CMP: The Critical Enabler for Hybrid Bonding 

Chemical Mechanical Planarization (CMP) is foundational to HBM manufacturing, ensuring planarity, Cu height control, and defect-free surfaces for die stacking. 

In TCB, CMP plays a supporting role since micro-bumps tolerate surface variation.  

In hybrid bonding, CMP becomes mission-critical, as bonding relies on ultra-flat, atomically smooth surfaces.  

Any CMP defect like Cu dishing, erosion, or contamination directly impacts yield, resistance, and reliability. This elevates CMP from a process step to a determinant of performance, interconnect density, and scaling in HBM4 and beyond. 

Co-optimization: Applied Materials + BE Semiconductor Industries (BESI) 

The collaboration between Applied Materials and BESI integrates CMP, surface preparation, and hybrid bonding into a single, controlled flow. 

• Combines Applied Materials’ strength in CMP and materials engineering with BESI’s leadership in hybrid bonding and die placement  
• Reduces process complexity, variability, and defect risks  
• Improves alignment accuracy and bonding yield  

The procurement of integrated hybrid bonding tools by SK Hynix reflects a strategic move to address key hybrid bonding challenges, particularly around CMP-driven surface uniformity, Cu dishing, particle defects, and ultra-tight roughness control. The integrated platform directly tends to tackle these critical bottlenecks, enabling more stable manufacturing, reducing yield risk, and accelerating the transition of hybrid bonding into high-volume production. 

Key Challenges: 

• HBM standard relaxation risk: Joint Electron Device Engineering Council (JEDEC’s) increase in allowable HBM height could delay hybrid bonding adoption, extending TCB’s lifecycle and creating uncertainty in equipment demand.  
• Process sensitivity: Hybrid bonding is highly sensitive to CMP quality defects like dishing, contamination, and voids which increase resistances and impact yield despite superior electrical performance.   

Impact on Memory Players: 

In the near term, delaying hybrid bonding can: 

• Reduce capital intensity  
• Leverage mature TCB processes for better yield  

However, long-term adoption remains inevitable due to enhanced performance requirements. 

A key driver is NVIDIA, whose AI workloads demand higher bandwidth and efficiency. Suppliers like Samsung, SK Hynix and Micron align HBM roadmaps with NVIDIA’s requirements meaning stronger performance demands could accelerate hybrid bonding adoption. 

SK Hynix’s lead in quality and supply of HBMs and other chips used in AI servers has been crucial in the current phase of the AI infrastructure boom. According to Counterpoint Research Report on Memory Solutions for Gen AI, SK Hynix continues to lead in high bandwidth memory, crucial for generative AI with innovations including front-end process improvements in memory cell design, back-end stacking enhancements and integration of logic circuits (IVC) in base dies for voltage control. Further, the memory squeeze is intensifying as AI deployment accelerates, leading to a structural supply shortage lasting through 2030. However, 2028 will likely serve as the inflection point, as a new wave of production clusters begins to ramp up.  

HBM5 Will be the True Inflection Point for Hybrid Bonding: 

HBM5 is going to be the true inflection point for hybrid bonding, enabling >20-layer stacking, finer pitch, and next-level bandwidth while requiring breakthroughs in CMP, yield, and cost to scale into high-volume manufacturing.  

For SK Hynix, early adoption of integrated solutions from Applied Materials and BESI provides a strategic advantage enabling it to meet future requirements in bandwidth, latency, power, and speed, regardless of interim standard relaxations. Leveraging Applied’s process modules (CVD, PVD, ECD, CMP, surface prep) expertise along with Besi’s hybrid bonder technology, will help build an essential foundation for achieving the stability and consistency required in advanced, high-volume chip production.  

We expect SK Hynix to introduce HBM5 in 2029-2030, aligned with next-generation AI GPU cycles, with hybrid bonding reaching mass adoption at the HBM5 node to enable higher performance and efficiency. 

Conclusion: 

HBM scaling beyond ~16 layers and rising AI performance demands are pushing micro-bump packaging to its limits. Hybrid bonding offers a scalable path forward with: 

• Sub-10µm interconnect pitch (vs 20µm-40µm for micro-bumps)  
• Higher bandwidth and power efficiency  
• Compatibility with logic-centric integration  

As HBM moves closer to logic-node requirements, hybrid bonding becomes essential to sustain performance scaling. The co-optimization of CMP and bonding led by Applied Materials and BESI is emerging as the key enabler of this transition.  

SK Hynix’s procurement of integrated hybrid bonding tools from Applied Materials and BE Semiconductor Industries will address critical challenges in HBM manufacturing while providing a strategic edge to meet next-generation performance needs and sustain HBM leadership, driving revenue growth and market share gains.