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AssigneeCree, Inc.
InventorsYuri Khlebnikov, Robert T. Leonard, Elif Balkas, Steven Griffiths, Valeri Tsvetkov, Michael Paisley
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Silicon carbide (SiC) wafers, SiC boules, and related methods are disclosed that provide improved dislocation distributions. SiC boules are provided that demonstrate reduced dislocation densities and improved dislocation uniformity across longer boule lengths. Corresponding SiC wafers include reduced total dislocation density (TDD) values and improved TDD radial uniformity. Growth conditions for SiC crystalline materials include providing source materials in oversaturated quantities where amounts of the source materials present during growth are significantly higher than what would typically be required. Such SiC crystalline materials and related methods are suitable for providing large diameter SiC boules and corresponding SiC wafers with improved crystalline quality.
A silicon carbide (SiC) wafer comprising a diameter of at least 145 millimeters (mm) and a total dislocation density (TDD) of less than or equal to 3000 per square centimeter (cm2) for any annular ring comprising a 1 mm width and an outer diameter corresponding to a radial wafer position in a range including 3 mm and 50 mm of a center of the SiC wafer.
A silicon carbide (SiC) wafer comprising a diameter of at least 145 millimeters (mm) and a coefficient of variation for total dislocation density (TDD) of less than or equal to 0.3 for a wafer area that is divided into annular rings with 1 mm widths wherein the wafer area is bounded by a radial wafer position of 3 mm from a center of the SiC wafer and 2 mm from a perimeter edge of the SiC wafer.
A silicon carbide (SiC) boule comprising a diameter in a range including 145 millimeters (mm) to 180 mm and a boule height greater than 50 mm.
A silicon carbide (SiC) boule comprising a diameter in a range including 145 millimeters (mm) to 180 mm and a boule height greater than or equal to 40 mm, wherein at least 50% of the height of the SiC boule is configured to produce a plurality of SiC wafers and each SiC wafer of the plurality of SiC wafers comprises a total dislocation density (TDD) of less than or equal to 4600 per square centimeter (cm2) for a wafer area that includes a center of the SiC wafer and is radially bounded by a radial wafer position of 2 mm from a perimeter edge of the SiC wafer.
A silicon carbide (SiC) wafer comprising a total dislocation density (TDD) of less than or equal to 3500 per square centimeter (cm2) for a wafer area that includes a center of the SiC wafer and is radially bounded by a radial wafer position of 2 millimeters (mm) from a perimeter edge of the SiC wafer, wherein the SiC wafer is taken from a boule position of greater than or equal to 40 mm as measured from a seed.
Dependencies are inferred from the claim text.