Patterned Polishing Pad for CMP Uniformity
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Solution Overview
Problem
Conventional polishing pads face issues with non-uniform surface roughness and durability during the CMP process, leading to reduced removal rate and planarization quality, especially in high-integration semiconductor manufacturing where precise curvature following and global planarization are critical.
Innovation Solution
A polishing pad with a pattern structure featuring a support layer and a pattern layer having protrusion patterns with specific dimensions and arrangements, which includes a bonding layer, allows for stable surface roughness and improved removal rate by controlling the contact area and slurry distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the polishing pad surface is continuously worn during polishing, then the polishing process can be maintained, but the surface roughness becomes non-uniform and the polishing pad durability decreases
Solution Approach 1:
The polishing pad surface is pre-formed with a pattern structure including protrusions and recesses before the polishing process begins. This preliminary structuring prevents the surface from becoming non-uniform during polishing, as the patterned surface maintains consistent contact properties throughout the pad's service life, thereby resolving the contradiction between maintaining productivity and ensuring reliability.
Solution Approach 2:
The polishing pad surface is divided into different regions with distinct properties: protrusion portions and recess portions. This local differentiation allows specific areas to perform different functions, with the protrusions providing stable contact points and the recesses managing slurry flow and wear distribution, thus maintaining both high removal rates and surface uniformity over time.
2Area of stationary object
If the surface roughness is too small, then the contact area with the polishing target increases, but the slurry flow is disturbed and removal rate decreases
Solution Approach 1:
The polishing pad surface is divided into protrusion portions and recess portions with different local properties. The protrusions provide controlled contact points that maintain appropriate contact area, while the recess portions create channels for slurry flow, preventing disturbance to slurry delivery and maintaining high removal rates.
Solution Approach 2:
The continuous polishing pad surface is segmented into discrete protrusion and recess regions. This segmentation allows the pad to simultaneously achieve sufficient contact area through the protrusions while maintaining open pathways for slurry flow through the recesses, resolving the contradiction between contact area and slurry flow.
3Productivity
If the surface roughness is too large, then the contact uniformity with the polishing target decreases, but the removal rate may increase, however scratches occur on the polishing target
Solution Approach 1:
The polishing pad surface is divided into protrusion portions that provide controlled roughness for material removal and recess portions that reduce peak stresses. This local differentiation allows the protrusions to achieve high removal rates while the overall patterned structure prevents excessive stress concentration that would cause scratches, thus resolving the contradiction between removal rate and scratch prevention.
Data Source
AI summary
A polishing pad, a polishing device including the same, and a method of preparing a polishing pad are provided. The polishing pad includes a support layer, and a pattern layer disposed on one surface of the support layer, and the pattern layer includes a plurality of protrusion patterns spaced apart from each other on the support layer, and has a greater rigidity than a rigidity of the support layer.