WO2014167884A1 - Diffraction grating, diffraction grating element, and charged particle beam device equipped with same - Google Patents

Abstract

This charged particle beam device generates an electron vortex beam by passing a charged particle beam through (A) a diffraction grating which includes a plurality of edge dislocations of differing orders, or (B) a diffraction grating element comprising a plurality of diffraction gratings which include edge dislocations of differing orders. The electron vortex beam has a plurality of ring-like diffraction spots of differing diameters which overlap on the diffraction image plane, and therefore is suited to devices for which it is necessary to irradiate a wide sample region, such as a transmission electron microscope.

Description

Diffraction grating, or diffraction grating element, or charged particle beam apparatus including the same

The present invention relates to a diffraction grating used to generate a charged particle helical wave, a diffraction grating element comprising the grating, or a charged particle beam apparatus including the diffraction grating element.

<Spiral wave>
In a coherent optical system, the phase of a propagating light wave is uniquely determined. Surfaces with the same phase are called wavefronts, and wave types such as plane waves and spherical waves are classified based on the shape of the wavefront. There are cases where the phase has a singular point that is not uniquely determined. For example, a spiral wave having a helical shape centered on an axis having an equiphase surface (generally parallel to the optical axis). This is a phase state where the phase changes by an integral multiple of 2π when the azimuth is rotated once, with the singular point at the center (helical axis) when viewed along a plane perpendicular to the wave propagation direction. It is a wave that has.

Fig. 1 shows a spiral wave 21 classified as a plane wave. As is apparent from the figure, the phase is singular on the helical axis 22 and the phase cannot be determined. This spiral wave is called a Laguerre-Gaussian beam or optical vortex (Hikari Uzu) in optics, and propagates while maintaining the orbital angular momentum. It applies a force to the isophase plane (wavefront) in the vertical direction. Can do. Therefore, it becomes possible to give momentum to the irradiation target, and it has been put into practical use as a manipulation technique such as optical tweezers for manipulating particles having a size of about a cell, for example. It has also been put to practical use as laser processing and super-resolution microspectroscopy.

Furthermore, multiple orbital angular momentums can be inherent in the portion of the helical axis that is the phase singularity (the helical winding strength can be selected as a topological charge (referred to as “helicality” for simplicity in this application)) Therefore, new technical developments are expected in the field of quantum information communication and in physical properties analysis and structural analysis such as analysis of magnetic images and solid images of atomic arrangements in X-rays.

The spiral wave (electron spiral wave) in the electron beam propagates while maintaining the orbital angular momentum, and is expected to create an unprecedented field of application as an electron beam probe (incident beam). For example, high sensitivity in magnetization measurement, measurement of a three-dimensional state, high-contrast / high-resolution observation of protein molecules and sugar chains, and the like. In particular, in the magnetization observation, the electron beam has the fundamental drawback that it is not sensitive to the magnetization parallel to the propagation direction, but the possibility of observing the magnetization in the electron beam propagation direction is possible with the electron spiral wave. There is. In addition to observation, there is a possibility of application to machining and magnetization control using orbital angular momentum. Therefore, along with the spin-polarized electron beam, it has begun to attract attention as a probe for the next-generation electron beam apparatus.

<Generation of spiral waves>
It is known that a diffraction grating including edge dislocations generates a spiral wave (having a spiral phase surface) as a diffraction wave (FIG. 2). The spiral wave 21 forms a ring-shaped diffraction spot 97 in place of the normal point-shaped diffraction spot 99 in the diffraction image 9. That is, if the diffraction grating 91 including edge dislocations is irradiated with the plane wave 23 and can be spatially separated on the diffraction surface, the desired spiral wave 21 can be extracted. The present application relates to a method and apparatus (diffraction grating) for using this spiral wave as a probe (incident beam) of a transmission type charged particle beam apparatus.

4 and 5 are diagrams showing the results of experiments conducted by the inventor prior to the invention. The helical degree of the helical wave is determined by the order of the edge dislocation, and the positive or negative of the helical degree or the polarity (right-handed or left-handed of the spiral) is determined by the positive / negative of the edge-shaped dislocation. That is, it is possible to control the helical wave generated by the edge dislocation. In the diffraction image, the diffraction point of the spiral wave is generated on both the left and right sides, and higher-order diffraction points are generated according to the contrast of the diffraction grating, which corresponds to a high-frequency spiral wave. It is possible to generate a plurality of types of helical waves from a diffraction grating including a dislocation (see FIGS. 4 and 5). On the other hand, the intensity of the generated spiral wave is dispersed and weakened.

<Fork lattice>
Although it is a discussion of tipping over at the end, a fork type diffraction grating including edge dislocations can be described as an interference fringe between a helical wavefront and a plane wave.

Plane wave 23 of spiral waves 21 and angularly alpha _x tilt in the x-axis direction propagation propagating on the optical axis 2 in FIG. 3, showing how to form an interference pattern including edge dislocations on the xy plane. In the drawing, one grid is inserted in the positive value portion on the y-axis. The end points of this lattice are the cores of edge dislocations. This interference relationship can be easily described by geometric optics.

A plane wave propagating at an angle α _x is expressed by Φ _p , and a helical wave Φ _s propagating on the optical axis is expressed by Equations 1 and 2. However, it is assumed that λ is the wavelength of the wave, the amplitude of the plane wave and the spiral wave is 1, and the distribution is uniform. The handling of the amplitude is the same in the following formulas 1 and 2 unless otherwise specified.

Here, η included in the phase term of the plane wave is a phase value at the point O where observation is performed, and is an initial phase value when the interference fringes are formed. Further, n _hm takes an integer value by the degree of spiraling, and the magnitude of the value indicates the strength of winding of the spiral, and the direction of winding of the spiral (right-handed or left-handed when viewed in the propagation direction) depending on the value of the value. This n _hm corresponds to the quantum number of the orbital angular momentum, and is known as a topological charge in the Laguerre Gaussian beam. φ is the phase value at the beginning of winding of the helix.

In the lower part of FIG. 3, as the simplest case, interference fringes in the case of n _hm = 1, η = 0, and φ = 0 are drawn. The intensity distribution is expressed as Equation 3.

The interference fringes including edge dislocations expressed by Equation 3 have a shape in which the modulation of Equation 5 is added to Equation 4, which is an interference fringe when two plane waves interfere with each other by being inclined by a relative angle α _x . .

Unless otherwise noted, in the present application, a grating figure expressed as “grating that characterizes a diffraction grating”, “basic grating”, and the like means that it is determined based on the interference fringes represented by Equation 4, and is proposed in the present application. The lower part of the lattice figure is drawn so as to correspond to this.

<Generation of spiral wave using fork type diffraction grating>
For example, there are mainly two methods (1) and (2) for generating a spiral wave in an electron beam.
(1) Transmitting through a spiral phase plate [Non-patent Document 1]
(2) A diffraction grating (fork type diffraction grating) including edge dislocations is used [Non-Patent Document 2].
The present application relates to the method (2). Hereinafter, the description will be made mainly using an electron microscope. However, the present application is not limited to an electron beam, but is applied to a charged particle beam apparatus including an ion beam.

