Focus Ring Replacement via Scatterometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for determining the replacement time of a focus ring in plasma processing apparatuses lack accuracy, often leading to premature or delayed replacement, resulting in decreased pattern uniformity on substrates.
Innovation Solution
A determination method that measures the shape or critical dimension of patterns formed on substrates using scatterometry, such as spectroscopic ellipsometry, to assess the condition of the focus ring and determine the optimal replacement time based on deviations from predetermined critical values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the focus ring is replaced according to a predetermined using time, then the replacement process is simple and automated, but the replacement may occur prematurely or be delayed, resulting in decreased pattern uniformity
Solution Approach 1:
The patent replaces the mechanical/time-based replacement system with an optical measurement system. Scatterometry is used to non-contactively measure the shape and critical dimensions of patterns on the substrate, which reflect the focus ring's erosion state. This substitution enables precise, real-time assessment of focus ring condition without relying on predetermined time schedules, thereby maintaining pattern uniformity while optimizing replacement timing.
Solution Approach 2:
The patent implements a feedback mechanism where the measured shape and critical dimension data are compared against reference values to determine the focus ring's erosion state. This feedback loop allows the system to dynamically assess focus ring performance and trigger replacement only when necessary, preventing both premature and delayed replacement, thus maintaining high pattern uniformity while improving replacement efficiency.
2Manufacturing precision
If the focus ring is replaced frequently to ensure pattern uniformity, then the pattern quality is maintained, but the focus ring life span is reduced and processing time is increased
Solution Approach 1:
The scatterometry-based measurement system provides continuous feedback on the focus ring's actual condition by monitoring pattern shape and critical dimensions. This feedback enables the system to distinguish between acceptable variations and actual degradation, allowing the focus ring to remain in service longer when performance is still adequate, thereby extending its effective life span without compromising pattern uniformity and reducing unnecessary replacement processing time.
Solution Approach 2:
The measurement system automatically assesses the focus ring's erosion state through scatterometry measurements of the patterns it produces. This self-service capability eliminates the need for manual inspection and enables the system to autonomously determine when replacement is truly necessary, optimizing the balance between maintaining pattern quality and minimizing replacement frequency.
3Manufacturing precision
If the focus ring is replaced frequently to ensure pattern uniformity, then the pattern quality is maintained, but the productivity is decreased due to increased replacement frequency
Solution Approach 1:
The patent employs scatterometry measurements to provide real-time feedback on focus ring performance through shape and critical dimension analysis. This feedback mechanism enables precise determination of the actual erosion state, allowing the system to maintain pattern uniformity while avoiding unnecessary replacements, thus preserving processing throughput and overall productivity.
Solution Approach 2:
The patent replaces time-based replacement scheduling with condition-based assessment using scatterometry. This substitution allows the focus ring to operate until actual degradation affects pattern quality, maximizing its productive service life while maintaining the required pattern uniformity, thereby improving overall processing throughput.
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 allows for accurate and timely replacement of focus rings, maintaining pattern uniformity and extending the life span of the focus ring by monitoring its erosion state, thus improving the quality and efficiency of the plasma processing.
Implementation Method 1
measuring a shape or a critical dimension of the pattern, the shape or the critical dimension may be measured by a scatterometry method
Data Source
AI summary
A determination method, a control method, a determination apparatus, a pattern forming system, and a storage medium can determine a replacement time of a focus ring accurately and quickly. The determination method is capable of determining the replacement time of a focus ring that surrounds a substrate to increase uniformity of a pattern in a surface of the substrate when the pattern is formed by etching a film on the substrate. The determination method includes measuring a shape or a critical dimension of the pattern; and determining the replacement time of the focus ring based on the measured shape or the measured critical dimension of the pattern.