Converged ion beam device

Abstract

A converged ion beam device is provided. Before actually irradiating the converged ion beam, at least the direction in which the beam irradiates the sample stage on which the sample is fixed can be understood. The converged ion beam device comprises: a converged ion beam column (20) for irradiating the converged ion beam (20A) to the sample (200); a sample stage (51) on which the sample is placed; and a sample carrier on which the sample stage is placed and which can move at least in the horizontal direction and the height direction, wherein the converged ion beam device (100) further comprises: a storage unit (6M) which pre-stores three-dimensional data of the sample stage and the irradiation axis of the converged ion beam, the three-dimensional data being associated with the carrier coordinates of the sample stage; a display unit (7); and a display control unit (6A) which, based on the three-dimensional data of the sample stage and the irradiation axis of the converged ion beam, causes the display unit to display the positional relationship between the virtual sample stage (51v) and the irradiation axis (20Av) of the converged ion beam when the sample stage is moved to a specified position by actuating the sample stage.

Description

Technical Field

[0001] The present invention relates to a converged ion beam device for processing a sample or the like. Background Art

[0002] Conventionally, samples have been processed and observed using a focused ion beam apparatus.

[0003] In addition, a technology has been developed that stores three-dimensional data of a converged ion beam column and a detector, and simulates and determines whether these devices will interfere with the sample based on the three-dimensional data of the sample when the sample is moved to a measurement point (Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2008-270072

[0005] Furthermore, when processing a microstructure such as a semiconductor device by irradiating it with a converged ion beam, the etching rate differs depending on the backlight of the structure, and thus processing streaks may occur in the sample due to a curtain effect.

[0006] Therefore, for example, the curtain effect is suppressed by rotating or tilting the sample stage on which the sample is placed on a horizontal plane and irradiating the structure of the sample with a converged ion beam at an angle. However, in practice, when irradiating the converged ion beam and performing processing, it is necessary to observe whether the curtain effect exists each time. Therefore, sometimes the sample is tilted too much and a problem occurs during processing, or the sample is tilted less and the curtain effect cannot be fully suppressed, etc., making it difficult to perform processing that appropriately suppresses the curtain effect. Summary of the invention

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a converged ion beam device that can at least grasp the direction in which the beam is irradiated onto a sample stage that fixes a sample before actually irradiating the converged ion beam.

[0008] In order to achieve the above-mentioned purpose, the converged ion beam device of the present invention comprises: a converged ion beam column, which is used to irradiate the sample with a converged ion beam; a sample stage, which carries the sample; and a sample carrier, which carries the sample stage and is movable at least in the horizontal direction and the height direction, and is characterized in that the converged ion beam device also comprises: a storage unit, which pre-stores three-dimensional data of the sample stage and the irradiation axis of the converged ion beam, and the three-dimensional data is associated with the carrier coordinates of the sample stage; a display unit; and a display control unit, which enables the display unit to display the positional relationship between the virtual sample stage and the virtual irradiation axis of the converged ion beam when the sample stage is moved to a specified position by actuating the sample stage based on the three-dimensional data of the sample stage and the irradiation axis of the converged ion beam.

[0009] According to the converged ion beam device, the positional relationship between the virtual sample stage and the irradiation axis of the converged ion beam is displayed, so before actually irradiating the converged ion beam, it is possible to at least understand the direction in which the beam will find the sample stage where the sample is fixed. As a result, for example, it is possible to determine the degree of processing fringes caused by the curtain effect due to the backlight of the structure of the sample, for example, it is possible to understand to what extent the sample should be tilted to suppress the curtain effect and perform appropriate processing.

[0010] In addition, since the positional relationship between the sample stage and the irradiation axis of the converged ion beam is displayed for a sample stage whose three-dimensional data is known, there is no need to separately obtain three-dimensional data of samples of different shapes etc. during each measurement. The orientation of the converged ion beam relative to the sample stage can be simply displayed, thereby improving operating efficiency and allowing a rough grasp of the relative positional relationship between the sample stage and the sample.

[0011] The converged ion beam device of the present invention may also include a conversion unit, which converts pre-input three-dimensional data of the sample into the coordinates of the stage according to the posture and loading position of the sample after being loaded on the sample stage, and the display control unit causes the display unit to display the positional relationship between the virtual sample, the virtual sample stage and the virtual irradiation axis of the converged ion beam when the sample stage is moved to the irradiation position based on the three-dimensional data of the sample obtained by the conversion by the conversion unit.

