Depth profile analysis with monolayer resolution using elastic recoil detection (ERD)

The conditions for obtaining optimum depth resolution in elastic recoil detection (ERD) analysis of thin films using high-energy heavy ions are investigated. We estimate the principle limits given by energy straggling and small-angle scattering effects and show that monolayer depth resolution can be expected under optimized experimental conditions. Such a resolution is demonstrated in an ERD experiment for the first time by discrete signals of adjacent (002) graphite layers which is obtained using a 60 MeV $\rm {}^{127}I^{23+}$ ion beam and detecting $\rm {}^{12}C^{5+}$ recoils with a magnetic spectrograph.