Other discoveries came by happy accident. As their ability to immolate tin improved, the process produced more debris than the hydrogen could clean up. Mirror performance was degrading. Then one day they noticed something funny: the mirrors didn’t degrade as quickly after the machine had been opened for maintenance. As it turned out, oxygen in the air that came in helped reverse the contamination. ASML built the occasional addition of small amounts of oxygen into the design.
By the middle of 2017, the company finally had a working demo that etched chips at an industry-friendly pace—125 wafers per hour. From his office in San Diego, Brown watched the demo in the Netherlands. He was elated; he’d changed into a Hawaiian shirt, proclaiming that he’d finally be able to go on vacation.
“This thing was like zzzt zzzt zzzt zzzt,” he recalls, mimicking the speed of the reticle zipping around, and the robotic arm sliding in a new wafer about every 30 seconds. “It was the last domino to basically say, ‘Yeah, EUV lithography will happen.’”
That year, ASML began finally shipping out machines that would revolutionize chipmaking. Once the market realized that ASML had a monopoly on the cutting-edge tools, its stock began to soar, reaching $549 and making the company’s market cap almost the size of Intel’s.
If you’re a gearhead like me, the machine is truly gorgeous to behold—a marvel of engineering. When I visited Wilton, they walked me over to view a massive block of milled aluminum that forms the top part of the device. It is eight feet long, six feet wide, and two feet thick. Gleaming like the chassis of a spaceship, it holds the glass reticle and also has mounted on it huge, barrel-shaped molecular pumps. Each pump contains tiny blades that spin at 30,000 RPM, sucking all gases out of the machine to produce a vacuum within. “They actually smack the molecules of the gas out of the way, one at a time,” Whelan told me.
One could argue that ASML’s chief success has not been so much in making machinery as in measuring it. When I pulled off my bunny suit, I visited the machine shop, where huge chunks of glass were being carved for the reticle. After each piece of glass is milled, it’s placed on machines that gradually smooth it for hundreds of hours over several weeks. As machine-shop manager Guido Capolino told me, they measure the glass all along to see how many imperfections are being removed, starting with coarse microns. He gestured at a polishing machine behind us, where glass pieces slowly revolved on top a slurry of wet polishing mix.