Focus Ring Temperature Measurement via Optical Interference
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Solution Overview
Problem
Existing temperature measurement methods for components in substrate processing chambers, such as focus rings, face challenges when surfaces are worn or deposited with foreign materials, leading to inaccurate measurements and increased costs due to complex assemblies.
Innovation Solution
A method using low-coherence light interference to measure the optical path length within a component, setting the measurement path to avoid worn or deposited surfaces, allowing for precise temperature determination by comparing the measured path length with pre-generated data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If the front or rear surface of the component is worn or deposited with foreign material, then the component is used over time in substrate processing, but the thickness measurement becomes inaccurate and temperature measurement precision deteriorates
Solution Approach 1:
The invention extracts the measurement function from the component surfaces that are subject to wear and deposition. By measuring the optical path length of light traveling through the interior of the component rather than reflecting from its surfaces, the measurement system is isolated from the harmful effects of surface degradation, allowing accurate temperature measurement throughout the component's service life.
Solution Approach 2:
The invention introduces an intermediary measurement approach using optical path length as an intermediate parameter. Instead of directly measuring surface properties that degrade, the system uses light transmission through the component's interior as an intermediary that remains stable over time, which then correlates to temperature through thermal expansion effects.
2Measurement precision
If a coating member is added with a predetermined space to protect the thin portion, then surface states are maintained, but device complexity and cost increase
Solution Approach 1:
The invention removes the need for additional protective coating members by extracting the measurement function from the component surfaces. The measurement system directly observes the interior of the focus ring through its transparent material, eliminating the requirement for separate protective layers and reducing overall device complexity.
Solution Approach 2:
The focus ring's transparent material serves multiple functions: it maintains the structural integrity of the component while simultaneously acting as an optical window for temperature measurement. This multi-functionality eliminates the need for separate protective coating members, reducing device complexity.
3Measurement precision
If multiple components are assembled to ensure precise measurement, then measurement accuracy is maintained, but manufacturing cost increases
Solution Approach 1:
The invention merges the temperature measurement function with the existing focus ring structure. By utilizing the focus ring's own transparent material as the measurement medium, the system combines structural and measurement functions into a single component, eliminating the need for separate measurement devices and reducing manufacturing costs.
Solution Approach 2:
The focus ring serves itself by using its own transparent material to enable temperature measurement. The component's inherent optical properties are exploited for measurement purposes, eliminating the need for external protective coatings or additional measurement components, thereby reducing manufacturing complexity and cost.
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
Enables accurate temperature measurement of components even when surfaces are worn or contaminated, ensuring precise process control in substrate processing without increasing component complexity or cost.
Implementation Method 1
measuring an optical path length of a predetermined path within the component by using optical interference of reflection lights of a low-coherence light from the component
Implementation Method 2
a relationship between a temperature of the component and an optical path length of a predetermined path within the component
Data Source
AI summary
A temperature measuring method of a component of a substrate processing chamber including a surface being worn or being deposited with a foreign material by using. The method includes: providing data representing a relationship between a temperature of the component and an optical path length of a predetermined path within the component; measuring an optical path length of the predetermined path within the component by using optical interference of reflection lights of a low-coherence light from the component when the low-coherence light is irradiated onto the component to travel through the predetermined path; and obtaining a temperature of the component by comparing the measured optical path length with the data.