JP2012186024A - Sample mounting device and charged particle beam device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly replace a sample on a sample stage with a plurality of degrees of freedom by a simple procedure.SOLUTION: A sample mounting device comprises: a sample stage 40 which is arranged in a sample chamber 17, and on which a sample to be an irradiation target of electron beams is placed; and a sample transfer device 80 which is attached to the sample chamber 17, and which transfers the sample from outside through a port 21 formed on a wall surface of the sample chamber toward the sample stage 40. The sample stage 40 and the sample transfer device 80 are integrally moved and driven in an inclined manner in a Y-direction, and the sample stage 40 is moved and horizontally, rotationally driven in X- and Z-directions, facilitating positioning operation when mounting or replacing the sample.

Description

  The present invention relates to a sample placement device and a charged particle beam device, and more particularly, a sample stage disposed in a sample chamber on which a sample to be irradiated with a charged particle beam is placed, attached to the sample chamber, The present invention relates to a sample placement device including a sample transfer device for inserting a sample from the outside of a sample chamber toward a sample stage from a port formed on a wall surface, and a charged particle beam device provided with the sample placement device.

  As a charged particle beam apparatus, there is a scanning electron microscope provided with a sample stage having five degrees of freedom (see Patent Document 1). FIG. 13 is a schematic diagram showing a sample carrying-in operation and a degree of freedom of movement of the sample in the scanning electron microscope. In such a scanning electron microscope 200, a sample stage 230 for holding a sample 220 is disposed in the sample chamber 210 as shown in FIG. As shown in FIG. 4B, the sample stage 230 has five degrees of freedom in the sample 220 in two directions (X, Y) perpendicular to the horizontal plane, up and down direction (Z), plane rotation (R), and tilt (T). It is equipped with a mechanism that can be moved with. According to the scanning electron beam apparatus including such a sample stage, the sample can be observed in an arbitrary posture and position. In FIG. 12A, reference numeral 240 indicates a lens barrel.

  In such a scanning electron microscope 200, there are various methods for exchanging the sample 220 held on the sample stage 230. One of them is to arrange an opening / closing door in the sample chamber 210 and pull out the sample stage 230 to exchange the held sample. However, although this method is reliable, there is a disadvantage that it takes time because the entire sample stage 230 is pulled out from the sample chamber 210 and the sample chamber 210 is mounted. Further, since the inside of the sample chamber 210 can be touched by hand, there is a risk that delicate parts such as a detector are broken.

  In order to cope with such a problem, there has been proposed one in which a sample transport device is disposed in the scanning electron microscope 200 and a sample is transported by a transport unit disposed outside the sample chamber 210 (see Patent Document 2).

JP 2002-319364 A JP 2002-313271 A

  However, in the case where the sample is transported from the outside of the sample chamber described above, the sample must be transferred to the transport stage in order to transport the sample to a sample stage having a plurality of degrees of freedom. Therefore, there is a problem that it takes time to change the sample. That is, when exchanging the sample, first, all the X, Y, Z, T, and R positions of the sample stage are moved to the transfer position, and then the sample is transferred from the transfer unit to the sample holder on the stage. After the delivery, an operation of returning the transport mechanism to the original transport unit position is required. For this reason, there is a problem that a complicated procedure is required for exchanging the sample and it takes time.

  Therefore, an object of the present invention is to provide a sample placement device and a charged particle beam device that can quickly exchange a sample on a sample stage having a plurality of degrees of freedom by a simple procedure.

  The invention of claim 1 that solves the above-mentioned problem is arranged in a sample chamber, a sample stage on which a sample to be irradiated with a charged particle beam is placed, and a sample stage that is attached to the sample chamber and formed on the wall surface of the sample chamber A sample transfer device that transfers a sample from the outside of the sample chamber toward the sample stage from the opened opening, wherein the sample stage and the sample transfer device are integrated in a predetermined direction In addition to the linear movement and rotation of the sample stage, the sample stage linearly moves and rotates the sample in a direction other than the predetermined direction.