[0012] According to this focused ion beam apparatus, in addition to the virtual sample stage, the positional relationship of the virtual sample is superimposed and displayed, so that the direction in which the beam actually irradiates the sample can be more accurately understood.

[0013] Here, the positional relationship between the virtual sample and the irradiation axis of the converged ion beam can be displayed, so the sample stage can be virtually moved on the screen so that the sample is located at the irradiation position.

[0014] In the converged ion beam device of the present invention, the sample stage can be tilted with a tilt axis parallel to the horizontal direction and orthogonal to the height direction as the center, and the converged ion beam device also has: an image acquisition unit, which acquires a plane image of the sample after being placed on the sample stage; and a three-dimensional data generation unit, which calculates the movement amount of the sample stage to the concentric height Zs and generates three-dimensional data of the sample, and the conversion unit converts the three-dimensional data of the sample generated by the three-dimensional data generation unit into the stage coordinates.

[0015] Although when the three-dimensional data of the sample is known, the known data can be imported, but in most cases the shapes of the samples are different, and generating three-dimensional data each time sometimes leads to a large workload. Therefore, according to the converged ion beam device, by calculating the concentric height Zs, the distribution of the thickness of the sample in the plane direction (height distribution) is obtained, so that the three-dimensional data of the sample can be generated.

[0016] In the converged ion beam device of the present invention, the storage unit may store an etching rate or a deposition rate when the sample is irradiated with the converged ion beam, and the display control unit may cause the display unit to display the virtual outline of the sample after etching or deposition according to a specified etching time or deposition time based on the positional relationship between the virtual sample and the irradiation axis of the virtual converged ion beam when the sample carrier is operated to move the sample to the irradiation position.

[0017] According to this focused ion beam apparatus, by displaying the outline of a virtual sample after etching or deposition for a predetermined etching or deposition time, the shape of the sample after etching or deposition can be grasped.

[0018] In addition, regarding the curtain effect caused by the backlight of the structure of the sample after etching or deposition, the positional relationship of the irradiation axis of the virtual convergent ion beam can be displayed in the outline. In this way, it is possible to understand the direction in which the beam irradiates the sample after etching or deposition.

[0019] The converged ion beam device of the present invention may also further include a gas ion beam column or a laser column, wherein the acceleration voltage of the gas ion beam column or the laser column is set to be lower than the acceleration voltage of the converged ion beam column, and the gas ion beam column or the laser column is used to irradiate the sample with a gas ion beam or a laser, and the storage unit pre-stores three-dimensional data of the irradiation axis of the gas ion beam or the laser, and the three-dimensional data is associated with the stage coordinates of the sample stage, and the display control unit also causes the display unit to display the positional relationship between the virtual sample stage, the virtual irradiation axis of the converged ion beam, and the virtual irradiation axis of the gas ion beam or the laser when the sample stage is moved to a specified position by moving the sample stage according to the three-dimensional data of the irradiation axis of the gas ion beam or the laser.

[0020] According to this converged ion beam device, the directions of gas ion beams and laser beams, which are wider than the converged ion beam and whose traveling directions are difficult to grasp, can be grasped, and the use of gas ion beams or laser beams is useful, for example, in suppressing a curtain effect.

[0021] In the converged ion beam device described in aspect 5, the display control unit causes the display unit to display the positional relationship between the virtual sample, the virtual sample stage, the virtual irradiation axis of the converged ion beam, and the virtual irradiation axis of the gas ion beam or the laser when the sample carrier is moved to the irradiation position based on the three-dimensional data of the sample obtained by conversion by the conversion unit.

[0022] According to the converged ion beam device, the positional relationship of the irradiation axis of the virtual converged ion beam can be displayed in the outline for the curtain effect caused by the backlight of the structure of the etched or deposited sample, etc. Thus, it is possible to understand the direction in which the beam irradiates the etched or deposited sample.

[0023] In the converged ion beam device of the present invention, in the converged ion beam device according to any one of the second to sixth aspects, the display control unit causes the display unit to display an irradiation range of the sample irradiated with the converged ion beam in an overlapping manner.

[0024] According to the focused ion beam apparatus, for example, the irradiation range of the sample with the focused ion beam can be easily grasped as a processing frame, and it can be understood how the sample can be processed using the focused ion beam.

