Electrostatic Chuck Surface Coating for Wear and Particle Control

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Solution Overview

Problem

Existing electrostatic chucks in semiconductor manufacturing lack sufficient hardness, density, and wear resistance, leading to particulate contamination and increased manufacturing costs.

Innovation Solution

A surface structure for electrostatic chucks comprising a substrate with a first protective coating and a second protective coating, where the second coating has higher hardness and lower porosity than the first, providing enhanced wear resistance and density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional thermal spraying techniques are used for surface treatment, then the manufacturing cost is reduced, but the coating density and hardness are insufficient

Engineering Contradiction:

Improvemanufacturing costVSAvoidcoating hardness

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent applies composite materials by combining two different protective coatings: a first protective coating (such as aluminum oxide) providing corrosion resistance and a second protective coating (such as titanium nitride) providing high hardness and wear resistance. This composite structure resolves the contradiction by achieving both cost-effectiveness and high performance through material combination rather than using a single expensive material throughout.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent implements local quality by applying different materials with different properties to different regions of the electrostatic chuck surface. The first protective coating is applied to areas requiring corrosion resistance, while the second protective coating with higher hardness is applied to areas requiring wear resistance. This localized approach optimizes both cost and performance by matching material properties to specific functional requirements.

Inventive Principle:

Principle #3Local quality

2Strength

If sintering techniques are used to increase hardness, then the coating hardness improves, but the manufacturing cost increases significantly

Engineering Contradiction:

Improvecoating hardnessVSAvoidmanufacturing cost

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by modifying the deposition parameters of the second protective coating to achieve high hardness without requiring sintering. By controlling deposition conditions such as plasma power, substrate temperature, and coating thickness (0.5-20 μm), the patent achieves hardness of 1000-1500 HV through physical vapor deposition alone, eliminating the need for expensive sintering processes while maintaining high hardness requirements.

Inventive Principle:

Principle #35Parameter changes

3Duration of action of moving object

If the electrostatic chuck surface is worn from frequent wafer loading and unloading, then the operational duration increases, but particulate matter adheres to wafer backside affecting yield

Engineering Contradiction:

Improveoperational durationVSAvoidparticulate contamination

Core Design Contradiction:

Duration of action of moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by providing a protective second coating layer that prevents wear before it occurs. This hard, low-porosity coating acts as a sacrificial barrier that protects the underlying substrate and first coating from wear during frequent wafer loading and unloading, thereby preventing particulate generation and contamination before the operational duration ends.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent applies the disposable principle by designing a thin second protective coating (0.5-20 μm) that is intended to wear gradually over time, protecting the more expensive substrate and first coating. This sacrificial layer can be replaced or re-deposited when worn, providing an economical solution to extend operational duration while maintaining low particulate contamination throughout its service life.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS20250191955A1Surface structure of an electrostatic chuck and method for forming the same

Publication Date: 2025.06.12 FEEDBACK TECH CORP

AI summary

The present invention relates to the surface structure of an electrostatic chuck used in semiconductor manufacturing processes. The surface structure comprises a substrate, a first protective coating disposed on the substrate, and a second protective coating disposed on the first protective coating. The first protective coating is deposited on the substrate and is made from materials selected from groups comprising metal oxides, fluorides, and nitrides. It serves as a universal protective barrier against wear, corrosion, and thermal effects. The second protective coating, which is deposited on the first protective coating, possesses a higher hardness than the first protective coating, thereby providing enhanced wear resistance. Additionally, the present invention offers a versatile and effective solution for improving the performance and lifespan of electrostatic chucks in semiconductor manufacturing.