JP2009053168A - Simple horizontality confirmation method for sample - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique capable of confirming easily that a sample face is located on the same face orthogonal to a rotation axis. <P>SOLUTION: A sample holder having a plurality of sample attaching windows attached with a plurality of samples having a specular sample face is rotated to make the plurality of sample attaching windows have the same locus, to arrange the individual sample attaching window sequentially in an arranging place, the sample attaching window located in the arranging place is rotated to observe the sample face, and the sample face is therein confirmed to be located on the same face orthogonal to the rotation axis. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for confirming that sample surfaces for analysis of a plurality of samples are on the same horizontal plane. More specifically, the present invention relates to a technique for confirming that the sample surfaces for analysis of a plurality of samples used for secondary ion mass spectrometry (SIMS) are on the same horizontal plane.

  SIMS is a highly sensitive analysis technique and is frequently used for depth direction analysis of trace elements.

  In SIMS, the irradiation angle of primary ions greatly affects the secondary ion intensity and depth resolution in measurement (see Non-Patent Documents 1 to 3). Since the primary ion gun is fixed, the incident angle of the primary ions with respect to the sample surface to be analyzed, that is, the irradiation angle can be changed by changing the angle of the stage (sample stage). For this reason, the spatial arrangement of the sample surface for analysis on the stage must be accurately grasped.

The sample is usually placed by attaching it to a sample holder and fixing the sample holder to the stage. It is not so difficult to make the stage and the holder mechanically accurate. However, with respect to the mounting of the sample to the sample holder, as schematically shown in FIG. 1, the sample 3 is placed in the sample mounting window 1 and pressed by a pressing plate called a mask 4 or schematically shown in FIG. As shown, since a simple method is employed in which the sample is pressed from the back surface 5 with a spring 6 and fixed, it is insufficient to accurately grasp the spatial arrangement of the sample surface. In particular, in order to analyze a plurality of samples under the same conditions, it is necessary to give the same spatial arrangement to the sample surfaces of the plurality of samples. It is difficult to eliminate the difference in the spatial arrangement of the sample surface.
Y. Kataoka, K. Yamazaki, M. Shigeno, Y. Tada, K. Wittmaack, "Surface roughening of silicon under ultra-low-energy cesium bombardment", Applied Surface Science, 2003, 203-204, p.43-47 Y. Kataoka, M. Shigeno, Y. Tada, K. Wittmaack, “Suprisingly large apparent profile shifts of As and Sb markers in Si bombarded by ultra-low energy Cs ion beams. of As and Sb markers in Si bombarded with ultra-low-energy Cs ion beams), Applied Surface Science, 2003, 203-204, p.329-334. K. Wittmaack, “Effect of surface roughening on secondary ion yields and erosion rates of silicon subject to oblique. oxygen bombardment) ”, Journal of Vacuum Science Technology A, 1990, Vol. 8 (3), p.2246-2250

  An object of the present invention is to solve the above-mentioned problems and to provide a technique capable of easily realizing the same spatial arrangement for a plurality of sample surfaces. Still other objects and advantages of the present invention will become apparent from the following description.

  According to an aspect of the present invention, there is provided a sample stage for realizing the same spatial arrangement on the sample surfaces of a plurality of samples, the first rotating shaft portion, the second rotating shaft portion, and the plurality of the sample surfaces. A sample holder having a plurality of sample mounting windows for mounting the sample, wherein the rotation axis of the first rotation shaft portion and the rotation shaft of the second rotation shaft portion are parallel, The sample holder is configured with respect to the first rotating shaft so that the sample mounting window can rotate about the rotating shaft of the first rotating shaft with the same locus; A sample stage is provided in which the sample holder is configured with respect to the second rotating shaft so that each sample mounting window can rotate about the rotating shaft of the second rotating shaft. The

  According to the aspect of the present invention, it can be easily confirmed that the sample surface is on the same plane orthogonal to a certain rotation axis. For this reason, if SIMS is performed for a plurality of samples whose spatial arrangement on the sample surface is confirmed using this sample stage, the irradiation angle of the primary ions can be made the same for the plurality of samples, and accurate analysis becomes possible.

  When the sample attachment window shows a circular shape when viewed from a direction that coincides with the rotation axis of the first or second rotation shaft portion, it is more easily confirmed that the sample attachment window is on the same plane perpendicular to a certain rotation axis. It is possible and preferable.

