CMOS-integrated Sensor Chip for In-Plane and Out-of-Plane Shear Stress

This paper reports on the design and characterization of a novel stress sensor chip in complementary metal oxide semiconductor (CMOS)-technology. The chip is capable of detecting two in-plane shear stress components and for the first time two out-of-plane shear stress components at multiple locations. On an area of 2.5 mm x 2 mm, the sensors are integrated with an instrumentation amplifier, an A/D-converter and digital logic for signal processing and data transmission via an (IC)-C-2-bus. The single sensor elements as separate test structures and the CMOS chip are characterized by the application of individual, homogeneous stress components. In every case, linear responses only of the designated sensors are observed. An encapsulation process with two-component epoxy resin reveals that mainly thermo-mechanical normal stress is generated during cooling-down. (C) 2010 Published by Elsevier Ltd.