Vertical Semiconductor Structure for Conformal Layer Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor device fabrication methods face challenges in achieving conformal deposition and improved step coverage, particularly in high-aspect-ratio structures, leading to non-uniform thickness and overhang issues in blocking and charge storage layers.
Innovation Solution
The method involves forming an alternating stack of dielectric and sacrificial layers, etching an opening, and using a fluorine-based surface treatment to convert non-conformal blocking and charge storage layers into conformal ones by adsorbing deposition inhibitors, ensuring uniform deposition and improved step coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods are used to form blocking and charge storage layers in high-aspect-ratio structures, then the deposition process is simpler and faster, but the layer thickness becomes non-uniform and overhang issues occur
Solution Approach 1:
The patent applies preliminary action by performing surface treatment on the substrate before deposition to modify surface properties, and by using a multi-step deposition process where layers are formed sequentially with intermediate treatments. This preliminary preparation enables subsequent conformal deposition in high-aspect-ratio structures by pre-establishing the necessary surface conditions and deposition patterns.
Solution Approach 2:
The patent introduces intermediary substances including deposition inhibitors and surface treatment agents that mediate between the deposition source and substrate. These intermediaries control the deposition process by temporarily modifying surface properties during deposition, enabling conformal coverage of complex geometries without requiring fundamentally new deposition equipment.
2Reliability
If non-conformal blocking layers are formed directly on etched openings, then the fabrication process is shorter, but step coverage is poor and reliability is reduced
Solution Approach 1:
The patent performs preliminary surface treatment and forms intermediary layers before the final blocking and charge storage layers. This preliminary action ensures proper step coverage and conformal deposition, improving device reliability by preventing defects that would otherwise require rework or lead to device failure.
Solution Approach 2:
The patent changes deposition parameters including temperature, pressure, and gas composition during the deposition process to achieve conformal coverage. By dynamically adjusting these parameters, the process achieves both good step coverage and reasonable fabrication time, balancing reliability requirements with production efficiency.
3Manufacturing precision
If deposition inhibitors are adsorbed to convert non-conformal layers to conformal layers, then step coverage improves, but additional process steps are required
Solution Approach 1:
The patent uses deposition inhibitors as intermediary substances that temporarily modify the substrate surface during deposition. These inhibitors act as mediators that control where and how material deposits, enabling conformal step coverage. The inhibitors are subsequently removed or integrated into the final structure, so the additional process steps introduce necessary control rather than permanent complexity.
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 enhances the reliability of vertical semiconductor devices by achieving conformal deposition and uniform thickness across the layers, improving the integration and performance of the semiconductor device.
Implementation Method 1
adsorbing a deposition inhibitor on a surface of the blocking layer to convert the non-conformal blocking layer into a conformal blocking layer
Implementation Method 2
using a fluorine-based surface treatment to convert non-conformal blocking and charge storage layers into conformal ones
Data Source
AI summary
A vertical semiconductor device and a method for fabricating the same may include forming an alternating stack of dielectric layers and sacrificial layers over a lower structure, forming an opening by etching the alternating stack, forming a non-conformal blocking layer on the alternating stack in which the opening is formed, adsorbing a deposition inhibitor on a surface of the blocking layer to convert the non-conformal blocking layer into a conformal blocking layer on which the deposition inhibitor is adsorbed, and forming a charge storage layer on the conformal blocking layer.