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:
Feb. 19, 2002
Filed:
Apr. 17, 2000
Shinn-Sheng Yu, Taichung, TW;
Hong-Chang Hsieh, Hsin-Chu, TW;
Taiwan Semiconductor Manufacturing Company, Hsin-chu, TW;
Abstract
A new process for fabricating a phase-shifting photomask is described. A photomask blank is provided comprising a chromium layer overlying a substrate and a resist layer overlying said chromium layer. The resist layer of the photomask blank is exposed to electron-beam energy and developed away whereby a first resist pattern remains. The chromium layer not covered by the first resist pattern is etched away and, simultaneously, the substrate not covered by the first resist pattern is etched into to a depth in namometers of ¼ the wavelength of the exposure tool whereby a substrate step is formed underlying the first resist pattern. Thereafter, a portion of the first resist pattern is ashed away to leave a second resist pattern smaller than the first resist pattern and exposing portions of the chromium layer underlying the first resist pattern. The exposed portions of the chromium layer not covered by the second resist pattern are etched away whereby portions of the underlying substrate step are exposed. The second resist pattern is removed to complete fabrication of the phase-shifting photomask.