KR100607874B1 - Objective aperture for eliminating background noise of high resolution image and pattern forming apparatus using thereof - Google Patents

Abstract

The present invention relates to an aperture of an objective lens for a pattern forming apparatus using atomic images in a transmission electron microscope or an electron beam lithography apparatus, and in particular, a transmitted beam and a diffracted beam from which an electron beam irradiated onto the specimen passes through the specimen. The present invention relates to a structure of an objective lens stop for a pattern forming apparatus using an atomic image in a transmission electron microscope or an electron beam lithography apparatus capable of eliminating background noise in high resolution image formation in which an image is formed by interference of a diffracted beam. .

Objective aperture, background noise, high resolution image, transmission electron microscope, electron beam lithography device, atomic image

Description

OBJECTIVE APERTURE FOR ELIMINATING BACKGROUND NOISE OF HIGH RESOLUTION IMAGE AND PATTERN FORMING APPARATUS USING THEREOF}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows a phenomenon occurring in an optical system of a transmission electron microscope.

Fig. 2A is a diagram showing the form of diffraction images of a transmission electron microscope obtained from a diamond crystal material;

Fig. 2B is a diagram showing the form of diffraction images of transmission electron microscopes obtained from a material of BCC crystal structure;

Fig. 2C is a diagram showing the form of diffraction images of transmission electron microscopes obtained from materials of FCC crystal structure.

Fig. 2D is a diagram showing the form of diffraction images of transmission electron microscopes obtained from HCP crystal structures;

Fig. 3 shows the relationship between the diffraction image of an electron microscope and the objective lens aperture

4 shows a high resolution image of a silicon single crystal

FIG. 5 shows an image of Fourier transforming the image of FIG. 4 through computer processing. FIG.

FIG. 6 is a view showing an objective lens aperture in which only a transmission beam and six diffraction beams can pass

7 is a high resolution image diagram obtained when using the objective lens aperture of FIG.

8 shows an objective lens aperture capable of passing a transmitted beam and 16 diffracted beams.

9 is a high resolution image of silicon obtained when using the objective lens aperture of FIG.

10 is a view showing an objective lens aperture in the form of a ring

11 is a view showing a silicon high resolution image obtained when using the objective lens aperture of FIG.

12A, 12B, 12C and 12D show the electron beam intensity distribution obtained when using the silicon high resolution image of FIG. 4 and the objective lens aperture of FIGS. 6, 8 and 10;

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture of an objective lens used in transmission electron microscopy, and more particularly to a structure of an objective aperture stop for a transmission electron microscope capable of removing background noise of a high resolution image. The objective lens aperture of this structure is also applicable to the objective lens aperture of the METHOD AND APPARATUS FOR GENERATING A PATTERN USING A CRYSTAL STRUCTURE OF MATERIAL in an electron beam lithography apparatus.

Hereinafter, the transmission electron microscope will be described. The transmission electron microscope is a microscope that irradiates the specimen with an electron beam, obtains an image with the transmitted electron beam, and analyzes the crystal structure of the image with a diffraction figure obtained with the diffracted electron beam. The transmission electron microscope generates electrons from the electron gun, collects the electron beam accelerated at high pressure with the focusing lens, and transmits it to the specimen to make an image with an objective lens.

In the case of general transmission electron microscope, the maximum magnification can be magnified by 1 million times, and nowadays, it is used as STEM (Scanning Transmission Electron Microscope) by adding the function of scanning electron microscope. In addition, recently, a component analysis device is attached to the component analysis of the minute portion is also performed.

The light source in the transmission electron microscope is an electron beam accelerated at high speed in a high vacuum state (1x10 ^-4 Pa or more). The electron beam penetrates the specimen (sample) and is projected through a series of electromagnetic or electrostatic fields, focusing on the fluorescent plate or photographic film. The wavelength of these electrons depends on the accelerating voltage and the electron wavelength at 100 kV is 0.004 nm. The theoretical resolution (resolution) of the electron microscope is about 0.001 nm, but the resolution used in biological samples is about 0.2 nm (side entry) and 0.14 nm (top entry).

In recent years, transmission electron microscopes using high voltages (500-1,000 kV) have been developed, allowing the observation of relatively thick tissue specimens. Electron microscopes have excellent magnification and resolution, and can observe the microstructure of cells and tissues that cannot be observed by optical microscopes, and even smaller structures than macromolecules such as proteins.

