AVS 52nd International Symposium
    Applied Surface Science Thursday Sessions
       Session AS+TF-ThM

Invited Paper AS+TF-ThM3
Semiconductor-Dielectric Interfaces: Composition and Structure

Thursday, November 3, 2005, 9:00 am, Room 206

Session: Thin Film Characterization
Presenter: L.C. Feldman, Vanderbilt University
Authors: L.C. Feldman, Vanderbilt University
S. Dhar, Vanderbilt University
J.R. Williams, Auburn University
L. Porter, Carnegie- Mellon University
J. Bentley, Oak Ridge National Laboratory
K.-C. Chang, Carnegie-Mellon University
Y. Cao, Carnegie-Mellon University
Correspondent: Click to Email
The semiconductor-dielectric interface is the key to a successful MOSFET technology and has played the essential role in the silicon revolution. Wide-band gap materials have presented a challenge to achieve the same degree of interface perfection as silicon, although considerable progress is underway. The SiC/SiO2 interface is of particular scientific interest in this development because of its close relationship to silicon, both in processing and structure. The oxidation process in SiC yields a heavily defected SiC/SiO2 interface giving rise to poor device characteristics. Systematic use of chemical modification and processing, combined with a careful analysis of interfacial structure, results in significant progress in reducing defects and increasing inversion layer carrier density and mobility. For example nitridation of this interface results in a remarkable improvement and is a driving force for understanding the nitrogen profile and concentration. The quantitative nitrogen profile is critical to this understanding and provides a significant depth profiling challenge. Using a variety of probes including medium energy ion scattering, secondary ion mass spectroscopy, nuclear profiling and electron energy loss spectroscopy we show that the nitrogen is confined to within ~1.5 nm of the buried interface, with concentrations that are crystal face dependent and vary from 0.5 to ~1.5 x 10@super 15@/cm@super 2@. From an analysis point of view the significant new finding is the comparison of techniques and the degree of quantitative agreement between the different probes. @FootnoteText@ Supported by DARPA, N00014-02-1-0628 and ONR,N00014-01-1-0616. Research at the O. R. N. L. was sponsored by the Division of Materials Sciences and Engineering, U.S. Department of Energy, under contract DE-AC05-00OR22725 with UT-Battelle, LLC.