AVS 50th International Symposium
    QSA-10 Topical Conference Monday Sessions
       Session QS-MoA

Paper QS-MoA8
The Thickness and Composition of Ultra-thin SiO@sub 2@ Layers on Si

Monday, November 3, 2003, 4:20 pm, Room 320

Session: Thin-Film Metrology
Presenter: C. Van der Marel, Philips Electronics, The Netherlands
Authors: C. Van der Marel, Philips Electronics, The Netherlands
M.A. Verheijen, Philips Electronics, The Netherlands
Y. Tamminga, Philips Electronics, The Netherlands
R.H.W. Pijnenburg, Technical University Eindhoven, The Netherlands
N. Tombros, State University of Groningen, The Netherlands
F. Cubaynes, Philips Research, IMEC, Belgium
Correspondent: Click to Email
Ultra-thin SiO2-layers are of importance for the semiconductor industry. One of the techniques that can be used to determine the chemical composition and thickness of this type of layers is XPS (X-ray Photoelectron Spectroscopy). As shown by Seah and Spencer,@footnote 1@ it is not trivial to characterize this type of layers in a reliable way. We carried out a series of systematic investigations on layers of SiO2 on Si (in the range from 0.3 to 3 nm). The samples were analyzed by means of TEM, RBS and XPS. The XPS-results were analyzed using the standard Cumpson formula (equation 2 in@footnote 1@), by means of Quases-Tougaard and using an overlayer-substrate model. We also examined the influence of various experimental parameters upon the results (e.g. irradiation time in RBS, objectivity of layer thickness determination in TEM, measuring time and pass energy in XPS). It was found that the ratio O:Si of the layers always corresponds to that of pure SiO2. Yet, for thickness below 2 nm, small but significant deviations were found between RBS and XPS on the one hand and TEM-results on the other hand. The results suggest that the density of SiO2-layers with a thickness below 2 nm is less than the density of bulk SiO2. @FootnoteText@@footnote 1@ M.P. Seah and S.J. Spencer, Surface and Interface Analysis 33 (2002) 640.