Stationary Wafer Cleaning With Vortex Spray and Low Chemical Waste
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Solution Overview
Problem
Conventional semiconductor wafer cleaning methods often result in wastage of cleaning chemicals and potential damage to the wafer due to high-speed rotation, which can lead to photoresist collapse and other forms of damage.
Innovation Solution
A method and apparatus utilizing a slim cell with an annular trough and multiple nozzles to spray a cleaning solution in a vortex pattern over a stationary semiconductor wafer, reducing chemical usage and minimizing contact with the wafer's backside, while maintaining the wafer immobile to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-speed rotation is used for wafer cleaning, then cleaning effectiveness is improved, but photoresist collapse and structural damage occur
Solution Approach 1:
The patent replaces the traditional mechanical rotation-based cleaning system with a stationary wafer cleaning system that uses multiple nozzles to spray cleaning solution. The cleaning effectiveness is achieved through the spray pattern and chemical action rather than mechanical rotation, thereby avoiding photoresist collapse while maintaining cleaning performance
Solution Approach 2:
The invention uses hydraulic spraying through multiple nozzles positioned around the wafer periphery to deliver cleaning solution. The nozzles spray in a controlled pattern that ensures effective cleaning without requiring wafer rotation, thus preventing structural damage to photoresist patterns
2Manufacturing precision
If traditional cleaning methods are used, then cleaning coverage is improved, but chemical wastage increases by up to 90%
Solution Approach 1:
The patent applies cleaning solution locally and selectively at the wafer periphery through strategically positioned nozzles. The cleaning action is concentrated where it is most needed (at the edges and surfaces exposed to contaminants during processing) rather than applying chemicals uniformly across the entire wafer surface, thereby reducing overall chemical consumption while maintaining effective cleaning coverage
Solution Approach 2:
The cleaning system is divided into multiple independent nozzle units positioned around the wafer periphery. Each nozzle targets specific zones, allowing precise control of chemical application. This segmented approach ensures that cleaning solution is applied only where required, minimizing waste while achieving comprehensive cleaning coverage through coordinated action of multiple nozzles
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
This approach significantly reduces chemical wastage, up to 70-90% less than conventional methods, and prevents damage to the wafer by maintaining it stationary during cleaning, ensuring efficient and effective removal of contaminants without photoresist collapse.
Implementation Method 1
spray a cleaning solution in a vortex pattern over a stationary semiconductor wafer
Data Source
AI summary
A method of cleaning a semiconductor wafer includes: loading a semiconductor wafer into a cell having an annular trough; moving a plurality of nozzles into operational orientations for spraying a cleaning solution onto a top surface of the loaded semiconductor wafer; spraying the cleaning solution from each nozzle onto the top surface of the loaded semiconductor wafer in a direction defined by each nozzle's operational orientation such that a patterned flow of cleaning solution is formed on the top surface of the loaded semiconductor wafer; and collecting the cleaning solution in the annular trough of the cell as it flows off the top surface of the loaded semiconductor wafer.