  As a specific configuration of the sample stage, since the structure is simple and it is easy to increase the reliability, the first base including the first bearing portion and the second base including the second bearing portion are provided. A base, wherein the sample holder is fixed to the first rotating shaft, the first bearing supports the first rotating shaft so as to be rotatable, and the first base is It is fixed to the second rotating shaft portion, the second bearing portion rotatably supports the second rotating shaft, and the second base is placed on the gonio head. preferable.

  Furthermore, from the viewpoint of ease of operation, an irradiation source for irradiating the sample mounting window with light, and an observation device or an imaging device for observing an image of the irradiation source reflected on the sample surface in the sample mounting window It is preferable to have. Moreover, it is preferable that the optical axis of the said irradiation source corresponds with the rotating shaft of said 2nd rotating shaft part. Further, when the gonio head surface is horizontal, it is preferable that the direction corresponding to the rotation axis of the first or second rotation shaft portion is the vertical direction.

  According to another aspect of the present invention, a sample holder having a plurality of sample attachment windows to which a plurality of samples having a mirror sample surface are attached is rotated so that the plurality of sample attachment windows have the same locus. The sample mounting windows are sequentially arranged at a certain location, the sample mounting windows at the location are rotated, the sample surface is observed, and the sample surface is on the same plane perpendicular to the rotation axis. A method for confirming the spatial arrangement of the sample surface is provided.

  According to the aspect of the present invention, there is provided a method capable of easily confirming that the sample surface is on the same plane orthogonal to a certain rotation axis. Therefore, if SIMS is performed on a plurality of samples whose spatial arrangement on the sample surface is confirmed by this method, the irradiation angle of the primary ions can be made the same for the plurality of samples, and an accurate analysis can be performed.

  From the viewpoint of ease of operation, it is possible to observe the sample surface by irradiating the sample mounting window with light and observing an image of an irradiation source reflected on the sample surface in the sample mounting window. preferable. Moreover, it is preferable that the optical axis of the light coincides with the rotation axis of the rotation.

  According to another aspect of the present invention, a secondary ion mass spectrometer equipped with the above sample stage or the above arrangement confirmation method confirmed that the sample surface is on the same plane perpendicular to the rotation axis. A secondary ion mass spectrometry method for performing secondary ion mass spectrometry on a plurality of samples is provided.

  By the method of the present invention, it can be easily confirmed that the sample surface is on the same plane orthogonal to a certain rotation axis. Therefore, if SIMS is performed on a plurality of samples whose spatial arrangement on the sample surface is confirmed by this method, the irradiation angle of the primary ions can be made the same for the plurality of samples, and an accurate analysis can be performed.

  Embodiments of the present invention will be described below with reference to the drawings, examples and the like. In addition, these figures, Examples, etc. and description illustrate the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention. In the drawings, the same reference numerals represent the same elements.

  It is important that the sample surface according to the present invention is a mirror surface, although it is not an essential condition. The degree of mirror surface in the present invention can be arbitrarily determined by those skilled in the art according to the purpose.

  In the method for confirming the spatial arrangement of the sample surface according to the present invention, a sample holder having a plurality of sample attachment windows to which a plurality of samples having a sample surface that is a mirror surface is attached, and the plurality of sample attachment windows have the same locus. The sample mounting windows are sequentially arranged at a certain location, and the sample mounting window at the location is rotated, the sample surface is observed, and the sample surface is orthogonal to the rotation axis. Make sure they are on the same plane. When the surface formed by the same locus and the surface orthogonal to the rotation axis are horizontal surfaces, the sample surface can be easily aligned with the horizontal surface. If the sample surface is not on the same plane orthogonal to the rotation axis, the attachment method may be arbitrarily corrected by manual or mechanical means, and then the same observation may be repeated.

  By adopting this method, by performing SIMS on a plurality of samples confirmed that the sample surface is on the same plane orthogonal to a certain rotation axis, the irradiation angle of the primary ions can be made the same for the plurality of samples, Accurate analysis is possible.

