Plasma Electrode Consumption Measurement via RF Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current plasma processing apparatuses face challenges in accurately measuring the consumption amount of upper electrodes, leading to productivity deterioration and impaired uniformity due to the need for chamber opening or unreliable estimation methods.
Innovation Solution
A plasma processing apparatus equipped with a power application unit that applies RF power without igniting plasma, allowing for the measurement of physical quantities which are used to calculate the inter-electrode distance and subsequently determine the consumption amount of the upper electrode, using a correlation function between RF power and inter-electrode distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the chamber is opened to measure electrode consumption, then measurement accuracy is improved, but productivity deteriorates and uniformity is impaired
Solution Approach 1:
The patent replaces the mechanical approach of opening the chamber with a electromagnetic field-based measurement system. RF power is applied to the electrode, and the resulting physical quantities (current, voltage, impedance) are measured to calculate consumption amount, eliminating the need for physical chamber opening and mechanical measurement tools.
Solution Approach 2:
The patent introduces RF power as an intermediary to indirectly measure electrode consumption. Instead of directly measuring the electrode dimension, the system uses RF power application to create measurable physical quantity changes that correlate with consumption, allowing indirect measurement without chamber opening.
2Productivity
If estimation methods are used to determine electrode consumption, then productivity is maintained, but measurement accuracy deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where physical quantities measured during RF power application are continuously monitored and used to calculate electrode consumption amount. This closed-loop approach provides accurate, real-time consumption data that feeds back into the control system, replacing unreliable open-loop estimation methods.
Solution Approach 2:
The patent changes the measurement parameters from indirect estimation to direct physical quantity measurement. By measuring current, voltage, or impedance changes when RF power is applied, the system transforms the consumption measurement from a theoretical estimation into a quantifiable physical measurement, significantly improving accuracy while maintaining productivity.
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 measurement of the upper electrode consumption amount without opening the chamber, improving productivity and uniformity by providing reliable control over the consumption amount, thus addressing the limitations of existing methods.
Implementation Method 1
A power application unit configured to apply a RF power to any one of the first electrode or the second electrode without igniting plasma
Data Source
AI summary
A plasma processing apparatus 100 is equipped with a shower head 16 and a placing table 2 facing each other. A first RF power supply 10a is configured to apply a RF power to any one of the shower head 16 or the placing table 2 without igniting plasma. A measuring device 204 is configured to measure a physical quantity of the RF power applied by the first RF power supply 10a. A process controller 91 is configured to acquire an inter-electrode distance by using the measured physical quantity of the RF power in a correlation function of the inter-electrode distance and the physical quantity of the RF power.