China achieves breakthrough in EUV field for chip manufacturing - SCMP
Kyiv • UNN
Chinese researchers have created an EUV light source platform, bringing the country closer to independent production of advanced chips. The development has reached internationally competitive parameters.
Chinese researchers have overcome a barrier to domestic production of advanced chips by creating an extreme ultraviolet (EUV) light source platform that operates with internationally competitive parameters, according to research, UNN writes, citing South China Morning Post.
Details
The group from the Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences was led by Lin Nan, who previously headed the light source technology department at ASML in the Netherlands.
ASML, the world's only manufacturer of EUV machines that are critical for producing chips with nodes smaller than seven nanometers, has been unable to sell its advanced models to China since 2019 due to pressure from the US, the publication notes.
In a call with investors on April 16, ASML CEO Christophe Fouquet said that "it is always possible to generate some EUV light, but it will take China many years to build an EUV machine."
Lin returned to China in 2021 and founded an advanced research group on photolithography technology, which was responsible for this work.
Prior to joining ASML, Lin was trained at Anne L'Huillier, the 2023 Nobel Prize winner in Physics and a member of the Royal Swedish Academy of Sciences, as part of a scholarship awarded by the European Union's Marie Skłodowska-Curie programme.
An article published in the March issue of the Chinese Journal of Lasers states that the group has developed an EUV light source with a laser plasma (LPP), a key component of photolithographic machines, which could be a breakthrough for China's semiconductor industry, the publication points out.
"The experimental platform will support the localization of solid-state laser-driven EUV light sources and measurement systems, playing a crucial role in China's efforts to develop EUV photolithography technology and its key components," the paper reads.
According to the paper, Lin and his team created a platform based on a solid-state laser, unlike ASML's industrial photolithographic devices, which use light obtained using CO2 technology to transfer circuit patterns to silicon and other substrates.
CO2 lasers provide power of more than 10 kilowatts and a high repetition rate compared to the lower performance of solid-state platforms.
"While commercial CO2 lasers have high power, they are large, inefficient in terms of grid connection efficiency (below 5 percent) and expensive in terms of operation and electricity," Lin and his colleagues wrote.
"Solid-state pulsed lasers, which have made rapid progress over the last decade, are now achieving output power in the kilowatt range and are expected to reach 10 times more in the future. They are compact in size, with a grid connection efficiency of around 20 percent, and may become a promising replacement for CO2 lasers as the driving force for the next generation of LPP-EUV photolithography," the paper says.
The experimental platform has achieved results that are on par with similar international research on solid-state LLP EUV, while achieving more than half the conversion efficiency ratio of commercially available light sources driven by CO2 lasers, the paper says.
Using a 1-micron solid-state laser, the team achieved a maximum conversion efficiency of 3.42 percent, exceeding the 3.2 percent recorded in 2019 by the Dutch Advanced Research Center for Nanolithography, and 1.8 percent by ETH Zurich in 2021.
A comparison of the data showed that the Chinese platform lags behind the University of Central Florida, which achieved 4.9 percent in 2007, and the Japanese University of Utsunomiya, which recorded a conversion efficiency of 4.7 percent last year, the publication writes.
According to the paper, the conversion efficiency of commercially available light sources for EUV photolithography, driven by a CO2 laser, is about 5.5 percent.
The researchers noted that kilowatt-level solid-state lasers with a wavelength of 1 micron, capable of providing sufficiently high conversion efficiency, have already been well developed and are commercially available.
"Even with a conversion efficiency of 3 percent, a solid-state LPP-EUV laser light source can provide power in the watt range, making it suitable for EUV exposure testing and mask testing," they wrote.
The researchers estimated that the theoretical maximum conversion efficiency of the platform could approach 6%.