  The sample surface may be observed by any method as long as it can be confirmed that the sample surface is on the same plane orthogonal to a certain rotation axis. It is simple and preferable to carry out by observing the image of the irradiation source reflected on the sample surface. There is no particular limitation on the type of light in this case, but when observation is performed visually, it is performed with visible light. Anything may be included in the “observation of the image of the irradiation source”. For example, the shape of the image of the irradiation source projected on the sample surface matches the shape of the irradiation source (for example, if the shape of the irradiation source is circular, the shape of the image is not an ellipse), or the sample surface It is possible to observe whether the position of the image of the irradiation source projected on the center of the sample surface is the same, and whether the position of the image of the irradiation source projected on the sample surface is the same when the sample is switched. Useful. The observation of the image of the irradiation source may be visual observation through an imaging device instead of direct visual observation. Furthermore, the shape and position of the image of the irradiation source may be determined and evaluated automatically or semi-automatically with or without an imaging device.

  It is practical and preferable that the optical axis of the irradiation source coincides with the rotation axis of the rotation, in other words, coincides with the rotation axis of the second rotation shaft portion in the following, There may be cases where other directions may be selected.

As the sample stage for realizing the same spatial arrangement on the sample surface of multiple samples,
A first rotating shaft portion, a second rotating shaft portion, and a sample holder having a plurality of sample mounting windows for mounting the plurality of samples,
The rotation axis of the first rotation shaft portion and the rotation shaft of the second rotation shaft portion are parallel,
The sample holder is configured with respect to the first rotating shaft so that the plurality of sample mounting windows can rotate around the rotating shaft of the first rotating shaft with the same locus. ,
Furthermore, the sample holder is configured with respect to the second rotation shaft portion so that each sample mounting window can rotate around the rotation shaft of the second rotation shaft portion.
A sample stage can be provided.

  There are no particular restrictions on the properties of each part, such as the material and shape not specified above.

  An example of the sample stage according to the present invention is shown in FIG. FIG. 3 shows the sample stage 31, the sample holder 32, and the like. The sample holder 32 is provided with six sample attachment windows 1. The sample is a system in which the measurement surface (sample surface) 2 is applied from below the holder, and the sample back surface 5 is fixed by a spring 6 (the sample back surface 5 and the spring 6 are not drawn in FIG. 3). See).

  The sample table 31 includes a first base 35 having a first rotating shaft portion 33, a first bearing portion 34, a second rotating shaft portion 36, and a second base having a second bearing portion 37. 38. The sample holder 32 is fixed to the first rotating shaft portion 33, the first bearing portion 34 rotatably supports the first rotating shaft portion 33, and the first base 35 is rotated second. Fixed to the shaft portion 36, the second bearing portion 37 rotatably supports the second rotating shaft 36, and the second base 38 is placed on the gonio head 39.

  The rotation axis XX of the rotation shaft portion 33 passes through the center of the sample holder 32, so that the sample mounting window 1 has the same locus around the rotation axis XX of the first rotation shaft portion 33. Can rotate to. The “same trajectory” in the present invention means that a plurality of sample mounting windows come to the same spatial position when the sample holder is rotated as in this case. Further, the “arrangement place” in the present invention is a place on the locus when the sample holder is rotated as described above, and a place for observing the sample surface by rotating the sample attachment window. Means.

  The rotation axis YY of the second rotation shaft portion 36 passes through the center of one sample mounting window 1 provided in the sample holder 32, and each sample mounting window is the sample mounting window 1 ( When in position a), the second rotary shaft 36 can rotate around the rotation axis Y-Y. In this example, the rotation axes XX and YY are both in the vertical direction, and the sample mounting window 1 is disposed in the horizontal direction.

  A circular light source 30 is installed on the extended line of the rotation axis Y-Y, and the circular light source can be projected on the mirror sample surface 2.

  In FIG. 3, when the second rotary shaft portion 36 is rotated around the rotary axis YY, the position of the light source reflected on the sample surface with respect to the sample is determined by a camera (not shown) installed coaxially with the light source. Can be confirmed. In this case, for example, if the center position of the image of the circular light source on the sample surface coincides with the center of the attachment window 1, it can be considered that the sample is attached horizontally in the window. If the center of the image of the circular light source is deviated from the center of the window, the sample is not level with the sample holder. In that case, correction may be performed by an arbitrary means such as re-installation. By repeating the above operation while rotating the sample holder and switching the sample coming to the position of the sample mounting window 1 (a) in FIG. 3, it is possible to confirm the mounting state of all the samples.

  In the above, the sample surface was observed by the position of the light source reflected on the sample surface, and it was confirmed that the sample surface was on the same plane orthogonal to a certain rotation axis. However, as described above, the observation of the sample surface is not limited to this. For example, the confirmation may be performed by matching the position of the light source reflected on the sample surface with a position other than the center of the sample mounting window 1. Moreover, you may observe the shape of the light source reflected on the sample surface.

