JP2006236601A - Orbital position detecting device, composition analyzer, orbit adjusting method for charged particle beam and position coordinate detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an orbital position detecting device capable of improving adjustment accuracy by simplifying adjustment work for an electron beam orbit and easily detecting shift of an electron beam in operating a device, to provide a composition analyzer provided with this and an orbit adjusting method for a charged particle beam, and to provide a position coordinate detecting device capable of easily detecting a coordinate position of a beam current measurement means such as a Faraday cup used for the orbital position detecting device. <P>SOLUTION: The beam current measurement means such as a segmented electrode 10 or the Faraday cup 20 etc. measuring a beam current of an ion beam L emitted from an accelerator Y1 is provided in a measurement chamber 73a of a sample analyzer. An orbital position of the ion beam L is detected based on an observed value of the beam current by the beam current measurement means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a trajectory position detecting device for detecting the trajectory position of a charged particle beam irradiated to an irradiated object such as a sample, a composition analyzer having the same, and a method for adjusting the trajectory of a charged particle beam. This is a technique for adjusting the trajectory of a charged particle beam irradiated to an irradiation object and detecting the trajectory deviation of the charged particle beam.

  Various apparatuses such as a composition analysis apparatus, a beam processing apparatus, and a radiotherapy apparatus are known as apparatuses using charged particle beams such as ion beams. In such an apparatus, the adjustment of the trajectory of the charged particle beam is conventionally performed by visually confirming the light emission position of the fluorescent plate previously placed at the irradiation position of the charged particle beam, or by the shielding plate previously placed at a predetermined position. This is performed while visually confirming whether or not the charged particle beam is blocked. Specifically, the beam trajectory adjustment mechanism provided in the beam generator that is the source of the ion beam or the like is operated (maneuvered) manually or electrically so that the trajectory of the charged particle beam coincides with a predetermined beam axis. The ion beam is adjusted by horizontally moving or tilting.

Here, a sample analyzer Y (an example of a composition analyzer) which is an example of a typical apparatus using the charged particle beam will be described below with reference to FIG. Patent Document 1 discloses an ion scattering analyzer configured in the same manner as the sample analyzer Y.
The sample analyzer Y shown in FIG. 8 is roughly configured to include an accelerator Y1 and a superconducting spectrometer unit (hereinafter abbreviated as “spectrometer unit”) Y2 disposed below the accelerator Y1.
The accelerator Y1 includes an ion source 71 that generates ions such as helium and an acceleration tube 72 that accelerates the generated ions to form an ion beam L, and emits the ion beam L to the spectrometer unit Y2. The emitted ion beam L is incident on the spectrometer unit Y2 via an optical system device such as an ion lens 80 or an objective collimator (not shown). The accelerator Y1 is provided with a known beam trajectory adjusting mechanism that adjusts the trajectory of the ion beam L.
The spectrometer unit Y2 applies a uniform magnetic field (magnetic field) parallel to the beam axis toward the upstream in the incident direction of the ion beam L passing through the measurement chamber 73 (corresponding to a vacuum vessel) and the measurement chamber 73. A solenoid coil 75 and a correction coil 76 generated within a predetermined range of the measurement chamber 73, a magnet yoke 90, a magnetic pole 91, an aperture 77 disposed on the upstream side in the beam incident direction in the magnetic field region in the measurement chamber 73, and A two-dimensional detector 78 is provided. The aperture 77 allows the ion beam L to pass in the incident direction and causes scattered ions (corresponding to scattered particles) scattered by the sample 74 (corresponding to the irradiated object) to be opposite to the incident direction of the ion beam L. An opening 77a that allows the ion beam to pass therethrough is provided at the center, and the opening 77a is disposed so as to coincide with the beam axis through which the ion beam L originally passes. The two-dimensional detector 78 has an opening 78a through which the ion beam L passes in the incident direction, and the opening 78a is arranged so as to coincide with the beam axis. The magnetic field is required for detection of specific scattered ions elastically scattered by the sample 74 disposed in the measurement chamber 73.
In such a configuration, the sample 74 is disposed in the measurement chamber 73, the inside of the measurement chamber 73 is evacuated to a predetermined degree of vacuum by an exhaust means such as a turbo molecular pump and a rotary pump (not shown), and the solenoid coil 75 and An ion beam L is made to enter the measurement chamber 73 from the accelerator Y1 with an excitation current applied to the correction coil 76 and a magnetic field applied to the measurement chamber 73. The ion beam L passes through the opening 78 a of the two-dimensional detector 78 and the opening 77 a of the aperture 77 and is irradiated on the sample 74. Scattered ions H are generated from the sample 74 irradiated with the ion beam L, and the scattered ions H are converged by a magnetic field, and only the scattered ions H under a specific condition pass through the opening 77a of the aperture 77 and are a two-dimensional detector. 78 is reached. The detection output of scattered ions H detected by the two-dimensional detector 78 is amplified by an amplifier (not shown) and counted (counted) by a multichannel analyzer or the like.
JP-A-7-190963

