Analysis system

Abstract

The purpose of the present invention is to obtain depth information of a multilayer structure quickly and with high precision. The analysis system comprises the following steps: (a) irradiating a sample SAM including a multilayer structure with an electron beam (EB1) from a first direction, thereby obtaining a first image of the sample (SAM) observed from the first direction; (b) irradiating the sample SAM with an electron beam (EB1) from a second direction intersecting the first direction, thereby obtaining a second image of the sample (SAM) observed from the second direction; (c) using the first image, the second image, and information of the sample (SAM) including the number of layers of the multilayer structure, the thickness of one layer or the thickness of each layer of the multilayer structure, and the depth from the first layer of the multilayer structure, to obtain the depth information of the multilayer structure.

Description

Technical Field

[0001] The present invention relates to an analysis system, and more particularly to an analysis system capable of acquiring depth information of a multilayer structure included in a sample. Background Art

[0002] In recent years, semiconductor devices have been miniaturized. In particular, in semiconductor devices with three-dimensional structures, high density and large capacity have developed rapidly by combining with stacking technology. In the manufacturing process of semiconductor devices, in order to manage the size of multi-layer structured patterns, it is necessary to evaluate the final quality of the patterns in each layer. In addition, in order to improve the quality of semiconductor devices, the formation of vertical and uniform patterns is indispensable, requiring rapid and high-precision evaluation of pattern shapes.

[0003] As a method for evaluating the current situation, there are the following methods: a method of cutting a sample little by little using a focused ion beam (FIB) while observing the sample to obtain depth information of the pattern; or a method of observing a sample generated by mechanical grinding using a charged particle beam device, predicting the inclination angle of the grinding surface, and thereby obtaining depth information of the pattern, etc.

[0004] For example, Patent Document 1 discloses a technique in which a sample is processed into a conical shape using FIB, a surface observation image of the formed slope is obtained using an electron microscope, and the depth of the pattern is calculated based on the starting position of the descending slope, the scanning distance of the electron beam, and the tilt angle.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2016 / 002341 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In the method using FIB, it is possible to evaluate the pattern with high precision, but there are problems such as narrow processing area, time-consuming evaluation, and difficulty in re-acquiring data. In addition, in the method of predicting the inclination angle of the grinding surface, although rapid evaluation can be performed, the depth information of the pattern can only be calculated by prediction, so there are problems such as low precision of the evaluation value of the pattern.

[0010] That is, a technology capable of quickly and accurately acquiring depth information of a multilayer structure without using FIB is required.

[0011] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0012] Means for solving problems

[0013] The outline of a typical embodiment among the embodiments disclosed in the present application will be briefly described as follows.

[0014] An analysis system in one embodiment comprises the following steps: (a) irradiating a sample including a multilayer structure with an electron beam from a first direction, thereby obtaining a first image of the sample observed from the first direction; (b) irradiating the sample with the electron beam from a second direction intersecting the first direction, thereby obtaining a second image of the sample observed from the second direction; (c) obtaining depth information of the multilayer structure using the first image, the second image, and information about the sample including the number of layers of the multilayer structure, the thickness of one layer or the thickness of each layer of the multilayer structure, and the depth from the first layer of the multilayer structure.

[0015] In addition, an analysis system in one embodiment comprises the following steps: (a) obtaining a first image of the sample observed from the first direction by irradiating an electron beam to the sample including a multilayer structure from the first direction; (b) specifying an observation range in the first image; (c) focusing the electron beam in the first direction on multiple parts of the sample using an objective lens within the specified observation range; (d) obtaining the distances between the objective lens and the focal position of the multiple parts of the sample based on the focusing result of the step (c), and generating a WD characteristic curve that graphs these distances; and (e) comparing information of the sample including the number of layers of the multilayer structure, the thickness of one layer or the thickness of each layer of the multilayer structure, and the depth from the first layer of the multilayer structure with the WD characteristic curve to obtain depth information of the multilayer structure.

[0016] Effects of the Invention

[0017] According to one embodiment, depth information of a multilayer structure can be acquired quickly and with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram showing an example of the charged particle beam device in the first embodiment.

[0019] Figure 2Aa This is a plan view of the sample in Implementation Example 1.

[0020] Figure 2Ba This is a cross-sectional view of the sample in Implementation Example 1.

[0021] Figure 2Ab This is a plan view of the sample in Implementation Example 1.

[0022] Figure 2Bb This is a cross-sectional view of the sample in Implementation Example 1.

[0023] Figure 3 This is a flowchart of the analysis system in Implementation Method 1.

[0024] Figure 4 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0025] Figure 5 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0026] Figure 6 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0027] Figure 7 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0028] Figure 8 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0029] Fig. 9 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0030] Fig.10 This is a record table showing a record example of each information in the first embodiment.

[0031] Fig.11 This is a schematic diagram showing an operation screen in Implementation Example 1.

[0032] Fig.12 This is a captured image and a record table of pattern analysis in the first embodiment.

[0033] Fig.13 This is a flowchart of the analysis system in Implementation Method 2.

[0034] Fig.14 This is a flowchart of the analysis system in Implementation Method 3.

[0035] Fig.15 This is a schematic diagram showing an operation screen in Implementation Example 3.

[0036] Fig.16 This is a schematic diagram showing an operation screen in Implementation Example 3.

[0037] Fig.17 This is a schematic diagram showing an operation screen in Implementation Example 3.

[0038] Fig.18 This is a record table showing a record example of each information in Implementation Example 3.

[0039] Fig.19This is a schematic diagram showing an operation screen in Implementation Example 1.

[0040] Fig. 20 This is a schematic diagram showing an example of a surface shape measuring device in a fourth embodiment.

[0041] Fig.21 This is a flowchart of the analysis system in Implementation Method 4.

[0042] Fig. 22 This is a schematic diagram showing an operation screen in Implementation Example 4. DETAILED DESCRIPTION

[0043] Hereinafter, the embodiments are described in detail based on the accompanying drawings. In addition, in all the drawings used to illustrate the embodiments, the same reference numerals are used for components having the same functions, and their repeated descriptions are omitted. In addition, in the following embodiments, the description of the same or identical parts is not repeated in principle except when particularly necessary.

[0044] In addition, the X direction, Y direction, and Z direction described in the present application intersect each other and are orthogonal to each other. In the present application, the Z direction may also be described as the up-down direction, height direction, or thickness direction of a certain structure.

[0045] (Implementation Method 1)

[0046] The following describes the analysis system in Implementation 1. Figure 1 The charged particle beam device 1 constituting a part of the analysis system will be described. Figure 1 In FIG. 1 , a scanning electron microscope (SEM) is exemplified as the charged particle beam device 1 .

[0047] <Structure of the charged particle beam device>

[0048] Figure 1 The charged particle beam device 1 shown is a device for analyzing (observing, measuring) the sample SAM by irradiating an electron beam EB1 from an electron gun 3 provided inside a column 2 to a sample SAM arranged in a sample chamber 7 .

[0049] The charged particle beam device 1 includes a sample chamber 7 and a column 2 installed in the sample chamber 7 and constituting an electron beam column. The column 2 includes an electron gun 3 capable of irradiating an electron beam EB1, a condenser lens 4 for focusing the electron beam EB1, a deflection coil 5 for scanning the electron beam EB1, and an objective lens 6 for focusing the electron beam EB1.

[0050] A sample stand (holder) 8 for mounting a sample SAM, a stage 9 for installing the sample stand 8, a stage controller 10, and a detector 11 are provided inside the sample chamber 7. Although not shown, an inlet / outlet port is provided inside the sample chamber 7.

[0051] When analyzing the sample SAM, the sample table 8 carrying the sample SAM is transported into the sample chamber 7 through the introduction / export port and set on the workbench 9. When taking out the sample SAM, the sample table 8 carrying the sample SAM is transported outside the sample chamber 7 through the introduction / export port.

[0052] The stage control device 10 is connected to the stage 9 and can displace the position and orientation of the stage 9. The displacement of the stage 9 displaces the position and orientation of the sample SAM.

[0053] The workbench control device 10 has an XY axis drive mechanism that can be driven in a direction parallel to the loading surface of the charged particle beam device 1, a Z axis drive mechanism that can be driven in a direction perpendicular to the loading surface, an R axis drive mechanism that can be driven in a rotational direction, and a T axis drive mechanism that can be driven in a direction inclined relative to the XY plane. These drive mechanisms are mechanisms used to analyze the sample SAM set on the workbench 9 and any part of the sample table 8. As a result, the part of the sample SAM that becomes the analysis object moves to the center of the shooting field of view and tilts in any direction.