  Similarly, the invention of claim 2 is the sample placement device according to claim 1, wherein the sample transfer device and the sample stage are integrally moved along one of two orthogonal axes in a horizontal plane and the The sample stage performs a tilting movement around the other axis in the horizontal plane, and the sample stage moves the sample along the vertical axis, moves in the direction along the other axis in the horizontal plane, and rotates around the vertical axis. It is characterized by letting.

  Similarly, the invention of claim 3 is the sample placement device according to claim 1 or 2, wherein the sample transfer device performs a seal between the sample insertion hole communicating with the opening of the sample chamber and the sample chamber. A horizontal moving member that includes a seal portion and is movable in a horizontal direction along the wall surface, a sample insertion hole portion that communicates with a hole portion of the horizontal water moving plate, and a seal portion that performs a seal between the horizontal moving member An inclined moving member rotatable along the horizontal moving member surface.

  Similarly, the invention according to claim 4 is the sample placement device according to any one of claims 1 to 3, wherein the inclined moving member moves the placed sample along the horizontal direction, and the sample is placed on the sample stage. It is provided with a sample insertion mechanism for directing and transporting.

  Similarly, the invention of claim 5 is the sample placement apparatus according to claim 4, wherein the sample insertion mechanism includes a lid member that seals the sample insertion hole of the inclined moving member.

  Similarly, the invention of claim 6 is the sample placement device according to any one of claims 1 to 5, wherein the sample stage receives the sample at a position where the sample transfer device has transferred the sample, and linearly reaches the observation position. It is characterized by moving.

  Similarly, the invention of claim 7 is the sample placement device according to any one of claims 3 to 6, wherein the sample stage includes an electric motor for moving the sample, and the horizontal moving member and the inclined moving member are: An electric motor for driving each member is provided.

  Similarly, the invention of claim 8 is the sample placement apparatus according to any one of claims 4 to 7, wherein the sample insertion mechanism is driven manually.

  Similarly, the invention of claim 9 is the sample placement device according to any one of claims 1 to 8, charged particle beam irradiation means for irradiating the sample with a charged particle beam, and the charged particle beam irradiated. A charged particle beam apparatus comprising: a detector that acquires a signal based on secondary charged particles from a sample.

  According to the sample placement device and the charged particle beam device according to the present invention, the sample stage and the sample transfer device are integrally moved linearly and rotated in a predetermined direction, and the sample stage is not a predetermined one. Since the sample is linearly moved and rotated in the direction, it is easy to align the sample when installing and replacing it, improving the observation efficiency of the sample, reducing the number of ports in the sample chamber, and necessary for alignment Therefore, the configuration of the sample placement device and the charged particle beam device can be simplified and inexpensive as a whole.

1 is a schematic diagram illustrating a basic configuration of a scanning electron microscope according to Example 1. FIG. FIG. 2 also shows a sample placement device for a scanning microscope, in which (a) is a schematic diagram showing a longitudinal section, (b) is a schematic diagram showing a horizontal section, and (c) is a schematic diagram showing the front. It is a schematic diagram which similarly shows the transfer state of the sample between the sample transfer apparatus and sample stage of a sample. It is a perspective perspective view which similarly shows the structure of the sample chamber of a scanning microscope. It is a perspective view which similarly shows the structure of the sample placement apparatus of a scanning microscope. It is sectional drawing equivalent to the AA line in FIG. 4 which similarly shows the structure of a sample placement apparatus. It is sectional drawing equivalent to the BB line in FIG. 5 which similarly shows the structure of a sample installation apparatus. It is the partially notched perspective view which similarly shows the structure of a sample installation apparatus. It is a perspective view which similarly shows the sample conveyance operation | movement of a sample setting apparatus. It is a perspective view which similarly shows the sample conveyance operation | movement of a sample setting apparatus. It is a perspective view which similarly shows the sample conveyance operation | movement of a sample setting apparatus. It is a perspective view which similarly shows the sample conveyance operation | movement of a sample setting apparatus. It is a schematic diagram which shows the carrying-in operation | movement of the sample of a scanning electron microscope, and the freedom degree of a sample.

