JP5400474B2 - Standard member for dimensional calibration of electron microscope apparatus, manufacturing method thereof, and calibration method of electron microscope apparatus using the same - Google Patents

Description

  The present invention relates to a dimension calibration standard member and a calibration method using the same, and more particularly to a dimension calibration standard member for an electron microscope apparatus and an electron microscope apparatus calibration method using the same.

In order to advance the miniaturization of semiconductor integrated circuits, it is indispensable to measure the dimensions with high accuracy because it greatly affects the device characteristics. An electron microscope apparatus is used for the measurement of the fine dimensions. Conventionally, a calibration standard sample is used when adjusting an electron microscope apparatus. The calibration standard sample is a member on which a pattern or a mark whose size and length are known in advance is formed. When adjusting the electron microscope apparatus, the image of the pattern or mark is acquired at a specific magnification, and the microscope apparatus is adjusted so that the pattern or mark is displayed at a predetermined size on the acquired image.
FIG. 5 shows the entire pattern forming surface of the standard member and its enlarged view. Here, the longitudinal diffraction grating region 501 is composed of a longitudinal diffraction grating unit 503 and positioning cross marks 505 and 506, and the lateral diffraction grating region 502 is a diffraction grating unit perpendicular to the longitudinal diffraction grating unit 503. 504 and positioning cross marks 505 and 506. Each pattern is a groove pattern obtained by etching a silicon substrate.
Since the accuracy of calibration is determined depending on the pitch dimension of the groove pattern of the one-dimensional diffraction grating, it is necessary to form the groove pattern with high accuracy. Laser interference exposure is used as a method for forming the groove pattern of the one-dimensional diffraction grating, and a diffraction grating with a 240 nm pitch is obtained. Further, since the miniaturization of semiconductor devices has been accelerated, the minimum processing dimension has become smaller than 100 nm, so that a diffraction grating having a finer pitch dimension, which is difficult to produce by laser interference exposure, is required. It has become. In order to form this finer diffraction grating, it has come to be performed by an electron beam drawing apparatus excellent in fine workability.

A method for producing a standard member for dimensional calibration by a conventional method will be described below. First, as shown in FIG. 6A, a resist 101 is applied on the silicon substrate 100. Next, according to the manufacturing flow shown in FIG. 9, pattern formation was performed by an electron beam batch exposure apparatus equipped with a stencil mask having openings 107 and 108 shown in FIG.
An aperture 107 corresponding to a diffraction grating unit pattern in which 25 linear grooves are arranged in a vertical direction at a pitch of 100 nm, which is one of calibration patterns, is selected by beam deflection (step 801), and a desired position on the sample is selected. Then, exposure is performed by beam deflection (step 802). Next, an aperture 108 corresponding to a diffraction grating unit pattern in which 25 linear grooves are arranged in a horizontal direction at a pitch of 100 nm, which is another calibration pattern, is selected by beam deflection (step 803). Exposure is performed at a desired position by beam deflection (step 804).
Next, the variable shaping rectangular opening 109 is selected (step 805), and the sample rotation correction marks 505 and 506 are exposed by the electron beam variable shaping method on the left and right sides of the periphery where the diffraction grating pattern is exposed (step 805). 806).
After the development, as shown in FIG. 6B, the oxide film is etched using the resist pattern 102 as a mask, and then the silicon substrate is etched by dry etching (step 807).
In drawing, as described above, the direction of the diffraction grating pattern in both the vertical and horizontal directions is prepared on the same substrate in the electron beam exposure. By using the electron beam batch exposure method as the diffraction grating pattern, it was possible to form a uniform pattern with a dimensional variation of 5 nm or less because exposure was performed using the same stencil mask at any position of the sample.
Further, as shown in FIG. 6C, since the resist, etching by-products, and the like are attached to the substrate surface, the obtained pattern is washed to obtain a silicon groove pattern 103 (step 813). In the cleaning process, by immersing in a mixed solution of sulfuric acid and hydrogen peroxide solution, organic deposits are removed and the substrate surface is oxidized by about 1-2 nm. Further, hydrofluoric acid treatment is performed to remove foreign substances and the like adhering to the substrate surface together with the surface oxide film, and then the substrate surface is kept clean by performing pure water cleaning.
Thereafter, the wafer 105 is diced as shown in FIG. 2 to divide the wafer 105 into chips 106 of a predetermined size, for example, 10 mm □ (step 814), and a cleaning process is performed (step 815). In this cleaning treatment, organic foreign matters are oxidized and removed with a mixed solution of sulfuric acid and hydrogen peroxide, and the oxide film formed on the surface is removed by immersion in a hydrofluoric acid solution, followed by replacement with pure water. .
Although the surface of the substrate becomes Si—H bonds by cleaning with hydrofluoric acid and pure water, a natural oxide film (SiO ₂ ) of about 0.7 nm is formed by leaving it in the atmosphere. Further, as shown in FIG. 3, sticking is performed on the pedestal (step 816), and the dimensional calibration standard member is completed.

