This article may be too technical for most readers to understand.(January 2020) |
Semiconductor device fabrication |
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MOSFET scaling (process nodes) |
Future
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In semiconductor manufacturing, the "7 nm" process is a marketing term for the MOSFET technology node following the "10 nm" node, defined by the International Technology Roadmap for Semiconductors. It is based on FinFET (fin field-effect transistor) technology, a type of multi-gate MOSFET technology.
The phrase "7 nm" does not refer to any dimension on the integrated circuits, and has no relation to gate length, metal pitch, or gate pitch; since at least 1997, "node" has become a commercial name for marketing purposes [1] that indicates new generations of process technologies, without any relation to physical properties. [2] [3] [4] However, the smallest dimension within an individual transistor, the fin width, can sometimes be 7 nm. [5] TSMC and Samsung's "10 nm" (10 LPE) processes are somewhere between Intel's "14 nm" and "10 nm" processes in transistor density.
Taiwan Semiconductor Manufacturing Company (TSMC) began production of 256 Mbit SRAM memory chips using a "7 nm" process called N7 in June 2016, [6] before Samsung began mass production of their "7 nm" process called 7LPP devices in 2018. [7] The first mainstream "7 nm" mobile processor intended for mass market use, the Apple A12 Bionic, was released at Apple's September 2018 event. [8] Although Huawei announced its own "7 nm" processor before the Apple A12 Bionic, the Kirin 980 on August 31, 2018, the Apple A12 Bionic was released for public, mass market use to consumers before the Kirin 980. Both chips were manufactured by TSMC. [9]
In 2019, [10] AMD released their "Rome" (EPYC 2) processors for servers and datacenters, which are based on TSMC's N7 node [11] and feature up to 64 cores and 128 threads. They also released their "Matisse" consumer desktop processors with up to 16 cores and 32 threads. However, the I/O die on the Rome multi-chip module (MCM) is fabricated with the GlobalFoundries' 14 nm (14HP) process, while the Matisse's I/O die uses the GlobalFoundries' "12 nm" (12LP+) process. The Radeon RX 5000 series is also based on TSMC's N7 process.
7 nm scale MOSFETs were first demonstrated by researchers in the early 2000s. In 2002, an IBM research team including Bruce Doris, Omer Dokumaci, Meikei Ieong and Anda Mocuta fabricated a 6 nm silicon-on-insulator (SOI) MOSFET. [12] [13] In 2003, NEC's research team led by Hitoshi Wakabayashi and Shigeharu Yamagami fabricated a 5 nm MOSFET. [14] [15]
In July 2015, IBM announced that they had built the first functional transistors with "7 nm" technology, using a silicon-germanium process. [16] [17] [18] [19]
In June 2016, TSMC had produced 256 Mbit SRAM memory cells at their "7 nm" process, [6] with a cell area of 0.027 square micrometers (550 F2)[ spelling? ] with reasonable risk production yields. [20]
In 2015, Intel expected that at the 7nm node, III-V semiconductors would have to be used in transistors, signaling a shift away from silicon. [21]
In April 2016, TSMC announced that "7 nm" trial production would begin in the first half of 2017. [22] In April 2017, TSMC began risk production of 256 Mbit SRAM memory chips using a "7 nm" (N7FF+) process, [6] with extreme ultraviolet lithography (EUV). [23] TSMC's "7 nm" production plans, as of early 2017,[ needs update ] were to use deep ultraviolet (DUV) immersion lithography initially on this process node (N7FF), and transition from risk to commercial volume manufacturing from Q2 2017 to Q2 2018. Also, their later generation "7 nm" (N7FF+) production was planned[ needs update ] to use EUV multiple patterning and to have an estimated transition from risk to volume manufacturing between 2018 and 2019. [24]
In September 2016, GlobalFoundries announced trial production in the second half of 2017 and risk production in early 2018, with test chips already running. [25]
