Wafer inspection apparatus

Abstract

The utility model provides a kind of wafer detection equipment, including wafer workpiece table, detection device and control device.Drive unit is electrically connected with control device, drive unit is configured to drive wafer loading platform to lift;Reading head is electrically connected with control device, reading head and grating ruler are configured to detect the position of wafer loading platform at least in the process that the upper surface of wafer on wafer loading platform moves from an initial position or moves downward;Height measuring unit is arranged on the upper side of wafer loading platform;Height measuring unit is configured to detect the distance between its and the upper surface of wafer supported on wafer loading platform, so that control device determines whether the upper surface of wafer reaches initial position.Wafer upper surface does not need to consider the thickness of entire wafer in the process of reaching target position, adapts to wafer of different thickness, can improve the applicability of wafer detection equipment, realizes measurement to unknown thickness wafer;Improve measurement rate, save manual focusing, improve equipment automation level.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a wafer inspection device. Background Technology

[0002] Scanning electron microscopy (SEM) is a large, precision instrument used for high-resolution micro-area morphology analysis, including defect review scanning electron microscopy (DR-SEM). DR-SEM is a device that uses ultra-high-resolution electron beam imaging technology to re-inspect defects in the integrated circuit manufacturing process. Its main function is to perform defect re-inspection and analysis, including acquiring high-resolution electron beam images, analyzing morphology based on the electron beam images, and collecting energy dispersive spectroscopy information to analyze composition. DR-SEM plays a significant role in integrated circuit manufacturing and can significantly improve manufacturing yield.

[0003] With the rapid development of semiconductor technology in recent years, wafers of varying thicknesses have emerged, typically ranging from 0.5mm to 1.7mm. However, the imaging distance of a scanning electron microscope (SEM) is a fixed value. Therefore, a wafer stage capable of vertical movement is needed to position the wafer at the target location, accommodating wafers of different thicknesses and ensuring a constant distance between the wafer's upper surface and the electron beam imaging device. However, due to the varying wafer thickness, the upward movement distance of the wafer after placement on the stage is uncertain. Thicker wafers require less upward movement, while thinner wafers require more. Maintaining a constant distance between the wafer's upper surface and the electron beam imaging device is problematic because the unknown thickness of the wafer makes the current upward movement distance unpredictable. Therefore, how to ensure wafers of different thicknesses reach the target position is a pressing issue in this field. Utility Model Content

[0004] In view of the above problems, this utility model is proposed to provide a wafer inspection device that overcomes or at least partially solves the above problems, so as to bring wafers of different thicknesses to the target position.

[0005] Specifically, this utility model provides a wafer inspection device, which includes:

[0006] Control device;

[0007] A wafer stage, comprising a drive unit, a wafer loading stage, a grating ruler, and a reading head corresponding to the grating ruler; the drive unit is electrically connected to a control device and configured to drive the wafer loading stage to move up and down; the reading head is electrically connected to the control device and the reading head and the grating ruler are configured to detect the position of the wafer loading stage during at least the process of the upper surface of the wafer on the wafer loading stage moving up or down from an initial position;

[0008] A height measuring unit is disposed on the upper side of the wafer loading stage and electrically connected to the control device; the height measuring unit is configured to detect its distance from the upper surface of the wafer supported on the wafer loading stage, so that the control device can determine whether the upper surface of the wafer has reached the initial position.

[0009] Optionally, the control device is further configured to determine the target position of the wafer loading stage when the upper surface of the wafer reaches the initial position.

[0010] Optionally, the control device is further configured to determine a target position of the wafer loading stage when the upper surface of the wafer reaches the initial position, the target position of the wafer loading stage corresponding to the target position of the upper surface of the wafer.

[0011] Optionally, the height measurement unit includes a capacitive sensor probe disposed on the upper side of the wafer loading stage.

[0012] Optionally, the wafer inspection equipment further includes an inspection device disposed on the upper side of the wafer loading stage; the inspection device is a scanning electron microscope configured to image the wafer on the wafer loading stage using an electron beam.

[0013] Optionally, the wafer stage includes:

[0014] A base on which the drive unit is mounted;

[0015] A lifting seat, wherein the lifting seat is movably mounted on the base; wherein

[0016] The wafer loading stage moves up and down with the lifting platform; the drive unit is configured to drive the lifting platform to move up and down;

[0017] The grating ruler extends in the vertical direction and is mounted on one of the base and the lifting seat, while the reading head is mounted on the other of the base and the lifting seat.

