Morphological and electrical characterization of Al/Ni/n-InP contacts with tapered Ni-layer [for MESFET]

We show how a thin Ni film as the first layer of Al/Ni/InP contacts improved the surface morphology after rapid thermal annealing (RTA). In order to find the optimum fabrication parameters (film thickness, annealing temperature and time, etc.), we have fabricated a unique sample in which the thickness of the inserted Ni layer tapered off in space. The electrical properties were evaluated by using scanning internal-photoemission microscopy (SIPM) which is capable of "mapping" the Schottky diode characteristics.