Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: In a crystal growth method, a seed crystal 8 and a source material 4 are provided in spaced relation inside of a growth crucible 6. Starting conditions for the growth of a crystal 14 in the growth crucible 6 are then established therein. The starting conditions include: a suitable gas inside the growth crucible 6, a suitable pressure of the gas inside the growth crucible 6, and a suitable temperature in the growth crucible 6 that causes the source material 4 to sublimate and be transported via a temperature gradient in the growth crucible 6 to the seed crystal 8 where the sublimated source material precipitates. During growth of the crystal 14 inside the growth crucible 6, at least one of the following growth conditions are intermittently changed inside the growth crucible 6 a plurality of times: the gas in the growth crucible 6, the pressure of the gas in the growth crucible 6, and the temperature in the growth crucible 6.

Abstract: A method of fabricating an SiC single crystal includes (a) physical vapor transport (PVT) growing a SiC single crystal on a seed crystal in the presence of a temperature gradient, wherein an early-to-grow portion of the SiC single crystal is at a lower temperature than a later-to-grow portion of the SiC single crystal. Once grown, the SiC single crystal is annealed in the presence of a reverse temperature gradient, wherein the later-to-grow portion of the SiC single crystal is at a lower temperature than the early-to-grow portion of the SiC single crystal.

Abstract: In the growth of a SiC boule, a growth guide is provided inside of a growth crucible that is charged with SiC source material at a bottom of the crucible and a SiC seed crystal at a top of the crucible. The growth guide has an inner layer that defines at least part of an opening in the growth guide and an outer layer that supports the inner layer in the crucible. The opening faces the source material with the seed crystal positioned at an end of the opening opposite the source material. The inner layer is formed from a first material having a higher thermal conductivity than the second, different material forming the outer layer. The source material is sublimation grown on the seed crystal in the growth crucible via the opening in the growth guide to thereby form the SiC boule on the seed crystal.

Abstract: In SiC sublimation crystal growth, a crucible is charged with SiC source material and SiC seed crystal in spaced relation and a baffle is disposed in the growth crucible around the seed crystal. A first side of the baffle in the growth crucible defines a growth zone where a SiC single crystal grows on the SiC seed crystal. A second side of the baffle in the growth crucible defines a vapor-capture trap around the SiC seed crystal. The growth crucible is heated to a SiC growth temperature whereupon the SiC source material sublimates and forms a vapor which is transported to the growth zone where the SiC crystal grows by precipitation of the vapor on the SiC seed crystal. A fraction of this vapor enters the vapor-capture trap where it is removed from the growth zone during growth of the SiC crystal.

Abstract: A physical vapor transport system includes a growth chamber charged with source material and a seed crystal in spaced relation, and at least one capsule having at least one capillary extending between an interior thereof and an exterior thereof, wherein the interior of the capsule is charged with a dopant. Each capsule is installed in the growth chamber. Through a growth reaction carried out in the growth chamber following installation of each capsule therein, a crystal is formed on the seed crystal using the source material, wherein the formed crystal is doped with the dopant.

Abstract: A physical vapor transport growth system includes a growth chamber charged with SiC source material and a SiC seed crystal in spaced relation and an envelope that is at least partially gas-permeable disposed in the growth chamber. The envelope separates the growth chamber into a source compartment that includes the SiC source material and a crystallization compartment that includes the SiC seed crystal. The envelope is formed of a material that is reactive to vapor generated during sublimation growth of a SiC single crystal on the SiC seed crystal in the crystallization compartment to produce C-bearing vapor that acts as an additional source of C during the growth of the SiC single crystal on the SiC seed crystal.

Abstract: A sublimation-grown silicon carbide (SiC) single crystal boule includes a deep level dopant introduced into the SiC single crystal boule during sublimation-growth thereof such that in a continuous section of the boule that is not less than 50% of a continuous length of said boule, the deep level dopant concentration at the boule center varies by not more than 25% from the average concentration of the deep level dopant in the continuous section of the boule.

Abstract: A crystal is sublimation grown in a crucible by way of a temperature gradient in the presence of between 1 and 200 Torr of inert gas. The pressure of the inert gas is then increased to between 300 and 600 Torr, while the temperature gradient is maintained substantially constant. The temperature gradient is then reduced and the temperature in the crucible is increased sufficiently to anneal the crystal. Following cooling and removal from the crucible, the crystal is heated in the presence of oxygen in an enclosure to a temperature sufficient to remove unwanted material from the crystal. Following cooling and removal from the enclosure, the crystal surrounded by another instance of the source material is heated in a crucible in the presence 200 and 600 Torr of inert gas to a temperature sufficient to anneal the crystal.

