JPH0646558B2 - Sample analysis method in X-ray microanalyzer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sample analysis method in an X-ray microanalyzer for acquiring characteristic X-ray intensity value data of each element in each pixel on the surface of a sample and analyzing the sample.

[Conventional technology]

In the X-ray microanalyzer, the sample surface is divided into a large number of pixels, and these pixels are sequentially irradiated with an electron beam to generate each element Θ1, Θ2, ..., Θn generated from each pixel (x, y).
Detecting (n ≧ 2) characteristic X-rays is performed. In such a device, the characteristic X-ray intensity value data relating to each of the detected elements Θ1, Θ2, ..., Θn (n ≧ 2) is temporarily stored in a storage device, and then an arbitrary element is selected based on an instruction from the operator. The characteristic X-ray intensity value data of Θi is read out and developed on the display device.

[Problems to be Solved by the Invention] When a characteristic X-ray intensity value of a certain element Θi is converted into an n-value and observed as a color mapping image with such an apparatus,
An overview of the situation of the distribution of X-ray intensity values can be known. However, in such a mapping image, the X-ray intensity value signal is compared with several reference levels to be n-valued, and different colors are assigned to values of different layers and displayed as a color mapping image. When the area displayed in the same color is seen in more detail, whether the X-ray intensity values of the pixels in this area are dispersed in a relatively wide range or concentrated in a narrow range, that is, It is not possible to know the degree of homogeneity of the sample in the region with respect to the element concentration. If the degree of uniformity of the sample in the region regarding the concentration of the element displayed as the mapping image can be known, the knowledge of the region can be deepened. In particular,
If the uniformity of the concentration of elements other than the element displayed as the mapping image in the region can be known, the knowledge of that portion can be further deepened.

The present invention has been made in view of such a point, and an object thereof is in a region of interest in a color mapping image,
An object of the present invention is to provide a sample analysis method in an X-ray microanalyzer capable of displaying a histogram showing a frequency distribution of characteristic X-ray intensities of pixels other than the elements displayed as a mapping image.

[Means for Solving the Problems] A sample analysis method in an X-ray microanalyzer of the present invention which achieves this object is to irradiate a sample with an electron beam to form each pixel (x, y) on a two-dimensional plane of the sample. For each element Θ1,
Θ2, ..., Θn (n ≧ 2) characteristic X-ray intensity value data I
1 (x, y), I2 (x, y), ..., In (x, y) are obtained, the obtained data is stored, and an arbitrary element Θi (i is 1, (2, ..., N) characteristic X-ray intensity value data Ii (x, y) is read, a distribution image of the element Θi is displayed in a color according to the read data value, and the distribution image of the distribution image is displayed. An area S of an arbitrary size is designated at an arbitrary position, and an element Θj other than the element Θi (j is 1,
It is characterized in that a histogram representing a frequency distribution for each X-ray intensity value of each pixel included in the designated area S is displayed for any of 2, ...

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a main part of an apparatus for carrying out the present invention, and FIG. 2 is a system configuration diagram showing an entire apparatus for carrying out the present invention.

In FIG. 2, 1 is an X-ray micro analyzer (hereinafter X
(Abbreviated as MA), 2 is a sample, EB is an electron beam, C
1, C2, C3 are dispersive crystals, D1, D2, D3 are X-ray detectors, T1, T2, T3 are X-ray counters, 3 is a CPU, 4
Is a storage device, 5 is a color graphic display, 6
Is a pointing device such as a digitizer or mouse,
Reference numeral 7 is a keyboard, and 8 is a bus line. The dispersive crystals C1, C2 and C3 have the characteristic X of the elements Θ1, Θ2 and Θ3, respectively.
The line is set to be selectable. Further, the pointing device 6 is for pointing this area by drawing an area having an arbitrary position, size and shape on the screen of the color graphic display 5 by a bright line according to an instruction of the operator.

In FIG. 1, 9 is an X-ray intensity value data storage unit, 10 is a writing / reading control unit, 11 is a region designating unit, 12 is a mapping element designating unit, and 13 is an element for which a histogram or a correlation graph to be described later is drawn. Target element designation part for designation, 14 is a function designation part, 15 is a function selection part, 1
6 is a histogram data creation unit, 18 is a level division processing unit, 19 is a color division processing unit, and 20 is a display control unit. As shown in FIG. 1, the storage device 4 is provided with an X-ray intensity value data storage unit 9, and this X-ray intensity value data storage unit further corresponds to each element Θ1, Θ2, Θ3. One-screen image storage areas A1, A2, A3 are provided. Each one-screen image storage area has a storage area of a predetermined depth for each pixel (x, y) in the sample scanning area by the electron beam EB.