[0018] Optionally, the wafer stage further includes:

[0019] A slider is movably disposed on the base in a horizontal direction. The slider has a first inclined surface that is inclined relative to the horizontal direction. The driving unit is used to drive the slider to move in the horizontal direction.

[0020] The lifting seat has a second inclined surface that is inclined relative to the horizontal direction and adapted to the first inclined surface. The second inclined surface is slidable on the first inclined surface so that the slider drives the lifting seat to rise and fall.

[0021] Optionally, the driving unit includes:

[0022] A lead screw extends along the direction of movement of the slider and is rotatably mounted on the base; the lead screw is threadedly connected to the slider so as to drive the slider to move horizontally when rotated.

[0023] A motor is mounted on the base, and the output shaft of the motor is connected to one end of the lead screw; the control device is electrically connected to the motor.

[0024] Optionally, a side seat is provided on the upper side of the base, the lifting seat is located on one side of the side seat in the horizontal direction, and the lifting seat is movably mounted on the side seat;

[0025] The lower end of the second inclined surface is adjacent to the side seat;

[0026] The side seat is provided with a mounting hole that penetrates the side seat in the horizontal direction;

[0027] The reading head is installed in the mounting hole, and the grating ruler is disposed on the surface of the lifting base facing the reading head.

[0028] Optionally, the wafer stage further includes:

[0029] A push rod is provided on the base; the wafer loading stage is provided with a through hole corresponding to the push rod, and the push rod is configured to extend upward through the through hole during the descent of the wafer loading stage.

[0030] Optionally, the wafer inspection equipment further includes:

[0031] A piezoelectric ceramic drive unit is disposed between the lifting base and the wafer loading stage, and is configured to drive the wafer loading stage to move up and down relative to the lifting base.

[0032] In this wafer inspection device, the presence of a height measurement unit allows the upper surface of the wafer to move to an initial position after it is placed on the wafer loading stage. Based on this initial position, a reading head and a grating ruler are used to detect the position of the wafer loading stage, thereby enabling the control device to start or stop the drive unit. In other words, after the upper surface of the wafer moves to the initial position, control is applied based on the data from the reading head to ensure the wafer loading stage reaches the corresponding target position, thus ensuring the upper surface of the wafer reaches the target position. In other words, when controlling the wafer's lifting and lowering, the initial position of the upper surface of the wafer is first acquired and determined. The position of the upper surface of the wafer does not depend on the wafer's thickness, and the process of the upper surface of the wafer loading stage moving from the initial position to the target position is also independent of the wafer's thickness. Therefore, the problem of uncertain lifting and lowering height of the wafer loading stage due to varying wafer thicknesses is solved. Because it is adaptable to wafers of different thicknesses, it can improve the applicability of wafer inspection equipment and enable measurement of wafers of unknown thickness; it can improve the measurement rate and automatically realize the imaging and focusing of the inspection device, eliminating the need for manual focusing and improving the automation level of the equipment.

[0033] Furthermore, in the wafer inspection equipment of this utility model, even if the detection range of the height measurement unit is small and limited, it does not affect the fact that the upper surface of the wafer can reach the target position. In other words, as long as the height measurement unit can measure a data, it can determine whether the upper surface of the wafer has reached the initial position. Once the initial position is determined, the reading head can be used to determine whether the upper surface of the wafer has reached the target position.

[0034] Furthermore, in the wafer inspection equipment of this invention, even if the data obtained by the height measurement unit for the initial position of wafers of different thicknesses are inconsistent (preferably consistent), the data of the reading head and the data of the height measurement unit can be unified according to the corresponding data relationship, and the data of the target position corresponding to the reading head can be determined, ensuring that the upper surface of the wafer can reach the target position.

[0035] The above and other objects, advantages and features of this utility model will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0036] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0037] Figure 1This is a schematic structural diagram of a wafer inspection device according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic exploded view of the wafer workpiece stage in a wafer inspection device according to an embodiment of the present invention;

[0039] Figure 3 This is another schematic exploded view of the wafer workpiece stage in a wafer inspection device according to one embodiment of the present invention;

[0040] Figure 4 This is a schematic partial structural diagram of the wafer workpiece stage in a wafer inspection device according to an embodiment of the present invention.

