JP5524755B2 - X-ray detection system and X-ray detection method - Google Patents

Description

The present invention relates to X-ray detection system and X-ray detection method, in particular, a scanning soft X-ray and cathodoluminescence of separation possible X-ray detection system at when attached to an electron microscope for spectroscopic analysis soft X-ray and X The present invention relates to a line detection method .

  When the sample is irradiated with a charged particle beam such as an electron beam, characteristic X-rays are generated from the sample. A technique for detecting the characteristic X-rays with a detector and measuring the composition of the sample is called energy dispersive X-ray spectroscopy. This technique utilizes the characteristic X-rays having the specific energy of the elements constituting the sample. The number of X-rays generated per unit time is counted for each X-ray energy to obtain information such as the elemental composition of the sample. Here, as a means for detecting X-rays, a semiconductor detection element using a semiconductor crystal such as silicon or germanium is generally used.

  On the other hand, when characteristic X-rays generated by irradiating a sample with a charged particle beam such as an electron beam are incident on the diffraction grating, the diffracted X-rays are separated. There is also a technique for detecting the diffracted X-rays with an X-ray CCD image sensor and imaging it.

  An apparatus for realizing this technique includes an electron beam irradiation unit that irradiates a sample with an electron beam, and an X-ray collection that collects characteristic X-rays emitted from the sample irradiated with the electron beam and guides them to a diffraction grating. An optical mirror, a diffraction grating that receives characteristic X-rays collected by the X-ray condenser mirror and generates diffracted X-rays, and an image sensor that detects diffracted X-rays generated by the diffraction grating. ing.

  This type of X-ray detection system is also described in Patent Document 1 below.

JP 2002-329473 A

  With the above X-ray detection system, when an electron beam is irradiated using a compound such as an oxide / nitrogen compound as a sample, light emission called cathode luminescence (CL), which has a wavelength different from that of the characteristic X-ray, is obtained in addition to the characteristic X-ray. Occur. The cathodoluminescence is reflected in the diffraction grating in a state close to total reflection and enters the image sensor. As a result, the signal level of the diffracted X-ray is relatively lowered on the image sensor, and the sampled spectrum becomes unclear, which adversely affects measurement time and measurement accuracy.

  In this case, it is desirable that the diffracted X-rays and cathodoluminescence can be separated, but there is a problem that there is no filter suitable for separating them.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a diffraction grating in a system in which a characteristic X-ray from a sample irradiated with an electron beam is diffracted by a diffraction grating and a spectrum is collected by an image sensor. And an X-ray detection system and an X-ray detection method capable of increasing the ratio of X-rays incident on the image sensor.

  That is, the present invention for solving the above problems is as described below.

(1) According to the present invention, an electron beam irradiation unit that irradiates a sample with an electron beam, and X-ray condensing that condenses characteristic X-rays emitted from the sample irradiated with the electron beam and guides them to a diffraction grating. mirror and a diffraction grating to produce diffracted X-rays by receiving the collected characteristic X-rays by the X-ray focusing mirror, having an image sensor for detecting the diffracted X-rays generated by the diffraction grating X In the X-ray detection system, the optical path width of the characteristic X-ray is arranged between the X-ray condensing mirror and the diffraction grating and is perpendicular to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor. An X-ray detection system, further comprising: a slit that regulates the position of the slit, and a slit adjustment unit that adjusts the position of the slit in the orthogonal direction .

(2) The sample was irradiated with an electron beam, and the characteristic X-rays emitted from the sample irradiated with the electron beam were condensed by an X-ray condenser mirror and led to the diffraction grating, and generated by the diffraction grating. In the X-ray detection method in which diffracted X-rays are detected by an image sensor, the position of the X-ray condenser mirror is set so that cathodoluminescence emitted from the sample irradiated with an electron beam does not enter the image sensor. Alternatively, the X-ray detection method is characterized in that the angle is adjusted.

(3) In the above (2), the X-ray focusing mirror adjusting unit changes the direction of the cathode luminescence in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor. The position or angle of the X-ray collector mirror is adjusted.