[0054] When the sample SAM is irradiated with the electron beam EB1 during analysis of the sample SAM, the detector 11 can detect secondary electrons EM2 emitted from the sample SAM. The detector 11 may be provided inside the sample chamber 7 or inside the column 2.

[0055] In addition, the charged particle beam device 1 includes an integrated control unit C0, and a display device 20 and an operating device 21 electrically connected to the integrated control unit C0 are provided outside or inside the charged particle beam device 1. The display device 20 is, for example, a display, and the operating device 21 is, for example, a mouse and a keyboard. A user uses the operating device 21 to perform operations on the display device 20, so that various information is input to the integrated control unit C0 or output from the integrated control unit C0.

[0056] The integrated control unit C0 includes a scanning signal control unit C1, a workbench control unit C2, and a computing unit C3, and controls them collectively. Therefore, in this application, it is sometimes described that the integrated control unit C0 performs the control performed by the scanning signal control unit C1, the workbench control unit C2, and the computing unit C3. In addition, the integrated control unit C0 including the scanning signal control unit C1, the workbench control unit C2, and the computing unit C3 is sometimes regarded as a control unit, and the integrated control unit C0 is simply referred to as a "control unit".

[0057] Scan signal control unit C1 is electrically connected to electron gun 3, condenser lens 4, deflection coil 5 and objective lens 6 to control their operations. Electron gun 3 generates electron beam EB1 upon receiving a control signal from scan signal control unit C1 and irradiates electron beam EB1 toward sample SAM.

[0058] The focusing lens 4, the deflection coil 5, and the objective lens 6 receive control signals from the scanning signal control unit C1 and excite the magnetic field. The electron beam EB1 is focused to an appropriate beam diameter by the magnetic field of the focusing lens 4. The electron beam EB1 is deflected by the magnetic field of the deflection coil 5 and performs a two-dimensional scan on the sample SAM. The electron beam EB1 is focused again on the sample SAM by the magnetic field of the objective lens 6.

[0059] Furthermore, by controlling the objective lens 6 through the scanning signal control unit C1 and adjusting the excitation intensity of the objective lens 6, the electron beam EB1 can also be focused on the sample SAM.

[0060] The stage control unit C2 is electrically connected to the stage control device 10 , and has a function of controlling the operation of each driving mechanism of the stage control device 10 so that the field of view and the coordinates of the stage 9 are always linked.

[0061] The calculation unit C3 includes an image acquisition unit C4 , an image combination unit C5 , an instruction input unit C6 , a storage unit C7 , and a pattern shape analysis unit C8 .

[0062] The image acquisition unit C4 is electrically connected to the detector 11 and controls its operation. In addition, the image acquisition unit C4 processes the secondary electrons EM2 detected by the detector 11 as a signal and can convert the signal into a captured image (image data). The captured image is output to the display device 20, and the user can confirm the captured image on the display device 20.

[0063] The image combining unit C5 combines the above-mentioned captured images acquired by the image acquiring unit C4, and can produce, for example, Figure 6 The wide area image is output to the display device 20 , and the user can check the wide area image on the display device 20 .

[0064] The instruction input unit C6 receives information input by the user on the display device 20 using the operation device 21. The storage unit C7 can store information such as the coordinates of the work table 9 and the acquired captured image (image data). In addition, each piece of information is related to each other.

[0065] The pattern shape analyzing unit C8 has a function of analyzing a plurality of pattern shapes included in the sample SAM.

[0066] The calculation unit C3 can perform calculations related to the stage coordinates, pattern shape analysis, multilayer structure depth information, etc., as described later, using the information received by the instruction input unit C6 and the information stored in the storage unit C7.

[0067] <Structure of sample SAM>

[0068] Figure 2Aa as well as Figure 2Ab This is a plan view of the sample SAM in embodiment 1. Figure 2Ba So along the Figure 2Aa A cross-sectional view of the sample SAM cut at the observation plane 30 along the AA line. Figure 2Bb So along the Figure 2Ab This is a cross-sectional view of the sample SAM cut at the observation plane 30 along the BB line.

[0069] The sample SAM in the first embodiment is, for example, a thin slice obtained from a part of a wafer on which various semiconductor devices are formed. Therefore, the sample SAM includes a semiconductor substrate, semiconductor elements such as transistors formed on the semiconductor substrate, a highly integrated large-scale integrated circuit (LSI) device composed of a plurality of transistors, a multilayer wiring layer including a plurality of gate electrodes, and an interlayer insulating film formed therebetween.

[0070] The sample SAM has an upper surface TS and a lower surface BS opposite to the surface TS. A part of the sample SAM is subjected to a grinding process by a grinding device such as an ion milling device, FIB, or a dimple grinder. Figure 2Aa and Figure 2Ba A diagram showing a sample after being milled by an ion milling device or FIB. Figure 2Ab and Figure 2Bb A diagram showing the SAM of a sample after being milled by an ion milling device or a dimple mill.

[0071] like Figure 2Aa , Figure 2Ba , Figure 2Ab as well as Figure 2Bb As shown, by this polishing process, an observation surface (polished surface) 30 which is an inclined surface is formed on a part of the upper surface TS of the sample SAM.

[0072] In addition, Figure 2Aa and Figure 2Ab 3 shows an enlarged view of a portion of the sample SAM including the observation surface 30. The sample SAM includes a plurality of patterns 32. The plurality of patterns 32 are semiconductor devices having, for example, a cylindrical structure extending in the Z direction. In addition, the plurality of patterns 32 are structures such as wiring or transistors of LSI having a multilayer structure.

[0073] exist Figure 2Ba as well as Figure 2Bb In the figure, a plurality of conductor layers such as the above-mentioned multilayer wiring layers are shown as a multilayer structure 31. That is, the sample SAM includes a plurality of conductor layers stacked in a direction from the upper surface TS of the sample SAM toward the lower surface BS of the sample SAM, that is, in a first direction (Z direction) as the multilayer structure 31. In addition, although not shown in detail here, the multilayer structure 31 is formed around the plurality of patterns 32.

[0074] When viewed in section, the observation surface 30 is inclined from the upper surface TS of the sample SAM toward the lower surface BS of the sample SAM. More specifically, when viewed in section, the observation surface 30 forms an inclined surface that is continuously inclined from the upper surface TS toward the lower surface BS. The grinding process performed by the grinding device is performed in a manner that all layers of the multilayer structure 31 are ground, and the bottom of the observation surface 30 is located at a position deeper than the lowest layer of the multilayer structure 31. Therefore, all layers of the multilayer structure 31 are exposed on the observation surface 30 and the cut surface.

[0075] <Analysis system>

[0076] Below, we will Figure 3 The steps S1-S16 shown in the flowchart are Figure 4-Figure 10 By comparison, the analysis system in Implementation Method 1 is described.

[0077] In addition, as described below, as a method for measuring the sample SAM, the analysis system includes a step performed in a polishing device, a step performed in a sample preparation device, and a step performed in the charged particle beam device 1. Therefore, not only the charged particle beam device 1 but also these polishing devices and sample preparation devices constitute a part of the analysis system.

[0078] In step S1, a sample SAM is prepared. First, a sample preparation device such as a diamond cutter is used to cut out a portion of a wafer, thereby preparing a sample SAM. Next, the cut sample SAM is transported from the sample preparation device to a grinding device. The grinding device is, for example, an ion milling device, a FIB, or a pit grinder.

[0079] Next, the upper surface TS of the sample SAM is polished using a polishing device, thereby forming an observation surface 30 on a portion of the upper surface TS. Next, the polished sample SAM is transferred from the polishing device to a sample preparation device, such as a FIB or an ion milling device.

[0080] Next, the sample SAM is cut at the observation surface 30 by the sample preparation device, thereby preparing Figure 2Ba or Figure 2Bb After that, the cut sample SAM is placed on the sample stand 8 .

[0081] The following uses Figure 2Aa and Figure 2Ba The case of the sample SAM shown is described below, but when using Figure 2Ab and Figure 2Bb The same method can be implemented also in the case of the sample SAM shown.

[0082] In step S2, the sample SAM is set. First, the sample stage 8 carrying the sample SAM is transported from the sample preparation device to the charged particle beam device 1. Next, the sample stage 8 carrying the sample SAM is set on the workbench 9 in a manner such that the upper surface TS of the sample SAM faces the electron gun 3. Thus, the upper surface TS including the observation surface 30 is configured to be perpendicular to the Z direction.

[0083] In step S3, the application is started. The user uses the operating device 21 to operate on the display device 20 to start the application. When the application is started, Figure 4 As shown, an operation screen 40a is displayed on the display device 20. The operation screen 40a is mainly used for the user to input instructions to the integrated control unit C0 and for the user to obtain various information from the integrated control unit C0.