[0041] Figure label:

[0042] Wafer workpiece stage 100; lifting seat 110; second inclined surface 120; slider 130; first inclined surface 131; motor 141; lead screw 142; top rod 150; base 161; side seat 162; first guide rail 163; mounting hole 164; wafer loading stage 200; flexible hinge 310; fixing block 311; lifting block 312; drive mating block 313; first spring 316; second spring 317; piezoelectric ceramic actuator 330; grating ruler 410; reading head 420; detection device 500; height measuring unit 510; wafer 600. Detailed Implementation

[0043] The following reference Figures 1 to 4 This description pertains to a wafer inspection apparatus according to embodiments of the present invention. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0044] Unless otherwise expressly specified and limited, the terms "set," "install," "connect," "link," "fix," and "couple" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0045] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] The wafer inspection equipment of this utility model is described below with reference to the accompanying drawings.

[0048] like Figures 1 to 4 As shown, this utility model embodiment provides a wafer inspection device, which may include a wafer workpiece stage 100, an inspection device 500, a height measurement unit 510, and a control device.

[0049] The wafer stage 100 includes a drive unit, a wafer loading stage 200, a grating ruler 410, and a reading head 420 corresponding to the grating ruler 410. The drive unit is electrically connected to a control device and configured to drive the wafer loading stage 200 to move up and down. The grating ruler 410 can move up and down synchronously with the wafer loading stage 200, while the reading head 420 is fixedly set; however, in some embodiments, the reading head 420 can move up and down synchronously with the wafer loading stage 200, while the grating ruler 410 is fixedly set. The reading head 420 is electrically connected to the control device, and the reading head 420 and the grating ruler 410 are configured to detect the position of the wafer loading stage 200 at least during the process of the upper surface of the wafer 600 on the wafer loading stage 200 moving up or down from an initial position, so that the control device can control the drive unit to operate or stop according to the position of the wafer loading stage 200. In other words, the drive unit can operate or stop based on the data from the reading head 420. When the data from the reading head 420 equals the target data, it indicates that the wafer loading stage 200 has reached the target position, the upper surface of the wafer has reached the target position, and the drive unit needs to stop. The wafer workpiece stage 100 achieves closed-loop control of the lifting height of the wafer loading stage 200 through the drive unit, the grating ruler 410, and the reading head 420, thereby driving the wafer loading stage 200 to move up and down.

[0050] The inspection device 500 is disposed on the upper side of the wafer loading stage 200. The inspection device 500 is used to acquire images of the wafer, such as a scanning electron microscope.

[0051] A height measuring unit 510 is disposed on the upper side of the wafer loading stage 200 and electrically connected to the control device. The height measuring unit 510 is configured to detect its distance from the upper surface of the wafer supported on the wafer loading stage 200, so that the control device can determine whether the upper surface of the wafer has reached the initial position. That is, the data obtained by the height measuring unit 510 can be used to determine whether the upper surface of the wafer has reached the initial position.

[0052] When the wafer inspection equipment of this utility model embodiment is working, the drive unit first moves the wafer loading stage 200 to the position where the wafer is installed, then places the wafer on the wafer loading stage 200, and then the drive unit works to make the wafer loading stage 200 move the wafer upward.

[0053] Because the height measuring unit 510 has a detection range, the upper surface of the wafer first enters the detection range of the height measuring unit 510, and then the control device determines that the upper surface of the wafer has reached the initial position based on the data detected by the height measuring unit 510. In some alternative embodiments, the height measuring unit 510 can always perform detection; that is, the detection range of the height measuring unit 510 is large, and the entire movement process of the wafer is detected by the height measuring unit 510.

[0054] The reading head 420 and the grating ruler 410 can continuously detect wafers as the wafer loading stage 200 rises, or they can begin detection when the upper surface of the wafer reaches its initial position. After the upper surface of the wafer reaches its initial position, the wafer loading stage 200 continues to move the wafer upwards or downwards, and determines whether the wafer loading stage 200 has reached the corresponding target position based on the data acquired by the reading head 420, i.e., whether the upper surface of the wafer has reached the corresponding target position. Once the upper surface of the wafer reaches the target position, the drive unit can stop operating. Subsequently, the detection device 500 can be used to acquire images, enabling automatic measurement of wafers of different thicknesses, or other tasks.

