Effect of contact size and placement, and of resistive inhomogeneities on van der Pauw measurements

Abstract

The measurement errors of resistivity and Hall coefficient in the van der Pauw technique due to contact lead size or lead placement errors is calculated for square and cloverleaf‐shaped samples, and compared to the results for a simple circular disk. Both the square and the cloverleaf greatly reduce these errors, compared to the circular sample shape. Another source of measurement error, sample inhomogeneity, is also analyzed, and it is shown that the error introduced by inhomogeneities is proportional to E² in the region of the inhomogeneity. Consequences of these results are discussed.