Large diameter, high quality SiC single crystals, method and apparatus

A method and system of forming large-diameter SiC single crystals suitable for fabricating high crystal quality SiC substrates of 100, 125, 150 and 200 mm in diameter are described. The SiC single crystals are grown by a seeded sublimation technique in the presence of a shallow radial temperature gradient. During SiC sublimation growth, a flux of SiC bearing vapors filtered from carbon particulates is substantially restricted to a central area of the surface of the seed crystal by a separation plate disposed between the seed crystal and a source of the SiC bearing vapors. The separation plate includes a first, substantially vapor-permeable part surrounded by a second, substantially non vapor-permeable part. The grown crystals have a flat or slightly convex growth interface. Large-diameter SiC wafers fabricated from the grown crystals exhibit low lattice curvature and low densities of crystal defects, such as stacking faults, inclusions, micropipes and dislocations.

Vanadium compensated, SI SiC single crystals of NU and PI type and the crystal growth process thereof

In a crystal growth apparatus and method, polycrystalline source material and a seed crystal are introduced into a growth ambient comprised of a growth crucible disposed inside of a furnace chamber. In the presence of a first sublimation growth pressure, a single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a first gas that includes a reactive component that reacts with and removes donor and/or acceptor background impurities from the growth ambient during said sublimation growth. Then, in the presence of a second sublimation growth pressure, the single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a second gas that includes dopant vapors, but which does not include the reactive component.

Method for synthesizing ultrahigh-purity silicon carbide

In a method of forming polycrystalline SiC grain material, low-density, gas-permeable and vapor-permeable bulk carbon is positioned at a first location inside of a graphite crucible and a mixture of elemental silicon and elemental carbon is positioned at a second location inside of the graphite crucible. Thereafter, the mixture and the bulk carbon are heated to a first temperature below the melting point of the elemental Si to remove adsorbed gas, moisture and/or volatiles from the mixture and the bulk carbon. Next, the mixture and the bulk carbon are heated to a second temperature that causes the elemental Si and the elemental C to react forming as-synthesized SiC inside of the crucible. The as-synthesized SiC and the bulk carbon are then heated in a way to cause the as-synthesized SiC to sublime and produce vapors that migrate into, condense on and react with the bulk carbon forming polycrystalline SiC material.

Vanadium Doped SiC Single Crystals and Method Thereof

A sublimation grown SiC single crystal includes vanadium dopant incorporated into the SiC single crystal structure via introduction of a gaseous vanadium compound into a growth environment of the SiC single crystal during growth of the SiC single crystal. 1. A method of growing vanadium-doped SiC single crystals comprising:(a) providing a growth crucible having SiC source material and a SiC single crystal seed in spaced relation therein;(b) heating the growth crucible of step (a) such that the SiC source material is heated to sublimation and a temperature gradient forms between the SiC source material and the SiC single crystal seed that causes the sublimated SiC source material to be transported to and precipitate on the SiC single crystal seed thereby growing a SiC crystal on the SiC single crystal seed; and(c) concurrent with step (b), introducing into the growth crucible a doping gas mixture that includes a carrier gas and a gaseous vanadium compound such that the growing SiC crystal is doped during the growth thereof with vanadium from the gaseous vanadium compound.2. The method of claim 1 , wherein the carrier gas includes an inert gas and hydrogen.3. The method of claim 1 , wherein the gaseous vanadium compound includes a halogen.4. The method of claim 3 , wherein the gaseous vanadium compound is vanadium chloride (VCl) claim 3 , where n=2 claim 3 , 3 claim 3 , or 4.5. The method of claim 4 , wherein:{'sub': 'n', 'the gaseous vanadium compound is vapors of the VCl; and'}{'sub': 'n', 'the doping gas mixture of step (c) is comprised of the VClvapors mixed with the carrier gas.'}6. The method of claim 5 , wherein the VClvapors are mixed with the carrier gas by passage of the carrier gas through a pool of liquid VCl.7. The method of claim 6 , wherein the VClvapors are mixed with the carrier gas outside the growth crucible.8. The method of claim 1 , wherein claim 1 , during step (c) claim 1 , the gaseous vanadium compound undergoes dissociation releasing ...

