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. 05, 2017
Filed:
Nov. 29, 2016
Asml Netherlands B.v., Veldhoven, NL;
Paul Frihauf, La Jolla, CA (US);
Andrew Liu, San Diego, CA (US);
Spencer Rich, Veldhoven, NL;
Matthew R. Graham, San Diego, CA (US);
Steven Chang, San Diego, CA (US);
Wayne J. Dunstan, San Diego, CA (US);
Daniel Jason Riggs, San Diego, CA (US);
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A method and apparatus for control of a dose of extreme ultraviolet (EUV) radiation generated by a laser produced plasma (LPP) EUV light source that combines pulse control mode and pulse modulation. The EUV energy created by each pulse is measured and total EUV energy created by the fired pulses determined, a desired energy for the next pulse is determined based upon whether the total EUV energy is greater or less than a desired average EUV energy times the number of pulses. If the desired pulse energy for the next droplet is within the range of one or more pulse modulation actuators, the pulse is modulated; otherwise, the pulse is fired to miss the droplet. This provides greater control of the accumulated dose as well as uniformity of the EUV energy over time, greater ability to compensate for pulses that generate EUV energy that is higher or lower than nominal expected values, and ability to provide an average EUV energy per pulse that is less than the nominal minimum EUV energy per pulse of the system.