Sloped Annular Flow Control Ring for Wafer Edge Contamination
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Solution Overview
Problem
During semiconductor manufacturing processes like plasma etching, unwanted particles and contaminants can accumulate in the process chamber and potentially damage the wafer, especially at the edge or periphery, due to inadequate venting and retention mechanisms in traditional horizontally planar plasma and gas flow control systems.
Innovation Solution
A perforated and sloped annular plasma and gas flow control device is introduced, which deflects unwanted particles away from the wafer surface by its angled design, reducing the likelihood of contamination and damage during etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional horizontally planar plasma and gas flow control system is used, then the structure is simple and easy to manufacture, but unwanted particles and contaminants accumulate in the process chamber and damage the wafer edge
Solution Approach 1:
The patent applies curvature by transitioning from a horizontally planar flow control device to a sloped annular configuration. The sloped surface angles downward from the inner circumference toward the outer circumference, creating a curved geometric profile that actively deflects particles away from the wafer. This curved geometry enables the system to redirect contaminant flow paths, preventing particle accumulation at the wafer edge while maintaining structural integrity and manufacturability.
2Object-affected harmful factors
If a sloped annular plasma and gas flow control device is used, then particle deflection and wafer protection are improved, but the device structure becomes more complex
Solution Approach 1:
The patent implements local quality by applying the sloped annular configuration specifically in the region where particle deflection is most critical - around the wafer periphery. The slope angle and geometry are optimized locally to match the particle flow patterns and wafer geometry, providing enhanced protection where needed most while keeping other areas of the chamber simpler. This localized approach addresses the contamination problem without requiring complex modifications throughout the entire system.
3Reliability
If inadequate venting is used in traditional systems, then the device complexity is reduced, but contaminants accumulate and damage the wafer
Solution Approach 1:
The sloped annular flow control device acts as an intermediary element between the plasma generation region and the wafer surface. It mediates the particle flow by intercepting and redirecting contaminants before they can reach the wafer, while simultaneously maintaining proper venting and pressure control. This intermediary structure enables both enhanced protection and sustained manufacturing efficiency by managing particle dynamics without requiring complete system redesign.
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 sloped annular plasma and gas flow control device effectively minimizes the landing and retention of unwanted particles on the semiconductor wafer, enhancing wafer acceptance testing and chip probe metrology by directing contaminants away from the wafer surface, thus improving the overall manufacturing process.
Implementation Method 1
the annular plate...acts and/or serves to control a plasma and/or gas flow through, and/or stabilize the pressure within, the process chamber
Data Source
AI summary
A method of plasma etching a semiconductor wafer includes: securing the semiconductor wafer to a mounting platform within a process chamber such that an outer edge of the semiconductor wafer is encircled by a sloped annular ring having a plurality of perforation therein, the sloped annular ring having an inner edge at a first end of the sloped annular ring and an outer edge at a second end of the sloped annular ring. Suitably, the first end is opposite the second end and the first end resides in a first plane and the second end resides in a second plane different from the first plane. The method further includes generating a plasma within the process chamber such that the semiconductor wafer is exposed to the plasma and creating a flow of at least one of plasma and gas through the perforations in the sloped annular ring.