Novel highly miniaturized multi-stress sensor field effect transistor with eight source/drain terminals

This paper reports on a novel field effect transistor based stress sensor with 8 source/drain terminals capable of measuring the two in-plane stress components (σ_xx-σ_yy) and σ_xy simultaneously. Its active area is only 13×13 μm² which makes it the smallest CMOS compatible stress sensor for the extraction of more than one in-plane stress component. The sensor is operated using the discrete spinning current method that makes it possible to eliminate undesired thermoelectric and magnetic effects. In contrast to diffused stress sensors the device can be turned on and off using a signal separate from the supply/output lines, viz., the gate voltage V_GS. Therefore, the integration into high density stress sensor arrays with much smaller device pitches is possible. In integrated systems the gate voltage controlled on/off switching is able to replace area-consuming transmission gates.