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:
Jul. 12, 2011
Filed:
Dec. 30, 2004
Ismail Kashkoush, Orefield, PA (US);
Gim-syang Chen, Allentown, PA (US);
Richard Novak, Plymouth, MN (US);
Ismail Kashkoush, Orefield, PA (US);
Gim-Syang Chen, Allentown, PA (US);
Richard Novak, Plymouth, MN (US);
Abstract
A system (FIG.) and methods for selectively etching silicon nitride in the presence of silicon oxide that provide high selectivity while stabilizing silicon oxide etch rates. The invention comprises a processing chamber (), dispense lines (), feed lines (), a recirculation line (), a process controller (), a concentration sensor (), a particle counter (), and a bleed line (). The invention dynamically controls the concentration ratio of the components of the etchant being used and/or dynamically controls the particle count within the etchant during the processing of the at least one substrate. As a result etchant bath life is increased and etching process parameters are more tightly controlled.