Method for correcting run-out error in height direction of spot scanning topography instrument

Abstract

The invention discloses a method for correcting a jumping error in a height direction of a spot scanning topography instrument, and solves the problems of jumping error in the height direction and low measurement precision of the spot scanning topography instrument in the prior art. A spot scanning morphology instrument adopted in the error correction method comprises a base, a gantry stand column and a Y-direction direct-drive motion table are arranged on the base, a vertical lead screw module is arranged on the gantry stand column, and a vertical motion assembly is arranged on the vertical lead screw module; the vertical movement assembly comprises a rotary table and a swing table which are connected. A high-precision displacement sensor is arranged on the swing table; an X-direction direct-drive moving table is arranged on the Y-direction direct-drive moving table; and a marble leveling platform is arranged on the X-direction direct-drive moving platform. According to the invention, a high-precision displacement sensor of the spot scanning topography instrument is utilized to effectively reduce the influence of run-out errors on the measurement result of the height information of the sample when the X-direction and Y-direction direct-drive motion tables walk; the non-contact measurement ensures the measurement efficiency and avoids the friction and abrasion between the probe and the sample at the same time; and the accuracy of sample morphology measurement is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of topography detection, and particularly to a method for correcting the height-direction jumping error of a point-scanning topography instrument. Background Art

[0002] At present, the topography detection of the sample surface mainly includes the method of visual photography and the method of scanning with a contact probe. The method of visual photography uses the photosensitive chip inside the camera to image the sample to be photographed, and then calculates the corresponding features or the dimensions between the features through an image processing algorithm. The method of contact probe scanning is to use a microprobe to continuously or intermittently contact the surface of the sample to be measured, sense and output the height change of the sample surface, and combine the position information of the planar motion to reconstruct the three-dimensional topography of the sample surface, so as to realize the topography detection of the sample surface.

[0003] The method of visual photography is difficult to obtain the height change of the sample surface topography and is generally only used for the detection in the planar dimension; such as the optical scanning three-dimensional topography instrument with the publication number CN 212903082 U. The method of contact probe scanning requires the probe to contact the surface of the sample to be measured multiple times, which has the risk of damaging the surface of the sample to be measured and exacerbates the wear of the scanning probe; such as a topography measurement system and method based on the self-gravity of the probe with the publication number CN 110514138 A.

[0004] The point-scanning topography instrument uses a non-contact high-precision displacement sensor, avoiding the existence of friction and wear of the contact probe; the high-precision displacement sensor obtains the height point cloud data of the sample surface topography, and combines the planar position information of the feedback-controlled planar motion stage to finely reconstruct the microscopic structure of the sample surface, so as to realize the three-dimensional topography detection of the sample surface; such as a free-form surface non-contact dimensional error separation detection method and device with the publication number CN 108225213 A. However, during the movement of its planar motion stage, due to factors such as the jumping error in the height direction between the slider and the guide rail, the height point cloud data obtained by the high-precision displacement sensor not only contains the information of the sample surface topography, but also contains the jumping error in the height direction during the movement of the planar motion stage, which seriously interferes with the accuracy of the sample surface topography detection. Summary of the Invention

[0005] Aiming at the deficiencies in the above background art, the present invention proposes a method for correcting the height-direction jumping error of a point-scanning topography instrument, which solves the problems of the existing point-scanning topography instrument having a jumping error in the height direction and low measurement accuracy.

[0006] The technical solution of the present invention is implemented as follows: a point scanning profiler comprises a base, a gantry column and a Y-direction direct drive motion table are arranged on the base, a vertical screw module is arranged on the gantry column, and a vertical motion component is arranged on the vertical screw module; the vertical motion component comprises a rotating table and a swinging table connected to each other; a high-precision displacement sensor is arranged on the swinging table; an X-direction direct drive motion table is arranged on the Y-direction direct drive motion table; an adjustment platform for placing a sample to be measured is arranged on the X-direction direct drive motion table; the vertical motion component and the adjustment platform are used to adjust the light output angle of the high-precision displacement sensor relative to the sample to be measured, the Y-direction direct drive motion table and the X-direction direct drive motion table move in coordination, so that the light output point of the high-precision displacement sensor can perform an "S"-shaped point scanning motion on the surface of the sample to be measured at a certain interval; the high-precision displacement sensor provided by the point scanning profiler is used to effectively reduce the influence of the runout error of the X-direction and Y-direction direct drive motion tables when walking on the sample height information measurement result; the non-contact measurement avoids the friction and wear between the probe and the sample while ensuring the measurement efficiency; and the accuracy of the sample profile measurement is effectively guaranteed.

