Abstract: Micropipe-free, single crystal, silicon carbide (SiC) and related methods of manufacture are disclosed. The SiC is grown by placing a source material and seed material on a seed holder in a reaction crucible of the sublimation system, wherein constituent components of the sublimation system including the source material, reaction crucible, and seed holder are substantially free from unintentional impurities. By controlling growth temperature, growth pressure, SiC sublimation flux and composition, and a temperature gradient between the source material and the seed material or the SiC crystal growing on the seed material during the PVT process, micropipe-inducing process instabilities are eliminated and micropipe-free SiC crystal is grown on the seed material.

Abstract: Micropipe-free, single crystal, silicon carbide (SiC) and related methods of manufacture are disclosed. The SiC is grown by placing a source material and seed material on a seed holder in a reaction crucible of the sublimation system, wherein constituent components of the sublimation system including the source material, reaction crucible, and seed holder are substantially free from unintentional impurities. By controlling growth temperature, growth pressure, SiC sublimation flux and composition, and a temperature gradient between the source material and the seed material or the SiC crystal growing on the seed material during the PVT process, micropipe-inducing process instabilities are eliminated and micropipe-free SiC crystal is grown on the seed material.

Abstract: An apparatus and method for growing bulk single crystals of silicon carbide is provided. The apparatus includes a sublimation chamber with a silicon vapor species phase outlet that allows the selective passage of atomic silicon vapor species while minimizing the concurrent passage of other vapor phase species. The apparatus can provide control of vapor phase stoichiometry within the sublimation chamber, which in turn can allow the production of bulk silicon carbide single crystals with reduced intrinsic point defects concentration.

Abstract: The invention is a method of inspecting a semiconductor wafer surface for scratches. The method includes positioning a semiconductor wafer for illumination by a radiation source and adjacent a background material that will absorb radiation from the radiation source, directing radiation at a surface of the wafer from the radiation source that has a wavelength that will be absorbed by the fundamental absorption of the wafer, filtering or otherwise limiting the radiation to allow only radiation having wavelengths that are absorbed by the fundamental absorption of the wafer to pass, and detecting radiation scattered on the surface of the wafer and filtered, by position, to thereby identify the location of the scratches on the surface of the wafer, while the absorption of the background material prevents other radiation from the source from interfering with the detection of the scratch-scattered radiation.

Abstract: High voltage silicon carbide (SiC) devices, for example, thyristors, are provided. A first SiC layer having a first conductivity type is provided on a first surface of a voltage blocking SiC substrate having a second conductivity type. A first region of SiC is provided on the first SiC layer and has the second conductivity type. A second region of SiC is provided in the first SiC layer. The second region of SiC has the first conductivity type and is adjacent to the first region of SiC. A second SiC layer having the first conductivity type is provided on a second surface, opposite the first surface, of the voltage blocking SiC substrate. First, second and third contacts are provided on the first region of SiC, the second region of SiC and the second SiC layer, respectively. Related methods of fabricating high voltage SiC devices are also provided.

Abstract: Silicon carbide high voltage semiconductor devices and methods of fabricating such devices are provided. The devices include a voltage blocking substrate. Insulated gate bipolar transistors are provided that have a voltage blocking substrate. Planar and beveled edge termination may be provided.

Abstract: High voltage silicon carbide (SiC) devices, for example, thyristors, are provided. A first SiC layer having a first conductivity type is provided on a first surface of a voltage blocking SiC substrate having a second conductivity type. A first region of SiC is provided on the first SiC layer and has the second conductivity type. A second region of SiC is provided in the first SiC layer, has the first conductivity type and is adjacent to the first region of SiC. A second SiC layer having the first conductivity type is provided on a second surface of the voltage blocking SiC substrate. A third region of SiC is provided on the second SiC layer and has the second conductivity type. A fourth region of SiC is provided in the second SiC layer, has the first conductivity type and is adjacent to the third region of SiC. First and second contacts are provided on the first and third regions of SiC, respectively. Related methods of fabricating high voltage SiC devices are also provided.

