Theoretical evidence for the kick-out mechanism for B diffusion in SiC

Rurali, Riccardo; Godignon, P.; Rebollo, J.; Ordejón, Pablo; Hernández, Eduardo

doi:10.1063/1.1515369

Cited by 28 publications

(21 citation statements)

References 24 publications

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“…Therefore, the minute change of the lattice parameters suggests that boron substitutes at the carbon site in these samples. We expect the boron substitution to be enhanced with a slow growth of crystal grains, and indeed, by the present synthetic method, the samples had much higher boron doping levels compared to the previous reports [30][31][32][33]. EPMA analysis with area-scans (within 50 × 50 µm 2 ) at various positions occasionally detected less than 0.05 at.% of Fe, together with Si, C and B, but no other elements, in all samples.…”

Section: Superconductivity In B-doped Sicsupporting

confidence: 60%

Superconductivity in carrier-doped silicon carbide

Muranaka

Kikuchi

Yoshizawa

et al. 2008

Science and Technology of Advanced Materials

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We report growth and characterization of heavily boron-doped 3C-SiC and 6H-SiC and Al-doped 3C-SiC. Both 3C-SiC:B and 6H-SiC:B reveal type-I superconductivity with a critical temperature T c = 1.5 K. On the other hand, Al-doped 3C-SiC (3C-SiC:Al) shows type-II superconductivity with T c = 1.4 K. Both SiC:Al and SiC:B exhibit zero resistivity and diamagnetic susceptibility below T c with effective hole-carrier concentration n higher than 10 20 cm −3 . We interpret the different superconducting behavior in carrier-doped p-type semiconductors SiC:Al, SiC:B, Si:B and C:B in terms of the different ionization energies of their acceptors.

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Section: Superconductivity In B-doped Sicsupporting

confidence: 60%

Superconductivity in carrier-doped silicon carbide

Muranaka

Kikuchi

Yoshizawa

et al. 2008

Science and Technology of Advanced Materials

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“…We used nonlocal Troullier-Martins 11 pseudopotentials 12 and the local density approximation. 13 The single-particle orbitals were represented using a double-basis set with energy shift 0.025 eV; 9 we have shown in our recent work, 14 that this basis is sufficiently flexible to reproduce the structural parameters and bulk modulus of 3C-SiC with great accuracy. In our calculations, the simulation cells contained 64 atoms in the case of 3C-SiC, and 96 in the case of the 4H polytype; in both cases, a set of four k-points generated according to the Monkhorst-Pack 15 scheme was used to sample the Brillouin zone.…”

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confidence: 99%

First-principles study of n-type dopants and their clustering in SiC

Rurali

Godignon

Rebollo

et al. 2003

Applied Physics Letters

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We report the results of an ab initio study of N and P dopants in SiC. We find that while N substitutes most favorably at a C lattice site, P does so preferably at a Si site, except in n-doping and Si-rich 3C-SiC. Furthermore, we consider a series of dopant complexes that could form in high-dose implantation, in order to investigate the dopant activation behavior in this limit. We find that all N complexes considered lead to passivation through the formation of a deep level. For P, the most stable aggregate is still an active dopant, while passivation is only observed for complexes with a higher formation energy. We discuss how these results could help in the understanding of the observed experimental high-dose doping and codoping behavior of these species.

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“…Diffusion processes mediated by the silicon interstitials and by carbon vacancies have been proposed to explain such fast diffusion rates. 37,38,39,40 Under silicon-rich conditions the carbon-site substitution is dominating. 41 Among other dopants, the insulator-to-metal transition was observed recently in nitrogen-doped 4H-SiC at carrier concentrations above 10 19 cm −3 .…”

Section: Introductionmentioning

confidence: 99%

Specific heat and electronic states of superconducting boron-doped silicon carbide

et al. 2008

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The discoveries of superconductivity in the heavily-boron doped semiconductors diamond 1 (C:B) in 2004 and silicon 2 (Si:B) in 2006 have renewed the interest in the physics of the superconducting state of doped semiconductors. Recently, we discovered superconductivity in the closely related "mixed" system heavily boron-doped silcon carbide (SiC:B).3 Interestingly, the latter compound is a type-I superconductor whereas the two aforementioned materials are type-II. In this paper we present an extensive analysis of our recent specific-heat study, as well as the band structure and expected Fermi surfaces. We observe an apparent quadratic temperature dependence of the electronic specific heat in the superconducting state. Possible reasons are a nodal gap structure or a residual density of states due to non-superconducting parts of the sample. The basic superconducting parameters are estimated in a Ginzburg-Landau framework. We compare and discuss our results with those reported for C:B and Si:B. Finally, we comment on possible origins of the difference in the superconductivity of SiC:B compared to the two "parent" materials C:B and Si:B.

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Theoretical evidence for the kick-out mechanism for B diffusion in SiC

Cited by 28 publications

References 24 publications

Superconductivity in carrier-doped silicon carbide

Superconductivity in carrier-doped silicon carbide

First-principles study of n-type dopants and their clustering in SiC

Specific heat and electronic states of superconducting boron-doped silicon carbide

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