Interconnect Barrier Projections for Diffusion-Resistant Contacts
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Solution Overview
Problem
The challenge of scaling down semiconductor devices has led to issues such as increased diffusion of conductive materials, which can affect the reliability and performance of interconnect structures in integrated circuits.
Innovation Solution
The formation of conductive structures with a barrier layer that surrounds the upper corners and sides, creating a profile similar to 'tiger teeth', along with a barrier layer extending below the top grain boundary, reduces diffusion by increasing the surface area in contact with the barrier material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If geometry size is decreased to increase functional density, then production efficiency is improved and costs are lowered, but diffusion of conductive materials increases affecting reliability
Solution Approach 1:
The barrier layer is applied selectively at critical locations where diffusion occurs most prominently, specifically at the upper corners and sides of conductive structures. This localized approach prevents excessive diffusion at these high-risk areas without requiring a complete redesign of the entire interconnect structure, thus maintaining reliability while supporting scaled geometries
Solution Approach 2:
The barrier layer extends in the vertical dimension below the top grain boundary of the conductive structure, creating downward projections. This vertical extension adds a new dimension to the barrier coverage, increasing the surface area in contact with the barrier material and providing enhanced diffusion prevention without increasing lateral footprint
2Reliability
If barrier layer surface area in contact with conductive material is increased to reduce diffusion, then interconnect integrity is improved, but device complexity increases
Solution Approach 1:
The barrier layer is concentrated at the upper corners and sides of the conductive structure where diffusion is most problematic. This localized application increases the effective barrier surface area at critical locations without requiring a complex multi-layer structure throughout the entire device, thus improving integrity while limiting complexity
Solution Approach 2:
The barrier layer extends vertically downward below the top grain boundary, utilizing the vertical dimension to increase contact surface area. This approach achieves enhanced diffusion prevention through vertical extension rather than through complex lateral multi-layer structures, improving reliability while maintaining relatively simple device architecture
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 enhances the integrity of interconnect structures by minimizing the diffusion of conductive materials, thereby improving the reliability and performance of semiconductor devices.
Implementation Method 1
The challenge of scaling down semiconductor devices has led to issues such as increased diffusion of conductive materials
Data Source
AI summary
Provided are devices with conductive contacts and methods for forming such devices. A method includes forming a lower conductive contact in a dielectric material and over a structure, wherein the lower conductive contact has opposite sidewalls that extend to and terminate at a top surface. The method also includes separating an upper portion of each sidewall from the dielectric material and locating a barrier material between the upper portion of each sidewall and the dielectric material. Further, the method includes forming an upper conductive contact over the lower conductive contact.