Nondestructive imaging and surface quality inspection of structured plates

Abstract

A system includes a stage, a detector and a measuring device. The stage is configured to hold a substrate. The substrate includes a plurality of tapered structures, and each of the plurality of tapered structures includes a tapered wall between first and second openings at opposite ends of the plurality of tapered structures. The detector is tilted at a first angle and configured to measure light reflected from the tapered wall at about 90 degrees to the tapered wall. The first angle depends at least in part a second angle between the tapered wall and a longitudinal axis running through the tapered structure. The measuring device is configured to determine a characteristic of the tapered wall and whether the characteristic of the tapered wall is above or below a threshold.

Dependencies are inferred from the claim text.