Microstructure and composition of focused-ion-beam-deposited Pt contacts to GaN nanowires

The structural and chemical character of focused-ion-beam (FIB)-deposited metal such as platinum (Pt) contacts on GaN nanowires to understand the composition and microstructure affect the electrical performance, were analyzed. Within the electron-beam-induced deposition (EBID)-Pt capping layer and ion-beam-induced deposition (IBID)-Pt contact, dark spotty contrast within a bright matrix suggested that dense Pt nanocrystallites were embedded within a low-density C matrix. On IBID-Pt-contacted GaN nanowire devices, the onset of linear current-voltage (I-V) characteristics as the nanowire diameter decreased. The results show that the IBID-Pt contacts were found to contain nanocrystalline Pt embedded in an amorphous matrix of C and Ga.