(4) The sample was irradiated with an electron beam, and characteristic X-rays emitted from the sample irradiated with the electron beam were condensed by an X-ray condenser mirror and led to a diffraction grating, and generated by the diffraction grating. In the X-ray detection method in which diffracted X-rays are detected by an image sensor, the X-ray focusing mirror and the X-ray collector mirror are arranged so that cathode luminescence emitted from the sample irradiated with an electron beam does not enter the image sensor. In this X-ray detection method, the position of the slit disposed between the diffraction grating and the diffraction grating is adjusted.

(5) In the above (4), the position of the slit is adjusted in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor.

  According to these inventions, the following effects can be obtained.

(1) In this invention, a slit is arranged between the X-ray condensing mirror and the diffraction grating, and the slit is adjusted by the slit adjusting unit in a direction perpendicular to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor. By adjusting the position of the light source and arranging a slit on the optical path of the cathodoluminescence, it becomes possible to block the cathodoluminescence and reduce the influence without affecting the image of the diffracted X-ray on the image sensor. .
(2) In this invention, the characteristic X-rays emitted from the sample irradiated with the electron beam are condensed by the X-ray condenser mirror and guided to the diffraction grating, and the diffraction X-rays generated by the diffraction grating are detected by the image sensor. Then, X-ray detection is performed, and at this time, the position or angle of the X-ray focusing mirror is adjusted by the X-ray focusing mirror adjustment unit.

  Here, characteristic X-rays are guided to the diffraction grating in a state close to parallel light by reflection at the X-ray condenser mirror. On the other hand, since cathodoluminescence has a longer wavelength than characteristic X-rays, it can be reflected by an X-ray collector mirror at an incident angle smaller than that of characteristic X-rays, and is guided to the diffraction grating at an incident angle smaller than that of characteristic X-rays. It is burned.

  For this reason, by adjusting the position or angle of the X-ray collector mirror by the X-ray collector mirror adjusting section, it becomes possible to guide the cathode luminescence outside the range of the diffraction grating and to enter the diffraction grating or the image sensor. It becomes possible to increase the ratio of characteristic X-rays.

( 3 ) In the above ( 2 ), the X-ray focusing mirror adjustment unit changes the direction of the light emitted in the direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor. By adjusting the position or angle of the collector mirror, it becomes possible to guide the cathodoluminescence outside the range of the diffraction grating, so that the influence of the cathodoluminescence can be reduced without affecting the image of the diffracted X-ray on the image sensor. It becomes possible to make it smaller.

(4) The position of the slit arranged between the X-ray condenser mirror and the diffraction grating is adjusted so that the cathodoluminescence emitted from the sample irradiated with the electron beam does not enter the image sensor. Therefore, it is possible to reduce the influence by blocking the cathodoluminescence without affecting the image of the diffracted X-ray on the image sensor.
( 5 ) In the above ( 4 ), a slit is arranged between the X-ray condensing mirror and the diffraction grating, and the slit adjustment unit extends in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor By adjusting the position of the slit by using and arranging the slit on the optical path of cathodoluminescence, it is possible to block the cathodoluminescence and reduce the effect without affecting the image of diffracted X-rays on the image sensor. become.

It is a block diagram which shows the structure of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the principal part of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the principal part of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the principal part of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the principal part of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the X-ray detection system to which embodiment of this invention is applied. It is a block diagram which shows the structure of the principal part of the X-ray detection system to which embodiment of this invention is applied.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments (embodiments) for carrying out an image forming apparatus of the present invention will be described below in detail with reference to the drawings.

<First Embodiment>
First, the configuration of the X-ray detection system of the first embodiment will be described with reference to FIGS. 1 and 2.

  In FIG. 1, a known basic member for holding each part such as a lens barrel and a gantry, a mechanism part for holding a vacuum, and the like are omitted, and the arrangement of the characteristic parts of the embodiment is mainly shown. Yes.

  The electron beam irradiation unit 10 is provided in a lens barrel portion of a scanning electron microscope and irradiates the sample 20 with an electron beam.

