Nanoparticle formation in Au thin films by electron-beam-induced dewetting

Abstract

We carried out investigations on electron-beam-induced nanoparticle formation in thin (5-30 nm) Au films on smooth SiO(2)/Si substrates. When the Au films were irradiated with an electron beam, the Au films broke up into nanoparticles through the dewetting process. The dominant wavelengths of the surface (corresponding to the pitch between nanoparticles) were closely related with the thickness of the Au. We then developed a new technique for the formation of periodically arranged Au nanoparticles using a holed substrate. The nanoholes induced heterogeneous nucleation and helped to form ordered nanoparticles between the holes. Two-dimensionally, periodically arranged Au nanoparticles with a pitch of 100 nm were obtained.

Effects of ion and nanosecond-pulsed laser co-irradiation on the surface nanostructure of Au thin films on SiO2 glass substrates

“…13 Metallic nanostructures can be prepared on the surface of metallic thin films deposited on dielectric or semiconductor substrates via irradiation of the surface with a quantum beam such as an ion beam, [14][15][16][17][18][19][20][21][22][23] nanosecond-pulsed laser, 24,25 or electron beam. 26 Surface nanostructures are formed by dewetting caused by irradiation with a quantum beam. [14][15][16][17][18][19][20][21][22][23][24][25][26] Under ion irradiation, metal nanoparticles that form on the surface through the dewetting process become embedded in SiO 2 glass 21,23 and Al 2 O 3 22 substrates because the viscosity of the substrate changes and it undergoes plastic flow during ion irradiation.…”

“…26 Surface nanostructures are formed by dewetting caused by irradiation with a quantum beam. [14][15][16][17][18][19][20][21][22][23][24][25][26] Under ion irradiation, metal nanoparticles that form on the surface through the dewetting process become embedded in SiO 2 glass 21,23 and Al 2 O 3 22 substrates because the viscosity of the substrate changes and it undergoes plastic flow during ion irradiation. 16,19 Laser-induced periodic surface structures (LIPSS) can be obtained via nanosecond-pulsed laser irradiation.…”

Ion irradiation synthesis of Ag–Au bimetallic nanospheroids in SiO2 glass substrate with tunable surface plasmon resonance frequency

“…1(b)) after thermal annealing because of the thermal induced homogeneous nucleation. 28,46 Asdeposited SiO 2 is quite different from the ion irradiated samples. With increasing irradiation fluence, the process of bimetallic film evolution under Ar-ion irradiation is clearly observed, with the formation of isolated photosensitive nanospheroids.…”

“…Purely chemical synthetic routes such as innovative colloidal self-assembly, [18][19][20]24,26 lithography methods such as electron beam lithography 28 and nanosphere lithography, 27,29 thermal deposition, 25 laser irradiation, 30 ion implantation and consequent annealing, 31,32 and ion irradiation and subsequent annealing [33][34][35] have been developed for manufacturing high efficiency platforms for the LSPR-based sensors. Nowadays, colloidal chemistry can produce a myriad of metal NPs in solutions with a variety of morphologies from sphere to complex core-shell, with very good control of the size distribution; [17][18][19][20][21][22][23] this control over the size, composition, and morphology of the NPs in a system can produce dramatically different absorption features in the visible or near-infrared spectrum.…”

Numerical simulations of nanostructured gold films

“…1). This is a simplification of the real structures, which have uneven height and less sharp walls, as they (1) are formed by partial melting and merging of several particles and (2) surface tension of molten gold forces particles to have a more round shape [4]. However, we expect that the effect of this slightly non-realistic shape is minimal and affects only the resonance position, but the general response of the particles is expected to stay the same.…”