| 31. |
- Hens, Philip, et al.
(författare)
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Defect generation and annihilation in 3C-SiC-(001) homoepitaxial growth by sublimation
- 2013
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Ingår i: Silicon Carbide and Related Materials 2012. - : Trans Tech Publications. - 9783037856246 ; , s. 283-286
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Konferensbidrag (refereegranskat)abstract
- In this paper we present an investigation on the defect generation and annihilation during the homoepitaxial growth step of cubic silicon carbide by sublimation epitaxy on templates grown by chemical vapor deposition on silicon substrates. Several structural defects like stacking faults, twins and star-defects show opposite evolution from the template layer into the sublimation grown material. While single planar defects tend to annihilate with increasing layer thickness, the defect clusters assigned to the star-defects are enlarging. These issues contribute to a balance of how to achieve the best possible quality on thick layers.
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| 32. |
- Hens, Philip, et al.
(författare)
-
Freestanding 3C-SiC grown by sublimation epitaxy using 3C-SiC templates on silicon
- 2012
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Ingår i: Materials Science Forum Vols 717 - 720. - : Trans Tech Publications Inc.. ; , s. 177-180
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Konferensbidrag (refereegranskat)abstract
- In this work a new approach for the production of freestanding cubic silicon carbide (3C-SiC) in (001) orientation is presented which is based on the combination of chemical vapor deposition (CVD) and the fast sublimation growth process (FSGP). Fast homoepitaxial growth of 3C-SiC using sublimation epitaxy on a template created by CVD growth on silicon substrates allows to obtain thick freestanding material with low defect densities. Using standard silicon wafers as substrate material permits a cost efficient process and the applying of wafers with different orientations. The (001) orientation used in this work will potentially allow further heteroepitaxial growth of other cubic semiconductors, like e.g. gallium nitride (GaN).
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| 33. |
- Hens, Philip, et al.
(författare)
-
Large area buffer-free graphene on non-polar (001) cubic silicon carbide
- 2014
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Ingår i: Carbon. - : Elsevier BV. - 0008-6223 .- 1873-3891. ; 80, s. 823-829
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Tidskriftsartikel (refereegranskat)abstract
- Graphene is, due to its extraordinary properties, a promising material for future electronic applications. A common process for the production of large area epitaxial graphene is a high temperature annealing process of atomically flat surfaces from hexagonal silicon carbide. This procedure is very promising but has the drawback of the formation of a buffer layer consisting of a graphene-like sheet, which is covalently bound to the substrate. This buffer layer degenerates the properties of the graphene above and needs to be avoided. We are presenting the combination of a high temperature process for the graphene production with a newly developed substrate of (0 0 1)-oriented cubic silicon carbide. This combination is a promising candidate to be able to supply large area homogenous epitaxial graphene on silicon carbide without a buffer layer. We are presenting the new substrate and first samples of epitaxial graphene on them. Results are shown using low energy electron microscopy and diffraction, photoelectron angular distribution and X-ray photoemission spectroscopy. All these measurements indicate the successful growth of a buffer free few layer graphene on a cubic silicon carbide surface. On our large area samples also the epitaxial relationship between the cubic substrate and the hexagonal graphene could be clarified. (C) 2014 Elsevier Ltd. All rights reserved.
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| 34. |
- Hens, Philip, et al.
(författare)
-
P- and n-type doping in SiC sublimation epitaxy using highly doped substrates
- 2009
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Ingår i: ECSCRM2008,2008. - Materials Science Forum Vols. 615-617 : Trans Tech Publications. - 9780878493340 ; , s. 85-88
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Konferensbidrag (refereegranskat)abstract
- The co-doping of nitrogen and aluminum has been studied in the sublimation epitaxy growth process. It is shown that the doping may be tuned from n-type to p-type by effect of substrate doping, growth face and volume of the growth crucible. The co-doped layers show a nearly ideal I V characteristic and luminescence at room temperature.
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| 35. |
- Hens, Philip, et al.
