Z1/2- and EH6-Center in 4H-SiC: Not Identical Defects ?

2012 ◽  
Vol 717-720 ◽  
pp. 251-254 ◽  
Author(s):  
Bernd Zippelius ◽  
Alexander Glas ◽  
Heiko B. Weber ◽  
Gerhard Pensl ◽  
Tsunenobu Kimoto ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Field ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Schottky Contacts ◽  
Double Peak ◽  
Carbon Vacancy ◽  
High Concentrations ◽  
Transient Spectroscopy ◽  
Dlts Spectra

Deep Level Transient Spectroscopy (DLTS) and Double-correlated DLTS (DDLTS) measurements have been conducted on Schottky contacts fabricated on n-type 4H-SiC epilayers using different contact metals in order to separate the EH6- and EH7-centers, which usually appear as a broad double peak in DLTS spectra. The activation energy of EH6(EC- ET(EH6) = 1.203 eV) turns out to be independent of the electric field. As a consequence, EH6is acceptor-like according to the missing Poole-Frenkel effect. Therefore, it can be excluded that the EH6-center and the prominent acceptor-like Z1/2-center belong to different charge states of the same microscopic defect as theoretically suggested. It is proposed that EH6is a complex containing a carbon vacancy and another component available at high concentrations. The activation energy of EH7(EC- ET(EH7) = 1.58 eV) has been evaluated indirectly by fitting the DLTS spectra of the EH6/7double peak taking the previously determined parameters of EH6into account.

Impact of Electric Field on Thermoemission of Carriers from Shallow Dislocation-Related Electronic States

2013 ◽  
Vol 205-206 ◽  
pp. 299-304 ◽  
Author(s):  
M. Trushin ◽  
Oleg F. Vyvenko
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Electric Field ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Dislocation Line ◽  
Electronic States ◽  
Energy Reduction ◽  
Transient Spectroscopy ◽  
Internal Charge

Shallow dislocation-related electronic states near the bottom of the conduction band in n-type Si bonded sample have been investigated with deep-level transient spectroscopy (DLTS), isothermal transient spectroscopy (ITS) and energy-resolved DLTS. The effect of thermoemission (TE) enhancement in external electric field was found and the dependence of the TE activation energy reduction as a function of the filling grade was obtained for these states. A new model of dislocation-strain-related Poole-Frenkel effect that accounts for the own electric field of internal charge of dislocation line is suggested and compared with the experimental data.

Evidence for Metastabile State of DX Center in AxGa1-xAs

1992 ◽  
Vol 262 ◽  
Author(s):  
Subhasis Ghosh ◽  
Vikram Kumar
Keyword(s):  
Activation Energy ◽  
Deep Level Transient Spectroscopy ◽  
Thermal Activation ◽  
Deep Level ◽  
Thermal Activation Energy ◽  
Dx Centers ◽  
Dx Center ◽  
Transient Spectroscopy ◽  
Silicon Doped ◽  
First Time

ABSTRACTPhoto-Deep Level Transient Spectroscopy with 1.38 eV light reveals a new level with thermal activation energy 0.2 eV of DX centers in silicon doped Alx Ga1-xAs (x = 0.26) for the first time. The observation of this level directly proves the negative-U properties of DX centers and the existence of thermodynamically metastable state DX.

In Situ Deep Level Transient Spectroscopy of Defect Evolution in Silicon Following Ion Implantation at 80 K

1998 ◽  
Vol 532 ◽  
Author(s):  
C. R. Cho ◽  
R. A. Brown ◽  
O. Kononchuk ◽  
N. Yarykin ◽  
G. Rozgonyi ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Room Temperature ◽  
Deep Level ◽  
Temperature Range ◽  
Type Silicon ◽  
Defect Annealing ◽  
Interstitial Defects ◽  
Transient Spectroscopy ◽  
Dlts Spectra

ABSTRACTThe evolution of defects in Czochralski and epitaxial p- and n-type silicon wafers following irradiation with He. Si or Ge ions at 80 K has been investigated by in situ deep level transient spectroscopy (DLTS). Defect annealing and formation reactions have been observed over the temperature range 80–350 K. In p-type silicon, new species-dependent levels are observed immediately after implantation, but these levels anneal out at or below room temperature. The wellknown divacancy and interstitial defects, usually reported after room temperature implantation, are revealed in the DLTS spectra only upon annealing at 160–200 K. In n-type silicon, vacancy-oxygen pairs are observed immediately after implantation. However, vacancy-related defects continue to form over a broad temperature range in samples implanted with Si or Ge. These observations are consistent with a model whereby vacancies and interstitials are released from defect clusters at temperatures >200 K to form divacancies and other defect pairs which are stable at room temperature.

Process-Induced Defects in High-Purity GaAs

1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle
Keyword(s):  
High Temperature ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Schottky Contacts ◽  
High Temperature Annealing ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTHigh temperature annealing of Si 3 N4 and SiO2 capped high purity LPE GaAs is shown to result in a reduction in the surface carrier concentration by about an order of magnitude. Au Schottky contacts made on the annealed samples were found to have severely degraded breakdown characteristics. Using deep level transient spectroscopy, deep levels at EC–.58eV, EC–.785eV were detected in the SiO2, capped samples and EC–.62eV, EC–.728eV in the Si3N4 capped Samples while none was detected in the unannealed samples.The electrical degradations are explained in terms of compensation mechanisns and depletion layer recombination-generation currents due to the deep levels.

