Electrostatic Chuck Polarity Switching for Edge Ring Attraction
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Solution Overview
Problem
The decrease in attraction force of the edge ring due to charge migration during plasma treatment in plasma processing apparatuses, which requires optimization of voltage polarity switching timing and cycle, necessitating significant man-hours.
Innovation Solution
Applying voltages to electrodes in the substrate support with reversed polarities for each process cycle to maintain the attraction force of the edge ring, using a controller to manage voltage polarity changes based on process cycles or wafer exchanges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage polarity is switched periodically during plasma treatment, then charge migration is suppressed and attraction force is maintained, but optimization of switching timing and cycle requires significant man-hours
Solution Approach 1:
The patent applies periodic voltage polarity switching to the electrode in the substrate support during plasma treatment. By alternating the voltage polarity at regular intervals, the patent prevents charge accumulation and migration that would otherwise occur with continuous single-polarity voltage application, thereby maintaining stable attraction force on the edge ring throughout the plasma processing cycle.
2Force
If voltage is applied to electrode to attract edge ring, then attraction force is generated, but charge migration occurs and attraction force decreases
Solution Approach 1:
The patent inverts the voltage polarity applied to the electrode periodically during plasma treatment. Instead of maintaining a constant positive or negative voltage, the system switches between positive and negative polarities. This inversion approach counteracts charge migration by periodically reversing the electric field direction, preventing charge accumulation that would otherwise reduce attraction force over time.
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
Maintains the attraction force of the edge ring, reducing heat transfer gas leakage and maintaining plasma treatment efficiency by canceling charge migration, thus stabilizing processing characteristics.
Implementation Method 1
an electrode is disposed in a substrate support, on which a focus ring is placed, to face the focus ring, and a voltage is applied to the electrode while periodically switching the polarity of the voltage during plasma treatment
Data Source
AI summary
An electrostatic attraction method is provided. In the electrostatic attraction method, voltages are applied to one or more electrodes disposed in a substrate support while reversing the polarities of the voltages for each process cycle for plasma treatment. The one or more electrodes are disposed in the substrate support at at least a position corresponding to a ring member placed on the substrate support to surround a substrate serving as a plasma treatment target placed on the substrate support.