Etching Characteristics of Graphene Film for Electronic Devices Using Inductively Coupled Plasma

Abstract

In this work, we studied the etching characteristics of graphene film in O-2/Ar inductively coupled plasmas. We determined the relationship between the plasma state and the change in the graphene surface to understand the etch mechanism. The resistance of the graphene film increased with increasing source power. With increasing source power, the surface roughness decreased and the Raman intensity ratio, i.e., ID/IG, increased. In addition, the ion current density and the optical emission intensity of O radicals increased with increasing source power. This indicated that more O radicals could react on the damaged site that was generated by ion bombardment. The highest sheet resistance was measured at an Ar fraction of 50% in the O-2/Ar gas mixture. On the other hand, the sheet resistances of pure Ar and O-2 gas plasmas were nearly the same. We confirmed that the O-2/Ar gas mixtures were more advantageous for etching graphene film, compared to pure Ar or O-2 plasmas. We concluded that the bombardment of Ar ions physically destroys the bonding in graphene. At the same time, the O radicals reacted chemically with graphene, forming CO gas as the etch product.