DEPOSITION RATE DEPENDENCE OF STEP COVERAGE OF SPUTTER-DEPOSITED ALUMINUM-(1.5-PERCENT) COPPER-FILMS

Al-(1.5%) Cu films were deposited at selected temperatures and rates i nto trenches on patterned wafers in order to study the deposition rate dependence of film step coverage. No substrate bias was applied to mi nimize resputtering of deposited material. Step coverage improves with increasing temperature and decreasing deposition rates. EVOLVE, a phy sically based low pressure deposition process simulator that incorpora tes curvature driven surface diffusion of adsorbed species, yields sim ulated film profiles in good agreement with experimental profiles. The results demonstrate that diffusion is a rate process critical to impr oving step coverage. (C) 1988 American Vacuum Society. [S0734-2101(98) 05905-3].