A New Approach to Temperature Dependent Ideality Factors in Schottky Contacts

1992 ◽  
Vol 260 ◽  
Author(s):  
Zs. J. Horváth
Keyword(s):  
Experimental Data ◽  
Low Temperatures ◽  
Schottky Diodes ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Temperature Dependent ◽  
Model Calculations ◽  
New Approach ◽  
Barrier Heights ◽  
Thermionic Field Emission

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.

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
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Gaussian Distribution ◽  
Ideality Factor ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Temperature Dependent ◽  
Semiconductor Interface ◽  
Zero Bias ◽  
Barrier Heights

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.

Comparative Study of Temperature Dependent Barrier Heights of Pd/ZnO Schottky Diodes Grown along Zn- and O-Faces

2012 ◽  
Vol 510-511 ◽  
pp. 265-270 ◽  
Author(s):  
M. Asghar ◽  
Khalid Mahmood ◽  
Adnan Ali ◽  
M.A. Hasan
Keyword(s):  
Barrier Height ◽  
Deep Level ◽  
Schottky Diodes ◽  
Thermionic Emission ◽  
Growth Conditions ◽  
Distribution Model ◽  
Metal Contacts ◽  
Temperature Dependent ◽  
Barrier Heights ◽  
Two Samples

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.

Characteristics of Metal/P+-Gaas Schottky Barrier Junction Formed by Focused-Ion-Beam Implantation

1989 ◽  
Vol 157 ◽  
Author(s):  
N. Watanabe ◽  
T. Tsukamoto ◽  
M. Okunuki
Keyword(s):  
Schottky Barrier ◽  
Focused Ion Beam ◽  
Diffusion Theory ◽  
Ion Beam ◽  
Schottky Diodes ◽  
Dose Range ◽  
Thermionic Emission ◽  
Depth Profiles ◽  
Barrier Heights ◽  
Thermionic Field Emission

ABSTRACTBeryllium (Be) depth profiles, carrier profiles, ideality factors (deviation from thermionic emission and diffusion theory) and Schottky barrier heights of Al/p+-GaAs Schottky diodes were investigated by using focused ion beam (FIB) and de-focused ion beam (DFIB) of 40keV Be+, with dose range from 5.0×1012ions/cm2 to 3.4×1014ions/cm2. Differences of the depth profiles between FIB implantation and DFIB implantation were observed, and it was confirmed that depth profiles of the ion implantations were affected by current densities of the ion probes. The other side, it was recognized that the ideality factors and the Schottky barrier heights of the Schottky diodes were depended on effect of thermionic field emission.

Temperature-Dependent Electrical Characteristics of Ag Schottky Contacts to Differently Grown O-Polar Bulk ZnO

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Hogyoung Kim ◽  
Ahrum Sohn ◽  
Yunae Cho ◽  
Dong-Wook Kim
Keyword(s):  
Electron Transport ◽  
Electrical Properties ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Temperature Dependent ◽  
Barrier Heights ◽  
Two Samples

The temperature-dependent electrical properties of Ag Schottky contacts to differently grown O-polar bulk ZnO single crystals were comparatively investigated in the temperature range of 100–300 K. Schottky contact to hydrothermal ZnO produced the higher barrier heights (lower ideality factors) than that of pressurized melt-grown ZnO. The modified Richardson plots for two samples produced the larger Richardson constant compared to the theoretical value of 32 A cm−2 K−2 for n-type ZnO, indicating that the inhomogeneous barrier height with the thermionic emission (TE) model could not explain the current transport. The conductive accumulation layers on the ZnO surfaces might not be removed effectively for two samples, which degraded the rectifying characteristics. The different electron transport characteristics between hydrothermal and pressurized melt-grown ZnO could be explained by the different degree of Ag-O formation at the interface.

Evaluation of On-State Resistance and Boron-Related Levels in n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 425-428 ◽  
Author(s):  
R.R Ciechonski ◽  
Samuele Porro ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova
Keyword(s):  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Depth Profiling ◽  
Thermionic Emission ◽  
Barrier Heights ◽  
Transient Spectroscopy ◽  
State Resistance ◽  
Thick Layers

Specific on-resistance Ron estimated from current density-voltage characteristics of Schottky diodes on thick layers exhibits variations from tens of mW.cm2 to tens of W.cm2 for different doping levels. In order to understand the occurrence of high on-state resistance, Schottky barrier heights were first estimated for both forward and reverse bias with the application of thermionic emission theory and were in agreement with a literature reported values. Decrease in mobility with the temperature was observed and its dependencies of T–1.3 and T–2.0 for moderately doped and low doped samples respectively were estimated. From deep level measurements by Minority Carrier Transient Spectroscopy, an influence of shallow boron related levels and D-center on dependence of on-state resistance was observed, being more pronounced in low doped samples. Similar tendency was observed in depth profiling of Ron. This suggests a major role of boron in a compensation mechanism thus resulting in high Ron.

Equivalent Circuit Model of Semiconductor Nanowire Diode by SPICE

2007 ◽  
Vol 7 (11) ◽  
pp. 4089-4093
Author(s):  
Sehan Lee ◽  
Yunseop Yu ◽  
Sungwoo Hwang ◽  
Doyeol Ahn
Keyword(s):  
Equivalent Circuit ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Equivalent Circuit Model ◽  
Thermionic Emission ◽  
Metal Structure ◽  
Circuit Model ◽  
Semiconductor Nanowire ◽  
Circuit Simulator ◽  
Thermionic Field Emission

An equivalent circuit model of nanowire diodes is introduced. Because nanowire diodes inevitably involve a metal-semiconductor-metal structure, they consist of two metal-semiconductor contacts and one resistor in between these contacts. Our equivalent circuit consists of two Schottky diodes and one resistor. The current through the reverse-biased Schottky diode is calculated from the thermionic field emission (TFE) theory and that of the forward-biased Schottky diode is obtained from the classical thermionic emission (TE) equation. Our model is integrated into the conventional circuit simulator SPICE by a sub-circuit with TFE and TE routines. The results simulated with our model by SPICE are in good agreement with various, previously reported experimental results.

