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. 29, 1998
Filed:
Sep. 21, 1995
Bernhard Poschenrieder, Poughkeepsie, NY (US);
Takashi Sato, Fishkill, NY (US);
Tsukasa Azuma, Poughkeepsie, NY (US);
Siemens Aktiengesellschaft, Munich, DE;
Kabushiki Kaisha Toshiba, Kanagawa-Ken, JP;
Abstract
A system and method of avoiding pattern shortening without resorting to generating a mask with a bias solve the direction dependent differences in exposure behavior in photolithography processes in the manufacture of semiconductor devices. Instead of designing a biased mask to solve the exposure problem, the pattern shortening effect is avoided by influencing the exposure process itself. By using an off axis illumination technique, the exposure is separated into different directions. In one embodiment, off axis illumination is applied in combination with special dipole apertures (i.e., two openings). The exposure is done in two or more parts, whereby the aperture is twisted between exposures. In another embodiment, off axis illumination is used in combination with special polarizer apertures. As with the first embodiment, the exposure is done in two or more parts, but in this case with differently polarized light.