Paper Info
Title
A detailed study of current–voltage characteristics in Au/SiO2/n-GaAs in wide temperature range
Abstract
The forward and reverse-bias current–voltage (I–V) characteristics of Au/SiO2/n-GaAs (MIS) type Schottky barrier diode (SBDs) have been investigated in the wide temperature range of 80–400K. The zero-bias barrier height (ϕBo) and ideality factor (n) assuming the thermionic emission (TE) mechanism show strong temperature dependence. While n decreases, ϕBo increases with increasing temperature. Such temperature dependence of ϕBo is an obvious disagreement with the reported negative temperature coefficient (αtemp) of barrier height. Therefore, we have reported a modification which includes the n and electron-tunneling parameter (αχ1/2δ) in the expression of reverse-saturation current (I0). After this modification, the value of αtemp obtained as −4×10−4eV/K which is very close to αtemp of GaAs band-gap (−5.4×10−4eV/K). Richardson plot of the ln(I0/T2) versus 1/T has two linear region; the first region is (200–400K) and the second region (80–150K). The values of the activation energy (Ea) and Richardson constant were obtained from this plot and the values of Ea and Richardson constants (A*) are much lower than the known values. These behaviors of the Au/SiO2/n-GaAs (MIS) type (SBDs) have been interpreted by the assumption of a double-Gaussian distribution of barrier heights (BHs) at the metal–semiconductor interface giving a mean BHs (ϕ¯Bo) of 1.20 and 0.68eV and standard deviation (σs) of 0.1503 and 0.0755V, respectively. Thus the modified ln (I0/T2)-q2σs2/2k2T2 versus q/kT for two different temperature ranges (200–400K and 80–150K) plot then gives mean barrier heights ϕ¯Bo and A*, 1.18 and 0.66eV and 7.08 and 3.81A/cm2K2, respectively. This value of the A* 7.08A/cm2K2 is very close to the theoretical value of 8.16A/cm2K2 for n-type GaAs. Hence, all these behaviours of the forward-bias I–V characteristics of the Au/SiO2/n-GaAs (MIS) type SBDs can be successfully explained on the basis of a TE mechanism with a double-Gaussian distribution of the BHs.
Year
DOI
Venue
2009
10.1016/j.microrel.2009.06.003
Microelectronics Reliability
DocType
Volume
Issue
Journal
49
8
ISSN
Citations 
PageRank 
0026-2714
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
H. Altuntaş100.34
Ş. Altındal243.03
H. Shtrikman300.34
S. Özçelik401.01