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

Paper AS-ThA6
Nitrogen Incorporation and Trace Element Analysis of Nanocrystalline Diamond Thin Films by SIMS

Thursday, November 5, 1998, 3:40 pm, Room 307

Session: SIMS - Depth Profiling and Molecular Surface Analysis
Presenter: D. Zhou, University of Central Florida
Authors: D. Zhou, University of Central Florida
F.A. Stevie, Cirent Semiconductor
J. Mckinley, Cirent Semiconductor
H. Gnaser, University of Kaiserslautern, Germany
Correspondent: Click to Email
Nitrogen has been recognized as an important impurity in diamond, and the nature of its electronic states has been a central concern in elucidating the electronic and the optical properties of both natural and synthetically grown diamond. Although substitutional nitrogen in diamond is a deep donor impurity, it can affect that optical transparency, thermal conductivity, and electron field emission characteristics of diamond. We report that nitrogen has been successfully incorporated into nanodiamond films produced from a N@sub 2@/CH@sub 4@ microwave plasma enhanced CVD. High mass resolution SIMS (with a Cs@super +@ source) characterization shows that the concentration of the incorporated nitrogen, monitored via CN@super -@ (26.0031 amu), can be as high as 10@super 21@ atoms/cm@super 3@ depending on the ratio of N@sub 2@ to CH@sub 4@ in the reactant gas and on the substrate temperature used for the film preparation. The SIMS depth profile demonstrates that the incorporated nitrogen is uniform through the diamond films (about 1 micron thick) except for the surface and the interface between the film and substrate. Furthermore, SIMS (with an O@sub 2@@super +@ source) analysis reveals that alkali elements such as Na, K and Li appear to be the major trace metallic impurities and/or contamination for the diamond thin films produced from CH@sub 4@/N@sub 2@, CH@sub 4@/Ar, or CH@sub 4@/H@sub 2@ discharge, but they are the bulk impurities only for the thin films prepared from CH@sub 4@/N@sub 2@ plasma. These alkali impurities could also play important roles in electronic properties such as electron field emission of nanodiamond thin films. The authors would like to acknowledge the support from the Advanced Materials Processing and Analysis Center and UCF/Cirent Materials Characterization Facility at University of Central Florida. D. Zhou also specially acknowledge valuable discussion with D. M. Gruen and A. R. Krauss at Argonne National Laboratory.