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:
Mar. 27, 2007
Filed:
Jul. 28, 2005
Jang-ik Park, Suwon-si, KR;
Chung-sam Jun, Suwon-si, KR;
Hwan-shik Park, Seoul, KR;
Samsung Electronics Co., Ltd., Gyeonggi-do, KR;
Abstract
In a method and apparatus for measuring a thickness of a metal layer formed on a semiconductor substrate first, second, and third light pulses are successively irradiated onto a top surface of the metal layer to generate respective first, second, and third second sonic waves in the metal layer. Interference between the first and second sonic waves alters a detected reflectivity of the third light pulse off the metal layer. Maximum interference of the sonic waves occurs where the first sonic wave travels to a bottom surface of the metal layer and back to the top surface in the same time that it takes for the second light pulse to arrive at the surface of the metal layer. Accordingly, the velocity of the first sonic wave and a time lag between the first and second light pulses are used to determine the thickness of the metal layer.