WO2014195998A1

WO2014195998A1 - Charged particle microscope, sample holder for charged particle microscope and charged particle microscopy method

Info

Publication number: WO2014195998A1
Application number: PCT/JP2013/065317
Authority: WO
Inventors: るり子常田; 研原田
Original assignee: 株式会社日立製作所
Priority date: 2013-06-03
Filing date: 2013-06-03
Publication date: 2014-12-11

Abstract

Provided is a device allowing charged particle-generated images to be taken in a rotation series around an x-axis, a y-axis and a z-axis of an observed area, having, in a sample holder of a charged particle beam device, a needle-shaped sample stage having a sample mounted at the tip, a first rotating fixture having the needle-shaped sample stage mounted thereon, and a holding rod having the first rotating fixture mounted at the tip, and constituted by a first rotation angle control mechanism rotating the holding rod inside a sample chamber around a first axis orthogonal to an optical axis of a microscope, a second rotation angle control mechanism for rotating the first rotating fixture inside the sample chamber around a second axis, and an angle setting mechanism for setting the angle between the first axis and the second axis to about 54.7 degrees.

Description

Charged particle beam microscope, charged particle beam microscope sample holder, and charged particle beam microscope method

The present invention relates to a microscope and a method for analyzing an electromagnetic field structure of a sample using a charged particle beam microscope.

As a method for reconstructing the three-dimensional electromagnetic field structure of a sample from a transmission electron microscope image, there is a method described in Non-Patent Document 1.

In order to reconstruct a vector component, that is, an orthogonal three component (x, y, z) assigned to each pixel, a magnetic field component Bx (x, y, z) in the x-axis direction from a rotation series image around the x-axis of the observation region. z) is reconstructed, and the magnetic field component By (x, y, z) in the y-axis direction is reconstructed from the rotation series image around the y-axis, and the remaining magnetic field component Bz (x, y, z) in the z-axis direction is reconstructed. Is calculated from the Maxell equation divB = 0, which is a characteristic of the magnetic field.

Also, the following sample holders are known as sample holders used for rotating series image photographing used for three-dimensional reconstruction.

Patent Document 1 states that “a sphere 5 at the tip of the sample holder 1, a sample holding rod 6 that passes through and fixed to the center of the sphere 5, and a rotating inner cylinder 3 having a spherical seat that holds the sphere 5, A tilting rod 4 for tilting the sphere 5 is provided, and a tip is inserted between the electron lenses 11 of the electron microscope 11. The sample 7 is held on the electron beam 12 side of the sample holding rod 6. The slope of the tip of the tilting rod 4 is pressed against one end of the sample holding rod 6 to operate the tilt of the Z-axis and the Y-axis, the tilting rod 4 is retracted, and the slope is rotated in a predetermined tilt direction. The inclination direction is changed again by pressing it down to the inclination angle of ”(see FIG. 1 of Patent Document 1 and“ Solution ”in“ Summary ”).

Further, “at the atmosphere side of the sample holder 1 are provided with two rotation driving mechanisms and one straight driving mechanism of a side entry type sample moving apparatus having a eucentric moving mechanism. The driving mechanism is used for 360 ° rotation of the X axis of 360 ° and is connected to the rotating inner cylinder 3. The other one of the rotation driving mechanism and the straight driving mechanism is the Z axis, Y axis tilting operation Θz, It is also used as Θy and is connected to a tilting rod 4 installed inside the rotating inner cylinder 3 ”(see paragraph“ 0013 ”of Patent Document 1).

JP 2004-688661 A JP 2001-256912 A

However, in the conventional technique, artifacts due to the projection angle limitation occur in the reconstructed image of the magnetic field component Bx and the reconstructed image of the magnetic field component By, and therefore Bz calculated from the Bx and By using the Maxell equation divB = 0 is further included in Bz Many artifacts were found to occur.

First, in the case where the sample holder shown in Patent Document 1 is used, it is possible to obtain a rotating series image in a range of ± 70 degrees around the x axis by installing the sample with the x axis aligned with the tilt axis of the sample cradle (12). Thereafter, using the moving mechanism (16), the y-axis of the sample is aligned with the tilt axis of the sample cradle (12), and a rotation series image in the range of ± 70 degrees around the x-axis can be obtained. However, artifacts due to projection angle limitation occur in Bx and By reconstructed from these rotated series images. Since components that do not satisfy the Maxell equation divB = 0 are mixed in Bx and By, more artifacts occur in Bz. Note that if the sample is tilted by ± 70 degrees or more, the cradle (12), the moving mechanism (16), etc. block the optical path of the incident electron beam or the transmitted electron beam, and it is impossible to obtain a projection image in the 360-degree range. Artifacts due to projection angle limitations cannot be eliminated.

Next, when the sample holder shown in Patent Document 2 is used, the sample is placed with the x-axis aligned with the rotation axis of the rotating inner cylinder 31, and the rotation θx is changed to obtain a rotation series image in the range of 360 degrees around the x-axis. Can be obtained. However, after that, it is difficult to adjust θy and θz using the tilting rod 4 so that the y-axis of the sample matches the rotation axis of the rotating inner cylinder 31.

