A very simple method of flattening Si(111) surface at an atomic level using oxygen-free water

Si(111) surfaces were found to be very easily flattened at an atomic level by immersing the wafers in water, from which dissolved oxygen wad removed b y the addition of sulfite ion as chemical deoxygenator, at room temperature . After the treatment with this oxygen-free water, the Si(lll) surfaces sli ghtly misoriented in the [11 (2) over bar] direction showed straight and pa rallel steps and wide terraces under atomic force microscopy observation. W hen wafers slightly misoriented in the opposite direction were treated in t he same manner, the steps showed a characteristic zigzag pattern with an an gle of 60 degrees. The steps that appeared on both surfaces were attributab le to monohydride steps generated on the edge of flat terraces.