Nanocrystalline Graphene Growth on Patterned Wiring for Low Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices miniaturize, the reduced line width of conductive wiring leads to increased current density and resistance, causing electromigration issues. There is a need for a method to selectively grow nanocrystalline graphene on substrates with desired patterns to reduce resistance.
Innovation Solution
A plasma chemical vapor deposition method is used to selectively grow nanocrystalline graphene on substrates with predetermined patterns. This involves arranging a substrate with a pattern in a reaction chamber, injecting a reaction gas mixture of carbon source, inert, and hydrogen gases, generating plasma, and growing nanocrystalline graphene at a controlled temperature and pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the line width of conductive wiring is reduced to achieve high integration, then the device size is reduced, but the resistance of the conductive wiring increases
Solution Approach 1:
The patent uses composite material structure by forming a cap layer comprising graphene and metal (such as copper) on the conductive wiring. This composite structure combines the low resistance of metal with the unique properties of graphene to reduce overall resistance and prevent electromigration, thereby solving the contradiction between reduced line width and increased resistance.
Solution Approach 2:
The patent applies local quality by selectively forming the graphene cap layer only on specific regions where electromigration is a concern. The cap layer is deposited on the upper surface of the conductive wiring in targeted areas, providing localized resistance reduction and electromigration protection without affecting the entire device structure.
2Quantity of substance
If conventional CVD method is used to grow graphene, then graphene can be synthesized, but the crystal size is at micrometer level instead of nanometer level
Solution Approach 1:
The patent applies parameter changes by modifying the CVD process conditions, specifically using plasma-enhanced CVD with controlled temperature (700-900°C), pressure, and gas composition (CH4, H2, and inert gas). These parameter adjustments enable precise control over crystal growth, producing nanocrystalline graphene with grain sizes of 1-100 nm instead of micrometer-level crystals from conventional CVD.
Solution Approach 2:
The patent uses periodic action through plasma treatment during the CVD process. The plasma is generated in periodic cycles to etch and refine the graphene crystals during growth, controlling the crystal size to nanometer scale while maintaining continuous graphene synthesis. This periodic plasma intervention prevents uncontrolled crystal coarsening.
3Manufacturing precision
If plasma CVD method is used to grow nanocrystalline graphene, then selective growth on patterned substrates is achieved, but the process requires precise control of multiple parameters
Solution Approach 1:
The patent applies preliminary action by pre-patterning the substrate with specific materials (such as metal patterns on dielectric substrate) before initiating the plasma CVD process. The substrate is prepared with desired geometric patterns and material compositions in advance, which then guide the selective growth of nanocrystalline graphene during plasma treatment, simplifying the overall process control.
Solution Approach 2:
The patent uses the substrate material pattern as an intermediary that mediates between the plasma treatment and the final graphene structure. The substrate's material composition and geometric pattern act as a template that directs where and how graphene grows during plasma CVD, enabling selective growth without requiring complex real-time process control.
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 method allows for the selective growth of nanocrystalline graphene on specific patterns, reducing the electrical resistance of conductive wiring and improving electromigration resistance, while maintaining a low process temperature and short growth time.
Implementation Method 1
generating a plasma of the reaction gas in the reaction chamber; and directly growing the nanocrystalline graphene on a surface of the desired and/or alternatively predetermined pattern by using the plasma of the reaction gas
Implementation Method 2
injecting a reaction gas into the reaction chamber, the reaction gas including a carbon source gas, an inert gas, and a hydrogen gas that are mixed
Data Source
AI summary
A method of forming nanocrystalline graphene according to an embodiment may include: arranging a substrate having a pattern in a reaction chamber; injecting a reaction gas into the reaction chamber, where the reaction gas includes a carbon source gas, an inert gas, and a hydrogen gas that are mixed; generating a plasma of the reaction gas in the reaction chamber; and directly growing the nanocrystalline graphene on a surface of the pattern using the plasma of the reaction gas at a process temperature. The pattern may include a first material and the substrate may include a second material different from the first material.