WO2011132767A1

WO2011132767A1 - Gas field ionization source and ion beam device

Info

Publication number: WO2011132767A1
Application number: PCT/JP2011/059895
Authority: WO
Inventors: 川浪義実
Original assignee: 株式会社日立ハイテクノロジーズ
Priority date: 2010-04-22
Filing date: 2011-04-22
Publication date: 2011-10-27

Abstract

Disclosed is a gas field ionization source (GFIS) that enables the inclination of an emitter chip to be adjusted, and the operation of which is stable and low cost. The gas field ionization source (GFIS) comprises a support body having a first reference surface perpendicular to the ion optical axis, a chip assembly comprising a base having an emitter chip and a second reference surface, and an inclined spacer positioned between the chip assembly and the support body. The inclined spacer has a fourth reference surface and a third reference surface that is inclined in relation to the fourth reference surface.

Description

Gas ionization ion source and ion beam apparatus

The present invention relates to a gas electrolytic ionization ion source and an ion beam apparatus using the same.

Patent Documents 1 and 2 are equipped with a gas field ionization ion source (Gas Field Ionization Ion Source, abbreviated as GFIS) and focused using gas ions such as hydrogen [H2], helium [He], neon [Ne], etc. An ion beam (abbreviated as FIB) apparatus is disclosed. These gas focused ion beams (abbreviation: gas FIB) are gallium [Ga: metal] focused ion beams (abbreviation: Ga--) from a liquid metal ion source (Liquid-Metal-Ion-Source, abbreviated as LMIS), which is often used at present. As in FIB), there is an advantage that the sample does not cause gallium [Ga] contamination. In addition, the gas ionization ion source (GFIS) is finer than the gallium focused ion beam (Ga-FIB) because of the narrow energy width of gas ions extracted from it and the small ion source size. A simple beam can be formed.

On the other hand, in Patent Document 3 and Non-Patent Document 1, by forming a minute protrusion at the tip of the emitter tip of the GFIS, or by reducing the number of atoms at the tip of the emitter tip to several or less, the radiation angle current of the ion source. It is disclosed that ion source characteristics are improved, such as an increase in density. As a manufacturing example of such a minute protrusion at the tip of the emitter chip (hereinafter referred to as a nanochip), in Non-Patent Document 1 and Patent Document 2, it is manufactured by using field evaporation from an emitter chip made of tungsten [W: metal]. It is disclosed. In this case, the nanotip is one or three atoms terminating in the [111] direction of the tungsten single crystal (W single crystal). In Non-Patent Document 2 and Patent Document 4, a nanochip is manufactured using a second metal material (for example, iridium [Ir]) different from the first metal material (for example, tungsten [W]) of the emitter chip. Is disclosed. In this case, the nanochip is a pyramid made of iridium [Ir], platinum [Pt], or the like formed at the end of the W single crystal in the [111] direction.

By the way, the emission angle of ions emitted from one atom at the tip of the nanotip is as narrow as about 1 °. Therefore, in an FIB apparatus equipped with a GFIS having a nanotip, means for aligning the emission direction of ions emitted from the nanochip with the optical axis of the subsequent ion optical system, that is, the ion optical axis, that is, the tilt adjustment means of the emitter chip is provided. I need it. This tilt adjusting means not only simply passes the ion beam through the ion optical system, but also serves to reduce excess aberrations generated by the electrostatic lens in the ion optical system. Normally, the position of the emitter tip with respect to the ion optical axis is adjusted. However, even if this is adjusted so that the emitted ions pass through the center of the electrostatic lens, if the tilt of the nanotip is large, an uncorrectable coma is used. This is because the aberration increases and the resolution of the FIB apparatus is lowered.

As for the tilt adjusting means of the emitter tip for ions and electrons, for example, in a GFIS having a nanotip as described in Patent Document 2, an emitter is provided by a gimbal mechanism provided on the atmosphere side of the ion source chamber. A method for adjusting the tilt of the tip is conventionally known. The tilt adjustment of the emitter tip by this gimbal mechanism is a method generally used in the FIB apparatus using GFIS.

Further, Patent Document 5 describes a method of attaching an emitter tip to a semi-fixed holder provided with a gimbal mechanism and attaching the holder to an ion source. Further, Patent Document 6 describes a method of effectively adjusting the inclination of the emitter tip by changing the electron emission direction by shifting the position of the emitter tip with respect to the extraction electrode.

Japanese Patent Laid-Open No. 7-192669 Special table 2009-517846 gazette JP 58-85242 A JP 2008-140557 A JP-A-62-51134 Japanese Patent Laid-Open No. 2002-216686

In order to operate the gas field ion source (GFIS) stably, it is necessary to set the base pressure in the vacuum vessel in which the emitter tip is stored (that is, the pressure before gas introduction) to an ultra-high vacuum. Further, in the focused ion beam (FIB) apparatus using GFIS, the vibration of the emitter tip is left as it is, which is the vibration of the ion beam on the sample, that is, the blur, and therefore, a design for suppressing the vibration of the emitter tip is necessary.

However, the gimbal mechanism generally used for adjusting the tilt of the emitter tip needs to be moved several centimeters on the atmosphere side in order to adjust the tilt of the emitter tip by several degrees. For this reason, the vacuum bellows necessary for airtightly defining the inside of the vacuum container in which the emitter chip is stored has to be large in diameter and long.

As a result, in the conventional GFIS and FIB apparatus in which the tilt adjustment of the emitter tip is performed by the gimbal mechanism, the surface area of the bellows is increased, so that the cost for the vacuum pump is increased to achieve ultrahigh vacuum, During the raising, the vacuum vessel is heated to increase the baking time for promoting the achievement of the ultra vacuum. Further, as the bellows becomes longer, the portion that supports the emitter tip is moved away from the vessel wall of the vacuum vessel, and external low-frequency vibration is easily transmitted to the emitter tip. Furthermore, since the gimbal mechanism moves the mechanism in a state where atmospheric pressure is applied by several centimeters, the drive device becomes large.

The present invention has been made to solve the above-described problems, and provides a gas field ion source (GFIS) capable of adjusting the tilt of an emitter tip, stable in operation, and low in cost. Objective.

In addition, the present invention provides an ion beam apparatus that facilitates adjustment of the axis of the ion beam and reduces the blur of the sample image by mounting such a gas field ion source (GFIS) in the ion beam apparatus. The purpose is to do.

A gas field ion source (GFIS) according to the present invention includes a support having a first reference surface arranged perpendicular to the ion optical axis, and a chip assembly including an emitter tip and a base having a second reference surface. And an inclined spacer disposed between the chip assembly and the support, and the inclined spacer has a fourth reference surface and a third reference surface inclined with respect to the fourth reference surface.

Here, the inclination azimuth of the ion emission direction from the emitter tip with respect to the direction perpendicular to the second reference plane of the base of the emitter tip is measured in advance. The tip assembly is mounted on the third reference surface of the inclined spacer so that the inclination direction of the ion emission direction from the emitter tip coincides with the maximum inclination direction of the third reference surface of the inclined spacer. Thereby, the direction of ion emission from the emitter tip is parallel to the ion optical axis.

Also, this chip assembly is associated with accessible tilt data (direction angle, tilt angle, etc.) of the fixed emitter chip.

Also, an ion beam apparatus equipped with a gas field ion source (GFIS) according to the present invention includes an aligner with a two-stage electrostatic deflector between two stages of electrostatic lenses. This aligner has a function of guiding the ion beam that has passed through the first-stage electrostatic lens to the second-stage electrostatic lens so that its source position does not move.

In the gas field ion source (GFIS) according to the present invention, a horizontal fine movement mechanism for adjusting the horizontal position of the tip of the emitter tip and a gimbal mechanism for adjusting the inclination of the emitter tip are provided. Yes. The moving amount and moving range of the movable part in the gimbal mechanism are smaller than the moving amount and moving range of the movable part in the horizontal fine movement mechanism.

According to the gas field ion source (GFIS) according to the present invention, since the adjustment of the tilt of the emitter tip is completed when the emitter tip is mounted, a complicated operation of adjusting the tilt of the emitter tip using the ion beam apparatus is not necessary. , Device cost required for the control can be reduced.

In addition, according to the ion beam apparatus of the present invention, the vacuum degree (base vacuum degree) serving as the base of the gas field ion source (GFIS) is improved, and the emitter tip is hardly affected by external vibration. Beam stability and focusing can be improved.

Also, the gas field ionization ion source (GFIS) according to the present invention can make the movable range of the gimbal mechanism less than or equal to the movable range of the horizontal fine movement mechanism, so that the entire ion source can be made small.

1 is an overall configuration diagram of an ion beam apparatus according to a first embodiment of the present invention. It is a block diagram of the gas field ionization ion source (GFIS) shown in FIG. It is a block diagram of the chip | tip assembly of the field ionization ion source (GFIS) shown in FIG. It is a block diagram of the support body of the field ionization ion source (GFIS) shown in FIG. It is a block diagram of the inclination spacer of the field ionization ion source (GFIS) shown in FIG. It is an external view of the state which attached | assembled the chip assembly to the inclination spacer. It is an external view of the state which assembled | attached the inclination spacer to which the chip assembly was fixed to the support body. It is a block diagram of the ion emission direction measuring apparatus used for the measurement of the ion emission direction of a chip assembly. It is a block diagram of the ion emission direction measuring apparatus used for the measurement of the ion emission direction of a chip assembly. It is a block diagram of the inclination spacer of the gas field ionization ion source (GFIS) of the ion beam apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram of the gas field ionization ion source (GFIS) of the ion beam apparatus which concerns on the 3rd Embodiment of this invention. It is a whole block diagram of the ion beam apparatus which concerns on the 4th Embodiment of this invention. It is basic operation explanatory drawing of the two-stage aligner with which the ion beam apparatus of the 4th Embodiment was equipped. It is basic operation explanatory drawing of the two-step aligner with which the ion beam apparatus which concerns on the 5th Embodiment of this invention was equipped. It is a block diagram of the gas field ionization ion source (GFIS) of the ion beam apparatus which concerns on the 6th Embodiment of this invention.

