Feature Depths

Feature depths can be determined from image sections. In such cases a feature depth is then determined by the placement of a single cursor on the top and bottom of the feature. A more statistically robust method of determining feature depths is the use of the "depth" feature which exploits image bearings or pixel histograms.

This image shows a 10 nm thick film of AuPd for SEM coating on V4 mica. An area has been scratched to allow for a film thickness measurement. A box has been place over a region of the scratch. The right shows a histogram of the pixel heights in that box. The broader portion of the bilobed distribution represents the film-- the narrower portion the substrate. For an ideally plane-fit image, the broadness of these histograms would reflect the R_a. The separation of the two distributions represents the feature depth which is found to be 10.12 nm. For this application that is ideal as a 10-12 nm film of AuPd is ideal for coating for SEM.