Abstract: A high quality single crystal wafer of SiC is disclosed having a diameter of at least about 3 inches and a 1c screw dislocation density of less than about 2000 cm 2.

Abstract: A silicon carbide seeded sublimation method is disclosed. The method includes the steps of nucleating growth on a seed crystal growth face that is between about 1° and 10° off-axis from the (0001) plane of the seed crystal while establishing a thermal gradient between the seed crystal and a source composition that is substantially perpendicular to the basal plane of the off-axis crystal.

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: A method of producing a high quality bulk single crystal of silicon carbide in a seeded growth system is disclosed. The method includes positioning the seed crystal in a crucible while exerting minimal torsional forces on the seed crystal to thereby prevent torsional forces from warping or bowing the seed crystal in a manner that that would otherwise encourage sublimation from the rear of the seed crystal or undesired thermal differences across the seed crystal.

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: A semiconductor crystal and associated growth method are disclosed. The crystal includes a seed portion and a growth portion on the seed portion. The seed portion and the growth portion form a substantially right cylindrical single crystal of silicon carbide. A seed face defines an interface between the growth portion and the seed portion, with the seed face being substantially parallel to the bases of the right cylindrical crystal and being off-axis with respect to a basal plane of the single crystal. The growth portion replicates the polytype of the seed portion and the growth portion has a diameter of at least about 100 mm.

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 high quality single crystal wafer of SiC is disclosed having a diameter of at least about 3 inches and a 1 c screw dislocation density of less than about 2000 cm?2.

Abstract: A high quality single crystal wafer of SiC is disclosed having a diameter of at least about 100 mm and a micropipe density of less than about 25 cm?2.

Abstract: The invention is an improvement in a method of producing a high quality bulk single crystal of silicon carbide in a seeded sublimation system. The improvement includes etching the front face on each of a first and second SiC seed to a depth of greater than about 20 ?m while protecting the opposite or back face on each of the first and second SiC seeds. Protection of the front faces occurs by placing the faces sufficiently close to one another to shield the back faces from being etched during etching of the respective unprotected front faces. Separation of the first and second SiC seeds occurs after the etching of the front faces is complete.

Abstract: A high quality single crystal wafer of SiC is disclosed. The wafer has a diameter of at least about 3 inches (75 mm) and at least one continuous square inch (6.25 cm2) of surface area that has a basal plane dislocation volume density of less than about 500 cm?2 for a 4 degree off-axis wafer.

Abstract: A method of producing a high quality bulk single crystal of silicon carbide in a seeded growth system is disclosed. The method includes positioning the seed crystal in a crucible while exerting minimal torsional forces on the seed crystal to thereby prevent torsional forces from warping or bowing the seed crystal in a manner that that would otherwise encourage sublimation from the rear of the seed crystal or undesired thermal differences across the seed crystal.

Abstract: A method is disclosed for producing a high quality bulk single crystal of silicon carbide in a seeded growth system 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 high quality single crystal wafer of SiC is disclosed having a diameter of at least about 100 mm and a micropipe density of less than about 25 cm?2.

Abstract: A silicon carbide seeded sublimation method is disclosed. The method includes the steps of nucleating growth on a seed crystal growth face that is between about 1° and 10° off-axis from the (0001) plane of the seed crystal while establishing a thermal gradient between the seed crystal and a source composition that is substantially perpendicular to the basal plane of the off-axis crystal.

Abstract: A silicon carbide seeded sublimation growth system and associated method are disclosed. The system includes a crucible, a silicon carbide source composition in the crucible, a seed holder in the crucible, a silicon carbide seed crystal on the seed holder, means for creating a major thermal gradient in the crucible that defines a major growth direction between the source composition and the seed crystal for encouraging vapor transport between the source composition and the seed crystal, and the seed crystal being positioned on the seed holder with the macroscopic growth surface of the seed crystal forming an angle of between about 70° and 89.5° degrees relative to the major thermal gradient and the major growth direction and with the crystallographic orientation of the seed crystal having the c-axis of the crystal forming an angle with the major thermal gradient of between about 0° and 2°.

Abstract: A high quality single crystal wafer of SiC is disclosed. The wafer has a diameter of at least about 3 inches, a warp of less than about 5 ?m, a bow less than about 5 ?m, and a total thickness variation of less than about 2.0 ?m.

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: The invention is an improvement in the method of producing a high quality bulk single crystal of silicon carbide in a seeded sublimation system. In a first embodiment, the improvement comprises reducing the number of macrosteps in a growing crystal by incorporating a high concentration of nitrogen atoms in the initial one (1) millimeter of crystal growth.

Abstract: The invention is an improvement in a method of producing a high quality bulk single crystal of silicon carbide in a seeded sublimation system. The improvement includes etching the front face on each of a first and second SiC seed to a depth of greater than about 20 ?m while protecting the opposite or back face on each of the first and second SiC seeds. Protection of the front faces occurs by placing the faces sufficiently close to one another to shield the back faces from being etched during etching of the respective unprotected front faces. Separation of the first and second SiC seeds occurs after the etching of the front faces is complete.