“Recovery” Effect of Electron Induced Damage in 4H-SiC Schottky Diodes

2003 ◽  
Vol 792 ◽  
Author(s):  
A. Castaldini ◽  
A. Cavallini ◽  
L. Rigutti ◽  
F. Nava ◽  
P.G. Fuochi ◽  
...  
Keyword(s):  
Deep Level ◽  
Collection Efficiency ◽  
Schottky Diodes ◽  
Chemical Vapour ◽  
Liquid Nitrogen Temperature ◽  
Charge Collection Efficiency ◽  
Before And After ◽  
Transient Spectroscopy ◽  
Lower Temperature ◽  
Different Doses

ABSTRACTThe effects of electron irradiation on the defects associated electronic levels in Schottky diodes on 4H silicon carbide epilayers grown by chemical vapour deposition were investigated by Deep Level Transient Spectroscopy (DLTS) and Capacitance-Voltage (C-V) characteristics. These investigations were performed before and after irradiation with 8.6 MeV electrons at different doses. After irradiation four new traps with enthalpies equal to (Ec-0.23 eV), (Ec-0.39 eV), (Ec-0.63 eV) and (Ec-0.75 eV) were detected. Their thermal stability, a key point to determine their structure on the basis of recent theoretical and experimental results, was carefully investigated since it was earlier observed that during DLTS temperature runs up to 500 K a slight but significant recovery of a few irradiation-induced levels occurs. This effect was previously observed in literature for the level (Ec-0.70 eV) after thermal treatment at 500 °C [1], but the present results indicate that it involves more than a single level and is also effective at lower temperature. DLTS analyses were also performed from room temperature to liquid nitrogen temperature and vice versa up to 500 K.The annealing kinetics is reported and a few conclusions on the structure of the defects involved in the recovery are drawn. The correlation with the diode charge collection efficiency is also reported.

scholarly journals Влияние нейтронного облучения на спектр дефектов с глубокими уровнями в GaAs, изготовленном методом жидкофазной эпитаксии в атмосфере водорода и аргона

2022 ◽  
Vol 56 (1) ◽  
pp. 53
Author(s):  
М.М. Соболев ◽  
Ф.Ю. Солдатенков
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Experimental Studies ◽  
Shallow Donor ◽  
Defect Clusters ◽  
Deep Traps ◽  
Capacitance Voltage ◽  
Before And After ◽  
Transient Spectroscopy ◽  
Different Doses

The results of experimental studies of capacitance– voltage characteristics, spectra of deep-level transient spectroscopy of graded high-voltage GaAs p+−p0−i−n0 diodes fabricated by liquid-phase epitaxy at a crystallization temperature of 900C from one solution–melt due to autodoping with background impurities, in a hydrogen or argon ambient, before and after irradiation with neutrons. After neutron irradiation, deep-level transient spectroscopy spectra revealed wide zones of defect clusters with acceptor-like negatively charged traps in the n0-layer, which arise as a result of electron emission from states located above the middle of the band gap. It was found that the differences in capacitance–voltage characteristics of the structures grown in hydrogen or argon ambient after irradiation are due to different doses of irradiation of GaAs p+−p0−i−n0 structures and different degrees of compensation of shallow donor impurities by deep traps in the layers.

Deep Levels in 4H Silicon Carbide Epilayers Induced by Neutron-Irradiation up to 1016 n/cm2

2006 ◽  
Vol 911 ◽  
Author(s):  
Anna Cavallini ◽  
Antonio Castaldini ◽  
Filippo Nava ◽  
Paolo Errani ◽  
Vladimir Cindro
Keyword(s):  
Deep Level ◽  
Collection Efficiency ◽  
Deep Levels ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
Temperature Range ◽  
Order Of Magnitude ◽  
Irradiation Level ◽  
Transient Spectroscopy ◽  
Induced Defects

AbstractWe investigated the electronic levels of defects introduced in 4H-SiC α-particle detectors by irradiation with 1 MeV neutrons up to a fluence equal to 8x1015 n/cm2. As well, we investigated their effect on the detector radiation hardness. This study was carried out by deep level transient spectroscopy (DLTS) and photo-induced current transient spectroscopy (PICTS). As the irradiation level approaches fluences in the order of 1015 n/cm2, the material behaves as highly resistive due to a very great compensation effect but the diodes are still able to detect with a acceptably good charge collection efficiency (CCE) equal to 80%. By further increasing fluence, CCE decreases reaching the value of ≈ 20% at fluence of 8x1015 n/cm2.The dominant peaks in the PICTS spectra occur in the temperature range [400, 700] K. Enthalpy, capture cross-section and order of magnitude of the density of such deep levels were calculated. In the above said temperature range the deep levels associated to the radiation induced defects play the key role in the degradation of the CCE. Two deep levels at Et = 1.18 eV and Et = 1.50 eV are likely to be responsible of such dramatic decrease of the charge collection efficiency. These levels were reasonably associated to an elementary defect involving a carbon vacancy and to a defect complex involving a carbon and a silicon vacancy, respectively.

