Papers by Keyword: Vapor Growth

Abstract: We report on the modeling of the temperature field and supersaturation in front of the SiC crystal growth interface of a physical vapor transport growth configuration. The data are compared with experimental results, like the growth of free standing 3C-SiC wafers with a diameter of 50 mm and a thickness of 870 µm. Special emphases is put on the precise handling of the materials properties which include the temperature dependency of the heat and electrical conductivity of the graphite parts at temperatures above 2000 °C.

Abstract: This work presents the crystalline quality investigation of 3C-SiC unseeded crystals grown from vapor phase. Samples were polished after different crystallographic planes from crystals grown with or without nitrogen flow. The structural and optical investigation showed that the central part of the samples exhibited a very good crystalline quality. The best samples proved to be the {100} growth sectors where the only defects found were stacking faults with a defect density under 103 cm-1. At the edges, i.e. between two adjacent growth sectors, structural investigation by transmission electron microscopy revealed stacking faults and hexagonal polytype inclusions. The nitrogen doping was found not to have an influence on the crystalline quality.

Abstract: Bulk crystals and epitaxial layers of 6H SiC have been grown and their surface morphologies have been investigated. Seeded sublimation has been employed to obtain bulk 6H SiC crystals whereas a silicon tetrachloride-propane based chemical vapor deposition (CVD) was used for growing epitaxial layers. The hot-zones were designed using numerical simulation. Growth rates up to 200 μm/hr could be achieved in the CVD process. A new growth-assisted hydrogen etching was developed to reveal the distribution of the micropipes present in the substrate. Morphological features were studied using Nomarski, atomic force microscopy (AFM), and scanning electron microscopy (SEM), and the structural quality was evaluated using synchrotron X-ray topography.