KR100849139B1 - Source scanning X-ray microscope system - Google Patents

Abstract

The present invention relates to an X-ray microscope system and an observation method using the same, specifically a laser generating unit for generating a laser beam; A scanning unit for outputting the output angle of the laser beam incident from the laser generator by changing a predetermined angle with time; A laser condenser for condensing the laser beam output from the scanning unit at a point on the ultra-short plane determined by the incident angle of the laser beam; An X-ray generator having a predetermined X-ray generation target for generating X-rays on a focal plane of the laser-concentrator so that X-rays may be generated when the laser beam output from the laser-condenser is irradiated; An X-ray condenser for condensing X-rays generated by the X-ray generator at different positions on the focal plane according to the generated position; A sample installation unit installed on the ultra-short surface of the X-ray light collecting unit and configured to install a sample to be observed; An X-ray measuring unit installed at a rear end of the sample installation unit and converting the amount of X-rays transmitted and collected by the sample installed in the sample installation unit into an electrical signal; It relates to an X-ray microscope system and an observation method using the same; comprising an X-ray image forming unit for converting the electrical signal measured by the X-ray measuring unit into a spatial signal over time.

According to the present invention, there is no need for expensive 2D CCD equipment and ultra-precision exercise equipment capable of detecting X-rays, and the size of the equipment can be miniaturized.

Description

Source scanning X-ray microscope system

1 is a cross-sectional view showing a conventional X-ray microscope system

2 is a block diagram showing an example of the configuration of the X-ray microscope system of the present invention

3 is a view for explaining the function of the relay lens of the present invention.

4 shows an example (galvano mirror) of the X-Y scanner of the present invention.

5 is a view showing a change in the light collecting position according to the incident angle in the laser light collecting unit of the present invention

6 is a view showing an example of the structure of a laser condenser, an X-ray generator and an X-ray condenser of the present invention;

7 is a view showing a change in the light collecting position according to the incident angle in the X-ray light collecting unit of the present invention

8 shows a sample of a sample used for explanation of the present invention.

FIG. 9 is a diagram illustrating a waveform of a signal measured through an X-ray measuring unit as a result of observing the sample of FIG. 8.

10 illustrates an embodiment of the present invention.

11 illustrates another embodiment of the present invention.

12 is a flow chart illustrating a method of the present invention.

The present invention relates to an X-ray microscope system, and in particular, does not use expensive CCD equipment, and relates to an X-ray microscope system capable of observing a sample using X-rays without ultra-precision movement of the sample.

In general, a microscope system refers to a system that magnifies and observes a minute portion of an object (hereinafter referred to as a sample), and includes an electron microscope using electrons as a light source, and an optical microscope system using visible light as a light source. .

In the case of the electron microscope system, the sample must be placed in a vacuum, and the physical and chemical pretreatment process of the sample is essential, so that biological samples such as living biological cells cannot be observed. Although observation of the sample is possible, since the visible light is used as the light source, there is a problem that the resolution is limited to about 200 nm by the diffraction limit of the light source by existing technology.

Recently, an X-ray microscope system using an X-ray wavelength region called a 'water window (λ = 2.3 to 4.4 nm)' has been studied. In the 'water window' region, proteins, which constitute water and biological samples, Because of the large X-ray absorption difference, the protein can be observed even through a water layer having a thickness of several microns, and the inside of the biological sample can be observed by the permeability of the X-ray.

1 shows a conventional X-ray microscope system.

The X-ray microscope system of FIG. 1 is configured to generate X-rays using a liquid target. The X-ray microscope system of FIG. 1 is installed inside the housing 20 and the housing 20 installed on the table 10 and the table 10, but below. The light source chamber 30 is configured, the mirror chamber 40 is configured above the light source chamber 30, and the imaging chamber 50 is configured at the upper end of the housing 20.

The housing 20 is formed in a cylindrical shape in which the separation partition 22 is formed at a predetermined depth, and the light source chamber 30 is installed below the separation partition 22 of the housing 20 as a reference. The housing 20 is closed by the first base plate 44 of the mirror chamber 40, and the bottom of the housing 20 is closed by the light source vacuum pump 34, so that the light source chamber 30 is constituted. The inside of 20 is made to be able to maintain a vacuum state.

The light source chamber 30 is provided with a discharge part 32 on a straight line of the nozzle part 31 provided on one side, and the light source part 33 to which the light source is irradiated between the nozzle part 31 and the discharge part 32 is provided. Is installed. The nozzle unit 31 forms a liquid target by spraying a high pressure liquid such as liquid nitrogen, and the light source unit 33 outputs a high power laser light such as a diode pump solid laser to the liquid target and has a wavelength range of 2.3 to 4.4 nm. The plasma emitting soft X-rays is generated.

The mirror chamber 40 is installed upward based on the separating partition wall 22 of the housing 20, and the first base plate 44 and the first base plate 44 fastened and fixed to an upper end of the separating partition wall 22. Laser condenser lens 41 provided on the upper surface of the upper surface of the laser collecting lens 41, the second base plate 45 located above the laser condensing lens 41, the holder portion and the upper surface of the second base plate 45 It consists of the X-ray condensing mirror 43 provided in the upper surface of the 2 base board 45, and located above the holder part.

