A 3D Vertical-Channel Ferroelectric/Anti-Ferroelectric FET With Indium Oxide

Abstract

A vertical channel ferroelectric-FET (FeFET) with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based ferroelectric (Fe-HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) and atomic layer deposition (ALD) Indium oxide (InOx) channel has been developed and demonstrated for 3D high-density memory applications. Reliable memory operation has been confirmed with memory window (MW) >1V in gate length (L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</sub> ) = 50nm short channel FeFETs. Polar-axis transition of Fe-HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> from in- plane in the initial film to out-of-plane after electrical cycling has been verified by both experimental and theoretical studies. A vertical channel anti-ferroelectric (AFe) FET (AFeFET) with ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> has been also demonstrated by making use of half-loop hysteresis in AFe, which can be a new solution for the weak erase problem seen in oxide semiconductor channel FeFETs.