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:
Jun. 15, 2004
Filed:
Oct. 18, 2002
Applicant:
Inventors:
Stefan Ottow, Dresden, DE;
Ulf Steuer, Dresden, DE;
Assignee:
Infineon Technologies AG, Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 2/1306 ;
U.S. Cl.
CPC ...
H01L 2/1306 ;
Abstract
An apparatus for assessing a silicon dioxide content of a phosphoric acid bath for etching silicon nitride and a system for etching silicon nitride bath utilize a sensor. In particular, the apparatus for assessing the silicon dioxide content of a phosphoric acid bath for etching silicon nitride of the present invention contains a sensor for measuring the NH concentration of the phosphoric acid bath, a storage unit for storing data which define a relationship between the silicon dioxide content and the NH concentration, and a device for calculating the silicon dioxide content of the basis of the measured NH concentration and the stored data.