Objective table

Abstract

The utility model provides an objective table, which is applied to a scanning electron microscope, and comprises a rotary bearing table of which the first surface is used for bearing a wafer to be tested; the rotary driving assembly is connected with the second surface of the rotary bearing table, and the rotary driving assembly is used for driving the rotary bearing table to rotate; and the translation driving assembly is connected with the second face of the rotary bearing table, and the translation driving assembly is used for driving the rotary bearing table to move in the transverse direction or the longitudinal direction. Thus, the wafer to be measured is moved in two modes of rotation and translation so that the position to be measured in the wafer to be measured is irradiated by the electron beam, the movable distance of the rotary bearing table can be reduced, on the basis, the space where the objective table is located can be reduced, the space occupied by the electron microscope chamber can be further reduced, the time required for vacuum pumping of the electron microscope chamber is further shortened, and the production efficiency is improved. Finally, the speed of measuring the critical dimension is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a stage. Background Art

[0002] Scanning electron microscopes can be used to detect the characteristic dimensions of semiconductors. The characteristic dimension measurement process may include: transferring the wafer to be tested to the electron microscope room; then extracting the gas inside the electron microscope room to make the electron microscope room in a vacuum environment; next, aligning the wafer to be tested with an optical microscope (OM) and a scanning electron microscope (SEM); next, driving the wafer to be tested through the stage, so that the electron gun emits an electron beam to scan the area to be tested in the wafer to be tested, and generating a two-dimensional image representing the surface morphology of the area to be tested; finally, moving the wafer to be tested out of the electron microscope room.

[0003] In the related art, when the electron gun is fixed, the movable distance of the stage needs to be set to twice the diameter of the wafer to be measured, so that the electron gun can scan any position in the wafer to be measured. Since the movable distance of the stage is large during the measurement process, the electron microscope room with a built-in stage needs to occupy a large space, resulting in a long time required to extract the gas inside the electron microscope room to make the electron microscope room in a vacuum environment, which reduces the speed of measuring critical dimensions. Utility Model Content

[0004] The technical problem to be solved by the present application is that the existing speed of measuring key dimensions is slow.

[0005] In order to solve the above technical problems, the present application provides a stage, comprising:

[0006] A rotating carrier table, wherein a first surface of the rotating carrier table is used for carrying a wafer to be tested;

[0007] A rotation driving assembly, the rotation driving assembly is connected to the second surface of the rotation bearing platform, and the rotation driving assembly is used to drive the rotation bearing platform to rotate;

[0008] A translation drive assembly is connected to the second surface of the rotating bearing platform, and is used to drive the rotating bearing platform to move horizontally or vertically.

[0009] In some embodiments of the present application, the rotation drive assembly includes:

[0010] A central shaft, one end of which is connected to the rotating bearing platform;

[0011] A gear, wherein the gear is sleeved on the central shaft;

[0012] A rotation drive mechanism is meshedly connected with the gear, and is used to drive the gear to drive the rotating support platform to rotate with the central axis as the center.

[0013] In some embodiments of the present application, the rotation drive mechanism includes:

[0014] at least one transmission wheel, the transmission wheel being meshedly connected with the gear;

[0015] A motor is connected to the transmission wheel, and the motor is used to drive the transmission wheel to rotate, so as to drive the rotating support platform to rotate through the gear.

[0016] In some embodiments of the present application, the rotation drive assembly further includes a bottom supporting platform, and the bottom supporting platform is fixedly connected to the motor.

[0017] In some embodiments of the present application, the rotary drive assembly further includes a bracket, one end of the bracket is fixedly disposed on the bottom supporting platform, and the other end of the bracket is in contact with the gear via a ball bearing.

[0018] In some embodiments of the present application, a first groove is provided on one side of the gear, and the first groove is annular;

[0019] The other end of the bracket comprises a supporting platform, on which a second groove is arranged; the diameter of the second groove is the same as that of the first groove, and the ball bearing is arranged between the second groove and the first groove.

[0020] In some embodiments of the present application, the translation drive assembly includes: a transverse track, a longitudinal track and a translation drive mechanism, the other end of the central axis directly contacts and is located on the transverse track or the longitudinal track, and the translation drive mechanism drives the central axis to move along the transverse track or the longitudinal track to drive the rotating support platform, the bottom support platform and the rotation drive assembly to move along the transverse track or the longitudinal track.

