Semiconductor Storage Device Contact Plug Stacking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor storage devices face challenges in improving operation reliability, particularly when a peripheral circuit is provided below the memory cell array, making it difficult to allocate space for contact plugs.
Innovation Solution
The semiconductor storage device incorporates a design with a first conductive layer stacked on a substrate, a second conductive layer separated from the first in a third direction, and a contact plug extending in the first direction. This configuration includes a first insulating layer between the second and third conductive layers, surrounding a contact plug area, and a second area with a pillar penetrating the first conductive layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a peripheral circuit is provided below the memory cell array, then the device integration is improved, but it becomes difficult to allocate space for contact plugs
Solution Approach 1:
The patent transitions from a two-dimensional planar layout to a three-dimensional stacked architecture. Contact plugs are arranged in multiple layers (first contact plugs, second contact plugs, third contact plugs) at different heights, allowing simultaneous accommodation of peripheral circuits and contact plugs through vertical stacking rather than competing for horizontal space.
Solution Approach 2:
The patent implements nested positioning where second contact plugs are located beneath first contact plugs, and third contact plugs are positioned beneath second contact plugs in the vertical direction. This nested arrangement maximizes space utilization by stacking functional elements vertically, enabling both peripheral circuits and contact plugs to coexist in the limited device area.
2Reliability
If contact plugs are allocated in the memory cell array area, then electrical connectivity is improved, but the layout complexity increases
Solution Approach 1:
The patent divides the contact plug structure into multiple segmented components: first contact plugs extending from the first conductive layer to the second conductive layer, second contact plugs extending from the second conductive layer to the third conductive layer, and third contact plugs extending from the third conductive layer to the fourth conductive layer. This segmentation allows independent optimization and simplifies the manufacturing process for each contact plug type.
Solution Approach 2:
The patent introduces insulating layers as intermediary elements between different conductive layers and contact plugs. These insulating layers provide electrical isolation and structural support, facilitating the complex multi-layer connectivity while maintaining manufacturing feasibility through standardized fabrication processes.
Data Source
AI summary
A semiconductor storage device includes a first conductive layer, a second conductive layer, a third conductive layer, a contact plug, a memory trench extending between the second conductive layer and the third conductive layer. The memory trench is formed around the contact plug, and surrounds a first area in which the contact plug is disposed. A second area is separated from the first area and includes a pillar penetrating the first conductive layer. The second conductive layer extends between the first and second areas, and is connected to the first conductive layer. The third conductive layer is on the opposite side of the first area to the second area, and is connected to the first conductive layer.