JPH0527938B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an ion microanalyzer (hereinafter referred to as
In particular, it relates to IMA, which allows easy selection and designation of analysis points and is suitable for highly efficient multi-point analysis on a limited sample surface.

[Background of the invention]

With conventional equipment, mass spectrometry Vol.23, No.4
As shown in the document titled "Development of an IMA data processing system" by Kato et al., p. 271-279 of 1975, raster scanning of the primary ion beam and control of sample micromovement are performed, but consideration must be given to the method of specifying the analysis position. It has not been.

In addition, the 9th Local Meeting materials of the 141st Committee on Microbeam Analysis of the Japan Society for the Promotion of Science p37~
“Application of SIMS to bioanalysis” by Tamura et al.
(2),” in order to improve analytical accuracy,
Multiple points are analyzed, but the method of specifying multiple points depends only on the analyst's selection, and no consideration is given to the equipment.

However, in IMA, a solid sample is irradiated with an accelerated primary ion beam, and the secondary ions emitted from the sample surface are collected using a mass spectrometer (mass/charge (M/
e) and performs elemental analysis of the sample.This device is capable of not only surface analysis of solid samples, but also depth analysis using sputtering, and has extremely high sensitivity. However, on the other hand, it is a destructive analysis from a microscopic point of view, and measurements cannot be repeated at the same location. Important for reliability.

[Purpose of the invention]

The present invention has been made in view of the above, and its purpose is to facilitate the selection and designation of analysis points.
The object of the present invention is to provide an ion microanalyzer that can perform highly efficient multi-point analysis on a limited sample surface.

[Summary of the invention]

In order to achieve the above object, the present invention provides an ion microanalyzer that irradiates a sample with a primary ion beam and performs mass analysis of secondary ions emitted from the surface of the sample, comprising: a deflection means for deflecting and scanning the primary ion beam; , a sample moving means for slightly moving the sample on the XY plane together with the sample stage; a display means for displaying an image of the sample set on the sample stage together with coordinates on a screen with scales for the X and Y axes; An input means for specifying the analysis point of the sample (the primary ion beam scanning area to be analyzed is called the analysis point) through the sample image on the screen, and the coordinates of this specified analysis point (hereinafter referred to as the analysis specified point) are stored. a storage means for controlling the sample moving means and the deflection means so that mass spectrometry is performed at the specified analysis point; The apparatus includes an image processing means for displaying the sample image on the display means to distinguish the sample image, and an alarm means for outputting an alarm when the specified analysis point overlaps with an already analyzed point.

With such a configuration, the sample image displayed on the screen of the display means is accompanied by coordinates on the XY plane.
By arbitrarily specifying an analysis point on the sample image on the display means using an input means (for example, a cursor, a light pen, etc.), the actual analysis point of the sample is specified. In addition, when performing multi-point analysis, it is possible to accurately and easily position each analysis point by adjusting the interval between each analysis point as intended by the operator while watching the X- and Y-axis scales shown on the screen. can be specified.

The coordinates of this specified analysis point are stored, and the control means controls the sample moving means based on this stored data.
The sample is moved so that the designated analysis point of the sample is at the primary ion beam irradiation position, and the deflection means is controlled to irradiate the sample with the primary ion beam while being deflected and scanned, and mass spectrometry is performed.

Further, the designated analysis point is shown in the sample image, but after mass spectrometry is performed, it is displayed as an already analyzed point. The specified analysis points are displayed in a different manner through image processing so as to be displayed differently from the already analyzed points. As a result, when specifying a new analysis point while looking at the screen, you can avoid overlapping with an existing analysis point, and also specify the analysis point while looking at the scale on the screen. Not only can you easily specify a high number of analysis points by keeping it at a reasonable level, but you can also easily understand the status of the analysis that has already been done on the screen. Furthermore, when specifying this analysis point, if the specified analysis point overlaps with an already analyzed point, a warning will be issued, thereby reliably preventing mistakes in specifying the analysis point.

[Embodiments of the invention]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the ion microanalyzer of the present invention.

In FIG. 1, a primary ion beam 2 generated by an ion source 1 is accelerated, deflected and scanned by a deflection electrode (deflection means) 3, and irradiated onto a sample 4. Secondary ions 5 emitted from the sample 4 on the sample holder are separated into mass/charge ratios by a mass spectrometer 6. A deflection power source 7 is connected to the deflection electrode 3, and the deflection power source 7 is controlled by a control section (control means) 10 to control the amount of deflection and the direction of deflection.

