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Fabrication of 25-nm-Pitched CoPt Magnetic Dot Arrays Using 30-keV-Electron Beam Drawing, RIE and Ion-Milling

In this study, we have fabricated 25-nm-pitched magnetic dot arrays using electron beam lithography (EBL), reactive ion etching (RIE) and ion-milling. We have used double mask method with calixarene resist and carbon film as a hard mask to transfer fine pattern to CoPt magnetic film. We transferred the calixarene resist dot arrays to carbon layer using O2 gas in RIE as a first mask, then transferred the carbon dot arrays to CoPt magnetic layer as a second hard mask using ion-milling. We demonstrated that double mask method is very suitable to fabricate 25-nm-pitched magnetic dot arrays with a dot size of 18 nm and a height of 15 nm for patterned media with 1 Tb/in2.