Temperature variation of current-voltage characteristics of Au/Ni/n-GaN Schottky diodes

DOĞAN S., Duman S., GÜRBULAK B., Tuezemen S., Morkoc H.

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES, cilt.41, sa.4, ss.646-651, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 41 Sayı: 4
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.physe.2008.10.020
  • Dergi Adı: PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.646-651
  • Anahtar Kelimeler: I-V, Schottky barrier height, Metal-semiconductor contact, Barrier inhomogeneity, N-TYPE GAN, ELECTRON-EMISSION MICROSCOPY, MOLECULAR-BEAM EPITAXY, V-T CHARACTERISTICS, BARRIER HEIGHT, ULTRAVIOLET PHOTODETECTORS, CURRENT TRANSPORT, CONTACTS, INHOMOGENEITIES, DEPENDENCE
  • Atatürk Üniversitesi Adresli: Evet

Özet

Current-voltage (I-V) characteristics of Au/Ni/n-GaN Schottky diodes have been measured in 40-320 K temperature range, and analyzed in terms of thermionic emission theory by incorporating the concept of barrier inhomogeneity at the metal/semiconductor interface through a Gaussian distribution function. The basic diode parameters such as ideality factor and barrier height were consequently extracted from electrical measurements. It was seen that ideality factors increased and barrier heights decreased with the decreasing temperature. Both the barrier height (Phi(b)) and the ideality factor (n) exhibit abnormal temperature dependence and are explained by invoking three sets of Gaussian distributions of barrier heights at 320-160K, 160-80K, and 80-40K. An experimental barrier height (BH) Phi(ap) value of about 0.963 eV was obtained for the Au/Ni/n-GaN Schottky diode at the room temperature (300 K). From the temperature-dependent I-V characteristics of the Ni/Au/n-GaN contact, that is, Phi(bo) and A* as 1.38 +/- 0.02. 0.87 +/- 0.02 and 0.51 +/- 0.02 eV; 47.91 +/- 2, 12.44 +/- 0.5 and 46.72 +/- 2A/cm(2) K-2, respectively, have been calculated from a modified In(Io/T-2)-q(2)sigma(2)(s)/2K(2)T(2) for the three temperature regions. (C) 2008 Elsevier B.V. All rights reserved.