SkyWater provides volume manufacturing, mainly on a 130nm mixed-signal process, as well as process development facilities from its 200mm wafer fab in Bloomington, Minnesota. And like most fabs, SkyWater is seeing strong demand. However, SkyWater’s business model is nuanced and it has a particular set of manufacturing processes. “The company divides into technology as a service and wafer services. The wafer services keep costs down for advanced technology services, which keep the margins up for the business as a whole,” said Sonderman.

Tom Sonderman, CEO of SkyWater Technology Inc.

In Fall 2019 SkyWater invested $170 million for cleanroom expansion and by July 2020 had moved equipment in. The expansion is partly for a US government backed rad-hard program (see SkyWater funded to expand, develop next rad-hard process). “We brought in a 90nm rad-hard process with dual-damascene copper interconnect. That will provide us with more advanced interconnect capability and additional lithography to help us move from 65nm to 45nm. We are the only pure-play foundry offering 65nm with dual-damascene copper on 200mm-diameter wafers,” Sonderman said.

Meanwhile as part of its advanced technology services business the company has moved into carbon nanotube FETs, photonics, MEMS and advanced packaging.

Has the investment resulted in increased capacity? Does SkyWater have extra capacity at this time of high demand for almost all forms of chip manufacturing?

“Yes, but it depends on how you measure it. A 200mm wafer with 30 mask layers takes a lot longer in the fab than a power wafer with just 3 mask layers.” SkyWater made an agreement with Steifpower Technology design and manufacture power MOSFETs and IGBTs and related power discrete devices to automotive standards (see Fabless power startup teams with SkyWater for automotive).

Next: More cleanroom

The investment provided an additional 16,000 square foot of building providing an additional 8,000 square foot of clean room space that can be dedicated to the dual-damascene copper. “We’ve also made productivity improvements as well. For example, we do wafer sort on site and this provides better in-line control and increases productivity by 30 percent,” said Sonderman.

SkyWater has also struck up a strong relationship with German chip company Infineon Technologies AG.

Skywater was born out of a chip manufacturing site that was previously owned by Cypress Semiconductor Corp. and originally established by Control Data Corp. As is often the case in wafer fab divestments SkyWater had a “take or pay” legacy manufacturing agreement with Cypress that was due to wind down over several years.

The completion of Infineon’s takeover of Cypress in April 2020 (see Infineon to swallow Cypress in a move to expand product …) provided an opportunity for SkyWater to renegotiate. The result was more of the same type of work. But SkyWater is open to making other chip types for Infineon, with its growing capabilities in MEMS and power semiconductors. This includes novel power MOSFET discretes with fin-type technology, said Sonderman.

Sonderman said that SkyWater’s wafer services divide into three strands. The majority is 130nm mixed-signal CMOS production on a process Cypress called S8, and which SkyWater has renamed S130. This is being performed for Infineon, Parade Technologies and others. The second strand is 90nm processes and below; including the 90nm rad-hard CMOS and 65nm CMOS. The third is power MOSFET discretes. Right now the volume work roughly divides 80:10:10 Sonderman said.

Next: next-gen processes

The other half of SkyWater’s business is advanced technology services – essentially helping customers develop advanced manufacturing processes for specialist products. Sonderman said SkyWater now has 60 engagements with 40 customers.

Sonderman is enthusiastic about the carbon nanotube FET and rad-hard developments on 90nm. Rad-hard circuits are strategic for military purposes but there is also the prospect the same technology will migrate to consumer applications. “Companies are talking about datacenters in space and Wi-Fi and cellular basestations in space. We are taking the rad-hard process to 65nm,” Sonderman said.

There is more room for more equipment in the extension to the fab, Sonderman said. In addition, Cypress had a floor set aside for testing and sorting. There is scope to make use of that area as a clean room to scale up copper manufacturing capability, Sonderman added. All this likely to be impacted by SkyWater’s operation of an advanced packaging facility in Kissimmee, south of Orlando, in central Florida (see SkyWater to ‘on-shore’ packaging of chips in Florida).

