JP6254060B2 - Vertical movement stage for charged particle beam apparatus and charged particle beam apparatus - Google Patents

Description

  The present invention relates to a vertical movement stage for a charged particle beam apparatus and a charged particle beam apparatus including the same.

  In charged particle beam application apparatuses such as CD-SEM, a highly accurate and highly rigid sample observation stage is required from the viewpoint of improving throughput and ensuring measurement accuracy. Especially for devices that require a vertical movement stage (Z stage) due to diverse measurement needs, vibration resistance and posture accuracy during and after movement without compromising the performance of the horizontal movement stage (planar XY stage) It needs to be kept well. For this reason, the vertical movement mechanism mounted on the Z stage is required to have a small size, light weight, high rigidity, and high posture accuracy.

  As a conventional vertical movement (Z direction movement) system, there are a wedge mechanism, a link (pantograph), a translation cam mechanism (dog mechanism), and the like, and driving in the Z direction is realized by an actuator that rotates and linearly drives. In particular, the Z stage based on the translation cam mechanism (dog mechanism) is configured to maintain the Z position by converting the horizontal force into the driving force in the Z direction by the inclined surface and the rotating roller, and stopping on the horizontal plane. The minimum required height of the mechanism is only the stroke length. Therefore, a compact configuration of the stage can be realized by using the translation cam mechanism. In addition, the translation cam mechanism has a high degree of freedom in design of the shape and has few components, so that it is easy to form a small and lightweight stage and is suitable for a Z stage that requires positioning only at arbitrary discontinuous points. Are known.

JP 2008-277283 A

  In the Z stage using the translation cam mechanism (dog mechanism), the top table holding the sample is supported by an elastic member such as a roller or a bearing. Therefore, the Z position accuracy and the Z position are reduced due to a reduction in stage rigidity and deformation of the elastic member. A decrease in reproducibility occurs.

  An object of the present invention is to provide a vertical movement stage having high rigidity, high accuracy, and high reproducibility without the load of the top table being applied to the elastic member.

  In one of the representative vertical movement stages of the present invention that solves the above problems, the top table is supported by a load receiving portion (for example, a spacer) that can be handled as a rigid body, not a roller or a bearing. The vertical movement stage includes a load receiving portion having a plurality of contact surfaces having different heights, and uses a cam portion to replace the plurality of contact surfaces (for example, surfaces on which spacers contact each other), thereby performing a vertical direction (Z Direction).

  For example, in order to solve the above-mentioned problem, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, a base table, a top table for holding a sample, a roller support portion fixed to the lower surface of the top table, and the roller support. A roller supported by a portion, an upper load receiving portion that is fixed to a lower surface of the top table or the roller support portion and receives a load of the top table, and is disposed between the base table and the top table, A moving unit that moves a relative position in the horizontal direction between the base table and the top table; and at least two inclined surfaces that change a relative position in the vertical direction between the base table and the top table; A cam portion that rotates on an inclined surface; and the top table fixed to an upper surface of the moving portion or the base table. Vertical motion stage having a lower load receiving portion for receiving a load is provided. In the vertical movement stage, the upper load receiving portion and the lower load receiving portion have contact surfaces that contact each other, and at least one of the upper load receiving portion and the lower load receiving portion is high. A plurality of contact surfaces of different sizes are provided.

  According to the present invention, a stage having high rigidity, high accuracy, and high reproducibility can be provided by supporting the top table by the load receiving portion that can be handled as a rigid body.

  Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. Further, problems, configurations and effects other than those described above will be clarified by the description of the following examples.

It is a side view of Z stage concerning the 1st example of the present invention. It is a side view of Z stage concerning the 1st example of the present invention. It is a side view of Z stage concerning the 1st example of the present invention. 1 is a front view of a Z stage according to a first embodiment of the present invention. It is a perspective view of the slider table of the Z stage which concerns on 1st Example of this invention. It is a side view of the electron beam application apparatus carrying the Z stage which concerns on 1st Example of this invention. It is a perspective view of the slider table of the Z stage which concerns on 2nd Example of this invention. It is the perspective view which showed the vibration direction of the top table of Z stage which concerns on 2nd Example of this invention. It is a perspective view of the slider table of Z stage concerning the 3rd example of the present invention. It is a front view of the Z stage which concerns on 4th Example of this invention. It is a side view of the electron beam application apparatus carrying the Z stage which concerns on 5th Example of this invention. It is a top view of the vacuum chamber of the electron beam application apparatus carrying the Z stage which concerns on 5th Example of this invention. It is a top view of the vacuum chamber of the electron beam application apparatus carrying the Z stage which concerns on 5th Example of this invention. It is a side view of the electron beam application apparatus carrying the Z stage which concerns on 5th Example of this invention. It is a side view of the translation cam mechanism and spacer which concern on 6th Example of this invention. It is a side view of the spacer which concerns on 7th Example of this invention. It is a front view of the Z stage which concerns on 8th Example of this invention. It is a front view of the Z stage which concerns on 9th Example of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The accompanying drawings show specific embodiments in accordance with the principle of the present invention, but these are for the understanding of the present invention, and are never used to interpret the present invention in a limited manner. is not. In each drawing, the same reference numerals are assigned to common components.

  As a sample observation apparatus, there is a charged particle beam apparatus that uses a secondary generated electron by scanning a charged particle beam (for example, electrons) on a sample surface. The present invention is applicable to all charged particle beam apparatuses. As a representative example of the charged particle beam apparatus, there is an electron microscope (SEM: Scanning Electron Microscope). Below, as an example, it demonstrates as an example applied to electron beam application apparatuses, such as length measurement SEM and review SEM.

[First embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6. FIG. 6 is a schematic side view showing the whole of an electron beam application apparatus equipped with a vertical movement stage (Z stage).

