<title>Improvement of sensitivity and depth resolution in conventional RBS and ERDA techniques using energy/momentum filters</title>

Abstract

Applications of electric and/or magnetic filters to Rutherford backscattering (RBS) and elastic recoil detection analysis (ERDA) were studied with the aim of improving their performance such as detection limit and depth resolution. A novel RBS technique combined with a charged particle energy filter (CPEF) has been proposed for the detection of contaminants on Si wafers. The CPEF is an electric deflector of charged particles. In this technique, it is placed between a sample and a detector and plays the role of filtering undesirable backscattered signals originated in silicon atoms in the sample from contaminant signals. Experimental results have shown that the CPEF can suppress the silicon signals selectively and appreciably. Another study has been done for ERDA technique using a charge particle energy filter (CPMF) for the analysis of hydrogen depth profile on the surface of a sample. The CPMF is a magnetic deflector of charged particle. It works to remove high energy backscattered particles. As a result, the thickness of the foil in front of a detector can be thinner. The results of calculation have shown that the thickness can be reduced by around 40%.