Plasma Process Abnormality Detection After Plasma Switching
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Solution Overview
Problem
Conventional plasma processing apparatuses fail to accurately detect abnormalities during a period immediately after switching between processing with different plasmas due to ignore times, leading to potential damage to the apparatus and substrate.
Innovation Solution
Implement an abnormality detection system that utilizes specific parameters, including voltage and current applied to the electrostatic chuck electrode, without considering chamber pressure during a predetermined period after plasma switching, and incorporates pressure monitoring during other times to enhance detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If abnormality detection is performed using all parameters including chamber pressure, then detection comprehensiveness is improved, but false positives increase during ignore time after plasma switching
Solution Approach 1:
The abnormality detection function is segmented into two distinct modes: during ignore time, only electrostatic chuck electrode parameters (voltage, current) are monitored; during normal operation, chamber pressure parameters are also included. This segmentation prevents false positives during plasma switching while maintaining comprehensive detection during stable operation.
Solution Approach 2:
The detection system dynamically adjusts which parameters are monitored based on the operational phase. The control unit determines whether the system is in ignore time or normal operation, and accordingly activates different detection parameter sets. This dynamic adaptation optimizes detection accuracy while minimizing false alarms.
2Stability of the object's composition
If ignore time is provided after plasma switching, then system stability is improved, but abnormality detection capability deteriorates
Solution Approach 1:
The monitoring system is divided into two operational segments: during ignore time, a restricted parameter set is monitored to avoid false detections; during normal operation, the full parameter set is monitored for comprehensive abnormality detection. This allows ignore time to be provided for system stability without permanently compromising detection capability.
Solution Approach 2:
The control unit preliminarily determines whether the system is in ignore time before performing abnormality detection. This preliminary assessment allows the system to temporarily adjust detection parameters during the ignore period, preventing false positives while maintaining the ability to detect true abnormalities once the ignore time expires.
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
Improves the accuracy of abnormality detection by reducing false positives during ignore times, effectively protecting the apparatus and substrate from damage.
Implementation Method 1
an electrostatic chuck system disposed inside the stage and having an electrostatic chuck electrode that, when applied with a voltage, chucks the substrate to the stage
Implementation Method 2
a plasma generation unit that, when applied with a high-frequency power, generates a first plasma and a second plasma in the chamber
Data Source
AI summary
A plasma processing apparatus includes an ESC system having an ESC electrode, a plasma generator generating first and second plasma, a controller controlling the ESC system and the plasma generator such that a first or second processing with the first or second processing is performed on a substrate chucked to a stage, and an abnormality detector detecting abnormality, based on a plurality of parameters. The abnormality detector performs an abnormality detection during predetermined period DT immediately after switching between the first processing and the second processing, based on a first parameter including a monitoring information related to voltage V and/or current I applied to the ESC electrode and does not include a monitoring information related to pressure PR within a chamber, and performs an abnormality detection during a predetermined period outside predetermined period DT, based on a second parameter including the monitoring information related to pressure PR within the chamber.