The measurements of bump heights and pit depth on compact discs (CD) with atomic force microscopes (AFMs) are quite different from the measurement of step heights on step height calibration standards. Both the bumps and the pits show much larger transition regimes and more structural irregularities. The irregularities disqualify the effective use of profile based algorithms, which minimize the influence of any remaining motion deviations of the scan apparatus, to determine the height. Therefore a histogram height algorithm has to be used. The results of the bump height and pit depth measurements varied about 20 nm over the different sample regions. The remaining approximately 30 nm difference between the average of the bump height and pit depth is believed to result from the sample preparation procedure. By itself, the large sample variation observed will result in rather in rather large measurement uncertainties for the measurement of the average height and depth of these features, if the averaging does not include a large amount of data taken at many different sample positions.
Proceedings Title: Proceedings of SPIE
Conference Dates: July 21, 1999
Conference Location: Denver, CO
Conference Title: Recent Advances in Metrology, Characterization, and Standards for Optical Digital Data Disks
Pub Type: Conferences
atomic force microscopy, compact disc, data storage, data versatile disc, metrology, step height