Copper Interconnect Residue Conversion for Leakage Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As integrated circuit component sizes decrease, electromigration-induced failures become a concern due to metallic residue left behind during metal cap deposition in copper interconnects, leading to leakage currents and time-dependent dielectric breakdown.
Innovation Solution
A post-deposition treatment process converts metallic residue into insulating material using nitrogen-based, oxygen-based, or silane-based ambients, rendering it electrically inert and preventing conductive pathways between interconnects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic cap is disposed on top of copper interconnects to improve electromigration resistance, then higher currents can flow through the conductor, but metallic residue is formed during deposition which creates leakage currents and dielectric breakdown
Solution Approach 1:
The patent converts the harmful metallic residue into a beneficial insulating material by exposing it to oxygen plasma or oxidizing chemicals. This transformation changes the residue from a conductive contaminant causing leakage currents into a non-conductive protective layer, thereby eliminating the harmful effect while retaining the electromigration protection benefits of the metallic cap
Solution Approach 2:
The patent changes the chemical state of the metallic residue from metallic (conductive) to oxidized (insulating). By controlling the oxidation process through plasma treatment or chemical exposure, the electrical conductivity parameter of the residue is fundamentally altered, preventing leakage currents and dielectric breakdown
2Productivity
If component sizes are decreased to increase integration density, then more circuits can be packed into the chip, but electromigration-induced failures become more frequent due to residue formation
Solution Approach 1:
By converting the residue into an insulating material, the patent eliminates the source of electromigration-induced failures. This allows continued scaling to higher integration densities without the penalty of increased failure rates from leakage currents and dielectric breakdown
Solution Approach 2:
The oxidized residue creates an inert, non-conductive environment around the interconnects, preventing electrical breakdown and electromigration-related failures. This inert layer protects the underlying copper structure even as dimensions are reduced and current densities increase
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
Significantly reduces leakage currents and improves yield by mitigating failures related to shorting and time-dependent dielectric breakdown, maintaining reliability of copper interconnects without degrading performance.
Implementation Method 1
oxidation converts the metallic residue 42 into the insulating material 52
Implementation Method 2
nitridation converts the metallic residue 42 into the insulating material 52
Implementation Method 3
silylation converts the metallic residue 42 into the insulating material 52
Data Source
AI summary
Techniques relate to treating metallic interconnects of semiconductors. A metallic interconnect is formed in a layer. A metallic cap is disposed on top of the metallic interconnect. Any metallic residue, formed during the disposing of the metallic cap, is converted into insulating material.