Sounding out more efficient semiconductor manufacturing

ASU electrical engineering professor’s company receives SBIR funding from NASA to reduce waste during semiconductor chip manufacturing

October 2, 2023

Current processes to make solar cells and power electronics have a manufacturing waste problem: Up to 95% of the initial block of material, known as a wafer or substrate, is destroyed when wafers are extracted from the substrate then thinned out. These semiconductor manufacturing processes are called wire sawing and backgrinding.

Mariana Bertoni, a professor of electrical engineering in the Ira A. Fulton Schools of Engineering at Arizona State University, and her former doctoral student Pablo Guimerá Coll sought to reduce the waste from wafer manufacturing. They developed a precise method to apply a crack to the semiconductor substrate material with a small amount of force, then use sound waves to accurately guide the crack to cut off only the needed amount. A wafer of semiconductor material sits on a table in a laboratory setting. A wafer of semiconductor material is shown in Arizona State University Professor Mariana Bertoni’s lab. Her company, Crystal Sonic, received funding from NASA’s 2022 SBIR Ignite program Phase II to advance their Sonic Lift-off manufacturing technology, which uses sound waves to cut semiconductor wafers for electronic devices. Photo courtesy Mariana Bertoni/ASU Download Full Image

The resulting clean and accurate cuts allow the substrate material to be used multiple times and eliminate the need for backgrinding altogether, ultimately reducing waste in the manufacturing process.

“I’ve always been fascinated by the process of spalling, even in nature, and the role of vibrations in breaking things,” Bertoni says.

This fascination with vibrations and spalling, a process in which a piece of material is broken off from a larger chunk, resulted in Bertoni and Coll’s manufacturing method, which they dubbed “Sonic Lift-off.” After Sonic Lift-off showed promise, Bertoni and Coll founded Crystal Sonic in 2018 to further develop and commercialize their research.

Bertoni now serves as the company’s chief technology officer, while Coll has since graduated with his doctoral degree in materials science and engineering and is now Crystal Sonic’s research and development director.

Crystal Sonic has continued to gain prominence from its ideas ­— the company won one of just 12 national $850,000 funding awards from NASA’s Small Business Innovation Research and Small Business Technology Transfer Program, known as SBIR and STTR, respectively, through SBIR Ignite Phase II for Sonic Lift-off, for which the agency sees potential use to manufacture solar cells that can be used in space. Fellow ASU spinout company Solestial, a business specializing in solar technology for use in space started by ASU electrical engineering alumnus and former Assistant Research Professor Stanislau “Stan” Herasimenka, took home another of the 12 funding spots.

SBIR and STTR programs are offered through all U.S. federal agencies to encourage the development of technology from American small businesses for uses in commercial and government settings. The SBIR Ignite program, started in 2022 and specific to NASA projects, looks to help small businesses by distributing funds on an accelerated timeline compared with lengthier traditional SBIR and STTR processes, allowing the companies to continue their research with minimal disruption and develop their technology more quickly.

Crystal Sonic was one of the first participants of the program and began involvement in SBIR Ignite with a Phase I award, which investigated the feasibility of Sonic Lift-off on large wafers.

Good vibrations

Sonic Lift-off uses a precise application of force to create a crack in semiconductor substrate material. After the substrate is cracked, sound waves guide the crack further into the substrate to create a clean cut through the material, producing a thin semiconductor device used in solar cells or power electronics chip manufacturing.

The technique’s use of sound waves to guide the crack results in a smooth finish, unlike the product from wire sawing, which is rough and requires another step of backgrinding to smooth it to a usable level for consumer devices.

Arno Merkle, Crystal Sonic’s CEO, explains Sonic Lift-off reduces substrate waste by allowing blocks of substrate that are typically used only once to be reused one or more additional times. He says the method’s primary application is for compound semiconductor materials such as gallium arsenide, gallium nitride and silicon carbide.

These materials are commonly used for power electronics applications such as certain types of solar panels and chips that convert electricity and regulate its flow in power grid components and electric vehicle drivetrains and chargers.

“Those kinds of chips are not typically the computer chips you’d think about, like the processor in your computer or phone,” Merkle says. “But they are used for other applications like sensors, so even the 3D sensors in your iPhone that measure facial recognition and other sensors for measuring light or distance are examples.”

Because of the difficulty of producing high-quality compound semiconductor materials and the high amount of waste that results from producing chips, devices using them are expensive to produce. Sonic Lift-off’s waste reduction could cut the single largest cost for compound semiconductor chips, which are facing accelerating demand, by at least half.

Lifting off toward the future

While Sonic Lift-off has been proven to successfully cut a bare wafer measuring four inches, the technology has not yet been tested in devices of such a size. Crystal Sonic’s SBIR Ignite Phase II grant will see the company build a second-generation version of the Sonic Lift-off tool and work with manufacturers of space solar technology to determine whether the method can be used in the production of functioning four-inch devices.

Merkle says in the future, Crystal Sonic hopes to process wafers for devices at even larger diameters.

“For things like silicon chips, they’re up to 12-inch wafers right now,” he says. “One of the technical questions we have is, ‘Can we demonstrate this on larger and larger diameter wafers?’”

