A unique solid–solid transformation of silver nanoparticles on reactive ion-etching-processed silicon

Abstract

Processes that combine nanoparticle suspensions with micromechanical or microelectronics platforms can reveal new phenomena unique to nanoscale objects. We report that silver nanoparticles react with silicon wafers that have been patterned by reactive ion etching (RIE) in SF(6)/O(2) plasma. This reaction results in the localized deposition of silver on the patterns. Through the modification of the reaction conditions, the reaction mechanism was explored. Redeposition of the sputtered RIE products is suggested as the key to this transformation. The new silver deposition process was utilized to localize the growth of gold nanoparticles and silicon nanowires on the vertical sidewalls of patterns in silicon, demonstrating a simple route to the fabrication of overhanging nanoscale objects.

SERS Substrates by the Assembly of Silver Nanocubes: High-Throughput and Enhancement Reliability Considerations

“…During the electrophoretic deposition, surface reactions involving electroactive species from the solution cannot be excluded, however, to date no detrimental effects on the silver nanocubes were recognized by imaging or spectroscopy. During the vertical deposition, the nanocubes may react on defect sites in the surface of the silicon substrate [31]. These reactions can be prevented by following standard surface cleaning and passivation procedures.…”

“…Larger markers were patterned around the array to allow the user to recognize the position of the columns and rows of the array by optical microscopy. The etched silicon wafer was rinsed with acetone, treated with oxygen plasma, and cleaned with aqua regia to remove any residue from the patterning process [31]. An SEM image of the asprepared substrate is shown in Figure 1.…”