By Brent Li
For decades, the global semiconductor industry bowed to one god: Moore’s Law. Cramming ever-smaller transistors onto silicon.
But you can’t worship Moore when you can’t get hold of cutting-edge tools — the extreme ultraviolet lithography machines made by Dutch company ASML that are needed to mass produce chips – and when you can’t match the manufacturing superiority of TSMC, the world’s biggest contract chipmaker.
So China’s technology giant Huawei decided to throw down the gauntlet and change the rules.
At the 2026 International Symposium on Circuits and Systems (ISCAS) in Shanghai this week, He Tingbo, president of Huawei’s semiconductor division, announced the Tau (τ) Scaling Law — a new theory aimed at redefining how the world measures and manufactures silicon.
On paper, it’s a technical pivot: away from pure transistor density, toward signal delay and system-wide efficiency. In plain English, Huawei is arguing that a smarter, better-organized chip can beat a smaller one.
The move is born out of necessity. Cut off from the world’s most advanced chipmaking tools due to Washington’s export controls on technology, Huawei cannot compete head on at the cutting edge of transistor miniaturization. Its Tau Scaling Law argues that rather than focusing on increasing transistor density, future computing gains will increasingly come from system-level optimisation — including advanced packaging, chip-to-chip communication and energy efficiency.
The market reaction was swift. Driven by sheer weight of the company’s influence, semiconductor stocks soared. Semiconductor Manufacturing International Corp. (SMIC) surged 18.8%, adding enough market cap to reach 1.25 trillion yuan ($172 billion). China’s STAR 50 index, which tracks the 50 largest and most liquid science and technology companies listed on the Shanghai STAR Market, hit an all-time high.
Whether the Tau Scaling Law will genuinely open a new future for Chinese chipmaking — or merely serve as a sophisticated PR stunt — remains to be seen. But Huawei’s message is already clear: if China cannot win the semiconductor race on America’s terms, it will try to redefine the race itself.
Shifting from space to time
For nearly six decades, the semiconductor industry has been governed by Moore’s Law — a theory focuses on geometric scaling, which suggests shrinking transistors to pack more of them into the same area will keep pushing chip products to deliver more processing power. But as transistors approach physical limits, shrinking them has led to escalating costs and severe power density issues, a phenomenon known as dark silicon.
Huawei’s Tau Scaling Law suggests abandoning transistor density as the sole holy grail. In circuit theory, Tau (τ) represents the time constant, which measures the speed at which a signal switches states. The lower the τ, the faster the chip operates. Therefore, Huawei proposes time scaling — systematically compressing the time it takes for signals to travel across a chip, rather than just shrinking the transistors themselves.
One of the core technologies underpinning this law is logic folding. In advanced chips, the tiny metal wires connecting transistors often create more delay than the transistors themselves. Huawei’s solution is to stop laying everything out on a flat 2D plane. Instead, it plans to vertically stack multiple layers of wafers using a micron-level alignment technique called hybrid bonding. This approach shortens the distance that signals need to travel, reducing transmission delays and improving efficiency.
Huawei is widely expected to incorporate this folding technology into its upcoming 2026 Kirin chip. In a paper published on ChinaXiv, Huawei claims this method has already achieved a 55% jump in transistor density and a 41% improvement in energy efficiency on an unchanged manufacturing node, meaning no new lithography equipment was needed, Sci-Tech Innovation Daily reported. Huawei says chips designed under the Tau Scaling Law could achieve transistor densities equivalent to a 1.4-nanometer process by 2031. By comparison, TSMC currently manufactures chips using a 2-nanometer process and plans to introduce a 1.4-nanometer node in 2028.
Born from blockades
This ambitious roadmap contrasts sharply with the struggles Huawei faced just a few years ago. In 2020, Huawei was a dominant force. Its TSMC-manufactured Kirin 9000 chip was the world’s first 5-nanometer mobile phone chip, which boasted built-in 5G capabilities and top-tier efficiency. According to hardware review channel Geekerwan, the chip outperformed the flagship offerings from Qualcomm at that time, sitting comfortably between Apple‘s A13 and A14 processors.
Then, U.S. sanctions severed the supply chain. In 2020, Washington tightened its rules, effectively banning foundries like TSMC and SMIC from manufacturing chips for Huawei if they used any American technology. While the U.S. granted export licenses to companies like Intel and Qualcomm to sell older 4G and PC chips to Huawei, core technologies were strictly blocked.
This forced Huawei’s smartphone chip business into years of silence. To this day, the manufacturers behind Huawei’s latest AI and smartphone chips remain a closely guarded secret. Yet, out of this extreme constraint, the company says it has designed and mass-produced 381 chips over the past six years.
A PR stunt or a new paradigm?
Armed with massive R&D capabilities and a powerful marketing engine, Huawei knows how to craft a narrative. The sudden introduction of the Tau Scaling Law delivers an appealing message for a domestic audience yearning for technological self-reliance.
However, a paper is still just a paper. Moore’s Law required decades of relentless industry validation before becoming the organizing principle of the semiconductor era. If a new law is to guide the post-Moore age, it will likely take five to 10 years to determine its viability. Huawei’s own paper acknowledges several unresolved challenges. For example, traditional Electronic Design Automation (EDA) tools — the specialized software engineers use to design integrated circuits — are built for conventional flat chips, not stacked 3D designs. Furthermore, increasing performance density without corresponding advances in thermal management risks severe overheating.
When Huawei’s next generation of folded Kirin and Ascend AI chips finally reach large-scale commercial deployment, their real-world performance against products from Apple and Nvidia will reveal the truth. Only then will it become clear whether the Tau Scaling Law represents a genuine technological breakthrough or is simply an elaborate PR stunt meant to rally the market.
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