Study of EUV induced defects on few-layer graphene

Graphene is a promising candidate material for nano-devices. Some of these devices may be used in harsh environments such as 13.5 nm extreme UV irradiation. Therefore it is critical to understand the radiation-hardness of graphene in order to keep those devices functional. We studied the defects on few-layer graphene induced by EUV irradiation. Raman spectroscopy was used to probe defects on graphene via a defect-activated Raman process, which is represented by a D peak in the spectrum. Our results show that EUV radiation results in an increase of the D peak intensity, which indicates damage to the graphene lattice. Meanwhile, EUV irradiation in a H2 background leads to more defects on graphene due to the generation of hydrogen plasma under irradiation. X-ray photoelectron spectroscopy (XPS) was also performed to analyze the surface composition of graphene after EUV irradiation. The results confirm that EUV irradiation transforms sp2 phase carbon to sp3 phase carbon.