[0021] In some embodiments of the present application, a pressure-bearing gasket is provided at the other end of the central axis.

[0022] In some embodiments of the present application, a first baffle is provided on both sides of the transverse track, and the first baffle is used to prevent the other end of the central axis from moving out of the transverse track; a second baffle is provided on both sides of the longitudinal track, and the second baffle is used to prevent the other end of the central axis from moving out of the longitudinal track.

[0023] In some embodiments of the present application, the track lengths of the transverse track and the longitudinal track are set to be the radius length of the wafer to be tested.

[0024] Compared with the prior art, the technical solution of the present application, by setting the rotating carrier table, the rotating drive assembly and the translation drive assembly, can move the wafer to be tested by rotation and translation so that the position to be tested is irradiated by the electron beam, and can reduce the movable distance of the rotating carrier table 11. On this basis, the space where the stage is located can be reduced, and then the space occupied by the electron microscope room can be reduced, thereby shortening the time required for evacuating the electron microscope room, and ultimately achieving an increase in the speed of measuring key dimensions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

[0026] Figure 1 is a schematic diagram of the structure of a stage according to some embodiments of the present application;

[0027] Figure 2 is a schematic structural diagram of a first rotary drive assembly according to some embodiments of the present application;

[0028] Figure 3 is a schematic structural diagram of a first rotary drive assembly according to some embodiments of the present application;

[0029] Figure 4 is a schematic diagram of the translation and / or rotation position of a wafer to be tested according to some embodiments of the present application;

[0030] Explanation of the accompanying figures: 11-rotating support platform, 12-rotating drive assembly, 13-translational drive assembly, 121-central axis, 122-gear, 123-rotating drive mechanism, 1231-transmission wheel, 1232-motor, 124-bottom support platform, 125-bracket, 126-ball, 131-transverse track, 132-longitudinal track and 133-translational drive mechanism. DETAILED DESCRIPTION

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation. It should be clearly understood that the drawings are only for the purpose of illustration and description and are not intended to limit the scope of disclosure of this specification.

[0032] It should be understood that the "module" and "circuit" used herein are a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0033] The terms used in this application are only used for the purpose of describing specific example embodiments and are not restrictive. When used in this specification, the terms "include", "comprise" and / or "contain" mean the existence of the associated integers, steps, operations, elements and / or components, but do not exclude the existence of one or more other features, integers, steps, operations, elements, components and / or groups or the addition of other features, integers, steps, operations, elements, components and / or groups in the carrier. When describing the association of different components in this specification, it can be a direct relationship or an indirect relationship. For example, "A and B are connected" can mean that A and B are directly connected, or A and B are indirectly connected through other components.

[0034] Scanning electron microscope-based tools are widely used for critical dimension measurement in both high-volume manufacturing and R&D stages. Improving the throughput of scanning electron microscopes can increase the production capacity of device manufacturers and shorten production cycle time, thereby reducing the cost of high-volume manufacturing. Scanning electron microscope-based tools need to work in a high-vacuum environment to obtain a high-quality electron beam. If the space occupied by the electron microscope chamber that needs to work in a high-vacuum environment can be reduced, the time required to evacuate the gas inside the electron microscope chamber to make the electron microscope chamber in a vacuum environment can be reduced, and the speed of measuring critical dimensions can also be increased.

[0035] A stage is set up in the electron microscope room. The movable distance of the stage during the measurement process is relatively large. Therefore, in an embodiment of the present application, a stage can be designed to reduce the movable distance of the stage while meeting the key dimension measurement requirements. On this basis, the space occupied by the stage can be reduced, and the space occupied by the electron microscope room can be reduced, thereby shortening the time required for evacuating the electron microscope room, and ultimately achieving an increase in the speed of measuring key dimensions.

[0036] Based on the above analysis, if Figure 1 As shown, the stage provided in the embodiment of the present application may include:

[0037] A rotating carrier 11, wherein a first surface of the rotating carrier 11 is used for carrying a wafer to be tested;

[0038] A rotation driving assembly 12, wherein the rotation driving assembly 12 is connected to the second surface of the rotation bearing platform 11, and the rotation driving assembly 12 is used to drive the rotation bearing platform 11 to rotate;

[0039] The translation driving assembly 13 is connected to the second surface of the rotating bearing platform 11 , and the translation driving assembly 13 is used to drive the rotating bearing platform 11 to move horizontally or vertically.

