30-nm scale fabrication of magnetic tunnel junctions using EB assisted CVD hard masks

30-nm scale fabrication of magnetic tunnel junctions (MTJs) was demonstrated. A scanning electron microscope (SEM) was used for chemical-vapor deposition (CVD) of carbon hard masks. Using electron beam (EB)-CVD, less than several 10-nm scale carbon pillar could be formed on MTJ films. Argon ion milling, of which incident angle from the normal of the film plane was determined 45° and 75°, was utilized to pattern the MTJs. TMR properties of 80-nm scale MTJs were successfully measured using DC-four-probe at room temperature.