  6 includes a column 109 for irradiating a sample with an electron beam, a vacuum chamber 108 connected to the column 109, a stage system 106 disposed in the vacuum chamber, and various configurations of the electron beam application apparatus. A control unit (not shown) for controlling the elements is provided.

  The column 109 includes an electron beam optical system (charged particle beam optical system). As an example, the electron beam optical system includes an electron source that emits an electron beam, an extraction electrode, a condenser lens, a deflection electrode, and an objective lens. The inside of the vacuum chamber 108 is evacuated by an exhaust device (not shown). In addition, the column 109 of the electron beam application apparatus may include other lenses, electrodes, and detectors in addition to this, or some of them may be different from the above, and the configuration of the electron beam optical system is limited to this. Absent.

  A stage system 106 is installed below the electron beam optical system of the column 109. The stage system 106 includes an X stage 102, a Y stage 103, and a Z stage 101. The stage system 106 is a stack type multi-axis stage system, in which the X stage 102 is mounted on the Y stage 103 and the Z stage 101 is mounted on the X stage 102.

  The X stage 102 and the Y stage 103 are each driven by a linear motor (not shown). Alternatively, the X stage 102 and the Y stage 103 may be driven by an actuator such as an electromagnetic motor and a ball screw.

  A sample holder 104 is mounted on the Z stage 101 of the stage system 106 (more specifically, on the top table 1 of the Z stage 101). The sample holder 104 sucks and holds the sample 105 to be measured. The X stage 102, the Y stage 103, and the Z stage 101 move the position of the sample 105 according to the designated image acquisition position. The stage system 106 can irradiate the sample 105 held by the sample holder 104 with the electron beam converged by the electron beam optical system, and perform measurement and length measurement by the column 109.

  FIG. 1 is a side view showing details of the Z stage 101. The Z stage 101 includes a top table 1, a base table 2, and a slider (moving unit) 6 disposed between the top table 1 and the base table 2.

  The slider 6 is connected on the base table 2 and moves in the horizontal direction. The slider 6 includes a slider table 6a, a linear guide 6b, and a guide rail 6c. The linear guide 6b is fixed to the slider table 6a. The guide rail 6c is fixed on the base table 2. The linear guide 6b is disposed on the guide rail 6c. Therefore, the movement of the slider table 6a in the X direction is allowed by moving the linear guide 6b on the guide rail 6c. Further, the movement of the slider table 6a in the other direction (Y, Z direction and rotation direction) can be restricted by moving the linear guide 6b on the guide rail 6c. The illustrated guide is a general linear guide, but may be a mechanism that guides a linear motion, and may be, for example, a more rigid cross roller guide.

  The base table 2 is provided with an actuator 9 as a drive mechanism for the slider 6 in the X direction. In the illustrated actuator 9, it is assumed that a rotary motor and a ball screw are used. However, any configuration may be used as long as the actuator can be driven in a linear direction. For example, an ultrasonic motor composed only of nonmagnetic parts is suitable. Unlike the electromagnetic motor, the ultrasonic motor does not have magnetism because the ultrasonic motor performs friction driving by high-frequency vibration of the piezoelectric element. Therefore, the influence on the charged particles used for measurement can be reduced. Moreover, when using electromagnetic motors, such as a DC motor, an AC motor, and a linear motor, what is necessary is just to use the structure which uses the magnetic shielding using an electromagnetic shield, or arrange | positions a motor in the position away from the charged particle beam.

  A Z guide 3 is provided on the base table 2. The Z guide 3 includes a Z guide driving unit 3a, a Z guide fixing unit 3b, and a guide mechanism 3c. The Z guide driving unit 3 a is a plate-like member, for example, and is fixed to the top table 1. The Z guide fixing portion 3 b is a plate-like member, for example, and is fixed on the base table 2. A guide mechanism 3c is provided between the Z guide driving unit 3a and the Z guide fixing unit 3b. The Z guide driving unit 3a moves in the vertical direction (Z direction) via the guide mechanism 3c, and the top table 1 moves up and down. In the Z guide 3, the guide mechanism 3c restrains the degree of freedom other than the Z direction of the Z guide driving unit 3a. The Z guide 3 is not limited to such a configuration, and may be a linear guide, a cross roller guide, or the like, similar to the slider 6.

  As the vertical movement mechanism of the top table 1, a translation cam mechanism (cam portion) 4, a first lower spacer 5b, and a second lower spacer 5c are provided on the upper surface of the slider table 6a of the slider 6. Is provided. Here, the first lower spacer 5 b and the second lower spacer 5 c are arranged so that a straight line connecting them is parallel to the drive direction of the translation cam mechanism 4.

  Further, an upper spacer (upper load receiving portion) 5 a that receives the load of the top table 1 and a cam follower 7 are provided on the lower surface of the top table 1. Here, the upper spacer 5 a is fixed at the center position of the lower surface of the top table 1. The cam follower 7 contacts the inclined surface of the translation cam mechanism 4. On the other hand, the upper spacer 5a and the first and second lower spacers 5b and 5c are arranged at the same position in the Y-axis direction. Therefore, the upper spacer 5a and the first and second lower spacers 5b and 5c are arranged to face each other. The upper spacer 5a has a contact surface in contact with the first lower spacer 5b or the second lower spacer 5c, and the first and second lower spacers 5b and 5c are in contact with the upper spacer 5a, respectively. Having a contact surface. According to this configuration, when the cam follower 7 moves on the inclined surface of the translation cam mechanism 4, the contact surface of the upper spacer 5a is changed to the contact surface of the first lower spacer 5b or the contact surface of the second lower spacer 5c. Can be placed on top. As a result, the top table 1 can be moved in the vertical direction to perform vertical positioning. Details of the vertical movement mechanism will be described below.