[0025] Effects of the Invention

[0026] According to the present invention, a converged ion beam apparatus is provided in which, before actually irradiating the converged ion beam, it is possible to grasp at least the direction in which the beam irradiates the sample stage for fixing the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram showing the overall structure of a focused ion beam device according to a first embodiment of the present invention.

[0028] Figure 2 This is an enlarged stereoscopic image of the sample stage.

[0029] Figure 3 It is a diagram showing the positional relationship between a virtual sample stage, an irradiation axis of a converged ion beam, and an irradiation axis of a gas ion beam.

[0030] Figure 4 This is a diagram showing an example of a planar image (SEM image) of a sample acquired by a SEM lens column.

[0031] Figure 5 This is a diagram showing a method of calculating the amount of movement of the sample stage in the height direction so that the irradiation position of the sample coincides with the concentric height.

[0032] Figure 6This is a diagram showing an example of a method for calculating the concentric height Zs in the second embodiment.

[0033] Figure 7 It is a figure which shows the irradiation position before and after tilting.

[0034] Figure 8 This is a diagram showing the outline of a virtual sample after etching for a predetermined etching time.

[0035] Fig. 9 This is a diagram showing a method of storing the etching rate for each sample as a table.

[0036] Fig.10 The figure shows the irradiation range (processing frame) of the sample with the converged ion beam.

[0037] Fig.11 This is a diagram showing a method of displaying the latest scanning position when a converged ion beam or electron beam is scanned on a sample surface.

[0038] Fig.12 This is a diagram showing the outline of a virtual sample after deposition for a predetermined deposition time.

[0039] Description of symbols

[0040] 4. Secondary electron detector (image acquisition unit)

[0041] 6Control Unit

[0042] 6A Display control unit

[0043] 6B conversion unit

[0044] 6C 3D Data Generation Department

[0045] 6M storage unit

[0046] 7Display unit

[0047] 10A electron beam

[0048] 20 Converging ion beam column

[0049] 20A Converged Ion Beam

[0050] Irradiation axis of 20Av virtual converging ion beam

[0051] 30 Gas Ion Beam Column

[0052] Irradiation axis of 30A gas ion beam

[0053] Irradiation axis of 30Av virtual gas ion beam

[0054] 50 sample carrier

[0055] 51 Sample table

[0056] 51v virtual sample stand

[0057] 100 Converging Ion Beam Device

[0058] 200 samples

[0059] 200v dummy sample

[0060] Virtual sample profile after 200Ev etching

[0061] Irradiation range of 200R focused ion beam

[0062] P1, P2 irradiation position

[0063] TA tilt axis. DETAILED DESCRIPTION

[0064] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0065] Figure 1 1 is a block diagram showing the overall structure of a focused ion beam device 100 according to an embodiment of the present invention. Figure 1 In the figure, the converged ion beam device 100 has an electron beam column (SEM column) 10, a converged ion beam column (FIB column) 20, a gas ion beam column 30, a secondary electron detector 4, an air gun 5, a control unit 6, a display unit 7, an input unit 8, a sample stage 50 and a sample table (sample holder) 51 arranged on the sample stage 50.

[0066] In addition, Figure 1 In the embodiment, the FIB column 20 and the electron beam column 10 may be exchanged so that the FIB column 20 is arranged vertically.

[0067] Part or all of the components of the focused ion beam device 100 are disposed in a vacuum chamber 40 , and the vacuum chamber 40 is decompressed to a predetermined vacuum level.

[0068] The sample stage 50 supports the sample stage 51 so as to be movable, and the sample 200 is placed on the sample stage 51. The sample stage 50 has a moving mechanism that can shift the sample stage 51 in five axes.

[0069] Specifically, if Figure 2As shown, the moving mechanism includes an XY moving mechanism 50xy for moving the sample stage 51 along the X-axis and the Y-axis which are parallel to the horizontal plane and orthogonal to each other, a Z moving mechanism 50z for moving the sample stage 51 along the Z-axis (height direction) which is orthogonal to the X-axis and the Y-axis, a rotating mechanism 50r for rotating the sample stage 51 around the Z-axis, and a tilting mechanism 50t for rotating the sample stage 51 around a tilting axis TA which is parallel to the X-axis. In addition, the tilting axis TA is orthogonal to the irradiation direction of the electron beam 10A and the converged ion beam 20A.

[0070] The above-mentioned moving mechanism can be realized by various actuators such as a piezoelectric element and a stepping motor.

