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:
Jun. 18, 2002
Filed:
Dec. 15, 1999
Masashi Okada, Ibaraki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Methods and apparatus are disclosed in which pulses of laser light are used to remove particles from a sample surface. The laser light can have a wavelength absorbed by water, and the sample surface can be coated with a film of water. To prevent decreasing the intensity of the laser light propagating from a source to the sample, a propagation path is provided from the source to the sample that contains an environment lacking water vapor or other gas that significantly absorbs at a wavelength similar to that at which water absorbs the laser light. The methods and apparatus can also include observing the sample in real time as the sample is being irradiated with the laser light. The methods and apparatus can also include vibrating the sample as the sample is being irradiated to facilitate removal of the particles, thereby allowing the intensity of the laser light to be decreased to levels that do not damage the sample surface.