Elastic recoil detection analysis on the ANSTO heavy ion microprobe R. Siegele * , I. Orlic, David D. Cohen Australian Nuclear Science and Technology Organisation, PMB 1, Menai 2234, NSW, Australia Abstract The heavy ion microprobe at the Australian Nuclear Science and Technology Organisation is capable of focussing heavy ions with an ME=q 2 of up to 100 amu MeV. This makes the microprobe ideally suited for heavy ion elastic recoil detection analysis (ERDA). However, beam currents on a microprobe are usually very small, which requires a detection system with a large solid angle. We apply microbeam heavy ion ERDA using a large solid angle DE  E telescope with a gas DE detector to layered structures. We demonstrate the capability to measure oxygen and carbon with a lateral resolution of 20 lm, together with determination of the depth of the contamination in thin deposited layers. Ó 2002 Published by Elsevier Science B.V. PACS: 82.80.Yc Keywords: Ion microprobe; ERDA; IBA 1. Introduction The high energy heavy ion microprobe [1] at the Australian Nuclear Science and Technology Or- ganisation (ANSTO), was designed for the use of microbeams in high energy heavy ion IBA appli- cations. It can focus ions with a mass energy product of up to ME=q 2 ¼ 100 amu MeV. We have demonstrated the use of heavy ion induced X-ray emission with 9 MeV He and 36 MeV C [1], as well as the use of the high energy 16 O(a; a) 16 O reso- nance at 7.62 MeV for the detection of oxygen [2] on the microprobe. All these techniques utilise the high energy, heavy ion capabilities of the ANSTO microprobe. PIXE and RBS are the most commonly used elemental analysis techniques on ion microprobes. However, PIXE is generally limited to elements heavier than Mg while RBS requires to de-con- volute the backscattering spectra originating from different target elements. This makes the detection of light elements such as oxygen or carbon difficult with both techniques. Heavy ion elastic recoil detection analysis (ERDA), which is complementary to RBS, pro- vides a way to profile these light elements. This is the reason, why the use of heavy ion ERDA has dramatically increased over the past 10 years and has become a standard IBA technique in many laboratories with Tandem accelerators. Using very heavy projectiles ERDA, is almost a universal Nuclear Instruments and Methods in Physics Research B 190 (2002) 301–305 www.elsevier.com/locate/nimb * Corresponding author. Tel.: +61-2-9717-3967; fax: +61-2- 9717-3257. E-mail address: rns@ansto.gov.au (R. Siegele). 0168-583X/02/$ - see front matter Ó 2002 Published by Elsevier Science B.V. PII:S0168-583X(01)01230-7