Improvement of the Refractory Metal/n-GaAs Interface by Low Temperature Anneal

1996 ◽  
Vol 448 ◽  
Author(s):  
A. Singh ◽  
L. Velásquez
Keyword(s):  
Ideality Factor ◽  
Forward Bias ◽  
Rf Sputtering ◽  
Frequency Dispersion ◽  
Interface States ◽  
Frequency Variation ◽  
Saturation Current ◽  
Zero Bias ◽  
Heat Treated ◽  
Schottky Junctions

AbstractThe W/n-GaAs Schottky junctions A and B of area 1.75×l0-2 cm2 were fabricated by deposition of W on the chemically etched polished surfaces of n-GaAs samples by rf sputtering using a rf powers of 300 Watt for 30 min. The W contact B was subjected to a 90 min. thermal anneal at 390 °C. The room temperature I-V and C-V/f (with 200 Hz < f < 1 MHz) measurements were carried out for both the as-deposited and thermally annealed W/n-GaAs Schottky junctions A and B, respectively. From the direct I-V data, the values of 1.09 and 8.1×10-8 A for the ideality factor (n) and the reverse saturation current (Io), respectively, were estimated for the diode B, compared to the values of n=1.70 and Io=6.3×10-6 A for the diode A. The observed frequency dispersion in the zero bias capacitance in the diode B was attributed to fast interface states with a time constant, τ2=6 μs and density, Nss2=5.8×1010 eV-1cm-2, whereas, both the slow interface states (with τ1=4 ms and density, Nss1=7.8×1012 eV-1cm-2) and fast states (with τ2=1 μs and density Nss2=8.6×1010 eV-1cm-2) were responsible for the observed frequency variation of the zero bias capacitance in the diode A. For the forward bias values in the range 20-100 mV, the frequency dispersion in the measured capacitance suggested the presence of both the fast and slow interface states (with time constants differing by three orders of magnitude) in the as-deposited and the heat treated W/n-GaAs interfaces. Thermal anneal at 390 °C for 90 min. lowered the density of states at the W/n-GaAs interface by two orders of magnitude and resulted in the formation of a high quality rectifying W contact to n-GaAs with a rectification ratio of 1.4×104, a low Io and an ideality factor close to unity.

scholarly journals Silicon carbide schottky diodes forward and reverse current properties upon fast electron radiation

2019 ◽  
Vol 8 (2) ◽  
pp. 428-437
Author(s):  
M. Azim Khairi ◽  
Rosminazuin Ab. Rahim ◽  
Norazlina Saidin ◽  
Yusof Abdullah ◽  
Nurul Fadzlin Hasbullah
Keyword(s):  
Silicon Carbide ◽  
Electron Irradiation ◽  
Ideality Factor ◽  
Reverse Bias ◽  
Series Resistance ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Bias Current ◽  
Saturation Current ◽  
Order Of Magnitude

This paper investigates on the reaction of 10 and 15MGy, 3MeV electron irradiation upon off-the-shelves (commercial) Silicon Carbide Schottky diodes from Infineon Technologies (model: IDH08SG60C) and STMicroelectronics (model: STPSC806). Such irradiation reduces the forward-bias current. The reduction is mainly due to the significant increase of the series resistance (i.e. Infineon: 1.45Ω at before irradiation → 121×103 Ω at 15MGy); STMicroelectronics: 1.44Ω at before irradiation → 2.1×109 Ω at 15MGy). This increase in series resistance gives 4.6 and 8.2 orders of magnitude reduction for the forward-bias current density of Infineon and STMicroelectronics respectively. It is also observed that the ideality factor and the saturation current of the diodes increases with increasing dose (i.e. ideality factor- Infineon: 1.01 at before irradiation → 1.05 at 15MGy; STMicroelectronics: 1.02 at before irradiation → 1.3 at 15MGy | saturation current- Infineon: 1.6×10-17A at before irradiation → 2.5×10-17A at 15MGy; STMicroelectronics: 2.4×10-15A at before irradiation → 8×10-15A at 15MGy). Reverse-bias leakage current density in model by Infineon increases by one order of magnitude after 15MGy irradiation, however, in model by STMicroelectronics decreases by one order of magnitude. Overall, for these particular samples studied, Infineon devices have shown to be better in quality and more radiation resistance toward electron irradiation in forward-bias operation while STMicroelectronics exhibit better characteristics in reverse-bias operation.