JP-A-4-289411 JP-A-6-333805 JP 7-218201 A

As described above, with the miniaturization of the semiconductor integrated circuit, the size of the sample to be measured is reduced, and the pitch of the diffraction grating of the standard sample is required to be reduced. This is because even if calibration is performed at a specified magnification using an electron microscope device, a slight difference may occur if the magnification is changed. Therefore, it is necessary to make the magnification used for calibration between the sample to be measured and the standard sample as much as possible. Because there is.
As described above, the standard sample has been miniaturized, and as a result, the influence of the dimensional variation of the sample due to the adhesion of contamination due to beam irradiation has become relatively large. FIG. 15A shows the shape of a standard sample with a pitch of 100 nm immediately after the start of electron beam irradiation, and FIG. 15B shows the shape after 5 minutes of electron beam irradiation. The pattern dimension changes by 20.6 nm before and after irradiation. did.
The contamination adhesion model may be as shown in FIG. First, the electron beam 1101 scans the standard sample 1102 with an electron microscope. At that time, the carbon 1103 remaining in the vacuum is also irradiated with the electron beam to become carbon radicals 1104, and the reactivity becomes high. The carbon radicals react on the surface of the sample 1102, and the carbon 1105 adheres to the substrate surface.
Not only does the appearance of the contamination deteriorate the appearance of the contamination, but the adhesion of the contamination is not uniformly applied by electron beam scanning, so the most important pitch as a standard sample is changed to increase reliability. You will lose.
The present invention has been made in view of the above points, and provides a standard member for dimensional calibration having a fine reference dimension for further reducing contamination adhesion, and a high-precision electron beam length measurement technique including the same. The purpose is to provide.

In order to solve this problem, the present invention comprises forming a silicon oxide film of 1 to 5 nm on the surface of the groove pattern of a standard sample containing at least silicon. As a method for performing this silicon oxidation, a plasma treatment with a gas containing oxygen, thermal oxidation, or oxidation with a mixed solution of sulfuric acid and hydrogen peroxide is performed. The oxidation treatment may be performed before being attached to the pedestal, or may be oxidized by plasma treatment with the pedestal after being attached to the pedestal. Here, the reason why it is difficult for contamination to occur by forming a silicon oxide film on the surface of the silicon substrate is that the Si—O bond is a stable bond compared to the Si—H bond and the like, and thus it is difficult to react with carbon radicals. Can be considered. Therefore, a dense oxide film is not formed in a thin oxide film of less than 1 nm, and the effect of reducing contamination is reduced. On the other hand, when the thickness exceeds 5 nm, the substrate is charged up by the oxide film, and the image is blurred, or accurate measurement becomes difficult. Therefore, the effect is further increased by setting the oxide film thickness to about 1 to 5 nm. However, although there are other conceivable mechanisms for the adhesion of contamination, the effect is still the same by attaching an oxide film.
Further, this oxide film needs to oxidize not only the surface of the pattern top but also the surface inside the groove. This is because contamination is supplied also from the inside of the groove, so that the entire region scanned by the electron beam needs to be protected by the oxide film. Patent Document 1 (JP-A-04-289411), a method for manufacturing of a standard scale, while performing etching are described SiO _2, Si ₃ N ₄ as a mask, which is a standard scale SiO ₂ This is used as a hard mask for the fabrication of the film and has a different purpose, and since there is an oxide film only on the pattern top, a sufficient effect of reducing contamination cannot be obtained. Patent Document 2 (Japanese Patent Laid-Open No. 06-333805) manufactures a standard sample based on each semiconductor process, and is different in configuration and purpose from the present invention. Further, although there is a description that the thermal oxide film is coated on the Si pattern, this is manufactured based on each semiconductor process, and the oxide film thickness is determined by the process. Further, it is not intended to be in the range of 1 to 5 nm where the effect of preventing contamination is obtained. Patent Document 3 (Japanese Patent Application Laid-Open No. 07-218201) describes a method of producing a laminated film and using the end face of the laminated film as a standard sample. In this case, oxidation produces a laminated film. Therefore, the purpose and application are different. Further, since it is a laminated film of silicon and silicon oxide film and does not have a structure in which a standard sample portion scanned with an electron beam is covered with an oxide film of 1 to 5 nm, an effect of reducing contamination cannot be expected.

