Analysis of temperature-dependent Schottky barrier parameters of Cu–Au Schottky contacts to n-InP

2012 ◽  
Vol 90 (1) ◽  
pp. 73-81 ◽  
Author(s):  
V. Lakshmi Devi ◽  
I. Jyothi ◽  
V. Rajagopal Reddy

In this work, we have investigated the electrical characteristics of Au–Cu–n-InP Schottky contacts by current–voltage (I–V) and capacitance–voltage (C–V) measurements in the temperature range 260–420 K in steps of 20 K. The diode parameters, such as the ideality factor, n, and zero-bias barrier height, Φb0, have been found to be strongly temperature dependent. It has been found that the zero-bias barrier height, Φb0(I–V), increases and the ideality factor, n, decreases with an increase in temperature. The forward I–V characteristics are analyzed on the basis of standard thermionic emission (TE) theory and the assumption of gaussian distribution of barrier heights, due to barrier inhomogeneities that prevail at the metal–semiconductor interface. The zero-bias barrier height Φb0 versus 1/2kT plot has been drawn to obtain the evidence of a gaussian distribution of the barrier heights. The corresponding values are Φb0 = 1.16 eV and σ0 = 159 meV for the mean barrier height and standard deviation, respectively. The modified Richardson plot has given mean barrier height, Φb0, and Richardson constant, A**, as 1.15 eV and 7.34 Acm−2K−2, respectively, which is close to the theoretical value of 9.4 Acm−2K−2. Barrier heights obtained from C–V measurements are higher than those obtained from I–V measurements. This inconsistency between Schottky barrier heights (SBHs) obtained from I–V and C–V measurements was also interpreted. The temperature dependence of the I–V characteristics of the Au–Cu–n-InP Schottky diode has been explained on the basis of TE mechanism with gaussian distribution of the SBHs.

2008 ◽  
Vol 22 (14) ◽  
pp. 2309-2319 ◽  
Author(s):  
K. ERTURK ◽  
M. C. HACIISMAILOGLU ◽  
Y. BEKTORE ◽  
M. AHMETOGLU

The electrical characteristics of Cr / p – Si (100) Schottky barrier diodes have been measured in the temperature range of 100–300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41×10-3 Acm-2 K -2 is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm-2 K -2 for p-type Si . It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p – Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.


2011 ◽  
Vol 1406 ◽  
Author(s):  
Cleber A. Amorim ◽  
Olivia M. Berengue ◽  
Luana Araújo ◽  
Edson R. Leite ◽  
Adenilson J. Chiquito

ABSTRACTIn this work, we studied metal/SnO2 junctions using transport properties. Parameters such as barrier height, ideality factor and series resistance were estimated at different temperatures. Schottky barrier height showed a small deviation of the theoretical value mainly because the barrier was considered fixed as described by ideal thermionic emission-diffusion model. These deviations have been explained by assuming the presence of barrier height inhomogeneities. Such assumption can also explain the high ideality factor as well as the Schottky barrier height and ideality factor dependence on temperature.


2013 ◽  
Vol 858 ◽  
pp. 171-176
Author(s):  
Nathaporn Promros ◽  
Ryūhei Iwasaki ◽  
Suguru Funasaki ◽  
Kyohei Yamashita ◽  
Chen Li ◽  
...  

n-Type NC-FeSi2/p-type Si heterojunctions were successfully fabricated by PLD, and their forward current-voltage characteristics were analyzed on the basis of thermionic emission theory (TE) in the temperature range from 300 down to 77 K. With a decrease in the temperature, the ideality factor was increased while the zero-bias barrier height was decreased. The calculated values of ideality factor and barrier height were 3.07 and 0.63 eV at 300 K and 10.75 and 0.23 eV at 77 K. The large value of ideality factor indicated that a tunneling process contributes to the carrier transport mechanisms in the NC-FeSi2 films. The series resistance, which was estimated by Cheungs method, was strongly dependent on temperature. At 300 K, the value of series resistance was 12.44 Ω and it was dramatically enhanced to be 1.71× 105 Ω at 77 K.


2008 ◽  
Vol 600-603 ◽  
pp. 1341-1344 ◽  
Author(s):  
Fabrizio Roccaforte ◽  
Ferdinando Iucolano ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Valeria Puglisi ◽  
...  

In this work, the electrical properties of Pt/GaN Schottky contacts were studied. The temperature dependence of the barrier height and ideality factor, and the low experimental value of the Richardson’s constant, were discussed considering the formation of an inhomogenous Schottky barrier. Local current-voltage measurements on Pt/GaN contact, performed with a conductive atomic force microscope, demonstrated a Gaussian distribution of the local barrier height values and allowed to monitor the degree of inhomogeneity of the barrier. The presence of defects, terminating on the bare GaN surface, was correlated with the electrical behavior of the inhomogeneous barrier.


1995 ◽  
Vol 378 ◽  
Author(s):  
A. Singh ◽  
N. Marcano

AbstractAl/n-GaAs Schottky barrier type diode was fabricated by thermal deposition of Al on chemically etched polished surface of (100) n-GaAs at a pressure of 4×10−6 Torr. Back ohmic contact to n-GaAs was prepared by thermal deposition of In, followed by a 90 min. anneal in Ar atmosphere at 390° C. The C−2 vs V characteristics were quite linear for reverse bias voltages in the range 0-4 V. Over the temperature range 300–360 K, the values of the barrier height and the net carrier density (Nd-Na), obtained from the C−2-V data, were in the range 1.33–1.26 V and 4.3×l0−16-5.0×l0−16 cm−3, respectively. The forward I-V data over the temperature range 300–400 K, indicated that the electrical current across the Al/n-GaAs Schottky junction was transported by the mechanisms of generation-combination (GR) in the space charge, thermionic emission (TE) and ohmic leak current. A value of (1.20±0.04) V for the zero bias barrier height was deduced from the temperature dependence of the TE reverse saturation current. The barrier height deduced from the I-V data was practically independent of temperature. The 20% change in Nd-Na with temperature, obtained from the C-V data, and important contributions of the GR and leak currents to the total forward current, suggested the presence of defect levels in the surface space charge layer in n-GaAs, which may be responsible for the discrepancy in the values of the barrier height obtained from the I-V and C-V data.