Abstract: High voltage silicon carbide (SiC) devices, for example, thyristors, are provided. A first SiC layer having a first conductivity type is provided on a first surface of a voltage blocking SiC substrate having a second conductivity type. A first region of SiC is provided on the first SiC layer and has the second conductivity type. A second region of SiC is provided in the first SiC layer, has the first conductivity type and is adjacent to the first region of SiC. A second SiC layer having the first conductivity type is provided on a second surface of the voltage blocking SiC substrate. A third region of SiC is provided on the second SiC layer and has the second conductivity type. A fourth region of SiC is provided in the second SiC layer, has the first conductivity type and is adjacent to the third region of SiC. First and second contacts are provided on the first and third regions of SiC, respectively. Related methods of fabricating high voltage SiC devices are also provided.

Abstract: A method is disclosed for producing a high quality bulk single crystal of silicon carbide in a seeded growth system and in the absence of a solid silicon carbide source, by reducing the separation between a silicon carbide seed crystal and a seed holder until the conductive heat transfer between the seed crystal and the seed holder dominates the radiative heat transfer between the seed crystal and the seed holder over substantially the entire seed crystal surface that is adjacent the seed holder.

Abstract: A process is described for producing silicon carbide crystals having increased minority carrier lifetimes. The process includes the steps of heating and slowly cooling a silicon carbide crystal having a first concentration of minority carrier recombination centers such that the resultant concentration of minority carrier recombination centers is lower than the first concentration.

Abstract: A method is disclosed for producing a high quality bulk single crystal of silicon carbide in a seeded growth system. The method includes positioning a seed crystal on the seed holder with a low porosity backing material that provides a vapor barrier to silicon carbide sublimation from the seed and that minimizes the difference in thermal conductivity between the seed and the backing material to minimize or eliminate temperature differences across the seed and likewise minimize or eliminate vapor transport from the rear of the seed that would otherwise initiate and propagate defects in the growing crystal.

Abstract: A method is disclosed for producing semi-insulating silicon carbide crystal with a controlled nitrogen content.

Abstract: A single polytype single crystal silicon carbide wafer is disclosed having a diameter greater than three inches and less than five inches, resistivity greater than 10,000 ohm-cm, a micropipe density less than 200 cm?2, and a combined concentration of shallow level dopants less than 5E16 cm?3.

Abstract: Methods of forming high voltage silicon carbide power devices utilize high purity silicon carbide drift layers that are derived from high purity silicon carbide wafer material, instead of prohibitively costly epitaxially grown silicon carbide layers. The methods include forming both minority carrier and majority carrier power devices that can support greater than 10 kV blocking voltages, using drift layers having thicknesses greater than about 100 um. The drift layers are formed as boule-grown silicon carbide drift layers having a net n-type dopant concentration therein that is less than about 2×1015 cm?3. These n-type dopant concentrations can be achieved using neutron transmutation doping (NTD) techniques.

Abstract: The invention herein relates to controlling the nitrogen content in silicon carbide crystals and in particular relates to reducing the incorporation of nitrogen during sublimation growth of silicon carbide. The invention controls nitrogen concentration in a growing silicon carbide crystal by providing an ambient atmosphere of hydrogen in the growth chamber. The hydrogen atoms, in effect, block, reduce, or otherwise hinder the incorporation of nitrogen atoms at the surface of the growing crystal.

Abstract: A garment for the transporting, observing, entertaining, training, and displaying of small animals, reptiles and insects (gerbils, mice, snakes, tarantulas, spiders, lizards, etc.) in the tunnels of the garment while on the shoulders of their owners. The garment consists of a see-through, mesh washable fabric panel on top and a brightly colored washable panel underneath, attached to each other using releasable fasteners. The fasteners also provide means to construct tunnel walls and nesting areas for the small animal. The fasteners further provide attachment to the garment tunnel's floor and walls for toys and other paraphernalia to entertain the pet and adorn the garment. This garment allows the owner to hold, observe, and transport his pet without damaging or soiling his clothes while his pet has a tunnel in which to play and rest safely. Also the owner can remove toys, food and nesting material in order to launder the garment.