In this paper, the concept of nanotopography in detection of surficial flatness of large-diameter silicon slices are explained, and the nanotopography, surficial flatness, micro-roughness, and their comparision thereof are described; moreover, the causes of their formation of nanotopography and the influences thereof are pointed out.

The microroughness of silicon surfaces after pre-oxidation cleaning is studied using atomic force microscopy,and the cleaning mechanism is analyzed by building surface reaction and oxide layer models.

The characteristic of microroughness surface scattering and the principle of the microroughness measurement based on scattering detection are briefly reviewed.

The comparative test results showed that acid corroding of old concrete interface may result in a significant increase of micro roughness of old concrete interface, leading to a significant increase of contact area of new and old concrete; and the modification of cement paste primer by introducing fly ash.

Based on the bond mechanism of new and old concrete repaired interface layer, an idea to significantly increase micro roughness of old concrete interface by using acid to wash it was proposed.

In order to distinguish light scattering between small particle above a surface and surface microroughness and identify the scattering sources of two kinds of scattering mechanisms,the polarized bidirectional reflectance distribution function(P-BRDF) is researched by use of ,■,■ right handed basis set.