Catalyst‐referred etching of 4HSiC substrate utilizing hydroxyl radicals generated from hydrogen peroxide molecules

We describe a new environmentally friendly planarization technique for 4H‐silicon carbide (SiC) substrates. The method uses hydroxyl (OH) radicals generated from hydrogen peroxide (H 2 O 2 ) molecules. The surface morphology and the removal rate show strong dependencies on the plane direction of the substrate. This is attributed to the oxidation mechanism wherein oxidation progresses through the exchange of the surface C‐sites with O atoms. A difference in the number of CSi bonds around the surface C‐sites causes a difference in the removal rate between the opposite faces. On the (0001) face, the oxidation progresses preferentially at the step edge, where the C‐sites are locally exposed. As a result, a step‐terrace structure is formed.