CMP Slurry Filtration and Restoration System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chemical mechanical polishing (CMP) processes face challenges in maintaining the quality and consistency of CMP slurries during integrated circuit fabrication, as they become depleted, imbalanced, or contaminated due to chemical reactions and waste accumulation, leading to compromised performance and efficiency.
Innovation Solution
A CMP processing system that includes a control unit to manage the flow and recycling of CMP slurries, utilizing a slurry filter and restoration system to filter, replenish, and recycle used slurry, maintaining its original composition and state, ensuring continuous quality and consistency throughout the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CMP slurry is reused without filtration and restoration, then productivity is improved by continuous operation, but manufacturing precision deteriorates due to slurry depletion and contamination
Solution Approach 1:
The system continuously filters and restores used CMP slurry to recover its polishing effectiveness, allowing the same slurry to be reused multiple times while maintaining consistent polish quality across production batches
Solution Approach 2:
The automated filtration and restoration system operates continuously during slurry usage, ensuring that the slurry maintains its chemical and physical properties throughout extended production periods without interruption to manufacturing precision
2Manufacturing precision
If CMP slurry is filtered and restored, then manufacturing precision is improved by maintaining slurry quality, but device complexity increases due to additional system components
Solution Approach 1:
The filtration system and restoration system are integrated into a single unified apparatus that performs both functions sequentially, reducing the number of separate equipment pieces while maintaining comprehensive slurry quality control
Solution Approach 2:
The system automatically monitors slurry conditions and activates filtration and restoration processes based on real-time parameters, eliminating the need for manual intervention and reducing operational complexity despite the added hardware
3Manufacturing precision
If CMP slurry is filtered through fine filters, then manufacturing precision is improved by removing contaminants, but loss of substance increases due to slurry retention in the filter
Solution Approach 1:
The system recovers slurry that would otherwise be lost in the filter by implementing a back-flush mechanism that reverses filter media saturation and returns retained slurry to the circulation system for continued use
Solution Approach 2:
The filter is periodically back-flushed at scheduled intervals to prevent saturation and recover accumulated slurry, balancing contaminant removal with material retention through cyclic operation rather than continuous loss
4Manufacturing precision
If restoration system replenishes slurry additives, then manufacturing precision is improved by maintaining chemical composition, but use of energy increases due to continuous monitoring and replenishment
Solution Approach 1:
Sensors continuously monitor slurry chemical parameters and provide feedback to the control system, which automatically activates the restoration system only when additives fall below threshold levels, optimizing energy usage while maintaining consistent polish chemistry
Solution Approach 2:
The system monitors and adjusts slurry parameters such as pH, oxidant concentration, and abrasive particle size, replenishing additives only when necessary to maintain optimal ranges, thereby reducing unnecessary energy consumption while ensuring manufacturing 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 system achieves improved polish stability and within-wafer thickness control, allowing for efficient reuse of CMP slurries, reducing waste, and enhancing production yield by maintaining slurry quality and consistency, even with varied topography and short polish times.
Implementation Method 1
a slurry filter to filter the used slurry
Implementation Method 2
perform chemical mechanical polishing with the polishing pad on the workpiece
Implementation Method 3
Chemical mechanical polish (CMP) processes can be used for the fabrication of an integrated circuit
Data Source
AI summary
A system controls a flow of a chemical mechanical polish (CMP) slurry into a chamber to form a slurry reservoir within the chamber. Once the slurry reservoir has been formed within the chamber, the system moves a polishing head to position and force a surface of a wafer that is attached to the polishing head into contact with a polishing pad attached to a platen within the chamber. A wafer/pad interface is formed at the surface of the wafer forced into contact with the polishing pad and the wafer/pad interface is disposed below an upper surface of the slurry reservoir. During CMP processing, the system controls one or more of a level, a force, and a rotation of the platen, a position, a force and a rotation of the polishing head to conduct the CMP processing of the surface of the wafer at the wafer/pad interface.