Resistive Switching in $\hbox{HfO}_{2}$ Probed by a Metal–Insulator–Semiconductor Bipolar Transistor

Resistive switching in thin HfO
₂
films is studied using a metal-insulator-semiconductor bipolar transistor structure. Using this structure, electron injection into the semiconductor valence band can be distinguished from injection into the conduction band. In addition, the p-n junction serves as a sensitive detector of damage induced by the switching effect. The implications of the obtained experimental results on the validity of various conduction mechanisms through the insulator are discussed.