Embodiments of the gas field ion source (GFIS) and ion beam apparatus according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is an overall configuration diagram of an ion beam apparatus according to the present embodiment.

The ion beam apparatus 200 of the present embodiment is a conventional focused ion beam (FIB) apparatus, which uses a gas field ion source (described later) of the present invention instead of the conventional gallium-liquid metal ion source (Ga-LMIS). GFIS) 100 is incorporated.

In FIG. 1, an ion beam apparatus 200 is configured such that an ion beam 5 emitted from the GFIS 100 enters an ion optical system 300, is focused by the ion optical system 300, and moves on a sample 6 placed on a sample stage 101. It is configured to irradiate.

The GFIS 100 includes an emitter tip 1, an extraction electrode 2, and a gas discharge port 3 of a gas supply pipe 30 that supplies an ionization gas to the tip of the emitter tip. The emitter tip 1 ionizes a gas supplied from the gas discharge port 3 and located at the tip of the tip by a high voltage (for example, a positive high voltage) applied from the extraction voltage application unit 4. The extraction electrode 2 extracts ions generated by the emitter tip 1 based on the extraction voltage (in this case, a negative extraction voltage) applied from the extraction voltage application unit 4, and extracts the ion beam 5 from the ion optical system 300. To release as.

The ion optical system 300 includes a lens system 102 including electrostatic lenses 102-1 and 102-2, a beam limiting aperture 102-3, and an aligner 102-4, and a deflection system 103 including deflectors 103-1 and 103-2. It has. The ion beam 5 incident on the ion optical system 300 is focused by the electrostatic lenses 102-1 and 102-2 and irradiated onto the sample 6. In addition, the irradiation position of the ion beam 5 on the sample 6 at that time is adjusted by deflecting the ion beam 5 by the deflectors 103-1 and 103-2.

At that time, the lens system 102 including the electrostatic lenses 102-1 and 102-2, the beam limiting aperture 102-3, and the aligner 102-4 is matched by the lens system controller 105 with the corresponding drivers 102-1 'to 102-4. 'The drive is controlled and controlled. The lens system controller 105 also controls the ion beam 5 emitted from the ion optical system 300 by driving and controlling the extraction voltage application unit 4. On the other hand, the deflection system 103 including the deflectors 103-1 and 103-2 is controlled by the deflection system controller 106 by driving and controlling the corresponding drivers 103-1 'and 103-2'.

Then, the secondary electrons 7 generated from the sample 6 by the irradiation of the ion beam 5 described above are detected by the secondary electron detector 104, converted into a digital signal via the A / D signal converter 104 ′, and The display 110 including the image generation unit forms a secondary electron observation image in which the signal intensity corresponds to the deflection intensity. The user can designate the position of irradiation with the ion beam 5 on the screen while viewing the secondary electron observation image using the display device 110.

Note that a portion for performing overall control of these

controllers

105 and 106 and the display 110 is not shown in FIG.

FIG. 2 is a block diagram of the gas field ion source (GFIS) shown in FIG. In the present embodiment, the atmosphere in which the emitter tip 1, the extraction electrode 2, and the gas emission port 3 are arranged is set to an ultrahigh vacuum independently of the atmosphere in the ion optical system 300 in which the lens system 102 and the deflection system 103 are arranged. I can keep it. For this purpose, the vacuum container 10 that houses the emitter chip 1 and the like is formed by a housing that is independent from an ion optical system housing (not shown) that houses the devices of the ion optical system 300. Thereby, the gas field ion source (GFIS) 100 is unitized.

The vacuum vessel 10 includes an exhaust port 11, each mounting port 12 (ion source sub-unit mounting port 12-1, cooling head mounting port 12-2, high voltage introduction terminal mounting port 12-3, gas supply pipe introduction port 12-4. ), And a box body in which the working exhaust port 13 is formed. The inside of the vacuum vessel 10 is maintained at an ultrahigh vacuum of a digit value of 10 ⁻⁸ Pa, for example, by an exhaust system (not shown) connected to the exhaust port 11. The working exhaust port 13 is an opening for emitting the ion beam 5 to the ion optical system 300. The vacuum vessel 10 is integrally attached to the ion optical system housing, and the internal exhaust is independent of the ion optical system 300 by the exhaust system with the working exhaust port 13 as a boundary. Is possible. The working exhaust port 13 is disposed and formed on the wall portion of the vacuum vessel 10 opposite to the wall portion where the ion source subunit mounting port 12-1 is formed so as to face the ion source subunit mounting port 12-1. ing.

The extraction electrode 2 is provided in the vacuum vessel 10 so that the beam extraction hole is coaxial with the working exhaust port 13 and is supported by a support member 14 erected on the inner wall of the vessel. At least a part of the support member 14 is formed by an insulating member 14 ′, and insulation between the extraction electrode 2 and the vacuum vessel 10 is removed. The extraction electrode 2 is connected to a high voltage introduction terminal 40-2 attached to the high voltage introduction terminal attachment port 12-3, and is supplied with an extraction voltage from the extraction voltage application unit 4. The gas supply pipe 30 is introduced into the vacuum vessel 10 through the gas supply pipe introduction port 12-4, and supplies a gas to be ionized from the gas discharge port 3 disposed in the vicinity of the tip of the emitter chip 1. The proximal end side of the gas supply pipe 30 is connected to a gas cylinder 31 via a valve 32. In the gas supply pipe 30, the gas discharge port 3 is made of oxygen-free copper with good heat transfer, and the portion other than the gas discharge port 3 is made of stainless steel with poor heat conduction. Further, the gas discharge port 3 is supported in the vacuum vessel 10 by a heat transfer support 22-2 made of oxygen-free copper having good heat transfer. In addition, a bent portion is formed in the middle portion of the gas supply pipe 30 in the vacuum vessel 10 to increase the heat conduction distance and prevent heat from entering from the outside.

In the example shown in the figure, the ion source subunit is composed of a horizontal fine movement mechanism 450, a terminal mounting portion 45 to which the high voltage introduction terminal 40-1 is mounted, and a plurality of thin stainless steel pipes to block heat from entering from the outside. A heat insulating support 24-1, an annular heat transfer support 22-1 formed of oxygen-free copper, a hollow columnar heat transfer insulator 23-1 formed of sapphire, and an emitter chip 1. The chip assembly 500 includes a support 400 that is positioned and mounted with an inclined spacer 600 interposed therebetween.

In this ion source subunit, a terminal mounting portion 45 is integrally connected and fixed to the movable portion 46 of the horizontal fine movement mechanism 450. The terminal mounting portion 45 is connected and fixed integrally with the heat transfer support 22-1 with the heat insulating support 24-1 interposed therebetween. The base of the heat transfer insulator 23-1 is fitted and fixed in the hole of the annular heat transfer support 22-1. A support 400 is attached and fixed to the tip of the heat transfer insulator 23-1. In these integrally connected and fixed states, the movable portion 46 of the horizontal fine movement mechanism 450 and the heat transfer insulator 23-1 are positioned and fixed coaxially. Further, the support 400 is mounted and fixed coaxially to the heat transfer insulator 23-1. As a result, the central axis of the movable portion 46 of the horizontal fine movement mechanism 450 is coaxial with the central axis of the support 400.

The horizontal fine movement mechanism 450 includes a disk-shaped annular base (fixed portion) 47, a movable portion 46 inserted with a gap in the central hole of the annular base, and the movable portion 46 disposed in the central hole of the annular base 47. And a positioning mechanism for adjustment. On the outer periphery of the movable part 46, a flange part for supporting the movable part 46 on the surface sliding surface 452 of the annular base is formed. The flange portion has a larger diameter than the center hole of the annular base 47. The movable portion 46 is supported by the annular base 47 so that the flange surface of the flange portion is brought into contact with the surface sliding surface 452 of the annular base 47 so as to be finely movable. The positioning mechanism includes a push rod 453 and a compression spring 454 that are disposed on the annular base 47 so as to sandwich the flange portion of the movable portion 46 in the radial direction. Accordingly, the position of the movable portion in the center hole of the annular base 47 can be adjusted by adjusting and fixing the advance / retreat position of the push rod 453 against the urging force of the compression spring 454.

