Light-Reactive Polishing Pad Rigidity Control
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Solution Overview
Problem
The polishing pad's rigidity changes as it wears, affecting the polishing rate control, making it difficult to accurately regulate the polishing rate of the substrate's periphery due to changes in thickness and deformation.
Innovation Solution
A polishing pad made of a light transmissive material with a light reactive material that changes its state in response to light, allowing for adjustment of rigidity through light wavelength, intensity, or irradiation time, compensating for changes in thickness and maintaining consistent polishing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the polishing pad is used repeatedly for substrate polishing, then the polishing pad becomes thinner due to wear, but the rigidity of the polishing pad changes and the deformation range narrows, making it difficult to accurately control the polishing rate
Solution Approach 1:
The polishing pad incorporates a light-reactive material that can dynamically change its rigidity in response to light irradiation. This allows the pad's mechanical properties to be adjusted in real-time, compensating for the rigidity changes caused by wear and maintaining consistent polishing rate control throughout the pad's service life
Solution Approach 2:
The invention changes the physical parameter of rigidity by introducing a light-reactive material that alters its mechanical properties when exposed to light. This enables the polishing pad to adapt its rigidity parameter to compensate for thickness reduction, thereby maintaining the deformation range necessary for accurate polishing rate control
2Productivity
If the polishing pad thickness decreases due to wear, then the deformation range of the polishing pad narrows, but accurate polishing rate control requires sufficient deformation range
Solution Approach 1:
The light-reactive material enables dynamic adjustment of the polishing pad's rigidity, allowing the deformation range to be maintained despite thickness reduction. By irradiating the pad with light, the rigidity can be modified to restore the necessary deformation characteristics for effective retainer ring control
Solution Approach 2:
The invention replaces the purely mechanical system with an opto-mechanical system by incorporating light-reactive material. This substitution allows optical energy to control mechanical properties, enabling remote and precise adjustment of the pad's deformation characteristics without physical intervention
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 solution effectively compensates for changes in rigidity due to wear, ensuring accurate control of the polishing rate and maintaining surface planarity, even as the pad thickness decreases, by altering the light reactive layer's properties to match the pad's thickness changes.
Implementation Method 1
a light reactive material that changes its state in response to light, allowing for adjustment of rigidity through light wavelength, intensity, or irradiation time
Data Source
AI summary
The present invention relates to a polishing pad and a polishing apparatus for use in polishing of a substrate, such as a wafer. Further, the present invention relates to a method of polishing a substrate, such as a wafer. At least a part of the polishing pad (30) is made of a light transmissive material (34) and a light reactive material (35). The light reactive material (35) is mixed into the light transmissive material (34).