Effect of Doping on the Interface States in Au Schottky Contact to p-In0.21Ga0.79As Grown on GaAs by Metal Organic Vapour Phase Epitaxy

1993 ◽  
Vol 318 ◽  
Author(s):  
A. Singh ◽  
P. Cova ◽  
R. A. MASUT
Keyword(s):  
Doping Concentration ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Schottky Contact ◽  
Frequency Dispersion ◽  
Vapour Phase ◽  
Interface State ◽  
Interface States ◽  
Vapour Phase Epitaxy ◽  
Order Of Magnitude

ABSTRACTEpitaxial p-In0.21Gao0.79As/Au Schottky barrier type diodes were fabricated by evaporation of Au on chemically etched surfaces of In0.21Ga0.79As:Zn layers grown on highly doped GaAs substrate by MOVPE. 1 MHz capacitance-voltage (C-V) and Capacitance-frequency (C-f) measurements were performed in the frequency range 1 KHz-1 MHz at room temperature in Au Schottky diodes made on four epitaxial In0.2 Ga0.79As:Zn samples with doping concentrations between 6×1014cm−3 and 4×1017 cm−3. Under forward bias, a large frequency dispersion in the junction capacitance was observed which was attributed to the interface states in thermal equilibrium with the semiconductor. The interface states capacitance extracted from the C-f data was analyzed in terms of Lehovec's theoretical model of interface state continuum with single time constant, and the characteristic parameters of the interface states (energy density (Nss), relaxation time (τ) and hole capture cross-section (σh)) were determined. In the samples with doping concentration in the range 1.5×1017-4.3×1017 cm−3, Nss was about an order of magnitude higher than in the sample having a doping concentration of 5.8×1014 cm−3. Over the interface states energy range 0.40-0.65 eV, Nss decreased exponentially with energy in the highly doped samples and σh increased with energy in all the samples.

Bias Annealing Effect on Hydrogen-Containing Au/N-Silicon Schottky Barrier

1993 ◽  
Vol 319 ◽  
Author(s):  
M.H. Yuan ◽  
Y.Q. Jia ◽  
G.G. Qin
Keyword(s):  
Schottky Barrier ◽  
Reverse Bias ◽  
Annealing Temperature ◽  
Interface States ◽  
Annealing Effect ◽  
Reversible Change ◽  
Semiconductor Interface ◽  
Zero Bias ◽  
Hydrogen Incorporation

AbstractAu/n-Si Schottky barrier (SB) incorporated by hydrogen has a 0.13 eV lower SB height (SBH) than that without hydrogen incorporation. For the hydrogen-containing SB, zero bias annealing (ZBA) decreases the SBH while reverse bias annealing (RBA) increases it. Besides, the ZBA and RBA cycling experiments reveal a reversible change of the SBH with in at least three cycles. The higher annealing temperature of RBA results in higher SBH. We interpret the above experimental facts as that hydrogen has an effect on metal-semiconductor interface states and then on the SBH, and both the bias on SB and temperature of annealing can influence the hydrogen effects on metal-semiconductor interface states.

scholarly journals The effects of electron irradiation and thermal dependence measurements on 4H-Sic Schottky diode

2017 ◽  
Vol 51 (12) ◽  
pp. 1721
Author(s):  
Sabuhi Ganiyev ◽  
M. Azim Khairi ◽  
D. Ahmad Fauzi ◽  
Yusof Abdullah ◽  
N.F. Hasbullah
Keyword(s):  
Barrier Height ◽  
Ideality Factor ◽  
Elevated Temperatures ◽  
Series Resistance ◽  
Schottky Diodes ◽  
High Energy ◽  
Bias Current ◽  
N Saturation ◽  
Saturation Current ◽  
Current Voltage

In this paper the effects of high energy (3.0 MeV) electrons irradiation over a dose ranges from 6 to 15 MGy at elevated temperatures 298 to 448 K on the current-voltage characteristics of 4H-SiC Schottky diodes were investigated. The experiment results show that after irradiation with 3.0 MeV forward bias current of the tested diodes decreased, while reverse bias current increased. The degradation of ideality factor, n, saturation current, Is, and barrier height, Phib, were not noticeable after the irradiation. However, the series resistance, Rs, has increased significantly with increasing radiation dose. In addition, temperature dependence current-voltage measurements, were conducted for temperature in the range of 298 to 448 K. The Schottky barrier height, saturation current, and series resistance, are found to be temperature dependent, while ideality factor remained constant. DOI: 10.21883/FTP.2017.12.45193.8646

Extraction of the Parameters from I-V Data for Nonideal Photodetectors: A Comparative Study

2005 ◽  
Vol 494 ◽  
pp. 83-88
Author(s):  
A. Vasić ◽  
P. Osmokrović ◽  
B. Lončar ◽  
S. Stanković
Keyword(s):  
Comparative Study ◽  
Ideality Factor ◽  
Series Resistance ◽  
Semiconductor Devices ◽  
Saturation Current ◽  
Made In

Parameters that characterize semiconductor devices are often determined with difficulty, and their values very frequently depend on the method used for measurements and analysis. The extraction of diode parameters from the obtained I-V measurements could be complicated by their dependence on the voltage and the presence of series resistance. Therefore, an interpretation of the experimental I-V data must be very carefully made. In this paper, some methods for obtaining diode parameters such as saturation current, ideality factor and series resistance are presented. An evaluation of these methods based on their application for the extraction of the relevant parameters of photodiodes is also performed. Some of the methods that produce reliable and reproducible results are evaluated based on the experimentally obtained results, and in the view of the complexity of the used methods and their limitations.