In the horizontal fine movement mechanism 450, the back surface of the annular base 47 is in contact with the outer surface of the vacuum vessel 10 so that the center hole of the annular base 47 and the ion source subunit mounting port 12-1 of the vacuum vessel 10 are coaxial. The vacuum vessel 10 is airtightly attached and fixed. At that time, the ion source subunit mounting opening 12-1 of the vacuum vessel 10 is connected to each part of the ion source subunit arranged in the vacuum vessel 10 including the movable portion 46 and the terminal mounting portion 45 of the horizontal fine movement mechanism 450. It is formed larger than the width dimension. Therefore, the ion source subunit can be attached and fixed to the vacuum vessel 10. In addition, a vacuum bellows 451 is provided between the back surface of the surface sliding surface 452 of the annular base 47 of the horizontal fine movement mechanism 450 and the terminal mounting portion 45 so as to surround the movable portion 46. Thus, the vacuum bellows 451 need only be provided so as to define the surface sliding surface 452 of the annular base 47 of the horizontal fine movement mechanism 450 with respect to the inside of the vacuum vessel 10. Thereby, the surface area of the vacuum bellows 451 is suppressed.

An applied voltage is applied to the emitter chip 1 from the extraction voltage applying unit 4 through the high voltage introduction terminal 40-1 mounted on the terminal mounting unit 45. For ionization, only one wiring for applying a potential to the emitter chip 1 through the high voltage introduction terminal 40-1 is sufficient. In the present embodiment, there are two wires for heating the filament part at the base of the emitter chip 1.

A cooling head 20 (for example, connected to a Gifford-McMahon refrigerator) is connected to the cooling head mounting port 12-2 of the vacuum container 10 from the outside of the container. The cooling head 20 includes a heat transfer support 22-1 of the ion source subunit via a heat transfer net 21-1 made of oxygen-free copper and a heat transfer net 21-2 made of oxygen-free copper. To the heat transfer support 22-2 that supports the gas discharge port 3 portion. These heat transfer nets 21-1, 21-2, and heat transfer supports 22-1 and 22-2 are further plated with gold in order to reduce heat radiation.

As a result, the emitter chip 1 is connected to the cooling head 20 introduced from the outside of the vacuum vessel 10, and the heat transfer mesh wire (oxygen-free copper) 21-1 and the heat transfer support (oxygen-free copper) 22-1. , And heat exchange through the heat transfer insulator (sapphire) 23-1. Further, the gas discharge port 3 portion (oxygen-free copper) is connected to the cooling head 20 with a heat transfer network wire (oxygen-free copper) 21-2 and a heat transfer support (oxygen-free copper) 22-2. It is cooled by exchanging heat through it.

As a result, since the heat transfer of each member is good, the emitter tip 1 and the gas discharge port 3 are cooled to substantially the same temperature. In addition, heat entry from the outside is prevented by making the portions of the ion source subunit excluding the heat insulating support 24-1 and the gas outlet 3 of the gas supply pipe 30 made of stainless steel having poor thermal conductivity. Has been. Some heat shield walls may be added to keep the temperature of each part stable.

In the gas field ion source (GFIS) 100 of the present embodiment configured as described above, the iridium [Ir] is formed as the emitter tip 1 on the [111] crystal face at the tip of the single crystal of tungsten [W]. ] Which formed an atomic pyramid of Helium [He] was used as a gas to be ionized. The temperatures of the emitter tip 1 and the gas discharge port 3 were maintained at about 60K. In this case, the extraction voltage of ions by the extraction electrode 2 is about 4 kV. In addition, in the GFIS 100, when a positive applied voltage is applied to the emitter tip 1 and a negative extracted voltage is applied to the extraction electrode 2 by the extraction voltage application unit 4, the gas is emitted from the gas discharge port 3 at a certain point. Some of the gas atoms (which may be molecules) that have reached the tip of the emitter tip 1 become positive ions due to field ionization, and ion emission occurs.

Next, the tilt adjustment of the emitter tip 1 of the gas field ion source (GFIS) 100 according to the present embodiment will be described. Here, the tilt adjustment of the emitter tip 1 is for adjusting (paralleling) the ion emission direction 506 from the emitter tip 1 to the ion optical axis 301 of the ion optical system 300 as shown in FIG. Refers to adjustment.

In the GFIS 100 according to the present embodiment, the direction of ion emission from the emitter tip 1 is determined by adjusting the bonding of (1) the support 400, (2) the inclined spacer 600, and (3) the tip assembly 500. Can be determined. That is, these are tilt adjusting means for the ion emission direction 506 of the emitter tip 1.

The support 400 is coupled to a horizontal fine movement mechanism 450 that finely moves in a plane perpendicular to the ion optical axis 301, and the horizontal fine movement mechanism 450 is a horizontal position adjusting means of the emitter chip 1.

Here, in the vacuum vessel 10, the distance between the emitter tip 1 and the extraction electrode 2 is usually separated by 1 mm or more. Therefore, the ion emission direction 506 is hardly affected by the positional deviation in the horizontal plane. If both are very close, the ion emission direction 506 may be affected, but this is not desirable. The reason is that if they are brought too close together, deflection chromatic aberration is generated, leading to blurring of the sample image.

In the GFIS 100 of the present embodiment, the ion emission direction 506 and the ion optical axis 301 are basically aligned by assembling the chip assembly 500, the inclined spacer 600, and the support body 400 with each other in an appropriate positional relationship (parallel). Can). Therefore, the mechanical axis alignment necessary for the ion beam apparatus 200 after the emitter tip 1 is attached only needs to be adjusted by the horizontal fine movement mechanism 450.

FIG. 3 is a configuration diagram of the chip assembly 500. In FIG. 3, it is displayed upside down from FIG. 2 so that the configuration can be easily grasped.

The emitter chip 1 is fixed via two filaments 503 to two terminal pins 502 inserted and erected in a base 501 as an insulator (sapphire). The terminal pin 502 and the filament 503, and the filament 503 and the emitter tip 1 are connected by welding, respectively. These are heated in vacuum after welding to remove residual thermal stress. The chip assembly 500 is provided with a reference for measuring the ion emission direction 506 from the emitter chip 1 in advance. This measuring method will be described later.

In the illustrated example, the base 501 is formed in a disk shape, and the back surface (second reference surface 504) fitted into the inclined spacer 600 on the side opposite to the surface on which the emitter chip 1 is disposed is the disk shape. This is a circular surface that is orthogonal to the center axis of the base 501 and coincides with the center. In addition, a predetermined position around the central axis of the base 501, that is, a predetermined radial direction (second reference direction 505) of the back surface (second reference surface 504) is provided on the outer peripheral surface or front surface of the disk-shaped base 501. Is provided with a reference direction mark 509. In the illustrated example, the reference direction mark 509 is configured by forming a notch at a peripheral surface position corresponding to the second reference direction 505 of the base outer peripheral surface.

Here, the inclination of the ion emission direction 506 from the emitter tip 1 with respect to the axial direction of the base 501, that is, the direction perpendicular to the second reference plane 504 is defined as an inclination angle (θ) 507. In addition, a direction angle (φ) 508 is an angle between a direction (inclination azimuth 510) in which the ion emission direction 506 is projected onto the second reference plane 504 and the second reference direction 505. In this case, the tilt data of the emitter chip 1 is represented by these tilt angle (θ) 507 and direction angle (φ) 508, or expression data equivalent to these values.

For this reason, for example, a storage container (not shown) for individually storing each chip assembly 500 so that the tilt data of each emitter chip measured in advance can be accessed when the chip assembly 500 including the emitter chip 1 is attached to the GFIS 100. Not). Thus, the inclination data is managed in association with each chip assembly 500, that is, each emitter chip 1. Each of the actual emitter tips 1 has an inclination angle (θ) 507 suppressed to about ± 2 ° by appropriately managing the crystal axis of the emitter tips 1 and welding to the terminal pins 502.

The reference direction mark 509 is configured by forming a notch in the base 501 in the illustrated example. However, the present invention is not limited to this as long as it indicates the predetermined radial direction (second reference direction 505) of the second reference surface 504 of the base 501. For example, by attaching the emitter chip 1 to the side surface of the filament 503 closer to one terminal pin 502, the attachment method of the filament 503 and the emitter chip 1 is made non-axisymmetric. In this case, either one of the terminal pins 502 can be substituted for the reference direction mark 509.

In addition, although the case where the inclination data of each emitter chip measured in advance is managed by directly entering the inclination data in the storage container of the chip assembly 500 has been described, the present invention is not limited thereto. The tilt data of each emitter chip 1 may be stored in a database in association with the identification data, and the corresponding identification data may be entered as an access code to the database in each storage container of the chip assembly 500. In addition to this, various methods such as enabling access to tilt data when the chip assembly 500 is attached can be considered.

FIG. 4 is a configuration diagram of the support 400. Note that FIG. 4 is also displayed upside down with respect to FIG. 2 so that the configuration can be easily grasped.

In the illustrated case, the support body 400 has a disk shape larger in diameter than the chip assembly 500 and the inclined spacer 600. A fitting recess 410 is formed on the surface of the support 400 on the side where the chip assembly 500 and the inclined spacer 600 are disposed. The back surface side (the fourth reference surface 603 side described later) of the inclined spacer 600 opposite to the mounting side of the chip assembly 500 is inserted into the fitting recess 410. A wiring hole 411 is formed through the support 400.

The peripheral wall portion of the fitting recess 410 supports the tilted spacer 600 in a state where the tilted spacer 600 is fitted with the back surface thereof in contact with the bottom of the fitting recess. In the illustrated example, the bottom portion (bottom surface) of the fitting recess with which the back surface (fourth reference surface 603 described later) of the inclined spacer 600 abuts is a first reference surface 401 that defines the axial direction of the ion optical axis 301. It has become. In this case, the ion optical axis 301 extends in the direction perpendicular to the bottom surface of the fitting recess 410 and is also the central axis of the fitting recess 410. Further, the central axis of the GFIS 100 is also parallel to the ion optical axis 301, and both axes are substantially coincident with each other.

