Aqueous compositions for making ultrapure water used in microelectronic device fabrication processes and methods of sterilizing ultrapure water delivery systems using the same

A method of sterilizing an ultrapure water delivery system for use in a microelectronic device, said method comprising:

• contacting an ultrapure water delivery system with water having a temperature ranging from about 28.degree. C. to about 34.degree. C. wherein the ultrapure water delivery system consists essentially of a water tank, a heat exchanger in fluid communication with the water tank, an ultraviolet sterilizer in fluid communication with and located downstream from the heat exchanger, an OR-polisher in fluid communication with and located downstream from the ultraviolet sterilizer, an MB-polisher in fluid communication with the OR-polisher and located downstream from the ultraviolet sterilizer, an ultrafilter in fluid communication with the OR-polisher, a by-pass line in fluid communication with the UV-sterilizer and the ultrafilter wherein the by-pass line by-passes the OR-polisher and the MB-polisher;
• and a second heat exchanger in fluid communication with the OR-polisher, the water tank, and the MB-polisher;
• and
• sterilizing the ultrapure water delivery system with a composition comprising hydrogen peroxide, peracetic acid, and water, wherein the composition by-passes the OR-polisher and the MB-polisher.