Infrared observation of the hydrogenation of Si surface in deoxygenated water

We have studied the removal of surface oxides from a partially oxidized Si(111) surface and the simultaneous hydrogenation of the new dangling bonds in hot water. The amount of remaining oxides decreased by lowering dissolved-oxygen concentration (DOC) from 4 to 0.004 ppm. After immersing in hot water with 0.004 ppm of DOC for 60 min, almost all of the surface was hydrogenated and only a tiny amount of silanol groups remained. We discuss the formation of the dihydride step-edges observed during the oxide removal.