  Further, according to the present invention, in the pattern having a pitch of 60 nm or less, the surface area of the scanned sample surface is set to be 3.1 times or more of the scanning area scanned by the electron beam. Even if contamination is uniformly applied by increasing the surface area, it is averaged and the amount of dimensional change can be reduced.

  With the above configuration, it is possible to provide a highly accurate standard member for dimensional calibration by significantly reducing the amount of contamination adhered to a standard sample used for calibration, and to realize a highly accurate electron beam length measurement technique including the standard member. .

The figure which shows the preparation methods of the standard member for dimensional calibration by one Example of this invention. The figure which shows a part of manufacturing method of the standard member for dimension calibration. The figure which shows a part of manufacturing method of the standard member for dimension calibration. The figure explaining the stencil mask for electron beam batch exposure apparatuses. The upper surface full view and partial enlarged view of the standard member for dimension calibration. The figure which shows the preparation methods of the standard member for dimension calibration by the conventional method. The figure explaining the electron microscope apparatus carrying the standard member for dimension calibration. The figure explaining an example of the production flow of the pattern for a calibration in the standard member for dimension calibration by this invention. The figure explaining an example of the production flow of the pattern for a calibration in the standard member for the dimension calibration by the conventional method. The figure explaining the structural example of the electron microscope apparatus by this invention. The figure explaining the contamination adhesion by electron beam irradiation. The figure which shows the preparation process process of the standard member for dimension calibration by the other Example of this invention. The figure which shows the standard member for dimension calibration before the electron beam irradiation by another Example. The figure which shows the standard member for dimension calibration after the electron beam irradiation by another Example. The figure which shows the contamination adhesion of the standard member for dimension calibration produced by the conventional method. The figure which shows the dependence of the pattern dimension by contamination with respect to the surface area of a standard sample, and the area ratio of a scanning range.

  An embodiment to which the present invention is applied will be described.