Abstract: A method of fabricating an SiC single crystal includes (a) physical vapor transport (PVT) growing a SiC single crystal on a seed crystal in the presence of a temperature gradient, wherein an early-to-grow portion of the SiC single crystal is at a lower temperature than a later-to-grow portion of the SiC single crystal. Once grown, the SiC single crystal is annealed in the presence of a reverse temperature gradient, wherein the later-to-grow portion of the SiC single crystal is at a lower temperature than the early-to-grow portion of the SiC single crystal.

Abstract: In the growth of a SiC boule, a growth guide is provided inside of a growth crucible that is charged with SiC source material at a bottom of the crucible and a SiC seed crystal at a top of the crucible. The growth guide has an inner layer that defines at least part of an opening in the growth guide and an outer layer that supports the inner layer in the crucible. The opening faces the source material with the seed crystal positioned at an end of the opening opposite the source material. The inner layer is formed from a first material having a higher thermal conductivity than the second, different material forming the outer layer. The source material is sublimation grown on the seed crystal in the growth crucible via the opening in the growth guide to thereby form the SiC boule on the seed crystal.

Abstract: In a crystal growth method, a seed crystal 8 and a source material 4 are provided in spaced relation inside of a growth crucible 6. Starting conditions for the growth of a crystal 14 in the growth crucible 6 are then established therein. The starting conditions include: a suitable gas inside the growth crucible 6, a suitable pressure of the gas inside the growth crucible 6, and a suitable temperature in the growth crucible 6 that causes the source material 4 to sublimate and be transported via a temperature gradient in the growth crucible 6 to the seed crystal 8 where the sublimated source material precipitates. During growth of the crystal 14 inside the growth crucible 6, at least one of the following growth conditions are intermittently changed inside the growth crucible 6 a plurality of times: the gas in the growth crucible 6, the pressure of the gas in the growth crucible 6, and the temperature in the growth crucible 6.

Abstract: A physical vapor transport system includes a growth chamber charged with source material and a seed crystal in spaced relation, and at least one capsule having at least one capillary extending between an interior thereof and an exterior thereof, wherein the interior of the capsule is charged with a dopant. Each capsule is installed in the growth chamber. Through a growth reaction carried out in the growth chamber following installation of each capsule therein, a crystal is formed on the seed crystal using the source material, wherein the formed crystal is doped with the dopant.

Abstract: In a physical vapor transport method and system, a growth chamber charged with source material and a seed crystal in spaced relation is provided. At least one capsule having at least one capillary extending between an interior thereof and an exterior thereof, wherein the interior of the capsule is charged with a dopant, is also provided. Each capsule is installed in the growth chamber. Through a growth reaction carried out in the growth chamber following installation of each capsule therein, a crystal is formed on the seed crystal using the source material, wherein the formed crystal is doped with the dopant.

Abstract: In a method of SiC single crystal growth, a SiC single crystal seed and polycrystalline SiC source material are provided in spaced relation inside of a graphite growth crucible along with at least one compound capable of forming SiO gas in the growth crucible. The growth crucible is heated whereupon the gaseous SiO forms and reacts with carbon in the growth crucible thereby avoiding the introduction of carbon into the SiC single crystal before and during the growth thereof and the SiC source material vaporizes and is transported via a temperature gradient in the growth crucible to the seed crystal where it precipitates and forms a SiC single crystal.

Abstract: The invention relates to substrates of semi-insulating silicon carbide used for semiconductor devices and a method for making the same. The substrates have a resistivity above 106 Ohm-cm, and preferably above 108 Ohm-cm, and most preferably above 109 Ohm-cm, and a capacitance below 5 pF/mm2 and preferably below 1 pF/mm2. The electrical properties of the substrates are controlled by a small amount of added deep level impurity, large enough in concentration to dominate the electrical behavior, but small enough to avoid structural defects. The substrates have concentrations of unintentional background impurities, including shallow donors and acceptors, purposely reduced to below 5·1016 cm?3, and preferably to below 1·1016 cm?3, and the concentration of deep level impurity is higher, and preferably at least two times higher, than the difference between the concentrations of shallow acceptors and shallow donors.