The Influence of Electron Beam Evaporation on MIS device

Impact of gate electrode formation process on Al2O3/GaN interface properties and channel mobility

“…Since the interface states in the measured energy range have an acceptor nature, the difference is attributable to the increase in both negatively charged interface states and positive fixed charges induced by EB evaporation. These phenomena are consistent with the case of a SiO 2 /Si MIS structure [14][15][16][17] and similar to the case of X-ray irradiation into a SiO 2 /Si system. [27][28][29] Taking these observations into account, the interface states and positive fixed charges induced by EB evaporation may have originated from the ionization of Al, O, Ga, and/or N atoms near the interface by the bremsstrahlung X-ray caused by the energy loss of electrons curved in an electromagnetic field and/or the characteristic X-ray generated by the bombardment of the metal target with accelerated electrons.…”

“…During device fabrication, metal deposition processes are frequently carried out by electron beam (EB) evaporation owing to its ability to deposit metals with high melting points. However, EB evaporation introduces defects in the bulk semiconductor and the MIS interface in Si [14][15][16][17] and III-V 18) material systems. In the case of GaN, it has been clarified that EB evaporation introduces bulk traps in the GaN layer.…”