Applications of Atomic Force Microscopy (AFM) in optical disc technology are summarized. AFM is ideally suited to the characterization of nanometer scale pit and bump structures in CD/DVD manufacturing

so the relationship between production variables and pits/bumps geometry as well as relations between pits/bumps geometry and electrical performance of discs can be established to perform direct quality control of CD/DVD manufacturing. Applications of AFM in optical disc technology mainly fall into three parts: qualitative analysis of topography of discs/stampers

semi quantitative analysis of pits/bumps geometry of discs/stampers and length analysis of data marks on bump with statistics technology. Qualitative analysis of topography of discs/stampers and semi quantitative analysis of pits/bumps geometry of discs/stampers are chiefly oriented to the measurements of high error rate at beginning of play

pit morphology and block error rate

track pitch variations

pit depth monitoring as well as bump morphology and its surface roughness. It is discovered that the efficiency of the cooling channels of the mold has deteriorated

resulting in the discs being separated from the stamper while they are too soft due to inadequate cooling in the area where high error rate and block error rate are frequently produced. Length analysis of data marks with statistics technology is aimed at the analysis of track pitch and pitch variation

bump length (offset

deviation

asymmetry) and AFM jitter

bump width and width variation

bump height and height variation as well as side wall angle (slope) and slope variation. Statistical analysis of AFM images yields important information about optical disc microstructure and in turn provides information about the performance of the manufacturing process. It is very useful to analyze geometric parameters by considering the fundamental length groups of the data marks. The obtained results demonstrate that AFM have particular advantages in the quality control of discs/stampers manufacturing.