A filter 47 is formed below the transmission hole at the bottom of the first base plate 44 to filter light having a wavelength other than X-rays.

The laser condenser lens 41 is installed on the upper surface of the first base plate 44, amplifies the X-ray wavelength obtained through the plasma generated in the light source chamber 30, and uses this to illuminate the biological sample. Phosphor condenser mirror is included.

The second base plate 45 is used as a focus blocking plate to block the direct light because the shielding film means 48 is installed below the central transmission hole.

On the other hand, a sample is placed on the transmission hole of the second base plate on the upper surface of the second base plate 45, the X-ray condensing mirror 43 includes a diffraction polishing plate, commonly referred to as a zone plate (zone plate) ) Is installed.

The imaging chamber 50 is composed of an optical amplifier and an imaging chamber 51 and a vacuum chamber 53 for maintaining the distance between the optical amplifier and the diffraction band of the imaging chamber 50.

When the liquefied nitrogen gas or the like is jet-jetted through the nozzle unit 31 configured in the light source chamber 30 to form a liquid target, the laser is irradiated to the liquid target to generate plasma that emits X-rays in the soft X-ray wavelength region. The generated soft X-ray wavelength is filtered by the filter 47 provided on the bottom surface of the first base plate 44 and the second light is amplified by the light amplified while passing through the condenser mirror 414 of the first base plate 44. The biological sample installed in the base plate 45 is illuminated.

The light illuminating the biological sample is amplified and enlarged by the diffraction polishing plate formed in the X-ray condensing mirror 43 to be obtained as an optical image in the imaging chamber 50. The imaging chamber 50 converts the optical image enlarged through the diffraction plate to be converted into an electrical signal using a device such as a charge coupled device (CCD) to be viewed or output through the screen from the outside.

In the conventional X-ray microscope system as described above, a two-dimensional CCD that radiates X-rays to an entire area corresponding to one screen region of a sample to be observed and detects the X-rays using an imaging device such as a zone plate. The image is obtained by forming an image on the surface. Therefore, an expensive two-dimensional CCD capable of recognizing X-rays is required, and the size of equipment is increased.

In order to solve the above problems, the present invention can accurately observe a sample without using a cost-effective two-dimensional CCD device capable of recognizing X-rays, and without using a positioning transport device having a precision that is intended for measurement. An x-ray microscope system and an observation method using the same are provided.

In order to achieve the above object, the present invention provides a laser generating unit for generating a laser beam; A scanning unit for outputting the output angle of the laser beam incident from the laser generator by changing a predetermined angle with time; A laser condenser for condensing the laser beam output from the scanning unit at a point on the ultracritical surface determined according to the incident angle of the laser beam; An X-ray generator having a predetermined X-ray generation target for generating X-rays on a focal plane of the laser-concentrator so that X-rays can be generated when the laser beam output from the laser-condenser is irradiated; An X-ray condenser for condensing X-rays generated by the X-ray generator at different positions on a focal plane according to the generated position; A sample installation unit installed on the ultra-short surface of the X-ray light collecting unit for installing a sample to be observed; An X-ray measuring unit installed at a rear end of the sample installing unit and converting an amount of X-rays transmitted and collected by a sample installed in the sample installing unit into an electrical signal; It provides an X-ray microscope system comprising a; X-ray image forming unit for converting the electrical signal measured by the X-ray measuring unit into a spatial signal over time.

On the other hand, the present invention to achieve the above object is a laser generating unit for generating a laser beam; A first axis scanning unit for outputting the output angle of the laser beam incident from the laser generation unit by changing a predetermined angle in a first axis direction with time; A laser condenser for condensing the laser beam output from the first axis scanning unit at a point on the ultra-short surface determined according to the incident angle of the laser beam; An X-ray generator having a predetermined X-ray generation target for generating X-rays on a focal plane of the laser-concentrator so that X-rays can be generated when the laser beam output from the laser-condenser is irradiated; An X-ray condenser for condensing X-rays generated by the X-ray generator at different positions on a focal plane according to the generated position; A sample installation unit installed on the ultra-short surface of the X-ray light collecting unit for installing a sample to be observed; An X-ray measuring unit installed at a rear end of the sample installing unit and converting the amount of X-rays transmitted and collected by the sample installed in the sample installing unit into an electrical signal; An X-ray image forming unit converting the electrical signal measured by the X-ray measuring unit into a spatial image signal as time passes; And a second axis scanning unit configured to move the laser light collecting unit and the X-ray generating unit together to be fixed to each other, and to move the laser light collecting unit and the X-ray generating unit in a second axis direction perpendicular to the first axis. It provides an X-ray microscope system comprising a.

The X-ray generation unit may include a pin photodiode measuring the intensity of X-rays generated from the X-ray generation target, and the X-ray image forming unit may be compared with the intensity of X-rays measured by the pin photodiode. It is preferable to convert the image into a spatial image signal using the relative value of the intensity of the X-rays measured by the X-ray measuring unit.

