Showing papers by "Adrian Powell published in 2016"
TL;DR: In this article, the growth of large diameter silicon carbide (SiC) crystals produced by the physical vapor transport (PVT) method is outlined, and methods to increase the crystal diameters, and to turn these large diameter crystals into substrates that are ready for the epitaxial growth of SiC or other non homogeneous epitaxially layers are discussed.
Abstract: The growth of large diameter silicon carbide (SiC) crystals produced by the physical vapor transport (PVT) method is outlined. Methods to increase the crystal diameters, and to turn these large diameter crystals into substrates that are ready for the epitaxial growth of SiC or other non homogeneous epitaxial layers are discussed. We review the present status of 150 mm and 200 mm substrate quality at Cree, Inc. in terms of crystallinity, dislocation density as well as the final substrate surface quality.
50 citations
TL;DR: In this article, the authors presented definite correlations between specific types of dislocations identified via Synchrotron White Beam X-Ray Topography (SWBXRT) and identified via selective etching of 4H-SiC substrates.
Abstract: Definitive correlations are presented between specific types of dislocations identified via Synchrotron White Beam X-Ray Topography (SWBXRT) and identified via selective etching of 4H-SiC substrates. A variety of etch conditions and the results on different faces of SiC substrates and epiwafers are examined. Hillocks formed on the carbon face of the substrate after KOH etching correlate very well to TSDs identified via SWBXRT. Topography of substrates and of vertical crystal slices reveals a large proportion of Threading Mixed character Dislocations (TMDs) in the population of Threading Screw Dislocations.
10 citations
TL;DR: In this article, aggregate epitaxial carrot distributions are observed at the crystal, wafer and dislocation defect levels, instead of individual extended carrot defect level, from combining large volumes of data, carrots are observed when both threading screw dislocations (TSD) and BPD densities are locally high as seen in full wafer maps.
Abstract: In this work, aggregate epitaxial carrot distributions are observed at the crystal, wafer and dislocation defect levels, instead of individual extended carrot defect level. From combining large volumes of data, carrots are observed when both threading screw dislocations (TSD) and basal plane dislocations (BPD) densities are locally high as seen in full wafer maps. Dislocation density distributions in areas of carrot formation are shown, and suggest TSD limit the formation of carrots in regions containing BPD. These data also add support for mechanisms requiring the need for both dissociated BPD and TSD for carrot formation.
3 citations