The Study of Graphene Materials Grown by Chemical Vapor Deposition and the Single-layer Graphene Transistors
Date Issued
2014
Date
2014
Author(s)
Ho, Po-Kuan
Abstract
The characteristics of single-layer graphene material and transistors was discussed in this thesis. The graphene grown by chemical vapor deposition was transferred from Cu foil to the target substrate. The single-layer graphene is visible on specific substrate due to the light interference, and Raman spectroscopy was used to certify the thickness and the quality of the graphene. Measured by I-V measurement and Hall measurement, the sheet resistance is 2000 Ω/square, hole mobility is 317 cm^2/V∙s, and sheet hole concentration is 8.8×10^12 cm^(-2) for single-layer graphene. Hall measurement was conducted with varied temperature as well, and the activation energy of 24 meV was fitted. The contact resistivity was calculated by transmission line measurement, and it is 5.60×10^3 Ω∙μm and 6.65×10^2 Ω∙μm with the contact metal of Au/Ti and Au respectively. The transistors with different structure were fabricated to improve the electrical performance and the reliability of the procedures. Protection of channel and Graphene-last structure enhanced the field effect mobility from 126 cm^2/V∙s to 226 cm^2/V∙s and 435 cm^2/V∙s respectively. Furthermore, the insulator capacitance was increased with thinner dielectric layer. The on/off current ratio of 2.7 was observed, and the field effect mobility of 834 cm^2/V∙s was measured.
Subjects
Chemical Vapor Deposition
Graphene
Materials
Transistors
Graphene-last
Transfer
Type
thesis
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