Rectifying Plate Gas Flow Bias in Substrate Processing
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Solution Overview
Problem
In vertical substrate processing apparatuses, the downward flow of process gas due to an exhaust port located below the processing vessel can lead to biased gas flow, degrading in-plane uniformity during heat treatment of multiple wafers.
Innovation Solution
A substrate processing apparatus design featuring a gas supply system that supplies process gas in parallel to the wafers, an exhaust system with a rectifying plate installed between the exhaust port and gas outlet, and disk-shaped members between the wafer holder's plates to manage gas flow, ensuring even distribution and reducing bias.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the exhaust port is formed below the processing vessel, then the exhaust part can effectively exhaust the process gas, but the process gas flow becomes biased to one side within the processing vessel
Solution Approach 1:
A rectifying plate is introduced as an intermediary component between the exhaust port and the process gas flow. The rectifying plate extends from the exhaust port upward to a height between 0.05L to 0.2L (where L is the distance from exhaust port to substrate), acting as a mediator to straighten and distribute the gas flow, preventing it from biasing to one side while maintaining effective exhaust
2Reliability
If the process gas is supplied from a gas supply part, then the heat treatment can be performed on the wafers, but the gas flow is likely to flow downward and become biased
Solution Approach 1:
The rectifying plate serves as a mediator between the gas supply system and the wafers, intercepting the downward-flowing process gas and redistributing it uniformly across the processing vessel, thereby maintaining heat treatment capability while eliminating flow bias
Solution Approach 2:
The rectifying plate changes the flow parameters of the process gas by extending it upward from the exhaust port, transforming the downward biased flow into a more uniform horizontal or upward flow pattern, with the optimal extension height being 0.05L to 0.2L of the distance from the exhaust port to the substrate
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 configuration effectively suppresses the downward bias in gas flow, enhancing in-plane uniformity and improving the consistency of heat treatment for wafers within the processing vessel.
Implementation Method 1
a rectifying plate installed in an outer wall of the inner tube or an inner wall of the outer tube between the exhaust port and the gas outlet in a circumferential direction of the processing vessel, wherein the rectifying plate is installed to extend upward from a position below a lower end of the substrate holder to a location corresponding at least to a lower end of the exhaust port
Implementation Method 2
a gas supply part configured to supply a process gas in parallel with respect to target surfaces of the plurality of substrates accommodated in the processing vessel
Implementation Method 3
an exhaust part configured to exhaust the process gas from the processing vessel through a gas outlet; an exhaust port formed in a sidewall opposite to the gas supply part via the substrate holder in the inner tube
Data Source
AI summary
A substrate processing apparatus includes: a substrate holder which holds a plurality of substrates; a processing vessel including an inner tube and an outer tube disposed outside the inner tube; a gas supply part which supplies a process gas in parallel to target surfaces of the substrates; an exhaust part which exhausts the process gas from the processing vessel through a gas outlet; an exhaust port formed in the inner tube; and a rectifying plate installed in an outer wall of the inner tube or an inner wall of the outer tube between the exhaust port and the gas outlet in a circumferential direction of the processing vessel. The rectifying plate is installed to extend upward from a position below a lower end of the substrate holder to a location corresponding at least to a lower end of the exhaust port.