3D Memory Discrete Charge Storage Segmentation
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Solution Overview
Problem
Current three-dimensional memory devices face challenges in effectively integrating discrete charge storage elements within a vertical stack configuration, which affects the density and efficiency of memory storage.
Innovation Solution
A method of forming a three-dimensional memory device involving an alternating stack of insulating and electrically conductive layers over a substrate, with memory openings filled by a vertical semiconductor channel and a tunneling dielectric layer, and discrete charge storage elements spaced apart by lateral protrusions of insulating layers, allowing for efficient charge storage and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If discrete charge storage elements are integrated in a vertical stack configuration, then memory storage density is improved, but manufacturing precision requirements worsen
Solution Approach 1:
The charge storage layer is segmented into discrete charge storage elements by laterally removing portions between adjacent vertical stacks. This segmentation approach enables precise spatial separation of charge storage elements while maintaining high density through vertical stacking, directly resolving the contradiction between storage density and manufacturing precision
Solution Approach 2:
The patent transitions from two-dimensional planar charge storage to three-dimensional vertical stacking with lateral protrusions. By utilizing the vertical dimension and creating lateral extensions, the design achieves higher storage density while the lateral protrusions provide self-aligned positioning that simplifies manufacturing precision requirements
2Productivity
If lateral protrusion portions are used to separate charge storage elements, then charge storage efficiency is improved, but device complexity worsens
Solution Approach 1:
The lateral protrusion portions serve multiple functions: they separate adjacent charge storage elements, provide self-aligned positioning references for manufacturing, and extend the charge storage capacity. This multi-functionality improves charge storage efficiency while avoiding additional complex structures, resolving the contradiction between productivity and device complexity
Solution Approach 2:
The lateral protrusion portions are formed during the stacking process before final charge storage element definition. This preliminary action establishes the spatial framework and separation structure in advance, enabling efficient charge storage while simplifying subsequent manufacturing steps and reducing overall device 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 configuration enhances memory storage density and efficiency by enabling precise placement and separation of charge storage elements, improving the overall performance of three-dimensional memory devices.
Implementation Method 1
the memory film comprises a tunneling dielectric layer and a vertical stack of discrete charge storage elements
Implementation Method 2
forming insulating layers comprising silicon oxide by performing an oxidation process that oxidizes surface portions of the silicon nitride layers and portions of the charge storage material layers
Data Source
AI summary
An alternating stack of disposable material layers and silicon nitride layers is formed over a substrate. Memory openings are formed through the alternating stack, and memory opening fill structures are formed in the memory openings, wherein each of the memory opening fill structures comprises a charge storage material layer, a tunneling dielectric layer, and a vertical semiconductor channel Laterally-extending cavities are formed by removing the disposable material layers selective to the silicon nitride layers and the memory opening fill structures. Insulating layers comprising silicon oxide are formed by oxidizing surface portions of the silicon nitride layers and portions of the charge storage material layers that are proximal to the laterally-extending cavities. Remaining portions of the charge storage material layers form vertical stacks of discrete charge storage elements. Remaining portions of the silicon nitride layers are replaced with electrically conductive layers.