JP2001357812A - Display device for observed image of specimen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a suitable micron marker in accordance with a display magnification on a screen. SOLUTION: This display device for the observed image of a specimen is to memorize the observed image of the specimen and to display all or a part of the memorized image by selecting an optional display area. A reference value of a length in the display area of a marker to show the actual scale of the specimen in the image to be displayed is set, and plural marker scales corresponding to a display magnification are set. The marker is displayed in the display area of the image by selecting the marker scale having the length in the display area, which is close to the reference value, from those plural marker scales, in order to make it as a micron marker to show the actual scale of the specimen, and the most suitable scale is displayed in accordance with the display magnification of the image, and the size of a part to be watched relative to the displayed image can be easily measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample observation image display device which stores an observation image of a sample, selects an arbitrary display area, and displays the whole or a part of the stored image.

[0002]

2. Description of the Related Art In a scanning electron microscope (SEM), the magnification is changed from a minimum magnification of several tens of times to a maximum magnification of several hundred thousand times by changing the size (scanning width) of a scanning area. For example, when the horizontal width of the image display area is 200 mm, the scanning width of the electron beam is 4 mm at a magnification of 50 times and 1 μm at a magnification of 200,000 times. To reduce the magnification to observe a wide range, the scanning width may be widened. However, if the scanning width of the electron beam is widened, the effect of deflection distortion appears greatly on the obtained image. The electron beam is deflected inside. Therefore, S
The maximum scanning width of the electron beam in the EM is usually several mm.
Before and after, the magnification at that time is about several tens.

Therefore, in a normal SEM, it is not possible to observe at once a region wider than the observation region at the limited minimum magnification. Therefore, when observing a large sample that cannot capture the entire observation image in one scan, first, as proposed separately by the present applicant, first divide the field of view into several times while shifting the field of view. It is necessary to scan each image, capture each observation image, combine them, record them in a frame memory, and then search for the field of view as appropriate to reduce / enlarge and display the image (for example, Japanese Patent Application No. Hei 11 (1999)).
-340571).

[0004]

However, an image (navigation image) completely corresponding to the stage position constructed in the apparatus as described above, or a synthetic SEM synthesized for wide area observation by other means. In the image (hereinafter collectively referred to as a composite SEM image)
There was no suitable marker to indicate the actual scale of the sample observed. Therefore, the size of the displayed sample could not be accurately determined.

FIG. 6 is a diagram showing an example in which a micron bar is added to an SEM image. For example, when a micron bar is attached to an SEM image, a micron bar is attached to each SEM image as shown in FIG. 6A, or a micron bar is attached to only one SEM image as shown in FIG. 6B. However, it does not mean that there is no problem in any case. It is shown in FIG.
If the position and size of the micron bar become inappropriate as shown in FIG.
This is because the micron bar is too small as shown in (D).

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to display an appropriate micron marker according to a display magnification of a screen.

For this purpose, the present invention provides a sample observation image display device for storing an observation image of a sample, selecting an arbitrary display area and displaying the whole or a part of the stored image. The reference value of the length in the display area of the marker indicating the actual scale is set, a plurality of marker scales are set in accordance with the display magnification, and the length of the length in the display area close to the reference value from the plurality of marker scales is set. A marker scale is selected and the marker is displayed in a display area of an image.

The reference value is the number of pixels at the displayed magnification, and a marker scale within a predetermined range with respect to the product of the reference value and the length of one pixel on the screen obtained based on the display magnification. Is selected, and the display position of the marker is movable to a designated position on the screen.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of a sample observation image display device according to the present invention, FIG. 2 is a diagram showing an example of a divided configuration of a composite image stored in a frame memory, and FIG. 3 is a configuration example of observation condition data. FIG. In FIG. 1, 1 is a scanning electron microscope (SEM), 2 is a control unit, 3 is observation condition data,
Reference numeral 4 denotes an image capture / combination processing unit, 5 denotes a frame memory, 6 denotes a display processing unit, and 7 denotes a display unit.