Vanadium doped SiC single crystals and method thereof

A sublimation grown SiC single crystal includes vanadium dopant incorporated into the SiC single crystal structure via introduction of a gaseous vanadium compound into a growth environment of the SiC single crystal during growth of the SiC single crystal.

Vanadium compensated, SI SiC single crystals of NU and PI type and the crystal growth process thereof

In a crystal growth apparatus and method, polycrystalline source material and a seed crystal are introduced into a growth ambient comprised of a growth crucible disposed inside of a furnace chamber. In the presence of a first sublimation growth pressure, a single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a first gas that includes a reactive component that reacts with and removes donor and/or acceptor background impurities from the growth ambient during said sublimation growth. Then, in the presence of a second sublimation growth pressure, the single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a second gas that includes dopant vapors, but which does not include the reactive component.

Large Diameter, High Quality SiC Single Crystals, Method and Apparatus

A method and system of forming large-diameter SiC single crystals suitable for fabricating high crystal quality SiC substrates of 100, 125, 150 and 200 mm in diameter are described. The SiC single crystals are grown by a seeded sublimation technique in the presence of a shallow radial temperature gradient. During SiC sublimation growth, a flux of SiC bearing vapors filtered from carbon particulates is substantially restricted to a central area of the surface of the seed crystal by a separation plate disposed between the seed crystal and a source of the SiC bearing vapors. The separation plate includes a first, substantially vapor-permeable part surrounded by a second, substantially non vapor-permeable part. The grown crystals have a flat or slightly convex growth interface. Large-diameter SiC wafers fabricated from the grown crystals exhibit low lattice curvature and low densities of crystal defects, such as stacking faults, inclusions, micropipes and dislocations.

"Method for Synthesizing Ultrahigh-Purity Silicon Carbide"

In a method of forming polycrystalline SiC grain material, low-density, gas-permeable and vapor-permeable bulk carbon is positioned at a first location inside of a graphite crucible and a mixture of elemental silicon and elemental carbon is positioned at a second location inside of the graphite crucible. Thereafter, the mixture and the bulk carbon are heated to a first temperature below the melting point of the elemental Si to remove adsorbed gas, moisture and/or volatiles from the mixture and the bulk carbon. Next, the mixture and the bulk carbon are heated to a second temperature that causes the elemental Si and the elemental C to react forming as-synthesized SiC inside of the crucible. The as-synthesized SiC and the bulk carbon are then heated in a way to cause the as-synthesized SiC to sublime and produce vapors that migrate into, condense on and react with the bulk carbon forming polycrystalline SiC material. 1. A method of forming polycrystalline SiC material comprising the steps of:(a) positioning bulk carbon at a first location inside of a graphite crucible, wherein the bulk carbon is gas-permeable and vapor-permeable;(b) positioning a mixture comprised of elemental silicon (Si) and elemental carbon (C) at a second location inside of the graphite crucible;(c) following steps (a) and (b), removing adsorbed gas, or moisture, or volatiles or some combination of adsorbed gas, moisture and volatiles from the mixture and the bulk carbon positioned inside of the graphite crucible by heating the mixture and the bulk carbon positioned inside of the enclosed crucible to a first temperature which is below the melting point of the elemental Si;(d) following step (c), forming as-synthesized silicon carbide (SiC) inside of the crucible by heating the mixture positioned inside of the enclosed crucible to a second temperature sufficient to initiate a reaction between the elemental Si and the elemental C of the mixture that forms the as-synthesized SiC inside of the crucible ...

Vanadium Compensated, SI SiC Single Crystals of NU and PI Type and the Crystal Growth Process Thereof