This is because θy and θz can only change ± 10 degrees. This is because the change ranges of θy and θz are limited by the angle at which the sample holding rod 6 contacts the rotating inner cylinder 3 that supports the sphere 5. If the hole diameter at the tip of the rotating inner cylinder 3 is increased in order to expand the rotation angle range of θy and θz to ± 45 degrees, the spherical body 5 will pop out when the tilting rod 4 is pressed to tilt the sample. . Therefore, since a rotation series image around the y axis cannot be obtained, the magnetic field component By cannot be obtained, and Bz cannot be calculated using the Maxell equation divB = 0.

In view of the above problems, an object of the present invention is to reduce artifacts generated by three-dimensional reconstruction in a technique for reconstructing a three-dimensional electromagnetic field structure of a sample from a charged particle beam image of the sample, and to achieve high accuracy. It is to provide a three-dimensional magnetic field structure.

In order to solve the above problems, the following apparatus and method have been devised. An example is shown below. That is, the sample holder of the present application is a sample holder used in a charged particle beam apparatus that irradiates a sample with a charged particle beam and observes the sample holder, and the sample holder includes a rotating jig having an attachment portion for attaching the sample to a tip portion thereof. A holding rod having a holding portion for holding the rotating jig, a first rotation angle control unit for rotating the holding rod around a first axis orthogonal to the charged particle beam, and the rotating jig for the second A second rotation angle control unit that rotates about an axis, and the holding unit includes an angle setting unit that determines an angle formed by the first axis and the second axis to an arbitrary angle. It is characterized by that.

Further, the charged particle beam apparatus of the present application includes a charging optical system that irradiates a sample with a charged particle beam, a sample holder that holds the sample, and a detection optical system that detects charged particles from the sample. In the particle beam apparatus, the sample holder includes a rotating jig having a mounting portion for attaching the sample to a tip portion, a holding rod having a holding portion for holding the rotating jig, and the holding rod as the charged particle beam. A first rotation angle control unit that rotates around a first axis that is orthogonal, and a second rotation angle control unit that rotates the rotary jig around a second axis, and the holding unit includes: And an angle setting unit that determines an angle between the first axis and the second axis as an arbitrary angle.

Further, the charged particle beam microscopic method of the present application includes a step of attaching a sample to a tip portion of a sample mounting base, a step of making the x axis of the sample parallel to a first rotation axis, and a step around the x axis of the sample. Obtaining a rotation series image, making the y-axis of the sample parallel to a first rotation axis, obtaining a rotation series image around the y-axis of the sample, and the z-axis of the sample as a first And a step of obtaining a rotation series image around the z-axis of the sample, wherein the x-axis, the y-axis, and the z-axis are orthogonal coordinate systems, respectively. To do.

電磁 By using this apparatus and method, the electromagnetic field distribution of the sample can be reconstructed.

2 is a plan view of a basic configuration of a holding rod tip used in Example 1. FIG. It is explanatory drawing which shows the relationship between the orthogonal coordinate system xyz fixed to the sample, the 1st axis | shaft, and the 2nd axis | shaft. It is a basic lineblock diagram of an electron beam interference microscope. FIG. 3 is a basic configuration diagram of a sample holder and a sample stage used in Examples 1 to 5. It is the block diagram which expanded the acicular sample stand and the protruding sample part. It is a basic block diagram of the 1st rotation jig used in Examples 1-4. 3 is a bird's-eye view of a basic configuration of a holding rod tip used in Example 1. FIG. It is a flowchart for imaging | photography the rotation series image around the x-axis, y-axis, and z-axis of the sample. 6 is a plan view of a basic configuration of a tip of a holding rod used in Example 2. FIG. It is a basic block diagram of the 1st rotation jig used in Examples 2-4. It is a top view of the basic composition of the inclination jig used in Example 2. FIG. FIG. 6 is a basic configuration diagram of a tip of a holding rod used in Example 3, and is a plan view viewed from the Y direction. FIG. 6 is a basic configuration diagram of a tip of a holding rod used in Example 3, and is a plan view viewed from the X direction. It is a basic block diagram of the holding rod tip used in Example 3, and is a bird's-eye view of the whole. 6 is a plan view of a basic configuration of a holding rod tip used in Example 4. FIG. It is a basic block diagram of the inclination jig | tool used in Example 4, and is a basic block diagram in the case of carrying out biaxial control by the combination of the movement amount of two wires using two wires and one screw. It is a basic block diagram of the inclination jig | tool used in Example 4, and is a basic block diagram in case each wire controls each axis | shaft using two wires and two screws. It is a basic block diagram of the inclination jig used in Example 4, and is a basic block diagram in the case of using two wires and two screws and performing biaxial control with a combination of movement amounts of the two wires. FIG. 10 is a plan view of a basic configuration of a holding rod tip used in Example 5. 6 is a basic configuration diagram of a first rotary jig used in Example 5. FIG. 10 is a bird's-eye view of a basic configuration of a holding rod tip used in Example 5. FIG. FIG. 10 is a plan view of a basic configuration of a holding rod tip used in Example 6. It is a basic block diagram of the sample holder and sample stage used in Example 6. FIG. 6 is a basic configuration diagram of a thin film sample and a needle sample stage used in Example 7.