Next is an example. FIG. 4 shows a fork-type diffraction grating having a spiral degree of 5 and an electron diffraction image thereof. The left side of FIG. 4A is an electron microscope image of a diffraction grating obtained by calculating a lattice pattern based on Equation 3 and processing a silicon nitride membrane (thickness: 200 nm) using a focused ion beam apparatus. Five lattices are inserted from the upper side in the figure and concentrated in the center. That is, this concentrated portion is the position of the core of the edge dislocation, and the order is fifth. The degree of helix and the degree of edge dislocation agree. When the helical degree is negative, the edge dislocation lattice is inserted from the lower side. White portions in the image are gaps that transmit electron beams, and black portions in between are the trunks of the lattice. The lattice spacing of the basic lattice (lower part on the left side of FIG. 4A) is 400 nm.

4 (a) is a small-angle electron diffraction image (recorded at a camera length of 1500 m) on the right side, showing up to five convenient diffraction spots of 0th order, ± 1st order, and ± 2nd order. The fact that the ± 1st order and ± 2nd order diffraction spots are in a ring shape is proof that an electron spiral wave is generated. Since a fork-type diffraction grating having a spiral degree of 5 is used, the ± first order spots are ± 5 degree spiral waves, and the ± second order spots are ± 10 degree spiral waves. The ring diameter increases with the degree of helix.

Fig. 4 (b) shows the calculation results. The left side of FIG. 4B is the calculation result based on the fork-type diffraction grating on the left side of FIG. 4A, and the right side of FIG. 4B is the 0th order, ± 1st order, and ± 2nd order diffraction images, respectively. It is a simulation result. The ± 1st-order diffraction spots correspond well with the experimental results, and the diameters of the ring-shaped spots are almost the same. In the calculation result, the ± 2nd-order diffraction image is extremely weak, but this does not cause streak in the diffraction image obtained by the simulation, so that the harmonics appear in the diffraction grating on the left side of FIG. This is because a sinusoidal intensity distribution that does not cause the problem is given. When harmonics are generated, it has been confirmed that high-order diffraction spots such as ± 2nd order and ± 3rd order are generated.

FIG. 5 shows fork-type gratings having a spiral degree of 1, 3, 5, 7, and 9 and their electron diffraction images (from the −1st order to the + 4th order). The number of edge dislocation lattices inserted corresponding to the degree of helix increases. Since the high-order diffraction spot becomes extremely dark, a plurality of diffraction images with different exposures are combined and displayed. Since it is a small-angle electron diffraction image (recorded at a camera length of 1500 m) with a large camera length, the outer shape of the fork-type grating is also reflected in the diffraction image, and the shape of each diffraction spot is not a circle but a square ring. However, there is no difference in the basic concept, and the ring diameter increases as the diffraction order increases, and the ring diameter increases as the spiral type fork diffraction grating increases, as in FIG. . That is, it can be seen that the ring diameter of the diffraction spot directly represents the helical degree of the helical wave.

US2012 / 0153144

As shown in the previous experimental results, the generation of the electron spiral wave itself can be realized with an electron microscope. The ring-shaped diffraction spot can be used as a probe for a scanning electron microscope as it is. By irradiating the sample with a ring-shaped diffraction spot and scanning it, an electron spiral wave with a degree of helicality immediately corresponding to the diffraction spot is obtained. An observation image using can be obtained.

However, since a transmission electron microscope must irradiate a certain area, it is impossible to use a diffraction spot as it is. In order to make an electron beam that can irradiate a certain area on the sample, it is necessary to extract a ring-shaped diffraction point and propagate it to the image plane of the fork-shaped diffraction grating to return it to a spiral wave with a predetermined frequency and polarity. . After narrowing down to at least a positive or negative diffraction spot, it must propagate to the vicinity of the image plane of the fork type diffraction grating. This means that after generating and selecting a spiral wave, an additional optical system is required before the sample is irradiated. This is a considerably severe restriction for an electron microscope or a charged particle beam apparatus in which the number and positions of optical elements such as an electron lens that can be used are limited.

In order to maintain the specified magnification on the sample, the irradiation optical system can be modified significantly (fork-type grating insertion, diffracted electron beam selection on the diffraction image plane, and imaging system for use as a probe). Or a propagation distance) is required.

If the magnification on the sample is not large, a part of the imaging system, such as an objective lens, can be used as the irradiation optical system, but the sample is inserted into an appropriate position other than the predetermined position for fine movement. This is a limitation.

In any case, unlike the scanning type, there are many restrictions on using the currently obtained electron spiral wave as a probe for a transmission electron microscope.

In order to solve the above problems, the diffraction grating of the present application is a diffraction grating that is used in a charged particle beam apparatus and generates a diffraction phenomenon in the charged particle beam, and the diffraction grating includes a plurality of diffraction gratings in the grating plane of the diffraction grating. It is characterized by having a shape including the edge dislocation.

Also, the charged particle beam apparatus of the present application is characterized in that, in the above, using the diffraction grating, the sample is irradiated with a diffracted charged particle beam for observation or processing.

The diffraction grating element of the present application is a diffraction grating element composed of a plurality of diffraction gratings that generate a diffraction phenomenon in a charged particle beam, and the plurality of diffraction gratings in the diffraction grating element are arranged in one plane. In addition, the plurality of diffraction gratings have a shape including edge dislocations in each grating plane.

The charged particle beam apparatus of the present application is characterized in that, in the above, the sample is irradiated with a diffracted charged particle beam and observed or processed using the diffraction grating element.

The charged particle beam device of the present application holds a light source of a charged particle beam, an irradiation optical system for irradiating the sample with a charged particle beam emitted from the light source, and a sample irradiated with the charged particle beam. A charged particle beam device having an imaging lens system for forming an image of the sample, wherein the charged particle beam device is more charged than the sample holding device on an optical axis of the charged particle beam device. A diffraction grating that generates a diffraction phenomenon in the charged particle beam on the upstream side in the traveling direction of the particle beam and has a shape including a plurality of edge dislocations in the lattice plane, or is diffracted by the charged particle beam A diffraction grating element composed of a plurality of diffraction gratings for generating a phenomenon, wherein the plurality of diffraction gratings are arranged in one plane, and the plurality of diffraction gratings include an edge dislocation in each grating plane. Times forming shape Grating element, characterized in that it comprises a.

According to the present invention, a spiral wave that can be used as a charged particle beam probe in a charged particle beam apparatus can be created.