[0071] The sample stage 50 moves the sample 200 to the irradiation position of the electron beam 10A, the converged ion beam 20A, and the gas ion beam 30A by shifting the sample stage 51 in five axes ( Figure 2 The irradiation point P1 is where the electron beam 10A, the converged ion beam 20A, and the gas ion beam 30A intersect.

[0072] At the irradiation point P1, the surface (cross section) of the sample 200 is irradiated with the electron beam 10A, the converged ion beam 20A, and the gas ion beam 30A (at Figure 2 Only the electron beam 10A and the converged ion beam 20A are shown for processing or SEM observation.

[0073] The control unit 6 can be composed of a computer having a CPU as a central processing unit, a storage unit 6M (RAM and ROM) for storing data and programs, and an input port and an output port for inputting and outputting signals with external devices. The CPU of the control unit 6 performs various calculations according to the program stored in the storage unit 6M, so that the control unit 6 controls the various components of the converged ion beam device 100. In addition, the control unit 6 is electrically connected to the control wiring of the electron beam column 10, the converged ion beam column 20, the gas ion beam column 30, the secondary electron detector 4, and the sample carrier 50.

[0074] The control unit 6 includes a display control unit 6A, a conversion unit 6B, and a three-dimensional data generation unit 6C, which will be described later.

[0075] In addition, the control unit 6 can drive the sample carrier 50 according to software instructions or operator input, adjust the position and posture of the sample 200, and adjust the irradiation position and irradiation angle of the electron beam 10A, the converged ion beam 20A and the gas ion beam 30A to the surface of the sample 200.

[0076] Furthermore, the control unit 6 is connected to an input unit 8 such as a keyboard for acquiring input instructions from an operator and a display unit 7 for displaying an image of a sample and the like.

[0077] Although not shown, the SEM column 10 has an electron source that emits electrons, and an electron optical system that shapes the electrons emitted from the electron source into a beam shape and scans. By irradiating the sample 200 with an electron beam 10A emitted from the electron beam column 10, secondary electrons are generated from the sample 200. The generated secondary electrons can be detected by a secondary electron detector (not shown) in the column or a secondary electron detector 4 outside the column, thereby obtaining an image of the sample 200. In addition, the reflected electron detector in the column can be used to detect the reflected electrons to obtain an image of the sample 200.

[0078] The electron optical system is configured to include, for example, a condenser lens for converging the electron beam 10A, an aperture for narrowing the electron beam 10A, an aligner for adjusting the optical axis of the electron beam 10A, an objective lens for converging the electron beam 10A on the sample 200 , and a deflector for scanning the electron beam 10A on the sample 200 .

[0079] The secondary electron detector 4 or the reflected electron detector in the SEM column 10 corresponds to the “image acquisition unit” in the claims.

[0080] Although not shown in the figure, the FIB column 20 has an ion source for generating ions, and an ion optical system for forming the ions emitted from the ion source into a converged ion beam and scanning. When the sample 200 is irradiated with the converged ion beam 20A as a charged particle beam from the FIB column 20, secondary charged particles such as secondary ions or secondary electrons are generated from the sample 200. The secondary charged particles are detected by the secondary electron detector 4 to obtain an image of the sample 200. In addition, the FIB column 20 performs etching processing (cross-section processing) on ​​the sample 200 within the irradiation range by increasing the irradiation amount of the converged ion beam 20A.

[0081] The ion optical system has a well-known structure, for example, it is composed of a focusing lens for converging the converged ion beam 20A, an aperture for reducing the converged ion beam 20A, an aligner for adjusting the optical axis of the converged ion beam 20A, an objective lens for converging the converged ion beam 20A on the sample, and a deflector for scanning the converged ion beam 20A on the sample.

[0082] Although not shown, the gas ion beam column 30 includes, for example, an ion source that generates argon ions, a condenser lens that converges the gas ion beam 30A from the ion source, a blanker, an aperture that narrows the ion beam, and an objective lens that converges the ion beam.

[0083] The acceleration voltage of the gas ion beam column 30 is set lower than the acceleration voltage of the converged ion beam column 20. For example, the gas ion beam column 30 is used to remove a curtain effect (processing stripes of a sample) generated during processing of the converged ion beam.

[0084] As the gas ion beam 30A, there is a rare gas such as argon or xenon, or an oxygen plasma beam.

[0085] In addition, the same effect can be obtained by using a laser column instead of the gas ion beam column 30 , and in this case, a laser beam is irradiated instead of the gas ion beam 30A.

