Sapphire Electrostatic Chuck Orientation for Stable Adsorption

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Sapphire electrostatic chucks face variability in adsorption force due to anisotropy, which depends on plane orientation, necessitating a solution for consistent and strong adsorption.

Innovation Solution

The electrostatic chuck design incorporates a plate-shaped body with an adsorption surface angled 45° or more relative to the c-plane of sapphire, utilizing sapphire's anisotropic properties to enhance adsorption force through increased dielectric constant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If sapphire is used as the electrostatic chuck material, then wear resistance and corrosion resistance are improved, but adsorption force consistency deteriorates due to anisotropy

Engineering Contradiction:

Improvewear resistanceVSAvoidadsorption force consistency

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent changes the crystal orientation parameter of sapphire from conventional c-plane (0°) to orientations where the angle between the adsorption surface and c-plane is 45° or more (such as a-plane, m-plane, or r-plane). This parameter change exploits sapphire's anisotropic properties to achieve both high wear resistance and consistent adsorption force, as these orientations have higher dielectric constants that provide more uniform electrostatic field distribution.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If conventional c-plane sapphire is used, then manufacturing is straightforward, but adsorption force varies depending on plane orientation

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidadsorption force uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent specifies using sapphire with crystal orientations where the angle between the adsorption surface and c-plane is 45° or more (a-plane, m-plane, or r-plane). These orientations, while requiring precise crystallographic control, provide superior adsorption force uniformity due to their higher and more isotropic dielectric constants, thereby achieving manufacturing precision in adsorption performance.

Inventive Principle:

Principle #35Parameter changes

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 angled design achieves a stronger and more consistent adsorption force, leveraging sapphire's high dielectric constant and mechanical properties for improved workpiece retention.

Implementation Method 1

an electrostatic chuck for adsorbing and holding a workpiece is used

Methodology Applied

Scientific EffectElectrostatic adsorption: Electrostatics

Implementation Method 2

utilizing sapphire's anisotropic properties to enhance adsorption force through increased dielectric constant

Methodology Applied

Scientific EffectDielectric constant: Dielectric Permittivity

Data Source

PatentUS12456640B2Electrostatic chuck

Publication Date: 2025.10.28 KYOCERA CORP

AI summary

An electrostatic chuck according to the present disclosure includes a plate-shaped body including an adsorption surface for mounting a workpiece, a base, and an electrode film located between the plate-shaped body and the base. The plate-shaped body and the base are made of sapphire. The angle between the adsorption surface and the c-plane of the sapphire is 45° or more.