Coaxial Liquid Feeder Arms for CMP Slurry Delivery and Cleaning
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Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) apparatuses face challenges with limited operation range of swing arms due to interference between slurry ejection nozzles and atomizers, requiring excessive space for additional devices, and unpredictable dilution of slurry by water droplets during cleaning.
Innovation Solution
A liquid feeder system with coaxially disposed first and second arms, each equipped with nozzles, allows independent control and retraction, minimizing space usage and preventing interference, enabling optimal slurry distribution and cleaning without dilution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a slurry ejection nozzle is provided on the distal end part of a swing arm to enable slurry delivery, then slurry can be fed onto the polishing pad, but the nozzle interferes with an atomizer positioned above the polishing pad, limiting the operation range of the swing arm
Solution Approach 1:
The patent introduces a vertical dimension for nozzle retraction, allowing the slurry ejection nozzle to move not only horizontally with the swing arm but also vertically to clear the atomizer. This dimensional addition resolves the interference conflict by enabling the nozzle to occupy different spatial zones at different times.
Solution Approach 2:
The patent makes the nozzle position dynamic by adding retraction capability. The nozzle transitions from a fixed position on the swing arm to a movable component that can be retracted vertically when the swing arm rotates to positions where it would otherwise interfere with the atomizer. This dynamic adjustment expands the operational range.
2Adaptability or versatility
If a large space is allocated for the swing arm swinging above the polishing pad and for installing devices such as a dresser or temperature control slider, then these devices can be installed and operated, but it becomes difficult to leave a space for the atomizer to swing
Solution Approach 1:
The patent segments the space above the polishing pad by introducing vertical retraction for the nozzle. This creates distinct operational zones: a lower zone for the atomizer and an upper zone for the swing arm when retracted. The segmentation allows multiple devices to coexist without spatial conflict.
Solution Approach 2:
By utilizing the vertical dimension for nozzle retraction, the patent effectively layers the device arrangement. The atomizer operates in the lower vertical space while the swing arm operates in the upper vertical space when retracted, allowing both to share the same horizontal footprint without interference.
3Productivity
If the atomizer is positioned above the polishing pad to clean the pad surface, then cleaning can be performed, but jetted water unpredictably drips after polishing, diluting the slurry and changing the amount of polishing per unit slurry
Solution Approach 1:
The patent extracts the harmful effect of water dripping onto the slurry by retracting the nozzle vertically when the atomizer is active. This separation in vertical space prevents the water jet from the atomizer from contaminating the slurry on the polishing pad, eliminating the dilution problem while maintaining cleaning effectiveness.
4Manufacturing precision
If the swing arm operation range is limited by interference with the atomizer, then component interference is avoided, but it becomes difficult to drop slurry required to polish a wafer onto an optimum position at an optimum timing
Solution Approach 1:
The patent makes the nozzle position dynamic through vertical retraction, allowing the swing arm to access optimal positions for slurry delivery without permanent interference with the atomizer. The nozzle can be retracted when needed and extended when in optimal positioning, achieving both precision and range.
Solution Approach 2:
By adding vertical movement capability, the patent decouples the horizontal positioning requirements from the vertical clearance requirements. The swing arm can achieve optimal horizontal positioning for slurry delivery while the vertical retraction dimension provides clearance from the atomizer when needed.
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
Enhances polishing performance by allowing full surface coverage with slurry and effective cleaning, reducing interference and space constraints, and minimizing polishing time through independent nozzle operations.
Implementation Method 1
a first nozzle configured to eject a first fluid onto a polishing table; a second nozzle configured to eject a second fluid onto the polishing table
Data Source
AI summary
A liquid feeder includes: a first arm having a first nozzle; a second arm having a second nozzle; a first rotation shaft supporting a proximal end part of the first arm; a second rotation shaft supporting a proximal end part of the second arm; a first rotation driver configured to rotate the first rotation shaft to turn the first arm from a fluid feed position to a retracted position; a second rotation driver configured to rotate the second rotation shaft to turn the second arm from a fluid feed position to a retracted position; and a controller. The first rotation shaft and the second rotation shaft are disposed coaxially with each other. The controller is capable of controlling the operation of the first rotation driver and the operation of the second rotation driver independently of each other.