[0084] On the operation screen 40 a , the user can switch the display unit 41 for wide area image capturing, the display unit 42 for depth information acquisition, and the display unit 70 for pattern analysis.

[0085] The wide area image capturing display unit 41 includes a captured image display unit 43, a condition display unit 44, a capture button B1, a reference button B2, a position specification tool addition button B3, and a wide area image generation start button B4.

[0086] The capture button B1 is used when the sample SAM is irradiated with an electron beam EB1 to obtain a captured image. The reference button B2 is used when a captured image captured in the past is output to the captured image display unit 43. The position designation tool addition button B3 is used when adding an observation range 45 described later. The wide-area image generation start button B4 is used when continuous shooting is performed in order to generate a wide-area image in step S6 described later.

[0087] The condition display unit 44 displays shooting conditions such as the start point coordinates, the end point coordinates, the magnification, and the number of shots. The condition display unit 44 also includes a button B5 for determining shooting conditions and a button B6 for setting more detailed shooting conditions.

[0088] In step S4, alignment is performed and a captured image observed from the first direction (Z direction), i.e., an overall image, is obtained. First, the user performs alignment including focusing of the electron beam EB1 relative to the sample SAM and changing the magnification. Then, the user clicks the capture button B1, irradiating the sample SAM with the electron beam EB1 from the first direction (Z direction), and obtaining an overall image including the observation surface 30.

[0089] like Figure 4 As shown in FIG. 1 , the acquired whole image observed from the first direction (Z direction) is output from the integrated control unit C0 to the captured image display unit 43. Thus, the user can grasp the outline of the sample SAM.

[0090] In step S5, the shooting conditions are set. Figure 5 As shown, the user drags, for example, a mouse as the operating device 21 in the captured image display unit 43 to designate an observation range 45 in the overall image including the observation surface 30. The integrated control unit C0 converts the designated observation range 45 into position coordinates of the sample SAM, and outputs the start point coordinates and the end point coordinates to the condition display unit 44.

[0091] Here, by the user clicking the button B3 for adding a position designation tool, it is possible to additionally designate an observation range 45. For example, it is possible to add another observation range 45 that is shifted in the Y direction with respect to the observation range 45 selected initially.

[0092] Next, the user inputs the shooting conditions such as the magnification and the number of shots in the condition display unit 44, and clicks the button B4 for starting the wide-area image generation. The integrated control unit C0 receives the input shooting conditions and starts continuous shooting for generating a plurality of shots of the sample SAM observed from the first direction (Z direction).

[0093] In step S6, the user clicks the B4 button to obtain a wide-area image of the sample SAM observed from the first direction (Z direction). First, the upper surface TS (observation surface 30) of the sample SAM set on the workbench 9 is irradiated with an electron beam EB1 in the first direction (Z direction).

[0094] Next, the detector 11 detects the secondary electrons EB2 released from the sample SAM as a signal. Next, in the image acquisition unit C4 of the integrated control unit C0, based on the detected signal, a captured image observed from the first direction (Z direction) is acquired. By sequentially performing these operations on the observation object within the observation range 45, a plurality of captured images are acquired.

[0095] Then, if Figure 6 As shown, the image combining unit C5 of the integrated control unit C0 combines the plurality of captured images acquired in step S5 to generate a wide area image viewed from the first direction (Z direction). The generated wide area image is output to the captured image display unit 43.

[0096] That is, in the integrated control unit C0 , a plurality of captured images and a wide-area image are acquired based on the above-mentioned signal detected by the detector 11 .

[0097] Furthermore, the integrated control unit C0 can associate the coordinates of the captured image with the coordinates of the stage 9. Therefore, the user can confirm the coordinate information of the target observation position, etc. In addition, these coordinates are stored in the storage unit C7 of the integrated control unit C0.

[0098] In addition, in step S6, the creation of a wide-area image is a prerequisite, but depending on the sample, there is a case where the creation of a wide-area image is not necessary and only one or several parts can be photographed. In this case, only the starting point coordinates are displayed on the condition display unit 44, and the end point coordinates are not displayed. The following description of the creation of a wide-area image also includes the case of photographing one or several parts.

[0099] In step S7, the reference coordinates are specified. Figure 6 As shown, in the captured image display unit 43, the user clicks on the first part of the multilayer structure 31 exposed in the observation surface 30. The first part is, for example, the first layer of the multilayer structure 31. As a result, the integrated control unit C0 specifies the first part as the reference coordinates (x1, y1) 46a observed from the first direction (Z direction) in the wide-area image. The specified reference coordinates (x1, y1) 46a are stored in the storage unit C7.

[0100] In the present application, the first layer of the multilayer structure 31 is the layer closest to the upper surface TS of the sample SAM, and corresponds to the uppermost layer of the multilayer structure 31. The same applies to the case where it is expressed as "the first layer of the multilayer structure 31" in the following description.

[0101] In addition, if Figure 6 As shown, if the sample can clearly confirm the multi-layer structure, it is easy to specify a layer suitable as a starting point, such as the first layer of the multi-layer structure, as the reference coordinate. However, depending on the sample, it is also conceivable that the multi-layer structure cannot be clearly confirmed. In this case, for example, the position of a specific pattern or the position of a structure having another shape can be specified as the reference coordinate (x1, y1) 46a.

[0102] In step S8, the sample SAM is tilted. A control signal is transmitted from the workbench control unit C2 of the integrated control unit C0 to the workbench control device 10, so that the T-axis drive mechanism of the workbench control device 10 is driven. That is, the workbench control device 10 is controlled in such a way that the cross-section of the sample SAM is opposed to the electron gun 3 in the second direction intersecting the first direction, so that the workbench 9 provided with the sample SAM is tilted. Thus, the user can observe the cross-section of the sample SAM from the second direction (Y direction). Here, the workbench 9 is tilted 90 degrees, and the first direction (Z direction) is orthogonal to the second direction (Y direction).

[0103] In addition, here, the first direction is described as the Z direction and the second direction is described as the Y direction, but the first direction and the second direction are not limited to the Z direction and the Y direction, and any direction may be any direction that intersects with each other.

[0104] In addition, in terms of the performance of the charged particle beam device 1, there is a case where the driving range of the T-axis driving mechanism of the stage control device 10 is less than 90 degrees. In this case, the user takes out the sample stage 8 carrying the sample SAM from the sample chamber 7, removes the sample SAM from the sample stage 8, places the sample SAM on the sample stage 8 again while tilting the sample SAM by 90 degrees, and returns the sample stage 8 carrying the sample SAM to the sample chamber 7.

[0105] In step S9 , alignment and acquisition of a captured image of the sample SAM observed from the second direction (Y direction), that is, a cross-sectional image, are performed in the same manner as in step S4 . The acquired cross-sectional image is output from the integrated control unit C0 to the captured image display unit 43 .

[0106] In step S10 , the reference coordinates are linked. First, the user switches the operation screen 40 a from the display unit 41 for wide area image capturing to the display unit 42 for depth information acquisition.

[0107] like Figure 7As shown, in the display unit 42 for acquiring depth information, a captured image display unit 43, a capture button B1, a reference button B2, and a position designation tool addition button B3 are provided, similarly to the display unit 41 for capturing wide-area images. In addition, a movement condition display unit 47 and a layer information display unit 48 are provided in the display unit 42 for acquiring depth information.

[0108] The movement condition display unit 47 is provided with a button B7 for moving to the reference position, a button B8 for linking to the first direction, and a button B9 for moving to the X coordinate. In addition, the layer information display unit 48 can display layer information such as the number of layers, the thickness of one layer, and the depth from the first layer.

[0109] like Figure 7 As shown, the cross-sectional image of the sample SAM observed from the second direction (Y direction) obtained in step S9 is displayed on the image display unit 43. When the user clicks button B7, the workbench control unit C2 of the integrated control unit C0 moves the workbench control device 10 so that the workbench 9 is located at the X coordinate x1 of the reference coordinate (x1, y1) 46a. The X coordinate position 49 of the workbench 9 after the movement is displayed on the image display unit 43.

[0110] Next, the user clicks the multilayer structure 31 at a position overlapping with the X-coordinate position 49 in the captured image display unit 43, thereby designating the Z coordinate z1 serving as the reference in the second direction (Y direction). That is, the user clicks the second portion of the multilayer structure 31 exposed on the observation plane 30 and corresponding to the coordinate x1 of the reference coordinate (x1, y1) 46a in the cross-sectional image, thereby designating the Z coordinate z1 serving as the reference in the second direction (Y direction).

