Spin Cover Inclined Surface for Substrate Cleaning Mist Control
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Solution Overview
Problem
Existing substrate cleaning apparatuses face challenges in preventing water marks and back contamination during the cleaning and drying processes, particularly due to the formation of droplets and mist when pure water impinges on stationary covers and the high-speed rotation of substrates, which can adversely affect semiconductor devices.
Innovation Solution
A substrate cleaning apparatus with a spin cover that rotates at the same speed as the substrate, featuring an inclined inner circumferential surface to direct cleaning solutions downward and minimize relative speed, thereby reducing droplet and mist formation, and incorporating a stationary cover to prevent gas swirling and mist reattachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the substrate is rotated at high speed for drying, then the drying efficiency is improved, but water droplets and mist are generated that reattach to the substrate causing water marks
Solution Approach 1:
A spin cover is introduced as an intermediary component between the substrate and the environment. The spin cover rotates at substantially the same speed as the substrate, creating a controlled environment that prevents water droplets and mist from reattaching to the substrate surface while allowing high-speed rotation for efficient drying
Solution Approach 2:
The spin cover is designed to rotate at substantially the same angular velocity as the substrate, creating equipotential conditions in the rotating reference frame. This minimizes relative motion between the spin cover and substrate, preventing the generation of harmful swirling flows and droplet rebound while maintaining high drying efficiency
2Device complexity
If pure water is supplied onto the substrate using a stationary cover, then the cleaning process is simple, but water droplets bounce back and reattach to the substrate
Solution Approach 1:
The stationary cover is replaced by a dynamic spin cover that rotates together with the substrate. This dynamic configuration eliminates the relative motion between the cover and substrate that causes water droplets to bounce back, while maintaining a relatively simple cleaning process structure
3Object-affected harmful factors
If the spin cover rotates at the same speed as the substrate, then droplet and mist formation is minimized, but the structure becomes more complex
Solution Approach 1:
The spin cover is merged with the substrate rotation system, both rotating at substantially the same speed around the same axis. This combining of rotation motions achieves effective mist suppression while avoiding the need for separate complex drive mechanisms, thus limiting the increase in 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 apparatus effectively prevents water marks and back contamination by ensuring that cleaning solutions are quickly discharged and not reattached to the substrate, maintaining a low relative speed between the substrate and spin cover to minimize mist formation and gas swirling, thus enhancing the yield of semiconductor products.
Implementation Method 1
a spin cover (3) provided around the substrate and rotatable at substantially the same speed as the substrate... The inner circumferential surface is, from a lower end to an upper end thereof, inclined radially inwardly
Implementation Method 2
the inner circumferential surface is, from a lower end to an upper end thereof, inclined radially inwardly
Implementation Method 3
incorporating a stationary cover to prevent gas swirling and mist reattachment
Data Source
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AI summary
A substrate cleaning apparatus is used to clean a substrate with a cleaning liquid. The substrate cleaning apparatus includes a substrate holding mechanism configured to hold a substrate horizontally, a rotating mechanism configured to rotate the substrate held by the substrate holding mechanism, a liquid supply nozzle for supplying a cleaning solution to the substrate, and a spin cover provided around the substrate and rotatable at substantially the same speed as the substrate. The spin cover has an inner circumferential surface shaped so as to surround the substrate. The inner circumferential surface is, from a lower end to an upper end thereof, inclined radially inwardly.