| 1. |
- da Silva, Antonio Ferreira, et al.
(författare)
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Electrical resistivity and metal-nonmetal transition in n-type doped 4H-SiC
- 2006
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 74:24
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Tidskriftsartikel (refereegranskat)abstract
- The electrical resistivity of 4H-SiC doped with nitrogen is analyzed in the temperature range 10-700 K for nitrogen concentrations between 3.5x10(15) and 5x10(19) cm(-3). For the highest doped samples, a good agreement is found between the experimental resistivity and the values calculated from a generalized Drude approach at similar dopant concentration and temperature. From these results, the critical concentration (N-c) of nitrogen impurities which corresponds to the metal-nonmetal transition in 4H-SiC is deduced. We find N-c similar to 10(19) cm(-3).
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| 2. |
- Marinova, Maya, et al.
(författare)
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Influence of Post-Growth Annealing on the Defects Nature and Distribution in VLS Grown (111) 3C-SiC Layers
- 2011
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Ingår i: Silicon Carbide and Related Materials 2010. ; , s. 241-244
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Konferensbidrag (refereegranskat)abstract
- The current communication focuses on the influence of a post-growth annealing on the evolution of defects inside (111) 3C-SiC layers grown by the Vapour Liquid Solid (VLS) mechanism in SiGe melts on Si-face on- and off axis 6H-SiC substrates. The layers are studied by Transmission Electron Microscopy (TEM) and Low Temperature Photoluminescence (LTPL). It was found that the growth on off-axis substrates results in a 3C-SiC layer containing mainly stacking faults (SFs) and microtwins (MT). The density of MT lamellae and SFs reduces in the layers grown on the on-axis substrate compared to off-axis substrate. In the layers grown on off-axis substrates the annealing strongly reduces the density of SFs inclined to the 3C/6H-SiC interface. Additionally, 3C to 6H polytypic transformation appears only at the interface, most probably starting from substrate step edges. This was only seen on off-axis seed since the step edges are more.
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| 3. |
- Peyre, Hervé, et al.
(författare)
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Low Temperature Photoluminescence Investigation of 3-Inch SiC Wafers for Power Device Applications
- 2012
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Ingår i: HeteroSiC & WASMPE 2011. ; , s. 164-168
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Konferensbidrag (refereegranskat)abstract
- Focusing on the change in aluminium-related photoluminescence lines in 4H-SiC versus doping concentration, we have used a combination of LTPL (Low Temperature PhotoLuminescence) and secondary ion mass spectrometry measurements to set new calibration curves. In this way, one can probe the change in aluminum concentration in the range 1017 to 1019 cm-3. When applied to LTPL maps collected on full 3-inch wafers, we show that such abacuses constitute a powerful tool to control efficiently the doping level of as-grown p+ (emitters) and p++ (contact) layers for power device applications.
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| 4. |
- Robert, Teddy, et al.
(författare)
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Effect of Inter-Well Coupling between 3C and 6H in-Grown Stacking Faults in 4H-SiC Epitaxial Layers
- 2011
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Ingår i: <em>Materials Science Forum Vols. 679-680 (2011) pp 314-317</em>. - : Trans Tech Publications Inc.. ; , s. 314-317
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Konferensbidrag (refereegranskat)abstract
- Both 3C and 6H stacking faults have been observed in a low doped 4H-SiC epitaxial layer grown in a hot-wall CVD reactor on a heavily doped (off-axis) 4H-SiC substrate. They appear differently on the different parts of sample, with energetic dispersion ranging from 3.01 eV to 2.52 eV. Since they behave as natural type-II quantum wells in the 4H-SiC matrix, the thickness dependence of the excitonic recombination is investigated using the standard effective mass approximation. The results are discussed in terms of built-in electric field and inter-well coupling effects.
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| 5. |
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