In February 2017, Intel announced Fab 42 in Chandler, Arizona, which was according to press releases at that time expected[ needs update ] to produce microprocessors using a "7 nm" (Intel 4 [26] ) manufacturing process. [27] The company had not, at that time, published any expected values for feature lengths at this process node.[ needs update ]
In April 2018, TSMC announced volume production of "7 nm" (CLN7FF, N7) chips. In June 2018, the company announced mass production ramp up. [7]
In May 2018, Samsung announced production of "7 nm" (7LPP) chips this year. ASML Holding NV is their main supplier of EUV lithography machines. [28]
In August 2018, GlobalFoundries announced it was stopping development of "7 nm" chips, citing cost. [29]
On October 28, 2018, Samsung announced their second generation "7 nm" process (7LPP) had entered risk production and was at that time expected to have entered mass production by 2019.[ needs update ]
On January 17, 2019, for the Q4 2018 earnings call, TSMC mentioned that different customers would have "different flavors" of second generation "7 nm". [30] [ needs update ]
On April 16, 2019, TSMC announced their "6 nm" process called (CLN6FF, N6), which was, according to a press release made on April 16, 2019, at that time expected to have been in mass products from 2021. [31] [ needs update ] N6 was at that time expected to have used EUVL in up to 5 layers, compared to up to 4 layers in their N7+ process. [32]
On July 28, 2019, TSMC announced their second gen "7 nm" process called N7P, which was projected to have been DUV-based like their N7 process. [33] Since N7P was fully IP-compatible with the original "7 nm", while N7+ (which uses EUV) was not, N7+ (announced earlier as "7 nm+") was to have been a separate process from "7 nm". N6 ("6 nm"), another EUV-based process, was at that time planned to have been released later than even TSMC's "5 nm" (N5) process, with the IP-compatibility with N7. At their Q1 2019 earnings call, TSMC reiterated their Q4 2018 statement [30] that N7+ was at that time expected to have generated less than $1 billion TWD in revenue in 2019. [34] [ needs update ]
On October 5, 2019, AMD announced their EPYC Roadmap, featuring Milan chips built using TSMC's N7+ process. [35] [ needs update ]
On October 7, 2019, TSMC announced they had started delivering N7+ products to market in high volume. [36] [ needs update ]
On July 26, 2021, Intel announced their new manufacturing roadmap, renaming all of their future process nodes. [26] Intel's "10 nm" Enhanced SuperFin (10ESF), which was roughly equivalent to TSMC's N7 process, would thenceforth be known as "Intel 7", while their earlier "7 nm" process would erstwhile be called "Intel 4". [26] [37] As a result, Intel's first processors based on Intel 7 were at that time planned to have started shipping by the second half of 2022,[ needs update ] whereas Intel announced earlier that they were planning to have launched "7 nm" processors in 2023. [38] [ needs update ]
In June 2018, AMD announced 7 nm Radeon Instinct GPUs launching in the second half of 2018. [39] In August 2018, the company confirmed the release of the GPUs. [40]
On August 21, 2018, Huawei announced their HiSilicon Kirin 980 SoC to be used in their Huawei Mate 20 and Mate 20 Pro built using TSMC's 7 nm (N7) process.[ needs update ]
On September 12, 2018, Apple announced their A12 Bionic chip used in iPhone XS and iPhone XR built using TSMC's 7 nm (N7) process. The A12 processor became the first 7 nm chip for mass market use as it released before the Huawei Mate 20. [41] [42] On October 30, 2018, Apple announced their A12X Bionic chip used in iPad Pro built using TSMC's 7 nm (N7) process. [43]
On December 4, 2018, Qualcomm announced their Snapdragon 855 and 8cx built using TSMC's 7 nm (N7) process. [44] The first mass product featuring the Snapdragon 855 was the Lenovo Z5 Pro GT, which was announced on December 18, 2018. [45]
On May 29, 2019, MediaTek announced their 5G SoC built using a TSMC 7 nm process. [46]
On July 7, 2019, AMD officially launched their Ryzen 3000 series of central processing units, based on the TSMC 7 nm process and Zen 2 microarchitecture.
