AVS 51st International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS-ThA

Paper PS-ThA8
Uniformity Study in Large-Area Showerhead Reactors

Thursday, November 18, 2004, 4:20 pm, Room 213A

Session: Plasma-Surface Interaction
Presenter: R. Sobbia, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Authors: R. Sobbia, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
L. Sansonnens, Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland
J. Bondkowski, UNAXIS France SA, France
Correspondent: Click to Email
Large area plasma enhanced chemical vapour deposition of thin films such as silicon nitride or amorphous silicon is widely used for thin film transistor fabrication in the flat panel display industry. A numerical three dimensional model to calculate the deposition uniformity over the whole electrode surface for RF rectangular showerhead reactors powered at 13.56 MHz is presented. The simulation tool is a commercially-available finite-volume software (CFDRC ACE+) which solves the multi-species, multi-reaction chemistry in capacitively coupled plasma. In order to simplify the three dimensional geometry, the injected gas flow distribution across the showerhead is calculated separately and introduced as volumetric source terms for the gas flow and species continuity equations via a dynamic library coupled with the main Solver. The model is applied to the particular case of silicon nitride deposition and the results are compared with uniformity profiles obtained in an industrial PECVD reactor. Perturbations due to reactor edges together with non-uniform distribution of voltage, gas flow and chemical species are investigated as possible sources of the inhomogeneity of the thin-film.