ALBUQUERQUE, N.M. — It seems the best way to produce next-generation “space wafers” is to not actually fly to space.
ACME Advanced Materials — an Albuquerque startup that planned to use suborbital flights to produce high-quality semiconductor wafers in microgravity — has opted instead to create its own microgravity environment with parabolic flights. Those flights use modified fixed-wing planes to create reduced gravity by flying sharply up and down.
The company may still eventually fly its wafers to space, but for now, it’s a lot cheaper to use reduced-gravity aircraft to produce the firm’s ‘S’-grade, or ‘space-grade’ wafers than the cost of rocketing them into suborbit, said ACME President and CEO Rich Glover.
“With suborbital flight you get a lot better microgravity, but it costs a whole lot more,” Glover said. “Parabolic flights are an order of magnitude less expensive, but the process is still good enough to result in superior processed material. As a business, we need to focus on that to maximize profit.”
ACME, which launched in 2013 and has received about $2 million in venture investment, uses the dead still of microgravity to smooth out defects in low-quality semiconductor wafers. The elimination of all gravitational pressure and interference allows the advanced materials that are used to make high-performance semiconductors, known as “wide bandgap” wafers, to be formed without the electrical defects that typically complicate production on Earth.
ACME plans to sell its “cured,” or “healed” wafers to companies at a lower price than prime wafers made on Earth.
The company has been flying defective wafers in batches of 100 into microgravity in specially prepared containers, with 99 percent of them coming back as defect-free, Glover said.
But ACME found it can achieve that same 99 percent cure rate with parabolic flights. Those flights achieve microgravity when the plane reaches its apex just before turning downward, like the weightless, floating feeling experienced on a roller coaster.
ACME has partnered with Sierra Industries — a flight operations and maintenance center in Uvalde, Texas — to pilot a Cessna aircraft for the company.
“Pilots at Sierra Industries have worked it out to give maximum time in microgravity with no jitters, shaking or vibrations,” Glover said. “They created an in-house app for flights that keeps track of all the forces and jitter on the craft during parabolic flight. We did 29 flights with them in 2015.”
ACME is now leasing the aircraft from Sierra but plans to buy the craft and contract Sierra to maintain and fly it when ACME moves into commercial production.
“It’s reliable, consistent and easy to ramp up,” Glover said. “We’re doing 100 wafers per flight now, but we can rapidly move to 300 per flight and then do multiple flights per day.”
The company will begin commercial production and sales by late 2016, after independent testing of its chips. Stanford and Stony Brook University in New York are now testing the wafers, and researchers say initial results are promising.
“We’ve conducted detailed preflight and post-flight analysis on these substrates and observe compelling modifications to the material structure,” said Debbie Senesky, head of Stanford’s EXtreme Environment Microsystems Lab. “The devices we’ve built on S-grade substrates also showed improved electrical performance when compared to devices built on traditional, unprocessed substrates.”