In FIG. 1, a scanning electron microscope 1 includes a means for irradiating a sample on a stage with a finely focused electron beam, a means for two-dimensionally scanning the electron beam on the sample, and a motor drive. The image capturing / synthesizing unit 4 sequentially captures image data obtained by scanning the sample in a plurality of times, and synthesizes a plurality of images, thereby obtaining a frame memory. 5 is performed. The display processing unit 6 displays an observation image in accordance with a display area selected from the synthesized image in the frame memory 5 and performs a process of displaying an appropriate micron marker, and has a display screen. Is the display unit 7.

The control unit 2 controls the scanning electron microscope 1 and the image capturing / synthesizing processing unit 4 while rewriting the observation condition data 3 based on an instruction input by the observer, so that the image data to the frame memory 5 is stored. The display control section 5 controls the display processing section 5 so as to display the whole image or the partially enlarged image on the screen of the display section 6. The observation condition data 3 stores, for example, information on image data to be written into the frame memory 5 and information for displaying a display area and a micron marker when displayed on the display unit 7 as observation conditions.

For example, as shown in FIG. 2, when a plurality of SEM images of X × Y size are combined in a frame memory to store an image of W × H size, as observation condition data,
For example, as shown in FIG. 3A, the image resolution X, Y, the imaging magnification mag, the scan width S, the number of divisions M × N are stored, and when this image is displayed, the display magnification α is stored. I do. Meanwhile, as the information for displaying the micron marker is stored, for example, FIG. 3 (B) the number of pixels microns markers as shown in P _M, notation micron marker length l, the ratio n. Pixels P _M is denoted length l which can be expressed by the nearest pixels to the number of pixels P _M, which is a reference value for displaying a micron marker magnification n.

Next, a method of determining a micron marker will be described. First, assuming that the observation condition data shown in FIG. 3 are respectively set, a display magnification α for the original image is set.
The length Δμ of one pixel on the screen in the case of Next, the length mu in number of pixels _{P M, μ '= Δμ ×} P
_M. On the other hand, the marker scale μ _i has a notation length l
And the magnification n, that is, μ _i = l _i × n _i ,
Micron marker, from the marker scale μ _i,
Extract the marker scale μ close to μ ′. For example, when focusing on the number of pixels P _M and displaying a micron marker within a range of 140 to 400 pixels for 200 pixels, the ratio k = μ
By calculating _i / μ ′, the marker scale μ that satisfies the condition of 0.7 <k <2, that is, the ratio k falls within the range of 0.7 to 2, may be extracted.

Next, the process of determining a micron marker according to the display magnification and drawing processing will be described. FIG. 4 is a view for explaining an example of determination and drawing processing of a micron marker by the sample observation image display device according to the present invention. First, as shown in FIG. 4, a display magnification α is obtained (step S11), a reference marker length μ ′ is calculated based on the display magnification α (step S12), and a marker scale μ _i is obtained (step S13). ). Then calculates the ratio k between the marker length mu 'as a marker scale mu _i and a reference (step S14), (0.7 in the example, for example, above) the ratio k K1 respectively, K2 (e.g., above In the example, it is compared with 2) and determined (steps S15 and S16). As a result, K1 <
If the condition is not satisfied for k <K2 further obtains the next marker scale mu _i (step S17), and the same procedure is repeated the process returns to step S14. Then, when the marker scale μ _i satisfying the condition of K1 <k <K2 is extracted, the obtained marker scale μ _i is adopted (step S18), and the micron marker is drawn at a predetermined position and is displayed on the screen together with the image. It is displayed (step S19). Further, it is determined whether or not there is a movement instruction for the displayed micron marker (step S).
20) If there is a movement instruction, the drawing position of the marker is moved to the instruction position (step S21).

FIG. 5 is a view showing a synthesized image observed by a scanning electron microscope and a display example of a display area and a micron marker, and shows an example in which 3 × 3 SEM images are synthesized at a photographing magnification of 20 times. ing. Of these, FIG.
FIG. 5A shows a case where the entire display area is selected and a micron marker corresponding to 5.0 mm is displayed at the upper left position.
In (B), a part is selected as a display area, and similarly, a micron marker corresponding to 1.0 mm is displayed at the upper left position.

