Simulation and experimental analysis of refractory metal and aluminum deposition over high aspect ratio VLSI topography
Simulation tools are used to analyse two VLSI metallization processes. The first example is the use of a collimator in the sputter deposition of refractory metal diffusion barrier layers. The second example is of subsequent contact hole filling by high temperature Al sputtering. A Monte Carlo model of the sputter flux transport from the target to the substrate is used to determine the film uniformities and to determine angular distributions. A second Monte Carlo simulator uses this information to model the growth of the sputtered film over VLSI topography such as contact holes, vias and trenches. The two models taken together provide an integrated package for producing a microstructural depiction and surface profile of the deposited film. The role of the collimator in determining thickness uniformity, bottom coverage and deposition rate is analyzed. For the case of high temperature Al sputtering, the importance of bulk diffusion in this process is shown, and the ability to fill high ratio contacts is demonstrated.
|Journal||Canadian Metallurgical Quarterly|
Smy, T, Dew, S.K., & Brett, M.J. (1995). Simulation and experimental analysis of refractory metal and aluminum deposition over high aspect ratio VLSI topography. Canadian Metallurgical Quarterly, 34(3), 195–202. doi:10.1016/0008-4433(95)00016-Q