Plasma generator advances semiconductor chip manufacturing studies

In the race to create smaller, denser microchips, some semiconductor manufacturers are turning to emerging technologies like extreme ultraviolet (EUV) lithography. This method uses very short wavelength light to blast patterns onto silicon wafers that can make chips with the smallest process nodes. In the process, a low-density hydrogen plasma forms along the EUV beam. This plasma prevents carbon build-up on the optics but may also affect the lifetime and performance of the machine.

Stodolna et al. presented an experimental setup that can generate the hydrogen plasma to enable further studies to improve EUV lithography. Previous plasma generators were complex and resource-intensive, but the team’s setup is simple and uses commercially available technology. Their setup primarily relies on a high-pressure, high-current electron beam gun that can generate short electron pulses to create a plasma through electron impact ionization. In tests, it was able to reproduce key parameters of the EUV-generated plasma.

“To me, the most exciting part is that we showed our plasma setup resembles multiple properties of EUV-generated plasma, including its temporal behavior, which has never been reproduced in non-EUV-generated plasma setups before,” said author Aneta Sylwia Stodolna. “As a result, we can now conduct more realistic plasma-material interaction studies for our customers.”

The researchers are already using the setup to investigate material lifetime studies and are working on upgrades, including connecting it to an X-ray photoelectron spectroscopy machine for in-depth analysis. An initial investigation of pulsed versus continuous wave plasma is showing the importance of temporal plasma properties in EUV-driven material damage processes.

Source: “A novel low-temperature and high-flux hydrogen plasma source for extreme-ultraviolet lithography applications,” by A.S. Stodolna, T.W. Mechielsen, P. van der Walle, C. Meekes, and H. Lensen, JVST: B (2024). The article can be accessed at https://doi.org/10.1116/6.0003701 .