In a world immersed in technology, the significance of microchips cannot be overstated. These tiny marvels, composed of billions of electronic components, are the driving force behind our modern way of life. From smartphones to self-driving cars, microchips underpin the very fabric of our existence.

The story of microchips began with a problem that early computers faced – their sheer size. Those computers used vacuum tubes and electrodes which created massive complexities, failures, and downtime. 

Then came the integrated circuit chip, a breakthrough that condensed the functions of these large tubes onto a small chip. Gordon Moore, co-founder of Intel, introduced Moore’s Law in 1965, predicting that the number of components on a chip would double every two years. When the prediction was made a chip could fit around a thousand transistors, Moore’s prediction has remained accurate to this day and now a chip has 10’s of billions of transistors.

Today, our smartphones possess more computing power than the computers that sent humans to the moon. The rapid advancement of microchip technology has been driven by groundbreaking innovations, and one machine stands at the forefront of this progress.

ASML and the EUV machine

Located in Veldhoven, Netherlands, ASML operates a vast campus that houses nearly 20,000 employees. Often referred to as “the most important company you’ve never heard of,” ASML has developed what is described as “the most complex machine ever built.” Their machines employ lithography to manufacture chips at industrial speeds, revolutionising the semiconductor industry.

ASML’s impact extends far beyond its campus. Its machines are used by chip manufacturers worldwide, including giants like TSMC and Intel. The company’s innovations have enabled chips to become faster, smaller, and more affordable. This, in turn, has fueled technological advancements like the Internet of Things, artificial intelligence, and self-driving cars.

However ASML’s journey began back in 1984 as a subsidiary of technology giant Phillips. At the time chip manufacturers like IBM were making their own machines but ASML believed they could become the leader in creating the next generation of chip manufacturing machines.

The way those early machines that ASML made worked was by passing electricity through a mercury filled bulb, which created blue light that could print features as low as a micron for the first time. 

The size of transistors on a chip is determined by the wavelength of the light source divided by the “numerical aperture” which is effectively how much a lens can further focus the beam of light.

So they soon switched to ultraviolet light, which due to its lower wavelength eventually got down to printing features just 220 nanometers wide, with subsequent improvements that were added to the lithography machines over time.

However ASML reached the limits of what was possible using ultraviolet light, so they needed to find the NGL, or Next Generation Lithography. ASML along with others in the industry believed that extreme ultraviolet light (EUV) was the solution, with a wavelength so small it was almost x-ray.

Despite being theoretically possible, as ASML’s chief business officer Christophe Fouquet explains, making EUV commercially viable was a monumental challenge “EUV was very early on, something that we thought, is going to be useful. Now, of course, the question was, can it even work because you need to have the light source. And you need to have even material optic that can basically reflect in this case, the light, have a sufficient lifetime, etc. So there were a lot of real physics problems to decide if EUV could work. And the feeling was that this could work because research had proven we could create light, it had proven we could find material that would be able to deal with a EUV light. So then the question was becoming an engineering question on how we produce those tools in volume, and with a productivity power, which is high enough to satisfy our customer needs.”

The Challenge of EUV Technology

EUV technology presented numerous challenges. Creating a powerful yet non-destructive EUV light source was paramount. 

“So we had to be able to produce 250 Watt of UV energy in order to make it viable for our customer. That requirement became the technology challenge because we had to first get a source that could go to 250 Watt and then we also needed to have a tool that could survive 250 Watt of UV light.” says Fouquet.

ASML achieved this by generating extreme ultraviolet light through a high-powered laser hitting tin droplets. These tiny droplets were vaporised, creating plasma that emitted EUV light. Ensuring the machine’s longevity with such intense light sources was another hurdle.

ASML’s research revealed that tin was one of the few materials suitable for generating and supporting UV light, making it an ideal choice for their machines. Tin droplets just 25 microns wide were used to create EUV light with two CO2 lasers fitted at each droplet, at a frequency of 20 kilohertz, which means this all happens 50,000 times a second.

Directing the beam

After successfully creating EUV light using the molten tin, the next challenge was directing the light into a beam and moving it through the machine. The problem with EUV is that it is absorbed by almost all material including air, which is why this machine works in a vacuum. ASML created a 100 layer mirror with materials designed to be as effective as possible at reflecting the EUV light.

The light is moved to the reticle which contains the pattern of the wafer that needs to be printed. This process requires nanometre accuracy to ensure each layer of the wafer is printed precisely. 

Fouquet explains, “Every layer we expose has to be exposed very accurately against the previous one. And very accurately means nanometer accurately. So we have to be accurate at a nanometer level, while moving the stage at a very, very high speed, and extremely high acceleration.”

These machines work with extreme precision and accuracy not seen in other machines on earth. Despite many in the industry trying to crack EUV lithography, ASML remains the only company ever to achieve it. It is their machines that are central to advancement in technology over the last few years and without this innovation computing power would be stalling.

Investment in the Future

While improvements and refinement on the EUV machines will continue to be made, eventually, just like with UV, the limits of what EUV can do will be reached. For technological advancement to continue we will need to find a new way to print even smaller transistors. Despite being the market leader within the advanced chip industry ASML understands to stay ahead of the competition they will need to continue innovating and find that next groundbreaking technology.

ASML’s commitment to innovation has been unwavering ever since their inception. They invest heavily in research and development, allocating 10-15% of their revenue consistently. This investment, coupled with a culture of collaboration, fuels their ability to stay at the forefront of chip-making technology.

Foucuet believes it is this mindset that makes them the best place for engineers to come and work, “Every layer we expose has to be exposed very accurately against the previous one. And very accurately means nanometer accurately. So we have to be accurate at a nanometer level, while moving the stage at a very, very high speed, and extremely high acceleration.”

ASML’s journey from a small part of Philips to the world’s leading chip-making technology provider showcases the power of innovation and collaboration. Their groundbreaking work in EUV lithography has reshaped the semiconductor industry, enabling the continued evolution of microchip technology. As technology continues to advance, ASML remains a driving force, ensuring that the world of tomorrow is built on even smaller, faster, and more powerful microchips. The company’s dedication to innovation and precision exemplifies their commitment to shaping the future of technology, one microchip at a time.