The first reference surface 401 that defines the axial direction of the ion optical axis 301 serves as a reference for attaching an inclined spacer 600 and a chip assembly 500 described later. A first reference direction 402 is set on the support 400.

FIG. 5 is a configuration diagram of the inclined spacer 600. 5A is an external perspective view of the inclined spacer 600, and FIG. 5B is a cross-sectional view of the inclined spacer 600 viewed from the radial direction. Note that FIG. 5 is also displayed upside down with respect to FIG. 2 so that the configuration can be easily grasped.

In the illustrated case, the inclined spacer 600 has a disk shape having an outer diameter that can be fitted into the fitting recess 410 of the support 400. The surface on the side where the chip assembly 500 is disposed and the back surface inserted into the fitting recess 410 of the support 400 are non-parallel. As shown in FIG. 5B, the plate thickness is linearly increased or decreased in the diameter direction. A fitting recess 609 is formed on the surface where the chip assembly 500 is disposed. The rear surface side (second reference surface 504 side) of the base 501 of the chip assembly 500 is fitted into the fitting recess 609.

The peripheral wall portion of the fitting recess 609 supports the chip assembly 500 so that the base 501 of the chip assembly 500 is fitted with the second reference surface 504 on the back surface of the base 501 being in contact with the bottom of the fitting recess. To do. The bottom portion (bottom surface) of the fitting recess 609 is parallel to the surface of the inclined spacer 600. When the back surface of the inclined spacer 600 is held horizontally as shown in FIG. 5B, the bottom portion (bottom surface) of the fitting recess 609 is not parallel to the surface of the inclined spacer 600, and An inclined surface is formed with respect to the back surface.

Here, the bottom portion (bottom surface) of the fitting recess parallel to the surface of the inclined spacer 600 is the third reference surface 601, and the back surface of the inclined spacer 600 is the fourth reference surface 603. In addition, for easy understanding, the third reference surface 601 is not parallel to the radial direction of the outer peripheral surface of the inclined spacer 600, and the fourth reference surface 603 is parallel to the radial direction of the outer peripheral surface of the inclined spacer 600. . The center axis 611 of the third reference surface 601 on the surface of the inclined spacer 600 and the bottom portion (bottom surface) of the fitting recess 609 shown by the alternate long and short dash line in FIG. 5B is the back surface of the inclined spacer 600 (fourth reference surface 603). ) Does not match the central axis.

On that basis, first, the inclination of increasing the thickness between the two surfaces is defined as a thickness increasing angle (α) 604. Further, a predetermined radial direction of the front surface (third reference surface 601) and the rear surface (fourth reference surface 603) is defined on the outer peripheral surface or surface of the inclined spacer 600 at a predetermined position around the axis of the inclined spacer 600. A reference direction mark 605 is provided. In the illustrated example, the reference direction mark 605 is configured by forming a notch at a predetermined radial direction position on the outer peripheral surface of the base, as in the case of the reference direction mark 505. A third reference direction 602 is set along the maximum inclination direction of the third reference surface 601 of the inclined spacer 600. A reference direction mark 605 defines a third reference direction 602.

Next, a method for properly assembling the chip assembly 500, the inclined spacer 600, and the support 400 will be described with reference to FIGS.

First, the chip assembly 500 is inserted into the fitting recess 609 of the inclined spacer 600, and the second reference surface 504 of the chip assembly 500 and the third reference surface 601 at the bottom (bottom surface) of the fitting recess 609 of the inclined spacer 600 are brought into contact with each other. The That is, the chip assembly 500 is fitted into the fitting recess 609 of the inclined spacer 600 so that the reference direction mark 505 of the chip assembly 500 matches the reference direction mark 605 of the inclined spacer 600.

FIG. 6 is an external view of the state in which the chip assembly 500 is assembled to the inclined spacer 600.

Next, in this state, the chip assembly 500 is rotated by the direction angle (φ) 508 relative to the inclined spacer 600. That is, as shown in FIG. 6, the angle between the second reference direction 505 of the chip assembly 500 and the third reference direction 602 of the inclined spacer 600 is matched with the direction angle (φ) 508 of the emitter chip 1. Thereafter, these are fixed using fixing parts not shown. Thus, the tilt direction 510 in the ion emission direction 506 is aligned with the maximum tilt direction of the third reference surface 601 of the tilted spacer 600.

Furthermore, in this state, the increasing angle (α) 604 of the thickness of the inclined spacer is made the same as the inclined angle (θ) 507 of the emitter chip 1. Thereby, the ion emission direction 506 coincides with the axis of the inclined spacer 600 perpendicular to the radial direction of the outer peripheral surface of the inclined spacer 600, that is, in this case, the vertical direction of the fourth reference surface 603 on the back surface of the inclined spacer 600. .

Further, the inclined spacer 600 to which the emitter chip 1 is fixed is inserted into the fitting recess 410 of the support 400. That is, the fourth reference surface 603 of the inclined spacer 600 and the first reference surface 401 at the bottom (bottom surface) of the fitting recess 410 of the support 400 are abutted.

FIG. 7 is an external view of a state in which the inclined spacer 600 to which the chip assembly 500 is fixed is assembled to the support 400.

Next, in this state, the inclined spacer 600 and the support body 400 are fixed using a fixing part (not shown). Thereby, an assembly of the support 400, the inclined spacer 600, and the chip assembly 500 is obtained. In this case, the fourth reference surface 603 of the inclined spacer 600 and the first reference surface 401 at the bottom (bottom surface) of the fitting recess 410 of the support body 400 are parallel to each other in the abutting state. The vertical direction of the fourth reference surface 603 on the back surface of the inclined spacer 600 coincides with the axial direction of the ion optical axis 301 defined by the direction perpendicular to the first reference surface 401. As a result, the ion optical axis 301 and the ion emission direction 506 are parallel to achieve the purpose of adjusting the tilt of the emitter tip 1.

Although not related to the tilt adjustment of the emitter chip 1, the wiring of the terminal pin 502 of the chip assembly 500 may be considered. For example, the first reference direction 402 of the support 400 and the second reference direction 505 of the chip assembly 500 may be matched when the inclined spacer 600 is fitted into the fitting recess 410 of the support 400. Thereby, benefits such as easy wiring can be obtained.

Here, the conditions for focusing the ion beam 5 on the sample 6 to a sub-nanometer unit digit value will be considered. It is assumed that the horizontal fine movement adjustment of the emitter tip 1 is properly performed by the horizontal fine movement mechanism 450. The deviation angle (tilt deviation) of the ion emission direction 506 with respect to the ion optical axis 301 needs to be suppressed to about 0.1 ° or less. Further, since the tilt deviation in the manufacturing stage of the chip assembly 500 is suppressed to ± 2 °, the deviation between the increase angle (α) 604 and the tilt angle (θ) 507 is about 0.1 ° or less, and the rotation angle and direction. The deviation of the angle (φ) 508 needs to be about 2 ° or less.

The adjustment using the increasing angle (α) 604 of the thickness of the inclined spacer 600 will be described. As the inclined spacer 600 shown in FIGS. 5A and 5B, eleven spacers having thickness increase angles (α) 604 that differ in increments of 0.2 ° from 0 ° to 2 ° were prepared in advance. By selecting an appropriate inclined spacer 600 from these, the deviation between the increase angle (α) 604 and the inclination angle (θ) 507 could be suppressed to about 0.1 ° or less.

In order to reduce the number of inclined spacers 600 and improve the accuracy of adjustment, for example, inclined spacers in increments of 0.5 ° (four at 0 to 1.5 °) and inclined spacers in increments of 0.1 ° ( It is also possible to use a plurality of 5) at 0 to 0.4 °.

Further, regarding the adjustment of the direction angle (φ) 508 of the emitter tip 1, the rotation angle between the tip assembly 500 and the inclined spacer 600 was adjusted with an accuracy of 1 ° by using the assembly jig shown in FIG.

FIG. 8 is an explanatory diagram of adjustment of the rotation angle between the chip assembly 500 and the inclined spacer 600 by the assembly jig.

The assembly jig 700 includes a reference base 704 and a rotation stage 701 that is rotatably attached to the reference base 704. A fitting recess 705 is formed in the rotary stage 701 in the same manner as the fitting recess 410 of the support 400 described above. In the fitting recess 705, the back surface side (fourth reference surface side) of the inclined spacer 600 is fitted. A second reference direction press 702 is fixed to the reference base 704. The tip end of the second reference direction pressing member 702 engages with the notch of the reference direction mark 509 of the chip assembly 500 to prevent relative rotation of the chip assembly 500 with respect to the reference base 704. A third reference direction presser 703 is fixed to the rotary stage 701. The tip end of the third reference direction presser 703 engages with the notch of the reference direction mark 605 of the inclined spacer 600 to prevent relative rotation of the inclined spacer 600 with respect to the rotary stage 701.

説明 Explain how to adjust the rotation angle. First, the rear surface side (second reference surface side) of the chip assembly 500 is fitted into the fitting recess 609 of the inclined spacer 600, and temporary assembly is performed before fixing using the fixing component. This is inserted into the fitting recess 705 of the rotary stage 701. The tips of the second reference direction presser 702 and the third reference direction presser 703 are engaged with the notches of the reference direction marks 509 and 605 of the chip assembly 500 and the inclined spacer 600, respectively. Then, the rotary stage 701 is rotated relative to the reference base 704 by the direction angle (φ) 508. Although the inclined spacer 600 rotates integrally with the rotary stage 701, the chip assembly 500 rotates relative to the inclined spacer 600 in a state of being fitted in the fitting recess 609 of the inclined spacer 600. Thereby, the rotation angle between the chip assembly 500 and the inclined spacer 600 is adjusted to the direction angle (φ) 508. Then, the purpose is achieved by fixing the chip assembly 500 and the inclined spacer 600.