  The X-ray focusing mirror unit 30 focuses the characteristic X-rays emitted from the sample 20 by the two mirrors 34 a and 34 b and guides them to the diffraction grating 50. Here, by condensing with the X-ray condensing mirror unit 30, the intensity of the characteristic X-rays incident on the diffraction grating 50 can be increased, the measurement time can be shortened, and the S / N ratio of the spectrum can be improved. . Details of the X-ray collector mirror unit 30 will be described later.

  The diffraction grating 50 receives characteristic X-rays collected by the X-ray condenser mirror unit 30 and generates diffracted X-rays having different diffraction states according to energy. This diffractive grating 50 is formed with unequally spaced grooves for aberration correction, and such unequally spaced diffractive gratings are nearly parallel to a large incident angle (diffraction grating surface (Y axis in FIG. 1)). When the light beam is incident at an angle, the focal point of the diffracted light is designed not on the Roland circle but on a plane substantially perpendicular to the light beam (light receiving surface of the image sensor 70: XZ plane in FIG. 1).

  The image sensor 70 is an X-ray CCD camera or an X-ray CMOS camera having sensitivity to soft X-rays in order to detect diffracted X-rays. Desirably, it comprises a back-illuminated X-ray CCD camera. The position of the image sensor 70 is adjusted so that the light receiving surface thereof coincides with the image plane of diffracted X-rays.

  The sample 20, the X-ray condensing mirror unit 30, the diffraction grating 50, and the image sensor 70 are not shown, but are provided in a spectroscope chamber evacuated by a vacuum pump and scanned via a gate valve. It shall be attached to the barrel of a scanning electron microscope.

  Further, details of the configuration of the diffraction grating 50 and its periphery in this X-ray detection system are described in Japanese Patent Application Laid-Open No. 2002-329473, to which the applicant of the present application separately applied. In addition, since a known system for processing diffracted X-rays obtained by the image sensor 70 can be used, description thereof is omitted.

  The X-ray condensing mirror unit 30 is a set of two mirrors 34a and 34b facing each other. The surfaces of the mirrors 34a and 34b facing each other are flat in the direction perpendicular to the paper surface (Z direction) in FIG. The distance between the mirrors is a curved surface with a narrow sample side (incident side) and a wide diffraction grating side (exit side). Thereby, compared with the case without a mirror, the intensity of the characteristic X-rays incident on the diffraction grating 50 can be increased, whereby the measurement time can be shortened and the S / N ratio of the spectrum can be improved.

  In addition, the X-ray collector mirror unit 30 is a fixed unit 31 whose position is fixed in the X-ray detection system, and an X-ray collector mirror adjustment unit 32 that adjusts the position or angle of the mirror holding unit 33 with respect to the fixed unit 31. (Adjustment members 32a, 32b, 32c, 32d), comprising a mirror holding portion 33 that can move on the fixed portion 31 (on the XY plane) and hold the mirrors 34a and 34b, a mirror 34a, and a mirror 34b. Has been.

  In addition, although the fixing | fixed part 31 may be provided as the X-ray condensing mirror part 30, you may use the chassis of an X-ray detection system, etc. as it is.

  The X-ray focusing mirror adjustment unit 32 includes adjustment members 32a and 32c provided at opposing positions so as to support the four corners of the mirror holding part 33, and adjustment members 32b and 32d provided at opposing positions. A specific example of a configuration in which each adjustment member finely adjusts the mirror holding portion 33 in the X direction or the −X direction on the XY plane is shown.

  In addition, the mirror holding portion 33 shows a specific example of a flat shape for the sake of simplification, but is not limited thereto, and is a cylindrical shape such as a mirror external housing that integrally holds the mirrors 34a and 34b. The structure may be used.

  Here, regarding the adjusting members 32a and 32c, 32b and 32d provided at the opposing positions, both of the opposing positions may be active adjusting members such as piezo elements, actuators, screws, or the like. May be an active adjustment member, and the other of the opposing positions may be a passive adjustment member made of an elastic body such as a spring or rubber.

  Also, depending on the direction of installation of the X-ray detection system, either one of the opposed positions is close to the ground, and gravity is used. ) Adjustment member can be omitted.

  Further, by using screws as the adjusting members 32a to 32d as a micrometer, it is possible to adjust while confirming the amount of displacement.