However, the above-described method for adjusting the trajectory of the charged particle beam directly checks the irradiation state of the fluorescent screen irradiated with the charged particle beam to see whether the trajectory of the charged particle beam is on a predetermined beam axis. In this case, an error exceeding the allowable range may occur in the adjustment. This error is a problem because it causes a decrease in the accuracy of fine processing using a beam and composition analysis using an ion beam.
In the sample analyzer Y (FIG. 8) described above, the measurement chamber 73 that accommodates and arranges the two-dimensional detector 78, the aperture 77, and the sample stage 79 (corresponding to the mounting stage) has a solenoid coil 75 and a correction coil 76. Since the surroundings are surrounded by, for example, the inside of the measurement chamber 73 cannot be visually observed, it is difficult to adjust the charged particle beam.
On the other hand, even if the trajectory of the charged particle beam is initially adjusted to coincide with the beam axis, the trajectory position of the charged particle beam may be gradually shifted. However, conventionally, there has been no effective method for easily detecting this shift. Therefore, for example, in the sample analyzer Y, the charged particle beam deviated (warped) from the beam axis collides with the aperture 77 before being irradiated onto the sample 74, and scattered ions and secondary electrons generated therefrom are generated. When detected by the two-dimensional detector 78, there is a problem that the composition analysis of the sample 74 cannot be performed accurately.
Accordingly, the present invention has been made in view of the above circumstances, and the first object thereof is to facilitate the adjustment work of the trajectory of the charged particle beam to improve the adjustment accuracy and to improve the adjustment accuracy during the operation of the apparatus. An object of the present invention is to provide an orbital position detecting device capable of easily detecting a deviation of a charged particle beam, a composition analyzing device including the same, and a charged particle beam orbit adjusting method.
On the other hand, the orbital position detecting device of the present invention comprises beam current measuring means such as a Faraday cup as will be described later. However, in the orbital position detecting device, the current measuring means must be arranged at a predetermined position accurately. Don't be. However, it is difficult to arrange the current measuring means at a predetermined position and to check whether the current measuring means is arranged at a predetermined position.
Accordingly, a second object of the present invention is to provide a position coordinate detection device capable of easily detecting the coordinate position of a beam current measuring means such as a Faraday cup used in the orbit position detection device. is there.

In order to achieve the above object, an orbital position detection apparatus of the present invention comprises beam current measuring means for measuring the beam current of a charged particle beam emitted from a charged particle beam generation source and applied to an irradiated object. The orbit position of the charged particle beam is detected based on the measurement value of the beam current by the current measuring means.
Thereby, the charged particle beam can be adjusted while monitoring the beam current measured by the beam current measuring means. In this way, the charged particle beam trajectory position can be easily adjusted because the charged particle beam trajectory position can be determined by the objective material of the beam current rather than by visual observation of the charged particle beam. And the adjustment error can be reduced. Furthermore, when the charged particle beam deviates from the normal trajectory, the deviation can be easily detected.
Here, it is conceivable that the beam current measuring means measures the beam current of a charged particle beam passing through a predetermined beam axis. For example, if the current value is measured only when it passes through the beam axis and is not measured when it does not pass, it is determined whether the charged particle beam is deviated depending on whether the current value is measured. Is possible. Conversely, the beam current measuring means may measure the beam current of a charged particle beam deviated (deviated) from a predetermined beam axis.