Here, a method for measuring the ion emission direction 506 of the chip assembly 500 in advance will be described.

FIG. 9 is a configuration diagram of an ion emission direction measuring apparatus 800 used for measurement of the ion emission direction 506 of the chip assembly 500.

The apparatus 800 is a manufacturing apparatus that performs a process of forming the tip of the emitter chip 1 into a nanochip, and is configured to measure the ion emission direction 506 in the final process of manufacturing the emitter chip 1. The chip assembly 500 is installed so that the second reference plane 504 is perpendicular to the central axis 801 of the vacuum chamber 806 and the tip of the emitter chip 1 is on the central axis 801 of the vacuum chamber 806. . At that time, the deviation of the emitter chip 1 from the central axis 801 of the vacuum chamber 806 is within 0.05 mm. The chip assembly 500 is installed such that the second reference direction 505 coincides with the reference direction (measurement direction) of the optical scale 803. The central axis of the optical scale 803 (that is, the zero point position on the scale) is aligned with the central axis 801 of the vacuum chamber 806. These do not have to be completely matched. In that case, the amount of deviation is measured in advance, and the measured value such as the tilt angle is corrected later.

In this way, the emitter tip 1 is placed in the vacuum chamber 806 of the ion emission direction measuring device 800, and nanotip processing is performed. An extraction electrode (not shown) in the vacuum chamber 806 is grounded, and an appropriate positive high voltage is applied to the emitter chip 1. Furthermore, ions are emitted from the emitter tip 1 by supplying an appropriate imaging gas. The emitted ion beam is irradiated onto a microchannel plate (MCP) 802, and a fluorescent plate portion provided on the back side of the MCP 802 emits light corresponding to the irradiation position. The light emitted from the fluorescent plate portion is enlarged and observed through the window 804 by the camera 805 and compared with the optical scale 803. Thereby, the amount of off-axis of the center axis of the chip assembly 500 and the direction of off-axis are measured. It is assumed that the chip assembly 500 coincides with the ion emission direction 506 or has a deviation within 0.05 mm. The measurement accuracy of the off-axis amount is within 0.1 mm. Here, the distance between the emitter tip 1 and the MCP 802 is 300 mm. Then, the tilt angle (θ) 507 is obtained from the distance 300 mm and the measured off-axis amount, and the direction angle (φ) 508 is obtained from the off-axis direction.

According to the present embodiment, the tip processing of the tip of the emitter chip 1 is completed, and before the emitter chip 1 is attached to the GFIS 100, individual tilt data (tilt angle (θ) 507 and Acquisition of the direction angle (φ) 508) is completed.

Therefore, according to the gas field ionization ion source (GFIS) 100 and the ion beam apparatus 200 according to the present embodiment, the entire ion beam apparatus 200 is compared with the conventional case in which the gimbal mechanism is used to adjust the tilt of the emitter tip 1. This eliminates the need for complicated tilt adjustment operations using the and reduces the cost of the equipment required for the control.

Further, it is only necessary to provide the vacuum bellows 451 so as to define the surface sliding surface 452 of the annular base 47 of the horizontal fine movement mechanism 450 with respect to the inside of the vacuum vessel 10. Therefore, the surface area of the vacuum bellows 451 can be suppressed. Further, the size and length of the vacuum bellows can be reduced as compared with a gas field ion source (GFIS) using a gimbal mechanism. Therefore, the degree of vacuum of the gas field ion source (GFIS) can be increased, and ion emission can be more stabilized.

Moreover, the distance from the wall of the vacuum vessel 10 to the emitter chip 1 can be shortened. Therefore, low-frequency vibration entering from the outside is difficult to be transmitted, and there is an effect that blur of the sample image due to vibration of the emitter tip 1 can be reduced.

<Second Embodiment>
The configuration of the ion beam apparatus according to the present embodiment is substantially the same as that of the ion beam apparatus 200 according to the first embodiment shown in FIG. The configuration of the gas field ion source (GFIS) is substantially the same as that of the GFIS 100 shown in FIG. 2, but the configuration of the inclined spacer 600 is different. for that reason. In the description of the present embodiment, the description of the same or similar components as those in the first embodiment will be omitted, and only the configuration of the inclined spacer 600 having a different configuration will be described.

FIG. 10 is a configuration diagram of the inclined spacer 600-2 of the gas field ion source (GFIS) according to the ion beam apparatus of the present embodiment. 10A is an external perspective view of the inclined spacer 600-2, and FIG. 10B is a cross-sectional view of the inclined spacer 600-2 viewed from the radial direction. Note that, in FIG. 10, as in the case of FIG. 5, the configuration is displayed upside down from FIG.

In the inclined spacer 600 shown in FIG. 5, the plate thickness is linearly increased or decreased in the diameter direction. Further, since the increase angle (α) 604 of the thickness of the inclined spacer 600 is fixed, it is necessary to prepare a plurality of types having different increase angles in order to increase the inclination adjustment accuracy.

In contrast, the inclined spacer 600-2 according to the present embodiment is characterized in that the thickness increasing angle (α) 604 is adjustable. One type of inclined spacer 600-2 can cope with various angles of increase (α) 604.

As shown in FIG. 10, the inclined spacer 600-2 has a disk shape having an outer diameter that can be fitted into the fitting recess 410 of the support 400. In the inclined spacer 600-2, the surface (third reference surface 601) on the side where the chip assembly 500 is disposed and the surface (fourth reference surface 603) inserted into the fitting recess of the support 400 are non-parallel. is there. However, the inclined spacer 600-2 does not have a shape in which the plate thickness linearly increases or decreases in the radial direction. Instead, a stepped hole 610 is formed at a position off the central axis of the inclined spacer 600-2 along the thickness direction, preferably along the central axis direction of the inclined spacer 600-2. An adjustment screw 607 whose overall length is shorter than the hole length of the stepped hole and whose threaded portion is longer than the hole length of the small diameter portion is screwed into the small diameter portion of the stepped hole 610. In addition, a spring 608 is provided between the screw head of the adjustment screw 607 and the step portion of the stepped hole to prevent the adjustment screw 607 from rattling.

Further, a notch 606 is formed on the peripheral surface opposite to the side where the stepped hole 610 is provided across the central axis of the inclined spacer 600-2. In the portion of the notch 606, the outer peripheral surface of the inclined spacer 600-2 is flat. Accordingly, the inclined spacer 600-2 adjusts the amount of protrusion of the adjusting screw 607 from the front or back surface of the inclined spacer 600-2 on the side where the small diameter portion is provided, so that the edge portion of the notch 606 is used as a fulcrum. The increase angle (α) 604 can be changed. At that time, by adjusting the protruding amount of the adjustment screw 607 and measuring the increase angle (α) 604, the adjustment screw 607 is screwed into the small diameter portion of the stepped hole, so that necessary alignment accuracy can be ensured. Here, from the accuracy of adjusting the rotation angle of the adjusting screw 607, 0.05 ° is realized as the alignment accuracy of the increased angle (α) 604 with the notch 606 as a fulcrum.

Since the fourth reference surface 603 of the inclined spacer 600-2 is difficult to be in thermal contact, it is necessary to consider that the thermal contact is sufficient for a component (not shown) that fixes the inclined spacer 600-2 and the support 400. It is.

Also, a plurality of adjustment screws 607 having different lengths may be prepared as the adjustment screws 607 without using the spring 608. A desired increase angle (α) 604 can be obtained by selecting an adjustment screw 607 having an appropriate length. However, in this case, the continuous angle adjustment of the increase angle (α) 604 with the notch 606 as a fulcrum is not possible.

Further, in the inclined spacer 600-2 according to the present embodiment, the stepped hole 610 into which the adjustment screw 607 is screwed also serves as the third reference direction mark 605-2. A line segment parallel to the surface (third reference surface 601) on the side where the third reference direction mark 605-2 and the chip assembly 500 are arranged passes through the central axis and intersects the notch surface of the notch 606. The extending direction corresponds to the third reference direction 602.

According to the inclined spacer 600-2 according to the ion beam apparatus of the present embodiment, there is an effect that a necessary material is reduced as compared with the inclined spacer 600 shown in FIG.

As described above, in the first and second gas field ionization ion sources (GFIS) and the ion beam apparatus, the configuration in which the increase angle α of the thickness can be continuously adjusted as the inclined spacer 600-2 has been described. However, the present invention is not limited to this embodiment, and various other design changes are possible.

<Third Embodiment>
The configuration of the ion beam apparatus according to the present embodiment is substantially the same as that of the ion beam apparatus 200 according to the first embodiment shown in FIG. 1, but horizontal fine movement in the gas field ion source (GFIS) 100 is performed. The arrangement of the mechanism 450 is different.

FIG. 11 is a configuration diagram of a gas field ion source (GFIS) 100-2 according to the present embodiment. In the figure, the configuration of the gas field ion source (GFIS) 100-2 is substantially the same as that of the GFIS 100 shown in FIG. 2, but the arrangement of the horizontal fine movement mechanism 450 with respect to the vacuum vessel 10 is different. In this example, the terminal mounting portion 45 constitutes a movable portion of the horizontal fine movement mechanism 450.

