Optimization of Multi-Layered Thin Films for Minimizing Resistive Losses in Acoustic Resonators II

As modern technologies increasingly rely on nanoscale devices, minimizing electrical resistance especially at metal-to-metal interfaces becomes critical. This project investigates contact resistance between stacked metal layers commonly used in MEMS/NEMS systems. Two designs were developed and fabricated on oxidized silicon wafers to explore the influence of metal combinations, ion gun pre-cleaning, square dimensions, and interpad spacing. Design 1 replicates a previously studied layout, while Design 2 introduces improved contact geometries. Several metal stacks, including Al, Cr/Al, and Ti/Al, were tested with varying ion gun durations. Electrical measurements were analyzed through MATLAB scripts to extract resistance values and trends. Although absolute contact resistance values could not always be extracted due to measurement limitations, the results clearly highlight the influence of surface preparation and adhesion layers. In particular, Ti/Al contacts showed consistently lower resistance than Cr/Al, and ion gun treatment was found to significantly improve interface performance. These findings provide insight into contact optimization for future integrated microsystems.