  Here, FIG. 2A shows a specific example in which the mirrors 34a and 34b are in a neutral state. Here, characteristic X-rays from the sample 20 are indicated by broken lines, and cathodoluminescence (CL) is indicated by two-dot chain lines. As shown in FIG. 2A, not only characteristic X-rays such as soft X-rays to be detected but also unnecessary cathodoluminescence is condensed by the X-ray condenser mirror 30 and incident on the diffraction grating 50. ing.

  Here, the characteristic X-rays are reflected and condensed in a state relatively close to parallel light (a large incident angle close to 90 °) by reflection by the mirrors 34a and 34b and guided to the diffraction grating.

  On the other hand, since cathodoluminescence has a longer wavelength than characteristic X-rays, it can be reflected by mirrors 34a and 34b at an incident angle smaller than that of characteristic X-rays, which is absorbed without being reflected by characteristic X-rays. is there. As a result, the cathodoluminescence tends to be guided to the diffraction grating 50 at an incident angle smaller than the characteristic X-ray.

  As a result, as shown in FIG. 2A, the cathodoluminescence tends to be relatively gathered and incident on the peripheral portion of the diffraction grating 50.

  Therefore, any one of the adjustment members 32a, 32b, 32c, and 32d provided at the four corners of the mirror holding portion 33 is adjusted in the X direction or the −X direction, and the mirror holding portion 33 is finely adjusted with respect to the fixed portion 31. .

  In the example shown in FIG. 2B, the adjusting member 32a is extended, the adjusting member 32c provided at the opposing position is compressed, the adjusting member 32b is compressed, and the adjusting member 32d provided at the opposing position is extended. Thus, the mirror holding portion 33 is rotated counterclockwise in the XZ plane. This rotation corresponds to changing the angle of the X-ray focusing mirror in the claims.

  As a result, the reflection angle is changed by rotating the mirrors 34a and 34b counterclockwise, and the cathode luminescence incident on the + X direction end of the diffraction grating 50 advances to a position away from the diffraction grating 50. Thus, neither diffraction by the diffraction grating 50 nor incidence to the image sensor 70 is eliminated.

  At this time, a part of the characteristic X-rays incident on the + X direction end of the diffraction grating 50 also moves to a position off the diffraction grating 50, but the cathode luminescence is surely out of the diffraction grating 50 range. Therefore, the ratio of X-rays incident on the diffraction grating 50 and the image sensor 70 can be increased.

  Although not shown, if the cathodoluminescence is incident on the end of the diffraction grating 50 in the −X direction, the mirror 34 a and 34 b are rotated in the clockwise direction so that the cathodoluminescence is −X of the diffraction grating 50. It can be removed from the direction end.

  In the example shown in FIG. 2C, the adjustment member 32a is compressed and the adjustment member 32c provided at the opposing position is extended, the adjustment member 32b is compressed and the adjustment member 32d provided at the opposite position is extended. Thus, the mirror holding portion 33 is shifted in the −X direction within the XZ plane. This shift movement corresponds to changing the position of the X-ray focusing mirror in the claims.

  By such a shift movement of the mirrors 34 a and 34 b in the −X direction, the positional relationship between the light source (sample 20) and the mirror is changed, and the reflection angle is changed. The reflection angle is changed by the mirror 34 a and the end of the diffraction grating 50 in the + X direction. The cathodoluminescence that has been incident on the laser beam proceeds to a position off the diffraction grating 50, and the diffraction at the diffraction grating 50 and the incidence on the image sensor 70 are eliminated.

  At this time, a part of the characteristic X-rays incident on the + X direction end of the diffraction grating 50 also moves to a position off the diffraction grating 50, but the cathode luminescence is surely out of the diffraction grating 50 range. Thus, the ratio of the characteristic X-rays incident on the diffraction grating 50 and the diffraction X-rays incident on the image sensor 70 can be increased.

  Although not shown, if the cathode luminescence is incident on the end of the diffraction grating 50 in the −X direction, the mirrors 34 a and 34 b are shifted in the + X direction to move the cathode luminescence to the − of the diffraction grating 50. It can be removed from the end in the X direction.

