JP2007018935A - Microscope with probe and probe contact method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly grasp a three-dimensional coordinate of a probe tip.
Image display means for displaying a microscope image 35 obtained by a first charged particle microscope and a microscope image 36 obtained by a second charged particle microscope simultaneously or by switching, a first charged particle microscope, and a second charged particle microscope A calculation processing unit that controls the stage control system and the probe driving mechanism, and the calculation processing unit includes a microscope image of the first charged particle microscope including the target position 23 on the sample and the tip of the probe 6; A three-dimensional relative position of the probe tip with respect to the target position is obtained from the microscope image of the second charged particle microscope containing the target position on the sample and the probe tip.
[Selection] Figure 5

Description

  The present invention relates to a charged particle microscope with a probe having a probe in a sample chamber. For example, a probe-equipped microscope and a probe approach that can accurately bring the probe into contact with a target position on the sample surface by grasping the three-dimensional relative coordinates of the probe tip using a plurality of mounted charged particle microscopes Regarding the method.

  In the manufacture of semiconductor integrated circuits such as microprocessors and semiconductor memories, measurement of wiring dimensions, detection of foreign matter and defects on wiring patterns, and failure analysis are actively performed using an electron microscope to improve product yield. It has been broken. A focused ion beam device (Focused Ion Beam: FIB) and scanning electron microscope (Scanning Electron Microscopy: SEM) are combined to inspect abnormal locations inside a sample such as a device chip or wafer. FIB-SEM composite devices are used. In the FIB-SEM composite apparatus, fine processing is performed using the sputtering phenomenon by FIB irradiation, the cross section of the defective part inside the sample is exposed, and the defective part is observed by SEM without taking the target sample out of the apparatus.

  In addition, in this FIB-SEM combined device equipped with a probe, a small sample piece cut out from the sample by FIB is connected to the probe and extracted, and high-resolution SEM, TEM (transmission electron microscope), STEM (scanning transmission) It becomes possible to observe with an electron microscope. The FIB-SEM composite apparatus with a probe is disclosed in Japanese Patent No. 3547143 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2002-150990 (Patent Document 2). Patent Document 1 discloses a method of extracting a micro sample from a sample (wafer) and processing it into a TEM sample. Patent Document 2 discloses an apparatus for directly viewing with a SEM equipped with a cross section of a micro sample extracted from the sample. It is disclosed. The process of extracting a minute sample piece is described in detail in Japanese Patent Laid-Open No. 2001-147070 (Patent Document 3). However, these patent documents do not describe a specific movement and contact method of the probe on the sample surface.

  Further, Japanese Patent Laid-Open No. 8-335613 (Patent Document 4) discloses a laser in which a CCD is installed directly under the probe for detecting the height of the probe and placed directly beside it in order to properly contact the probe with the bump on the sample surface. A method is described in which the bump height is detected by a length measuring device and the probe is brought into contact with the bump from the information of both. Japanese Patent Application Laid-Open No. 11-248800 (Patent Document 5) discloses a probe driving motor which monitors a change in a probe image with a first camera above the probe and a second camera on the side of the probe. Feedback to the controller is shown. In these Patent Documents 4 and 5, the means for monitoring the probe or the sample is installed directly above or below the probe and directly next to it.

  Conventionally, the work of bringing the probe close to or in contact with a minute portion of the sample accurately in a vacuum sample chamber is performed by an operator visually observing a microscope image and depending on his / her skill.

Japanese Patent No. 3547143 JP 2002-150990 A JP 2001-147070 A JP-A-8-335613 Japanese Patent Laid-Open No. 11-248800 Japanese Patent No. 3577839

The prior art has the following problems.
In a state where the probe is separated from the sample, the three-dimensional positional relationship between the probe tip position and the target point is not clear.

  When the microscope is installed perpendicular to the sample surface and there is a probe between the microscope and the sample, the positional relationship in the plane parallel to the sample surface of the probe is easy to grasp, but the distance from the sample is difficult to grasp. In particular, the secondary electron image (Scanning Ion Microscopy image; hereinafter abbreviated as SIM image) by FIB irradiation has a deep depth of focus, so when the probe is within 10 μm above the sample surface, the probe and sample are in focus. , I can not grasp the height of the probe.

  Further, in the apparatus configuration in which the optical axis of the microscope is inclined with respect to the sample surface, it is difficult to grasp not only the height position of the probe tip but also the positional relationship in the plane parallel to the sample plane. In particular, in the case of a SEM and FIB multifunction device that can observe almost the same part of the sample, at least one of the optical axes is inclined with respect to the sample surface. Will observe. Thus, when the probe is separated from the sample, it is difficult to accurately obtain the three-dimensional positional relationship between the probe tip position and the target point.

  Further, the method of installing the monitoring means in the direction directly above and right side of the probe as disclosed in Patent Documents 4 and 5 indicates the distance between the objective lens end and the sample surface when the monitoring means is a charged particle beam. Since the working distance is several millimeters to several tens of millimeters, it is limited to a case where the target sample and the sample stage are very small. Of course, when the target sample is a wafer having a diameter of 200 mm or 300 mm, it is impossible to observe the probe height from the side.

  Furthermore, it is difficult to set the probe driving speed unless the three-dimensional positional relationship between the probe tip position and the target position on the sample is clear. That is, when the probe speed is set to be high despite the distance between the probe and the sample being short, there is a risk that the probe or the sample piece will rapidly come into contact with the sample or the sample fixing base and the probe or the sample piece will be damaged. On the contrary, when the probe speed is set to be slow although the distance between the probe and the sample is sufficiently long, the time until contact becomes too long. Therefore, it is advantageous to accurately grasp the positional relationship between the probe tip and the target position and drive the probe at a desired speed.

  In this way, in order to drive the probe at the optimum probe speed according to its position and bring the probe tip into contact with the target location of the sample accurately, the three-dimensional positional relationship between the probe and the target position to be contacted is grasped. It is a big problem to do.

  In view of the above-described problems, the present invention provides a probe-equipped microscope and a probe contact method capable of quickly grasping the three-dimensional coordinates of the probe tip in a plurality of charged particle microscopes and a probe-equipped microscope in which a probe is installed in a sample chamber. For the purpose.

  A microscope with a probe according to the present invention includes a sample stage on which a sample can be moved, a stage control system for controlling the movement of the sample stage, a first charged particle microscope, and an optical axis of the first charged particle microscope. A second charged particle microscope having an optical axis inclined with respect to the optical axis, a mechanical probe, a probe driving mechanism for driving the probe, a microscope image by the first charged particle microscope, and a microscope by the second charged particle microscope The image display means which displays an image simultaneously or switchingly, and a calculation processing part which controls a 1st charged particle microscope, a 2nd charged particle microscope, a stage control system, and a probe drive mechanism. The calculation processing unit includes a microscope image of the first charged particle microscope including the target position on the sample and the tip of the probe, and a microscope of the second charged particle microscope including the target position on the sample and the tip of the probe. From the image, the three-dimensional relative position of the probe tip with respect to the target position is obtained.

  Further, in bringing the probe tip into contact with the target position on the sample, the first microscopic image containing the target position on the sample and the tip of the probe obtained by the first charged particle microscope, and the first charged particles Based on the target position on the sample acquired by the second charged particle microscope having the optical axis inclined with respect to the optical axis of the microscope and the second microscope image containing the tip of the probe, A three-dimensional relative position of the tip of the probe is obtained, and driving of the probe is controlled using the obtained relative position information.

