In context: Lithography machines are among the most complex and expensive used in chip manufacturing. They generate stable beams of light in the ultraviolet spectrum and filter that light until it resembles the inverse of a microprocessor’s floor plan. They focus and point light onto a photosensitive wafer with a degree of precision on the order of tens of nanometers to cut out the floor plan.
Huawei has patented a component used in EUV lithography systems that is required to manufacture high-end processors at sub-10nm nodes. It solves the problem of interference patterns created by ultraviolet light that would otherwise cause the wafer to become uneven.
Huawei has addressed an issue in the final stage of chip manufacturing that is reduced by the tiny wavelengths of extreme ultraviolet (EUV) light. His patent describes an array of mirrors that split the beam of light into several sub-beams that collide with their own microscopic mirrors. Each of these mirrors spins differently to create different interference patterns in the light so that when they recombine the interference patterns cancel out to create an even beam.
EUV lithography systems are currently manufactured exclusively by the Dutch company ASML. EUV lithography is based on the same principles as older forms of lithography, but uses light with a wavelength of about 13.5 nm, which is almost an X-ray. ASML generated the ultraviolet light at from rapidly moving molten tin droplets about 25 microns in diameter.
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“As they fall,” explains ASML, “the droplets are first hit by a low-intensity laser pulse that flattens them into a pancake shape. Then, a more powerful laser pulse vaporizes the flattened droplet to create a plasma that emits EUV light. To produce enough light to make microchips, this process is repeated 50,000 times per second. »
ASML needed more than 6 billion euros and 17 years to develop the first batch of EUV lithography machines that could be sold. But before they are completed, the US government is pressuring the Dutch government to ban exports to China, limiting the country to old DUV (deep ultraviolet) technology. So far, only five companies are using or have announced their intention to use ASML EUV lithography systems: Intel and Micron in the United States, Samsung and SK Hynix in South Korea, and TSMC in Taiwan.
Chinese companies like Huawei could then send their designs to fabs like TSMC for manufacturing with EUV lithography. But since the United States imposed sanctions on China, this is less and less possible. Huawei needs access to advanced nodes that use EUV lithography to continue improving its custom processors, which target everything from smartphones to data centers. It still has a long way to go before it can build its own EUV systems, but they are getting a lot of capital and government support to make it happen.