Plasma Power Matching Using Reflected-Wave Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In substrate processing for semiconductor device manufacturing, stable plasma generation is challenging when using multiple high-frequency power sources due to interference from differences in frequency, leading to noise and instability in the plasma process.
Innovation Solution
The technique involves a substrate processing apparatus with multiple plasma generators, each connected to a high-frequency power source with a matcher to match load impedances. Additionally, a high-frequency oscillator, directional coupler, filter, and power monitor are used to extract and filter noise signals, allowing for feedback control to reduce noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple high-frequency power sources are used for plasma generation, then plasma generation capability is improved, but frequency interference and noise increase causing instability
Solution Approach 1:
The system segments the plasma generation process by using multiple independent high-frequency power sources, each operating separately to contribute to overall plasma generation capability while maintaining individual control to minimize interference
Solution Approach 2:
The system implements feedback control by measuring the reflected wave component and using this information to adjust the matchers, thereby maintaining optimal impedance matching and reducing frequency interference effects that would otherwise cause plasma instability
Solution Approach 3:
The system dynamically changes the impedance parameters through adjustable matchers to compensate for frequency differences between multiple power sources, reducing noise and maintaining plasma stability despite operating multiple high-frequency sources simultaneously
2Power
If multiple high-frequency power sources operate simultaneously, then processing power increases, but frequency differences generate noise interfering with stable plasma generation
Solution Approach 1:
The system extracts and measures the reflected wave component separately from the main power transmission path, allowing independent analysis and compensation of noise signals without affecting the primary plasma generation process
Solution Approach 2:
The matcher acts as an intermediary device between the high-frequency power sources and the plasma generation region, mediating the impedance mismatch and frequency interference effects before they can significantly impact plasma stability
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 approach enables stable plasma generation even with multiple high-frequency power sources, improving the consistency and quality of substrate processing for semiconductor devices by reducing noise interference and maintaining plasma stability.
Implementation Method 1
a high-frequency oscillator configured to oscillate a high-frequency
Implementation Method 2
a directional coupler disposed at a subsequent stage of the high-frequency oscillator, and configured to extract a part of a traveling wave component from the high-frequency oscillator and a part of a reflected wave component from a corresponding matcher
Implementation Method 3
a filter configured to remove a noise signal included in the reflected wave component extracted by the directional coupler
Implementation Method 4
activating a process gas such as a precursor gas, a reaction gas, or the like, which is supplied into the process chamber, by using plasma
Implementation Method 5
a plurality of matchers installed between the plurality of high-frequency power sources and the plurality of plasma generators, and configured to respectively match load impedances of the plasma generators with output impedances of the high-frequency power sources
Data Source
AI summary
There is provided a technique that includes: high-frequency power sources supplying power to plasma generators; and matchers installed between the high-frequency power sources and the plasma generators and matching load impedances of the plasma generators with output impedances of the high-frequency power sources, wherein at least one of the high-frequency power sources includes: a high-frequency oscillator; a directional coupler at a subsequent stage of the high-frequency oscillator, which extracts a part of a traveling wave component from the high-frequency oscillator and a part of a reflected wave component from the matcher; a filter removing a noise signal in the reflected wave component extracted by the directional coupler; and a power monitor measuring the reflected wave component after passing through the filter and the traveling wave component extracted by the directional coupler and feedback-controlling the matcher to reduce a ratio between the reflected wave component and the traveling wave component.