3D Memory Contact Plug Spacer Structure Against Electrical Bridging
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Solution Overview
Problem
The integration limit of semiconductor devices with single-layer memory cells on a substrate and the need for improved operational reliability in three-dimensional semiconductor devices.
Innovation Solution
A semiconductor device structure featuring a first contact plug with varying widths, surrounded by multiple spacers to maintain distance and prevent electrical bridges, and a manufacturing method involving sacrificial layers and spacer formations to ensure stable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If single-layer memory cells are used on a substrate, then manufacturing process is simpler, but integration density reaches its limit
Solution Approach 1:
The patent transitions from two-dimensional single-layer memory cell arrangement to three-dimensional stacked memory cell structure. Multiple memory cell layers are vertically stacked on the substrate, enabling significant increase in integration density while maintaining manufacturing feasibility through adapted fabrication processes
2Quantity of substance
If three-dimensional stacked memory cells are implemented, then integration density improves, but manufacturing complexity increases
Solution Approach 1:
The manufacturing process is segmented into distinct stages: forming sacrificial layers, creating contact holes through specific openings, depositing spacer layers, and removing sacrificial materials. Each stage is independently controlled and optimized, making the complex three-dimensional fabrication process manageable and repeatable
Solution Approach 2:
Sacrificial layers are formed in advance before contact holes are created. These preliminary sacrificial structures define the spatial configuration for subsequent contact hole formation and spacer deposition, enabling precise three-dimensional positioning without requiring complex real-time alignment processes
3Ease of manufacture
If contact plugs are formed without spacers, then manufacturing process is simpler, but electrical bridges may occur reducing reliability
Solution Approach 1:
Spacer layers are introduced as intermediary structures between contact plugs and surrounding materials. These spacers provide electrical isolation and physical separation, preventing harmful electrical bridges while maintaining accurate contact plug alignment and connection reliability
4Ease of manufacture
If contact plug alignment is not precisely controlled, then manufacturing is easier, but device performance deteriorates due to misalignment
Solution Approach 1:
The spacer layers are formed through conformal deposition processes that automatically self-align to the contact hole structures. The spacers self-adjust to the contact plug positions and dimensions, eliminating the need for separate alignment steps and ensuring precise positioning without adding manufacturing complexity
Data Source
AI summary
A semiconductor device includes a first contact plug penetrating a source structure, the first contact plug having a first portion having a first width and a second portion having a second width that is larger than the first width, a stack formed on the source structure and the first contact plug, a second contact plug penetrating the stack, the second contact plug connected to the first contact plug, a first spacer surrounding the first portion and the second portion of the first contact plug, and a second spacer surrounding the first spacer to surround the second portion of the first contact plug.