It is a schematic diagram of a spiral wave (planar shape). It is a schematic diagram which shows a mode that a helical wave is produced | generated from an edge dislocation (third order) diffraction grating. It is a schematic diagram which shows formation of the interference fringe containing edge dislocation by interference with a helical wave and a plane wave. It is a 5th-order fork type diffraction grating and a small angle electron diffraction image. It is a 5th-order fork type diffraction grating and a small angle electron diffraction image. The first-order, third-order, fifth-order, seventh-order, and ninth-order fork diffraction gratings and their respective small-angle electron diffraction images are shown in order from the top. FIG. 3 is a schematic diagram of a diffraction grating in which fork-type gratings that generate spiral waves having a degree of spiral of 2, 3, and 1 are linearly arranged. It is a conceptual diagram of the design point of Fig.6 (a). It is a simulation result of the diffraction grating containing the core of three edge dislocations of FIG. 6, and its diffraction image. FIG. 5 is a schematic diagram of a fork-type diffraction grating in which edge dislocations that generate spiral waves having spiral degrees of 2, 1, and 3 at an angle of 45 degrees from the upper right to the lower left are arranged linearly. FIG. 4 is a schematic diagram of a fork-type diffraction grating in which edge dislocations that generate spiral waves having a degree of spiral of 2, 2, and 2 at an oblique angle of 45 degrees from the upper right to the lower left are linearly arranged. FIG. 5 is a schematic diagram of a fork-type diffraction grating in which edge dislocations that generate helical waves having a degree of spiral of 2, 2, and 2 are arranged in a straight line in the same direction as the basic grating. FIG. 4 is a schematic diagram of a fork-type diffraction grating in which edge dislocations that generate helical waves having a spiral degree of 2, 2, and 2 at an angle of 90 degrees with a basic grating are arranged linearly. It is a schematic diagram of a diffraction grating element in which diffraction gratings having ninth-order, first-order, and fifth-order edge dislocations are arranged. It is a schematic diagram of a diffraction grating element in which diffraction gratings having first-order, ninth-order, and fifth-order edge dislocations are arranged. It is a figure which shows the example which aligned the phase of the basic grating of a diffraction grating. It is a figure which shows the example arrange | positioned shifting the phase of the fundamental grating of a diffraction grating. It is a figure which shows the experimental result of a diffraction grating element. It is a figure which shows the simulation result of a diffraction grating element. It is a schematic diagram of a diffraction grating element in which a plurality of diffraction gratings having different external shapes are arranged on a plane. It is a schematic diagram which shows an example of the transmission electron microscope provided with the diffraction grating element. It is a figure which shows an example of the schematic diagram of a diffraction grating and a diffraction grating element demonstrated to Example 6, and the simulation result of a diffraction image. FIG. 9 is a schematic diagram of a diffraction grating and a diffraction grating element, and a simulation result of a diffraction image, illustrating Example 7. FIG. It is the figure which copied the diffraction grating shown to Fig.17 (a), and the 0th-order and +/- 1 order simulation result. FIG. 9 is a schematic diagram of a diffraction grating and a diffraction grating element, and a simulation result of a diffraction image, illustrating Example 8. FIG. It is the figure which copied the diffraction grating shown to Fig.18 (a), and the 0th-order and +/- 1st-order simulation result. FIG. 10 is a schematic diagram of a diffraction grating and a diffraction grating element and a simulation result of a diffraction image for explaining Example 9. FIG. It is the figure which copied the diffraction grating shown in Drawing 19 (a), and the 0th order, ± 1st order, and ± 2nd order simulation result. FIG. 10 is a schematic diagram of a diffraction grating and a diffraction grating element and a simulation result of a diffraction image for explaining Example 10. FIG. It is the figure which copied the diffraction grating shown in Fig.20 (a), and the 0th-order and +/- 1st-order simulation result. It is a schematic diagram which shows an example of the transmission electron microscope provided with the diffraction grating element.

The present application proposes the following (1) to (3) as optical elements for generating a spiral wave.
(1) Fork-type lattice having a plurality of edge dislocations,
(2) Or a diffraction grating element in which a plurality of fork-type diffraction gratings are arranged on a plane so that charged particle beam irradiation can be performed at once.
(3) Alternatively, a plurality of diffraction gratings having appropriate and various outer shapes, or a diffraction grating element in which the arrangement of a plurality of diffraction gratings on a plane is optimized,
This is a proposal.

According to the present application, the following (1) to (3) are possible.
(1) By using a fork-type grating having a plurality of edge dislocations and generating ring-shaped diffraction spots having different spirals, that is, different diameters, superimposed on diffraction spot positions of the same order, they are transmitted on the diffraction image plane. A spiral wave that can be used as a probe for a charged particle beam device
(2) Alternatively, it is possible to generate electron diffraction images of a plurality of fork-type diffraction gratings at a time so that diffraction spots having different spiralities are superimposed on diffraction spot positions of the same order and transmitted on the diffraction image plane. A spiral wave that can be used as a probe for a charged particle beam device
(3) Alternatively, by utilizing the fact that small-angle diffraction also reflects the shape of the diffraction grating, the outer shape of the plurality of diffraction gratings is appropriately selected, or the arrangement of the plurality of diffraction gratings is optimized to obtain a diffraction image. Creates a spiral wave that can be used as a probe for a transmission charged particle beam device on the surface,
It becomes possible.

These are also effective as elements for creating spiral waves in charged particle beams such as electron beams (electron waves), light waves, X-rays, and other waves. Although the description which mainly illustrated the electron beam apparatus (especially electron microscope) becomes main, this application is not limited to an electron beam. In addition, the diffraction grating referred to in the present application mainly refers to a diffraction grating that does not have a lens action on the beam of the charged particle beam apparatus.

<Fork type diffraction grating with multiple edge dislocations>
A plurality of spiral axes of a spiral wave can be distributed on a plane, and each coordinate on the xy plane can be handled independently including (x _m , y _m ), including the degree of spiral. That is, the phase term of Formula 2 indicating a spiral wave may be changed to Formula 6.

Here, the intensity distribution of the interference fringes having a plurality of edge dislocations, that is, the grating pattern of the fork type diffraction grating is shown in Equation 7.

When there are multiple edge dislocations, the relationship between the core position of each edge dislocation (corresponding to the position of the helical axis of the helical wave) and the phase of the fundamental lattice at that position is Affect each other, and therefore, different from the case where there is one edge dislocation (Equation 3, or FIGS. 4 and 5), it varies in various ways. However, adjustment is possible by the position (x _m , y _m ) of each core and the phase term η of the plane wave.

In the simplest case expressed by Equation 3, or in the diffraction grating including one edge dislocation illustrated in FIGS. 4 and 5, there is no problem. However, as described above, the diffraction grating including a plurality of edge dislocations. Then, the cores of the second and third edge dislocations are not always located at the trunk portion of the lattice. In actual diffraction grating fabrication, it is necessary to consider the mechanical strength of the grating, and it is desirable that the edge dislocation core be positioned near the center of the trunk of the grating. In this case, an appropriate lattice pattern may be drawn by adjusting the core positions (x _m , y _m ) of the second and third edge dislocations and the phase term η.

<Example 1>
FIG. 6 shows a straight line of fork-type gratings that generate spiral waves with spiral degrees of 2, 3, and 1, respectively, at an angle of 45 degrees diagonally from upper right to lower left, that is, at an angle of 45 degrees with the orientation of the basic grating. It is a schematic diagram of the arrange | positioned diffraction grating. FIG. 6A shows a diffraction grating pattern calculated based on Equation 7, which corresponds to a design drawing. FIG. 6B is a conceptual diagram depicting the design point of FIG. 6A in an easy-to-understand manner. The outer shape is a 45 degree diagonal angle from the upper right to the lower left with respect to the circular lattice. It shows that the edge dislocations are arranged in a straight line. Further, the hatched portion on the lower right side of the circle indicates that this is the basic grating portion of this diffraction grating. Thereafter, in order to clarify the characteristics of the diffraction gratings without depending on the resolution of the drawing, a drawing as shown in FIG. 6B is attached to each diffraction grating.

FIG. 7 is a simulation result of a diffraction grating including the three edge dislocation cores of FIG. 6 and its diffraction image. The ring-shaped diffraction spots observed or calculated in FIGS. 4 and 5 are not generated. That is, the diffraction spot from the diffraction grating including the cores of the three edge dislocations indicates a spiral wave that can irradiate the region, and can be used as a probe in a transmission type charged particle beam apparatus. I understand that.