[0040] In the embodiment of the present application, the first surface of the rotating support table 11 may also be provided with a fixing device for fixing the wafer to be tested, such as a limit block, a buckle, a pressing sheet, etc. This is not limited in the embodiment of the present application.

[0041] In the embodiment of the present application, during the rotation of the rotating platform 11 , the relative position between the rotating platform 11 and the wafer to be tested does not change.

[0042] In some embodiments of the present application, Figure 1 As shown, the rotary drive assembly 12 includes:

[0043] A central shaft 121, one end of which is connected to the rotating support platform 11;

[0044] A gear 122, wherein the gear 122 is sleeved on the central shaft 121;

[0045] The rotation driving mechanism 123 is meshed with the gear 122 , and is used to drive the gear 122 to drive the rotating support platform 11 to rotate around the central axis 121 .

[0046] In the embodiment of the present application, one end of the central shaft 121 may be connected to the rotating support platform 11 by welding, so that when the central shaft 122 rotates, the rotating support platform 11 also rotates.

[0047] In the embodiment of the present application, the central shaft 121 can be made of high-torque materials such as alloy and steel, so that the central shaft 12 can withstand sufficient torsional pressure, extending the service life of the long central shaft 121 and thus the service life of the long stage.

[0048] In the embodiment of the present application, the central axis 121 and the rotating support platform 11 may be integrally formed.

[0049] In the embodiment of the present application, the gear 122 can be sleeved on the central shaft 121 in a detachable connection manner. Specifically, the detachable connection manner includes key connection, pin connection, bolt connection, and the like.

[0050] It can be understood that the gear 122 is sleeved on the central shaft 121 and can be detached so that the gear 122 can be fixed on the central shaft 121 and the relative position of the gear 122 and the central shaft 121 does not change when the rotation drive mechanism 123 is used to drive the gear 122 to rotate.

[0051] In some embodiments of the present application, Figure 1 As shown, the rotation drive mechanism 123 includes:

[0052] At least one transmission wheel 1231, wherein the transmission wheel 1231 is meshedly connected with the gear 122;

[0053] The motor 1232 is connected to the transmission wheel 1231 , and the motor 1232 is used to drive the transmission wheel 1231 to rotate, so as to drive the rotating support platform 11 to rotate through the gear 122 .

[0054] In the embodiment of the present application, the rotation drive mechanism 123 also includes a controller, a power supply, a signal transceiver, etc., so that the motor 1232 can receive control instructions such as turning on, changing the speed, turning off, setting the rotation direction, etc.

[0055] In the embodiment of the present application, after the motor 1232 rotates according to the control instruction, the motor 1232 drives the transmission wheel 1231 to rotate, the transmission wheel 1231 drives the meshing gear 122 to rotate, the central shaft 121 rotates with the gear 122, and then drives the rotating support platform 11 to rotate.

[0056] In the embodiment of the present application, since the required rotation accuracy needs to be considered during the rotation of the rotating support platform 11, the number of the transmission wheels 1231 can be determined based on the rotation accuracy, the motor speed, the gear size of the transmission wheel 1231 and the gear size of the gear 122.

[0057] In the embodiment of the present application, if the rotation driving mechanism 123 includes a plurality of transmission wheels 1231 , the gear sizes of the transmission wheels 1231 may be the same or different.

[0058] In some embodiments of the present application, Figure 2As shown, the rotation driving assembly 12 further includes a bottom supporting platform 124 , and the bottom supporting platform 124 is fixedly connected to the motor 1232 .

[0059] In this way, the bottom supporting platform 124 can be used to support the motor 1232 so that the relative position of the motor 1232 is in a stable state, ensuring that the position relationship between the motor 1232 and the transmission wheel 1231, and the position relationship between the transmission wheel 1231 and the gear 122 are in a relatively stable state, thereby improving the rotation accuracy of the stage and further improving the accuracy of measuring key dimensions.

[0060] In some embodiments of the present application, Figure 3 As shown, the rotation driving assembly 12 further includes a bracket 125 , one end of the bracket 125 is fixedly disposed on the bottom bearing platform 124 , and the other end of the bracket 125 is in contact with the gear 122 via a ball 126 .

[0061] In the embodiment of the present application, the bracket 125 is used to support the gear 122 so that the gear 122 can be in a horizontal state.

