MEASURING FRACTAL DIMENSION OF A ROUGH SURFACE: USING BET METHOD BEFORE AND AFTER SPUTTERING
AMIR PISHKOO *
Physics and Accelerators Research School, NSTRI, P.O. Box 14395-836, Tehran, Iran.
*Author to whom correspondence should be addressed.
Fractal dimension is a convenient parameter which can be applied to surfaces. Using the BET technique and box-counting dimension idea, molecules at di erent sizes adsorbed on a rough material surface can be used to measure the fractal dimension of material surfaces. This paper discusses how the BET method may be utilized to measure surface roughness of target material. This quantity can be measured for target material i.e. (before and after sputtering), for substrate (before sputtering) or for thin lm (after sputtering). The quantity | Dbs − Das | which is the di erence between two fractal dimensions is a measure caused by the change in surface roughness of target material before and after sputtering.
Keywords: Fractal dimension, BET theory, Rough surface, Sputtering