Current-transport mechanism in Au/V-doped PVC+TCNQ/p-Si structures

2015 ◽  
Vol 29 (13) ◽  
pp. 1550076 ◽  
Author(s):  
H. Tecimer ◽  
Ö. Vural ◽  
A. Kaya ◽  
Ş. Altındal
Keyword(s):  
Temperature Coefficient ◽  
Transport Mechanism ◽  
Forward Bias ◽  
Thermionic Emission ◽  
Negative Temperature ◽  
Positive Temperature ◽  
Current Transport ◽  
Insulator Layer ◽  
Zero Bias ◽  
Current Transport Mechanism

The forward and reverse bias current–voltage (I–V) characteristics of Au/V-doped polyvinyl chloride+Tetracyanoquino dimethane/porous silicon (PVC+TCNQ/p-Si) structures have been investigated in the temperature range of 160–340 K. The zero bias or apparent barrier height (BH) (Φ ap = Φ Bo ) and ideality factor (n ap = n) were found strongly temperature dependent and the value of n ap decreases, while the Φ ap increases with the increasing temperature. Also, the Φ ap versus T plot shows almost a straight line which has positive temperature coefficient and it is not in agreement with the negative temperature coefficient of ideal diode or forbidden bandgap of Si (α Si = -4.73×10-4 eV/K ). The high value of n cannot be explained only with respect to interfacial insulator layer and interface traps. In order to explain such behavior of Φ ap and n ap with temperature, Φ ap Versus q/2kT plot was drawn and the mean value of (Φ Bo ) and standard deviation (σs) values found from the slope and intercept of this plot as 1.176 eV and 0.152 V, respectively. Thus, the modified ( ln (Io/T2)-(qσs)2/2(kT)2 versus (q/kT) plot gives the Φ Bo and effective Richardson constant A* as 1.115 eV and 31.94 A ⋅(cm⋅K)-2, respectively. This value of A*( = 31.94 A⋅( cm ⋅K)-2) is very close to the theoretical value of 32 A ⋅(cm⋅K)-2 for p-Si. Therefore, the forward bias I–V–T characteristics confirmed that the current-transport mechanism (CTM) in Au/V-doped PVC+TCNQ/p-Si structures can be successfully explained in terms of the thermionic emission (TE) mechanism with a Gaussian distribution (GD) of BHs at around mean BH.

Characterization of Nanocrystalline p-CuO/n-Si Hetrojunction Prepared by RF-Sputtering

2014 ◽  
Vol 1024 ◽  
pp. 120-123
Author(s):  
Nezar Gassem Elfadill ◽  
M. Roslan Hashim ◽  
Khaled M. Chahrour ◽  
Chun Sheng Wang
Keyword(s):  
Cupric Oxide ◽  
Pure Copper ◽  
Rf Sputtering ◽  
Saturation Current ◽  
Font Size ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
Current Voltage ◽  
Capacitance Voltage

Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}Nanocrystalline cupric oxide (CuO) film was prepared by sputtering of pure copper metal on n-type single crystalline Si substrate under argon-oxygen ambient. Structural and morphological analyses of the as-deposited CuO films were performed by X-ray diffraction (XRD) diffractometer and Field Emission Scanning Electron Microscopy (FESEM). The results show Single crystalline granular nanocrystalline (002) CuO films, with 18 nm crystallite size. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were performed for p-CuO/n-Si hetrojunction. Diode parameters such as saturation current (Is=9.5E-6 A) and ideality factor (n=1.86) were extracted from the dark I-V characteristics. Potential barrier height of the junction (ϕi=1.1V) was revealed from (1/C2- V) plot. Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Calibri","sans-serif";}

Shallow P+-N Junction Fabrication by Plasma Immersion Ion Implantation

1991 ◽  
Vol 223 ◽  
Author(s):  
C. A. Pico ◽  
X. Y. Qian ◽  
E. Jones ◽  
M. A. Lieberman ◽  
N. W. Cheung
Keyword(s):  
Ion Implantation ◽  
Ideality Factor ◽  
High Frequency ◽  
Cyclotron Resonance ◽  
High Field ◽  
Electron Cyclotron Resonance ◽  
Forward Bias ◽  
Electron Cyclotron ◽  
Significant Damage ◽  
Plasma Immersion Ion Implantation

ABSTRACTPlasma immersion ion implantation (PIII) has been applied to fabricate shallow p-n junction diodes and MOS test structures. BF3 ions created by an electron cyclotron resonance source were implanted into n-type Si(100) at an accelerating voltage of −2 kv. The implant doses ranged from 4 × 1014/cm2 to 4 × 1015/cm2. In some cases, the top layers of the Si(100) substrates were preamorphized by a 3 × 1015/cm2 to 1016/cm2 implant of SiF4 by PIII at −7.2 kV prior to the BF3 implant. The ideality factor exhibited in both non- and preamorphized samples during forward bias is 1.02 to 1.05. Reverse leakages were measured at 30 nA/cm2 at −5V. High frequency capacitance and high field breakdown measurements of the oxide test structures showed no significant damage to the oxide.

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