CMP Slurry Recirculation with Separate Pad Cleaning Channels
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) processes face challenges in efficiently recovering and reusing used abrasive slurry due to the complexity and cost of additional treatments required, such as adding solvents or chemicals, and the risk of scratching from agglomerates in the recovered slurry.
Innovation Solution
A surface processing method that includes circulating slurry through separate channels for supply and recovery, and cleaning the processing pad with a distinct waste liquid channel, allowing used slurry to be reused without additional treatments, while maintaining high processing quality and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If used slurry is recovered and reused through conventional methods, then material loss is reduced, but device complexity and operational costs increase due to additional treatments
Solution Approach 1:
The flow channel is segmented into distinct regions: a first flow channel for slurry supply and a second flow channel for cleaning solution supply. This segmentation allows independent circulation paths for slurry and cleaning solution, enabling reuse of slurry without contamination while maintaining simple device structure
Solution Approach 2:
The cleaning solution supply mechanism serves multiple functions: it cleans the processing pad during idle periods and supplies cleaning solution through the same nozzles that supply slurry during processing. This multi-functionality reduces the need for separate cleaning systems, simplifying the overall device structure
2Device complexity
If cleaning solution is supplied through the same circulation system as slurry, then device complexity is reduced, but slurry contamination and processing quality deteriorate
Solution Approach 1:
The circulation system is divided into separate flow channels: the first flow channel exclusively for slurry circulation and the second flow channel for cleaning solution circulation. This spatial segmentation prevents mixing between slurry and cleaning solution, ensuring processing quality while maintaining manageable device complexity
Solution Approach 2:
The system operates in periodic cycles: during processing periods, slurry is supplied through the first flow channel; during idle periods, cleaning solution is supplied through the second flow channel. This temporal separation ensures that cleaning operations do not interfere with processing operations, maintaining manufacturing precision
3Manufacturing precision
If cleaning is performed during idle periods using separate flow channel, then processing quality is maintained, but device complexity increases
Solution Approach 1:
The flow channel is segmented into functional zones with a bypass configuration that allows cleaning solution to be directed to specific regions of the processing pad during idle periods. This targeted cleaning approach maintains processing quality while minimizing the complexity increase by using a relatively simple bypass structure
Solution Approach 2:
A third flow channel acts as an intermediary for cleaning solution supply, connecting the cleaning solution reservoir to the processing pad through bypass passages. This intermediary channel enables independent cleaning operations without disrupting the primary slurry circulation system, balancing processing quality maintenance with acceptable device 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 method effectively recirculates and reuses used slurry, maintaining processing rates and quality without significant decreases, reducing environmental impact and operational costs.
Implementation Method 1
During the planarization process, the slurry circulates through a circulation flow channel for the slurry, which includes a slurry supply flow channel that supplies the slurry to the processing pad and a slurry recovery flow channel that recovers the slurry after use
Implementation Method 2
When the processing pad is cleaned with the cleaning solution, the cleaning solution is discharged through a waste liquid flow channel, which is separate from the circulation flow channel, allowing liquid waste to flow through the waste liquid flow channel
Implementation Method 3
planarizing the processing surface of the workpiece through chemical and mechanical actions by moving the workpiece and the processing pad relative to each other with the slurry interposed between the processing surface of the workpiece and the processing pad
Data Source
AI summary
A surface processing method according to the present disclosure includes: supplying slurry containing at least abrasive grains between a processing surface of a workpiece and a processing pad; planarizing the processing surface of the workpiece through chemical and mechanical actions by moving the workpiece and the processing pad relative to each other with the slurry interposed between the processing surface of the workpiece and the processing pad; and cleaning the processing pad with a cleaning solution. During the planarization process, the slurry circulates through a circulation flow channel for the slurry, which includes a slurry supply flow channel and a slurry recovery flow channel. The cleaning solution for cleaning the processing pad is discharged through a waste liquid flow channel, which is separate from the circulation flow channel, allowing liquid waste to flow through the waste liquid flow channel.