Composite Barrier Via Structure for Low-Resistance IC Interconnects
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Solution Overview
Problem
Integrated circuit devices face challenges in maintaining electrical reliability due to increased resistance and leakage current in metal wiring layers, as well as electromigration issues as they are downscaled.
Innovation Solution
The integration of a conductive barrier structure with multiple layers of metal nitride films and Ru films surrounding the upper metal plug, which reduces contact resistance and suppresses electromigration by enhancing barrier properties and preventing impurity penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If metal wiring layers are downscaled to improve integration density, then device miniaturization is achieved, but resistance increase and leakage current occur
Solution Approach 1:
The patent employs a composite barrier structure consisting of multiple metal nitride films (such as TaN, WN) combined with Ru films. This composite material approach creates a multi-layered barrier that effectively suppresses electromigration and prevents impurity penetration while maintaining low contact resistance, thereby resolving the contradiction between device downsizing and electrical reliability
Solution Approach 2:
The barrier structure is nested within the metal wiring layer configuration, with the conductive barrier structure positioned between the metal plug and the insulating structure. This nested arrangement allows the barrier function to be integrated within the existing wiring architecture without increasing overall device volume, thus maintaining miniaturization while improving reliability
2Volume of moving object
If metal wiring layers are downscaled to improve integration density, then device miniaturization is achieved, but electromigration increases
Solution Approach 1:
The multi-layered composite barrier structure combining metal nitride films with Ru films creates enhanced resistance to electromigration. The different materials provide complementary barrier properties that collectively prevent metal atom migration more effectively than single-material barriers, addressing the electromigration issue in downscaled devices
Solution Approach 2:
The conductive barrier structure is specifically positioned at critical interfaces where electromigration occurs most severely - between the metal plug and insulating structure. This localized barrier placement targets the specific regions most susceptible to electromigration without requiring complete restructuring of the entire wiring system
3Reliability
If conductive barrier structure with multiple layers is used to suppress electromigration, then reliability is improved, but device complexity increases
Solution Approach 1:
The barrier function is segmented into multiple thin layers of different materials rather than using a single thick barrier layer. This segmentation allows each layer to perform specific functions (electromigration suppression, impurity blocking, contact resistance reduction) while maintaining overall structural simplicity and compatibility with existing manufacturing processes
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 configuration enhances the reliability of the integrated circuit device by reducing contact resistance and preventing metal migration and impurity penetration, thereby improving the overall performance and longevity of the metal wiring layers.
Implementation Method 1
an upper conductive barrier structure that surrounds a sidewall and a lower surface of the upper metal plug... preventing impurity penetration
Implementation Method 2
which reduces contact resistance and suppresses electromigration by enhancing barrier properties
Implementation Method 3
suppresses electromigration by enhancing barrier properties
Data Source
AI summary
An integrated circuit device includes a lower insulating structure disposed over a substrate, a lower wiring structure that passes through the lower insulating structure in a vertical direction, an upper insulating structure disposed on the lower insulating structure, and an upper wiring structure that passes through the upper insulating structure in the vertical direction and contacts the lower wiring structure. The upper wiring structure includes an upper metal plug and an upper conductive barrier structure that surrounds a sidewall and a lower surface of the upper metal plug. The upper conductive barrier structure includes a first barrier portion that faces a sidewall of the upper insulating structure, and a second barrier portion interposed between the lower wiring structure and the upper metal plug. The first barrier portion and the second barrier portion have different structures from each other.