Analysis device, analysis method, and program

Abstract

To provide an analysis device, an analysis method, and a program, in which the time required to analyze the X-ray scattering intensity distribution is reduced.SOLUTION: An analysis device 100 according to an embodiment includes: a fusion part 110 that, if electron density patterns of a plurality of adjacent layers in orthogonal mesh data divided into the plurality of layers in a Z direction coincide, fuses the adjacent layers about the fused layer and calculates the layer information about the fused layer; and a calculation part 140 that calculates the scattering intensity distribution of the X-ray incident into a target structure expressed by the orthogonal mesh data from the Z direction on the basis of the layer information.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an analysis device, an analysis method, and a program. [Background technology]

[0002] Patent Document 1 discloses a technique for performing structural analysis of proteins using X-rays by using the maximum entropy method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3891338 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a need for a technology that can reduce the time required to analyze the distribution of scattered X-ray intensity.

[0005] The present invention has been made to solve such problems, and has an object to provide an analysis device, an analysis method, and a program that reduce the time required to analyze the scattering intensity distribution of X-rays. [Means for solving the problem]

[0006] An analysis device according to an embodiment includes: a fusion unit that calculates layer information for one layer obtained by fusing the multiple layers when it is detected that adjacent layers have the same electron density pattern in the orthogonal mesh data divided into multiple layers in the Z direction in which the X-rays are incident; a calculation unit that calculates a scattering intensity distribution of X-rays that hit a target structure represented by the orthogonal mesh data based on layer information related to the fused layer; Equipped with.

[0007] An analysis method according to an embodiment includes: a step of fusing adjacent layers when the electron density patterns of adjacent layers match in the orthogonal mesh data divided into a plurality of layers in the Z direction, and calculating layer information on the fusing layers; calculating a scattering intensity distribution of X-rays incident on a target structure represented by the orthogonal mesh data from the Z direction based on layer information on the fused layer; Includes.

[0008] In one embodiment, the program On the computer, a process of fusing adjacent layers when the electron density patterns of adjacent layers match in the orthogonal mesh data divided into a plurality of layers in the Z direction, and calculating layer information on the fusing layers; A process of calculating a scattering intensity distribution of X-rays incident on a target structure represented by the orthogonal mesh data from the Z direction based on layer information related to the fused layer; Execute the command. Effect of the Invention

[0009] The present invention can provide an analysis device, an analysis method, and a program that reduce the time required to analyze the scattering intensity distribution of X-rays. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram for explaining scattering vectors of X-rays applied to a target structure. [Diagram 2] FIG. 1 is a block diagram showing a configuration of an analysis device according to a first embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of a target structure represented by a rectangular parallelepiped mesh. [Figure 4] FIG. 2 is a diagram for explaining a state in which a plurality of layers are fused together by the analysis device according to the first embodiment. [Diagram 5] FIG. 4 is a diagram showing an example of list information indicating the electron density pattern of each layer. [Figure 6]FIG. 2 is a perspective view showing an example of a target structure represented by a rectangular parallelepiped mesh. [Figure 7] FIG. 1 is a diagram for explaining a verification result of the analysis method according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In addition, in each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary.

[0012] Consideration leading to the embodiment First, the circumstances by which the present inventor arrived at the invention according to the embodiment will be described. Fig. 1 is a diagram for explaining scattering vectors when a plane wave X-ray is applied to a target structure having periodicity. In the formulas in the following explanation, bold alphabets represent vectors. Since bold alphabets cannot be used in documents, normal formatting is used, and "(bold)" is added immediately after the relevant alphabet.

[0013] The wave vector of the X-ray is denoted as k (boldface), and the wave vector of the scattered wave is k s (boldface). The scattering vector q (boldface) is expressed as k s In this case, the scattering intensity distribution I(q(bold)) is expressed as the square of the three-dimensional Fourier transform equation obtained by solving the Schrödinger equation using the Born approximation, as shown in equation (1).