The Influence of an In-Situ Electric Field on H+ and He+ Implantation Induced Defects in Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
J. Ravi ◽  
Yu. Erokhin ◽  
S. Koveshnikov ◽  
G.A. Rozgonyi ◽  
C.W. White
Keyword(s):  
Electric Field ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Spectroscopy Technique ◽  
Deep Traps ◽  
Observed Behaviour ◽  
Proton Implantation ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTThe influence of in-situ electronic perturbations on defect generation during 150 keV proton implantation into biased silicon p-n junctions has been investigated. The concentration and spatial distribution of the deep traps were characterized using a modification of the double corelation deep level transient spectroscopy technique (D-DLTS). With the in-situ electric field applied, a decrease in concentration of vacancy-related, as well as H-related, traps was observed. 500 keV He+ implantation was also performed to supplement the above studies and to differentiate any passivation effects due to hydrogen. A model based on the charge states of hydrogen and vacancies was used to explain the observed behaviour.

Electrically Active Deep Levels in ScN

2001 ◽  
Vol 699 ◽  
Author(s):  
Florentina Perjeru ◽  
Xuewen Bai ◽  
Martin E. Kordesch
Keyword(s):  
Activation Energy ◽  
Vapor Deposition ◽  
Deep Level Transient Spectroscopy ◽  
Physical Vapor Deposition ◽  
Deep Level ◽  
Reactive Sputtering ◽  
Deep Levels ◽  
Si Substrates ◽  
Transient Spectroscopy

AbstractWe report the electronic characterization of n-ScN in ScN-Si heterojunctions using Deep Level Transient Spectroscopy of electrically active deep levels. ScN material was grown by plasma assisted physical vapor deposition and by reactive sputtering on commercial p+ Si substrates. Deep level transient spectroscopy of the junction grown by plasma assisted physical vapor deposition shows the presence of an electronic trap with activation energy EC-ET= 0.51 eV. The trap has a higher concentration (1.2–1.6 1013cm−3) closer to the ScN/Si interface. Junctions grown by sputtering also have an electronic trap, situated at about EC-ET= 0.90 eV.

Characterisation of the Subthreshold Damage in MeV Ion Implanted p Si

1998 ◽  
Vol 510 ◽  
Author(s):  
Shabih Fatima ◽  
Jennifer Wong-Leung ◽  
John Fitz Gerald ◽  
C. Jagadish
Keyword(s):  
Point Defects ◽  
Deep Level Transient Spectroscopy ◽  
Damage Evolution ◽  
Peak Concentration ◽  
Deep Level ◽  
Extended Defects ◽  
Transmission Electron ◽  
Transient Spectroscopy ◽  
P Type ◽  
Dlts Spectra

AbstractSubthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for the extended defects. Also the mass dependence on the damage evolution has been observed, where rod-like defects are observed in the case of Si and (rod-like defects and loops) for Ge and Sn despite the fact that peak concentration of vacancies for Ge and Sn are normalized to the peak number of vacancies for Si.

Characterization of Deep Level Defects in 4h and 6H SIC Via DLTS, SIMS And MEV E-Beam Irradiation

1996 ◽  
Vol 423 ◽  
Author(s):  
J. P. Doyle ◽  
M. O. Aboelfotoh ◽  
M. K. Linnarsson ◽  
B. G. Svensson ◽  
A. Schöner ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Doping Concentration ◽  
Secondary Ion Mass Spectrometry ◽  
Deep Level ◽  
Schottky Contacts ◽  
Structural Defects ◽  
Beam Irradiation ◽  
Transient Spectroscopy ◽  
Secondary Ion

AbstractElectrically active defects in both 4H and 6H polytypes of SiC have been observed through the use of deep level transient spectroscopy (DLTS). Schottky contacts were grown by vapor phase epitaxy (VPE) with doping concentrations, the epitaxial layer having a doping concentration in the range of 1014 cm−3 to 1017cm−3. Numerous levels have been found in the as-grown n-type 6H-SiC samples and secondary ion mass spectrometry (SIMS) and MeV electron irradiation have been employed to corrrelate the defect levels to impurities or structural defects. In contrast, only a single level is observed in the as-grown 4H-SiC samples.

Donor-like Deep Level Defects in GaN Characterized by Double-correlation Deep Level Transient Spectroscopy

2005 ◽  
Vol 892 ◽  
Author(s):  
Mo Ahoujja ◽  
M Hogsed ◽  
Y. K. Yeo ◽  
R. L. Hengehold
Keyword(s):  
Activation Energy ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Peak Intensity ◽  
Spectral Peaks ◽  
Deep Donor ◽  
Radiation Induced ◽  
Si Doped ◽  
Transient Spectroscopy ◽  
Capacitance Transient

AbstractSi doped GaN grown by molecular beam epitaxy on sapphire substrates were characterized by capacitance transient spectroscopy. Conventional deep level transient spectroscopy (DLTS) measurements displayed six deep level defects, labeled A1, A, B, C1, C, and D, with activation energy ranging from 0.20 to 0.82 eV below the conduction band. Based on the logarithmic dependence of the DLTS spectral peaks on the filling pulse width, it is deduced that the defects A, B, C, and D are concentrated in the vicinity of line dislocations. Double-correlation DLTS (DDLTS) measurements, on the other hand, showed that only defects A (0.82 eV) and D (0.22 eV) exhibited deep donor-like characteristics. Following a 1.0 MeV electron irradiation of the GaN sample, one radiation-induced peak, E, with activation energy less than 0.20 eV was observed in the DLTS spectrum. However, after annealing at 350 °C, this DLTS peak intensity was found to diminish significantly.

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