Development of an Optimization Procedure for Magnetron-Sputtered Thin Films to Facilitate Combinatorial Materials Research

High-throughput experimentation (HTE) is an experimental paradigm that has shown potential for accelerating the evaluation of material systems by synthesizing a sample with a variation of material parameters and using parallel or fast serial characterization. Magnetron sputtering is one of the most widely used thin-film synthesis techniques in the HTE field. One major bottleneck for HTE magnetron sputtering is identifying appropriate sputtering conditions. Here, a Nelder–Mead optimization procedure with soft constraints is used to determine sputtering conditions of a desired deposition rate distribution using a continuum based sputter model. The optimization procedure uses a multiple stage multistart method to overcome issues with initialization and multiple minima. The procedure was validated against a simulated thin film. The method was able to determine a gun power, gun tilt, and substrate height within 1% of the simulation sputtering conditions in 29.8 s. This result is 3–4 orders of magnitude faster than the traditional experimental approaches. The optimization was also validated against experimentally measured thickness profiles. During validation, the optimized sputtering conditions yielded a thickness profile that was within error of the experimental measurement and the model.