Method and apparatus for the continuous on-site chemical reproce

Details Method and apparatus for the continuous on-site chemical reproce Method and apparatus for the continuous on-site chemical reproce

1988-04-19

1989-08-08

Niebling, John F.

Chemistry: electrical and wave energy

Processes and products

Electrostatic field or electrical discharge

204 82, 204104, 156642, 423531, 134 12, 134 13, 134 21, 134 254, 134109, C25F 500

Patent

active

048550230

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acid, peroxydisulfuric acid, and ultrapure water used in a semiconductor wafer cleaning process is continuously withdrawn after use. The withdrawn oxidant is reprocessed continuously by contacting with alumina to remove fluoride ions.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. The resulting solution is continuously returned to the wafer cleaning process to be mixed with the major portion of the purified sulfuric acid.

REFERENCES:
patent: 3677701 (1972-07-01), Hellingsworth et al.
patent: 3728154 (1973-04-01), Suzuki
patent: 4085016 (1978-04-01), Janjua et al.
patent: 4329155 (1982-05-01), Schlegel
patent: 4397719 (1983-08-01), Yoshida

Affiliated with

Also associated with

Rating

Method and apparatus for the continuous on-site chemical reproce does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for the continuous on-site chemical reproce, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for the continuous on-site chemical reproce will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-903853