Abstract: A method for controlled growth of silicon carbide and structures produced by the method are disclosed. A crystal of silicon carbide (SiC) can be grown by placing a sacrificial substrate in a growth zone with a source material. The source material may include a low-solubility impurity. SiC is then grown on the sacrificial substrate to condition the source material. The sacrificial substrate is then replaced with the final substrate, and SiC is grown on the final substrate. A single crystal of silicon carbide is produced, wherein the crystal of silicon carbide has substantially few micropipe defects. Such a crystal may also include a substantially uniform concentration of the low-solubility impurity, and may be used to make wafers and/or SiC die.

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 for controlled growth of silicon carbide and structures produced by the method are disclosed. A crystal of silicon carbide (SiC) can be grown by placing a sacrificial substrate in a growth zone with a source material. The source material may include a low-solubility impurity. SiC is then grown on the sacrificial substrate to condition the source material. The sacrificial substrate is then replaced with the final substrate, and SiC is grown on the final substrate. A single crystal of silicon carbide is produced, wherein the crystal of silicon carbide has substantially few micropipe defects. Such a crystal may also include a substantially uniform concentration of the low-solubility impurity, and may be used to make wafers and/or SiC die.

Abstract: A physical vapor transport growth technique for silicon carbide is disclosed. The method includes the steps of introducing a silicon carbide powder and a silicon carbide seed crystal into a physical vapor transport growth system, separately introducing a heated silicon-halogen gas composition into the system in an amount that is less than the stoichiometric amount of the silicon carbide source powder so that the silicon carbide source powder remains the stoichiometric dominant source for crystal growth, and heating the source powder, the gas composition, and the seed crystal in a manner that encourages physical vapor transport of both the powder species and the introduced silicon-halogen species to the seed crystal to promote bulk growth on the seed crystal.

Abstract: A physical vapor transport growth technique for silicon carbide is disclosed. The method includes the steps of introducing a silicon carbide powder and a silicon carbide seed crystal into a physical vapor transport growth system, separately introducing a heated silicon-halogen gas composition into the system in an amount that is less than the stoichiometric amount of the silicon carbide source powder so that the silicon carbide source powder remains the stoichiometric dominant source for crystal growth, and heating the source powder, the gas composition, and the seed crystal in a manner that encourages physical vapor transport of both the powder species and the introduced silicon-halogen species to the seed crystal to promote bulk growth on the seed crystal.

Abstract: A method for controlled growth of silicon carbide and structures produced by the method are disclosed. A crystal of silicon carbide (SiC) can be grown by placing a sacrificial substrate in a growth zone with a source material. The source material may include a low-solubility impurity. SiC is then grown on the sacrificial substrate to condition the source material. The sacrificial substrate is then replaced with the final substrate, and SiC is grown on the final substrate. A single crystal of silicon carbide is produced, wherein the crystal of silicon carbide has substantially few micropipe defects. Such a crystal may also include a substantially uniform concentration of the low-solubility impurity, and may be used to make wafers and/or SiC die.

Abstract: A bipolar device has at least one p? type layer of single crystal silicon carbide and at least one n? type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.

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 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 physical vapor transport growth technique for silicon carbide is disclosed. The method includes the steps of introducing a silicon carbide powder and a silicon carbide seed crystal into a physical vapor transport growth system, separately introducing a heated silicon-halogen gas composition into the system in an amount that is less than the stoichiometric amount of the silicon carbide source powder so that the silicon carbide source powder remains the stoichiometric dominant source for crystal growth, and heating the source powder, the gas composition, and the seed crystal in a manner that encourages physical vapor transport of both the powder species and the introduced silicon-halogen species to the seed crystal to promote bulk growth on the seed crystal.

Abstract: A method of forming a bipolar device includes forming at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide on a substrate. Stacking faults that grow under forward operation of the device are segregated from at least one of the interfaces between the active region and the remainder of the device. The method of forming bipolar devices includes growing at least one of the epitaxial layers to a thickness greater than the minority carrier diffusion length in that layer. The method also increases the doping concentration of epitaxial layers surrounding the drift region to decrease minority carrier lifetimes therein.

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: 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 method is disclosed for producing highly uniform semi-insulating characteristics in single crystal silicon carbide for semiconductor applications. The method includes irradiating a silicon carbide single crystal having net p-type doping and deep levels with neutrons until the concentration of 31P equals or exceeds the original net p-type doping while remaining equal to or less than the sum of the concentration of deep levels and the original net p-type doping.

Abstract: A bipolar device has at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.

Abstract: A method is disclosed for producing highly uniform semi-insulating characteristics in single crystal silicon carbide for semiconductor applications. The method includes irradiating a silicon carbide single crystal having net p-type doping and deep levels with neutrons until the concentration of 31P equals or exceeds the original net p-type doping while remaining equal to or less than the sum of the concentration of deep levels and the original net p-type doping.

Abstract: A bipolar device has at least one p-type layer of single crystal silicon carbide and at least one n-type layer of single crystal silicon carbide, wherein those portions of those stacking faults that grow under forward operation are segregated from at least one of the interfaces between the active region and the remainder of the device.

Abstract: A substrate for use in semiconductor devices, fabricated of silicon carbide and having a resistivity of greater than 1500 Ohm-cm. The substrate being characterized as having deep level impurities incorporated therein, wherein the deep level elemental impurity comprises one of a selected heavy metal, hydrogen, chlorine and fluorine. The selected heavy metal being a metal found in periodic groups IIIB, IVB, VB, VIB, VIIB, VIIIB, IB and IIB.

Abstract: A method for epitaxially growing a-axis .alpha.-SiC on an a-axis substrate is provided. A section is formed from the SiC crystal by making a pair of parallel cuts in the crystal. Each of these cuts is parallel to the c-axis of the crystal. The resulting section formed from the crystal has opposing a-face surfaces parallel to the c-axis of the crystal. A gas mixture having hydrocarbon and silane is passed over one of the a-face surfaces of the section. The hydrocarbon and silane react on this a-face surface to form an epitaxial layer of SiC. Preferably, the SiC is grown at a temperature of approximately 1450.degree. C.

Abstract: A method of fabrication of low dislocation single crystal indium-doped gallium arsenide, and improved crystal structure. The method is an improved liquid encapsulant Czochralski process with an indium doping level of 5.times.10.sup.19 to 3.times.10.sup.20 indium atoms per cubic centimeter incorporated into the large diameter, long single crystal. The initial melt of elemental indium, gallium, and arsenic contain about 1 atom percent of indium, and inclusion of the indium permits high yield growth of crystals with desired near stoichiometric or slightly arsenic rich composition which exhibit the desired electrical characteristics.