October 13, 2014 ACME Advanced Materials Inc. is moving the semiconductor manufacturing industry into space.
The Albuquerque startup, which launched last year, has created a breakthrough process to turn low-grade semiconductor wafers into top-performing material for power electronics by tapping the dead stillness of microgravity. 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.
“We take crappy wafers, the lowest grade we can buy, and use a microgravity environment to turn them into what the industry would call prime ‘A’-grade wafers,” said ACME President and CEO Rich Glover. “We call them ‘S’-grade, or ‘space-grade’ wafers. They’re better wafers than you can get on the market today, and at a better price.”
Since last spring, the company has been sending batches of low-grade wafers for conversion to high-grade on contract flights in Texas, although details of the suborbital launches remain confidential.
“We signed a three-year agreement with a flight partner,” Glover said. “We’ve flown monthly since April.
ACME’s process represents a double breakthrough. First, it’s turning next-gen silicon carbide wafers – which provide much greater capability for power electronics than standard silicon wafers – into top-quality wafers at lower cost than is available today. That alone is a major eye-catcher in the semiconductor industry, where public- and private-sector researchers are scrambling to find affordable ways to produce silicon carbide and gallium nitride wafers without defects to provide the electrical conductivity needed for everything from automobiles to consumer appliances and LEDs.
Apart from that achievement, ACME is also breaking new ground in the emerging space industry by launching a novel manufacturing process in microgravity.
“There is no production manufacturing at all yet in the space industry,” Glover said. “I believe this is a first.”
The company has attracted significant backing from local and international venture investors. Cottonwood Technology Fund in New Mexico and Pangea Ventures of Canada have made a seven-figure investment in ACME since last year.
“Large corporations are looking for how to get better-performing wide bandgap materials, but they’re generally only working to improve the process incrementally over time,” said Cottonwood managing partner David Blivin. “This company has largely leapfrogged all that. They’ve proven that their process works, representing a leap to optimal performance for these wafers rather than the incremental improvements under investigation today.”
The Pangea investment in ACME is particularly important. That firm specializes in chemistry and materials science. It bills itself as “the world leader” in advanced materials venture capital.
“This is quite extraordinary,” said Pangea general partner Chris Erickson. “ACME is doing what others didn’t even consider as a possibility, and they’re doing it in a way that is cost competitive with existing wafer producers and extremely profitable.”
Wide bandgap wafers are considered the wave of the future for power electronics because they can operate at higher temperatures than silicon, and they have greater durability and reliability at higher voltages and frequencies. That can immensely improve the performance and efficiency of electrically powered devices.
Given the promise of wide bandgap wafers, in January the U.S. Department of Energy announced a new, $140 million research partnership with 18 companies and seven universities to create a cost-effective process for making the wafers over the next five years.
The challenge is that silicon carbide and gallium nitride are naturally hard elements that are very difficult to grow without defects. Those defects, in turn, interfere with electrical flow on the wafers, causing power loss and reducing the reliability of the devices that use them.
“The defects are like potholes in a highway that slow everybody down because they have to go around,” Glover said. “Our process eliminates those defects so you can go straight ahead at full speed.”
Defects form in the wafers largely because of the pressure and interference when growing wide bandgap materials on the ground. The push and pull of gravity-related conditions keeps the atoms from settling to their lowest energy state on the wafer, Glover said. In contrast, ACME’s process involves varying the temperature, pressure and vacuum cycles in a microgravity environment free of all jitters, bumps and spikes.
“We remove all the forces and allow the atoms to relax into preferred low energy states, and that makes the electrical defects go away,” Glover said. “It smooths the wafer out.”
It’s like a Chinese checker board where the marbles are stuck in between the holes, Glover said. The microgravity environment allows the atoms to fall into the right places, like marbles falling into the holes on the board.
Rather than try to grow silicon carbide or gallium nitride wafers in space, ACME takes inexpensive, damaged wafers and sends them into microgravity to “heal” them. It prepares the wafers at a 2,000-square-foot office in Albuquerque’s Northeast Heights. It then works with subcontractors in Texas to package the wafers into space-ready containers, followed by flight to suborbit.
The company says 99 percent of the wafers it sends up come back defect-free.
“In the last batch of 100 wafers, we had just one defective wafer come back,” Glover said. “All the rest were healed.”
Although ACME has only healed four-inch wafers so far, its process is fully scalable to larger wafers. That’s particularly valuable to the semiconductor industry, which wants quality wide bandgap wafers of up to 12 inches – the standard today for silicon wafers.
The process also works just as well with extra layers of materials applied on top of the base wafer. Manufacturers apply that layering process, known as “epitaxial layers,” or epi, to add capabilities. And, although to date the company has only flown silicon carbide wafers, it’s now working to adapt its process to include gallium nitride wafers.
“It’s hard to overstate the significance of this technology,” Blivin said. “Not only is ACME using a very unique approach to produce these wafers, but the process easily scales to larger diameter wafers. More importantly, their technology works with all wide bandgap materials, with or without epi.”
ACME expects to sell its services to companies that supply it with defective wafers for conversion to high-quality ones. Companies can buy defective wafers today for as little as $250, and ACME would charge $750 or less for each one it heals. That compares to up to $1,500 or more today for prime ‘A’-grade wafers.
The company says it’s capable of healing 250 four-inch wafers per month now. But it can rapidly scale up to 1,000 wafers monthly within 90 days, and up to 5,000 in six months. It expects to grow from five employees today to 20 in the next two years.