[0007] A method for correcting the height runout error of a point scanning profiler, using the above-mentioned point scanning profiler, the error correction method steps are as follows: S1: adjusting the adjustment platform to keep it horizontal; then adjusting the height of the high-precision displacement sensor so that the overall surface height change information of the adjustment platform is within the range of the high-precision displacement sensor, and adjusting the turntable and the swing table on the vertical motion component so that the height measurement result of the high-precision displacement sensor at a certain scanning point is minimized; S2: Control the movement of the X-axis direct-drive motion stage and the Y-axis direct-drive motion stage, so that the emission light point of the high-precision displacement sensor is on the upper surface of the adjustment platform, and performs an "S"-shaped point scanning movement at a certain interval relative to the adjustment platform, and the sampling points are evenly distributed on the upper surface of the adjustment platform; the high-precision displacement sensor obtains the corresponding sampling point (X ’ , Y ’ ) coordinates, denoted as Z ’ , where for the starting point (X1 ’ , Y1 ’ ) coordinates, denoted as Z1 ’ , we can get the relative position of any subsequent scanning point to the starting point (X1 ’ , Y1 ’ )Height direction runout error: △Z ’ =Z ’ -Z1 ’ ; S3: The height point cloud data Z obtained in step S2 ’Perform the following operations: (a) Eliminate gross errors using the 3σ criterion; (b) Fill in the gaps using the neighborhood interpolation method; (c) Establish a cell grid using the regular grid triangulation method, and divide each quadrilateral grid cell into two triangles in the way of the upper-right diagonal and the lower-left diagonal; (d) According to the triangulation result, calculate the height data corresponding to the coordinates of any interpolation point using the bilinear interpolation method, and denote it as Z ’’ ; S4: Height point cloud data Z ’ After processing, the coordinates of any point within the point scan boundary can be obtained (X ’’ , Y ’’ ), and the corresponding height data Z ’’ and the height jump error of this point relative to the starting point (X1 ’ , Y1 ’ ): △Z ’’ =Z ’’ -Z1 ’ ; S5: Place the sample to be measured on the adjustment platform, and use a high-precision displacement sensor to perform point scanning on the sample to be measured, so that its scanning range is within the boundary of the point scanning range of the above adjustment platform, and make the coordinates of its first scanning point (X1 ’’’ , Y1 ’’’ ) coincide with the starting point coordinates (X1 ’ , Y1 ’ ). Thereafter, the coordinates of any scanning point are denoted as (X ’’’ , Y ’’’ ), and the height data measured by the high-precision displacement sensor is denoted as Z ’’’ ; The obtained height point cloud data Z ’’’ After being processed by the methods (a), (b), and (c) in S3, the height data without the sample to be measured corresponding to this arbitrary scanning point (X ’’’ , Y ’’’ ) is calculated by the bilinear interpolation method in S3(d), and is denoted as Z ’’ . Then, the original height jump error of this arbitrary scanning point relative to the starting point (X1 ’ , Y1 ’ ): △Z ’’’ =Z ’’ -Z1 ’ . After that, the height point cloud data of the sample to be measured after correcting the original height jump error is obtained: Z R =Z ’’’ -△Z ’’’ .

[0008] Further preferably, the leveling platform adopts a marble leveling platform; the Y-direction direct drive moving platform includes a first linear guide rail and a first platform. The first linear guide rail is arranged symmetrically along the Y-direction on the base; the first platform is slidably connected to the first linear guide rail through a first connecting slider. A matching first linear motor magnetic rail and a first linear motor coil are arranged between the two first linear guide rails. The first linear motor magnetic rail is fixed to the bottom of the first platform, and the first linear motor coil is fixed to the base; when the first linear motor coil is energized, the first linear motor magnetic rail and the first platform move along the first linear guide rail to achieve stable adjustment of the Y-direction of the Y-direction direct drive moving platform.

[0009] Further preferably, a first grating scale is arranged along the Y-direction at the bottom of the first platform. The first grating scale is located on one side of one of the first linear guide rails. A first reading head is arranged on the side of the first grating scale facing the first linear motor magnetic rail; two first fixed limit blocks are also arranged along the Y-direction on the base, and a first moving limit block is arranged at the bottom of the first platform. The first moving limit block moves with the first platform between the two first fixed limit blocks.

[0010] Further preferably, the X-direction direct drive moving platform includes a second linear guide rail and a second platform. The second linear guide rail is arranged symmetrically along the X-direction on the first platform; the second platform is slidably connected to the second linear guide rail through a second connecting slider. A matching second linear motor magnetic rail and a second linear motor coil are arranged between the two second linear guide rails. The second linear motor magnetic rail is fixed to the bottom of the second platform, and the second linear motor coil is fixed to the first platform. When the second linear motor coil is energized, the second linear motor magnetic rail and the second platform move along the second linear guide rail to achieve stable adjustment of the X-direction of the X-direction direct drive moving platform.

