An ultra-thin CMOS in-plane stress sensor

This paper presents a CMOS stress sensor for uniaxial, in-plane flex measurement. The sensor is to be fabricated as an ultra-thin chip in order to adapt to surface shape. The sensor generates 2×10-bit data from piezo-resistive elements, via on chip stress insensitive readout circuitry. Unlike the directional selectivity of the strain gauges, the uniaxial in-plane stress vector can be measured in any direction by this sensor. In addition, the MOSFET stress macro model used for the sensor flex simulations is presented. It is used for the sensor flex simulations. It supports DC, AC, and transient analysis with any analog simulator.