When the three edge dislocations in FIG. 6 (a) are enlarged, it can be seen that the core of the edge dislocation is located almost at the center of the trunk of the lower basic lattice. This is the result of adjusting the position of each edge dislocation and the phase of the plane wave based on Equation 7 so that the position of the edge dislocation is almost at the center of the trunk of the lattice in order to maintain the mechanical strength of the grating. is there.

FIG. 6A illustrates a diffraction grating including a core of three edge dislocations, but the present application does not limit the number of edge dislocations to three. If a large number of edge dislocations are arranged in a range where an incident wave such as an electron beam can be irradiated, the number of spiral waves superimposed on one diffraction spot position increases, and a high density and uniform area irradiation probe can be obtained.

As described above, FIG. 6A shows a fork type diffraction grating that can generate a plurality of spiral waves having different spiral degrees by superimposing them on one diffraction spot position on the diffraction image plane.

<Example 2>
FIG. 8 shows a diffraction grating having an angle of 45 degrees obliquely from the upper right to the lower left, that is, a diffraction grating having an angle of 45 degrees with the orientation of the basic grating, as in FIG. FIG. 8B is a schematic diagram of a fork-type diffraction grating in which edge dislocations for generating spiral waves of 2, 1, and 3 and spiral waves of degrees 2, 2, and 2 are arranged in a straight line. The position of the core of the edge dislocation is adjusted so as to be approximately at the center of the trunk of the lattice, as in FIG.

As described above, FIG. 8 shows that a plurality of spirals can be arbitrarily selected in size and position. By designing the diffraction grating to be used in this way, it is possible to adjust and control the distribution and density of the spiral wave generated by being superimposed on one diffraction spot position on the diffraction image plane.

<Example 3>
FIG. 9 is an example of a diffraction grating having a plurality of edge dislocations as in FIG. In FIG. 9, the three edge dislocations are all secondary dislocations and form a straight line, but in FIG. 9A, the arrangement is vertical (same orientation (parallel) to the lattice of the basic lattice). In 9 (b), the horizontal direction (vertical (90 degrees) with the basic lattice). It is the same as in FIGS. 8 and 6A that the position of the edge dislocation is adjusted so as to be approximately at the center of the trunk of the lattice. In FIG. 9A, the basic grating is located in the lower part of the core of the lowest secondary edge dislocation, and the influence of the basic grating on the diffraction grating as a whole is small. This corresponds to the fact that the diffraction spot has a spread in the diffraction image.

As described above, FIG. 9 shows that the orientation of the array of cores of a plurality of edge dislocations can be designed. By designing a diffraction grating to be used in this way, it is possible to adjust and control the distribution and density of the spiral wave generated by superimposing on one diffraction spot position on the diffraction image plane, as in the previous embodiment. is there.

<Example 4>
FIG. 10 shows an example of a diffraction grating element in which three diffraction gratings are arranged on one plane. FIG. 10A shows a diffraction grating element in which diffraction gratings having ninth-order, first-order, and fifth-order edge dislocations are arranged clockwise from above. Similarly, FIG. 10B shows a diffraction grating element in which diffraction gratings having first-order, ninth-order, and fifth-order edge dislocations are arranged clockwise from above. However, FIG. 10B shows an arrangement in which each basic lattice is rotated by ± 5 degrees.

In this example, it is possible to superimpose a plurality of spiral waves on one diffraction spot position on the diffraction image plane as long as a plurality of arbitrarily selected diffraction gratings are arranged in a range where incident waves such as electron beams can be irradiated. There is an advantage over the previous embodiment in the simplicity of design. The degree of edge dislocation to be selected, the number of diffraction gratings to be arranged, the positions to be arranged, the orientation of the basic grating of each diffraction grating, and the like are arbitrary. In particular, if the orientations of the basic gratings of the respective diffraction gratings are slightly shifted from each other, the orientation in which the diffraction spot is formed in the diffraction image also changes with the orientation of the basic grating, which is effective for area irradiation. In FIG. 10B, the diffraction grating having the lower right 9th-order edge dislocation gives an azimuth angle of 5 degrees clockwise, and the diffraction grating having the lower left 5th-order edge dislocation gives an azimuth angle of 5 degrees counterclockwise. Yes. These angles and the order of dislocations are examples, and the present application is not limited to these values.

FIG. 10 illustrates a diffraction grating element including a diffraction grating having three edge dislocations, but the present application is not limited to three. When a large number of diffraction gratings are arranged in a range where incident waves such as electron beams can be irradiated, the number of spiral waves superimposed on one diffraction spot position increases, and a high-density and uniform area irradiation probe can be obtained.

Here, the difference between the diffraction grating element shown in FIG. 10 and the diffraction grating including a plurality of edge dislocations shown in FIGS. In the diffraction grating including a plurality of edge dislocations shown in FIGS. 6, 8, and 9, there is one basic grating, and a ring-shaped spiral wave is formed in the diffraction spot of the diffraction image based on the periodicity and phase of the basic grating. A plurality of waves to be generated are superimposed. The phases of the plurality of waves are unified by the basic lattice.

On the other hand, in the diffraction grating element composed of a plurality of diffraction gratings, the periodicity and phase of each basic grating are arbitrary and are not uniquely determined. That is, even if diffraction gratings having edge dislocations of the same order are arranged, if diffraction gratings with the phase of each basic grating shifted by π are arranged, the diffraction spot is weakened due to interference in the diffraction image and the diffraction spot becomes dark. Become. This can be used to control the intensity of the diffraction spot. This can be an advantage in terms of controlling the intensity of the diffraction spot, but in general, the diffraction spot is inferior in intensity compared to the transmission spot, and the observation using the diffraction spot as a probe has a problem of improving the S / N ratio of the image. Therefore, it is desirable that the phases of the fundamental gratings of the respective diffraction gratings are aligned. That is, it is desirable that the intensity of the diffraction spot is large.

Therefore, an example in which the phases of the basic gratings of the diffraction grating are aligned is shown in FIG. FIG. 11 shows a basic grating (white broken line grating) superimposed on the diffraction grating element of FIG. The lower side of the three diffraction gratings (having 9th-order, 1st-order, and 5th-order edge dislocations clockwise from the top) is a portion of the basic grating. It can be seen that the trunk (black line) of this basic lattice coincides with the white broken lines of the basic lattice (see arrows). That is, the three diffraction gratings have the same basic grating.

On the other hand, FIG. 12 shows an example in which the phases of the basic grating are not aligned. FIG. 12 shows the same combination of diffraction gratings as in FIG. 11, but the positions of the lower first-order and fifth-order diffraction gratings are exactly ¼ period of the basic grating (the first order grating is +1/4 period, The fifth-order lattice is shifted by ¼ period) in the horizontal direction in the figure. That is, the phases of the basic grating are not aligned.

When actually designing and manufacturing a diffraction grating element, it is desirable that the basic grating is unified (see FIG. 11) as described above.