  Hereinafter, a scanning electron microscope as a charged particle beam apparatus according to an embodiment for carrying out the present invention will be described with reference to the drawings. Hereinafter, a scanning electron microscope will be described as an example as an embodiment, but the present invention relates to charged particles such as an electron beam microanalyzer (EPMA), a focused ion beam device (FIB), or an electron beam thin film transistor (TFT) array inspection device. Applicable to beam device.

  FIG. 1 is a schematic diagram showing a schematic configuration of a scanning electron microscope according to an embodiment. The scanning electron microscope 10 includes an optical microscope 30 in the same housing, and acquires and displays SEM image data and optical image data of an observation region in a sample. First, the basic configuration of the scanning electron microscope 10 will be described.

  The scanning electron microscope 10 converges the electron beam 13 generated from the electron beam source 12 in the upper part of the lens barrel 11 with the condenser lens 14, deflects it with the deflection coil 15, and adjusts the convergence and focus with the objective lens 16, The sample on the sample holder 18 in the sample chamber 17 is scanned. The sample holder 18 is disposed on a sample stage 40 having a triaxial degree of freedom. The sample stage 40 includes a known drive mechanism such as a motor and a screw mechanism, and the sample holder 18 has three degrees of freedom in one direction (left-right direction: X), up-down direction (Z), and horizontal rotation (R) of the sample installation plane. You can move with. In the sample stage 40, an X-direction moving mechanism 41, a Z-direction moving mechanism 42, and a horizontal rotation mechanism 43 are arranged from the lower stage. In the scanning electron microscope 10, in addition to the movement in the X, Z, and R directions, the sample holder 18 can be moved in a direction perpendicular to the X direction (front-rear direction: Y) and a tilt direction (T). In the first embodiment, the movement of the two axes (Y, T) is performed by moving the sample stage 40 together with a sample transfer device 80 described later.

  In such a scanning electron microscope 10, charged particles 19 such as secondary electrons and reflected electrons generated from the sample holder 18 are detected by a secondary electron detector 20, and an electron beam is detected by an SEM image display control means (not shown). SEM image data is obtained in synchronization with the 13 scanning states, and the SEM image is displayed on an image display device (not shown).

  The optical microscope 30 includes an optical system in the optical barrel, and also includes a light source that illuminates the sample holder 18, an electronic image sensor such as a CCD image sensor, and a CMOS element, and outputs optical image data. Then, an enlarged optical image of the observation region of the sample on the sample holder 18 is displayed on an image display device (not shown). Here, the optical axis of the optical microscope 30 is inclined at a predetermined angle so as to intersect the electron beam optical axis in the observation region of the sample holder 18. The optical microscope 30 may be disposed so as to coincide with the optical axis of the scanning electron microscope. In this embodiment, there is no adverse effect on the observation conditions of each other. For example, if a through-hole is formed in the optical system of an optical microscope in order to pass an electron beam, adverse effects such as partial darkening of the optical image of the optical microscope may occur, but this embodiment eliminates such an effect. can do.

  Here, the imaging magnification of the scanning electron microscope 10 and the optical microscope 30 can be appropriately changed according to the purpose of imaging. In the scanning electron microscope 10, the sample holder 18 can be observed by being inclined at an arbitrary angle. When the sample surface is inclined in a direction perpendicular to the optical axis of the optical microscope 30, a good optical image can be obtained by the optical microscope 30. Can be obtained. In FIG. 1, the optical microscope 30 is not drawn corresponding to the tilt direction of the sample holder 18, but actually the optical axis of the optical microscope 30 includes the electron beam optical axis and is orthogonal to the paper surface of FIG. 1. Placed in the plane to be

  Next, the sample placement device will be described. 2A and 2B show a sample placement apparatus for a scanning microscope according to Example 1, wherein FIG. 2A is a schematic diagram showing a longitudinal section, FIG. 2B is a schematic diagram showing a horizontal section, and FIG. FIG. 3 and FIG. 3 are schematic views showing the sample transfer state between the sample transfer device and the sample stage.