[0086] The air gun 5 releases a predetermined gas such as an etching gas toward the sample 200. While the etching gas is supplied from the air gun 5, the sample 200 is irradiated with the electron beam 10A, the converged ion beam 20A, or the gas ion beam 30A, thereby increasing the etching speed of the sample based on the beam irradiation. In addition, by supplying a compound gas from the air gun 5 while the sample 200 is irradiated with the electron beam 10A, the converged ion beam 20A, or the gas ion beam 30A, local gas components can be precipitated (deposited) near the irradiation area of ​​the beam.

[0087] <First Embodiment>

[0088] Next, refer to Figure 3 The display process of the focused ion beam device 100 according to the first embodiment of the present invention will be described.

[0089] The storage unit 6M stores in advance three-dimensional data of the sample stage 51 , the irradiation axis of the converged ion beam 20A, and the irradiation axis of the gas ion beam 30A, and the three-dimensional data is associated with the stage coordinates of the sample stage 50 .

[0090] Moreover, if Figure 3 As shown in (a), the display control unit 6A causes the display unit 7 to display the positional relationship between the virtual sample stage 51v, the irradiation axis 20Av of the converged ion beam 20A, and the irradiation axis 30Av of the gas ion beam 30A when the sample stage 50 is operated to move the sample stage 51 to a specified position, based on the three-dimensional data of the sample stage 51, the irradiation axis of the converged ion beam 20A, and the irradiation axis 30A of the gas ion beam 30A.

[0091] Here, "virtual" does not refer to the actual image of the sample stage 51, the converged ion beam 20A, etc. (for example, the image observed by the SEM lens tube 10), but rather to the image generated on the computer based on the above three-dimensional data, such as the actual sample stage 51v and the irradiation axis 20Av, and "v" is added to the end of the number to indicate "virtual". Figure 3 In (a), the sample stage 50 is assumed to move in the XY directions as indicated by the arrows.

[0092] Furthermore, “moving the sample stage 51 to a predetermined position” means that when the sample 200 is placed on the sample stage 51, the position of the sample stage 51 is moved so that the sample 200 is approximately located at the irradiation position irradiated by the converged ion beam 20A. The shape of the sample stage 51 is known, and the user can roughly grasp the relative positional relationship between the sample stage 51 and the sample 200.

[0093] In addition, in the present embodiment, the "irradiation position" is consistent with the eucentric height Zs described later. In addition, the intersection position where the electron beam 10A, the converged ion beam 20A, and the gas ion beam 30A intersect is also consistent with the eucentric height Zs. The eucentric height is the height of the sample stage 50 at which a specific observation point on the sample does not move even if the sample is tilted when the sample is placed on the sample stage.

[0094] In addition, when Figure 3 The position of (a) is as follows Figure 3 When the sample stage 50 is tilted around the tilt axis TA as shown in (b), the positional relationship among the sample stage 51v, the irradiation axis 20Av of the converged ion beam 20A, and the irradiation axis 30Av of the gas ion beam 30A changes, and the changes in the irradiation mode of the converged ion beam 20A and the gas ion beam 30A on the sample stage 51 can be understood.

[0095] In this way, the positional relationship between the virtual sample stage 51v and the irradiation axis 20Av of the converged ion beam 20A is displayed. Therefore, before actually irradiating the converged ion beam 20A, it is possible to at least understand the direction in which the converged ion beam 20A irradiates the sample stage 51 fixing the sample.

[0096] As a result, for example, the degree to which processing streaks are generated due to the curtain effect caused by the backlight of the structure of the sample 200 can be determined, and for example, the degree to which the sample should be tilted to suppress the curtain effect and perform appropriate processing can be understood.

[0097] In addition, since the positional relationship between the sample stage 51 and the irradiation axis of the converged ion beam 20A is displayed for the sample stage 51 whose three-dimensional data is known, there is no need to separately obtain three-dimensional data of the sample 200 with different shapes etc. during each measurement. The orientation of the converged ion beam 20A relative to the sample stage 51 can be simply displayed, thereby improving the operating efficiency and roughly understanding the relative positional relationship between the sample stage 51 and the sample 200.

[0098] From this point of view, it is premised that the three-dimensional shape of the sample stage 51 is known and that the sample stage 51 is firmly fixed to a predetermined position of the sample stage 50 without shaking.

