Using Rutherford Backscattering Spectroscopy depth profiling to characterize targets at SUNY Geneseo

Rutherford Backscattering Spectroscopy (RBS) is an ion beam analytical technique that can be used to study the properties of thin films. In this technique, a beam of energetic protons or alpha particles is incident on the sample and the energy of the scattered ions is measured. The energy spectrum reveals characteristics about the sample including thickness and elemental composition. RBS can be further developed using a technique known as depth profiling, in which a more sophisticated fitting of the resulting energy spectrum is used to measure the concentration of dopants in the sample as a function of depth. At SUNY Geneseo, we have been performing RBS experiments using ion beams from our 1.7 MV Pelletron particle accelerator. RBS has been used to measure the elemental composition and thickness of various thin layers of copper and gold deposited on a silicon wafer using Geneseo's thin film evaporator. Other targets have been produced at Geneseo using thermal diffusion and ion implantation. The goal of these studies is to develop a technique to use RBS depth profiling to measure the energy spectrum of heavy ions accelerated from the rear side of a target illuminated with ultra-intense laser light. Funded in part by a grant from the DOE through the Laboratory of Laser Energetics.