Normal-stress Semiconductor Sensor Using a Combined Square-shaped van der Pauw Structure

Abstract

A combined square-shaped van der Pauw (VDP) sensor is proposed for calculation of the difference of the in-plane normal-stresses in this work. In previous works, two separate measurements were required, which is so inconvenient and tricky, because the different pair of point-contacts were used for 0 and/or 90 degree oriented resistance measurement. This work analytically presented how to resolve these problems by using a combined VDP configuration and compared the in-plane normal-stresses differential sensitivities for the different silicon planes and the coordinate systems (un-primed or primed). Furthermore, we offered another approach using the voltage difference, in which the sensitivity was observed to be linearly proportional to the unstressed value of voltage V-ref (= I x R).