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. 23, 2004
Filed:
Nov. 07, 2001
Tony S. Kaushal, Cupertino, CA (US);
Chuong Quang Dam, San Jose, CA (US);
Yongqi Hu, Santa Clara, CA (US);
Applied Materials Inc., Santa Clara, CA (US);
Abstract
Endpoint of a chemical mechanical polishing process is detected by monitoring acoustical emissions produced by contact between a polishing pad and a wafer. The acoustic information is resolved into a frequency spectrum utilizing techniques such as fast Fourier transformation. Characteristic changes in frequency spectra of the acoustic emissions reveal transition in polishing between different material layers. CMP endpoint indicated by a change in the acoustic frequency spectrum is validated by correlation with other sensed properties, including but not limited to time-based changes in amplitude of acoustic emissions, frictional coefficient, capacitance, and/or resistance. CMP endpoint revealed by a change in acoustic frequency spectrum can also be validated by comparison with characteristic frequency spectra obtained at endpoints or polishing transitions of prior operational runs.