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. 28, 2004
Filed:
Nov. 21, 2003
Endpoint detection in chemical-mechanical polishing of patterned wafers having a low pattern density
Xinhui Wang, Poughkeepsie, NY (US);
Leping Li, Poughkeepsie, NY (US);
Yingru Gu, Pougheepsie, NY (US);
Hung-Chin Guthrie, Saratoga, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A chemical-mechanical polishing (CMP) system and method includes pumping polishing slurry from a CMP apparatus through a sampling tube to an endpoint detection apparatus during a polishing operation, and flushing the sampling tube while a polishing operation is not in progress. The flushing of the sampling tube is commenced in accordance with a control signal from the endpoint detection apparatus terminating the polishing operation; the flushing is terminated in accordance with a starting signal to the CMP apparatus. The pump, which pumps a sample of slurry into the endpoint detection apparatus, continuously pumps slurry and/or water. Clogging of the slurry sampling tube is thus eliminated, thereby ensuring robust operation of the CMP apparatus. Contamination of the sampling tube is also avoided, so that the system may reliably provide sensitive endpoint detection and process control, even when a film of low pattern density is polished.