Microwave Plasma CVD Pressure Sequencing for Clean Graphene Films
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Solution Overview
Problem
Graphene film formation using microwave plasma CVD faces challenges such as irregular particle increase and difficulty in igniting plasma at low pressures, which can lead to unexpected particle generation during plasma ignition.
Innovation Solution
A substrate processing method involving a plasma processing apparatus that controls internal pressure and microwave power to generate plasma at specific pressures and power levels, suppressing unexpected particle generation by managing the plasma ignition sequence and carbon-containing gas supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma is ignited at low pressure to form graphene film, then film formation efficiency is improved, but plasma ignition becomes difficult and unexpected particles are generated
Solution Approach 1:
The patent applies preliminary action by first igniting plasma at a first pressure before reducing the pressure to a second lower pressure for graphene film formation. This preliminary plasma ignition at higher pressure ensures stable plasma establishment before transitioning to the low-pressure film formation stage, preventing unexpected particle generation while maintaining film formation efficiency
Solution Approach 2:
The patent employs dynamics by dynamically adjusting the pressure during the process - maintaining a first pressure during plasma ignition and then reducing to a second pressure for film formation. This dynamic pressure control allows the system to optimize conditions at each stage, ensuring both reliable plasma ignition and efficient graphene film formation
2Productivity
If microwave power is increased to generate plasma at low pressure, then film formation is improved, but unexpected particles are generated during plasma ignition
Solution Approach 1:
The patent applies preliminary action by first generating plasma at a higher first pressure before reducing pressure to the second level for film formation. This preliminary plasma generation at higher pressure prevents unexpected particle formation that would occur if plasma were ignited directly at low pressure, while still enabling high-quality film formation in the subsequent low-pressure stage
Solution Approach 2:
The patent employs parameter changes by transitioning from a first pressure to a second lower pressure, and from a first microwave power to a second microwave power. These controlled parameter changes allow the system to avoid the harmful effect of particle generation during plasma ignition while maintaining the benefits of low-pressure plasma for high-quality graphene film formation
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 effectively suppresses the generation of unexpected particles during graphene film formation, improving the consistency and quality of the film by stabilizing the plasma state and reducing particle formation sources.
Implementation Method 1
supplying a plasma generating gas into the process container to generate plasma of first power at a first pressure
Implementation Method 2
a microwave plasma CVD (Chemical Vapor Deposition) device is used to form a graphene film
Implementation Method 3
supplying a carbon-containing gas into the process container to form a graphene film on the substrate
Data Source
AI summary
A method of processing a substrate includes placing the substrate on a stage in a process container, supplying a plasma generating gas into the process container to generate plasma of first power at a first pressure, controlling an inside of the process container to a second pressure lower than the first pressure, and supplying a carbon-containing gas into the process container to form a graphene film on the substrate.