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:
Feb. 27, 2001
Filed:
May. 06, 1998
Leping Li, Poughkeepsie, NY (US);
James Albert Gilhooly, Saint Albans, VT (US);
Clifford Owen Morgan, III, Burlington, VT (US);
Cong Wei, Poughkeepsie, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Detection of the endpoint for removal of a target film overlying a stopping film by removing the target film with a process that selectively produces a gaseous chemical reaction product (for example ammonia when polishing a wafer with a nitride film in a slurry containing KOH) with one of the stopping film and the target film, mixing the gaseous chemical reaction product present with a separate gas to form solid particles, and monitoring the amount of the solid particles as the target film is removed. Also, detection of a substance at very low concentrations in a liquid, by extracting the substance present as a gas from the liquid, mixing the gas with another substance to form solid particles, and monitoring the amount of the solid particles to detect the substance.