  Further, according to the first embodiment, since the adjustment is performed by the X-ray condensing mirror unit 30, the light is incident on the diffraction grating 50 by unnecessary cathode luminescence removal without being affected by the type of the diffraction grating 50 to be used. A good effect of increasing the ratio of characteristic X-rays can be obtained.

  The adjustment operation of the adjustment members 32a to 32d is performed by a control unit (not shown) based on the result of analysis of diffraction X-rays of the image sensor 70, manual screw rotation operation by the operator, manual actuator extension / compression operation by the operator. ) Automatic control or the like.

  Moreover, when a change does not arise in adjustment of the above adjustment members 32a-32d, it can hold | maintain a favorable condition by adjusting by rotation feed operation of a screw, and fixing as it is.

<Modification (1) of First Embodiment>
Here, a modified example (1) of the first embodiment will be described.

  The mirror holding portion 33 is placed on the fixed portion 31 via a rotation mechanism (not shown) such as a rotation shaft or a rotation rail that can only rotate in the XY plane in the direction of FIG. It may be arranged.

  In this case, at least one of the adjustment members 32a to 32d described above may be used. FIG. 3A shows an example using only the adjustment member 32a. Also in this case, an operation equivalent to that shown in FIG.

<Modification (2) of First Embodiment>
Here, a modification (2) of the first embodiment will be described.

  The mirror holding portion 33 is disposed on the fixed portion 31 via a shift movement mechanism (not shown) such as a shift movement sliding mechanism capable of only shifting in the direction of FIG. Also good.

  Also in this case, at least one of the adjustment members 32a to 32d described above may be used. FIG. 3B shows an example in which only the adjustment member 32a is used. Also in this case, an operation equivalent to that shown in FIG.

Second Embodiment
Here, the configuration of the X-ray detection system of the second embodiment will be described with reference to FIGS. 4 and 5.

  In FIG. 4, as in FIG. 1, known basic members for holding each part such as a lens barrel and a gantry, a mechanism part for holding a vacuum, etc. are omitted, and the arrangement of the characteristic parts of the embodiment is omitted. It is shown in a state centered on.

  Here, the same parts as those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the second embodiment as well, the adjustment members 32a to 32d of the first embodiment can be applied, but the adjustment members 32a to 32d are shown in FIG. 4 but are not essential.

  4 differs from FIG. 1 in that slits 42a and 42b are provided on the optical path of the diffracted X-rays between the X-ray condensing mirror section 30 and the diffraction grating 50, and the diffraction X on the light receiving surface of the image sensor 70 is different. The slit adjustment unit 41 further adjusts the positions of the slits 42a and 42b in a direction (X direction in FIG. 4) orthogonal to the energy dispersion direction (Z direction in FIG. 4) of the line image. In addition, the slit adjustment part 41 and the slits 42a and 42b constitute the slit part 40. The slits 42a and 42b are preferably made of a material that blocks X-rays, cathode luminescence, and the like.

  The slit adjusting unit 41 can use various moving mechanisms or driving mechanisms, and may be an electric one using a linear motor or an actuator, or manually adjusted by a rotational feed operation of a screw from the outside. It may be mechanical. This point is the same as the X-ray focusing mirror adjustment unit 32 (adjustment members 32a, 32b, 32c, 32d) of the first embodiment.

  Further, a configuration may be adopted in which a drive mechanism is provided on the slits 42a and 42b side, and moves on the rail. Further, the slits 42a and 42b may be opened and closed in conjunction with the slit adjusting unit 41, or the slits 42a and 42b may be opened and closed individually.

  Here, FIG. 5A shows a specific example in which the slits 42a and 42b are in the initial state or the slit open state. Here, as in FIG. 2, the characteristic X-rays from the sample 20 are indicated by broken lines, and the cathodoluminescence (CL) is indicated by two-dot chain lines. As shown in FIG. 5 (a), not only characteristic X-rays such as soft X-rays to be detected but also unwanted cathodoluminescence is condensed by the X-ray condenser mirror unit 30, and the slits 42a and 42b. , And is incident on the diffraction grating 50.

  Here, as in the case described with reference to FIG. 2A, the cathodoluminescence tends to be relatively concentrated and incident on the peripheral portion of the diffraction grating 50 as shown in FIG.

