Japanese startup foundry Rapidus is set to open the company’s 2-nm pilot fab in April 2025, CEO Atsuyoshi Koike told EE Times in an interview. The big hurdles for the new rival of Taiwan Semiconductor Manufacturing Co. (TSMC) and Samsung still lie ahead, according to an analyst who recently visited Rapidus in Japan.

Rapidus and TSMC are two chipmakers that the Japanese government is counting on to rebuild the nation’s declining semiconductor industry. Rapidus, if successful, will make leading-edge 2-nm chips, while TSMC will make less advanced silicon at its established base in Kumamoto, Japan.

Koike is counting on the support of IBM and global R&D organization imec to start commercial production of the world’s most advanced silicon just two years behind industry heavyweight TSMC. Koike’s single-wafer processing innovation will provide Rapidus a competitive advantage over TSMC and Samsung by accelerating cycle time, he says.

“If it is the same cost, if I can provide [cycle time] two times, three times faster than the usual fab, which will the customer prefer?” Koike asked. “We are not fast enough to start 2 nm [before TSMC], but we can catch up because we have high-speed feedback to ramp up quickly.”

Koike says that single-wafer processing can deliver more of the key data that Rapidus will need to take chip yields to volume production quality 40% faster than other foundries.

“The single-wafer concept would have to make innovation a hundred times better than with a batch reactor,” Koike said. “That is the starting point.”

People are realizing that single-wafer processing can boost yield through better data, but the big foundries will have difficulty adopting the technology, according to Koike.

“TSMC or Samsung cannot follow this kind of idea,” Koike said. “All the engineers believe batch reactors are much more effective. High productivity. They cannot change.”

For decades, chipmakers have used batch reactors that process 50 silicon wafers in one go. Rapidus says it has persuaded key semiconductor toolmakers like Tokyo Electron and Applied Materials to provide the range of single-wafer equipment that Rapidus will need.

“I have so many good friends like [Applied Materials CEO] Gary Dickerson,” Koike said. “Tokyo Electron is the same. They gradually understood what I’m thinking about. I have worked with many equipment companies like Applied, Lam, Tokyo Electron, Dai Nippon Screen, to develop new single-wafer equipment.”

Around the end of 2024, Rapidus will install its first EUV lithography tool. It will not be High-NA EUV.

“It will take time to establish that technology,” Koike said. A tool like ASML’s NXE: 3800E “should be great,” he added.

Predicting the success of an ambitious project is complex, given the path that Rapidus is taking to commercialize an advanced production process is unproven, according to Paul Triolo, who advises global tech clients at Albright Stonebridge Group. He visited Rapidus about a month ago.

“The firm has competent management, the strong backing of the Japanese government and well-regarded technology partners, such as imec and IBM,” Triolo told EE Times. “One of the challenges will be landing anchor clients for Rapidus foundry services—those firms will have to be assured that the advanced process technology being pioneered by the Rapidus-IBM-imec team is capable of delivering on performance and cost in a compelling way that’s on par with global leaders TSMC and Samsung.”

Rapidus will need to figuratively pull itself up by the bootstraps, according to Triolo. The foundry needs to prove its process technology can scale at quality and cost while winning over clients who are putting their advanced designs at stake.

The company expects to add more AI chip designers like Tenstorrent and Esperanto to its list of partners. Koike says several Silicon Valley companies are interested in becoming customers, but he declines to name any on the record.

The company plans to make AI chips for low-power edge computing, as well as high-speed silicon for high-performance computing in data centers.

Rapidus, which counts Sony, Denso, Toyota, SoftBank and Kioxia among its early investors, will need more outside investment to start commercial production. Koike estimates his company will need a total of ¥5 trillion (about $31.8 billion). The Japanese government will provide Rapidus with subsidies based on its annual results, according to Koike.

Fabrication and packaging united

Koike is bringing chip fabrication and packaging together at Rapidus. The two processes have traditionally been handled by separate companies.

Engineers on the front-end and the back-end are separated by a big wall, Koike said.

“No discussion. They speak different languages. I have removed this wall in my company so they can discuss with each other.”

By uniting fabrication and packaging under one roof, Rapidus will also improve cycle time, Koike added.

The company will include hybrid bonding as one of its advanced packaging technologies and is currently working on very narrow pitch tech.

Rapidus is also developing known good die (KGD) testing with test companies and will provide an assembly design kit (ADK)—a first for the semiconductor industry.

“A PDK [process design kit] is for the front-end, but I will create an ADK,” Koike said.

Advanced packaging will be another major challenge for Rapidus, according to Triolo.

“It remains unclear whether Rapidus will develop its own proprietary approaches to advanced packaging, as TSMC, Intel, and Samsung have done with their foundry services, or will seek to align with [other] efforts to establish some more standard approaches to chiplets and advanced packaging,” he said.

Rapid ramp up

So far, Rapidus has not had any delays with construction of its fab in the city of Chitose on Japan’s northern Hokkaido Island, according to Koike.

Rapidus has contracted Kajima, one of Japan’s oldest and largest construction companies, to build the fab.

“They are working at this moment with 2,000-3,000 employees,” Koike says. Kajima will have 5,000 workers on the project around October, he added.

Rapidus hired more than 400 engineers and expects to add 300 more to the headcount each year.

Still, the company faces considerable workforce development challenges, given the demand for skilled workers in Japan as other semiconductor makers expand capacity, such as TSMC, Western Digital, Micron and Kioxia, according to Triolo.

“So far, Rapidus has been able to hire away some engineering talent from other industry players, but long-term prospects for landing sufficient numbers of engineers and operators for a high-volume production facility in Chitose will remain challenging,” he said.

This year, Koike will send about 200 engineers to Albany, New York, where it is paying IBM an undisclosed amount to commercialize the U.S. company’s 2-nm technology. IBM will potentially become a Rapidus customer, according to sources who declined to be identified. IBM did not reply to EE Times’ request for comment.

By: DocMemory
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