[0014]

number

[0015] If the incident X-ray has a spread represented by the distribution W(k (bold)), the scattered intensity distribution I smearI(q(boldface)) is calculated by the two-dimensional convolution integral of I(q(boldface)) and W(k(boldface)) as shown in equation (2). I smear While (q(bold)) is a two-dimensional convolution integral, I(q(bold)) is a three-dimensional Fourier transform. Therefore, the time it takes to compute I(q(bold)) is usually about 1 / 2 the time it takes to compute I(q(bold)). smear This is longer than the time it takes to calculate (q(bold)).

[0016]

number

[0017] In general, the above I(q (boldface)) is calculated for a target structure modeled as a combination of primitive shapes such as a rectangular parallelepiped or a cylinder, for which the 3D Fourier transform can be analytically solved. However, structural data obtained by process simulations and topography simulations that reflect physical processes generally cannot be expressed by primitive shapes alone, and must be expressed as a mesh. Furthermore, since it is not possible to analytically solve the integral (3D Fourier transform) for a structure expressed as a mesh, it is necessary to express the target structure as a sufficiently fine rectangular parallelepiped mesh and solve the numerical integral, which poses the problem of a long time required to analyze the X-ray scattering intensity distribution.

[0018] Therefore, the present disclosure provides an analysis device, an analysis method, and a program that reduce the time required to analyze the scattering intensity distribution when a plane wave X-ray is incident on a complex structure represented by a rectangular parallelepiped mesh.

[0019] EMBODIMENT 1 2 is a block diagram showing a configuration of the analysis device 100 according to the first embodiment. The analysis device 100 may be a computer device operated by a processor executing a program stored in a memory. The analysis device 100 may be composed of a plurality of computer devices. In this case, the components or functions constituting the analysis device 100 may be distributed and arranged in the plurality of computer devices. The plurality of computers may be connected via a network or directly connected via a cable or the like. As the processor, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an FPGA (field-programmable gate array), or the like may be used.

[0020] The analysis device 100 includes a fusion unit 110, a detection unit 120, an adjustment unit 130, a calculation unit 140, and a storage unit 150. The storage unit 150 is realized by a storage device accessible by the processor.

[0021] The fusion unit 110 detects whether the electron density patterns of adjacent layers match in orthogonal mesh data divided into multiple layers in the Z direction in which X-rays are incident. The fusion unit 110 may determine whether the electron density patterns match based on a threshold. For example, the fusion unit 110 compares the electron density of a mesh of one electron density pattern with the electron density of a corresponding mesh of the other electron density pattern. The fusion unit 110 may determine that the electron density patterns match when the number of meshes whose electron densities differ from the corresponding mesh is less than a threshold.

[0022] Then, the fusion unit 110 fuses adjacent layers together and calculates information about the fused layers (called layer information). The layer information indicates, for example, the coordinates and thickness of the layers in the Z direction.

[0023] The detection unit 120 detects that the electron density patterns of the non-adjacent layers match. The detection unit 120 may determine whether the electron density patterns match based on a threshold value, similar to the fusion unit 110. Specifically, the detection unit 120 detects that the non-adjacent electron density patterns match after the fusion unit 110 fuses the adjacent layers.

[0024] The adjustment unit 130 adjusts the thresholds used in the fusion unit 110 and the detection unit 120. The adjustment unit 130 may adjust the thresholds in response to an input from a user using, for example, a keyboard, a mouse, or the like.

[0025] The calculation section 140 calculates the scattering intensity according to the following formula (3): In formula (3), the results of a two-dimensional Fourier transform (for example, a fast Fourier transform) in the XY plane are added in the Z direction.

[0026]

number

[0027] The electron density pattern ρ k (x i ,y j) are consistent, calculations for multiple layers in equation (3) can be performed at once. In this case, z k and Δz k The coordinates and thickness of the merged layer in the Z direction may be substituted into . The calculation unit 140 performs calculations for the merged layer in one go based on the layer information calculated by the fusion unit 110. In equation (3), an analytical solution of the integral included in equation (1) is used for the Z direction, and the mesh width in the Z direction, i.e., the thickness of the layer, does not need to be thin.