  According to the present invention, it is possible to accurately measure the three-dimensional positional relationship between a probe and a target position of a sample based on observation images of a plurality of charged particle microscopes. Thereby, since the probe speed according to the three-dimensional position of the probe can be set, the probe can be brought close to or brought into contact with the sample at an optimum probe speed in a short time.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same members are described with the same reference numerals. The position and number of the probes are arbitrary, but in the following description, the number of probes is assumed to be one for the sake of simplicity. In each embodiment, the combination of the first charged particle microscope and the second charged particle microscope is arbitrary. For example, the first charged particle microscope is a scanning electron microscope (SEM), the second charged particle microscope. Can be a focused ion beam microscope (FIB). Further, in the figure showing the apparatus configuration from the side, only the upward direction and the lateral direction are shown as the movement directions of the probe and the sample stage, and the orthogonal direction is omitted from the drawing.

[Embodiment 1]
FIG. 1 is a schematic configuration diagram showing an example of a microscope with a probe according to the present invention. The sample 2 is placed on the sample stage 3 and is movable in at least three orthogonal X, Y, and Z directions. The optical axis of the first charged particle microscope 4 is perpendicular to the sample surface (Z direction), and the optical axis of the second charged particle microscope 5 is inclined with respect to the sample surface.

  The probe 6 is mounted on a probe driving mechanism 7 that can be driven in three orthogonal axes. Secondary particles from the sample by the charged particle beam irradiation from the first charged particle microscope 3 and the second charged particle microscope 5 are detected by the signal detector 8. This apparatus has a gas supply source 9 that supplies gas to the charged particle beam irradiation unit, and can supply etching or deposition gas from a nozzle 10 at the tip. The sample stage 2, the first charged particle microscope 4, the second charged particle microscope 5, the probe driving mechanism 7, the signal detector 8, and the gas supply source 9 are a stage control system 11, a first microscope control system 12, a first 2 Connected to a microscope control system 13, a probe control system 14, a signal detector control system 15, and a gas supply source control system 16, which are placed under the control of the arithmetic processing unit 17. The signal of the signal detector 8 is processed by the arithmetic processing unit 17, and images of the first charged particle microscope 4 and the second charged particle microscope 5 are displayed on the image display means 18. The image display unit 18 also includes an instruction input unit, and the instruction input from the image display unit 18 is reflected in the control of the various control systems by the arithmetic processing unit 17.

  The positional relationship between the first charged particle microscope 4 and the second charged particle microscope 5 and the probe 6, the coordinate system of the sample stage 3, and the coordinate system of the probe fine movement mechanism 7 will be described with reference to FIG.

  The optical axis 21 of the first charged particle microscope is aligned with the Z axis in an orthogonal triaxial coordinate system in which the target point 23 to be contacted by the probe 6 on the surface of the sample 2 is the origin and the direction perpendicular to the sample surface is the Z axis. The optical axis 22 of the second charged particle microscope intersects the sample surface at the target point 23 and is inclined at an angle θ with respect to the X axis, and the first charged particle microscope and the second charged particle microscope. The charged particle beam irradiated from is set in a direction (indicated by reference numerals 24 and 25 in FIG. 2) toward the target point 23. As shown in FIG. 2, the probe drive mechanism 7 has the same coordinate system as the three-axis movement direction of the sample stage 3. The operation of bringing the tip of the probe 6 into contact with the target location of the sample 2, at least the probe movement immediately before the contact, is performed by bringing the probe 6 closer to the sample 2 from above in the vertical direction. Thereby, unexpected damage and misalignment of the probe can be avoided.

  The apparatus configuration will be described with reference to FIG. When the first charged particle microscope 4 is FIB and the second charged particle microscope 5 is SEM, analog information such as secondary electrons and reflected electrons obtained by the signal detector 8 using the SEM is converted to AD. Digitally converted by the device 31 and taken into the image display means 18 to form a two-dimensional image. Here, as an example, a secondary electron image (hereinafter referred to as an SEM image) is taken as an example of the image. In addition, a two-dimensional image can be acquired from the FIB by a similar method. Here, a secondary electron image (hereinafter referred to as a SIM image) is taken as an example. When acquiring these SEM image and SIM image, the signal detector 8 is used. For example, when switching from the SEM image to the SIM image, the electron beam irradiation from the SEM is stopped and the ion beam irradiation from the FIB is started. By that, it switches to the SIM image. Alternatively, SEM observation can be performed simultaneously with FIB processing by changing the scanning speed of SEM and FIB, detecting secondary electrons at a period synchronized with each scanning, and processing data in a computer.

  In the present embodiment, using the image obtained by the first charged particle microscope 4, the relative coordinates of the tip of the probe 6 with respect to the target position 30 where the sample 2 is to be contacted are measured. The coordinates are measured by analyzing the image obtained by the image display means 18. In addition, the calculation processing unit 32 performs this measurement, data processing of measurement values, and data accumulation. When observed with the first charged particle microscope 4 whose optical axis is perpendicular to the sample surface, the probe tip position coordinates are in the X direction (screen horizontal method) and Y direction (screen vertical direction) with respect to the target position 30. It is determined by the number of pixels, the observation magnification, and the total number of pixels in the vertical and horizontal directions of the screen. The probe speed is determined by the probe drive controller 33, and the probe 6 is driven by the probe drive mechanism 7 based on the probe drive speed.

The details of the operation method performed before driving the probe in such an apparatus configuration will be described.
First, as a preliminary operation, the field of view of the first charged particle microscope and the field of view of the second charged particle microscope are adjusted to be substantially the same, and the portion observed with one microscope can be observed with the other microscope. Set as follows. At this time, as an initial setting, if both microscopes are set to the same magnification, the object can be observed without a sense of incongruity even by switching screens. Further, when the microscope is observed from two directions, an image with different observation directions is displayed, so that the operator feels uncomfortable. Thus, by performing rotation correction on one image so that the observation images are in the same direction, both screens can be observed in substantially the same state. Furthermore, the tip of the probe is set at a height of about 10 μm to 100 μm from the sample surface within the field of view, and the position is registered, and the probe usually has a distance of mm to cm from the beam irradiation position of the sample. Retreat to a separated position.

  A method of moving the probe tip 8 to the target position will be described with reference to the flowchart of FIG. 4 and FIG. When the first charged particle microscope has an optical axis parallel to the Z axis and the second charged particle microscope has an optical axis inclined with respect to the Z axis as in this embodiment, the calculation processing unit The relative distance in the XY direction of the probe tip with respect to the target position is obtained from the microscope image of the first charged particle microscope, and the relative distance in the Z-axis direction of the probe tip with respect to the target position is obtained from the microscope image of the second charged particle microscope.

  First, using the image 35 of the first charged particle microscope and the image 36 of the second charged particle microscope, as shown in FIGS. A command is sent to the stage control system to move the sample stage so as to enter (S01), and the sample stage is actually moved within the XY plane (S02). If the target position 23 is at the center of the image, the target point 23 is conveniently located at the center of the image of the second microscope, regardless of whether the magnification of the first microscope is enlarged or reduced. The target position does not necessarily have to be set at the center of the image.