[0099] Furthermore, in this example, the positional relationship of the irradiation axis line 30Av of the virtual gas ion beam 30A is also superimposed and displayed, so it is also possible to recognize in which direction the gas ion beam 30A irradiates the sample stage 51.

[0100] As a result, the direction of the gas ion beam 30A, which is wider than the converged ion beam 20A and whose traveling direction is difficult to grasp, can be grasped, which is useful when, for example, a curtain effect is suppressed using the gas ion beam 30A. The same is true for a laser beam.

[0101] Incidentally, it is of course not essential to display the irradiation axis line 30Av of the gas ion beam 30A, and it is sufficient to display at least the positional relationship between the virtual sample stage 51v and the irradiation axis line 20Av of the convergent ion beam 20A.

[0102] <Second Embodiment>

[0103] Next, refer to Figure 3 to Figure 7 The display process of the focused ion beam device 100 according to the second embodiment of the present invention will be described.

[0104] In the second embodiment, in addition to the virtual sample stage 51v, a Figure 3 The positional relationship of the virtual sample 200v shown by the dotted line can therefore more accurately determine the direction in which the focused ion beam 20A actually irradiates the sample 200.

[0105] Here, in the second embodiment, since the positional relationship between the virtual sample 200v and the irradiation axis line 20Av of the converged ion beam 20A can be displayed, the sample stage 50 may be virtually moved on the screen so that the sample 200 is located at the irradiation position.

[0106] The conversion unit 6B can display a virtual sample 200v by converting the three-dimensional data of the sample input in advance into stage coordinates based on the posture of the sample 200 placed on the sample stage 51, the posture of the sample 200 placed on the sample stage 51 at the placement position, and the placement position.

[0107] Here, an example of a method of converting three-dimensional data of a sample into stage coordinates will be described.

[0108] First, the user places the actual sample 200 on the sample stage 51. Next, in order to obtain the "posture and placement position of the sample 200 after being placed on the sample stage 51", the electron beam 10A or the converged ion beam 20A is irradiated on at least three points (aiming points) on the surface of the sample 200, and the coordinate data of the stage coordinate system of each point is obtained through the sample image.

[0109] On the other hand, for example, the coordinate system of the three-dimensional data of the sample 200 stored in the storage unit 6M also knows the coordinate data of each point in advance, so it is possible to compare the two coordinate data, correct the scale and perform conversion processing. In addition, since the measurement is performed using more than three points, tilt correction can also be performed. As a result, the three-dimensional data of the sample 200 can be associated with the stage coordinate system, and the state of the sample 200 placed on the sample stage 51 can be accurately recognized as three-dimensional data.

[0110] Furthermore, when the three-dimensional data of the sample is known, the known data may be imported. However, the shapes of the samples are often different, and generating three-dimensional data each time may cause a large workload.

[0111] Therefore, after the user places the actual sample 200 on the sample stage 51, Figure 4 As shown, an electron beam 10A is irradiated from the SEM column 10, and a plane image (SEM image) 200pi of the sample 200 is obtained by the secondary electron detector 4 or the reflected electron detector. The plane image 200pi is an image along the XY plane. In addition, P1 and P2 in the plane image 200pi represent different irradiation positions (measurement points) on the surface of the sample 200.

[0112] Then, if Figure 5 As shown, the three-dimensional data generating unit 6C calculates the movement amount when the sample stage 50 is moved in the height direction Z so that the irradiation positions P1 and P2 of the sample 200 coincide with the concentric heights Zs1 and Zs2, respectively.

[0113] Next, the three-dimensional data generating unit 6C calculates the movement amount of the sample stage 50 when the position Px on the surface of the sample stage 51 where the sample 200 does not exist reaches the concentric height Zsx.

[0114] At this time, the height of the surface of the sample 200, that is, the concentric position, is approximately the same. When the thickness of the sample stage 51 is tx, and the thicknesses of P1 and P2 are t1 and t2, respectively,

[0115] Concentric position of position P1 = Zs1 + tx + t1 = Zsx + tx

[0116] Thus, t1=Zsx-Zs1 can be used to calculate t2. Therefore, by scanning the surface of the sample 200 and calculating the concentric height Zs at multiple irradiation positions, the distribution of the thickness of the sample 200 in the XY direction (height distribution) can be obtained, and thus, three-dimensional data of the sample 200 can be generated.

[0117] Here, refer to Figure 6An example of a method for calculating the concentric height Zs at each irradiation position P1 will be described.

