Stacked Conductive Layer Structure for Low-Resistance Word Lines
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Solution Overview
Problem
Miniaturization of semiconductor devices leads to increased wiring resistance in word lines due to reduced conductive layer height, and thinning or omitting barrier films to reduce resistance degrades reliability such as leakage characteristics.
Innovation Solution
A semiconductor device with a stacked body of alternately arranged conductive and insulation layers, where the conductive layers include a first metal layer with a higher content of a reactive substance and a second metal layer with a lower content, eliminating the need for a barrier film by optimizing the chemical vapor deposition process to reduce fluorine diffusion and enhance adhesiveness between layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the height of conductive layers is reduced for miniaturization, then the device size is reduced, but the wiring resistance of word lines increases
Solution Approach 1:
The conductive layer is constructed as a composite structure with a first metal layer (tungsten) and a second metal layer (copper), where each layer contributes different properties. The tungsten layer provides low resistance and good adhesion, while the copper layer provides excellent conductivity, achieving low wiring resistance in a miniaturized structure
Solution Approach 2:
The patent changes the chemical composition parameters of the conductive layer by controlling the content of reactive substances (such as carbon and nitrogen) in the tungsten layer. By optimizing these compositional parameters, the layer achieves both low resistance and high adhesion without requiring additional barrier films
2Reliability
If additional barrier films are added to improve leakage characteristics, then the reliability improves, but the device complexity and manufacturing steps increase
Solution Approach 1:
The patent merges the functions of the conductive layer and the barrier layer into a single integrated structure. The first metal layer (tungsten) combines the electrical conduction function with the barrier function, eliminating the need for separate barrier films and reducing structural complexity while maintaining leakage prevention
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 approach reduces wiring resistance and improves reliability by minimizing leakage characteristics without the need for additional barrier films, maintaining performance within limited height constraints.
Implementation Method 1
the conductive layers each include a first metal layer and a second metal layer. The first metal layer contains a first metal element and a substance that is reactive with a material gas containing the first metal element
Data Source
AI summary
A semiconductor device according to an embodiment includes a stacked body including a plurality of conductive layers and a plurality of first insulation layers alternately stacked in a first direction. The conductive layers each include a first metal layer and a second metal layer. The first metal layer contains a first metal element and a substance that is chemically reactive with a material gas containing the first metal element. The second metal layer contains the first metal element and has a lower content of the substance than the first metal layer. The first metal layer is disposed between the first insulation layers and the second metal layer.