JP2007164990A - Microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microscope capable of obtaining dimensions of an observation object easily and correctly even if an aspect ratio of an image is changed. <P>SOLUTION: The scanning electron microscope scans electron beams on a test piece two-dimensionally and produces two dimensional image data 40 based on secondary electrons emitted from the test piece and composes scales 41a, 41b for expressing a prescribed length (1 μm) on the image data along two vertical and horizontal directions mutually perpendicular. The size of the scales 41a, 41b composed on the image data 40 is determined by a proportional calculation based on the size of observation range (scanning range). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microscope that generates a two-dimensional image, such as a scanning electron microscope (SEM).

  A scanning electron microscope is known as a microscope used in the analysis of semiconductor elements. A scanning electron microscope is an apparatus that irradiates an electron beam so as to scan a sample two-dimensionally and generates secondary electrons emitted from the sample as a two-dimensional image. In addition to being displayed on a monitor, an image obtained by a scanning electron microscope can be output to a printer.

Also, when observing an image obtained with a scanning electron microscope on a monitor or a printed photograph, a micron is used so that the observer can visually and intuitively determine the size of the observation object in the sample. A one-dimensional scale (scale scale) called a bar is displayed together with the observation object (for example, see Patent Document 1).
JP 2001-68050 A

  However, in the scanning electron microscope described in Patent Document 1, since the scale display is performed in one direction along one side of the image, the aspect ratio is changed when the image is output to a monitor or printer. As a result, when determining the size of the object to be observed, there is a risk of erroneously determining the dimension in the direction in which the scale is not displayed, which is a problem. In addition, the same problem occurs when the aspect ratio of the image is changed by image processing software or the like.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a microscope capable of easily and correctly obtaining the dimensions of an observation object even when the aspect ratio of the image is changed. And

  In order to achieve the above object, the microscope of the present invention generates a two-dimensional image from the observation range on the sample, and synthesizes a scale representing a predetermined length along two directions perpendicular to each other. It is characterized by doing.

  The microscope scans the observation range two-dimensionally with an electron beam, generates a two-dimensional image based on secondary electrons emitted from the sample, and extends along the two directions perpendicular to the image. Thus, it is preferable to synthesize a scale representing a predetermined length.

  Moreover, it is preferable that the size of the scale to be combined in the image is determined by proportional calculation based on the size of the observation range.

  The scale is preferably L-shaped. Furthermore, it is also preferable that the scale has a cross shape.

  According to the microscope of the present invention, a two-dimensional image is generated from the observation range on the sample, and a scale representing a predetermined length is synthesized with this image along two directions perpendicular to each other. Even when the aspect ratio is changed, the dimensions of the observation object can be easily and correctly obtained.

  In FIG. 1 showing the configuration of a scanning electron microscope 10, an electron beam 12 emitted from an electron gun 11 is narrowed down by a converging lens 13 and an objective lens 14, and irradiated onto the surface of a sample 16 fixed to a sample stage 15. At the same time, the deflection coil 17 scans the sample 16 in a predetermined scanning range two-dimensionally. The scanning drive unit 18 determines a scanning range (observation range) according to the magnification (observation magnification) set by the operation setting unit 19, and drives the deflection coil 17 so that the electron beam 12 scans within the scanning range. To do. This scanning range is large when the set magnification is small, and is small when the set magnification is large.

  By irradiating the sample 16 with the electron beam 12, secondary electrons 20 are generated from the sample 16. The secondary electrons 20 are detected by the secondary electron detector 21, and the detection signal is amplified by the amplifier 22 and then input to the image processing unit 23. At the same time, scanning range information of the electron beam 12 corresponding to the set magnification is input from the scanning drive unit 18 to the image processing unit 23.

  The image processing unit 23 generates two-dimensional image data of the secondary electrons 20 based on the input detection signal and scanning range information, and generates a scale (scale scale) corresponding to the scanning range. This scale is combined with the image data. The image processing unit 23 inputs the image data to the image memory 24, and the image data input to the image memory 24 is output to a monitor (image display device) 25 or a printer (printing device) 26 at any time for display or display. Printing is done.

