Defect formation in single layer graphene under extreme ultraviolet irradiation

- Study two mechanisms for inducing defects in graphene during extreme ultraviolet irradiation.
- Defects formed due to Photon induced chemical reactions with residual gases.
- Defects also due to breaking sp2 bonds by photon and/or photoelectrons induced bond cleaving.
- TPD experiments prove that EUV radiation results in water dissociation on the graphene surface.
- Provides the starting point to study patterning graphene structures without using resists.

We study extreme ultraviolet (EUV) radiation induced defects in single-layer graphene. Two mechanisms for inducing defects in graphene were separately investigated: photon induced chemical reactions between graphene and background residual gases, and breaking sp2 bonds, due to photon and/or photoelectrons induced bond cleaving. Raman spectroscopy shows that D peak intensities grow after EUV irradiation with increasing water partial pressure in the exposure chamber. Temperature-programmed desorption (TPD) experiments prove that EUV radiation results in water dissociation on the graphene surface. The oxidation of graphene, caused by water dissociation, is triggered by photon and/or photoelectron induced dissociation of water. Our studies show that the EUV photons break the sp2 bonds, forming sp3 bonds, leading to defects in graphene.