Effect of gas condition on graphene synthesized by rapid thermal chemical vapor deposition

Graphene was synthesized using rapid thermal chemical vapor deposition (RT-CVD) equipment designed to produce large-area graphene at high speed. The effects of methane (CH₄), argon (Ar), and hydrogen (H₂) gases were investigated between 800°C and 1,000°C during heating and cooling in the graphene synthesis process. The findings reveal that multilayer domains increased due to hydrogen pretreatment with increase in temperature. Furthermore, when pretreated with the same gas, it was confirmed that the post-argon-treated sample cooled from 1,000°C to 800°C had a higher I_D/I_G value than that of the other samples. This result was consistent with the sheet resistance properties of graphene. The sample prepared in methane atmosphere maintained during both the pre-treatment and post-treatment demonstrated the lowest sheet resistance of 787.49 Ω/sq. Maintaining the methane gas atmosphere in the high-temperature region during graphene synthesis by RT-CVD reduced the defects and improved the electrical property.