Next, a command is issued to the probe drive control system so that the tip of the probe 6 enters the field of view of the first charged particle microscope (S03), and it is operated (S04). The probe tip step moves the probe tip into the field of view. The probe tip 8 is recognized from the image 35 of the first charged particle microscope (S05), and as shown in FIG. 5A, the coordinates of the probe tip 8 with respect to the target point 23 coordinates are measured. Here, the coordinates of the target position 23 are (0, 0), and the coordinates of the probe tip 8 are (x ₁ , y ₁ ). (S06).

Next, the screen is switched to the observation screen of the second charged particle microscope. If the image display means is in an environment where the images of the first and second charged particle microscopes can be displayed at the same time, the operation moves to the operation with the image of the second charged particle microscope. The image of the probe tip 8 is also recognized in the image of the second charged particle microscope (S07), and the coordinates of the probe tip 8 with respect to the coordinates of the target position 23 are measured as shown in FIG. 5B. Here, the coordinates of the target position are (0, 0), and the probe tip coordinates are (y ₂ , z ₂ ) (S08). The coordinate values x ₁ , y ₁ , and y ₂ are obtained from the coordinate component X value and Y value measured in steps S 06 and S 08, the number of vertical and horizontal pixels of the image, the X value, the number of pixels corresponding to the Y value, and the observation magnification.

Since the first charged particle microscope 4 is installed perpendicular to the surface of the sample 2, the obtained x ₁ and y ₁ values are the X component and Y component of the spatial coordinates of the probe tip 8. On the other hand, since the second charged particle microscope 5 is installed at an inclination, the horizontal dimension of the image is reliable, but the vertical direction is a compressed diagram. That is, although the y value is reliable, the z value must be corrected for the tilt of the second charged particle microscope. Specifically, the z value is obtained from the number of vertical pixels of the image, the number of pixels of the measured Z-direction component z ₂ , the observation magnification and the tilt angle of the optical axis, and the actual height z _h of the probe tip 8 with respect to the sample surface is Using the tilt angle θ of the optical axis of the second microscope and the observation magnification M, the calculation processing unit calculates the following equation (1).
z _h = z ₂ / Mcosθ (1)

Thereby, the three-dimensional relative coordinates (x ₁ , y ₁ , z _h ) of the probe tip 8 with respect to the target position 23 are obtained (S09). Next, the calculation means instructs the probe control means to move by the relative coordinates (x ₁ , y ₁ , z _h ) (S10). The probe control means operates the X, Y, and Z axis drive shafts of the probe drive mechanism 7, moves the probe, and stops the probe movement when it contacts the target position (S20).

  Next, a series of probe movements in which the probe in the retracted position is called into the microscope visual field and brought into contact with the target position will be described with reference to FIG.

  In FIG. 6, the probe 6A in the retracted position is called to a spatial position in the microscope field registered in advance. The probe at this time is denoted by reference numeral 6B. Here, since the drive system has an error of about 1 μm on both the XYZ axes, even if the call coordinates are designated, it does not move to an accurate position. In this state, as described above, the three-dimensional relative coordinates of the tip 50B of the probe 6B with respect to the target position 23 are obtained. The height of the probe 6B is about 30 μm from the sample surface. This was determined from a sufficiently spaced distance at which the charged particle microscope is focused on the sample surface, which is the target position, and the probe tip, and at a low risk of collision with the sample. Based on these coordinates, the probe drive mechanism is instructed to move the probe, and the operation is started.

  In this embodiment, the probe 6B is first moved only in the X axis and moved so that the x coordinate becomes zero. When x = 0, the probe tip 50B is in contact with the YZ plane. Next, only the Y axis is operated and moved until the y coordinate of the probe tip becomes zero. At this time, the probe tip reached the XZ plane, which is indicated by reference numeral 50C. That is, it is on the Z axis that is the intersection line of the YZ plane and the XZ plane. Next, the Z axis of the probe drive system is moved, but if the absolute value of the z coordinate obtained previously is moved so as to reach the XY plane, the target position cannot be accurately reached due to the error of the probe drive system, In the worst case, the probe can be damaged. Therefore, here, first, a command is given to the drive system so as to move the probe by 90% of the z coordinate value. As for the movement of the X axis, the Y axis, and the Z axis so far, any of the axes may be given priority to move, or a plurality of axes may be driven simultaneously. After moving a predetermined distance, the probe is temporarily stopped. The probe at this time is denoted by reference numeral 6D. Here, the positional relationship between the tip 50D of the probe 6D and the target position 23 is confirmed and corrected if necessary. First, correction in the XY plane is performed by the first charged particle microscope. The confirmation of the z direction may be performed by the second charged particle microscope, but z may be lowered immediately after XY in-plane correction because it moves a short distance at a slow speed. If the contact with the sample cannot be detected by moving a predetermined 0.1z, the probe is stopped immediately above the target position due to an error in the drive system. In this case, the probe is further fined by 0.005z. Can be lowered to contact. The probe in contact with the target position 23 is denoted by reference numeral 6E.

  Next, the moving speed of the probe will be described. The moving speed of the probe is pre-registered in advance in the probe drive mechanism control system 7 in several stages according to the position of the probe. In the present embodiment, the speed is changed in three steps from the retracted position 6A to the target position 23, and is fast at a place far from the target position and decelerated at a close place, so that the target place is accurately and efficiently (in a short time). I moved it. For example, the probe 6A at the retracted position is called, the probe moving speed is 10 to 30 mm / second (referred to herein as the high speed mode) up to the position of the probe 6B, and the distance from the probe 6B position to the probe 6D position is 5 to 20 μm / second. Second (low speed mode), further, the probe moving speed was reduced to 0.5 to 1 μm / second (slow speed mode) by moving only the Z axis from the probe 6D position to the target position 23. By pre-registration of the plurality of probe driving speeds, when the probe is far from the sample surface, the probe can be approached at a high speed, and as the sample surface is approached, the speed can be decreased and approached. The probe tip can be approached efficiently. As a specific example, an operation that took about 3 minutes for the probe at the retracted position to contact the target position is about 5 seconds after the movement command is issued to the probe at the retracted position by such a shift operation. The position could be touched.

  Next, a probe access method from the calling position to immediately before the target position will be described below.

  FIG. 7 shows a flow in which the probe called in the charged particle microscope image reaches the target position. This flow shows a flow from moving toward a target at a predetermined speed, switching to the fine speed mode immediately before the target position, contacting the target position, and stopping.

  As the previous operation, the probe at the retracted position is called, and first, relative coordinates (x, y, z) with respect to the target position of the probe tip at the calling position are obtained (S09). Here, the target coordinate is (0, 0, 0). The method for obtaining these coordinates has been described above. The subsequent probe operation means only commands to move to the target position (0, 0, 0) (S11), but the actual probe operation involves the following steps. Immediately before reaching the final contact, the probe decelerates the moving speed from the low-speed movement so far to the fine-speed movement, contacts the target position, and stops. The coordinates at which the probe decelerates at a slow speed is calculated as (0, 0, kz), and moves slowly to the shift coordinates (0, 0, kz) (S12). Here, 0 <k <1, and in this embodiment, k = 0.1. That is, the probe is shifted at a slight speed just above the target position and at 1/10 the height z of the calling position. Specifically, if the call height is 50 μm, the position to decelerate is 5 μm immediately above the target position. From the calling position to the deceleration position, only the X and Y axes move at a predetermined low speed, and the probe descends from the deceleration position along the Z axis at a predetermined fine speed (S13). These probe moving speeds are registered in advance. The probe contacts the target position by the slow movement, detects this contact (S14), and stops the probe (S20). By such a flow, since the probe does not have a moving component in the x direction or the y direction at the time of contact with the sample, the probe can contact the target position accurately without dragging the sample surface or colliding with the sample surface.

