Intel to present 3D stacked Nanoribbon Transistors for Continued Moore’s Law Scaling at IEDM 2020

Intel to present stacked gate-all-around FET (GAA-FET) technology, i.e., a complementary FET (CFET) at IEDM2020. In CFETs, the idea is to stack both nFET and pFET wires on each other. A CFET could stack one nFET on top of a pFET wire, or two nFETs on top of two pFET wires. This ‘folding’ of the nFET and pFET eliminates the n-to-p separation bottleneck, reducing the cell active area footprint (LINK). Please find the announcement below:

Home-2020 - IEDM 2020 ieee-iedm.org IEDM Conference 2020. To Be Held Virtually December 12-18. The on demand portion of the conference will begin on December 5th. Intel to present 3D stacked Nanoribbon Transistors for Continued Moore’s Law Scaling: 

Stacked NMOS-on-PMOS Nanoribbons: From planar MOSFETs, to FinFETs, to gate-all-around (GAA) or nanoribbon devices, novel transistor architectures have played a critical role in driving performance predicted by Moore’s Law. Intel researchers will describe what may be the next step in that evolution: NMOS-on-PMOS transistors built from multiple self-aligned stacked nanoribbons. This architecture employs a vertically stacked dual source/drain epitaxial process and a dual metal gate fabrication process, enabling different conductive types of nanoribbons to be built so that threshold voltage adjustments can be made for both top and bottom nanoribbons. The approach combines excellent electrostatics (subthreshold slope of <75 mV/dec) and DIBL (<30mV/V for gates ≥30nm) with a path to significant cell size reduction due to the self-aligned stacking. These devices were used to build a functional CMOS inverter with well-balanced voltage transfer characteristics. (Paper #20.6, “3-D Self-Aligned Stacked NMOS-on-PMOS Nanoribbon Transistors for Continued Moore’s Law Scaling,” C.-Y. Huang et al, Intel) 

Paper #20.6, “3-D Self-Aligned Stacked NMOS-on-PMOS Nanoribbon Transistors for Continued Moore's Law Scaling,” C.-Y. Huang et al, Intel

Paper Information (IEDM 2020) : LINK

Figures from IEDM 2020 Press briefing Material -Press kit : LINK

In the images above:

·        (1) shows the evolution of transistor architectures from planar, to FinFETs, to nanoribbons and to a 3D CMOS architecture.

·        (2) (a) shows a 3D schematic diagram of stacked CMOS Si nanoribbon transistors with NMOS on PMOS, (b) describes the process flow; (c) is a TEM image of a stacked multiple-nanoribbon CMOS inverter with a 40-nm gate length and inner (V_ss) and outer (V_cc) contacts, a common gate input (V_IN) and an inverter output node (V_OUT); while (d) is a TEM image of two Si NMOS nanoribbons atop 3 Si PMOS nanoribbons.

·       (3) (a) is a process flow of the vertically stacked dual S/D EPI process, while (b) shows P-EPI selectively grown on the bottom three nanoribbons, (c) shows N-EPI selectively grown on the top two nanoribbons, and (d) features TEM and EDS images showing selective N-EPI and P-EPI growth on the stacked nanoribbon transistors.

·       (4) (a) is a process flow of the vertically stacked dual metal gate process; (b) is a TEM image and (c, d) are EDS images of the dual metal gate with N-WFM (WFM = work function metal) on the top two nanoribbons and P-WFM on the bottom three nanoribbons.