Perpendicular patterned media in an (Al0.9Ga0.1)(2)O-3/GaAs substrate for magnetic storage

By using electron beam lithography, chemically assisted ion beam etching, a nd electroplating, we have fabricated high aspect ratio magnetic columns, 6 0-170 nm in diameter, embedded in an aluminum-gallium-oxide/gallium-arsenid e [(Al0.9Ga0.1)(2)O-3/GaAs] substrate. In our previous work, we demonstrate d storage of data in individual columns spaced 2 mu m apart. Here the elect roplated Ni columns are in the form of tracks (0.5 and 0.25 mu m in the dow n-track direction, and 1 mu m in the cross-track direction), corresponding to areal densities of 1.3 and 2.6 Gbits/in.(2), respectively. In this repor t: we describe in more detail the issues in the fabrication of patterned me dia samples, such as dry etching and oxidation of AlGaAs, and electrodeposi tion of Ni into GaAs substrate. Initial characterization of the resulting m agnets using magnetic force microscopy are also presented. (C) 1999 America n Vacuum Society. [S0734-211X(99)06906-1].