As a specific example of the beam current measuring means, for example, a configuration including a Faraday cup disposed at a predetermined position on a predetermined beam axis is conceivable. Thus, for example, when the Faraday cup is irradiated with a charged particle beam that does not coincide with the beam axis, the current detected at this time is attenuated (decreased) than the current detected when they coincide. Of course, no current is detected when the charged particle beam deviates significantly from the normal orbit. Therefore, in this case, the orbital position of the charged particle beam can be detected based on the detected current attenuation or based on the fact that no current was detected.
When an opening for passing the charged particle beam in the incident direction of the charged particle beam is provided on the bottom surface of the Faraday cup, a current flows when the charged particle beam that coincides with the beam axis is irradiated to the Faraday cup. Is detected (a minute amount even if detected), but when the Faraday cup is irradiated with a charged particle beam that does not coincide with the beam axis, a current is detected (or the detected current increases (rises)). It will be. Therefore, in this case, the orbital position of the charged particle beam can be detected based on the detected current or the increased amount of detected current.
As another example of the beam current measuring means, an electrode member disposed at a predetermined position on the beam axis and having an opening at the center for allowing the charged particle beam to pass in the incident direction of the charged particle beam is provided. It is also conceivable to be configured. With this configuration, a charged particle beam that does not coincide with the beam axis cannot pass through the opening and collides with the electrode member. At this time, since the current detected by the electrode member increases (rises), the orbital position of the charged particle beam can be detected based on the increased amount.
In this case, it is desirable that the electrode member has a plurality of electrodes arranged around the opening at the center. Thereby, it is possible to detect the coordinates of the collision position (namely, the orbit position) of the charged particle beam depending on which electrode collided. As a result, the tilt direction and deviation of the charged particle beam, or the moving direction during adjustment can be known, and adjustment is further facilitated.
The charged particle beam entrance side of the Faraday cup has an electrode plate formed with an entrance for the charged particle beam, and the electrode member is disposed on the electrode plate via an insulating layer. What is configured is also an example of the beam current measuring means.

In addition, it is desirable that the electrode member has two or more electrodes. From the viewpoint of improving the detection accuracy of the position coordinate of the charged particle beam, the electrode member is subdivided to subdivide the detected position coordinate. Is preferably a large number. If the electrode member is equally divided into a plurality of electrodes, the detection accuracy of the detected position coordinates is further improved. Furthermore, even if the plurality of electrodes of the electrode member are symmetrically arranged with the opening at the center as the center, improvement in the detection accuracy can be expected.
Furthermore, it is conceivable to apply a predetermined potential to the plurality of electrodes of the electrode member. For example, when this orbital position detector is used in a composition analyzer using scattered ions, unnecessary particles such as secondary electrons other than the scattered ions required for composition analysis can be captured by the electrode member, and noise can be detected. Is suppressed, and a highly accurate composition analyzer can be realized. Furthermore, since secondary electrons generated when a charged particle beam such as an ion beam collides with the electrode member are drawn back to the electrode member, current measurement accuracy can be improved.

As the arrangement positions of the beam current measuring means, for example, it is desirable to arrange a plurality of them at predetermined positions on a predetermined beam axis. That is, if at least two or more beam current measuring means are arranged along the beam axis, for example, even if a charged particle beam incident at an angle passes through the first current measuring means, Since it collides with the current measuring means of the eye, the collision position, that is, the orbital position and incident angle of the charged particle beam can be reliably detected.
Further, in order to accurately adjust the trajectory of the charged particle beam with respect to the irradiated object, the beam current measuring means is disposed in the vicinity of the mounting table of the irradiated object that is arranged farthest from the charged particle beam generation source. Preferably they are arranged. For example, it is conceivable to arrange the beam current measuring means below the stage for placing the irradiated object. In this case, the charged particle beam is shielded by the above-mentioned mounting table. However, the above-described problem due to the shielding can be prevented by providing an opening for allowing the charged particle beam to pass in the incident direction of the charged particle beam. Easily resolved.

Further, the present invention can also be understood as a composition analysis device including the above-described orbit position detection device. That is, by irradiating an object to be irradiated arranged in a vacuum vessel with an accelerated charged particle beam and measuring an energy spectrum of scattered ions scattered from the object to be irradiated, composition analysis of the object to be irradiated is performed. A configuration in which the composition analyzer to be performed includes the above-described orbit position detection device is conceivable.
As a result, for example, even when the charged particle beam cannot be physically visually observed by a solenoid coil or a correction coil constituting the composition analyzer, the measured beam current is used as an objective material for charged particles. The position of the beam trajectory can be known. As a result, the orbital position of the charged particle beam can be easily adjusted.
In addition, the composition analyzer has an opening that allows the charged particle beam to pass in the incident direction of the charged particle beam and also allows scattered particles scattered by the irradiated object to pass in a direction opposite to the incident direction of the charged particle beam. In the case where an aperture having a central portion is provided, it is desirable that the beam current measuring means is provided on the mounting table on which the object to be irradiated is mounted and / or the aperture. This eliminates the need for a support member for the beam current measuring means.

