Compact Multi-Stress Sensitive Field Effect Transistor with Eight Source/Drain Contacts

Abstract:
This paper reports on the merger of two field effect transistor based stress sensors with four source/drain contacts into a compact octagonal device which enables one to extract the two in-plane stress tensor components (sigmaxx –sigmayy) and sigmaxy simultaneously. The active area of the resulting structure is only 13 x 13 micrometer2 which makes it the smallest stress sensor for the extraction of both in-plane components to date. Undesired thermoelectric and magnetic contributions to the output signal are eliminated by applying the discrete spinning current method. As a field effect device, the sensor benefits of the advantage of an independent on/off signal, namely the gate voltage. This makes it possible to avoid the implementation of area-consuming transmission gates in integrated sensor arrays.