[0111] Next, when the user clicks button B8, the integrated control unit C0 designates the second part as reference coordinates (x1, z1) 46b in the cross-sectional image, and makes reference coordinates (x1, y1) 46a correspond to reference coordinates (x1, z1) 46b. In addition, the correspondence between reference coordinates (x1, z1) 46b, reference coordinates (x1, y1) 46a, and reference coordinates (x1, z1) 46b is stored in the storage unit C7.

[0112] In step S11, the observation coordinates (x2, y2) 46c are designated and the workbench 9 is moved. First, when the user clicks, for example, the reference button B2, the integrated control unit C0 causes the captured image display unit 43 to display the wide-area image ( ) observed from the first direction (Z direction) obtained in step S6. Figure 6 ).

[0113] Next, in the captured image display unit 43, the user clicks on the third portion of the multilayer structure 31 exposed in the observation plane 30. The third portion is a portion different from the first portion, for example, a layer different from the first layer of the multilayer structure 31. Thus, the integrated control unit C0 specifies the third portion as the observation coordinate (x2, y2) 46c observed from the first direction (Z direction) in the wide-area image.

[0114] like Figure 8 As shown, the integrated control unit C0 causes the movement condition display unit 47 to display the X coordinate x2 of the designated observation coordinate (x2, y2) 46c. Next, when the user clicks the button B9 for movement, the table control unit C2 of the integrated control unit C0 causes the table control device 10 to move so that the table 9 is located at the X coordinate x2 of the observation coordinate (x2, y2) 46c.

[0115] Fig. 9 Indicated in Figure 8 The operation screen 40a after the workbench 9 is moved. Fig. 9 As shown in FIG. 1 , the X-coordinate position 49 of the worktable 9 after the movement is displayed on the captured image display unit 43 .

[0116] Next, the user specifies the Z coordinate z2 by clicking the multilayer structure 31 at a position overlapping the X coordinate position 49 in the captured image display unit 43. That is, the user specifies the Z coordinate z2 by clicking the fourth portion of the multilayer structure 31 that is exposed on the observation plane 30 and corresponds to the coordinate x2 of the observation coordinate (x2, y2) 46c in the cross-sectional image.

[0117] The integrated control unit C0 designates the fourth portion as observation coordinates (x2, z2) 46d in the cross-sectional image and stores the corresponding relationship between observation coordinates (x2, y2) 46c and observation coordinates (x2, y2) 46c and observation coordinates (x2, z2) 46d in the storage unit C7.

[0118] Next, when the user clicks the button B9, the integrated control unit C0 moves the worktable 9 toward the designated observation coordinates (x2, z2) 46d.

[0119] In step S12, alignment is performed. The user performs focusing of the electron beam EB1 on the sample SAM and changes the magnification, etc., in order to perform detailed observation of the target observation coordinate (x2, z2) 46d.

[0120] In step S13, the image viewed from the second direction (Y direction) is acquired. After step S12, the user clicks the capture button B1 to capture the image, and the image viewed from the second direction (Y direction) is acquired. The acquired image is stored in the storage unit C7.

[0121] In addition, step S12 and step S13 are not essential from the viewpoint of obtaining the depth information of the multilayer structure 31 , and may be omitted.

[0122] In step S14, depth information of the multilayer structure 31 is obtained. When the user clicks the button B10 for obtaining depth information, the calculation unit C3 of the integrated control unit C0 calculates the depth (distance in the Z direction) of the observation coordinate (x2, z2) 46d from the reference coordinate (x1, z1) 46b.

[0123] The user inputs information of the sample SAM including the number of layers of the multilayer structure 31 , the thickness of one layer or each layer of the multilayer structure 31 , and the depth from the first layer of the multilayer structure 31 into the layer information display unit 48 .

[0124] In addition, by comparing the input information with the calculation result of the depth of the observation coordinate (x2, z2) 46d from the reference coordinate (x1, z1) 46b, the calculation unit C3 of the integrated control unit C0 calculates the number of layers of the observation coordinate (x2, z2) 46d from the reference coordinate (x1, z1) 46b.

[0125] Here, when the reference coordinate (x1, z1) 46b is located in the first layer of the multilayer structure 31, the calculation unit C3 of the integrated control unit C0 calculates the depth and the number of layers of the observation coordinate (x2, z2) 46d from the upper surface TS of the sample SAM. In other words, the calculation unit calculates the layer of the multilayer structure 31 in which the observation coordinate (x2, z2) 46d is located.

[0126] In this way, the wide-area image and the cross-sectional image are used to obtain the depth information of the multilayer structure 31. That is, the depth information of the multilayer structure 31 includes the depth and the number of layers of the observation coordinate (x2, z2) 46d from the reference coordinate (x1, z1) 46b, and the depth and the number of layers of the observation coordinate (x2, z2) 46d from the upper surface TS of the sample SAM. In addition, this information is stored in the storage unit C7.

[0127] Then, in step S15, it is determined whether to observe other observation coordinates. If observation of other observation coordinates is not performed (No), the next step is step S16. If observation of other observation coordinates is performed (Yes), steps S11 to S14 are repeated. The integrated control unit C0 can assign depth information to all target observation coordinates at the nanometer level.

[0128] In addition, the coordinates obtained in steps S1 to S15 and the depth information of the multilayer structure 31 are recorded as Fig.10 Such a record table is stored in the storage unit C7.

[0129] According to the technology disclosed in the first embodiment as described above, by linking the coordinates of the wide-area image observed from the first direction (Z direction) and the cross-sectional image observed from the second direction (Y direction), the worktable 9 is moved from the reference coordinates to the observation coordinates, thereby acquiring the depth information of the multilayer structure 31. In addition, the user can directly obtain the depth information of the multilayer structure 31 at the nanometer level.

[0130] As other means for obtaining the depth information of the multilayer structure 31, there are means using FIB or means predicting the inclination angle of the grinding surface. However, the means using FIB has problems such as a narrow processing area, time-consuming evaluation, and difficulty in retrieving data. The means predicting the inclination angle of the grinding surface has problems such as low accuracy of the depth information.

[0131] Compared with the unit using FIB, the analysis system of embodiment 1 can be performed in a wide area and in a short time, and the data can be easily obtained again. In addition, compared with the unit predicting the inclination angle of the grinding surface, the analysis system of embodiment 1 can obtain high-precision depth information. That is, in the analysis system of embodiment 1, the depth information of the multilayer structure 31 can be obtained quickly and with high precision.

[0132] In step S16, the plurality of patterns 32 included in the sample SAM are analyzed. First, the user switches the operation screen 40a from the display unit 42 for acquiring depth information to the display unit 70 for pattern analysis.

[0133] like Fig.11 As shown, the pattern analysis display unit 70 is provided with the captured image display unit 43, the image reading setting unit 71, the pattern detection button B19 and the pattern analysis button B20. In addition, the image reading setting unit 71 is provided with the reading button B17 and the reference button B18.

[0134] In the image reading setting section 71, the user inputs the number of layers or depth of the sample SAM, and by clicking the reading button B17, the integrated control section C0 performs an image at the input position, i.e., the observation coordinates (x3, y3, z3) 46e, based on the depth information of the multilayer structure 31 acquired in step S14, and displays the captured image on the captured image display section 43. In addition, the user can click the reference button B18 to select a previously acquired image.

[0135] Next, when the user clicks the button B19 for pattern detection, the integrated control unit C0 detects the plurality of patterns 32 using image recognition technology, assigns numbers to the plurality of patterns 32 , and displays the numbers on the captured image display unit 43 .

[0136] Next, when the user clicks the button B20 for pattern analysis, the pattern shape analysis unit C8 automatically measures the diameter of each of the plurality of patterns 32 in the observation coordinate (x3, y3, z3) 46e using image recognition technology. Then, the pattern shape analysis unit C8 obtains pattern shape information such as the major axis diameter, minor axis diameter, average diameter, and roundness for each of the plurality of patterns 32. This pattern shape information is stored in the storage unit C7.

[0137] The observation coordinates (x3, y3, z3) 46e described here represent the coordinates of the center position of the captured image being observed. Therefore, the calculated number of layers also represents the number of layers at the center position of the captured image being observed.

[0138] The integrated control unit C0 records the acquired pattern shape information as a record table, such as Fig.12 As shown, it is possible to output a record table together with the observed photographic image. In addition, such pattern shape information is associated with other information and recorded in Fig.10 in the record table.

[0139] As described above, according to the analysis system of the first embodiment, it is possible to obtain not only the depth information of the multilayer structure 31 but also the pattern shape information of the plurality of patterns 32 included in the sample SAM.