  Although the probe tip reaches the target position by the basic flow as described above, in practice, prior to the operation of bringing the probe into contact with each target position, registration of the probe tip shape and the focusing condition at the probe tip calling position The above-described flow flows more reliably by performing registration. These are described here.

Pre-registration of the probe tip shape will be described using the flowchart of FIG.
First, the image magnification of the first charged particle microscope and the second charged particle microscope is set to the lowest (S001). In this embodiment, the magnification is 500 times. Next, a command for calling the probe at the retracted position is issued from the GUI (S002). The probe driving means operates toward the preset call position, and the probe moves within the image field (S003). During this time, the microscope may be in operation or in a blanking state, but when the probe is stopped, the probe can be confirmed with the first charged particle microscope. The probe is confirmed from the image of the first charged particle microscope (S004). The confirmation method may be that the operator visually confirms, or the probe position in the image may be confirmed by using an image recognition function installed in the computer without relying on visual observation.

  Next, if necessary, the position of the probe is corrected so that the probe is substantially at the center of the image, and the observation magnification is increased to a predetermined magnification (S005). In this embodiment, it was 3000 times. The shape of the probe tip is registered at this magnification (S006). At the time of registration, selection is made so that only the probe becomes a registered image so that unnecessary information is not included in the registered image.

  Next, switch to the second charged particle microscope and look at the probe. The observation magnification was the same as that of the first charged particle microscope used in step S001. However, since the first charged particle microscope and the second charged particle microscope are originally set so that almost the same point can be observed on the sample surface, the probe tip located several tens of μm above the sample surface has a high magnification. As it happens, it may happen that the field of view is not entered by switching from the first to the second microscope. Therefore, when switching to the second charged particle microscope, it is a good idea to first view at the lowest magnification used in step S001. The probe tip position is confirmed at a low magnification, and the probe tip shape is registered at the same magnification as in step S005 (S007).

  These steps S001 to S007 are performed before each probing operation, and are performed before the above-described step S01.

  Next, registration of the focusing condition at the tip at the probe calling position will be described with reference to FIG.

  Originally, the first charged particle microscope and the second charged particle microscope are set so that they can be focused and observed on the same surface on the sample surface. Due to the switching, it may happen that the probe tip located several tens of μm above the sample surface is not focused. If the probe is not focused by switching to the second charged particle microscope, the probe tip cannot be confirmed, and the probe tip, which is the original purpose, cannot be moved to the target position. Therefore, an adjustment flow in which the probe tip that is several tens of μm above the sample surface is focused on both the first microscope and the second microscope may be added to the flow of FIG. FIG. 9 is a flow including an adjustment flow. Steps having the same step number are the same as the step contents of FIG.

  First, after step S001, the coordinates of the probe calling position are input from the probe operating means GUI and registered (S0011). In this case, the magnification is such that the tip of the probe and the target position enter the screen even at a high magnification performed in step S005. The probe height is set to about 10 to several tens of μm, and in this embodiment, 50 μm, and these numerical values are entered by the GUI and registered. Thereafter, the above-mentioned contents are advanced from step S002 to step S005, and after step S005, the lens condition is adjusted so that the probe tip and the target position are in focus with the first charged particle microscope, and the condition is stored. (S0051)

  Similarly, for the second microscope, the lens conditions are adjusted so that the probe tip and the target position are in focus, and the conditions are stored (S0052). Thereby, after step (S005), the focus is automatically adjusted, and subsequent steps such as registration of the probe tip shape and measurement of the positional relationship with the target position can be smoothly performed.

[Embodiment 2]
In the first embodiment, the case where the moving coordinate system of the probe is the same as the moving coordinate system of the stage as shown in FIG. 2 has been described. Even if it has, it can be similarly applied.

  FIG. 10 shows the positional relationship between the probe and the target location 23 when the probe 6 has the same xy axis as the stage movement axis and the third axis is in the probe axis direction. Here, the third coordinate axis is called the p-axis, and the observation direction 24 of the SEM as the first charged particle microscope and the observation direction 25 of the FIB as the second charged particle microscope are the same as those in FIG. The p-axis is inclined at an angle φ with respect to the y-axis and is in a vertical positional relationship with the x-axis.

  In such a positional relationship between the probe and the target location, a method for efficiently bringing the probe 6 into contact with the target location 23 will be described with reference to FIG. FIG. 11A shows an observation image 35 obtained by SEM when the probe 6 is called from the retracted position, and FIG. 11B shows an observation image 36 obtained by the inclined FIB. Since the FIB is inclined with respect to the sample surface (XY plane), the scale of the image 36 by FIB differs in the vertical and horizontal directions, and the vertical dimension is determined by the inclination angle of the FIB optical axis and the observation magnification. When there is an error in the corner, the dimensional accuracy in the Z-axis direction on the screen is low. FIG. 11A shows the relationship between the movement axes X and Y axes of the probe 6 when observed with the SEM and the movement axes X and Y of the sample stage on which the sample having the target location is placed. The state corresponding to the axis is shown. FIG. 11B shows the relationship between the stage movement axes Y and Z axes and the probe movement axes Y and P axes when observed by FIB, and shows a state in which the probe axes coincide with the P axes.

  In the state in which the probe is called, there is a variation in the probe tip position. Therefore, immediately after calling into the SEM and FIB images in which the probe 6 and the target location 23 are in the field of view, as shown in FIG. The probe position is moved in the X-axis direction (horizontal direction of the screen) to correct the probe axis so that it passes through the target position 23 and coincides with the Y-axis (vertical direction of the screen). As shown in FIG. The probe axis is moved in the Y-axis direction, and the Y-axis (horizontal direction of the screen) is adjusted so that it passes through the target position 23 and coincides with the P-axis (a straight line having the same tilt angle as the probe tilt angle).

  Next, in FIG. 11B, the p-coordinate of the probe tip with respect to the target position 23 is read from the image, and this P-coordinate is transmitted to the probe driving mechanism to drive the probe 6 only on the P-axis to reach the target position.

  In this embodiment, 10% of the P coordinate at the calling position, that is, the position of 0.1p is used as the speed change position and the final xy position correction is performed in the present embodiment. The contact can be made at a very low speed only on the P axis and can be stopped accurately without stopping the probe tip.

[Embodiment 3]
FIG. 12 is a diagram showing the relationship between the optical axes of the first and second charged particle microscopes with respect to the stage coordinates and the probe, and FIG. 13 particularly shows the first and second embodiments. It is a top view of an apparatus configuration showing a positional relationship of the charged particle microscope.

  In the present apparatus example, as shown in FIG. 12, the optical axis 71 of the first charged particle microscope is on the YZ plane of the stage movement coordinate system, and the angle formed with the Y axis (sample surface) is θ. The optical axis 72 of the charged particle microscope is in the XZ plane, and the angle formed with the X axis (sample surface) is φ. In FIG. 12, reference numeral 73 indicates the charged particle beam irradiation direction of the first charged particle microscope, and reference numeral 74 indicates the charged particle beam irradiation direction of the second charged particle microscope. It faces the origin of the coordinate system. Also in this example, the moving coordinate system of the probe is the same as the moving coordinate system of the sample stage.

