Abstract: A piezoresistive transistor device includes a first transistor cell having a first piezoelectric material body and a first piezoresistive material body arranged in a stacked configuration. A first electrical resistance of the first piezoresistive material body is dependent upon a voltage applied across the first piezoelectric material body by way of a pressure applied by the first piezoelectric material body to the first piezoresistive material body. A second transistor cell includes a second piezoelectric material body and a second piezoresistive material body arranged in a stacked configuration. A second electrical resistance of the second piezoresistive material body is dependent upon a voltage applied across the second piezoelectric material body by way of a pressure applied by the second piezoelectric material body to the second piezoresistive material body.

Abstract: A power transistor device includes a semiconductor substrate, a gate trench extending into the semiconductor substrate, a transistor gate provided in the gate trench, and an insulating structure formed between the transistor gate and a side wall of the gate trench. The insulating structure is configured to electrically insulate the transistor gate from a channel region which extends along the side wall of the gate trench. The insulating structure includes a layer of piezoelectric material.