FIG. 13 shows the experimental results (FIG. 13 (a)) and the simulation results (FIG. 13 (b)). The phases of the basic gratings described above are substantially matched. In the design of a fork-type diffraction grating including edge dislocations, the effect of the spiral wave is the largest at the core of the edge dislocation and decreases as it moves away from it, but basically the effect continues to infinity. . Therefore, even if the basic gratings coincide with each other, when the diffraction grating is actually manufactured with a finite size, the influence remains on the period and phase of the basic grating. This problem is more conspicuous as the lattice has a higher degree of spiralness, that is, a higher degree of edge dislocations.

The diffraction image is shown on the right side of FIG. Although the four diffraction spots from the −1st order to the second order are shown, in the experimental result of FIG. 13A, the three ring-shaped diffraction spots are not arranged on the concentric circles. The center position is shifted. This is because the position of each diffraction grating and the slight deviation of the above-mentioned basic grating appear sharply in the image because of the small-angle diffraction. However, the experimental results indicate that three ring-shaped diffraction spots are superimposed on one diffraction spot position, and the idea of the present application is realized.

The simulation result of FIG. 13B also shows that the ± 1st-order diffraction spot does not have the ring shape seen in FIG. 4B, and spreads, and region irradiation can be performed using this diffraction spot. It is shown that.

In addition, although not shown in the drawings, in an actual experimental system, there are a method of blurring a ring-shaped diffraction spot, that is, a plurality of methods effective for area irradiation. For example, a method of increasing the opening angle of the incident wave incident on the diffraction grating or the diffraction grating element to widen the spot diameter on the diffraction image plane, that is, the distribution of the spiral wave, and the focus of the lens that forms the diffraction image There is a method of causing the diffraction image itself to blur by shifting. Since both are controlled by the optical system upstream of the sample, it can be adjusted independently of the imaging condition of the sample (for example, adjustment of magnification or adjustment of focus).

<Example 5>
FIG. 14 shows another example of the diffraction grating element 93 in which a plurality of diffraction gratings 91 having different outer shapes are arranged on a plane. A diffraction image that generates a spiral wave is small-angle diffraction, and the outer shape and arrangement position of the diffraction grating are reflected in the diffraction image. The difference in the azimuth angle of each diffraction grating, the difference in the outer shape of each diffraction grating, and the order of the edge dislocation possessed by each diffraction grating as seen from the position of the optical axis 2 of the irradiation probe to the diffraction grating element (however, FIG. , Etc.) are superimposed on one diffraction spot of the diffraction image to generate a spiral wave of region irradiation.

<Example 6>
FIG. 15 is an example of a charged particle beam apparatus provided with a diffraction grating element 93 for irradiating a sample with a spiral wave. Although a transmission electron microscope is illustrated as an example, it is not limited to an electron microscope.

The diffraction grating element 93 disposed in the irradiation optical system is adjusted by, for example, the first condenser lens 41 for the irradiation opening angle and the irradiation angle with the optical axis 2. A diffraction image of the diffraction grating element 93 is formed on the sample by the second condenser lens 42 below the diffraction grating element 93. A diffraction spot to be used for observation as a probe is selected by, for example, the diaphragm 15 and irradiated on the sample. The electron beam that has passed through the sample 3 passes through the objective lens 5 and the imaging lens system (61, 62, 63, 64) on the lower side thereof, is enlarged to a predetermined magnification, and forms an image on the image receiving surface 89. The sample image 35 is observed on a screen of an image data monitor 76, for example, via a detector 79 and a controller 78, or stored as image data in a recording device 77.

These apparatuses are systematized as a whole, and an operator confirms the control state of the apparatus on the monitor 52 screen, and uses the system control computer 51 via the interface 53 to use the electron source 1, the acceleration tube 40, Each lens (41, 42, 5, 61, 62, 63, 64), sample 3, diaphragm 15, detector 79, etc. can be controlled. The assumed charged particle beam apparatus includes a beam deflection system, an evacuation system, and the like. However, since there is no direct relationship with the present application, illustration and description are omitted.

<Example 7>
First, FIG. 16 shows a schematic diagram of the diffraction grating and the diffraction grating element described up to Example 6 and an example of a simulation result of the diffraction image. FIGS. 16A, 16B, and 16C show edge dislocation gratings (left figure) having orders of 1st order, 5th order, and 9th order, respectively, and waves (in this case, charged particles) transmitted through the respective diffraction gratings. It is a simulation result (right figure) of the diffraction image by line. In the right figure, the 0th-order diffraction spot corresponding to the transmitted wave is located at the center of the diffraction image, and the diffraction spots corresponding to the 1st- to 4th-order diffraction waves are shown on the right and left sides, respectively. Centering on the 0th order spot, for example, the right side corresponds to a positive diffraction spot and the left side corresponds to a negative diffraction spot.

Each diffraction spot has a characteristic ring shape, which indicates that the diffraction spot is a spiral wave having a spiral degree determined by the diffraction order and the edge dislocation order. In general, the helical degree is represented by the product of the order of diffraction spots and the order of edge dislocations. For example, in FIG. 16A, the diffraction spot of the spiral wave has a spiral degree of 1 degree, 2 degrees, 3 degrees, and 4 degrees in the right direction from the 0th order spot. In FIG. In the right direction, it is a diffraction spot of a spiral wave having a spiral degree of 5, 10, 10, 15, and 20 degrees. It can be seen that the ring diameter of the spiral diffraction spot increases corresponding to the degree of helix.

FIG. 16D is also a schematic diagram of the diffraction grating and the diffraction grating element up to Example 6 and a diagram showing an example of the simulation result of the diffraction image. FIG. 16D shows an example (left figure) of an edge dislocation grating element composed of three edge dislocation gratings of the first order, the fifth order, and the ninth order, and a wave transmitted through the diffraction grating element ( Here is a simulation result (right figure) of a diffraction image by charged particle beams. By generating ring-shaped diffraction spots having different spirals, that is, having different diameters, with the same center in the same diffraction plane, a spiral wave can be generated by superimposing them so as to irradiate a spatial region in the form of a plane wave. Here, the plane wave refers to a wave (in this case, a charged particle beam) having a certain irradiation region as used in a transmission electron microscope (TEM) or the like.

Since a plane wave-shaped irradiation region is generated, the irradiation spiral probe is suitable for a normal transmission electron microscope that is not a scanning type. The left figure in FIG. 16D is displayed at a different magnification from the left figures in FIGS. 16A to 16C for convenience of display, but the relationship between the magnifications is a scale bar of 5 μm in the figure. It is shown and clarified. The magnification of the diffraction image is the same in FIGS.

In Example 7, in order to generate a suitable irradiation spiral probe in a transmission electron microscope or the like using a spiral wave as an irradiation probe based on the above idea, the center of the ring-shaped diffraction spot by the spiral wave is the same. In this case, ring-shaped diffraction spots having different diameters are generated in the same diffraction plane, and are superimposed to generate a spiral wave that can irradiate a spatial region in a plane wave shape. Further, in the following embodiments including this embodiment, by making the spiral degree of the ring-shaped diffraction spots to be superimposed the same, the spiral wave is generated and the spiral wave is generated so that the spatial region can be irradiated in a plane wave shape. It is characterized by that.

That is, specifically, a diffraction grating element provided with a plurality of edge dislocation gratings having the same order of edge dislocations, the basic lattice spacing, and the lattice orientation, and having different outer diameters (diameters) of the gratings is used. Further, a charged particle beam apparatus is used that observes or processes a sample by irradiating the sample with a charged particle beam diffracted by the diffraction grating element.

