FOUP Surface Purge Unit for Uniform Inert Gas Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor processing pods face challenges in maintaining low oxygen partial pressure during consecutive wafer processing, leading to potential oxidation of thin wiring, especially with the lid open, due to uneven gas distribution and limited replacement efficiency using porous sintered materials.
Innovation Solution
A pod design featuring shelves for wafer placement, a lid for sealing, and a surface purge unit with vent holes that eject inert gas parallel to the wafers, ensuring uniform gas distribution and efficient replacement, even when the lid is open, using a mount base gas supply system to maintain low oxidative gas partial pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a porous sintered material is used to supply inert gas through a tower-shaped nozzle, then the oxygen partial pressure can be reduced, but the gas distribution becomes uneven and replacement efficiency is limited
Solution Approach 1:
The single tower-shaped nozzle is segmented into multiple gas supply ports distributed across the pod bottom surface. This segmentation allows gas to be supplied from multiple locations simultaneously, achieving uniform gas distribution throughout the pod interior while effectively reducing oxygen partial pressure.
Solution Approach 2:
The gas supply approach transitions from a vertical one-dimensional tower nozzle to a two-dimensional distributed array of supply ports on the pod bottom. This dimensional change enables comprehensive gas distribution across the entire pod interior space, eliminating the uneven distribution problem.
2Productivity
If the lid is kept open during consecutive wafer processing, then processing time is reduced, but oxidative gases enter the pod and increase oxygen partial pressure
Solution Approach 1:
Inert gas is supplied in advance and continuously from multiple ports on the pod bottom before and during the wafer processing period. This preliminary and continuous gas supply establishes a protective inert atmosphere that prevents oxidative gases from entering the pod even when the lid is open, enabling consecutive processing without oxidation concerns.
Solution Approach 2:
The invention maintains a continuous inert gas atmosphere within the pod by supplying inert gas from multiple distributed ports. This creates a protective environment that allows the lid to remain open during processing while preventing oxidation, thus improving productivity without compromising wafer quality.
3Quantity of substance
If a high flow rate of inert gas is supplied to prevent oxidative gas diffusion, then oxygen partial pressure is reduced, but the complexity of the gas supply system increases
Solution Approach 1:
The gas supply system is segmented into multiple simple ports distributed on the pod bottom rather than a single complex high-flow nozzle. This segmentation allows the use of multiple low-flow supplies that collectively achieve the same protective effect, reducing the complexity of individual components while maintaining effective oxygen partial pressure control.
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 effectively keeps the partial pressure of oxidative gases, such as oxygen, at a low level during continuous processing, preventing oxidation of wafers and allowing for consecutive processing with the lid open, thereby improving wafer quality and reducing processing time and apparatus load.
Implementation Method 1
a surface purge unit ejecting a specific gas from a plurality of vent holes that the surface has toward the contents in a direction parallel to narrow surfaces of the contents arranged along the height direction
Implementation Method 2
the increase in the partial pressure of the oxidative gases is reduced by the supply of inert gas through the tower-shaped nozzle
Data Source
AI summary
An object is to prevent the partial pressure of oxidative gas over time in an FOUP mounted on an FIMS system and left open. A surface purge unit is provided on a side opposite to the opening of the FOUP in such a way that wafers supported in the FOUP is located between the opening and the surface purge unit. The surface purge unit ejects inert gas from a plurality of vent holes provided in its surface toward the opening. Uniform purging or replacement of the interior of the FOUP with inert gas can be achieved by creating inert gas flow from an inert gas supply part extending over a surface in the direction from the interior of the FOUP toward the opening along the wafer surface.