Electrical shielding box measurement of the negative hydrogen beam from Penning ion gauge ion source

The cold-cathode Penning ion gauge (PIG) type ion source has been used for generation of negative hydrogen (H(-)) ions as the internal ion source of a compact cyclotron. A novel method called electrical shielding box dc beam measurement is described in this paper, and the beam intensity was measured under dc extraction inside an electrical shielding box. The results of the trajectory simulation and dc H(-) beam extraction measurement were presented. The effect of gas flow rate, magnetic field strength, arc current, and extraction voltage were also discussed. In conclusion, the dc H(-) beam current of about 4 mA from the PIG ion source with the puller voltage of 40 kV and arc current of 1.31 A was extrapolated from the measurement at low extraction dc voltages.     

Comparative studies of parameters calibration for focused ion beam deposition

This paper describes the interaction between operating parameters of target wafer surface. We use an organometallic (C) precursor gas in the focused ion beam deposition process. Under the beam intensity conditions (30kV), the influences of the on-target beam control parameters, such as dwell time, beam spacing, minimum frame time and scan type, were investigated by the deposition tests. The analysis was carried out with the variation of dimensions and shapes of the single pattern. The operating parameters considered in this research are implemented in the next double-patterning deposition. The test presented how their interaction appeared on the processing results. The analysis configured out the FIB induced deposition of single pattern with the variation of operating parameters. Additionally the result shows that the sequent beam job influenced the double-patterning deposition significantly. On-beam target conditions should be optimized for the target complicated shapes and high aspect-ratios     

Influence of the configuration of the magnetic field of an ion diode on the parameters of an ion beam

The distribution of magnetic-field induction in the accelerating gap of an ion diode with external magnetic insulation is studied. The absence of a device for preliminary plasma production is a distinguishing feature of this diode. It is shown that a certain configuration of the magnetic field near the anode surface allows an increase in the ion-diode efficiency to 70%, and the ion-current density at the diode focus then reaches 350 A/cm².     

束流参数对光学镜面离子束加工去除函数的影响分析

在离子束光学镜面修形加工中,束函数的形状和大小决定了加工的修形能力和加工效率.虽然束函数的形状和大小可以通过一组工艺参数进行调节,然而,这组工艺参数对束函数影响的理论计算较为复杂,而且理论计算值与实验值也吻合的通常存在差异.为了找出工艺参数对束函数的影响规律,本文通过实验研究了离子束的几个主要的工艺参数(屏栅电压、屏栅电流、加速栅电压、中和极功率、氩气流量)对束函数的影响规律,建立了光学镜面离子束加工基本工艺参数数据库,为光学镜而离子束修形加工的工艺参数选择提供了指导依据.     

Quantification of hydrogen in solids by two methods of ion beam analysis

In any analytical problem, the question of rendering the measured data quantitative is demanding, and frequently sets the limit to the accuracy attainable. Quite typically dead-reckoning methods are not feasible, and one has to resort to the use of standards or reference materials. Two established methods of hydrogen analysis in solids are the nuclear resonance reaction techniques (traditionally fluorine-19 or nitrogen -15) and (heavy) ion elastic recoil scattering. The quantitative integrity of these two methods is tested as well as the limit of detection by using carefully prepared silicon samples which have been hydrogen-implanted to two different depths at different concentrations.The two techniques are shown to give linear calibration curves when referenced to the ion implantation data. However elastic recoil scattering is more rapid and sensitive than the resonance technique. Furthermore the substantially higher integrated doses associated with the resonance technique result in the production of mesa growths on diamond surfaces, which effect is not observed with the lower doses characteristic of elastic recoil scattering.     

Electrostatic energy analyzer measurements of low energy zirconium beam parameters in a plasma sputter-type negative ion source

A plasma sputter-type negative ion source is utilized to produce and detect negative Zr ions with energies between 150 and 450 eV via a retarding potential-type electrostatic energy analyzer. Traditional and modified semi-cylindrical Faraday cups (FC) inside the analyzer are employed to sample negative Zr ions and measure corresponding ion currents. The traditional FC registered indistinct ion current readings which are attributed to backscattering of ions and secondary electron emissions. The modified Faraday cup with biased repeller guard ring, cut out these signal distortions leaving only ringings as issues which are theoretically compensated by fitting a sigmoidal function into the data. The mean energy and energy spread are calculated using the ion current versus retarding potential data while the beam width values are determined from the data of the transverse measurement of ion current. The most energetic negative Zr ions yield tighter energy spread at 4.11 eV compared to the least energetic negative Zr ions at 4.79 eV. The smallest calculated beam width is 1.04 cm for the negative Zr ions with the highest mean energy indicating a more focused beam in contrast to the less energetic negative Zr ions due to space charge forces.     

