Variable Resistance Memory Contact Plug Barrier Layers
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Solution Overview
Problem
Existing variable resistance memory devices face challenges in reliably connecting metal interconnection layers to variable resistance layers without damaging either component, which affects the reliability and performance of the memory device.
Innovation Solution
A variable resistance memory device design that includes a substrate with a metal interconnection layer, an interlayer insulating layer, a barrier metal layer with sub-barrier metal layers, and a plug metal layer to form a contact plug, allowing for reliable electrical connection between the metal interconnection layer and the variable resistance structure without causing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal interconnection layer is directly connected to a variable resistance layer, then the electrical connection is simple, but the metal interconnection layer or variable resistance layer may be damaged
Solution Approach 1:
The patent introduces a contact plug structure comprising multiple barrier metal layers (first barrier metal layer, second barrier metal layer, and third barrier metal layer) as intermediary components between the metal interconnection layer and the variable resistance layer. These barrier metal layers prevent direct contact that would cause damage, while enabling reliable electrical connection through the layered protective structure.
Solution Approach 2:
The contact plug is constructed as a composite structure with multiple different metal layers, each serving specific functions: the first barrier metal layer prevents elution of the metal interconnection layer, the second barrier metal layer prevents diffusion, and the third barrier metal layer prevents reaction with the variable resistance layer. This composite approach resolves the contradiction by combining multiple materials with complementary protective properties.
2Ease of manufacture
If a simple contact structure is used, then the manufacturing process is simple, but elution, diffusion, and reaction issues occur during connection
Solution Approach 1:
The contact plug is segmented into multiple distinct barrier metal layers, where each layer addresses a specific reliability issue: the first barrier metal layer prevents elution of the metal interconnection layer, the second barrier metal layer prevents diffusion, and the third barrier metal layer prevents reaction with the variable resistance layer. This segmentation allows each layer to be optimized for its specific protective function while maintaining a relatively simple overall manufacturing process.
Data Source
AI summary
A variable resistance memory device includes a metal interconnection layer on a substrate, an interlayer insulating layer on the metal interconnection layer and defining a contact hole for exposing a portion of the metal interconnection layer, a barrier metal layer including a plurality of sub-barrier metal layers inside the contact hole, a plug metal layer on the barrier metal layer and burying the contact hole, and a variable resistance structure on the barrier metal layer and the plug metal layer.