Excess Precursor Removal Mechanism for ALD Translation Systems
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Solution Overview
Problem
In atomic layer deposition (ALD) on flexible substrates, excess non-chemisorbed precursor molecules are transported with the substrate into the reactive second precursor zone, leading to increased deposition rates and decreased barrier layer properties, resembling chemical vapor deposition (CVD) behavior, particularly at high substrate translation speeds.
Innovation Solution
Implementing an excess precursor removal mechanism, such as a heater, plasma generator, or microwave radiation, between the first and second precursor zones to liberate and remove non-chemisorbed precursor molecules from the substrate surface before exposure to the second precursor, utilizing pressure differentials and inert gases to inhibit mixing and migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If substrate translation speed is increased to improve productivity, then deposition rate increases, but excess non-chemisorbed precursor molecules are transported into the second precursor zone causing CVD-type deposition and degraded barrier layer properties
Solution Approach 1:
The patent applies preliminary action by introducing a precursor removal zone between the first and second precursor zones that actively removes excess non-chemisorbed precursor molecules from the substrate surface before the substrate enters the second precursor zone. This preliminary removal prevents the transport of excess precursor into the second zone, maintaining ALD characteristics even at high substrate translation speeds that increase productivity.
2Loss of time
If substrate translation speed is increased to reduce processing time, then throughput improves, but precursor transport between zones increases leading to loss of ALD characteristics
Solution Approach 1:
The patent introduces an intermediary precursor removal zone that acts as a mediator between the first and second precursor zones. This intermediary zone contains mechanisms (such as heated regions, plasma sources, or additional purge systems) that actively remove excess precursor molecules from the substrate surface, preventing direct transport between precursor zones and maintaining ALD characteristics despite high substrate translation speeds that reduce processing time.
3Manufacturing precision
If precursor pulse duration is extended to improve film quality, then barrier properties improve, but cycle time increases reducing productivity
Solution Approach 1:
The patent extracts the excess precursor removal function from the traditional ALD cycle by introducing a dedicated precursor removal zone between the first and second precursor zones. This extraction allows for shorter precursor pulse durations while maintaining film quality, because the removal zone actively eliminates excess precursor that would otherwise require longer purge times, thereby reducing overall cycle time and improving productivity.
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 approach maintains ALD characteristics by preventing excess precursor transport, ensuring consistent and high-quality thin film deposition, even at higher substrate speeds, while avoiding substrate degradation by localized heating or energy application that does not affect the substrate temperature.
Implementation Method 1
Implementing an excess precursor removal mechanism, such as a heater, plasma generator, or microwave radiation, between the first and second precursor zones to liberate and remove non-chemisorbed precursor molecules from the substrate surface
Implementation Method 2
Implementing an excess precursor removal mechanism, such as a heater, plasma generator, or microwave radiation, between the first and second precursor zones to liberate and remove non-chemisorbed precursor molecules from the substrate surface
Implementation Method 3
Implementing an excess precursor removal mechanism, such as a heater, plasma generator, or microwave radiation, between the first and second precursor zones to liberate and remove non-chemisorbed precursor molecules from the substrate surface
Implementation Method 4
utilizing pressure differentials and inert gases to inhibit mixing and migration
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Systems and methods for ALD thin film deposition 200, 300 include a mechanism 280, 380 for removing excess non-chemisorbed precursors from the surface of a substrate 210, 310 in a translation-based process involving multiple separate precursor zones 214, 216, 314, 316. Excess precursor removal mechanisms 280, 380 according to the present disclosure may introduce localized high temperature conditions, high energy conditions, or azeotropes of the excess precursor, to liberate the excess precursor before it reaches a separate precursor zone, thereby inhibiting CVD deposition from occurring without causing heat-induced degradation of the substrate.