Automated analysis of data mark microstructure of various media in the optical disc industry

We have developed a new technique for measuring pit geometry, track pitch, jitter and wobble on compact discs (CD) and digital versatile discs (DVD). This method uses direct physical inspection with an atomic force microscope (AFM). The images are analyzed by our automated method and yield statistically robust results, so that process windows can be determined. In both types of media we report a variety of statistical parameters including mean and standard deviation and create trend charts and other graphs. In addition to the media previously mentioned we demonstrate imaging the data marks of a written CD-RW using surface potential.