[0055] In the wafer inspection equipment of this embodiment, because it has a height measurement unit 510, after the wafer is placed on the wafer loading stage 200, the upper surface of the wafer is first moved to an initial position. Then, based on the initial position, the position of the wafer loading stage 200 is detected by the reading head 420 and the grating ruler 410, thereby enabling the control device to control the start or stop of the drive unit according to the position of the wafer loading stage 200. Since the distance between the initial position and the corresponding target position of the upper surface of the wafer is usually a fixed value, after the upper surface of the wafer moves to the initial position, the movement distance of the wafer loading stage is equal for wafers of any thickness. That is, after the upper surface of the wafer moves to the initial position, only the data from the reading head 420 is used to control the corresponding distance difference of the movement of the wafer loading stage 200. In other words, the initial position of the upper surface of the wafer is first acquired and determined. The position of the upper surface of the wafer does not need to be determined based on the thickness of the wafer, that is, the thickness of the entire wafer does not need to be considered. The lifting height of the wafer loading stage can be a fixed value after the upper surface of the wafer reaches the initial position. Therefore, compared with the existing solution that only uses the reading head to control the drive unit to work or stop, the wafer inspection equipment of this utility model embodiment can solve the problem of uncertain lifting height of the wafer loading stage 200 due to different wafer thicknesses.

[0056] Therefore, the wafer inspection equipment of this embodiment first uses the height measurement unit 510 to determine the initial position of the upper surface of the wafer, and then switches to using the reading head to control the drive unit, so that the drive unit stops after reaching the conductive target position on the upper surface of the wafer. The initial position of the upper surface of the wafer in this embodiment can also be understood as the switching position of the drive unit to use the reading head's value to control the drive unit during the process of the upper surface of the wafer reaching the target position. It should also be noted that when inspecting a wafer, the process of first using the height measurement unit 510 to determine the initial position of the upper surface of the wafer, and then switching to using the reading head to control the drive unit, so that the drive unit stops after reaching the conductive target position on the upper surface of the wafer, may occur once or multiple times.

[0057] Furthermore, even if the detection range of the height measurement unit 510 is small and limited, it does not affect the fact that the upper surface of the wafer can reach the target position. In other words, as long as the height measurement unit 510 can measure a data point, it can determine whether the upper surface of the wafer has reached the initial position. Once the initial position is determined, the reading head 420 can be used to determine whether the upper surface of the wafer has reached the target position.

[0058] In some embodiments of the present invention, the control device is further configured to determine the target position of the wafer loading stage 200 when the upper surface of the wafer reaches the initial position, the target position of the wafer loading stage 200 corresponding to the target position of the upper surface of the wafer.

[0059] Normally, the upper surface of wafers of different thicknesses reaches the same initial position, that is, the data obtained by the height measurement unit 510 is consistent. In other words, when the height measurement unit 510 obtains the data corresponding to the initial position, it determines that the upper surface of the wafer has reached the initial position.

[0060] Furthermore, the distance the upper surface of the wafer needs to rise or fall from the initial position to the target position is fixed. Therefore, the distance the wafer loading stage rises or falls from the initial position corresponding to the upper surface of the wafer is fixed. In other words, the difference between the data of the reading head 420 at the initial position on the upper surface of the wafer and the data of the reading head 420 at the target position on the upper surface of the wafer is fixed.

[0061] Therefore, starting from the initial position corresponding to the upper surface of the wafer, the data from the reading head 420 controls the drive unit. When the data from the reading head 420 changes by a corresponding difference, it indicates that the upper surface of the wafer has reached the target position. Furthermore, when the upper surface of the wafer reaches the initial position, the control device can determine the target data of the reading head, i.e., the target position of the wafer loading stage 200, through simple calculation based on the current data from the reading head 420 and the corresponding difference. The corresponding difference value for the reading head 420 can be preset in the wafer inspection equipment.