In such a configuration, the horizontal movement mechanism of the sample 2 is operated to move the sample 2 two-dimensionally in a state where the sample is irradiated with the electron beam EB. As a result, each pixel (x, y) of the sample 2 is sequentially irradiated with the electron beam EB. Among the characteristic X-rays generated from each pixel (x, y) of the sample 2 by the irradiation of the electron beam EB, the characteristic X-rays of the elements Θ1, Θ2, Θ3 are X-rays via the dispersive crystals C1, C2, C3, respectively. It is detected by the line detectors D1, D2, D3. Therefore, the count value signals of the characteristic X-rays of the respective elements Θ1, Θ2, Θ3 in each pixel (x, y) are sent from the X-ray counters T1, T2, T3 to the storage device 4 via the bus line 8. Storage device 4
X related to element Θ1 of each pixel (x, y) sent to
The line intensity value data is stored in the storage area of the image storage area A1 of the X-ray intensity value data storage section 9 corresponding to each pixel (x, y). Similarly, the characteristic X-ray intensity value data of the element Θ2 is stored in the image storage area A2, and the characteristic X-ray intensity value data of the element Θ3 is stored in the image storage area A3. Therefore, when the operator uses the keyboard 7 to instruct the color mapping display of the characteristic X-ray intensity distribution of the element Θ1, the mapping element designating section 12 sends a signal instructing the writing / reading control section 10 to select the element Θ1. The read control unit 10 sets A in the image storage area of the X-ray intensity value data storage unit 9.
All data stored in No. 1 are sequentially read and sent to the level division processing unit 18. The level classification processing unit 18 compares the transmitted X-ray intensity value data with a plurality of preset reference levels. The number and value of the reference levels can be set arbitrarily. In the case of this embodiment, if four reference levels are set as the reference levels, the level division processing unit 18 classifies the transmitted X-ray intensity value data into the inside and outside of each of the reference levels. By doing so, the value is converted into five values and sent to the color classification processing section 19. Color code processing unit 1
In 9, the hue corresponding to the hierarchical value is assigned to the 5-valued data sent by the level division processing unit 18, and a signal for displaying each with the assigned hue is sent to the display control unit 20. As a result, a color mapping image showing the characteristic X-ray intensity distribution of the element Θ1 is displayed on the color graphic display 5, as shown in FIG.
Similarly, when the operator instructs the display of the characteristic X-ray intensity distribution image of the element Θ2, an image as shown in FIG. 3 (b) is displayed on the display 5 based on the data stored in A2 of the image storage area. To be done. Among such X-ray intensity distribution images,
For example, when an area of interest is found while observing the characteristic X-ray intensity distribution image of the element Θ2, and the frequency distribution of the characteristic X-ray intensity value of the element Θ1 taken by the pixels included in this area is to be known. To do this, do the following:

That is, first, the operator operates the pointing device 6,
Under the control of the area designating section 11, the area S is surrounded by a bright line F as shown in FIG. After the designation of the area is completed in this way, the keyboard 7 is used to instruct that the target of the frequency distribution display is the element Θ1. Based on this instruction, the target element designating unit 13 notifies the writing / reading control unit 10 that the data in the image storage area A1 is selected as the data to be read. Further, when a graphic display is made in the form of a histogram with the keyboard 7, the function designating section 14 controls the function selecting section 15 so that the data sent from the X-ray intensity value data storing section 9 is guided to the histogram data creating section 16. Function selector 1
Set 5. Therefore, when the display of the frequency distribution is instructed, of the data stored in the image storage area A1 of the X-ray intensity value data storage unit 9, the instructed area S based on the area instruction signal from the area designating unit 11 is sent. Only the data of the pixels included in is read by the writing / reading control unit 16 and sent to the histogram data creation unit 16 via the function selection unit 15. Histogram data creation unit 16
In, it is determined where each of the sent data falls within a large number of layers that have been set at regular intervals, and each time the data is classified into each layer, it corresponds to that layer. By counting up the counted value,
Create frequency distribution data of X-ray intensity values. Since the data created by the histogram data creation unit 16 is sent to the display control unit 20, the X-ray intensity value of the element Θ1 as shown in FIG. 4 is displayed on the graphic display 5 under the control of the display control unit 20. A histogram showing the frequency distribution of is displayed. By looking at this display, the operator
If the width of the histogram is narrow, the variation in the amount of the element Θ1 distributed in the designated region is small, and it can be known that the sample is relatively homogeneous with respect to the concentration of the element Θ1. If wide, element Θ1
It can be seen that the concentrations of H2 and H2 differ slightly slightly, and the degree of homogeneity of the sample is low.

