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:
Aug. 26, 2008
Filed:
May. 17, 2005
Jeffrey T. Hastings, Lexington, KY (US);
James G. Goodberlet, Melrose, MA (US);
Feng Zhang, Cambridge, MA (US);
Henry I. Smith, Sudbury, MA (US);
Jeffrey T. Hastings, Lexington, KY (US);
James G. Goodberlet, Melrose, MA (US);
Feng Zhang, Cambridge, MA (US);
Henry I. Smith, Sudbury, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A method or system of spatial-phase locking a beam used in maskless lithography provides a fiducial grid with a single spatial-period, the fiducial grid being rotated at an angle with respect to a direction of scanning the beam; detects a signal generated in response to the beam being incident upon the fiducial grid; determines frequency components of the detected signal; and determines a two-dimensional location of the beam from phases of two determined fundamental frequency component. The method or system further determines a size of the beam from relative amplitudes of the determined fundamental and harmonic frequency components and/or determine a shape of the beam from relative amplitudes of the determined fundamental and harmonic frequency components. The method or system corrects a deflection of the beam in response to the determined two-dimensional location, and/or adjusts the size of the beam in response to the determined size, and/or adjusts the shape of the beam in response to the determined shape. If the method or system spatial-phase locks a plurality of beams used in maskless lithography, a fiducial grid with a varying spatial-period is utilized. In the plural beam method or system, the frequency components for each beam are determined using frequency-division multiplexing.