AVS 51st International Symposium
    Applied Surface Science Friday Sessions
       Session AS-FrM

Invited Paper AS-FrM9
Quantitative Profiling of Thin Films by Means of Elastic Recoil Detection Analysis (ERDA) with High Energetic Heavy Ions

Friday, November 19, 2004, 11:00 am, Room 210A

Session: FIB and Novel Ion Analysis Methods
Presenter: W. Bohne, Hahn Meitner Institut Berlin GmbH, Germany
Authors: W. Bohne, Hahn Meitner Institut Berlin GmbH, Germany
J. Röhrich, Hahn Meitner Institut Berlin GmbH, Germany
E. Strub, Hahn Meitner Institut Berlin GmbH, Germany
Correspondent: Click to Email
Heavy-Ion ERDA (Elastic Recoil Detection Analysis) can be used to characterize thin solid layers. The concentrations of chemical elements can be determined as well as the layers' thickness and depth profiles. For the measurement, the sample is irradiated with a heavy ion beam. Atoms of the sample are recoiled and detected with an energy and mass dispersive spectrometer. Since the ERDA principle is based on the classical Rutherford scattering theory, the expected yields for the given conditions can be calculated exactly. Therefore, ERDA is a standard-free method. Absolute concentrations can be determined for all detected chemical elements simultaneously, including hydrogen, with almost the same sensitivity. With the time-of-flight ERDA setup at the Hahn-Meitner-Institut (HMI), there are measured almost 500 samples per year. As a standard projectile beam gold ions with an energy of 350 MeV are used. Typical requests are determination of the stoichiometry, in-depth element distributions, concentration of impurities, and the validation or calibration of data from other analytical methods. Typical artifacts or systematic uncertainties of these methods can be ruled out by comparison with the ERDA data. There will be presented a selection of current ERDA measurements mainly concerning the characterization of materials for thin film photovoltaic devices developed at the HMI. Also a comparison with other analytical methods will be shown. The pros and cons of ERDA measurements will be dicussed.