Angular Distributions of Molecular Beam Flux : 1st Report, Evaporation from a Two-Dimensional Crucible

Abstract

The angular distributions of molecular beam flux evaporated from a two-dimensional crucible partially filled with liquid are studied by use of the direct simulation Monte Carlo method. As the Knudsen number increases, the molecular flux is collimated near the center-line of the crucible. The collimation also increases as the liquid level in the crucible lowers. The thickness distributions of the film deposited on the holder surface perpendicular to the center-line of the crucible are calculated by assuming that every molecule incident on the holder is deposited on it. When the distance between the crucible exit and the holder is 50 times the crucible width, the thickness distribution can accurately be estimated by regarding the crucible as a point evaporation source.