Sonderman said that there are plans to partner there with European research institute IMEC on the production of silicon interposers for advanced chiplet-style manufacturing/packaging. There is 36,000 square foot of cleanroom manufacturing space and an additional 24,000 square foot of support and laboratory space not dedicated to manufacturing.

“IMEC’s interposer technology will be a fundamental part of the facility. Advanced packaging is part of the CHIPS for America Act, a $24 billion initiative to support domestic IC production,” said Sonderman. “The Florida facility has got engagements. They were awarded a DARPA contract which is why there is a team of IMEC engineers there. We expect to ramp production in 2021.”

“Traditional OSAT companies [outsourced assembly and test] aren’t really suited to heterogenous assembly,” said Sonderman. It is also the case that the companies that do this at volume are nearly all located in south-east Asia. “We want to be able to support final assembly, package and test all in the US. If you look at something like the iPhone 12 mini, it is an exercise in heterogenous integration.”

Next: Buy more fabs?

When asked whether SkyWater’s IC production capacity is sold out, Sonderman is somewhat coy. “We’re always looking for new customers but we are not there to provide flex capacity; to be an additional or second source.”

When asked whether SkyWater wants to expand capacity through acquisition Sonderman is more assertive. “There are a lot of 200mm wafer fabs in the US.” Sonderman lists OnSemi, NXP Semiconductors and Infineon as examples.

Infineon acquired Fab 25, a 200mm wafer fab in Austin, Texas, along with the rest of Cypress  in 2020. It would likely make sense for Infineon to move some production out as it balances up its internal manufacturing and then sell off the fab with a legacy supply contract. And given the existing relationship between Infineon and SkyWater that sounds like a deal that is waiting to be done.

All Sonderman will say is: “There is a trend for IDMs to outsource. That trend will continue. We continue to look at existing facilities.”

But Sonderman also stressed that because SkyWater splits its effort between volume production and high margin technology services its business model does not depend on scale.

Next: Common interest

Is SkyWater an essentially a US operation or could it also strike partnerships and acquisitions overseas?

“We are partnering overseas. Note our relationship with IMEC. We are looking at different corridors we can open up. Our rad-hard program can help us engage with the European Space Agency. We plan to have a strong partnership with the European Union.”

We asked Sonderman to say more about how SkyWater can engage with the European Union and how quickly. Is that through the existing relationship with Infineon? Or could it be through a complementary relationship with X-Fab? Could EU engagement be related to recent renewed European focus on the strategic significance of semiconductors?

“You’re correct – our ongoing relationship with Infineon stemming from our Cypress heritage is an important one. We hope to see that expand in the future as there is good alignment for various IoT and power management applications. Beyond Infineon, the EU is home to many strong global industrial sensor and control suppliers as well as automotive and even medical device and diagnostic OEMs that align well with our capabilities and value proposition. We are actively working to identify and select representative partners to accelerate plans for increasing our access to these EU markets and expect the region will be a meaningful driver of growth in the coming years.”

Sonderman concluded: “Your point about the EU’s strategic emphasis of semiconductors is important. Both the US and EU currently have a strong focus on strengthening microelectronics supply chains in the western hemisphere. As a US-owned and operated Department of Defense Trusted Foundry, we of course have existing strategic relationships with a number of US-based agencies – but we also feel that our business model and geographic value proposition supports EU objectives to improve supply chain transparency with robust IP security and will lead to additional powerful industry partnerships between our continents.”

Related links and articles:

News articles:

SkyWater forms partnership to open US advanced packaging facility

Carbon nanotube FETs ready to compete with silicon, say SkyWater, MIT

Fabless power startup teams with SkyWater for automotive

Free chips courtesy of Google, SkyWater, eFabless

SkyWater to ‘on-shore’ packaging of chips in Florida

SkyWater funded to expand, develop next rad-hard process

Globalfoundries, SkyWater sign deal to strengthen US chip supply

CEO interview: Sonderman on SkyWater’s technology foundry model

Infineon to swallow Cypress in a move to expand product …

If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :    eeNews on Google News


Linked Articles