Source: Shutterstock

After Semiconductor Manufacturing International Corp. (SMIC), China’s largest foundry, became included in the U.S. Department of Commerce’s Entity List, Chinese semiconductor industry has seen its pursuit of Moore’s Law stalled. Prevented from obtaining the U.S. equipment “uniquely necessary” for process nodes at 10nm and below, SMIC, and by extension China’s chip industry, has turned a part of its focus on mature process technologies and advanced packaging. 

However, rumors have surfaced that the United States is mulling to further curtail China’s semiconductor industry by preventing SMIC from accessing U.S. equipment capable of manufacturing at 14nm and blow. 

♦ Further reading – Choked by sanctions, China’s chip industry views heterogenous integration as a way forward

As reported by Wall Street Journal, the National Security Council, backed by the Defense Department and others, seeks to amend the wording to fix certain loopholes in the original restrictions. The current wording gives exporters the opportunities to adjust their equipment, enabling them to produce chips at 10nm or below, thus circumventing the U.S. restrictions. In turn, the proposed amendment would see the words “uniquely necessary” replaced by “capable of”, closing the loopholes.

Even though the action targets China’s advanced process technologies, it endangers mature nodes as well. Certain equipment, such as those used for etching, can also be used for both 40nm and 14nm technologies alike. Consequently, if the change is implemented, it would block another path of Chinese semiconductor development.

♦ Further reading – Amidst strategic shift, SMIC parts ways with its TSMC veterans

Given the symbolic status of SMIC’s 14nm process, if it fell under sanctions, it would also be another blow to the Chinese foundry’s advanced fabrication.

As SMIC’s first process node based on FinFET technology, 14nm represents a milestone: back in 2017, SMIC hired Mong-Song Liang, a former R&D head of TSMC, to lead its FinFET development, and successfully reached a breakthrough within a year, firmly placing SMIC at the forefront of China’s chip industry. The FinFET breakthrough also provided SMIC a basis on which to develop its “N+1”, “N+2” and 7nm process nodes. 

As SMIC previously indicated, its 14nm process had entered volume production in Q4 2019, and trial production of N+1 also began in the end of 2020. Even though some mistook it as an equivalent of 7nm, N+1 lowers power consumption by 57%, increases performance by 20%, and reduces logic area by up to 63%. Unlike N+2 and 7nm, N+1 also doesn’t depend on the EUV lithography machines currently inaccessible to SMIC.

When U.S. sanctions first hit, SMIC slowed down its pursuit of advanced nodes, and focused on 14nm instead. The foundry claimed its 14nm yield was already on par with that of TSMC – something still in dispute.

Nevertheless, the first round of U.S. sanctions already severely impeded SMIC’s FinFET-based processes: since the beginning of Q1 2021, SMIC’s quarterly analysis of revenue has replaced the term “14/28nm” with “FinFET/28nm”. Some interpreting it as a sign of difficulties with processes below 14nm. It is worth noting that “FinFET/28nm” technology only accounted for 18.2% of SMIC’s revenue in Q3 2021, while 40/45nm accounted for 13.9% of it.

Fearing further sanctions would worsen the ongoing chip shortage crisis, however,  some Commerce Department officials are reportedly against the proposal.

 

References: WSJ, UDN