In a crystal growth apparatus and method, polycrystalline source material and a seed crystal are introduced into a growth ambient comprised of a growth crucible disposed inside of a furnace chamber. In the presence of a first sublimation growth pressure, a single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a first gas that includes a reactive component that reacts with and removes donor and/or acceptor background impurities from the growth ambient during said sublimation growth. Then, in the presence of a second sublimation growth pressure, the single crystal is sublimation grown on the seed crystal via precipitation of sublimated source material on the seed crystal in the presence of a flow of a second gas that includes dopant vapors, but which does not include the reactive component. 1. A crystal growth method comprising:(a) providing a SiC single crystal seed and a polycrystalline SiC source material in spaced relation inside of a growth crucible that is disposed inside of a furnace chamber, the growth crucible disposed inside of a furnace chamber defining a growth ambient; and(b) sublimation growing a SiC single crystal on the SiC seed crystal via precipitation of sublimated SiC source material on the SiC seed crystal in the presence of a reactive atmosphere in the growth ambient that removes donor and/or acceptor background impurities from the growth ambient.2. The method of claim 1 , wherein the reactive atmosphere includes a halide vapor compound and one or more gases.3. The method of claim 2 , wherein:the halide vapor compound is comprised of (1) fluorine or chlorine, and (2) tantalum or niobium; andthe one or more gases includes argon, hydrogen, or a mixture of argon+hydrogen.4. The method of claim 2 , further including:(c) following step (b), changing the atmosphere in the growth ambient to a non-reactive atmosphere; and(d) following step (c), introducing ...

Cmp pad conditioning tool

The present disclosure provides a CMP pad conditioning tool with at least one integral abrasive protrusion. The present disclosure further provides a method for preparing this CMP pad conditioning tool, along with a method for using said tool to condition a CMP pad.

Method for synthesizing ultrahigh-purity silicon carbide

In a method of forming polycrystalline SiC grain material, low-density, gas-permeable and vapor-permeable bulk carbon is positioned at a first location inside of a graphite crucible and a mixture of elemental silicon and elemental carbon is positioned at a second location. The mixture and the bulk carbon are heated to a first temperature below the melting point of the elemental Si to remove adsorbed gas, moisture and/or volatiles from the mixture and the bulk carbon. The mixture and bulk carbon are then heated to a second temperature that causes the elemental Si and the elemental C to react forming as-synthesized SiC inside of the crucible. The as-synthesized SiC and the bulk carbon are then heated in a way to cause the as-synthesized SiC to sublime and produce vapors that migrate into, condense on and react with the bulk carbon forming polycrystalline SiC material.

Vanadium compensated, si sic single crystals of nu and pi type and the crystal growth process thereof

LARGE DIAMETER, HIGH QUALITY SiC SINGLE CRYSTALS, METHOD AND APPARATUS

A method and system of forming large-diameter SiC single crystals suitable for fabricating high crystal quality SiC substrates of 100, 125, 150 and 200 mm in diameter are described. The SiC single crystals are grown by a seeded sublimation technique in the presence of a shallow radial temperature gradient. During SiC sublimation growth, a flux of SiC bearing vapors filtered from carbon particulates is substantially restricted to a central area of the surface of the seed crystal by a separation plate disposed between the seed crystal and a source of the SiC bearing vapors. The separation plate includes a first, substantially vapor-permeable part surrounded by a second, substantially non vapor-permeable part. The grown crystals have a flat or slightly convex growth interface. Large-diameter SiC wafers fabricated from the grown crystals exhibit low lattice curvature and low densities of crystal defects, such as stacking faults, inclusions, micropipes and dislocations.

Method for synthesizing ultrahigh-purity silicon carbide

Method for preparing an aluminum doped silicon carbide crystal by providing a compound including aluminum and oxygen in a capsule comprised of a first and second material

The present disclosure generally relates to silicon carbide crystals which may be used in optical applications, and to methods for producing the same. In one form, a composition includes an aluminum doped silicon carbide crystal having residual nitrogen and boron impurities. The concentration of aluminum in the silicon carbide crystal is greater than the combined concentrations of nitrogen and boron in the silicon carbide crystal, and the silicon carbide crystal includes an optical absorption coefficient of less than about 0.4 cm−1 at a wavelength in a range between about 400 nm to about 800 nm.

Method for preparing an aluminum doped silicon carbide crystal by providing a compound including aluminum and oxygen in a capsule comprised of a first and second material

The present disclosure generally relates to a physical vapor transport system including a chamber, a growth crucible positioned within the chamber, the growth crucible sealable with a growth crucible lid, and a doping capsule positioned within the growth crucible. The doping capsule includes an outer crucible fitted with an outer crucible lid, an inner crucible fitted with an inner crucible lid, the inner crucible fitted with the inner crucible lid positioned within the outer crucible, and a capillary channel formed by a first aperture in the outer crucible lid and a second aperture in the inner crucible lid.