FinFET With Improved Subthreshold Swing and Drain Current Using 3-nm Ferroelectric Hf_0.5Zr_0.5O₂

Abstract

High-performance negative capacitance p-type FinFETs (p-FinFETs) with a 3-nm-thick ferroelectric (FE) hafnium zirconium oxides (Hf <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> Zr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) layer are fabricated based on a conventional high-κ metal gate FinFETs fabrication flow. The devices show improved subthreshold swing values [34.5 mV/dec for 500-nm gate length (L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> ) and 53 mV/dec for 20-nm-L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> devices] and slight hysteresis voltages (~9 mV for L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> = 500 nm and ~40 mV for L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">G</sub> = 20-nm transistors). With the integrated FE film, a strong driving current enhancement (up to 260%) is also obtained compared with that of conventional FinFETs. The inherent reasons for the improved characteristics contribute to the low-interface state density (D <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">it</sub> ) and the perfect channel electrostatic integrity.