The details of the technique for reconfiguring the magnetic field component Bx (x, y, z) and the magnetic field component By (x, y, z) are shown in Non-Patent Document 1. That is, in Non-Patent Document 1, the magnetic field component Bx (x, y, z) in the x-axis direction is reconstructed from the rotating series transmission electron microscope image around the x axis of the sample, and from the rotating series transmission electron microscope image around the y axis. The magnetic field component By (x, y, z) in the y-axis direction is reconstructed, and the remaining magnetic field component Bz (x, y, z) in the z-axis direction can be calculated from the Maxell equation divB = 0, which is the magnetic field characteristic. It is shown.

On the other hand, in the present invention, the magnetic field component Bz (x, y, z) is also reconstructed from a rotating series transmission electron microscope image around the z axis.

FIG. 1 shows a specific configuration for realizing acquisition of a rotating series transmission electron microscope image around the z axis. A holding rod having a needle-like sample stand 150 with the sample 10 attached to the tip, a first rotating jig 130 with the needle-like sample stand 150 attached, and a holding rod 120 with the first rotating jig 130 attached to the tip. A first rotation angle control mechanism for rotating 120 around a first axis perpendicular to the microscope optical axis in the sample chamber, and a second rotation for rotating the first rotary jig 130 around the second axis within the sample chamber A sample holder 100 having an angle control mechanism and an angle setting mechanism for setting an angle formed by a first axis and a second axis to be close to 54.7 degrees is illustrated. Here, the vicinity of 54.7 degrees is an example of a representative angle at which the sample does not deviate when the second axis rotates, and is not limited to this angle as long as the accuracy is satisfied. Absent.

FIG. 2 shows the relationship between the orthogonal coordinate system xyz fixed to the sample, the first axis, and the second axis. The second axis is aligned with the center of xyz. That is, the angle between the second axis and the x axis, the angle between the second axis and the y axis, and the angle between the second axis and the z axis are 54.7 degrees. After setting the x-axis parallel to the first rotation axis that is orthogonal to the microscope optical axis, the sample is rotated around the x-axis using the first rotation angle control mechanism to obtain a rotation series image around the x-axis. Can do. Then, after setting the y-axis of the sample in parallel with the first rotation axis using the second rotation angle control mechanism, the sample is rotated around the y-axis using the first rotation mechanism, A rotating series image can be obtained.

Similarly, after setting the z-axis of the sample to be parallel to the first rotation axis using the second rotation angle control mechanism, the sample is rotated around the z-axis using the first rotation mechanism, Can be obtained. Hereinafter, the embodiment is shown.

As described above, rotation series images around three axes orthogonal to each other can be taken, and each vector component can be directly reconstructed from each rotation series image. Therefore, a highly accurate three-dimensional electromagnetic field distribution with less artifacts can be reconstructed. Can be configured.

Example 1 shows an example in which a sample processed into a protrusion is mounted on the sample holder of FIG. Details will be described later with reference to FIG. As a form of the second rotation angle control mechanism, a second rotary jig 140 having a bevel gear portion 131 processed into the first rotary jig 130 and a bevel gear portion 141 processed to mesh with the bevel gear portion 131. Therefore, a control mechanism that rotates the first rotary jig 130 by rotating the second rotary jig 140 is employed. In addition, as a form of the angle setting mechanism, it is a tapered surface 121 on which the first rotating shaft 150 is installed, and an angle formed between the normal line of the tapered surface 121 and the first rotating shaft is set to around 54.7 degrees. Adopted structure. Details are shown below.

First, FIG. 3 schematically shows an electron beam interference microscope comprising a two-stage electron biprism interference optical system as an apparatus used for photographing a sample. As a premise, an orthogonal coordinate system fixed to the mirror is set as XYZ.

The electron gun 1 as an electron source is positioned at the most upstream part in the direction in which the electron beam flows, and the electron beam is brought to a predetermined speed by the accelerating tube 40, and then the irradiation optical system (the first irradiation lens 41, the first irradiation lens). The sample 3 placed on the sample holder 100 is irradiated from the Z direction through the two irradiation lens 42). The first irradiation lens 41 and the second irradiation lens 42 use condenser lenses.

The electron beam that has passed through the sample 10 is imaged by the objective lens 5. A first electron biprism 91 is disposed below the objective lens 5, and a second electron biprism 93 is disposed below the first imaging lens 61.

Electron beam interference microscope images in which the interference fringe interval s and the interference region width W are determined by the first and second electron biprisms (91, 93) are the second, third, and fourth imaging lenses (62, 63, 64) and adjusted to a predetermined magnification, and recorded on the observation recording surface 89 by an image observation / recording medium 79 (for example, a TV camera or a CCD camera). Thereafter, it is reproduced as an amplitude image, a phase image, etc. by the arithmetic processing unit 77 and displayed on the monitor 76, for example.

Next, FIG. 4 is a basic configuration diagram of the sample holder and the sample stage. The sample holder 100 includes a holding cylinder 110 and a holding rod 120 in the holding cylinder 110. The holding cylinder 110 has an opening 111 through which an electron beam can pass. The holding rod 120 can rotate 360 degrees around the first axis independently of the holding cylinder 110. Generally, the diameter of the holding cylinder is designed to be 7 to 8 mm, and the diameter of the holding rod is designed to be 3 mm.

