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. 11, 1997
Filed:
Jul. 19, 1995
Seiko Instruments Inc., , JP;
Abstract
A method of forming a mask for photolithography comprises forming a transparent conductive film on a transparent substrate. The substrate and an electrode having a sharp front end are immersed in an electrolytic solution. The sharp front end of the electrode and the transparent film are then positioned close to each other while controlling a distance therebetween. The substrate and the electrode are then scanned relative to each other in two-dimensions while maintaining the distance between the sharp front end of the electrode and the transparent film constant. Thereafter, an electrochemical reaction is processed on the substrate while a voltage is applied between the transparent film and the electrode to form a mask pattern on the substrate. During repair of the mask thus formed, the substrate and the electrode are immersed in the electrolytic solution. The sharp front end of the electrode and a portion of the mask pattern to be repaired are positioned close to one another, and a distance between the sharp front end of the electrode and the mask pattern is controlled by detecting a tunnelling current flowing therebetween. Thereafter, a voltage is applied between the electrode and the mask pattern to either deposit a pattern material onto the portion of the mask pattern to be repaired or to dissolve a pattern material from the portion of the substrate pattern to be repaired.