METHOD FOR MACHINING/CLEANING BY HYDROXIDE ION IN ULTRAPURE WATER

Title:

METHOD FOR MACHINING/CLEANING BY HYDROXIDE ION IN ULTRAPURE WATER

Document Type and Number:

WIPO Patent Application WO/2000/034995

Kind Code:

A1

Abstract:

A highly efficient method for clean machining a work only by hydroxide ions in ultrapure water without leaving any impurities on the surface of the work, or cleaning the surface of a work by completely removing minute impurity metals adhering to the surface. Readhesion of impurity metals is prevented by increasing the density of hydroxide ions and by quickly removing the reaction substances produced when impurity metals are bonded to hydroxide ions from the surface. A work and a high-pressure nozzle are opposed to each other at a predetermined interval in an ultrapure water bath. An ion exchange material or catalyst material for increasing hydroxide ions is disposed between the surface of the work and the end of the nozzle opposed to the work. A voltage is applied between the nozzle serving as a cathode and the work serving as an anode. Ultrapure water is jetted from the nozzle to form a high-speed shear flow near the surface of the work, and hence hydroxide ions are supplied to the surface. Thus, material removal or oxide coating formation can be effected by chemical elution or oxidation by hydroxide ions, or minute impurity metals adhering to the surface of a work are separated and removed.

Inventors:

MORI YUZO (JP)
ISHIKAWA TOSHIO (JP)

Application Number:

PCT/JP1999/006829

Publication Date:

June 15, 2000

Filing Date:

December 07, 1999

Export Citation:

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Assignee:

JAPAN SCIENCE & TECH CORP (JP)
MORI YUZO (JP)
ISHIKAWA TOSHIO (JP)

International Classes:

C25D11/32; C25F1/00; C25F3/00; H01L21/00; (IPC1-7): H01L21/3063; B08B3/10; C25D11/32; H01L21/304; H01L21/316

Foreign References:

JPH0254800A	1990-02-23
JPS63306630A	1988-12-14
EP0194734A1	1986-09-17
JPH0936079A	1997-02-07

Other References: