3D simulation for sub-micron metallization

A program for the three-dimensional (3D) simulation of layer deposition processes has been developed. A triangular discretization of the device geometry is used in combination with a particle redistribution model. The algorithms implemented perform geometric calculations to determine the rates of particle exchange between different parts of the surface and between surface and gas. For advancing the surface, a 3D version of the 2D string algorithm has been developed. Because of the universality of the routines implemented, the simulator is applicable to different techniques for layer deposition. Examples for the 3D simulation of low-pressure chemical vapor deposition, sputter deposition, and evaporation are shown. The comparison between a 2D and a 3D simulation of layer deposition in a contact hole shows significant 3D effects and therefore the necessity of using 3D simulators for predicting the shape of layers deposited on topography features such as deep contact holes.