The Double Gaussian Distribution of Inhomogeneous Barrier Heights in Al/GaN/p-GaAs (MIS) Schottky Diodes in Wide Temperature Range

Zeyrek S., Buelbuel M. M., Altindal Ş., Baykul M. C., Yuezer H.

BRAZILIAN JOURNAL OF PHYSICS, cilt.38, sa.4, ss.591-597, 2008 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 38 Sayı: 4
  • Basım Tarihi: 2008
  • Doi Numarası: 10.1590/s0103-97332008000500011
  • Dergi Adı: BRAZILIAN JOURNAL OF PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.591-597
  • Anahtar Kelimeler: MIS diode, Barrier inhomogeneities, Double Gaussian distribution, Temperature, Dependence, Nitride passivation, C-V CHARACTERISTICS, CURRENT-VOLTAGE CHARACTERISTICS, I-V, CURRENT TRANSPORT, ELECTRICAL CHARACTERISTICS, NITRIDATION, DEPENDENCE, CONTACTS, PASSIVATION, SURFACE
  • Gazi Üniversitesi Adresli: Evet

Özet

The current-voltage ( I-V) characteristics of metal-insulator-semiconductor (Al/GaN/p-GaAs) Schottky barrier diodes (SBDs) were investigated over a wide temperature range of 80-380 K. By using the thermionic emission (TE) theory, the zero bias barrier height Phi(B0) calculated from I-V characteristics was found to increase with increasing temperature as the ideality factor n decreases with increasing temperature, and especially the activation energy plot is nonlinear at low temperatures. The observed variation in the Phi(B0) and n is attributed to the spatial barrier inhomogeneities in SBD by assuming a Gaussian distribution (GD) of barrier heights (BHs). The experimental I-V-T characteristics of the SBDs have shown a double Gaussian distribution having mean barrier heights (Phi) over bar (B) of 0.854 eV and 0.395 eV and standard deviations sigma(s) for 0.142 V and 0.059 V, respectively. The modified ln( I-0/T-2)-q(2)sigma(2)(0)/2(kT)(2) vs q/kT plot gives Phi(B0) and Richardson constant A* as 0.858 eV and 0.364 eV, and 78.5 and 128 A/cm(2)K(2), respectively, without using the temperature coefficient of the barrier height. Hence, the results have shown that the I-V-T characteristics of the Al/GaN/p-GaAs SBDs can be successfully explained on the basis of TE mechanism with a double Gaussian distribution of the barrier heights.