YAG Ceramic Body Plasma Resistance via Sintering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for producing sintered ceramic bodies with high purity, high density, and low porosity, particularly for yttrium aluminum oxide phases like YAG, face challenges such as difficulty in achieving phase purity, high mechanical strength, and resistance to corrosion and erosion in plasma etch environments, leading to contamination and yield loss in semiconductor processing.
Innovation Solution
A sintered ceramic body comprising 90-99.9% polycrystalline yttrium aluminum garnet (YAG) with controlled volumetric porosity and purity, fabricated using a method that includes combining yttrium oxide and aluminum oxide powders, calcination, and pressure-assisted sintering to achieve high density and low porosity, without the use of sintering aids, enabling the production of large dimension components with enhanced corrosion and erosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional sintering methods are used to produce yttrium aluminum oxide ceramic bodies, then high density is achieved, but significant volumetric porosity remains and phase purity deteriorates
Solution Approach 1:
The patent applies parameter changes by implementing a two-stage sintering process with specific temperature ranges and durations. The first stage (1400-1600°C for 2-6 hours) promotes phase formation while the second stage (1600-1800°C for 0.5-4 hours) achieves densification. This controlled parameter progression enables achieving >98% phase purity and >95% theoretical density without excessive grain growth or phase degradation that occurs with single-stage high-temperature sintering.
2Use of energy by moving object
If sintering aids are added to promote densification of yttrium aluminum oxide, then high density is achieved, but corrosion and erosion resistance deteriorates
Solution Approach 1:
The patent extracts and eliminates sintering aids from the composition entirely. By using only stoichiometric yttrium aluminum oxide powder without any additives, the invention achieves high density (>95% theoretical) through optimized sintering parameters alone. This removal of sintering aids preserves the intrinsic corrosion and erosion resistance of the yttrium aluminum oxide material, which would otherwise be degraded by impurity contamination from additive particles.
3Manufacturing precision
If prolonged sintering time is used to achieve high density, then volumetric porosity is reduced, but grain growth is exaggerated and mechanical strength decreases
Solution Approach 1:
The patent applies periodic action through a two-stage sintering process with distinct purposes and time durations. The first stage (1400-1600°C for 2-6 hours) focuses on phase formation and initial densification, while the second stage (1600-1800°C for 0.5-4 hours) completes densification. This time-limited, staged approach achieves <5% volumetric porosity while controlling grain growth to maintain mechanical strength, avoiding the excessive grain growth that occurs with prolonged single-stage sintering.
4Use of energy by moving object
If high sintering temperature is applied to reduce porosity, then density increases, but phase purity deteriorates due to phase transformations
Solution Approach 1:
The patent applies preliminary action by conducting the first sintering stage at 1400-1600°C for 2-6 hours to establish the correct phase composition and stoichiometry before applying the higher temperature second stage. This preliminary phase formation ensures that when the second stage (1600-1800°C) is applied for densification, the material already has the stable yttrium aluminum oxide phase structure that resists transformation, thereby maintaining phase purity (>98%) while achieving high density.
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 results in a ceramic body with improved resistance to corrosion and erosion, maintaining high purity and density, which reduces contamination and yield loss in semiconductor processing, and allows for the fabrication of large dimension components with enhanced mechanical strength and handling capabilities.
Implementation Method 1
a method that includes combining yttrium oxide and aluminum oxide powders, calcination, and pressure-assisted sintering to achieve high density and low porosity
Implementation Method 2
combining yttrium oxide and aluminum oxide powders, calcination, and pressure-assisted sintering
Data Source
AI summary
Disclosed herein is a sintered ceramic body comprising from 90% to 99.9% by volume of polycrystalline yttrium aluminum garnet (YAG) as measured using XRD and image processing methods and a volumetric porosity of from 0.1 to 4% as calculated from density measurements performed in accordance with ASTM B962-17. The sintered ceramic body may have a total purity of 99.99% and greater and a grain size of from 0.3 to 8 μm. A method of making the sintered ceramic body is also disclosed.