[0062] In some embodiments of the present application, a first groove is set on one side of the gear 122, and the first groove is annular; the other end of the bracket 125 includes a supporting platform, and a second groove is set on the supporting platform; the second groove has the same diameter as the first groove, and the ball 126 is set between the second groove and the first groove.

[0063] In the embodiment of the present application, the bottom supporting platform 124 is adapted to the gear 122 , one end of the bracket 125 is a supporting platform, the second groove is arranged on the first surface of the supporting platform, a supporting portion is arranged on the second surface of the supporting platform, and the supporting portion is fixedly connected to the bottom supporting platform 124 .

[0064] In an exemplary embodiment, the support portion may include three support legs, which are welded on the bottom support platform 124 .

[0065] In another example, the bracket 125 may be in a truncated cone shape, the supporting portion is the side surface of the bracket 125, the bottom surface of the side surface is a circular ring plane, and the supporting portion may be fixedly disposed on the bottom supporting platform 124 by welding, snap connection, bolt connection, etc.

[0066] In this way, the other end of the bracket 125 contacts the gear 122 via the ball bearing, so that the bracket 125 can support the gear 122 without affecting the rotation of the gear 122 .

[0067] In some embodiments of the present application, Figure 1 As shown, the translation drive assembly 13 includes: a transverse rail 131, a longitudinal rail 132 and a translation drive mechanism 133. The other end of the central axis 121 directly contacts and is located on the transverse rail 131 or the longitudinal rail 132. The translation drive mechanism 133 drives the central axis 121 to move along the transverse rail 131 or the longitudinal rail 132 to drive the rotating support platform 11, the bottom support platform 124 and the rotating drive assembly 124 to move along the transverse rail 131 or the longitudinal rail 132.

[0068] In the embodiment of the present application, the translation driving mechanism 133 can move the other end of the central axis 121 along the transverse track 131 or the longitudinal track 132 through a transmission chain, magnetism, traction, etc.

[0069] It is understandable that the transverse track 131 and the longitudinal track 132 do not cross each other.

[0070] In some embodiments of the present application, a pressure-bearing gasket is disposed at the other end of the central shaft 121. The other end of the central shaft 121 is directly in contact with and located on the transverse track 131 or the longitudinal track 132 through the pressure-bearing gasket.

[0071] In this way, the pressure between the other end of the central axis and the transverse track 131 or the longitudinal track 132 is reduced, the driving resistance of the translation drive mechanism 133 is reduced, the energy consumption required for translating the rotating carrier 11 is reduced, and the operation efficiency of the carrier is improved.

[0072] In some embodiments of the present application, first baffles are provided on both sides of the transverse track 131, and the first baffles are used to prevent the other end of the central axis 121 from moving out of the transverse track 131; second baffles are provided on both sides of the longitudinal track 132, and the second baffles are used to prevent the other end of the central axis 121 from moving out of the longitudinal track 132.

[0073] In this way, the relative position of the central axis 121 can be kept in a stable state, and the positional relationship between the central axis 121 and the transverse track 131, as well as the positional relationship between the central axis 121 and the longitudinal track 132 can be ensured to be in a relatively stable state, thereby improving the rotation accuracy of the stage and further improving the accuracy of measuring key dimensions.

[0074] In some embodiments of the present application, the track lengths of the transverse track 131 and the longitudinal track 132 are set to be the radius length of the wafer to be tested.

[0075] In the embodiment of the present application, the rotating support platform 11 is rotated and translated, and the electron beam emitted by the scanning electron microscope can irradiate any position of the wafer to be tested.

[0076] In the embodiments of the present application, Figure 4 As shown in (a), in the rectangular coordinate system, the origin position is the position irradiated by the electron beam emitted by the scanning electron microscope, and the origin position coincides with the center position of the wafer to be tested. Assuming that the wafer to be tested is located at one end of the transverse track 131 and at one end of the longitudinal track 132, the movable distance of the wafer to be tested in the transverse and longitudinal directions is the radius length of the wafer to be tested, then the wafer to be tested located in the fourth quadrant in the rectangular coordinate system can be irradiated by the electron beam.

[0077] In the first example, Figure 4 As shown in (b) in the figure, the first position to be measured in the wafer to be measured is located in the fourth quadrant, so the first position to be measured can be irradiated by the electron beam by translating the wafer to be measured in the horizontal and / or vertical directions.