In a transmission electron microscope, when an electron beam penetrates an object (sample), it diffracts according to Bragg's law to form a diffraction pattern on a back focal plane. The image which selects and observes only the transmission beam which does not diffract out of the beam transmitted through the sample by the objective aperture is called Bright Field Image (BFI), and the image which selects and observes only the diffraction beam diffracted from the specific surface. This is called Dark Field Image (DFI).

The optical system of the transmission electron microscope is composed of many complex systems such as electron guns, multiple focusing lenses, objective lenses, projection lenses, and fluorescent plates, but the phenomena occurring in this complex system can be simplified to a system consisting of an electron beam, a specimen, and a single lens. Can be. Fig. 1 is a diagram schematically showing a phenomenon occurring in an optical system of a transmission electron microscope, and shows this simplified system.

In Fig. 1, the horizontal line (horizontal line) in the center refers to the optical axis, and the electron beam emitted after interacting with the object (after passing through the object) after being irradiated to the object (the specimen) passes the objective lens and forms a diffraction image on the rear focal plane of the lens. Form. Next, behind the diffraction image, an image enlarged by the magnification of the lens is formed on the image surface.

가 렌즈에 의해 생기는 회절상은 물체함수

를 푸리에 변환(Fourier Transformation)한

로 표현할 수 있다. 여기서 ｋ는 역공간(reciprocal space)에서의 좌표를 나타낸다. 회절상 뒤에 형성되는 상은 이 회절상의 함수

를 다시 푸리에 변환한

로 표현할 수 있다. 여기서 -부호는 원래의 물체에 대해 반전(inversion)되어 있음을 의미하며

는

와 같은 실공간에서의 좌표를 의미한다.Mathematically, this is a function that represents an object

The diffraction image produced by the lens is the object function

Fourier Transformation

Can be expressed as Where ｋ represents the coordinate in reciprocal space. The phase formed after the diffraction image is a function of this diffraction image

Fourier transformed back

Can be expressed as Where the-sign means inversion of the original object

Is

It means the coordinates in real space, such as

Here, when the image is made by transmitting only the transmission electron beam through the aperture to the rear focal plane where the diffraction image is formed, it becomes a clear night image. Is one of.

And by not using an aperture (or using a fairly large aperture), images can be formed by using a transmission beam and a diffraction beam together to form a high resolution transmission electron microscope image.

In a transmission electron microscope, a high resolution image is an image caused by a phase difference due to interference between a transmission beam and an diffraction beam passing through an object. When observing such high resolution images, it can be found that high resolution images are not sharpened by diffraction beams far from the optical axis and beams generated by background noise.

Computer processing techniques of electron microscopy images are often used to eliminate this phenomenon. Computer processing techniques of electron microscopy images allow the computer to enter an image to calculate the transmission function in the intensity distribution of the image to be processed to facilitate the analysis of the image obtained directly from the microscope, and Fourier transform the transmission function to the rear focal plane. The diffraction wave of can be obtained. Multiplying this diffraction wave by its conjugate complex number yields the intensity of the diffraction wave, that is, the diffraction image.

In this diffraction mode, the form of the microscope transfer function or the phase contrast transfer function multiplies the diffraction wave with a mask of the form in which it transmits the information of the spatial frequency and diffraction point containing the information produced in the region of interest and does not transmit the background noise. Fourier transform to obtain a wave at the top and multiply it by a conjugate complex wave to get a clear image with background noise canceled.

This can be done easily using a computer. However, the computer processing technology of the electron microscope image has a problem in that an additional computer software capable of processing a computer and an image may be additionally installed since the image obtained from the transmission electron microscope needs to be input to the computer for processing.

An object of the present invention is to prevent the phenomenon that the high resolution image is not clear by the beam caused by the background noise of the diffraction beam and the image distant from the optical axis when observing the high resolution image as described above.

Another object of the present invention is due to the background noise on the diffraction beam and the distant optical axis when observing high resolution images.

It is an object of the present invention to provide a structure of an objective lens aperture that can prevent a phenomenon in which a high resolution image is not sharpened by a beam generated in a beam without using computer processing.

