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:
Dec. 30, 2003
Filed:
Sep. 13, 2002
Larry Frisa, Round Rock, TX (US);
Karl Mautz, Round Rock, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
The present invention relates to a method of determining a thickness of at least one layer on at least one semiconductor wafer ( ), comprising the steps of: projecting a first laser pulse ( ) on a surface ( ) of the at least one layer ( ), thereby generating an acoustical wave due to heating of the surface of the at least one layer ( ); after a propagation time of the acoustical wave, projecting a series of second laser pulses ( ) on the surface ( ) of the at least one layer ( ); measuring reflected laser pulses ( ) of the second laser pulses ( ), thereby sensing the times of reflection property changes of the surface ( ) of the at least one layer ( ); and determining the thickness of the at least one layer ( ) by analyzing the times of reflection property changes. The present invention further relates to a system for determining a thickness of a layer ( ) on a semiconductor wafer ( ).