Gap Silicon Deposition with Plasma Passivation Selectivity
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Solution Overview
Problem
Current plasma-enhanced methods for depositing silicon-containing materials on semiconductor substrates lack versatility and tunability, particularly in controlling chemisorption and achieving precise topological selectivity for advanced device manufacturing.
Innovation Solution
A method involving exposure of a substrate to a high ion energy plasma to modify specific areas, followed by a low ion energy plasma for passivation, and subsequent contact with a vapor-phase silicon precursor to selectively deposit silicon in gaps, reducing chemisorption on modified areas by at least 60% and allowing conformal deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single plasma-enhanced deposition method is used, then deposition speed is improved, but control over chemisorption and topological selectivity deteriorates
Solution Approach 1:
The single plasma-enhanced deposition process is segmented into two distinct plasma steps: a first plasma step that modifies specific areas of the substrate surface, and a second plasma step that performs the actual deposition. This segmentation allows independent optimization of each step - the first plasma enables selective area modification for topological control, while the second plasma provides controlled chemisorption and deposition, thereby resolving the contradiction between deposition speed and manufacturing precision.
Solution Approach 2:
The first plasma treatment is applied selectively to specific areas of the substrate surface, creating local quality differences. By modifying only predetermined areas rather than the entire surface, the method achieves topological selectivity and controls where chemisorption occurs. This local quality approach allows precise spatial control over deposition while maintaining overall process efficiency.
2Manufacturing precision
If high ion energy plasma is used to modify surface areas, then topological selectivity is improved, but unwanted chemisorption on modified areas increases
Solution Approach 1:
The first plasma step performs a preliminary action by modifying the substrate surface in predetermined areas before the actual deposition occurs. This preliminary modification creates a surface state that is later selectively passivated, preventing unwanted chemisorption. By performing this preparation step in advance, the method achieves precise topological selectivity while controlling where subsequent chemisorption takes place.
Solution Approach 2:
A passivation layer or passivation treatment acts as an intermediary between the first plasma-modified areas and the silicon precursor. This intermediary prevents direct chemisorption on the modified areas while allowing it on unmodified areas. The passivation step mediates the interaction between the plasma-modified surface and the deposition precursor, thereby controlling the quantity and location of chemisorption.
3Device complexity
If conventional deposition methods are used, then process simplicity is maintained, but versatility and tunability of deposition control deteriorates
Solution Approach 1:
The deposition process is made dynamic and tunable by independently adjusting parameters of two separate plasma steps. Each plasma step can be optimized with different gases, powers, pressures, and durations, providing versatile control over deposition characteristics. This dynamic approach allows the same basic process to be adapted for different deposition requirements while maintaining a relatively simple two-step structure.
Solution Approach 2:
The two-step plasma method serves multiple functions within a unified process framework. The first plasma can perform surface modification, cleaning, or activation depending on parameters, while the second plasma performs deposition. This multi-functionality provides versatility in controlling deposition outcomes while maintaining process simplicity through a standardized two-step approach that can be applied to various deposition scenarios.
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 enables precise control over silicon deposition, enhancing topological selectivity and filling gaps from the bottom upwards, improving the manufacturing of semiconductor devices by reducing chemisorption on passivated areas and ensuring uniformity and accuracy in silicon material distribution.
Implementation Method 1
exposing the substrate to a first plasma having high ion energy to modify predetermined areas of the gap inner surface
Implementation Method 2
exposing the substrate to a second plasma having low ion energy to passivate the modified areas of the gap surface
Implementation Method 3
contacting the substrate with a vapor-phase silicon precursor to chemisorb the silicon precursor on unmodified areas of the gap
Data Source
AI summary
The disclosure relates to methods of depositing a material comprising silicon in a gap. The method comprises providing a substrate, the substrate comprising the gap, wherein the gap comprises an inner surface and exposing the substrate to a first plasma having high ion energy to modify predetermined areas of the gap inner surface. The method further comprises exposing the substrate to a second plasma having low ion energy to passivate the modified areas of the gap surface to form passivated modified areas on the gap surface and contacting the substrate with a vapor-phase silicon precursor to chemisorb the silicon precursor on unmodified areas of the gap for depositing material comprising silicon on the unmodified areas. The current disclosure further relates to a method of controlling chemisorption of a vapor-phase silicon precursor on a substrate, and to a semiconductor processing assembly for performing the methods according to the current disclosure.