Showerhead Gas Flow Uniformity via Pressurized Volume Release
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Solution Overview
Problem
Showerheads in semiconductor fabrication processes often experience spatially non-uniform gas flow initially, leading to material thickness non-uniformities, which are unacceptable for advanced technology nodes, especially in cyclic deposition processes where gas flow durations are short.
Innovation Solution
Pressurizing a volume with gas and releasing it to the showerhead using isolation valves to rapidly establish a spatially uniform gas flow across the faceplate, reducing the time to achieve uniformity to less than 0.5 seconds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gas is delivered directly to the showerhead in conventional steady state flow design, then the system is simple to operate, but spatially non-uniform gas flow develops initially causing material thickness non-uniformities
Solution Approach 1:
The patent applies preliminary action by pressurizing the gas in a volume before delivering it to the showerhead. This pre-pressurization ensures that when the gas is released, it rapidly establishes spatially uniform flow across the faceplate, eliminating initial non-uniformities without requiring complex showerhead design modifications.
Solution Approach 2:
The system is segmented into distinct functional components: a gas source, a pressurizable volume, an isolation valve, and the showerhead. This segmentation allows independent optimization of each component, enabling simple showerhead design while achieving uniform flow through the pressurization mechanism.
2Manufacturing precision
If gas flow duration is extended to achieve uniform flow distribution, then spatially uniform gas flow is achieved, but deposition throughput decreases
Solution Approach 1:
The patent changes the pressure parameter of the gas before delivery. By pressurizing the gas in a controlled volume and then rapidly releasing it, the system achieves spatially uniform flow distribution in a short time, eliminating the need for extended gas flow durations and thereby maintaining high deposition throughput.
3Loss of time
If pressurized gas is released to the showerhead, then the time to develop spatially uniform gas flow is reduced, but the system complexity increases due to isolation valves and pressurization volume
Solution Approach 1:
The gas is pre-pressurized in a volume before being delivered to the showerhead. This preliminary pressurization action enables rapid establishment of uniform flow when the gas is released, significantly reducing the time to achieve spatial uniformity while keeping the added complexity manageable through simple valve control.
4Ease of operation
If conventional steady state flow is used in cyclic deposition processes, then the system is easy to operate, but material thickness non-uniformities occur due to transient flow issues
Solution Approach 1:
The patent implements periodic pressurization and release cycles of the gas. During each deposition cycle, the gas is pressurized in the volume and then rapidly released to the showerhead, creating periodic pulses of uniform flow that eliminate transient non-uniformities while maintaining simple cyclic operation.
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 method improves deposition processes by minimizing transient flow issues, resulting in reduced thickness non-uniformities and increased growth rate, enhancing the throughput of deposition processes like iALD by at least 20% and improving film thickness uniformity to less than 5%.
Implementation Method 1
pressurizing a volume with a gas. The pressurized gas is released to a showerhead... reduces the duration of time to develop a spatially uniform gas flow across the faceplate of the showerhead
Data Source
AI summary
Methods, apparatus, and systems for depositing materials with gaseous precursors are provided. In certain implementations, the methods involve providing a wafer substrate to a chamber of an apparatus. The apparatus includes a showerhead to deliver a gas to the chamber, a volume, and an isolation valve between the volume and the showerhead. A gas is delivered the volume when the isolation valve is closed, pressurizing the volume. The isolation valve is opened to allow the gas to flow to the showerhead when the gas is being delivered to the volume. A material is formed on the wafer substrate using the gas. In some implementations, releasing the pressurized gas from the volume reduces the duration of time to develop a spatially uniform gas flow across the showerhead.