(författare)
-
Sublimation growth of thick freestanding 3C-SiC using CVD-templates on silicon as seeds
- 2012
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Ingår i: Materials letters (General ed.). - : Elsevier. - 0167-577X .- 1873-4979. ; 67:1, s. 300-302
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Tidskriftsartikel (refereegranskat)abstract
- Cubic silicon carbide is a promising material for medium power electronics operating at high frequencies and for the subsequent growth of gallium nitride for more efficient light emitting diodes. We present a new approach to produce freestanding cubic silicon carbide (3C-SiC) with the ability to obtain good crystalline quality regarding increased domain size and reduced defect density. This would pave the way to achieve substrates of 3C-SiC so that the applications of cubic silicon carbide material having selectively (111) or (001) oriented surfaces can be explored. Our method is based on the combination of the chemical vapor deposition method and the fast sublimation growth process. Thin layers of cubic silicon carbide grown heteroepitaxially on silicon substrates are for the first time used for a subsequent sublimation growth step to increase layer thicknesses. We have been able to realize growth of freestanding (001) oriented 3C-SiC substrates using growth rates around 120 μm/h and diameters of more than 10 mm. The structural quality from XRD rocking curve measurements of (001) oriented layers shows good FWHM values down to 78 arcsec measured over an area of 1 × 2 mm2, which is a quality improvement of 2–3 times compared with other methods like CVD.
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| 36. |
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| 37. |
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| 38. |
- Jacobson, H, et al.
(författare)
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Lateral enlargement of silicon carbide crystals
- 2002
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Ingår i: Materials Science Forum, Vols. 389-393. ; , s. 39-42
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Konferensbidrag (refereegranskat)abstract
- A new growth technique for lateral enlargement of silicon carbide crystals is presented. The technique is based on sublimation growth but modified with respect to temperature gradients and geometry as compared to conventional setup. Simulation of the temperature distribution for lateral growth as well as the growth mechanism is discussed. Synchrotron white beam x-ray topographs have been evaluated concerning threading defects along the 0001 direction. Finally, a comparison between laterally grown 4H, 6H-silicon carbide and a commercial 4H-silicon carbide wafer is demonstrated, and shows that this growth technique makes it possible to enlarge seed crystals without screw dislocations and micropipes along the 0001 direction.
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| 39. |
- Jacobson, H., et al.
(författare)
-
Lateral enlargement of silicon carbide crystals
- 2004
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248 .- 1873-5002. ; 270:1-2
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Tidskriftsartikel (refereegranskat)abstract
- A new growth technique for lateral enlargement of silicon carbide crystals is presented and evaluated. The technique is based on PVT growth but modified with respect to temperature gradients and geometry as compared to conventional setup. Simulation of the temperature distribution for lateral growth as well as the growth mechanism is discussed. High-resolution X-ray diffraction and synchrotron white beam X-ray topography have been evaluated concerning structural defects. The results show that this growth technique makes it possible to enlarge seed crystals without threading screw dislocations and micropipes along the 0001 direction, but stacking faults are introduced due to the crystal stacking sequence along the <11¯00> directions. © 2004 Elsevier B.V.
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| 40. |
- Jacobson, H., et al.
(författare)
-
Structural impact of LPE buffer layer on sublimation grown 4H-SiC epilayers
- 2003
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Ingår i: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 256:3-4, s. 276-282
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this work was to study the effect of a liquid phase epitaxy buffer layer on the development of defects in sublimation grown epitaxial layers of 4H-SiC. The results were analyzed with the aid of optical microscope, scanning electron microscope, high-resolution X-ray diffraction and synchrotron white beam X-ray topography. A pronounced effect of the liquid phase epitaxy buffer layer on formation of dislocations and micropipes is observed in the sublimation epitaxy layers. It has been shown that during sublimation growth of epilayer with a thin liquid phase epitaxy buffer layer (0.1µm) defects may undergo transformation and stacking faults can be formed. Sublimation grown epilayers grown on a thick liquid phase epitaxy buffer layer (1µm) also showed a symmetrical distribution of misfit dislocations along the <112¯0> and [11¯00] directions. © 2003 Elsevier B.V. All rights reserved.
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