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:
Jul. 05, 1988
Filed:
Aug. 11, 1986
Hiroyuki Hasebe, Yokohama, JP;
Masayuki Suzuki, Yokohama, JP;
Yasuo Matsuoka, Kawasaki, JP;
Takashi Tsuchiya, Kitakami, JP;
Kinya Usuda, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A resist is coated on a photomask and a predetermined pattern is exposed on the resist. The photomask is dipped in a developing solution together with an electrode which exhibits a stable potential in the developing solution, so that a change in current flowing between the photomask and the electrode is detected on the basis of a change in capacitance between the photomask and the developing solution, while developing the pattern formed on the resist. The current abruptly changes (e.g., exhibits its peak) around the time at which the resist is removed and a chromium underlying layer of the photomask is exposed. The time obtained by multiplying the time until the change appears by a predetermined coefficient is regarded as the time corresponding to the end of the developing step.