| 摘要 |
A via hole depth measurement apparatus generates a light beam of white light, divides the light beam into a measurement and reference beams, focuses the measurement beam and projects it onto a sample, reflects the reference beam and advances it along the original optical path, continuously changes a relative optical path length difference between optical path lengths of the measurement and reference beams, combining reflected light from the sample and from the reflected reference beam and generates an interference beam, changes a relative distance between an objective lens which focuses the measurement beam and the sample, detects a relative position between the objective lens and the sample, receives the interference beam and outputs an interference signal, and, and outputs recessed portion depth information based on displacement information based on the interference signal and the relative position between the objective lens and the sample. |