  First, the basic configuration of the sample placement device 100 will be described with reference to FIG. The sample setting device 100 includes a sample stage 40 and a sample transfer device 80. The sample transfer device 80 includes a horizontal movement mechanism 50 that allows a plate-like member 51 that is a horizontal movement member to move in the Y direction at an arrangement portion of the sample replacement port 21 in the sample chamber 17, and an outside of the plate-like member 51. A plate-like member 61, which is a tilt-moving member, is arranged on the outside of the plate-like member 61, and a tilt-moving mechanism 60 that drives the rotational movement around the Y axis, that is, the tilt (T) of the sample. And a sample insertion mechanism 70 for performing 18 insertions.

  The plate-like member 51 of the horizontal movement mechanism 50 is provided with an opening 55 that communicates with the port 21 for exchanging the sample, and in the Y direction while maintaining a sealed state with the sample chamber 17 by a known drive mechanism using a motor as a drive source. Driven.

  Further, the plate-like member 61 of the tilt moving mechanism 60 has an opening 65 communicating with the sample exchange port 21 and the opening 55, and is sealed with the plate-like member 51 by a known drive mechanism using a motor as a drive source. The sample holder 18 is rotationally driven so as to be inclined. The tilt moving mechanism 60 moves in the Y direction together with the horizontal moving mechanism 50.

  Further, the tilt moving mechanism 60 includes a support member 45 that supports the sample stage 40. The support member 45 communicates with the openings 55 and 65 and the sample replacement port 21 so as to project into the sample chamber 17 in the horizontal direction. The sample stage 40 is supported. Therefore, the sample stage 40 moves with the linear movement of the horizontal movement mechanism 50 to move the sample holder 18 in the Y direction, and rotates with the rotation of the tilt movement mechanism 60 to tilt the sample holder 18. Further, as described above, the sample stage 40 includes the X-direction moving mechanism 41, the Z-direction moving mechanism 42, and the horizontal rotating mechanism 43. These include a known driving mechanism such as a screw mechanism using a motor as a driving source. Rotate horizontally, vertically and horizontally. The motors that drive the mechanisms are driven and controlled by a scanning electron microscope control device realized by a computer.

  Therefore, in the scanning electron microscope 10 according to the first embodiment, the sample stage 40 and the sample transfer device 80 are driven to drive the sample holder 18 with five degrees of freedom of X, Y, Z, R, and T. it can. The X-direction moving mechanism 41 of the sample stage 40 can drive the sample stage 40 in the X direction along the support member 45 to move the sample stage 40 from the observation position on the electron microscope to the sample transfer position.

  The sample insertion mechanism 70 includes a lid member 71 that closes the opening 65 provided in the plate-like member 61 of the tilt movement mechanism 60 and an insertion member 72 into which the sample holder 18 is inserted. In this embodiment, the lid member 71 is manually moved horizontally, and the sample holder 18 is moved from the outside of the sample chamber 17 to the sample transfer position in the sample chamber 17. The insertion member 72 has a notch 72a for placing the sample holder 18 thereon. Further, in a state where the lid member 71 is installed in the tilt movement mechanism 60, the lid member 71 and the plate-like member 61 of the tilt movement mechanism 60 are in a sealed state, and as a result, the sample chamber 17 is in a sealed state.

  Next, an outline of the sample exchange operation will be described with reference to FIG. When the sample is carried into the sample chamber, after the sample chamber 17 is brought to atmospheric pressure, the insertion member 72 of the sample insertion mechanism 70 is pulled out from the sample chamber 17 and the sample holder 18 is disposed in the notch 72a.

  Next, the sample stage 40 is moved to the position (a) in the figure by the X direction moving mechanism 41. At this time, the sample stage 40 is set to a height at which it does not contact the insertion member 72 by the Z direction moving mechanism 42. Then, the insertion member 72 is inserted into the sample chamber 17 and placed at the sample transfer position. In this state, since the lid member 71 seals the sample chamber 17, the inside of the sample chamber 17 can be brought into a vacuum state necessary for observation.

  Further, the Z-direction moving mechanism 42 is driven at the sample transfer position to lift the sample holder 18 from below and place it on the sample stage 40. In this state, the sample holder 18 is moved horizontally to the observation position ((b)). It arrange | positions at predetermined | prescribed height (the same (c)). When the sample is carried out of the sample chamber, the procedure reverse to the above procedure is taken.

