Multilayer YAG Chamber Components for Plasma Erosion Resistance
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Solution Overview
Problem
Current methods for producing ceramic sintered bodies with high purity, high density, and low porosity for use in plasma etch chambers are limited, leading to corrosion and erosion issues, and existing yttrium aluminum oxide components face challenges in achieving phase purity and mechanical strength, especially at larger dimensions.
Innovation Solution
A multilayer ceramic sintered body comprising polycrystalline yttrium aluminum garnet (YAG) with alumina and zirconia layers, where the zirconia is stabilized or partially stabilized, is used, with a controlled coefficient of thermal expansion to form a unitary body, achieving high purity and low porosity through spark plasma sintering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sintering methods are used to produce yttrium aluminum oxide components, then the components can be manufactured with existing processes, but the resulting components have significant volumetric porosity and reduced density leading to accelerated corrosion
Solution Approach 1:
The patent applies spark plasma sintering which uses pulsed direct current to generate localized plasma at particle contact points, enabling densification at lower temperatures (1400-1600°C) and shorter times (5-30 minutes) compared to traditional sintering. This parameter change in the sintering process achieves >99% theoretical density with minimal porosity, resolving the contradiction between manufacturability and density control.
Solution Approach 2:
The patent replaces traditional thermal conduction-based sintering with spark plasma sintering that uses electrical discharge and plasma generation. The electrical sparks create localized melting and rapid solidification at particle interfaces, achieving superior densification without the need for prolonged high-temperature exposure that causes grain growth and porosity.
2Manufacturing precision
If high temperatures and prolonged sintering durations are used to densify yttrium aluminum oxide, then density improves, but grain growth is exaggerated adversely affecting mechanical strength
Solution Approach 1:
The patent uses periodic pulsed electrical discharge in spark plasma sintering, where current is applied in short pulses (5-30 minutes) rather than continuous heating. This periodic action allows rapid densification during pulse intervals while preventing sustained high-temperature exposure that would cause excessive grain growth, thereby maintaining mechanical strength alongside high density.
Solution Approach 2:
The patent rushes through the sintering process by using intense localized energy from electrical sparks to achieve rapid densification in minutes rather than hours. This skipping of the prolonged high-temperature holding period that traditionally causes grain growth enables high density to be achieved without the adverse effects of extended thermal exposure.
3Manufacturing precision
If sintering aids are added to promote densification of yttrium aluminum oxide, then density improves, but corrosion and erosion resistance degrades and impurity contamination increases
Solution Approach 1:
The patent extracts or removes the need for sintering aids by using spark plasma sintering technology. The electrical discharge mechanism enables densification through direct particle bonding via localized melting and solidification, eliminating the requirement for additive materials that would compromise corrosion resistance and introduce impurities.
Solution Approach 2:
The patent introduces electrical energy and plasma as an intermediary mechanism to achieve densification without chemical additives. The electrical sparks act as a mediator that facilitates particle bonding through localized energy input, replacing the role of sintering aids while maintaining material purity and corrosion resistance.
4Reliability
If yttrium aluminum oxide components are used in plasma etch chambers, then corrosion resistance is achieved, but particle release from component surfaces contaminates wafers reducing yield
Solution Approach 1:
The patent achieves near-theoretical density (>99%) with minimal porosity through spark plasma sintering, creating a dense microstructure that eliminates void spaces where particles could detach. This pneumatic-level densification ensures that the corrosion-resistant surface remains intact without releasing particles during plasma etch operations.
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 solution provides enhanced corrosion resistance, mechanical strength, and reduced particle generation, enabling the production of large, phase-pure YAG components with improved etch resistance and handling capabilities for semiconductor processing.
Implementation Method 1
The green compact is placed in a mold and sintered by applying a pressure of from 50 to 200 MPa and a current of from 10 to 100 kA for a period of from 5 to 30 minutes at a temperature of from 1400° C. to 1600° C.
Implementation Method 2
sintered by applying a pressure of from 50 to 200 MPa and a current of from 10 to 100 kA for a period of from 5 to 30 minutes at a temperature of from 1400° C. to 1600° C.
Data Source
AI summary
Disclosed herein are plasma chamber components that comprise a ceramic sintered body comprising at least one first layer comprising a surface having a surface area and at least one crystalline phase of from 90% to 99.8% by volume of poly crystalline yttrium aluminum garnet (YAG), at least one second layer comprising alumina and zirconia wherein the zirconia comprises at least one of stabilized and partially stabilized zirconia, and optionally, at least one third layer comprising at least one selected from the group consisting of YAG, alumina, and zirconia.