The X-ray microscope system further includes a visible light two-dimensional CCD for detecting a position where the X-rays are generated by using the visible light generated when the X-rays are generated by the X-ray generator, wherein the scanning unit is visible It is preferable to correct the output angle of the laser beam by using the X-ray generating position detected by the light beam two-dimensional CCD.

The X-ray microscope system may further include a filter disposed between the X-ray generation target and the X-ray condenser, and configured to pass only X-rays having a predetermined wavelength.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing the configuration of the X-ray microscope system of the present invention.

X-ray microscope system of the present invention is the laser generating unit 110, the scanning unit 120, the laser collecting unit 130, the X-ray generating unit 140, the X-ray collecting unit 150, the sample installation unit 160, X-ray measurement It includes a unit 170 and the X-ray image forming unit 180.

The laser generator 110 outputs a laser beam for generating X-rays.

Various lasers may be used depending on the wavelength of X-rays to be generated and the type of target used for X-ray generation. A representative example of the laser that may be generated in the laser generator 110 is Nd: YAG laser.

Since a method of generating a laser is a general technique in the art to which the present invention pertains, a detailed description thereof will be omitted.

The scanning unit 120 is positioned on the path of the laser beam generated by the laser generation unit 110, and changes the output angle of the incident laser beam generated by the laser generation unit 110 by a predetermined angle as time passes. Output

The generated laser is different from the position focused on the X-ray generator through the laser condenser 130 according to the change in the angle changed by the scanning unit 120, so that the generated X-rays are installed in the sample installation unit 160. The position at which the sample is scanned changes. The size of the changed angle is determined according to the type, focal length, and the like of the mirrors used in the laser condenser 130 and the X-ray condenser 150.

3 shows an example of the scanning unit 120. In the embodiment shown in FIG. 4, the scanning unit 120 includes an XY scanner 121 and relay lenses 122-1 and 122-2. do.

The X-Y scanner 121 changes the angle of the laser incident from the laser generator 110 on the X-axis and the Y-axis.

The X-Y scanner 121 shown in FIG. 3 represents an Acousto-Optic Deflector (AOD) as one of the representative devices that can be used as the X-Y scanner 121. Acoustic optical deflector is a device for changing the diffraction angle of light by modifying the medium by sound waves or ultrasonic waves, by changing the diffraction angle of the laser beam by using an electrical signal to change the output angle of the incident laser beam.

The relay lenses 122-1 and 122-2 allow the light deflected from the XY scanner 121 to move within a certain area so that the deflected laser beam does not leave the opening of the lens or the like constituting the laser condenser 130. .

The number of relay lenses 122-1 and 122-2 is determined by the distance between the XY scanner 121 and the laser condenser 130, the refractive indices of the relay lenses 122-1, 122-2, and the like. When the distance between the laser condenser 130 and the laser condenser 130 is short, there is no fear that the deflected laser beam may leave the opening of the laser condenser 130, the relay lenses 122-1 and 122-2 may not be provided. Can be carried out.

A device that can be used in addition to the acoustic optical deflector as the X-Y scanner 121 is a galvano mirror. The galvano mirror adjusts the angle of the mechanically reflected surface as shown in FIG. 5 so that the incident laser beam is outputted with the output angles changed on the X and Y axes.

As shown in FIG. 4, when the two galvano mirrors 123-1 and 123-2 are used, the laser generated by the laser generator 110 is refracted by a predetermined angle to the X-axis and the Y-axis.

The XY scanner 121 may be set to change the angle of the laser beam which is automatically output at a predetermined periodic interval by its own timer (not shown), and may correspond to the X-ray measuring unit 170 or the X-ray image forming unit 180. It may be set to change the angle of the laser beam in conjunction.

The device that can be used as the X-Y scanner 121 is not limited to the above-described example, and any device capable of changing the output angle of the incident laser beam can be used in addition to the device described above.

When the relay lens 122 changes the output angle of the laser beam in the XY scanner 121, the relay lens 122 prevents the laser beam output from the scanning unit 120 from entering the laser condenser 130 and is directed to another place. For this purpose, the laser beam is incident on the laser condenser 130 without changing the angle of the laser beam output from the XY scanner 121.

The laser concentrator 130 is positioned on the path of the laser beam output by the scanning unit 120, performs the same function as a general objective lens, and is composed of a mirror or lens made of a material that is durable to the laser beam. The laser beam output from the scanning unit 120 is focused on a point on the focal plane.

As the laser condenser 130, an objective lens composed of one or more lenses may be used, or a mirror such as a Wolter mirror may be used.

5 illustrates an example of an objective lens that may be used as the laser condenser 130. As shown in FIG. 5, the position where the laser beam is focused on the focal plane is different depending on the angle at which the laser beam is incident on the laser concentrator 130.

That is, the laser beam incident in the A direction is focused at the A 'position, and the laser beam incident in the B direction is focused at the B' position.