On August 6, 2019, Samsung announced their Exynos 9825 SoC, the first chip built using their 7LPP process. The Exynos 9825 is the first mass market chip built featuring EUVL. [47]
On September 6, 2019, Huawei announced their HiSilicon Kirin 990 4G & 990 5G SoCs, built using TSMC's N7 and N7+ processes. [48]
On September 10, 2019, Apple announced their A13 Bionic chip used in iPhone 11 and iPhone 11 Pro built using TSMC's 2nd gen N7P process. [49]
7 nm (N7 nodes) manufacturing made up 36% of TSMC's revenue in the second quarter of 2020. [50]
On August 17, 2020, IBM announced their Power10 processor. [49]
On July 26, 2021, Intel announced that their Alder Lake processors would be manufactured using their newly rebranded "Intel 7" process, previously known as "10 nm Enhanced SuperFin". [26] These processors were, at that time, expected based on press releases to have been planned to have been released in the second half of 2021.[ needs update ] The company earlier confirmed a 7 nm, now called "Intel 4", [26] microprocessor family called Meteor Lake to be released in 2023. [51] [52] [ needs update ]
The "7 nm" foundry node is expected to utilize any of or a combination of the following patterning technologies: pitch splitting, self-aligned patterning, and EUV lithography. Each of these technologies carries significant challenges in critical dimension (CD) control as well as pattern placement, all involving neighboring features.
Pitch splitting involves splitting features that are too close together onto different masks, which are exposed successively, followed by litho-etch processing. Due to the use of different exposures, there is always the risk of overlay error between the two exposures, as well as different CDs resulting from the different exposures.
Spacer patterning involves depositing a layer onto pre-patterned features, then etching back to form spacers on the sidewalls of those features, referred to as core features. After removing the core features, the spacers are used as an etch mask to define trenches in the underlying layer. While the spacer CD control is generally excellent, the trench CD may fall into one of two populations, due to the two possibilities of being located where a core feature was located or in the remaining gap. This is known as 'pitch walking'. [53] Generally pitch = core CD + gap CD + 2 * spacer CD, but this does not guarantee core CD = gap CD. For FEOL features like gate or active area isolation (e.g., fins), the trench CD is not as critical as the spacer-defined CD, in which case, spacer patterning is actually the preferred patterning approach.
When self-aligned quadruple patterning (SAQP) is used, there is a second spacer that is utilized, replacing the first one. In this case, the core CD is replaced by core CD - 2* 2nd spacer CD, and the gap CD is replaced by gap CD - 2 * 2nd spacer CD. Thus, some feature dimensions are strictly defined by the second spacer CD, while the remaining feature dimensions are defined by the core CD, core pitch, and first and second spacer CD's. The core CD and core pitch are defined by conventional lithography, while the spacer CDs are independent of lithography. This is actually expected to have less variation than pitch splitting, where an additional exposure defines its own CD, both directly and through overlay.
Spacer-defined lines also require cutting. The cut spots may shift at exposure, resulting in distorted line ends or intrusions into adjacent lines.
Self-aligned litho-etch-litho-etch (SALELE) has been implemented for "7 nm" BEOL patterning. [54]
Extreme ultraviolet lithography (also known as EUV or EUVL) is capable of resolving features below 20 nm in conventional lithography style. However, the 3D reflective nature of the EUV mask results in new anomalies in the imaging. One particular nuisance is the two-bar effect, where a pair of identical bar-shaped features do not focus identically. One feature is essentially in the 'shadow' of the other. Consequently, the two features generally have different CDs which change through focus, and these features also shift position through focus. [55] [56] [57] This effect may be similar to what may be encountered with pitch splitting. A related issue is the difference of best focus among features of different pitches. [58]
EUV also has issues with reliably printing all features in a large population; some contacts may be completely missing or lines bridged. These are known as stochastic printing failures. [59] [60] The defect level is on the order of 1K/mm2. [61]
The tip-to-tip gap is hard to control for EUV, largely due to the illumination constraint. [62] A separate exposure(s) for cutting lines is preferred.
