Deuterium absorption from the D₂O exposure of oxidized 4H-SiC (0001), (000 1 ¯), and (11 2 ¯ 0) surfaces

We report results on deuterium absorption on several oxidized 4H-SiC surfaces following D₂O vapor absorption. Absorption at the oxide/semiconductor interface is strongly face dependent with an order of magnitude more deuterium on the C-face and a-face than on the Si-face, in contrast to the bulk of the oxides which show essentially no face dependence. Annealing in NO gas produces a large reduction in interfacial deuterium absorption in all cases. The reduction of the positive charge at the interface scales linearly with the interface D content. These results also scale with the variation in interface trap density (D_it) and mobility on the three faces after wet oxidation annealing.