Abstract: This invention relates to a device intended to perform various chemical determinations in several wet chemical processes commonly used in semiconductor applications, including, but not limited to, those referred to as front end of line (FEOL) cleans, back end of line (BEOL) cleans, and copper electroplating. The device provides continuous or near continuous sensing of critical parameters such as component concentrations and metallic impurity concentrations. The device is capable of storing data for transmission after completion of the process, or transmitting data in real time as it is acquired. The device makes use of ISFET's and ChemFET's coupled with reference electrodes to detect small variations in the chemical properties of various wet chemical processes. The device can further either store the data for later analyses or transmit the data in real or near real time for more temporal analysis and control.

Abstract: 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.

Abstract: 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.

Abstract: A system for automatically filling a bubbler, or other vapor delivery system from a reservoir, is disclosed in which the conduit system is purged and pressurized with inert gas, using a unique refill reservoir, level sensing and valving system.

Abstract: A system for automatically filling a bubbler, or other vapor delivery system from a reservoir, is disclosed in which the conduit system is purged and pressurized with inert gas, using a unique refill reservoir, level sensing and valving system.

Abstract: 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.

Abstract: 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.