Attenuated phase shift masks have been used in production for 90 nm node for adequate focus windows for arbitrarily pitched contacts with the ArF laser wavelength (193 nm), [63] [64] whereas this resolution enhancement is not available for EUV. [65] [66]
At 2021 SPIE's EUV Lithography conference, it was reported by a TSMC customer that EUV contact yield was comparable to immersion multipatterning yield. [67]
Due to these challenges, "7 nm" poses unprecedented patterning difficulty in the back end of line (BEOL). The previous high-volume, long-lived foundry node (Samsung "10 nm", TSMC "16 nm") used pitch splitting for the tighter pitch metal layers. [68] [69] [70]
Process | Immersion (≥ 275 WPH) [71] | EUV (1500 wafers/day) [72] |
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Single-patterned layer: 1 day completion by immersion | 6000 wafers/day | 1500 wafers/day |
Double-patterned layer: 2 days completion by immersion | 6000 wafers/2 days | 3000 wafers/2 days |
Triple-patterned layer: 3 days completion by immersion | 6000 wafers/3 days | 4500 wafers/3 days |
Quad-patterned layer: 4 days completion by immersion | 6000 wafers/4 days | 6000 wafers/4 days |
Due to the immersion tools being faster presently, multipatterning is still used on most layers. On the layers requiring immersion quad-patterning, the layer completion throughput by EUV is comparable. On the other layers, immersion would be more productive at completing the layer even with multipatterning.
The "7 nm" metal patterning currently practiced by TSMC involves self-aligned double patterning (SADP) lines with cuts inserted within a cell on a separate mask as needed to reduce cell height. [73] However, self-aligned quad patterning (SAQP) is used to form the fin, the most important factor to performance. [74] Design rule checks also allow via multi-patterning to be avoided, and provide enough clearances for cuts that only one cut mask is needed. [74]
This section's factual accuracy is disputed .(September 2023) |
The naming of process nodes by 4 different manufacturers (TSMC, Samsung, SMIC, Intel) is partially marketing-driven and not directly related to any measurable distance on a chip – for example TSMC's "7 nm" node was previously similar in some key dimensions to Intel's planned first-iteration "10 nm" node, before Intel released further iterations, culminating in "10nm Enhanced SuperFin", which was later renamed to "Intel 7" for marketing reasons. [75] [76]
Since EUV implementation at "7 nm" is still limited, multipatterning still plays an important part in cost and yield; EUV adds extra considerations. The resolution for most critical layers is still determined by multiple patterning. For example, for Samsung's "7 nm", even with EUV single-patterned 36 nm pitch layers, 44 nm pitch layers would still be quadruple patterned. [77]
Samsung | TSMC | Intel | SMIC | |||||||
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Process name | 7LPP [78] [79] | 6LPP [80] | N7 [81] | N7P [33] | N7+ [82] | N6 | Intel 7 [26] [ disputed ] (10nm) [83] | N+1 (>7 nm) | N+2 (7 nm) | 7 nm EUV |
Transistor density (MTr/mm2) | 95.08–100.59 [84] [85] | 112.79 | 91.2–96.5 [86] [87] | 113.9 [86] | 114.2 [31] | 100.76–106.1 [88] [89] 60.41 [90] | 89 [91] | 113.6 [92] | Unknown | |
SRAM bit-cell size | 0.0262 μm2 [93] | Unknown | 0.027 μm2 [93] | Unknown | Unknown | 0.0312 μm2 | Unknown | Unknown | Unknown | |
Transistor gate pitch | 54 nm | Unknown | 57 nm | 54 nm | Unknown | 63 nm | Unknown | |||
Transistor fin pitch | 27 nm | Unknown | N/A | Unknown | Unknown | 34 nm | Unknown | Unknown | Unknown | |
Transistor fin height | Unknown | Unknown | N/A | Unknown | Unknown | 53 nm | Unknown | Unknown | Unknown | |
Minimum (metal) pitch | 46 nm | Unknown | 40 nm | 40 nm [94] | Unknown | 42 nm | Unknown | |||
EUV implementation | 36 nm pitch metal; [77] 20% of total layer set | Unknown | None, used self-aligned quad patterning (SAQP) instead | 4 layers | 5 layers | None. Relied on SAQP heavily | None | None | Yes (after N+2) | |
EUV-limited wafer output | 1500 wafers/day [72] | Unknown | N/A | ~ 1000 wafers/day [95] | Unknown | N/A | Unknown | Unknown | Unknown | |
Multipatterning (≥ 2 masks on a layer) | Fins Gate Vias (double-patterned) [96] Metal 1 (triple-patterned) [96] 44 nm pitch metal (quad-patterned) [77] | Unknown | Fins Gate Contacts/vias (quad-patterned) [97] Lowest 10 metal layers | Same as N7, with reduction on 4 EUV layers | Same as N7, with reduction on 5 EUV layers | multipatterning with DUV | multipatterning with DUV | Unknown | ||
