SiC substrate and SiC ingot
In a SiC substrate according to the present embodiment, a proportion of a first region in which a difference between a maximum value and a minimum value of absorption coefficient for light having a wavelength of 1064 nm is 0.25 cm −1 or less is 70% or more of the total area.
1. A SiC substrate, wherein a proportion of a first region, in which a difference between a maximum value and a minimum value of absorption coefficient for light having a wavelength of 1064 nm is in a range of 0.25 cm −1 , is 70% or more of a total area thereof.
2. The SiC substrate according to claim 1 , wherein the proportion of the first region is 80% or more of the total area thereof.
3. The SiC substrate according to claim 1 , wherein the proportion of the first region is 90% or more of the total area thereof.
4. The SiC substrate according to claim 1 , wherein the proportion of the first region is 95% or more of the total area thereof.
5. The SiC substrate according to claim 1 , wherein a diameter of the SiC substrate is 149 mm or more.
6. The SiC substrate according to claim 1 , wherein a diameter of the SiC substrate is 199 mm or more.
7. The SiC substrate according to claim 1 , wherein a maximum absorption coefficient of the SiC substrate for light having a wavelength of 1064 nm is 3.00 cm −1 or less.
8. The SiC substrate according to claim 1 , wherein a maximum absorption coefficient of the SiC substrate for light having a wavelength of 1064 nm is 2.75 cm −1 or less.
9. The SiC substrate according to claim 1 ,
wherein the substrate includes a portion other than a high nitrogen concentration region called a facet,
wherein the substrate includes a dopant for determining a conductivity type and a dopant that is incorporated as an impurity, and
wherein the dopant for determining a conductivity type is nitrogen.
10. The SiC substrate according to claim 9 , wherein the proportion of the first region to the total area thereof is obtained by
dividing number of measurement points, at which absorption coefficient is within ±0.125 cm −1 of an average value of absorption coefficients of total measurement points, wherein measurement thereof is performed in one direction with a spot diameter of 1 mm and a measurement interval of 10 mm at the measurement points, by number of the total measurement points, and
multiplying the divided value by 100.
11. A SiC ingot, wherein, when cutting out a SiC substrate therefrom and evaluating a cut surface thereof, a proportion of a first region, in which a difference between a maximum value and a minimum value of absorption coefficient for light having a wavelength of 1064 nm is in a range of 0.25 cm −1 , is 70% or more of a total area of the cut surface.
12. The SiC ingot according to claim 11 ,
wherein the ingot includes a portion other than a high nitrogen concentration region called a facet,
wherein the ingot includes a dopant for determining a conductivity type and a dopant that is incorporated as an impurity, and
wherein the dopant for determining a conductivity type is nitrogen.
13. The SiC ingot according to claim 12 , wherein the proportion of the first region to the total area thereof is obtained by
dividing number of measurement points, at which absorption coefficient is within ±0.125 cm −1 of an average value of absorption coefficients of total measurement points, wherein measurement thereof is performed in one direction with a spot diameter of 1 mm and a measurement interval of 10 mm at the measurement points, by number of the total measurement points, and
multiplying the divided value by 100.