Segmented Polishing Pads for Uniform Substrate Planarization
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Solution Overview
Problem
Existing substrate polishing apparatuses face challenges in achieving uniform polishing and improved efficiency, especially when dealing with large substrates where maintaining uniformity across small unit areas is crucial.
Innovation Solution
A substrate polishing apparatus is designed with a stage for loading substrates, a pressing unit that exerts pressure perpendicular to the substrate, a rotary unit for revolving the pressing unit, and a plurality of polishing pads and a nozzle part for uniform slurry distribution. The polishing pads are spaced apart and can exert different pressures, allowing for precise control over the polishing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a single large polishing pad is used, then the substrate surface can be covered, but uniform polishing across small unit areas becomes difficult to control
Solution Approach 1:
The single large polishing pad is divided into multiple smaller polishing pads (first polishing pad, second polishing pad, third polishing pad, etc.) arranged in an array. Each small polishing pad independently polishes a specific region of the substrate, allowing precise control of polishing uniformity across different unit areas while collectively covering the entire substrate surface.
2Manufacturing precision
If multiple polishing pads are used to improve uniformity, then polishing precision improves, but device complexity increases
Solution Approach 1:
Multiple small polishing pads are merged into a single pressing unit that can be collectively pressed against the substrate by one pressing mechanism. The pressing unit integrates multiple polishing functions into one coordinated system, reducing operational complexity while maintaining the uniformity benefits of multiple pads.
Solution Approach 2:
The pressing unit is designed to perform multiple functions: it simultaneously presses multiple polishing pads, controls slurry distribution through integrated nozzles, and maintains consistent pressure across all pads. This multi-functionality reduces the need for separate mechanisms for each pad, simplifying the overall device structure.
3Manufacturing precision
If uniform pressure is applied across the substrate, then polishing consistency improves, but adaptability to different substrate conditions decreases
Solution Approach 1:
Each polishing pad is equipped with an independent pressure control mechanism, allowing the pressure applied by each pad to be individually adjusted according to local substrate conditions. This enables different regions of the substrate to receive customized pressure levels, enhancing adaptability while maintaining overall polishing consistency through coordinated control.
Solution Approach 2:
The pressure control system is designed to dynamically adjust the pressing force of each polishing pad based on real-time substrate conditions. The pressing unit can modify pressure distribution during the polishing process, transitioning from static uniform pressure to dynamic adaptive pressure, thereby achieving both consistency and versatility.
4Productivity
If slurry is supplied uniformly across the substrate, then polishing efficiency improves, but slurry distribution control becomes less precise
Solution Approach 1:
The slurry supply system is segmented into multiple nozzle groups, each associated with specific polishing pads. Slurry is supplied locally to each polishing pad through dedicated nozzles, ensuring precise slurry distribution control at each polishing zone while maintaining high overall polishing efficiency through parallel operation of multiple pads.
Solution Approach 2:
The pressing unit acts as an intermediary between the slurry supply system and the substrate, distributing slurry evenly across multiple polishing pads through integrated nozzles. This intermediary structure ensures uniform slurry application to each pad, which then transfers the slurry to the substrate in a controlled manner, achieving both efficiency and precision.
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 apparatus achieves uniform polishing across large substrates with improved efficiency, allowing for precise control of polishing pressures and slurry distribution, which enhances the accuracy and uniformity of the polishing process.
Implementation Method 1
a plurality of polishing pads provided between the pressing unit and the substrate and used to polish the substrate
Implementation Method 2
The polishing pads may be spaced apart from each other in a direction parallel to a motion of the substrate
Implementation Method 3
a nozzle part configured to supply a slurry onto the substrate
Data Source
AI summary
A substrate polishing apparatus including a stage configured to load a substrate, the stage having a flat surface, which is parallel to a first direction and a second direction, and on which the substrate is loaded, a pressing unit configured to exert a pressure on the substrate in a third direction, a rotary unit configured to revolve the pressing unit around a central axis parallel to the third direction, when viewed in a plan view, a plurality of polishing pads provided between the pressing unit and the substrate to be in contact with the substrate, and a nozzle part configured to supply a slurry onto the substrate. The polishing pads may be spaced apart from each other in a direction and may have a rectangular shape in the plan view.