  Therefore, as shown in FIG. 5B, the direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor, that is, the optical path between the X-ray condenser mirror 30 and the diffraction grating 50. The slit adjustment unit 41 adjusts the slits 42a and 42b so as to approach each other in the X direction so that the outer portion in the X direction is narrowed.

  As the slits 42a and 42b approach each other in the X direction in this manner, the optical path is narrowed, and the cathodoluminescence incident on the + X direction end of the diffraction grating 50 is blocked and cannot travel to the diffraction grating 50. Neither diffraction by the diffraction grating 50 nor incidence on the image sensor 70 is eliminated.

  At this time, depending on the adjustment by the slit adjusting unit 41, a part of the characteristic X-rays incident on the + X direction end of the diffraction grating 50 is also blocked and cannot reach the diffraction grating 50. By reliably blocking the laser beam from reaching 50, the ratio of the characteristic X-rays incident on the diffraction grating 50 and the diffraction X-rays incident on the image sensor 70 can be increased.

  Although not shown in the figure, even when cathodoluminescence is incident on the end of the diffraction grating 50 in the −X direction, the cathode luminescence is blocked and the diffraction is prevented by bringing the slits 42a and 42b close to each other in this way. It is not possible to proceed to the grating 50, and neither diffraction at the diffraction grating 50 nor incidence to the image sensor 70 is eliminated.

  In the example shown in FIG. 5C, the X-direction of the optical path between the X-ray condensing mirror 30 and the diffraction grating 50, that is, the direction orthogonal to the energy dispersion direction of the diffracted X-ray image on the light receiving surface of the image sensor. One of the slits 42a and 42b is adjusted by the slit adjusting unit 41 so as to narrow the side where the cathodoluminescence passes, which is an outer portion in the direction. Here, the slit adjustment unit 41 adjusts the slit 42b in the −X direction, that is, to narrow the optical path.

  In this way, the optical path is narrowed by the slit 42 b, and the cathodoluminescence incident on the + X direction end of the diffraction grating 50 is blocked and cannot proceed to the diffraction grating 50, and diffraction at the diffraction grating 50 is also transmitted to the image sensor 70. Is also eliminated.

  At this time, depending on the adjustment by the slit adjusting unit 41, a part of the characteristic X-rays incident on the + X direction end of the diffraction grating 50 is also blocked and cannot reach the diffraction grating 50. By blocking so as not to reach 50, the ratio of the characteristic X-rays incident on the diffraction grating 50 and the diffraction X-rays incident on the image sensor 70 can be increased.

  In the example shown in FIG. 5C, only the slit 42b is moved in the −X direction to block the cathode luminescence, but the slits 42a and 42b are simultaneously moved in the −X direction to obtain the cathode luminescence. May be shut off.

  Although not shown, when the cathodoluminescence is incident on the end of the diffraction grating 50 in the −X direction, the cathodoluminescence is adjusted by narrowing the optical path by moving at least the slit 42a in the X direction. Is blocked and cannot proceed to the diffraction grating 50, and there is no diffraction at the diffraction grating 50 and no incident on the image sensor 70.

  Further, according to the second embodiment, since the adjustment is made in the slit portion 40, the characteristic X-rays incident on the diffraction grating 50 by unnecessary cathodoluminescence removal are not affected by the type of the diffraction grating 50 to be used. It is possible to obtain a good effect of increasing the ratio.

  In the second embodiment, depending on the ambiguity of the collected spectrum on the image sensor 70 due to the influence of cathodoluminescence, the attenuation of characteristic X-rays (soft X-rays) to be measured is allowed to some extent. However, by positively removing the cathodoluminescence by the slit portion 40, a better soft X-ray spectrum can be detected as a result.

  The above adjustment operation of the slits 42a and 42b by the slit adjustment unit 41 includes a manual screw rotation operation by an operator, a manual actuator or linear motor operation by an operator, and a control unit based on the analysis result of diffraction X-rays of the image sensor 70. Any of automatic control (not shown) or the like may be used.

