High-Frequency Ceramic Polishing to Reduce Plasma Particles

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing ceramic components in semiconductor plasma processing chambers suffer from corrosion, erosion, and surface roughness issues, leading to contamination and yield loss due to poor inter-layer adhesion and high porosity of corrosion-resistant coatings, which are prone to cracking and flaking.

Innovation Solution

A method for polishing large-dimensioned sintered ceramic bodies to achieve a uniform surface smoothness of 2-1.5 microinches by grinding, lapping, and vibrational polishing with orbital sanders using grit particles of varying sizes, resulting in a polished surface with Ra and Rz values of ≤2 microinches and porosity of <0.045%, suitable for semiconductor devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If corrosion resistant coatings are deposited by vapor deposition or spray techniques, then corrosion resistance is improved, but inter-layer adhesion deteriorates and porosity increases

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidinter-layer adhesion

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces conventional vapor deposition and spray techniques with a mechanical polishing process using abrasive pads and slurries. This mechanical approach directly densifies the ceramic surface and creates strong inter-layer bonds through mechanical interlocking, eliminating the adhesion problems inherent in coating-based solutions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the surface treatment parameters from coating deposition to mechanical polishing with controlled abrasive particle sizes (from coarse to fine grit), polishing pressure, and slurry composition. These parameter changes enable progressive surface densification and smoothing that simultaneously improves both corrosion resistance and inter-layer adhesion.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If chamber components are exposed to plasma processing environment, then semiconductor processing is enabled, but surface corrosion and erosion occur

Engineering Contradiction:

Improvesemiconductor processing capabilityVSAvoidsurface corrosion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary mechanical polishing and surface densification treatments before the ceramic components are exposed to the plasma processing environment. By pre-densifying the surface and removing porous structures through controlled abrasive polishing, the components are prepared to resist subsequent plasma corrosion and erosion, reducing particle generation during semiconductor processing.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If surface roughness is reduced to improve corrosion resistance, then component lifetime is extended, but manufacturing complexity increases

Engineering Contradiction:

Improvecomponent lifetimeVSAvoidpolishing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the polishing process into multiple sequential stages, each using progressively finer abrasive grit sizes. This segmentation allows systematic reduction of surface roughness from coarse to fine levels, with each stage removing defects introduced by the previous stage. The multi-stage approach makes the complex polishing process manageable and controllable while achieving the required surface quality for extended component lifetime.

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

The method produces highly polished ceramic surfaces with enhanced mechanical strength and corrosion resistance, reducing particle generation and extending component lifetime in harsh plasma environments.

Implementation Method 1

a device comprising a plurality of orbital sanders that vibrate elliptically each of which comprises a polishing pad

Methodology Applied

Scientific EffectVibration: Vibration

Implementation Method 2

polishing the at least one surface in a series of polishing steps... wherein the polishing is performed with a device comprising a plurality of orbital sanders

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS20250222558A1High frequency polishing of ceramics

Publication Date: 2025.07.10 HERAEUS CONAMIC NORTH AMERICA LLC

AI summary

A method of polishing a surface of a polycrystalline sintered ceramic body, the method comprising the steps of: a) providing a sintered ceramic body comprising a polycrystalline material and having a density of from about 99.5% to about 99.999% of the polycrystalline material's theoretical density, wherein the sintered ceramic body has at least one surface; b) grinding the at least one surface until the surface has (I) a flatness of no more than 25 microns on average measured over four quadrants of the at least one surface at angles of 0°, 90°, 180°, and 270° as measured with a spherometer, (ii) an Ra of less than 14 microinches, and (iii) an Rz of less than 160 microinches; c) after the grinding step, lapping the at least one surface with a lapping plate and a lapping media slurry; d) after lapping, successively polishing the at least one surface.