The X-ray generator 140 is positioned so that the X-ray generation target (not shown) is provided on the focal plane of the laser condenser 130. When the laser beam focused on the focal plane of the laser condenser 130 is irradiated to the X-ray generation target, X-rays are generated in the plasma state.

There may be various materials that can be used as X-ray generation targets. 1 may use a liquid target such as liquid nitrogen, or may use a solid target such as Mylar (trade name of polyethylene terephthalate). The wavelength of X-rays generated may vary depending on the constituent elements, and metal targets are used to have a wide bandwidth.

Depending on the characteristics of the X-ray generation target used in the X-ray generator 140, the laser concentrator 130 and the X-ray concentrator 150 may be installed in a straight line, or the laser concentrator 130 and the X-ray concentrator 150 may be installed to achieve a predetermined angle.

For example, when the X-ray generation target has a property of transmitting light, and the laser light may be collected on the opposite side of the X-ray generation target to form a plasma, the laser condenser 130 and the X-ray condenser 150 may be It can be installed to be located in a straight line. If a material having a property of not transmitting light is used as the X-ray generation target, the X-ray concentrator 150 may have a predetermined angle with the laser condenser 130 so that X-rays generated from the X-ray generation target may be incident. Is preferably installed to have an angle of 90 degrees.

The angle formed by the laser condenser 130 and the X-ray concentrator 150 may be such that X-rays generated by the X-ray generator 140 may be incident on the X-ray concentrator 150. In FIG. 6, the X-ray concentrator 150 may be formed such that the same plane as the surface formed by the X-ray generator 141 installed in the X-ray generator 140 forms an angle smaller than the angle formed by the laser condenser 130. Since the X-rays generated at 141 are focused on the X-ray condenser 150, the microscope system of the present invention can perform a normal function.

When the laser concentrator 130 and the X-ray concentrator 150 are installed in a straight line, the generated X-rays must pass through the X-ray generation target 141. In this case, since the amount of light is reduced, the laser beam The light unit 130 and the X-ray light collecting unit 150 may be installed to form a predetermined angle.

The X-ray concentrator 150 is installed at a position where X-rays generated by the X-ray generator 140 may be incident, and any position of the X-rays generated by the X-ray generator 140 on the focal plane of the X-ray concentrator 150. To condense on.

The mirror used in the X-ray concentrator 150 is a kind of mirror capable of condensing incident X-rays into one point, and preferably, a Wolter mirror, an ellipsoid mirror, or the like may be used.

In this case, the location focused on the focal plane may vary depending on the location of the light source generated in the X-ray generation target, as shown in FIG. 8, which is the same principle as in the laser condenser 130. That is, the X-rays generated at the A position are condensed at the A 'position, and the X-rays generated at the B position are condensed at the B' position.

In other words, the position where the laser beam is focused by the laser concentrator 130 is changed according to the angle of the laser beam output from the scanning unit 120, and the laser beam and the X-ray generation target are located at the position where the laser beam is focused. X-rays are generated by the interaction, and the position where the X-rays are collected by the X-ray concentrator 150 is changed according to the position where the X-rays are generated.

Meanwhile, the overall magnification, that is, the X-ray microscope, depends on the size of the light source generated by irradiating the X-ray generation target of the X-ray generation unit 140 with the size of the light source generated by the laser beam, the size of the plasma, and the magnification of the mirror used for the X-ray condenser 150. The resolution of the system is determined.

For example, if the diameter of the light source generated in the X-ray generation target is 5 microns, and the magnification of the mirror used in the X-ray condenser 150 is 100 times, on the focal plane of the mirror used in the X-ray condenser 150 The diameter of the collected X-rays is 50 nm. That is, the sample can be observed in units of 50 nm. (In other words, the X-ray transmittance information of the sample portion corresponding to 50 nm size is obtained from the focal plane.) If the X-rays collected at 50 nm size are moved on the sample surface at 50 nm intervals, the sample can be observed at 50 nm resolution. Will be.

That is, the X-ray condenser 150 such as a Wolter mirror serves to reduce and project the X-ray generating light source having a size of 5 microns down to 50 nm, and the XY scanner 121 such as an acoustic optical deflector (AOD) and a galvano mirror. ) Moves the position of the 5 micron laser beam focused by the X-ray generating unit by 5 microns, thereby moving the position of the X-ray on the sample surface to 50 nm.

At this time, the laser beam scanned by the XY scanner 121 such as a galvano mirror and an acoustic optical deflector (AOD) is out of the optical axis while reaching the opening of the lens of the laser condenser 130, etc. The relay lens is a device that keeps it constant in the opening of the lens and does not change the incident angle.

Subsequently, the laser beam focused on the X-ray target by the condenser lens (let's say the focal length f) is 5 microns in diameter when the scanner scans the scan angle (theta radians). It is always present at the position f * theta from above (in this sense, a lens used as a condenser lens is called an f-thata lens).

The sample installation unit 160 is positioned so that the sample is installed on the ultra-short surface of the X-ray light collecting unit 150 and performs a function of fixing the sample. The method of fixing and installing the sample is the same as the general X-ray microscope system, so a detailed description thereof will be omitted.

