Gas Distributor Pre-Chambers Homogeneous CVD Flow
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Solution Overview
Problem
Existing gas distributors in CVD reactors face issues with non-homogeneous gas distribution, leading to premature reactions, contamination, and reduced efficiency due to narrow flow cross-sections and increased pressure drops, making them unsuitable for large substrates and difficult to maintain.
Innovation Solution
The gas distributor design features radial and circumferential distribution of gases through pre-chambers and gas distributing chambers connected by channels, ensuring temperature homogeneity and minimizing pressure drop, with gases exiting through multiple outlet openings at the bottom, allowing for precise control of gas flow and dwell time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple feed-through pipes are used to supply gas to large substrates, then gas distribution coverage is improved, but pressure drop increases and device complexity increases
Solution Approach 1:
The gas distributor is divided into multiple gas volumes (first gas volume, second gas volume, etc.) that can be independently supplied with different process gases. Each gas volume has its own supply line opening, allowing gas to be introduced at multiple locations rather than through multiple feed-through pipes crossing chamber walls. This segmentation reduces pressure drop while maintaining coverage for large substrates.
Solution Approach 2:
Instead of adding more feed-through pipes in the vertical dimension (which increases pressure drop), the patent distributes supply line openings across multiple horizontal planes (first plane, second plane, etc.). This dimensional transition allows gas to be supplied from multiple levels, improving coverage without increasing pressure loss.
2Area of stationary object
If multiple feed-through pipes are used to supply gas to large substrates, then gas distribution coverage is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The gas distributor is segmented into multiple gas volumes with supply line openings at different locations. This allows the structure to be manufactured as a single integrated component rather than assembling multiple feed-through pipes, simplifying manufacturing while maintaining the ability to supply large substrates effectively.
Solution Approach 2:
The gas distributor structure serves multiple functions: it distributes gas to large substrates, maintains gastight seals, and provides multiple supply points without requiring separate feed-through pipes for each supply line. The integrated design with supply line openings at various planes achieves coverage for large substrates while simplifying manufacturing.
3Quantity of substance
If gas volumes are disposed one above another extending over entire cross-sectional area, then gas distribution is achieved, but non-homogeneous gas flow occurs
Solution Approach 1:
Each gas volume is supplied with process gas at its specific location through supply line openings positioned at different planes. This local supply approach ensures that each gas volume receives appropriate gas flow independently, preventing non-homogeneous flow patterns that would occur with centralized feed-through pipes and creating more uniform gas distribution throughout the chamber.
4Manufacturing precision
If precursors are mixed early before introduction into reaction chamber, then deposition homogeneity is improved, but premature reactions and contamination occur
Solution Approach 1:
Different process gases including precursors are supplied separately into different gas volumes (first gas volume, second gas volume, etc.) that are spatially separated. This prevents premature mixing and reactions upstream of the substrate. The gases are distributed homogeneously only when they reach the substrate level, avoiding contamination and particle formation while still achieving uniform layer deposition.
Solution Approach 2:
The gas distributor acts as an intermediary structure that separately transports different process gases through dedicated gas volumes and supply lines. This intermediary system maintains separation of precursors and reactive gases until they reach the substrate, preventing harmful premature reactions while ensuring homogeneous mixing occurs at the deposition interface.
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 design achieves homogeneous gas distribution with reduced pressure drop and temperature non-homogeneity, enhancing the deposition of layers on substrates with improved uniformity and scalability for larger substrates, while maintaining efficiency and ease of maintenance.
Implementation Method 1
gases are distributed in a radial direction in a first plane and then distributed in a circumferential direction in a second plane, lying under said first plane
Implementation Method 2
minimizing pressure drops
Implementation Method 3
ensuring temperature homogeneity
Implementation Method 4
stable precursor and reactive gas mixing
Implementation Method 5
gases are distributed in a radial direction in a first plane and then distributed in a circumferential direction
Data Source
AI summary
A gas distributor for a CVD or OVPD reactor comprises two or more gas volumes (1, 2) into each of which opens a feed pipe (3, 4) for a process gas, each gas volume (1, 2) being connected to a plurality of corresponding process gas outlets (6, 7) which open into the bottom (5) of the gas distributor. In order to increase the homogeneity of the gas composition, the two gas volumes (1, 2) comprise pre-chambers (10, 10′, 11) located in a first common plane (8) and a plurality of gas distribution chambers (12, 13) each associated with a gas volume are provided in a second plane (9′) adjacent to the bottom of the gas distributor. The pre-chambers (10, 10′, 11) and gas distribution chambers (12, 13) associated with each gas volume (1, 2) are connected with connection channels (14, 15).