Speaker
Dr
Federico Picollo
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
Description
In the present work we report about an innovative ion beam fabrication technique whereby sub-superficial graphitic nanostructures can be created in diamond.
Ion beam implantation is an effective tool to modify diamond. In particular ion-damaged diamond can be converted to graphite, which is electrically conductive and displays an higher reactivity to chemical etching with respect to the chemically inert pristine structure. This phase transition occurs in sub-superficial layers because it is due to the peculiar damage profile of high energy (MeV) ions, which mostly damage the target material at their end of range.
In the last years, micro beam lines were employed in diamond ion beam implantation, thus opening the way to the fabrication of micro-structures in this material. Femtosecond laser can be also employed to induce the diamond graphitization both on the surface and in the bulk. The mentioned techniques are versatile tools for diamond modification but offer a spatial resolution limited to some micrometers.
The presented strategy consists in the combination of ion beam lithography and focused ion beam (FIB) milling. FIB milling plays a key role in the fabrication process, indeed it is employed to create the masks through which ions are implanted in diamond. The masks are realized on thin metal layers (<10 µm) deposited directly on the crystal in order to reach nanometric resolution (no mask banding, no scattering, high thermal dissipation, etc.). Moreover, masks with variable thickness profiles are feasible tuning opportunely the FIB ion milling doses; these masks allow to modulate the ions penetration range for the creation of structures (i.e. conductive paths, fluidic channels, etc.) at the desired variable depths.
We will present the electrical and structural characterization of the sub-superficial graphitic nanochannels.
Moreover, a prototype of single cell biosensors realized with the above described technique will be shown. The biosensor has 16 electrodes converging inside a circular area of 20 µm diameter (typical neuroendocrine cells size) for simultaneous recording of amperometric signals.
Primary author
Dr
Federico Picollo
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
Co-authors
Dr
Alfio Battiato
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
Mr
Ettore Bernardi
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
Paolo Olivero
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
Prof.
ettore vittone
(INFN Sezione di Torino; Physics Department and “NIS” Inter-departmental centre, University of Torino; Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino, Italy.)