A method for manufacturing the standard member for dimensional calibration according to the present invention will be described with reference to the manufacturing flow shown in FIGS. First, as shown in FIG. 1A, a resist 101 is applied on a silicon substrate 100. Next, pattern formation was performed using an electron beam batch exposure apparatus equipped with a stencil mask having openings 107 and 108 shown in FIG.
An aperture 107 corresponding to a diffraction grating unit pattern in which 25 linear grooves are arranged in a vertical direction at a pitch of 100 nm, which is one of calibration patterns, is selected by beam deflection (step 801), and a desired position on the sample is selected. Then, exposure is performed by beam deflection (step 802). Next, an aperture 108 corresponding to a diffraction grating unit pattern in which 25 linear grooves are arranged in a horizontal direction at a pitch of 100 nm, which is another calibration pattern, is selected by beam deflection (step 803). Exposure is performed at a desired position by beam deflection (step 804).
Next, the variable shaping rectangular opening 109 is selected (step 805), and the sample rotation correction marks 505 and 506 are exposed by the electron beam variable shaping method on the left and right sides of the periphery where the diffraction grating pattern is exposed (step 805). 806).
After the development, as shown in FIG. 1B, the oxide film is etched using the resist pattern 102 as a mask, and then the silicon substrate is etched by dry etching (step 807).
In drawing, as described above, the direction of the diffraction grating pattern in both the vertical and horizontal directions is prepared on the same substrate in the electron beam exposure. By using the electron beam batch exposure method as the diffraction grating pattern, it was possible to form a uniform pattern with a dimensional variation of 5 nm or less because exposure was performed using the same stencil mask at any position of the sample.
Further, as shown in FIG. 1C, since the resist, etching by-products, and the like are attached to the surface of the obtained pattern, a cleaning process is performed to obtain a silicon pattern 103 (step 808). In the cleaning process, by immersing in a mixed solution of sulfuric acid and hydrogen peroxide solution, organic deposits are removed and the substrate surface is oxidized by about 1-2 nm. Further, hydrofluoric acid treatment is performed to remove foreign matters and the like adhering to the substrate surface together with the oxide film. However, it has been confirmed by the inventors that if this substrate is used as it is, contamination by electron beam irradiation is often attached. Therefore, as shown in FIG. 1D, the substrate surface was exposed to oxygen plasma to form a 4 nm oxide film 104 on the surface of the silicon groove pattern including the inner surface of the groove (step 809).
Thereafter, the wafer 105 is diced as shown in FIG. 2 to divide the wafer 105 into chips of a predetermined size, for example, 10 mm □ (step 810), and a cleaning process is performed (step 811). Here, if hydrofluoric acid treatment is performed during the cleaning treatment, the oxide film formed in step 809 is removed. Therefore, hydrofluoric acid treatment need not be performed, and cleaning with a mixed solution of sulfuric acid and hydrogen peroxide is performed. And replace with pure water. Further, as shown in FIG. 3, the pedestal is pasted (step 812), and the dimensional calibration standard member is completed. In the standard member for dimensional calibration manufactured by the process shown in FIG. 15, the dimensional variation due to the adhesion of contamination by the electron beam irradiation for 5 minutes was 20.6 nm, but the dimension having a silicon oxide film of 4 nm on the surface. That of the standard member for calibration was greatly reduced to 3.0 nm.
Here, oxygen plasma was performed after substrate cleaning, and after dicing, a cleaning method by oxidation with a mixed solution of sulfuric acid and hydrogen peroxide water was performed. However, what is important here is that an oxide film having a thickness of 1 to 5 nm is formed on the surface of the groove pattern of the standard member for dimensional calibration attached to the pedestal. Here, as a method for producing this surface oxide film, the substrate was once taken to have a surface oxide film by cleaning with hydrofluoric acid, and then an oxide film was formed on the surface by a mixed solution of oxygen plasma and sulfuric acid / hydrogen peroxide solution. However, there are other thermal oxidation methods, and various combinations can be used. However, a natural oxide film having a thickness of less than 1 nm is formed by leaving it in the atmosphere even after hydrofluoric acid treatment, but if it is less than 1 nm, a sufficient effect cannot be obtained and an oxide film having a thickness of 1 nm or more is necessary. Met. In addition, it is necessary to control the formation of the oxide film because things other than oxygen are taken into the substrate surface by the atmosphere in which the natural oxide film is formed and the surface may be contaminated. This silicon oxide film thickness measuring method can be measured by a spectroscopic ellipsometer or XPS, and the thickness of the oxide film can be measured by rupturing a standard member and observing it with a transmission electron microscope. .

  In another embodiment, oxygen plasma cleaning may be performed after being attached to the base (step 812 in FIG. 8). By doing so, even if hydrofluoric acid cleaning with higher cleaning capability is performed in the cleaning of step 810, it becomes possible to attach a silicon oxide film that reduces the adhesion of contamination in a later process.

Next, calibration of the electron microscope apparatus using the standard member for dimensional calibration will be described with reference to FIG. A sample wafer 32 including a device pattern having a design dimension of 50 nm and a standard member 35 attached to a holder 34 are mounted on a stage 33 of an electron microscope apparatus as shown in FIG. When measuring a device pattern having a design dimension of 50 nm, the magnification of the electron microscope apparatus is set to 200,000 times or more. At this magnification, a diffraction grating having a pitch of 240 nm, which is a conventional dimensional standard, does not allow one pitch to be included in the scanning of the electron beam 30 focused by the electron optical system 36, so that the apparatus cannot be calibrated.
For this magnification calibration, the pitch dimension of the diffraction grating unit pattern 503 in the vertical direction shown in FIG. 5 is measured with an electron microscope apparatus. First, in order to search for a diffraction grating unit pattern 503 in which 25 linear grooves are arranged at a pitch of 100 nm, the parallelism in the moving direction of the sample and the electron microscope apparatus is corrected using the positioning cross marks 505 and 506. Next, the pitch dimension of the diffraction grating unit pattern 503 in the array is measured with the secondary electron signal waveform from the secondary electron signal detector 31. Similarly, calibration was performed by obtaining the pitch dimension of 20 or more different diffraction grating unit patterns 503 and setting the average value to 100.21 nm. Furthermore, using the lateral diffraction grating pattern 504, the magnification of the lateral electron microscope apparatus can be adjusted with high accuracy.

