Transistor Switches Using Active Piezoelectric Gate Barriers

This paper explores the consequences of introducing a piezoelectric gate barrier in a normal field-effect transistor. Because of the positive feedback of strain and piezoelectric charge, internal charge amplification occurs in such an electromechanical capacitor resulting in a negative capacitance. The first consequence of this amplification is a boost in the ON-current of the transistor. As a second consequence, employing the Lagrangian method, we find that using the negative capacitance of a highly compliant piezoelectric barrier, one can potentially reduce the subthreshold slope of a transistor below the room-temperature Boltzmann limit of 60 mV/decade. However, this may come at the cost of hysteretic behavior in the transfer characteristics.