Semiconductor Plug Structure With Diffusion-Barrier Sidewall Insulation
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Solution Overview
Problem
The scaling down of semiconductor devices poses challenges in achieving improved quality, yield, performance, and reliability while reducing complexity, particularly due to issues such as metal ion diffusion leading to shorts between adjacent conductive features.
Innovation Solution
A semiconductor device design featuring a plug structure with a bottom conductive layer, a middle conductive layer, a top conductive layer, and an insulating covering layer, where the insulating covering layer prevents metal ions from diffusing and contaminating adjacent elements, along with a method for fabricating this structure involving sequential formation of conductive layers and dielectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal layers are used in plug structures, then electrical conductivity is improved, but metal ion diffusion causes shorts between adjacent conductive features
Solution Approach 1:
An insulating covering layer is introduced as an intermediary between the middle conductive layer and the surrounding environment. This covering layer acts as a barrier that prevents metal ions from the conductive layer from diffusing into adjacent dielectric materials, thereby eliminating the harmful effect of metal ion diffusion while preserving the electrical conductivity function of the plug structure.
Solution Approach 2:
A thin insulating covering layer is deposited over the middle conductive layer to form a protective shell. This thin film structure effectively contains the metal ions within the conductive layer, preventing their diffusion into surrounding materials, while maintaining the overall plug structure's electrical functionality.
2Productivity
If device dimensions are scaled down, then computing ability is improved, but manufacturing complexity and defects increase
Solution Approach 1:
The insulating covering layer is formed over the middle conductive layer before subsequent processing steps. This preliminary protective action prevents metal ion diffusion issues from arising during later manufacturing steps, thereby simplifying the overall manufacturing process and reducing defects even as device dimensions are scaled down to improve computing ability.
3Length of moving object
If conductive layers are made thinner, then device scaling is improved, but metal ion diffusion becomes more problematic
Solution Approach 1:
The insulating covering layer serves as a mediator that decouples the relationship between conductive layer thickness and metal ion diffusion. By providing this protective barrier, thinner conductive layers can be used for device scaling without the increased risk of metal ion diffusion, as the covering layer blocks the diffusion path regardless of the conductive layer thickness.
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
The design enhances the reliability and electrical characterization performance of semiconductor devices by preventing metal ion diffusion and reducing shorts between conductive features.
Implementation Method 1
the insulating covering layer may prevent the metal ions in the middle conductive layer from diffusing out to contaminate adjacent elements
Data Source
AI summary
A method for fabricating a semiconductor device includes providing a substrate; sequentially forming a layer of first conductive material, a layer of second conductive material, a layer of third conductive material, and an anti-reflective coating layer over the substrate; performing a plug etch process to turn the layer of first conductive material into a bottom conductive layer on the substrate, turn the layer of second conductive material into a middle conductive layer on the bottom conductive layer, and turn the layer of third conductive material into a top conductive layer on the middle conductive layer; selectively forming an insulating covering layer on a sidewall of the middle conductive layer, wherein the bottom conductive layer, the middle conductive layer, the top conductive layer, and the insulating covering layer together configure a plug structure; and forming a first dielectric layer on the substrate and surrounding the plug structure.