  Further, the present invention irradiates the object to be irradiated with an accelerated charged particle beam, and measures the energy spectrum of scattered ions scattered from the object to be irradiated, whereby the object to be irradiated is measured. The charged particle beam is measured by measuring the beam current of the charged particle beam, and detecting the orbital position of the charged particle beam based on the measured value of the charged particle beam. It can also be understood as a method of adjusting the trajectory of the charged particle beam by adjusting the trajectory of the charged particle beam by moving or tilting the charged particle beam generation source while referring to the position.

Furthermore, a position coordinate detection device for the beam current measuring means applied to the orbit position detection device, wherein the laser generation source emits and emits a laser, and the optical axis of the laser emitted from the laser generation source. A half mirror provided on the optical axis for reflecting a laser on the optical axis to a predetermined beam axis of the charged particle beam orthogonal to the optical axis and transmitting a laser substantially parallel to the beam axis; The laser on the beam axis, which is disposed downstream of the charged particle beam incident direction from the current measuring means or the beam current measuring means and reflected by the half mirror, is reflected in the direction opposite to the incident direction of the laser. The coordinate position of the laser is detected by detecting the intensity of the laser reflected by the corner cube and the corner cube and transmitted through the half mirror. The laser position detection means and, is configured by including the position coordinate detection device is considered that.
With the position coordinate detection device configured in this way, the coordinate position of the laser reflected after being irradiated onto the corner cube is detected, so that the Faraday cup used in the orbit position detection device is detected from the coordinate position. The center position coordinates of the beam current measuring means such as can be obtained. As a result, it is possible to calculate the installation position of the beam current measuring means and the amount of deviation thereof from the center position coordinates.

According to the present invention, since the charged particle beam can be adjusted while monitoring the measured beam current, the charged particle beam is not visually observed but is charged by an objective material such as the beam current. It becomes possible to recognize the trajectory position of the beam. Therefore, the orbital position of the charged particle beam can be easily adjusted. As a result, the adjustment error can be reduced and the adjustment accuracy can be improved.
Furthermore, when the charged particle beam deviates from the beam axis, the deviation can be easily detected.
Further, it becomes possible to easily detect the coordinate position of a beam current measuring means such as a Faraday cup used in the orbit position detecting device.

Hereinafter, embodiments and examples of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. It should be noted that the following embodiments and examples are examples embodying the present invention, and do not limit the technical scope of the present invention.
<< First Embodiment >>
First, the sample analyzer according to the first embodiment of the present invention will be described with reference to FIGS. The sample analyzer irradiates a sample placed in a measurement chamber with an accelerated ion beam (an example of a charged particle beam) and measures the energy spectrum of scattered ions scattered from the sample, thereby An apparatus for analyzing the composition of a sample, such as a parallel magnetic field type Rutherford backscattering analysis apparatus. Since the configuration of this sample analyzer is not significantly different from that of the conventional sample analyzer Y described above, the description of the overall configuration of the sample analyzer here is omitted, and the interior of the measurement chamber 73a different from the conventional one is omitted. The configuration will be described in detail. 1 is a sectional view of the measurement chamber 73a, FIG. 2 is a diagram for explaining the configuration of the divided electrodes, FIG. 3 is a schematic sectional view of a Faraday cup, FIG. 4 is a sectional view of a sample stage, and FIG. It is a figure explaining the method of adjusting a track.
As shown in FIG. 1, the measurement chamber 73a includes a two-dimensional detector 78 for detecting specific scattered ions from the sample in order from the upstream side in the incident direction of the ion beam L, and an aperture 77 having an opening 77a at the center. In this respect, there is no difference from the measurement chamber 73 of the conventional sample analyzer Y. The measurement chamber 73a is different from the conventional one in an example of beam current measuring means for measuring the beam current of the ion beam L having a positive or negative charge at a predetermined position on the beam axis in the measurement chamber 73a. The divided electrode 10 (an example of an electrode member) and the Faraday cup 20 are provided. In the first embodiment, an example in which two beam current measuring means of the split electrode 10 and the Faraday cup 20 are provided at predetermined positions on the beam axis of the ion beam L will be described. 10 or the Faraday cup 20 may be provided, or at least one of the divided electrodes 10 or the Faraday cup 20 may be provided.

