4-Nitrobenzene Grafted in Porous Silicon: Application to Optical Lithography.
In this work, we report a method to process porous silicon to improve its chemical resistance to alkaline solution attacks based on the functionalization of the pore surface by the electrochemical reduction of 4-nitrobenzendiazonium salt. This method provides porous silicon with strong resistance to the etching solutions used in optical lithography and allows the fabrication of tailored metallic contacts on its surface. The samples were studied by chemical, electrochemical, and morphological methods. We demonstrate that the grafted samples show a resistance to harsh alkaline solution more than three orders of magnitude larger than that of pristine porous silicon, being mostly unmodified after about 40 min. The samples maintained open pores after the grafting, making them suitable for further treatments like filling by polymers. Optical lithography was performed on the functionalized samples, and electrochemical characterization results are shown.
Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria, S.P. 8 km 0.700, 09042, Monserrato, CA, Italy. mariavitalia.tiddia@dsf.unica.it.
Mariavitalia
http://orcid.org/0000-0002-4634-1463
M
Tiddia
Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria, S.P. 8 km 0.700, 09042, Monserrato, CA, Italy. guido.mula@dsf.unica.it.
Guido
G
Mula
Dipartimento di Ingegneria Meccanica, Chimica e dei Materiali, Università degli Studi di Cagliari, Via Marengo 3, 09123, Cagliari, CA, Italy.
Elisa
E
Sechi
Dipartimento di Ingegneria Meccanica, Chimica e dei Materiali, Università degli Studi di Cagliari, Via Marengo 3, 09123, Cagliari, CA, Italy.
Annalisa
A
Vacca
Nanofacility Piemonte INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135, Torino, Italy.
Eleonora
E
Cara
Nanofacility Piemonte INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135, Torino, Italy.
Natascia
N
De Leo
Nanofacility Piemonte INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135, Torino, Italy.
Matteo
M
Fretto
Nanofacility Piemonte INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135, Torino, Italy.
Luca
L
Boarino
4-Nitrobenzenediazonium grafting; Improved chemical resistance; Optical lithography; Porous silicon
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