Rotating Cleaning Plate Inducing Turbulent Flow for Showerhead Maintenance
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Solution Overview
Problem
In chemical vapor deposition processes, particularly for Group III-nitride semiconductor fabrication, the deposition of precursor materials on hot hardware components like showerheads leads to non-uniform flow distribution and reduced quality of processed substrates due to precursor breakdown and deposition on reactor surfaces.
Innovation Solution
A cleaning plate with a circular ring and central hub, featuring turbulence-inducing structures, is positioned adjacent to the showerhead, introducing a cleaning gas that is rotated to induce turbulent flow, increasing retention time and reducing concentration gradients, causing deposited material to react and be exhausted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cleaning gas is introduced into the processing chamber to remove deposited material from the showerhead, then the cleaning effectiveness is improved, but the cleaning gas flows too quickly across the showerhead surface, reducing retention time and cleaning efficiency
Solution Approach 1:
The cleaning plate is rotated during the cleaning process, creating mechanical motion that enhances mixing and increases the retention time of cleaning gas near the showerhead surface. This rotation also helps distribute the cleaning gas more uniformly across the showerhead, improving overall cleaning effectiveness without requiring increased gas flow rates.
Solution Approach 2:
Turbulence-inducing structures are incorporated into the cleaning plate to create turbulent flow patterns in the cleaning gas. This turbulence increases the retention time of cleaning gas near the showerhead by creating eddies and recirculation zones, allowing the cleaning gas to remain in contact with deposited material longer and improve cleaning efficiency.
2Productivity
If the cleaning gas flow rate is increased to improve cleaning speed, then the productivity is improved, but the concentration gradients within the cleaning gas increase, reducing cleaning uniformity
Solution Approach 1:
Rotation of the cleaning plate creates continuous motion that prevents stagnant zones and promotes uniform distribution of cleaning gas across the showerhead surface. This mechanical motion helps eliminate concentration gradients that would otherwise form with high-speed laminar flow, maintaining cleaning uniformity while enabling faster cleaning rates.
Solution Approach 2:
The turbulence-inducing structures on the cleaning plate create controlled turbulent flow that enhances mixing of the cleaning gas. This turbulence reduces concentration gradients by promoting more uniform gas distribution and increasing mass transfer rates, allowing for both high cleaning speed and uniform cleaning results.
3Productivity
If the showerhead operates for extended periods to increase throughput, then the productivity is improved, but deposited material accumulates on the showerhead, degrading flow distribution uniformity and substrate quality
Solution Approach 1:
The cleaning system is designed to be integrated into the existing MOCVD chamber without requiring external cleaning equipment or disassembly of the showerhead. The cleaning plate can be positioned and operated within the same chamber, allowing for quick in-situ cleaning that minimizes downtime and maintains high throughput while preventing degradation of flow distribution uniformity.
Solution Approach 2:
The cleaning process efficiently removes deposited material from the showerhead surface, restoring the original flow distribution characteristics. By regularly removing accumulated precursor material, the system maintains optimal performance and extends the operational intervals between cleanings, thereby improving overall productivity while preserving flow uniformity.
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 method efficiently removes deposited material from showerheads, enhancing cleaning efficiency, reducing downtime, and extending the interval between maintenance cleanings, thereby improving substrate quality and process throughput.
Implementation Method 1
The turbulence-inducing structures induce a turbulent flow of cleaning gas while the cleaning plate is rotated during a cleaning process
Implementation Method 2
A material deposited on the surface of the showerhead is then heated and reacts to form a volatile compound which is then exhausted from the processing chamber
Implementation Method 3
A material deposited on the surface of the showerhead is then heated and reacts to form a volatile compound
Data Source
AI summary
Embodiments of the invention generally relate to apparatus and methods for cleaning chamber components using a cleaning plate. The cleaning plate is adapted to be positioned on a substrate support during a cleaning process, and includes a plurality of turbulence-inducing structures. The turbulence-inducing structures induce a turbulent flow of cleaning gas while the cleaning plate is rotated during a cleaning process. The cleaning plate increases the retention time of the cleaning gas near the showerhead during cleaning. Additionally, the cleaning plate reduces concentration gradients within the cleaning plate to provide a more effective clean. The method includes positioning a cleaning plate adjacent to a showerhead, and introducing cleaning gas to the space between the showerhead and the cleaning plate. A material deposited on the surface of the showerhead is then heated and vaporized in the presence of the cleaning gas, and then exhausted from the processing chamber.