[0062] In some alternative embodiments, the corresponding difference value corresponding to the reading head 420 can also be obtained by conversion. Specifically, when the upper surface of the wafer is in the initial position, the height measurement unit 510 has a measurement value. When the upper surface of the wafer is in the target position, the wafer device has a target value corresponding to the height measurement unit 510. The height difference can be determined based on the target value and the measurement value, and then the height difference can be converted into the corresponding difference value corresponding to the reading head 420.

[0063] However, in some embodiments of this invention, due to motion errors in the drive unit or other reasons, the data from the height measurement unit 510 is inconsistent each time the upper surface of the wafer reaches its initial position. This results in a discrepancy between the data from the reading head 420 at the initial position on the upper surface of the wafer and the data from the reading head 420 at the target position on the upper surface of the wafer; that is, the corresponding difference for the reading head 420 is not a constant. However, since the data from the height measurement unit 510, i.e., the measured value, has already been obtained, and the wafer equipment has a preset target value corresponding to the height measurement unit 510 (this data can be obtained experimentally or calculated, etc., and can be measured without the height measurement unit 510), the height difference can be determined based on the target value and the measured value. Then, based on this height difference and the data relationship between the height measurement unit 510 and the reading head 420, the corresponding difference between the data from the reading head 420 at the initial position on the upper surface of the wafer and the data from the reading head 420 at the target position on the upper surface of the wafer can be obtained. Then, the target position of the wafer loading stage 200 can be determined based on the data of the reading head 420 being in its initial position on the upper surface of the wafer and the corresponding difference value of the reading head 420.

[0064] Based on the data of the reading head 420 at its initial position on the upper surface of the wafer and the corresponding difference, the data of the reading head 420 at its target position on the upper surface of the wafer can be determined, specifically as follows:

[0065] For example, the imaging distance A of the detection device 500. When the distance between the upper surface of the wafer and the detection device 500 is A, the value corresponding to the height measurement unit 510 can be B, that is, the target value corresponding to the height measurement unit 510 is B; the coordinates of the grating ruler encoder, that is, the data of the reading head 420 at the target position on the upper surface of the wafer, can be Value. The detection value of the height measurement unit 510 when it reaches the initial position on the upper surface of the wafer is Value1, which is usually less than B, that is, the measurement value of the height measurement unit 510 is Value1. When the upper surface of the wafer reaches the initial position, the coordinates of the grating ruler encoder, that is, the data of the reading head 420, is Value2, which is usually less than Value. Then Value = Value2 - (Value1 - B) * k. k is the data relationship between the reading head 420 and the height measurement unit 510, that is, the proportional coefficient.

[0066] In this embodiment of the invention, even if the data from the height measurement unit 510 are consistent after the upper surface of the wafer reaches the initial position, the steps of this embodiment can still be used for operation. In the wafer inspection equipment of this embodiment of the invention, even if the data obtained by the height measurement unit 510 for detecting the initial position of wafers of different thicknesses are inconsistent (preferably consistent), the data from the reading head 420 and the data from the height measurement unit 510 can be unified according to the corresponding data relationship, and the data of the target position corresponding to the reading head 420 can be determined, ensuring that the upper surface of the wafer can reach the target position.

[0067] In some alternative embodiments of this utility model, the difference between the data of the upper surface of the wafer at the initial position and the data of the reading head 420 at the target position on the upper surface of the wafer, or the data of the reading head 420 at the target position on the upper surface of the wafer, can also be obtained by looking up a table.

[0068] In some embodiments of this invention, the height measurement unit 510 includes a capacitive sensor probe, disposed on the upper side of the wafer loading stage 200. The capacitive sensor probe may be of model CSH2FL(20)-CRm1,4, which is a capacitive sensor model manufactured by Micro-Epsilon GmbH in Germany, belonging to the CSH series of sensor products of that brand. The capacitive sensor probe is connected to a main controller of model DT6530. This capacitive sensor probe has a measurement distance of 2mm and a measurement resolution of 30nm, enabling high-precision distance measurement.

[0069] In some embodiments of this invention, the detection device 500 is a scanning electron microscope, configured to image the wafer on the wafer loading stage 200 using an electron beam. Preferably, the scanning electron microscope is a scanning electron microscope used in defect re-inspection equipment.

[0070] In some embodiments of this utility model, such as Figures 2 to 4 As shown, the wafer workpiece stage 100 also includes a base 161 and a lifting seat 110.

