Influence of microroughness of Si and native oxide on adsorption of organic carbon in water

The relationship between adsorption of organic carbon present in water and Si surface roughness is examined, The mean roughnesses, R-a, of Si(100) surface after etching in HF solution is the same as that of Si(111) surface. There is no difference between the roughness of the native oxide formed during rinse in ultrapure water and that of the native oxide/Si interface for Si(111). The roughness shows a constant value over all rinse times. These studied observations indicate that the microroughness of the Si surface does not serve as the dominant adsorption site for organic carbon. It is also shown that the field-enhanced oxidation at the beginning of the growth of the native oxide film is important to discuss the dominant adsorption site.