The next big thing in chipmaking is in the hands of one company, and it’s coming in 2025

If we stick to its relevance from a technological point of view, most influential company of the semiconductor industry is not TSMC. Neither does Samsung. Not Intel. These three companies and many other chipmakers owe much of their technology development to the Dutch company ASML.

This company does not manufacture integrated circuits. This produces something even more important: photolithography equipment used by major semiconductor manufacturers. Moreover, it has no competition since it is currently the only manufacturer of photolithography machines to have been able to develop extreme ultraviolet (UVE) equipment.

These devices are extraordinarily complex. So much so that ASML’s competitors, including Japanese companies Canon and Nikon, were forced to retire during the race to get them back on their feet. Currently TSMC and Samsung use them to produce their chips, which allowed them to increase the competitiveness of their integrated circuits.

Intel also purchased this equipment from ASML, but is not currently using it in production for the end customer. Here are some figures on these machines which allow us to situate the context and can help us to understand their extraordinary complexity: each of them costs 140 million euros, weighs about 50 tons and consists of no less than 100,000 parts. Here it is.

UVE photolithography and Rayleigh criterion

The task of a lithography team is to transfer with high precision a geometric pattern on the surface of a silicon semiconductor wafer. This definition invites us to have a good idea of ​​the relevance of the optical elements that make up this machine. At first glance, this does not seem like a very complex procedure, but in reality, it is. It is extraordinarily complex.

Currently, the most advanced integration technology is UVE, and it is only in the hands of ASML

And that’s because geometric patterns are getting smaller and smaller, so transferring them to the wafer surface with the necessary precision is increasingly difficult as lithographic processes become more refined. Currently, the most advanced integration technology, as we have seen, is UVE, and is solely in the hands of ASML. However, there is a reason why a lot of research is needed to further develop lithography equipment: there is a limit to the maximum resolution of a photolithographic process.

This value is described by an expression called Rayleigh criterionAnd it’s the authentic ASML bible. This is the equation that inevitably conditions the development of semiconductor integration technology:

Criteria

It seems like a complicated mathematical expression, but luckily it’s not. The term ‘CD’ lodged to the left of the equal comes from the English expression critical dimension and identifies the extent to which it is possible to miniaturize the components that make up an integrated circuit. It is this parameter that semiconductor manufacturers want to reduce at all costs to continue to refine their integration technology.

The term ‘CD’ (critical dimension) identifies the extent to which it is possible to miniaturize the components that make up an integrated circuit

On another side, the ‘k₁’ factor it is a coefficient delimited by the physical parameters which condition the manufacturing process of the semiconductor. The physical limit imposed by photolithography on silicon is ‘k₁ = 0.25’, so manufacturers do their best to refine their technology in order to bring this coefficient as close as possible to this limit value.

The following parameter, identified by the Greek letter lambda (‘λ’), tells us what is the wavelength of light used in the manufacturing process of semiconductors. One of the most important challenges faced by the companies we are talking about is precisely to reduce the wavelength of light in order to increase the resolution of the photolithographic process.

The last ingredient in the recipe is the ‘NA’ parameter (numerical aperture), which identifies the aperture value of the optics used by the lithography team. In this context, this parameter essentially reflects the same as the aperture value when we talk about camera opticsit therefore conditions the quantity of light that the optical elements are able to collect. As one might guess, the more light they collect, the better.

Asmlmaquina

The most advanced photolithography equipment designed and manufactured by ASML is extraordinarily complex. The UV light source is housed in the lower right corner of the machine and the wafers move through it with amazing precision.

UVE High-NA photolithography will arrive in 2025

It’s not a sprint race. It’s more of a long distance race. For the technologies involved in the development of photolithography to continue to progress, it is necessary support researchand ASML has been working on lithography equipment for several years which will undoubtedly replace the UVE photolithography machines it currently produces for TSMC, Intel, Samsung and a few other customers.

Your Next Generation Lithography Process it’s called High NA, and is the result of increasing the aperture value of the “NA” optics of your current EUV process from 0.33 to 0.55. Described in this way, it doesn’t seem like a big step forward, but if we stop for a moment to think about all that we went over a few lines above when we investigated the Rayleigh criterion we will realize that developing the NA parameter is an effective way to act on the critical dimension.

The first UVE High-NA lithography equipment will be ready to start R&D tests at the end of 2023

To introduce this remarkable improvement into their next photolithography equipment, ASML engineers are forced to redesign all optical elements of its UVE lithography machines (in this field it has the help of the German company of optical experts Carl Zeiss), and also to redesign all the robotic components which are responsible for solving the movement of the wafers inside of the machine to guarantee that it will be carried out with the necessary precision.

According to ASML, the first units of this equipment will be ready by the end of 2023, and will be used by its customers for R&D. Its strategy is to start with these machines the production of chips with 2nm lithography, and from there continue to refine this process more and more, so it seems reasonable to accept that it will remain in force for at least a decade. However, the most exciting news is that ASML is confident that its customers will scale up production with its lithographic equipment. UVE High-NA in. They are literally around the corner.

Pictures: ASML

More information: ASML

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