Damage mechanism of graphene nanoribbons field effect transistors during focused ion beam etching

Abstract

The fabrication of graphene nanoribbons (GNRs) is a familiar method to open the band gap of graphene. As one of the most novel means, focused ion beam (FIB) etching is expected to become the mainstream of GNRs production. Monte Carlo analysis is devoted to simulate the process of ion scattering in FIB etching GNRs. In the process of scattering, charged ions collide with solid materials continuously, which changes the direction and energy of ions in solid. Therefore, the information such as the motion track of the scattered ions, the damage of recoil atoms and the sputtering of surface atoms can be obtained, through the calculation of the scattering angle as well as nuclear energy loss of the charged ions. Combined with Raman spectroscopy and atomic force microscope (AFM) characterization, it is revealed that FIB etching indirectly induces the structure defects on GNRs and affects electrical performance.