Semiconductor Manifold Trunk Layout for Uniform Station Flow
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Solution Overview
Problem
Multi-station semiconductor processing tools experience undesirable station-to-station nonuniformity and cross-talk between manifolds due to inherent variabilities in fluid delivery systems, particularly at low-flow regimes, leading to variations in deposition rates and thickness.
Innovation Solution
Implementing flow restrictors, such as orifices, to create choked flow in each manifold leg and using isolation valves at the manifold trunk to prevent cross-talk, ensuring uniform fluid distribution across processing stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If flow restrictors are added to create choked flow in each manifold leg, then station-to-station flow uniformity is improved, but device complexity increases
Solution Approach 1:
The fluid delivery system is segmented into multiple independent manifold legs, each equipped with its own flow restrictor. This segmentation allows independent control of flow to each processing station, compensating for inherent variabilities in leg lengths and diameters, thereby achieving uniform flow distribution across all stations.
Solution Approach 2:
Flow restrictors are used to change the flow regime from subcritical to choked (sonic) flow. By adjusting the restrictor parameters (orifice size, shape), the system transitions to a flow regime where mass flow rate becomes independent of downstream pressure variations, stabilizing flow uniformity across stations.
2Manufacturing precision
If isolation valves are installed at the manifold trunk to prevent cross-talk, then flow balance between stations is improved, but device complexity increases
Solution Approach 1:
Isolation valves are installed at the manifold trunk to segment the fluid delivery system into independent channels for each processing station. This prevents cross-talk where fluid from one station could inadvertently flow to another station, ensuring that flow adjustments at one station do not affect others and maintaining flow balance.
Solution Approach 2:
Isolation valves act as intermediary components between the manifold trunk and individual station inlets. These valves serve as controllable barriers that can be opened or closed to prevent unwanted fluid communication between different station pathways, eliminating cross-contamination and flow interference.
3Reliability
If choked flow is created in each manifold leg, then resistance to flow variations is improved, but pressure drop increases
Solution Approach 1:
The system deliberately changes the flow parameter regime by creating choked flow conditions where the Mach number reaches unity at the restrictor throat. In this regime, mass flow rate becomes insensitive to downstream pressure changes, providing inherent compensation for flow variations. The pressure drop is managed by selecting appropriate restrictor dimensions that achieve choked flow while maintaining acceptable upstream pressure levels.
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
Achieves more uniform and balanced station-to-station flow, reducing nonuniformity and cross-talk, thereby enhancing the consistency of semiconductor processing.
Implementation Method 1
flow restrictors, such as orifices, positioned at or near the manifold trunks and that create choked flow within each leg of the manifold
Data Source
AI summary
The present disclosure relates to a system for a semiconductor processing. The system includes a semiconductor processing chamber having a plurality of processing stations, a plurality of manifold trunks, a plurality of valves, and a plurality of fluid manifolds. Each manifold trunk includes an outlet, a common flowpath, a plurality of trunk inlets, a plurality of orifices, and a plurality of valve interfaces.