EUV Lithography: What is it and why is it the future?

EUV lithography is on the lips of many experts and analysts in the semiconductor industry. That is why in this article we will deal with this topic so that you understand what it is and why it is important for the future of chips.

Global manufacturing is increasingly concentrated in a few megasites, with more and more being invested to achieve smaller integration sizes. These mega plazas give manufacturers a competitive advantage by providing access to cheap and abundant labor, raw materials, and other production services. One of the main obstacles to the adoption of EUV technology has been cost, as it is too expensive to deploy this technology on a reasonable scale to all foundries and their customers.

However, adopting it for advanced chips is vital. Not doing so would mean having an obsolete chip , with very high energy consumption, greater overheating, and lower speed. For this reason, in this article he reviews what EUV lithography is, its advantages over other alternative technologies, how it works and where it is currently used.

Maybe you might be interested in:

  • How a chip is made.
  • What is photolithography.

Index of contents

  • What is EUV lithography?
  • Why is EUV lithography important for manufacturing?
  • Advantages of EUV lithography
  • Disadvantages of EUV Lithography
  • Where is EUV used today?

What is EUV lithography?

The term EUV (Extreme UltraViolet) lithography comes up more and more as the semiconductor shortage looms, but what exactly does it mean and why is it crucial? If you use a relatively new smartphone or smartwatch, or one of the latest generations of video game consoles, you are benefiting from EUV lithographic technology in the CPUs, GPUs, RAM, flash memory, or SoCs that these devices use.

In the semiconductor industry, EUV refers to extreme ultraviolet lithography , a soft X-ray technology with a wavelength of 13.5nm . This means that it enables very fine resolutions in the fabrication of electronics by photolithography, one of the most important steps in semiconductor manufacturing, and as such is expected to create the potential for radical progress in the industry. The most advanced microchips contain billions of transistors; With each new generation of chips, manufacturers introduce more and more to create faster, more powerful, and more energy efficient chips.

Currently, DUV (Deep UltraViolet) lithography is still widely used, which is one step behind, but is cheaper and sufficient to manufacture many other chips less advanced than processing units, such as those destined for sectors such as the automobile , other consumer electronics products, etc.

Photolithography is a pattern-making process in which a silicon wafer coated with a photoresist or photosensitive polymer is selectively exposed to light through a photomask. Exposed pathways on the polymer surface can then dissolve, providing patterned access to an underlying substrate. These patterns are then used to form the ultra-fine microscopic structures that make up a semiconductor chip.

Since light is unable to directly define features smaller than its own wavelength, the short wavelength of EUV light sources allows for finer, denser patterns than any previous method. The 13.5nm wavelength, in particular, is less than a tenth of that provided by scanners with ArF (argon fluoride) excimer laser lamps. To generate extreme ultraviolet light during the lithography process, a CO2 laser fires two separate laser pulses at a rapidly moving droplet of tin, vaporizing the tin. The tin vapor turns into plasma, which in turn emits EUV light, and all of this happens 50,000 times per second.

EUV moves away from deep ultraviolet lithography (DUV) methods . Since all matter absorbs EUV radiation, EUV lithography requires a vacuum. Current systems use at least two condensing multilayer mirrors and six projection multilayer mirrors, which manufacturer ASML says have the world’s flattest surface that guide light onto the wafer. But these mirrors absorb 96% of light emissions, meaning an ideal source would be much brighter than those used in previous systems.

The introduction of EUV scanners has made scaling more affordable and has allowed chipmakers to continue to adhere to Moore’s law , according to which the number of transistors on an integrated circuit doubles approximately every two years. However, EUV systems are only manufactured by an ASML company, which supplies this type of photolithography machines to large foundries such as Intel, Samsung, TSMC, etc.

Demand for ASML’s technology has skyrocketed, causing backlogs and sending the company’s share price soaring by more than 340% since the end of 2018. In fact, ASML is valued higher than some of its major customers, including Intel. Producing their machines presents a unique challenge, however, as the modules needed to make them are held back by a shortage of chips. The machines that make the chips also need them.

Ultimately, the availability of EUV systems looks set to test the ability of chipmakers like Intel, Samsung and TSMC (Taiwan Semiconductor Manufacturing Company) to get all of their planned production factories up and running. This supply and demand loop affects ASML clients’ decisions about how to design their manufacturing portfolios in the coming years and ultimately how quickly manufacturing capacity could catch up with demand.

Why is EUV lithography important for manufacturing?

EUV lithography is an important technology for next-generation semiconductor fabrication . It will allow the industry to continue with Moore’s law and extend its useful life. It also makes it possible to reduce the size of features in semiconductor devices, increasing their capacity and performance.

The traditional photolithography (DUV) process currently used to create patterns for semiconductor devices is reaching its fundamental limits. The minimum size of features that can be printed by this EUV process is expected to reach the very small scale of a few nanometers or less , which will be sufficient for applications such as computing and communication.

Advantages of EUV lithography

EUV lithography has its advantages like everything else, among which are:

  • Smaller feature sizes– One of the most important advantages of EUV lithography is that it allows features to be reduced in size. This means that a chip with the same functionality as one created with today’s technology would have about 20 times more circuits per chip. This would increase the performance and capacity of computing devices, help communication networks handle more data, and reduce power consumption on a massive scale.
  • Lower cost and higher productivity– Another advantage of EUV is that it could help reduce costs and increase productivity ( yield ). Compared to current lithography machines, an EUV machine is more cost-effective in the long run due to the increased number of chips per wafer (since it takes up less floor space).

The ability to reduce the size of embedded devices such as transistors and interconnects on a chip results in lower power consumption on the chip, increased switching capacity (so the clock frequency can be increased), and can have a higher density of transistors per unit area, which allows more complex and powerful circuits to be created.

Disadvantages of EUV Lithography

Of course, this technology also has its drawbacks :

  • Cost– Although EUV lithography is expected to bring many benefits, it also has one major limitation: the price of ASML machines. It is too expensive to be used on a large scale in all production lines. Over the last two decades, many efforts have been made to reduce the cost of this technology, but they have been hampered by certain critical problems.

Where is EUV used today?

Today, EUV lithography is used in the production of certain advanced microchips, such as SoCs, CPUs, GPUs, RAM and flash memories, chipsets , and more. At the moment, only the most advanced IDMs and foundries are using this type of machine. Companies that design and manufacture less advanced chips, such as others for consumer electronics, vehicles, etc., continue to use DUVs.