LINE-PROFILE MEASUREMENT WITH A SCANNING PROBE MICROSCOPE

Profilometry of high-aspect-ratio, submicron lithographic features with a scanning force microscope is possible if the instrument satisfies several requirements. The probe must be slender enough to reach into narrow holes without sacrificing stability. The force sensor must follow the surface without damaging the sample or the probe. Finally, a position monitor must measure the location of the probe. With such an instrument, high-resolution depth measurements are straightforward. Width measurements are more difficult because of the mixing of the probe shape with sidewalls, but this problem can be overcome through careful control of the probe shape. Measurements of high-aspect ratio features with a characteristic size less than 0.5 mum will be shown, and some of the distortions caused by the probe-sample interaction will be discussed.