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:
Apr. 04, 1995
Filed:
Sep. 29, 1992
David A Vidusek, Camas, WA (US);
Hiroki Tabuchi, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Sharp Microelectronics Technology, Inc., Camas, WA (US);
Abstract
Sub-micron features are defined photo-lithographically by combining phase-shifting techniques with conventional photo lithographic techniques. In a first step, phase-shifting edges are defined in a photoresist layer. Dark-bands develop at the phase-shifting edges due to wavefront interference of an illuminating radiation in a subsequent exposure step. Development leaves behind sub-micron sections of photoresist which were covered by the dark-band regions. The dark-band sections are hardened and overcoated with a new layer of photoresist. A second pattern is projected onto the second layer of photoresist using conventional techniques. The second pattern is developed so as to create features having dimensions reduced by parts of the dark-band sections previously developed.