AVS 45th International Symposium
    Applied Surface Science Division Friday Sessions
       Session AS+VT-FrM

Paper AS+VT-FrM5
A Comparison Auger and TOF-SIMS Depth Profiling of Silicon Oxide Nitride Multilayers Using Low Incident Ion Energy

Friday, November 6, 1998, 9:40 am, Room 307

Session: Application of Surface Analysis Techniques to Semiconductor Technology
Presenter: S.E. Molis, IBM Corporation, East Fishkill Facility
Authors: S.E. Molis, IBM Corporation, East Fishkill Facility
R.E. Davis, IBM Corporation, East Fishkill Facility
D.W. Kisker, IBM Research Division
D. Paul, Physical Electronics
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The ever-shrinking dimensions of semiconductor devices have placed steadily more difficult challenges in front of analytical instruments and methods as well as fabrication tools and processing. In the future, this shrinkage will have a proportionally greater impact on the vertical dimensions. The SIA Technology Roadmap lists for example a gate oxide thickness equivalent of 2-3 nm by the year 2001, and a phasing out of SiO2 in favor of alternative dielectric materials. The difficulty of this analytical challenge makes it likely that no single technique will be able to tackle any type of complex process problem alone. Rather, a synergistic approach involving the strengths of each will be called for. New techniques are needed, and the current limits of current techniques must be extended. This paper describes one approach, teaming TOF-SIMS and Auger electron spectroscopy, with sputter ion gun designs which can provide adequate sputter rates at impact energies of less than 500 eV, to improve depth resolution. A Ni-Cr multilayer standard of thicker dimensions was used to measure and optimize experimental conditions. A set of various thin oxide and nitride single films and multilayers wa examined by both techniques, to mutual advantage. The TOF-SIMS approach generally gave superior depth resolution compared to Auger, although not as good as the structural view of X-TEM. The SIMS matrix effect was interpreted by comparison to the Auger profiles. TOF-SIMS was able to give some insight into the question of hydrogen content of the films. The propensity for thermal damage was also studied.