Two Dimensional X-Ray Diffraction Mapping of Basal Plane Orientation on SiC Substrates

Abstract

We have performed 2D X-ray diffraction mapping of the SiC lattice basal plane orientation over full 2” SiC substrates. Measurements of the omega angle were made in two perpendicular directions <11-20> and <1-100>, which gives the complete vectorized tilt of the basal planes. The Mapping revealed two characteristic bending behaviors on measured commercial wafers. The first is characterized by large variations in omega angle across the wafer in both crystallographic directions. The continuously changing omega angle in both directions gives the wafer an apparent rotationally symmetric bending which is concave towards the growth direction. The second characteristic behavior is seen in wafers with lower degree of omega angle variation. The variations in this type of wafers are not changing linearly, but are bending the basal planes with two-fold symmetry.