Huawei announced the “Tau Law” at the 2026 Institute of Electrical and Electronics Engineers (IEEE) International Symposium on Circuits and Systems, calling it a “new principle” to guide the future development of the semiconductor industry. However, industry experts believe that the “Tau Law” is not a breakthrough as the technique of “stacking” it employs is not a new method.
Huawei’s semiconductor business group president, He Tingbo, delivered a keynote speech on “New Semiconductor Path in Practice” at the IEEE International Symposium on Circuits and Systems held at the Shanghai International Convention Center on May 25, 2026, introducing the so-called “Tau Law.” Huawei claims that this is a “new principle” guiding the future development of the semiconductor industry.
For the past several decades, semiconductor advancements have largely relied on Moore’s Law, continuously shrinking transistors to make circuits denser, distances shorter, and power consumption lower. This has led to faster, smaller, and more energy-efficient chips. Huawei believes that the key to future chip competitiveness lies not just in further transistor miniaturization but also in “transmission efficiency.” The “Tau Law” advocates for 3D stacking, minimizing data movement and reducing signal transmission time through coordinated system design to enhance efficiency.
According to a report by Taiwan’s Economic Daily News, the chairman of ASE Technology Holding Co., Ltd., Todd D. Childs, expressed his views on the “Tau Law” on June 2. He mentioned that the “stacking” method employed in the “Tau Law” is not a new innovation, as Taiwan Semiconductor Manufacturing Co., Ltd. (TSMC) has already been using similar techniques like the CoWoS advanced packaging and the High Bandwidth Memory (HBM).
Childs stated that the “Tau Law” is an attempt to circumvent the U.S. blockade, as the U.S. restrictions on EUV equipment have hindered Huawei’s access to these devices. Consequently, Huawei cannot cram more transistors into a limited planar space. Therefore, the company has opted to place more transistors in a vertical 3D space. Childs commented, “While this may be a solution, it is not a new one, indeed.”
Extreme Ultraviolet Lithography (EUV) is one of the most essential and complex pieces of equipment in modern semiconductor industry. It can be understood as a machine that etches ultra-small circuits on wafers. An EUV machine comprises over 100,000 parts, with dimensions equivalent to several cargo containers and weighing up to 180 tons.
Since 2019, U.S.-led export controls have prohibited the sale of EUV machines to China. ASML remains the sole global enterprise with the capability of mass-producing EUV and High-NA EUV lithography equipment. EUV employs 13.5nm extreme ultraviolet light for exposure, serving as the core technology for 5nm, 3nm, 2nm, and even the forthcoming 1.4nm processes.
NVIDIA CEO Jensen Huang also expressed that “this is a breakthrough for Huawei, but not a threat to TSMC.” TSMC and Taiwan have been developing 3D packaging and chip stacking technologies for over a decade.