A simple approach to sub-100 nm resist nanopatterns with a high aspect ratio

Abstract

A simple methodology to prepare sub-100 nm resist nanopatterns with a high aspect ratio for the transfer of device nanofeatures is demonstrated. The novel method is based on a two- or multi-step developing process with the incorporation of an ∼4 nm thick metal film to protect the fine resist nanopatterns in the developer solution. Using this approach, sub-100 nm resist nanopatterns of different shapes were readily fabricated using the positive- and negative-tone electron-beam resists. Subsequently, fine device nanostructures could be readily converted from these fine resist nanopatterns with a high aspect ratio.

Fabrication of ultrahigh density metal–cell–metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

“…The thickness and images of all nanopatterns were measured using an atomic force microscope (AFM, Dimension 3100) or a field emission scanning electron microscope (FESEM, JSM 7401F). The exposure energies of the resists and measurement methods for the nanopatterns and MR nanocells were similar to those reported previously [19,20].…”

“…Hence, in order to minimize the difficulty in resist lift-off, higher resist nanopatterns (namely larger aspect ratio) were required using the common transfer method via dry-etch and lift-off procedures. This posed a process difficulty for the device fabrication, as it was hard to achieve a high aspect ratio of ≤70 nm resist nanopatterns, with normal commercial electron-beam resists, by using a conventional method in the lithography process [20,23]. As such, the sidewall defects and difficult lift-off issues were critical obstacles in the conversion of device nanopatterns [23].…”

Domain configurations in Co/Pd and L10-FePt nanowire arrays with perpendicular magnetic anisotropy

“…21,[29][30][31][32] However, studies of PMA nanowires arrays made of CoCrPt (linewidth < 50 nm), Co/Pt (linewidth < 80 nm), and Cu/Ni/Cu (linewidths ≥ 100 nm) generally demonstrated the viability of electron beam, interference or BCP lithography techniques in producing nanowires or analyzed anisotropy contributions to the wires. 17,[33][34][35] Another study of PMA Co/Pt line arrays (linewidths and gap ~200 nm) illustrated Co/Pt magnetic configurations that were used for magnetic force microscopy (MFM) tip calibration. 36 Work on PMA Co/Pd multilayers and L1 0 -FePt has investigated single nanowires, dot arrays and thin films.…”

Novel Hybrid Organic–Inorganic Spin‐on Resist for Electron‐ or Photon‐Based Nanolithography with Outstanding Resistance to Dry Etching

“…[7][8][9] A slightly simplifi ed method has been obtained by means of a two-step developing process: after a partial development, a ∼ 4 nm thin metal fi lm is deposited on the nanopatterned resist, which is then fully developed. [ 10 ] This method allows an enhancement of the aspect ratio of the resist features but is still too complex.…”