Showerhead Assembly With Tapered Apertures for Faster Gas Purging
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Solution Overview
Problem
Existing gas distribution systems in gas-phase reactors suffer from gas lingering on horizontal surfaces of the distribution plate, leading to increased purge time, vacuum requirements, film stress, particle generation, and poor film quality due to extended gas exposure.
Innovation Solution
The gas distribution system features apertures with tapered sections and a conduit design to minimize perpendicular surface area, facilitating uniform gas flow and reducing stagnation points, thereby enhancing gas purging efficiency and minimizing film stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional cylindrical apertures with horizontal surfaces are used, then gas distribution is simple, but gas lingers on horizontal surfaces causing extended purge time and vacuum requirements
Solution Approach 1:
The patent replaces traditional cylindrical apertures with tapered apertures that have curved surfaces instead of horizontal surfaces. The tapered geometry eliminates flat surfaces where gas can stagnate, allowing gas to flow through more efficiently and be purged faster from the distribution plate.
Solution Approach 2:
The patent changes the geometric parameters of the apertures from cylindrical to tapered configurations. By modifying the aperture shape parameters (introducing taper angles and eliminating horizontal surfaces), the gas flow characteristics improve, reducing purge time and vacuum requirements.
2Manufacturing precision
If gas flows over horizontal surfaces of the distribution plate, then gas distribution is straightforward, but film stress increases and film quality deteriorates
Solution Approach 1:
The tapered aperture design with curved surfaces prevents gas from lingering over horizontal surfaces, thereby eliminating the cause of film stress. Gas flows smoothly through the tapered passages without creating stress conditions that would degrade film quality.
Solution Approach 2:
By changing the aperture geometry from cylindrical to tapered, the gas flow parameters are optimized to prevent film stress. The modified aperture parameters ensure uniform gas distribution without creating the conditions that lead to stressed films and poor manufacturing quality.
3Object-generated harmful factors
If gas lingers on the distribution plate surface, then gas flow path is simple, but particle generation increases and vacuum pressure must be reduced
Solution Approach 1:
The tapered aperture design eliminates horizontal surfaces where gas can stagnate and decompose to form particles. The curved tapered geometry ensures continuous gas flow without stagnation zones, significantly reducing particle generation and maintaining better vacuum conditions.
Solution Approach 2:
By modifying the aperture parameters from cylindrical to tapered geometry, the gas residence time on the distribution plate is reduced. This parameter change prevents excessive gas decomposition that would generate particles and maintain acceptable vacuum pressure levels.
4Manufacturing precision
If extended gas exposure time occurs on the distribution surface, then gas delivery is simple, but precursor decomposition increases causing poor film quality
Solution Approach 1:
The tapered aperture geometry changes the gas flow parameters, reducing the residence time of gas on the distribution plate surface. This time parameter optimization prevents excessive precursor decomposition while maintaining adequate gas distribution, thereby improving film quality.
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 redesigned apertures reduce particle generation, decrease purge time, and improve film quality by allowing more processing runs between cleanings and reducing vacuum demands.
Implementation Method 1
gasses flow from the showerhead assembly in a downward direction toward the substrate and then radially outward over the substrate
Data Source
AI summary
Showerhead assemblies, gas distribution plates, and systems including the same are disclosed. Exemplary showerhead assemblies include a gas distribution plate. Exemplary gas distribution plates include apertures designed to direct a flow of gas and to reduce stagnation of gas on surfaces of the plates.