An Ion Microprobe facility

An ion micro-beam facility has been developed at the Institute in collaboration with SUNY at Albany (Indo-US Collaboration). It has been developed along the -30 deg port of the switching magnet. The system has a micro-slit at the beam focus following the swiching magnet. This is always fixed at 100 micron. This is followed by a 5 m section of drift tube at the end of which lies a micro-quad (Dyer Enegy, USA). The system has a demagnification ratio of 15:1. The IOP microbeam system had been designed for a 0.5 micron beam spot. The detectors include: a) an SEM detector, b) an X-ray detector (Si(Li)), c) a Si surface barrier detector, (all in front), and d) an optical microscope at the back for beam focusing and positioning. The system is capable of generating x-ray as well as charge particle images of a sample ~ 100 micron square in area. In some earlier runs we had gone to about 3 micron in beam size which has been sufficient to get some interesting pictures of Au and Ag islands on Si (111) surface, x-ray image of a SQUID structure. Some attempts had also been made to use a proton beam for writing purposes on plymers etc. (Collaborators: D. P. Mahapatra, B. N. Dev, B. Rout, H. Bakhru, A. Haberl and B. B. Rath)

An early resolution scan on 1000 mesh Au grid and an Au elemental map of Au islands sitting on a Si(111) surface are shown as typical examples.