Vapor Delivery Device Segmented Gas Flow
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Solution Overview
Problem
Conventional vapor delivery systems for solid precursor compounds in semiconductor manufacturing face issues with non-uniform flow rates and sublimation, leading to erratic delivery of precursor vapors, especially when using solid organometallic compounds, which affects the composition of semiconductor films in reactors.
Innovation Solution
A delivery system that splits the carrier gas into two streams, where one stream flows through the solid precursor at an elevated temperature to prevent channel formation and cavities, while the other stream bypasses the precursor, combining downstream to maintain a constant and uniform concentration of precursor vapor, capable of delivering high flux rates to multiple reactors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher carrier gas flow rates are used to increase sublimation rate, then material erosion and cavity formation increase, but sublimation rate improves
Solution Approach 1:
The delivery device is divided into multiple independent channels (first channel, second channel, third channel) that separately control different gas flows through the granular solid precursor. This segmentation allows each channel to maintain optimal flow rates without causing cavity formation, while collectively achieving high sublimation rates.
Solution Approach 2:
Different regions of the granular solid precursor are exposed to different carrier gas flow rates through the segmented channels. The first channel provides a first flow rate, the second channel provides a second flow rate, and the third channel provides a third flow rate, creating local quality variations that prevent uniform cavity formation while maintaining overall high productivity.
2Speed
If carrier gas flow rate is increased to improve delivery speed, then channel formation through the granular bed occurs, but delivery rate increases
Solution Approach 1:
The carrier gas flow is segmented into multiple channels with different flow rates. The first channel carries precursor vapor at a first flow rate, the second channel carries carrier gas at a second flow rate, and the third channel carries carrier gas at a third flow rate. This segmentation prevents any single channel from eroding the granular bed and forming harmful channels.
Solution Approach 2:
The second channel acts as an intermediary that introduces additional carrier gas at a controlled flow rate between the first and third channels. This intermediary flow helps distribute the total carrier gas flow in a way that prevents channel formation while maintaining high delivery speed through the combined effect of all three channels.
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 system ensures a uniform and constant delivery of precursor vapor to reactors, preventing channel formation and cavities, achieving high flux rates up to 2,000 micromoles per minute with minimal concentration fluctuations, and can supply multiple reactors simultaneously.
Implementation Method 1
A first stream of a carrier gas is transported to a delivery device and a first proportional valve
Implementation Method 2
Solid precursors however, are placed in a cylindrical vessel or container and subjected to a constant temperature below their melting points to vaporize them
Implementation Method 3
combining the first stream and the second stream to form a third stream
Data Source
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AI summary
A method comprises transporting a first stream of a carrier gas to a delivery device that contains a solid precursor compound. The first stream of carrier gas is at a temperature greater than or equal to 20°C. The method further comprises transporting a second stream of the carrier gas to a point downstream of the delivery device. The first stream and the second stream are combined to form a third stream, such that the dewpoint of the vapor of the solid precursor compound in the third stream is lower than the ambient temperature. The flow direction of the first stream, the flow direction of the second stream and the flow direction of the third stream are unidirectional and are not opposed to each other.