On the other hand, the sample 4 is mounted on a sample holder on a fine movement table (specimen moving means) 8 in the XY plane, and the fine movement table 8 is controlled by a fine movement table power source 9 controlled by a control unit 10. and the direction of micro-movement is controlled.

The control signals 7A and 9A from the control section 10 are values input from the input circuit (input means) 11.
Further, a storage device 12 , a display device 13 , and an alarm circuit 14 are connected to the control unit 10 .

The storage device 12 stores data on the shape and dimensions of the sample holder and the sample, micro-movement position data, data on the analysis point of the sample (analysis position and scanning area of the primary ion beam at that position), etc. It is input from the circuit 11. Input circuit 11
is a keyboard numeric keypad and display device (e.g.
It consists of a cursor 13 (display means such as CRT, liquid crystal imager, etc.) and a light pen (cursor in this embodiment).

The display device 13 displays the sample set on the sample holder (sample table) based on the stored contents of the storage device 12 together with the holder along with the XY plane coordinates. In addition, the display device 13 or the control unit 15 includes
It is equipped with an image processing means for displaying an analysis point (analysis designated point) designated through a cursor operation of the input circuit 11 in a display manner different from that of already analyzed points in the sample image on the display device 13. Alarm circuit 14
has a function of displaying an alarm when the specified analysis point shown on the display device 13 overlaps with an already analyzed point.
15 is an arithmetic circuit within the control section 10.

Here, before explaining the control of mass spectrometry, the second
The figure shows a specific display example of the display device 13, FIG. 3 shows an example of the arrangement of the sample holder and sample, FIG. 4 shows the advantages of the present invention and conventional problems when specifying an analysis point, and FIGS. How to specify the analysis points in this embodiment will be explained with reference to FIG.

On the screen of the display device 13, as shown in FIG. 2a, images of the sample holder and the sample are displayed with XY plane coordinates, and X-axis and Y-axis scales are attached to indicate dimensions. X axis 0 to 3×10 ⁴ in Figure 2 a, Y
A rectangle with an axis of 0 to 5×10 ⁴ corresponds to a sample holder expressed in μm. Eight circles therein represent samples. A plurality of small squares within the circular sample represent craters analyzed by raster scanning the primary ion beam. Figure 2b shows the second
In the partially enlarged display example of Figure a, the analysis points that have already been analyzed (already analyzed points) among the analysis points specified by the input circuit 11 are shown by solid lines, and the unanalyzed or input circuit 1
Analysis points newly specified from 1 onwards (analysis specified points) are distinguished and displayed using broken lines, blinking, or the like. This distinguishing display may be a color-coded display.

FIG. 3 is a plan view showing one embodiment of the sample holder, in which eight samples 4 shown in circles are mounted on the sample holder 16. When displayed in XY coordinates,
They are arranged with X ₁ Y ₁ , X ₁ Y ₂ , X ₁ Y ₃ , ...X ₂ Y ₄ as the center, and FIG. 4 shows an enlarged view of the X ₁ Y ₁ section.

In Figure 4a, the analyzed points are X ₁₁ , X ₁₂ ,
Assuming that Y ₁₁ , Y ₁₂ is a rectangle with vertices, the next points to be analyzed are specified in the quadrilateral region with vertices X ₁₁ , X ₁₂ , Y ₁₃ , Y ₁₄ separated by ΔY. In this embodiment, by setting this ΔY to an appropriate interval while looking at the scale displayed on the screen of the display device 13, analysis can be performed a maximum of N times on this Y axis.

By the way, in the conventional method, ΔY was specified by visual observation using an optical microscope, so if the sputter etching crater (hole) in the analyzed area is unclear or if the operation area is estimated incorrectly, As shown in FIG. 4b, the points may overlap with already analyzed points. In the case of bulk analysis, the data will be highly inaccurate and the analysis will be useless. Analysis at a depth of several μm requires several hours, and this time consumption is extremely uneconomical. To avoid this duplication,
As shown in FIG. 4c, if ΔY is set a little larger, there will be no overlap, but the number of analysis points on the Y axis will be reduced, and 1/1 of the N times in the case of FIG. 4a according to the present invention. It becomes 2-1/3.

Next, an example of specifying an analysis point will be explained with reference to FIGS. 5 and 6.

