After 20 Years, Energetiq’s First EUV Source Is Still Going Strong

While working for The University at Albany’s College of Nanotechnology, Science, and Engineering in 2004, Associate Professor Gregory Denbeaux was in search of something novel. He needed a product that could reliably create Extreme Ultraviolet (EUV) photons to further his research on EUV lithography. Despite the recent emergence of EUV lithography as the next logical step in semiconductor miniaturization, finding a compact and affordable EUV source was not an easy task at the time. Luckily, a small startup company based in Massachusetts was working on a solution that fit the bill. 

Although Energetiq is widely recognized today for its flagship Laser-Driven Light Source technology, the company’s humble beginnings were more closely tied to its unique Electrodeless Z-Pinch™ EUV source. The source uses a patented design that inductively couples current into the Z-pinch plasma to generate clean, 13.5 nm EUV light. Given Professor Denbeaux’s need for such a cutting-edge source and Energetiq’s desire to break into the EUV market, it was a perfect match. After learning more about the source’s potential capabilities, he and his colleagues purchased Energetiq’s first ever model for sale known as the “EQ-10M.” A simplified version of Energetiq’s current EQ-10R-HP source, the EQ-10M arrived at the university in 2005. 

After almost two decades, the EQ-10M is still actively being used for research today. How often the source gets utilized can vary from month to month, but according to Professor Denbeaux, a group of students are currently using the EQ-10M nearly every day. Through the years, the source’s purpose has mainly been to help create photoresists for EUV lithography research, accounting for about 80 percent of its applications. This has been due in part to the overall scarcity of EUV photons. 

In fact, Professor Denbeaux believes there may have been a long stretch of time where he and his team were using the EQ-10M source to produce more EUV photons than any other company in the field. “Early on in EUV, there were micro-exposure tools which did small field patterning to test the EUV process. This was before ASML built their first Alpha Demo Tool,” said Professor Denbeaux. “The problem with those tools was that they had an EUV light source that wasn’t reliable. So for quite a long time in the history of EUV, I believe that I had made more EUV photons for research, development, and printing than these major companies because we were reliably running this source over and over again for years.” 

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The procurement of EUV photons continues to be a challenging endeavor even now. “20 years later, I still go to meetings where folks say, ‘I have a great idea for an EUV resist! I’ve made the molecule and tested it in electron-beam lithography,’ because that’s all they have. They think it will be a great solution for EUV lithography, but they’ve never actually seen an EUV photon. The photons are still that rare.”

The breadth of EUV photon research conducted by Professor Denbeaux and his team using the EQ-10M source is truly remarkable. Contributing to over 40 works in esteemed publications such as the Journal of Photopolymer Science and Technology and national conferences like Advances in Patterning Materials and Processes, the EQ-10M continues to be the basis of relevant research 20 years after its conception. Recently, an article published in the peer-reviewed scientific journal ACS Macro Letters recognized Professor Denbeaux’s efforts toward developing self-immolative photoresists specifically designed for extreme ultraviolet (EUV) lithography.¹ These photoresists incorporate end-cap groups that enhance their performance. The synthesis process is incredibly detailed, highlighting how these modifications improve resolution, sensitivity, and overall material stability under EUV exposure. The article emphasizes the importance of these advancements in achieving higher fidelity patterns necessary for modern semiconductor manufacturing. Findings presented by Professor Denbeaux and others suggest that these new photoresists can effectively meet the rigorous demands of EUV lithography, making them promising candidates for future applications in the industry. 

Like any new product at the forefront of technology, the EQ-10M source has inevitably needed a few repairs over time. Natural erosion of some components, such as the copper bore used to generate current flow, led to a readjustment of the original specification for tightening the bore. This readjustment eventually created excessive stress on the ceramic spacers on either side of the bore, causing them to crack. Professor Denbeaux and his team were able to work with Energetiq to quickly replace these spacers in just one day, avoiding any significant downtime. On a separate occasion, there was a series of faults being triggered by a programmable logic controller (PLC) located inside the unit. Matt Besen, one of Energetiq’s co-founders, was able to walk the team at the university through a PLC replacement procedure without anyone from Energetiq having to step onsite. There’s no question that the personal relationship formed between Energetiq and Professor Denbeaux’s team has largely contributed to the source’s ongoing success.      

As for the university’s plan if the EQ-10M ever fails to meet its demands? Professor Denbeaux has already gone ahead and purchased a backup EQ-10R model source from Energetiq. The university’s willingness to continue investing in Energetiq’s EUV products is a testament to both the quality of the sources and the longstanding partnership between both parties which continues to grow. 

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References

1. Deng, J., Bailey, S., Ai, R., Delmonico, A., Denbeaux, G., Jiang, S., & Ober, C. (2022). Synthesis of end-cap enabled self-immolative photoresists for extreme ultraviolet lithography. ACS Macro Letters, 11(7), 1048-1054. https://doi.org/10.1021/acsmacrolett.2c0039