[0071] The lifting platform 110 is vertically and flexibly mounted on the base 161. The wafer loading stage 200 is positioned above the lifting platform 110 and moves up and down with it. In other words, the wafer loading stage 200 is used to mount wafers; the wafer loading stage 200 is mounted on the lifting platform 110, and the wafers rise or fall with the wafer loading stage 200 and the lifting platform 110. The drive unit is configured to drive the lifting platform 110 to move up and down.

[0072] A linear encoder 410 extends vertically and is mounted on either the base 161 or the lifting seat 110. A reading head 420 is mounted on the other of the two. In other words, the linear encoder 410 is mounted on the base 161 and the reading head 420 is mounted on the lifting seat 110; or, the linear encoder 410 is mounted on the lifting seat 110 and the reading head 420 is mounted on the base 161. Since the lifting seat 110 can be raised and lowered relative to the base 161, the reading head 420 rises and falls relative to the linear encoder 410 when the lifting seat 110 rises and falls.

[0073] In some embodiments of this utility model, such as Figures 2-4 As shown, a side seat 162 is provided on the upper side of the base 161, and a lifting seat 110 is located on one side of the side seat 162 in the horizontal direction, and the lifting seat 110 is movably mounted on the side seat 162. A grating ruler 410 is mounted on the lifting seat 110, and a reading head 420 is mounted on the side seat. By mounting the reading head 420 on the side seat, the grating ruler 410 can correspond to the reading head 420 when it moves up and down with the lifting seat 110, and the reading head 420 and the side seat 162 do not interfere with the movement of the lifting seat 110 and the grating ruler 410.

[0074] Furthermore, the side seat 162 is provided with a mounting hole that extends horizontally through it, meaning that the extension direction of the mounting hole is consistent with the relative direction of the lifting seat 110 and the side seat 162. The reading head 420 is mounted in the mounting hole, and the grating ruler 410 is disposed on the surface of the lifting seat 110 facing the reading head 420. The reading head 420 can not only extend from the mounting hole but also correspond to the grating ruler 410. Moreover, the mounting hole has a simple structure, making it easy to manufacture the side seat 162.

[0075] The side seat 162 is provided with a first guide rail 163 extending in the vertical direction. The lifting seat 110 is provided with a guide member that cooperates with the first guide rail 163. The guide member is slidably cooperates with the first guide rail 163 in the vertical direction, thereby enabling the lifting seat 110 to move in the vertical direction.

[0076] In some embodiments of this utility model, such as Figures 2-4 As shown, the wafer workpiece stage 100 of this utility model embodiment also includes a slider 130, which is movably disposed on the base 161 in the horizontal direction. The slider 130 has a first inclined surface 131 that is inclined relative to the horizontal direction.

[0077] The lifting platform 110 has a second inclined surface that is relatively horizontally inclined and adapted to the first inclined surface. The second inclined surface is slidable on the first inclined surface, so that the slider drives the lifting platform 110 to rise and fall. That is, when the slider 130 moves in the horizontal direction, the first inclined surface 131 slides relative to the second inclined surface 120, thereby causing the slider 130 to lift the lifting platform 110 or lower the lifting platform 110, which in turn causes the lifting platform 110 to drive the wafer loading stage 200 to rise and fall. The drive unit is mounted on the base 161 and is used to drive the slider to move in the horizontal direction, thereby driving the lifting platform 110 to rise and fall.

[0078] For example Figure 2 , Figure 3 As shown, the horizontal direction is the front-to-back direction. The first inclined surface 131 is inclined relative to the front-to-back direction, and the front end of the first inclined surface 131 is located below its rear end. The second inclined surface 120 is also inclined relative to the front-to-back direction, and the front end of the first inclined surface 131 is located below its rear end. That is, when the slider 130 moves in the front-to-back direction, the first inclined surface 131 slides relative to the second inclined surface 120, thereby causing the slider 130 to lift the lifting seat 110 or lower the lifting seat 110. Thus, by adjusting the position of the lifting seat 110 in the vertical direction, the height of the wafer loading stage 200 can be quickly adjusted, achieving the adjustment of the height of the wafer loading stage 200.