[0118] exist Figure 6 In the process, first, the sample surface S0 before tilting is tilted from a predetermined direction ( Figure 6 The electron beam 10A is irradiated (in the vertical direction) to obtain the Y coordinate (Y0) of the irradiation position P1.

[0119] Next, the control unit 6 tilts the sample at an angle θ along the tilt axis TA, and the sample surface tilts to S0t. At this time, the Y coordinate of the irradiation position P1 moves by ΔY to Yθ0 ( Figure 6 to the right in the middle).

[0120] The amount of movement at this time can be approximated by the following formula:

[0121] Formula 2: ΔY=Y0-YΘ0≒Zs×sinΘ

[0122] Y0, YΘ0, and Θ are known. Therefore, Zs can be calculated using the following formula 3.

[0123] Formula 3: Zs = (Y0-Yθ0) / sinθ

[0124] In addition, Formula 2 is recorded in the storage unit 6M or in the calculation program of the concentric height Zs, and the control unit 6 reads the formula.

[0125] Then, the control unit 6 controls the height of the sample stage 50 so that the sample surface S1 (irradiation position P1 ) after the sample surface S0 is moved by +Zs in the height direction coincides with the concentric height Zs.

[0126] In addition, even if the SEM image is observed, Yθ0 itself cannot usually be identified. Therefore, if P1 itself has a characteristic quantity (a concave portion that can be distinguished from the surroundings, a backlight, etc.), the displacement of the characteristic quantity in the Y-axis direction before and after the tilt can be calculated.

[0127] In addition, if Figure 7 As shown in FIG. 1 , when P1 itself has no feature quantity, the displacement of the feature quantity PF in the vicinity of P1 before and after the inclination in the Y-axis direction may be calculated.

[0128] <Third Embodiment>

[0129] Next, refer to Figure 8 , Fig. 9 The display process of the focused ion beam device 100 according to the third embodiment of the present invention will be described.

[0130] In the third embodiment, based on the second embodiment, Figure 8As shown, an outline 200Ev of a virtual sample 200v after being etched by the converged ion beam 20A for a predetermined etching time is also superimposed and displayed, so that it is possible to understand how the sample 200 is actually etched.

[0131] At this time, for example Fig. 9 As shown, the display control unit 6A reads out the etching rate per unit time of a predetermined type of sample A based on the table stored in the storage unit 6M.

[0132] On the other hand, Figure 8 As shown, for example, the storage unit 6M stores the irradiation axis 20Av as the center and Fig. 9 The beam diameter 20d is used for effective etching at an etching rate.

[0133] Then, the display control unit 6A reads the above etching rate and, according to Figure 8 The etching amount for a predetermined etching time is calculated based on the direction of the irradiation axis line 20Av relative to the virtual sample 200v and the irradiation position P1 at which the irradiation axis line 20Av irradiates the surface of the sample 200v.

[0134] Then, the display control unit 6A calculates the contour 200Ev of the virtual sample 200v after etching based on the etching amount and displays it.

[0135] In this way, by displaying the outline 200Ev of the virtual sample 200v after etching for a predetermined etching time, the shape of the sample after etching can be understood.

[0136] like Fig.12 As shown, as a third embodiment, a virtual outline 200T of a sample 200 v may be superimposed and displayed when deposition is performed using the converged ion beam 20A instead of etching.

[0137] In addition, when deposition is performed, the etching rate and etching time are respectively referred to as the deposition rate and deposition time. Fig. 9 The deposition rate per unit time is stored in a table.

[0138] Furthermore, the positional relationship of the irradiation axis 20Av of the virtual converged ion beam 20A can be displayed in the outline 200Ev or 200T for the curtain effect caused by the backlight of the structure of the etched or deposited sample 200. Thus, it is possible to understand the direction in which the converged ion beam 20A irradiates the etched or deposited sample 200.

[0139] The present invention is not limited to the above-described embodiments, and naturally includes various modifications and equivalents within the concept and scope of the present invention.

[0140] like Fig.10As shown, the display control unit 6A may also cause the display unit 7 to overlap and display the irradiation range (processing frame) 200R of the sample 200 irradiated by the converged ion beam 20A. In this way, the irradiation range 200R of the sample 200v irradiated by the converged ion beam 20A can be easily grasped, and it can be understood how the sample 200 can be processed using the converged ion beam 20A.

