Forming Gas Annealing of the Carbon PbC Center in Oxidized Porous 3C- and 4H-SiC: An EPR Study

Previous Electron Paramagnetic Resonance (EPR) studies identified the carbon dangling bond center as the main paramagnetic interface defect in 3C, 4H, 6H-SiC/SiO2. We demonstrate that this defect, called PbC center, can be passivated by forming gas annealing at 400°C. We have measured the PbC density at annealed 4H- and 3C-SiC/SiO2 interfaces and attributed its reduction to the transformation of the dangling bonds into EPR inactive C-H bonds. We have also studied the reverse phenomenon occurring during vacuum annealing at temperatures ranging from 600°C up to 1000°C and have determined a dissociation energy of ≈4.3 eV for the 3C and 4H polytypes.

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Temperature Dependent Line-Shape of the Silicon Dangling Bond EPR-Resonance in Polycrystalline Silicon

MRS Proceedings ◽

10.1557/proc-452-1019 ◽

1996 ◽

Vol 452 ◽

Cited By ~ 1

Author(s):

N. H. Nickel ◽

E. A. Schiff

Keyword(s):

Electron Paramagnetic Resonance ◽

Polycrystalline Silicon ◽

Room Temperature ◽

Dangling Bond ◽

Temperature Dependent ◽

Paramagnetic Resonance ◽

Temperature Electron ◽

Motional Narrowing ◽

G Value ◽

Electron Paramagnetic

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.

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Electron Paramagnetic Resonance Study of Carbon Antisite-Vacancy Pair in p-Type 4H-SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.556-557.453 ◽

2007 ◽

Vol 556-557 ◽

pp. 453-456 ◽

Cited By ~ 5

Author(s):

T. Umeda ◽

Norio Morishita ◽

Takeshi Ohshima ◽

Hisayoshi Itoh ◽

Junichi Isoya

Keyword(s):

Electron Paramagnetic Resonance ◽

Electron Irradiation ◽

Electron Paramagnetic Resonance Study ◽

Dangling Bond ◽

Charged State ◽

Paramagnetic Resonance ◽

Vacancy Pair ◽

P Type ◽

Electron Paramagnetic ◽

Positively Charged

Carbon antisite-vacancy pair (CSiVC) is a fundamental defect in SiC, and is theoretically predicted to be very stable in p-type materials. However, this pair was found only in the form of a negatively charged state (i.e., the SI5 center = CSiVC −) in n-type and semi-insulating 4H-SiC, and yet, its presence has not been shown in p-type SiC. In this report, we present the first EPR observation on positively charged CSiVC pairs in p-type 4H-SiC. By carefully examining p-type samples after electron irradiation, we found a pair of new defects with C3v and C1h symmetries. They correspond to “c-axial” pairs (C3v) and “basal” pairs (C1h) of CSiVC +, respectively. The positively charged pairs are characterized by a strong 13C hyperfine interaction due to a dangling bond on a carbon antisite (CSi), which is successfully resolved for the c-axial pairs.

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