| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 105 === Graphenes were deposited on nickel foils by inductively coupled plasma (ICP)-assisted thermal chemical vapor deposition. Methane, ammonia (NH3), and hydrogen (H2) were used as precursor gases, and the effects of different NH3 flow rates, different H2 etching times, and different rf-powers on the properties of graphenes are investigated. The residual gas of process, microstructure, transmittance, and electrical properties of graphenes were analyzed by residual gas analyzer, Raman scattering spectrometer (RSS), UV-Visible spectrophotometer, and Hall effect measurement system. Residual gas analysis results show that the H2 and nitrogen atoms increase with increasing the NH3 flow rate. According to the results of RSS and UV-Visible, the number of graphene layers decreases with increasing the NH3 flow rate. This is because the NH3 gas has the etching effect. When the NH4 flow rate is 6 sccm, the graphene has the least defects. Additionally, Raman mapping show that the uniformity and the coverage of wafer-size graphene are good. The number of graphene layers increases with raising working temperature and rf- power, so appropriate etching time is required to reduce the defects. Finally, RSS and Hall effect results show that are parameters with the working temperature is 1273 K, the H2 etching time is 60 s and the rf-power is 150 W, the graphene has the best quality.
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