The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 2011
Filed:
Jul. 17, 2008
Haruhiko Kusunose, Kanagawa, JP;
Haruhiko Kusunose, Kanagawa, JP;
Lasertec Corporation, Kanagawa, JP;
Abstract
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.