  FIG. 2 shows the image data generated by the image processing unit 23 as described above. In the image data 40, a scale 41a representing the length in the horizontal direction and a scale 41b representing the length in the vertical direction perpendicular thereto are combined. The scales 41a and 41b are so-called micron bars each representing a length of 1 μm, and the size (length) in the image data 40 is determined by proportional calculation from the size of the scanning range. For example, when one direction of the scanning range is 5 μm, the sizes of the scales 41a and 41b synthesized in the image data 40 are determined on the basis of the length obtained by dividing the length of the direction into five equal parts. .

  With the scales 41 a and 41 b, when observing the image data 40 that is displayed on the monitor 25 or printed by the printer 26, the observer visually determines the size of the observation object 42 in the sample 16. It can be judged intuitively.

  The scales 41a and 41b are combined with the image data 40. Even when the aspect ratio of the image is changed during display on the monitor 25 or printing by the printer 26, the lengths of the scales 41a and 41b are accordingly changed. In addition, since the observer is also changed, the observer can easily obtain the correct dimensions without making a mistake in determining the vertical and horizontal dimensions of the observation object 42. FIG. 3 shows an example in which the aspect ratio of the image data 40 is modified. In this case, the vertical scale 41b is larger than the horizontal scale 41a.

  Further, when the image data 40 is output to an external device other than the monitor 25 and the printer 26 and the vertical and horizontal magnification is changed by the image processing software, the lengths of the scales 41a and 41b are similarly changed. Therefore, in this case as well, the observer will not erroneously determine the vertical and horizontal dimensions of the observation object 42.

  In the above embodiment, the scale 41a is arranged along the lower side of the image data 40, and the scale 41b is arranged along the right side of the image data 40. However, the present invention is not limited to this, and the scale 41a, 41b may be arranged at an appropriate position, and the scales 41a and 41b may be integrated. FIG. 4 (A) is an example in which the left end of the scale 41a and the lower end of the scale 41b are joined to make the scales 41a and 41b L-shaped. FIG. 4B shows an example in which the scale 41a and the scale 41b are coupled at the respective centers, and the scales 41a and 41b are cross-shaped.

  In the above embodiment, the lengths of the scales 41a and 41b are each 1 μm. However, the present invention is not limited to this, and may be changed to an appropriate length according to the scanning range. May be of different lengths.

  Furthermore, in the above-described embodiment, the scanning electron microscope is described as an example. However, the present invention is not limited to this, and an optical microscope or a scanning tunnel microscope can be used as long as it generates a two-dimensional image. The present invention can be applied to various microscopes such as a scanning probe microscope such as an STM (Scanning Tunneling Microscope) and an atomic force microscope (AFM).

It is a schematic block diagram which shows a scanning electron microscope. It is a figure which shows the image data produced | generated by the image process part. It is a figure which shows the example in which the aspect ratio of image data was changed. It is a figure which shows the modification of a scale, (A) is an example which made the scale L-shaped, (B) is an example which made the scale cross shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Scanning electron microscope 16 Sample 18 Scan drive part 21 Secondary electron detector 23 Image processing part 24 Image memory 25 Monitor 26 Printer 40 Data 41a Scale 41b Scale 42 Observation object

Claims (5)

  A microscope characterized in that a two-dimensional image is generated from an observation range on a sample, and a scale representing a predetermined length is combined with the image along two directions perpendicular to each other.   The observation range is scanned two-dimensionally with an electron beam, a two-dimensional image is generated based on secondary electrons emitted from the sample, and the image has a predetermined length along two directions perpendicular to each other. The microscope according to claim 1, wherein a scale representing the above is synthesized.   The microscope according to claim 1 or 2, wherein the scale to be synthesized in the image is determined by proportional calculation based on the size of the observation range.   The microscope according to any one of claims 1 to 3, wherein the scale is L-shaped.   4. The microscope according to claim 1, wherein the scale has a cross shape.

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