Interconnected Lattice Polishing Pad for CMP
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Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) pads suffer from suboptimal contact area and fluid flow patterns, leading to defect formation and the need for frequent conditioning, which compromises planarization efficiency and pad life.
Innovation Solution
A polishing pad with an interconnected lattice structure featuring vertically aligned polishing elements and junctions, forming a self-renewing surface that maintains consistent contact area and facilitates efficient slurry flow, eliminating the need for diamond conditioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polishing pads are used, then the polishing process can be performed, but the real contact area is suboptimal and fluid flow patterns are poor leading to defect formation
Solution Approach 1:
The polishing pad is divided into multiple discrete polishing elements arranged in a lattice structure, where each element is a separate component that can independently contact the workpiece. This segmentation allows for optimized contact mechanics and fluid flow patterns while maintaining structural integrity through the lattice arrangement.
Solution Approach 2:
The lattice structure creates localized regions with different properties - solid polishing elements for contact and void spaces for fluid flow. This local differentiation optimizes both the real contact area for polishing and the fluid flow paths for slurry delivery and debris removal, resolving the contradiction between polishing quality and structural simplicity.
2Duration of action of stationary object
If conventional polishing pads are used, then polishing can occur, but frequent conditioning is required which compromises pad life
Solution Approach 1:
The lattice structure is designed to be self-renewing through its wear characteristics. As the polishing elements wear, the lattice geometry maintains its functional properties, automatically renewing the polishing surface without requiring external conditioning interventions. This self-service mechanism extends pad life while maintaining consistent polishing efficiency.
3Area of stationary object
If conventional pads are used, then polishing can be performed, but the contact area is small and fluid flow is restricted
Solution Approach 1:
The lattice structure transitions from a conventional two-dimensional surface to a three-dimensional architecture with vertical polishing elements. This dimensional change increases the real contact area by adding vertical contact surfaces while the open lattice geometry maintains fluid flow channels, resolving the contradiction between contact area and structural complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The lattice structure achieves higher real contact area, improved slurry flow patterns, and extended pad life, reducing defectivity and maintaining consistent polishing performance across multiple cycles while enhancing planarization efficiency.
Implementation Method 1
facilitates efficient slurry flow
Implementation Method 2
achieves higher real contact area
Implementation Method 3
The polishing pad and wafer typically rotate relative to one another
Implementation Method 4
The wafer surface is polished and made planar by chemical and mechanical action of the polishing layer and polishing medium on the surface
Implementation Method 5
The origin of glazing is plastic flow of the polymeric material due to frictional heating and shear at the points of contact between the pad and the workpiece
Data Source
AI summary
The polishing pad (104) is useful for polishing at least one of magnetic, optical and semiconductor substrates (112) in the presence of a polishing medium (120). The polishing pad (104) includes a plurality of polishing elements (402, 502, 602, 702). The polishing elements (402, 502, 602, 702) are aligned in a vertical direction and having a first and a second end. A plurality of junctions (404, 510, 610, 710) connects the first and second ends of the polishing elements (402, 502, 602, 702) with at least three polishing elements at each of the plurality of junctions (404, 510, 610, 710) for forming a tier. Each tier representing a thickness in the vertical direction between the first and second ends of the polishing elements (402, 502, 602, 702). And an interconnected lattice structure (400, 600) forms from connecting sequential tiers of the plurality of junctions (404, 504) that connect the polishing elements (402, 502, 602, 702).