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:
Jul. 15, 2014
Filed:
Nov. 22, 2011
Robert L. Hsieh, Los Altos, CA (US);
Khiem Nguyen, San Jose, CA (US);
Warren W. Flack, San Jose, CA (US);
Andrew M. Hawryluk, Los Altos, CA (US);
Robert L. Hsieh, Los Altos, CA (US);
Khiem Nguyen, San Jose, CA (US);
Warren W. Flack, San Jose, CA (US);
Andrew M. Hawryluk, Los Altos, CA (US);
Ultratech, Inc., San Jose, CA (US);
Abstract
An alignment system for aligning a wafer when lithographically fabricating LEDs having an LED wavelength λis disclosed. The system includes the wafer. The wafer has a roughened alignment mark with a root-mean-square (RMS) surface roughness σ. The system has a lens configured to superimpose an image of the reticle alignment mark with an image of the roughened alignment mark. The roughened alignment marked image is formed with alignment light having a wavelength λthat is in the range from about 2σto about 8σ. An image sensor detects the superimposed image. An image processing unit processes the detected superimposed image to measure an alignment offset between the wafer and the reticle.