  The calibration of the electron microscope apparatus using the standard member for dimensional calibration will be described. This electron microscope apparatus has an apparatus configuration as shown in FIG. In the measurement, the electron beam 42 irradiated from the electron gun 41 is narrowed down by lenses 43 and 45, and scanned by a deflector 44 on a stage 46 that is mounted on a stage 47 and includes a diffraction grating pattern having a pre-set pitch dimension. The secondary electrons 48 generated at this time are detected by the secondary electron detector 49, and the waveform is obtained from the beam deflection control unit 50 and the secondary electron signal processing unit 51. A dimension is calculated from this waveform, and the dimension is displayed and stored as a correct dimension by a dimension calibration calculation. That is, the dimension is calculated by the dimension calculation unit 53 from the waveform of the waveform display unit 52, the correct dimension is obtained by the dimension calibration calculation unit 54, displayed by the dimension display unit 55, and stored in the dimension storage unit 56. In the electron microscope apparatus of the present invention, as shown in FIG. 10, a difference calculating unit 57 and a calibration state display unit 58 for reference comparison are further provided for calibration comparison, and a diffraction grating in which the pitch dimension is preliminarily established. The correctness of the calibration is obtained by comparing the pattern, the pitch dimension, and the reference dimension, and can be displayed.

  As described above, by attaching an oxide film of 1 to 5 nm on the surface of the standard sample, it becomes possible to reduce the amount of contamination caused by electron beam irradiation.

  Next, another embodiment of the present invention will be described. In a standard sample having a pitch of 60 nm or less, a countermeasure against contamination can be taken by setting the surface area of the groove pattern of the standard sample to 3.1 times or more of the scanning area scanned by the electron beam. Increasing the surface area can be achieved by increasing the groove depth. This groove depth can be achieved by increasing the dry etching time in the process of making a standard sample, for example, step 807 in FIG. At this time, it goes without saying that the resist is made thicker as necessary as the dry etching time becomes longer. Alternatively, as a standard sample manufacturing method, for example, there is a method in which silicon and a silicon oxide film are alternately sputtered and a so-called superlattice is used.

  This method is shown in FIG. First, silicon oxide films 1202 and silicon 1203 are alternately stacked on the silicon substrate 1201 by 20 nm each using a sputtering apparatus (FIG. 12A). This laminated film thickness can be set to a predetermined thickness by adjusting the sputtering time. Next, the laminated substrate is built and the base sample 1204 is pinched and bonded (FIG. 12B), and the surface is polished so that the height is the same as the base substrate (FIG. 12C). Thereafter, the silicon oxide film of the laminated film is etched by cleaning the surface with hydrofluoric acid to prepare a standard sample. At this time, the groove depth can be adjusted by changing the concentration of hydrofluoric acid or the immersion time. By adjusting the etching depth at this time, as shown in FIG. 13, a sample 1205 having an etching depth of 10 nm and a sample 1206 having a thickness of 40 nm were produced. Sample 1205 has a surface area of 1.5 times the scanning range of the electron beam microscope apparatus, while sample 1206 has a surface area of 3.5 times. When this sample was irradiated with an electron beam with an electron beam inspection apparatus for 3 minutes, the pattern size of the sample 1205 increased by 8 nm (FIG. 14A), whereas the sample 1206 had an increase of only 0.4 nm. (FIG. 14B).

  FIG. 16 shows the dependency of the pattern size due to contamination on the ratio of the surface area of the standard sample to the scanning range of the electron microscope (surface area of the standard sample ÷ scanning range of the electron microscope). As shown in the figure, the CD fluctuation width exceeded 3% when the area ratio became 3 or less, but when the area ratio increased to 3.1 or more, the dimensional change due to contamination became 3% or less. Furthermore, when the ratio was 4 or more, the dimensional change due to contamination was 1.5% or less, and a significant effect was obtained. Therefore, the area ratio needs to be 3.1 or more in order to suppress the dimensional variation due to contamination. This is because the carbon radicals supplied during electron beam irradiation by the electron beam inspection device are not dependent on the sample within the irradiation field but are uniformly attached to the sample surface. The dimensional variation due to the adhesion increases, and the amount of adhesion increases once a certain amount of contamination has adhered. The amount by which this contamination is adhered is amplified when the surface area of the standard sample is less than 3 times the scanning range of the electron microscope at a pattern pitch of 60 nm or less, and is at least 3.1 times. It is necessary to do more.