The X-ray measuring unit 170 is located on the opposite side of the X-ray condenser 150 based on the sample installing unit 160 and measures the amount of X-rays passing through the sample installed in the sample installing unit 160.

The X-ray measuring unit 170 has a photodiode with high sensitivity in X-rays (a typical photodiode converts only a signal in the visible light region into an electrical signal, and in the case of X-rays, it is often not properly detected, and thus has a wavelength of X-rays). Photodiodes should be used to detect the signal) or a one-channel photodetector amplifier (eg a combination of a Phosphor plate and a Photo Multiplier Tube).

A PIN photodiode is a photodiode of a structure in which a layer of intrinsic (i-type) semiconductor is bonded between a p-region and an n-region. By adjusting the thickness of the i-region, it is possible to make devices with optimum sensitivity and frequency response, which makes them suitable for X-ray sensing.

As the output angle of the laser beam is changed by the scanning unit 120, the position where the X-ray is generated by irradiating the laser beam to the X-ray generating target from the X-ray generating unit 140 is changed. The position at which the X-rays passing through the light collecting unit 150 is irradiated is changed. Therefore, when the angle changed in the scanning unit 120 is changed little by little so that the interval in the sample unit is equal to the resolution, the sample surface can be scanned at an appropriate resolution.

In the case of using the sample as shown in FIG. 8, the result detected by the X-ray measuring unit 170 is illustrated in FIG. 9.

In FIG. 8, it is assumed that the size of each cell of the sample has a length of 50 nm on one side, a cell displayed in black is an area where X-rays are not easily transmitted, and a cell displayed in white is an area where X-rays may be transmitted.

If the resolution of the X-ray microscope system is 50 nm and scanning from the left to the right and from the top to the bottom of the sample, the amount of light detected over time, that is, the amount of light converted into an electrical signal by the PIN photodiode, is shown in FIG. 8.

As shown in FIGS. 8 and 9, the amount of transmitted X-rays while the X-rays are being irradiated to the first five cells, that is, the four cells 201 to 204 and the first cell 205 of the second row, Although the value is small, the value is low. However, while X-rays are irradiated to the three cells 206 to 208 thereafter, the amount of transmitted X-rays is large, indicating a high value.

As described above, a region in which many X-rays are transmitted while the X-ray scans the sample generates a high electrical signal, and a region in which the X-rays transmits a low electrical signal. In FIG. 8 and FIG. 9, for convenience of explanation, two regions, one having a high transmittance and one having a low transmittance, are divided. However, the biological sample may have various transmittances according to the properties of its components.

When the transmittance of X-rays, i.e., the amount of transmitted X-rays, is measured in each time zone, that is, in each region of the sample, through the X-ray measuring unit 170, the X-ray image forming unit 180 measures the X-ray measuring unit 170. The converted values are converted into spatial image signals.

In the X-ray image forming unit 180, the pattern on which the sample is scanned is registered in advance, or the scanning pattern is received from the scanning unit 120. The X-ray image forming unit 180 measures the scanned pattern and the measured pattern as shown in FIG. 10. The values are used to form an image with the amount of transmission in each space.

The formed image may be output through a monitor or printed through a printer.

The present invention will be described through one more specific embodiment of FIG. 10.

The laser beam generated from the laser generator 310 is laser condenser 330 through an XY scanner 321 composed of an acoustic optical deflector (AOD) or a galvano mirror and relay lenses 322-1 and 322-2. The incident angle is changed by a predetermined angle and is incident, and the light is collected by moving a predetermined distance on the focal plane through the laser condenser 330.

The laser beam focused by the laser condenser 330 is irradiated to different positions of the X-ray generating target 341 of the X-ray generator 340 according to the incident angle, and X-rays are generated at the irradiated position.

When X-rays are generated, not only X-rays but also visible light are generated. The position of the generated visible light is again output through the laser condenser 330, and the output visible light passes through the beam splitter 323 reflecting the visible light other than the laser beam and passes through the lens unit again. Is incident on. Therefore, in the CCD 325, the position of the formed dot is changed depending on the scanning situation. This information can be used to know the X-ray irradiation position on the sample surface, and the positional information calculated by the scan angle is corrected using this information.

In order to additionally obtain information on the intensity of the laser beam, the photodiode 324 is detected by using a beam splitter that transmits most of the focused laser beam and reflects only a small portion thereof. This information can be used to manage the conversion efficiency of X-rays.

The CCD 325 detects the position of the light source generated in the X-ray generator 340 using the visible light generated by the X-ray generator 340 together with the X-rays. The CCD used in this case needs to be able to detect only visible light and does not need enough performance to detect X-rays.

The position of the light source detected by the CCD 325 is transmitted to the scanning unit 320 to determine whether the scanning unit 320 outputs the laser beam at the correct angle so that the light source is generated at the correct position. It is used to correct the output angle of the laser beam.

An X-ray generation target 341 is installed on the focal plane of the laser condenser 330 in the X-ray generator 340.

