The Gate-All-Around (GAAFET) era begins

As the conclusion of a multi-year development process, Samsung’s foundry group announced this morning that the company has officially started production on its first 3nm chip production line. Samsung’s 3nm process is the industry’s first commercial manufacturing process hub to leverage gate-all-around transistor (GAAFET) technology, a major milestone in silicon lithography and potentially a major incentive for Samsung to compete with TSMC.

Samsung’s relatively spartan announcement, which comes on the last day of the second quarter, announces that Samsung has begun manufacturing chips on a GAAFET-compatible 3nm production line. The company won’t reveal the specific version of the node used here, but based on previous Samsung roadmaps, this is undoubtedly Samsung’s first 3GAE process – essentially Samsung’s earliest process node within a family. According to Samsung, the line will initially be used to produce chips for “high performance, low power computing”, with later mobile processors. Samsung’s early process nodes have traditionally been reserved for the company’s internal use, so while Samsung isn’t announcing any specific 3nm chips today, it’s only a matter of time before we announce a 3nm SoC from Samsung LSI.

Samsung has been quiet for the most part this year about its progress on 3nm/GAAFET. The last major news we heard from the company regarding the matter was at the company’s Foundry Forum event several months ago, where the company reiterated its plans to begin production of 3GAE by the end of 2022. Given the tech’s previous lull and groundbreaking nature, there has been more than any concern that 3GAE would be delayed beyond 2022 — on top of the delays that pushed the tech out of its original 2021 launch window — but with today’s announcement, Samsung appears to be to want to rest.

That said, the devil is in the details in these announcements, especially as to what is and is not said. Notably, today’s announcement from Samsung makes no mention of “high volume” manufacturing, which is the traditional milestone when a process node is ready for commercial use. So by just saying that 3nm is in production, Samsung’s announcement leaves the company quite a bit of leeway as to how many chips they can produce — and at what yields. The company was already producing test chips in 2021, so the matter is more nuanced than just starting up the fab, so the line between PR and production is blurred to say the least.

Still, today’s announcement marks a significant moment for Samsung, which has been working on 3nm/GAAFET technology since before 2019, when they initially announced the technology. Samsung’s particular flavor of GAA transistor technology is Multi Bridge Channel FET (MBCFET), a nanosheet-based implementation. Nanosheet-based FETs are extremely adaptable, and nanosheet width is an important metric in defining strength and performance characteristics: the higher the width, the higher the performance (at higher power). As a result, transistor designs targeting low power can use smaller nanosheets, while logic requiring higher performance can go for the wider sheets.

Along with today’s production announcement, Samsung has also offered some updated size and performance figures comparing 3GAE to older nodes. Officially, 3GAE can offer 45% less power consumption or 23% better performance compared to Samsung’s 5nm process (the company doesn’t specify which flavor), with an overall feature size reduction of 16%. These figures differ significantly from Samsung’s earlier (2019) figures, which compared the technology to Samsung’s 7LPP node. Given the change in baselines, it’s not clear at this point whether 3GAE lives up to Samsung’s initial claims, or whether they should shy away from the first version of their 3nm technology.

What is clear, however, is that Samsung has more significant improvements in mind for the second iteration of 3nm, which we know is 3GAP(loop). According to today’s press release, Samsung expects a 50% power reduction or a 30% performance improvement over the same 5nm baseline, with a much larger area reduction of 35%. Today’s announcement does not provide a date for 3GAP, but according to previous roadmaps, 3GAP is expected to land about a year after 3GAE. 3GAP is also when we expect Samsung to open the door to third-party customers, although given the harsh competitive environment, nothing should be taken for granted.



Samsung Process Roadmap (July 2021)

The launch of Samsung’s 3nm process technology comes as the company works to regain its foothold against arch-rival TSMC, which has clearly taken the lead in the 5nm/4nm generation. The gap between TSMC and Samsung has been big enough that major customers such as Qualcomm have transitioned high-performance chips such as Snapdragon 8 series from Samsung to TSMC, and at present, Samsung has achieved few major 5nm/4nm wins compared to TSMC. . If all goes well, Samsung could be the first fab with GAAFET technology to provide a temporary but material advantage over TSMC, whose 3nm process still uses older FinFET-like transistors. But to make that happen, Samsung needs to reverse their previous technical glitches and deliver a performant, high-efficiency process that’s far enough ahead to chase skeptical customers.