Electrical and structural characterisation of Ni/Ge/n-GaAs interface

L. David, B. Kovács, I. Mojzes, B. Pécz, J. Lábár, L. Dobos

Research output: Article


The structural and electrical behaviour of Ni/Ge layers deposited onto n-type GaAs by electron beam evaporation were studied. The samples have been annealed for 20 min at different temperatures in flowing forming gas - H2:N2 (5%:95%) - in a tube furnace. When the annealing temperature was increased the Schottky barrier heights calculated from I-V and C-V characteristics decreased, and the I-V characteristics of the samples heat treated at 600°C became linear. The contact resistance of the samples with linear characteristic was measured with Cox method. The calculated specific resistivity was 4.4 × 10-4 ohmcm2 in the case of sample heat treated at 550°C and 5.1 × 10 5 ohmcm2 after annealing at 600°C. In the sample annealed at 550°C protrusions appeared with the size of 20-30 nm at the interface of semiconductor-metal. Detectable amount of Ge was found in addition to Ni, As, and G in the protrusions. Moreover, those features contain significantly less Ga than As. The protrusions containing Ge play a role in the formation of the low barrier contact.

Original languageEnglish
Pages (from-to)395-398
Number of pages4
Issue number3-4
Publication statusPublished - júl. 1 1998


ASJC Scopus subject areas

  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films

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