Capacitance Electrode Layout for Edge Ring Deviation Measurement
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Solution Overview
Problem
Existing measuring devices struggle to accurately determine the deviation amount between the center of an edge ring and the center of the measuring device in plasma processing apparatuses.
Innovation Solution
A measuring device with four or more sensor electrodes arranged at equal intervals along its peripheral edge measures capacitances with an object to identify sensor electrodes that satisfy a reliability standard, allowing for accurate calculation of the deviation amount based on these measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If capacitance measurement is used to determine deviation amount, then positioning information can be obtained, but measurement accuracy is insufficient
Solution Approach 1:
The measuring device is divided into multiple sensor electrodes (four or more) arranged circumferentially around the peripheral edge. Each sensor electrode independently measures capacitance to the edge ring, allowing segmentation of the measurement function across multiple sensing points rather than relying on a single measurement location.
Solution Approach 2:
Different sensor electrodes are positioned at different locations around the periphery to capture local capacitance variations. By selecting sensor electrodes based on local measurement quality (capacitance values meeting reliability standards), the system ensures accurate deviation calculation from reliable local measurements.
2Reliability
If all sensor electrodes are used for measurement, then more data is available, but measurement reliability decreases due to noisy data
Solution Approach 1:
Instead of using all sensor electrodes uniformly, the system selectively uses only those sensor electrodes whose capacitance measurements meet predetermined reliability standards. This partial action approach filters out noisy or unreliable measurements while retaining sufficient data for accurate deviation calculation.
Solution Approach 2:
The system evaluates capacitance measurement values from each sensor electrode against reliability standards and uses this feedback to determine which sensor electrodes to include in the deviation calculation. This feedback mechanism ensures that only reliable measurements contribute to the final deviation amount.
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 solution enables precise measurement of the deviation amount by identifying reliable sensor electrodes, thereby enhancing the accuracy of the center position alignment between the measuring device and the edge ring.
Implementation Method 1
measuring device includes a disc-shaped base substrate, and four or more sensor electrodes arranged at equal intervals along a peripheral edge of the base substrate in a circumferential direction and configured to measure measurement values indicating capacitances between the four or more sensor electrodes and an object disposed at a lateral side
Data Source
AI summary
There is a method for measuring a deviation amount of a measuring device, comprising: transferring, by using a transfer device, the measuring device to a position in an area specified by transfer position data; acquiring measurement values using four or more sensor electrodes of the measuring device; identifying two or more sensor electrodes among the four or more sensor electrodes, the two or more sensor electrodes outputting, as the measurement values, capacitances that satisfy a reliability standard; and calculating the deviation amount based on the measurement values of the identified two or more sensor electrodes.