[0079] In some embodiments of this utility model, such as Figures 2-4 As shown, the lower end of the first inclined surface is adjacent to the side seat 162. That is, the dimension of the end face of the lifting seat 110 near the side seat 162 in the vertical direction is larger than the dimension of the other end in the vertical direction. Since the grating ruler 410 is set on the surface of the lifting seat 110 facing the reading head 420, the grating ruler 410 has a larger installation space on the lifting seat, which facilitates the installation of the grating ruler 410. In addition, the grating ruler 410 can have a larger height dimension, thereby giving the grating ruler 410 a larger height measurement range.

[0080] In some optional embodiments of this utility model, the drive unit includes a lead screw 142 and a motor 141. The lead screw 142 is connected to the motor 141 so that the motor 141 drives the lead screw 142 to rotate. The lead screw extends along the moving direction of the slider and is rotatably mounted on the base; the lead screw is threadedly connected to the slider so that it drives the slider to move horizontally when rotated. The motor can be a stepper motor. The control device is electrically connected to the motor.

[0081] In some optional embodiments of this invention, the driving unit is a linear motor, which is directly connected to the slider 130 so that the linear motor directly drives the slider 130 to move in the horizontal direction. The control device is electrically connected to the linear motor.

[0082] In some embodiments of this utility model, the wafer workpiece stage 100 further includes a piezoelectric ceramic drive unit disposed between the lifting base 110 and the wafer loading stage 200, configured to drive the wafer loading stage to move up and down relative to the lifting base. The piezoelectric ceramic drive unit includes multiple flexible hinges 310 and multiple piezoelectric ceramic actuators 330.

[0083] Multiple piezoelectric ceramic actuators 330 are mounted on a lifting base and are correspondingly arranged with multiple flexible hinges 310. Each flexible hinge 310 includes a fixing block 311, a lifting block 312, a driving engagement block 313, a first spring 316, and a second spring 317. The fixing block 311 is mounted on the lifting base, and the lifting block 312 is mounted on the wafer loading stage 200. The driving engagement block 313 is located between the fixing block 311 and the lifting block 312 and is connected to the corresponding piezoelectric ceramic actuator 330, so that the piezoelectric ceramic actuator 330 drives the driving engagement block 313 to move up and down.

[0084] The first spring piece 316 is connected between the driving engagement block 313 and the fixed block 311. The second spring piece 317 is connected between the driving engagement block 313 and the lifting block 312. The first spring piece 316 and the second spring piece 317 are elastically deformable, that is, the first spring piece 316 and the second spring piece 317 can bend and deform under external force and can recover.

[0085] For example, when the piezoelectric ceramic actuator 330 drives the drive mating block 313 to rise, the drive mating block 313 tilts upward as a whole, and the end of the drive mating block 313 near the lifting block 312 rises. During this process, the first spring 316 and the second spring 317 are bent by force, allowing the drive mating block 313 to tilt and the end of the drive mating block 313 near the lifting block 312 to rise smoothly. As another example, when the piezoelectric ceramic actuator 330 drives the drive mating block 313 to descend, the end of the drive mating block 313 near the lifting block 312 descends due to gravity or under the influence of the piezoelectric ceramic actuator 330. During this process, the bent first spring piece 316 and the bent second spring piece 317 are respectively subjected to the tension of the fixed block 311 and the driving engagement block 313 and the tension of the lifting block 312 and the driving engagement block 313. The first spring piece 316 and the second spring piece 317 are restored from the bent state to the straight state, so that the end of the driving engagement block 313 near the lifting block 312 can descend smoothly.

[0086] In some embodiments of this utility model, such as Figures 2-4As shown, the lower surface of the fixing block 311 is connected to the lifting seat. The upper surface of the lifting block 312 is connected to the wafer loading stage 200. The fixing block, lifting block, drive mating block, first spring, and second spring are integrally molded from the same material. The entire flexible hinge 310 can be installed simply by fixing the fixing block 311 and the lifting block 312 to the lifting seat 110 and the wafer loading stage 200 respectively, resulting in high installation efficiency. The first spring 316 connects between the lower part of the corresponding fixing block 311 and the lower part of the corresponding drive mating block 313 to form an upward-opening first clearance groove. The second spring 317 connects between the upper part of the corresponding lifting block 312 and the middle part of the corresponding drive mating block 313 to form a downward-opening clearance groove.

