Deep Hole Traps in As-Grown 4H-SiC Epilayers Investigated by Deep Level Transient Spectroscopy

2006 ◽  
Vol 527-529 ◽  
pp. 501-504 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto
Keyword(s):  
Detection Limit ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Low Energy ◽  
Deep Hole ◽  
Meaningful Change ◽  
Low Energy Electron ◽  
Transient Spectroscopy ◽  
P Type ◽  
Thermal Stability Of

Deep levels in as-grown p-type 4H-SiC epilayers have been investigated by DLTS. Three deep hole traps (HK2, HK3 and HK4) can be detected by DLTS in the temperature range from 350K to 700K. They are energetically located at 0.84 eV (HK2), 1.27 eV (HK3) and 1.44 eV (HK4) above the valence band edge. The activation energy of the traps does not show any meaningful change regardless of applied electric field, indicating that the charge state of the deep hole traps may be neutral after hole emission (donor-like). By the low-energy electron irradiation, the HK3 and HK4 concentrations are significantly increased, suggesting that the origins of the HK3 and HK4 may be related to carbon displacement. Study on the thermal stability of these hole traps has revealed that the trap concentrations of HK3 and HK4 are reduced to below the detection limit (1-2 × 1011 cm-3) by annealing at 1350°C. The HK2 is thermally more stable than HK3 and HK4, and becomes lower than the detection limit by annealing at 1550°C.

Deep Levels in P-Type 4H-SiC Induced by Low-Energy Electron Irradiation

2013 ◽  
Vol 740-742 ◽  
pp. 373-376 ◽  
Author(s):  
Kazuki Yoshihara ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Low Energy ◽  
Epitaxial Layers ◽  
Before And After ◽  
Low Energy Electron ◽  
Transient Spectroscopy ◽  
P Type

We have characterized deep levels in as-grown and electron irradiated p-type 4H-SiC epitaxial layers by the current deep-level transient spectroscopy (I-DLTS) method. A part of the samples were irradiated with electrons in order to introduce defects. As a result, we found that electron irradiation to p-type 4H-SiC created complex defects including carbon vacancy or interstitial. Moreover, we found that observed deep levels are different between before and after annealing, and thus annealing may change structures of defects.

Deep Levels in Electron-Irradiated n- and p-type 4H-SiC Investigated by Deep Level Transient Spectroscopy

2007 ◽  
Vol 556-557 ◽  
pp. 331-334 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto
Keyword(s):  
Charge State ◽  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Low Energy ◽  
Annealing Stage ◽  
Low Energy Electron ◽  
Transient Spectroscopy ◽  
P Type

The authors have investigated deep levels in electron-irradiated n- and p-type 4H-SiC epilayers by deep level transient spectroscopy (DLTS). By low-energy electron irradiation at 116 keV, the Z1/2 and EH6/7 concentrations are increased in n-type samples, and the concentrations are almost unchanged after annealing at 950°C for 30 min. In p-type samples, the unknown centers, namely EP1 and EP2, are introduced by irradiation. By annealing at 950°C, the unknown centers are annealed out. The HK4 center (EV + 1.44 eV) is increased by the electron irradiation and subsequent annealing at 950°C. The dependence of increase in the trap concentrations by irradiation (NT) on the electron fluence reveals that NT for the Z1/2 and EH6/7 centers is in proportional to the 0.7 power of electron fluence, while the slope of the plot is 0.5 for the HK4 center. The Z1/2 and EH6/7 centers show similar annealing stage and are thermally stable up to 1500-1600°C, while the HK4 center is annealed out at about 1350°C. The Z1/2 and EH6/7 centers may be derived from a same origin (single carbon vacancy: VC) but different charge state. The HK4 center may be a complex including VC.

Current-Mode Deep Level Spectroscopy of Vanadium-Doped HPSI 4H-SiC

2020 ◽  
Vol 1004 ◽  
pp. 331-336
Author(s):  
Giovanni Alfieri ◽  
Lukas Kranz ◽  
Andrei Mihaila
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Scientific Community ◽  
Minority Carrier ◽  
Deep Level ◽  
Current Mode ◽  
Low Energy ◽  
The Other ◽  
Carrier Trap ◽  
Low Energy Electron ◽  
Transient Spectroscopy

SiC has currently attracted the interest of the scientific community for qubit applications. Despite the importance given to the properties of color centers in high-purity semi-insulating SiC, little is known on the electronic properties of defects in this material. In our study, we investigated the presence of electrically active levels in vanadium-doped substrates. Current mode deep level transient spectroscopy, carried out in the dark and under illumination, together with 1-D simulations showed the presence of two electrically active levels, one associated to a majority carrier trap and the other one to a minority carrier trap. The nature of the detected defects has been discussed in the light of the characterization performed on low-energy electron irradiated substrates and previous results found in the literature.