  Next, the apparatus configuration will be described with reference to FIG. The first charged particle microscope 81 is SEM, and the second charged particle microscope 82 is FIB. The optical axis 83 of the first charged particle microscope 81 and the optical axis 84 of the second charged particle microscope 82 intersect on the surface of the sample 85, and the probe 86 can be moved by the probe driving device 87. The sample 85 is mounted on the sample stage 89 and has at least three XYZ movement axes. In addition, a signal detector, a gas supply source, and the like are also mounted, but the description thereof is omitted in this embodiment. 12 and 13 are somewhat different in the orientation and details of the device, but this is for easy understanding of the explanation and is not essential.

Next, a method for automatically moving the probe tip 8 to the target position will be described with reference to FIG.
FIG. 14A shows an image 91 obtained by viewing the target point 88 and the probe 86 with the first charged particle microscope, and FIG. 14B shows a positional relationship between the target point 88 and the probe 86 viewed with the second charged particle microscope. FIG. 6 is a schematic diagram of an image 92.

  As in this embodiment, the first charged particle microscope has an optical axis inclined with respect to the Z axis, and the second charged particle microscope has an optical axis that is in the XZ plane and inclined with respect to the Z axis. In this case, the calculation processing unit obtains the relative distance in the Y direction of the tip of the probe with respect to the target position from the microscope image of the second charged particle microscope, and X of the tip of the probe with respect to the target position from the microscope image of the first charged particle microscope. The relative distance in the direction is obtained, and the relative distance in the Z-axis direction of the tip of the probe with respect to the target position is obtained from the microscopic image of the first charged particle microscope or the microscopic image of the second charged particle microscope.

  First, using the image 91 by the first charged particle microscope, the sample stage is moved so that the target point 88 of the sample 85 enters the observation image, and the probe driving mechanism is operated so that the probe 86 enters the observation field of view. . In particular, if the target point 88 is at the center of the image 91, it is convenient because the target point is located at the center of the image, regardless of whether the magnification of the microscope is enlarged or reduced. It is not always necessary to set the center.

  When the X and Z coordinates of the tip of the probe 86 measured by the first charged particle microscope are measured, the probe 86 is never moved and is switched to the screen of the second charged particle microscope. Note that if there is an environment in which the first and second charged particle microscope images can be viewed simultaneously on different screens, there is no need to switch the images, and attention is paid to the image of the second charged particle microscope.

Next, as shown in FIG. 14B, the target point 88 and the tip of the probe 86 are placed in the same field of view in the image 92 of the second charged particle microscope. Since the optical axis of the microscope is tilted with respect to the sample surface, the top and bottom of the screen (the z direction in FIGS. 14A and 14B) are compressed images according to the tilt angle of the optical axis. Yes. However, the x direction in FIG. 14A and the length of the y axis in FIG. 14B can be derived from the dimensions on the image and the observation magnification. Z ₁ and z ₂ are apparent z coordinates obtained in each image.

The coordinates in the z direction are obtained by the following expression (2) from the dimensions z ₁ and z ₂ on the image, the observation magnification M, and the inclination angles θ and φ of each optical axis.
_{z = z 1 / Mcosθ = z} 2 / Mcosφ (2)

  As shown in FIG. 14, two types of images can be obtained by two charged particle microscopes. However, since both images are observed images from an inclined position, for example, the probe is placed on the Y axis on the screen of FIG. When operated in the direction, the probe in the screen appears to move up and down. Further, when the X axis is operated on the screen of FIG.

  Furthermore, since both screens are images compressed in the vertical direction compared to the horizontal direction, the vertical distance measured on the screen needs to be corrected. On the contrary, the horizontal dimension is reliable, and the distance is obtained from the number of pixels and the magnification. Thus, to make the tip of the probe 86 reach the target point 88 instantaneously, the three axes of xyz must be skillfully operated.

Therefore, the probe is operated as follows. This will be described with reference to FIG.
FIG. 15A is an image viewed with the first charged particle microscope 82, and the probe 86 called from the retracted position and the target position 88 are within the screen. The target position 88 is the origin, the vertical direction is the Z axis, and the horizontal direction is the X axis. Here, as shown in FIG. 15B, the probe 86 is moved in parallel to the X axis toward the Z axis, and when reaching the Z axis, the probe operation is stopped. The stopped probe is indicated by reference numeral 86a. By this operation, it can be said that the tip of the probe 86 is in the YZ plane.

  Next, FIG. 15C is an image obtained by viewing the probe 86a and the target position 88 with the second charged particle microscope. The vertical direction is the Z axis and the horizontal direction is the Y axis. Here, the probe 86a is moved in parallel to the Y axis, that is, right side on the screen, and moved toward the Z axis, that is, a vertical line passing through the target position (FIG. 15D). When the Z axis is reached, the probe movement is stopped. The probe at this time is denoted by reference numeral 86b. By this operation, the probe tip on the YZ plane moves toward the Z axis in the YZ plane, that is, the XZ plane, and stops when the probe reaches the XZ plane. Therefore, the probe 86b crosses the YZ plane and the XZ plane. The line is located on the very Z axis, that is, in front of the target location.

  Finally, only the Z axis of the probe is operated to approach the target position, and finally it can be brought into precise contact with the target position. As for the moving speed to the target position, 90% of the Z value of the probe 86b is lowered at a somewhat high speed and decelerated at the remaining 10% as shown in the first embodiment. The probe at this time is denoted by reference numeral 86c in FIG. Finally, the probe 86c was lowered at a slow speed so as to contact the target position 88.

  As described above, even if the optical axes of the two charged particle microscopes are both inclined, the probe can be brought into contact with the target position accurately and quickly.

  To make the embodiment shown in FIG. 13 more convenient, as shown in FIG. 16, in addition to the first charged particle microscope 81 and the second charged particle microscope 83, a third microscope on the Z axis is used. As 101, an optical microscope was installed. This enables high-precision positioning of the probe tip position by the first charged particle microscope and the second charged particle microscope, as well as observation at a low magnification, alignment of the pattern under the passivation film, and wafer alignment.

  As described above, by switching between the two charged particle microscopes, the spatial position of the probe tip can be accurately known and can be accurately moved to the target position on the sample. In addition, since the current position of the probe can be grasped, the moving speed can be set with peace of mind, and the probe can be efficiently moved to the target position on the sample surface.

[Embodiment 4]
The present embodiment relates to an operation screen (graphical user interface) necessary for operating the probe as in the above-described embodiment. FIG. 17 is a diagram illustrating an example of a probe operation screen.

  The image display unit 120 displays a probe operation screen 121 and a stage operation screen 122. The probe operation screen 121 includes image display units 123 and 124 by the first and second charged particle microscopes. The image display unit 123 includes SEM images, SIM images, OM images (optical microscope images), CAD ( There is an image selection unit 125 for selecting image display contents from the menu of the wiring design diagram). In the present embodiment, the SIM selection button 126 is activated on the image display unit 123 to display a SIM image, and the SEM selection button 127 is selected on the image display unit 124. The method of selection is not limited to this, and combinations are free. The image display units 123 and 124 have visual field dimension setting units 128a and 128b corresponding to the observation magnification of each image.

