Consiglio Nazionale delle Ricerche

Tipo di prodottoArticolo in rivista
TitoloHigh Anodic-Voltage Focusing of Charge Carriers in Silicon Enables the Etching of Regularly-Arranged Submicrometer Pores at High Density and High Aspect-Ratio
Anno di pubblicazione2018
Autore/iChiara Cozzi, Giovanni Polito, Lucanos M. Strambini, Giuseppe Barillaro
Affiliazioni autoriIEIIT-CNR; Università di Pisa
Autori CNR e affiliazioni
  • inglese
AbstractThe anodic dissolution of silicon in acidic electrolytes is a well-known technology enabling the silicon machining to be accurately controlled down to the micrometer scale in low-doped n-type silicon electrodes. Attempts to scale down this technology to the submicrometer scale has shown to be challenging, though it premises to enable the fabrication of meso and nano structures/systems that would greatly impact the fields of biosensors and nanomedicine. In this work, we report on the electrochemical etching at high anodic voltages (up to 40 V) of two-dimensional regular arrays of millions pores per square centimeter (up to 30 × 106 cm-2) with sub-micrometric diameter (down to ~860 nm), high depth (up to ~40 ?m), and high aspect-ratio (up to ~45) using low-doped n-type silicon electrodes (resistivity 3-8 ? cm). The use of high anodic voltages, which are over one order of magnitude higher than that commonly used in electrochemical etching of silicon, tremendously improves hole focusing at the pore tips during the etching and enables, in turn, the control of electrochemical etching of submicrometer-sized pores when spatial period reduces below 2 ?m. A theoretical model allows experimental results to be interpreted in terms of an electric-field-enhanced focusing of holes at the tip apex of the pores at high anodic voltages, with respect to the pore base, which leads to a smaller curvature radius of the tip apex and enables, in turn, the etching of pore tips to be preferentially sustained over time and space.
Lingua abstractinglese
Altro abstract-
Lingua altro abstract-
Pagine da1
Pagine a9
Pagine totali9
RivistaFrontiers in Chemistry
Attiva dal 2013
Editore: Henry and Kamila Markram - Svizzera
Lingua: inglese
ISSN: 2296-2646
Titolo chiave: Frontiers in Chemistry
Numero volume della rivista6
Fascicolo della rivista-
Verificato da refereeSì: Internazionale
Stato della pubblicazionePublished version
Indicizzazione (in banche dati controllate)-
Parole chiavenanostructuring, anodization, porous silicon, submicrometer pores, carrier focusing, high voltage
Link (URL, URI)-
Titolo parallelo-
Data di accettazione-
Note/Altre informazioni-
Strutture CNR
  • IEIIT — Istituto di elettronica e di ingegneria dell'informazione e delle telecomunicazioni
Moduli/Attività/Sottoprogetti CNR
  • DIT.AD001.020.001 : MICROSYS - Microsistemi integrati e Elettronica di potenza
Progetti Europei-