CMP Cleaning Device Using Twin-Fluid Injection for Pad Maintenance
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Solution Overview
Problem
Conventional chemical-mechanical polishing equipment cleaning devices are inefficient in removing slurry particles and alien substances from polishing pads, leading to wafer scratches and reduced polishing pad lifetime, and fail to effectively manage friction heat generated during the polishing process.
Innovation Solution
A cleaning device that uses a dual-fluid system, where cleaning liquid and compressed gas are mixed and pressure-injected onto the polishing pad, utilizing an irrotatable center shaft and nozzle block to generate twin-fluid, which enhances the removal of slurry particles and includes a mechanism to inject only compressed gas for cooling during the polishing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If only cleaning liquid is injected in a single manner, then the cleaning device structure is simple, but the rate of removing slurry particles and alien substances is low
Solution Approach 1:
The patent combines cleaning liquid injection and compressed gas injection into a single cleaning device structure. The cleaning liquid is injected through nozzles arranged in a circular pattern, while compressed gas is injected through a central nozzle. This merging of multiple cleaning mechanisms into one device increases the removal rate of slurry particles and alien substances from the polishing pad while maintaining reasonable structural complexity.
2Reliability
If cleaning liquid is continuously injected, then alien substances are removed effectively, but friction heat generated during polishing is not managed
Solution Approach 1:
The patent implements periodic action by alternating between cleaning liquid injection and compressed gas injection. During polishing operations, compressed gas is injected to cool the polishing pad and manage friction heat. Cleaning liquid is injected periodically to remove alien substances. This periodic alternation between cooling and cleaning functions ensures both effective alien substance removal and friction heat management, preventing wafer scratches while controlling pad temperature.
3Productivity
If a single-fluid cleaning system is used, then the device complexity is low, but the cleaning effectiveness and cooling capability are insufficient
Solution Approach 1:
The patent applies multi-functionality by designing a cleaning device that performs both cleaning and cooling functions using a dual-fluid system. The cleaning liquid injected through circular nozzles removes alien substances from the polishing pad surface, while compressed gas injected through the central nozzle cools the pad to manage friction heat. This universal cleaning device structure enables simultaneous cleaning and cooling operations, significantly improving cleaning effectiveness and thermal management capability.
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 dual-fluid system significantly improves the removal rate of slurry particles and alien substances, preventing wafer scratches and extending the polishing pad's lifetime while effectively managing friction heat.
Implementation Method 1
the nozzle block mixing cleaning liquid supplied through the first channel with compressed gas supplied through the second channel so as to generate twin-fluid and pressure-injecting the mixed-generated twin-fluid on the polishing pad
Implementation Method 2
a mechanism to inject only compressed gas for cooling during the polishing process
Data Source
AI summary
A cleaning device for chemical-mechanical equipment, which includes: an irrotatable center shaft irrotatably coupled with a spindle which is rotated, the irrotatable center shaft including a first channel and a second channel formed in an interior of the irrotatable center shaft, cleaning liquid flowing into the first channel and compressed gas flowing into the second channel; and a nozzle block coupled with the spindle so as to revolve about the irrotatable center shaft above a polishing pad, the nozzle block mixing cleaning liquid supplied through the first channel with compressed gas supplied through the second channel so as to generate twin-fluid, and pressure-injecting the mixed twin-fluid on the polishing pad. Accordingly, cleaning liquid is pressurized so as to be rapidly injected on a polishing pad so that slurry particles and alien substances on the polishing pad are completely removed. Furthermore, wafer scratch can be prevented and the life of the polishing pad can also be increased.