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:
Dec. 05, 2000
Filed:
Feb. 17, 1999
Kikuo Saka, Takarazuka, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A method of determining the amount of exposure is provided, in which a projection exposure is carried out onto a photoresist film using a photomask, having a plurality of openings with transmittance values different from one opening to the next stepwise, and through which light beams are irradiated for the exposure. Subsequently, the openings from which the photoresist is completely removed are observed and a lowest light transmittance value is found among the corresponding openings, to thereby the minimum amount of the exposure E.sub.th for removing the photoresist film is determined. The minimum amount of the projection exposure is found by exposing a plurality of portions with a single exposure step, and the determination of amount of the exposure becomes feasible with relative ease.