Huawei develops a path to 2nm chip production without EUV lithography
By ForGeeks
Huawei has filed a patent that describes a technology for making 2nm-class chips relying solely on DUV lithography equipment. These machines are still available to the company, while shipments of ASML’s EUV machines are under severe export restrictions.
What Huawei’s patent offers
A document filed in 2022 and recently published, highlighted by semiconductor researcher Frederick Chen, describes a multiple exposure technique capable of providing a metal pitch on the order of 21nm. Such a figure corresponds to “2nm-class” – the same level that TSMC and Samsung are preparing for by using EUV for processes below 3nm.
Such a figure is the same level that TSMC and Samsung are preparing for by using EUV for processes below 3nm.
A key element of the development is the optimized Self-Aligned Quadruple Patterning (SAQP) process. It reduces the number of DUV exposures required to four – a noticeable reduction compared to traditional multiple patterning schemes where the number of passes is much higher, increasing the complexity and cost of production.
Self-Aligned Quadruple Patterning (SAQP) is a key element of the development.
By taking this approach and leveraging existing DUV infrastructure, Huawei and its manufacturing partner SMIC expect to make the leap from the recently demonstrated Kirin 9030, made in the N+3 process, to a future 2nm node – without the need for prohibited EUV equipment.
Fabrication risks remain high
Despite the technical novelty, analysts are cautious about the prospects. Even with proven performance in the lab, the commercialization of such dense SAQP paternization is seriously questionable.
Four-fold patching at these sizes could result in low chip yields, increased defect rates and significantly higher production costs than the single-exposure EUV lithography that the industry already uses for 3nm and below process technologies.
At this size, SAQP paternization could lead to low chip yields, higher defect rates and significantly higher production costs than the single-exposure EUV lithography that the industry already uses for 3nm and below.
If Huawei and SMIC succeed in bringing the SAQP solution into mass production, it will be a telling example of technological circumvention of sanctions. But for now, the patent is more about demonstrating the company’s intentions and the limits China is willing to go to increase its independence in the semiconductor industry.
