I-V, C-V, and Hall Effect Studies of Indium-Doped Lpe GaAs

1988 ◽  
Vol 144 ◽  
Author(s):  
J.F. Chen ◽  
K. Xie ◽  
C.R. Wie
Keyword(s):  
Carrier Concentration ◽  
Field Emission ◽  
Schottky Diodes ◽  
Thermionic Emission ◽  
Etch Pit Density ◽  
Trap State ◽  
Etch Pit ◽  
Forward Current ◽  
In Doping ◽  
Thermionic Field Emission

ABSTRACTWe have studied the effects of In doping on the electrical properties of a liquid phase epitaxially (LPE) grown GaAs. The I–V characteristics of Au-GaAs Schottky diodes show, for the layer with In concentration of 2.4 × 1019 cm−3, an ideality factor close to 1.04 over more than seven decades of current. For the same sample, the reverse I–V characteristics are close to an ideal Schottky diode and can be fitted by a theoretical curve, combining the thermionic field emission and thermionic emission. The electrical improvement is closely related to the low etch pit density and other structural improvements. This indicates that, as in the LEC growth, In has effects on the reduction of disloation density in the LPE grown GaAs epi-layer. For doping levels higher than 6×1019 cm−3, an excess forward current is produced at low voltages and low temperatures. A large leakage current is observed under the reverse bias. This property is attributed to a high field effect, with field emission via a trap state as the most likely cause. Hall measurements showed that the ratio of free-carrier concentration ND−NA to the total-carrier concentration ND+NA increased with increasing In concentration.

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.

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.

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.

X-Ray, Photoluminescence and Etching Studies of Indium-Doped LPE GaAs Layers

1988 ◽  
Vol 144 ◽  
Author(s):  
J.F. Chen ◽  
C. R. Wie ◽  
F. A. Junga
Keyword(s):  
Phase Diagram ◽  
Sharp Increase ◽  
Emission Spectra ◽  
Etch Pit Density ◽  
Double Crystal ◽  
X Ray ◽  
Etch Pit ◽  
In Doping ◽  
Good Crystalline Quality ◽  
Pseudobinary Phase Diagram

ABSTRACTThe effects of In doping on the structural properties of liquid phase epitaxially (LPE) grown GaAs layers are studied. The distribution coefficient of In in the GaAs at 800 ° C was determined to be 0.033 which was consistent with the value calculated from the pseudobinary phase diagram of the ternary system at a dilute In concentration. The full widths at halfmaximum (FWHM) of x-ray double crystal rocking curves show that a GaAs epi-layer of good crystalline quality can be obtained by doping In to a concentration up to 4.3 × 1019 cm−3, beyond which a sharp increase in the FWHM is observed. Etch pit density (EPD) measurement shows that the dislocation density is reduced by doping the epi-layer with In. At the optimal In concentration of 2.4 × 1019 cm−3, the EPD is reduced by a factor of 20 when measured at the surface of a 9 um thick epilayer.Photoluminesce measurements made at 15 K show two sharp emission spectra near the bandedge. The relative intensities of the two emissions, I(l.49eV)/I(l.5eV) are reduced with increasing In content. This suggests that incorporation of Carbon acceptors is suppressed by In doping in the GaAs epilayers. The FWHM as small as 5 meV of the bandedge transition was obtained for the epi-layer doped with In concentration of 2.4 × 1019 cm−3.

Current Transport Study of Schottky and P-N Junction Solar Cells Using Metal-Induced Growth Poly-Si Thin Films

2004 ◽  
Vol 836 ◽  
Author(s):  
Chunhai Ji ◽  
Joon-Dong Kim ◽  
Wayne A. Anderson
Keyword(s):  
Barrier Height ◽  
Field Emission ◽  
Ideality Factor ◽  
Carrier Density ◽  
Transport Mechanism ◽  
Thermionic Emission ◽  
Current Transport ◽  
Oxygen Level ◽  
Thermionic Field Emission ◽  
One Step

AbstractPoly-Si thin films deposited at low temperature by using the metal-induced growth (MIG) method have the advantage of less metal impurity contaminations and relative large grains with preferred crystal orientation of (220). In recent research, the Schottky solar diode made of MIG poly-Si shows Jsc of 12 mA/cm2 and Voc of 0.214V. In this paper, current transport mechanisms were studied by current-voltage-temperature (I-V-T) testing from 100 K to 400K. For the samples deposited by a one-step sputtering process, the large value of ideality factor (n) and abnormal increase of barrier height with the temperature implies that the current transport mechanism does not follow the pure thermionic-emission theory, which was proven to be thermionic-field emission due to the highly doped Si film. By using a two-step sputtering process, the ideality factor and Au-Schottky barrier height at room temperature were about 1.5 and 0.7 eV, which was improved from one-step sputtering. Hydrogenation by electron cyclotron resonance (ECR) plasma can further improve the Schottky diode ideality factor and barrier height. Although a low-level Phosphors-doped Si target was used for poly-Si thin film deposition, a thermionic-field emission mechanism was still found by plotting the activation energy (E0) versus the testing temperature range. Capacitance-voltage (C-V) analysis revealed an unexpected carrier density of 1017 cm−3 level, which is 1000 times higher than the doping density level in the Si film. “Oxygen thermal donor” effect was assumed due to high oxygen level (1020 cm−3) detected by SIMS and processing at ∼ 600 °C. Increasing of the total carrier density due to the oxygen donor may cause the transport mechanism change from pure thermionic emission to thermionic-field emission. Reducing oxygen in the Si film by filtering the sputtering gas to 50 ppb oxygen level was proven to be effective. C-V results gave ∼1016 cm−3 level of carrier density after using oxygen filtering. P-N junction solar cells were made by B-ion implantation into n-type Si film and dopant activation at 700 °C. I-V-T study showed similar curves for P-N junction as for Schottky junction devices. This implies that the current transport was dominated by the Si films instead of the junctions for both Schottky and P-N junction devices.

