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:
Aug. 14, 2001
Filed:
Nov. 24, 1997
Kai Chiu Wong, Sunnyvale, CA (US);
Cypress Semiconductor Corporation, San Jose, CA (US);
Abstract
The invention enables extension of the useful life of a chemical bath used to process a substrate. The invention can employ an improved rinsing method that removes defects from a substrate with sufficient effectiveness to obtain acceptable defect levels even as the quality (e.g., composition and/or contaminant level) of the chemical bath degrades over time such that substrates that are immersed in the bath accumulate more defects than can be adequately removed by previous rinsing methods. For example, the invention can enable a stagnant chemical bath to be used for a period greater than 24 hours without replacing the bath fluid. Similarly, it is expected that use of the invention can enable a recirculated chemical bath to be used for a period greater than 48 hours without replacing the bath fluid. In particular, the invention can advantageously enable a chemical bath to be used continuously for such extended periods of time, thus reducing the costs associated with stopping use of a chemical bath (to replace the bath fluid or for any other reason). The invention can be used with chemical baths of any of a variety of fluids, including both liquid and gas baths. For example, the invention can be used with a chemical bath that includes (or consists essentially of) sulfuric peroxide, a chemical bath that includes (or consists essentially of) phosphoric acid, or a chemical bath that includes (or consists essentially of) a metal stripping solvent.