First, the divided electrode 10 will be described. The split electrode 10 measures only the beam current of an ion beam deviating from the beam axis through which the ion beam L should originally pass, and has an opening through which the ion beam L passes in the incident direction. Part 12 is provided. Similarly to the two-dimensional detector 78 and the aperture 77, the divided electrode 10 is also arranged so that the opening 12 coincides with the beam axis.
The arrangement of the divided electrode 10 may be anywhere as long as it is on the beam axis in the measurement chamber 73a, but in the first embodiment, a member for supporting the divided electrode 10 is excluded. In order to do this, the divided electrode 10 is disposed by being attached to the upper surface of the aperture 77. The divided electrodes 10 arranged in this way are shown in FIG. 2A is a view of the aperture 77 as viewed from above, FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A, FIG. 2C is an enlarged view of a portion C of FIG. It is the B section enlarged view of (a).

As shown in FIG. 2, the divided electrode 10 is formed in an annular shape having a smaller diameter than the aperture 77, and the opening 12 at the center thereof is disposed so as to overlap the opening 77 a of the aperture 77. Has been.
Further, as shown in FIG. 2A, the divided electrode 10 includes four electrodes 10a to 10d, and is arranged annularly with the opening 12 at the center as a center. These electrodes 10a to 10d are formed in the same shape, and are arranged symmetrically with the opening 12 as the center. That is, the divided electrode 10 is configured to be equally divided into a plurality of electrodes.

The electrodes 10a to 10d are connected to a known current measuring instrument capable of monitor display via signal lines 13a to 13d, and when the ion beam L collides with the electrodes 10a to 10d on the current measuring instrument side. Each current (beam current) flowing through the electrodes 10a to 10d is measured, and each measured current value is displayed on the screen. The current measuring device only needs to measure at least the value of the beam current, and various current measuring means can be used as a matter of course.
In the present embodiment, the aperture 77 is formed of a conductive member. Therefore, the aperture 77 also functions as an electrode in the same manner as the electrodes 10a to 10d. Therefore, the aperture 77 is also connected to the current measuring device via the signal line 14. In order to block the conduction between the aperture 77 and the electrodes 10a to 10d, the electrodes 10a to 10d are connected to the upper surface of the aperture 77 through an insulating layer 11, as shown in FIGS. It is arranged.
Thus, in the case of a sample analyzer having the measurement chamber 73a in which the divided electrode 10 is provided, for example, the ion beam L is deviated from the beam axis (curved) when adjusting the trajectory of the ion beam L or during operation of the apparatus. When the ion beam L collides with the electrode member 10 or when a part of the ion beam L collides with the electrode member 10, the beam current of the ion beam L is measured. It is possible to detect that the trajectory of the ion beam L is at a position shifted from the beam axis.

Next, the Faraday cup 20 which is an example of a beam current measuring unit will be described. The Faraday cup 20 has a cup-shaped metal third electrode 23 for receiving the ion beam L and directly measuring the beam current, as shown in FIG. Has a structure.
Specifically, as shown in FIG. 3A, the Faraday cup 20 has a negative potential (with respect to the third electrode 23, the third electrode 23, and a first electrode 21 described later). A second electrode 22 for suppressing secondary electrons from the third electrode 23 by applying an electric field and suppressing low-speed secondary electrons contained in the ion beam L by applying a negative bias) -Vs; The diameter of the ion beam for measuring ions and the first electrode (corresponding to the electrode plate) for limiting the diameter of the ion beam L to be measured so that a part of the ion beam does not collide with the second electrode 22. The first electrode 21 for limiting the flow rate and the absorber 24 that is provided on the bottom surface of the third electrode 23 and absorbs the kinetic energy of the ion particles of the ion beam L are configured.
The first electrode 21 and the second electrode 22 are provided on the incident side of the ion beam L of the third electrode 23, and the second electrode 22 is located above the third electrode 23. The first electrode 21 is disposed above the second electrode via an insulating member 25. In addition, incident ports 21 a and 22 a through which the ion beam L passes in the incident direction are formed at the center of each of the first electrode 21 and the second electrode 22. The entrance 21a is formed to have a diameter substantially the same as the opening 77a of the aperture 77, and the entrance 22a is formed to have a larger diameter than the entrance 21a.
The Faraday cup 20 may be configured by disposing the divided electrode 10 on the upper surface of the first electrode 21 via an insulating layer (not shown).