H- beam extraction from a cesium seeded field effect transistor based radio frequency negative hydrogen ion source

H(-) beam was successfully extracted from a cesium seeded ion source operated using a field effect transistor inverter power supply as a radio frequency (RF) wave source. High density hydrogen plasma more than 10(19) m(-3) was obtained using an external type antenna with RF frequency of lower than 0.5 MHz. The source was isolated by an isolation transformer and H(-) ion beam was extracted from a single aperture. Acceleration current and extraction current increased with the increase of extraction voltage. Addition of a small amount of cesium vapor into the source enhanced the currents.     

Generation of an ion beam in a glow-discharge source

A mechanism of ion extraction from a glow-discharge ion source based on a hollow cathode and used for elemental analysis of solids, is considered Experiments have shown that two oppositely directed ion flows are formed from ions produced in the region of negative glow-discharge fluorescence. One flow has an ion energy ≥ 100 eV, is directed to the cathode, and bombards and sputters the analyzed sample. The sputtered atoms diffuse into the negative-glow region and are ionized. The second flow (low-energy ions) is extracted from the same negative-glow region and transported from the cathode to the surface of the anode chamber owing to an ambipolar diffusion. These ions are extracted from a hole in the anode chamber of a standard ion source by an electric field and are used for mass-spectrum analysis. The energy-distribution width for these ions is ∼5 eV. The intensity of the ion beam extracted from the anode hole is an order of magnitude higher than the intensity of the ion beam extracted from the cathode region. Original Russian Text ? G.G. Sikharulidze, 2009, published in Pribory i Tekhnika Eksperimenta, 2009, No. 2, pp. 105–109.     

The prospects of a subnanometer focused neon ion beam

The success of the helium ion microscope has encouraged extensions of this technology to produce beams of other ion species. A review of the various candidate ion beams and their technical prospects suggest that a neon beam might be the most readily achieved. Such a neon beam would provide a sputtering yield that exceeds helium by an order of magnitude while still offering a theoretical probe size less than 1-nm. This article outlines the motivation for a neon gas field ion source, the expected performance through simulations, and provides an update of our experimental progress.     

含氢氧化物陶瓷的水分裂与氢发射催化作用之离子束技术研究

Recently,we have proposed a new model of one Wav diffusion for the D-H replacement observed for D-implanted SrCeo.95 Yb0.05O3-δ exposed to air vapor at room temperature:absorption of H+ and adsorption of OH due to dipole induced splitting of H2O* physisorbed at the surface,diffusion of H+ in the bulk and emission of DH molecule due to local molecular recombination of H+ with D implanted in traps and subsequent trapping of H+ in the vacant trap.     

Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source

We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au(60 +). The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented.     

Experimental study of ion beam optics in a two-stage accelerator

Hydrogen ion beam optics in a two-stage linear acceleration system is studied by examining the beam divergence as a function of the voltage and gap distribution, the beam perveance, the background gas pressure, the aspect ratio, and the total accelerating energy (60-110 keV). The system consists of four electrodes with single, cylindrical, straight-bore apertures acting as an extraction-accel-decel column. An optimum relation between the field ratio and the extraction perveance is obtained from measurements for the minimum beam divergence condition. The HWHM divergence angle is <0.3 degrees under optimum conditions. Qualitative agreement between the measurements and a previous theoretical study is noticed. A potential application of the results to high energy neutral beam injectors for fusion research is also discussed.     

Ion optical design of a collinear laser-negative ion beam apparatus

An apparatus for photodetachment studies on atomic and molecular negative ions of medium up to heavy mass (M ? 500) has been designed and constructed. Laser and ion beams are merged in the apparatus in a collinear geometry and atoms, neutral molecules and negative ions are detected in the forward direction. The ion optical design and the components used to optimize the mass resolution and the transmission through the extended field-free interaction region are described. A 90° sector field magnet with 50 cm bending radius in combination with two slits is used for mass dispersion providing a resolution of M∕ΔM?800 for molecular ions and M∕ΔM?400 for atomic ions. The difference in mass resolution for atomic and molecular ions is attributed to different energy distributions of the sputtered ions. With 1 mm slits, transmission from the source through the interaction region to the final ion detector was determined to be about 0.14%.     

