Negative Capacitance Transistors
The physics of ordered and correlated systems allow for fundamental improvement of the energy efficiency when a transition happens between two distinguishable states. For ferroelectric materials where such order forms due to interaction between many dipoles, thermodynamics dictate that charge can be switched with much lower energy compared to conventional dielectrics. This leads to a situation where a ferroelectric material can be stabilized at a state of negative capacitance. In this tutorial, I shall discuss the physical origin of negative capacitance and how it can be stabilized to obtain an amplification of the electrostatic field. When combined with the gate of ta transistor, this state of stabilized negative capacitance could lead to reduction in the supply voltage and/or increase of the ON current of a transistor. I shall discuss our understanding of this phenomena based on the most recent experimental results and possible pathways to optimize transistor performance for scaled nodes.