[0140] (Implementation Method 2)

[0141] Below, use Fig.13 , the analysis system of the second embodiment is described. In addition, the following mainly describes the differences from the first embodiment.

[0142] In embodiment 2, the timing of forming the cross-section of the sample SAM is different from that in embodiment 1. The cross-section of the sample SAM is formed after obtaining a wide-area image from a first direction (Z direction), specifying reference coordinates (x1, y1) 46a, and specifying observation coordinates (x2, y2) 46c.

[0143] Below, use Fig.13 The analysis system in Implementation Example 2 is described with reference to each step S21-S40 shown in the flowchart.

[0144] In step S21, the observation surface 30 of the sample SAM is formed by the same method as step S1. Figure 2Aa or Figure 2Ab In this state, the sample SAM is mounted on the sample stand 8.

[0145] In steps S22 to S27, the same operations as steps S2 to S7 are performed. The integrated control unit C0 acquires a wide-area image of the sample SAM observed from the first direction (Z direction), and specifies the reference coordinates (x1, y1) 46a in the wide-area image.

[0146] In step S28, the observation coordinates (x2, y2) 46c are designated before the reference coordinates (x1, z1) 46b are designated. Figure 6 The reference coordinates (x1, y1) 46a shown are designated, and Figure 8 The designation of the observation coordinates (x2, y2) 46c is shown.

[0147] In step S29, the sample SAM is taken out. First, the sample SAM is taken out from the sample chamber 7, and then the sample SAM is taken out from the sample stage 8. Thereafter, the sample SAM is transported to a sample preparation device such as a FIB or an ion milling device.

[0148] In step S30, the cut surface is formed. The sample SAM is cut at the observation surface 30 by the sample preparation device, thereby preparing Figure 2Ba or Figure 2Bb Sample SAM shown.

[0149] The following uses Figure 2Aa and Figure 2Ba The sample SAM shown is used to illustrate the case, but Figure 2Ab and Figure 2Bb The same method can be implemented also in the case of the sample SAM shown.

[0150] In step S31, the sample SAM is placed on the sample stage 8 in such a manner that the cut surface is irradiated with the electron beam EB. First, the cut sample SAM is placed on the sample stage 8. Next, the sample stage 8 is transported to the charged particle beam device 1, and the sample stage 8 is placed on the workbench 9. At this time, the cut surface of the sample SAM is arranged to be perpendicular to the Z direction in such a manner as to face the electron gun 3.

[0151] In step S32, the application is started by the same method as step S3 and the like.

[0152] In step S33, alignment is performed by the same method as step S9, and an image of the sample SAM observed from the second direction (Y direction), that is, a cross-sectional image is acquired.

[0153] In steps S34-S38, the same operations as steps S10-S14 are performed. That is, the integrated control unit C0 designates the second part of the multilayer structure 31 corresponding to the coordinate x1 of the reference coordinate (x1, y1) 46a in the cross-sectional image as the reference coordinate (x1, z1) 46b observed from the second direction (Y direction). In addition, the integrated control unit C0 designates the fourth part of the multilayer structure 31 corresponding to the coordinate x2 of the observation coordinate (x2, y2) 46c in the cross-sectional image as the observation coordinate (x2, z2) 46d observed from the second direction (Y direction).

[0154] Afterwards, the calculation unit C3 of the integrated control unit C0 calculates the depth and number of layers of the observation coordinate (x2, z2) 46d from the reference coordinate (x1, z1) 46b, and calculates the depth and number of layers of the observation coordinate (x2, z2) 46d from the upper surface TS of the sample SAM.

[0155] In step S39 , similarly to step S15 , steps S34 to S38 are repeated until observation of all observation coordinates is completed.

[0156] In this way, also in the second embodiment, the depth information of the multilayer structure 31 can be acquired quickly and with high accuracy.

[0157] In addition, if the sample SAM is cut initially as in Embodiment 1, it is unknown whether the cut surface is a surface where the pattern of the multilayer structure 31 can be clearly observed. In contrast, in Embodiment 2, the sample SAM is cut later, so it is easy to generate a surface where the pattern of the multilayer structure 31 can be clearly observed.

[0158] On the other hand, in the second embodiment, the sample SAM needs to be cut in accordance with the position of the reference coordinate (x1, y1) 46a specified before the cutting of the sample SAM. However, the accuracy depends on the performance of the sample preparation device, so the cutting position may slightly deviate from the position of the reference coordinate (x1, y1) 46a. From this point of view, the first embodiment is more suitable than the second embodiment.

[0159] In step S40 , similarly to step S16 , the plurality of patterns 32 are analyzed and pattern shape information of the plurality of patterns 32 is acquired.

[0160] (Implementation 3)

[0161] Below, use Figure 14-Figure 18 , the analysis system in Implementation Example 3 is described. In addition, the following mainly describes the differences from Implementation Example 1.

[0162] In embodiment 3, no cross section is formed on the sample SAM, and the distance between the objective lens 6 and the focal position, i.e., the working distance (hereinafter referred to as WD), is obtained by focusing the electron beam EB1 in the first direction (Z direction), and the depth information of the multilayer structure 31 is obtained based on the WD.

[0163] Below, we will Fig.14 The steps S41-S56 shown in the flowchart are Figure 15-18 By comparison, the analysis system in Implementation Method 3 is described.

[0164] In step S41, the observation surface 30 of the sample SAM is formed by the same method as step S1. Figure 2Aa or Figure 2Ab state, no truncation surface is formed.

[0165] In steps S42-S44, the same operations as steps S2-S4 are performed. First, the sample table 8 carrying the sample SAM is placed on the workbench 9 in such a way that the upper surface TS of the sample SAM faces the electron gun 3. Then, the application is started. Then, alignment is performed and the captured image observed from the first direction (Z direction), that is, the overall image, is obtained.

[0166] When you start the application, Fig.15 As shown, an operation screen 40b is displayed on the display device 20. The operation screen 40b is mainly used for the user to input instructions to the integrated control unit C0 and for the user to obtain various information from the integrated control unit C0.

[0167] On the operation screen 40 b , the user can switch the display unit 51 for WD acquisition setting, the display unit 52 for WD characteristic curve (profile), the display unit 53 for observation, and the display unit 70 for pattern analysis.

[0168] The display unit 51 for WD acquisition setting includes a captured image display unit 54, a WD acquisition setting unit 55, a mode selection unit 56, a capture button B1, a reference button B2, a position specification tool addition button B3, and a WD data acquisition start button B12.

[0169] The WD acquisition setting unit 55 displays acquisition conditions such as the start point coordinates, the end point coordinates, the magnification, and the number of WD acquisition times. In addition, a button B11 for determining the WD acquisition conditions is provided in the WD acquisition setting unit 55. The mode selection unit 56 displays a check box for selecting the pre-scan mode or the imaging mode.

[0170] When the user clicks the capture button B1 , the upper surface TS of the sample SAM is irradiated with the electron beam EB1 from the first direction (Z direction), and an entire image including the observation surface 30 is acquired.

[0171] In step S45 , WD acquisition setting is performed. In the captured image display unit 43 , the user specifies the observation range 57 in the entire image including the observation surface 30 by, for example, dragging a mouse as the operating device 21 .

[0172] The integrated control unit C0 converts the designated observation range 57 into the position coordinates of the sample SAM, and outputs the start point coordinates and the end point coordinates to the WD acquisition setting unit 55. The integrated control unit C0 receives detailed settings such as the number of WD acquisitions or the WD acquisition interval, calculates the WD acquisition position, and displays the final observation range 57 on the captured image display unit 43.

[0173] Here, by clicking the button B3 for adding a position designation tool, the user can further add and designate an observation range 57. For example, another observation range 57 shifted in the Y direction with respect to the initially selected observation range 57 can be added. In this case, a plurality of WD characteristic curves described later are generated, so by comparing them with each other, more accurate depth information of the multilayer structure 31 can be obtained.

[0174] The user can select the pre-scan mode or the imaging mode in the mode selection unit 56. In both the pre-scan mode and the imaging mode, the electron beam EB1 is focused in the first direction (Z direction) on a plurality of observation locations as target positions in the sample SAM within the designated observation range 57 using the objective lens 6.

[0175] In the pre-scan mode, the first observation part is automatically focused, the data is stored in the recording unit C7, the workbench 9 is moved to the next observation part, and the next observation part is automatically focused. That is, the pre-scan mode is a mode in which the WD value is stored by repeatedly focusing without acquiring the captured image. In this case, the acquisition of the captured image is performed after the WD characteristic curve is generated.

