Stress coefficient extractions on MOSFET micro-sensors

The MOSFET (Metal-Oxide-Semiconductor Field-Effective-Transistor) has the potential to be a suitable chip stress monitoring tool for microelectronic packaging because the measurements are nondestructive, in-situ, real-time, and the sensor is relatively small. To this end, this paper studies the stress behaviors of both types of the MOSFET micro stress sensors. In this work, a self-developed four-point bending (4PB) measurement methodology is employed and the stress coefficient calibrations on the MOSFET sensors were next performed. After measurements, stress coefficients for both types of the MOSFET were successfully extracted with discussions. After comparing with the previous extracted temperature coefficients on the same devices, it is also concluded that the temperature effect is extremely important for the MOSFET sensor applications.