scholarly journals Forward Current Transport Properties of AlGaN/GaN Schottky Diodes Prepared by Atomic Layer Deposition

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 194 ◽  
Author(s):  
Hogyoung Kim ◽  
Seok Choi ◽  
Byung Joon Choi
Keyword(s):  
Schottky Diodes ◽  
Thermionic Emission ◽  
Tunneling Current ◽  
Atomic Layer ◽  
Emission Model ◽  
Current Transport ◽  
Tunneling Model ◽  
Surface And Interface ◽  
Forward Current ◽  
Layer Deposition

Atomic layer deposited AlGaN on GaN substrate with different thicknesses was prepared and the electron transport mechanism of AlGaN/GaN Schottky diodes was investigated. Above 348 K, both 5 and 10 nm thick AlGaN showed that the thermionic emission model with inhomogeneous Schottky barrier could explain the forward current transport. Analysis using a dislocation-related tunneling model showed that the current values for 10 nm thick AlGaN was matched well to the experimental data while those were not matched for 5 nm thick AlGaN. The higher density of surface (and interface) states was found for 5 nm thick AlGaN. In other words, a higher density of surface donors, as well as a thinner AlGaN layer for 5 nm thick AlGaN, enhanced the tunneling current.

Improvement of Surface Roughness for 4H-SiC Epilayers Grown on 4° Off-Axis Substrates

2010 ◽  
Vol 645-648 ◽  
pp. 119-122 ◽  
Author(s):  
Takashi Aigo ◽  
Hiroshi Tsuge ◽  
Hirokatsu Yashiro ◽  
Tatsuo Fujimoto ◽  
Masakazu Katsuno ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Growth Process ◽  
Schottky Diodes ◽  
Etch Pit Density ◽  
Standard Process ◽  
High Quality ◽  
Etch Pit ◽  
Good Surface ◽  
Density Evaluation ◽  
Koh Etching

The epitaxial growth process was optimized in order to obtain good surface morphology for epilayers grown on 4˚ off-axis substrates. The optimization was carried out from growth temperatures and gas chemistry including C/Si ratio. Step-bunching was significantly suppressed by the optimized process and a surface roughness Ra of 0.2 nm was achieved. Etch pit density evaluation by KOH etching indicated that the basal plane dislocations were reduced to less than 50 cm-2 by the use of 4˚ off-axis substrates. Photoluminescence evaluation showed that the epilayer grown by the optimized process had a better crystalline quality than that grown by a standard process. Schottky diodes fabricated on the epilayer by the optimized process represented the ideality factor n of 1.01 and the barrier height of 1.67eV. These results demonstrate that high quality epilayers with smooth surfaces comparable to those on 8˚off-axis substrates were obtained on 4˚off-axis substrates.

scholarly journals Current Transport Mechanism in Palladium Schottky Contact on Si-Based Freestanding GaN

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 297
Author(s):  
Moonsang Lee ◽  
Chang Wan Ahn ◽  
Thi Kim Oanh Vu ◽  
Hyun Uk Lee ◽  
Yesul Jeong ◽  
...  
Keyword(s):  
Charge Transport ◽  
Point Defect ◽  
Transport Mechanism ◽  
Deep Level ◽  
Schottky Diodes ◽  
Schottky Contact ◽  
Thermionic Emission ◽  
Reverse Current ◽  
Thermionic Field Emission ◽  
Transient Spectroscopy

In this study, the charge transport mechanism of Pd/Si-based FS-GaN Schottky diodes was investigated. A temperature-dependent current–voltage analysis revealed that the I-V characteristics of the diodes show a good rectifying behavior with a large ratio of 103–105 at the forward to reverse current at ±1 V. The interface states and non-interacting point defect complex between the Pd metal and FS-GaN crystals induced the inhomogeneity of the barrier height and large ideality factors. Furthermore, we revealed that the electronic conduction of the devices prefers the thermionic field emission (TFE) transport, not the thermionic emission (TE) model, over the entire measurement conditions. The investigation on deep level transient spectroscopy (DLTS) suggests that non-interacting point-defect-driven tunneling influences the charge transport. This investigation about charge transport paves the way to achieving next-generation optoelectronic applications using Si-based FS-GaN Schottky diodes.

1/f Noise in Ti–Au/n-Type GaAs Schottky Barrier Diodes

2015 ◽  
Vol 14 (03) ◽  
pp. 1550029 ◽  
Author(s):  
Alexey V. Klyuev ◽  
Arkady V. Yakimov ◽  
Irene S. Zhukova
Keyword(s):  
Schottky Barrier ◽  
Field Emission ◽  
Thermionic Emission ◽  
Low Frequency ◽  
Schottky Barrier Diodes ◽  
Transport Mechanisms ◽  
Current Dependence ◽  
Current Voltage ◽  
Thermionic Field Emission ◽  
Multiple Charge

We have studied the forward current–voltage (I–V) characteristics of Ti–Au /n-type GaAs Schottky barrier diodes. However, we found some anomalies in I–V characteristics. Hence, we have considered a model that incorporates thermionic emission, thermionic-field emission and leakage components. Leakage component is linear and visible at rather small currents. The anomalies observed in the diode parameters were effectively construed in terms of the contribution of these multiple charge transport mechanisms across the interface of the diodes. It is shown that thermionic-field emission and leakage are the sources of low-frequency (1/f) noise in such type of diodes. Various Schottky diode parameters were also extracted from the I–V characteristics and current dependence of spectrum of 1/f voltage noise.

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.

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