  Further, in the case where there is no change in the adjustment of the slit adjusting unit 41 described above, it is possible to maintain a good situation by adjusting the screw by a rotary feed operation and fixing it as it is.

<Third Embodiment>
Here, the configuration of the X-ray detection system of the third embodiment will be described with reference to FIGS. 6 and 7.

  In FIG. 6, as in FIGS. 1 and 4, known basic members for holding each part such as a lens barrel and a gantry, a mechanism part for holding a vacuum, and the like are omitted, and features of the embodiment are omitted. The arrangement of the parts is shown in the center.

  Here, the same parts as those in FIG. 1 of the first embodiment and FIG. 4 of the second embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the third embodiment as well, the adjustment members 32a to 32d of the first embodiment can be applied, so that they are shown in FIG. 6, but they are not essential.

  6 differs from FIG. 1 and FIG. 4 in that the slit 62 disposed at a predetermined distance on the diffraction surface side of the diffraction grating 50 and the energy dispersion of the image of the diffracted X-ray on the light receiving surface of the image sensor. It further has a slit adjusting part 61 for adjusting the position of the slit 62 in the direction. In addition, the slit part 60 is comprised by the slit adjustment part 61 and the slit 62. FIG. In addition, the slit 62 is preferably made of a material that blocks various types of materials such as X-rays, cathodoluminescence, charged particles, and neutral particles.

  The characteristic X-ray beam incident on the rear end side (side closer to the image sensor 70) of the diffraction grating 50 as viewed from the X-ray collection mirror section 30 and the diffraction grating 50 viewed from the X-ray collection mirror section 30. A point (hereinafter referred to as a cross point (see FIG. 7A)) where a diffracted X-ray beam diffracted on the tip side (side closer to the X-ray condensing mirror unit 30) intersects is determined, and the surface of the diffraction grating 50 It is desirable that the distance between the surface and the cross point be a predetermined distance, and the slit 62 can block a distance beyond the predetermined distance from the surface of the diffraction grating 50 (see FIG. 7B).

  That is, by arranging the slit 62 so that the tip of the slit 62 is in contact with the cross point, the sample 20 and the X-ray condensing mirror unit 30 do not affect the diffraction by the diffraction grating 50 and do not pass through the diffraction grating 50. It is possible to effectively block unnecessary light (cathode luminescence, characteristic X-rays that do not become diffracted X-rays, charged particles, neutral particles, etc. (see FIG. 7A)) directly reaching the image sensor 70. .

  Since the position of the cross point described above varies depending on the energy of the characteristic X-ray and the type of the diffraction grating 50, the slit 62 can be adjusted in the Z direction by the slit adjustment unit 61 as shown in FIG. 7B. It is desirable.

  As described above, the slit 62 is arranged at a predetermined distance on the diffraction surface side of the diffraction grating 50, and in the energy dispersion direction (Z direction in FIG. 7) of the image of the diffracted X-ray on the light receiving surface of the image sensor. By adjusting the slit 62 to adjust the tip position of the slit 62 to the cross point, various unnecessary lights other than the characteristic X-ray diffracted by the diffraction grating 50 can be efficiently obtained without inhibiting the characteristic X-ray and the diffraction X-ray. Can be blocked.

  The slit adjusting unit 61 can use various moving mechanisms or driving mechanisms, and may be an electric unit using a linear motor or an actuator, or manually adjusted by a screw rotational feed operation from the outside. It may be mechanical. This point is the same as in the first embodiment and the second embodiment.

  Also in this third embodiment, if there is no change in the adjustment of the slit adjusting unit 61 described above, a favorable state is maintained by adjusting it by rotating the screw and feeding it as it is. can do.

<Fourth embodiment>
Here, the configuration of the X-ray detection system of the fourth embodiment will be described with reference to FIGS. 8 and 9.

  In FIG. 8, similar to FIG. 1, FIG. 4, and FIG. 6, a known basic member for holding each part such as a lens barrel and a gantry, a mechanism part for holding a vacuum, and the like are omitted and implemented. The arrangement of the feature portions of the form is shown in the center.

  Here, the same parts as those in FIG. 1 of the first embodiment, FIG. 4 of the second embodiment, and FIG. 6 of the second embodiment are denoted by the same reference numerals, and redundant description is omitted.