In the first embodiment, the Faraday cup 20 is arranged in the vicinity of the sample stage 79, more specifically below (or below) the sample stage 79, as shown in FIG. (On the bottom). In this case, the sample stage 79 prevents the ion beam L from being incident on the Faraday cup 20. However, the sample stage 79 is formed of a member having a beam transmission property, or a central portion of the sample stage 79. By providing an opening for allowing the ion beam L to pass through, the incident to the Faraday cup 20 can be ensured.
Further, as shown in FIG. 4, the sample stage 79 can be rotationally controlled by an electric motor 79c such as a motor around the center axis 79b, and is positioned in a circumferential direction away from the center axis 79b of the sample stage 79. If the Faraday cup 20 is provided below the opening 79a, the opening 79a is provided in the center of the opening 79a so that the ion beam L passes through the center of the opening 79a. Even if the sample 74 is analyzed, the ion beam L can be incident on the Faraday cup 20 by rotating the sample stage 79. This makes it possible to easily and quickly switch from sample analysis to orbital position confirmation of the ion beam L.
Thus, in the case of the sample analyzer having the measurement chamber 73a in which the Faraday cup 20 is provided, for example, the ion beam L is incident on the Faraday cup 20 only when the ion beam L passes on the beam axis. Since the beam current is measured, it is possible to detect that the orbit of the ion beam L is at a position coincident with the beam axis when the beam current is measured. If the beam current is not measured or if it is less than a predetermined value even if measured, it can be detected that the trajectory of the ion beam L is at a position off the beam axis.

  The Faraday cup 20 is generally provided with the cup-shaped third electrode 23. For example, the incident port of the first electrode 21 is provided at the center of the bottom surface of the third electrode 23. A Faraday cup provided with an opening (not shown) having the same diameter as 21a may be used. Any Faraday cup having such an opening can be placed anywhere on the beam axis in the measurement chamber 73a. In this case, the measurement of the beam current in the Faraday cup means that the trajectory of the ion beam L is at a position off the beam axis, and the fact that the beam current is not measured means that the trajectory of the ion beam L is This means that the position coincides with the beam axis.

Here, a method for initially adjusting the trajectory of the ion beam L performed when a sample analyzer is installed will be described with reference to FIG.
The ion beam L emitted from the accelerator Y1 to the spectrometer Y2 often has its orbit off the beam axis at the initial stage of adjustment, and any one of the four electrodes 10a to 10d of the divided electrode 10 is used. Clash. For example, in this initial stage, it is assumed that the ion beam L collides with the electrode 10a as shown in FIG.
In this case, on the monitor screen of the current measuring device, the value of the current flowing through the electrode 10a is displayed to be extremely higher than that of the other electrodes, so that the adjustment operator determines that the orbital position of the ion beam L is in the direction of the electrode 10a. Can be recognized. Therefore, the adjustment operator easily adjusts the trajectory of the ion beam L to coincide with the beam axis as shown in FIG. 5C by changing the trajectory in the direction opposite to the direction of the electrode 10a. be able to. In addition, by referring to the current value of each electrode on the monitor screen during trajectory adjustment, it is possible to immediately recognize an adjustment error, etc., so that adjustment can be performed quickly without making an adjustment error. .
In the initial stage, when the trajectory of the ion beam L is at the position shown in FIG. 5B, the current value flowing through the electrodes 10a and 10b is transferred to the other electrodes on the monitor screen of the current measuring device. Since it is displayed higher than that, it can be recognized that the trajectory position of the ion beam L is between the electrodes 10a and 10b, and the subsequent adjustment can be easily performed.

  In the first embodiment, the sample analyzer has been described as an example. However, the beam current measuring means such as the divided electrode 10 and the Faraday cup 20 necessary for adjusting the ion beam L is the above-described one. For example, the present invention can be applied to an electron microscope using a charged particle beam such as an ion beam or a beam processing apparatus using the charged particle beam. That is, the present invention is regarded as an orbital position detecting device that includes a beam current measuring means and detects the orbital position of the charged particle beam based on the measured value of the beam current. It becomes possible to apply to the apparatus.

