Method of manufacturing silicon carbide ingot

Abstract

The disclosure provides a silicon carbide seed crystal and a method of manufacturing a silicon carbide ingot. The silicon carbide seed crystal has a silicon surface and a carbon surface opposite to the silicon surface. A difference D between a basal plane dislocation density BPD 1 of the silicon surface and a basal plane dislocation density BPD 2 of the carbon surface satisfies the following formula (1), a local thickness variation (LTV) of the silicon carbide seed crystal is 2.5 μm or less, and a stacking fault (SF) density of the silicon carbide seed crystal is 10 EA/cm 2 or less: D =(BPD 1 −BPD 2 )/BPD 1 ≤25%  (1).

What is claimed is: 
     
         1 . A method of manufacturing a silicon carbide ingot, comprising:
 disposing a silicon carbide seed crystal on a top of a crucible;   disposing a silicon carbide based raw material in the crucible;   heating the silicon carbide based raw material to form a thermal field in the crucible, so that the silicon carbide based raw material is sublimated in the thermal field of the crucible, wherein a radial temperature gradient of the thermal field in the crucible is greater than or equal to 5° C./cm and less than or equal to 50° C./cm;   growing the sublimed silicon carbide into a silicon carbide single crystal after being in contact with the silicon carbide seed crystal disposed on the top of the crucible;   growing the silicon carbide single crystal continuously on the silicon carbide seed crystal to obtain silicon carbide ingots.   
     
     
         2 . The method of manufacturing the silicon carbide ingot according to  claim 1 , wherein the radial temperature gradient is greater than or equal to 5° C./cm and less than or equal to 45° C./cm. 
     
     
         3 . The method of manufacturing the silicon carbide ingot according to  claim 1 , a basal plane dislocation density (BPD) of a carbon surface of the grown silicon carbide ingot is 300 EA/cm 2  or less, a stacking fault (SF) density of the carbon surface of the grown silicon carbide ingot is 10 EA/cm 2  or less, and a threading screw dislocation (TSD) density of the carbon surface of the grown silicon carbide ingot is 35 EA/cm 2  or less. 
     
     
         4 . The method of manufacturing the silicon carbide ingot according to  claim 1 , wherein the silicon carbide seed crystal comprises a silicon surface and a carbon surface opposite to the silicon surface, wherein a difference D between a basal plane dislocation density BPD 1  of the silicon surface and a basal plane dislocation density BPD 2  of the carbon surface satisfies a formula (1) as follows, a local thickness variation (LTV) of the silicon carbide seed crystal is 2.5 μm or less, and a stacking fault (SF) density of the silicon carbide seed crystal is 10 EA/cm 2  or less:
     D =(BPD1−BPD2)/BPD1≤25%  (1).