  The translation cam mechanism 4 has an inclined surface 4a having a positive inclination and an inclined surface 4b having a negative inclination along the X-axis direction. The two inclined surfaces 4a and 4b have different lengths. Further, the height of the inclined surface is the smallest at the left end (on FIG. 1), and is the highest point at a position slightly to the right of the center of the inclined surface. The inclination of the inclined surface of the translation cam mechanism 4 represents the ratio of the input horizontal direction (X-axis direction) force and the output vertical direction (Z-axis direction) force. The smaller the inclination, the smaller the input force can be designed. .

  The height of the first lower spacer 5b is lower than that of the second lower spacer 5c, and the difference in height is the stroke amount in the vertical direction (Z direction). The Z stage 101 in FIG. 1 is stationary at the first position (low position), and the upper spacer 5a and the first lower spacer 5b are in contact with each other. In the figure, the shape of the spacer contact surface is square, but the shape of the spacer can be any shape as long as the contact with the surface is possible and the rigidity can be secured. In addition, rigidity can be ensured, so that the contact area between spacers is large. Moreover, the Z stage 101 with low vibration can be provided by ensuring rigidity. The material constituting the spacer is preferably a metal that can be used in a vacuum and is nonmagnetic. In order to reduce dust generation due to contact, it is desirable to use the same material for the upper spacer 5a and the first and second lower spacers 5b and 5c.

  The cam follower 7 includes a circular roller 7a and a roller holder (roller support portion) 7b that connects the roller 7a. A roller holder 7 b is fixed to the lower surface of the top table 1, and the outer peripheral surface of the roller 7 a comes into contact with the inclined surface of the translation cam mechanism 4. That is, the cam follower 7 and the translation cam mechanism 4 are arranged at the same position in the Y-axis direction. When the vertical movement of the top table 1 is stopped (that is, when the upper spacer 5a is placed on the first lower spacer 5b or the second lower spacer 5c), the roller 7a is a translation cam. It may be in contact with the inclined surface of the mechanism 4 or may not be in contact with the inclined surface. A configuration in which the roller 7a does not contact the inclined surface of the translation cam mechanism 4 when the top table 1 is stopped is preferable because the processing accuracy and elastic deformation of the roller 7a do not directly affect the stage accuracy. In the case of this configuration, processing for obtaining rigidity and accuracy and part costs can be suppressed.

  FIG. 4 is a front view of the Z stage 101. An upper spacer 5 a is fixed at the center position of the lower surface of the top table 1. Two cam followers 7 are fixed to the left and right of the upper spacer 5a (with the upper spacer 5a interposed therebetween). The Z guides 3 are provided on both sides of the top table 1 in the Y direction, and the two Z guides 3 constrain degrees of freedom other than the vertical direction (Z direction).

  Two translation cam mechanisms 4 are arranged on the slider table 6a so as to face the two cam followers 7. And the cam follower 7 is arrange | positioned on the inclined surface of the translation cam mechanism 4 so that the force of a horizontal direction can be converted into a perpendicular direction. For example, the translation cam mechanism 4 and the cam follower 7 are arranged so that the acting position of the resultant force of the driving force in the Z-axis direction acting on them coincides with the center of gravity G (see FIG. 4) of the top table 1 and its attached fixture. It is desirable that Here, the attached fixed object of the top table 1 refers to, for example, the cam follower 7 or the Z guide driving unit 3a fixed to the top table 1.

  FIG. 5 is a perspective view of the slider table 6 a of the slider 6. Two translation cam mechanisms 4 are arranged on both sides in the Y direction of the slider table 6a. In this way, by arranging the translation cam mechanisms 4 on both sides in the Y direction of the slider table 6a, the acting position of the resultant force of the Z direction driving force acting on the cam follower 7 becomes the center of gravity of the top table 1 and its attached fixed object. It is desirable to do so.

  As shown in FIG. 5, the two translation cam mechanisms 4 and the first and second lower spacers 5b and 5c are arranged so as not to interfere with each other. In accordance with the horizontal drive of the slider 6, the roller 7a of the cam follower 7 moves up / down the inclined surface of the translation cam mechanism 4, and the upper spacer between the first and second lower spacers 5b, 5c. The two translation cam mechanisms 4 and the first and second lower spacers 5b and 5c are arranged so that the transfer operation of 5a is interlocked.

  For example, the X-direction distance d1 (that is, the horizontal stroke of the slider 6) between the first grounding point 4d and the second grounding point 4e on the inclined surface of the translation cam mechanism 4, and the first and second lower spacers 5b. It is desirable that the X-direction distance d2 between the centers of 5c coincide with the position of the resultant force of the Z-direction driving force acting on the cam follower 7 with the position of the center of gravity of the top table 1 and its attached fixture. . Here, the first contact point 4d is a contact point (see FIG. 1) between the roller 7a and the inclined surface of the translation cam mechanism 4 when the upper spacer 5a and the first lower spacer 5b are in contact with each other. . The second grounding point 4e is a grounding point (see FIG. 3) between the roller 7a and the inclined surface of the translation cam mechanism 4 when the upper spacer 5a and the second lower spacer 5c come into contact with each other. Since the horizontal stroke of the slider 6 and the X-direction distance d2 between the first and second lower spacers 5b and 5c coincide with each other, the upper spacer 5a is moved to the first position at the end of the stroke of the slider 6. And the second lower spacers 5b and 5c come into contact with each other, and the vertical driving of the top table 1 is stopped. Under the above restrictions, the first lower spacer 5 b and the second lower spacer 5 c may be freely arranged on the slider table 6 a of the slider 6.

