AVS 50th International Symposium
    Thin Films Thursday Sessions
       Session TF-ThM

Paper TF-ThM3
Initial Growth of High Rate Deposited Silicon Thin Films Studied by In-situ Spectroscopic Ellipsometry and Attenuated Total Reflection Infrared Spectroscopy

Thursday, November 6, 2003, 9:00 am, Room 329

Session: Modeling & Fundamentals in Thin Film Deposition
Presenter: P.J. Van den Oever, Eindhoven University of Technology, The Netherlands
Authors: P.J. Van den Oever, Eindhoven University of Technology, The Netherlands
I.J. Houston, Eindhoven University of Technology, The Netherlands
J. Hong, Eindhoven University of Technology, The Netherlands
M.C.M. van de Sanden, Eindhoven University of Technology, The Netherlands
W.M.M. Kessels, Eindhoven University of Technology, The Netherlands
Correspondent: Click to Email
The trend towards high rate deposition in thin film research - driven by industrial demands - raises several issues in order to maintain good film properties. One particular issue in this respect is the control of the nucleation and initial growth in terms of film density and surface roughness. Therefore, we have investigated the growth of silicon-based films at growth rates up to 10 nm/s as deposited by the expanding thermal plasma technique. The time evolution of the dielectric functions, bulk thickness and surface roughness has been obtained from real time spectroscopic ellipsometry measurements and the surface roughness evolution has been compared to atomic force microscopy data. Attenuated total reflection infrared spectroscopy has been employed to obtain the hydrogen depth profile of the films. For hydrogenated amorphous silicon, the film growth is found to be homogeneous after nucleation. Hydrogenated microcrystalline silicon on the other hand shows a nucleation region of crystallites, which is followed by columnar film growth after the crystallites have reached coalescence. This is supported by the hydrogen depth profile where the nucleation and presence of the crystallites is accompanied by the emergence of surface-like bonded hydrogen that can be attributed to hydrogen passivating the grain boundaries of the crystallites. For silicon nitride films a clear difference has been observed in the surface roughness evolution between silicon-rich and nitrogen-rich films as deposited under different plasma conditions. This difference can be attributed to different growth modes that are determined by the surface free energy and the specific surface reactions taking place during film growth.