  When the center of the sample mounting window is used as described above, it is preferable that the sample mounting window has a circular shape when viewed from a direction coinciding with the rotation axis of the first rotation shaft portion. Since the rotation shaft of the first rotation shaft portion and the rotation shaft of the second rotation shaft portion are parallel, the second rotation shaft portion instead of the direction that coincides with the rotation shaft of the first rotation shaft portion. You may choose a direction that matches the axis of rotation.

  In FIG. 3, a camera is used as an observation device or an imaging device for observing an image of the irradiation source reflected on the sample surface, but any other observation device or imaging device can be used. Furthermore, you may observe with the naked eye directly or indirectly, without using an observation apparatus and an imaging device.

  The sample stage itself according to the present invention may be arranged in any space, but when the gonio head surface is leveled, the direction corresponding to the rotation axis of the first or second rotation shaft portion is the vertical direction. It is practical and preferable.

  If the sample stage according to the present invention is used with a secondary ion mass spectrometer or as a part of a secondary ion mass spectrometer, the irradiation angle of primary ions can be made the same for a plurality of samples, and accurate analysis can be performed. It becomes possible.

  FIG. 4 schematically shows an example in which the sample stage according to the present invention is used as a part of a secondary ion mass spectrometer. The secondary ion mass spectrometer 40 includes ion guns 41 and 42, a neutralizing gun 43, and an analyzer 44, and the analyzer 44 analyzes the secondary ion intensity generated from the sample by irradiation of primary ions by the ion guns 41 and 42. To do.

  The sample is attached to the sample stage 31 according to the present invention and placed on the gonio head 39. A camera is placed coaxially with the light source 30 above the gonio head 39. A photograph of the antigen thus reflected on the sample surface is shown in FIG. In FIG. 5, the x mark is the center of the circular sample mounting window, and the Y mark is the center of the image of the light source. Six samples made of the same material were manually attached and adjusted so that the Y mark matched the X mark in the photograph of FIG.

  In this example, the light source applied to the surface of the specular sample is circular, and is coaxial with the observation camera immediately above the sample mounting window. However, the position of the light source can be adjusted with a camera installed on the extension of the rotation axis, such as by providing an aperture so that the shape of the light source reflected on the sample surface is circular even when illuminated by a light source from an oblique direction, or by changing the shape of the light source. It is also possible to confirm. Even in this case, the light source and the camera do not interfere with the arrangement of the ion gun and the analyzer in the SIMS analysis chamber.

  In addition, the invention shown to the following additional remarks can be derived from the content disclosed above.

(1) A sample stage for realizing the same spatial arrangement on the sample surfaces of a plurality of samples,
A first rotating shaft portion, a second rotating shaft portion, and a sample holder having a plurality of sample mounting windows for mounting the plurality of samples,
The rotation axis of the first rotation shaft portion and the rotation shaft of the second rotation shaft portion are parallel,
The sample holder is configured with respect to the first rotating shaft so that the plurality of sample mounting windows can rotate around the rotating shaft of the first rotating shaft with the same locus. ,
Further, the sample holder is configured with respect to the second rotation shaft portion so that each sample mounting window can rotate around the rotation shaft of the second rotation shaft portion.
Sample stage.

  (2) The sample stage according to appendix 1, wherein the sample mounting window shows a circular shape when viewed from a direction coinciding with the rotation axis of the first or second rotation shaft portion.

(3) The sample stage includes a first base including a first bearing and a second base including a second bearing.
The sample holder is fixed to the first rotating shaft,
The first bearing portion rotatably supports the first rotating shaft portion,
The first base is fixed to the second rotating shaft portion,
The second bearing portion rotatably supports the second rotating shaft,
The second base is placed on the gonio head,
Sample stage according to appendix 1 or 2.

  (4) Furthermore, it has an observation device or an imaging device for observing an image of an irradiation source that irradiates light on the sample mounting window and an image of the irradiation source reflected on the sample surface in the sample mounting window 4. The sample stage according to any one of 3.

  (5) The sample stage according to appendix 4, wherein an optical axis of the irradiation source coincides with a rotation axis of the second rotation shaft portion.

  (6) The sample stage according to any one of appendices 3 to 5, wherein when the gonio head surface is horizontal, a direction coinciding with the rotation axis of the first or second rotation shaft portion is a vertical direction.