Release status | 2018 risk production 2019 production | 2020 production | 2017 risk production 2018 production [6] | 2019 production | 2018 risk production [6] 2019 production | 2020 risk production 2020 production | 2021 production [26] | April 2021 risk production, mass production unknown | Late 2021 risk production, quietly produced since July 2021 [98] | Postponed due to US embargo |
GlobalFoundries' "7 nm" 7LP (Leading Performance) process would have offered 40% higher performance or 60%+ lower power with a 2x scaling in density and at a 30-45+% lower cost per die over its "14 nm" process. The Contacted Poly Pitch (CPP) would have been 56 nm and the Minimum Metal Pitch (MMP) would have been 40 nm, produced with Self-Aligned Double Patterning (SADP). A 6T SRAM cell would have been 0.269 square microns in size. GlobalFoundries planned to eventually use EUV lithography in an improved process called 7LP+. [99] GlobalFoundries later stopped all "7 nm" and beyond process development. [100]
Intel's new "Intel 7" process, previously known as "10 nm Enhanced SuperFin" (10ESF), is based on its previous "10 nm" node. The node will feature a 10-15% increase in performance per watt. Meanwhile, their old "7 nm" process, now called "Intel 4", was at that time expected to have been released in 2023. [101] [ needs update ] Few details about the "Intel 4" node had at that time been made public, although its transistor density had at that time been estimated to be at least 202 million transistors per square millimeter. [26] [102] [ needs update ] As of 2020, Intel had been experiencing problems with its "Intel 4" process to the point of outsourcing production of its Ponte Vecchio GPUs. [103] [104] [ needs update ]
Photolithography is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer.
Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as computer processors, microcontrollers, and memory chips that are present in everyday electronic devices. It is a multiple-step photolithographic and physio-chemical process during which electronic circuits are gradually created on a wafer, typically made of pure single-crystal semiconducting material. Silicon is almost always used, but various compound semiconductors are used for specialized applications.
Taiwan Semiconductor Manufacturing Company Limited is a Taiwanese multinational semiconductor contract manufacturing and design company. It is the world's second most valuable semiconductor company, the world's largest dedicated independent ("pure-play") semiconductor foundry, and its country's largest company, with headquarters and main operations located in the Hsinchu Science Park in Hsinchu, Taiwan. It is majority owned by foreign investors, and the central government of Taiwan is the largest shareholder. In 2023, the company was ranked 44th in the Forbes Global 2000.
A photomask is an opaque plate with transparent areas that allow light to shine through in a defined pattern. Photomasks are commonly used in photolithography for the production of integrated circuits to produce a pattern on a thin wafer of material. In semiconductor manufacturing, a mask is sometimes called a reticle.
The 90 nm process refers to the technology used in semiconductor manufacturing to create integrated circuits with a minimum feature size of 90 nanometers. It was an advancement over the previous 130 nm process. Eventually, it was succeeded by smaller process nodes, such as the 65 nm, 45 nm, and 32 nm processes.
Extreme ultraviolet lithography is a cutting-edge technology used in the semiconductor industry for manufacturing integrated circuits (ICs). It is a type of photolithography that uses extreme ultraviolet (EUV) light to create intricate patterns on silicon wafers.
Next-generation lithography or NGL is a term used in integrated circuit manufacturing to describe the lithography technologies in development which are intended to replace current techniques. Driven by Moore's law in the semiconductor industries, the shrinking of the chip size and critical dimension continues. The term applies to any lithography method which uses a shorter-wavelength light or beam type than the current state of the art, such as X-ray lithography, electron beam lithography, focused ion beam lithography, and nanoimprint lithography. The term may also be used to describe techniques which achieve finer resolution features from an existing light wavelength.
