Papers by Keyword: Spiral Growth

Abstract: The growth process of silicon carbide crystals by physical vapor transport (PVT) on Si-face (0001) on-axis 6H-SiC substrates was analyzed. The growth rate was observed to be almost inversely proportional to the deposition pressure (R ∝ p-1) meaning that the growth rate is not limited by the number of growth spirals but by the vapor phase transport of the depositing species from the source to the sample surface. Analysis of the spiral step width shows an inverse square root dependence on the growth rate (y0 ∝ R-½). This experimental result is in accordance with the Burton, Cabrera and Frank theory and hence it can be concluded that there is no back-stress effect present.

Abstract: We investigated the polytype transition process from 4H-SiC to 6H-SiC during solution growth from the viewpoint of growth mode. The polarity dependence of the dominant grown polytype was similar to those of the sublimation growth and the CVD growth that 4H-SiC relatively grew stably on the C-face. Moreover, the polytype transition occurred during spiral growth. The 6H-SiC expanded to periphery overgrowing on the 4H-SiC. In contrast, there is no sign that 4H-SiC grew on 6H-SiC.

Abstract: We report on further observations of homoepitaxially grown 4H silicon carbide (SiC) cantilevers on commercial on-axis mesa patterned substrates. Mesa shapes with hollow interiors were designed to significantly increase the ratio of dislocation-free cantilever area to pregrowth mesa area. Mesas that did not contain axial screw dislocations (SD’s) continued to expand laterally until uncontrolled growth in the trench regions rises up to interfere / merge with the laterally expanding cantilevers. Molten KOH etching revealed high defect density in regions where trench growth merged with the laterally expanding cantilevers. The remaining portions of the cantilevers, except for central coalescence points, remained free of dislocations.