Temperature-dependent profile of the surface states and series resistance in (Ni/Au)/AIGaN/AIN/GaN heterostructures
Author
Taşçıoğlu, I.
Aydemir, U.
Şafak, Y.
Özbay, Ekmel
Date
2010-03-28Source Title
Surface and Interface Analysis
Print ISSN
0142-2421
Electronic ISSN
1096-9918
Publisher
Wiley
Volume
42
Issue
6-7
Pages
812 - 815
Language
English
Type
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Abstract
The profile of the interface state densities(N ss) and series resistances (R s) effect on capacitance-voltage (C-V) and conductancevoltage (G/ω-V) of (Ni/Au)/Al xGa 1-xN/AIN/ GaN heterostructures as a function of the temperature have been investigated at 1 MHz. The admittance method allows us to obtain the parameters characterizing the metal/semiconductor interface phenomena as well as the bulk phenomena. The method revealed that the density of interface states decreases with increasing temperature. Such a behavior of N ss can be attributed to reordering and restructure of surface charges. The value of series R s decreases with decreasing temperature. This behavior of R s is in obvious disagreement with that reported in the literature. It is found that the N ss and R s of the structure are important parameters that strongly influence the electrical parameters of (Ni/Au)/Al xGa 1-XN/AlN/GaN(x = 0.22) heterostructures. In addition, in the forward bias region a negative contribution to the capacitance C has been observed, that decreases with the increasing temperature.
Keywords
(Ni/Au)/AlGaN/AlN/GaN heterostructuresFrequency dependence
Interface states
Negative capacitance
Series resistance