<< Second Embodiment >>
Next, a position coordinate detection apparatus for the beam current measuring means according to the second embodiment of the present invention will be described with reference to FIGS. This position coordinate detection apparatus is applied to the orbital position detection apparatus and the sample analysis apparatus described in the first embodiment, and is provided with an arrangement position (arrangement position) of beam current measuring means such as the Faraday cup 20. ) Position coordinates are detected. Here, the position coordinate detection device will be described as detecting the position coordinates of the Faraday cup 20 as an example of the beam current measuring means, but of course, the divided electrode 10, the aperture 77 and the coordinates of the position where the two-dimensional detector 78 is disposed are also applicable. FIG. 6 is a cross-sectional view of the Faraday cup in which the corner cube is arranged, and FIG. 7 is a cross-sectional view of the measurement chamber 73 to which the position coordinate detection device is applied.
As shown in FIG. 7, the position coordinate detection apparatus is provided on a laser generation source 82 for generating and emitting a laser, and an optical axis 82a of the laser emitted from the laser generation source 82, and the optical axis 82a. The upper laser beam is reflected on the beam axis of a predetermined ion beam (charged particle beam) orthogonal to the optical axis 82a and transmits a laser substantially parallel to the beam axis. A corner cube 84 (see FIG. 6) that is disposed and reflects the laser on the beam axis reflected by the half mirror 83 in a direction opposite to the incident direction of the laser, and is reflected by the corner cube 84 and the half An optical power meter 81 (laser position detector) detects the coordinate position of the laser by detecting the intensity of the laser transmitted through the mirror 83. As an example) of which is configured with, the respective components are mounted or disposed in the measuring chamber 73.

The optical power meter 81 counts the number of incident laser particles and detects the intensity of the laser according to the count value counted within a predetermined time. The laser incident surface of the power meter 81 is formed with a plurality of fine lattice-like windows (incident windows), and the laser incident position is determined by determining which window has the most laser particles incident thereon. Is detected. In place of the optical power meter 81, a so-called semiconductor detector may be used.
The corner cube 84 is disposed at the center of the bottom surface of the Faraday cup 20 as shown in FIG. The optical power meter 81 is arranged so that its detection center coincides with the beam axis.
By using the position coordinate detection apparatus configured as described above, after being reflected by the half mirror 83 on the optical power meter 81 and passing on the beam axis of the ion beam (the axis through which the laser L1 passes in FIG. 6). The incident position of the laser L2 reflected by the corner cube 84 in the optical power meter 81 can be detected. Therefore, for example, if the position coordinates of the beam axis of the ion beam are registered in the optical power meter 81 in advance, the difference d between the beam axis of the ion beam (that is, the axis through which the laser L1 passes) and the laser L2 (FIG. 6). Reference) can be calculated. That is, since the laser L1 passes on the beam axis of the ion beam, the difference d is calculated as a difference from the center position where the Faraday cup 20 should be originally placed. Here, the calculation of the difference d is performed by a control unit (not shown) built in the optical power meter 81 or a control device (not shown) connected to the optical power meter 81.
The position coordinates of the beam axis of the ion beam are not registered in the optical power meter 81 in advance, and the laser L1 and the laser L2 are reflected by reflecting the laser L1 to the optical power meter 81, for example. Even if it is an Example which calculates the said difference d from these position coordinates by detecting a position coordinate, it does not matter.

Sectional drawing of the measurement chamber of the sample analyzer which concerns on the 1st Embodiment of this invention. The figure explaining the structure of a division | segmentation electrode. A schematic sectional view of a Faraday cup. Sectional drawing of a sample stand. The figure explaining the method of adjusting the orbit of an ion beam. Sectional drawing of the Faraday cup by which a corner cube is arrange | positioned. Sectional drawing of the measurement chamber to which the position coordinate detection apparatus was applied. The whole figure which shows schematic structure of the conventional sample analyzer Y. FIG.

