Piezoelectric Strain Modulation in FETs

We report on a feature for the transistor, a piezoelectric layer to modulate the strain in the channel. The strain is proportional to the gate-source voltage, and thus increases as the device is turned on. As a result, the device has the leakage current of a relaxed device and the lower threshold voltage of a strained device. Our results, obtained by combining electrical and mechanical simulations, demonstrate that strain modulation can result in a 9 mV/decade smaller subthreshold swing for a FinFET.