Incidentally, in a general-purpose transmission electron microscope, a sample holder is inserted between in-lens objective lenses. The lens gap in an in-lens objective lens is about 5 mm, and if a light element cover for suppressing X-ray generation is provided, the thickness that can be inserted into the lens gap is about 3 mm.

On the other hand, FIG. 3 is an apparatus for observing the electromagnetic field structure of the sample. In order to avoid a change in the magnetic field structure of the sample due to a strong magnetic field in the lens gap, the sample is placed between the objective lens 5 and the second irradiation lens 42. insert. Since the size of the sample chamber in the Z direction is 10 mm or more, it is possible to increase the diameter of the holding cylinder and holding rod. However, if the diameter of the holding cylinder and holding bar is increased, a new design such as a sample stage is required. I need it.

There is also a need to perform sample processing using a focused ion beam processing apparatus and sample shape evaluation using a general-purpose transmission electron microscope with a common sample holder. For the above reasons, the sample holder used in this example is also made to have a holding cylinder diameter of 7 to 8 mm and a holding rod diameter of 3 mm in consideration of the purpose used in many apparatuses. Therefore, the size of each component of the sample holder varies depending on the apparatus in which the holder is used, and is not necessarily limited to the size described above.

The sample holder 110 is inserted into the sample stage from the X direction. The position of the sample 10 in the X, Y, and Z directions is controlled using three linear actuators 101 to 103 including a pulse motor and an encoder (not shown) of the sample stage. For example, a pulse motor 104 that rotates the holding rod 120 is used as the first rotation angle control mechanism that controls the rotation of the holding rod 120. Further, other than the pulse motor may be used as long as the above operation can be realized with high accuracy.

FIG. 5 shows the shape of the sample 10 formed in a protruding shape and the basic structure of the needle-like sample stage 150 on which the sample 10 is mounted. The sample 10 has a pedestal portion 13, an observation region 11 in the sample 10, and a protrusion 12 that encloses the observation region 11, and is placed at the tip of a needle-like sample table 150. In order to obtain a transmission electron image, the diameter of the protrusion 12 is reduced from 50 nm to 200 nm.

Further, even when the sample 10 is rotated about the first axis or the second axis is rotated, the needle-like sample stage 150 does not block the electron beam (that is, the optical path of the microscope). The sample stage 150 is conical or polygonal with a taper angle of 35 degrees or less. The needle-like sample stage 150 has a tapered part 151, a grip part 152 used when the needle-like specimen stage 150 is handled with tweezers, etc., and a screw part 153 used for attaching / detaching the needle-like sample stage 150 and the first rotary jig 130. And a cylindrical or polygonal guide portion 154 having a diameter smaller than the diameter of the screw portion 153.

The general-purpose tweezers have a flat inner surface at the tip of the tweezers. However, if a dedicated tweezer in which a groove that fits the grip portion 152 of the needle-shaped sample table 150 is formed inside the tweezers tip, Handling becomes easy. Further, when the needle-like sample stage 150 is inserted into the first rotating jig 140, the screw portion 153 can be easily inserted by inserting the guide portion 154 having a diameter smaller than that of the screw portion 153 into the screw hole portion 133 first. become.

Incidentally, the shape of the protrusion 12 does not necessarily have to be thinned as shown in the drawing, and may have a shape protruding from the pedestal portion 13. In this embodiment, the needle-like sample stage 150 is described as a conical shape having a taper angle of 30 degrees.

FIG. 6 shows the basic structure of the first rotary jig 130. The first rotary jig 130 has a bevel gear portion 131, an insertion portion 132 that is inserted into the holding rod 120, and a screw hole portion 133 that is used to attach and detach the needle-like sample table 150. A line connecting the sample 10 and the outermost periphery of the bevel gear 131 so that the first rotating jig does not block the microscope optical path even if the sample 10 is rotated about the first axis or the second axis. The length of the grip portion 152 and the diameter of the bevel gear 131 are determined so that the angle formed by the second axis is 35 degrees or less. This time, the angle formed between the line connecting the sample 10 and the outermost periphery of the bevel gear 131 and the second axis was 30 degrees.

Fig. 7 shows the basic structure of the tip of the holding rod 120. A first rotating jig 130 is attached to the tip of the holding rod 120, a second rotating jig 140 having a bevel gear portion 141 installed so as to mesh with the bevel gear portion 131, and the second rotating jig 140 is held by the holding rod. A motor (not shown) that rotates independently from 120 is configured. The rotation of the motor causes the second rotary jig 140 to rotate via the support column 142, and this rotation causes the first rotary jig 130 to rotate.

1 will be described in more detail. The arrangement | positioning of the 1st axis | shaft in the front-end | tip of the holding rod 120, a 2nd axis | shaft, the 1st rotation jig 130, and the 2nd rotation jig 140 is shown. A tapered surface 121 is provided at the tip of the holding rod 120 as an angle setting mechanism for setting the direction of the second axis. Further, the angle formed between the normal line of the tapered surface and the first rotation axis is set in the vicinity of 54.7 degrees.

