Self-assembled Au nanoparticles in SiO2 by ion implantation and wet oxidation

Abstract

Implantation, annealing, and oxidation processes have been used to form Au nanoparticles with a narrow size and depth distribution in a SiO 2 layer. Different approaches have been attempted: in particular, the gettering of Au to fill preformed nanocavities ͑obtained by H-implantation and annealing͒ and thus overcome the broad particle size distribution that is normally associated with nanoparticles formed by implantation and annealing. The results suggest that nanocavities cannot be directly formed in SiO 2 by H-implantation and a subsequent annealing due partly to the high mobility of H atoms in SiO 2. However, cavities formed in Si are useful in obtaining a narrow size and depth distribution of Au precipitates: the Si substrate can then be oxidized to form Au nanoparticles in SiO 2. Sequential wet oxidations of Si samples containing Au nanoparticles have revealed several interesting phenomena, namely, segregation of Au particles at a growing oxide interface, Au-enhanced oxidation, dissolution and reprecipitation of Au precipitates during oxidation, and preferential wetting of Au on the oxide layer. In particular, the Au dissolution and reprecipitation processes are Si interstitial mediated. By completely oxidizing the top Si layer, an array of Au precipitates can be confined at a precise depth within a SiO 2 layer corresponding to the front interface of a buried oxide layer. The size distribution of the resulting Au precipitates in SiO 2 is smallest when Au is first gettered to cavities and vacancies are subsequently introduced into the Si layer prior to oxidation.

A Novel Non‐Enzymatic Glucose Sensor Based on Cobalt Nanoparticles Implantation‐Modified Indium Tin Oxide Electrode

“…The implantation process is low‐cost, facile and environmental friendly without the use of any other chemicals. Furthermore, due to the size of metallic nanoparticles on the substrate can be controlled just by the implantation condition, the implantation of metallic ions has been widely studied 30, 43–46. Therefore, metallic ion implantation is a promising and applicable method for the mass production of non‐enzymatic glucose sensors.…”

Gold-implanted plasmonic quartz plate as a launch pad for laser-driven photoacoustic microfluidic pumps

“…The photoacoustic launch pad was created by Au ion implantation in a 0.5-mm-thick quartz window at 60 keV to a dose of 6 ×10 16 per cm square (12–16). The acceleration voltage was chosen so that Au ions are implanted within 50 nm below the surface (12).…”