Study of Metal Oxide Semiconductor Field Effect Transistor with Double-Layered Ferroelectric Capacitor

摘要

The switching characteristics of a negative-differential-capacitance field-effect transistor (NCFET) whose gate electrode is connected in series to a double-layered ferroelectric (FE) capacitor (double-layered NCFET) are experimentally compared with those of a single-layered NCFET. The hysteresis of the NCFET is an undesirable characteristic for logic-device applications. The hysteresis window can be removed through capacitance matching by matching the gate capacitance of the metaloxide-semiconductor field-effect transistor (MOSFET) and the capacitance of the FE capacitor. This work proposes and experimentally demonstrates that a double-layered FE capacitor can better match the capacitances between the FE capacitor and MOSFET by reducing the coercive voltages and producing higher negative capacitances than the single-layered one. It is found that the double-layered NCFET has a similar to 40% narrower hysteresis window than the single-layered NCFET.