AVS 52nd International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeA

Paper TF-WeA10
Vinyltrimethylsilane (VTMS) as a Probe of Chemical Reactivity and Surface Structure of a TiCN Diffusion Barrier Deposited on Silicon

Wednesday, November 2, 2005, 5:00 pm, Room 306

Session: Fundamentals of Thin Films
Presenter: A.V. Teplyakov, University of Delaware
Authors: L. Pirolli, University of Delaware
A.V. Teplyakov, University of Delaware
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This study presents the first molecular level investigation of chemical reactivity of a surface of an amorphous diffusion barrier film deposited on a Si(100)-2x1 single crystal. Vinyltrimethylsilane (VTMS) is chosen as a probe molecule because of its role as a ligand in a common copper deposition precursor, hexafluoroacetylacetonato-copper-vinyltrimethylsilane. Surface chemistry of vinyltrimethylsilane (VTMS) on TiCN-covered Si(100)-2x1 has been investigated using multiple internal reflection Fourier-transform infrared spectroscopy (MIR-FTIR), Auger electron spectroscopy (AES), thermal desorption mass spectrometry, and computational analysis. On a film deposited at 600 K, VTMS adsorbs molecularly at cryogenic temperatures even at submonolayer coverages, the major pathway for its temperature-programmed evolution is desorption. Adsorption at room temperature leads to chemisorption via a double bond attachment. The desorption studies combined with the computational analysis suggest that the adsorption of VTMS occurs preferentially in two configurations: across the surface C-Ti bond and on a corner Ti, but not across the Ti-N bond.