As shown in the figure, for example, when a marker having a length of about 200 pixels is displayed in the display area, if one pixel on the screen is equivalent to N mm, 200 pixels are displayed.
The pixel will be N × 200 mm. In the case of displaying the entire composite image, N × 200 is a poorly cut number, for example, 5.
If it is 123 mm, it is displayed with a well-cut 5 mm, and the marker is also displayed with a length of 200-Δ. Similarly, when displaying a part of the composite image, one pixel on the screen is N ′ mm
200 pixels is N '× 200 m
m. N ′ × 200 is a poorly cut number, for example, 0.
If it is 9123 mm, it is displayed with a sharp 1 mm, and the marker is also displayed with a length of 200 + Δ '. Thus, the micron marker can be displayed at a length that is always easy to see according to the display area of the synthesized image.

The present invention is not limited to the above embodiment, but can be variously modified. For example, in the above embodiment, the length of the pixel is calculated in accordance with the display magnification and the marker scale within a predetermined range is extracted.
A marker scale corresponding to each display magnification may be set in a table in advance, and the marker scale of the table may be read from the determined display magnification. Marks to be displayed as micron markers are straight lines, dotted lines,
It is possible to select arbitrarily such as a straight line with an auxiliary scale line,
It is needless to say that the marker may be such that the length is expressed by displaying the width, such as → || ←, instead of the straight line. Furthermore, the example in which the marker is displayed on the composite SEM image has been described. However, not only the SEM image but also the other observation images are stored in the entire image data in the memory, and the entire image data is selected as the display area. The same may be applied when a part is selected to observe an image.

[0018]

As is apparent from the above description, according to the present invention, an observation image of a sample is stored, and an arbitrary display area is selected to display the whole or a part of the stored image. In the display device, a reference value of a length in a display area of a marker indicating a real scale of a sample in an image to be displayed is set, and a plurality of marker scales are set in accordance with a display magnification. Select a marker scale with a length in the display area that is close to the value and display the marker in the display area of the image, so display the optimal scale as a micron marker indicating the actual scale of the sample according to the display magnification of the screen This makes it possible to easily measure the size of the region of interest in the displayed image.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a sample observation image display device according to the present invention.

FIG. 2 is a diagram illustrating an example of a divided configuration of a composite image stored in a frame memory.

FIG. 3 is a diagram illustrating a configuration example of observation condition data.

FIG. 4 is a diagram for explaining an example of micron marker determination and drawing processing by the sample observation image display device according to the present invention.

FIG. 5 is a diagram showing a display example of a synthesized image observed by a scanning electron microscope, a display area, and a micron marker.

FIG. 6 is a diagram showing an example in which a micron bar is added to an SEM image.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Scanning electron microscope (SEM), 2 ... Control part, 3 ... Observation condition data, 4 ... Image acquisition and synthesis processing part, 5 ... Frame memory, 6 ... Display processing part, 7 ... Display part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masumi Katakami 3-1-2, Musashino, Akishima-shi, Tokyo Japan Electronic Engineering Co., Ltd. F-term (reference) 5C054 AA01 AA05 CA00 FA01 FA02 FD02 FD07 FE14 HA05

Claims (4)

[Claims] 1. A sample observation image display device which stores an observation image of a sample, selects an arbitrary display area, and displays the whole or a part of the stored image, and displays the actual scale of the sample in the displayed image. In addition to setting a reference value for the length in the display area of the marker to be indicated, setting a plurality of marker scales according to the display magnification, and selecting a marker scale having a length in the display area close to the reference value from the plurality of marker scales. A sample observation image display device, wherein the marker is displayed in a display area of an image. 2. The sample observation image display device according to claim 1, wherein the reference value is the number of pixels at a displayed magnification. 3. The sample observation according to claim 2, wherein a marker scale within a predetermined range is selected with respect to a product of the reference value and a length of one pixel on a screen obtained based on a display magnification. Image display device. 4. The sample observation image display device according to claim 1, wherein a display position of the marker is movable to a designated position on a screen.