Sensor Chip Electrostatic Capacitance Directional Measurement
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Solution Overview
Problem
In plasma processing apparatuses, the non-uniform distance between the processing target object and the focus ring leads to non-uniform plasma distribution and local particle adhesion, requiring precise correction of coordinate information for the transfer device, which is challenging due to the influence of electrostatic capacitance in unintended directions.
Innovation Solution
A sensor chip with a specific electrode configuration, including a first, second, and third electrode, allows for high-directivity electrostatic capacitance measurement by isolating the third electrode to reflect capacitance only in the desired direction, enabling accurate measurement of the distance between the focus ring and the processing target object.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an electrostatic capacitance sensor is used to detect the position of the processing target object, then the position can be detected for coordinate correction, but the measurement accuracy is degraded due to electrostatic capacitance influence from unintended directions
Solution Approach 1:
The sensor chip employs electrodes with different shapes and arrangements at different locations to create direction-sensitive electrostatic capacitance measurement. The first electrode has a first shape configured to detect capacitance in a first direction, while the second electrode has a second shape configured to detect capacitance in a second direction perpendicular to the first direction, enabling selective measurement that eliminates interference from unintended directions
Solution Approach 2:
The sensor chip is divided into multiple independent electrode units (first electrode and second electrode) that can be independently configured and measured. This segmentation allows the system to separately measure electrostatic capacitance in different directions and process the measurements to eliminate interference, thereby improving position detection accuracy
2Manufacturing precision
If the distance between the processing target object and focus ring is non-uniform, then coordinate correction is required, but plasma distribution becomes non-uniform and particle adhesion occurs
Solution Approach 1:
The sensor chip measures the distance between the processing target object and focus ring before the actual plasma processing begins. This preliminary measurement allows the system to detect non-uniform distances and correct coordinate information in advance, preventing plasma distribution non-uniformity and particle adhesion during the processing step
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 configuration enables precise measurement of electrostatic capacitance in a specific direction, improving the accuracy of coordinate correction and ensuring uniform plasma distribution and reducing particle adhesion, thereby enhancing processing uniformity and efficiency.
Implementation Method 1
sensor chip for measuring electrostatic capacitance... the third electrode reflects electrostatic capacitance only in a direction in which a front face of the third electrode faces
Data Source
AI summary
Electrostatic capacitance can be measured with high directivity in a specific direction. A sensor chip that measures the electrostatic capacitance includes a first electrode, a second electrode and a third electrode. The first electrode has a first portion. The second electrode has a second portion extended on the first portion of the first electrode, and is insulated from the first electrode within the sensor chip. The third electrode has a front face extended in a direction which intersects with the first portion of the first electrode and the second portion of the second electrode, and is provided on the first portion and the second portion. The third electrode is insulated from the first electrode and the second electrode within the sensor chip. No portion is extended from the first electrode to be positioned above the first portion.