[0176] In the shooting mode, the first observation part is automatically focused and the image is acquired, and the data is stored in the recording unit C7. After that, the workbench 9 is moved to the next observation part, and the next observation part is automatically focused and the image is acquired. That is, the shooting mode is a mode in which the value of WD is stored by acquiring the image observed from the first direction (Z direction) while focusing.

[0177] When the user clicks the button B12 for starting WD data acquisition, the integrated control unit C0 starts acquiring the WD value within the observation range 57 in the pre-scan mode or the imaging mode.

[0178] In step S46 , the stage control unit C2 of the integrated control unit C0 moves the stage control device 10 and the stage 9 to the starting point coordinates of the observation range 57 .

[0179] In step S47 , the scanning signal control unit C1 of the integrated control unit C0 irradiates the upper surface TS of the sample SAM with the electron beam EB1 from the first direction (Z direction), and the objective lens 6 is used to focus on the starting point coordinates of the observation range 57 .

[0180] In step S48, the mode is determined. If the pre-scan mode is selected, the subsequent step is step S50, and if the imaging mode is selected, the subsequent step is step S49.

[0181] In the shooting mode of step S49, the captured image is acquired while focusing.

[0182] In step S50, the calculation unit C13 of the integrated control unit C0 acquires information on the x-coordinate, y-coordinate, and the distance WD between the objective lens 6 and the focal position for the focused portion. The acquired information is stored in the storage unit C7.

[0183] In step S51, the stage 9 is moved to the next observation site, and the next observation site is automatically focused. Thereafter, steps S47 to S51 are repeated until the WD and other information of all target observation sites are acquired.

[0184] In step S52 and step S53, first, Fig.16 As shown in FIG. 4 , the user switches the display section 51 for WD acquisition setting to the display section 52 for WD characteristic curve on the operation screen 40 b .

[0185] The display unit 52 for the WD characteristic curve is provided with a captured image display unit 54 , a layer information display unit 58 , and a button B13 for obtaining the WD characteristic curve.

[0186] In step S52, the information of the sample SAM is input. The user inputs the information of the sample SAM including the number of layers of the multilayer structure 31, the thickness of one layer or each layer of the multilayer structure 31, and the depth from the first layer of the multilayer structure 31 to the layer information display unit 58. The calculation unit C3 of the integrated control unit C0 associates the information of the sample SAM input by the user with the information of the WD of all the observation parts.

[0187] In step S53, the WD characteristic curve is generated. Fig.17 As shown in FIG. 4 , the user switches from the display unit 52 for the WD characteristic curve to the display unit 53 for observation on the operation screen 40 b .

[0188] The observation display unit 53 is provided with a captured image display unit 54 , an observation position selection unit 59 , an observation condition setting unit 60 , a button B13 for acquiring a WD characteristic curve, and a button B14 for capturing.

[0189] When the user clicks the button B13 for obtaining the WD characteristic curve, the integrated control unit C0 generates a WD characteristic curve that is a graph of the distance (WD) between the objective lens 6 and the focal position at multiple observation locations of the sample SAM. In addition, the area outside the observation surface 30 is depicted as a flat line in the WD characteristic curve. Therefore, the user can determine that the flat line corresponds to the upper surface TS of the sample SAM.

[0190] Here, the operation unit C3 of the integrated control unit C0 can obtain the depth information of the multilayer structure 31 contained in the sample SAM by comparing the information of the sample SAM input by the user (the number of layers of the multilayer structure 31, the thickness of one layer or the thickness of each layer of the multilayer structure 31, and the depth of the first layer starting from the multilayer structure 31, etc.) with the WD characteristic curve.

[0191] That is, it is possible to know the depth of the specified position on the WD characteristic curve from the upper surface TS of the sample SAM and which layer of the multilayer structure 31 it corresponds to. In other words, the depth information of the multilayer structure 31 includes the depth of the specified position on the WD characteristic curve from the upper surface TS of the sample SAM and the number of layers.

[0192] In addition, depending on the sample SAM, the observation surface 30 formed by the grinding process is sometimes not the target surface shape. For example, there are sometimes bumps and depressions on the observation surface 30. In this case, by generating a WD characteristic curve, the user can quickly judge the success or failure of the shape of the observation surface 30. For example, when the difference in the bumps and depressions of the observation surface 30 is large, the user can use the button B3 for adding the position designation tool to add another observation range 57.

[0193] In step S54, the mode is determined. If the pre-scan mode is selected, the next step is step S55, and if the imaging mode is selected, the next step is step S56.

[0194] In the pre-scan mode of step S55 , it is possible to generate a captured image at a desired portion of the sample SAM.

[0195] For example, Fig.17As shown, first, the user sets various observation conditions in the observation condition setting section 60. Next, the user selects "Select from WD characteristic curve" in the observation position selection section 59. Next, the user specifies a specified position in the WD characteristic curve. Next, the user clicks the capture button B14, and the portion of the sample SAM corresponding to the specified above-mentioned specified position is irradiated with an electron beam EB1 from the first direction (Z direction), thereby obtaining a captured image of the sample SAM observed from the first direction (Z direction).

[0196] The photographing here is continuous photographing, and a plurality of photographed images are acquired by continuously photographing the observation range 57 , and a wide-area image can be acquired by joining the plurality of photographed images.

[0197] As another method of acquiring a captured image, the user can also select “the number of layers from the surface” or “the depth from the surface” in the observation position selection unit 59 to acquire a captured image of the region input thereto.

[0198] Furthermore, in step S49 or step S55 , when observing or photographing from the first direction (Z direction), it is assumed that there is foreign matter on the upper surface TS of the sample SAM and the pattern of the multilayer structure 31 cannot be accurately detected.

[0199] At this time, Figure 2Aa and Figure 2Ba In the case of the sample shown, the x coordinate of the foreign matter portion is maintained, and the y coordinate position is moved to another position. The x coordinate is shifted by several points while the position is considered to be the same depth, and an image is obtained while the pattern of the multilayer structure 31 can be observed at another position without foreign matter.

[0200] in addition, Figure 2Ab and Figure 2Bb The observation plane 30 of the sample shown is substantially symmetrical with respect to the Z axis, so it is assumed that WD at two certain depths is acquired. In this case, the target pattern can be observed by specifying the position of the same depth on the WD characteristic curve.

[0201] Moreover, in Figure 2Aa and Figure 2Ab ,or Figure 2Ba and Figure 2Bb In the sample shown, a three-dimensional WD characteristic curve can be obtained by acquiring WD not only for one column but also for the entire surface of the observation surface 30. Therefore, by displaying the three-dimensional WD characteristic curve on the captured image display unit 54, for example, by adding color to the same depth position designated by the user, the user can select another position and capture another pattern 32.

[0202] In particular, when a mechanical grinding device such as a pit grinder is used instead of an ion milling device or FIB in the grinding process for forming the observation surface 30, the above-mentioned foreign matter is easily generated on the observation surface 30. However, even in such a case, as described above, the pattern of the multilayer structure 31 can be observed at another position without foreign matter.

[0203] Furthermore, by observing a plurality of positions at the same depth on the WD characteristic curve, it is also possible to compare differences in pattern shapes at these plurality of locations.

[0204] In addition, the coordinates obtained in steps S41 to S55 and the depth information of the multilayer structure 31 are recorded as Fig.18 Such a record table is stored in the storage unit C7. The integrated control unit C0 can obtain the depth and the number of layers of the predetermined position from the upper surface TS of the sample SAM by performing calculations based on the predetermined position on the WD characteristic curve.

[0205] As described above, in the analysis system according to the third embodiment, the three-dimensional information of the sample SAM can also be obtained at the nanometer level, and the depth information of the multilayer structure 31 can be obtained quickly and accurately.

[0206] In step S56, the analysis of the plurality of patterns 32 is performed in the same manner as in step S16. Fig.19 As shown in FIG. 4 , the user switches the operation screen 40b from the observation display unit 53 to the pattern analysis display unit 70. The operation performed on the pattern analysis display unit 70 is the same as the method described in step S16.

[0207] In the image reading setting section 71, the user inputs the number of layers or depth of the sample SAM, and by clicking the reading button B17, the integrated control section C0 performs an image at the input position, i.e., the observation coordinates (x3, y3, z3) 46e, based on the depth information of the multilayer structure 31 acquired in step S53, and displays the captured image on the captured image display section 43. In addition, the user can click the reference button B18 to select a previously acquired image.

[0208] Thereafter, by the same method as step S16 in the first embodiment, pattern shape information of the plurality of patterns 32 can be acquired.

[0209] (Implementation 4)

[0210] Below, use Figure 20-22 , the analysis system in Implementation Example 4 is described. In addition, the following mainly describes the differences from Implementation Example 3.

