Negative Capacitance Field-Effect Transistor (NCFET): Strong Beyond CMOS Device

Field-effect transistors may be able to overcome the so-called “Boltzmann tyranny” of power dissipation with the incorporation of ferroelectric negative capacitance (NC) into their design. Negative capacitance field-effect transistor (NCFET) is quickly becoming a popular alternative technology that promises to increase the power efficiency of transistors by many times while still being compatible with the current CMOS fabrication method. The transistor’s gate stack of an NCFET contains a ferroelectric (FE) layer that exhibits a negative capacitance effect that amplifies the internal voltage. However, it remains a challenging task to realize the stable negative capacitance in the non-hysteretic non-transient regime. The problem arises due to the lack of understanding regarding the fundamental origin of the negative capacitance (NC), specifically how the emergence of the domain state can be utilized to implement the NCFET. The emphasis in this book chapter is to discuss a novel architecture for field-effect transistor based on ferroelectric domains that feature a static negative capacitance that is stable in both directions. The performance of field-effect transistors can be significantly improved by applying a dielectric coating on the ferroelectric capacitor, enabling the tuning of negative capacitance.