[0078] In the second example, Figure 4 As shown in (c) in FIG. 1 , the second position to be tested in the wafer to be tested is located in the third quadrant, so the wafer to be tested is first rotated to rotate the second position to be tested to the fourth quadrant. Then, as Figure 4 As shown in (d) in the figure, by translating the wafer to be tested in the horizontal and / or vertical directions, the second position to be tested can be irradiated by the electron beam.

[0079] In an embodiment of the present application, a stage is provided, by providing the rotating stage 11, the rotating drive assembly 12 and the translation drive assembly 13, the wafer to be tested can be moved by rotation and translation so that the position to be tested is irradiated by the electron beam. Under the premise of meeting the critical dimension measurement requirements, the movable distance of the rotating stage 11 can be reduced, and on this basis, the space where the stage is located can be reduced, and then the space occupied by the electron microscope room can be reduced, thereby shortening the time required for vacuuming the electron microscope room, and finally achieving an increase in the speed of measuring critical dimensions.

[0080] It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the beneficial effects that may be produced may be any one or a combination of the above, or any other beneficial effects that may be obtained.

[0081] In summary, after reading the contents of this application, those skilled in the art will appreciate that the aforementioned application contents may be presented only in an exemplary manner and may not be restrictive. Although not explicitly stated herein, those skilled in the art will appreciate that this application is intended to encompass various reasonable changes, improvements and modifications to the embodiments. These changes, improvements and modifications are within the spirit and scope of the exemplary embodiments of this application.

[0082] It should also be understood that although the terms first, second, third, etc. can be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present application, the first element in some embodiments can be referred to as the second element in other embodiments. The same reference numerals or the same reference signs represent the same elements throughout the specification.

Claims

1. A stage, characterized in that: Applications in scanning electron microscopy include: A rotating carrier table, wherein a first surface of the rotating carrier table is used for carrying a wafer to be tested; A rotation driving assembly, the rotation driving assembly is connected to the second surface of the rotation bearing platform, and the rotation driving assembly is used to drive the rotation bearing platform to rotate; A translation drive assembly is connected to the second surface of the rotating bearing platform, and is used to drive the rotating bearing platform to move horizontally or vertically.

2. The stage according to claim 1, characterized in that: The rotary drive assembly comprises: A central shaft, one end of which is connected to the rotating bearing platform; A gear, wherein the gear is sleeved on the central shaft; A rotation drive mechanism is meshedly connected with the gear, and is used to drive the gear to drive the rotating support platform to rotate with the central axis as the center.

3. The stage according to claim 2, characterized in that: The rotary drive mechanism comprises: at least one transmission wheel, the transmission wheel being meshedly connected with the gear; A motor is connected to the transmission wheel, and the motor is used to drive the transmission wheel to rotate, so as to drive the rotating support platform to rotate through the gear.

4. The stage according to claim 3, characterized in that: The rotary drive assembly further comprises a bottom bearing platform, and the bottom bearing platform is fixedly connected to the motor.

5. The stage according to claim 4, characterized in that: The rotary drive assembly further comprises a bracket, one end of which is fixedly arranged on the bottom bearing platform, and the other end of which is in contact with the gear via a ball bearing.

6. The stage according to claim 5, characterized in that: A first groove is arranged on one side of the gear, and the first groove is annular; The other end of the bracket comprises a supporting platform, on which a second groove is arranged; the diameter of the second groove is the same as that of the first groove, and the ball bearing is arranged between the second groove and the first groove.

7. The stage according to claim 4, characterized in that: The translation drive assembly includes: a transverse track, a longitudinal track and a translation drive mechanism. The other end of the central axis directly contacts and is located on the transverse track or the longitudinal track. The translation drive mechanism drives the central axis to move along the transverse track or the longitudinal track to drive the rotating support platform, the bottom support platform and the rotation drive assembly to move along the transverse track or the longitudinal track.

8. The stage according to claim 7, characterized in that: A pressure-bearing gasket is arranged at the other end of the central shaft.

9. The stage according to claim 7, characterized in that: A first baffle is arranged on both sides of the transverse track, and the first baffle is used to prevent the other end of the central axis from moving out of the transverse track; a second baffle is arranged on both sides of the longitudinal track, and the second baffle is used to prevent the other end of the central axis from moving out of the longitudinal track.

10. The stage according to claim 8, characterized in that: The track lengths of the transverse track and the longitudinal track are set to be the radius length of the wafer to be tested.

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