  The probe call button 129 is a button for introducing the probe at the retracted position into the observation visual field, and the measurement button 130 designates at least two points of the probe tip 137 and the target point 88 on the image display unit 123 or 124. Thus, the coordinates along the probe driving axis of the probe tip 137 with respect to the target point 88 are measured. An existing point device such as a mouse, a numeric keypad, or a touch pen is used as a method for designating a measurement location on the screen. Each point indicated on the screen is a coordinate divided into two-axis components in the probe movement coordinate system, and the actual size is calculated in consideration of the number of pixels on the screen, the observation magnification, and the tilt angle of the optical axis of the observation microscope. For example, in the case of the arrangement of the third embodiment, the relative coordinates (x, z) of the probe tip with the target point as the origin from the first image display unit 123a is the probe tip coordinate from the second image display unit 123a. (Y, z) becomes clear, and (x, y, z) is obtained as the three-dimensional coordinates of the probe tip. The movement button 131 is a button for instructing to move the probe to the target point 88 based on the probe tip coordinates (x, y, z) obtained by the above operation. Further, the retreat button 132 instructs to return the probe to a position where it waits outside the field of view. When the probe tip safely reaches the target point by moving the probe, a contact stop sign 133 is displayed on the screen. Further, in the event of any accident, the emergency stop button 134 is pushed to ensure the safety of the entire system.

  Next, the stage operation screen 122 will be described. For the point of interest 88 on the sample, which is the movement destination of the probe, the coordinates obtained by another inspection apparatus or previously known coordinates are input as three-dimensional information on the stage operation screen 122. In this operation, wafer Z-direction correction and chip-by-chip alignment are performed in advance. After inputting the coordinates 135 of the target position, pressing the stage operation button 136 moves the stage in the X and Y directions, and the visual fields of the first and second charged particle microscopes are displayed on the image display units 123 and 124. The

  It is needless to say that such an operation screen can include a large number of other functions, duplicate portions can be deleted, and the operation screen does not necessarily have to display a plurality of screens at the same time.

[Embodiment 5]
In the above-described embodiment, an example of an apparatus configuration in which the optical axes of a plurality of charged particle microscopes intersect at the sample surface has been shown, but the present invention can also be applied to a structure that does not intersect. In this example, as shown in FIG. 18, for example, the optical axis 232 of the first charged particle microscope 231 intersects the sample 233 perpendicularly, and the optical axis 235 of the second charged particle microscope 234 does not intersect perpendicularly with the sample 233. The probe driving means 236 is installed on the sample stage 237 and can move together with the sample 233.

First, the x and y coordinates (x ₃ , y ₃ ) of the probe 238 are obtained by the first charged particle microscope 231, and after moving the stage, the probe 238 and the target position are introduced into the observation field of view of the second charged particle microscope 234. Thus, the X and Z coordinates (x ₃ , z ₃ ) of the probe 238 are known.

In this way, the relative three-dimensional coordinates (x ₃ , y ₃ , z _h3 ) of the probe tip with respect to the target position on the sample surface are known, and this information is sent to the probe driving means 236 and operated, whereby the probe tip is operated. Can be moved to the target position.

[Embodiment 6]
In the present embodiment, an example in which a plurality of charged particle microscopes are mounted has been described. However, FIG. 19 illustrates that even a single charged particle microscope can be used. In this embodiment, only one charged particle microscope 141 whose posture can be changed is mounted, the probe 143 can be operated in the sample chamber 142, and placed on the optical axis 144 and the sample stage 145 of the charged particle microscope 141. This is an apparatus configuration having a mechanism (not shown) that can change the optical axis so that the intersection with the surface of the sample 146 does not shift. Further, the probe 143 is configured to enter the field of view of the charged particle microscopes 141 and 141 ′ even when the optical axis 144 of the charged particle microscope 141 is perpendicular to the surface of the sample 146 or is inclined.

When the tip of the probe 143 is observed when the optical axis 144 is perpendicular to the surface of the sample 146, the coordinates (x ₄ , y ₄ ) of the probe tip can be obtained by the same method as described above. Next, the probe tip is observed by tilting the optical axis by an angle ω with respect to the original position, and coordinates (x ₄ , z ₄ ) of the probe tip are obtained. From this z ₄ value and the optical axis tilt angle ω, the actual height z _h4 of the probe can be obtained in the same manner as described above. With these operations, the coordinates (x ₄ , y ₄ , z _h4 ) of the probe tip can be obtained. Using these coordinates, the probe 143 can be moved to a target position on the sample 146. The specific operation procedure may be the same as the method shown in the above embodiment.

  It is conceivable to observe the tip of the probe from a different direction by deflecting the beam at a large angle as a conventional technique for changing the optical path with the same optical system, but in this case, the deflection angle of FIB or SEM is at most several degrees. Therefore, the three-dimensional coordinates of the probe tip cannot be measured accurately. The present method that can greatly change the observation angle has an advantage that the obtained coordinate position error can be reduced.

[Embodiment 7]
The present embodiment relates to the probe moving method shown in the first embodiment, and in particular, the probe tip and the target position are extracted from the image, and the relative position relationship is automatically measured, thereby specifying the target position and moving the probe. This is an example in which the process until completion is simplified. This will be described with reference to FIG.

The operator inputs the coordinates (x ₀ , y ₀ ) of the target position on the image display means (S31), and instructs the stage movement. As a result, the arithmetic processor commands the stage control system, and the stage moves and stops so that the target point falls within the observation field of view of the charged particle microscope. After the stage is stopped or moved, the probe driving control system is commanded in parallel so that the probe in the retracted state also enters the observation field of view. At this time, the target point is close to the center of the visual field, but the probe tip is preferably located in the visual field where the target point and the probe do not overlap. After stopping the probe and the stage, an image in which the target point and the probe tip coexist is acquired by microscopic observation from two directions, and relative coordinates of the probe tip with respect to the target point are acquired by image recognition. At the time of acquisition, the arithmetic processing unit is instructed to display on the probe operation screen of the image display unit that the probe is movable.

  After confirming the completion of the stage movement displayed on the image display unit and the display indicating that the probe is movable, the operator presses a jog button that gives a probe movement command (S32). The arithmetic processor sends the relative coordinates of the probe tip obtained earlier to the probe drive control system, operates the fine movement mechanisms of the XYZ axes, and stops the probe movement when the coordinates of the probe tip coincide with the target point. (S33).

  Thus, the operator can move the probe to the target point only by inputting the target point and operating the command button for moving the probe. An example of an image display unit for performing this operation is shown in FIG. At least one of a stage operation screen 162 and a probe operation screen 163 is displayed on the image display unit 161, and at least a coordinate input unit 164 for inputting the coordinates of the target point and a stage movement button 165 are arranged on the stage operation screen 162. The probe operation screen 163 includes at least a microscope screen 166a, 166b, a probe movement button 167, and a movement completion display section 168.

  During the screen operation by the operator as described above, the arithmetic processor instructs and confirms measurement of two points from the stage control system, the probe drive control system, and the image, and processes a continuous flow.