The diffraction grating elements used in this Example 7 have the same degree of spiraling, but there are a plurality of types of lattice plane sizes of the edge dislocation gratings constituting the diffraction grating elements, so that the diffraction grating elements are generated from the respective diffraction waves. The ring-shaped diffraction spots have different diameters. Therefore, by superimposing ring-shaped diffraction spots with the same spiral degree and different spot diameters on the same plane, a spiral wave can be generated that can irradiate a spatial region in a plane wave form with the same spiral degree. it can. Furthermore, since the degree of spiraling is uniform, the strength of the interaction between the irradiated sample and the irradiated spiral wave probe is constant within the irradiated region, allowing observation of the sample with a more uniform contrast or processing of the sample. It becomes.

The present embodiment will be described with reference to FIGS. 17 (a) and 17 (b). FIG. 17A is a schematic diagram of a diffraction grating and a diffraction grating element for explaining Example 7 and a simulation result of a diffraction image. FIG. 17B is a diagram (image diagram) showing a copy of the diffraction grating shown in FIG. 17A and the 0th and ± 1st order simulation results. As shown in FIGS. 17A to 17D, each of the diffraction gratings has third-order edge dislocations, and the basic lattice spacing and the lattice orientation are the same. The left side of FIG. 17 shows an edge dislocation grating, and the right side of FIG. 17 shows a simulation result of a diffraction image by a wave (in this case, a charged particle beam) transmitted through each diffraction grating.

In the right diagram of FIG. 17, the 0th-order diffraction spot corresponding to the transmitted wave is located at the center of the diffraction image, and the diffraction spots corresponding to the 1st- to 4th-order diffraction waves are shown on the left and right, respectively. The configuration of the above figure is the same as that of FIG. The relationship of diffraction images by the wave (charged particle beam) transmitted through the diffraction grating or the diffraction grating element and the diffraction grating in the explanatory diagrams of the present application is the same in the subsequent drawings unless otherwise specified.

(A), (B), and (C) in FIG. 17 (a) are the cases where the outer diameter of the lattice plane changes in order of large (RL), medium (RM), and small (RS) in this order, These are edge dislocation gratings and diffraction images from the gratings when the area of the grating changes from large to medium to small. As shown in FIG. 17A and FIG. 17B, it can be seen that the ring diameter of the ring-shaped diffraction spot increases as the grating outer diameter decreases. However, in FIGS. 17A to 17C, the first-order and second-order diffraction spots look like multiple rings, but the outer ring of these multiple rings is the Fraunhofer diffraction created by the aperture shape. Is equivalent to In this embodiment, a ring-shaped diffraction spot corresponding to the main maximum of the innermost Fraunhofer diffraction is considered.

FIG. 17 (D) shows an example of a diffraction grating element having a plurality of types in the size of the lattice plane of the edge dislocation grating. The left diagram of FIG. 17A (D) shows the diffraction gratings (A) to (C) of FIG. 17 (a) arranged on the same plane with the same basic grating spacing and grating orientation. It is a diffraction grating element. (D) in FIG. 17A is a diffraction grating element in which diffraction gratings having large (RL), medium (RM), and small (RS) outer diameters are arranged counterclockwise from above. The right figure in (D) of FIG. 17A is a diffraction image by a wave (charged particle beam) transmitted through the diffraction grating element in the left figure. Ring diffraction spots having the same spiral degree but different ring diameters are diffracted the same. It is shown that a spiral wave is generated that can be generated in a plane and superimposed to irradiate a spatial region in a plane wave shape. In particular, the ± 1st-order diffraction spot is not a ring shape but a plane wave incident probe that irradiates a region. In other words, the ring-shaped central portion (core portion) of the ± 1st-order diffraction spot is small.

For the convenience of display, the edge dislocation lattice image of FIG. 17 (d) is displayed at a different magnification from the left figure of FIGS. 17 (a) to 17 (c), but the relationship between the magnifications is a scale bar of 5 μm. Is shown in the figure to clarify. The magnification of the diffraction image is the same in FIGS.

In this way, if diffraction grating elements composed of edge dislocation gratings having different outer diameters are used, ring-shaped diffraction spots having different diameters can be obtained on the same diffraction plane even if the order of the edge dislocations is the same. Therefore, the ring-shaped diffraction spots from the respective edge-shaped dislocation gratings are superimposed, and a plane wave irradiation spiral probe suitable for a normal transmission electron microscope or the like is generated.

<Example 8>
The present embodiment will be described with reference to FIGS. 18 (a) and 18 (b). FIG. 18A is a schematic diagram of a diffraction grating and a diffraction grating element for explaining Example 8, and a simulation result of a diffraction image. FIG. 18B is a diagram (image diagram) showing a copy of the diffraction grating shown in FIG. 18A and simulation results of the 0th order and ± 1st order. (A) and (B) of FIG. 18 (a) each have a third-order edge dislocation, and the three edge dislocation lattices having the same basic lattice interval and lattice orientation and different outer diameters are in the same plane. Above, an example of a diffraction grating element (left side in the figure) arranged in a direction perpendicular to the orientation of the basic grating, and a simulation result of a diffraction image by a wave (charged particle beam in this case) transmitted through the diffraction grating element is there. The diffraction pattern on the right side of FIG. 18 (a) has a larger display magnification than those of FIGS. 16 and 17 (a), and corresponds to the first-order and second-order diffracted waves respectively on the left and right with the zeroth-order diffraction spot as the center. Only diffraction spots are shown.

Further, in (A) of FIG. 18 (a), the arrangement of the edge dislocation lattices is arranged in the order of large (RL), medium (RM), and small (RS) from the left side in the drawing. On the other hand, in (B) of FIG. 18A, they are arranged in the order of small (RS), medium (RM), and large (RL) from the left side in the figure. However, in the diffraction image (right figure), there is no significant difference between (A) and (B) in FIG. 18A (see also FIG. 18B). The reason for this is that the diffraction image is a Fraunhofer diffraction image with an infinite propagation distance, and the information on the grating position is lost, and the information is only the direction and the interval (spatial frequency). Therefore, in a diffraction grating element having a plurality of diffraction gratings having different sizes, the position of each diffraction grating on the same plane theoretically does not matter.

However, in an actual device, Fraunhofer diffraction with an infinite propagation distance is not feasible, and it becomes an observation of a Fraunhofer diffraction image at a finite distance, so the positional relationship with the optical axis depends on the experimental conditions. This may be reflected as the center deviation of the ring-shaped diffraction spot. Therefore, in FIG. 18A of the eighth embodiment, the diffraction gratings are arranged in the direction perpendicular to the orientation of the basic grating (in this case, in the lateral direction), and the ring-shaped diffraction spots of the ring-shaped diffraction spots are reliably ensured even in an actual apparatus. It is an example of the diffraction grating element comprised so that a center might correspond.

<Example 9>
The present embodiment will be described with reference to FIGS. 19 (a) and 19 (b). FIG. 19A is a schematic diagram of a diffraction grating and a diffraction grating element for explaining Example 9, and a simulation result of a diffraction image. FIG. 19B is a diagram (image diagram) showing the diffraction grating shown in FIG. 19A and the simulation results of the 0th order, ± 1st order, and ± 2nd order.