  As described above, in the scanning electron microscope 10, the sample stage 40 and the sample transfer device 80 move integrally in the Y direction and the tilt direction (T). There is no need to adjust the position in the two directions. Further, the horizontal rotation (R) can be freely set after the sample is set. For this reason, the position control of the sample stage 40 at the time of exchanging the sample only needs to be performed in the two directions of the X direction and the Z direction, the control becomes simple, and the sample can be exchanged quickly and safely.

  Furthermore, the detail of the sample placement apparatus of the scanning electron microscope which concerns on Example 1 is demonstrated. 4 is a perspective perspective view showing the configuration of the sample placement device of the scanning microscope according to the first embodiment, FIG. 5 is a perspective view showing the configuration of the sample placement device, and FIG. 6 is the same as FIG. 4 showing the configuration of the sample placement device. 7 is a cross-sectional view corresponding to the line A-A, FIG. 7 is a cross-sectional view corresponding to the line BB in FIG. 5 showing the configuration of the sample setting device, and FIG. is there.

  The sample stage 40 includes an X direction driving motor 46, a Z direction driving motor 47, and a horizontal rotation driving motor 48. The sample stage 40 is moved along a guide rail 49 disposed along the support member 45 by driving the X-direction drive motor 46 to adjust the position in the X direction during sample observation. It is possible to move between the observation position and the sample transfer position.

  The horizontal movement mechanism 50 of the sample transfer device 80 includes a Y-direction driving motor 52 and a screw mechanism, and moves the plate member 51 in the horizontal direction. Between the plate-like member 51 and the sample chamber 17, a seal member 53 made of an O-ring is arranged to form a seal portion.

  The tilt movement mechanism 60 of the sample transfer device 80 includes a T-direction driving motor 62 and a screw mechanism, and rotates the plate-like member 61 around the Y axis that penetrates the opening 65. Between the plate-like member 61 and the plate-like member 51 of the horizontal movement mechanism 50, a seal member 63 made of an O-ring is disposed to form a seal portion. Further, the plate-like member 61 is provided with a seal member 64 made of an O-ring that forms a seal portion with the lid member 71.

  The lid member 71 of the sample insertion mechanism 70 is held on the plate-like member 61 by two-stage slide type guide shafts 73 and 74 and can be moved manually by an operator. When the insertion member 72 is pulled out from the sample chamber 17, the notch 72a can be disposed outside the sample chamber, so that the sample holder 18 can be easily attached to the notch 72a. Further, a handle 75 for pull-in and pushing operation is attached to the lid member 71.

  Next, the loading of the sample holder 18 into the sample chamber 17 will be described. 9 to 12 are perspective views illustrating the sample transport operation of the sample setting apparatus according to the first embodiment. First, as shown in FIG. 9, the handle 75 is pulled, the insertion member 72 of the sample insertion mechanism 70 is pulled out from the sample chamber 17, and the sample holder 18 on which the sample is placed is placed in the notch 72a.

  Next, as shown in FIG. 10, the Z-direction driving motor 47 is driven to lower the height position of the sample stage 40, and the X-direction driving motor 46 is driven to move the sample stage 40 along the guide rail 49. And move it to the sample transfer position. Further, as shown in FIG. 11, the lid member 71 is moved to the sample chamber 17 side to seal the sample chamber 17. As a result, the insertion member 72 is inserted into the sample chamber 17, and the sample holder 18 disposed in the notch 72a is disposed at the sample transfer position. In this state, the Z-direction driving motor 47 is driven to raise the sample stage 40 and hold the sample holder 18 on the sample stage 40. Since the sample chamber 17 is hermetically sealed, the sample chamber can be in a vacuum state necessary for observation.

  Then, as shown in FIG. 12, the X-direction driving motor 46 is driven again, the sample stage 40 is moved, and the sample holder 18 is moved to the observation position. As described above, the sample holder 18 can be arranged at the observation position, and observation can be performed. It should be noted that the sample is carried out by a procedure reverse to the procedure for carrying in the sample.

  As described above, according to the scanning electron microscope 10 of the present invention, it is easy to align the sample during installation and exchange, and the sample observation efficiency can be improved, and the number of ports in the sample chamber can be reduced. In addition, since the moving mechanism necessary for alignment can be omitted, the configuration of the sample placement device and the charged particle beam device can be simplified and inexpensive as a whole.