It is still another object of the present invention to obtain a mask-like object used in computer processing of an image to obtain a background noise-free image in a pattern forming apparatus using a transmission electron microscope or an atomic image for high resolution image observation. It is to provide a lens aperture.

In order to achieve the above object, the present invention provides an image computer process by using an improved objective lens aperture that can remove background noise of a high resolution image in a pattern forming apparatus using a transmission electron microscope or an atomic image. It is intended to provide an aperture structure capable of obtaining a clear resolution image without additional processing such as processing.

Hereinafter, the transmission electron microscope will be described. In the transmission electron microscope, electrons pass through the specimen (object) to form a diffraction image on the rear focal plane of the lens according to the crystal structure of the specimen. When the diffraction image is seen, the shape of the diffraction image changes depending on the crystal structure of the specimen, and the distance between the transmission point and the diffraction point is determined by the interplanar distance d _hkl of the plane indicated by the diffraction point.

Fig. 2 is a diagram showing the form of diffraction images of transmission electron microscopes obtained from specimens of typical crystal structures.

Specifically, FIG. 2A shows a diffraction image of a transmission electron microscope obtained from a diamond crystal material in the electron beam direction, and FIG. 2B is a transmission electron obtained from a material of a BCC (body centered cubic) crystal structure. Figure 2c is a view showing the form of the diffraction image of the microscope along the electron beam direction, Figure 2c is a view showing the form of the diffraction image of the transmission electron microscope obtained in the material of the FCC (face centered cubic) crystal structure along the electron beam direction, Figure 2d The diffraction image of the transmission electron microscope obtained from the material of the HCP (hexagonal closed packed) crystal structure along the direction of the electron beam.

If we obtain a diffraction plot from an unknown material, we can find its lattice constant, using Bragg's equation. The camera constant (L) required at this time is usually measured in advance using a known standard sample such as Au.

3 is a diagram showing a relationship between a diffraction image of an electron microscope and an objective lens aperture. Since the diffraction image of the electron microscope is made by enlarging the intersection of the Ewald sphere and the reciprocal lattice, the distance measured in the diffraction image of FIG. 3 is considered to be an enlargement of the actual reverse lattice vector. The magnification of the microscope is the ratio of the radius of L and Ewald sphere in FIG. 3 and can be expressed by the following equation.

L / k = λL

Where L is the distance from the specimen to the surface where the objective lens aperture is located, which is determined from the magnification of the imaging lens of the microscope, k is the magnitude of the wave vector, and λ is the wavelength of the electron beam.

L sin2θ_B

L2θ_B 이 된다. When r _hkl shown in Fig. 3 is the distance from the transmission point to the diffraction point of the diffraction image, r _hkl = L tanθ when the diffraction angle is very small, such as electron diffraction.

L sin2θ _B

L2θ _B is obtained.

d_hkl sinθ_B 이며, 여기에서 회절각이 아주 작은 경우에는 λ

2d_hklθ_B 이므로, r_hkl = λL/d_hkl결국 이 된다On the other hand, λ from Bragg's law

d _hkl sin θ _B , where λ if the diffraction angle is very small

Since 2d _hkl θ _B , r _hkl = λL / d _hkl is

In general, in order to obtain a high resolution image, the specimen is irradiated with a convergence angle without irradiating the electron beam in parallel with the specimen. In this case, the diffraction beam and the diffraction beam have a disc shape instead of a point, and the diameter b _disc of the _disc is determined by the following equation.

b _disc = 2Lａ

Where a is the convergence semiangle of the electron beam.

Since the high resolution image is formed by the phase difference due to the interference phenomenon between the transmission beam and the diffraction beam, an aperture having a structure capable of passing the transmission beam and the diffraction beam together is necessary to form the high resolution image. The structure of the aperture can be changed by the shape of the diffraction image defined in the crystal structure of the specimen, the distance between the diffraction beam and the transmission beam, and the convergence half angle of the electron beam.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the effects obtained when the present invention is applied will be predicted by using computer processing of an electron microscope image.

