SiC epitaxial wafer, and method of manufacturing the same
A method of manufacturing a SiC epitaxial wafer in which a SiC epitaxial layer is formed on a SiC single crystal substrate, the method including identifying a total number of large-pit defects caused by micropipes in the SiC single crystal substrate and large-pit defects caused by substrate carbon inclusions, both of which are contained in the SiC epitaxial layer, using microscopic and photoluminescence images. Also disclosed is a method of manufacturing a SiC epitaxial wafer in which a SiC epitaxial layer is formed on a single crystal substrate, the method including identifying locations of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions in the SiC epitaxial layer, using microscopic and photoluminescence images.
1. A method of manufacturing a SiC epitaxial wafer in which a SiC epitaxial layer is formed on a SiC single crystal substrate, comprising:
a step of forming a SiC epitaxial layer on a SiC single crystal substrate,
a step of obtaining microscopic and photoluminescence images of the SiC epitaxial wafer using an inspection apparatus,
a step of identifying large-pit defects caused by micropipes in the SiC single crystal substrate and large-pit defects caused by substrate carbon inclusions, both of which are contained in the SiC epitaxial layer, using the microscopic and photoluminescence images,
a step of distinguishing the large-pit defects caused by micropipes in the substrate and the large-pit defects caused by substrate carbon inclusions by comparing the microscopic and photoluminescence images of the SiC epitaxial wafer with microscopic and the photoluminescence images of a SiC single crystal substrate in the same ingot as the SiC single crystal substrate,
a step of identifying a total number of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions based on the distinguishing step,
wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 1 defect/cm 2 or less.
2. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of identifying locations of the large-pit defects caused by micropipes in the SiC single crystal substrate in the SiC epitaxial layer, using the microscopic and photoluminescence images.
3. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of identifying locations of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions in the SiC epitaxial layer, using the microscopic and photoluminescence images.
4. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a density of the large-pit defects caused by micropipes in the SiC single crystal substrate is 10 defect/cm 2 or less.
5. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a density of the large-pit defects caused by micropipes in the SiC single crystal substrate is 0.5 defect/cm 2 or less.
6. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 0.1 defect/cm 2 or less.
7. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 0.01 defect/cm 2 or less.
8. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 0 defect/cm 2 .
9. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of selecting the SiC epitaxial wafer in which a total density of the large-pit defects caused by micropipes and the large-pit defects caused by substrate carbon inclusions is 1 defect/cm 2 or less.
10. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of selecting the SiC epitaxial wafer in which a total density of the large-pit defects caused by micropipes and the large-pit defects caused by substrate carbon inclusions is 0.1 defect/cm 2 or less.
11. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of selecting the SiC epitaxial wafer in which a total density of the large-pit defects caused by micropipes and the large-pit defects caused by substrate carbon inclusions is 0.01 defect/cm 2 or less.
12. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of selecting the SiC epitaxial wafer in which a total density of the large-pit defects caused by micropipes and the large-pit defects caused by substrate carbon inclusions is 0 defect/cm 2 .
13. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein a total density of the micropipes in the SiC single crystal substrate and the substrate carbon inclusions is 1 defect/cm 2 or less.
14. The method of manufacturing a SiC epitaxial wafer according to claim 1 , further comprising: a step of selecting a SiC single crystal substrate in which a total density of the micropipes in the SiC single crystal substrate and the substrate carbon inclusions is 1 defect/cm 2 or less.
15. The method of manufacturing a SiC epitaxial wafer according to claim 1 , wherein the SiC epitaxial wafer has no basal plane dislocations (BPD) in the SiC epitaxial layer and a BPD density in the SiC single crystal substrate of 400/cm 2 or less.
16. A method of manufacturing a SiC epitaxial wafer in which a SiC epitaxial layer is formed on a single crystal substrate, comprising:
a step of forming a SiC epitaxial layer on a SiC single crystal substrate,
a step of obtaining microscopic and photoluminescence images of the SiC epitaxial wafer using an inspection apparatus,
a step of identifying large-pit defects caused by micropipes in the SiC single crystal substrate and large-pit defects caused by substrate carbon inclusions, both of which are contained in the SiC epitaxial layer, using the microscopic and photoluminescence images,
a step of distinguishing the large-pit defects caused by micropipes in the substrate and the large-pit defects caused by substrate carbon inclusions by comparing the microscopic and photoluminescence images of the SiC epitaxial wafer with microscopic and the photoluminescence images of a SiC single crystal substrate in the same ingot as the SiC single crystal substrate,
a step of identifying locations of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions in the SiC epitaxial layer based on the distinguishing step,
wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 1 defect/cm 2 or less.