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:
Oct. 02, 2001
Filed:
Jun. 20, 2000
Stanley F. Wanat, Scotch Plains, NJ (US);
M. Dalil Rahman, Flemington, NJ (US);
Abstract
The present invention provides a method for reducing the metal ion content of a film-forming resin, said method comprising the steps of: a) providing a solution of the film-forming resin in a water-immiscible solvent system comprising at least one water-immiscible solvent; b) providing a washing solution comprising water or a dilute solution of a water-soluble metal ion chelating agent; c) feeding the solutions from a) and b) through two separate inlet ports into a liquid/liquid centrifuge, one of said inlet ports feeding solution from a), the second inlet port feeding the solution from b) into said liquid/liquid centrifuge at a feed rate ratio of the solution from a) to that from b) from about 10/90 to about 90/10, at a temperature of from about 0° C. up to a maximum temperature that is less than the boiling point of the lowest boiling water-immiscible solvent in the water-immiscible solvent system; and d) rotating the mixture from step c) inside said liquid/liquid centrifuge at a rotational speed sufficient to separate the mixture from step c) into two separate phases, and then collecting the two separate phases, each through a separate outlet port, into two separate containers, wherein the heavier phase (H) comprises the film-forming resin having a reduced metal ion content in the water-immiscible solvent system, with a minor amount of water; and the lighter phase (L) comprises: 1) an aqueous solution of metal ions and a minor amount of a mixture of 2) the water-immiscible solvent system, and 3) the film-forming resin. The present invention also provides for a method for producing a photoresist composition and a method for producing a microelectronic device utilizing a film-forming resin produced by the aforementioned method.