FIG. 19A shows a case where the number of diffraction gratings having a small diffraction grating surface is larger than the number of diffraction gratings having a large diffraction grating surface ((B) in FIG. 19A). ), (C)). In other words, the number of diffraction gratings having a certain area is smaller than the number of diffraction gratings having a smaller area. In this case, it is suitable for generating a spiral probe capable of irradiating a plane wave-like space region.

When the diffraction grating surface is relatively smaller than other diffraction gratings, the intensity (amount) of the wave (here, charged particle beam) diffracted from the smaller diffraction grating surface is small. Since the diffraction spot diffracted from the smaller diffraction grating surface becomes a diffraction spot having a large ring diameter in the diffraction plane, the intensity of the ring-shaped diffraction spot is further reduced.

For example, (A) in FIG. 19 (a) is an example of one diffraction grating (RL only) having a large diffraction grating surface, and (B) in FIG. 19 (a) has a relatively large grating surface size. This is an example of a diffraction grating element in which large (RL), medium (RM), and small (RS) diffraction gratings are arranged at an angle of 45 degrees with respect to the orientation of the basic grating. Comparing (A) and (B) in FIG. 19A, the intensity of the innermost ring is strong for the ± 1st-order or second-order ring-shaped diffraction spots, and (A) in FIG. , (B) are not significantly changed (see also (A), (B) of FIG. 19B). In FIG. 19A (B), a ring-shaped diffraction spot by a diffraction grating having a small size is located outside the innermost ring-shaped spot. This means that the ring-shaped contrast corresponding to the submaximal of Fraunhofer diffraction seen in (A) of FIG. 19 (a) has disappeared, that is, the superposition of a plurality of ring-shaped diffraction spots.

However, it can be seen that the contribution from a diffraction grating having a small diffraction grating surface is relatively small. (C) in FIG. 19A is an example of a diffraction grating element when the number of diffraction gratings having a small diffraction grating surface is large. Specifically, a diffraction grating element having one grating (RL) having a relatively large diffraction surface, four middle gratings (RM), and four smaller gratings (RS). It is an example.

In FIG. 19A (C), it can be seen that the intensity at the outer periphery of the ring-shaped diffraction spot is increased as compared with (B). In FIG. 19A (C), the arrangement of each lattice has fourfold symmetry. That is, in the figure, small lattices (RS) are arranged on the upper, lower, left and right sides of the large lattice (RL), and middle lattices (RM) are disposed obliquely on the upper right, lower right, upper left, and lower left of the large lattice (RL). Has been. In this way, in FIG. 19C (C), since the arrangement of each grating has a four-fold symmetry, a grating pattern corresponding to the four-fold symmetry can be seen in the diffraction image (FIG. 19B). (See also (C))). This means that the intensity of the outer periphery of the ring-shaped diffraction spot is increased to such an extent that the formation of the pattern can be seen.

Here, for example, when focusing on (B) large (RL) and medium (RM) in FIG. 19A, the diffraction grating having a certain area with respect to the optical axis (see FIG. 21) is smaller. It can be said that it is provided closer to the diffraction grating having the area.

<Example 10>
As mentioned in Example 9, increasing the size of the irradiation region of the wave (charged particle beam in this case) that irradiates the diffraction grating element means a decrease in intensity per unit area of the irradiation probe. Therefore, it is important to efficiently arrange a plurality of diffraction gratings having different grating plane sizes in the wave irradiation region. Here, “efficient” means that the gaps between the lattices or the area of the gaps are arranged to be small.

The present embodiment will be described with reference to FIGS. 20 (a) and 20 (b). FIG. 20A is a schematic diagram of a diffraction grating and a diffraction grating element for explaining Example 10 and a simulation result of a diffraction image. FIG. 20B is a diagram (image diagram) showing a copy of the diffraction grating shown in FIG. 20A and the 0th and ± 1st order simulation results.

In FIG. 20A, (A) shows a case where a diffraction grating (RM) having a medium grating surface is arranged in four directions of a diffraction grating (RL) having a large grating surface, and further, a grating is provided at the periphery thereof. This is an example in which a diffraction grating (RS) having a small surface size is arranged. For example, this is an example of a diffraction grating element including one grating (RL) having a relatively large diffraction surface, four intermediate gratings (RM), and 20 small gratings (RS). . For example, middle grids (RM) are arranged on the upper, lower, left, and right sides of the larger grid (RL), and five smaller grids (RS) are arranged on the upper right, lower right, upper left, and lower left of the large grid (RL). A small lattice group consisting of is arranged. Of course, the number of diffraction surfaces is not limited to the exemplified number as long as it has a plurality of gratings having relatively different sizes.

When comparing the diffraction image of FIG. 20A with the diffraction image of FIG. 19C, the diffraction image of FIG. 20A has four times at each diffraction grating position. The lattice pattern corresponding to the symmetry is more prominent than (C) in FIG. 19A (see also (A) in FIG. 20B and (C) in FIG. 19A). This is a manifestation of the effect of increasing the intensity of the diffraction image. However, when the intensity distribution of the diffraction image having the lattice pattern is used as an irradiation probe for the sample, new artifacts are introduced in observation and processing. There is a fear. This is due to the fact that Fraunhofer diffraction with an infinite propagation distance is not possible in Example 7.

Therefore, an example in which the positions of the diffraction gratings are randomized to reduce the symmetry is shown in FIG. For comparison, the number of diffraction gratings is not changed between (A) and (B) in FIG. In (B) of FIG. 20A, the center of the large lattice (RL) and the center of the middle lattice (RM) are not arranged in a straight line, and are below the large lattice (RL). The middle grid (RM) is displaced. Also, the lattice (RM) on the right side of the large lattice (RL) is shifted. The small lattice groups are arranged diagonally in the upper right, lower right, upper left, and lower left of the large lattice (RL), but the arrangement positions are not symmetrical. For example, the line connecting the center of the large lattice (RL) and the center of the small lattice (RS) is not regularly arranged. The diffraction image of FIG. 20A (B) is the same as the diffraction image of FIG. 20A (A), and the ring-shaped diffraction spots have the same spread, and the four-fold symmetry pattern disappears. Is clear. In this way, by effectively arranging a plurality of diffraction gratings having different grating plane sizes, the spiral wave having the same spiral degree and a spatially widened area can be avoided while avoiding the above-mentioned artifact. An irradiation probe can be realized.

<Example 11>
FIG. 21 is an example of a charged particle beam apparatus including a diffraction grating element 94 for irradiating a sample with a spiral wave. Drawing and explanation are made with a transmission electron microscope as an example, but the present application is not limited to an electron microscope.

First, the diffraction grating element 94 arranged in the irradiation optical system imitates the shape of (D) of FIG. 17A as an example. Of course, the shape is not limited to this. The electron beam 27 irradiating the diffraction grating element 94 is adjusted by, for example, the first condenser lens 41 to adjust the irradiation opening angle and the irradiation angle with the optical axis 2. At this time, the irradiation region of the electron beam 27 that irradiates the diffraction grating element 94 is adjusted so that the edge dislocation included in each diffraction grating 91 on the diffraction grating element 94 is included in the irradiation region. A diffraction image of the diffraction grating element 94 is formed on the sample by the second condenser lens 42 below the diffraction grating element 94.

