AVS 45th International Symposium
    Applied Surface Science Division Thursday Sessions
       Session AS-ThM

Paper AS-ThM8
Quantitative High-Resolution Imaging with Sputter-Initiated Resonance Ionization Spectroscopy

Thursday, November 5, 1998, 10:40 am, Room 307

Session: Gaede-Langmuir Award Address and Quantitative Surface Analysis
Presenter: K.F. Willey, Atom Sciences, Inc.
Authors: K.F. Willey, Atom Sciences, Inc.
H.F. Arlinghaus, Westfälische Wilhelms-Universität Münster, Germany
T.J. Whitaker, Atom Sciences, Inc.
Correspondent: Click to Email
The demand for sub-micron lateral analysis, as a result of decreasing material size, has been met by the development of liquid metal ion gun (LMIG) sources capable of achieving spot sizes less than 50 nm. The trade-off however, is the reduction in ion beam current at the sample. Therefore, highly sensitive detection techniques are required. Our technique, Sputter-Initiated Resonance Ionization Spectroscopy (SIRIS), incorporates resonant ionization of sputtered neutral particles with time-of-flight mass detection. The two major advantages this approach has over conventional SIMS are that analysis of neutrals generally increases the detection efficiency by at least two orders of magnitude, and that resonance ionization nearly eliminates mass interferences. Additionally, analysis of neutrals substantially removes matrix effects, which is crucial for quantitative surface analysis. Sputtering is achieved with a gallium LMIG, a mass-filtered microbeam ion gun, and a mass-filtered low-energy sputtering ion gun. Sub-micron lateral resolution and few nanometer depth resolution have been obtained by eroding the sample with the low-energy ion gun while analyzing with the LMIG. In our presentation, we will describe the SIRIS technique and its dynamic range for quantitative analysis and imaging capabilities as they pertain to semiconductor research. In particular, Ge and B depth profiles on near one µm spot size and Cu trace element images obtained from Cd precipitates in CdZnTe films will be presented.