  Next, the principle of the raising / lowering operation by changing the spacer by the translation cam mechanism 4 will be described with reference to FIGS. 1, 2, and 3. FIG. In this embodiment, the actuator 9 drives the slider 6 in the horizontal direction, so that the translation cam mechanism 4, the first lower spacer 5b, and the second lower spacer 5c move in the horizontal direction. At this time, when the cam follower 7 moves on the translation cam mechanism 4, the upper spacer 5a moves in the vertical direction (Z direction), and the upper spacer 5a is moved to the first and second lower spacers 5b having different heights. 5c can be contacted. As a result, the top table 1 can be positioned in the vertical direction. This will be described in more detail below.

  FIG. 1 shows a stationary state at a first position (low position) of two-point positioning in the vertical movement mechanism. In the stationary state at the first position, the contact surface of the upper spacer 5a contacts the contact surface of the lower spacer 5b. The driving in the horizontal direction (X-axis direction) is constrained by the frictional force between the top table 1 and the slider 6 that is constrained in the horizontal direction by the Z guide 3. Even if the actuator 9 has a driving force, the slider 6 does not drive in the horizontal direction within a force range equal to or less than the frictional force depending on the weight of the top table 1. When a horizontal force greater than the static friction force is applied to the slider 6 by the actuator 9, the slider 6 starts moving in the horizontal direction (X-axis negative direction). By this movement, the roller 7a of the cam follower 7 rises on the inclined surface of the translation cam mechanism 4 fixed on the slider table 6a of the slider 6, and the top table 1 and the upper spacer 5a attached thereto rise. In conjunction with this rise, the first lower spacer 5b and the second lower spacer 5c fixed on the slider table 6a of the slider 6 also move in the horizontal direction (X-axis negative direction).

  FIG. 2 shows a state in which the slider 6 is moved in the horizontal direction (X-axis negative direction) from the state of FIG. If the movement of the slider 6 in the horizontal direction (X-axis negative direction) is continued using the actuator 9, the ascending operation is switched to the descending operation at the highest point 4 c of the inclined surface of the translation cam mechanism 4. When the slider 6 continues to move in the horizontal direction beyond the highest point 4c, the top table 1 is lowered. The spacer located below the upper spacer 5a is switched from the first lower spacer 5b to the second lower spacer 5c in accordance with the ascending operation and the descending operation.

  FIG. 3 shows a stationary state at the second position (high position) when the slider 6 is moved in the horizontal direction (X-axis negative direction) from the state of FIG. As the slider 6 moves in the horizontal direction (X-axis negative direction), the second lower spacer 5c moves below the upper spacer 5a, and the contact surface of the upper spacer 5a and the second lower spacer 5c contact each other. The surface comes into contact. Thereafter, when the actuator 9 stops, the top table 1 is restrained by the friction between the upper spacer 5a and the second lower spacer 5c and stops.

  As described above, the upper spacer 5a is replaced between the first lower spacer 5b and the second lower spacer 5c by the movement of the slider 6 in the horizontal direction. The difference in height between the first lower spacer 5b and the second lower spacer 5c is the amount of movement in the vertical direction (Z direction). According to this configuration, it is possible to position only two arbitrary points designed in advance according to the dimensions of the mechanism parts. Further, the top table 1 can be held by friction caused by contact between the upper spacer 5a and the first and second lower spacers 5b and 5c. That is, it is not necessary to hold the top table 1 by the actuator 9. Therefore, unlike the prior art, no actuator is required to maintain the height of the top table, and heat generation by the actuator or the like can be prevented, and a low heat generation vertical movement mechanism can be provided.

  As described above, in this configuration, the top table 1 is lowered after reaching the highest point once, so that the transfer from the first lower spacer 5b to the second lower spacer 5c is realized. Therefore, in addition to the required amount of stroke in the vertical direction (Z direction), a stroke of several mm for reaching the highest point is required. If the top surface of the sample 105 and the objective lens 109a may come into contact when the top table 1 reaches the highest point, the X stage 102 and the Y stage 103 are used to move the Z table 101 in the horizontal direction. It is desirable to drive in the vertical direction after retracting from just below 109a.

  According to the present embodiment, the top table can be supported by a spacer that can be handled as a rigid body, not by an elastic member such as a roller or a bearing. Conventionally, there has been a problem that the position accuracy and the position reproducibility decrease due to the deformation of the elastic member. However, in this embodiment, since the top table is held by a rigid body such as a spacer, it has high rigidity, high accuracy, and high reproducibility. A Z stage (vertical movement stage) 101 can be provided. In addition, since the top table is held by a rigid spacer, a low-vibration Z stage (vertical movement stage) 101 can be provided. Furthermore, since this embodiment does not require holding by the actuator when the top table 1 is stationary, heat generation by the actuator or the like can be prevented, and the Z stage 101 with low heat generation can be provided.

  In this embodiment, since the positioning accuracy in the height direction depends on the height difference between the first lower spacer 5b and the second lower spacer 5c, feedback using a position sensor or the like. Controls and control devices are not necessarily required. When the stage accuracy cannot be sufficiently obtained due to the inclination of the spacer contact surface or the variation in processing accuracy, the slider 9 may be positioned in the horizontal direction (X direction) by the actuator 9 using a controller and a sensor (not shown). .

  Note that the fixing position of the upper spacer 5 a is not limited to the lower surface of the top table 1. For example, the upper spacer 5 a may be fixed to the roller holder (roller support portion) 7 b of the cam follower 7.

  Moreover, although the example which provided the 1st lower side spacer 5b and the 2nd lower side spacer 5c on the slider 6 was demonstrated in the above-mentioned example, it is not limited to this. For example, a configuration may be adopted in which a plurality of upper spacers having different heights are provided and one lower spacer is provided. In the above example, the lower spacer is provided as two separate components. However, an integrated lower spacer having a plurality of contact surfaces with different heights may be provided. Therefore, the upper spacer (upper load receiving portion) and the lower spacer (lower load receiving portion) have contact surfaces that contact each other, and at least one of the upper spacer and the lower spacer has a different height. A plurality of contact surfaces may be provided.

