Beams of electrons and ions are now fairly routinely focused to dimensions in the nanometer range. Since the beams can be used to locally alter material at the point where they are incident on a surface, they represent direct nanofabrication tools. The authors will focus here on direct fabrication rather than lithography, which is indirect in that it uses the intermediary of resist. In the case of both ions and electrons, material addition or removal can be achieved using precursor gases. In addition ions can also alter material by sputtering (milling), by damage, or by implantation. Many material removal and deposition processes employing precursor gases have been developed for numerous practical applications, such as mask repair, circuit restructuring and repair, and sample sectioning. The authors will also discuss structures that are made for research purposes or for demonstration of the processing capabilities. In many cases the minimum dimensions at which these processes can be realized are considerably larger than the beam diameters. The atomic level mechanisms responsible for the precursor gas activation have not been studied in detail in many cases. The authors will review the state of the art and level of understanding of direct ion and electron beam fabrication and point out some of the unsolved problems.

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Gas-assisted focused electron beam and ion beam processing and fabrication

The fairly recent availability of commercial focused ion beam (FIB) microscopes has led to rapid development of their applications for materials science. FIB instruments have both imaging and micromachining capabilities at the nanometer–micrometer scale; thus, a broad range of fundamental studies and technological applications have been enhanced or made possible with FIB technology. This introductory article covers the basic FIB instrument and the fundamentals of ion–solid interactions that lead to the many unique FIB capabilities as well as some of the unwanted artifacts associated with FIB instruments. The four topical articles following this introduction give overviews of specific applications of the FIB in materials science, focusing on its particular strengths as a tool for characterization and transmission electron microscopy sample preparation, as well as its potential for ion beam fabrication and prototyping.

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Focused Ion Beam Microscopy and Micromachining

Cu specimens were exposed to Ga + ion bombardment for varying conditions of ion energy, ion dose, and incident angle in a focussed ion beam workstation Conventional transmission electron microscopy investigations were employed to analyze the Ga + ion induced damage The extent of visible damage was minimized by reducing the ion energy and furthermore by using grazing incident ions Concentration depth profiles of the implanted Ga were measured by Auger electron spectroscopy Concentrations of up to 20 at% Ga were found several nanometers below the surface Ga contents of more than 2 at% were detected within a depth of up to ∼50 nm Mechanical consequences in terms of possible hardening mechanisms are discussed, taking into account the experimental findings along with Monte Carlo simulations A non-negligible influence of the ion damage is predicted for submicron-sized samples

FIB damage of Cu and possible consequences for miniaturized mechanical tests

There is set forth herein an imaging terminal having an image sensor array and a variable lens assembly for focusing an image onto the image sensor array. In one embodiment, an imaging terminal can include one or more focusing configuration selected from the group comprising a full set focusing configuration, a truncated set focusing configuration and a fixed focusing configuration. When a full set focusing configuration is active, a full set of candidate focus settings can be active when the imaging terminal determines a focus setting of the terminal responsively to a trigger signal activation. When a truncated set focusing configuration is active, a truncated range of candidate focus settings can be active when the imaging terminal determines a focus setting of the terminal responsively to a trigger signal activation. When a fixed focusing configuration is active, the focus setting of the imaging lens assembly can be fixed so that a predetermined lens assembly focus setting is active when a trigger signal is active.

Imaging terminal having focus control

An optical imager includes: an image sensor for capturing images of targets and outputting image signals; a lens for focusing the target on the image sensor as a function of lens position; a memory for storing predetermined lens positions determined from predetermined target sizes; and a controller for determining current target size based on captured images and positioning the lens at a predetermined lens position by correlating current target size with predetermined target sizes.

Autofocusing optical imaging device

Calculation of Local Temperature Rise in Focused-Ion-Beam Sample Preparation

An object of the present invention is to provide a focused ion beam apparatus that is capable of obtaining a much larger beam current and forming a focused ion beam with smaller aberration than a conventional focused ion beam apparatus no matter whether the level of acceleration is high or low. The focused ion beam apparatus according to the present invention includes a liquid metal ion source, an extraction electrode for extracting an ion beam from the liquid metal ion source, an acceleration (ground) electrode for accelerating an ion beam, and an electrostatic lens for converging an ion beam. When the acceleration voltage applied to the liquid metal ion source is lower than an emission threshold voltage of the liquid metal ion source, the voltage of the extraction electrode is at a lower potential than the voltage of the acceleration (ground) electrode. The polarity of a voltage applied to the electrostatic lens changes in accordance with the polarity of a voltage applied to the extraction electrode. The present invention makes it possible to exercise a deceleration mode focusing method at a high acceleration voltage from the dielectric strength voltage of an electrostatic lens and exercise an acceleration mode focusing method at a low acceleration voltage with an electrostatic lens having the same focal length as for the deceleration mode focusing method.

Focused ION beam apparatus

An emitter of a Ga liquid metal ion source is constituted to include W12 of a base material and Ga9 of an ion source element covering a surface as construction materials. By making back-sputtered particles become elements (W and Ga) of the Ga liquid metal ion sour source, if back-sputtered particles attach to the Ga liquid metal ion source, contamination which may change physical characteristics of Ga9 does not occur. A W aperture is used as a beam limiting (GUN) aperture to place Ga of approx. 25 mg (of melting point of 30° C.) on a surface of a portion included in a beam emission region (Ga store). When emitting ions to the beam limiting (GUN) aperture, Ga in the emission region melts and diffuses on a surface of the beam emission region of the W aperture.

Liquid metal ion gun

A gradient charged particle beam apparatus capable of moving highly accurately to a specific position by eliminating influences of warp inside a wafer surface is provided. A portion 46 having a mark 47 for aligning visual field alignment positioned in advance to the same horizontal and the same height as a stage plane as a reference point is arranged on a wafer holder. A height of an observation point on a sample is adjusted to the height of the mark 47 and the visual field of a gradient column is brought into conformity with the visual field of a vertical column by use of a known offset between the gradient column and the vertical column at that time.

Wafer alignment method for dual beam system

PURPOSE:To make it possible to emit a low energy electron beam without reducing the velocity of the electron beam and at low field emission voltage, by keeping the distance between a cathode and an anode small using a specified work method. CONSTITUTION:It is possible to decrease a field emission voltage required for obtaining the density of a constant field emission current by shortening distance between a cathode 1 and an anode 9. A tungsten single crystal wire 6 is welded on the top position of a V-shaped welded tungsten filament 5, and fixed on an anode cylinder 10 through a support stem 7, insulation glass 8 and a pressure ring 11. A platinum disc 9 with a small hole in its center is placed at the aperture part of the anode cylinder 10. A minute distance is formed by electropolishing between plate 9 and cathode 1 after polishing wire 6, under such a condition that wire 6 is isolated from the edge of the hole of plate 9. Because of this distance, the electron beam with low energy can be emitted at a low voltage.

Hiroyasu Kaga

Papers

Calculation of Local Temperature Rise in Focused-Ion-Beam Sample Preparation

Focused ION beam apparatus

Liquid metal ion gun

Wafer alignment method for dual beam system

Field emission cathode