[0028] In addition, even in non-adjacent layers, the electron density pattern ρ k (x i ,y j ) are consistent, the result of the two-dimensional Fourier transform, ρ k (q m ,q n Therefore, the calculation unit 140 calculates the same electron density pattern ρ k (x i ,y j ) the result of the two-dimensional Fourier transform ρ k (q m ,q n Specifically, the calculation unit 140 uses the calculation result ρ k (q m ,q n ) is written to the storage unit 150, and when performing calculations for a layer having a corresponding electron density pattern, the calculation result ρ k (q m ,q n ) from the storage unit 150. The calculation unit 140 may assign the two-dimensional Fourier transform of the electron density patterns of adjacent layers or the electron density patterns of non-adjacent layers to any of the multiple processor cores, and execute parallel processing with the multiple processor cores. One two-dimensional Fourier transform may be assigned to one processor core.

[0029] Next, the operation of the analysis device 100 will be specifically described with reference to Figures 3, 4, and 5. Figure 3 shows a target structure represented by a rectangular parallelepiped mesh. For simplicity, the target structure is represented in two dimensions. The up-down direction represents the Z direction, and the left-right direction represents the X direction or the Y direction. Meshes with the same hatching correspond to the same electron density. The target structure includes 20 layers from 0th to 19th.

[0030] The fusion unit 110 of the analysis device 100 detects that the electron density patterns in adjacent layers match. The fusion unit 110 detects that the electron density patterns in the first and second layers match. Then, the fusion unit 110 detects that the electron density patterns in the sixth and seventh layers match. Then, the fusion unit 110 detects that the electron density patterns in the eleventh to thirteenth layers match. Then, the fusion unit 110 detects that the electron density patterns in the fourteenth and fifteenth layers match. Then, the fusion unit 110 detects that the electron density patterns in the sixteenth to nineteenth layers match.

[0031] The merging unit 110 merges layers with matching electron density patterns and calculates layer information (e.g., thickness). Figure 4 shows the target structure after merging layers with matching electron density patterns. The number of layers included in the target structure has been reduced from 20 to 10. The layer information is included in the list information described below.

[0032] Next, the detection unit 120 of the analysis device 100 detects that the electron density patterns match in non-adjacent layers in Fig. 4. The detection unit 120 detects that the electron density patterns in the 0th, 2nd, 4th, 6th, and 8th layers match. Then, the detection unit 120 detects that the electron density patterns in the 1st, 3rd, 5th, 7th, and 9th layers match.

[0033] FIG. 5 is a diagram for explaining list information showing the detection result of the detection unit 120. For each layer in the target structure shown in FIG. 4, the coordinate Z, the thickness ΔZ, and the number ρ of the electron density pattern are shown. Pattern 0 represents the electron density patterns of the 0th, 2nd, 4th, 6th, and 8th layers in FIG. 4. Pattern 1 represents the electron density patterns of the 1st, 3rd, 5th, 7th, and 9th layers. Pattern 2 represents the electron density pattern of the 10th layer. According to the detection result of the detection unit 120, formula (4) is obtained from formula (3).

[0034]

number

[0035] Then, the calculation unit 140 calculates the scattering intensity distribution according to the formula (4). k1 (qm,qn)~ρ k3 When calculating (qm, qn), a fast Fourier transform is performed.

[0036] In the first embodiment, the fusion unit 110 reduces the number of layers from 20 to 1, thereby reducing the number of times the fast Fourier transform is performed from 20 to 11. Furthermore, by using the list shown in Fig. 5, the number of times the fast Fourier transform is performed is reduced to 3, and it is expected that the calculation speed will increase by 6.67 (=20 / 3) times.

[0037] The present inventors have studied the calculation of the scattering intensity distribution when X-rays are applied to the three-dimensional structure of an object shown in FIG. 6. In FIG. 6, the mesh is shown coarser than that of the structure actually used in the study. A rectangular parallelepiped hole is opened in a multilayer film 22 on a rectangular parallelepiped substrate 21. The substrate 21 and the multilayer film 22 are stacked in the Z direction. Meshes with the same hatching correspond to the same material, i.e., the same electron density.