In addition, the operating range of the sample stage in a general-purpose transmission electron microscope is ± 1.0 mm in the X direction, 1.0 mm in the Y direction, and ± 0.5 mm in the Z direction. It is necessary to determine the movement of the sample when the sample is rotated within a range that can be followed by the sample stage.

Therefore, the microscope optical axis and the first axis are determined to intersect. Further, the position of the hole into which the first rotary jig is inserted is determined so that the second axis intersects the intersection of the microscope optical axis and the first rotation axis.

By installing the sample 10 at the intersection of these three axes, the sample movement can be minimized when the sample is rotated around the first and second axes. Further, even if the sample 10 is rotated around the first axis and the second axis, the member of the sample holder (particularly, the tapered portion 151) does not block the optical axis of the microscope, and the x-axis and y-axis In addition, a rotation series image in a 360-degree range can be captured around each of the z axes.

Finally, the photographing procedure will be described with reference to FIG. The shooting procedure mainly consists of the following procedures.
A first axis perpendicular to the microscope optical axis and the x-axis of the sample are set in parallel (S1).
A rotation series image around the x-axis of the sample is taken using the first rotation angle control mechanism (S2).
The y-axis of the sample is set parallel to the first rotation axis using the second rotation angle control mechanism (S3).
A rotation series image around the y-axis of the sample is taken using the first rotation angle control mechanism (S4).
The z axis of the sample is set parallel to the first rotation axis using the second rotation angle control mechanism (S5).
A rotation series image around the z-axis of the sample is taken using the first rotation angle control mechanism (S6).

As described above, the magnetic field component Bx (x, y, z) in the x-axis direction is reconstructed from the rotation series image around the x-axis of the sample, and the magnetic field component By ( Refer to Non-Patent Document 1 for details of the technique for reconstructing x, y, z). In the same procedure, the magnetic field component Bz (x, y, z) in the z-axis direction is reconstructed from the rotation series image around the z-axis to reconstruct the three-dimensional magnetic field structure.

Note that Non-Patent Document 1 shows a technique for reconstructing a three-dimensional magnetic field structure using a rotating series phase image reproduced from a Lorentz image. It is possible to apply the technique shown here to a rotating series phase image reproduced from an electron beam interference microscope image. Further, a rotation series image may be taken using a Lorentz scanning transmission electron microscope image. The sample holder and the microscopic method of the present invention can also be used when analyzing the three-dimensional structure of the observation region from rotation series images around the x-axis, y-axis, and z-axis taken with an apparatus other than the above. is there.

Example 2 shows an example in which a sample processed into a protrusion is mounted on the sample holder of FIG. In the present embodiment, as a form of the second rotation angle control mechanism, the first bevel gear portion 131 processed in the first rotating jig 130 and the second bevel gear portion 131 processed so as to mesh with the first bevel gear portion 131 are used. A second rotating jig 140 having a bevel gear portion 141 is used, and a control mechanism that rotates the first rotating jig 130 by rotating the second rotating jig 140 is employed. In addition, the angle setting mechanism includes an inclined jig 160 to which the first rotating shaft 130 is attached and a tapered surface 121 at the tip of the holding rod to which the inclined jig 160 is attached, which is formed between the second axis and the first axis. A structure in which the angle of the tapered surface 121 is designed so that the angle is in the vicinity of 54.7 degrees is adopted. The difference between the first embodiment and the second embodiment is an inclined jig 160. Further, a spring 134 is added in order to prevent the first rotary jig 130 from rattling or shifting.

FIG. 10 shows a structure in which the structure of the first rotary jig is changed with the addition of the spring. When the first rotating jig 130 is mounted, the inclined jig 160 is sandwiched between the bevel gear portion 131 and the holding jig 135, and the spring 134 is installed between the holding jig 135 and the inclined jig 160. The holding jig 135 is provided with a screw for adjusting the distance between the holding jig 135 and the tilting jig 160, and the spring strength is adjusted by adjusting the distance between the holding jig 135 and the tilting jig 160.

The spring 134 may be installed between the bevel gear portion 131 and the inclined jig 160. Further, as shown in FIG. 11, the tilt jig 160 has a hole 161 through which the insertion portion 132 of the first rotary jig 130 passes, a hole 162 through which the column portion 142 of the second rotary jig 140 passes, and the tilt jig. Screw holes 163-1 and 163-2 were provided for attaching 160 to the support rod 120. However, as long as each component can be fixed, it is not always necessary to perform the process as shown in FIG. Further, even if the spring 134 is provided between the bevel gear portion 131 and the holding rod 120 of the first embodiment, it is possible to prevent the first rotating jig 130 from rattling or shifting.

Since the first rotating jig and the angle setting mechanism are the same as those in the first embodiment, description of the microscope main body and the photographing procedure is omitted.

Example 3 shows an example in which a sample processed into a protruding shape is mounted on a sample holder using the configuration shown in FIGS. 12 (A) and 12 (B).

In the present embodiment, as a form of the second rotation angle control mechanism, the first bevel gear portion 131 processed in the first rotating jig 130 and the second bevel gear portion 131 processed so as to mesh with the first bevel gear portion 131 are used. A second rotating jig 140 having a bevel gear portion 141 is used, and a control mechanism that rotates the first rotating jig 130 by rotating the second rotating jig 140 is employed. In addition, as the form of the angle setting mechanism, the tilting jig 160 to which the first rotating shaft 130 is attached, the pivot portion 164 provided in the tilting jig 160, the wire 166 attached to the tilting jig 160, and the tilting jig 160 A mechanism that has an attached spring 167, a support 122 provided on the holding rod 120, and a pivot receiving part 123 provided on the support 122, and controls the inclination angle of the inclination jig 160 by moving the wire 166. Adopted.

