Semiconductor Substrate Processing Gas Flow Control
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Solution Overview
Problem
In existing substrate processing apparatuses for semiconductor manufacturing, the velocity of source gas supplied to the center parts of substrates is reduced, leading to non-uniformity in substrate processing quality both on individual substrates and between them.
Innovation Solution
The apparatus is designed with a gas penetration preventing cylinder and specific gas flow control mechanisms to maintain higher gas velocity at the center parts of substrates, including a shorter distance between the inner tube wall and the cylinder, and a gas exhaust outlet configuration that prevents gas flow between the upper end plate and the top plate, ensuring uniform gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If source gas is supplied horizontally between stacked substrates, then substrate processing can be performed, but the velocity of source gas at the center surface parts of substrates decreases leading to non-uniform processing quality
Solution Approach 1:
The gas distribution plate is designed with different hole distributions in different regions: the central region has holes oriented in the gas supply direction to maintain high gas velocity at substrate centers, while the radial region has holes oriented radially to distribute gas uniformly at the edges. This local differentiation resolves the contradiction by optimizing gas flow characteristics for each specific region of the substrate.
Solution Approach 2:
The gas distribution plate is segmented into distinct functional regions: a central region for maintaining high gas velocity and radial regions for uniform distribution. This segmentation allows each region to independently optimize its gas flow characteristics, preventing the velocity reduction that occurs in uniform horizontal flow configurations.
2Manufacturing precision
If gas flows freely in the space between inner tube wall and substrate holder, then gas distribution may be improved, but gas flows into non-relevant areas causing particle generation
Solution Approach 1:
The harmful gas flow into non-relevant areas is extracted and removed from the system by providing a dedicated exhaust outlet in the gas distribution plate. This prevents particles from generating on the inner tube wall while maintaining the benefits of gas flow distribution in the relevant substrate processing areas.
Solution Approach 2:
The gas distribution plate acts as an intermediary between the gas supply system and the substrate holder, controlling and directing gas flow to appropriate areas. It mediates the gas flow to prevent it from reaching the inner tube wall where particle generation would occur, while still achieving uniform distribution across substrates.
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 enhances the uniformity of substrate processing quality by maintaining higher gas velocity at the center parts of substrates, preventing gas flow into non-relevant areas, and reducing particle generation, thus improving processing efficiency and film thickness uniformity.
Implementation Method 1
a conductance of a space between an inner wall of the inner tube and a gas penetration preventing cylinder is smaller than a conductance of a region where the plurality of substrates are stacked
Data Source
AI summary
Substrate processing uniformity is improved in the surfaces of wafers and between the wafers. A method of manufacturing a semiconductor device, including: loading a substrate holder into an inner tube, the substrate holder holding a plurality of substrates in a state where the plurality of substrates are horizontally oriented and stacked; forming thin films on the plurality of substrates by supplying a source gas to an inside of the inner tube; and unloading the substrate holder from the inner tube, wherein the forming the thin films is performed in a state where a conductance of a space between an inner wall of the inner tube and a gas penetration preventing cylinder is smaller than a conductance of a region where the plurality of substrates are stacked.