Edge Ring RF Amplitude Control via Variable Capacitor
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Solution Overview
Problem
Edge ring erosion in processing chambers leads to undesirable plasma processing characteristics at the substrate edges, reducing usable real estate and requiring frequent replacement, which is costly and causes downtime.
Innovation Solution
A substrate support with an electrostatic chuck, a ceramic layer, and a ring-shaped electrode embedded in the ceramic ring, coupled to a variable capacitor, allows adjustment of RF amplitude to reposition the plasma sheath and mitigate erosion effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the edge ring is used for extended processing, then productivity increases, but the edge ring erodes and plasma processing characteristics deteriorate
Solution Approach 1:
The patent applies the Dynamics principle by making the RF power to the edge ring adjustable and controllable. A control system monitors plasma parameters and dynamically adjusts the RF power level to the edge ring during processing, allowing the system to adapt to erosion while maintaining stable plasma characteristics and extending edge ring life.
Solution Approach 2:
The patent implementsParameter changes by varying the RF power parameter delivered to the edge ring. By changing the power level in response to detected plasma conditions or edge ring wear, the system maintains optimal processing characteristics while extending the operational life of the edge ring beyond traditional replacement intervals.
2Reliability
If the edge ring is replaced frequently to maintain processing quality, then plasma processing characteristics are maintained, but downtime and operational costs increase
Solution Approach 1:
The patent applies the Feedback principle by implementing a control system that continuously monitors plasma parameters and edge ring condition, then adjusts the RF power to the edge ring in real-time. This closed-loop feedback mechanism maintains processing quality without requiring frequent manual intervention or replacement, thereby reducing downtime.
Solution Approach 2:
The system implementsSelf-service by automatically adjusting the RF power to the edge ring based on monitored plasma conditions. The control system self-regulates the power distribution to compensate for edge ring erosion, eliminating the need for frequent manual replacements and reducing operational downtime.
3Reliability
If higher RF power is applied to the edge ring, then plasma sheath position is maintained, but edge ring erosion accelerates
Solution Approach 1:
The patent applies the Dynamics principle by implementing dynamic, real-time adjustment of RF power to the edge ring. Rather than using static high power, the system continuously adapts the power level based on plasma conditions and edge ring wear state, maintaining plasma sheath position while minimizing cumulative erosion damage.
Solution Approach 2:
The patent implementsParameter changes by varying the RF power parameter delivered to the edge ring based on monitored plasma conditions. By dynamically changing the power level rather than maintaining constant high power, the system maintains plasma sheath position while reducing the rate of erosion and extending edge ring operational life.
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
The solution extends the life of the edge ring by adjusting the plasma sheath, preventing undesirable processing effects and reducing the need for frequent replacements, thereby minimizing downtime and consumable costs.
Implementation Method 1
a variable capacitor coupled to the electrode through one or more transmission lines
Implementation Method 2
an electrostatic chuck having one or more chucking electrodes embedded therein for chucking a substrate to the electrostatic chuck
Implementation Method 3
an inductively coupled plasma apparatus positioned above the lid
Data Source
AI summary
The present disclosure generally relates to apparatuses and methods that control RF amplitude of an edge ring. The apparatuses and methods include an electrode that is coupled to ground through a variable capacitor. The electrode may be ring-shaped and embedded in a substrate support including an electrostatic chuck. The electrode may be positioned beneath the perimeter of a substrate and/or the edge ring. As the plasma sheath drops adjacent the edge ring due to edge ring erosion, the capacitance of the variable capacitor is adjusted in order to affect the RF amplitude near the edge of the substrate. Adjustment of the RF amplitude via the electrode and variable capacitor results in adjustment of the plasma sheath near the substrate perimeter.