Single-Wafer Chamber With Radial Flow for Low-Chemical Cleaning
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Solution Overview
Problem
Conventional wet cleaning processes for semiconductor wafers are inefficient due to high chemical consumption, complex equipment, and incompatibility with advanced processing concepts, necessitating a more compact and effective method for both wet and dry processing that reduces chemical usage and processing steps.
Innovation Solution
An enclosed processing system with a top and bottom plate that confines processing fluids within a small space, allowing radial flow without wafer rotation, and a drainage system with a conduit that provides pressure resistance for uniform fluid flow and reduced fluid usage, enabling additional features like sonic transducers and heating elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spin chambers are used for wet cleaning, then wafer cleaning can be performed, but the equipment becomes large and complicated
Solution Approach 1:
The patent extracts and eliminates the spin chuck, drive mechanism, and large liquid capturing cup from the cleaning system. Instead of rotating the wafer, the invention uses a stationary wafer with nozzles that dispense liquids and generate radial flow to achieve cleaning without the complex rotating components
Solution Approach 2:
The patent replaces the mechanical rotation system (spin chuck with motor) with a fluid dynamics-based system. Liquids are dispensed onto the stationary wafer surface and forced to flow radially outward by pressure, eliminating the need for mechanical rotation while achieving similar cleaning effectiveness
2Reliability
If conventional wet cleaning processes are used, then wafer surfaces can be cleaned, but large amounts of ultrapure chemicals are required
Solution Approach 1:
The patent applies local quality by using multiple nozzles positioned at different locations (center, intermediate, and edge positions) to dispense liquids locally across the wafer surface. This targeted local application of cleaning chemicals ensures effective coverage while minimizing overall chemical consumption compared to conventional methods
Solution Approach 2:
The patent uses hydraulic principles to force liquids to flow radially across the wafer surface under pressure. This controlled fluid flow ensures efficient chemical utilization and complete coverage of the wafer surface, reducing the total amount of chemicals needed while maintaining cleaning effectiveness
3Reliability
If spin chambers with large liquid capturing cups are used, then liquids can be collected during rotation, but the chamber size increases
Solution Approach 1:
The patent extracts and removes the large liquid capturing cup from the system entirely. Instead, a drainage system with a conduit is provided downstream from the processing space to direct and collect liquids after they flow radially across the wafer surface, significantly reducing the chamber volume required
Solution Approach 2:
Instead of collecting liquids during rotation as in conventional spin chambers, the invention inverts the approach by using a stationary wafer where liquids flow radially outward and are then directed through a drainage conduit for collection. This reversal of the collection mechanism enables a much more compact chamber design
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 reduces chemical consumption, enhances surface preparation by ensuring uniform fluid flow and drying, and allows for more compact and efficient processing without compromising effectiveness, improving equipment utilization and environmental isolation.
Implementation Method 1
The drainage system contains a conduit, which is positioned downstream from the processing space and configured to temporarily trap or retain at least a portion of a processing fluid dispensed within the processing space and directed through the conduit. The portion of the processing fluid retained within the conduit provides a pressure resistance against the processing fluid(s) dispensed within the processing space.
Implementation Method 2
The enclosed chamber includes a top plate and a bottom plate, which physically confine the processing fluid(s) within a relatively small, enclosed processing space (PS). This forces the processing fluid(s) to flow radially across the wafer surface(s) without the need to rotate the wafer
Implementation Method 3
A spin chamber uses a spin chuck and drive mechanism (e.g., a stepper motor) to rotate or spin a semiconductor wafer mounted onto the spin chuck, at least one liquid nozzle for dispensing one or more liquids onto the wafer surface(s) while the semiconductor wafer is spinning, and a large cup for capturing the liquids that are ejected from the wafer surface(s) by the centrifugal forces generated during rotation of the spin chuck.
Data Source
AI summary
Improved processing systems and methods are provided for wet and dry processing of a semiconductor wafer. Provided is an enclosed chamber for processing a semiconductor wafer within a processing space and a drainage system for directing processing fluids out of the processing space. The enclosed chamber includes a top plate and a bottom plate, which physically confine the processing fluids within a relatively small, enclosed processing space. This forces the processing fluids to flow radially across the wafer surface(s) without the need to rotate the wafer. The drainage system contains a conduit that is downstream from the processing space and configured to retain a portion of a processing fluid dispensed within the processing space. The portion retained within the conduit provides a pressure resistance against the processing fluid(s) dispensed within the processing space to improve wet and dry processing of the wafer surfaces.