2 nm process

By 2018, a number of transistor architectures had been proposed for eventual replacement of FinFET, most of which are based on the concept of GAAFET:[8] horizontal and vertical nanowires, horizontal nanosheet transistors[9][10] (Samsung MBCFET, Intel Nanoribbon), vertical FET (VFET), complementary FET (CFET), stacked FET, and negative-capacitance FET (NC-FET) which uses drastically different materials.[11]

In late 2018, TSMC chairman Mark Liu predicted chip scaling would continue to 3 nm and 2 nm nodes;[12] however, as of 2019, other semiconductor specialists were undecided as to whether nodes beyond 3 nm could become viable.[13] TSMC began research on 2 nm in 2019[14]—expecting to transition from FinFET to GAAFET transistor type.[15] In July 2021, TSMC received governmental approval to build its 2 nm plant. In August 2020 it began building an R&D lab for 2 nm technology in Hsinchu, expected to become partially operational by 2021.[16] In September 2020 TSMC confirmed this and stated that it could also install production at Taichung dependent on demand.[17] According to the Taiwan Economic Daily (2020) expectations were for high yield risk production in late 2023.[18][19] According to Nikkei the company expects to install production equipment for 2 nm by 2023.[20]

Intel's 2019 roadmap scheduled potentially equivalent 3 nm and 2 nm nodes for 2025 and 2027 respectively, and in December 2019 announced plans for 1.4 nm production in 2029.[21]

At the end of 2020, seventeen European Union countries signed a joint declaration to develop their entire semiconductor industry, including developing process nodes as small as 2 nm, as well as designing and manufacturing custom processors, assigning up to 145 billion euro in funds.[22][23]

In May 2021, IBM announced it had produced chips with 2 nm class GAAFET transistors using three silicon layer nanosheets with a gate length of 12 nm.[24][25][26]

In July 2021, Intel unveiled its process node roadmap from 2021 onwards. The company confirmed their 2 nm process node called Intel 20A,[notes 1] with the "A" referring to angstrom, a unit equivalent to 0.1 nanometer.[27] At the same time they introduced a new process node naming scheme that aligned their product names to similar designations from their main competitors.[28] Intel's 20A node is projected to be their first to move from FinFET to Gate-All-Around transistors (GAAFET); Intel's version is named 'RibbonFET'.[28] Their 2021 roadmap scheduled the Intel 20A node for volume production in 2024 and Intel 18A for 2025.[27][28]

In October 2021, at Samsung Foundry Forum 2021, Samsung announced it would start mass production with its MBCFET (multi-bridge channel FET, Samsung's version of GAAFET) 2 nm process in 2025.[29]

In April 2022, TSMC announced its GAAFET N2 process technology would enter risk production phase at the end of 2024 and production phase in 2025.[1] In July 2022, TSMC announced that its N2 process technology will feature backside power delivery and will offer 10–15% higher performance at iso power or 20–30% lower power at iso performance and over 20% higher transistor density compared to N3E.[30]

In July 2022, Samsung made a number of disclosures regarding the company's forthcoming process technology called 2GAP (2nm Gate All-around Production): the process remains on track for 2025 launch into mass production; number of nanosheets will increase from 3 in 3GAP to 4; the company works on several improvements of metallization, namely "single-grain metal" for low-resistance vias and direct-etched metal interconnect planned for 2GAP and beyond.[31]

In August 2022, a consortium of Japanese companies funded a new venture with government support called Rapidus for manufacturing of 2 nm chips. Rapidus signed agreements with imec[32] and IBM[33] in December 2022.

In April 2023, at its Technology Symposium, TSMC introduced two more processes of its 2nm technology platform: N2P featuring backside power delivery and scheduled for 2026 and N2X for high-performance applications. It was also revealed that ARM Cortex-A715 core fabbed on N2 process using high-performance standard library gains 16.4% of speed at iso power, saves 37.2% of power at iso speed, or gains ~10% of speed and saves ~20% of power simultaneously at iso voltage (0.8 V) compared to the core fabbed on N3E using 3-2 fin library.[34]

In July 2021, Intel has planned 18A production for 2025.[27] Intel's February 2022 roadmap added that 18A will deliver 10% improvement in performance per watt compared to Intel 20A and will become manufacturing-ready in 2024 H2.[3]

In December 2021, Vertical-Transport FET (VTFET) CMOS logic transistor design with a vertical nanosheet was demonstrated at sub-45 nm gate pitch.[37]

In May 2022, imec presented a process technology roadmap which extends current biannual cadence of node introduction and square-root-of-two node naming rule to 2036. The roadmap ends with process node A2 (for 2 angstroms) named by analogy with TSMC's naming scheme to be introduced by then.[38]

Apart from dimensional scaling of transistor structures and interconnect, innovations forecast by imec are as follows:

• transistor architecture (forksheet FET, CFET, CFET with atomic (2D material) channel);
• deployment of high-NA (0.55) EUV tools with the first $400 million tool to be completed at ASML in 2023, and the first production tool to be shipped to Intel in 2025;
• further reduction of standard cell height (eventually to "less than 4" tracks);
• back-side power distribution, buried power rails;
• new materials (ruthenium for metallization (interconnects), graphene, WS₂ monolayer for atomic channel);
• new manufacturing techniques (subtractive metallization, direct metal etch);
• air gaps to further reduce relative permittivity of intermetal dielectric and, therefore, interconnect capacitance;
• IC design innovations (2.5D chiplets, 3D interconnect), more advanced EDA tools.

In September 2022, Samsung presented their future business goals which includes an aim to mass produce 1.4 nm by 2027.[39]

• Merritt, Rick (26 March 2018), "2nm: End of the Road ?", www.eetasia.com