Electroluminescence Studies Of Si Bulk Materials Using Al-Si Schottky Diodes

1997 ◽  
Vol 486 ◽  
Author(s):  
Chun-Xia Du ◽  
Wei-Xin Ni ◽  
Kenneth B. Joelsson ◽  
Guang-Di Shen ◽  
Göran V. Hansson
Keyword(s):  
Radiative Decay ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Schottky Contacts ◽  
Injection Current ◽  
Bulk Materials ◽  
Temperature Dependent ◽  
Intense Light

AbstractElectroluminescence (EL) of Si bulk materials has been studied using lowly doped substrate with two Al-Si Schottky contacts. By applying a forward bias on the structure, the intense light emissions at 1.094 eV due to the TO-phonon assisted recombination was obtained at 40 K while other TA- and 2TO-associated transitions were also observed. The Si-TO EL peak persists up to RT with a radiative decay of ∼ 5 μs. EL emission mechanisms of these Si Schottky diodes are discussed based on temperature dependent- and injection current-dependent EL measurements.

Metallurgical and Electrical Characteristics of MoAlx Schottky Contacts to n-GaAs

1992 ◽  
Vol 260 ◽  
Author(s):  
T. S. Huang ◽  
J. G. Peng ◽  
C. C. Lin
Keyword(s):  
Thermal Processing ◽  
Annealing Temperature ◽  
Schottky Diodes ◽  
Schottky Contacts ◽  
Electrical Characteristics ◽  
Interfacial Stability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Heights ◽  
Current Voltage

ABSTRACTThe interfacial stability, surface morphology and electrical characteristics of MoAlx contacts to n-GaAs have been investigated by using x-ray diffraction, scanning electron microscopy, sheet resistance and current-voltage measurements. The compositions of rf-cosputtered MoAlx films were x = 0.35, 2.7, and 7.0, respectively. The contacts were annealed by rapid thermal processing in the temperature range 500–1000 °C for 20 s. The interfaces of MoAl0.35/GaAs and MoAl2,7/GaAs were stable up to 900 °C, while the interfaces of MoAl7.0/GaAs were less stable and reactions occurred above 800 °C. The variations of sheet resistances and the barrier heights of the Schottky diodes as a function of annealing temperatures can be well correlated to the interfacial stability. The MoAl2.7/n-GaAs diodes exhibited the best stability and were characterized by the highest barrier height (0.98 V) and nearly unit ideality factor (1.11) after annealing at 900 °C. For all thermally stable MoAlx/n-GaAs Schottky diodes, the barrier heights increased with annealing temperature.

Conduction in Polycrystalline Silicon: Generalized Thermionic Emission-Diffusion Theory and Extended State Mobility Model

1982 ◽  
Vol 13 ◽  
Author(s):  
A.N. Khondker ◽  
D.M. Kim ◽  
R.R. Shah
Keyword(s):  
Experimental Data ◽  
Grain Size ◽  
Grain Boundary ◽  
Material Properties ◽  
Polycrystalline Silicon ◽  
Diffusion Theory ◽  
Thermionic Emission ◽  
Mobility Model ◽  
Extended State ◽  
Thermionic Field Emission

ABSTRACTWe present a general theory of conduction in polysilicon. The theoretical framework reconciles two apparently divergent approaches for modeling conduction processes in polysilicon and provides a physical basis to correctly interpret and to point out the deficiencies of previously reported thermionic and thermionic field emission theory. This model is based on an extended state mobility in the disordered grain boundary and the thermionic emission-diffusion theory for conduction of current. The attractive features of our theory are (a) it can explain the experimental data without the use of an artificial factor, f, (b) the conduction process is characterized explicitly by the inherent material properties of the grain and the grain boundary. Our model is particularly suited for describing the electrical properties of laser restructured polysilicon, where because of large grain size the diffusion process is expected to be dominant.

Equivalent Circuit Model of Semiconductor Nanowire Diode by SPICE

2007 ◽  
Vol 7 (11) ◽  
pp. 4089-4093 ◽  
Author(s):  
Sehan Lee ◽  
Yunseop Yu ◽  
Sungwoo Hwang ◽  
Doyeol Ahn
Keyword(s):  
Equivalent Circuit ◽  
Schottky Diode ◽  
Schottky Diodes ◽  
Equivalent Circuit Model ◽  
Thermionic Emission ◽  
Metal Structure ◽  
Circuit Model ◽  
Semiconductor Nanowire ◽  
Circuit Simulator ◽  
Thermionic Field Emission

An equivalent circuit model of nanowire diodes is introduced. Because nanowire diodes inevitably involve a metal-semiconductor-metal structure, they consist of two metal-semiconductor contacts and one resistor in between these contacts. Our equivalent circuit consists of two Schottky diodes and one resistor. The current through the reverse-biased Schottky diode is calculated from the thermionic field emission (TFE) theory and that of the forward-biased Schottky diode is obtained from the classical thermionic emission (TE) equation. Our model is integrated into the conventional circuit simulator SPICE by a sub-circuit with TFE and TE routines. The results simulated with our model by SPICE are in good agreement with various, previously reported experimental results.

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