AVS 45th International Symposium
    Manufacturing Science and Technology Group Thursday Sessions
       Session MS-ThP

Paper MS-ThP4
Fluid Simulation of Distributed Gas Injection for Aluminum and Photoresist Etch

Thursday, November 5, 1998, 5:30 pm, Room Hall A

Session: Manufacturing Science and Technology Group Poster Session
Presenter: D.F. Beale, Lam Research Corporation
Authors: D.F. Beale, Lam Research Corporation
N. Williams, Lam Research Corporation
Correspondent: Click to Email
The differences between two gas injection designs were studied via 3D fluid simulations. The two cases considered were a typical showerhead injected reactor with side pumping and a novel distributed injection reactor. In the novel design, gas entered the reaction chamber subsonically through a hexagonal array of cells. Each cell consisted of a circular gas inlet port with a concentric annular outlet port. Simulations of both designs were performed for a typical low pressure Aluminum etch and a high pressure photoresist (PR) strip. Plasma effects were not considered because the commercial fluid simulation used predicts Al etch trends well@footnote 1@ and because the stripper plasma was distant from the wafer. Peclet number values calculated from simulation output showed more diffusive transport in the novel geometry than in the standard one. This difference was important for the transport-limited etching of Al by Cl@sub 2@, but not for the interface-limited etching of PR by O@sub 2@. Differences between the two etch chemistries were further characterized via Reynolds numbers, Knudsen numbers and sticking coefficients calculated from simulation output. Axisymmetric 2D simulations of a showerhead-injected reactor and 3D simulations of a novel injection reactor with 19 inlet/outlet cells were performed. @FootnoteText@ @footnote 1@"Trends in aluminum etch rate uniformity in a commercial inductively coupled plasma etch system", JVST B 16(3), May/Jun 1998.