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:
Aug. 06, 2002
Filed:
Jun. 19, 2000
Chin-Hsiang Lin, Kaohsiung, TW;
Shy-Jay Lin, Taipei, TW;
Sheng-Chi Chin, Hsin-Chu, TW;
Wei-Zen Chou, Taipei, TW;
Taiwan Semiconductor Manufacturing Company, Hsins-Chu, TW;
Abstract
An improved phase-shift photomask and method of fabrication are described. The method for making this phase-shift mask involves depositing an opaque film, such as chromium (Cr), on a transparent plate, such as SiO (quartz plate). An electron beam photoresist layer is deposited on the Cr film and is partially exposed in regions A and completely exposed in closely spaced alternate regions B by an electron beam. The exposed photoresist is then developed. The Cr film is etched in regions B while the remaining resist in regions A protect the Cr from etching. The e-bean resist is plasma etched back to remove the resist over regions A and then the quartz plate in regions B is recessed to a depth d by plasma etching while the Cr protects the quartz in regions A from etching. The recess is etched to a depth to provide an optical path difference between A and B of ½ wavelength (180°) when UV light is transmitted through the mask to expose resist on a product substrate. This 180° phase-shift minimizes the diffracted light under the Cr film between regions A and B and improves the DOF and therefore the photoresist resolution. Since a single e-beam resist is used to make the mask it is more manufacturing cost effective with improved alignment accuracy between regions A and B.