EUV lithography: the brave new nanochip era

4 min read

These are exciting times for chip manufacturers. Whereas once they could rely on piling more transistors onto the surface of each chip, such developments have become more challenging to achieve.

Now an advanced manufacturing technique known as extreme ultraviolet (EUV) lithography is set to bring game-changing benefits by making it possible to fabricate chips on smaller scales than ever before.EUV lithography is not entirely new - the first prototype tool (NXE:3100) was first shipped in 2010. However, it has taken the best part of ten years to develop the technology, which is expected to be in high-volume use by 2020.

EUV lithography makes chips cheaper, more powerful, faster and less power hungry. So it is a key element in the production of the hi-tech componentry required to facilitate the Internet of Things (IoT) and 5G, as well as AI and machine learning.

The dominant global player in the field of EUV lithography is Dutch company ASML, which manufactures and sells its tools to the 'big three' global semiconductor fabricators – Intel, Samsung and Taiwan Semiconductor Manufacturing Company (TSMC). They share the same goal - to save Moore’s Law – a law first expounded by the co-founder of Intel, Gordon Moore, observing that the number of transistors in an integrated circuit doubles about every two years and predicting that this trend would continue indefinitely.

In order to succeed in keeping Moore’s Law on track, ASML has been exploring ways to reduce transistor sizes (often referred to as node sizes) still further and has made considerable strides in the field of EUV lithography which enables more precise and efficient production of semiconductors at small transistor scales – around 7nm node size, or even 5nm. In what can only be described as a giant leap forward, the company has recently announced plans to introduce the NXE:3400C, specified at 170 wafers per hour, later this year.

EUV – how it works

The technology uses light with a very short wavelength to construct fine patterns more quickly and accurately. Think of the old technology as a large paint brush, and an EUV light source as a fountain pen. The latter is much better equipped to produce smaller transistor sizes capable of making processors and other electronic devices cheaper, more powerful and more energy efficient.

Two major markets for EUV lithography are processors for smart phones and servers where power, size, and efficiency are important factors. For example, for smart phones, the Samsung Galaxy s10 has a processor with an 8nm node size, and the iPhone XS Max has a processor with an 7nm node size. An example of a server processor using 7nm node size is Huawei's Kunpeng 920 CPU.

Demonstrating the ongoing focus on node size reduction, Samsung Foundry has recently announced the release of its product design kit for 3nm Gate-All-Around (GAA) process. Compared to 7nm technology, it allows designers to utilise a 45 percent reduction in chip area with 50 percent lower power consumption or 35 percent higher performance. The GAA-based process node is likely to be widely used in next-generation applications such as automotive, AI and IoT.

More powerful and efficient processors are taking advantage of these smaller node sizes to accelerate the way to the Internet of Things (IoT). In doing so, a wider range and quantity of IoT devices are becoming commercially viable, suitable for use in a wider range of applications, where there are size, power and/or cost limitations. One area where smaller node sizes is proving particularly useful is servers. For example, they are enabling IoT devices to process vast amounts of data as quickly as possible in order to realise the potential of autonomous vehicles.

Huge computing resources are also needed to operate AI and machine learning systems. The efficiency of data centres or mainframes are significantly improved by node size reduction. For similar reasons, ‘big data’ collection and processing are also affected by smaller node sizes. Smaller and more powerful processors, and smaller sensors have enabled large data sets to be collected on a wide range of applications. For example, retailers can monitor shoppers’ movements whilst instore, and hospital managers can make informed decisions about how to streamline treatment processes.

Capitalising on the EUV opportunity

Despite the opportunities in terms of potential applications of EUV technology, these are challenging times for semiconductor manufacturers. Global sales dipped sharply in Q1 2019 and a recent report by Gartner has revealed that the costs of manufacturing equipment for leading-edge semiconductor manufacturing are rising at a rate of between 7 – 10 percent per year. This is putting pressure on fabricators at a critical time.

The key to making the most of the market opportunity could lie in further technological refinements and the fabrication of semiconductors suitable for the most demanding quality control applications. We can already see a positive trend in patent filings in the past five years by the 'big three' in EUV-based technology – for example, Intel filed 11 patent applications involving the use of EUV technology in 2012/13, rising to 61 in 2016/17. This could suggest that they are innovating using EUV technology to gain a competitive advantage in the marketplace.

In an evolving marketplace, innovators should take steps to secure ownership of any intellectual property assets by seeking patent protection. In doing so, not only will they benefit from a 20-year period of exclusivity to assist them in optimising commercial gains, they could also consider licensing their inventions to third parties in exchange for royalty payments. The latter could prove crucial if new entrants start to compete for a share of the marketplace as it grows. Since large-scale chip manufacturing is only performed in a handful of countries, patent applications will not need to be filed widely, which could help to minimise cost.

For all involved in semiconductor fabrication, it is important to stay focused on innovation in order to realise the potential of EUV lithography and develop technologies for the next generation. The rapid take up of IoT devices, along with growing use of AI and autonomous driving technologies, mean nanometric node sizes are fast becoming essential for technological progress.

Jim Ribeiro is a partner and patent attorney at European intellectual property firm, Withers & Rogers. A member of the firm’s Electronics, Computing and Physics group, he has specialist knowledge of semiconductor fabrication.