Area-Selective ALD for 3D V-NAND Integration
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Solution Overview
Problem
Conventional top-down lithography and etching processes face limitations in high-aspect-ratio and high-integration three-dimensional electronic devices, such as V-NAND, leading to inter-cell non-uniformity and operation errors due to the inability to effectively pattern and deposit thin films on complex substrate structures.
Innovation Solution
An area-selective deposition method using atomic layer deposition (ALD) with aminosilane-based inhibitors is employed, where silicon oxide and silicon nitride areas with different surface functional groups are treated to selectively adsorb silicon precursors and inhibitors, allowing for precise deposition of silicon oxide layers on specific areas, enhancing selectivity and freedom in patterning and integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional top-down lithography and etching processes are used for high-aspect-ratio three-dimensional devices, then device integration density can be increased, but inter-cell non-uniformity and operation errors occur due to inability to effectively pattern and deposit thin films on complex substrate structures
Solution Approach 1:
The patent applies area-selective deposition where different regions of the substrate (silicon oxide areas vs. silicon nitride areas) exhibit different surface characteristics that enable selective adsorption of precursors. This local differentiation in surface properties allows precise control over where thin films are deposited, solving the non-uniformity problem while maintaining high integration density
Solution Approach 2:
The patent changes surface chemical parameters by introducing functional groups through surface treatment. The silicon oxide area and silicon nitride area are treated to form different functional groups, which fundamentally alter the surface reactivity and enable selective precursor adsorption, thereby achieving uniform deposition control on complex three-dimensional structures
2Manufacturing precision
If area-selective deposition using aminosilane-based inhibitors is employed, then selectivity of thin-film deposition is increased, but process complexity increases due to multiple supply and purge steps
Solution Approach 1:
The patent performs preliminary surface treatment to form functional groups on different substrate areas before the main deposition process. This preliminary action creates the selective surface characteristics needed for area-selective deposition, allowing the subsequent ALD process to proceed with high selectivity. The inhibitor material is also pre-positioned on specific areas to prevent deposition where not desired
Solution Approach 2:
The deposition process is segmented into distinct supply and purge steps, with the inhibitor material supply step being a separate, controlled operation. This segmentation allows precise control over where and when deposition occurs, achieving high selectivity by isolating the inhibitor action from the main precursor deposition
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 method enables the formation of high-aspect-ratio/high-integration devices by increasing the selectivity of thin-film deposition and expanding the degree of freedom in device integration, particularly beneficial for three-dimensional V-NAND devices, while allowing for precise control over film formation on different material surfaces.
Implementation Method 1
a first supply step of supplying a silicon precursor into the reactor to selectively adsorb the silicon precursor to a surface of the silicon oxide area
Implementation Method 2
a second supply step of supplying an inhibitor material into the reactor to selectively adsorb the inhibitor material to a surface of the silicon nitride area
Implementation Method 3
a third supply step of supplying an oxygen-containing source into the reactor
Data Source
AI summary
A deposition method may include: providing a structure to be deposited that includes a silicon oxide area and a silicon nitride area having different surface characteristics from each other; and performing an atomic layer deposition (ALD) process in a reactor provided with the structure to selectively form a silicon oxide layer on the silicon oxide portion between the silicon oxide portion and the silicon nitride portion. The ALD process may include: supplying a silicon precursor into the reactor to selectively adsorb the silicon precursor to a surface of the silicon oxide portion; purging the reactor; supplying an inhibitor material into the reactor to selectively adsorb the inhibitor material to a surface of the silicon nitride portion; purging the reactor; supplying an oxygen-containing source into the reactor; and purging the reactor.