Semiconductor Interconnects with Twin Boundaries for Electromigration Resistance
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Solution Overview
Problem
Existing interconnect structures in semiconductor devices face reliability issues due to electromigration and stress migration, which degrade performance as device geometries shrink, leading to increased resistivity and potential device failure.
Innovation Solution
Incorporating high-density twin boundaries in the conductive structure, formed through specific electrodeposition processes and lattice mismatch techniques, to suppress electromigration and stress migration, while maintaining resistance and adhesion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional interconnect structures are used, then device density can be increased through geometry shrinkage, but electromigration and stress migration occur leading to increased resistivity and device failure
Solution Approach 1:
The patent changes the crystallographic parameters of the conductive material by introducing twin boundaries with specific orientations (e.g., {111} twin boundaries in FCC metals). This parameter change in the material structure creates barriers to dislocation motion and atomic migration, thereby suppressing electromigration and stress migration while maintaining the scaled geometry needed for high device density
Solution Approach 2:
The patent creates a composite microstructure within the conductive material by combining regions with different crystallographic orientations separated by twin boundaries. This composite structure at the micro-scale provides both the electrical conductivity needed for interconnect function and the structural barriers needed to prevent migration phenomena, resolving the reliability issue while maintaining device density
2Productivity
If geometry shrinkage is pursued to increase device density, then more devices can be packed, but electromigration and stress migration effects are exacerbated
Solution Approach 1:
The patent introduces local variations in crystallographic quality by creating twin boundaries at specific locations within the conductive material. These local structural features act as barriers to atomic migration and dislocation motion, providing localized protection against electromigration and stress migration effects that would otherwise be exacerbated by geometry shrinkage
Solution Approach 2:
The patent modifies the microstructural parameters of the conductive material by controlling the density, orientation, and spacing of twin boundaries. This parameter change creates a hierarchy of length scales where the twin boundary spacing is much smaller than the overall interconnect dimensions, allowing the material to maintain low resistivity while providing frequent barriers to migration 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
The implementation of high-density twin boundaries effectively reduces electromigration and stress migration, enhancing the reliability of semiconductor device interconnects without increasing resistivity, thereby improving device performance and longevity.
Implementation Method 1
Incorporating high-density twin boundaries in the conductive structure, formed through specific electrodeposition processes and lattice mismatch techniques, to suppress electromigration and stress migration
Implementation Method 2
formed through specific electrodeposition processes
Data Source
AI summary
A method of forming a semiconductor device structure includes: forming a first conductive structure over a substrate, the first conductive structure including twin boundaries; and wherein the forming the first conductive structure includes manipulating process conditions so as to promote formation of the twin boundaries resulting in a promoted density of twin boundaries such that the first conductive structure has an increased failure current density (FCD) relative to a baseline FCD of an otherwise substantially corresponding second conductive structure which has an unpromoted density of twin boundaries, the unpromoted density being less than the promoted density and such that the first conductive structure has a resistance which is substantially the same as the second conductive structure.