The difference between Example 2 and Example 3 is that a mechanism for controlling the inclination angle of the inclination jig 160 is added. Two support columns 122 are provided at the tip of the support rod 120, and the inclined shaft 160 and the holding rod 120 are sandwiched using screws 125. On both sides of the tilting jig 160, there are two pivots 164 on a third axis orthogonal to the first and second axes, and two pillars 122 that receive them on a support column 122 provided at the tip of the support rod 120. A receiving portion 123 is provided. A spring 167 is attached between one end of the inclination jig 160 and the tip of the holding rod, and a wire 166 is attached to the other end of the inclination jig 160, and the inclination angle of the inclination jig 160 is controlled by moving the wire 166. To do.

Since the angle setting mechanism and the procedure for setting the angle of the tilting jig using the angle setting mechanism are the same as those in the second embodiment except that S1 in FIG. 8 is added, the description of the microscope main body and the imaging procedure is omitted. .

Example 4 shows an example in which a sample processed into a protruding shape is mounted on a sample holder using the configuration of FIG. In the present embodiment, as a form of the second rotation angle control mechanism, the first bevel gear portion 131 processed in the first rotating jig 130 and the second bevel gear portion 131 processed so as to mesh with the first bevel gear portion 131 are used. A second rotating jig 140 having a bevel gear portion 141 is used, and a control mechanism that rotates the first rotating jig 130 by rotating the second rotating jig 140 is employed.

In addition, as a form of the angle setting mechanism, the inclination jig 160 to which the first rotation shaft 130 is attached, the pivot receiving portion 165 provided in the inclination jig 160, the wire 166 attached to the inclination jig 160, and the inclination jig 160. A mechanism for controlling the inclination angle of the inclination jig 160 by moving the wire 166 is employed.

The difference between Example 3 and Example 4 is that a mechanism for tilting not only around the third axis of the tilting jig 160 but also around the fourth axis is added. The tilt jig 160 and the tilt angle control method using the wire 166 will be described with reference to FIGS. 14A to 14C.

When two wires-166 and one spring are attached at the position shown in FIG. 14 (A), the tilt jig is moved to the third axis by moving the first wire and the second wire in the same direction. Inclined around the fourth axis by moving in the opposite direction. In FIG. 14A, two-axis control is performed using two wires and one screw in order to minimize the number of parts.

Next, as shown in FIG. 14B, it is possible to perform two-axis control with two wires and two springs. The tilt jig can be tilted around the third axis by moving the first wire 166-1 and tilted around the fourth axis by moving the second wire.

Further, as shown in FIG. 14C, it is not necessary to attach the wire and the spring on the third axis or the fourth axis, and the first wire 166-1 is attached at a position where it does not interfere with other parts. By adjusting the movement of the second wire 166-2 as appropriate, the tilt jig can be tilted around the third axis and the fourth axis.

Since the angle setting mechanism and the angle setting mechanism can be tilted not only around the third axis but also around the fourth axis, they are the same as those in the third embodiment, and thus the description of the microscope main body and the photographing procedure is omitted. To do.

Example 5 shows an example in which a sample processed into a protruding shape is mounted on a sample holder using the configuration of FIG. In this embodiment, as a form of the second rotation angle control mechanism, there are a pulley part 136 processed in the first rotary jig 130 and a wire 137 hung on the pulley part 136, and the wire 137 is moved by moving the wire 137. A control mechanism for rotating one rotary jig 130 was adopted. In addition, as a form of the angle setting mechanism, it is a tapered surface 121 on which the first rotating shaft 150 is installed, and an angle formed between the normal line of the tapered surface 121 and the first rotating shaft is set to around 54.7 degrees. Adopted structure.

FIG. 16 shows the basic structure of the first rotary jig 130. The first rotary jig 130 has a pulley portion 136 for hooking a wire 137, an insertion portion 133 inserted into the holding rod 120, and a screw hole portion 132 used for detaching the needle-like sample table 150. A line connecting the sample 10 and the outer periphery of the pulley portion and the second so that the first rotating jig does not block the microscope optical path even if the sample 10 is rotated around the first axis or the second axis. The length of the grip portion 152 and the diameter of the pulley were determined so that the angle formed by the axis of the grip portion was 35 degrees or less, and this time 30 degrees.

Next, FIG. 17 shows the basic structure of the tip of the holding rod 120. A first rotating portion 130 is attached to the tip of the holding rod 120, and a wire-137 is hung on the pulley portion 136 of the first rotating jig 130. The first rotating jig 130 is rotated by moving the wire 137 using a motor (not shown) that moves the wire 137.