The X-ray generating target 341 used in the embodiment of FIG. 8 is a solid target, and is formed in a strip type to prevent the broken solid target from being continuously used because the continuous laser beam is continuously irradiated to only one place. To be replaced continuously. Since the strip type X-ray generation target is described in US Patent No. 4,700,371 and corresponds to a known technology, a detailed description thereof will be omitted.

On the other hand, the X-ray generator 340 is installed with a PIN photodiode 342 to measure the intensity of the X-rays generated.

The PIN photodiode 342 installed in the X-ray generator 340 measures whether the intensity of the generated X-rays is constant, and is generated in the laser generator 310 using the measured value as in the photodiode 324. It may be used to correct the intensity of the laser beam, and may be used to correct the X-ray transmission amount measured by the X-ray measuring unit 370.

Since the X-rays generated by the X-ray generator 340 are not output in only one direction but are generated in all directions, the PIN photodiode 342 installed in the X-ray measuring unit 370 includes a light source and a PIN photodiode 342. It may be installed wherever there is no object blocking it.

On the other hand, X-rays generated from the light source is preferably incident on the X-ray condenser 350 through the filter 343. The filter 343 is intended to block all signals having a wavelength other than X-ray, and is preferably manufactured using titanium (Ti), aluminum, or the like.

The wavelength of X-rays generated may vary depending on the material constituting the target. Solid targets containing carbon elements can be used to generate X-rays with wavelengths around 3.37 nm. Targets containing nitrogen and carbon can be used to generate X-rays containing wavelength bands such as 2.87 nm and 3.37 nm. The target may be used to generate a wide band of X-rays. In this case, the filter is used to select and use these wavelengths.

Therefore, it is possible to block visible light with a thickness of about 200 microns of aluminum, and to select an appropriate wavelength with a metal such as titanium to achieve information selection effect according to the wavelength.

The X-rays passing through the filter are collected at a specific position of the sample installed in the sample installation unit 360 through the X-ray condenser 350 configured as a bolter mirror, and the X-rays passing through the sample at the focused position are PIN photodiodes 370. It is converted into an electrical signal by the X-ray image forming unit (not shown) is converted into a spatial image and output again.

When converting into a spatial image, the intensity of X-rays measured by the PIN photodiode 370 may be normalized to a relative intensity with the intensity of X-rays measured by the PIN photodiode 342. In this case, there is an advantage that a relatively accurate result can be obtained even when the intensity of the laser beam or X-ray changes in the middle.

The amount of X-rays transmitted through the sample can be sufficiently detected by the PIN photodiode 370, but an amplifier that amplifies the X-rays when the amount detected by the PIN photodiode is small for the purpose of increasing the repetition rate of the laser (not shown). ) Can be used in addition.

The sample and the detection device are preferably placed in a vacuum to prevent the absorption of X-rays by air or in a helium gas environment separated from the X-ray generator by a thin film of silicon nitride.

In the above-described systems and methods, the scanning unit 120 is responsible for scanning the two axes of the X axis and the Y axis using only the XY scanner 121 such as an AOD and a galvano mirror. For example, a device such as an acoustic optical deflector (AOD) and a galvano mirror may be used to scan only one axis and the other one may be mechanically scanned.

In particular, as shown in FIG. 6, when the system is configured with the laser condenser 130 and the X-ray condenser 150 at a predetermined angle rather than in a straight line, that is, the surface forming the X-ray generation target 141 is a laser beam If it is not perpendicular to the light unit 130, it is not a big problem when the Y-axis scan is performed using an acoustic optical deflector (AOD) or the like, but when the X-axis scan is performed, the focal plane where the laser beam is focused The X-ray generation target 141 may not exist in the case. That is, since the distance between the surface constituting the X-ray generation target 141 and the laser condenser 130 is not constant, only one portion of the X-ray generation target 141 is positioned on the focal plane of the laser condenser 130. do. In this case, when the laser beam is focused on a portion of the X-ray generation target 141 that is not located on the focal plane, X-rays of sufficient light amount may not be generated, which may cause a problem.

In the case of FIG. 6, the scan of the Y axis is performed using an acoustic optical deflector (AOD), and the scan of the X axis is performed by mechanically moving the laser condenser 130 and the X-ray generator 140. Doing so can prevent the above problems.

In this case, only the laser concentrator 130 and the X-ray generator 140 may be fixed to mechanically move by a predetermined distance in the X-axis direction, and the scanning unit 120 (only scans the Y-axis) and the laser condenser may be performed. 130 and the X-ray generating unit 140 may be mechanically moved in a predetermined distance in the X-axis direction in conjunction with each other, the laser generating unit 110, the scanning unit 120 (only scanning of the Y-axis), The laser concentrator 130 and the X-ray generator 140 may be mechanically moved by a predetermined distance in the X-axis direction in cooperation with each other.

In addition, the laser condenser 130 and the X-ray generator 140 may be mechanically moved along the X-axis and the Y-axis without the acoustic optical deflector, or the laser generator 110 or the laser condenser ( 130 and the X-ray generator 140 may be mechanically moved to the X-axis and the Y-axis by interlocking with each other, so that both the X-axis and the Y-axis scan may be performed mechanically.

