Size-Filtered Multimetal Interconnect Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interconnect level structures in semiconductor chips face challenges in integrating metal structures with different properties, such as electromigration resistance and electrical resistivity, due to the need for compromise among various device performance requirements.
Innovation Solution
A size-filtered metal interconnect structure is created by forming trenches of different widths in a dielectric layer, where a blocking material is deposited and selectively etched to allow for the formation of metal structures with varying widths and compositions, enabling the use of materials with specific electromigration resistance and electrical resistivity for anode, cathode, and fuselink components in an electrically programmable fuse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different metal structures require different properties for optimal performance, then device performance is improved, but integration within the same metal interconnect level becomes difficult
Solution Approach 1:
The patent segments the metal interconnect level into different regions based on trench width. Wide trenches receive a first metal material optimized for electromigration resistance, while narrow trenches receive a second metal material optimized for other properties. This spatial segmentation allows different metal structures to have different properties within the same interconnect level, resolving the contradiction between performance optimization and integration difficulty.
Solution Approach 2:
The patent applies local quality by assigning different metal materials to different local regions (wide vs. narrow trenches) based on their specific requirements. Each local region receives the material property best suited for its function, enabling optimal performance for each metal structure while maintaining integration at the same interconnect level.
2Ease of manufacture
If a single metal material is used for all metal structures, then manufacturing is simplified, but optimal performance for different device components cannot be achieved
Solution Approach 1:
The patent changes the parameter of metal material type based on trench width. By using trench width as the distinguishing parameter, the process automatically selects the appropriate metal material (first metal for wide trenches, second metal for narrow trenches). This parameter-based differentiation maintains manufacturing simplicity through a systematic approach while enabling optimal performance for different device components.
3Reliability
If metal structures with different compositions are formed, then electromigration resistance and electrical conductivity are enhanced, but the manufacturing process becomes more complex
Solution Approach 1:
The patent applies local quality by assigning different metal materials to different local regions (wide vs. narrow trenches) based on their specific requirements. Each local region receives the material property best suited for its function, enabling optimal performance for each metal structure while maintaining integration at the same interconnect level.
Solution Approach 2:
The patent changes the parameter of metal material type based on trench width. By using trench width as the distinguishing parameter, the process automatically selects the appropriate metal material (first metal for wide trenches, second metal for narrow trenches). This parameter-based differentiation maintains manufacturing simplicity through a systematic approach while enabling optimal performance for different device components.
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 allows for the formation of metal structures with tailored properties, enhancing electromigration resistance and electrical conductivity, thereby improving the performance and efficiency of interconnects in semiconductor chips.
Implementation Method 1
A blocking material layer is conformally deposited to completely fill trenches having a width less than a threshold width
Implementation Method 2
An isotropic etch is performed to remove the blocking material layer in wide trenches, i.e., trenches having a width greater than the threshold width
Data Source
AI summary
A size-filtered metal interconnect structure allows formation of metal structures having different compositions. Trenches having different widths are formed in a dielectric material layer. A blocking material layer is conformally deposited to completely fill trenches having a width less than a threshold width. An isotropic etch is performed to remove the blocking material layer in wide trenches, i.e., trenches having a width greater than the threshold width, while narrow trenches, i.e., trenches having a width less than the threshold width, remain plugged with remaining portions of the blocking material layer. The wide trenches are filled and planarized with a first metal to form first metal structures having a width greater than the critical width. The remaining portions of the blocking material layer are removed to form cavities, which are filled with a second metal to form second metal structures having a width less than the critical width.