  Further, the moving mechanism is not limited to the illustrated slider 6. The moving mechanism may be any moving unit that moves the relative position in the horizontal direction between the base table 2 and the top table 1.

  Further, the cam portion is not limited to the illustrated translation cam mechanism 4. The cam portion may be provided with at least two inclined surfaces that change the vertical relative position between the base table 2 and the top table 1. The cam part should just be comprised so that the horizontal relative position of the base table 2 and the top table 1 can be changed, when a roller rotates the said inclined surface.

  The first lower spacer 5b and the second lower spacer 5c may be provided on the base table 2 instead of on the slider 6. In accordance with this, a moving unit that moves the relative position of the base table 2 and the top table 1 in the horizontal direction may be provided. For example, the top table 1 side may be moved by the moving unit and replaced with a plurality of lower spacers on the base table 2.

  Note that the modification described above can also be applied to the embodiments described below.

[Second embodiment]
Next, the second embodiment will be described with reference to FIGS. 7 and 8, the same reference numerals as those in the first embodiment indicate the same parts, and the description thereof will be omitted.

  FIG. 7 shows the arrangement of the first lower spacer 5b, the second lower spacer 5c, and the translation cam mechanism 4 on the slider 6 of the second embodiment. Components different from those of the first embodiment are a first lower spacer 5b, a second lower spacer 5c, a translation cam mechanism 4 fixed on the slider table 6a, and a cam follower 7 fixed to the top table 1 (not shown). The upper spacer 5a is the same as that of the first embodiment. The translation cam mechanism 4 and spacers arranged on the slider table 6a can be characterized by the performance of the stage system depending on the arrangement position and the number of spacers.

  FIG. 8 is a diagram for explaining the vibration direction of the top table 1. For example, as shown in FIG. 4, when the top table 1 is constrained by the two Z guides 3, the top table 1 is rotated around the X axis as the assumed vibration direction as shown in FIG. There is a rotational pitch θY. The direction in which vibration is likely to occur is determined by the shape of the top table 1. For example, in the shape of the top table 1 as shown in FIG. 8, the inertia moment in the direction around the X axis increases due to the mass of the Z guide drive unit 3 a fixed to the top table 1. Vibration is more likely to occur.

  FIG. 7 shows a configuration in which the top table 1 is supported by two spacers. As shown in FIG. 7, two sets of first and second lower spacers 5b and 5c are arranged on both sides in the Y-axis direction on the slider table 6a. In addition, two upper spacers 5a are fixed to the lower surface of the top table 1 (not shown) at positions corresponding to the two sets of first and second lower spacers 5b and 5c.

  In the example of FIG. 7, the translation cam mechanism 4 is fixed at the center position of the slider table 6a. A cam follower 7 (not shown) used for driving the vertical movement is fixed to a position corresponding to the translation cam mechanism 4, that is, a center position of the lower surface of the top table 1.

  In the example of FIG. 7, two sets of first and second lower spacers 5b and 5c are arranged along the direction of the rotating roll around the X axis in FIG. Thus, by supporting the top table 1 at two points on both sides in the Y-axis direction, it is possible to suppress vibration of the rotating roll around the X-axis of the top table 1 in FIG. The configuration of the top table 1 in FIG. 8 has a shape that tends to vibrate around the X axis. However, the first and second lower spacers 5b and 5c are arranged in accordance with the shape and configuration of the top table 1. You may change it. For example, this is the case where the top table has a shape that is long in one direction, or the load that is mounted has an eccentric center of gravity. Two spacers may be arranged along an axis in a direction in which vibration is likely to occur. By disposing the upper spacer 5a, the first lower spacer 5b, and the second lower spacer 5c in the direction in which the top table 1 easily vibrates, a stage system with small vibration can be configured.

[Third embodiment]
Next, the third embodiment will be described with reference to FIG. In FIG. 9, the same reference numerals as those in the first and second embodiments indicate the same parts, and thus the description thereof will be omitted.

  FIG. 9 shows an arrangement of the first lower spacer 5 b, the second lower spacer 5 c, and the translation cam mechanism 4 on the slider 6. Components different from the first to second embodiments are fixed to a first lower spacer 5b, a second lower spacer 5c, a translation cam mechanism 4, and a top table 1 (not shown) fixed on the slider table 6a. The cam follower 7 and the upper spacer 5a are the same as those in the first and second embodiments.

  In this embodiment, three sets of first and second lower spacers 5b and 5c are used. As shown in FIG. 9, the first and second lower spacers 5b and 5c are arranged on the slider table 6a so that the center positions of the three sets coincide with the apexes of the equilateral triangle. In addition, on the lower surface of the top table 1 (not shown), three upper spacers 5a are fixed at positions corresponding to the three sets of first and second lower spacers 5b and 5c.

  One translation cam mechanism 4 is arranged at the center position of the slider table 6a, but the number and position thereof do not interfere with the first and second lower spacers 5b and 5c, and the vertical acting on the cam follower 7. You may arrange | position freely under the restriction | limiting that the action position of the resultant force of a direction drive force becomes the gravity center of the top table 1. FIG.

  By arranging the three sets of first and second lower spacers 5b and 5c on the slider table 6a so as to coincide with the vertex of the equilateral triangle, the top table 1 can be supported at the position of the equilateral triangle. . According to this configuration, an effect of suppressing vibrations in two directions of the rotating roll around the X axis and the rotating pitch (roll and pitch) around the Y axis shown in FIG. 8 is obtained. Further, the stage rigidity is increased by increasing the number of contact points for supporting the top table 1. In order for the upper spacer 5a fixed to the top table 1 and the first and second lower spacers 5b and 5c to come into contact with each other at all three points, the first and second lower spacers 5b and 5c are in contact with each other. What is necessary is just to raise the processing precision of a surface.

