According to a report from analyst firm TechInsights, Chinese foundry SMIC has been producing chips based on its 7nm process node for MinerVa’s Bitcoin Miner SoC, which has been apparently shipping since July of 2021 (h/t to SemiAnalysis). TechInsights has reverse-engineered the chip, saying the “initial images suggest it is a close copy of TSMC 7nm process technology,” a telling discovery after Taiwan-based TSMC has sued SMIC twice in the past for copying its process technology. The discovery comes as China aims to build its own homegrown semiconductor production, with the heavily-sanctioned SMIC leading the way, while the US government is on the cusp of approving large subsidies for US-based chipmakers.
TechInsights says that TSMC, Intel, and Samsung have all developed much more sophisticated technology than SMIC’s 7nm node, remaining at least two nodes ahead, but the significance of SMIC’s mass-produced 7nm can’t be overstated — SMIC has been heavily sanctioned by the US government, restricting its access to advanced chipmaking tools, like those based on EUV technology. However, the firm’s existing tools can be used to produce 7nm chips (and possibly smaller), albeit with less desirable economics and yield. That’s hardly a concern for China as it seeks technological independence from Western countries by developing its own indigenously-produced chips.
SMIC originally announced its 7nm node back in 2020, with it and partner Innosilicon saying they had taped out a chip on the N+1 version of the 7nm node. It remains unclear if the Minerva Bitcoin mining chip, which Techinsights purchased on the open market, has any association with that initial efforts. At the time, SMIC claimed that it also had an N+2 version of its 7nm node in the works, and we aren’t sure if the Minerva chip uses the N+1 or N+2 version of the process technology.
As a reminder, the process naming node convention, like “7nm,” has turned into more of a marketing exercise for the chipmakers rather than a metric tied to any sort of physical measurement. In the real world, a plethora of factors influences the economics and performance of a process node, which you can read about here.
TechInsights is selling individual reports based on its analysis of the chip — a digital floorplan analysis, advanced CMOS process analysis, and a process flow analysis — with more details, including transistor density, to give a better idea of how SMIC’s node stacks up against competing industry nodes.
Taiwan-based TSMC has sued SMIC twice (in 2002 and 2006) for copying its process technology, and TechInsights’ assertion that SMIC has likely copied TSMC’s 7nm will likely lead to further legal battles between the two firms.
The MinerVa mining chip looks to be quite basic and measures only 4.6 x 4.2 mm, implying that SMIC is still in the early stages of chip development. These types of small, simple chips often serve as learning nodes while the process technology is further refined. Mining chips are perfect for this purpose — as you can see in the image above, they are deployed en masse. In this case, the miner has 120 chips per board to create a machine that consumes up to 3300W of power.
We can expect that SMIC will eventually make larger, more complex chips based on its 7nm process node as yields improve over time. The US has long prevented SMIC from procuring EUV tools from ASML, and has recently explored tightening the sanctions noose even further by restricting its access to even comparatively-simple DUV chipmaking tools from ASML. That tactic will slow China’s advance, but the country has continued to plow money into developing its own ecosystem of chipmaking tools and software (EDA). As SMIC has proven, even less-sophisticated equipment can be used to create advanced process nodes.
