Analysis of Thermal Treatment Influence on Graphene Oxide Thin Film Deposited by Modified Coating Process

Graphene Oxide (GO) is made up of single or several closely-spaced graphene sheets with plenty of functional group, and can be considered as insulator. Recently GO material is attracting more and more interest for gas sensor application because of its excellent properties. In this work, GO dispersion was prepared by dispersing high-purity GO nanosheets into water. Isopropyl alcohol (IPA) and related solvent were used to adjust its viscosity and surface tension. Modified coating process was developed to get a more uniform GO thin film. After GO film deposition, it was then annealed to remove the residue solvent and make the film stable. Thickness uniformity was checked by Cross-Sectional SEM. For 2 inch wafer sample, 1 sigma of within wafer GO film uniformity can reach to less than 3 percent by modified coating process. XRD was used to check influence of different annealing condition on GO film. As shown in XRD data, 2Theta value of XRD peak angle was increasing with increasing temperature and time. According to Bragg’s law, 2theta value is inversely proportional to lattice distance, and increasing of 2theta value means decreasing of GO film layer distance, which may indicate the decomposition and loss of oxygen-contained functional group.