Automated Wafer Cleaning with Multi-Stream Nozzle Segmentation
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Solution Overview
Problem
Conventional spin cleaning methods for wafers are inadequate in removing all undesirable artifacts deposited during integrated circuit processing, leading to suboptimal production yields.
Innovation Solution
An automated wafer cleaning system utilizing multiple dispensing nozzles that apply cleaning substances at non-orthogonal angles and varying locations on a spinning wafer, combining liquid and gas streams to effectively dislodge and remove surface contaminants through directional application and controlled motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional spin cleaning with orthogonal liquid stream is used, then the process is simple, but cleaning effectiveness is insufficient to remove all artifacts
Solution Approach 1:
The cleaning system is segmented into multiple independent nozzle assemblies, each capable of dispensing cleaning liquid at different angles and positions. This segmentation allows the system to achieve superior cleaning effectiveness through coordinated multi-angle spraying while maintaining modular complexity that can be managed and controlled independently.
Solution Approach 2:
The invention transitions from single-direction (orthogonal) liquid application to multi-dimensional cleaning by introducing nozzles that spray at various angles relative to the wafer surface. This dimensional change in liquid application direction enables the removal of artifacts that conventional orthogonal spraying cannot eliminate, directly improving cleaning effectiveness.
2Reliability
If multiple nozzles with varying angles are used, then artifact removal is more thorough, but the system becomes more complex
Solution Approach 1:
Multiple nozzle assemblies are merged into a single integrated cleaning system that operates in coordination. The nozzles are positioned and angled to work together, with their liquid streams converging on the wafer surface from different directions. This merging approach achieves thorough artifact removal while consolidating control mechanisms, thereby managing system complexity.
Solution Approach 2:
The nozzle assemblies are designed with multi-functionality, capable of dispensing cleaning liquid at multiple angles and positions to address various types of artifacts. This universal design allows a single nozzle assembly to perform multiple cleaning functions, reducing the total number of specialized components needed and managing overall system complexity.
3Reliability
If liquid cleaning solution is applied orthogonally, then the process is straightforward, but some artifacts remain on the wafer surface
Solution Approach 1:
The cleaning system incorporates dynamic positioning and angling of nozzle assemblies, allowing the liquid application direction to be adjusted and optimized for different wafer conditions and artifact types. This dynamic capability enables thorough cleaning while automating the complexity, making the process easier to operate despite the multi-dimensional cleaning approach.
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 achieves more effective cleaning than conventional methods, ensuring thorough removal of artifacts and improving wafer production yields by leveraging directional forces and rotational momentum.
Implementation Method 1
spinning the wafer to remove the solution, and thus, dry the wafer
Implementation Method 2
applying a first stream of liquid along a line starting from an initial point on the wafer adjacent to the center of the wafer, through the center of the wafer, and ending at an edge of the wafer
Data Source
AI summary
In an embodiment, a method includes: spinning a wafer around an axis of rotation at a center of the wafer; applying a first stream of liquid along a line starting from an initial point on the wafer adjacent to the center of the wafer, through the center of the wafer, and ending at an edge of the wafer; applying a second stream of liquid to an inner third of the line starting at the initial point and ending at a boundary point; applying a third stream of liquid to a middle third of the line starting at the boundary point; applying a fourth stream of liquid to an outer third of the line ending at the edge of the wafer; applying a fifth stream of liquid along the line starting from the initial point and ending at the edge of the wafer; and applying a stream of gas along the line starting from the initial point and ending at the edge of the wafer.