Journal of Applied Physics · 1978 · 21 citations · 10 references
EngineeringMaterials EngineeringMaterials ScienceInterface ScienceSemiconductor MaterialsThin FilmsDopingSemiconductor Device MaterialsSemiconductor InterfacesSemiconductor PhysicsSemiconductor SurfacesSemiconductor Thin FilmsDoping In Thin FilmsEpitaxial InterfacesEpitaxial Thin FilmsInterdiffusionInterdiffusion At InterfacesOhmic ConductionOhmic ContactsSemiconductor Characterization
Ohmic contacts to n-type GaAs have been developed using epitaxial Ge films on GaAs alloyed with Ni overlayers by solid-state diffusion at temperatures of 450–550 °C. The contacts are smooth and continuous, showing no evidence of phase separation or other surface structure. Interdiffusion at the Ge-GaAs and Ni/Ge-GaAs interfaces was examined by Auger electron spectroscopy (AES) sputter profiling techniques. An abrupt profile is observed at both the as-deposited and sintered Ge-GaAs interface. With the presence of a Ni overlayer, significant interdiffusion between Ge and GaAs is revealed by AES profiles. These results, together with the current-voltage (I-V) characteristics of similar contacts prepared on p-type GaAs, indicate the presence of a Ge-doped n+ layer at the Ni/Ge-GaAs interface.
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Investigation of the AuGeNi system used for alloyed contacts to GaAs
M. Wittmer, R. Pretoriüs, J. W. Mayer et al. · Solid-State Electronics · 1977 · 61 citations