Thin film manufacturing process wins Millennium Technology Prize
Finnish physicist Tuomo Suntola has won the 2018 Millennium Technology Prize for his invention of atomic layer deposition (ALD) — a nanoscale technology that makes it possible to manufacture ultrathin material layers for microprocessors and digital memory devices.
An initiative of Technology Academy Finland, the Millennium Technology Prize is a €1 million award presented every second year in honour of a pioneering technological innovation that improves people’s quality of life and promotes sustainable development. The 2018 prize was presented to Dr Suntola by the President of the Republic of Finland, Sauli Niinistö, on 22 May.
ALD is a chemical process for the stepwise growing of thin films, allowing complex, three-dimensional structures to be built one atomic layer at a time. Inside a vacuum, the first chemicals are introduced to react with the surface material. Once the surface material is saturated, the reaction stops automatically. Then the second chemical’s vapour is introduced to react with the first monolayer to form another atomic layer. By repeating the process, a desired thin film thickness is achieved. The resulting ALD thin film forms an extremely durable, and uniform, high-quality coating.
“The advantage we get with this approach is that we get highly ordered material, and in fact we let nature take care of the perfection and the control,” Dr Suntola said of his invention.
ALD is instrumental in numerous high-tech sectors. Components with thin films made with the ALD technique are used in practically all modern computers and smartphones; in fact, the extremely thin isolating or conducting films needed in microprocessors and computer memory devices can only be manufactured using ALD technology.
“ALD is a key technology in semiconductor devices,” Dr Suntola said, claiming that “we couldn’t have the same density of transistors in integrated circuits without ALD.
“One very important property is the conformal coating property, which means that we get extremely perfect control over thickness, even with very complex surfaces. And that’s something we need in modern semiconductors,” he continued.
“Nanoscale devices have three-dimensional structures, so it’s not only a plain surface that must be coated, but very complex surface structures. And with ALD, we can perfectly handle complex surfaces.”
ALD technology is constantly evolving, enabling IT equipment to keep becoming smaller and less expensive yet more powerful. Dr Suntola’s innovation has been thus credited as one of the key factors in the continuation of the famous Moore’s Law: the efficiency of microchips has doubled at approximately two-year intervals while their price has decreased.
“The ALD method is a textbook example of a technology that is hidden from users but is nevertheless vital for visible development,” said Professor Päivi Törmä, Chair of the Millennium Technology Prize Selection Committee. “ALD has also made the ownership of information technology more democratic, thereby contributing to the wider access to information and communication.”
Suntola developed ALD technology and the equipment for the manufacture of thin films back in the 1970s and then acquired international patents for them, thus enabling the industrial production of thin films on a mass scale. According to Törmä, Suntola’s innovations “led to the large-scale commercial utilisation of the ALD method”, with the physicist having realised “the huge potential of atomic layer deposition and thin film technology in microelectronics and information technology”.
“When the semiconductor sector came to understand the significance of ALD technology in the early 2000s, its use exploded,” noted Dr Suntola. Today the global market of equipment and chemicals used for the manufacture of ALD films is estimated to be about US$2 billion, and the market value of consumer electronics relying on ALD technology is at least US$500 billion.
But the innovation isn’t confined to the IT sector, with a great future predicted in many other fields as well. Research has already yielded promising results with manufacturing ALD thin films for medical instruments and coating of implants, and start-ups have been formed to commercialise the technology in applications such as controlled release in the human body.
The ALD method can also be used to improve the efficiency of solar panels, LED lights and lithium batteries for electric cars and its use has also been researched for environmentally friendly packaging materials. ALD films are used in optical applications, and also on watches and silver jewellery to prevent corrosion.
“One native property of ALD films is that they are defect-free and they have very high density, which means that they are excellent chemical barriers,” Dr Suntola said. “[Those] kind of barriers are needed in many devices.”
Dr Suntola said it was “a great honour” to receive the Millennium Technology Prize, “especially because the innovation has proved useful in so many applications that improve the quality of life for humanity”.
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