Geometrical effects in contact resistance measurements: Finite element modeling and experimental results

Abstract

We find experimentally and calculate by a numerical method the geometrical contribution to resistance due to current bending and constriction in 4-point contact resistance measurements in two configurations: 2I (cross stripes) and 2L. The geometrical effects in thin film couples increase in a 2I and decrease in a 2L with decreasing film thickness/width ratios, rendering the 2L configuration most suitable for interface resistance studies, particularly when the thickness to width ratios are less than 0.5. A set of scaling equations is provided, which enables the application of our results to predict geometrical contributions in these geometries for different materials and dimensions.