It is also possible to scan by moving only the sample installation unit 160 mechanically, but in this case it is necessary to move very precise mechanically, expensive equipment is required, and the probability of error actually increases.

That is, if you want to scan in 50nm unit to move the sample installation unit 160 in 50nm unit is very difficult to move so precisely, there is a problem that is very vulnerable to small vibration.

However, in the case of the present invention, by using the method of moving the components before the X-ray condenser 150, rather than moving the sample installation unit 160, only a few microns of precision obtained by multiplying the magnification of the X-ray condenser by the final resolution Therefore, it is not necessary to increase the precision of the entire apparatus, and there is a strong advantage in vibration, thereby solving the above problems.

For example, if the sample is to be scanned in units of 50 nm, and the magnification of the X-ray concentrator 150 is 50 times, the X-ray condenser 140 and the components linked thereto are moved by 2.5 μm, Since the installation unit 160 scans by 50 nm, there is no need to mechanically move the unit by 50 nm.

FIG. 11 is a block diagram illustrating an example configuration of a system for performing a scan of one axis mechanically.

The X-ray microscope system of FIG. 11 is similar to the X-ray microscope system of FIG. 3. The laser generating unit 410, the scanning unit 420, the laser condenser 430, the X-ray generator 440, the X-ray condenser 450, It includes a sample installation unit 460, the X-ray measuring unit 470 and the X-ray image forming unit 480, the functions of the other components except for the scanning unit 420 is the same as described in FIG.

In the embodiment illustrated in FIG. 11, the scanning unit 420 includes a first axis scanning unit 421 and a second axis scanning unit 422.

The first axis scanning unit 421 is positioned on the path of the laser beam generated by the laser generation unit 410, and the output angle of the laser beam generated by the laser generation unit 410 is adjusted over time. Output by changing a predetermined angle in one axis direction.

An acoustic optical deflector (AOD), a galvano mirror, or the like may be used as the first axis scanning unit 421, and a relay lens may be further included so that the deflected light does not leave the opening of the laser condenser 430.

The second axis scanning unit 422 performs a mechanical scan in a second axis direction perpendicular to the first axis.

As described above, for the mechanical scanning, the laser condenser 430 and the X-ray generator 440 may be fixed to each other to move together, and the first axis scanning unit 421, the laser condenser 430, and the like. The X-ray generators 440 may be fixed to each other to move together, and the laser generator 410, the first axis scanning unit 421, the laser condenser 430, and the X-ray generators 440 may be fixed to each other. You can also move them together.

The second axis scanning unit 422 controls the interlocked devices to move a predetermined distance in the axial direction that is mechanically scanned.

In the embodiment of FIG. 11, as an example, the laser generating unit 410, the first axis scanning unit 421, the laser condenser 430, and the X-ray generating unit 440 are fixed to each other to move together, and the second axis scanning is performed. The unit 422 shows a configuration for controlling their movement.

12 is a flow chart illustrating a method of the present invention. For convenience of explanation, the following description will focus on the components shown in FIG. 10.

First, the laser generator 310 outputs a laser beam for generating X-rays (501).

At this time, the laser generating unit 310 preferably outputs the laser beam while monitoring whether the laser beam is output at a constant intensity using a value output from the photodiode 324 or the PIN photodiode 342.

The scanning unit 320 changes the output angle of the incident laser beam generated by the laser generator 310 and outputs it by changing a predetermined angle with time.

The time for changing the angle of the output laser beam may be a predetermined period, or may be changed by receiving a signal to change the angle from the X-ray measuring unit 370 or the X-ray image forming unit.

The X-ray measuring unit 370 or the X-ray image forming unit passes through a specific point of the sample and waits until the intensity of the input signal reaches a steady state and then moves to the next observation point of the sample. In order to observe the sample in a manner that gives a signal to change the angle of the laser beam output to the scanning unit 320 in order to.

On the other hand, the scanning unit 320 preferably receives a feedback on the position of the light source detected by the CCD 325 to correct the output angle of the laser beam so that the light source is generated in a predetermined correct position.

2 and 10, the scanning unit 320 refracts the laser beam to scan the X and Y axes in both the incident angle and the incident position of the laser condenser 330. In the case of FIG. 11, however, one axis is scanned by a method of refracting a laser beam by the first axis scanning unit 421, and the other axis is configured by the second axis scanning unit 422. As described above, the scan is performed by changing the position where the X-ray is irradiated to the sample fixed to the sample installation unit 160 by moving mechanically.

The laser beam output from the scanning unit 320 is collected at a point on the focal plane of the laser condenser 330 in which the X-ray generation target 341 is installed by the laser condenser 330 (503).

The focusing position of the laser beam is changed by the scanning unit 320 as the scanning angle of the laser beam changes. Specifically, the position focused on the X axis is determined by the product of the scanning angle in the X axis direction and the focal length, and the position focused on the Y axis is determined by the product of the scan angle in the Y axis direction and the focal length.