In the GFIS 100-2 according to the present embodiment, since the sliding surface 452 of the horizontal fine movement mechanism 450-2 in FIG. 11 is in the container of the vacuum container 10-2, the vacuum bellows 451 shown in FIG. 2 is not necessary. . Further, it is not necessary to finely move the high voltage introduction terminal 40-1. By not providing the vacuum bellows 451, the distance from the wall of the vacuum vessel 10-2 to the emitter chip 1 is shortened.

Further, the number of parts from the wall of the vacuum vessel 10-2 to the support 400 and the number of parts to be subjected to horizontal fine movement by the horizontal fine movement mechanism 450-2 can be reduced. A high voltage introduction terminal 40-1 is fixed to the vacuum vessel 10-2. Therefore, the components that need to be finely moved are the heat insulation support (stainless steel thin pipe) 24-1, the heat transfer support (oxygen-free copper) 22-1, the heat transfer insulation (sapphire) 23-1, and the chip. It is only the support body 400 to which the assembly 500 and the inclined spacer 600 are assembled.

As described above, according to the present embodiment, since a large vacuum bellows is not used for the tilt adjustment and horizontal position adjustment of the emitter tip 1, the degree of vacuum of the GFIS 100 can be increased, and ion emission is further stabilized. There is an effect to.

Further, since the distance from the wall of the vacuum vessel 10-2 to the emitter tip 1 is short, low frequency vibration entering from the outside is difficult to be transmitted, and there is an effect that the blur of the sample image due to the vibration of the emitter tip 1 can be reduced.

Further, since the number of parts from the wall of the vacuum vessel 10-2 to the support 400 is small, the first reference surface 401 of the support 400 is kept perpendicular to the ion optical axis 301 (that is, the central axis of the GFIS 100-2). Increases accuracy.

Furthermore, since the tilt adjustment accuracy of the emitter tip 1 is improved, there is an effect that the focusing property of the ion beam 5 is enhanced.

<Fourth embodiment>
FIG. 12 is an overall configuration diagram of the ion beam apparatus 200-2 of the present embodiment. The configuration of the ion beam apparatus 200-2 according to the present embodiment is substantially the same as the configuration of the ion beam apparatus 200 shown in FIG. 1, but the aligner 102-4 is different.

In FIG. 1, the aligner is only the aligner 102-4, which is a one-stage deflector. However, in the present embodiment, as shown in FIG. 12, the aligner includes an aligner 102-5 and an aligner 102-6. It is characterized by comprising two stages of electrostatic deflectors.

Hereinafter, the operation of the ion beam apparatus 200-2 of the present embodiment will be described with reference to FIG.

FIG. 13 is a diagram for explaining the basic operation of the two-stage aligner provided in the ion beam apparatus 200-2 of the present embodiment.

Usually, the ion optical axis 301 of the ion optical system 300-2 is set to a mechanical central axis depending on the assembled state of each part of the apparatus. In the tilt adjustment of the emitter tip 1, the ion emission direction 506 from the emitter tip 1 is aligned with this mechanical central axis.

However, in reality, as in the ion beam apparatus 200-2 shown in FIG. 12, when there are two stages of electrostatic lenses, there are individual differences between the electrostatic lenses 102-1 and 102-2. A slight misalignment remains in the horizontal direction (the vertical direction of the lens center axis) depending on the assembled state or the like. The same applies to the case where there are more than two stages of electrostatic lenses.

Therefore, even if the ion beam 5 passes through the center of the first stage (first stage) electrostatic lens 102-1 perpendicularly, the ion beam 5 transmitted through the first stage electrostatic lens 102-1 is caused by the above-described deviation. It does not pass through the center of the second stage electrostatic lens 102-2. Therefore, it is necessary to correct the ion beam 5 by deflecting it with an electrostatic deflector called an aligner.

Normally, the second stage electrostatic lens 102-2 is sufficiently away from the first stage electrostatic lens 102-1, and the ion beam 5 is incident on the center of the second stage electrostatic lens 102-2 vertically. Close to. Therefore, since the influence of coma aberration due to oblique incidence is not visible, it is not necessary to adjust the incident angle of the ion beam 5 to the second stage electrostatic lens 102-2.

The deflection correction of the ion beam 5 described so far can be handled in the same manner and is effective even for the slight angular deviation remaining after the tilt adjustment of the emitter tip 1 described above.

However, considering that the ion beam 5 is focused on the sample to a sub-nanometer unit digit value, it is not sufficient to use only one aligner. This is because, in the ion beam apparatus 200-2 shown in FIG. 12, when the aligner is only one stage of the aligner 102-5 in the figure, the ion beam passes through the first stage electrostatic lens 102-1. The virtual light source No. 5 is shifted from the light source position 1010 to the light source position 1010-2. As a result, deflection chromatic aberration is generated, resulting in blurring of the sample image.

Therefore, in this embodiment, the ion beam 5 deflected by the first-stage aligner 102-5 is further deflected in the opposite direction by the second-stage aligner 102-6, and the ion beam 5 is then electrostatically charged by the second-stage aligner 102-6. The center of the lens 102-2 is passed. At the same time, the blur of the sample image is improved by returning the virtual light source of the ion beam 5 that has passed through the first stage lens 102-1 from the light source position 1010-2 to the original light source position 1010.

For this purpose, the control system was configured so that the deflection of the aligner 102-5 and the deflection of the aligner 102-6 were interlocked while maintaining a constant intensity ratio (deflection intensity ratio) in the opposite directions. In this control system, the optimum value of the deflection intensity ratio is obtained by calculation from the arrangement of the electrostatic lenses 102-1 and 102-2 and the arrangement of the aligners 102-5 and 102-6.

For more accuracy, the aligner 102-5 adjusts the deflection so that the ion beam 5 scans in the vicinity of the hole of the second stage electrostatic lens 102-2, and is generated from the sample 6 in conjunction with the scanning. A sample image is made using secondary electrons. In addition, the deflection intensity ratio may be finely adjusted so that the blur of the sample image is minimized.

In this way, finally, the deflection of the aligner 102-5 is fixed when the ion beam 5 passes through the center of the second stage electrostatic lens 102-2. At the same time, the deflection of the aligner 102-6 is fixed in conjunction with it.

<Fifth embodiment>
The configuration of the ion beam apparatus according to the present embodiment is substantially the same as the configuration of the ion beam apparatus 200-2 shown in FIG.

This embodiment is characterized in that a signal (deflection signal) is given to the aligners 102-5 and 102-6 which are two-stage electrostatic deflectors.

The control system performs control to superimpose another signal on the signals to the aligners 102-5 and 102-6 described in the fourth embodiment.

Hereinafter, the operation of the ion beam apparatus 200-3 according to the present embodiment will be described with reference to FIG. FIG. 14 is a diagram for explaining the basic operation of the two-stage aligner provided in the ion beam apparatus 200-3 of the present embodiment.

By adopting the structures of the first to third embodiments described above, mechanical displacement of the emitter tip 1 in the ion beam apparatus 200-3 is suppressed. However, the mechanical vibration due to the suspended structure of the emitter tip 1 is not zero. Therefore, the virtual light source of the emitter chip 1 may move between the light source position 1000 and the light source position 1001 due to the vibration of the emitter chip 1. Accordingly, the irradiation position of the ion beam 5 focused on the sample 6 through the second stage electrostatic lens 102-2 may move.

Therefore, in this embodiment, the ion beam 5 is used so as to cancel the movement between the light source position 1010 and the light source position 1011 of the virtual light source using the two-stage aligner 102-5 and the aligner 102-6. It is characterized by performing deflection control.

For this reason, the control system is configured to interlock the deflection of the aligner 102-5 and the deflection of the aligner 102-6 while maintaining a constant intensity ratio (deflection intensity ratio) in the same direction.

The optimum value of the deflection intensity ratio can be obtained by calculation from the arrangement of the electrostatic lenses 102-1 and 102-2 and the arrangement of the aligners 102-5 and 102-6.

The vibration of the emitter tip 1 is recognized as blur if the sample image acquisition time is long, but if the acquisition time is shortened, the image will be distorted. By analyzing this, vibration can be captured. Basically, since the vibration of the emitter tip 1 is a mechanical natural vibration, the vibration is in the same direction at a low frequency.

Based on the acquired vibration, the control system finally performs control to apply a deflection signal that vibrates in a certain direction to the aligner 102-5 so as to cancel the vibration. At the same time, the deflection of the aligner 102-6 is controlled to vibrate in conjunction with it.

<Sixth Embodiment>
The configuration of the ion beam apparatus according to the present embodiment is substantially the same as the configuration of the ion beam apparatus 200 according to the first embodiment shown in FIG. 1, but the configuration of the gas field ion source (GFIS) 100 is the same. Different.

FIG. 15 is a configuration diagram of a gas field ion source (GFIS) 100-3 according to the present embodiment. The configuration of the gas field ion source (GFIS) 100-3 is substantially the same as the configuration of the GFIS 100 shown in FIG. 2, except that a gimbal mechanism 450-4 is disposed on the horizontal fine movement mechanism 450-3. Different. The movable portion of the horizontal fine movement mechanism 450-3 is divided into an upper member 46-1 and a lower member 46-2, which are in contact with each other by a sliding surface 452-4. The sliding surface 452-4 is formed in a spherical shape with the emitter tip 1 as the center. The upper member 46-1 can move in the circumferential direction along the sliding surface 452-4. The lower member 46-2 constitutes a fixed part of the gimbal mechanism 450-4, and the upper member 46-1 constitutes a movable part of the gimbal mechanism 450-4.