Explanation of symbols

L ... Ion beams L1, L2 ... Laser 10 ... Split electrode (an example of beam current measuring means)
10a to d ... Electrode 11 ... Insulating layer 12 ... Opening 20 ... Faraday cup (an example of beam current measuring means)
21 ... 1st electrode 22 ... 2nd electrode 23 ... 3rd electrode 24 ... Absorber 25 ... Insulating layer 73, 73a ... Measurement chamber 74 ... Sample 75 ... Solenoid coil 76 ... Correction coil 77 ... Aperture 78 ... Two-dimensional Detector 79 ... Sample stand 81 ... Optical power meter (an example of energy detection means)
82 ... Laser generation source 83 ... Half mirror 84 ... Corner cube 90 ... Magnet yoke 91 ... Magnetic pole

Claims (16)

An orbital position detection device for detecting the orbital position of a charged particle beam emitted from a charged particle beam generation source and applied to an irradiated object,
A beam current measuring means for measuring the beam current of the charged particle beam;
An orbital position detecting device, wherein the orbital position of the charged particle beam is detected on the basis of the measured value of the beam current by the beam current measuring means.   2. The orbit position detecting device according to claim 1, wherein the beam current measuring means measures a beam current of a charged particle beam passing through a predetermined beam axis.   The orbital position detecting device according to claim 1, wherein the beam current measuring means measures a beam current of a charged particle beam deviating from a predetermined beam axis.   The orbital position detection device according to any one of claims 1 to 3, wherein the beam current measuring means includes a Faraday cup disposed at a predetermined position on a predetermined beam axis.   The beam current measuring means includes an electrode member disposed at a predetermined position on a predetermined beam axis and having an opening at the center for allowing the charged particle beam to pass in the incident direction of the charged particle beam. Item 4. The orbit position detection device according to any one of Items 1 and 3.   The track position detecting device according to claim 5, wherein the electrode member has a plurality of electrodes arranged around the opening of the central portion. The Faraday cup has an electrode plate in which an entrance of the charged particle beam is formed on the incident side of the charged particle beam;
The track position detecting device according to claim 5 or 6, wherein the electrode member is disposed on the electrode plate via an insulating layer.   The orbital position detection device according to claim 6 or 7, wherein the plurality of electrodes of the electrode member are equally divided.   The orbital position detection device according to any one of claims 6 to 8, wherein the plurality of electrodes of the electrode member are arranged symmetrically with respect to the opening of the central portion.   The orbital position detection device according to claim 5, wherein a predetermined potential is applied to the electrode of the electrode member.   The orbital position detecting device according to any one of claims 1 to 10, wherein a plurality of the beam current measuring means are arranged at predetermined positions on a predetermined beam axis.   The orbital position detection device according to any one of claims 1 to 11, wherein the beam current measuring means is disposed in the vicinity of the mounting table for the irradiated object. A composition for performing composition analysis of the irradiated object by irradiating an irradiated object with an accelerated charged particle beam disposed in a vacuum vessel and measuring an energy spectrum of scattered ions scattered from the irradiated object. An analyzer,
A composition analyzer comprising the orbit position detector according to any one of claims 1 to 12. An aperture having at its center an opening that allows the charged particle beam to pass in the incident direction of the charged particle beam and allows scattered particles scattered by the irradiated object to pass in a direction opposite to the incident direction of the charged particle beam; In addition,
14. The composition analyzer according to claim 13, wherein the beam current measuring means is provided on a mounting table and / or the aperture for mounting the irradiated object. A composition for performing composition analysis of the irradiated object by irradiating an irradiated object with an accelerated charged particle beam disposed in a vacuum vessel and measuring an energy spectrum of scattered ions scattered from the irradiated object. A charged particle beam trajectory adjustment method applied to an analyzer,
The beam current of the charged particle beam is measured, the orbital position of the charged particle beam is detected based on the measured value of the charged particle beam, and the orbit of the charged particle beam is determined while referring to the detected orbital position. Method for adjusting trajectory of charged particle beam to be adjusted. Beam current measuring means for measuring a beam current of a charged particle beam emitted from a charged particle beam generation source and applied to an object to be irradiated is provided, and the charged particles are measured based on a measurement value of the beam current by the beam current measuring means. A position coordinate detecting device for the beam current measuring means applied to an orbital position detecting device characterized by detecting the orbital position of a beam,
A laser source that emits and emits a laser;
Provided on the optical axis of the laser emitted from the laser source, the laser on the optical axis is reflected to a predetermined beam axis of the charged particle beam orthogonal to the optical axis and substantially the same as the beam axis. A half mirror that transmits the parallel laser;
The beam current measuring means or the beam current measuring means is arranged downstream of the incident direction of the charged particle beam, and the laser on the beam axis reflected by the half mirror is opposite to the incident direction of the laser. A corner cube to reflect,
Laser position detection means for detecting the coordinate position of the laser by detecting the intensity of the laser reflected by the corner cube and transmitted through the half mirror;
A position coordinate detection apparatus comprising:

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