BEOL Compatible Dual-Gate Ultra Thin-Body W-Doped Indium-Oxide Transistor with Ion = 370μA/μm, SS = 73mV/dec and Ion /Ioff Ratio > 4×109
Wriddhi Chakraborty, Benjamin Grisafe, Huacheng Ye, Ian V. Lightcap, Kai Ni, Suman Datta
Abstract
We experimentally demonstrate BEOL compatible (<; 250C thermal budget) 1 % W-doped amorphous In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (IWO) back-gate (BGFET) and dual-gate (DGFET) field-effect transistors with 7nm channel thickness. The 100nm channel length IWO DGFET exhibits excellent subthreshold slope (SS) of 73m V /dec, record ID,SAT of 370μA/μm, and on-off ratio > 4×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9</sup> at V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DS</sub> = 1V and V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> -V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sub> =2V We provide insight into the electrostatic gate control efficiency through temperature and frequency dependent admittance measurement. We identify fundamental transport mechanisms that limit electron mobility inamorphous IWO as a function of gate-bias (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">GS</sub> ) and temperature. Benchmarking shows that IWO DGFET is a promising BEOL transistor for enabling high-performance monolithic three-dimensional (M3D) integrated circuits.