Episode Summary:
Neon, the gas of advertising signage from Las Vegas to small-town diners across America, is suddenly a hot commodity. Although famous for its colorful discharge in advertising applications, it’s an important process gas, especially in the semiconductor industry.
As a buffer gas in krypton/argon lasers used in the photolithography that underpins chipmaking, neon is consumed in quantity. Production of neon is by the familiar fractional distillation from liquid air, and as a result, it’s a by-product of large-scale oxygen production. And no industry demands oxygen in quantities as great as steelmaking.
The massive steel complexes of eastern Ukraine became the globe’s dominant supplier of neon for this reason, and today they are a war zone. The resulting shortages are driving the semiconductor industry to find innovative solutions to shortages of this critical industrial input.
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Transcript of this week's show:
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When most people think about neon, they think of the glowing discharge tubes that made the signage of 1950s and 1960s America. It was the original application of the controlled ionization of gas in a glass tube, but another much more significant development of the 1950s, the laser, is the reason why neon gas is a critical commodity today. Why? The short answer is, photolithography.
Photolithography is the core technology of integrated circuit manufacturing, the process by which extraordinarily small surface detail is etched into silicon substrates. 4 decades ago, the light source for this process could be a simple mercury vapor arc lamp emitting at a wavelength of 365 nanometers. While focal length and beam control were once the primary determinants of resolution in the process, the drive for ever higher transistor density has reduced the size of substrate features to incredibly small dimensions. 14 nanometers is now common, and the drive is on to widely adopt single digit resolution. 9 nanometers is almost inconceivably small.
How small? Approximately 10,000 times smaller than the diameter of a human hair. At these scales, the wavelength of light used in the process is important and is proportional to resolution. Shorter wavelength means higher density. The current state of the art uses excimer laser technology in the deep ultraviolet, with a wavelength of just under 200 nanometers. and the excimer lasers used in semiconductor manufacturing use well known laser gases such as argon and fluorine, with neon as a buffer gas. In operation, the active and buffer gases degrade, and are periodically discarded. And where does the manufacturing world buy neon?
Until recently, Ukraine, produced 25 percent of the world’s neon, as a byproduct of the nation’s large steel production base pre-war, and according to Reuters, two Ukrainian companies, Ingas and Cryoin, produce 45% to 54% of the neon used in chip manufacturing around the world. Overall, chip making represents 75 percent of the global demand for neon, with the rest used mainly for industrial lasers and those used for eye surgery. With a global shortage of integrated circuits already impacting multiple industries, the stakes are high.
The Beijing based Global Times has reported that neon prices have risen 65 percent since the beginning of the year and that Chinese production will be slow to ramp up to infill the global supply chain. Neon can be made anywhere, by distillation of liquid air, but with neon having a mass fraction of one part in 79,000 in the atmosphere, the gas will be expensive.
There are solutions, however. In the short term, the Taiwanese major TSMC has announced a program to recycle and purify spent neon for recycling and the laser makers themselves are optimizing operating procedures to reduce neon consumption. But the real solution may come from the relentless drive for higher density. IBM has announced 2nm technology, with junctions smaller than a single strand of DNA.
Photolithography on this scale uses extreme ultraviolet technology, centered on lasers focused on droplets of molten tin to produce a plasma in a vacuum. It’s expensive and complex, but it can create light with wavelengths under 14nm. Veldhoven, Netherlands-based ASML has shipped equipment for advanced chips to customers including TSMC and as 5 and 2 nm technology becomes commonplace, the need for neon as a laser gas may decrease significantly.
But with a near monopoly on extreme ultraviolet technology and a full order book, it’s unlikely that the transition can happen faster than it is already happening. In the short term, the semiconductor shortages look set to continue.