AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP51
Influence of Flux Anisotropy on Microstructure of Sputter Deposited Cr Films

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Aspects of Thin Films Poster Session
Presenter: S.Yu. Grachev, Netherlands Institute of Metals Research, the Netherlands
Authors: S.Yu. Grachev, Netherlands Institute of Metals Research, the Netherlands
J.-D. Kamminga, Netherlands Institute of Metals Research, the Netherlands
G.C.A.M. Janssen, Netherlands Institute of Metals Research, the Netherlands
Correspondent: Click to Email
Sputter deposition is widely used to produce metal and compound thin films. The immanent feature of sputter deposition is that the arriving flux possesses a wide angular distribution. The flux distribution at the coated surface is influenced by the pressure of sputtering gas and by the tilt/rotation of the substrate. It is known, that the anisotropy of the flux distribution can become a source of anisotropic microstructure and, as a consequence, the anisotropy of film properties. In our study we concentrated on the influence of the flux anisotropy on the microstructure of Cr films. There are several sources for anisotropy in the Hauzer HC 750 industrial deposition system we used. First, the elongation of the target (600x120mm@super 2@) induces a flux distribution with arriving angles up to 60° to the substrate normal. This flux distribution results in strong anisotropy of the surface morphology and in-plane crystallographic texture. Second, we tilted the substrate around an axis parallel to the target elongation. This introduced anisotropy in the perpendicular direction. As a consequence, the in-plane texture of the film was turned by 90° with respect to the texture in films grown on substrates parallel to the target. Planetary rotation around axes parallel to the target elongation was also studied. The tilt of the columnar microstructure of samples on tilted substrates is dependent on Ar pressure. At low Ar pressure the tilt is close to the substrate tilt (43° for 45° substrate tilt). The tangent rule predicts the inclination of 26.5°. The discrepancy is attributed to the complicated flux angular distribution from the elongated target. At higher Ar pressure the tilt of the columnar structure was smaller due to the smearing out of the flux distribution.