scholarly journals The Carbon Vacancy Related EI4 Defect in 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 399-402 ◽  
Author(s):  
Nguyen Tien Son ◽  
Patrick Carlsson ◽  
Junichi Isoya ◽  
Norio Morishita ◽  
Takeshi Ohshima ◽  
...  

Electron paramagnetic resonance (EPR) was used to study high-purity semi-insulating 4H-SiC irradiated with 2 MeV electrons at room temperature. The EPR signal of the EI4 defect was found to be dominating in samples irradiated and annealed at ~750°C. Additional large-splitting 29Si hyperfine (hf) lines and also other 13C and 29Si hf structures were observed. Based on the observed hf structures and annealing behaviour, the complex between a negative carbon vacancy-carbon antisite pair (VCCSi–) and a distance positive carbon vacancy ( ) is tentatively proposed as a possible model for the EI4 defect.

1969 ◽  
Author(s):  
D.A. Bozanic ◽  
D.C. Buck ◽  
F.H. Harris ◽  
R.E. Huber ◽  
D. Mergerian ◽  
...  

1997 ◽  
Vol 504 ◽  
Author(s):  
A. Darwish ◽  
D. Ila ◽  
E. K. Willams ◽  
D. B. Poker ◽  
D. K. Hensley

ABSTRACTThe effect of the ion implantation (Fe) on LiNbO3, MgO, and A12O3 crystals is studied using electron paramagnetic resonance (EPR). EPR measurements on these crystals were performed as a function of fluence at room temperature. The fluence was 1 × 1014 and 1 × 1016 ions/cm2. The unpaired carrier concentration increases with increasing fluence. The photosensitivity of these crystals was determined by observing in situ the effect of the laser illumination on the EPR signal and measuring the decay and the growth of the EPR signal. The EPR signal of Fe3+ was found to decrease in both MgO, and Al2O3; and was found to increase in LiNbO3. This indicated that in case of MgO, and A12O3 Fe3+ will transfer into Fe2+/Fe4+, but in case of LiNbO3 Fe2+/ Fe4+ will transfer into Fe3+; increasing the EPR signal. This was found primary due to some Fe2+ and Fe4+ ions, which is not intentionally doped on the LiNbO3 crystal but exist as a defect on the crystal.


2007 ◽  
Vol 556-557 ◽  
pp. 465-468 ◽  
Author(s):  
Nguyen Tien Son ◽  
Patrick Carlsson ◽  
Björn Magnusson ◽  
Erik Janzén

Vacancies, divacancies and carbon vacancy-carbon antisite pairs are found by electron paramagnetic resonance (EPR) to be dominant defects in high-purity semi-insulating (HPSI) 4HSiC substrates having different thermal activation energies of the resistivity ranging from ~0.8 eV to ~1.6 eV. Based on EPR results and previously reported data, the energy positions of several acceptor states of the vacancies and vacancy-related complexes are estimated. These deep levels are suggested to be associated to different thermal activation energies and responsible for the semiinsulating behaviour in HPSI SiC substrates. Their role in carrier compensation is discussed.


1996 ◽  
Vol 452 ◽  
Author(s):  
N. H. Nickel ◽  
E. A. Schiff

AbstractThe temperature dependence of the silicon dangling-bond resonance in polycrystalline (poly-Si) and amorphous silicon (a-Si:H) was measured. At room temperature, electron paramagnetic resonance (EPR) measurements reveal an isotropie g-value of 2.0055 and a line width of 6.5 and 6.1 G for Si dangling-bonds in a-Si:H and poly-Si, respectively. In both materials spin density and g-value are independent of temperature. While in a-Si:H the width of the resonance did not change with temperature, poly-Si exhibits a remarkable T dependence of ΔHpp. In unpassivated poly-Si a pronounced decrease of ΔHpp is observed for temperatures above 300 K. At 384 K ΔHpp reaches a minimum of 5.1 G, then increases to 6.1 G at 460 K, and eventually decreases to 4.6 G at 530 K. In hydrogenated poly-Si ΔHpp decreases monotonically above 425 K. The decrease of ΔHpp is attributed to electron hopping causing motional narrowing. An average hopping distance of 15 and 17.5 Å was estimated for unhydrogenated and H passivated poly-Si, respectively.


1991 ◽  
Vol 46 (7) ◽  
pp. 579-582 ◽  
Author(s):  
A. B. Vassilikou-Dova ◽  
K. Eftaxias

Abstract In clear, blue, transparent bipyramidal crystals of the rare mineral benitoite, BaTiSi3O9, para­ magnetic defects have been investigated by electron paramagnetic resonance at room temperature and 9.43 GHz. They are attributed to Sn3+ and Fe3+ . A pair of satellites recorded for a wide angular rage around B0 || c (~40°) and a relative intensity of ~ 13% to the central signal is most likely due to hyperfine interaction with 117Sn and 119Sn isotopes. Attempts to bleach the colour of the crystal were unsuccessful.


Biochemistry ◽  
1993 ◽  
Vol 32 (18) ◽  
pp. 4842-4847 ◽  
Author(s):  
Ina Sieckmann ◽  
Klaus Brettel ◽  
Christian Bock ◽  
Arthur van der Est ◽  
Dietmar Stehlik

2008 ◽  
Vol 600-603 ◽  
pp. 381-384 ◽  
Author(s):  
Patrick Carlsson ◽  
Nguyen Tien Son ◽  
Björn Magnusson ◽  
Anne Henry ◽  
Erik Janzén

High-purity, semi-insulating 6H-SiC substrates grown by high-temperature chemical vapor deposition were studied by electron paramagnetic resonance (EPR). The carbon vacancy (VC), the carbon vacancy-antisite pair (VCCSi) and the divacancy (VCVSi) were found to be prominent defects. The (+|0) level of VC in 6H-SiC is estimated by photoexcitation EPR (photo-EPR) to be at ~ 1.47 eV above the valence band. The thermal activation energies as determined from the temperature dependence of the resistivity, Ea~0.6-0.7 eV and ~1.0-1.2 eV, were observed for two sets of samples and were suggested to be related to acceptor levels of VC, VCCSi and VCVSi. The annealing behavior of the intrinsic defects and the stability of the SI properties were studied up to 1600°C.


Sign in / Sign up

Export Citation Format

Share Document