AVS 49th International Symposium
    Applied Surface Science Wednesday Sessions
       Session AS-WeM

Paper AS-WeM7
Nitrided Silicon-Silicon Dioxide Interface: Electrical and Physico-Chemical Characterization by Complementary Surface Techniques

Wednesday, November 6, 2002, 10:20 am, Room C-106

Session: Optical Methods and High-k Dielectrics Characterization
Presenter: L. Vanzetti, ITC-irst, Italy
Authors: L. Vanzetti, ITC-irst, Italy
E. Iacob, ITC-irst, Italy
M. Barozzi, ITC-irst, Italy
D. Giubertoni, ITC-irst, Italy
M. Bersani, ITC-irst, Italy
M. Anderle, ITC-irst, Italy
P. Bacciaglia, ST Microelectronics, Italy
B. Crivelli, ST Microelectronics, Italy
M.L. Polignano, ST Microelectronics, Italy
M.E. Vitali, ST Microelectronics, Italy
Correspondent: Click to Email
The scaling down of MOS devices into the submicron regime needs high-quality ultrathin gate dielectrics. Silicon oxide nitridation is widely used to improve oxide reliability and to reduce interface degradation induced by electrical stress. Analytical issues in this field include electrical characterisation, nitrogen quantitative depth distribution and chemical characterisation. In this work NO and N@sub2@O nitrided oxide layers with thicknesses in the range 70-120Å were studied. Different analytical techniques were used, namely the Elymat (Electrolytic Metal Tracer), SIMS and XPS. Surface recombination velocity was obtained from photocurrent measurements by a modification of the Elymat technique allowing the control of surface potential. The so-obtained surface recombination velocity was shown to be directly related to the interface state density of the as-grown oxide. Surface recombination velocity was correlated with nitrogen content in the silicon oxide layer, obtained by SIMS measurements. XPS analyses allow to explain the different electrical behaviour. In fact XPS measurements provide a complete chemical characterisation of these interfaces. In addition a comparison between quantified SIMS depth profiles and XPS etch-back depth profiles shows very good agreement in nitrogen profile shape and quantification. This approach results very effective for the full characterisation of this type of materials.