Substrate Gap Feedback Control for Uniform Plasma Processing
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Solution Overview
Problem
The challenge in substrate processing is maintaining a consistent gap between the substrate and the dielectric plate due to variations in substrate thickness and deformation, leading to processing uniformity issues.
Innovation Solution
A substrate processing apparatus with a gap measurement unit and controller that adjusts the gap between the substrate and dielectric plate using a driver, allowing for precise gap control during and between plasma generation periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the height of the lower electrode or dielectric plate is adjusted to match the gap to the process recipe, then the gap can be initially set correctly, but the actual gap may not match due to substrate thickness variation and deformation
Solution Approach 1:
The system performs preliminary gap measurement and adjustment before the etching process begins. The controller measures the actual gap between the substrate and dielectric plate using a sensor, and adjusts the lower electrode height accordingly to ensure the gap matches the process recipe requirements before plasma generation starts.
Solution Approach 2:
The system implements continuous feedback control by measuring the actual gap during the process and automatically adjusting the lower electrode height to maintain the desired gap. The controller receives gap measurement data and sends correction signals to the driver to maintain processing uniformity throughout the etching process.
2Reliability
If the gap is adjusted dynamically during plasma generation, then processing uniformity can be maintained, but the system complexity increases
Solution Approach 1:
The controller continuously receives gap measurement feedback during plasma generation and automatically adjusts the lower electrode height to maintain the desired gap. This closed-loop feedback system ensures processing uniformity is maintained throughout the etching process despite substrate deformation or thickness variations.
Solution Approach 2:
The system performs self-adjustment by automatically correcting the gap based on real-time measurements without requiring manual intervention. The controller autonomously sends correction signals to the driver to maintain the optimal gap, enabling the system to self-correct for substrate variations during processing.
3Manufacturing precision
If the lower electrode height is adjusted frequently to compensate for substrate variations, then gap consistency improves, but processing time increases
Solution Approach 1:
The system performs gap measurement and adjustment in advance before the etching process begins, ensuring the gap is correctly set before plasma generation starts. This preliminary adjustment prevents the need for frequent interruptions during processing, maintaining both precision and efficiency.
Solution Approach 2:
The gap adjustment is performed continuously and automatically during the process setup and execution without interrupting the main etching operation. The controller continuously monitors and adjusts the gap while the process runs, ensuring continuous useful action without stopping for manual recalibration.
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
Ensures efficient and uniform processing by maintaining a desired gap, enhancing processing consistency and stability.
Implementation Method 1
a high frequency power source for generating plasma in the processing space
Implementation Method 2
Plasma refers to an ionized gas state formed of ions, radicals, electrons, and the like, and is generated by a very high temperature, strong electric fields, or RF electromagnetic fields
Data Source
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AI summary
Provided is a control method of a substrate processing apparatus, the control method including: a chuck moving operation of placing the substrate on a lower electrode and moving the lower electrode to a pre-set height; a gap measuring operation of measuring a gap between a top surface of the substrate and a dielectric plate positioned above the lower electrode; a correction determining operation of comparing the gap measured in the gap measuring operation with a pre-memorized process recipe to determine whether a correcting operation to correct the gap is necessary; and a correcting operation of moving the lower electrode so that the gap is consistent with the process recipe when it is determined that the correcting operation is necessary.