Paper PS1-TuM6
Atomic Layer Etching of Graphene using O₂ Radical and Ar Neutral Beam

Tuesday, October 19, 2010, 9:40 am, Room Aztec

Graphene is a two-dimensional hexagonal lattice of carbon atoms with the thickness of one or a few atomic layers. Due to its material stability and strength, absence of defects, and unique electronic band-structure, graphene holds considerable promise for a number of applications in nanoscale electronics, optoelectronics, and mechanics in addition to showing fundamental interest in condensed matter physics. Many potential applications, such as graphene-based high-speed field-effect transistors, require graphene to be patterned to the nanoscale and, in some cases, graphene needs to be etched precisely with atomic layer precision. However, through the conventional reactive ion etching, it is difficult to control the etch depth precisely due to the fluctuation of the etch process in addition to the damage to the graphene by the reactive ions.

In this study, to overcome the above problems, the atomic layer etching technique (ALET) has been applied in the etching of graphene, and the etch characteristics of graphene by ALET were investigated. For the adsorption gas, O₂ was used, and Ar neutral beam was used for the desorption of the adsorbed compound. For the few layer graphene deposited on the SiO₂ (300 nm)/ Si substrate, the monolayer etching condition of graphene was observed by supplying O₂ radical at a pressure higher than the critical pressure during the adsorption step and by supplying an Ar beam at a dose higher than the critical dose. Self-limited etching of graphene could be obtained using O₂ radical ALET.