| 1. |
- Kawahara, Koutarou, et al.
(författare)
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Investigation on origin of Z(1/2) center in SiC by deep level transient spectroscopy and electron paramagnetic resonance
- 2013
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 102:11
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Tidskriftsartikel (refereegranskat)abstract
- The Z(1/2) center in n-type 4H-SiC epilayers-a dominant deep level limiting the carrier lifetime-has been investigated. Using capacitance versus voltage (C-V) measurements and deep level transient spectroscopy (DLTS), we show that the Z(1/2) center is responsible for the carrier compensation in n-type 4H-SiC epilayers irradiated by low-energy (250 keV) electrons. The concentration of the Z(1/2) defect obtained by C-V and DLTS correlates well with that of the carbon vacancy (V-C) determined by electron paramagnetic resonance, suggesting that the Z(1/2) deep level originates from V-C.
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| 2. |
- Kawahara, Koutarou, et al.
(författare)
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Quantitative comparison between Z1∕2 center and carbon vacancy in 4H-SiC
- 2014
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Ingår i: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 115:14, s. 143705-
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Tidskriftsartikel (refereegranskat)abstract
- In this study, to reveal the origin of the Z(1/2) center, a lifetime killer in n-type 4H-SiC, the concentrations of the Z(1/2) center and point defects are compared in the same samples, using deep level transient spectroscopy (DLTS) and electron paramagnetic resonance (EPR). The Z(1/2) concentration in the samples is varied by irradiation with 250 keV electrons with various fluences. The concentration of a single carbon vacancy (V-C) measured by EPR under light illumination can well be explained with the Z(1/2) concentration derived from C-V and DLTS irrespective of the doping concentration and the electron fluence, indicating that the Z(1/2) center originates from a single V-C.
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| 3. |
- Trinh, Xuan Thang, et al.
(författare)
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Electron paramagnetic resonance studies of carbon interstitial related defects in 4H-SiC
- 2015
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In n-type 4H-SiC grown by chemical vapor deposition and irradiated by low-energy (250 keV) electrons, an electron paramagnetic resonance center, labeled EI8a, was observed at room temperature. A short anneal at temperatures in the range of 300-500 °C in darkness changes EI8a to a new center, labeled EI8b, which can be converted back by illumination at room temperature. We show that EI8a and EI8b are the two different configurations of the same defect, labeled EI8, with C1h symmetry and an electron spin S=1/2. The EI8 center is stable up to ~650 °C and annealed out at ~800 °C. Based on the observed hyperfine structures due to the hyperfine interaction between the electron spin and the nuclear spins of four 29Si atoms and three 13C atoms, the EI8 center is suggested to be related to a carbon interstitial cluster.
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