Anisotropic radius of curvature of crystal planes in wide-bandgap semiconductor wafers measured by x-ray diffraction
Keyword(s):
X Ray
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Abstract Conventionally, the radius of curvature of crystal planes in a wafer is measured by position-dependent x-ray diffraction along a particular diagonal direction of the wafer. However, we show herein that this method is not reliable for assessing the wafer’s real three-dimensional curvature. Using commercial 2-inch 4H-SiC, GaN, AlN, and β-Ga2O3 wafers, we demonstrate that the choice of the diagonal direction along which the position-dependent x-ray diffraction was acquired strongly affects not only the apparent radius of curvature but also whether it is convex or concave.