  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 disrupting the network of 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 cleave the sp2 bonds, forming sp3 bonds, leading to defects in
graphene.