[0038] In FIG. 6, the mesh is shown coarser than it actually is, but the target structure is divided into 4208 in the X direction, 1216 in the Y direction, and 5200 in the Z direction. x [1 / nm] and Y component q y The sampling points of [1 / nm] were set to 4208 and 1216, respectively. When the conventional technology was used, that is, when the formula (3) was used without fusing layers with matching electron density patterns or using the results of fast Fourier transform, the calculation time of the scattering intensity distribution was 1877 seconds. On the other hand, when the layers with matching electron density patterns were fusing and the results of fast Fourier transform were used, the calculation time of the scattering intensity distribution was 13 seconds. Therefore, even if the time of 41 seconds required to detect layers with matching electron density patterns is taken into consideration, the calculation speed according to the first embodiment is 34.8 times that of the conventional technology.

[0039] As shown in FIG. 7, the results of calculating the scattering intensity distribution using the conventional technique are consistent with the results of calculating the scattering intensity distribution using the first embodiment. For ease of viewing, the square root of the scattering intensity distribution is plotted for the main part of the scattering vector, and q x =q y The intensity at e = 0 is normalized to 1. For the entire area calculated, the maximum absolute value of the difference at each point between the calculation results according to the first embodiment and the calculation results according to the conventional technology is 1.16*e -71 and is small enough.

[0040] In the first embodiment, by fusing adjacent layers, the number of two-dimensional Fourier transforms can be reduced, and the calculation time can be reduced. In addition, by using information on non-adjacent layers with the same electron density distribution, the number of two-dimensional Fourier transforms can be further reduced, and the calculation time can be further reduced.

[0041] In the above examples, the program includes instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disc (DVD), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0042] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0043] 100 Analyzer 110 Fusion section 120 Detection unit 130 Adjustment section 140 Calculation section 150 Storage section 21 Substrate 22 Multilayer film

Claims

1. a fusion unit that, when electron density patterns of adjacent layers match each other in the orthogonal mesh data divided into a plurality of layers in the Z direction, fuses the adjacent layers and calculates layer information regarding the fused layers; a calculation unit that calculates a scattering intensity distribution of X-rays incident on a target structure represented by the orthogonal mesh data from the Z direction based on layer information related to the fused layer; An analysis device equipped with:

2. a detector for detecting coincidence of electron density patterns of non-adjacent layers; The calculation unit calculates the scattering intensity distribution further based on the detection result of the detection unit. The analysis device according to claim 1 .

3. The detection unit detects that the electron density patterns of the non-adjacent layers match after the fusion unit fuses the adjacent layers. The analysis device according to claim 2 .

4. When the electron density patterns of the non-adjacent layers match, the calculation unit writes a calculation result obtained by performing a two-dimensional Fourier transform on the electron density pattern into a storage device, and reads out the calculation result from the storage device when performing a calculation on a layer having the electron density pattern.

4. The analysis device according to claim 2 or 3.

5. The calculation unit assigns two-dimensional Fourier transform of the electron density patterns of the adjacent layers or the non-adjacent layers to any of a plurality of processor cores, and executes parallel processing in the plurality of processor cores. The analysis device according to claim 4.

6. an adjustment unit for adjusting a threshold value for determining whether the electron density patterns of the adjacent layers match and whether the electron density patterns of the non-adjacent layers match; The analysis device according to claim 2 or 3, further comprising:

7. a step of fusing adjacent layers when electron density patterns of adjacent layers match in the orthogonal mesh data divided into a plurality of layers in the Z direction, and calculating layer information for the fusing layers; calculating a scattering intensity distribution of X-rays incident on a target structure represented by the orthogonal mesh data from the Z direction based on layer information related to the fused layer; Analysis methods including:

8. On the computer, a process of fusing adjacent layers when the electron density patterns of adjacent layers match each other in the orthogonal mesh data divided into a plurality of layers in the Z direction, and calculating layer information for the fusing layers; A process of calculating a scattering intensity distribution of X-rays incident on a target structure represented by the orthogonal mesh data from the Z direction based on layer information related to the fused layer; A program that executes the following.

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