  In the above-described embodiment, the sample stage 40 and the sample transfer device 80 are integrally moved and moved in the Y direction and tilted (T). However, the sample stage 40 is rotated in the Y direction or tilted (T). Only one of them may be linked. In this case, the configuration of the sample transfer device can be simplified. In the above-described embodiment, the sample insertion mechanism 70 is manually operated. However, this can be automatically performed using a motor or the like as a drive source. In the above embodiment, the sample chamber is brought to atmospheric pressure every time the sample is exchanged. However, an air lock device having a double door is arranged to carry in and exchange the sample while keeping the vacuum state of the sample chamber 17. be able to.

DESCRIPTION OF SYMBOLS 10 Scanning electron microscope 11 Lens tube 12 Electron beam source 13 Electron beam 14 Condenser lens 15 Deflection coil 16 Objective lens 17 Sample chamber 18 Sample holder 19 Charged particle 20 Secondary electron detector 21 Port 30 Optical microscope 40 Sample stage 41 X direction movement Mechanism 42 Z-direction moving mechanism 43 Horizontal rotation mechanism 45 Support member 46 X-direction drive motor 47 Z-direction drive motor 48 Horizontal rotation drive motor 49 Guide rail 50 Horizontal movement mechanism 51 Plate-like member (horizontal movement member)
52 Y-direction driving motor 53 Seal member 55 Opening 60 Inclination moving mechanism 61 Plate member (inclination moving member)
62 T direction driving motor 63 Seal member 64 Seal member 65 Opening 70 Sample insertion mechanism 71 Cover member 72 Insert member 72a Notch 73, 74 Guide shaft 75 Handle 80 Sample transfer device 100 Sample installation device

Claims (9)

A sample stage disposed in the sample chamber and on which a sample to be irradiated with a charged particle beam is placed, and a sample chamber attached to the sample chamber and directed from the opening formed on the wall surface of the sample chamber toward the sample stage A sample placement device comprising a sample transfer device for transferring a sample from the outside,
The sample stage and the sample transfer device integrally move linearly and rotate in a predetermined direction,
The sample stage is characterized in that the sample stage linearly moves and rotates the sample in a direction other than the predetermined direction. The sample transfer device and the sample stage integrally move along one of the two orthogonal axes in the horizontal plane and tilt around the other axis in the horizontal plane,
The sample setting apparatus according to claim 1, wherein the sample stage moves the sample along a vertical axis, moves in a direction along the other axis in a horizontal plane, and rotates about the vertical axis. The sample transfer device includes:
A horizontal movement member that is movable in the horizontal direction along the wall surface, and includes a seal portion that seals between the sample insertion hole and the sample chamber communicating with the opening of the sample chamber;
A tilt moving member that is provided with a seal portion that seals between the sample insertion hole portion that communicates with the hole portion of the horizontal horizontal movement plate and the horizontal movement member, and that is rotatable along the horizontal movement member surface;
The sample placement device according to claim 1, wherein the sample placement device is provided.   4. The tilt moving member includes a sample insertion mechanism that moves a placed sample along a horizontal direction and conveys the sample toward a sample stage. 5. Sample placement device.   The sample placement device according to claim 4, wherein the sample insertion mechanism includes a lid member that seals a sample insertion hole of the inclined moving member.   6. The sample setting device according to claim 1, wherein the sample stage receives a sample at a position where the sample transfer device has transferred the sample and moves linearly to an observation position.   The said sample stage is provided with the electric motor for a sample movement, The said horizontal movement member and the said inclination movement member are provided with the electric motor for each member drive, The Claim 1 characterized by the above-mentioned. Sample placement device.   The sample placement device according to any one of claims 4 to 7, wherein the sample insertion mechanism is manually driven.   The sample placement device according to any one of claims 1 to 8, charged particle beam irradiation means for irradiating the sample with a charged particle beam, and secondary charged particles from the sample irradiated with the charged particle beam. A charged particle beam device comprising: a detector for acquiring a signal based on the detector;