Air Liquide America, L.p.

Startec Ventures, Inc.

Athens Corporation

Air Liquide Electronics Chemicals & Services, Inc.

R Scot Clark

Joe G Hoffman

Wallace I Yuan

John B Davison

Bruce A Lipisko

David W Persichini

Alan W Jones

Allen H Jones, Jr

Tracey Jacksier

Hwa-Chi Wang

Mindi Xu

Stephen S Baird

Alan H Jones

Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration The method comprises bubbling purified ammonia vapor into ultra-pure hydrofluoric acid. The inventive method and system can be used as an on-site subsystem in a semiconductor device fabrication facility for supplying the buffered-hydrofluoric acid and ammonium fluoride to points of use in the semiconductor device fabrication facility.

On-site generation of ultra-high-purity buffered-HF and ammonium fluoride

Provided is a novel on-site system and method for providing ultra-high-purity nitric acid to a point of use. The system includes a source of nitric acid at a concentration greater than 68 wt %; a reflux distillation column having an inlet in communication with the nitric acid source for introducing nitric acid into the column, a reboiler, and a condensate outlet to provide a flow of nitric acid condensate from the column; a reservoir in communication with the condensate outlet for receiving the flow of nitric acid condensate; and piping for delivering nitric acid from the reservoir to a point of use. The system and method can be used as an on-site subsystem, in a semiconductor device fabrication facility for supplying the nitric acid condensate to points of use in the semiconductor device fabrication facility.

On-site manufacture of ultra-high-purity nitric acid

A system for purification and generation of hydrofluoric acid on-site at a semiconductor device fabrication facility. An evaporation stage (optionally with arsenic oxidation) is followed by a fractionating column to remove most other impurities, an Ionic Purifier column to suppress contaminants not removed by the fractionating column, and finally the HF Supplier (HFS).

On-site manufacture of ultra-high-purity hydrofluoric acid for

System and method for on-site mixing of ultra-high-purity chemicals for

Highly purified ammonia for use in processes for the production of high-precision electronic components is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.

Point-of-use ammonia purification for electronic component manufacture

Highly purified ammonia for use in semiconductor manufacturing is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.

On-site ammonia purification for semiconductor manufacture

Highly purified HCl for use in semiconductor manufacturing is prepared on-site by drawing HCl vapor from a liquid HCl reservoir, and scrubbing the filtered vapor in a low-pH aqueous scrubber.

On-site manufacture of ultra-high-purity hydrochloric acid for

A process for preparing ultra-high-purity buffered hydrofluoric acid on-site at a semiconductor manufacturing facility (front end). Anhydrous ammonia is purified by scrubbing in a high-pH liquor, and then combined with high-purity aqueous HF which has been purified by a similar process. The generation is monitored by a density measurement to produce an acid whose pH and buffering are accurately controlled.

On-site generation of ultra-high-purity buffered-HF for semiconductor

Method and apparatus for the distillation of liquids which is particularly suited for the removal of soluble impurities and insoluble and non-volatile particles of 10 microns to 0.2 micron or less in size. A substantially elongated distillation chamber having walls equipped with axially disposed concentric boiling rings spaced from the walls near the bottom, and a packing stop, packing redirector rings for condensed vapor, and a reflux condenser in the upper part of the distillation chamber provide, during distillation, a smooth convective upward flow of distilling liquid and vapor proximate the walls and boiling rings and a smooth convective downward flow of distilling liquid and vapor substantially centrally of the distillation chamber.

Apparatus for the continuous on-site chemical reprocessing of ultrapure

Semiconductor wafers and other electronic parts which similarly require ultra-high purity manufacturing environments are treated with ultra-high purity liquid cleaning and etching agents prepared at the site of use from gaseous raw materials which have been purified to a level compatible with semiconductor manufacturing standards, combined when appropriate with ultra-pure water.

Manufacture of high precision electronic components with ultra-high

Method for the production of ultrapure sulfuric acid including distillation of sulfuric acid material for the removal of soluble impurities and insoluble and non-volatile particles of 10 microns to 0.2 micron or less in size. Reprocessing is also provided. Distillation takes place in a distillation chamber having walls which are provided with means within the chamber to provide smooth convective upward flow of distilling liquid and vapor proximate the walls and means for smooth convective downward flow substantially centrally of the distillation chamber. Redirection means and packing together with reflux means insure the washing of rising vapor and direct the condensing vapor substantially centrally of the distillation chamber. Ultrapure sulfuric acid is also provided having 5 or less particles per cubic centimeter of a size of 0.5 micron and larger and less than 10 ppb of any specific trace impurity such as cations.

Method for making ultrapure sulfuric acid

An improved wafer cleaning process wherein a novel oxidant solution comprising ultrapure sulfuric acid, peroxydisulfuric acid, and ultrapure water used in a semiconductor wafer cleaning process is continuously withdrawn after use. The withdrawn oxidant is reprocessed continuously by contacting with alumina to remove fluoride ions. Water is continuously separated or stripped from the oxidant solution by heating the solution and bubbling an inert gas therethrough. The separated oxidant is continuously distilled and condensed to form a purified stream of sulfuric acid. The major portion of this stream is continuously returned to the wafer cleaning process. The remaining minor portion is continuously cooled, subjected to analysis for purity, and diluted with ultrapure water prior to electrochemical treatment in the anode compartment of an electrochemical cell. This converts at least a portion of the dilute sulfuric acid to peroxydisulfuric acid. The resulting solution is continuously returned to the wafer cleaning process to be mixed with the major portion of the purified sulfuric acid.

Growing community of inventors

Fallbrook, CA, United States of America

R Scot Clark