Shroud-Based Radical-Enhanced ALD Precursor Interaction Control
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Solution Overview
Problem
Conventional radical-enhanced atomic layer deposition (REALD) methods require separate reaction chambers due to precursor gas interactions, leading to increased costs and waste, as well as inefficient use of resources.
Innovation Solution
The system and method involve a shroud that directs gaseous radical species to selectively expose substrates to precursor gases, minimizing unwanted interactions and allowing for reduced precursor gas usage by maintaining the radical species in a controlled environment within the shroud, thereby enabling thin film deposition in the same chamber as other processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate reaction chambers are used to prevent precursor gas interactions, then precursor interaction is reduced, but device complexity and cost increase
Solution Approach 1:
The reaction chamber is segmented into distinct zones using physical barriers (baffles) and flow control structures. The precursor injection zone is separated from the radical generation zone, allowing both zones to coexist in a single chamber while preventing unwanted precursor-radical interactions until the precursor reaches the substrate surface
Solution Approach 2:
Inert gas flows are used as intermediaries to transport precursors from the injection zone to the substrate while preventing direct contact between precursors and radicals. The inert gas acts as a protective medium that carries the precursor through the reaction chamber without allowing premature reaction
2Productivity
If precursor gas is present throughout the reaction chamber, then process efficiency improves, but unwanted precursor interactions increase
Solution Approach 1:
Different regions of the reaction chamber have different gas compositions and functions. The precursor injection zone contains high precursor concentration, while the radical generation zone maintains high radical concentration. The precursor is allowed to diffuse throughout the chamber but reacts only in specific localized regions near the substrate surface where radicals are present
3Productivity
If radical species are continuously introduced, then deposition rate increases, but precursor waste increases
Solution Approach 1:
Precursors are introduced and allowed to adsorb onto the substrate surface in advance, forming a precursor layer before radical introduction. This preliminary precursor deposition ensures that when radicals are introduced, they react efficiently with the pre-positioned precursors, reducing precursor waste and improving deposition rate
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 reduces waste and time required for reactant introduction, allowing for efficient thin film deposition with reduced equipment costs and environmental impact by controlling the reaction location and minimizing unwanted product formation outside designated areas.
Implementation Method 1
A shroud is provided within a reaction chamber. The shroud is configured to direct a secondary gas towards a substrate when the substrate is present in the reaction chamber.
Implementation Method 2
A radical generator is configured to generate a gaseous radical species from the secondary gas when the secondary gas is present and flowing.
Implementation Method 3
Methods and systems for inhibiting precursor interactions during radical-enhanced atomic layer deposition
Data Source
AI summary
This disclosure relates to methods and systems for inhibiting precursor interactions during radical-enhanced atomic layer deposition. A substrate may be completely exposed to a precursor gas. Meanwhile, a gaseous radical species is directed through a shroud towards the substrate. The gaseous radical species flows through the shroud under sufficient flow and pressure conditions to substantially prevent the precursor gas from flowing into the shroud. The shroud can be alternately positioned over selected regions of the substrate to thereby alternately expose the selected regions of the substrate to the radical species and the precursor gas multiple times. A thin film of reaction product is formed in the selected regions of the substrate and not on undesired surfaces.