The support 400, the chip assembly 500, and the inclined spacer 600 that support the emitter chip can be pivoted about the tip of the emitter chip by the gimbal mechanism.

The rotational positioning mechanism by the gimbal mechanism 450-4 includes a push rod 453-4 and a compression spring 454-4 disposed on the lower member 46-2 so as to sandwich the upper member 46-1 in the radial direction. ing. Accordingly, the position of the upper member 46-1 relative to the lower member 46-2 can be adjusted by adjusting and fixing the advance / retreat position of the push rod 453-4 against the urging force of the compression spring 454-4. . A micrometer head is attached to the push rod 453-4, and the tilt angle of the emitter chip 1 can be adjusted with an accuracy of 0.1 ° or less.

A vacuum bellows 451 is provided between the terminal mounting portion 45 and the annular base 47 so as to surround the heat insulating support 24-1. The aperture of the vacuum bellows 451 is about 100 cm ² , and atmospheric pressure presses the terminal mounting portion 45 with a force of about 100 kg. Therefore, in order to ensure smooth movement on the sliding surface 452-4, a plurality of balls are charged between the contact surfaces.

In this embodiment, after the ion beam apparatus is assembled, fine adjustment in the horizontal direction by the horizontal fine movement mechanism 450-3 can be performed, and final adjustment of the tilt angle of the chip can be performed by the gimbal mechanism 450-4. That is, not only the tip tilt adjustment using the support 400, the chip assembly 500, and the tilt spacer 600 but also the tip tilt adjustment using the gimbal mechanism 450-4 can be performed. Therefore, compared with the case of the first embodiment, the accuracy of the tilt angle of the chip in the manufacturing stage of the chip assembly 500 can be relaxed without increasing the number of tilt spacers 600 having different angles. . Therefore, the manufacturing cost of the chip assembly 500 can be suppressed. The allowable value of the tip tilt deviation in the manufacturing stage of the tip assembly 500 is ± 2 ° in the first embodiment, but can be increased to ± 5 ° in the present embodiment. The tolerance for the deviation of the center position can be increased from ± 0.05 mm to ± 0.1 mm. Furthermore, in this embodiment, since the measurement accuracy of the tip tilt angle can be relaxed, the measurement cost can be suppressed. For example, in the present embodiment, the allowable value of measurement accuracy can be relaxed from ± 0.05 ° to ± 0.2 °.

Here, as the inclined spacer 600, six different thickness increasing angles (α) 604 were prepared in advance from 0 ° to 5 ° in 1 ° increments. This is about half of the number of the inclined spacers 600 in the case of the first embodiment. By selecting an appropriate inclined spacer 600 from these, the deviation between the increase angle (α) 604 and the inclination angle (θ) 507 can be made to be about 0.5 ° or less.

In the present embodiment, the tilt deviation of the chip in the manufacturing stage of the chip assembly 500 is shared by both the tilt adjustment using the tilt spacer 600 and the tilt adjustment using the gimbal mechanism 450-4. For example, it is assumed that the tip tilt deviation at the manufacturing stage of the tip assembly 500 is ± 5 °. In this case, the adjustment amount of the tip inclination by the gimbal mechanism 450-4 may be about ± 0.7 °, not ± 5 °. The adjustment amount ± 0.7 ° may be obtained by the mean square of the adjustment step ± 0.5 ° by the inclined spacer 600 and the measurement accuracy of the tip inclination angle ± 0.2 °, but here it is obtained by a simple sum. .

Usually, the moving amount and the movable range of the movable part in the gimbal mechanism are larger than the moving amount and the movable range of the movable part in the horizontal fine movement mechanism. For example, the horizontal movement amount and movable range of the movable part of the gimbal mechanism may be larger than twice the horizontal movement amount and movable range of the movable part of the horizontal fine movement mechanism. However, in this example, since the adjustment amount of the tip inclination by the gimbal mechanism 450-4 is small, the moving amount and the movable range of the movable part (upper member 46-1) of the gimbal mechanism 450-4 are relatively small. In this example, the amount of movement and the movable range of the movable part (upper member 46-1) of the gimbal mechanism 450-4 are at least smaller than twice the amount of movement and the movable range of the movable part of the horizontal fine movement mechanism 450-3. Furthermore, the moving amount and the movable range of the movable part (upper member 46-1) of the gimbal mechanism 450-4 can be made smaller than the moving amount and the movable range of the movable part of the horizontal fine movement mechanism 450-3.

The distance from the sliding surface 452-4 of the gimbal mechanism 450-4 to the tip of the emitter tip 1 is about 100 mm. That is, the rotation radius of the upper member 46-1 is about 100 mm. In order to rotate the upper member 46-1 by ± 0.7 ° around the rotation center, it is necessary to move the upper member 46-1 by ± 1.2 mm in the direction of the sliding surface 452-4. When this is converted into the amount of movement in the horizontal direction, it is ± 1 mm. The horizontal fine movement mechanism 450-3 is designed such that the amount of movement in the horizontal direction on the sliding surface 452 is ± 2 mm. The amount of movement of the upper member 46-1 of the movable part in the gimbal mechanism 450-4 is smaller than this.

In this example, the gimbal mechanism 450-4 is provided on the horizontal fine movement mechanism 450-3. Therefore, the amount of movement of the upper member 46-1 is the sum of the amount of movement due to adjustment of the horizontal fine movement mechanism 450-3 and the amount of movement due to adjustment of the gimbal mechanism 450-4. However, since the amount of movement of the upper member 46-1 in the gimbal mechanism 450-4 is small and can be absorbed by the extension of the vacuum bellows 451, there is no need to change the aperture.

As described above, according to the present embodiment, it is not necessary to increase the size of the vacuum bellows provided in the horizontal fine movement mechanism even if a gimbal mechanism is added. Therefore, the GFIS can be reduced in size. Further, the use of the vacuum bellows can increase the degree of vacuum inside, and has an effect of further stabilizing ion emission.

In this embodiment, the gimbal mechanism 450-4 is arranged above the horizontal fine movement mechanism 450-3. However, since the movable ranges thereof are approximately the same, the same effect can be obtained even if the arrangement is reversed.

DESCRIPTION OF SYMBOLS 1 ... Emitter tip, 2 ... Extraction electrode, 3 ... Gas discharge port, 4 ... Extraction voltage application part, 5 ... Ion beam, 6 ... Sample, 7 ... Secondary electron, 10, 10-2, 10-3 ... Vacuum container , 11 ... Exhaust port, 12-1 ... Ion source subunit installation port, 12-2 ... Cooling head installation port, 12-3 ... High voltage introduction terminal installation port, 12-4 ... Gas supply pipe introduction port, 13 ... Operation Exhaust port, 14 ... support member, 14 '... insulating member, 20 ... cooling head, 21-1, 21-2 ... heat transfer mesh wire (oxygen-free copper), 22-1, 22-2 ... heat transfer support (Oxygen-free copper), 23-1 ... heat transfer insulator (sapphire), 24-1 ... heat insulation support (stainless steel thin pipe), 21 ... heat transfer net, 22 ... heat transfer support, 23 ... heat transfer Thermal insulator, 24 ... Thermal insulation support, 30 ... Gas supply pipe, 31 ... Gas cylinder, 32 ... Valve, 40- DESCRIPTION OF SYMBOLS 1,40-2 ... High voltage introduction terminal, 45 ... Terminal mounting part, 46 ... Movable part, 46-1 ... Upper member, 46-2 ... Lower member, 47 ... Annular base, 100, 100-2, 100- DESCRIPTION OF SYMBOLS 3 ... Gas field ionization ion source, 101 ... Sample stage, 102 ... Lens system, 102-1, 102-2 ... Electrostatic lens, 102-3 ... Beam limiting aperture, 102-4, 102-5, 102-6 ... Aligner 103 ... Deflection system 103-1, 103-2 ... Deflector 104 ... Secondary electron detector 105 ... Lens system controller 106 ... Deflection system controller 110 ... Display 200, 200-2 , 200-3 ... ion beam device, 300, 300-2 ... ion optical system, 301 ... ion optical axis, 400 ... support, 401 ... first reference plane, 402 ... first reference direction, 410 ... fitting recess, 411: Wiring hole, 450, 4 0-2, 450-3 ... Horizontal fine movement mechanism, 450-4 ... Gimbal mechanism, 451 ... Vacuum bellows, 452, 452-4 ... Sliding surface, 453, 453-4 ... Push rod, 454, 454-4 ... Push spring , 500 ... Chip assembly, 501 ... Base, 502 ... Terminal pin, 503 ... Filament, 504 ... Second reference plane, 505 ... Second reference direction, 506 ... Ion emission direction, 507 ... Inclination angle, 508 ... Direction angle, 509 Reference direction mark, 600, 600-2 ... Inclined spacer, 601 ... Third reference surface, 602 ... Third reference direction, 603 ... Fourth reference surface, 604 ... Thickness increase angle, 605, 605-2 ... Reference direction Mark, 606 ... Notch, 607 ... Screw, 608 ... Spring, 700 ... Assembly jig, 701 ... Rotation stage, 702, 703 ... Reference direction pressing, 800 ... Ion emission Direction measuring device, 801 ... center axis, 802 ... MCP, 803 ... optical scale, 804 ... window, 805 ... camera, 1000, 1001 ... virtual light source of emitter chip, 1010, 1010-2, 1011 ... first stage (first stage) Virtual light source of ion beam through the electrostatic lens.