Defects in an Electron-Irradiated 6H-SiC Diode Studied by Alpha Particle Induced Charge Transient Spectroscopy: Their Impact on the Degraded Charge Collection Efficiency

2012 ◽  
Vol 717-720 ◽  
pp. 267-270
Author(s):  
Naoya Iwamoto ◽  
Atsushi Koizumi ◽  
Shinobu Onoda ◽  
Takahiro Makino ◽  
Takeshi Ohshima ◽  
...  
Keyword(s):  
Alpha Particle ◽  
Deep Level ◽  
Collection Efficiency ◽  
High Energy ◽  
Electron Trap ◽  
Charge Collection ◽  
High Energy Electron ◽  
Charge Collection Efficiency ◽  
Induced Charge ◽  
Transient Spectroscopy

Defects in electron-irradiated 6H-SiC diodes have been studied by single alpha particle induced charge transient spectroscopy and deep level transient spectroscopy (DLTS) in order to identify critical defects responsible for the charge collection efficiency (CCE) decreased by high-energy electron irradiation. The defect X2 detected by the charge transient spectroscopy and the electron trap Ei detected by the DLTS had a similar activation energy of around 0.50 eV. In addition, the annealing at 200oC completely removed defects X2 and Ei, and restored the CCE. The defect X2 is attributed to the electron trap Ei, and responsible for the decreased CCE.

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.

scholarly journals Deep levels in n-type Schottky and p+-n homojunction GaN diodes

2000 ◽  
Vol 5 (S1) ◽  
pp. 922-928
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Yellow Luminescence ◽  
Arrhenius Behavior ◽  
Electron Level ◽  
Transient Spectroscopy ◽  
Electron And Hole Traps

The deep level spectra in both p+-n homojunction and n-type Schottky GaN diodes are studied by deep level transient spectroscopy (DLTS) in order to compare the role of the junction configuration on the defects found within the n-GaN layer. Both majority and minority carrier DLTS measurements are performed on the diodes allowing the observation of both electron and hole traps in n-GaN. An electron level at Ec−Et=0.58 and 0.62 V is observed in the p+-n and Schottky diodes, respectively, with a concentration of ∼3−4×1014 cm−3 and a capture cross section of ∼1−5×10−15 cm2. The similar Arrhenius behavior indicates that both emissions are related to the same defect. The shift in activation energy is correlated to the electric field enhanced-emission in the p+-n diode, where the junction barrier is much larger. The p+-n diode configuration allows the observation of a hole trap at Et−Ev=0.87 eV in the n-GaN which is very likely related to the yellow luminescence band.

Improved SiO2/ 4H-SiC Interface Defect Density Using Forming Gas Annealing

2019 ◽  
Vol 963 ◽  
pp. 465-468
Author(s):  
Stephan Wirths ◽  
Giovanni Alfieri ◽  
Alyssa Prasmusinto ◽  
Andrei Mihaila ◽  
Lukas Kranz ◽  
...  
Keyword(s):  
Defect Density ◽  
Deep Level ◽  
Flat Band ◽  
Temperature Dependent ◽  
Mos Capacitors ◽  
Interface Defect ◽  
Before And After ◽  
Oxide Deposition ◽  
Transient Spectroscopy ◽  
Post Deposition

We investigated the influence of forming gas annealing (FGA) before and after oxide deposition on the SiO2/4H-SiC interface defect density (Dit). For MOS capacitors (MOSCAPs) that were processed using FGAs at temperatures above 1050°C, CV characterization revealed decreased flat band voltage shifts and stretch-out for different sweep directions and frequencies. Moreover, constant-capacitance deep level transient spectroscopy (CC-DLTS) was performed and showed Dit levels below 1012 cm-2eV-1 for post deposition FGA at 1200°C. Finally, lateral MOSFETs were fabricated to analyze the temperature-dependent threshold voltage (Vth) shift.

scholarly journals Low Voltage High-Energy α-Particle Detectors by GaN-on-GaN Schottky Diodes with Record-High Charge Collection Efficiency

