 7–11 www.elsevier.com/locate/susc * Corresponding author. Tel.: +39-6-49913316; fax: +39-6- 490324. E-mail address: valeria.dicastro@uniroma1.it (V. Di Cas- tro). 0039-6028/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0039-6028(02)01166-4