Semiconductor Wiring Structure With Capping Layer Pattern
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Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in forming reliable contact plugs due to alignment errors and chemical damage, leading to increased contact resistance and failure rates as wiring dimensions shrink.
Innovation Solution
A semiconductor device structure featuring a capping layer pattern within the contact openings to prevent chemical permeation, ensuring accurate contact between contact plugs and improving electrical characteristics by using a capping layer pattern that encloses the contact plugs and has etching selectivity relative to the insulation layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the contact hole size is reduced to accommodate smaller wiring dimensions, then the integration density is improved, but the alignment error margin is reduced and misalignment likelihood increases
Solution Approach 1:
A capping layer is introduced as an intermediary protective structure between the contact plug and the etching chemicals. This capping layer has etching selectivity that allows it to be removed after protecting the contact plug during the etching process, thereby enabling precise contact hole formation without direct chemical damage to the contact plug
2Area of moving object
If wet cleaning or wet etching processes are used to enlarge contact hole width, then the contact hole opening is improved, but chemical permeation damages the underlying contact plug or conductive wiring
Solution Approach 1:
The capping layer is formed on the contact plug before the wet etching process to preemptively protect it from chemical permeation. The capping layer's etching selectivity ensures it remains intact during the etching process that enlarges the contact hole, preventing the harmful chemical action from reaching the contact plug
Solution Approach 2:
The capping layer serves as a protective intermediary that allows the wet etching process to proceed with enlarged contact hole formation while preventing direct chemical contact with the contact plug, thus resolving the contradiction between hole enlargement and chemical damage prevention
3Length of stationary object
If the contact plug has high aspect ratio to connect adjacent wirings, then the vertical connectivity is improved, but the difficulty of forming contact plugs at desired positions increases
Solution Approach 1:
The contact plug is formed in advance with the required high aspect ratio structure before the contact hole etching process. The capping layer is then formed on this pre-formed contact plug, protecting it during subsequent processing steps, thereby enabling the formation of high aspect ratio contact plugs without compromising manufacturability
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 capping layer pattern effectively prevents chemical damage and misalignment issues, enhancing the reliability and electrical performance of semiconductor devices by maintaining contact integrity and reducing contact failures.
Implementation Method 1
a capping layer pattern within the contact openings to prevent chemical permeation
Data Source
AI summary
A wiring structure in a semiconductor device may include a first insulation layer formed on a substrate, a first contact plug, a capping layer pattern, a second insulation layer and a second contact plug. The first insulation layer has a first opening that exposes a contact region of the substrate. The first contact plug is formed on the contact region to partially fill up the first opening. The capping layer pattern is formed on the first contact plug to fill up the first opening. The second insulation layer is formed on the capping layer pattern and the first insulation layer. The second insulation layer has a second opening passing through the capping layer pattern to expose the first contact plug. The second contact plug is formed on the first contact plug in the second opening. Since the wiring structure includes the capping layer pattern, the wiring structure may prevent a contact failure by preventing chemicals from permeating into the first contact plug.