[Fourth embodiment]
Next, a fourth embodiment will be described with reference to FIG. In FIG. 10, the same reference numerals as those in the first to third embodiments denote the same components, and thus the description thereof will be omitted.

  The fourth embodiment shown in FIG. 10 has a configuration in which a spring is added to the configuration of the first embodiment. In the present embodiment, two pressurizing springs 8 are provided so as to connect the top table 1 and the base table 2. The two pressurizing springs 8 can increase the frictional force of the contact surface between the upper spacer 5a and the first and second lower spacers 5b and 5c, and can appropriately adjust the holding force of the top table 1.

  As shown in FIG. 10, the two pressurizing springs 8 connect the lower surface of the top table 1 and the upper surface of the base table 2 and are arranged so as to be bilaterally symmetrical on the outer side in the Y direction of the slider 6. A tension spring is used as the pressurizing spring 8. In the illustrated example, two pressurizing springs 8 are used, but three or more pressurizing springs 8 may be used. Further, the positions of the two pressurizing springs 8 may be changed by being rotated 90 ° with respect to the Z axis at the center of the stage so as to be symmetrical to the outside in the X direction of the slider 6.

  In the first embodiment, the slider 6 is held in the X-axis direction by the frictional force between the upper spacer 5a and the first and second lower spacers 5b and 5c depending on the weight of the top table 1. It was. In the present embodiment, an effect of increasing the holding force in the X-axis direction of the slider 6 by increasing the frictional force by applying a compression force by the pressurizing spring 8 to the weight of the top table 1 is obtained. An appropriate holding force in this case depends on acceleration during driving of an X stage (not shown) on which the Z stage 101 is mounted and a Y stage, and a higher holding force is required as the acceleration is higher. Further, although the required driving force in the Z direction is increased by the pressurizing spring 8, the thrust of the actuator 9 may be increased in accordance with the strength of the pressurizing spring 8.

[Fifth embodiment]
Next, a fifth embodiment will be described with reference to FIGS. 11 to 14, the same reference numerals as those in the first to fourth embodiments denote the same parts, and thus the description thereof will be omitted.

  In the fifth embodiment, the actuator 9 is removed from the configuration of the first embodiment, and a lifting rod 107a and a lowering rod 107b necessary for external actuation are added. As shown in FIG. 11, the inner wall on both sides in the X direction of the vacuum chamber 108 is provided with a lifting rod 107a and a lowering rod 107b for external actuation. The ascending rod 107 a and the descending rod 107 b are disposed at the same height as the slider 6. Further, as shown in FIG. 12, the ascending rod 107a and the descending rod 107b are arranged not at the position immediately below the column 109 but at a position shifted in the Y-axis negative direction from the Y-axis center position of the vacuum chamber 108. Therefore, the Z direction driving of the Z stage 101 can be performed at a position retracted from the column 109.

  Next, the principle of driving by external actuation will be described with reference to FIGS. FIG. 11 shows a state in which the upper spacer 5a is in contact with the first lower spacer 5b. When the Z stage 101 is driven in the Z direction, first, the X stage 102 is moved on the X stage rails 102 a and 102 b and stopped near the center of the X axis of the vacuum chamber 108. FIG. 12 shows a state in which the X stage 102 is stopped near the center of the X axis of the vacuum chamber 108.

  Next, the Y stage 103 is moved in the Y axis negative direction on the Y stage rails 103a and 103b. Then, as shown in FIG. 13, the Y stage 103 is stopped at a position where the straight line connecting the ascending rod 107 a and the descending rod 107 b coincides with the center of the X stage 102.

  Next, the X stage 102 is moved in the X axis positive direction on the X stage rails 102a and 102b. At this time, the X stage 102 moves in the positive X-axis direction, so that the X-axis direction end of the slider table 6a of the slider 6 comes into contact with the ascending rod 107a. After that, when the X stage 102 continues to move in the positive direction of the X axis, as shown in FIG. 14, the ascending rod 107a pushes the end of the slider table 6a in the X axis direction. Thus, the slider 6 moves. Therefore, when the X stage 102 continues to move in the positive direction of the X axis, the roller 7a of the cam follower 7 goes up the inclined surface of the translation cam mechanism 4, and the upper spacer 5a is moved from the first lower spacer 5b to the second lower spacer. It can be transferred to 5c.

  In this way, by moving the slider 6 without using an actuator, it is possible to drive in the Z direction as in the first embodiment. Here, the required thrust of the X stage 102 is the sum of the force for driving the structure on the X stage 102 in the horizontal direction and the force for driving the top table 1 in the vertical direction.

  In the case of the lowering operation, the lowering rod 107b installed on the inner wall of the vacuum chamber 108 on the opposite side of the ascending rod 107a in the X-axis direction may be used. By moving the X stage 102 in the negative X-axis direction, the X-axis direction end of the slider table 6a of the slider 6 comes into contact with the descending rod 107b. When the X stage 102 continues to move in the negative X-axis direction, the roller 7a of the cam follower 7 descends the inclined surface of the translation cam mechanism 4, and the upper spacer 5a is moved from the second lower spacer 5c to the first lower spacer 5b. Can be replaced. Thereby, the lowering operation in the Z direction can be realized in the same manner as the rising operation.

  As described above, since the X stage 102 is responsible for the drive mechanism of the Z stage 101, there is no need to mount the actuator used in the first to fourth embodiments on the Z stage 101, and a smaller and lighter stage system is configured. can do. In addition, the influence of the magnetic field on the electron beam due to electromagnetic noise such as an actuator mechanism such as a motor and wiring (not shown) necessary for driving can be reduced.

