Scientists at the Chinese Academy of Sciences' Shanghai Institute of Optics and Fine Mechanics have built a laser-produced plasma extreme ultraviolet light-source platform that hit 3.42% conversion efficiency. The result, published in a March 2025 paper, marks a concrete step toward domestic production of the lithography machines needed to make the world's most advanced chips.
The EUV breakthrough
EUV lithography uses light at 13.5 nanometers to etch circuits smaller than 7 nanometers. The light source is the hardest part. It requires firing high-power laser pulses at tiny tin droplets to create a plasma that emits EUV radiation. Collecting and focusing that light without losing most of it has been a decades-long engineering challenge.
The Shanghai team's platform achieved 3.42% conversion efficiency — meaning that fraction of the laser energy turned into usable EUV light. That number is still well below the 5-6% range of commercial systems from ASML, but it's a significant jump from earlier Chinese lab results that hovered around 1%.
EUV lithography is the choke point for sub-7nm semiconductor production. Without it, you can't make the processors that power smartphones, AI accelerators, and advanced military hardware. China has been trying to build its own EUV tools for years, but the light source has been the biggest bottleneck.
The platform is still a lab prototype. It's not a complete lithography machine. But the researchers say the efficiency gain brings them closer to a source that could eventually be integrated into a full scanner. The next steps involve scaling up the laser power and improving the collector optics — both expensive, long-lead-time problems.
The ASML factor
ASML, the Dutch company that dominates the EUV market, has been barred by the Dutch government from selling its most advanced machines to China. That ban, aligned with U.S. export controls, means Chinese chipmakers like SMIC can't buy the Twinscan NXE systems needed for 5nm and 3nm production.
China's domestic chip industry has been forced to rely on older deep-UV lithography, which can't reach the same resolution. The Shanghai Institute's work is part of a broader national push to break that dependency. Other Chinese labs and companies are working on different parts of the EUV tool chain — the mirrors, the vacuum systems, the wafer stages.
No timeline has been given for when a full Chinese EUV machine might be ready. The 3.42% efficiency is a milestone, but turning a lab result into a factory-floor tool that runs 24/7 with sub-nanometer precision is a different game entirely.
