Micro-, nano-fabrication and integration

Micro- and nano-fabrication is key to research in nanophotonics, where the structures of interest have dimensions ranging from a few nanometers to several microns. As a matter of fact, the effects we study take place when the specimen dimensions are comparable to the optical wavelength of interest. Furthermore, our experiments require structures that combine a variety of materials, including metals, polymers, dielectrics and semiconductors.

Some examples of realized structures

The following images illustrate some of the different structures we are fabricating for our research.

Complex optofluidic chip integrating plasmonic nanostructures for optical trapping and multilayered microfluidic channels.
 
Different structures realized by focused ion beam (FIB): (a) Regular and (b) circular array of apertures. (c) Single aperture surrounded by concentric grooves.
 
Array of bowtie antennas made of gold on a dielectric substrate. The structures are realized using direct e-beam writing. The gap is in the order of 30nm.
 
Large area of hybrid dielectric-plasmonic nanostructures consisting of a silicon cavity at the bottom, a dielectric spacer and an aluminum disk on the top. Fabrication based on a combination of lift-off and plasma etching.
 
We keep developping novel nanofabrication techniques for plasmonics. This picture shows a comparison between structures with very small featuers fabricated using plasma etching (left images) or lift-off (right images). The scalebars are 20 nm, except in panels (d) and (f) where they are 100 nm. Sub-10 nm features can be realized using etching.

Infrastructure

EPFL Center of MicroNanoTechnology Most fabrication takes place at the EPFL Center of MicroNanoTechnology (CMI), which provides an outstanding infrastructure in over 500 square meters of class 100 and 1000 clean rooms. The center is equipped with modern and powerful processing machines and managed by a very competent staff.
 
Particularily important for our work are the dual beam FIB (Nova 600 Nanolab) from FEI Company and the newly acquired e-beam direct writing system (Vistec EBPG5000).