First Demonstration of Junctionless Accumulation-Mode Bulk FinFETs With Robust Junction Isolation

Abstract

A junctionless-accumulation-mode (JAM) p-channel MOSFET is successfully implemented based on a junction-isolated bulk FinFET for the first time. The JAM devices with a fin width of 16 nm show outstanding transfer characteristics: 1) subthreshold swing (SS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">min</sub> ) = 68 mV/dec; 2) drain-induced-barrier-lowering is 9 mV/V; and 3) I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> ratio >1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> . The JAM devices with smaller fin widths or longer gate lengths give superior short-channel characteristics and higher threshold voltages (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> ) due to their enhanced gate electrostatic controllability. The reverse back bias modulates V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">th</sub> and SS favorably by virtue of a body-tied device, maintaining the substrate current due to junction leakage of <;1 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-11</sup> A.