Grain Growth Promotion Layer for Semiconductor Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art interconnect structures suffer from low electromigration resistance due to a high number of electromigration paths resulting from the microstructure and average grain size of the conductive material, which is expected to worsen with the scaling of semiconductor devices.
Innovation Solution
The implementation of a grain growth promotion layer to form a conductive region within the interconnect structure with a bamboo microstructure and an average grain size larger than 0.05 microns, reducing electromigration by minimizing grain boundaries and enhancing the reliability and performance of the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional interconnect structures are used, then manufacturing is simpler, but electromigration resistance is low due to high number of electromigration paths
Solution Approach 1:
The patent applies local quality by creating a specific grain structure (bamboo microstructure with grains larger than 0.05 microns) in the conductive material region. This localized microstructural control reduces electromigration paths specifically where needed, without changing the overall interconnect structure. The grain growth promotion layer is applied locally at the conductive material interface to achieve this specific grain structure.
Solution Approach 2:
The patent uses composite materials by introducing a grain growth promotion layer (comprising Ru, Ir, Rh, Mo, Re, Hf, Nb or alloys thereof) in combination with the conductive material (Cu, Al, W or alloys). This composite structure promotes the formation of large-grained bamboo microstructure, which reduces electromigration while maintaining electrical conductivity.
2Reliability
If grain size is reduced, then more grains fit in the interconnect, but electromigration resistance decreases due to more grain boundaries
Solution Approach 1:
The patent applies parameter changes by modifying the grain size parameter to be larger than 0.05 microns and forming a bamboo microstructure where grains extend through the thickness of the conductive material. This parameter change reduces the number of grain boundaries and electromigration paths. The grain growth promotion layer facilitates achieving this specific grain size parameter.
3Reliability
If bamboo microstructure is formed with large grain size, then electromigration is reduced, but manufacturing process becomes more complex
Solution Approach 1:
The patent uses an intermediary approach by introducing a grain growth promotion layer as a mediator between the diffusion barrier and the conductive material. This intermediate layer facilitates the formation of large-grained bamboo microstructure during the filling process, achieving improved electromigration resistance without requiring complex post-processing steps.
4Reliability
If conventional polycrystalline microstructure is used, then manufacturing is easier, but electron scattering is higher and electrical resistance is higher
Solution Approach 1:
The patent applies local quality by creating a specific grain structure (bamboo microstructure with grains larger than 0.05 microns) in the conductive material region. This localized microstructural control reduces electromigration paths specifically where needed, without changing the overall interconnect structure. The grain growth promotion layer is applied locally at the conductive material interface to achieve this specific grain structure.
Solution Approach 2:
The patent uses composite materials by introducing a grain growth promotion layer (comprising Ru, Ir, Rh, Mo, Re, Hf, Nb or alloys thereof) in combination with the conductive material (Cu, Al, W or alloys). This composite structure promotes the formation of large-grained bamboo microstructure, which reduces electromigration while maintaining electrical conductivity.
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 solution significantly reduces electromigration, providing a conductive material with lower electron scattering and electrical resistance, resulting in improved performance and reliability, capable of withstanding higher current densities.
Implementation Method 1
a grain growth promotion layer which promotes the formation of a conductive region within the interconnect structure that has a bamboo microstructure and an average grain size of larger than 0.05 microns
Implementation Method 2
a diffusion barrier located within said at least one opening
Data Source
AI summary
An interconnect structure of the single or dual damascene type and a method of forming the same, which substantially reduces the electromigration problem that is exhibited by prior art interconnect structures, are provided. In accordance with the present invention, a grain growth promotion layer, which promotes the formation of a conductive region within the interconnect structure that has a bamboo microstructure and an average grain size of larger than 0.05 microns is utilized. The inventive structure has improved performance and reliability.