R. Vandewalle et al., ON THE RELATIONSHIP BETWEEN INTERFACIAL DEFECTS AND SCHOTTKY-BARRIER HEIGHT IN AG, AU, AND AL N-GAAS CONTACTS/, Journal of applied physics, 74(3), 1993, pp. 1885-1889
The variation of the Schottky barrier height in Ag, Au, and Al/n-GaAs
contacts has been investigated as a function of the annealing temperat
ure of the GaAs substrate. Angle resolved x-ray photoemission spectros
copy measurements show that the substrate surface changes from As-rich
into Ga-rich over the applied annealing range. Two distinct barrier h
eights (about 0.85 and 0.65 eV) are found, depending on the metal and
the annealing temperature. These values correspond to the Fermi level
pinning positions expected for amphoteric defect reactions involving t
he As(Ga) and Ga(As) antisites, respectively. Changes in the barrier h
eight are found at annealing temperatures associated with the removal
of these defects.