In addition, there is slippage between the pulley and the wire as a problem when the first rotating jig is rotated by the pulley and the wire instead of the bevel gear. If there is slippage, there may be a difference between the amount of movement of the motor and the amount of rotation of the first rotating shaft. Therefore, it is more preferable to provide means for directly measuring the rotation angle of the first rotating jig. This time, the rotation angle can be measured in the microscope by attaching marks 138 at equiangular intervals on the top surface of the pulley or on the base 13 of the sample (see FIG. 5).

In order to create marks with equal intervals, a needle-like sample stage is mounted on a sample holder that can set the rotation axis of the bevel gear and the optical axis of the focused ion beam processing apparatus in parallel, and the bevel gears are equiangularly spaced. As an example, a method of processing a mark with an ion beam each time the substrate is rotated by the ion beam.

Since other than the second rotation angle control mechanism is the same as that of the first embodiment, description of the microscope main body and the photographing procedure is omitted. Further, the form of the fifth embodiment can be used for the second rotation angle control mechanism in the second, third, and fourth embodiments. In this case, the wire 137 is passed through the hole 162 provided in the inclined jig 160.

The sample holder used in Examples 1 to 5 includes the holding cylinder 110 and the holding rod 120, but the holding cylinder 110 is not an essential part. That is, by using the sample holder shown in FIG. 19, it can be applied to other embodiments. Since the sample drift at the tip of the holding rod 120 is suppressed by using the holding cylinder 110, the sample holder of FIG. 4 is more suitable for high resolution observation. On the other hand, the measurement shown in FIG. 19 can be performed with a reduced number of parts. Except for the presence or absence of the holding cylinder 110, the operation is the same as in the first to fifth embodiments.

In Examples 1 to 6, samples processed into protrusions are mounted on sample holders, but it is also possible to mount samples processed into thin films on these sample holders. FIG. 20 shows the shape of the thin film processed sample 10 and the basic structure of the needle-like sample stage 150 on which the sample 10 is mounted. The sample 10 has a column portion 15 and a thin film portion 14 that encloses the observation region 11, and is placed at the tip of a needle-like sample stage 150.

In order to obtain a transmission electron image, the thickness of the thin film portion 12 is reduced from 50 nm to 200 nm. When the sample 10 is rotated about the first axis and the second axis, there is an angle range in which the column portion cuts off the microscope optical path, and thus a projection image in a 360-degree range cannot be obtained. Therefore, the magnetic field component Bx reconstructed from the rotation series image around the x axis, the magnetic field component By reconstructed from the rotation series image around the y axis, and the magnetic field component Bz reconstructed from the rotation series image around the z axis are projected. Artifacts due to angle limitations occur.

However, compared to Bz calculated using the Maxell equation divB = 0 from the magnetic field component Bx and the magnetic field component By where the projection angle range is restricted, the artifacts generated in Bz are greatly reduced. Depending on the observation purpose, the observation region may not be included in the protrusion, and in this case, it is effective to adopt the sample shape of FIG.
Except for the difference in the sample shape, this is the same as in Examples 1 to 6, so description of the microscope main body, imaging procedure, etc. is omitted.

Examples 1 to 7 show examples in which the sample holder is used in an observation apparatus, but it is also possible to use this sample holder in common with a sample processing apparatus. Although not shown, the sample observation device and the sample processing device are used in common, so that the sample can be prevented from being damaged when the needle-like sample table 150 is detached from the sample holder.

Also, in the sample processing apparatus, by using this sample holder, the incident direction of the charged particle beam with respect to the sample can be arbitrarily set, and there is an advantage that the degree of processing increases.

DESCRIPTION OF SYMBOLS 1 ... Electron source or electron gun, 2 ... Optical axis, 10 ... Sample, 11 ... Sample observation area | region, 12 ... Sample protrusion part, 13 ... Sample base part, 14 ... Sample thin film part, 15 ... Sample support | pillar , 18 ... Vacuum container, 19 ... Electron source control unit, 27 ... Electron beam trajectory, 39 ... Sample stage control unit, 40 ... Acceleration tube, 41 ... First irradiation (condenser) lens, 42 ... Second irradiation (Condenser) lens 47... Second irradiation lens control unit 48. First irradiation lens control unit 49... Acceleration tube control unit 5. Objective lens 51. Monitor, 53 ... Control system computer interface, 59 ... Objective lens control unit, 61 ... First imaging lens, 62 ... Second imaging lens, 63 ... Third imaging lens, 64 ... Fourth imaging 66 ... control unit for fourth imaging lens, 67 ... control unit for third imaging lens, 68 ... control unit for second imaging lens, 69 ... control unit for first imaging lens, 76 ... image observation Monitor of recording device, 77 ... Image recording device, 78 ... Control unit for image observation / recording medium, 79 ... Image observation / recording medium (for example, TV camera or CCD camera), 8 ... Interference fringe, 89 ... Observation / recording surface 91 ... Central fine wire electrode of the first electron biprism, 93 ... Central fine wire electrode of the second electron biprism, 97 ... Control unit of the second electron biprism, 98 ... First electron Linear biprism control unit, 100 ... Sample holder, 101 ... X direction moving linear actuator, 102 ... Y direction moving linear actuator, 103 ... Z direction moving linear actuator 104, a pivot portion at the tip of the sample holder, 105 ... a motor for rotating around the first axis, 110 ... a holding cylinder, 111 ... an opening of the holding cylinder, 120 ... a holding rod, 121 ... a tapered surface at the tip of the holding rod, 122 ... Support rod end strut portion, 123... Holding rod tip pivot receiving portion, 124... Holding rod tip pivot portion, 125. Holding rod tip strut holding screw, 130... First rotating jig, 131. 1 is a bevel gear portion of a rotating jig, 132 is a insertion portion of a first rotating jig, 133 is a screw hole portion of the first rotating jig, 134 is a spring of the first rotating jig, and 135 is a spring of the first rotating jig. Retaining jig, 136 ... first rotating jig pulley section, 137 ... wire for first rotating jig, 138 ... mark for measuring the rotation angle of the first rotating jig, 140 ... second rotating jig, 141 ... first 142, the bevel gear part of the rotary jig 2 ... Supporting part of second rotating jig, 150... Needle sample table, 151. Tapered part of needle sample table, 152. Grip part of needle sample table, 153. Screw part of needle sample table, 154. Guide part of the sample stage, 160... Tilting jig, 161... Hole 161 for passing the insertion part 132 of the first rotating jig through the tilting jig, 162... The column part 142 or wire of the second rotating jig to the tilting jig. 137, a hole for passing through 163, screw holes 163 for mounting the tilting jig to the

