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:
May. 21, 2002
Filed:
Sep. 11, 2000
Dirk Maarten Knotter, Eindhoven, NL;
Leonardus Cornelus Robertus Winters, Nijmegen, NL;
Servatius Maria Vleeshouwers, Nijmegen, NL;
Koninklijke Philips Electronics, N.V., Eindhoven, NL;
Abstract
Arrangement and method for detecting the end of life of an aqueous bath utilized in semiconductor processing, the bath containing water, an amount of hydrogen peroxide and an amount of a predetermined chemical species, which is either an acid or a base, in accordance with the following steps: adding a predetermined additional amount of the hydrogen peroxide and/or the predetermined chemical species at predetermined time intervals, measuring at least one parameter of the aqueous bath, thereby obtaining a measured parameter value, the at least one parameter being selected from a set of parameters including bath pH and bath conductivity; reading a predicted value of said at least one parameter from a memory storing a curve of predicted values of said at least one parameter as a function of time, said curve depending on said predetermined additional amount of said hydrogen peroxide and/or said predetermined chemical species, and depending on said predetermined time intervals; establishing the end of life of said aqueous bath on the basis of a predetermined deviation between said measured parameter value and said predicted value.