4 is a diagram showing a high resolution image of a silicon single crystal having a diamond structure. In other words, Fig. 4 shows a silicon single crystal having a diamond structure in which the electron beam is incident in a direction perpendicular to the plane of the zone axis (011) using a transmission electron microscope without using an objective lens aperture. High resolution image obtained. FIG. 5 shows a Fourier transformed image of the image of FIG. 4 through computer processing. When Fourier transformed the image of FIG. 4 through computer processing, a diffraction image obtained at the rear focal plane of the objective lens appears. Is not an image. In order to remove background noise from such an image, an aperture of a structure that passes the transmission beam and the diffraction beam together but does not pass other background noise is required.

FIG. 6 is a view showing an objective lens aperture in which only a transmission beam and six diffraction beams can pass without passing the background noise. That is, by using the objective lens aperture of the type that can pass only the transmission beam and six diffraction beams close to the transmission beam as shown in FIG. 6 on the rear focal plane of the objective lens, a clear high resolution image can be obtained in the transmission electron microscope.

FIG. 7 is a diagram showing a high resolution image obtained by using an objective lens aperture having the structure of FIG. This figure will be the same as the Fourier transformed image after performing a computer process of applying a mask having the same shape as that of FIG. 6 to a Fourier transformed diffraction image (FIG. 5).

The computer processing by applying the mask of the form as shown in FIG. 6 to the image of FIG. 5 obtained by Fourier transforming the image of FIG. 4 through computer processing is desired information for forming an image among the information in the image of FIG. The task of preserving only the beam information (here six diffraction beams and transmitted beams) and removing other information means performing computer processing such as applying a mask. The Fourier transform of the masked image, that is, the image having only the information of six diffracted beams and transmitted beams, can obtain an image without background noise. Therefore, the computer processing process of applying a mask to remove only the information of the desired image and removing other image information is performed by using one aperture beam and six diffraction beams passing through the aperture of the aperture using the aperture of the structure shown in FIG. The same technical effect as the process of forming an image using only the beam and not passing through the remaining holes may be blocked by using an aperture so as not to be involved in image formation.

In Fig. 6, the position of the hole for passing the diffraction beam of the aperture is the same as that of the 111 and 002 diffraction beams on the diffraction of the single crystal of silicon, and the distance between the hole for passing the transmission beam and the diffraction beam hole for passing the diffraction beam is r _111. = λL / d ₁₁₁ , r ₀₀₂ = λL / d ₀₀₂ and the diameter of each hole should be less than b _disc = 2La. Because the diameter (b _disc) is not greater than 2La background noise is completely removed.

Fig. 8 is a diagram showing an objective lens aperture capable of passing a transmission beam and 16 diffraction beams when a silicon single crystal is used as a specimen. As another type of objective lens aperture, when using an objective lens aperture capable of passing through a transmission beam and 16 diffraction beams, the positions of the holes for passing the diffraction beams of the aperture are 111, 002, 220, on the diffraction of the single crystal of silicon. 113, 222 The position of the diffraction beam is the same, and the distance between the hole passing through the transmission beam and the hole passing through each diffraction beam is r ₁₁₁ = λL / d ₁₁₁ , r ₀₀₂ = λL / d ₀₀₂ , r ₂₂₀ = λL / d ₂₂₀ , r ₁₁₃ = λL / d ₁₁₃ , r ₂₂₂ = λL / d ₂₂₂ and the diameter of each hole should be less than b _disc = 2La. Because the diameter (b _disc) is not greater than 2La background noise is completely removed.

The high resolution image obtained by using this aperture is obtained by performing computer processing of applying a mask having the same shape as that of FIG. 8 to a diffraction image (FIG. 5) obtained by Fourier transforming the image of FIG. Will be the same. 9 is a view showing a silicon high resolution image obtained when using the objective lens aperture of FIG.

