Filter Unit Capacitance Adjustment for Plasma Uniformity
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Solution Overview
Problem
In plasma processing apparatuses, the difference in frequency characteristics between filter units connected to electrical members leads to non-uniform plasma distribution and reduced processing accuracy due to varying stray capacitance caused by size and layout constraints, making it difficult to maintain uniform frequency attenuation across heaters.
Innovation Solution
An adjustment method for filter units involving measurement and adjustment of frequency characteristics by attaching a capacitive member to adjust capacitance, ensuring that each filter unit's frequency characteristic matches a reference unit, thereby reducing resonance frequency deviations and improving plasma distribution uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filter units are connected to multiple electrical members in a plasma processing apparatus, then high frequency power can be removed from heaters, but differences in stray capacitance due to size and layout constraints cause non-uniform plasma distribution
Solution Approach 1:
The patent applies local quality by individually adjusting the capacitance of each filter unit to compensate for differences in stray capacitance caused by their specific locations and layouts. Each filter unit receives a customized capacitance value to achieve uniform frequency characteristics across all units, rather than using a uniform design for all filter units.
Solution Approach 2:
The patent changes the capacitance parameter of each filter unit individually to compensate for variations in stray capacitance. By adjusting the capacitance value of each filter unit based on its specific electrical characteristics and location, the system achieves uniform frequency characteristics despite differences in physical layout and size constraints.
2Manufacturing precision
If the stage is divided into multiple regions with independent heaters to improve temperature control accuracy, then temperature distribution control is enhanced, but more filter units are required increasing complexity
Solution Approach 1:
The patent manages the complexity of multiple filter units by applying parameter changes - specifically, individually adjusting the capacitance of each filter unit. This allows the system to handle multiple filter units required for multi-region temperature control while maintaining uniform frequency characteristics, thus managing the complexity through precise parameter optimization rather than structural simplification.
3Adaptability or versatility
If filter units with different stray capacitance are used due to layout constraints, then installation flexibility is improved, but frequency characteristic uniformity deteriorates
Solution Approach 1:
The patent resolves this contradiction by applying local quality - each filter unit is individually adjusted according to its specific location and stray capacitance characteristics. This allows the system to maintain installation flexibility with different layouts while achieving uniform frequency characteristics through localized capacitance adjustments for each filter unit.
Solution Approach 2:
The patent uses parameter changes by adjusting the capacitance value of each filter unit individually. This allows the system to accommodate different physical layouts and installation constraints while compensating for the resulting stray capacitance variations, thereby maintaining frequency characteristic uniformity despite installation flexibility.
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 method effectively reduces the difference in frequency characteristics among filter units, enhancing the uniformity of plasma distribution and processing accuracy by individually adjusting capacitance to match the reference unit's frequency characteristic.
Implementation Method 1
an attachment process of attaching a capacitive member for adjusting a capacitance between wirings in each of the remaining filter units; a second measurement process of measuring a frequency characteristic of each of the remaining filter units to which the capacitive member is attached
Implementation Method 2
a distributed constant type filter including a passive component such as a coil may be used
Data Source
AI summary
An adjustment method for filter units in a plasma processing apparatus includes a first measurement process of measuring a frequency characteristic of a reference filter unit selected among the filter units, and an adjustment process of adjusting a frequency characteristic of each of remaining filter units selected among the filter units excluding the reference filter unit. Further, the adjustment process includes an attachment process of attaching a capacitive member for adjusting a capacitance between wirings in each of the remaining filter units, a second measurement process of measuring a frequency characteristic of each of the remaining filter units to which the capacitive member is attached, and an individual adjustment process of adjusting a capacitance of the capacitive member such that the frequency characteristic of each of the remaining filter unit to which the capacitive member is attached becomes close to the frequency characteristic of the reference filter unit.