scholarly journals Radiation-produced defects in germanium: experimental data and models of defects

2017 ◽  
Vol 51 (12) ◽  
pp. 1632
Author(s):  
V.V. Emtsev ◽  
D.S. Poloskin ◽  
G.A. Oganesyan ◽  
V.V. Kozlovski
Keyword(s):  
Experimental Data ◽  
Defect Formation ◽  
Deep Level ◽  
Minor Role ◽  
Radiation Defects ◽  
Electrical Measurements ◽  
Group V ◽  
Before And After ◽  
Transient Spectroscopy ◽  
A Minor

The problem of radiation-produced defects in n-Ge before and after n-> p conversion is discussed in the light of electrical data obtained by means of Hall effect measurements as well as Deep Level Transient Spectroscopy. The picture of the dominant radiation defects in irradiated n-Ge before n-> p conversion appears to be complicated, since they turn out to be neutral in n-type material and unobserved in the electrical measurements. It is argued that radiation-produced acceptors at ~ EC-0.2 eV previously ascribed to vacancy-donor pairs (E-centers) play a minor role in the defect formation processes under irradiation. Acceptor defects at ~ EV+0.1 eV are absolutely dominating in irradiated n-Ge after n-> p conversion. All the radiation defects under consideration were found to be dependent on the chemical group-V impurities. Together with this, they are concluded to be vacancy-related, as evidenced positron annihilation experiments. A detailed consideration of experimental data on irradiated n-Ge shows that the present model of radiation-produced defects adopted in literature should be reconsidered. DOI: 10.21883/FTP.2017.12.45178.8599

On the Influence of Illumination During Ion Damage Defect Anneal of Silicon

1995 ◽  
Vol 396 ◽  
Author(s):  
A. Tanabe ◽  
S. Ashok
Keyword(s):  
Electron Cyclotron Resonance ◽  
Deep Level ◽  
Hydrogen Plasma ◽  
Minor Role ◽  
Extended Defects ◽  
Rapid Thermal Anneal ◽  
Thermal Generation ◽  
Ion Damage ◽  
Transient Spectroscopy ◽  
A Minor

AbstractAn exploratory deep level transient spectroscopy (DLTS) study on the possible role of illumination during thermal annealing has been carried out on Si with extended defects generated by Ar implantation and electron cyclotron resonance (ECR) hydrogen plasma. Experiments with rapid thermal anneal (RTA) using quartz-halogen lamps show only a minor role for illumination on anneal of defects generated by Ar ion damage as well as thermal generation of defects under post-hydrogenation anneal. However, significant differences are evident relative to conventional furnace anneal and it appears likely that recombination-assisted defect reactions may be quite significant in Si processing when high intensity sources such as arc lamps are adapted in RTA systems.

Electronic States of Grain Boundaries in Bicrystal Silicon

1982 ◽  
Vol 14 ◽  
Author(s):  
C. M. Shyu ◽  
L. J. Cheng ◽  
K. L. Wang
Keyword(s):  
Density Of States ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Electronic States ◽  
Boundary Plane ◽  
Tilt Boundary ◽  
Electrical Measurements ◽  
Transient Spectroscopy ◽  
A Minor ◽  
P Type

ABSTRACTElectronic states at a 20° symmetrical(100) tilt boundary in p-type silicon were studied using deep level transient spectroscopy (DLTS) and other electrical measurements. The data can be explained with a model in which the local barrier height at the grain boundary varies on a scale much smaller than the boundary plane (∼I mm2) under study. Based on a relationship between the carrier capture cross section and energy level deduced from the experimental data, we have been able to calculate the distribution of the density of states in the energy bandgap at the boundary, which contains two groups of continuously distributed states; a major one whose density of states increases monotonically with the position of the state from the valance band, and a minor narrow one whose density of states is centered at Ev,+0.20 eV.

Defect-Formation Dependence on Group V-Dopant Atoms in Electron-Irradiated Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
O.O. Awadelkarim ◽  
A. Henry ◽  
B. Monemar ◽  
J.L. Lindström
Keyword(s):  
Room Temperature ◽  
Defect Formation ◽  
Deep Level ◽  
Electron Trap ◽  
Defect States ◽  
Group V ◽  
Doped Silicon ◽  
Temperature Electron ◽  
Transient Spectroscopy ◽  
Dopant Atoms

AbstractThe defect states introduced in P-, As- and Sb-doped silicon upon room-temperature electron-irradiation are studied by deep-level transient spectroscopy (DLTS). Evidence is provided for the involvement of the P-atom and the vacancy in the defect complex giving rise to the prominent electron trap commonly observed at ≈ EC-0.4 eV (EC being the edge of the conduction band). This electron trap together with another at EC-0.30 eV, apparently phosphorus related, exhibit configurationally metastable behaviour. Other electron traps observed at EC-0.27 eV and Ec-0.51 eV in Sb-doped material and EC-0.34 eV in As-doped material are attributed to complexes involving Sb and As atoms, respectively.