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5107 ◽  
Author(s):  
Sandupatla ◽  
Arulkumaran ◽  
Ranjan ◽  
Ing ◽  
Murmu ◽  
...  
Keyword(s):  
Low Voltage ◽  
Collection Efficiency ◽  
Schottky Diodes ◽  
High Energy ◽  
Charge Collection ◽  
Charge Carrier Density ◽  
Free Standing ◽  
Charge Collection Efficiency ◽  
High Charge ◽  
Drift Layer

A low voltage (–20 V) operating high-energy (5.48 MeV) α-particle detector with a high charge collection efficiency (CCE) of approximately 65% was observed from the compensated (7.7 × 1014 /cm3) metalorganic vapor phase epitaxy (MOVPE) grown 15 µm thick drift layer gallium nitride (GaN) Schottky diodes on free-standing n+-GaN substrate. The observed CCE was 30% higher than the bulk GaN (400 µm)-based Schottky barrier diodes (SBD) at –20 V. This is the first report of α–particle detection at 5.48 MeV with a high CCE at –20 V operation. In addition, the detectors also exhibited a three-times smaller variation in CCE (0.12 %/V) with a change in bias conditions from –120 V to –20 V. The dramatic reduction in CCE variation with voltage and improved CCE was a result of the reduced charge carrier density (CCD) due to the compensation by Mg in the grown drift layer (DL), which resulted in the increased depletion width (DW) of the fabricated GaN SBDs. The SBDs also reached a CCE of approximately 96.7% at –300 V.

Carrier loss by rapid thermal-annealing in Si-doped GaAs grown by MOCVD (metal-organic chemical vapour deposition)

1991 ◽  
Vol 69 (3-4) ◽  
pp. 353-356
Author(s):  
C. Aktik ◽  
J. F. Currie ◽  
F. Bosse ◽  
R. W. Cochrane ◽  
J. Auclair
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Deep Level ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Before And After ◽  
Metal Organic ◽  
Si Doped

Si-doped GaAs epitaxial layers grown by metal-organic chemical vapour deposition exhibit substantial carrier density loss after rapid thermal annealing (RTA) at temperatures higher than 850 °C. Hall-effect, capacitance–voltage, deep-level transient spectroscopy, and secondary ion mass spectroscopy measurements were performed on samples before and after RTA. We show that the reduction of free-carrier concentration in the entire thickness of the epitaxial layer is accompanied by the deterioration of the mobility and the enhancement of donor-like deep-level concentration at 0.305 eV below the conduction band, which is in good agreement with the model of silicon donor neutralization by formation of neutral silicon–hydrogen complexes.

Charge Collection Efficiency of 6H-SiC P+N Diodes Degraded by Low-Energy Electron Irradiation

2010 ◽  
Vol 645-648 ◽  
pp. 921-924 ◽  
Author(s):  
Naoya Iwamoto ◽  
Shinobu Onoda ◽  
Takeshi Ohshima ◽  
Kazutoshi Kojima ◽  
Atsushi Koizumi ◽  
...  
Keyword(s):  
Electron Irradiation ◽  
Collection Efficiency ◽  
Alpha Particles ◽  
Low Energy ◽  
Energy Electron ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
Before And After ◽  
Low Energy Electron

The effect of electron irradiation on the charge collection efficiency of a 6H-SiC p+n diode has been studied. The diodes were irradiated with electrons of energies from 100 keV to 1 MeV. The charge collection efficiencies of the samples were measured for alpha particles before and after the electron irradiation. The electron irradiation at 100 keV does not affect the charge collection efficiency, while the electron irradiation at 200 keV or higher decreases the charge collection efficiency. The degree of the degradation of the diodes correlates with the energy of the electron irradiation.

Effect of the Depletion Region of a-Si:H Schottky Diodes on the Time-of-Flight Mobility-Lifetime Product

1990 ◽  
Vol 192 ◽  
Author(s):  
N. Wyrsch ◽  
P. Roca i Cabarrocas ◽  
S. Wagner ◽  
V. Viret
Keyword(s):  
Collection Efficiency ◽  
Schottky Diodes ◽  
Time Of Flight ◽  
Internal Field ◽  
Laser Wavelength ◽  
Depletion Region ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
Trapping Time ◽  
Transient Photoconductivity

ABSTRACTThe effect of the depletion region in amorphous silicon Schottky diodes on the mobility-deep trapping lifetime product μτ of electrons has been investigated using transient photoconductivity techniques. We varied the laser wavelength of the exciting laser in time-of-flight (TOF) measurements. The results are correlated with measurements of the internal field by means of the charge collection efficiency, and with measurement of the deep-trapping time by the Delayed-Field TOF technique (DFTOF). We find that the electron μτ decreases from the bulk toward the top surface.

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