The Piezojunction Effect in Silicon Integrated Circuits and Sensors

Mechanical stress affects the magnitude of base-emitter voltages of forward biased bipolar transistors. This phenomenon is called the piezojunction effect. The piezojunction effect is the main cause of inaccuracy and drift in integrated temperature sensors and bandgap voltage references. The aim of this text is twofold. Firstly, to describe techniques that can reduce the mechanical-stress-induced inaccuracy and long-term instability. Secondly, to show that the piezojunction effect can act upon various types of mechanical-sensor structures.