ASML Holding N.V. is a Dutch multinational corporation founded in 1984. ASML specializes in the development and manufacturing of photolithography machines which are used to produce computer chips.
The "32 nm" node is the step following the "45 nm" process in CMOS (MOSFET) semiconductor device fabrication. "32-nanometre" refers to the average half-pitch of a memory cell at this technology level.
The "22 nm" node is the process step following 32 nm in CMOS MOSFET semiconductor device fabrication. The typical half-pitch for a memory cell using the process is around 22 nm. It was first demonstrated by semiconductor companies for use in RAM memory in 2008. In 2010, Toshiba began shipping 24 nm flash memory chips, and Samsung Electronics began mass-producing 20 nm flash memory chips. The first consumer-level CPU deliveries using a 22 nm process started in April 2012 with the Intel Ivy Bridge processors.
Multiple patterning is a class of technologies for manufacturing integrated circuits (ICs), developed for photolithography to enhance the feature density. It is expected to be necessary for the 10 nm and 7 nm node semiconductor processes and beyond. The premise is that a single lithographic exposure may not be enough to provide sufficient resolution. Hence additional exposures would be needed, or else positioning patterns using etched feature sidewalls would be necessary.
The "14 nanometer process" refers to a marketing term for the MOSFET technology node that is the successor to the "22 nm" node. The "14 nm" was so named by the International Technology Roadmap for Semiconductors (ITRS). Until about 2011, the node following "22 nm" was expected to be "16 nm". All "14 nm" nodes use FinFET technology, a type of multi-gate MOSFET technology that is a non-planar evolution of planar silicon CMOS technology.
A multigate device, multi-gate MOSFET or multi-gate field-effect transistor (MuGFET) refers to a metal–oxide–semiconductor field-effect transistor (MOSFET) that has more than one gate on a single transistor. The multiple gates may be controlled by a single gate electrode, wherein the multiple gate surfaces act electrically as a single gate, or by independent gate electrodes. A multigate device employing independent gate electrodes is sometimes called a multiple-independent-gate field-effect transistor (MIGFET). The most widely used multi-gate devices are the FinFET and the GAAFET, which are non-planar transistors, or 3D transistors.
In semiconductor fabrication, the International Technology Roadmap for Semiconductors (ITRS) defines the "10 nanometer process" as the MOSFET technology node following the "14 nm" node.
GlobalFoundries Inc. (GF) is a multinational semiconductor contract manufacturing and design company incorporated in the Cayman Islands and headquartered in Malta, New York. Created by the divestiture of the manufacturing arm of AMD, the company was privately owned by Mubadala Investment Company, a sovereign wealth fund of the United Arab Emirates, until an initial public offering (IPO) in October 2021.
Per the International Technology Roadmap for Semiconductors, the 45 nm process is a MOSFET technology node referring to the average half-pitch of a memory cell manufactured at around the 2007–2008 time frame.
In semiconductor manufacturing, the International Roadmap for Devices and Systems defines the "5 nm" process as the MOSFET technology node following the "7 nm" node. In 2020, Samsung and TSMC entered volume production of "5 nm" chips, manufactured for companies including Apple, Marvell, Huawei and Qualcomm.
In semiconductor manufacturing, the "3 nm" process is the next die shrink after the "5 nm" MOSFET technology node. South Korean chipmaker Samsung started shipping its "3 nm" gate all around (GAA) process, named "3GAA", in mid-2022. On 29 December 2022, Taiwanese chip manufacturer TSMC announced that volume production using its "3 nm" semiconductor node ("N3") was under way with good yields. An enhanced "3 nm" chip process called "N3E" may have started production in 2023. American manufacturer Intel planned to start 3 nm production in 2023.
In semiconductor manufacturing, the "2 nm process" is the next MOSFET die shrink after the "3 nm" process node.
Preceded by 10 nm | MOSFET semiconductor device fabrication process | Succeeded by 5 nm |