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By Bipin Parekh, Saksatha Ly
Mykrolis Corporation, 80 Ashby Road, Bedford, MA 01730, USA
KS Cheng
Millipore Corporation, 80 Ashby Road, Bedford, MA 01730, USA
Sellmer Reinhard, Jörg Leberzammer
SEZ AG, Draubodenweg 29, 9500 Villach, Austria
Introduction
Wet cleaning processes continue to advance to meet the challenges of manufacturing semiconductor devices of ever-increasing performance and smaller geom etries. The new materials, manufacturing processes, larger wafer size, aggressive dimension shrinks and ESH considerations will drive the development of new cleaning methods for both FEOL and BEOL cleaning processes. Of the many emerging wet cleaning techniques, the ozone/DI based methods offer advantages of less resource consumption and comparable wafer cleaning performance to the standard processes. Ozone-DI chemistry is already being practiced in the wafer cleaning and photoresist removal applications [1-19].
This paper describes the design and performance of the newly developed all-PFA hollow fiber Ozone-DI contactors. Its key advantages are--smaller footprint, high gas transfer efficiency/recovery, rapid start-up, and improved cost of ownership. Also, described is the field testing of the ozone contactor in a new single wafer spin cleaning process tool that uses a repetitive DI-O3 / DHF clean at room temperature
Ozone-DI process requirements and challenges
The ozone concentration required in the wet processing and cleaning applications are reported to be in the following range:
[1] Oxide growth for hydrophilic surface
(6-20 ppm bubble free dissolved ozone)
Si + 2O3 SiO2 + 2O2
[2] Photoresist and surfactant removal
(80-120 ppm dissolved ozone- bubbles)
(-CH2-)x + 3O3 CO2 + H2O+ 3O2
[3] Organi |