FIG. 5 is a diagram showing an example of specifying analysis points. As shown in FIG.
6 is displayed on the display device 13, and the analysis order of the sample 4 is designated by operating the input circuit 11 using a cursor while viewing the screen. Note that when X is the horizontal direction, Y is the vertical direction, Z is the vertical direction, and T is the tilt angle, the origin 0 is assumed to be X ₀ , Y ₀ , Z ₀ , and T ₀ . Next, the sixth
As shown in the analysis point display example shown in the figure, each channel (CH1 in Figure 5) is
~CH8) enlarged views are displayed one after another. here,
When various analysis conditions such as the analyzer and scanning area are input for each channel from the input circuit 11, the result shown in FIG.
The scanning area (analysis point) of each analysis position as shown in is specified. In this case, the origin 0 is set to X ₀ , Y ₀ , Z ₀ ,
As T ₀ , the analysis positions of each channel from the origin 0 are expressed as X ₁ , Y ₁ , Z ₁ , T ₁ , ..., X ₈ , Y ₈ , Z ₈ , T ₈ .

When the analysis point is specified as described above, the analysis point is stored in the storage device 12, and based on this storage data, the control section 10 controls the fine movement stage 8, so that the specified analysis point of the sample is set to the primary ion beam. The sample is moved to the irradiation position, and then the deflection electrode 7 is controlled to irradiate the sample 4 with the primary ion beam while being deflected and scanned, and mass spectrometry is performed. For example, channel 1 is the first channel, channel 8 is the second channel, etc.
To analyze, first, from the origin 0, X ₁ , Y ₁ ,
After moving to Z ₁ and T ₁ and completing the analysis according to the analysis conditions, the comparison calculation circuit 15 calculates (X ₈ −X ₁ , Y ₈
−Y ₁ , Z ₈ −Z ₁ , T ₈ −T ₁ ), and the sample holder 16 is moved by the movement of the fine movement stage 8 to perform the next analysis. The same applies to the case where a plurality of analysis points are designated for each channel as shown in FIG.

When the specified analysis point is analyzed, the corresponding analysis point shown on the display screen changes from a broken line to a solid line.

According to the present embodiment described above, (1) It is easy to select and specify analysis points, and duplicate analysis can be avoided.

(2) Analysis points can be selected efficiently, and highly efficient multi-point analysis is possible on a limited sample surface.

(3) Since the sample position and analysis position can be displayed, operability is significantly improved.

(4) The work status of multipoint mass spectrometry can be recognized through the screen.

There are advantages such as

[Effects of the Invention] As described above, according to the present invention, it is possible to specify an analysis point and to perform mass spectrometry through the screen of the display device.
By using the Y-axis scale, the display of the designated analysis point to distinguish it from the already analyzed points, and the overlap warning between the designated analysis point and the already analyzed point, it is easy to select and specify the analysis point, and it is possible to easily select and specify the analysis point. This has the effect of enabling efficient multi-point analysis, improving operability, and being able to know the progress of multi-point mass spectrometry work.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the ion microanalyzer of the present invention, Fig. 2 is a diagram showing an example of sample display by the display device of Fig. 1, and Fig. 3 is a plan view showing an embodiment of the sample holder. 4 is an enlarged view of an example of specifying an analysis point, FIG. 5 is a view showing an example of specifying an analysis point in the present invention, and FIG. 6 is a view showing an example of displaying an analysis point. 1...Ion source, 2...Primary ion beam, 3
... Deflection electrode, 4 ... Sample, 5 ... Secondary ion,
6...Mass spectrometer, 7...Deflection power supply, 8...Fine movement table, 9...Fine movement table power supply, 10...Control unit, 11...
... input circuit, 12 ... storage device, 13 ... display device, 14 ... alarm circuit, 15 ... comparison calculation circuit,
16...Sample holder.

Claims (1)

[Scope of Claims] 1. An ion microanalyzer that irradiates a sample with a primary ion beam and performs mass analysis of secondary ions emitted from the surface of the sample, comprising: a deflection means that deflects and scans the primary ion beam; A sample moving means for slightly moving the sample on the XY plane together with the sample stage; a display means for displaying the image of the sample set on the sample stage along with the coordinates on a screen with scales on the X and Y axes; and a display means for displaying the image of the sample on the screen. an input means for specifying an analysis point of the sample (the primary ion beam scanning area to be analyzed is referred to as an analysis point) through the input means; a storage means for storing the coordinates of the specified analysis point (hereinafter referred to as an analysis specified point); , a control means for controlling the sample moving means and the deflecting means so that mass spectrometry is performed at the designated analysis point; and a display means for visually displaying the designated analysis point and the analyzed point in different ways. An ion microanalyzer comprising: an image processing means for distinguishing and displaying in a sample image; and an alarm means for outputting an alarm when the designated analysis point overlaps an already analyzed point.