화학공학소재연구정보센터
Thin Solid Films, Vol.270, No.1-2, 627-631, 1995
Simulation of Collimated Flux Distributions During Physical Vapor-Deposition
We use the Monte Carlo simulations to estimate flux distributions leaving a single hexagonal collimator cell and on the surface of a flat substrate. We assume the Maxwellian flux distribution for the species entering the collimator, and that the pressure is low enough that the transport inside the collimator cells is collisionless. Flux distributions at the exit of a collimator cell are obtained as functions of position in the plane of the collimator exit. The dependence of flux on the angle measured relative to collimator axis (theta) is broader at the corner of the collimator exit than that at the center of the collimator exit. The fluxes leaving the center of the collimator cell and averaged over the entire cell exit do not depend on the angle measured around the axis of the collimator cell (phi). At each corner of the collimator, there is a maximum in the flux at the phi value corresponding to that corner. We simulate both collisionless and collisional transport from the collimator exit to the flat substrate and estimate the flux distributions of species as functions of position on the flat wafer surface due to a single collimator cell. Tie flux distributions as a function of position for the entire collimator are obtained by summing fluxes from all contributing collimator cells. The flux distributions on the flat substrate due to the entire collimator do not depend on phi. The theta dependencies of the fluxes on a hat substrate depend on the position of the substrate relative to the collimator cell. Collisional transport from the collimator exit to the substrate broadens flux distributions on the flat substrate, relative to collisionless transport.