,

축) 이동 및 회전이동의 기능이 필요하지만, 도10의 조 리개는 회전이동없이 2 축의 이동만으로 시편의 회절상에 정렬시킬 수 있는 장점이 있다.이러한 조리개에서 투과빔용 구멍의 중심에서 회절빔용 링구멍의 중심까지의 거리(두께)는 r_hkl = λL/d_hkl 에 의해 결정된다. 투과빔용 구멍의 지름(b_disc )과 링의 내주면에서 외주면까지의 길이(두께:b_hkl)는 빔의 수렴반각(a)와 대물 렌즈 조리개가 위치한 면까지 현미경의 결상 렌즈의 배율에서 결정되는 거리(L)에 의해 결정된다. b_disc는 2La보다 작아야 하며, b_hkl도 마찬가지이다. 이 또한 배경잡음을 완전히 제거하기 위함이다. 전자빔의 수렴반각이 0이 되면 이론적으로는 구멍의 지름이 0에 가까워질 수 있다. 또한 링의 갯수도 변화시킬 수 있다. 링의 갯수는 얼마나 많은 회절빔을 포함시켜 이미지를 형성할 것인가에 대한 선택의 문제로서, r_hkl = λL/d_hkl 에서 면간거리 d_hkl 에 의해 투과빔용 구멍의 중심에서 회절빔용 링의 외주면까지의 정해지는 거리에 따라 복수의 링을 선택할 수 있으며, 링의 분포는 관찰하는 시편에서 나오는 회절상의 형태에 따라 변화될 수 있다. Fig. 10 is a view showing an objective lens aperture in the form of a ring. This is another type of objective lens aperture, and the above-described aperture is used for specimens having diffraction beams having different crystal structures but having similar interplanar distances because the arrangement of the holes and the distance between the holes vary according to the crystal structure of the specimen. A diaphragm of the form shown in FIG. 10 may be manufactured. In addition, in order to align the diaphragm of FIG. 6 or FIG.

,

Although the function of axial) rotation and rotational movement is required, the aperture of Fig. 10 has the advantage of being able to align on the diffraction of the specimen by only two axis movements without rotational movement. The distance (thickness) to the center of is determined by r _hkl = λL / d _hkl . The diameter (b _disc ) of the hole for the transmission beam and the length (thickness: b _hkl ) from the inner circumferential surface to the outer circumferential surface of the ring are determined by the magnification of the imaging lens of the microscope from the converging half angle (a) of the beam and the plane where the objective lens aperture is located. Determined by (L). b _disc must be less than 2La, and b _hkl is the same. This is also to completely remove the background noise. If the convergence half of the electron beam is zero, the diameter of the hole can theoretically be close to zero. You can also change the number of rings. The number of rings is a matter of choice as to how many diffraction beams are included to form an image, from r _hkl = λL / d _hkl to the center of the hole for transmission beams to the outer circumferential surface of the ring for diffraction beams by the interplanar distance d _hkl . A plurality of rings can be selected according to a predetermined distance, and the distribution of the rings can be changed according to the shape of the diffraction image coming out of the specimen to be observed.

FIG. 11 is a diagram illustrating a silicon high resolution image obtained when the objective lens aperture of FIG. 10 is used. As shown in Fig. 11, the high resolution image of silicon obtained using such a ring-type aperture can be expected by a computer processing method as described above.

The objective lens aperture of this structure of the present invention is also applicable to the pattern forming method using atomic images and the objective lens aperture for device electron beam lithography apparatus. A method and apparatus for forming a pattern using an atomic image are described in Korean Patent Application No. 2001-17694. By applying the method and apparatus, the object of the present invention can be realized.

12A, 12B, 12C, and 12D are diagrams showing electron beam intensity distributions obtained when the silicon high resolution image of FIG. 4 and the objective lens aperture of FIGS. 6, 8, and 10 are used.

As described above, when the objective lens diaphragm is manufactured so that only the transmission beam and the diffraction beam can pass, the background noise generated from the specimen can be removed from the transmission electron microscope, so that the background intensity of the electron beam is uniform. Higher intensity portions of the electron beam may exhibit nearly identical intensity of the electron beam in an image. As a result of estimating such an effect using a computer processing method, as shown in FIG. 12, the above-mentioned three objective lens apertures can be confirmed through the distribution of the intensity of the electron beam in almost the same area.

The present invention is also applicable to the pattern formation method using the atomic image in the electron beam lithography apparatus and the aperture structure of the objective lens for the device. A method and apparatus for forming patterns using atomic images are described in Korean Patent Application No. 2001-17694 (name: Pattern forming method and apparatus using crystal structure of material). If the objective lens aperture described above is applied to this apparatus, the same effect as described above can be obtained.