2014 ◽  
Vol 895 ◽  
pp. 439-443
Author(s):  
Tarriq Munir ◽  
Azlan Abdul Aziz ◽  
Mat Johar Abdullah ◽  
Mohd Fadzil Ain

This paper reports the temperature dependent DC and RF characteristics of n-GaN Schottky diode simulated using Atlas/Blaze developed by Silvaco. It was found that as the temperature increases from 300K to 900K the forward current decreases due to lowering of the Schottky barrier with an increase in series-resistance and ideality factor. These observations indicates that tunneling behavior dominates the current flow rather than thermionic emission. Furthermore, the breakdown voltage decreases in reverse bias and insertion loss for RF behavior increases with respect to temperature due to the increase in capacitance near diode junction.Keywords: Atlas/Blaze, Schottky barrier, series resistance, ideality factor, insertion loss.


2012 ◽  
Vol 510-511 ◽  
pp. 265-270 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan

In this study, the effect of polar face on Schottky barrier diodes has been investigated. Two samples of ZnO were grown hydrothermally under similar growth conditions. The Palladium (Pd) metal contacts of area 0.78 mm2were fabricated on both faces and were studied comprehensively using DLS-83 Deep Level Spectrometer over temperature range of 160K330K. The current-voltage (IV) measurements revealed that the ideality factor n and barrier height ϕBwere strongly temperature dependent for both faces (Zn and O-face) of ZnO, indicating that the thermionic emission is not the dominant process, which showed the inhomogenity in the barrier heights of grown samples. This barrier height inhomogenity was explained by applying Gaussian distribution model. The extrapolation of the linear ϕapverses n plot to n = 1 has given a homogeneous barrier height of approximately 0.88±0.01 eV and 0.76±0.01 eV for Zn and O-faces respectively. ϕapversus 1/T plot was drawn to obtain the values of mean barrier height for Zn and O-face (0.88±0.01 eV, 0.76±0.01 eV) and standard deviation (δs) (0.015±0.001 V, 0.014±0.001 V) at zero bais respectively. The value of δsfor the Zn-face is larger than O-face, showing that inhomogenity in the barrier heights is more in the sample grown along Zn-face as compared to the sample grown along O-face.


2010 ◽  
Vol 09 (03) ◽  
pp. 135-138
Author(s):  
A. ALI ◽  
M. YASAR ◽  
F. NASIM ◽  
A. S. BHATTI

The Schottky contacts of Ag/SiO2 /p- Si were fabricated by thermal evaporation at 20 K. The effect of annealing temperatures varying from 373 to 773 K on the morphology and electrical properties of these contacts was investigated. The average grain size increased while the density of grains decreased with increasing temperature. Ideality factor initially observed was as high as 4.15 with a low barrier height of 0.04 eV for contact grown at 20 K. Annealing resulted in shift of ideality factor and barrier height towards ideal behavior. Thus, it is demonstrated that Ag/SiO2 /p- Si contacts grown at low temperature can be modified by annealing.


1992 ◽  
Vol 260 ◽  
Author(s):  
Zs. J. Horváth

ABSTRACTSchottky diodes often exhibit anomalous current-vol tage characteristics at low temperatures (T) with T dependent ideality factors (IF) and apparent barrier heights (BH) evaluated for the thermionic emission. In this paper theoretical expressions are first presented for the T dependences of the IF and the apparent BH for the thermionic-field emission (TFE) including the bias dependence of BH. Model calculations are reported, which has been performed using these expressions, and their results are compared with the available experimental data. It is shown that the T dependence of the 1 Fs and apparent BHs often may be explained self consistently by the TFE with anomalously high characteristic energies Eoo.


2013 ◽  
Vol 313-314 ◽  
pp. 270-274
Author(s):  
M. Faisal ◽  
M. Asghar ◽  
Khalid Mahmood ◽  
Magnus Willander ◽  
O. Nur ◽  
...  

Temperature dependent current-voltage (I-V) and capacitance-voltage (C-V) measurements were utilized to understand the transport mechanism of Pd Schottky diodes fabricated on Zn- and O-faces of ZnO. From I-V measurements, in accordance with the thermionic emission mechanism theory, it was found that the series resistance Rsand the ideality factor n were strongly temperature dependent that decreased with increasing temperature for both the faces (Zn and O-face) of ZnO revealing that the thermionic emission is not the dominant process. The barrier height øB(I-V)increased with increasing temperature for both faces. The measured values of ideality factor, barrier height and series resistance for Zn- and O-faces at room temperature were 4.4, 0.60 eV, 217 Ω and 2.8, 0.49 eV, 251 Ω respectively. The capacitance-voltage (C–V) measurements were used to determine the doping concentration Nd, the built-in-potential Vbi, and the barrier height øB(C-V). The doping concentration was found to be decreased with increasing depth. The barrier height øB(C-V)calculated for O-polar and Zn-polar faces decreases with increasing temperature. The values of barrier height øB(C-V)determined from C-V measurements were found higher than the values of barrier height øB(I-V). Keeping in view the calculated values of ideality factor, barrier height, and series resistance shows that O-polar face is qualitatively better than Zn-polar face.


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