Comparative Analysis of 12-nm Gate-all-Around Vertically Stacked Nanosheet Field Effect Transistor for High-k Gate-oxide Dielectrics

As the dimensions of 2D FETs decrease, issues such as short-channel effects emerge, prompting the search for improved device designs. 3D structures like FinFETs offer enhanced gate controllability and better electrical characteristics. Despite this, short channel effects remain a concern for FinFETs with channel lengths below 22 nm. This has led to the adoption of GAAFETs (gate-all-around FETs), which provide gate coverage from all directions. GAAFETs represent the latest advancement in 3D device technology and are increasingly utilized in chip manufacturing processes. In the work below, we studied the electrical properties of a 12-nm vertically stacked nanosheet gate-all-around field effect transistor (VNSFET) by varying gate-oxide material and replacing gate-oxide material with high- k dielectric materials (SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>, Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>, HfSiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>, Ta<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf>, TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>). Temperature variations for devices are also considered along gate oxide dielectric variations The obtained results showed that ON current increases and OFF current decreases with the increase in dielectric constant. We compared our simulation results with predicted data from the International Roadmap for Devices and Systems [2]. Additionally, it was observed that TiO2 is superior to other gate oxides.