Plasma Power Supply Waveform Transition Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma processing technologies face instability due to fluctuations in high frequency power supply, leading to impedance matching issues and unstable plasma states.
Innovation Solution
A plasma processing apparatus with a power supply method that stepwise or continuously changes the low levels of high frequency power waveforms during transition periods, maintaining synchronized or offset control of duty ratios to stabilize plasma conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high frequency power is supplied with pulse waves having fixed high and low levels, then plasma generation is enabled, but plasma instability occurs due to load fluctuations and impedance matching issues
Solution Approach 1:
The patent applies dynamics by making the low level of the pulse wave adjustable rather than fixed. The control unit dynamically changes the low level from an initial value to a target value based on plasma state detection, allowing the system to adapt to varying plasma conditions and maintain stability while facilitating impedance matching.
Solution Approach 2:
The patent implements parameter changes by modifying the low level parameter of the pulse wave supplied to the plasma. By changing this parameter from an initial value to a target value based on detected plasma state, the system optimizes plasma stability and impedance matching without altering the fundamental pulse wave structure.
2Reliability
If the low level of pulse wave is fixed, then power supply control is simple, but plasma state cannot be stabilized due to load fluctuations
Solution Approach 1:
The patent implements feedback by detecting the plasma state and using this information to control the adjustment of the pulse wave's low level. The control unit continuously monitors plasma conditions and adjusts the low level accordingly, creating a closed-loop system that stabilizes plasma while managing complexity through intelligent control.
Solution Approach 2:
The system transitions from static to dynamic control by making the low level adjustable based on real-time plasma state detection. This dynamic adjustment capability enables plasma stabilization while the control unit manages the complexity through automated decision-making algorithms.
3Adaptability or versatility
If continuous wave power is used, then plasma generation is stable, but flexibility in plasma process control is reduced
Solution Approach 1:
The patent employs periodic action by using pulse waves instead of continuous waves to supply power to the plasma. The pulse wave structure with adjustable low levels provides periodic on-off cycling that enables both plasma generation and flexible process control, overcoming the limitations of continuous wave operation.
Solution Approach 2:
By making the pulse wave's low level dynamically adjustable, the system gains the flexibility of periodic action while maintaining plasma stability. The ability to change the low level from initial to target values based on plasma state provides adaptability without sacrificing reliability.
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 reduces plasma load fluctuations and maintains plasma stability by adjusting power levels in the low sections of high frequency power waveforms, ensuring consistent plasma processing.
Implementation Method 1
a first high frequency power source that is connected to the first electrode; and a second high frequency power source that is connected to the first electrode or the second electrode
Implementation Method 2
a process chamber; a mounting stage that is arranged within the process chamber
Data Source
AI summary
A plasma processing apparatus includes a process chamber; a mounting stage; first and second electrodes; first and second high frequency power sources, wherein the first power source supplies a waveform of one of a first pulse wave having high and low levels of first high frequency power or a continuous wave in the first period, supplies a waveform of the other in the second period, and stepwise or continuously changes the low level of the first pulse wave in the transition period, wherein the second power source supplies a waveform of one of a second pulse wave having high and low levels of second high frequency power or a continuous wave in the first period, supplies a waveform of the other in the second period, and stepwise or continuously changes the low level of the second pulse wave in the transition period.