  In the above-described embodiments, the method has been described in which the sample is almost stopped once entering the observation screen, and the probe is actively operated to move to the target point. The present invention is not limited to this embodiment, and a method of moving the target point on the sample surface to the tip of the probe by moving the stage positively while almost stopping the probe entering the field of view is also applicable.

[Embodiment 8]
Another embodiment will be described with reference to FIG. The probe-equipped microscope 171 in FIG. 22 includes a first charged particle microscope 173 that can be changed in a vertical and inclined state with respect to the surface of the sample 172, and a second charged particle microscope 174 that is fixed vertically. 176 is mounted so as not to cross the surface of the sample 172, the probe 177 is arranged to operate under the first charged particle microscope 173, and the sample 172 is connected to the first charged particle microscope 173. The sample stage 178 can be reciprocated so that it can be observed with the second charged particle microscope 174. In particular, in this example, SEM was used as the first charged particle microscope 173, and FIB was used as the second charged particle microscope 174. The purpose of this apparatus is to observe the surface of the semiconductor device, which is the sample 172, with a SEM (first charged particle microscope) 173 ′, and observe the defective portion of the wiring by SEM from the direction perpendicular to the surface of the sample 172. While displaying the wiring, display the observation image of the substance by SEM, and search for the disconnection or short circuit. Thereafter, the sample stage 178 is moved, and wiring connection work and unnecessary part deletion work by the FIB (second charged particle microscope) 174 are performed on the defective part. The stage 178 is returned to the SEM 173 ′ again, and the probe 177 is contacted with the wiring of the sample 172 and measured in order to confirm the electrical characteristics of the processing region. By using the probe moving technique of the present invention when the probe 177 is touched to a specific wiring, the probe can be accurately and more quickly moved to the target position.

  FIG. 23 shows an example of an image display unit 181 for observing and operating the sample 172 and the probe 177 provided in the probe-equipped microscope 171 shown in FIG. The present embodiment shows an example in which a plurality of probes 177a and 177b are installed under the first charged particle microscope, and the probe operation screen 182 displayed on the image display unit 181 shows a computer design indicating the structure of the sample. The SEM image 185 by the figure screen 183 and the first charged particle microscope is selected and displayed by the image selection unit 184. The probe selection unit 186 on the probe operation screen selects the first probe 177a and designates the position to be measured on the computer design drawing screen 183 with the pointer 187, so that the probe 177a moves to the target plug 188a to be measured. . If necessary, this behavior can be observed on the SEM screen 185. When the first probe 177a comes into contact with the target plug 188a, the contact display portion 189 changes color. Similarly, for other measurement points, the second probe 177b moves and contacts the target position 190 by selecting the second probe with the probe selection unit 186 and designating the measurement position on the computer design drawing screen 183. .

  These workflows are not uniquely limited. Specify the destination for the first and second probes, measure the coordinates of each probe tip with the second charged particle microscope, It may be operated.

  Thus, by measuring the three-dimensional coordinates of the probe tip by changing the observation direction of a plurality of microscopes or a single microscope according to the present invention, electrical measurement of a minute region can be performed easily and accurately in a short time. You can do it.

[Embodiment 9]
The arrangement of the first charged particle microscope and the second charged particle microscope in the microscope with a probe of the present embodiment is similar to FIG. 12, but the optical axis of the first charged particle microscope is Y in the XY plane. The only difference is in the WZ plane formed by the W and Z axes that form an angle η with the axis.

  That is, the first and second charged particle microscopes are in an XYZ coordinate system of three orthogonal axes with the target point 23 to be contacted by the probe 6 on the sample surface as the origin and the Z axis as the direction perpendicular to the sample surface. The probe can also move along the same three orthogonal axes. The optical axis of the first charged particle microscope is in the WZ plane formed by the W axis and the Z axis that form an angle η with the Y axis in the XY plane, and forms an angle θ with the W axis through the origin. The optical axis of the second charged particle microscope lies on the XZ plane and forms an angle φ with the X axis through the origin. FIG. 24 shows the relationship between the optical axes of the first and second charged particle microscopes of the microscope with a probe and the probe with respect to the stage coordinate system as seen from the Z-axis direction.

In the case of this example, the y coordinate of the tip of the probe 6 can be obtained from the observation image of the second charged particle microscope, as in the third embodiment. The x coordinate of the tip of the probe 6 can be obtained as follows. Now, in the observation image of the first charged particle microscope, if the apparent x coordinate value is a, the x coordinate value has the following relationship with a, y, and angle η from the geometrical relationship.
a = xcosη + ysinη

Therefore, the x coordinate in the XYZ coordinate system is expressed by the following equation (3), where M is the observation magnification.
x = (a−ysinη) / Mcosη (3)

  Further, as described in Embodiment 3, the z coordinate of the probe tip is determined by the value obtained by dividing the z interval in the observation image by cos θ and the observation magnification.

  As described above, even when the two charged particle microscopes are not orthogonal to each other, the three-dimensional relative position of the probe tip with respect to the target position on the sample is obtained, and the probe is based on the information. To drive the probe tip into contact with the target position on the sample.

  As described above, by taking the apparatus configuration shown in FIGS. 2, 10, 13, 16, 18, 19, 22 and so on as an example, according to the present invention, the tip of the probe in the vacuum sample chamber is placed at a desired position on the sample. It was shown that contact can be made accurately. By using the method for accurately detecting the probe tip position according to the present invention, for example, the electron microscope sample preparation method disclosed in Patent Document 1 can be performed more accurately and in a short time, and image recognition can be performed. The effect that can be automated by using such as.

  Furthermore, even when the number of probes installed in the sample chamber is plural, the above-described method can be applied. For example, it can be applied to the measurement of electrical characteristics of a fine region disclosed in Japanese Patent No. 3577839 (Patent Document 6).

The schematic diagram which shows the apparatus structural example of this invention. The schematic diagram which shows the relationship between the coordinate system of a stage, the optical axis of a microscope, and the coordinate system of a probe. The figure explaining the outline of an apparatus. The flowchart which shows the procedure for moving a probe front-end | tip to a target point. The figure explaining the procedure at the time of calculating | requiring the three-dimensional coordinate of a probe front-end | tip. The flowchart which shows the procedure of the last stage which moves a probe front-end | tip to a target point. The schematic diagram which shows the relationship between the coordinate system of a stage, the optical axis of a microscope, and the coordinate system of a probe. The plane schematic diagram which shows another apparatus structural example of this invention. The figure explaining the procedure at the time of calculating | requiring the three-dimensional coordinate of a probe front-end | tip. The plane schematic diagram which shows another apparatus structural example of this invention. Explanatory drawing which shows a probe contact detection method. The figure explaining the relationship between the coordinate system of a probe and the coordinate system of a stage. The schematic diagram which shows another apparatus structural example of this invention. The figure explaining the method of calculating | requiring the coordinate of a probe front-end | tip. The figure explaining the movement of a probe. The schematic diagram which shows another apparatus structural example of this invention. The figure which shows the structural example of the image display part which performs a probe operation command. The schematic diagram which shows another apparatus structural example of this invention. The schematic diagram which shows another apparatus structure of this invention. The flowchart which shows the simple probe movement procedure. The figure which shows the structural example of the image display part which simplifies a probe operation command. The schematic diagram which shows the apparatus structural example of the microscope which has a some probe. The figure which shows the structural example of the image display part in the microscope which has a some probe. The top view which shows the relationship between the optical axis of a microscope with respect to a stage coordinate system, and a probe.

