AVS 51st International Symposium
    Thin Films Friday Sessions
       Session TF-FrM

Paper TF-FrM4
Analysis of Ti and TiN Thin Film Nucleation, Coalescence, and Growth by Rotating Compensator Multichannel Ellipsometry

Friday, November 19, 2004, 9:20 am, Room 303C

Session: In-Situ/Ex-Situ & Real-Time Monitoring
Presenter: C. Chen, The Penn State University
Authors: C. Chen, The Penn State University
B. Hong, Sungkyunkwan University, Korea
P. Sunal, The Penn State University
M.W. Horn, The Penn State University
R. Messier, The Penn State University
R.W. Collins, University of Toledo
Correspondent: Click to Email
Real time spectroscopic ellipsometry has been applied in the rotating-compensator configuration to characterize the nucleation, growth, and optical properties of titanium and titanium nitride thin films deposited by magnetron sputtering on silicon wafers with thermally-grown silicon oxide and nitride overlayers. The ellipsometer used in this study incorporates recent instrumentation advances for a wide spectral range (1.5 to 6.5 eV), including a dual Xe/D@sub 2@ source with an intervening iris for spectral flattening. The real time ellipsometric spectra collected throughout film deposition on the smooth wafer substrates are analyzed in terms of a transition from a one-layer to a two-layer optical model. This transition simulates the overall thin film structural evolution including nucleation, coalescence, and surface roughening during growth. In the initial stages, the spectra are particularly sensitive to smoothening that occurs during coalescence. In the case of Ti deposition on SiO@sub 2@ covered Si wafers, for example, this effect is maximized within a narrow deposition parameter window of Ar sputtering gas pressure and plasma power. In this case, 15-20 Å thick Ti clusters coalesce, yielding surface roughness only a monolayer in thickness after ~100 Å of Ti bulk layer deposition. The evolution of the optical properties of the Ti layer with cluster size during nucleation and with bulk thickness during growth provides additional information on the structure of the film and its electronic properties. Finally, insights from these studies can be used to direct the fabrication of alternating multilayer and nanocomposite films for hard-coating applications.