Further, for example, when displaying a histogram of the element Θ3, the keyboard 7 may be used to indicate that the target element is Θ3. Based on this instruction, the target element designating unit 13 determines that the data in the image storage area A3 is In order to notify the write / read control unit 10 that the data is to be read, the data contained in the area S among the data in the image storage area A3 is read and processed, and a histogram regarding the element Θ3 is displayed on the graphic display 5. be able to. The above-described embodiment is only one embodiment of the present invention, and the present invention can be modified and implemented.

For example, in the above-described embodiment, the pointing device is used to indicate an area having not only an arbitrary position and size but also an arbitrary shape. However, K1 and K2 in FIG. , K3, a rectangle whose size is changed stepwise and its position is arbitrarily changed may be displayed, and the region may be designated by instructing the position and size of this rectangle.

Further, in the above-described embodiment, the case where characteristic X-rays of three kinds of elements are detected has been shown for simplification of description, but the number of characteristic X-rays of more elements is not limited to three kinds. It may be stored in the storage device.

Further, in the above-described embodiment, the characteristic X-ray intensity data is directly used to display the histogram or the correlation graph, but after the characteristic X-ray intensity data is converted into the concentration value by using the calibration curve method or the like, You may make it display a histogram or a correlation graph.

[Effects of the Invention] In the present invention, a histogram showing the frequency distribution for each X-ray intensity value of elements other than the element displayed as the mapping image in the region of interest in the mapping image is displayed. It is possible to know the uniformity of the concentration of the elements other than the elements indicated by, and it is possible to deepen the knowledge of the region.

In the present invention, for example, the element Θj on the display screen
When there is little change in the distribution of the distribution, the color of the distribution image is almost the same over the entire area of the display screen, so that the region of interest cannot be designated, and the uniformity of the concentration of the element Θj in the region of interest cannot be specified. Can solve the problem of not being able to know the extent of. This is because a color distribution image of the element Θi having a large spatial variation of the element distribution on the display screen is displayed, the region of interest is observed by observing the image, and each X-ray intensity value of the element Θj in the region is indicated. This is because the degree of uniformity regarding the concentration of the element Θj in the region of interest can be known by displaying the histogram showing the frequency distribution of.

[Brief description of drawings]

FIG. 1 is a view showing a main part of an apparatus for carrying out the present invention, FIG. 2 is a drawing for showing a system configuration of the apparatus for carrying out the present invention, and FIG. 3 is a color graphic display. FIG. 4 is a diagram for explaining an instruction of an arbitrary area in the displayed screen, FIG. 4 is a diagram for explaining a display example of a graphic display, and FIG. 5 is a diagram for showing another embodiment of the present invention. is there. 1: X-ray microanalyzer 2: sample, EB: electron beam C1, C2, C3: dispersive crystal D1, D2, D3: X-ray detector T1, T2, T3: X-ray counter 3: CPU, 4: storage device 5: Color graphic display 6: Pointing device 7: Keyboard, 8: Bus line 9 ... X-ray intensity value data storage unit 10: Write / read control unit 11: Area designation unit 12: Mapping element designation unit 13: Target element designation unit 14 : Function designation unit, 15: Function selection unit 16: Histogram data creation unit 18: Level division processing unit 19: Color division processing unit, 20: Display control unit

Claims (1)

[Claims] 1. A sample is irradiated with an electron beam, and each element Θ1, Θ2, ... For each pixel (x, y) on a two-dimensional plane of the sample.
Θn (n ≧ 2) characteristic X-ray intensity value data I1 (x,
y), I2 (x, y), ..., In (x, y), the obtained data is stored, and an arbitrary element Θi (i is 1, 2, ..., From the stored data) (any of n) characteristic X-ray intensity value data Ii (x, y) is read, a distribution image of the element Θi is displayed in a color according to the read data value, and an arbitrary position of the distribution image is displayed. An area S having an arbitrary size is designated, and elements Θj other than the element Θi (j is 1, 2, ...,
area S designated for any of n other than i)
A method for analyzing a sample in an X-ray microanalyzer, characterized in that a histogram representing a frequency distribution for each X-ray intensity value of each pixel included in is displayed.