Ceramic Gas Distribution Plate Embedded Electrode
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Solution Overview
Problem
Current ceramic gas distribution plates with embedded electrodes face challenges in high-temperature applications and chemical compatibility due to the limitations of the hot press manufacturing process, which is costly and lacks dimensional accuracy for precise machining of through holes.
Innovation Solution
A method involving ceramic green sheets, metal screen printing for electrode placement, and machining through holes before sintering, using materials like molybdenum or tungsten with matched thermal expansion coefficients, and incorporating radially arranged slot-shaped holes for improved gas distribution and plasma conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hot press manufacturing process is used to embed metal electrode in ceramic plate, then electrode embedding is achieved, but manufacturing cost and time increase significantly due to extensive machining and grinding required after sintering
Solution Approach 1:
The patent applies preliminary action by performing all machining operations (drilling and grinding through-holes) on the ceramic green body before sintering. This allows the through-holes to be created when the ceramic material is still soft and easily machinable, eliminating the need for costly and time-consuming post-sintering machining. The green body machining is followed by electrode embedding and then sintering, which locks the precisely positioned features in place.
2Reliability
If hot press manufacturing process is used to embed metal electrode in ceramic plate, then electrode embedding is achieved, but manufacturing cost increases due to expensive post-sintering grinding
Solution Approach 1:
The patent applies preliminary action by performing all machining operations (drilling and grinding through-holes) on the ceramic green body before sintering. This allows the through-holes to be created when the ceramic material is still soft and easily machinable, eliminating the need for costly and time-consuming post-sintering machining. The green body machining is followed by electrode embedding and then sintering, which locks the precisely positioned features in place.
3Reliability
If hot press manufacturing process is used to embed metal electrode in ceramic plate, then electrode embedding is achieved, but dimensional accuracy deteriorates due to limitations in setting horizontal and vertical location and planarity
Solution Approach 1:
The patent applies preliminary action by performing all machining operations (drilling and grinding through-holes) on the ceramic green body before sintering. This allows the through-holes to be created when the ceramic material is still soft and easily machinable, eliminating the need for costly and time-consuming post-sintering machining. The green body machining is followed by electrode embedding and then sintering, which locks the precisely positioned features in place.
Solution Approach 2:
The patent replaces the hot press mechanical embedding system with a green body machining and sintering system. Instead of using hot press to embed electrodes with limited dimensional control, the invention machines precise features into the green body, embeds electrodes with precise positioning, and then uses sintering to permanently lock the features in their exact positions. This substitution of the mechanical embedding process with a machining-plus-sintering process achieves superior dimensional accuracy.
4Temperature
If ceramic plate is used as gas distribution device, then high temperature and chemical compatibility are achieved, but CCP plasma generation capability is lost
Solution Approach 1:
The patent applies composite materials by creating a hybrid structure that combines ceramic and metal properties within a single integrated component. The ceramic body provides high-temperature resistance and chemical compatibility, while the embedded metal electrode provides electrical conductivity for CCP plasma generation. The through-holes penetrate both materials, enabling gas distribution through the ceramic while maintaining electrical continuity through the metal electrode, thus achieving both thermal/chemical stability and plasma generation capability simultaneously.
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 approach reduces manufacturing costs and time, enhances dimensional accuracy, and allows for the use of ceramic gas distribution plates in high-temperature CCP reactors with improved chemical resistance and precise gas distribution.
Implementation Method 1
printing an electrode on at least one of an upper surface of the ceramic lower portion and a lower surface of the ceramic upper portion using metal screen printing process
Implementation Method 2
sintering the ceramic upper portion and the ceramic lower portion to form the gas distribution plate
Implementation Method 3
The electrode is made of a material having a coefficient of thermal expansion that matches a coefficient of thermal expansion of the ceramic upper portion and the ceramic lower portion
Data Source
AI summary
A gas distribution plate for a substrate processing system includes a ceramic lower portion of the gas distribution plate including a plurality of ceramic green sheets. A ceramic upper portion of the gas distribution plate includes a plurality of ceramic green sheets. An electrode is printed on at least one of an upper surface of the ceramic lower portion and a lower surface of the ceramic upper portion using metal screen printing. A first plurality of through holes is machined through the ceramic lower portion and the ceramic upper portion of the gas distribution plate prior to sintering.