Izvorni znanstveni članak
AlNiGe as a new dedicated material for contacts to n-GaAs
Lajos Dávid
; Kandó Kálmán Polytechnic, Institute of Microelectronics and Technology, H-1084 Budapest, Tavaszmezö u. 17., Hungary
Balázs Kovács
; Technical University of Budapest, Department of Electronics Technology, H-1521 Budapest, Hungary
Béla Pécz
; Research Institute for Technical Physics of the Hungarian Academy of Sciences, H-1325 Budapest, P. O. Box 76, Hungary
Imre Mojzes
; Technical University of Budapest, Department of Electronics Technology, H-1521 Budapest, Hungary
László Dobos
; Research Institute for Technical Physics of the Hungarian Academy of Sciences, H-1325 Budapest, P. O. Box 76, Hungary
Gyula Vincze
; Research Institute for Technical Physics of the Hungarian Academy of Sciences, H-1325 Budapest, P. O. Box 76, Hungary
Sažetak
Al(150 nm)/Ni(30 nm)/Ge(40 nm) layers have been deposited onto n-type GaAs by thermal evaporation. The samples have been annealed for 20 minutes in flowing forming gas H2:N2 (30%:70%). The alloying behaviour of the specimens has been investigated by electron microscope. The contacts show a bilayer structure in the case of as-deposited samples. The top layer is pure Al and the second one is Ni-Ge. The metal-semiconductor interface is sharp. Annealing at 400 °C resulted in the formation of florets on the surface assumed to be AlGe eutectic; meanwhile, randomly distributed pits of size 10 nm have been grown into the GaAs. The samples annealed at 450 °C show bilayer structure. The top layer is pure Ge and the second one consists of Al-Ni(Ge). On samples annealed at 500 °C thick alloyed layer has been found with deep pyramidal pits of size 0.25 µm. The interface region between GaAs and the pits contains substantial amount of Al. Contrary to the published results, I-V (current-voltage) characteristics of the annealed specimens show that the contacts remained rectifying at each applied annealing process. The temperature dependence of parameters evaluated from either current-voltage or capacitance-voltage characteristics prove that the characteristic form of conductance is the anomalous thermionic-field emission.
Ključne riječi
Hrčak ID:
299597
URI
Datum izdavanja:
2.5.1996.
Posjeta: 178 *