Cross-Flow Wafer Boat Layout for Uniform Vertical Furnace Deposition
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Solution Overview
Problem
Semiconductor processing apparatuses face challenges in achieving uniform gas flow between substrates, leading to non-uniform processing characteristics and reduced process efficiency, particularly in vertical furnaces used for deposition processes like CVD and ALD.
Innovation Solution
The semiconductor processing apparatus incorporates a reaction chamber with a gas distributor and exhaust system designed to create a cross-flow path between substrates, using arc-shaped manifolds and baffles to direct gas flow uniformly across the substrate boat, ensuring balanced gas distribution and efficient precursor utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If vertical furnaces are used for deposition processes, then the footprint of the apparatus is reduced and operational costs are saved, but uniform gas flow between substrates becomes difficult to achieve
Solution Approach 1:
The patent transitions from traditional vertical gas flow to horizontal cross-flow by redirecting the gas flow direction through specially designed gas distributors and exhaust systems. This dimensional change in flow pattern enables uniform gas distribution across multiple substrates arranged in a vertical rack, achieving both compact footprint and uniform processing characteristics.
Solution Approach 2:
The gas distributor is designed with multiple gas injection ports positioned at different locations to create localized gas flow zones. Each port delivers gas directly to specific substrate regions, ensuring uniform precursor distribution across all substrates while maintaining the vertical furnace configuration for space efficiency.
2Manufacturing precision
If gas injectors are used to address flow uniformity, then some improvement is achieved, but non-uniformity problems persist
Solution Approach 1:
The gas distribution system is segmented into multiple independent gas injection ports and exhaust channels. Each segment can be optimized for specific flow characteristics, and the segmented design prevents flow interference between adjacent substrates, ensuring consistent and reliable processing results across all substrates.
Solution Approach 2:
The patent introduces horizontal flow channels as intermediary pathways between the vertical furnace structure and the substrates. These channels act as mediators to distribute gas uniformly across the substrate array, eliminating the non-uniformity issues associated with direct vertical injection while maintaining system reliability.
3Productivity
If substrates are arranged in a vertical rack, then more substrates can be processed per run and throughput is improved, but gas flow distribution between substrates becomes non-uniform
Solution Approach 1:
The patent maintains the vertical rack configuration for high throughput but introduces horizontal cross-flow as a secondary dimension. This creates a two-dimensional flow pattern where gas moves horizontally across each substrate level while the rack maintains vertical stacking, enabling both high substrate capacity and uniform gas distribution.
Solution Approach 2:
The gas distributor incorporates locally optimized injection ports positioned to deliver gas directly to each substrate's active area. This localized delivery ensures that each substrate receives uniform precursor flux regardless of its vertical position in the rack, maintaining consistent layer thickness across all substrates processed in parallel.
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 enhances uniformity of layer thickness, improves step coverage, and increases process throughput by optimizing gas flow and precursor usage, particularly beneficial for high surface area structures like DRAM and VNAND manufacturing.
Implementation Method 1
a gas distributor for providing gas into the reaction space... the gas flow path may substantially be directed in between the substrates
Implementation Method 2
a gas exhaust for removing gas from the reaction space... to form a flow path, in use, from the gas distributor to the gas exhaust
Implementation Method 3
The boat, the gas distributor and the gas exhaust may be constructed and arranged to at least partially enclose the substrates in the boat
Data Source
Figure 1~3b
Figure 4a~5b
Figure 5c~6b
AI summary
A semiconductor processing apparatus for processing a plurality of substrates is provided. In a preferred embodiment, the apparatus comprises a reaction chamber. The reaction chamber comprises a reaction space for receiving a substrate boat constructed and arranged for holding the plurality of substrates. The rection chamber further comprise a gas distributor for providing gas into the reaction space and a gas exhaust for removing gas from the reaction space. The boat, the gas distributor and the gas exhaust are constructed and arranged to at least partially enclose the substrates in the boat and to form a gas flow path, in use, from the gas distributor to the gas exhaust, wherein the gas flow path is substantially being directed in between the substrates.