Interesting research on LPP EUV light sources by this team in China
Abstract
Extreme ultraviolet lithography (EUVL) has been demonstrated to meet the industrial requirements of new-generation semiconductor fabrication. The development of high-power EUV sources is a long-term critical challenge to the implementation of EUVL in high-volume manufacturing (HVM), together with other technologies such as photoresist and mask. Historically, both theoretical studies and experiments have clearly indicated that the CO2 laser-produced plasma (LPP) system is a promising solution for EUVL source, able to realize high conversion efficiency (CE) and output power. Currently, ASML's NXE:3400B EUV scanner configuring CO2 LPP source system has been installed and operated at chipmaker customers. Meanwhile, other research teams have made different progresses in the development of LPP EUV sources. However, in their technologies, some critical areas need to be further improved to meet the requirements of 5 nm node and below. Critically needed improvements include higher laser power, stable droplet generation system and longer collector lifetime. In this paper, we describe the performance characteristics of the laser system, droplet generator and mirror collector for different EUV sources, and also the new development results.
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advancing from 2015
This Research Paper looks to have been published in 2022. It looks like they are making a huge national push in the development of LPP EUVL.
The good news is that the Wuhan Uni and Huazhong Uni Team seems to have already developed a MOPA C02 Laser of at least 27kw Laser Power.
This is similar to the Gigaphoton MOPA C02 Laser which also produces 27kw of Laser Power. The Gigaphoton EUV Light Source uses a 27Kw Laser to produce Source Power of 250W.
The current Model ASML EUVL NXT3400 uses a 30kw MOPA C02 Laser and also produces Source Power of 250W.
As we can see, everything is gradually falling into place in the development of the EUVL in China.
What really slowed down the development of the EUVL for ASML in the initial stages was the search for a powerful C02 Laser and also the development of the pre-pulse technique for the illumination of the tin droplet.
It looks like a prototype of the Chinese EUVL is not too far away. The Light Source R&D would be close to completion.