IDTechEx Explores the Role of 3D Cu-Cu Hybrid Bonding in Powering Future HPC and AI Products

BOSTON, April 18, 2024 /PRNewswire/ -- Semiconductor packaging has evolved from traditional 1D PCB levels to cutting-edge 3D hybrid bonding at the wafer level, achieving interconnecting pitches as small as single micrometers and over 1000 GB/s bandwidth. Key parameters, including Power, Performance, Area, and Cost, are crucial considerations. Power efficiency is enhanced through innovative packaging techniques, while Performance benefits from shorter interconnection pitches. Area requirements vary for high-performance chips and 3D integration's smaller z-form factor. Cost reduction strategies involve exploring alternative materials and improving manufacturing efficiency. In the realm of 3D integration, microbump technology continues to advance for achieving smaller pitches, with groundbreaking Cu-Cu connection methods like hybrid bonding leading the way, achieving <1 micron-level pitches. This article introduces Cu-Cu hybrid technology, including its development, the high-level methodology to achieve it, and key applications. This article shares some of the research from the IDTechEx report, "Advanced Semiconductor Packaging 2024-2034: Forecasts, Technologies, Applications."

 

 

Introduction to microbump and hybrid bonding technology

Microbump technology, a well-established technology in semiconductor packaging, relies on the Thermal Compression Bonding (TCB) process and has a widespread application across various products. Its evolutionary path primarily revolves around continually scaling bumping pitch. However, a significant hurdle arises as the shrinking solder ball sizes lead to heightened formation of Intermetallic Compounds (IMCs), consequently compromising conductivity and mechanical properties. Moreover, the proximity of contact gaps may induce solder ball bridging during reflow, posing a risk of chip failure. Since solder and IMCs exhibit higher resistivity than copper, their utilization in high-performance component packaging encounters limitations.

On the other hand, hybrid bonding presents a paradigm shift by establishing interconnections through a combination of dielectric material (for example, SiO2 or SiCN) and embedded metal (Cu). Notably, Cu-Cu hybrid bonding has achieved pitches below 10 micrometers, typically around single-digit µm values. This advancement brings forth several benefits, including expanded I/O, heightened bandwidth, improved 3D vertical stacking, enhanced power efficiency, and reduced parasitics and thermal resistance attributed to the absence of underfill. However, challenges persist in the form of manufacturing complexities and elevated costs associated with this advanced technique.