Microstructural tomography of a superalloy using focused ion beam microscopy

A focused ion beam (FIB) microscope has been used to simultaneously depth profile and image the γ–γ^′ microstructure of a nickel base superalloy using normal incidence milling in order to characterize the precipitate microstructure in three dimensions (3D). The normal incidence milling rates of the γ and γ^′ phases in this alloy are closely matched when the orientation of the depth-profiled surface is near , which allows for uniform material removal to depths up to a couple of microns. Depth-profiling experiments consisted of automated ion milling and collection of ion-generated secondary-electron images at specified intervals, and was demonstrated for a voxel resolution of roughly . Image-processing software was used for automated processing of the 2D image sequence to render the γ precipitate structure in 3D.     

Positron analysis as a quantitative technique in ion beam analysis

Ion beam analyses are most typically carried out by prompt in-situ measurement of charged particles or of electromagnetic radiation. Characteristically the excess of positive electric charge of the product nuclei, consequent on ion beam irradiation, has as a result a radioactive decay scheme in which positron emission occurs. This present analysis opportunities of considerable sensitivity and uniqueness. In many cases the lifetimes are short and special arrangements have to be made to get maximal advantage for analysis.     

A two-coordinate detector for a beam of atomic hydrogen or deuterium

The profile of an atomic beam in the region where it forms is an important characteristic of a polarized atomic hydrogen (or deuterium) source. A mathematical model for a two-coordinate resistive detector of atomic hydrogen beams is presented. Metering equipment and a technique for measuring an atomic beam profile are described, and the results of our measurements are presented.Translated from Pribory i Tekhnika Eksperimenta, No. 1, 2005, pp. 141–145.Original Russian Text Copyright © 2004 by Trofimov, Vasilev, Kovalev, Kravtsov.     

Production of a highly charged uranium ion beam with RIKEN superconducting electron cyclotron resonance ion source

A highly charged uranium (U) ion beam is produced from the RIKEN superconducting electron cyclotron resonance ion source using 18 and 28 GHz microwaves. The sputtering method is used to produce this U ion beam. The beam intensity is strongly dependent on the rod position and sputtering voltage. We observe that the emittance of U(35+) for 28 GHz microwaves is almost the same as that for 18 GHz microwaves. It seems that the beam intensity of U ions produced using 28 GHz microwaves is higher than that produced using 18 GHz microwaves at the same Radio Frequency (RF) power.     

A review of focused ion beam sputtering

This paper reviews the applications of focused ion beam (FIB) sputtering for micro/nano fabrication. Basic principles of FIB were briefly discussed, and then empirical and fundamental models for sputtering yield, material removal rate, and surface roughness were presented and compared. The empirical models were more useful for application compared to fundamental models. Fabrication of various micro and nano structures was discussed. Trimmed atomic force microscope (AFM) tips were tested in measurement and imaging of high aspect ratio nanopillars where higher accuracy and clarity were observed. Micromilling tool fabricated using FIB sputtering was used to machine microchannels. Slicing and dwell time control approaches on FIB sputtering were presented for the fabrication of three dimensional microcavities. The first approach is preferred for practical applications. The maximum aspect ratio of 13:1 of the microstructures was achieved. The minimum size of the nanopore was in the range of 2–10 μm. Cavities of microgear of 70 μm outside diameter were sputtered with submicrometer accuracy and 2–5 nm average surface roughness. The microcavities were then filled with polymer in a subsequent micromodling process. The replicated microcomponents were inspected with scanning electron microscope where faithful duplication of accuracy and surface texture of the cavity was observed.     

Investigations on the structure of the extracted ion beam from an electron cyclotron resonance ion source

Using improved beam diagnostic tools, the structure of an ion beam extracted from an electron cyclotron resonance ion source (ECRIS) becomes visible. Especially viewing targets to display the beam profile and pepper pot devices for emittance measurements turned out to be very useful. On the contrary, diagnostic tools integrating over one space coordinate like wire harps for profile measurements or slit-slit devices, respectively slit-grid devices to measure the emittance might be applicable for beam transport investigations in a quadrupole channel, but are not very meaningful for investigations regarding the given ECRIS symmetry. Here we try to reproduce the experimentally found structure on the ion beam by simulation. For the simulation, a certain model has to be used to reproduce the experimental results. The model is also described in this paper.     

Study on the sensitive element of ion beam etching depth

In this paper, a sensitive element of ion beam etching depth is studied and a formula is obtained. Experimental results show that the relative error of etching depth is smaller than 0.98%. This has a practical significance to ion beam micro-fabrication.