Polishing Pad Traversing Grooves Slurry Flow Distribution
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Solution Overview
Problem
Conventional polishing pads fail to achieve optimal slurry flow distribution during the chemical mechanical polishing process, leading to inefficient polishing characteristics.
Innovation Solution
The polishing pad features a surface pattern with traversing grooves that have a non-zero angle with the motion direction and include carrier compatible grooves in the leading region of the carrier ring, allowing for controlled slurry flow and distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional circular grooves are used in the polishing pad, then the polishing pad structure is simple, but most slurry is contained in the grooves and only a small portion flows to the surface, resulting in poor slurry flow distribution
Solution Approach 1:
The polishing pad surface is divided into multiple regions with different groove patterns: a first region with circular grooves and a second region with radial grooves. This segmentation allows different areas to serve different functions - the circular grooves contain slurry while the radial grooves channel it toward the surface, solving the contradiction between slurry containment and surface flow.
Solution Approach 2:
Different groove patterns are applied to different regions of the polishing pad. The first region (central area) uses circular grooves optimized for slurry containment, while the second region (outer area) uses radial grooves optimized for slurry transport to the surface. This local differentiation optimizes slurry flow distribution without requiring complete redesign of the entire pad structure.
2Quantity of substance
If edge extending grooves are used to extend to the polishing layer edge, then slurry can flow out easily, but most slurry is squeezed over the edge by the carrier ring and only a small portion flows between the polishing layer and substrate
Solution Approach 1:
The groove system is segmented into circular grooves in the central region and radial grooves in the outer region. The radial grooves extend toward the edge but are positioned and angled to channel slurry downward between the polishing layer and substrate rather than allowing it to be squeezed over the edge by the carrier ring, thus improving polishing efficiency.
Solution Approach 2:
The groove patterns are designed with specific angles relative to the carrier ring motion. The radial grooves are angled such that they channel slurry in a direction that exploits the relative motion between carrier and pad to force slurry downward into the polishing interface rather than outward over the edge, adding a directional component to slurry flow control.
3Adaptability or versatility
If the polishing pad uses a uniform groove pattern, then the structure is simple to manufacture, but it cannot provide optimal slurry flow distribution for different polishing process requirements
Solution Approach 1:
The polishing pad is divided into at least two regions with different groove patterns - a first region with circular grooves and a second region with radial grooves. This segmentation provides adaptability for different polishing requirements while maintaining manufacturing simplicity through the use of standard groove formation techniques applied to different zones.
Solution Approach 2:
The combined circular and radial groove pattern creates a multi-functional surface that can accommodate different polishing process requirements. The circular grooves provide slurry containment and distribution, while the radial grooves provide directed flow to the surface, making the single pad design adaptable to various polishing applications without requiring multiple specialized pads.
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
This design enhances polishing efficiency by ensuring the slurry flows effectively along the grooves, improving polishing performance and reducing slurry consumption.
Implementation Method 1
a portion of the slurry flows outward in a radial direction from the circular grooves to the surface of the polishing layer due to the centrifugal force generated from the rotation of the polishing pad
Implementation Method 2
Through the mechanical friction generated by the relative motion and the chemical effects of the slurry, a portion of the surface layer of the article is removed
Data Source
AI summary
A polishing pad used in conjunction with a carrier ring to polish a substrate and has a motion direction when polishing is provided. The carrier ring has at least one carrier groove, and the substrate has a substrate radius. The polishing pad has a polishing layer and a surface pattern. The surface pattern has traversing grooves, and an angle between the tangent line of each traversing groove and the tangent line of the motion direction is not equal to 0 degree. Each traversing groove respectively has a traversing groove trajectory corresponding to the motion direction, and the traversing groove trajectory of the traversing groove has a trajectory width smaller than the substrate radius. At leading region of the carrier ring corresponding to the motion direction, the traversing grooves have at least one carrier compatible groove which aligns with the at least one carrier groove of the carrier ring.