[0211] In Embodiment 4, the 3D information data of the sample SAM obtained by another method different from Embodiment 3 is compared with the WD characteristic curve to calibrate the WD characteristic curve. The other method is a method performed in a device different from the charged particle beam device 1, for example, a method performed in the surface shape measurement device 101. Thus, the 3D information of the sample SAM can be obtained with higher accuracy.

[0212] Fig. 20 The surface shape measuring device 101 shown is, for example, a white interference microscope, which can obtain 3D information (e.g., position coordinates x, y, z) of the upper surface TS of the sample SAM. The surface shape measuring device 101 includes a lens barrel 102, a workbench 109, a workbench control device 110, and an integrated control unit C10. The integrated control unit C10 is electrically connected to a display device 20 and an operating device 21 provided inside or outside the surface shape measuring device 101.

[0213] The lens barrel 102 includes a white light source 103 , a first beam splitter 104 , a second beam splitter 105 , an objective lens 106 , a reference surface 107 , and a camera 108 .

[0214] The workbench 109 and the workbench control device 110 are arranged outside the lens barrel 2 and are placed in the atmosphere. The workbench 109 can carry the sample SAM. The workbench control device 110 is connected to the workbench 109 and can displace the position and direction of the workbench 109. The position and direction of the sample SAM are displaced by the displacement of the workbench 109. The workbench control device 110 has a mechanism substantially the same as the workbench control device 10 of the charged particle beam device 1.

[0215] The white light source 103 emits white light WL1. The first beam splitter 104 and the second beam splitter 105 split the emitted white light WL1 into two beams, irradiating one beam to the reference surface 107 and the other beam to the surface of the sample SAM. The reflected light WL2 reflected from both the reference surface 107 and the sample SAM forms an image in the measurement camera 108. The objective lens 106 focuses the white light WL1 so that the focus is on the sample SAM set on the workbench 109.

[0216] The integrated control unit C10 includes an optical system control unit C11, a workbench control unit C12, and a computing unit C13, and performs overall control over them. Therefore, in this application, it is sometimes described that the integrated control unit C10 performs the control performed by the scanning signal control unit C11, the workbench control unit C12, and the computing unit C13. In addition, the integrated control unit C10 including the scanning signal control unit C11, the workbench control unit C12, and the computing unit C13 is sometimes regarded as a control unit, and the integrated control unit C10 is simply referred to as a "control unit".

[0217] The optical system control unit C11 is electrically connected to the white light source 103 , the first beam splitter 104 , the second beam splitter 105 , the objective lens 106 , and the reference surface 107 , and controls the operations thereof.

[0218] The table control unit C12 is electrically connected to the table control device 110 , and controls the operation of each driving mechanism included in the table control device 110 .

[0219] The calculation unit C13 includes a surface information acquisition unit C14 , an instruction input unit C15 , and a storage unit C16 .

[0220] The surface information acquisition unit C14 is electrically connected to the camera 108, and converts the reflected light WL2 detected by the camera 108 as a signal into 3D information data. That is, the 3D information data is data generated based on the reflected light WL2 reflected by the sample SAM when the sample SAM is irradiated with white light WL1. The 3D information data is output to the display device 20, and the user can confirm the 3D information data on the display device 20.

[0221] The instruction input unit C15 receives information input by the user on the display device 20 using the operation device 21. The storage unit C16 can store information such as the coordinates of the worktable 9 and the acquired three-dimensional information data of the sample SAM. In addition, each information is related to each other.

[0222] Below, we will Fig.21 The steps S61-S80 shown in the flowchart are Fig. 22 By comparison, the analysis system in Implementation Method 4 is explained.

[0223] In step S61, the observation surface 30 of the sample SAM is formed by the same method as step S41.

[0224] In step S62 , the surface shape of the sample SAM is measured. The user places the sample SAM on the stage 109 of the surface shape measurement device 101 and turns on the power of the surface shape measurement device 101 .

[0225] The integrated control unit C10 receives the surface shape measurement instruction from the user and starts measuring the surface shape of the sample SAM. The measured surface shape of the sample SAM is stored in the storage unit C16 as 3D information data. Thus, the final quality of the sample SAM can be determined before the sample SAM is inserted into the charged particle beam device 1.

[0226] In addition, the surface shape measurement device 101 is electrically connected to the charged particle beam device 1 via a network or the like. Therefore, the acquired three-dimensional information data can be linked to the WD and the WD characteristic curve acquired in the charged particle beam device 1 .

[0227] In steps S63 to S72 , the same operations as steps S42 to S51 are performed. The sample SAM is transported from the surface shape measurement device 101 to the charged particle beam device 1 , and the information of WD is acquired by the integrated control unit C0 via the application.

[0228] In step S73 , the charged particle beam device 1 reads data (three-dimensional information data) of another method, and in step S74 , sets fitting conditions.

[0229] like Fig. 22 As shown in FIG. 4 , the display unit 52 for the WD characteristic curve of the operation screen 40 b is provided with an accuracy selection unit 61. In addition, in the accuracy selection unit 61, a check box for selecting fitting with other methods is provided as a method for selecting the accuracy for obtaining the depth information of the multilayer structure 31. In addition, in the accuracy selection unit 61, a button B15 for reading data of other methods and a button B16 for starting fitting are also provided.

[0230] In the accuracy selection unit 61, the user selects fitting with other methods (selects "yes"), and the integrated control unit C0 accepts the selection. Next, the user clicks the button B15 for reading data of other methods, and the integrated control unit C0 reads data of other methods (3D information data).

[0231] In step S75, the 3D information data and the WD information are fitted. When the user clicks the fitting start button B16, the integrated control unit C0 fits the read 3D information data and the WD information. In addition, as a fitting method, for example, curve fitting or three-point alignment can be cited.

[0232] That is, the WD of a plurality of observation locations of the sample SAM is compared with the three-dimensional information data acquired by the surface shape measurement device 101. Then, as a result of the comparison, the WD is corrected.

[0233] Here, the resolution of the surface shape measuring device 101 (white interference microscope) is angstroms. Since the surface shape measuring device 101 has sufficient analysis accuracy for the nano-level multilayer structure 31, the WD of multiple observation locations of the sample SAM is a combination of fragmentary information, whereas the 3D information data based on the surface shape measuring device 101 is continuous information. Therefore, by correcting the WD to be consistent with the more accurate 3D information data, a more accurate WD characteristic curve can be obtained.

[0234] In steps S76 to S80, the same operations as steps S52 to S56 are performed, that is, the information of the sample SAM is input, the WD characteristic curve is generated, and the image captured in the pre-scan mode is acquired.

[0235] In addition, the WD characteristic curve in the fourth embodiment is generated by graphing the corrected WD.

[0236] As described above, in the analysis system of the fourth embodiment, the depth information of the multilayer structure 31 can be acquired with higher accuracy than that of the third embodiment.

[0237] As mentioned above, although this invention was specifically described based on the said embodiment, this invention is not limited to the said embodiment, Various changes can be made within the range which does not deviate from the summary.

[0238] Explanation of symbols

[0239] 1 Charged particle beam device

[0240] 2 barrels

[0241] 3Electron Gun

[0242] 4 Focusing lens

[0243] 5 Deflection Coil

[0244] 6 Objective lens

[0245] 7. Sample Room

[0246] 8. Sample table

[0247] 9 Workbench

[0248] 10 workbench control device

[0249] 11 Detector

[0250] 20 Display devices

[0251] 21Operation equipment

[0252] 30 Observation surface (grinding surface)

[0253] 31Multi-layer structure

[0254] 32 patterns

[0255] 40a, 40b operation screen

[0256] 41 Display unit for wide-area image capture

[0257] 42 Display unit for acquiring depth information

[0258] 43 Image display unit

[0259] 44 Condition display unit

[0260] 45 Observation Range

[0261] 46a Reference coordinates (x1, y1)

[0262] 46b Reference coordinates (x1, z1)

[0263] 46c Observation coordinates (x2, y2)

[0264] 46d Observation coordinates (x2, z2)

[0265] 46e Observation coordinates (x3, y3, z3)

