Electrostatic Chuck Electrode Layout for Groove Discharge Prevention
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Solution Overview
Problem
Existing electrostatic chucks (ESCs) used in plasma processing experience abnormal discharge issues due to reduced dielectric strength and withstand voltage margin after wear and tear, leading to inefficient maintenance and reuse.
Innovation Solution
The ESC design incorporates a dielectric member with a substrate support surface and grooves, featuring electrode layer segments applied with high voltage, where at least one segment is positioned under areas without grooves, maintaining dielectric strength and preventing abnormal discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electrode layer segments are positioned under grooves to enable substrate support, then substrate support functionality is improved, but dielectric strength is reduced leading to abnormal discharge
Solution Approach 1:
The patent applies different electrode layer configurations to different regions of the dielectric member. Specifically, in regions where grooves are formed for substrate support, the electrode layer is positioned at a lower depth or omitted entirely, while in groove-free regions, the electrode layer extends closer to the upper surface. This local differentiation maintains dielectric strength in critical areas while preserving substrate support functionality in groove regions.
Solution Approach 2:
The electrode layer is divided into multiple electrode layer segments positioned at different depths and locations within the dielectric member. This segmentation allows certain segments to be positioned under grooves for substrate support while other segments are positioned in groove-free regions to maintain dielectric strength, thereby resolving the contradiction between support functionality and electrical reliability.
2Ease of repair
If ESC is used after wear and tear, then reuse is achieved, but abnormal discharge occurs due to reduced withstand voltage margin
Solution Approach 1:
The patent pre-configures the electrode layer segments at optimized positions before the ESC undergoes wear and tear. By positioning certain electrode segments in groove-free regions from the outset, the design anticipates future wear scenarios and ensures that dielectric strength is maintained even after extended use, thereby enabling safe maintenance and reuse.
Solution Approach 2:
The patent incorporates additional dielectric material or positions electrode segments deeper in certain regions to create a cushioning effect that compensates for future wear. This preliminary cushioning ensures that even after wear and tear reduces the overall dielectric thickness, the critical withstand voltage margin is maintained, preventing abnormal discharge during reuse.
3Force
If electrode layer is positioned closer to upper surface for effective clamping, then clamping force is improved, but dielectric strength is reduced causing abnormal discharge
Solution Approach 1:
The patent positions the electrode layer at different depths in different regions: in groove-free regions, the electrode layer extends closer to the upper surface to maximize clamping force, while in regions where grooves are present, the electrode layer is positioned deeper or omitted to maintain dielectric strength. This local differentiation resolves the contradiction between clamping force and electrical reliability.
Solution Approach 2:
The electrode layer is segmented into multiple portions at different depths. Upper segments are positioned closer to the surface in regions where this provides clamping benefit without compromising dielectric strength, while lower segments are positioned deeper in regions where dielectric strength is critical. This segmentation allows simultaneous optimization of both clamping force and dielectric strength.
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 enhances the maintenance and reuse of ESCs by reducing abnormal discharge and maintaining dielectric strength, ensuring effective substrate clamping and processing.
Implementation Method 1
maintaining dielectric strength and preventing abnormal discharge
Implementation Method 2
an electrode to which a voltage is applied to clamp and hold a substrate
Implementation Method 3
a high voltage applied to a bias electrode for drawing ion components in plasma to the substrate
Data Source
AI summary
An electrostatic chuck for supporting a substrate includes a dielectric member having a substrate support surface, a groove formed on an upper surface of the dielectric member, and a plurality of electrode layer segments to which a high voltage is applied. The plurality of electrode layer segments are located in the dielectric member. At least one electrode layer segment of the plurality of electrode layer segments is located under a portion of the upper surface of the dielectric member where the groove is not formed. None of the plurality of electrode layer segments is located at a position under the groove and higher than the at least one electrode layer segment.