  Also in the fourth embodiment, the adjustment members 32a to 32d of the first embodiment can be applied, and are shown in FIG. 8, but this is not essential.

  8 differs from FIG. 1 and FIG. 4 in that a slit 62 ′ is disposed between the diffraction grating 50 and the image sensor 70, and the energy dispersion direction of the image of the diffracted X-rays on the light receiving surface of the image sensor 70 (see FIG. 8). 8), the position of the slit 62 ′ can be adjusted by the slit adjusting portion 61 ′. The slit 62 'is preferably made of a material that blocks X-rays, cathodoluminescence, and the like.

  With such a configuration, as shown in FIGS. 9A and 9B, components other than the characteristic X-rays diffracted by the diffraction grating 50 (not reaching the diffraction grating and being behind the diffraction grating) (Propagating characteristic X-rays, cathodoluminescence, etc.) can be blocked.

  Then, reflected light and scattered light generated by being reflected and scattered by various members inside the apparatus are incident on the image sensor 70 by the characteristic X-rays and the cathode luminescence that travel to the rear side of the diffraction grating 50 as described above. This (see FIG. 9A) can be prevented.

  Since the optical path of diffracted X-rays and unnecessary light varies depending on the energy of the characteristic X-rays and the type of the diffraction grating 50, the slit 62 ′ is moved in the Z direction by the slit adjusting unit 61 ′ as shown in FIG. 9B. It is desirable to be adjustable. Thus, characteristic X-rays traveling behind the diffraction grating 50 can be efficiently blocked and removed without hindering the path of the diffracted X-rays.

  The slit adjustment unit 61 ′ can use various moving mechanisms or drive mechanisms, and may be an electric one using a linear motor or an actuator, or a manual screw feed operation from the outside. It is also possible to use a mechanical device that is adjusted by the above. This is the same as the first embodiment, the second embodiment, and the third embodiment.

DESCRIPTION OF SYMBOLS 10 Electron beam irradiation part 20 Sample 30 X-ray condensing mirror part 40 Slit part 50 Diffraction grating 60 Slit part 70 Image sensor

Claims (5)

An electron beam irradiation unit for irradiating the sample with an electron beam;
An X-ray condenser mirror that condenses characteristic X-rays emitted from the sample irradiated with the electron beam and guides it to a diffraction grating;
A diffraction grating to produce diffracted X-rays by receiving the collected characteristic X-rays by the front Symbol X-ray focusing mirror,
An image sensor for detecting diffracted X-rays generated by the diffraction grating;
In an X-ray detection system having
A slit that is disposed between the X-ray collector mirror and the diffraction grating and that defines the optical path width of the characteristic X-ray in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor; ,
A slit adjuster for adjusting the position of the slit in the orthogonal direction;
An X-ray detection system further comprising : The sample is irradiated with an electron beam, the characteristic X-rays emitted from the sample irradiated with the electron beam are condensed by an X-ray condenser mirror and guided to a diffraction grating, and the diffraction X-ray generated by the diffraction grating In the X-ray detection method in which image is detected by an image sensor,
  An X-ray detection method characterized in that the position or angle of the X-ray focusing mirror is adjusted so that cathodoluminescence emitted from the sample irradiated with an electron beam does not enter the image sensor. The position or angle of the X-ray collector mirror is adjusted so as to change the direction of cathodoluminescence in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor. The X-ray detection method according to claim 2. The sample is irradiated with an electron beam, the characteristic X-rays emitted from the sample irradiated with the electron beam are condensed by an X-ray condenser mirror and guided to a diffraction grating, and the diffraction X-ray generated by the diffraction grating In the X-ray detection method in which image is detected by an image sensor,
The position of the slit arranged between the X-ray collector mirror and the diffraction grating is adjusted so that the cathodoluminescence emitted from the sample irradiated with the electron beam does not enter the image sensor. An X-ray detection method characterized by the above. 5. The X-ray detection method according to claim 4, wherein the position of the slit is adjusted in a direction orthogonal to the energy dispersion direction of the image of the diffracted X-ray on the light receiving surface of the image sensor.