Focus Ring Wear Measurement Using Horizontal Optical Detection
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Solution Overview
Problem
The existing methods for measuring the wear of consumable components, such as focus rings, in plasma etching processes are either inaccurate due to direct human observation or risk damaging the components during measurement with physical contact.
Innovation Solution
A substrate treating apparatus with a lift pin module and a measurement unit that uses a light receiving member to calculate the wear of consumable components by measuring the height change when light interference occurs, allowing for non-contact, precise wear assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a measuring instrument is brought into direct contact with the focus ring to measure wear, then the degree of wear can be identified, but the focus ring may be damaged (e.g., scratched) by the physical contact
Solution Approach 1:
The patent replaces the mechanical contact measurement system with an optical measurement system. A light source emits light toward the focus ring, and a light receiving member detects the reflected or transmitted light. The wear amount is calculated based on changes in light intensity or pattern, eliminating physical contact between the measuring instrument and the focus ring, thus preventing damage while maintaining measurement accuracy.
Solution Approach 2:
The patent introduces light as an intermediary medium between the measurement system and the focus ring. Instead of direct mechanical contact, the measurement is performed by detecting optical properties (intensity, reflection, transmission) of light that interacts with the focus ring's surface. This intermediary approach allows wear measurement without transmitting mechanical forces that could damage the component.
2Ease of operation
If an operator directly opens the process chamber to identify the degree of wear, then the wear can be visually inspected, but it may be difficult to appropriately identify the degree of wear at the required time
Solution Approach 1:
The patent replaces manual visual inspection with an automated optical measurement system. The light source and light receiving member are positioned to automatically measure the focus ring's wear without requiring chamber opening or operator intervention. The system calculates wear amount based on optical signal changes, providing both ease of operation (automatic measurement) and precision (quantitative data).
Solution Approach 2:
The measurement system is designed to perform wear measurement automatically during or between etching processes without requiring external intervention. The system self-calibrates and self-measures by detecting optical property changes of the focus ring, enabling timely and accurate wear identification without operator involvement in the measurement process.
3Productivity
If the focus ring is etched together with the substrate through repeated etching processes, then the substrate can be processed, but the shape of the focus ring is gradually changed affecting etching characteristics
Solution Approach 1:
The patent implements a feedback mechanism where the optical measurement system continuously or periodically monitors the focus ring's wear during substrate processing. The measured wear data is fed back to the control system, which can alert operators or automatically adjust process parameters before the wear significantly affects etching characteristics. This feedback loop maintains process consistency while allowing high productivity by enabling timely focus ring replacement.
Solution Approach 2:
The measurement system detects focus ring wear in advance before it reaches critical levels that would compromise etching quality. By performing preliminary wear assessment during normal operation, the system allows for proactive focus ring replacement, ensuring etching process consistency is maintained throughout the substrate production run.
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 and non-damaging measurement of consumable component wear, ensuring timely replacement and maintaining etching process consistency without physical contact, thus preventing damage.
Implementation Method 1
a measurement unit that measures a degree of wear of the consumable component and has a light receiving member that receives light emitted in a horizontal direction
Data Source
AI summary
An apparatus for treating a substrate includes a process chamber having a process space, a support unit that supports the substrate in the process space, a lift pin module having a lift pin that moves a consumable component on the support unit in an up/down direction, and a measurement unit that measures a degree of wear of the consumable component and has a light receiving member that receives light emitted in a horizontal direction.