Dynamic Mixing Manifold Exits for Gas Transport Delay Resolution
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Solution Overview
Problem
Gas transport delays in gas delivery systems for semiconductor processing cause adverse effects on etch rates and critical dimensions due to non-stabilized flows and hardware differences, leading to mismatched etch rates in process chambers.
Innovation Solution
A gas delivery system with multiple mass flow controllers and a mixing manifold featuring dynamically controlled mixing manifold exits, which automatically adjust to minimize delays by positioning exits proximate to low flow MFCs, reducing the volume of gas flow and enhancing mixing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If gases are mixed in a traditional mixing manifold with spatially separated inlets, then mixing occurs, but gas transport delays increase due to the volume required for low flow gases to travel and mix with high flow carrier gases
Solution Approach 1:
The mixing manifold is divided into multiple zones with multiple exit ports positioned at different locations. This segmentation allows low flow gases to mix with high flow carrier gases at different stages along the flow path, reducing the distance and time required for complete mixing while maintaining efficient gas combination.
Solution Approach 2:
Multiple exit ports are positioned at different spatial locations and orientations within the mixing manifold. This multi-dimensional arrangement allows gases to be delivered through multiple pathways simultaneously, reducing the effective transport distance and time for low flow gases to reach the process chamber.
2Adaptability or versatility
If hardware differences exist in gas boxes with multiple gas feeds, then various gases can be supplied, but etch rate matching issues arise due to different transport delays
Solution Approach 1:
The system incorporates sensors and control mechanisms that monitor gas flow rates and mixing effectiveness in real-time. Based on this feedback, the system dynamically adjusts flow rates, timing, and manifold exit port selection to compensate for hardware variations between different gas boxes, ensuring consistent etch rates across all process chambers.
Solution Approach 2:
The gas delivery system uses dynamic control of flow rates and timing for each gas feed, rather than fixed parameters. This allows the system to adapt to hardware differences between gas boxes by adjusting operational parameters in real-time, maintaining consistent gas mixing quality and etch rate performance across multiple chambers.
3Quantity of substance
If low flow gases are delivered through a mixing manifold, then process gases are supplied, but etch rates are adversely affected due to non-stabilized flows in short process recipes
Solution Approach 1:
Low flow process gases are pre-mixed with high flow carrier gases in the mixing manifold before being delivered to the process chamber. This preliminary mixing action stabilizes the flow of low flow gases by the time they reach the chamber, ensuring consistent etch rates even in short process recipes where there is minimal time for flow stabilization to occur naturally.
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 solution effectively reduces gas transport delays, ensuring timely and efficient mixing of process gases, thereby improving etch rates and maintaining consistent dimensions on silicon wafers during short etch recipes.
Implementation Method 1
The time required to fill the low flow gas volume from the MFC until it mixes with the high flow gas, as well as its diffusion through the high flow gas, determines the total transport delay to the reaction chamber.
Data Source
AI summary
In one embodiment, an apparatus for providing a gas mixture of a plurality of gases, may have a plurality of mass flow controllers (MFCs), a mixing manifold in fluid connection with each plurality of MFCs, a plurality of mixing manifold exits positioned on the mixing manifold; and an isolation device in fluid connection with each of the plurality of mixing manifold exits.