Then, a diffraction spot to be used for observation as an irradiation probe for the sample is selected by, for example, the diaphragm 15 and irradiated onto the sample 3. The electron beam 27 that has passed through the sample 3 passes through the objective lens 5 and the imaging lens system (61, 62, 63, 64) on the lower side thereof, is enlarged to a predetermined magnification, and forms an image on the image receiving surface 89. . The sample image 35 can be observed on a screen of an image data monitor 76, for example, via a detector 79 and a controller 78, and can also be stored as image data in a recording device 77.

These apparatuses are systematized as a whole, and an operator confirms the control state of the apparatus on the monitor 52 screen, and uses the system control computer 51 via the interface 53 to use the electron source 1, the acceleration tube 40, Each lens (41, 42, 5, 61, 62, 63, 64), the sample 3, the diaphragm 15, the detector 79, the diffraction grating element 94, and the like can be controlled.

Note that the assumed charged particle beam apparatus includes a beam deflection system, a vacuum exhaust system, and the like, but illustration and description of these facilities are omitted in the present application.

As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

DESCRIPTION OF SYMBOLS 1 ... Electron source, 15 ... Aperture, 17 ... Control system of aperture, 18 ... Vacuum container, 19 ... Control system of electron source, 2 ... Optical axis, 21 ... Spiral wave, 23 ... Plane wave, 3 ... Sample, 35 ... Sample 39 ... control system of sample holding device, 40 ... acceleration tube, 41 ... first condenser lens, 42 ... second condenser lens, 47 ... control system of second condenser lens, 48 ... control system of first condenser lens 49 ... Accelerating tube control system, 5 ... Objective lens, 51 ... System control computer, 52 ... System control computer monitor, 53 ... System control computer interface, 59 ... Objective lens control system, 61 ... First intermediate lens 62 ... second intermediate lens, 63 ... first projection lens, 64 ... second projection lens, 66 ... second projection lens control system, 67 ... first projection lens control system, 68 ... second intermediate , 69 ... control system of the first intermediate lens, 71 ... image surface of the sample by the objective lens (first image surface), 72 ... image surface of the sample by the first intermediate lens (second image surface), 73 ... image surface (third image surface) of sample by second intermediate lens, 74 ... image surface (fourth image surface) of sample by first projection lens, 76 ... monitor for image data, 77 ... image data recording device, 78 DESCRIPTION OF SYMBOLS ... Image data controller, 79 ... Image detector, 89 ... Image-receiving surface, 9 ... Diffraction image, 91 ... Diffraction grating, 93 ... Diffraction grating element, 95 ... Basic grating, 96 ... Control of diffraction grating or diffraction grating element holding device System 97 ... Ring diffraction spot, 99 ... Point diffraction spot

Claims (21)

1. A diffraction grating that is used in a charged particle beam device and generates a diffraction phenomenon in a charged particle beam,
   The diffraction grating has a shape including a plurality of edge dislocations in a grating plane of the diffraction grating.
2. In claim 1,
   The diffraction grating characterized in that the orientation of the branched trunk of the grating characterizing the edge dislocation is the same direction as the orientation of the grating characterizing the diffraction grating.
3. In claim 1,
   Each of the cores of the plurality of edge dislocations exists in a central portion of a trunk of the grating characterizing the diffraction grating.
4. In claim 1,
   The diffraction grating, wherein the cores of the plurality of edge dislocations are arranged on a straight line.
5. In claim 4,
   The diffraction grating, wherein a straight line connecting the cores of the plurality of edge dislocations is an orientation of the grating characterizing the diffraction grating.
6. In claim 4,
   A diffraction grating characterized in that a straight line connecting the cores of the plurality of edge dislocations forms an angle of 45 degrees with the orientation of the grating characterizing the diffraction grating.
7. In claim 4,
   A diffraction grating characterized in that a straight line connecting each core of the plurality of edge dislocations forms an angle of 90 degrees with the orientation of the grating characterizing the diffraction grating.
8. A diffraction grating element composed of a plurality of diffraction gratings that generate a diffraction phenomenon in a charged particle beam,
   The plurality of diffraction gratings in the diffraction grating element are arranged in one plane;
   The diffraction grating element, wherein the plurality of diffraction gratings have a shape including edge dislocations in each grating plane.
9. In claim 8,
   The diffraction grating element characterized in that the orientations of the gratings characterizing each diffraction grating in the plurality of diffraction gratings are the same direction.
10. In claim 9,
    In the edge dislocation included in each of the plurality of diffraction gratings, the direction of the branched trunk of the grating characterizing the edge dislocation is the same as the direction of the grating characterizing the diffraction grating. element.
11. In claim 9,
    The diffraction grating element characterized in that the gratings characterizing each diffraction grating in the plurality of diffraction gratings are arranged in the same period and in the same phase.
12. In claim 1,
    A charged particle beam apparatus, wherein the sample is irradiated with a diffracted charged particle beam and observed or processed using the diffraction grating.
13. In claim 8,
    A charged particle beam apparatus for observing or processing a sample by irradiating a sample with a diffracted charged particle beam using the diffraction grating element.
14. A charged particle beam light source, an irradiation optical system for irradiating the sample with the charged particle beam emitted from the light source, a sample holding device for holding the sample irradiated with the charged particle beam, and an image of the sample A charged particle beam device having an imaging lens system for imaging
    A diffraction grating for generating a diffraction phenomenon in the charged particle beam on the optical axis of the charged particle beam apparatus on the upstream side in the traveling direction of the charged particle beam with respect to the sample holding device, and a plurality of blades in the grating plane A diffraction grating element having a shape including a dislocation, or a diffraction grating element composed of a plurality of diffraction gratings that generate a diffraction phenomenon in the charged particle beam, wherein the plurality of diffraction gratings are arranged in one plane A charged particle beam apparatus comprising: a diffraction grating element in which the plurality of diffraction gratings have a shape including edge dislocations in each grating plane.
15. In claim 14,
    In the charged particle beam device,
    One diffraction spot among diffraction spots which are transmitted through the diffraction grating or the diffraction grating element and have a ring shape due to a diffraction phenomenon,
    A charged particle beam apparatus characterized by irradiating and observing or processing the sample as an irradiation charged particle beam.
16. In claim 8,
    In the plurality of diffraction gratings, each grating plane includes edge dislocations of the same order.
17. In claim 8,
    A diffraction grating element characterized in that the plurality of diffraction gratings have the same grating interval characterizing each grating.
18. In claim 8,
    A diffraction grating element, wherein the plurality of diffraction gratings have different diameters.
19. In claim 8,
    In the plurality of diffraction gratings, the diffraction grating having a first area, and a diffraction grating having a second area relatively smaller than the first area,
    The number of diffraction gratings having the first area is smaller than the number of diffraction gratings having the second area.
20. In claim 8,
    In the plurality of diffraction gratings, the diffraction grating having a first area, and a diffraction grating having a second area relatively smaller than the first area,
    A diffraction grating element, wherein the diffraction grating having the first area is provided closer to the optical axis of the charged particle beam to be irradiated than the diffraction grating having the second area.
21. In claim 14,
    The diffraction grating element has a diffraction grating having a first area and a diffraction grating having a second area relatively smaller than the first area,
    A charged particle beam apparatus, wherein a diffraction grating having the first area is provided closer to an optical axis of the charged particle beam to be irradiated than a diffraction grating having the second area.
    

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