Explanation of symbols

2: sample, 4: first charged particle microscope, 5: second charged particle microscope, 6: probe, 18: image display unit, 23: target point, 120: image display means, 121: probe operation screen, 122 : Stage operation screen, 123: First microscope image, 124: Second microscope image

Claims (18)

A sample stage that can be moved in the XY direction by placing the sample in an XYZ rectangular coordinate system;
A stage control system for controlling the movement of the sample stage;
A first charged particle microscope;
A second charged particle microscope having an optical axis inclined with respect to the optical axis of the first charged particle microscope;
A mechanical probe,
A probe driving mechanism for driving the probe;
Image display means for displaying a microscope image by the first charged particle microscope and a microscope image by the second charged particle microscope simultaneously or by switching;
A calculation processing unit that controls the first charged particle microscope, the second charged particle microscope, the stage control system, and the probe driving mechanism;
The calculation processing unit includes a microscope image of the first charged particle microscope in which the target position on the sample and the tip of the probe are entered, and the second in which the target position on the sample and the tip of the probe are entered. A probe-equipped microscope having a measurement function for obtaining a three-dimensional relative position of the tip of the probe with respect to the target position from a microscope image of the charged particle microscope. The microscope with a probe according to claim 1, wherein the first charged particle microscope has an optical axis parallel to the Z axis, and the second charged particle microscope has an optical axis inclined with respect to the Z axis,
The calculation processing unit obtains a relative distance in the XY direction of the tip of the probe with respect to the target position from the microscope image of the first charged particle microscope, and the microscope with respect to the target position from the microscope image of the second charged particle microscope. A probe-equipped microscope characterized by obtaining a relative distance in the Z-axis direction of the tip of the probe. 2. The microscope with a probe according to claim 1, wherein the first charged particle microscope has an optical axis inclined with respect to the Z axis, and the second charged particle microscope is in the XZ plane and is relative to the Z axis. With an inclined optical axis,
The calculation processing unit obtains a relative distance in the Y direction of the tip of the probe with respect to the target position from the microscope image of the second charged particle microscope, and the microscope with respect to the target position from the microscope image of the first charged particle microscope. The relative distance in the X direction of the tip of the probe is obtained, and the relative distance in the Z-axis direction of the tip of the probe with respect to the target position from the microscope image of the first charged particle microscope or the microscope image of the second charged particle microscope. What is required is a microscope with a probe.   4. The microscope with a probe according to claim 3, wherein the optical axis of the first charged particle microscope is in the YZ plane.   The microscope with a probe according to claim 1, wherein the first charged particle microscope and the second charged particle microscope are arranged so as to observe substantially the same part of the sample.   6. The probe-equipped microscope according to claim 5, further comprising a mechanism for tilting the first charged particle microscope about an observation point of the sample.   2. The microscope with a probe according to claim 1, wherein the first charged particle microscope and the second charged particle microscope are arranged at positions where their optical axes do not intersect with each other on the sample surface, A probe-equipped microscope characterized by having a structure in which the sample stage is reciprocated so that the sample stage can be observed with the charged particle microscope and the second charged particle microscope.   The microscope with a probe according to claim 1, wherein the calculation processing unit controls movement of the probe driving mechanism or the sample stage based on three-dimensional relative position information of the tip of the probe with respect to the target position. A probe-equipped microscope having a probe contact function for instructing a stage control system to bring the probe tip into contact with the target point.   2. The microscope with a probe according to claim 1, wherein the image display unit includes a measurement instruction unit that instructs measurement of a three-dimensional relative position of the tip of the probe with respect to the target position based on the displayed microscope image. The calculation processing section activates the measurement function when an instruction is input to the measurement instruction section.   9. The microscope with a probe according to claim 8, wherein the image display means has a probe access instruction section, and the calculation processing section activates the probe contact function when an instruction is input to the probe access instruction section. A microscope with a probe.   2. The microscope with a probe according to claim 1, wherein the image table means registers a shape of a tip portion of the probe based on a microscope image obtained by the first charged particle microscope and a microscope image obtained by the second charged particle microscope. A microscope with a probe, characterized by having an indicator.   12. The microscope with a probe according to claim 11, wherein the calculation processing means has a function of identifying a probe tip position from a microscope image based on the stored image information of the tip of the probe. microscope. In a probe contact method in which the tip of a probe is brought into contact with a target position on a sample placed on a sample stage movable in an XY direction in an XYZ orthogonal coordinate system,
Obtaining a first microscope image containing a target position on the sample and a tip of the probe by a first charged particle microscope;
A second charged particle microscope having an optical axis inclined with respect to the optical axis of the first charged particle microscope obtains a second microscope image containing a target position on the sample and the tip of the probe;
A probe contact method, wherein a three-dimensional relative position of a tip of the probe with respect to a target position on the sample is obtained based on the first microscope image and the second microscope image. The probe contact method according to claim 13, wherein the first charged particle microscope has an optical axis parallel to the Z axis, and the second charged particle microscope has an optical axis inclined with respect to the Z axis,
The relative distance in the XY direction of the tip of the probe with respect to the target position is obtained from the microscope image of the first charged particle microscope, and the Z axis of the tip of the probe with respect to the target position is obtained from the microscope image of the second charged particle microscope. A probe contact method characterized by obtaining a relative distance in a direction. 15. The probe contact method according to claim 14, wherein when the optical axis of the second charged particle microscope is in the XZ plane and forms an angle θ with the X axis and the observation magnification is M, the second charged particle microscope is used. when the distance in the Z axis direction of the apparent tip of the probe to the target position obtained from the particle microscope microscopic image and Z _2, and obtaining the relative distance Z _h of the Z-axis direction from: Probe contact method.
_{Z h} = Z 2 / Mcosθ 14. The probe contact method according to claim 13, wherein the first charged particle microscope has an optical axis inclined with respect to the Z axis, and the second charged particle microscope is in the XZ plane and inclined with respect to the Z axis. Optical axis,
The relative distance in the Y direction of the tip of the probe with respect to the target position is obtained from the microscope image of the second charged particle microscope, and the X direction of the tip of the probe with respect to the target position is obtained from the microscope image of the first charged particle microscope. The relative distance in the Z-axis direction of the tip of the probe with respect to the target position is obtained from the microscope image of the first charged particle microscope or the microscope image of the second charged particle microscope. Probe contact method. 17. The probe contact method according to claim 16, wherein an optical axis of the first charged particle microscope is in a WZ plane formed by a W axis and a Z axis that form an angle η with the Y axis in the XY plane, and the angle with the W axis. θ, the optical axis of the second charged particle microscope is in the XZ plane and forms an angle φ with the X axis,
The relative distance in the Y-axis direction of the tip of the probe with respect to the target position obtained from the microscope image of the second charged particle microscope is y, and the probe with respect to the target position obtained from the microscope image of the first charged particle microscope The probe contact method is characterized in that the relative distance x in the X-axis direction is obtained from the following equation, where a is the apparent relative distance in the X-axis direction of the tip, and M is the observation magnification.
x = (a−ysinη) / Mcosη   15. The probe contact method according to claim 14, wherein the tip of the probe is moved to a position immediately above the target position on the sample, and then the tip of the probe is lowered in the Z-axis direction to contact the target position on the sample. A probe contact method characterized by:

Images