Point Defects in 4H-SiC Epilayers Introduced by 4.5 MeV Electron Irradiation and their Effect on Power JBS SiC Diode Characteristics

2013 ◽  
Vol 205-206 ◽  
pp. 451-456 ◽  
Author(s):  
Pavel Hazdra ◽  
Vít Záhlava ◽  
Jan Vobecký
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Radiation Defects ◽  
Electrical Parameters ◽  
Power Diodes ◽  
Defect Centers ◽  
Measurement Results ◽  
Transient Spectroscopy ◽  
State Resistance

Electronic properties of radiation damage produced in 4H-SiC by electron irradiation and its effect on electrical parameters of Junction Barrier Schottky (JBS) diodes were investigated. 4H‑SiC N‑epilayers, which formed the low‑doped N-base of JBS power diodes, were irradiated with 4.5 MeV electrons with fluences ranging from 1.5x1014 to 5x1015 cm-2. Radiation defects were then characterized by capacitance deep-level transient spectroscopy and C-V measurement. Results show that electron irradiation introduces two defect centers giving rise to acceptor levels at EC‑0.39 and EC‑0.60 eV. Introduction rate of these centers is 0.24 and 0.65 cm‑1, respectively. These radiation defects have a negligible effect on blocking and dynamic characteristics of irradiated diodes, however, the acceptor character of introduced deep levels and their high introduction rates deteriorate diode’s ON-state resistance already at fluences higher than 1x1015 cm‑2.

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.

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.

Renal prostanoids after unclipping the denervated one-kidney, one-clip hypertensive rat

1985 ◽  
Vol 249 (4) ◽  
pp. F542-F545 ◽  
Author(s):  
R. Vandongen ◽  
H. McGowan ◽  
H. Anderson ◽  
A. Barden
Keyword(s):  
Blood Pressure ◽  
Neural Mechanisms ◽  
Renal Nerves ◽  
Minor Role ◽  
Similar Extent ◽  
Before And After ◽  
Blood Pressures ◽  
A Minor ◽  
Prostanoid Synthesis ◽  
Stimulation Of

The contribution of the renal nerves in maintaining blood pressure and modulating renal prostanoid synthesis was examined in established (less than 8 wk in duration) one-kidney, one-clip (1K,1C) hypertension in the rat. Systolic blood pressure was measured for 7 days after renal denervation, at which time the renal artery clip was removed. Twenty-four-hour urinary excretion of PGE2 and 6-keto-PGF1 alpha (stable degradation product of PGI2) was determined before and after denervation and unclipping. Compared with sham-denervated rats, denervation (n = 15) resulted in a small but significant fall in blood pressure (from 216 +/- 4 to 182 +/- 4 mmHg after 48 h) and an increase in urinary 6-keto-PGF1 alpha (from 31 +/- 4 to 43 +/- 5 ng/24 h after 24 h). There was no change in PGE2 excretion. Seven days after surgery, blood pressures were similar in denervated (202 +/- 4 mmHg) and sham-denervated (211 +/- 5 mmHg) rats and fell to a similar extent 24 h after unclipping (142 +/- 3 and 147 +/- 4 mmHg, respectively). Urinary 6-keto-PGF1 alpha increased from 25 +/- 5 to 74 +/- 11 in denervated and 21 +/- 2 to 72 +/- 9 ng/24 h in sham-denervated rats in the 24 h after unclipping. PGE2 excretion increased approximately twofold over this period. These findings indicate that the renal nerves have only a minor role in established hypertension in the 1K,1C rat and that the reversal of hypertension and stimulation of renal prostanoid synthesis following unclipping is not dependent on neural mechanisms.

The Meyer–Neldel Rule in Conduction Mechanism of the Electrospun ZnO Nanofibers

NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650025 ◽  
Author(s):  
Andrzej Stafiniak ◽  
Marek Tłaczała
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Conduction Mechanism ◽  
Deep Level ◽  
Electrical Measurements ◽  
Thermally Activated ◽  
Theoretical Assumptions ◽  
Different Temperatures ◽  
Zno Nanofibers ◽  
Improved Model

An analytical model describing the conductivity of ZnO nanofibers depending on the grains size is proposed. The research is based on the thermal dc electrical measurements of a single electrospun ZnO nanofiber calcined at different temperatures. In the our previous research, we showed that electrical conduction of ZnO nanofibers is mainly thermally activated. The activation energy of conductivity was strongly dependent on the grain size, which in turn depended on the calcination temperature. This could be due to migration of a point defect in the grain of ZnO and could change the carrier concentration. Our recent studies have shown that ZnO nanofibers behavior is consistent with the Meyer–Neldel rule. This indicates an exponential energy distribution of deep level traps in the material. Based on the theoretical assumptions and experimental data, the improved model of conductivity in a single ZnO nanofiber calcined at different temperatures was proposed.

“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.

Point Defects in Gallium Arsenide Characterized by Positron Annihilation Spectroscopy and Deep Level Transient Spectroscopy

1994 ◽  
Vol 373 ◽  
Author(s):  
R. Mih ◽  
R. Gronsky
Keyword(s):  
Gallium Arsenide ◽  
Positron Annihilation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Czochralski Method ◽  
Positron Annihilation Spectroscopy ◽  
Crystallographic Data ◽  
Electrical Measurements ◽  
Vacancy Defects ◽  
Transient Spectroscopy

AbstractPositron annihilation lifetime spectroscopy (PALS) is a unique technique for detection of vacancy related defects in both as-grown and irradiated materials. We present a systematic study of vacancy defects in stoichiometrically controlled p-type Gallium Arsenide grown by the Hot- Wall Czochralski method. Microstructural information based on PALS, was correlated to crystallographic data and electrical measurements. Vacancies were detected and compared to electrical levels detected by deep level transient spectroscopy and stoichiometry based on crystallographic data.

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