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In this paper, we used micro-Raman spectroscopy in cross-section to investigate the effect of different doping on the distribution of stress in the silicon substrate and the grown 3C-SiC film. The 3C-SiC films with a thickness up to 10 μm were grown on Si (100) substrates in a horizontal hot-wall chemical vapor deposition (CVD) reactor. To quantify the influence of doping on the stress distribution, samples were non-intentionally doped (NID, dopant incorporation below 10 16 cm -3 ), strongly n-type doped ([N] > 10 19 cm -3 ), or strongly p-type doped ([Al] > 10 19 cm -3 ). Sample NID was also grown on Si (111). In silicon (100), we observed that the stress at the interface is always compressive. In 3C-SiC, instead, we observed that the stress at the interface is always tensile and remains so in the first 4 µm. In the remaining 6 µm, the type of stress varies according to the doping. In particular, for 10 μm thick samples, the presence of an n-doped layer at the interface maximizes the stress in the silicon (~700 MPa) and in the 3C-SiC film (~250 MPa). In the presence of films grown on Si(111), 3C-SiC shows a compressive stress at the interface and then immediately becomes tensile following an oscillating trend with an average value of 412 MPa.

In this review paper, several new approaches about the 3C-SiC growth are been presented. In fact, despite the long research activity on 3C-SiC, no devices with good electrical characteristics have been obtained due to the high defect density and high level of stress. To overcome these problems, two different approaches have been used in the last years. From one side, several compliance substrates have been used to try to reduce both the defects and stress, while from another side, the first bulk growth has been performed to try to improve the quality of this material with respect to the heteroepitaxial one. From all these studies, a new understanding of the material defects has been obtained, as well as regarding all the interactions between defects and several growth parameters. This new knowledge will be the basis to solve the main issue of the 3C-SiC growth and reach the goal to obtain a material with low defects and low stress that would allow for realizing devices with extremely interesting characteristics.

The growth of 3C-SiC shows technological challenges, such as high supersaturation, a silicon-rich gas phase and a high vertical temperature gradient. We have developed a transfer method creating high-quality 3C-SiC-on-SiC (100) seeding stacks, suitable for use in sublimation "sandwich" epitaxy (SE). This work presents simulation data on the change of supersaturation and the temperature gradient between source and seed for the bulk growth. A series of growth runs on increased source to seed distances was characterized by XRD and Raman spectroscopy. Results show a decrease in quality in terms of single-crystallinity with a decrease in supersaturation. Morphology analysis of as-grown material indicates an increasing protrusion dimension with increasing thickness. This effect limits the achievable maximal thickness. Additional polytype inclusions were observed, which began to occur with low supersaturation (S ≤ 0.06) and prolonged growth (increase of carbon gas-species).

We report on the reproducible growth of two inch 3C-SiC crystals using the transfer of chemical vapor deposition (CVD)-grown (100) oriented epitaxial layers. Additional experiments, in which the diameter of the free-standing layers is increased, are presented, indicating the upscale potential of this process. The nucleation and growth of cubic silicon carbide is supported by XRD and Raman measurements. The rocking curve data yield a full-width-at-half-maximum (FWHM) between 138 to 140 arc sec for such grown material. Analysis of the inbuilt stress of the bulk-like material shows no indications of any residual stress., Competing Interests: The authors declare no conflict of interest.