Electrostatic Chuck Edge Curvature for Particle and Discharge Control

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Solution Overview

Problem

The enlargement of the electrostatic adsorption electrode in electrostatic chuck members leads to a decrease in adsorption force uniformity across the wafer surface, increasing the likelihood of charged foreign particles being electrostatically adsorbed to the side surfaces, which causes abnormal discharge and reduces productivity.

Innovation Solution

The electrostatic chuck member features a side peripheral surface with a first and second curved surface in the circumferential direction, an inclined surface between them, and specific curvature radii to disperse the electrostatic field, reducing the attachment of charged foreign particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the electrostatic adsorption electrode is enlarged, then the adsorption force uniformity across the wafer surface is improved, but the field intensity at the side surface increases causing more charged foreign particles to be electrostatically adsorbed

Engineering Contradiction:

Improveadsorption force uniformityVSAvoidcharged foreign particle attachment

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The side peripheral surface is designed with a curved shape instead of a flat surface. The curvature radius is specifically set to be 0.5 mm to 5 mm to disperse the electrostatic field concentration at the side surface, reducing the attachment of charged foreign particles while maintaining the enlarged electrode area for uniform adsorption.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The curvature radius of the side peripheral surface is optimized within a specific range (0.5 mm to 5 mm) to control the electrostatic field distribution. This parameter change allows the electrode to maintain both large area for uniform adsorption and reduced field intensity at the side surface to minimize particle attachment.

Inventive Principle:

Principle #35Parameter changes

2Area of stationary object

If the electrostatic adsorption electrode is enlarged, then the processing area is increased, but the distance between the side surface and the electrode decreases increasing field intensity

Engineering Contradiction:

Improveelectrode areaVSAvoidfield intensity at side surface

Core Design Contradiction:

Area of stationary objectVSStress or pressure

Solution Approach 1:

By curving the side peripheral surface with a specific radius (0.5 mm to 5 mm), the geometry is modified to reduce electric field concentration at the side surface while preserving the enlarged electrode area, thus maintaining both large processing area and reduced field intensity.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Ease of manufacture

If an inclined portion is provided in the periphery to improve plasma cleaning effect, then the cleaning effectiveness is improved, but the attachment of charged foreign particles to the side surface during manufacturing process is not suppressed

Engineering Contradiction:

Improveplasma cleaning effectivenessVSAvoidcharged foreign particle attachment during processing

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The curved side peripheral surface with optimized curvature radius (0.5 mm to 5 mm) provides both effective plasma cleaning access and reduced electrostatic field concentration, simultaneously achieving cleaning effectiveness and suppression of charged particle attachment during processing.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 design effectively suppresses the attachment of charged foreign particles and abnormal discharge, enhancing semiconductor chip yield and productivity by dispersing the electrostatic field and reducing the surface area for particle attachment.

Implementation Method 1

an electrostatic adsorption electrode which is provided on a side opposite to the placement surface or in the base body

Methodology Applied

Scientific EffectElectrostatic adsorption: Electrostatic Induction

Implementation Method 2

a side peripheral surface which is continuous to the placement surface in the base body includes at least a first curved surface which is a convex surface and is provided in a circumferential direction in a peripheral portion of the placement surface

Methodology Applied

Scientific EffectElectrostatic field dispersion: Electric Field

Data Source

PatentUS20260040882A1Electrostatic chuck member, electrostatic chuck device, and method for manufacturing electrostatic chuck member

Publication Date: 2026.02.05 SUMITOMO OSAKA CEMENT CO LTD

AI summary

An electrostatic chuck member includes: a base body wherein one main surface thereof is a placement surface on which a plate-shaped sample is placed; and an electrostatic adsorption electrode provided on a side opposite to the placement surface or in the base body, in which a side peripheral surface that is continuous to the placement surface in the base body includes at least a first curved surface that is a convex surface and is provided in a circumferential direction in a peripheral portion of the placement surface and a second curved surface that is provided in the circumferential direction at a different height position from the first curved surface.