Advanced nanoscale material processing with focused ion beams

Abstract

Articles you may be interested inThe effects of carbon coating on nanoripples induced by focused ion beam Appl. Phys. Lett. 94, 073103 (2009); 10.1063/1.3054641 Producing metastable nanophase with sharp interface by means of focused ion beam irradiationWe present an approach for the generation of metallic Ga dots and In nano-crystallites which, in contrast to conventional bottom-up or top-down processes, is based on a subtractive self-organization process relying on material decomposition induced by focused ion beam exposure. The diameters of the Ga dots range from 120 to 850 nm with an aspect ratio of about 0.4 at a dot density of up to 7 ϫ 10 7 /cm 2 . Two-dimensional ordered arrays of freestanding dots were fabricated by a site control technique relying on prepatterned holes and an irradiation mediated migration and agglomeration. By the analogous technique we generated indium nanocrystallites on the (100) InAs surface with sizes ranging from about 50 nm to a few microns obviously due to a preferential loss of arsenic atoms during Ga + focused ion beam irradiation. The influence of the ion dose, the beam energy, and the dose rate on the surface evolution was investigated by atomic force microscopy, scanning electron microscopy, Auger electron spectroscopy, and x-ray diffraction measurements.

Mechanisms of nanodot formation under focused ion beam irradiation in compound semiconductors

“…The formation of metallic nanodots on III-V semiconductors under ion irradiation has been attributed to the preferential sputtering of the group V element, 9,19,25 followed by nucleation, growth and ripening of group III nanodots. A broader understanding of the FIB response of these materials is required for FIB directed tailoring of nanostructures to be used for demanding electronic and optoelectronic applications.…”

“…For instance, group III metallic nanodots and clusters show interesting optical qualities 1,2 that make them promising for use in negative index of refraction materials. [7][8][9][10] Both of these methods provide a simple synthesis route for the creation of nanostructures over large areas, but a drawback is that those nanostructures may be at random locations and in a distribution of sizes. 6 While it is possible to create group III dots by direct deposition of metal atoms on a surface, [3][4][5] it is also possible to induce their formation in compound semiconductors using ion irradiation.…”

“…The Ga + FIB response of GaAs, 7,10,11,14,15 InP, 13 InAs, 8 and GaSb ͑Refs. [7][8][9]11,12 The FIB-created metallic nanodots on GaAs and InAs have been identified as nearly pure Ga ͑Refs. FIB irradiation of InP, GaAs, and InAs in those studies has been shown to produce group III nanodots of varying sizes and morphologies, a phenomenon which has been attributed to preferential sputtering of the group V element followed by assembly of the excess group III atoms.…”

Real-time observation of FIB-created dots and ripples on GaAs

“…Another type of ion beam, namely the focused ion beam (FIB) of Ga + , has also been employed to grow and dope [19], tailor [20][21][22], and synthesize and self-assemble nanostructures [8,[22][23][24][25][26][27] on the GaAs(001) surface. It is indeed possible to create arrays of self-assembled quantum dots [8,[23][24][25][26] on GaAs(001) by FIB nanomachining. Ga dots with similar characteristics to the ones formed with Ar + [15][16][17], Cs + and O + 2 [18] ion beams were produced with 50 keV Ga + beams at normal incidence.…”

Suspended HOPG nanosheets for HOPG nanoresonator engineering and new carbon nanostructure synthesis

“…Carbon nanostructures can also be grown with electron and ion beam methods [34], and particularly with the focused ion beam (FIB) [35][36][37][38]. The FIB is not only a post-processing tool for microelectronics fabrication, but is also an instrument used to grow, synthesize, selfassemble, and tailor new nanoscale structures such as ripples [39], quantum dots [40][41][42], hollow bulk nanofins [43], nanometric holes [44][45][46], nanopores [47], nanocones [48] and nanodroplets [49,50]. In particular, new graphitebased micro-and nanostructures can be created by a FIB.…”