We introduce a 3C-SiC growth concept on off-oriented 4H-SiC substrates using a sublimation epitaxial method. A growth model of 3C-SiC layer development via a controlled cubic polytype nucleation on in situ formed on-axis area followed by a lateral enlargement of 3C-SiC domains along the step-flow direction is outlined. Growth process stability and reproducibility of high crystalline quality material are demonstrated in a series of 3C-SiC samples with a thickness of about 1 mm. The average values of full width at half-maximum of ω rocking curves on these samples vary from 34 to 48 arcsec indicating high crystalline quality compared to values found in the literature. The low temperature photoluminescence measurements also confirm a high crystalline quality of 3C-SiC and indicate that the residual nitrogen concentration is about 1–2 × 10¹⁶ cm^–3. Such a 3C-SiC growth concept may be applied to produce substrates for homoepitaxial 3C-SiC growth or seeds which could be explored in bulk growth of 3C-SiC.

We investigated the formation of structural defects in thick (∼1 mm) cubic silicon carbide (3C-SiC) layers grown on off-oriented 4H-SiC substrates via a lateral enlargement mechanism using different growth conditions. A two-step growth process based on this technique was developed, which provides a trade-off between the growth rate and the number of defects in the 3C-SiC layers. Moreover, we demonstrated that the two-step growth process combined with a geometrically controlled lateral enlargement mechanism allows the formation of a single 3C-SiC domain which enlarges and completely covers the substrate surface. High crystalline quality of the grown 3C-SiC layers is confirmed using high resolution X-ray diffraction and low temperature photoluminescence measurements.

We demonstrate growth of thick SiC layers (100–200 µm) on nominally on-axis hexagonal substrates using sublimation epitaxy in vacuum (10⁻⁵ mbar) at temperatures varying from 1700 to 1975 °C with growth rates up to 270 µm/h and 70 µm/h for 6H- and 4H–SiC, respectively. The stability of hexagonal polytypes are related to process growth parameters and temperature profile which can be engineered using different thermal insulation materials and adjustment of the induction coil position with respect to the graphite crucible. We show that there exists a range of growth rates for which single-hexagonal polytype free of foreign polytype inclusions can be maintained. Further on, foreign polytypes like 3C–SiC can be stabilized by moving out of the process window. The applicability of on-axis growth is demonstrated by growing a 200 µm thick homoepitaxial 6H–SiC layer co-doped with nitrogen and boron in a range of 10¹⁸ cm⁻³ at a growth rate of about 270 µm/h. Such layers are of interest as a near UV to visible light converters in a monolithic white light emitting diode concept, where subsequent nitride-stack growth benefits from the on-axis orientation of the SiC layer.

We present a technique for etching of SiC which is based on sublimation and can be used to modify the morphology and reconstruction of silicon carbide surface for subsequent epitaxial growth of various materials, for example graphene. The sublimation etching of 6H-, 4H- and 3C-SiC was explored in vacuum (10⁻⁵ mbar) and Ar (700 mbar) ambient using two different etching arrangements which can be considered as Si-C and Si-C-Ta chemical systems exhibiting different vapor phase stoichiometry at a given temperature. The surfaces of different polytypes etched under similar conditions are compared and the etching mechanism is discussed with an emphasis on the role of tantalum as a carbon getter. To demonstrate applicability of such etching process graphene nanoribbons were grown on a 4H-SiC surface that was pre-patterned using the thermal etching technique presented in this study.

The growth of fluorescent SiC using Fast Sublimation Growth Process was demonstrated using different types of SiC source materials. These were prepared by (i) high-temperature hot pressing, (ii) chemical vapor deposition and (iii) physical vapor transport. The optimized growth rates of 50 μm/h, 170 μm/h and 200 μm/h were achieved using the three types of sources, respectively. The best results in respect to growth rates are obtained using higher density sources. Fluorescent SiC layers with mirror-like morphology, very good crystal quality and yellowish or warm white light photoluminescence at room temperature were grown using all three types of the source materials.