White House seeks to restrict China’s access to GAA chip technology and the high bandwidth memory that's critical for AI accelerators

The U.S. Government is said to be considering further restrictions on China’s access to cutting-edge semiconductor technology. Now, people familiar with the matter say the Biden administration wants to further restrict the gate-all-around (GAA) transistor technology used to manufacture leading-edge chips. The administration is also considering limits on high-bandwidth memory (HBM), which is critical for AI accelerators.

GAA nanosheet transistors improve density while delivering power and performance benefits, but they are only used on the most cutting-edge process nodes. Currently, only Samsung has this tech in production with its 3nm node. Intel will adopt GAA in its future 20A node, and TSMC will follow with its A16 process. 

Existing sanctions prevent China from acquiring the equipment needed for 3nm and below production. Still, there are other ways for the country to circumvent those restrictions and bolster the performance of its existing process nodes. China fab SMIC could theoretically port GAA transistor technology to its existing 7nm process node. While this would not offer the full benefits of using the technology with 3nm and below processes, it would conceivably offer improvements in both power and performance. Since GAA is accomplished with single-patterning, China could potentially pull off the feat with its existing chipmaking tools.

A Huawei exec recently said he believes China should work to make better use of its existing 7nm process node. The chipmaker’s Cloud Services CEO, Zhang Ping’an, doesn’t believe China can acquire chipmaking equipment for 3.5nm or smaller chips anytime soon.

This suggestion, along with the possibility that China could find a way to produce GAA technology with its existing equipment, is likely prompting the U.S. Government to explore additional sanctions against the Asian country.

GAA technology is already restricted, and there has been no official word from the White House on the conditions of any heightened curbs. Those who did speak on the matter only did so on condition of anonymity because the discussions were still private. Nor did the people know when officials might make a final decision. Experts are still determining how narrow or broad to make such a rule.

Policymakers aim to make it more difficult for China to develop and manufacture the highly sophisticated computing systems needed for AI models. New restrictions on HBM exports would also be a key chokepoint. However, those discussions are purportedly not as far along as the enhanced GAA restrictions, so it could be some time before we see those officially announced.