AVS 46th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP22
In-Plane Texturing in Evaporated Cr Films

Monday, October 25, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: J.F. Whitacre, University of Michigan
Authors: J.F. Whitacre, University of Michigan
Z.U. Rek, Stanford Synchrotron Radiation Laboratory
J.C. Bilello, University of Michigan
S.M. Yalisove, University of Michigan
Correspondent: Click to Email
The evolution of crystallographic texture in Cr films thermally evaporated using no energetic assistance was examined. In particular, the existence of an in-plane texture in films deposited onto obliquely oriented substrates was studied. All films were grown using electron-beam evaporation in a UHV chamber on (100) test-grade Si wafers with native oxide. The substrates were positioned such that their surface normals were oriented either 0° or 60° with respect to the adatom flux vector. Texturing, grain development, and surface morphology were studied using x-ray and electron diffraction, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The films grown on substrates oriented perpendicular to the flux vector developed a strong (110) out-of-plane texture, but showed no signs of in-plane texturing. These films had well-defined crystalline columnar grain structures and faceted surface morphologies. Those films grown on obliquely oriented substrates also displayed columnar grain structures and surface facets, though they were inclined ~35° with respect to the substrate surface normal. Despite this tilt, the out-of-plane texture was still (110). A heuristic model is proposed which describes the evolution of in-plane texture in evaporated films and accounts for the morphology and grain development observed. The combination of obliquely arriving adatoms and anisotropic surface facets creates an in-plane shadowing phenomena. If surface diffusion lengths are limited to grain dimensions, the model shows how grains with particular in-plane crystallographic orientations will grow at the expense of others. This process is modeled numerically and compared with experimental results. Work supported under ARO Army contracts DAAH 04-95-1-0120 and DAAG 55-98-1-0382. Some data collected at SSRL, funded by the US DoE.