  (7) A secondary ion mass spectrometer provided with the sample stage according to any one of appendices 1 to 6.

(8) Each sample mounting window is rotated by rotating a sample holder having a plurality of sample mounting windows to which a plurality of samples having mirror sample surfaces are mounted so that the plurality of sample mounting windows have the same locus. Are placed sequentially in a certain place,
Rotate the sample mounting window at the arrangement location, observe the sample surface, and confirm that the sample surface is on the same plane orthogonal to the rotation axis.
How to check the spatial arrangement of the sample surface.

  (9) The spatial arrangement according to appendix 8, wherein the sample surface is observed by irradiating light to the sample mounting window and observing an image of an irradiation source reflected on the sample surface at the sample mounting window. Confirmation method.

  (10) The spatial arrangement confirmation method according to appendix 8 or 9, wherein an optical axis of the light coincides with the rotation axis of the rotation.

  (11) Secondary ion mass spectrometry is performed on a plurality of samples that have been confirmed to be on the same plane perpendicular to the rotation axis of the sample surface by the arrangement confirmation method according to any one of appendices 8 to 10. Ion mass spectrometry.

It is a schematic diagram which shows the attachment state of a sample. It is another schematic diagram which shows the attachment state of a sample. It is a schematic diagram which shows an example of the sample stand which concerns on this invention. It is a schematic diagram which shows the example which used the sample stand which concerns on this invention as a part of secondary ion mass spectrometer. It is a photograph which shows the mode of the light source reflected on the sample surface which is a mirror surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample attachment window 2 Sample surface 3 Sample 4 Mask 5 Sample back surface 6 Spring 30 Light source 31 Sample stand 32 Sample holder 33 First rotating shaft part 34 First bearing part 35 First base 36 Second rotating shaft part 37 Second bearing portion 38 Second base 39 Goniometer 40 Secondary ion mass spectrometer 41, 42 Ion gun 43 Neutralizing gun 44 Analyzer

Claims (8)

A sample stage for realizing the same spatial arrangement on the sample surfaces of a plurality of samples,
A first rotating shaft portion, a second rotating shaft portion, and a sample holder having a plurality of sample mounting windows for mounting the plurality of samples,
The rotation axis of the first rotation shaft portion and the rotation shaft of the second rotation shaft portion are parallel,
The sample holder is configured with respect to the first rotating shaft so that the plurality of sample mounting windows can rotate around the rotating shaft of the first rotating shaft with the same locus. ,
Furthermore, the sample holder is configured with respect to the second rotation shaft portion so that each sample mounting window can rotate around the rotation shaft of the second rotation shaft portion.
Sample stage.   The sample stage according to claim 1, wherein the sample mounting window has a circular shape when viewed from a direction that coincides with a rotation axis of the first or second rotation shaft portion. The sample stage includes a first base including a first bearing and a second base including a second bearing;
The sample holder is fixed to the first rotating shaft,
The first bearing portion rotatably supports the first rotating shaft portion,
The first base is fixed to the second rotating shaft portion,
The second bearing portion rotatably supports the second rotating shaft,
The second base is placed on the gonio head,
The sample stage according to claim 1 or 2.   Furthermore, it has an observation apparatus or an imaging device for observing the irradiation source which irradiates light to the sample attachment window, and the image of the irradiation source reflected on the sample surface in the sample attachment window The sample stage according to any one of the above.   The secondary ion mass spectrometer provided with the sample stand in any one of Claims 1-4. A sample holder having a plurality of sample mounting windows to which a plurality of samples having a mirror sample surface are mounted is rotated so that the plurality of sample mounting windows have the same locus, and the individual sample mounting windows are arranged. Place them in place,
Rotate the sample mounting window at the arrangement location, observe the sample surface, and confirm that the sample surface is on the same plane orthogonal to the rotation axis.
How to check the spatial arrangement of the sample surface.   The spatial arrangement confirmation method according to claim 6, wherein the sample surface is observed by irradiating light to the sample mounting window and observing an image of an irradiation source reflected on the sample surface in the sample mounting window. .   A secondary ion mass spectrometry method in which secondary ion mass spectrometry is performed on a plurality of samples that have been confirmed by the arrangement confirmation method according to claim 6 or 7 that the sample surface is on the same plane orthogonal to a rotation axis.

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