Multidimensional CMOS in-plane stress sensor

This paper reports on a novel multidimensional CMOS based stress sensor. The sensor uses an individual n-well to detect all in-plane stress components through the application of the switching current method. To reduce the system´s non-linearities the sensor features a middle contact for improved biasing conditions. A bending-bridge setup was used to apply stress to the device. The behavior was modelled using a novel combination of the finite element method and a nonlinear SPICE network simulation. The device supplies information about the angular dependence of the resistive components and the orthogonal offset voltage. These may be used to extract the three in-plane stress components.