关键词: 混合键合, 先进封装, 铜焊盘, 表面改性, 晶粒控制

Abstract: As the scaling of transistors gradually decelerates, advanced packaging and three-dimensional integration technologies have emerged as crucial pathways for the continuous enhancement of integrated circuit system performance. Hybrid bonding, a bonding process with high-density three-dimensional integration capabilities, is playing an increasingly important role in applications such as artificial intelligence chip manufacturing. The copper pad serves as the interface for signal transmission and power supply in hybrid bonding, and its physicochemical properties determine the yield and reliability of the process. At present, leading international semiconductor companies have made remarkable progress in the field of hybrid bonding brass pad technology, not only establishing a systematic process of high-density metallization-plasma activation-low temperature bonding, but also microscaling the key dimensions (diameter and pitch) of the brass pad to the sub-micron level through technical iterations. In contrast, China's universities and scientific research institutions are still in the early stage of exploration in the research of hybrid bonding Cu pad, compared with the international advanced level, there is still a significant gap in the process capacity and technology accumulation to achieve ultra-high density hybrid bonding. This paper systematically investigates the effects of the geometric morphology, surface chemical characteristics, and grain structure of copper pads on bonding performance. It summarizes the optimization strategies and technical adjustments in this field, providing references for research aimed at enhancing the capabilities of hybrid bonding processes.

Key words: hybrid bonding, advanced packaging, copper pad, surface modification, grain control