2.1 Milling by
Focused Ionic Beam
(FIB)
1. A layer of optical resist Shipley S1813 is deposited on a silicon
nitride (Si 3 N 4 ) membrane by spin-coating (Fig. 2b).
2. Focused ionic beam (FIB) milling is used to defined a structure
from the backside of silicon nitride membrane [10], where
gallium ions interact with the resist polymer (S1813), producing low-energy secondary electrons (see Note 1).
3. The lithographic process is formed to induce inversion of the
resist (from positive to negative tone) in a thin layer of polymer
surrounding the milled surface (Fig. 2c).
4. The sample is immersed in a solvent (typically acetone) to
remove the unexposed resist, whereas the exposed polymer
became insoluble (see Note 2).
2.2 Coating of Gold
Layer
The nanochannels and the nitride membrane are coated with a thin
layer of gold (see Note 3), which covers the whole sample surface
constituting an uninterrupted conductive film (Fig. 3) whose shape
is determined by insoluble resist attached to the membrane.
2.3 Passivation of
the Gold Planar
Surface
1. Complete passivation of the gold planar surface of the device is
carried out by spin-coating a layer of the epoxy polymer
SU8 onto the membrane with gold-coated nanochannels (see
Note 4).
Fig. 2 Schematic of plasmonic hollow nanostructures fabrication method
Soft Electroporation Through 3D Hollow Nanoelectrodes
15
Focused Ionic Beam
(FIB)
1. A layer of optical resist Shipley S1813 is deposited on a silicon
nitride (Si 3 N 4 ) membrane by spin-coating (Fig. 2b).
2. Focused ionic beam (FIB) milling is used to defined a structure
from the backside of silicon nitride membrane [10], where
gallium ions interact with the resist polymer (S1813), producing low-energy secondary electrons (see Note 1).
3. The lithographic process is formed to induce inversion of the
resist (from positive to negative tone) in a thin layer of polymer
surrounding the milled surface (Fig. 2c).
4. The sample is immersed in a solvent (typically acetone) to
remove the unexposed resist, whereas the exposed polymer
became insoluble (see Note 2).
2.2 Coating of Gold
Layer
The nanochannels and the nitride membrane are coated with a thin
layer of gold (see Note 3), which covers the whole sample surface
constituting an uninterrupted conductive film (Fig. 3) whose shape
is determined by insoluble resist attached to the membrane.
2.3 Passivation of
the Gold Planar
Surface
1. Complete passivation of the gold planar surface of the device is
carried out by spin-coating a layer of the epoxy polymer
SU8 onto the membrane with gold-coated nanochannels (see
Note 4).
Fig. 2 Schematic of plasmonic hollow nanostructures fabrication method
Soft Electroporation Through 3D Hollow Nanoelectrodes
15