support rod

120, 164, a pivot part of the tilting jig, 165, a pivot receiving part of the tilting jig, 166, a wire of the tilting jig, 167,. Slant jig spring,

Claims

A sample holder used in a charged particle beam apparatus for irradiating and observing a charged particle beam on a sample,
The sample holder is
A rotating jig having a mounting part for attaching the sample to the tip part;
A holding rod having a holding portion for holding the rotating jig;
A first rotation angle control unit that rotates the holding rod around a first axis orthogonal to the charged particle beam;
A second rotation angle control unit for rotating the rotary jig around a second axis,
The sample holder, wherein the holding unit includes an angle setting unit that sets an angle formed by the first axis and the second axis to an arbitrary angle.
In claim 1,
The sample holder, wherein the holding portion has a tapered surface that defines an angle formed by the first axis and the second axis in the vicinity of 54.7 degrees.
In claim 1,
The holding rod has a first gear that rotates in the first axial direction;
The rotating jig has a second gear to which rotation is transmitted from the first gear,
The sample holder, wherein the second rotation angle control unit rotates the rotating jig by a rotating operation of the first gear and the second gear.
In claim 1,
The holding rod has a wire connected to the rotary jig,
The said angle setting part rotates the said rotation jig with the said wire, The sample holder characterized by the above-mentioned.
In claim 1,
The holding portion has a tapered surface in an inclined relationship with the first axis,
The sample holder, wherein the angle setting section determines an angle formed by the first axis and the second axis to an arbitrary angle by a pivot provided on the tapered surface.
In claim 1,
The sample holder is characterized by having a mark that can be observed by the charged particle beam device and marked at an equiangular interval with respect to the second rotation.
A charged particle beam apparatus comprising: an irradiation optical system that irradiates a sample with a charged particle beam; a sample holder that holds the sample; and a detection optical system that detects charged particles from the sample;
The sample holder is
A rotating jig having a mounting part for attaching the sample to the tip part;
A holding rod having a holding portion for holding the rotating jig;
A first rotation angle control unit that rotates the holding rod around a first axis orthogonal to the charged particle beam;
A second rotation angle control unit for rotating the rotary jig around a second axis,
The charged particle beam apparatus, wherein the holding unit includes an angle setting unit that determines an angle between the first axis and the second axis as an arbitrary angle.
In claim 7,
The charged particle beam apparatus according to claim 1, wherein the holding portion has a tapered surface that defines an angle formed by the first axis and the second axis in the vicinity of 54.7 degrees.
In claim 7,
The holding portion has a tapered surface in an inclined relationship with the first axis,
The charged particle beam device according to claim 1, wherein the angle setting unit determines an angle formed by the first axis and the second axis by a pivot provided on the tapered surface.
Attaching the sample to the tip of the sample mount;
Making the x-axis of the sample parallel to the first axis of rotation;
Obtaining a rotating series image about the x-axis of the sample;
Making the y-axis of the sample parallel to the first rotation axis;
Obtaining a rotating series image about the y-axis of the sample;
Making the z-axis of the sample parallel to the first axis of rotation;
Obtaining a rotational series image about the z-axis of the sample,
The charged particle beam microscopic method, wherein the x-axis, the y-axis, and the z-axis are orthogonal coordinate systems.
In claim 10,
Making the x-axis of the sample parallel to the first rotation axis, making the y-axis of the sample parallel to the first rotation axis, and making the z-axis of the sample parallel to the first rotation axis Is a step of rotating the sample around a second axis inclined near 54.7 degrees with respect to the first rotation axis.
In claim 10,
The step of obtaining a rotation series image of the sample around the x-axis, the step of obtaining a rotation series image of the sample around the y-axis, and the step of obtaining a rotation series image of the sample around the z-axis include the rotation angle of the sample. A charged particle beam microscopic method characterized in that the range is one rotation or more in each axis.
In claim 10,
A charged particle beam microscope, further comprising a step of irradiating the sample with a second charged particle beam and processing the sample into a protrusion or a thin film.