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Spectral response of Au–Ti Schottky barrier on semi‐insulating GaAs
Author(s) -
Ghita R. V.,
Logofatu C.,
Negrila C.,
Cotirlan C.,
Ghita P.,
Manea A. S.,
Lazarescu M. F.
Publication year - 2007
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.200674107
Subject(s) - schottky barrier , thermionic emission , torr , materials science , optoelectronics , schottky diode , annealing (glass) , diode , tungsten , analytical chemistry (journal) , chemistry , electron , composite material , physics , chromatography , quantum mechanics , metallurgy , thermodynamics
For the fabrication of the rectifying contact, respectively the Schottky diode structure on semi‐insulating GaAs (100) oriented, Cr‐doped, with a resistivity of ρ ∼ 10 6 –10 7 Ω cm we have used Au–Ti contact. The Ti contact was deposited on a plasma etched GaAs surface in high vacuum (10 –8 torr), Au was deposited in medium vacuum (10 –6 torr) and the Au–Ti/GaAs interface was formed by a rapid thermal annealing procedure at T = 320 – 360 °C in low vacuum (10 –1 torr). The representative I – V characteristics in dark and under illumination at different power levels are presented. It is worth to mention that we estimate a barrier height of Φ B ∼ 0.84 V (in the frame of thermionic emission model). The spectral response at two operating points and at different temperatures is presented. The signal has a maximum in the Δ λ range (850–950) nm, which corresponds to the generation of photo‐carriers due to a band‐to‐band direct transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)