Claims (16)

In the objective lens aperture for sharpening the retardation image of the transmission beam and the diffraction beam formed by passing the electron beam passed through the specimen and the specimen through the objective lens, A transmission beam hole for passing only the transmission beam; And The distance from the transmission beam hole is determined according to the lattice constant of the specimen, and the number and direction are determined according to the crystal structure of the specimen, and the plurality of diffraction beam holes are positioned at the diffraction beam passing position passing only the diffraction beam. Objective lens aperture characterized in that. The method of claim 1, wherein the specimen is a silicon single crystal, the position of the diffraction beam hole is the same as the position of the 111 and 002 diffraction beams on the diffraction image of the silicon single crystal, the transmission beam hole and the diffraction for the 111 diffraction beam The distance between the beam holes r ₁₁₁ = lambda L / d ₁₁₁ , for the 002 diffraction beam is r ₀₀₂ = lambda L / d ₀₀₂ , the diameter of each hole is less than 2La (where a is the convergence half angle of the electron beam) Objective aperture. delete  The method of claim 1, The specimen is a silicon single crystal, and the position of the diffraction beam hole is the same as the position of the diffraction beam in the directions of 111, 002, 220, 113, and 222 on the diffraction image of the silicon single crystal, and for each of the diffraction beams, The distance between the diffraction beam holes is r ₁₁₁ = λ L / d ₁₁₁ , r ₀₀₂ = λ L / d ₀₀₂ , r ₂₂₀ = λ L / d ₂₂₀ , r ₁₁₃ = λ L / d ₁₁₃ , r ₂₂₂ = λ L / d ₂₂₂ , respectively. The aperture of each objective is characterized in that the diameter of each hole is less than 2La (where a is the convergence half angle of the electron beam). delete In the objective lens aperture in which an electron beam irradiated to a specimen and passed through the specimen passes through a transmission beam and a diffraction beam formed through the objective lens, A transmission beam hole for passing only the transmission beam; And The distance from the transmission beam hole is determined according to the lattice constant of the specimen so that the distance from the center of the transmission beam hole to the center of the ring hole is λ L / d _hkl , and the ring diffraction beam hole allows only the diffraction beam to pass. Objective lens aperture characterized in that made. delete delete delete delete delete delete In the pattern forming apparatus using an atomic image having an objective lens aperture through which a beam of electrons irradiated onto a specimen and passed through the specimen passes through the objective lens and a diffraction beam passes through A transmission beam hole for passing only the transmission beam; And The distance from the transmission beam hole is determined according to the lattice constant of the specimen, and the number and direction are determined according to the crystal structure of the specimen, and the plurality of diffraction beam holes are positioned at the diffraction beam passing position passing only the diffraction beam. Pattern forming apparatus using an atomic image, characterized in that having an objective lens aperture. The method of claim 13, wherein the specimen is a silicon single crystal, the position of the diffraction beam hole is the same as the position of the 111 and 002 diffraction beams on the diffraction image of the silicon single crystal, the transmission beam hole and the diffraction for the 111 diffraction beam The distance between the beam holes is r ₁₁₁ = lambda L / d ₁₁₁ , and for the 002 diffraction beam, r ₀₀₂ = lambda L / d ₀₀₂ , and the diameter of each hole is less than 2La (where a is the convergence half angle of the electron beam). Pattern forming apparatus using an atomic image characterized by having.  The method of claim 13, The specimen is a silicon single crystal, and the position of the diffraction beam hole is the same as the position of the 111, 002, 220, 113, and 222 diffraction beams on the diffraction image of the silicon single crystal. The distance between the diffraction beam holes is r ₁₁₁ = λ L / d ₁₁₁ , r ₀₀₂ = λ L / d ₀₀₂ , r ₂₂₀ = λ L / d ₂₂₀ , r ₁₁₃ = λ L / d ₁₁₃ , r ₂₂₂ = λ L / d ₂₂₂ , respectively. Wherein each hole has an objective lens aperture of less than 2 La (where a is the convergence half of the electron beam). In the pattern forming apparatus using an atomic image having an objective lens aperture through which a beam of electrons irradiated onto a specimen and passed through the specimen passes through the objective lens and a diffraction beam passes through A transmission beam hole for passing only the transmission beam; And The distance from the transmission beam hole is determined according to the lattice constant of the specimen so that the distance from the center of the transmission beam hole to the center of the ring hole is λ L / d _hkl , and the ring diffraction beam hole allows only the diffraction beam to pass. Pattern forming apparatus using an atomic image, characterized in that having an objective lens aperture, characterized in that made.

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