[0266] 47 Movement condition display unit

[0267] 48th floor information display

[0268] 49X coordinate position

[0269] 51 WD acquisition setting display unit

[0270] 52 WD characteristic curve display

[0271] 53 display unit for observation

[0272] 54 Image display unit

[0273] 55 WD Acquisition Setting Department

[0274] 56 mode selection unit

[0275] 57 Observation Range

[0276] 58th floor information display

[0277] 59 Observation position selection unit

[0278] 60 Observation condition setting unit

[0279] 61 precision selection unit

[0280] 70 Display unit for pattern analysis

[0281] 71 Image reading setting unit

[0282] 101 Surface shape measuring device

[0283] 102 lens barrel

[0284] 103 white light source

[0285] 104 First beam splitter

[0286] 105 Second beam splitter

[0287] 106 objective lens

[0288] 107 Reference surface

[0289] 108 Camera

[0290] 109 workbench

[0291] 110 workbench control device

[0292] B1 Capture button

[0293] B2 Reference button

[0294] B3 Position specification tool additional button

[0295] B4 Button to start wide area image generation

[0296] B5 Button for deciding shooting conditions

[0297] B6 Button for detailed settings of shooting conditions

[0298] B7 Button for moving to the reference position

[0299] B8 Button for linking with the first direction

[0300] B9 button for moving to X coordinate

[0301] B10 Button for acquiring depth information

[0302] B11 Button for determining the acquisition condition

[0303] B12 Button for starting WD data acquisition

[0304] B13 WD characteristic curve acquisition button

[0305] B14 Capture button

[0306] B15 Button for reading data by other methods

[0307] B16 Fitting start button

[0308] B17 Read-in button

[0309] B18 Reference button

[0310] B19 pattern detection button

[0311] B20 pattern analysis button

[0312] BS lower surface

[0313] C0 Integrated Control Department (Control Department)

[0314] C1 Scanning Signal Control Unit

[0315] C2 workbench control unit

[0316] C3 Operation Unit

[0317] C4 Image Acquisition Unit

[0318] C5 Image combination

[0319] C6 indication input section

[0320] C7 Storage

[0321] C8 Pattern Shape Analysis Department

[0322] C10 Integrated Control Department (Control Department)

[0323] C11 Optical System Control Unit

[0324] C12 workbench control unit

[0325] C13 calculation unit

[0326] C14 Surface information acquisition unit

[0327] C15 indicates input part

[0328] C16 Storage Unit

[0329] EB1 Electron Beam

[0330] EB2 secondary electrons

[0331] SAM Sample

[0332] TS upper surface

[0333] WL1 White Light

[0334] WL2 reflects light.

Claims

1. A parsing system, characterized in that: The following steps are required: (a) irradiating a sample including a multilayer structure with an electron beam from a first direction, thereby obtaining a first image of the sample observed from the first direction; (b) irradiating the sample with the electron beam from a second direction intersecting the first direction, thereby acquiring a second image of the sample observed from the second direction; and (c) obtaining depth information of the multilayer structure using the first captured image, the second captured image, and information of the sample including the number of layers of the multilayer structure, the thickness of one layer or the thickness of each layer of the multilayer structure, and the depth from the first layer of the multilayer structure, The sample has: upper surface; a lower surface on the opposite side of the upper surface; an observation surface formed on a portion of the upper surface in a manner inclined from the upper surface toward the lower surface; as well as a truncation plane, which is truncated at the observation plane, The step (c) comprises the following steps: (c1) in the first captured image, specifying a first portion of the multilayer structure exposed on the observation surface as a first reference coordinate (x1, y1) viewed from the first direction; (c2) in the second captured image, specifying a second portion of the multilayer structure that is exposed on the observation surface and corresponds to the coordinate x1 of the first reference coordinate (x1, y1) as a second reference coordinate (x1, z1) observed from the second direction; (c3) in the first captured image, specifying a third portion of the multilayer structure that is exposed on the observation surface and is different from the first portion as a first observation coordinate (x2, y2) observed from the first direction; (c4) in the second captured image, specifying a fourth portion of the multilayer structure that is exposed on the observation surface and corresponds to the coordinate x2 of the first observation coordinate (x2, y2) as the second observation coordinate (x2, z2) observed from the second direction; and (c5) calculating the depth of the second observation coordinate (x2, z2) from the second reference coordinate (x1, z1), The depth information of the multilayer structure includes the depth of the second observation coordinate (x2, z2) from the second reference coordinate (x1, z1).

2. The analysis system according to claim 1, characterized in that: A portion of the multilayer structure is exposed on the observation surface and the cut surface, In the step (a), the upper surface is irradiated with the electron beam. In the step (b), the cross section is irradiated with the electron beam.

3. The analysis system according to claim 1, characterized in that: The step (c) further comprises the following steps: (c6) calculating the number of layers from the second observation coordinate (x2, z2) to the second reference coordinate (x1, z1) by comparing the information of the sample with the calculation result of the step (c5); and (c7) after step (c6), when the second reference coordinate (x1, z1) is located in the first layer of the multilayer structure, calculating the depth and the number of layers of the second observation coordinate (x2, z2) from the upper surface of the sample, The depth information of the multilayer structure further includes the number of layers from the second observation coordinate (x2, z2) to the second reference coordinate (x1, z1), the depth and number of layers from the second observation coordinate (x2, z2) to the upper surface of the sample.

4. The analysis system according to claim 1, characterized in that: The analysis system also has the following steps: (d) preparing the sample having the upper surface and the lower surface; (e) after step (d), forming the observation surface on a portion of the upper surface by performing a grinding process on a portion of the upper surface; and (f) After the step (e), the sample is cut at the observation surface to form the cut surface.

5. The analysis system according to claim 4, characterized in that: After step (d), step (e) and step (f), step (a), step (b) and step (c) are performed.

6. The analysis system according to claim 4, characterized in that: After the steps (d) and (e), the step (a) is performed, After step (a), step (c1) and step (c3) are performed. After the steps (c1) and (c3), the step (f) is performed, After step (f), step (b) is performed, After step (b), step (c2) and step (c4) are performed, After the steps (c2) and (c4), the step (c5) is performed.

7. A parsing system, characterized in that: The following steps are required: (a) irradiating a sample including a multilayer structure with an electron beam from a first direction, thereby obtaining a first image of the sample observed from the first direction; (b) specifying an observation range in the first captured image; (c) focusing the electron beam in the first direction at a plurality of locations in the sample within the specified observation range using an objective lens; (d) based on the focusing result of step (c), obtaining the distances between the objective lens and the focal position at the plurality of locations of the sample, and generating a WD characteristic curve in which these distances are graphed; and (e) comparing information of the sample including the number of layers of the multilayer structure, the thickness of one layer or each layer of the multilayer structure, and the depth from the first layer of the multilayer structure with the WD characteristic curve to obtain depth information of the multilayer structure, The specimen has an upper surface, The depth information of the multilayer structure includes the depth of a predetermined position on the WD characteristic curve from the upper surface of the sample and the number of layers.

8. The analysis system according to claim 7, characterized in that: The sample also has: a lower surface on the opposite side of the upper surface; and an observation surface formed on a portion of the upper surface in a manner inclined from the upper surface toward the lower surface; A portion of the multilayer structure is exposed on the observation surface, In the steps (a) and (c), the upper surface is irradiated with the electron beam. The observation range of the step (b) includes the observation surface.

9. The analysis system according to claim 8, characterized in that: In the step (c), the focusing is performed and the electron beam is irradiated from the first direction to the plurality of locations in the sample, thereby acquiring a second image of the sample observed from the first direction.

10. The analysis system according to claim 8, characterized in that: The analysis system also has the following steps: (f) After step (d), a predetermined position is designated in the WD characteristic curve, and the portion of the sample corresponding to the designated predetermined position is irradiated with the electron beam from the first direction, thereby obtaining a third image of the sample observed from the first direction.

11. The analysis system according to claim 7, characterized in that: The analysis system also includes a charged particle beam device, which has: an electron gun, which can irradiate the electron beam; a workbench, which can set the sample; a workbench control device, which is connected to the workbench and can displace the position and orientation of the workbench; the objective lens, which can focus the electron beam on the sample; a detector, which can detect secondary electrons released from the sample as a signal when the sample set on the workbench is irradiated with the electron beam; and a control unit, which controls the respective actions of the electron gun, the workbench control device, the objective lens and the detector. The control unit can obtain the first captured image based on the signal detected in the detector, can perform the focusing by controlling the objective lens, can generate the WD characteristic curve based on the focusing result, and can use the WD characteristic curve to obtain depth information of the multilayer structure contained in the sample.

12. The analysis system according to claim 11, characterized in that: In the step (d), the distances between the objective lens and the focal positions of the plurality of locations of the sample are compared with the three-dimensional information data of the sample obtained in a surface shape measuring device different from the charged particle beam device. Based on the comparison result, the distance between the objective lens and the focal position of the plurality of locations of the sample is corrected. The WD characteristic curve is generated by graphing these corrected distances.

13. The analysis system according to claim 12, characterized in that: The surface shape measuring device is a white interference microscope, The three-dimensional information data is data generated based on reflected light reflected from the sample when the sample is irradiated with white light.

Images