Multi-nozzle Vortex Flow Wet Processing Tool
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Solution Overview
Problem
Wet processing tools often suffer from process non-uniformity due to stagnant or slow flow regions, which can lead to deposition of silicon oxide during etching processes, particularly with hot phosphoric acid used for etching silicon nitride, resulting in non-uniform etching and residual material formation.
Innovation Solution
A wet chemical processing tool with multiple nozzles configured to induce specific vortex flow patterns by actuating and de-actuating liquid flow through each nozzle, creating unique processing-step vortex flow patterns to prevent stagnant regions and enhance uniformity, employing a container with a substrate holder and liquid supply tubes connected to a flow controller to manage the flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single nozzle is used to inject liquid onto the substrate, then the device complexity is reduced, but process uniformity deteriorates due to stagnant flow regions
Solution Approach 1:
The single nozzle is segmented into multiple nozzles (at least three) arranged around the substrate. Each nozzle injects liquid toward a different peripheral portion, creating multiple vortex flow patterns that collectively cover the entire substrate surface, eliminating stagnant regions and improving etching uniformity.
Solution Approach 2:
The liquid injection is extended from a single central point to multiple peripheral locations around the substrate. This spatial redistribution creates vortex flows that rotate in different directions, ensuring comprehensive coverage of the substrate surface and preventing localized stagnation.
2Productivity
If liquid flow is continuous through all nozzles, then productivity is maintained, but residual material deposition increases due to stagnant regions
Solution Approach 1:
The liquid flow through the nozzles is operated periodically rather than continuously. Different nozzles are activated in sequence, creating time-varying vortex patterns that prevent residual material from accumulating in any single location, thereby eliminating silicon oxide deposition while maintaining processing throughput.
Solution Approach 2:
The system transitions from a static flow pattern to a dynamic one where the active nozzles change over time. This dynamic operation creates varying vortex patterns that continuously redistribute the liquid flow, preventing stagnant regions and the associated harmful deposition.
3Manufacturing precision
If multiple nozzles are activated simultaneously, then etching uniformity improves, but device complexity and control difficulty increase
Solution Approach 1:
Instead of activating all nozzles simultaneously, the system uses periodic activation where different nozzles are turned on in sequence. This temporal separation simplifies the control logic compared to coordinating multiple simultaneous flows, while still achieving uniform etching through the cumulative effect of multiple vortex patterns.
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 tool achieves enhanced uniformity in wet chemical processing by generating distinct vortex flow patterns that prevent the accumulation of residual materials, ensuring consistent etching across the substrate surface and reducing deposition of silicon oxide.
Implementation Method 1
each of the at least three nozzles is configured to inject a liquid therefrom toward a respective peripheral portion of the volume to induce a respective single-injection vortex flow pattern
Data Source
AI summary
A wet chemical processing tool is provided, which includes an assembly of a container and at least three nozzles. The container includes a volume configured to contain at least one substrate therein. The wet chemical processing tool includes a flow controller configured to actuate and de-actuate flow of the liquid through each of the at least three nozzles. The flow controller can be operated by an automated program that includes a plurality of wet processing steps. At least two of the plurality of wet processing steps generate a respective unique processing-step vortex flow pattern by de-actuating flow of the liquid from a respective set of at least one deactivated nozzle selected from the at least three nozzles while actuating each of the at least three nozzles that does not belong to the set of at least one deactivated nozzle.