Polishing Pad Arc Grooves with Inclined Walls
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Solution Overview
Problem
Conventional polishing pads with concentric circular grooves inefficiently distribute slurry during the chemical mechanical polishing process, limiting the effectiveness of planarization due to inadequate slurry flow to the polishing surface.
Innovation Solution
A polishing pad with a polishing layer and arc grooves, where each groove has inclined walls with angles less than 90 degrees, forming fan-shaped regions and interposed regions that enhance slurry flow through centrifugal and inertial forces, allowing for improved distribution and utilization of slurry during the polishing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional concentric circular grooves are used in the polishing pad, then the structure is simple and easy to manufacture, but the slurry flow distribution is inefficient and most slurry remains trapped in the grooves
Solution Approach 1:
The patent applies asymmetry by changing the groove cross-section from a conventional symmetric circular shape to an asymmetric shape with different wall angles. The groove has a first wall with angle α and a second wall with angle β, where α ≠ β. This asymmetric design creates directional flow paths that efficiently guide slurry from the groove interior to the polishing surface, resolving the contradiction by maintaining manufacturing simplicity while dramatically improving slurry delivery.
Solution Approach 2:
The patent employs parameter changes by optimizing the wall angles of the groove cross-section. By controlling the first wall angle α and second wall angle β to be less than 90 degrees and different from each other, the groove geometry is tuned to exploit centrifugal force during rotation. This parameter optimization enables efficient slurry ejection onto the polishing surface while keeping the groove structure simple to manufacture.
2Productivity
If the polishing pad rotates at high speed to improve polishing efficiency, then productivity increases, but centrifugal force traps slurry in the grooves and reduces slurry flow to the surface
Solution Approach 1:
The patent converts the harmful effect of centrifugal force (which traps slurry in conventional grooves) into a beneficial effect. By designing the groove cross-section with specific wall angles (α < 90°, β < 90°, α ≠ β), the centrifugal force generated during high-speed rotation is directed to efficiently eject slurry from the groove onto the polishing surface. This resolves the contradiction by making the high-speed rotation beneficial for slurry delivery rather than harmful.
Solution Approach 2:
The patent applies dynamics by designing the groove structure to be optimized for rotational motion. The asymmetric cross-section with angled walls is specifically configured to interact with centrifugal force during rotation, creating dynamic slurry flow paths that enhance delivery to the polishing surface. This dynamic design allows the groove structure to adapt to the rotational environment and convert rotational energy into effective slurry ejection.
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 described polishing pad design significantly improves slurry flow distribution, enhancing the polishing process by ensuring a consistent and effective application of slurry across the polishing surface, leading to improved planarization and surface smoothing.
Implementation Method 1
part of the slurry flows to the surface of the polishing layer 102 through the centrifugal force generated from the rotation of the polishing pad 100
Implementation Method 2
enhance slurry flow through centrifugal and inertial forces
Data Source
AI summary
A polishing pad, a polishing method and a method of forming a polishing pad are provided. The polishing pad includes a polishing layer and a plurality of arc grooves. The arc grooves are disposed in the polishing layer. Each of the arc grooves has two ends, and at least one end thereof has an inclined wall. The angle between the inclined wall of each groove and the surface plane of the polishing layer is less than 90 degree.