  In addition, the surface area of the standard sample is at least 3.1 times the scanning range of the electron microscope, and the effect is further enhanced by forming an oxide film on the surface of the standard sample to 1 to 5 nm.

30 ... Electron beam, 31 ... Secondary electron detector, 32 ... Wafer, 33 ... Stage, 34 ... Holder, 35 ... Calibration chip, 36 ... Electro-optical system ,
41 ... electron gun, 42 ... electron beam, 43, 45 ... lens, 44 ... deflector, 46 ... wafer, 47 ... stage, 48 ... secondary electrons, 49 ... Secondary electron detector, 50 ... Beam deflection control unit, 51 ... Secondary electron signal processing unit, 52 ... Waveform calculation unit, 53 ... Dimension calculation unit, 54 ... Dimensions Calibration calculation unit, 55... Dimension display unit, 56... Dimension storage unit, 57... Difference calculation unit with reference value, 58.
DESCRIPTION OF SYMBOLS 100 ... Silicon substrate, 101 ... Resist, 102 ... Resist pattern, 103 ... Silicon diffraction grating pattern, 104 ... Silicon oxide film, 105 ... Wafer, 106 ... Calibration chip 107, 108 ... diffraction grating pattern openings, 109 ... variable shaping rectangular openings,
501,502 ... Diffraction grating region, 503,504 ... Diffraction grating pattern, 505,506 ... Cross pattern for position detection,
1101 ... Electron beam, 1102 ... Silicon diffraction grating pattern, 1103, 1105 ... Carbon, 1104 ... Carbon radical,
1201 ... Silicon substrate, 1202 ... Silicon oxide film, 1203 ... Silicon, 1204 ... Base sample, 1205 ... Sample with 10nm etching depth, 1206 ... Sample with 40nm etching depth, 1301 ... Contamination.

Claims (6)

In a standard member for calibrating dimensions of an electron microscope apparatus comprising an array of diffraction gratings including at least silicon and having a pitch dimension required in advance,
Dimensional calibration of an electron microscope apparatus characterized in that a silicon oxide film having a thickness of 1 nm or more to 5 nm or less is formed by oxidation treatment on the entire surface including the inner surface of the groove of the groove pattern of the standard member for dimensional calibration. Standard parts for use. In the standard member for dimensional calibration of the electron microscope apparatus according to claim 1,
A standard member for calibrating dimensions of an electron microscope apparatus, comprising an array of longitudinal diffraction gratings and an array of lateral diffraction gratings as the array of diffraction gratings. In the method of manufacturing a standard member for calibrating dimensions of an electron microscope apparatus comprising an array of diffraction gratings including at least silicon and having a pitch dimension required in advance,
Create a diffraction grating groove pattern by etching the silicon substrate,
A method of manufacturing a standard member for dimensional calibration of an electron microscope apparatus, wherein a silicon oxide film having a thickness of 1 nm to 5 nm is formed on an entire surface including an inner surface of a groove of the groove pattern by oxidation treatment. In the manufacturing method of the standard member for dimensional calibration of the electron microscope apparatus according to claim 3 ,
A method for producing a standard member for dimensional calibration of an electron microscope apparatus, characterized in that the surface is exposed to plasma using oxygen as a gas as a method of oxidizing the surface. In the manufacturing method of the standard member for dimensional calibration of the electron microscope apparatus according to claim 3 ,
A method for manufacturing a standard member for dimensional calibration of an electron microscope apparatus, characterized in that an oxidation treatment is performed after removing a surface oxide film by hydrofluoric acid treatment. A method for calibrating an electron microscope apparatus using a standard member for dimensional calibration,
A diffraction grating in which a silicon oxide film of 1 nm or more to 5 nm or less by oxidation treatment is formed on the entire surface including at least the inner surface of the groove of the groove pattern of the diffraction grating unit, and the pitch dimension is required on the silicon substrate in advance. A standard member for calibrating a size having a diffraction grating unit pattern consisting of the above arrangement is arranged, the diffraction grating unit pattern is measured, the difference between the length measurement result and the pitch dimension is calculated, compared with a reference value, and calibrated. A method for calibrating an electron microscope apparatus, characterized in that

Images