Ceramic Electrostatic Chuck Structure for RF Breakdown Resistance

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Solution Overview

Problem

Traditional electrostatic chucks in substrate processing systems face issues with high RF voltage breakdown, thermal stress, and misalignment due to material differences between ceramic top plates and metal or composite metal baseplates, leading to limited operating ranges and control over RF voltages.

Innovation Solution

The electrostatic chuck design features both the top and baseplates made of ceramic materials with high purity levels, minimizing thermal expansion mismatches and eliminating the risk of high-voltage breakdown and coating cracking, thereby enhancing operational temperature ranges and RF voltage control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional metal or composite metal baseplates are used with ceramic top plates, then manufacturing ease and cost are improved, but thermal stress and misalignment occur due to material differences

Engineering Contradiction:

Improvebaseplate manufacturingVSAvoidthermal stress and alignment

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies homogeneity by making both the top plate and baseplate from ceramic materials with matching thermal expansion coefficients. This eliminates the material mismatch between traditional ceramic top plates and metal baseplates, preventing thermal stress and misalignment while maintaining manufacturing feasibility through standardized ceramic processing techniques.

Inventive Principle:

Principle #33Homogeneity

Solution Approach 2:

The patent uses composite ceramic structures where both top and base plates are made of ceramic materials bonded together. This composite approach resolves the contradiction by creating a thermally compatible composite structure that eliminates thermal stress issues while remaining manufacturable through established ceramic bonding processes.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If traditional metal or composite metal baseplates are used, then ease of manufacture is improved, but high-voltage breakdown and coating cracking risk increase

Engineering Contradiction:

Improvebaseplate manufacturingVSAvoidhigh-voltage breakdown and coating cracking

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

By using uniform ceramic materials for both top and base plates with identical or compatible dielectric properties, the patent eliminates the interface between dissimilar materials that causes high-voltage breakdown and coating cracking. This homogeneous ceramic construction maintains reliability while being manufacturable.

Inventive Principle:

Principle #33Homogeneity

3Adaptability or versatility

If ceramic top plates with metal or composite metal baseplates are used, then RF voltage control is limited, but if ceramic-to-ceramic configuration is used, then RF voltage control is improved

Engineering Contradiction:

ImproveRF voltage control rangeVSAvoidmaterial configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The homogeneous ceramic-to-ceramic construction provides consistent dielectric properties throughout the structure, enabling broader and more precise RF voltage control. This uniform material composition eliminates the electrical discontinuities present in ceramic-metal configurations, expanding the operational RF voltage range.

Inventive Principle:

Principle #33Homogeneity

4Reliability

If ceramic-to-ceramic configuration is used, then thermal stress and high-voltage breakdown risks are reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvethermal stress and breakdown resistanceVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the electrostatic chuck into separate ceramic top plate and baseplate components that are bonded together. This segmentation allows each component to be manufactured independently using optimized ceramic processing techniques, then assembled through reliable bonding methods, thereby managing manufacturing complexity while achieving superior reliability.

Inventive Principle:

Principle #1Segmentation

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 ceramic-to-ceramic configuration reduces thermal stress and high-voltage breakdown risks, allowing for increased operating temperature ranges and improved control over RF voltages, enabling more efficient substrate processing.

Implementation Method 1

The intermediate layer bonds the top plate to the baseplate

Methodology Applied

Scientific EffectBonding: Adhesive

Implementation Method 2

a top plate configured to electrostatically clamp to a substrate

Methodology Applied

Scientific EffectElectrostatic clamping: Electrostatics

Data Source

PatentUS11848177B2Multi-plate electrostatic chucks with ceramic baseplates

Publication Date: 2023.12.19 LAM RES CORP

AI summary

An electrostatic chuck for a substrate processing system is provided. The electrostatic chuck includes: a top plate configured to electrostatically clamp to a substrate and formed of ceramic; an intermediate layer disposed below the top plate; and a baseplate disposed below the intermediate layer and formed of ceramic. The intermediate layer bonds the top plate to the baseplate.