[0087] In some embodiments of this invention, the wafer stage 100 further includes a push rod 150. The push rod 150 is disposed on the base 161; the wafer loading stage 200 has a through hole corresponding to the push rod 150, and the push rod 150 is configured to extend upward through the through hole during the descent of the wafer loading stage. When the wafer loading stage 200 is lowered to its lowest position, the upper end of the push rod 150 is located above the wafer loading stage 200, so that the push rod 150 can lift the wafer on the wafer loading stage 200 for removal from the wafer loading stage 200.

[0088] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A wafer inspection device, characterized in that, include: Control device; A wafer workpiece stage, the wafer workpiece stage having a drive unit, a wafer loading stage, a grating ruler, and a reading head corresponding to the grating ruler; The drive unit is electrically connected to the control device, and the drive unit is configured to drive the wafer loading stage to move up and down; the reading head is electrically connected to the control device, and the reading head and the grating ruler are configured to detect the position of the wafer loading stage during the process of at least the upper surface of the wafer on the wafer loading stage moving up or down from an initial position. A height measuring unit is disposed on the upper side of the wafer loading stage and electrically connected to the control device; the height measuring unit is configured to detect its distance from the upper surface of the wafer supported on the wafer loading stage, so that the control device can determine whether the upper surface of the wafer has reached the initial position.

2. The wafer inspection equipment according to claim 1, characterized in that, The control device is also configured to determine the target position of the wafer loading stage when the upper surface of the wafer reaches the initial position.

3. The wafer inspection equipment according to claim 1, characterized in that, The height measurement unit includes a capacitive sensor probe, which is disposed on the upper side of the wafer loading stage.

4. The wafer inspection equipment according to claim 3, characterized in that, Also includes: A testing device is disposed on the upper side of the wafer loading stage; The detection device is a scanning electron microscope, configured to image the wafer on the wafer loading stage using an electron beam.

5. The wafer inspection equipment according to claim 1, characterized in that, The wafer workpiece stage also includes: A base on which the drive unit is mounted; A lifting seat, wherein the lifting seat is movably mounted on the base; wherein The wafer loading stage moves up and down with the lifting platform; the drive unit is configured to drive the lifting platform to move up and down; The grating ruler extends in the vertical direction and is mounted on one of the base and the lifting seat, while the reading head is mounted on the other of the base and the lifting seat.

6. The wafer inspection equipment according to claim 5, characterized in that, The wafer workpiece stage also includes: A slider is movably disposed on the base in a horizontal direction. The slider has a first inclined surface that is inclined relative to the horizontal direction. The driving unit is used to drive the slider to move in the horizontal direction. The lifting seat has a second inclined surface that is inclined relative to the horizontal direction and adapted to the first inclined surface. The second inclined surface is slidable on the first inclined surface so that the slider drives the lifting seat to rise and fall.

7. The wafer inspection equipment according to claim 6, characterized in that, The driving unit includes: A lead screw extends along the direction of movement of the slider and is rotatably mounted on the base; the lead screw is threadedly connected to the slider so as to drive the slider to move horizontally when rotated. A motor is mounted on the base, and the output shaft of the motor is connected to one end of the lead screw; the control device is electrically connected to the motor.

8. The wafer inspection equipment according to claim 6, characterized in that, A side seat is provided on the upper side of the base, and the lifting seat is located on one side of the side seat in the horizontal direction, and the lifting seat is movably mounted on the side seat. The lower end of the second inclined surface is adjacent to the side seat; The side seat is provided with a mounting hole that penetrates the side seat in the horizontal direction; The reading head is installed in the mounting hole, and the grating ruler is disposed on the surface of the lifting base facing the reading head.

9. The wafer inspection equipment according to claim 8, characterized in that, The wafer workpiece stage also includes: A push rod is provided on the base; the wafer loading stage is provided with a through hole corresponding to the push rod, and the push rod is configured to extend upward through the through hole during the descent of the wafer loading stage.

10. The wafer inspection equipment according to claim 6, characterized in that, The wafer workpiece stage also includes: A piezoelectric ceramic drive unit is disposed between the lifting base and the wafer loading stage, and is configured to drive the wafer loading stage to move up and down relative to the lifting base.

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