Purge Gas Restrictor for Substrate Processing Apparatus
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Solution Overview
Problem
In vertical type substrate processing apparatuses, by-products adhere to the lower portion of the process vessel, affecting film formation and substrate processing quality.
Innovation Solution
A substrate processing apparatus with a process vessel, lid, substrate retainer, insulating structure, process gas supply mechanism, purge gas supply unit, and a restrictor that regulates the flow of purge gas to prevent by-products from adhering to the lower portion by intensively purging the region with high gas concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If purge gas is supplied uniformly to the entire lower region of the process vessel, then the structure is simple, but by-products still adhere to regions with low gas flow
Solution Approach 1:
The patent applies local quality by dividing the purge gas supply into different regions with different flow rates. The first region (where by-products tend to adhere) receives a higher flow rate of purge gas compared to the second region. This is achieved by positioning the purge gas supply unit to create a non-uniform flow distribution, thereby intensively removing by-products from critical areas without unnecessarily increasing the overall system complexity.
2Manufacturing precision
If the flow rate of purge gas is increased throughout the entire lower region, then by-product adhesion is suppressed, but gas concentration in other regions becomes too low affecting substrate processing
Solution Approach 1:
The patent implements local quality by creating a non-uniform purge gas flow distribution where the first region (prone to by-product adhesion) receives a higher flow rate while the second region receives a lower flow rate. This selective approach maintains sufficient gas concentration in the second region for proper substrate processing while intensively purging by-products from the first region, thus resolving the contradiction between suppressing adhesion and maintaining gas concentration.
3Manufacturing precision
If a complex purge gas supply mechanism is used to achieve non-uniform flow distribution, then by-product adhesion is prevented, but the apparatus complexity and cost increase
Solution Approach 1:
The patent applies self-service by utilizing the natural flow characteristics of the purge gas supply unit to automatically create the desired non-uniform flow distribution. The purge gas supply unit is positioned and configured to naturally deliver higher flow rates to the first region and lower flow rates to the second region without requiring additional complex flow control mechanisms, valves, or regulators for each region. This simple yet effective approach prevents by-product adhesion while maintaining apparatus simplicity.
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 solution effectively suppresses by-product adhesion, improves substrate processing quality, and maintains film uniformity without increasing the complexity or cost of the apparatus.
Implementation Method 1
a restrictor disposed in the gap, wherein the restrictor is configured to regulate a flow of the purge gas such that a flow rate or a conductance of the purge gas supplied to a first portion of the lower region of the process vessel is greater than a flow rate or a conductance of the purge gas supplied to a second portion of the lower region of the process vessel
Implementation Method 2
a purge gas supply unit configured to supply a purge gas to a lower region of the process vessel via a gap between the insulating structure and the lid
Data Source
AI summary
A technique capable of preventing by-products from adhering to a lower portion of a process vessel utilizes a substrate processing apparatus including: a process vessel having a process chamber; a lid configured to close a lower end opening of the process vessel; a substrate retainer; an insulating structure; a process gas supply mechanism configured to supply a process gas; a purge gas supply unit configured to supply a purge gas to a lower region of the process vessel via a gap between the insulating structure and the lid; and a restrictor disposed in the gap. The restrictor regulates flow of the purge gas such that the flow rate of the purge gas supplied to a first portion of the lower region of the process vessel is greater than a flow rate of the purge gas supplied to a second portion of the lower region of the process vessel.