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. 15, 2011
Filed:
Jul. 09, 2008
Klaus Flock, Mountain View, CA (US);
Jeff T. Fanton, Los Altos, CA (US);
Klaus Flock, Mountain View, CA (US);
Jeff T. Fanton, Los Altos, CA (US);
KLA-Tencor Corporation, San Jose, CA (US);
Abstract
In embodiments of the present invention a second, different waveplate is introduced into a single rotating compensator normal incidence ellipsometer. The second waveplate provides a quarter wavelength retardation that is different from and complementary to that of the first waveplate in order to increase the spectral range for which useful retardation is available, especially towards the deep UV spectrum. The sensitivity for the system may also be increased in the conventional spectral range, since each of the two waveplates may be optimized for its own, somewhat more narrow spectral range of operation. With the proper choice of two waveplates of different retardation, the useful spectral range may be extended from typically 190-820 nm to 150-1000 nm, and beyond if necessary, while increasing the sensitivity within the conventional wavelength range at the same time.