An experimental setup for growth of thin films and advanced sample analysis coupled to the 5 MV tandem accelerator of the Universidad Auto ´noma de Madrid A. Rivera * , R. Andrzejewski, A. Guirao, R. Gonza ´lez-Arrabal, E. Andrzejewska, N. Gordillo, J.E. Prieto, D.O. Boerma Centro de Microana ´ lisis de Materiales, Universidad Auto ´ noma de Madrid, Campus de Cantoblanco, Ediff. 22, Faraday 3., E-28049 Madrid, Spain Available online 12 May 2006 Abstract We describe an experimental setup with a unique set of features. It consists of a number of ultra-high vacuum chambers (UHV) con- nected by transfer rods. It is employed for epitaxial growth of thin films. The surface symmetry of the as-grown samples can be inves- tigated by low energy electron diffraction (LEED) and their composition as well as the atomic positions in external layers can be studied by low energy ion scattering (LEIS) with time-of-flight (TOF). The power of this unique multiple-hit LEIS/TOF equipment is based on the use of a 1D-position sensitive detector. In addition, ions with energies in the MeV range are used to perform Rutherford backscat- tering with channelling (RBS/channeling) or elastic recoil detection (ERD). Ellipsometry, Kerr effect and resistivity measurements will also be available in situ. The combination of these techniques allows us to extensively characterize grown samples. In addition, high- energy heavy ions are exploited for film modification. Ó 2006 Elsevier B.V. All rights reserved. PACS: 34.50.Dy; 68.49.h; 81.15.z Keywords: LEIS; TOF; RBS; ERDA; Surface characterization; MBE 1. Motivation Our goal is to perform accurate studies in thin films, nanostructures and surfaces grown in situ or ex situ. For this purpose, we are building a experimental setup with a rich set of facilities both for characterization and sample growth with an additional facility to exchange samples in UHV with other setups within our Surface Science Net- work. An important item is the LEIS/TOF [1] system equipped with a multiple hit 1D-position sensitive detector, allowing the simultaneous measurement of azimuthal scans for a range of glancing angles of the scattered and recoiled atoms. Most LEIS/TOF systems include multiple channel plate (MCP) detectors without position sensitivity; with the exception of the setup developed in the group of Raba- lais [2]. In order to perform sophisticated LEIS/TOF mea- surements it is not only necessary to have the right equipment but also appropriate computer codes to extract information from the experimental data. We will use the program TRIC [3] recently developed in our group to sim- ulate the data for trial surface structures. Basically, the pro- gram calculates trajectories from the point of entry in the sample until they hit the detector, like in Marlowe [4]. By smart sampling of ion trajectories, rather than by brute force, the program is a factor of at least 10 4 faster than Marlowe. The power and necessity of appropriate codes for LEIS/TOF was previously shown with conventional setups [5]. Now, the combined use of a position sensitive detector and the code TRIC will allow accurate structure determination in a very effective way. In the most favour- able cases, the atom position can be given with a precision 0168-583X/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2006.03.166 * Corresponding author. Tel.: +34 914973611; fax: +34 914973623. E-mail address: antonio.rivera@uam.es (A. Rivera). www.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 249 (2006) 935–938 NIM B Beam Interactions with Materials & Atoms