In the region where the focused laser beam is irradiated to the X-ray generation target 341, a plasma phenomenon occurs and X-rays are generated (504). That is, X-rays are generated at the position where the laser beam is focused.

The intensity of the generated X-rays is measured by the PIN photodiode 342 installed in the X-ray generator 340, and thus may be used to correct the intensity of the laser beam generated by the laser generator 310. It may be used to correct the X-ray transmission amount measured by 370.

The generated X-rays are incident on the X-ray condenser 350 formed of a Wolter mirror or the like and condensed at one point of the sample 370 located on the focal plane of the X-ray condenser 350.

The location where the light is focused depends on the location of the light source where the X-rays are generated. For example, when the reduction factor of the Wolter mirror used as the X-ray condenser is M, and the position on the X-axis where the X-ray is generated is Xx and the position on the Y-axis is Yy, the position on the X-axis of the X-rays focused on the sample is Xx. / M, and the position on the Y axis is Yy / M.

X-rays transmitted through the sample 370 are incident on the X-ray measuring unit 370, and the transmission amount thereof is measured by an electrical signal (506).

As described above, the measured value may be corrected by the value measured by the PIN photodiode 342 or the photodiode 324.

In operation 507, the scanning unit 320 adjusts the angle of the laser beam or positions the component generating the laser beam or the laser beam and X-rays. Move to the X-ray to the next observation point of the sample.

When the observation of the sample is completed, the X-ray image forming unit forms a value measured by the X-ray measuring unit 370 as a spatial image (507). The process of forming a spatial image may be performed at the same time after the observation at all points of the sample is completed, but may be performed whenever the observation at any one point is completed.

The preferred embodiment of the present invention has been described above by way of example. However, the protection scope of the present invention is not limited to the above-described embodiment, but is defined by the claims to be described later.

As described above, according to the present invention, in constructing an X-ray microscope having high resolution, an expensive two-dimensional CCD device capable of detecting X-rays or a high-precision transfer device is not required, and the size of the equipment can be miniaturized. There is an advantage.

Claims (5)

A laser generator for generating a laser beam; A scanning unit for outputting the output angle of the laser beam incident from the laser generator by changing a predetermined angle with time; A laser condenser for condensing the laser beam output from the scanning unit at a point on the ultracritical surface determined according to the incident angle of the laser beam; An X-ray generator having a predetermined X-ray generation target for generating X-rays on a focal plane of the laser-concentrator so that X-rays can be generated when the laser beam output from the laser-condenser is irradiated; An X-ray condenser for condensing X-rays generated by the X-ray generator at different positions on a focal plane according to the generated position; A sample installation unit installed on the ultra-short surface of the X-ray light collecting unit for installing a sample to be observed; An X-ray measuring unit installed at a rear end of the sample installing unit and converting the amount of X-rays transmitted and collected by the sample installed in the sample installing unit into an electrical signal; And And an X-ray image forming unit converting the electrical signal measured by the X-ray measuring unit into a spatial image signal as time passes. A laser generator for generating a laser beam; A first axis scanning unit for outputting the output angle of the laser beam incident from the laser generation unit by changing a predetermined angle in a first axis direction with time; A laser condenser for condensing the laser beam output from the first axis scanning unit at a point on the ultra-short surface determined according to the incident angle of the laser beam; An X-ray generator having a predetermined X-ray generation target for generating X-rays on a focal plane of the laser-concentrator so that X-rays can be generated when the laser beam output from the laser-condenser is irradiated; An X-ray condenser for condensing X-rays generated by the X-ray generator at different positions on a focal plane according to the generated position; A sample installation unit installed on the ultra-short surface of the X-ray light collecting unit for installing a sample to be observed; An X-ray measuring unit installed at a rear end of the sample installing unit and converting the amount of X-rays transmitted and collected by the sample installed in the sample installing unit into an electrical signal; An X-ray image forming unit converting the electrical signal measured by the X-ray measuring unit into a spatial image signal as time passes; And The laser condenser and the X-ray generator may be fixed to each other and moved together, a second axis scanning unit for moving the laser condenser and the X-ray generator in a second axis direction perpendicular to the first axis; X-ray microscope system, characterized in that. The method of claim 1 or 2, wherein the X-ray generator comprises a pin photodiode measuring the intensity of X-rays generated from the X-ray generation target, The X-ray image forming system converts the X-ray image forming unit into a spatial image signal by using a relative value of the intensity of the X-rays measured by the X-ray measuring unit in comparison with the intensity of the X-rays measured by the pin photodiode. . The method of claim 1, wherein the X-ray microscope system And a visible light source two-dimensional CCD for detecting a location where the X-rays are generated by using visible light generated when the X-rays are generated by the X-ray generator. The scanning unit X-ray microscope system, characterized in that for correcting the output angle of the laser beam using the X-ray generating position detected by the visible light source two-dimensional CCD. The method of claim 1 or 2, wherein the X-ray microscope system The X-ray microscope system is installed between the X-ray generation target and the X-ray light collecting unit, and further comprising a filter for passing only X-rays of a predetermined wavelength.

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