FROM MONATOMIC STEP SELF-ORGANIZATION ON THE SILICON SURFACE TO SUBNANOMETER METROLOGY
It is shown that investigations of self-organization and morphological rearrangements on an atomically clean Si(111) surface by in situ ultrahigh vacuum reflection electron microscopy ensure understanding of fundamental processes that can be applied in metrology. By means of high-resolution electron microscopy, a natural oxide formed on the Si(111) surface under ambient conditions is shown to replicate the height of an atomic step with high accuracy. Based on this fact, we have developed methods for creating measures of vertical dimensions in the 0.31-31 nm range with an error of less than 0.05 nm in the entire measurement range. It is shown that it is possible to create extremely wide “atomically smooth” surfaces (up to 230 μm) and to use them as reference mirrors in interferometric microscopes. Crystalline samples containing a verified number of monoatomic steps and “atomically smooth” surface areas are included into the State Secondary Standard as a measure of height and flatness in the angstrom range.