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:
Sep. 10, 1996
Filed:
May. 03, 1994
Koji Tsubusaki, Kanagawa-ken, JP;
Fumio Komatsu, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A critical dimension measuring equipment includes a filtering circuit for inputting image data from a SEM and performs spatial filtering processing of the image data, a histogram processing circuit implements histogram processing of the image data, a threshold value detection circuit obtains a threshold value based on a discriminant criteria method, a three-value conversion processing circuits implements three-value conversion of the image data based on the threshold value, a first calculation circuit obtains the area and perimeter of the bottom section of the pattern based on this data, a second calculation circuit obtains the diameters of the patterns based on this data, and a critical shape recognition circuit decide whether the pattern is circular or elliptical based on the critical diameter, calculates the diameter of the circle based on the area if the pattern is circular, and calculating the major axis and the minor axis of the ellipse based on the area and the perimeter if the pattern is elliptical.