  In the above configuration, external actuation is performed by the X stage 102. However, if there is not enough space in the X direction of the vacuum chamber 108 due to an increase in the size of the stage, it is possible to perform Z driving using the Y stage 103. . In this case, in FIG. 11, the ascending rod 107 a and the descending rod 107 b are installed on both sides in the Y direction of the inner wall of the vacuum chamber 108. The Z stage 101 is installed in a direction rotated by 90 °. That is, unlike FIG. 11, the Z stage 101 may be arranged so that the moving direction of the slider 6 of the Z stage 101 coincides with the Y-axis direction. In this configuration, the thrust required for driving is increased by the mass of the X stage 102, but the thrust of the Y stage 103 may be increased. As described above, the driving device for the Z stage 101 can be constituted by the horizontal movement stage (X stage 102 or Y stage 103), the ascending rod 107a, and the descending rod 107b.

[Sixth embodiment]
Next, a sixth embodiment will be described with reference to FIG. In FIG. 15, the same reference numerals as those in the first to fifth embodiments indicate the same parts, and the description thereof will be omitted.

  In the first to fifth embodiments, the Z drive only for positioning at two points is limited. However, the present embodiment is configured to enable positioning at three points. As shown in FIG. 13, a first lower spacer 5b, a second lower spacer 5c, and a third lower spacer 5d are provided on the slider table 6a. The first lower spacer 5b, the second lower spacer 5c, and the third lower spacer 5d have different heights. In addition, the translation cam mechanism 41 is alternately arranged with a pair of inclined surfaces with a right shoulder rising and a inclined surface with a right shoulder descending, and each pair has a vertex. Therefore, the translation cam mechanism 41 has an inclined surface that forms two peaks so as to correspond to the three lower spacers 5b, 5c, and 5d.

  As shown in FIG. 15, the top table 1 rises, falls, rises and falls in response to the slider 7 moving to the left while the roller 7 a of the cam follower 7 rolls on the inclined surface of the translation cam mechanism 41. Drive in the Z direction in order. In the present embodiment, the third lower spacer 5d is installed at an intermediate position between the first lower spacer 5b and the second lower spacer 5c. Can be increased to a point. Other operations are the same as those in the first to fifth embodiments. This is not limited to three points, and it is possible to further increase the number of stages based on the required height and the length of the slider in the X direction and the stroke limit.

[Seventh embodiment]
Next, a seventh embodiment will be described with reference to FIG. In FIG. 16, the same reference numerals as those in the first to sixth embodiments indicate the same parts, and the description thereof will be omitted.

  As shown in FIG. 16, a rigid hemisphere 51 is attached to the tip of the first lower spacer 5b as a structure for reducing the contact area between the first lower spacer 5b and the upper spacer 5a. The second lower spacer 5c (not shown) has the same configuration. In the present embodiment, the configuration other than the first lower spacer 5b and the hemisphere 51 is the same as that of the first to sixth embodiments.

  As shown in FIG. 16, the hemisphere 51 is fixed to the upper surface of the first lower spacer 5b. Similarly, the hemisphere 51 is fixed to the second lower spacer 5c. The hemisphere 51 and the lower part of the upper spacer 5a come into contact with each other at the contact point 52, and the top table 1 of the Z stage 101 is positioned.

  In this embodiment, in order to bring the upper spacer 5a and the first and second lower spacers 5b and 5c into contact with each other at a point or a minimum area, the tip portions of the first and second lower spacers 5b and 5c are used. Is formed in a spherical shape. By replacing the surface contact spacer in FIG. 1 with the small contact spacer shown in FIG. 16, the contact point after driving in the Z direction is likely to be the same point. Therefore, the displacement of the position in the Z direction due to the variation in the contact surface with the surface-shaped spacer can be reduced, and the reproduction accuracy of the position and orientation of the top table 1 in the Z direction is ensured.

  In FIG. 16, the hemisphere 51 is attached to the first lower spacer 5b, but a hemisphere may be attached to the upper spacer 5a, or the upper spacer 5a and the first and second lower spacers 5b. You may attach a hemisphere to both of 5c.

[Eighth embodiment]
Next, an eighth embodiment will be described with reference to FIG. In FIG. 17, the same reference numerals as those in the first to seventh embodiments indicate the same parts, and the description thereof will be omitted.

  In the first to seventh embodiments, the slider 6 is composed of a single slider table 6a. However, in this embodiment, the slider 6 is divided into two sliders 61 and 62 as shown in FIG. Each of the slider 61 and the slider 62 is provided with a translation cam mechanism 4, a first lower spacer 5b, and a second lower spacer 5c. In the present embodiment, the other configurations are the same as those in the first to seventh embodiments.

  In this embodiment, in order to drive the slider 61 and the slider 62 in synchronization, two drive mechanisms are provided. For example, two actuators for driving the sliders 61 and 62 or other driving mechanisms (not shown) are mounted. When driving by an external mechanism as in the fifth embodiment, the ascending rod 107a and the descending rod 107b may be provided by the number of sliders.

  By dividing the slider 6 into the small slider 61 and the slider 62, a space can be secured between the slider 61 and the slider 62. Accordingly, the degree of freedom in design is increased, and compatibility with other mechanisms is facilitated. In this case, it is assumed that the other mechanism is a lift pin mechanism used at the time of sample transport by the robot arm mechanism. In addition, the stage system can be reduced in size and weight.

[Ninth embodiment]
Next, a ninth embodiment will be described with reference to FIG. In FIG. 18, the same reference numerals as those in the first to eighth embodiments denote the same parts, and the description thereof will be omitted.

  In this embodiment, a shielding mechanism that can be expanded and contracted in the vertical direction is disposed around the slider 6. For example, in FIG. 18, the bellows 10 is disposed around the slider 6 as a retractable shielding mechanism. The bellows 10 can cope with a change in height between the top table 1 and the base table 2 by driving in the Z direction by expansion and contraction of the bellows. The bellows 10 is arranged so as to surround the slider 6, but may be arranged outside the Z guide 3, that is, so as to surround the entire stage.

