Athens Corporation

Occidental Chemical Corporation

Morton Thiokol Inc.

John B Davison

Joe G Hoffman

R Scot Clark

Wallace I Yuan

Bruce A Lipisko

David W Persichini

Alan W Jones

Allen H Jones, Jr

Gerald A Krulik

Raymond J Jasinski

Alan H Jones

Chung-Tseng Hsu

Pamela J Peerce-Landers

Chung Hsu

Stephen C Davis

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

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

Disclosed is an atomic absorbtion spectrophotometer method and apparatus, for automated real time analysis of an analyte in a continuous process stream. The apparatus comprises a sample arm for delivering a quantity of sample from a sample cup to a sample atomizer. The sample cup is in valved communication with each of a source of fluid sample and a source of wash solution. In a preferred embodiment, the sample cup is additionally in valved communication with a source of a reference control. Additionally disclosed is an easily serviceable sample atomizer, having a tungsten coil heating element removably secured therein.

Atomic absorption process monitoring

A method for purifying hydrofluoric acid, comprising the steps of filtering the hydrofluoric acid to remove particulates, passing the filtered acid through a cation exchange material and an anion exchange material to remove ions therefrom, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the cation exchange material for a predetermined level of cationic impurity representative of actual or impending ionic breakthrough in the cation exchange material, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the anion exchange material for a predetermined level of anionic impurity representative of ionic breakthrough in the anion exchange material, automatically interrupting flow of acid through the anionic or cationic exchange material at or prior to the time the breakthrough in such material occurs, while the flow is interrupted, regenerating the anionic or cationic exchange material, resuming the flow after the exchange material is regenerated, passing the acid from the cationic and anionic exchange materials through an ultrafilter and into a storage container, and monitoring the level of particulate impurities in acid that has passed through the anion and cation exchange materials and automatically passing the acid in the storage container through a filter when the level of particulates exceeds a predetermined level, until the particulates are below the predetermined level. Also disclosed is an apparatus for performing the foregoing process.

Method and apparatus for purifying hydrogen fluoride

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.

Method and apparatus for the continuous on-site chemical reprocessing of

A continuous process and apparatus for the repurification of ultrapure liquids. An oxidant solution comprising ultrapure sulfuric acid, peroxydisulfuric acid, and ultrapure water is continuously withdrawn from a process 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 causing the water to vaporize from the solution. 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 process. The remaining minor portion is continuously cooled, subjected to analysis for purity, and diluted with ultrapure water. The diluted sulfuric acid is further cooled 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 process to be mixed with the major portion of the purified sulfuric acid. A system of apparatus to conduct the processes is provided which also includes means for continuously analyzing the minor portion for purity and trace elements.

An electroless copper plating bath is improved so as to facilitate its regeneration in an electrodialysis cell. The bath includes elevated amounts of an added salt, preferably as Na salt. The elevated sodium ion level serves as additional counter-cation to hydroxyl ion which is produced at the cathode of the electrodialysis cell. The excess anion from the added salt increases the rate of out-migration of by-products, such as formate ions and sulfate ions, relative to hydroxyl ions through an anion permselective membrane.

Copper bath for electroless plating having excess counter-cation and

The instant invention relates to a process for the conversion of an aryl halide into an aryl cyanide, which comprises the steps of:

Electrochemical maintenance of catalyst activity

An electrolytic process for producing hydrogen peroxide in an aqueous alkaline solution includes simultaneously passing an aqueous alkaline electrolyte and oxygen through a fluid permeable conductive cathode comprising reticulated vitreous carbon foam, separating the fluid permeable conductive cathode from an anode by a barrier and connecting the fluid permeable conductive electrode and the anode with an external power source to cause generation of hydrogen peroxide ion within the aqueous alkaline solution.

Growing community of inventors

Mission Viejo, CA, United States of America

John B Davison