In the future, Crystal Sonic aims to move on to Phase III of SBIR Ignite, which would see further commercialization of Sonic Lift-off. Merkle says the company plans to start commercialization in the space solar technology industry with potential future market expansion to manufacturers of wide-band-gap semiconductor devices.

With the company’s success and growth as development progresses on Sonic Lift-off, Crystal Sonic has moved out of space rented from Bertoni’s lab on ASU’s Tempe campus into Connect Labs in downtown Phoenix, located in a building created through a collaboration between ASU, development company Wexford and the city of Phoenix.

“We emerged out of ASU’s campus earlier this summer,” Merkle says. “We outgrew that, and we’re hiring two new people to the team. We’re excited to be here in the community of some emerging startups in the Valley of the Sun.”

TJ Triolo

Communications Specialist, Ira A. Fulton Schools of Engineering


image title

‘College Tour en Español’ debuts at ASU

October 2, 2023

New film features students sharing personal stories about their ASU success in Spanish

“Do I belong?” Those three words ran through Pedro Gonzalez-Ochoa’s mind before he began his college experience at Arizona State University. 

The 22-year-old is now working toward his master’s degree in biomedical engineering at Barrett, The Honors College. Not only does Gonzalez-Ochoa belong at ASU, he’s thriving — and his success is captured on film.  

During a special red carpet premiere at ASU’s West campus on Oct. 1, hundreds of Hispanic families had the opportunity to watch the "College Tour en Español,” a 30-minute film narrated by Gonzalez-Ochoa and several other Sun Devils, which is scheduled for livestreaming on Amazon Prime later this year. 

The film is the first produced by ASU exclusively in Spanish and it’s designed to reach Latino students and inspire them to go on to college.

The episode provides a sweeping visual tour of ASU where 10 Sun Devils share their personal academic journeys at the most innovative university in the country; one that has increasingly enrolled more students of Hispanic descent throughout the years. 

Last year, ASU was designated a Hispanic-Serving Institution, which means at least 25% of its student body identifies as Hispanic or Latino. The university has also earned the prestigious Seal of Excelencia in education for the second year in a row. 

But despite numerous accolades and advancements, there continues to be barriers for Hispanic students, both real and perceived. 

“When my mother was 17 and pregnant, she made the decision to leave Mexico and give me a better life,” Gonzalez-Ochoa said.

He invited his mother to the film’s premiere where students were asked questions about their struggles after the viewing. Gonzalez-Ochoa said his mother faced financial hardship after coming to America. When he got to college, homework became difficult but he always kept his mother in mind and persevered. 

“It’s everything I’ve ever dreamed of (graduating from college). These highs mean nothing to me if I can’t share them with her,” Gonzalez-Ochoa said.

The film focuses on student choices and personalized learning experiences at ASU’s distinct campuses, as well as the degrees available through ASU Online. The desire to learn with a focus on technology is one of the reasons why Mexican immigrant Sandra Perez opted to study at ASU. 

Shortly after she began her studies, Perez’s husband passed away and she thought of quitting often. But she persevered and graduated with a Master of Science in program evaluation and data analytics in May 2022.

“As immigrants, we put obstacles in front of us that are not really there,” said Perez. “I knew I wanted to participate in the ‘College Tour en Español’ immediately. I just hope this film reaches worldwide audiences.” 

Vanessa Ruiz, deputy vice president for outreach within ASU’s Educational Outreach and Students Services, presided over the discussion after the premiere and talked about the numerous resources available to Latino students at ASU.

“We intentionally provide one of the most world-class college experiences accessible to any and all students, and to students who are not yet qualified; we create pathways to admission,” Ruiz said. 

“I am very thankful to ASU for all the financial aid I have received,” said Fatima Botello, an ASU undergraduate and Obama Scholar. 

Botello is set to graduate in May 2024 with degrees in psychology and Spanish literature and culture.

“I am basically here on a full ride and, honestly, would not be here had it not been for ASU,” she said. 

ASU’s affordability was highlighted several times during the film’s premiere. Ninety percent of Arizona residents receive some form of financial assistance or scholarships, and all Arizona residents that are Pell grant eligible pay $0 in tuition thanks to the Arizona Promise Program.

After the premiere, ASU Provost Nancy Gonzales presented each participating student with a $1,000 scholarship to continue their studies, courtesy of ASU and Helios Education Foundation. She stressed that Hispanic students do belong at ASU. 

“Just listening to these stories shows that our model is working but having a 26% Hispanic student body rate is not enough. Those numbers need to continue to rise,” Gonzales said. “I am immensely proud of the incredible students who volunteered to tell their stories in order to inspire future ASU students. They represent the best of our Latino students, a community that now totals more than 31,000 students enrolled.” 

Helios President and CEO Paul Luna also encouraged students who are still deciding on college to take the initiative and enroll at ASU. 

“Whatever your reasons are for holding back, you must know that ASU is the type of university that works with every student and all families to make sure they come out successful,” Luna said.

When asked if all their efforts were worth it, all 10 students were in agreement. 

“Claro que si,” they said. Translation: “Absolutely it was, yes!”

Top photo: Attendees watch the premiere of the "College Tour en Espanol" during a special event at ASU's West campus.

Veronica Sanchez

Director , Media Relations and Strategic Communications