Deep Levels in As-Grown and Electron-Irradiated P-type 4H-SiC

2006 ◽  
Vol 911 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto
Keyword(s):  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Capture Cross Section ◽  
Arrhenius Plot ◽  
Deep Level ◽  
Deep Levels ◽  
Emission Time ◽  
Transient Spectroscopy ◽  
P Type ◽  
Thermal Stability Of

AbstractDeep levels in as-grown and electron-irradiated p-type 4H-SiC have been investigated by deep level transient spectroscopy (DLTS). Three hole traps, namely HK2, HK3, and HK4, could be detected in the temperature range from 350K to 700K. Activation energies of the hole traps were estimated to be 0.84 eV for HK2, 1.27 eV for HK3, and 1.44 eV for HK4 from the Arrhenius plot of emission-time constants assuming temperature-independent capture cross section. By double-correlated DLTS (DDLTS), they were revealed to be donor-like (+/0) traps. The concentrations of HK3 and HK4 centers were clearly increased by low-energy (116 keV) electron irradiation. Based on thermal stability of the HK3 and HK4 centers up to 1350°C and the dependence of HK4 concentration on the electron fluence, they may originate from a complex including defect(s) caused by carbon displacement.

Thermal Stability of Defect Centers in n- and p-Type 4H-SiC Epilayers Generated by Irradiation with High-Energy Electrons

2010 ◽  
Vol 645-648 ◽  
pp. 423-426 ◽  
Author(s):  
Sergey A. Reshanov ◽  
Svetlana Beljakowa ◽  
Bernd Zippelius ◽  
Gerhard Pensl ◽  
Katsunori Danno ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Systematic Study ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
High Energy ◽  
Defect Centers ◽  
High Energy Electrons ◽  
Transient Spectroscopy ◽  
P Type ◽  
Thermal Stability Of

This paper comprises a systematic study of the thermal stability of defect centers observed in n- and p-type 4H-SiC by deep level transient spectroscopy (DLTS); the defects are generated by irradiation with high-energy electrons of 170 keV or 1 MeV.

Persistent Photoconductivity And Thermal Recovery Kinetics Of Low Energy Ar + Bombarded GaAs

1991 ◽  
Vol 223 ◽  
Author(s):  
A. Vaseashta ◽  
L. C. Burton
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Thermal Recovery ◽  
Low Energy ◽  
Persistent Photoconductivity ◽  
Transport Parameters ◽  
Excellent Correlation ◽  
Proposed Model ◽  
Transient Spectroscopy ◽  
Kinetics Of

ABSTRACTKinetics of persistent photoconductivity, photoquenching, and thermal and optical recovery observed in low energy Ar+ bombarded on (100) GaAs surfaces have been investigated. Rate and transport equations for these processes were derived and simulated employing transport parameters, trap locations and densities determined by deep level transient spectroscopy. Excellent correlation was obtained between the results of preliminary simulation and the experimentally observed values. The exponential decay of persistent photoconductivity response curve was determined to be due to metastable electron traps with longer lifetime and is consistent with an earlier proposed model.

scholarly journals Impact of Hydrogenation on Electrical Properties of NiSi2 Precipitates in Silicon

2005 ◽  
Vol 108-109 ◽  
pp. 279-284 ◽  
Author(s):  
O.F. Vyvenko ◽  
N.V. Bazlov ◽  
M.V. Trushin ◽  
A.A. Nadolinski ◽  
Michael Seibt ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Deep Level Transient Spectroscopy ◽  
Molecular Hydrogen ◽  
Deep Level ◽  
Hydrogen Plasma ◽  
Extended Defects ◽  
Transient Spectroscopy ◽  
P Type ◽  
Plasma Hydrogenation ◽  
Type Sample

Influence of annealing in molecular hydrogen as well as of treatment in hydrogen plasma (hydrogenation) on the electrical properties of NiSi2 precipitates in n- and p-type silicon has been studied by means of deep level transient spectroscopy (DLTS). Both annealing and hydrogenation gave rise to noticeable changes of the shape of the DLTS-peak and of the character of its dependence on the refilling pulse duration that according to [1] allows one to classify the electronic states of extended defects as “band-like” or “localized”. In both n- and p-type samples DLTS-peak in the initial as quenched samples showed bandlike behaviour. Annealing or hydrogenation of n-type samples converted the band-like states to the localised ones but differently shifted the DLTS-peak to higher temperatures. In p-type samples, the initial “band-like” behaviour of DLTS peak remained qualitatively unchanged after annealing or hydrogenation. A decrease of the DLTS-peak due to precipitates and the appearance of the peaks due to substitutional nickel and its complexes were found in hydrogenated p-type sample after removal of a surface layer of 10-20µm.

Sign in / Sign up

Export Citation Format

Share Document