Claims

An emitter tip having a needle-like tip;
A gas supply system for supplying gas to the vicinity of the tip of the emitter tip;
An extraction electrode provided at a tip of the emitter tip, and
An extraction voltage application unit that applies an extraction voltage between the emitter tip and the extraction electrode to ionize and release the gas, thereby forming an electric field;
A vacuum vessel containing at least the emitter tip and the extraction electrode, the inside of which is evacuated;
In a gas field ion source having
A support having a first reference surface disposed perpendicular to the ion optical axis;
A chip assembly having a base for supporting the emitter chip and the emitter chip, the base having a second reference surface on a side opposite to the surface on which the emitter chip is mounted;
An inclined spacer having a third reference surface and a fourth reference surface opposite to the third reference surface, wherein the third reference surface is inclined with respect to the fourth reference surface;
The support and the chip assembly are arranged such that the fourth reference surface of the inclined spacer contacts the first reference surface of the support and the second reference surface of the base contacts the third reference surface of the inclined spacer. The gas field ion source is characterized in that the inclined spacer is disposed between the two.
A gas field ion source according to claim 1,
The tip assembly is arranged so that the tilt direction of the ion emission direction from the emitter tip with respect to the direction perpendicular to the second reference plane of the base coincides with the maximum tilt direction of the third reference plane of the tilt spacer. 3. A gas field ion source characterized by being arranged on a reference plane.
A gas field ion source according to claim 2,
The increasing angle of the thickness of the inclined spacer representing the inclination of the third reference surface with respect to the fourth reference surface corresponds to the inclination angle θ of the ion emission direction from the emitter tip with respect to the direction perpendicular to the second reference surface of the base. The gas field ion source is characterized in that the inclined spacer is selected.
A gas field ion source according to claim 2,
A gas field ionization is characterized in that a reference direction mark indicating the rotational position of the base is formed on the base, and a reference direction mark indicating the maximum inclination direction of the third reference surface is formed on the inclined spacer. Ion source.
A gas field ion source according to claim 1,
The gas field ionization ion source according to claim 1, wherein a concave portion with which the inclined spacer is engaged is formed on the support, and a concave portion with which the base is engaged is formed on the inclined spacer.
A gas field ion source according to claim 1,
The gas field ion source is characterized in that the inclined spacer is configured such that an inclination of the third reference plane with respect to the fourth reference plane can be adjusted.
A gas field ion source according to claim 1,
The vacuum vessel is provided with a horizontal fine movement mechanism for adjusting the horizontal position of the tip of the emitter chip, and the horizontal fine movement mechanism includes a movable part provided in a support part connected to the support, A gas field ionization ion source comprising: a fixed portion that is in contact with the movable portion via a planar sliding surface.
A gas field ion source according to claim 7,
The vacuum container is provided with a gimbal mechanism for pivoting the support body around the tip of the emitter chip, and the gimbal mechanism includes a movable part provided in a support part connected to the support body, A gas field ionization ion source comprising: a fixed portion in contact with the movable portion via a spherical sliding surface.
A gas field ion source according to claim 8,
The gas field ion source is characterized in that the movable range of the movable part of the gimbal mechanism is smaller than the movable range of the movable part of the horizontal fine movement mechanism.
A gas field ion source according to claim 7,
A gas field ionization ion source, wherein a vacuum bellows is provided between the support connected to the support and a planar sliding surface of the horizontal fine movement mechanism so as to surround the support.
In an assembling method of a gas field ion source that forms an electric field by applying an extraction voltage between an emitter tip and an extraction electrode, and ionizes and releases the gas supplied to the tip of the emitter chip by the electric field.
Forming a tip assembly by attaching an emitter tip having a needle-like tip to the base; and
Measuring an inclination angle and an inclination direction of an ion emission direction from the emitter tip with respect to a vertical direction of the base;
Providing an inclined spacer having a bottom surface and an inclined surface inclined with respect to the bottom surface;
Mounting the chip assembly on the inclined surface of the inclined spacer so that the inclination direction of the ion emission direction matches the maximum inclination direction of the inclined surface of the inclined spacer;
Mounting the inclined spacer mounted with the chip assembly on a support;
Mounting a structure composed of the chip assembly, the inclined spacer and the support in a vacuum vessel;
Using a horizontal fine movement mechanism provided in the vacuum vessel, adjusting the horizontal position of the emitter tip so that the ion emission direction is aligned with the ion optical axis;
A method for assembling a gas field ion source having:
A method for assembling a gas field ion source according to claim 11,
Pivoting the support around the tip of the emitter tip so that the ion emission direction is aligned with the ion optical axis using a gimbal mechanism provided in the vacuum vessel;
A method for assembling a gas field ion source having:
A method for assembling a gas field ion source according to claim 11,
The step of preparing the inclined spacer includes the step of selecting the inclined spacer so that the angle of the inclined surface with respect to the bottom surface matches the inclination angle of the ion emission direction from the emitter tip with respect to the vertical direction of the base. A method for assembling a gas field ion source characterized by the following.
A method for assembling a gas field ion source according to claim 13,
The step of selecting the inclined spacer includes
Preparing in advance a plurality of inclined spacers with different angles of the inclined surface with respect to the bottom surface;
A method of assembling a gas field ion source, comprising: selecting an inclined spacer having an angle of an inclined surface with respect to a bottom surface closest to an inclination angle in the ion emission direction from the plurality of inclined spacers.
A method for assembling a gas field ion source according to claim 11,
The step of attaching the chip assembly to the inclined surface of the inclined spacer comprises:
Forming a reference direction mark indicating the maximum inclination direction of the inclined surface on the inclined spacer;
Forming a reference direction mark indicating the rotational position of the base on the base;
Measuring a direction angle that is an angle from a reference direction mark of the base to a tilt azimuth of an ion emission direction from the emitter tip;
Disposing the chip assembly on the inclined surface of the inclined spacer such that the reference direction mark of the base is aligned with the reference direction mark of the inclined spacer;
Rotating the tip assembly on the inclined surface of the inclined spacer by the direction angle, and assembling the gas field ion source.
A method for assembling a gas field ion source according to claim 11,
The step of attaching the inclined spacer to the support includes attaching the inclined spacer to the support so that a reference direction mark of the inclined spacer is aligned with a reference direction mark formed on the support. A method for assembling a gas field ion source.
A gas field ion source that generates an ion beam that irradiates the sample;
A lens system for focusing an ion beam emitted from the gas field ion source;
A deflection system for deflecting an ion beam emitted from the gas field ion source;
A secondary particle detector for detecting secondary particles emitted from the sample by irradiation of an ion beam;
An image generation unit that forms a secondary particle image by associating the secondary particle signal from the secondary particle detector with the deflection of the ion beam;
In an ion beam apparatus having
The gas field ion source is:
A support having a first reference surface disposed perpendicular to the ion optical axis;
A chip assembly having a base for supporting the emitter chip and the emitter chip, the base having a second reference surface on a side opposite to the surface on which the emitter chip is mounted;
An inclined spacer having a third reference surface and a fourth reference surface opposite to the third reference surface, wherein the third reference surface is inclined with respect to the fourth reference surface;
The support and the chip assembly are arranged such that the fourth reference surface of the inclined spacer contacts the first reference surface of the support and the second reference surface of the base contacts the third reference surface of the inclined spacer. The inclined spacer is disposed between
The lens system is
A two-stage electrostatic lens;
An aligner constituted by two stages of electrostatic deflectors provided between the electrostatic lenses,
By deflecting the ion beam deflected by the first-stage aligner in the opposite direction by the second-stage aligner, the ion beam passes through the center of the second-stage electrostatic lens, and thereby the second-stage static lens. An ion beam device configured to correct aberration due to a shift between electrolenses.
An ion beam device according to claim 17,
The ion beam apparatus according to claim 1, wherein the aligner applies a deflection that vibrates in a certain direction to the ion beam so as to cancel the vibration of the ion beam caused by the vibration of the emitter tip.
An assembly having a chip assembly, an inclined spacer, and a support, and attached to a gas field ion source,
The support is formed with a first reference surface arranged perpendicular to the ion optical axis, and a reference direction mark indicating a rotational position,
The chip assembly has an emitter tip and a base that supports the emitter tip, and the base has a second reference surface on a side opposite to the surface on which the emitter tip is mounted,
The inclined spacer has a third reference surface and a fourth reference surface opposite to the third reference surface, and the third reference surface is inclined with respect to the fourth reference surface,
The support and the chip assembly are arranged such that the fourth reference surface of the inclined spacer contacts the first reference surface of the support and the second reference surface of the base contacts the third reference surface of the inclined spacer. An assembly to be mounted on a gas field ion source, wherein the inclined spacer is disposed between the two.
An assembly to be mounted on the gas field ion source according to claim 19,
The tip assembly is arranged so that the tilt direction of the ion emission direction from the emitter tip with respect to the direction perpendicular to the second reference plane of the base coincides with the maximum tilt direction of the third reference plane of the tilt spacer. 3. An assembly mounted on a gas field ion source characterized by being disposed on a reference plane.