Flow Distributor Jets for Precursor Delivery
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Solution Overview
Problem
Conventional containers for delivering chemical vapor from solid precursors in semiconductor fabrication face challenges in achieving high precursor utilization, particularly at low container fill levels, due to inefficient carrier gas momentum and plugging issues, leading to reduced delivery rates and increased residue during cleaning and refilling.
Innovation Solution
The design incorporates a container with a flow distributor featuring multiple small jets angled between 60 to 90 degrees, which impinges a carrier gas onto the precursor surface with sufficient momentum to enhance sublimation rates, reducing precursor residue and facilitating efficient delivery even at low fill levels, using a container with a cylindrical or rectangular shape and a showerhead or cross-shaped flow distributor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional containers use a single inlet tube positioned above the precursor surface, then the structure is simple, but the carrier gas momentum is insufficient to perturb the precursor surface at low fill levels, resulting in reduced precursor delivery rates
Solution Approach 1:
The single inlet tube is segmented into multiple small jets (e.g., 3-10 jets with diameters of 0.02-0.1 inches) arranged in a flow distributor. This segmentation allows the carrier gas flow to be distributed across multiple points, creating sufficient momentum at each jet to effectively perturb the precursor surface even at low fill levels, thereby maintaining high precursor delivery rates without significantly increasing structural complexity
Solution Approach 2:
The flow distributor is positioned at a specific height above the precursor surface (e.g., 0.5-2 inches) to optimize the momentum transfer from the jets to the precursor surface. This dimensional positioning ensures that the carrier gas maintains sufficient velocity and momentum when impinging on the precursor, solving the low delivery rate issue at low fill levels while keeping the structure relatively simple
2Productivity
If the inlet tube is positioned below the precursor surface to increase momentum, then carrier gas can perturb the surface more effectively, but plugging issues occur due to solids accumulating in the inlet
Solution Approach 1:
The flow distributor with multiple small jets is positioned above the precursor surface rather than below it. This extraction of the gas injection point from the submerged position eliminates the plugging problem caused by solids accumulating in the inlet tube, while the multiple jets maintain sufficient momentum to effectively perturb the precursor surface and sustain high delivery rates
Solution Approach 2:
Instead of bubbling carrier gas upward through the liquid precursor from below, the invention inverts the approach by directing carrier gas downward onto the precursor surface from above. This inversion prevents solid accumulation and plugging in the inlet while maintaining effective momentum transfer to the precursor surface through the multiple jet configuration
3Productivity
If uniform heating of the precursor chamber is implemented to increase precursor utilization, then sublimation rate improves, but the container structure becomes more complex and difficult to clean
Solution Approach 1:
The heating structure is designed to provide localized heating zones rather than uniform heating throughout the entire chamber. The precursor container walls are heated at specific locations (e.g., bottom and side walls) to create controlled temperature gradients that promote uniform sublimation of the precursor while maintaining a relatively simple heating structure that is easy to clean and maintain
4Productivity
If improved carrier gas circulation is implemented to enhance precursor utilization, then delivery efficiency increases, but the container structure becomes more complex
Solution Approach 1:
The carrier gas circulation system is merged with the precursor delivery system by using the same carrier gas flow that delivers the precursor to also provide the circulation function. The multiple jets in the flow distributor not only deliver carrier gas but also create effective circulation patterns that enhance precursor utilization, eliminating the need for separate circulation components and maintaining structural simplicity
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 design reduces sublimation rate variability by up to 3% and maintains high precursor delivery rates at low container fill levels, improving utilization and simplifying cleaning and refilling processes.
Implementation Method 1
The delivery of chemical vapor from a solid precursor by sublimation, is one of the subject matters of the present invention
Data Source
AI summary
Described herein are delivery containers, systems and methods using same for providing improvements to precursor utilization in the containers for deposition process, as well as the cleaning and refilling of the containers. The containers are designed with structures which allow a carrier gas to be delivered from a flow distributor. The flow distributor comprises a plurality of small openings (jets) through which the carrier gas enters the precursor chamber and impinges upon the surface of the chemical precursors to produce a vapor.