TSMC's CoWoS® Sustainability Drive: Turning Waste into Wealth, Saving NT$700 Million with Recycled Wafers

Driving a circular economy is a cornerstone of TSMC's sustainable operations. As production capacity expands, demand for TSMC's CoWoS® (Chip on Wafer on Substrate) advanced packaging technology is experiencing rapid growth. As a result, the consumption of dummy dies – essential for reinforcing the structural stability of packaging – has also surged. To enhance resource efficiency, TSMC has partnered with suppliers to develop a specialized processing technology. This innovation successfully re-engineers scrap wafers from the front-end process which would otherwise be discarded into dummy dies that meet the stringent specifications and quality requirements of the back-end process. As of December 2025, dummy dies re-manufactured from recycled wafers are expected to be integrated into Advanced Backend Fab 3, Advanced Backend Fab 5, and Advanced Backend Fab 6. This initiative is estimated to reduce carbon emissions by 10,205 metric tons annually and generate an impressive green benefit of NT$746 million, marking a new milestone in resource regeneration.

Innovative Recycling Process Gives New Life to Scrap Wafers

CoWoS® technology involves stacking and integrating multiple chips onto a wafer and substrate. During the packaging process, dummy dies are crucial for maintaining structural stability, and are typically cut from new wafers. To improve resource circularity, in 2024, TSMC's Materials Supply Chain Management Organization, in collaboration with the Advanced Packaging Technical Board & Module Excellence Division, joined forces with suppliers to research and develop a recycling and regeneration process for front-end scrap wafers. This led to the creation of a rigorous screening, grinding, cleaning, and inspection protocol. This meticulous process ensures that the quality of recycled wafers meets the precise specifications required for dummy die production in CoWoS® technology, achieving both sustainable resource utilization and green innovation.

TSMC is dedicated to expanding the scope of resource circularity. In addition to successfully recycling wafers for reuse in CoWoS® technology, the company is also evaluating its application for dummy die production in Integrated Fan-Out (InFO) packaging technology. This continuous effort aims to extend green benefits and actively pursue the sustainable objectives of "minimizing waste generation, maximizing resource circularity, and optimizing supplier management."