Sidewall roughness measurement: a comparison of in- and off-line AFM techniques

CD-mode AFM data contains information about the roughness of the line sidewalls. In this paper, sidewall roughness information from an in-line CD-mode AFM will be compared to AFM measurements taken on the same samples off-line using a destructive sample preparation. Correlation between in-line and off-line measurements shows that there are applications for which the CD-mode AFM could be used to gain information about sidewall roughness. With software and tip development, it is likely that the in-line technique will be useful for etch development applications. However, due to noise floor and tip shape limitations, applications involving smoother sidewalls require the off-line technique.