  Even when dust is generated by the sliding of the translation cam mechanism 4 and the cam follower 7 and the contact between the upper spacer 5a and the lower spacers 5b and 5c, the bellows 10 can block the diffusion of dust. By this interruption, a stage system that does not affect the sample measurement can be configured. Further, a mechanism that does not allow dust to go outside may be used as long as it is not a mechanism that completely blocks the entire periphery like the bellows 10.

  The present invention is not limited to the above-described embodiments, and includes various modifications. The above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Moreover, the structure of another Example can also be added to the structure of a certain Example. Further, with respect to a part of the configuration of each embodiment, another configuration can be added, deleted, or replaced.

DESCRIPTION OF SYMBOLS 1 ... Top table 2 ... Base table 3a ... Z guide drive part 3b ... Z guide fixing | fixed part 3c ... Guide mechanism 3 ... Z guide 4 ... Translation cam mechanism (cam part)
5a: Upper spacer (upper load receiving part)
5b: First lower spacer (lower load receiving portion)
5c ... Second lower spacer (lower load receiving portion)
5d ... Third lower spacer (lower load receiving portion)
51 ... Hemisphere 6 ... Slider (moving part)
6a ... Slider table 6b ... Linear guide (horizontal guide)
6c ... guide rail 7 ... cam follower 7a ... roller 7b ... roller holder (roller support)
8 ... Pressurizing spring 9 ... Actuator 10 ... Bellows 101 ... Z stage 102 ... X stage 103 ... Y stage 104 ... Sample holder 105 ... Sample 106 ... Stage system 107a ... Lifting rod 107b ... Lowering rod 108 ... Vacuum chamber 109 ... column

Claims (13)

A vertical movement stage for a charged particle beam device,
A base table,
A top table for holding the sample;
A roller support portion fixed to the lower surface of the top table and a roller supported by the roller support portion;
An upper load receiving portion fixed to the lower surface of the top table or the roller support portion and receiving a load of the top table;
A moving unit disposed between the base table and the top table and moving a horizontal relative position between the base table and the top table;
A cam portion having at least two inclined surfaces for changing a vertical relative position between the base table and the top table, wherein the roller rotates the inclined surface;
A lower load receiving portion that is fixed to the upper surface of the moving portion or the base table and receives the load of the top table;
The upper load receiving portion and the lower load receiving portion have contact surfaces that contact each other, and at least one of the upper load receiving portion and the lower load receiving portion has a plurality of contact surfaces having different heights. A vertical movement stage characterized by comprising: The vertical movement stage according to claim 1,
The lower load receiving part is fixed on the moving part,
By moving the moving portion in the horizontal direction, the cam portion and the lower load receiving portion move in the horizontal direction, and the upper load receiving portion and the lower load receiving portion are in contact with each other. Vertical moving stage. The vertical movement stage according to claim 1,
The at least two inclined surfaces are composed of an inclined surface having a positive inclination and an inclined surface having a negative inclination;
By moving the moving portion in the horizontal direction, the roller moves up and down along the inclined surface, and the upper load receiving portion and the lower load receiving portion are in contact with each other. . The vertical movement stage according to claim 1,
The horizontal stroke of the moving part and the distance between the plurality of contact surfaces coincide, and the upper load receiving part and the lower load receiving part are in contact at the end of the stroke of the moving part. Vertical movement stage characterized by The vertical movement stage according to claim 1,
The lower load receiving portion includes a plurality of load receiving portions having different heights as the plurality of contact surfaces. The vertical movement stage according to claim 5,
The vertical load stage, wherein the lower load receiving portion includes two or more sets of load receiving portions having different heights. The vertical movement stage according to claim 2,
A vertical movement stage comprising a plurality of the moving parts, wherein the lower load receiving part is disposed in each of the plurality of moving parts. The vertical movement stage according to claim 1,
The vertical movement stage further comprising a spring connecting the top table and the base table. The vertical movement stage according to claim 1,
A vertical movement stage further comprising a drive mechanism for driving the moving unit in a horizontal direction. The vertical movement stage according to claim 9 ,
The vertical movement stage is arranged on a horizontal movement stage,
The drive mechanism includes a plurality of rods that come into contact with the moving unit, and the horizontal movement stage.
The vertical movement stage, wherein the horizontal movement stage moves the vertical movement stage in the horizontal direction, so that one of the plurality of rods comes into contact with the movement unit, and the movement unit moves in the horizontal direction. The vertical movement stage according to claim 1,
At least one of the contact surface of the lower load receiving portion and the contact surface of the upper load receiving portion includes a hemisphere. The vertical movement stage according to claim 1,
The vertical movement stage further comprising an extendable shielding mechanism surrounding the periphery of the moving unit. A column including a charged particle beam optical system for irradiating the sample with a charged particle beam;
A stage system comprising a horizontal movement stage and a vertical movement stage, and holding the sample;
A charged particle beam device comprising:
The vertical movement stage is
A base table,
A top table for holding the sample;
A roller support portion fixed to the lower surface of the top table and a roller supported by the roller support portion;
An upper load receiving portion fixed to the lower surface of the top table or the roller support portion and receiving a load of the top table;
A moving unit disposed between the base table and the top table and moving a horizontal relative position between the base table and the top table;
A cam portion having at least two inclined surfaces for changing a vertical relative position between the base table and the top table, wherein the roller rotates the inclined surface;
A lower load receiving portion that is fixed to the upper surface of the moving portion or the base table and receives the load of the top table;
The upper load receiving portion and the lower load receiving portion have contact surfaces that contact each other, and at least one of the upper load receiving portion and the lower load receiving portion has a plurality of contact surfaces having different heights. A charged particle beam apparatus comprising:

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