3-D simulation of LPCVD using segment-based topography discretization

A new method for three-dimensional (3-D) simulation of low pressure chemical vapor deposition (LPCVD) in arbitrary geometries using a segment-based topography discretization with triangles, combined with a redistribution model for reactive particles, is presented. Simulation results for different geometries like rectangular and rotational symmetric holes are shown. The step coverage predicted by 3-D simulations is compared to step coverage from 2-D simulations. The step coverage calculated using 3-D simulations is significantly smaller than from 2-D simulations. Therefore, 3-D simulations are necessary for the accurate description of layer deposition in device structures with arbitrary geometry where 3-D effects have to be taken into account. A comparison between a simulated 3-D profile and experimental data from tungsten LPCVD in a contact hole shows a very good agreement between experiment and simulation.