EFEM Load-Port Ducts for Inert Gas Mixing, Humidity and Oxygen Reduction
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Solution Overview
Problem
Conventional equipment front end modules (EFEMs) for semiconductor manufacturing are costly and complex due to the use of nitrogen purging systems to maintain a non-reactive environment, leading to substrate corrosion, interlayer defects, and device non-uniformity.
Innovation Solution
An EFEM design with ducts proximate load ports that induce low pressure and gas mixing by recirculating inert gas, eliminating the need for nitrogen purging, thereby reducing humidity and oxygen levels within substrate carriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nitrogen purging systems are used to maintain a non-reactive environment, then substrate corrosion and device non-uniformity are reduced, but operational costs and system complexity increase
Solution Approach 1:
The patent removes the nitrogen purging system entirely from the EFEM design. Instead of using active nitrogen gas flow to maintain non-reactive environment, the system relies on passive sealing of the EFEM chamber and controlled atmosphere management through the duct system, thereby eliminating the complexity and cost of nitrogen supply infrastructure while maintaining substrate protection
Solution Approach 2:
The EFEM system creates its own protective atmosphere through internal recirculation and pressure control. The duct system with flow elements generates low pressure zones that draw gas through the chamber, allowing the system to self-regulate its atmosphere without external nitrogen supply, making the system self-sufficient for maintaining non-reactive conditions
2Object-affected harmful factors
If nitrogen purging systems are used to reduce humidity and oxygen levels, then substrate corrosion is prevented, but operational costs increase
Solution Approach 1:
The patent uses pneumatic principles through the duct system with flow elements that create pressure differentials. By generating low pressure zones during substrate transfer, the system naturally draws gas through the chamber and maintains reduced humidity and oxygen levels without requiring continuous nitrogen flow, significantly reducing operational energy costs while maintaining protection against moisture and oxygen
Solution Approach 2:
The system changes the pressure parameter dynamically during substrate transfer operations. By creating temporary low pressure conditions only when needed (during loading/unloading), the system achieves effective atmosphere control and moisture/oxygen exclusion without the continuous energy consumption of traditional nitrogen purging, reducing operational costs while maintaining protection
3Reliability
If conventional bottom purging with pressurized nitrogen is used, then non-reactive environment is maintained, but hardware cost and complexity increase
Solution Approach 1:
Instead of pressurizing the chamber with nitrogen from the bottom as in conventional systems, the patent inverts the approach by creating low pressure zones through ducts with flow elements. This inverted pressure management approach achieves the same non-reactive environment maintenance but eliminates the need for complex pressurized nitrogen delivery hardware, reducing manufacturing cost while maintaining reliability
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 EFEM achieves faster and more efficient humidity and oxygen reduction in substrate carriers, improving device performance and reducing operational costs and complexity compared to conventional systems.
Implementation Method 1
one or more ducts of the plurality of ducts comprises a plurality of flow elements configured to cause a low pressure condition at a location of the one or more load ports
Implementation Method 2
a plurality of ducts that provide a return gas flow path enabling recirculation of gas from the EFEM chamber to the upper plenum
Data Source
AI summary
An equipment front end module (EFEM) having walls, a first wall including one or more load ports and an EFEM chamber formed between the walls. The EFEM further includes an upper plenum at a top of the EFEM and including an opening into the EFEM chamber. Ducts provide a return gas flow path enabling recirculation of gas from the EFEM chamber to the upper plenum, the ducts proximate the one or more load ports. The one or more ducts includes flow elements configured to cause a low pressure condition at a location of the one or more load ports.