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:
Sep. 14, 2004
Filed:
Nov. 19, 2001
Yuan-Cheng Yu, Hsinchu, TW;
Chin-Chuan Hsieh, Hsin-Chu, TW;
Taiwan Semiconductor Manufacturing Co., Ltd, Hsin Chu, TW;
Abstract
A variable transmission focal mask to compensate lens heating is disclosed. A semiconductor fabrication alignment and exposure equipment includes an exposure and alignment unit, a variable transmission mask, and a stage. The unit has a light source and a lens. The mask is under the lens, and at least indirectly measures focus. The mask further can adjust the focus in real time in response to determining that the focus is out of specification. A wafer is placed on the stage for exposure to the light source through a mask or a reticle. The variable transmission mask normally has a substantially high transmission of light rating that can be adjusted downward to adjust the focus. For example, the mask can be a liquid crystal display (LCD) that can be darkened to so reduce its transmission of light rating.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile