We have proposed the novel etching technology of Pt using a hard mask in reactive ion etching plasmas. By the insertion of a Ti mask layer and increasing the wafer temperature in O2 plasma by a dual frequency reactive ion etcher (RIE), we have obtained a higher Pt etching slope, This result not only enlightens the next generation of (DRAM) and FRAM technology, but also develops the basic technology ofpatterning inert materials.