Fin-Type Stacked Memory Device Shared Assist Gate
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Solution Overview
Problem
The challenge in nonvolatile semiconductor memory devices is to achieve higher integration and capacity while maintaining reliability, which is hindered by the need for complex fabrication techniques and the spacing requirements of assist gates in fin-type stacked structures, leading to increased pitch between these structures.
Innovation Solution
The solution involves a nonvolatile semiconductor memory device design where adjacent fin-type stacked structures are connected differently at their ends, allowing for a shared assist gate electrode configuration that reduces the pitch between assist gate electrodes and enhances integration, while maintaining reliability by ensuring that damage during patterning does not affect the channel path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between fin type stacked structures is increased to separate assist gates for independent control, then the assist gates can be independently patterned and controlled, but the pitch between fin type stacked structures increases, reducing integration density
Solution Approach 1:
The patent merges the assist gate electrodes of adjacent fin type stacked structures into a single shared electrode. This shared assist gate electrode extends across multiple fin type stacked structures, allowing them to be controlled together as a group. By combining the assist gate functions, the patent eliminates the need for separate assist gates, thereby reducing the pitch between fin type stacked structures and improving integration density while maintaining reliable control through the shared electrode.
2Area of moving object
If the pitch between fin type stacked structures is reduced for higher integration, then integration density increases, but the assist gate electrodes may interfere with each other or require complex patterning
Solution Approach 1:
The patent combines multiple assist gate electrodes into a single shared electrode that serves multiple fin type stacked structures. This merging approach simplifies the patterning process by reducing the number of separate electrodes that need to be formed, thereby lowering fabrication complexity. The shared electrode can be patterned as a single continuous structure, avoiding the need for complex multi-step patterning processes that would be required if separate assist gates were maintained at reduced pitches.
3Reliability
If the fin type stacked structures are arranged perpendicularly and joined at ends for stability, then structural reliability is enhanced, but the assist gates must be separated requiring greater distance
Solution Approach 1:
The patent merges the assist gate functions by creating a shared electrode that spans across multiple fin type stacked structures arranged in a perpendicular configuration. This approach maintains the stable perpendicular arrangement and end-joining of the fin type stacked structures while eliminating the need for lateral separation of assist gates. The shared electrode provides the necessary control function without requiring additional distance between the vertically arranged structures.
Data Source
AI summary
According to one embodiment, a memory device includes first and second fin type stacked structures each includes first to i-th memory strings (i is a natural number except 1) that are stacked in a first direction, the first and second fin type stacked structures which extend in a second direction and which are adjacent in a third direction, a first portion connected to one end in the second direction of the first fin type stacked structure, a width in the third direction of the first portion being greater than a width in the third direction of the first fin type stacked structure, and a second portion connected to one end in the second direction of the second fin type stacked structure, a width in the third direction of the second portion being greater than a width in the third direction of the second fin type stacked structure.