AVS 49th International Symposium
    Thin Films Friday Sessions
       Session TF-FrM

Paper TF-FrM11
Effect of Metal Underlayers on Low Temperature Silicon Growth

Friday, November 8, 2002, 11:40 am, Room C-101

Session: Fundamentals of Thin Flm Growth
Presenter: K. Xu, University of Delaware
Authors: K. Xu, University of Delaware
A. Pradhan, University of Delaware
S.I. Shah, University of Delaware
Correspondent: Click to Email
Previously, we have reported the effect of Kr on the crystallinity of Si films grown at low temperatures on temperature sensitive substrates. An additional contribution to the Si film crystallinity comes from metal underlayers. Silicon films were deposited on glass, metal-coated glass and metal-coated polymer substrates at temperatures between 130-200°C. X-ray diffraction showed that the films deposited on substrates with gold underlayers were polycrystalline while those deposited on bare glass or polymer substrates were x-ray amorphous. Atomic force microscopy (AFM) was used to study the topography and ad-atom diffusion on the surface. AFM micrographs showed that the polycrystalline silicon films had an average grain size of 95nm. The surface diffusion length was calculated from the AFM micrographs. The results showed films deposited on substrates with gold underlayers had larger diffusion lengths which help to increase the grain size. In order to understand the effect of the underlayer grain size, gold films were annealed to temperatures up to 400°C. Silicon films deposited on these annealed substrates showed even higher crystallinity and larger grain size. The results of XRD, AFM and Raman characterizations will be presented. We will correlate the grain size to the diffusion length and present a model for grain growth in silicon films on temperature sensitive substrates.