INVESTIGATION OF THIN-FILMS BY HIGH-ENERGY ERDA

Thin film samples were investigated by high-energy elastic recoil dete ction analysis (HE-ERDA), using heavy-ion beams such as e.g. 420 MeV I -127, which allows detection of all target elements simultaneously. A time-of-flight detection system consisted of channel plate detectors f or start and stop. The recoils are finally stopped in a semiconductor detector delivering a total energy signal. The particle's mass is deri ved by its energy and time-of-flight. Accurate energy loss measurement of all particles up to the highest mass region and for all energies i s attainable using the time-of-flight signal. Depth profiles were eval uated using the stopping powers of Biersack, Littmark and Ziegler. Hea vy-ion stopping powers are accurate only to about 10%. For high-precis ion measurements calibration samples were used to correct the high-ene rgy stopping powers of projectile and recoils. Samples of TiN on steel prepared by ion beam aided deposition (IBAD) technique, thin vapor de posited layers of Al and Ni on a Si substrate and a SiC layer on a Si substrate were investigated. The measurements provided absolute values for concentration and depth for all isotopes in the samples. The maxi mum measurable depth was 2-4 mum, depending on the recoil mass. The at tained resolution was comparable to RBS measurements.