Structural and optical studies of gamma irradiated N-doped 4H-SiC

Vali, Indudhar Panduranga; Shetty, Pramoda Kumara; Mahesha, M.G.; Sathe, Vasant; Phase, D. M.; Choudhary, R. J.

doi:10.1016/j.nimb.2018.12.016

Cited by 17 publications

(8 citation statements)

References 38 publications

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“…The last characteristic peak (iii) marked could be attributed to the defect states in the bandgap [ 22 ]. It can be seen that the intensity of sample I at peak (iii) increased significantly after ion implantation, compared with the substrate (sample S).…”

Section: Resultsmentioning

confidence: 99%

Characteristics of Activation Rate and Damage of Ion-Implanted Phosphorous in 4H-SiC after Different Annealing by Optical Absorption

Xiang

Wang

et al. 2022

Micromachines

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We investigated the ellipsometer-based characterization method being used to quickly evaluate the depth of the damage layer in ion-implanted 4H-SiC. This method had the advantages of low cost, convenience, and non-destructiveness. Optical absorption of n-type 4H-SiC substrate, P+ ion-implanted, laser-annealed, and conventional high-temperature annealed wafers were investigated at room temperature. Three peaks were observed in the absorption spectra collected for various samples. The degree of electrical activation after laser annealing or high-temperature annealing was evaluated qualitatively from the absorption peak intensity at 2.67 eV. The circular transmission line method (CTLM) results were consistent with the optical absorption results. However, it was found that the effective carrier concentration after laser annealing was significantly lower than that after high-temperature annealing.

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Section: Resultsmentioning

confidence: 99%

Characteristics of Activation Rate and Damage of Ion-Implanted Phosphorous in 4H-SiC after Different Annealing by Optical Absorption

Xiang

Wang

et al. 2022

Micromachines

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“…As noticed, irradiated sample have shown peak shift towards the higher side. This suggesting a decrease in the c-axis lattice constant of the material, where c can be evaluated by using the relation [18]: where = 1.5402 Å . The change in the lattice constant ( Δc∕c ) was found to be 1.36 × 10 −3 .…”

Section: Methodsmentioning

confidence: 99%

“…The doping type, n-type (or (1) c = × l 2 sin 00l , p-type) can be seen from the presence (or absence) of the free electron absorption band or Biedermann absorption bands (c). These bands are known to be responsible for the green-brownish colour of polytypes [18,20,21]. After NI, marginal variations in the absorption spectra were observed such as shift in the absorption band edge (a), increased tailing (or widening) of the absorption edge (b) and the narrowing of absorption bands (c) and (d).…”

Section: Methodsmentioning

confidence: 99%

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Thermal neutron irradiation effects on structural and electrical properties of n-type 4H‒SiC

Vali

Shetty

Mahesha

et al. 2020

J Mater Sci: Mater Electron

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In this article, the thermal neutron irradiation (NI) effects on the structural properties of n-4H-SiC and electrical properties of Al/n-4H-SiC Schottky contacts have been reported. The noticeable modifications observed in the irradiated samples were studied by using different techniques. The X-ray diffraction studies revealed a decrease in the lattice parameter of the irradiated samples due to isotopic modifications and irradiation-induced defects in the material. As a result, the energy bandgap, Urbach energy, longitudinal optical phonon-plasmon coupling mode, free carrier concentration, defect related photoluminescence and nitrogen bound exciton photoluminescence bands were prominently affected in the irradiated samples. The current-voltage characteristics of neutron irradiated Al/n-4H-SiC Schottky contacts were also strikingly affected in terms of zero-bias offset as well as decrease in the forward current. These modifications along with the increase in the Schottky junction parameters (such as ideality factor, Schottky barrier height and series resistance) were attributed to neutron-induced isotopic effects and decrease in the free carrier concentration due to induced defect states.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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“…The first one is to grow a 4H-SiC epitaxial layer of certain thickness and doping on a degenerately doped 4H-SiC substrate [2,12]. In general the characteristics of SiC-based devices can be influenced by the presence of impurities, extended and point defects, that can be introduced during each step of the growth [13][14][15][16][17][18][19]. Therefore, to reach the full potential of SiC devices is fundamental to grow highly uniform and not defective epitaxial layers.…”

Section: Introductionmentioning

confidence: 99%

Defects in epitaxial 4H-SiC revealed by exciton recombination

Migliore,

Cannas,

Mario Gelardi

et al. 2024

J. Phys.: Condens. Matter

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In this work, we conducted an analysis of 4H-SiC epitaxial layer grown on two distinct 4H-SiC substrates (both 6 inches in diameter) using non-invasive techniques such as micro-Raman spectroscopy, steady-state absorption spectroscopy, and time-resolved photoluminescence spectroscopy. We have shown that despite the doping homogeneity, confirmed by micro-Raman and steady-state absorption spectroscopy, the carrier lifetime, assessed by monitoring the excitonic band at 3.2 eV by time-resolved photoluminescence spectroscopy, depends on the position on the wafer. This variability is attributed to the presence of defects, such as impurities or point defects, which are not uniformly distributed on the epitaxial layer and, in addition to extended defects, affect the charge carrier recombination. Additionally, it is found that interactions with the underlying substrate could contribute to these effects as evidenced in regions of the substrate characterized by differences of doping.

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Structural and optical studies of gamma irradiated N-doped 4H-SiC

Cited by 17 publications

References 38 publications

Characteristics of Activation Rate and Damage of Ion-Implanted Phosphorous in 4H-SiC after Different Annealing by Optical Absorption

Characteristics of Activation Rate and Damage of Ion-Implanted Phosphorous in 4H-SiC after Different Annealing by Optical Absorption

Thermal neutron irradiation effects on structural and electrical properties of n-type 4H‒SiC

Defects in epitaxial 4H-SiC revealed by exciton recombination

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