Selective Silicon Nitride Deposition With In-Situ Densification
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Solution Overview
Problem
Current 3D-NAND manufacturing processes using high temperature atomic layer deposition (ALD) or chemical vapor deposition (CVD) for silicon nitride (SiN) result in poor quality films due to the need for low deposition temperatures, which are not suitable for forming high-quality silicon-containing dielectric layers.
Innovation Solution
A method involving pre-cleaning, exposure to a growth inhibitor, and selective deposition of a silicon-containing dielectric layer in a processing tool without breaking vacuum, followed by densification, to form high-quality silicon-containing dielectric films on 3D-NAND devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high temperature ALD or CVD is used for silicon nitride deposition, then film quality is improved, but deposition temperature requirement conflicts with selective deposition needs
Solution Approach 1:
The method applies preliminary actions by pre-cleaning the substrate surface and exposing it to a growth inhibitor before deposition. This prepares the surface to enable selective deposition at lower temperatures while maintaining film quality, resolving the contradiction between temperature requirements for quality vs. selectivity
Solution Approach 2:
The invention changes the deposition temperature parameter from high temperature (traditional ALD/CVD) to low temperature (selective deposition), while compensating for the quality loss through post-deposition densification processing. This parameter change allows selective deposition to occur at temperatures that enable pattern definition
2Device complexity
If selective deposition is used to eliminate patterning steps, then manufacturing complexity is reduced, but film quality deteriorates due to low deposition temperatures
Solution Approach 1:
The method merges multiple functions into the deposition process: selective deposition eliminates separate patterning steps, while post-deposition densification compensates for film quality issues. The growth inhibitor layer is also reused as an etch mask in subsequent processing, further reducing manufacturing complexity while maintaining film quality
Solution Approach 2:
The invention introduces post-deposition densification processing to change the physical parameters of the deposited film. This densification step improves film quality (reducing voids, increasing density) without requiring higher deposition temperatures, thus maintaining the benefits of selective deposition
3Productivity
If low deposition temperature is used for selective deposition, then patterning steps are eliminated, but wet etch rate decreases resulting in poor film quality
Solution Approach 1:
The method changes the physical state and density parameters of the film through post-deposition densification processing. This increases the film density and improves wet etch rate without requiring higher deposition temperatures, thus maintaining process integration benefits while improving film quality
Solution Approach 2:
The growth inhibitor layer serves as an intermediary that enables selective deposition at low temperatures. After deposition, it is removed and reused as an etch mask, allowing the low-temperature deposition to proceed while still achieving the necessary pattern definition and film quality control
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
The method enables the formation of high-quality silicon-containing dielectric films with improved wet etch rates, enhancing the performance of 3D-NAND devices by ensuring selective deposition and maintaining film quality throughout the process.
Implementation Method 1
exposing the top surface of the film stack to a growth inhibitor
Implementation Method 2
selectively depositing a silicon-containing dielectric layer
Implementation Method 3
densifying the silicon-containing dielectric layer
Data Source
AI summary
Methods of manufacturing memory devices are provided. The method comprises pre-cleaning a top surface of a film stack, the film stack comprising alternating layers of a first material layer and a second material layer and having one or more of a memory hole and a slit pattern opening extending through the film stack; exposing the top surface of the film stack to a growth inhibitor; selectively depositing a silicon-containing dielectric layer in a region of the film stack; and densifying the silicon-containing dielectric layer. The processing method is performed in a processing tool without breaking vacuum.