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| 2. |
- Asghar, M., et al.
(author)
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Characterization of deep level defects in sublimation grown p-type 6H-SiC epilayers by deep level transient spectroscopy
- 2012
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In: Physica B: Condensed Matter. - : Elsevier. - 0921-4526.
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Conference paper (peer-reviewed)abstract
- In this study deep level transient spectroscopy has been performed on boron-nitrogen co-doped 6H-SiC epilayers exhibiting p-type conductivity with free carrier concentration (N-A-N-D)similar to 3 x 10(17) cm(-3). We observed a hole H-1 majority carrier and an electron E-1 minority carrier traps in the device having activation energies E-nu + 0.24 eV, E-c -0.41 eV, respectively. The capture cross-section and trap concentration of H-1 and E-1 levels were found to be (5 x 10(-19) cm(2), 2 x 10(15) cm(-3)) and (1.6 x 10(-16) cm(2), 3 x 10(15) cm(-3)), respectively. Owing to the background involvement of aluminum in growth reactor and comparison of the obtained data with the literature, the H-1 defect was identified as aluminum acceptor. A reasonable justification has been given to correlate the E-1 defect to a nitrogen donor.
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| 3. |
- Asghar, M., et al.
(author)
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Study of deep level defects in doped and semi-insulating n-6H-SiC epilayers grown by sublimation method
- 2012
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In: Physica B: Condensed Matter. - : Elsevier. - 0921-4526.
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Conference paper (peer-reviewed)abstract
- Deep level transient spectroscopy (DLTS) is employed to study deep level defects in n-6H-SiC (silicon carbide) epilayers grown by the sublimation method. To study the deep level defects in n-6H-SiC, we used as-grown, nitrogen doped and nitrogen-boron co-doped samples represented as ELS-1, ELS-11 and ELS-131 having net (N-D-N-A) similar to 2.0 x 10(12) cm(-3), 2 x 10(16) cm(-3) and 9 x 10(15) cm(3), respectively. The DLTS measurements performed on ELS-1 and ELS-11 samples revealed three electron trap defects (A, B and C) having activation energies E-c - 0.39 eV, E-c - 0.67 eV and E-c - 0.91 eV, respectively. While DLTS spectra due to sample ELS-131 displayed only A level. This observation indicates that levels B and C in ELS-131 are compensated by boron and/or nitrogen-boron complex. A comparison with the published data revealed A, B and C to be E-1/E-2, Z(1)/Z(2) and R levels, respectively.
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| 4. |
- Beshkova, Milena, et al.
(author)
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Properties of 3C-SiC Grown by Sublimation Epitaxy on Different Type of Substrates
- 2010
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In: Materials Science Forum, Vols. 645-648. - : Transtec Publications; 1999. ; , s. 183-186
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Conference paper (peer-reviewed)abstract
- 3C-SiC layers have been grown by using sublimation epitaxy at a temperature of 2000 degrees C, on different types of on-axis 6H-SiC(0001) substrates. The influence of the type of substrate on the morphology of the layers investigated by Atomic Force Microscopy (AFM) is discussed. Stacking faults are studied by reciprocal space map (RSM) which shows that double positions domains exists.
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| 5. |
- Beshkova, Milena, et al.
(author)
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Sublimation epitaxy of 3C-SiC grown at Si- and C-rich conditions
- 2012
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In: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 86:10, s. 1595-1599
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Journal article (peer-reviewed)abstract
- 3C-SiC layers have been grown by using sublimation epitaxy at a source temperature of 2000 degrees C, under vacuum conditions (andlt;10(-5) mbar) on well oriented (on-axis) 6H-SiC (0001) substrates. Close space sublimation growth geometry has been used in a RF-heated furnace employing high-purity graphite crucible with a possibility to change the growth environment from Si vapor-rich to C vapor-rich. The optical microscopy in transmission mode reveals continuous 3C-domains for 3C-SiC with less than 0.4% 6H-inclusions for the layer grown at Si-rich conditions, and separate 3C-SiC domains for the layer grown at C-rich conditions. The type of 6H-inclusions for layers with continuous domain structure investigated by Atomic Force Microscopy (AFM) is discussed. 2Theta-omega scan shows 0006 and 111 peaks coming from the substrate and the layer, respectively with a higher intensity of the 111 peak for 3C-SiC grown at Si-rich conditions which is related with the continuous character of the 3C-SiC domains.
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| 6. |
- Eriksson, Jens, et al.
(author)
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The influence of substrate morphology on thickness uniformity and unintentional doping of epitaxial graphene on SiC
- 2012
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In: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 100:24, s. 241607-
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Journal article (peer-reviewed)abstract
- A pivotal issue for the fabrication of electronic devices on epitaxial graphene on SiC is controlling the number of layers and reducing localized thickness inhomogeneities. Of equal importance is to understand what governs the unintentional doping of the graphene from the substrate. The influence of substrate surface topography on these two issues was studied by work function measurements and local surface potential mapping. The carrier concentration and the uniformity of epitaxial graphene samples grown under identical conditions and on substrates of nominally identical orientation were both found to depend strongly on the terrace width of the SiC substrate after growth.
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| 7. |
- Hens, Philip, et al.
(author)
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Defect generation and annihilation in 3C-SiC-(001) homoepitaxial growth by sublimation
- 2013
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In: Silicon Carbide and Related Materials 2012. - : Trans Tech Publications. - 9783037856246 ; , s. 283-286
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Conference paper (peer-reviewed)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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| 8. |
- Hens, Philip, et al.
(author)
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Freestanding 3C-SiC grown by sublimation epitaxy using 3C-SiC templates on silicon
- 2012
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In: Materials Science Forum Vols 717 - 720. - : Trans Tech Publications Inc.. ; , s. 177-180
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Conference paper (peer-reviewed)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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| 9. |
- Hens, Philip, et al.
(author)
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Sublimation growth of thick freestanding 3C-SiC using CVD-templates on silicon as seeds
- 2012
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In: Materials letters (General ed.). - : Elsevier. - 0167-577X .- 1873-4979. ; 67:1, s. 300-302
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Journal article (peer-reviewed)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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| 10. |
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