US Patent 7264677 Process for treating solid surface and substrate surface

Ruthenium, osmium and their oxides can be etched simply and rapidly by supplying an atomic oxygen-donating gas, typically ozone, to the aforementioned metals and their oxides through catalysis between the metals and their oxides, and the ozone without any damages to wafers and reactors and application of the catalysis not only to the etching but also to chamber cleaning ensures stable operation of reactors and production of high quality devices.