On the Vertically Stacked Gate-All-Around Nanosheet and Nanowire Transistor Scaling beyond the 5 nm Technology Node

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

9 Scopus Citations
View graph of relations

Author(s)

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number1739
Journal / PublicationNanomaterials
Volume12
Issue number10
Online published19 May 2022
Publication statusPublished - May 2022

Link(s)

Abstract

This work performs a detailed comparison of the channel width folding effectiveness of the FinFET, vertically stacked nanosheet transistor (VNSFET), and vertically stacked nanowire transistor (VNWFET) under the constraints of the same vertical (fin) height and layout footprint size (fin width) defined by the same lithography and dry etching capabilities of a foundry. The results show that the nanosheet structure has advantages only when the intersheet spacing or vertical sheet pitch is less than the sheet width. Additionally, for the nanowire transistors, the wire spacing should be less than 57% of the wire diameter in order to have a folding ratio better than a FinFET with the same total height and footprint. Considering the technological constraints for the gate oxide and metal gate thicknesses, the minimum intersheet/interwire spacing should be in the range of 7 to 8 nm. Then, the VNSFET structure has the advantage of boosting the chip density over the FinFET ones only when the sheet width is wider than 8 nm. On the other hand, the VNWFET structure may have a better footprint sizing than the FinFET ones only when the nanowire diameter is larger than 14 nm. In addition, considering the different channel mobilities along the different surface directions of the silicon channel and also some other unfavorable natures such as more complicated processes, more significant surface roughness scattering, and parasitic capacitance effects, the nanosheet transistor does not show superior scaling capability than the FinFET counterpart when approaching the ultimate technology node.

Research Area(s)

  • vertically stacked nanosheet transistor, FinFET, nanowire transistor, channel width folding, nano CMOS, ANALYTICAL-MODEL

Download Statistics

No data available