Plasma Processing Filter Distributed Constant Line Noise Blocking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional plasma processing apparatuses face challenges in reliably and reproducibly blocking high-frequency noise, especially when dual frequency power is applied, leading to instability and reduced reproducibility in plasma processes, particularly at higher frequencies above 13.56 MHz.
Innovation Solution
The apparatus incorporates a filter with a single coil forming part of the power feed line and a tube-shaped outer conductor, creating a distributed constant line with regular multiple resonance frequencies, allowing for high impedance at specific frequencies to block high-frequency noise effectively, thereby stabilizing the power feed circuit and improving process reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional filter is used to block high frequency noise, then noise blocking function is provided, but stable and reproducible impedance characteristics cannot be achieved especially at frequencies above 13.56 MHz
Solution Approach 1:
The invention utilizes electromagnetic resonance (analogous to mechanical vibration principles) by designing the distributed constant line with specific electrical length to create resonance at target noise frequencies. This resonance produces high impedance that effectively blocks noise while providing stable and reproducible characteristics across multiple frequencies including those above 13.56 MHz
Solution Approach 2:
The invention changes the electrical parameters of the power feed line by transforming it into a distributed constant line with controlled characteristic impedance and specific electrical length. This parameter transformation enables the line to exhibit resonance at frequencies that are integer multiples of its fundamental resonant frequency, providing stable noise blocking across a broad frequency range
2Adaptability or versatility
If dual frequency power is applied for plasma control, then plasma process capability is improved, but high frequency noise enters the heater power supply causing operation failure
Solution Approach 1:
The distributed constant line acts as an intermediary element between the heater and the power feed line. It provides high impedance at resonance frequencies to block noise from reaching the heater power supply, while maintaining low impedance at the fundamental frequency to allow necessary power transmission. This intermediary function protects the heater power supply from noise-induced operation failures
Solution Approach 2:
The invention converts the harmful high frequency noise into a beneficial filtering mechanism by designing the distributed constant line to resonate at the noise frequencies. The noise frequencies themselves become the target frequencies for resonance-based filtering, transforming the harmful electromagnetic interference into the basis for effective noise blocking
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 configuration ensures stable and reproducible impedance characteristics, effectively blocking high-frequency noise across multiple frequencies, enhancing the reliability and reproducibility of plasma processes by providing sufficient impedance to high-frequency noise, thus protecting the power feed circuit and maintaining process stability.
Implementation Method 1
a distributed constant line that forms parallel resonance at multiple frequencies
Data Source
AI summary
A parallel resonance frequency can be adjusted in order to stably and securely block different high frequency noises flowing into a line such as a power feed line or a signal line from electric members including a high frequency electrode within a processing chamber. A filter 102(1) coaxially accommodates a coil 104(1) within a cylindrical outer conductor 110, and a ring member 122 is coaxially installed between the coil 104(1) and the outer conductor 110. The ring-shaped member 122 may be a plate body of a circular ring shape on a plane orthogonal to an axial direction of the outer conductor 110 and made of a conductor such as cupper or aluminum and electrically connected with the outer conductor 110 while electrically insulated from the coil 104(1).