[0141] In addition, if Fig.11 As shown, the display control unit 6A may also display the latest scanning position SR when the converged ion beam 20A or electron beam 10A is scanned on the surface of the sample 200. In this way, the position of the current converged ion beam 20A or electron beam 10A irradiated on the sample 200v can be easily grasped.

[0142] The converged ion beam device of the present invention only needs to have a converged ion beam column, and an electron beam column and a gas ion beam column are not essential structures.

[0143] In addition, the calculation method of the concentric height is not limited to the above method.

[0144] The image acquisition unit is not limited to the reflected electron detector or the secondary electron detector 4 in the electron beam column 10 , and may be a detection unit of an optical camera or the like.

Claims

1. A converging ion beam device, comprising: A convergent ion beam column, which is used to irradiate the sample with a convergent ion beam; a sample stage on which the sample is placed; and A sample stage, on which the sample stage is placed, is movable at least in the horizontal direction and the height direction, It is characterized in that The converging ion beam device also has: a storage unit that pre-stores three-dimensional data of the sample stage and the irradiation axis of the converged ion beam, wherein the three-dimensional data is associated with the stage coordinates of the sample stage; Display unit; as well as A display control unit, which, based on the three-dimensional data of the sample stage and the irradiation axis of the converged ion beam, causes the display unit to display the positional relationship between the virtual sample stage and the irradiation axis of the converged ion beam when the sample stage is moved to a specified position by operating the sample stage, wherein the specified position places the sample at an irradiation position that is consistent with the concentric height when irradiated by the converged ion beam. The concentric height corresponds to a height of the sample stage at which a specific observation point on the sample does not move even if the sample is tilted in a state where the sample is placed on the sample stage.

2. The focused ion beam device according to claim 1, wherein: The converged ion beam device further comprises a conversion unit, which converts the three-dimensional data of the sample input in advance into the coordinates of the stage according to the posture and placement position of the sample after being placed on the sample stage. The display control unit causes the display unit to display the positional relationship between the virtual sample, the virtual sample stage, and the virtual irradiation axis of the converged ion beam when the sample carrier is moved to the irradiation position based on the three-dimensional data of the sample obtained by conversion by the conversion unit.

3. The focused ion beam device according to claim 2, wherein: The sample stage can be tilted around a tilt axis parallel to the horizontal direction and orthogonal to the height direction. The converging ion beam device also has: an image acquisition unit that acquires a planar image of the sample placed on the sample stage; and a three-dimensional data generating unit that calculates the amount of movement of the sample stage to the concentric height and generates three-dimensional data of the sample, The conversion unit converts the three-dimensional data of the sample generated by the three-dimensional data generation unit into the stage coordinates.

4. The focused ion beam device according to claim 2 or 3, wherein: The storage unit stores an etching rate or a deposition rate when the sample is irradiated with the converged ion beam. The display control unit causes the display unit to display the virtual outline of the sample after etching or deposition according to a specified etching time or deposition time, based on the positional relationship between the virtual sample and the virtual irradiation axis of the converged ion beam when the sample carrier is moved to the irradiation position.

5. The focused ion beam device according to claim 2 or 3, wherein: The converged ion beam device further comprises a gas ion beam column or a laser column, wherein an acceleration voltage of the gas ion beam column or the laser column is set to be lower than an acceleration voltage of the converged ion beam column, and the gas ion beam column or the laser column is used to irradiate the sample with a gas ion beam or a laser. The storage unit stores in advance three-dimensional data of the irradiation axis of the gas ion beam or laser, wherein the three-dimensional data is associated with the stage coordinates of the sample stage. The display control unit also causes the display unit to display the positional relationship between the virtual sample stage, the virtual irradiation axis of the converged ion beam, and the virtual irradiation axis of the gas ion beam or laser when the sample stage is moved to a specified position by operating the sample stage based on the three-dimensional data of the irradiation axis of the gas ion beam or laser.

6. The focused ion beam device according to claim 5, wherein: The display control unit causes the display unit to display the positional relationship between the virtual sample, the virtual sample stage, the virtual irradiation axis of the converged ion beam, and the virtual irradiation axis of the gas ion beam or the laser when the sample carrier is moved to the irradiation position based on the three-dimensional data of the sample obtained through conversion by the conversion unit.

7. The focused ion beam device according to claim 2 or 3, wherein: The display control unit causes the display unit to display an irradiation range of the sample irradiated with the converged ion beam in an overlapping manner.

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