Tech War: New US Restrictions Could Deny China Access to Chip Making Services from TSMC, Samsung
The US is proposing more limits on China's access to sophisticated chip architecture and high-end memory chips. A possible concentration on gate all-around (GAA) architecture and high bandwidth memory (HBM) AI memory chips. Restrictions could target foreign wafer fabs with GAA capacity, preventing chip manufacturing for China-based customers.
These restrictions might effectively limit China's access to top wafer foundries like Taiwan Semiconductor Manufacturing Co (TSMC) and Samsung Electronics.
The restrictions would specifically target China's access to advanced chip architectures such as gate all-around (GAA) and high bandwidth memory (HBM) AI memory chips. GAA is a next-generation transistor structure utilised in advanced chip production, notably at the 3-nanometer and below nodes, which Chinese foundries have yet to achieve.
If applied, the limitations may target foreign wafer fabs with GAA capability, preventing them from manufacturing chips for Chinese clients. According to Brady Wang, associate director at research firm Counterpoint, this measure has the ability to unite allied countries capable of manufacturing GAA structures to desist from producing for Chinese chip design businesses.
Samsung has already begun employing the GAA transistor architecture for their 3-nanometer process, while TSMC, the world's largest contract chip maker, has a variant of GAA on its technology roadmap for its 2-nanometer-grade N2 process.
The United States has previously limited China's access to GAA technology, including electronic design automation (EDA) software, which is barred from being sold to China in August 2022. Last October, the United States tightened the limitations by requiring licencing for shipments of etching and deposition techniques used to achieve GAA structures in logic and memory chips.
Despite these limitations, Chinese companies are aggressively looking into developing their own EDA software for GAA transistors as part of a larger national effort to replace foreign technologies with indigenous ones. The National Centre of Technology Innovation for EDA, a state-funded research organisation, has already included design tools for GAA structures on its technology roadmap.
In addition to design software restrictions, China has been restricted from importing extreme ultraviolet (EUV) lithography systems since 2019. These systems are essential for manufacturing operations below the 7-nanometer node. Currently, only three chip manufacturers, TSMC, Samsung, and Intel, use ASML-made EUV systems in large production.
The United States is also closely monitoring the use of high bandwidth memory (HBM) chips, which are in high demand due to their application in AI designs. While there is no official prohibition on HBM chips in China, overseas orders for silicon wafers placed by China and other countries of concern will inform institutions such as foreign foundries and exporters if the design includes more than 50 billion transistors and HBM chips.
HBM chips use 3D stacking technology, in which layers of dynamic random-access memory chips are vertically interconnected. This technology has proven difficult for mature players outside of China, providing China an advantage in this regard.
It's unclear whether the new limits will limit chips for consumer devices. However, Chinese design companies may be able to employ the current FinFET architecture as an alternative to GAA, working down to 3-nanometers and compensating for the performance disparity with larger die sizes for each chip.
US considering further restrictions on China's access to advanced chip architecture and high-end memory chips
Potential focus on gate all-around (GAA) architecture and high bandwidth memory (HBM) AI memory chips
Restrictions could target foreign wafer fabs with GAA capability, cutting off chip fabrication for China-based clients
Source: SCMP