Substrate Purge Gas Flow Layout to Prevent Reverse Contamination
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges with contamination due to particles generated from mechanical members and reverse flow of purge gas, leading to process defects and substrate contamination.
Innovation Solution
The substrate processing apparatus includes a substrate support unit, a processing fluid supply unit, and a purge gas supply member with a first and second supply means to discharge purge gas in opposite directions, eliminating the need for mechanical members and controlling purge gas flow rates to prevent reverse flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a mechanical member such as a bearing is installed to rotatably fix the inner pipe of the lower fluid supply unit, then the substrate support unit can rotate smoothly, but friction between the mechanical member and rotating parts generates particles that contaminate the substrate and processing space
Solution Approach 1:
The patent removes the mechanical bearing from the system entirely. Instead of having the inner pipe rotate with the support member, the inner pipe is fixed to the lower fluid supply unit body, which remains stationary. The fluid supply function is maintained without any rotating mechanical connections, thereby eliminating particle generation from mechanical friction.
Solution Approach 2:
The patent replaces the mechanical rotation system with a stationary fluid supply system. The lower fluid supply unit body is fixed to the substrate support unit, and the inner pipe is fixed to the body, eliminating mechanical rotating parts. The fluid supply function is maintained through this stationary configuration without requiring mechanical bearings or rotating joints.
2Object-affected harmful factors
If purge gas is supplied to discharge contaminants from the processing space, then contamination is removed, but reverse flow of purge gas can reintroduce contaminants to the substrate and processing space
Solution Approach 1:
The patent employs asymmetric flow control by supplying purge gas from multiple nozzles positioned at different locations and orientations. The first purge gas nozzle supplies gas in a first direction while the second purge gas nozzle supplies gas in a second direction, creating an asymmetric flow pattern that prevents reverse flow and ensures contaminants are consistently directed outward without reintroduction to the substrate area.
Solution Approach 2:
The patent applies preliminary anti-action by supplying purge gas in multiple directions simultaneously to counteract any potential reverse flow before it can occur. The multi-directional purge gas supply creates a pressure field that prevents contaminants from flowing back toward the substrate, proactively preventing contamination rather than reacting to it after reverse flow occurs.
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 prevents particle contamination and reverse flow of purge gas, ensuring efficient cleaning of the substrate and maintaining a clean processing environment.
Implementation Method 1
a first supply means configured to discharge the purge gas in a first direction toward a lower surface of the substrate; and a second supply means configured to discharge the purge gas in a second direction opposite to the first direction
Data Source
AI summary
Proposed are a substrate processing apparatus and a substrate processing method capable of efficiently preventing contamination of a substrate and a processing space caused by a reverse flow of purge gas.