Focused ion beam

About: Focused ion beam is a research topic. Over the lifetime, 12154 publications have been published within this topic receiving 179523 citations. The topic is also known as: FIB.

Real-time observation of ripple structure formation on a diamond surface under focused ion-beam bombardment

Abstract: Ripple structures on a diamond surface are created and imaged in real time by focused ion-beam bombardment, and further examined by atomic force microscopy. Beyond a critical incidence angle depending on the ion energy, a ripple structure emerges, and its wavelength remains constant until it breaks down at \ensuremath{\sim}75\ifmmode^\circ\else\textdegree\fi{}. The wavelength is independent of the ion flux, but increases linearly with energy. Addition of a conjectured term representing the redistribution of ion-induced surface species to Makeev, Cuerno, and Barab\'asi's equation allows a quantitative description of the wavelength dependence on the incidence angle.

Focused-Ion-Beam Fabrication of Slanted Grating Couplers in Silicon-on-Insulator Waveguides

Abstract: We have designed and fabricated an efficient grating coupler for coupling light between optical fibers and silicon-on-insulator waveguides. The coupler consists of 88-nm-wide slits, etched at an angle of 58deg to the surface normal. They are defined by direct etching with a focused ion beam, using iodine gas and an alumina hard mask. The measured efficiency is 46%

Nanomanipulator and actuator fabrication on glass capillary by focused-ion-beam-chemical vapor deposition

Abstract: Three-dimensional (3D) nanostructures on a glass capillary have a number of useful applications such as manipulators, actuators, and sensors in the various microstructures. We observed a phenomenon that two diamondlike-carbon pillars on a tip of glass capillary fabricated by 30 keV Ga+ focused-ion-beam-chemical vapor deposition (FIB-CVD) with a precursor of phenanthrene vapor was able to work as a manipulator during FIB irradiation. It became clear that it was caused by electronic charge repulsion between two pillars, which accumulated electric charge by FIB irradiation. By applying this moving mechanism, we have developed a 3D nanomanipulator and actuator on a tip of glass capillary by FIB-CVD. Furthermore, in situ observations of movement for a 3D nanomanipulator and actuator have been demonstrated by applying voltage onto a Au-coated glass capillary.

Scanning probe tip geometry optimized for metrology by focused ion beam ion milling

Abstract: We have developed a novel technique for producing tips for scanning probe microscopy. The shape of the tip is optimized for applications where high aspect ratio surfacetopography is the norm, as with integrated circuit structures. The technique involves focused ion beam(FIB)milling of a tip which was previously shaped to a nominal geometry by electrochemical etching. The ion milling pattern is annular, and the ion beam is collinear with the axis of the tip. The process allows control of the ion milling dose using 20 keV Ga+ with submicron control of the annular patterns. The result is a narrow, tapered structure approximately 20 μm in length which ends in a point with a radius of curvature between 30 and 50 nm when grains dominate the sputter process, and radii of about 3–4 nm when there is no evidence of grain structure effects. This microstructure is 3 μm in diameter at the base and it protrudes from a portion of the shank of the macrostructure where the diameter is about 15 μm. We have sufficient control over the sputter process to yield the final tip length, taper, and radius. Cone angles between 12° and 15° over the first two microns from the apex can be achieved routinely, by the correct choice of annulus and ion dose. Sputter simulations predict the correct shape of the final tip profile, and show the effect of varying the ion beam focus, dose, and inner and outer annulus radii. Tips with the desired geometry have been produced in polycrystalline tungsten, iridium, and platinum‐iridium. Significant improvements in scanning tip microscopy(STM) images have been consistently observed with these FIB milled tips.

Focused Ion Beam Nanopatterning for Optoelectronic Device Fabrication

Abstract: Recent photonic device structures, including distributed Bragg reflectors (DBRs), one-dimensional (1-D) or two-dimensional (2-D) photonic crystals, and surface plasmon devices, often require nanoscale lithography techniques for their device fabrication. Focused ion beam (FIB) etching has been used as a nanolithographic tool for the creation of these nanostructures. We report the use of FIB etching as a lithographic tool that enables sub-100-nm resolution. The FIB patterning of nanoscale holes on an epitaxially grown GaAs layer is characterized. To eliminate redeposition of sputtered materials during FIB patterning, we have developed a process using a dielectric mask and subsequent dry etching. This approach creates patterns with vertical and smooth sidewalls. A thin titanium layer can be deposited on the dielectric layer to avoid surface charging effects during the FIB process. This FIB nanopatterning technique can be applied to fabricate optoelectronic devices, and we show examples of 1-D gratings in optical fibers for sensing applications, photonic crystal vertical cavity lasers, and photonic crystal defect lasers.