Atomic Layer Etch Reset for Selective Deposition
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Solution Overview
Problem
Current selective deposition methods for semiconductor substrates face challenges such as material specificity, narrow process windows, and defects due to inability to assess and control nucleation delays, leading to deteriorated deposition selectivity and residual material accumulation on undesirable surfaces.
Innovation Solution
The method involves alternating between atomic layer deposition (ALD) and atomic layer etch (ALE) processes to selectively deposit materials on semiconductor substrates with different nucleation delays, using a nucleation delay differential to control the deposition and etching cycles, thereby resetting and reestablishing the differential to enhance selectivity and reduce defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If selective deposition is performed on semiconductor substrates with different substrate materials, then deposition selectivity is improved, but nucleation delay differential degrades as deposition proceeds leading to residual material accumulation
Solution Approach 1:
The patent applies periodic action by alternating between deposition cycles and atomic layer etch (ALE) reset cycles. During deposition cycles, material is selectively deposited on substrates with shorter nucleation delays. When nucleation delay differential degrades below a threshold, ALE reset cycles are performed to remove residual materials and restore the nucleation delay differential. This periodic alternation maintains deposition selectivity throughout the process by resetting the differential before it completely degrades.
Solution Approach 2:
The patent implements feedback control by monitoring the nucleation delay differential between different substrate materials during the deposition process. When the differential degrades below a predetermined threshold, the system triggers an ALE reset cycle to restore the differential. This feedback mechanism ensures that deposition selectivity is maintained by dynamically adjusting the process based on the actual state of the nucleation delay differential.
2Productivity
If deposition cycles are repeated on the same substrate, then throughput is improved, but residual material accumulates on undesirable surfaces reducing deposition quality
Solution Approach 1:
The patent uses periodic action by inserting ALE reset cycles between deposition cycles. This allows multiple deposition cycles to be performed on the same substrate (improving throughput) while periodically removing residual materials that would otherwise accumulate on undesirable surfaces (maintaining deposition quality). The periodic ALE resets enable sustained high-quality deposition over extended production runs.
3Manufacturing precision
If atomic layer etch is used to reset nucleation delay differential, then deposition selectivity is restored, but process complexity increases
Solution Approach 1:
The patent merges the deposition and etch processes into a single integrated system that can perform both ALD and ALE cycles without breaking vacuum. By combining these processes in one chamber with unified control, the system reduces the operational complexity that would otherwise arise from coordinating separate deposition and etch tools, process chambers, and vacuum systems.
Solution Approach 2:
The patent applies universality by designing a single process chamber capable of performing multiple functions: both atomic layer deposition and atomic layer etch. This multi-functional chamber can switch between deposition and etching modes as needed, eliminating the need for separate specialized chambers and reducing overall process complexity while maintaining the ability to restore nucleation delay differential effectively.
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 expands the process window for selective deposition, reduces defects by removing residual materials, and allows for repeated deposition on the same substrate, improving throughput and separation between metal and dielectric areas.
Implementation Method 1
at least some of the deposition precursor adsorbs onto the surface of the substrate during the exposing of the substrate to the deposition precursor
Implementation Method 2
igniting a plasma
Data Source
AI summary
Methods are provided for conducting a deposition on a semiconductor substrate by selectively depositing a material on the substrate. The substrate has a plurality of substrate materials, each with a different nucleation delay corresponding to the material deposited thereon. Specifically, the nucleation delay associated with a first substrate material on which deposition is intended is less than the nucleation delay associated with a second substrate material on which deposition is not intended according to a nucleation delay differential, which degrades as deposition proceeds. A portion of the deposited material is etched to reestablish the nucleation delay differential between the first and the second substrate materials. The material is further selectively deposited on the substrate.