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- Iwata, H., et al.
(författare)
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A new type of quantum wells : Stacking faults in silicon carbide
- 2003
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Ingår i: Microelectronics Journal. - 0026-2692. ; 34:5, s. 371-374
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We report on a new type of quantum wells with the width as thin as 10Å, which are composed of SiC only, and consequently have ideal interfaces. These quantum wells are actually stacking faults in SiC. Certain types of stacking faults in SiC polytypes create small 3C-like regions, where the stacking sequences along the c-axis become locally cubic in the hexagonal host crystals. Since the conduction band offsets between the cubic and hexagonal polytypes are very large with the conduction band minima of 3C-SiC lower than that of the other polytypes, such thin 3C inclusions can introduce locally lower conduction bands, thus acting as quantum films perpendicular to the c-axis. One mechanism for the occurrence of stacking faults in the perfect SiC single crystals is the motion of partial dislocations in the basal planes, the partial dislocations leaving behind stacking fault regions. © 2003 Elsevier Science Ltd. All rights reserved.
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| 2. |
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| 3. |
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| 4. |
- Iwata, H., et al.
(författare)
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Electronic properties of stacking faults in 15R-SiC
- 2003
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Ingår i: Silicon carbide and related materials. - Uetikon-Zuerich : Trans Tech Publications Inc.. - 0878499202 ; , s. 531-534
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Konferensbidrag (refereegranskat)abstract
- A first-principles calculation of stacking faults in 15R-SiC is reported. All the geometrically distinguishable stacking faults which can be introduced by the glide of partial dislocations in (0001)-basal planes are investigated: there exist as many as five different stacking faults in 15R-SiC. Electronic properties and stacking fault energies of these extended defects are studied based on the density functional theory in the local density approximation. Stacking fault energies are also calculated using the axial next nearest neighbor Ising (ANNNI) model.
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| 5. |
- Iwata, H, et al.
(författare)
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Electronic Properties of Stacking Faults in 15R-SiC
- 2003
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Ingår i: 4th Euopean Conference on Silicon Carbide and Related Materials (ECSCRM 2002) LINKOPING, SWEDEN, SEP 02-25, 2002. ; , s. 531-534
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Konferensbidrag (refereegranskat)
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| 6. |
- Iwata, H., et al.
(författare)
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Electronic structure of twin boundaries in 3C-SiC, Si and diamond
- 2003
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Ingår i: Silicon carbide and related materials 2002. - Uetikon-Zuerich : Trans Tech Publications Inc.. - 878499202 ; , s. 527-30
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Konferensbidrag (refereegranskat)abstract
- We report on a first-principles band structure calculation of twin boundaries in 3C-SiC, Si, and diamond, based on the density functional theory in the local density approximation. It is found that the electron wave functions belonging to the conduction and valence band edge states in 3C-SiC tend to be localized almost exclusively on different sides of the boundaries, while there is no such feature in Si and diamond. We have interpreted these localization and segregation phenomena as a consequence of the electrostatic field caused by the spontaneous polarization due to the hexagonal symmetry around twin boundaries. A mechanism for the creation of twin boundaries, i.e., propagation of partial dislocations in neighboring basal planes, has been investigated using total energy calculations, and it has been realized that the double-intrinsic-stacking-fault structure in 3C-SiC, coinciding with the extrinsic stacking faults, is much energetically favored.
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| 7. |
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| 8. |
- Iwata, H, et al.
(författare)
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Stacking fault - Stacking fault interactions and cubic inclusions in 6H-SiC : an ab initio study
- 2002
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Ingår i: Materials Science Forum, Vols. 433-436. ; , s. 921-924
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Konferensbidrag (refereegranskat)abstract
- We report on a first-principles supercell calculation of cubic inclusions in 6H-SiC. Motions of successive partial dislocations having the same Burgers vector in the basal planes can lead to a 3C-like region in the perfect 6H-SiC crystal, which corresponds to multiple stacking faults. We have calculated the electronic structures and the total energies of 6H-SiC crystals containing in stacking faults (m=1-4) in the adjacent basal planes, based on the density functional theory in the local density approximation. It has been found that 3C-like sequences in the 6H-host crystals can act as planar quantum wells, in which conduction band electrons can be confined. The total energy calculations using both the supercell method and the axial next nearest neighbor Ising model (ANNNI) have revealed that the 2nd stacking fault energy in 6H-SiC is about 6 times larger than that of an isolated stacking fault.
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| 9. |
- Iwata, H., et al.
(författare)
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Stacking fault - stacking fault interactions and cubic inclusions in 6H-SiC : an ab initio study
- 2003
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Ingår i: Silicon carbide and related materials. - Uetikon-Zuerich : Trans Tech Publications Inc.. - 0878499202 ; , s. 921-924
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Konferensbidrag (refereegranskat)abstract
- We report on a first-principles supercell calculation of cubic inclusions in 6H-SiC. Motions of successive partial dislocations having the same Burgers vector in the basal planes can lead to a 3C-like region in the perfect 6H-SiC crystal, which corresponds to multiple stacking faults. We have calculated the electronic structures and the total energies of 6H-SiC crystals containing m stacking faults (m=l-4) in the adjacent basal planes, based on the density functional theory in the local density approximation. It has been found that 3C-like sequences in the 6H-host crystals can act as planar quantum wells, in which conduction band electrons can be confined. The total energy calculations using both the supercell method and the axial next nearest neighbor Ising model (ANNNI) have revealed that the 2nd stacking fault energy in 6H-SiC is about 6 times larger than that of an isolated stacking fault.
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