[0011] Further preferably, a second grating scale is arranged along the X-direction at the bottom of the second platform. The second grating scale is located on one side of one of the second linear guide rails. A second reading head is arranged on the side of the second grating scale facing the second linear motor magnetic rail; two second fixed limit blocks are also arranged along the X-direction on the first platform, and a second moving limit block is arranged at the bottom of the second platform. The second moving limit block moves with the second platform between the two second fixed limit blocks.

[0012] Further preferably, the adjusting platform is centrally arranged on the upper surface of the second platform, and is provided with at least three leveling screws and at least two locking screws relative to the second platform; the adjusting platform is evenly provided with at least three through holes along its central axis direction, and threaded sleeves are fixedly provided in the through holes; the leveling screws are threadedly connected to the threaded sleeves, and the second platform is provided with positioning blind holes matching the leveling screws; at least two vertical countersunk holes are symmetrically provided in the middle of the adjusting platform, and threaded holes corresponding to the vertical countersunk holes are provided on the second platform, and the locking screws are threadedly connected to the threaded holes after passing through the vertical countersunk holes; the height of the adjusting platform is adjusted by rotating the leveling screw, and when it is in a suitable position and a suitable state, the locking screw is rotated to lock the adjusting platform, and the above adjustment is used for leveling the adjusting platform and locking after leveling to improve the measurement accuracy.

[0013] Further preferably, the vertical screw module includes a vertical support arranged on the gantry column, the vertical support is provided with a vertically arranged first screw and a first guide rail, the first screw is threadedly connected with a first slide, the first slide is slidably matched with the first guide rail, and the upper end of the first screw is connected to a first motor arranged on the vertical support; the turntable is arranged on the front panel of the first slide, and the swing table is arranged on the front panel of the turntable; the swing table is provided with a clamping seat for fixing the high-precision displacement sensor.

[0014] Further preferably, the turntable is connected to the first slide seat via an adapter plate, the turntable includes a fixed seat and a limit seat rotatably arranged on the adapter plate, the fixed seat is rotatably provided with a scaled round table and an arc-shaped baffle matching the round table; a rotating shaft is provided on the outer side of the round table, a limit slot is provided on the limit seat, the end of the rotating shaft extends into the limit slot, and the limit seat is provided with a driving screw connected to the round table via a worm gear.

[0015] Further preferably, the swing platform includes a matching arc base and an arc swing platform, an arc rail is provided in the arc base, an arc groove is provided at the bottom of the arc swing platform, the arc rail and the arc groove are slidably matched, a driving worm is provided on the arc base, a worm gear rack is provided at the bottom of the arc swing platform, the driving worm is meshed with the worm gear rack; a limit rod is provided on one side of the arc swing platform, a limit plate is provided on one side of the arc base, an arc limit groove is opened on the limit plate, and the limit rod is located in the arc limit groove.

[0016] The beneficial effects of the present invention are as follows: the present invention utilizes the high-precision displacement sensor provided by the point scanning profiler to effectively reduce the influence of the runout error of the X-direction direct-drive motion stage and the Y-direction direct-drive motion stage during their movement on the measurement results of the sample height information; and the non-contact measurement adopted not only ensures the measurement efficiency, but also avoids the friction and wear between the probe and the sample; and effectively ensures the accuracy of the sample profile measurement.

[0017] The point scanning profiler of the present invention adopts an X-axis direct-drive motion stage and a Y-axis direct-drive motion stage driven by a linear motor to directly generate linear motion, greatly simplifying the structure, reducing the motion inertia, and significantly improving the dynamic response performance and positioning accuracy; in combination with an indium steel grating ruler, it can achieve micron-level or even nanometer-level precision control, is suitable for applications with high precision, high efficiency and high dynamic performance, and further improves the measurement accuracy.

[0018] The method for correcting the height direction runout error of the present invention utilizes the high-precision displacement sensor of the point scanning topography instrument to obtain the surface error of the first linear guide and the second linear guide after the motion is superimposed through a single point scan. Afterwards, as long as the sample to be measured is within the above-mentioned point scanning boundary, the guide rail runout error at the corresponding coordinate of the sample to be measured can be obtained through the bilinear interpolation method. This part of the error is subtracted from the height data of the sample to be measured to obtain the actual height change data of the sample surface, thereby conveniently and quickly realizing the correction of the height direction runout error of the point scanning topography instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the Y-axis direct-drive motion platform; Figure 3 It is a schematic diagram of the structure of the X-axis direct-drive motion stage; Figure 4 This is a schematic diagram of the adjustment platform structure; Figure 5 It is a schematic diagram of the vertical screw module structure; Figure 6 It is a schematic diagram of the structure of the vertical motion component; Figure 7 Point cloud data obtained by scanning the upper surface of the adjustment platform with high-precision displacement sensor; Figure 8 It is the runout error curve of the single slider linear guide in height direction; Figure 9 Schematic diagram of the principle of using neighborhood interpolation method to fill in the gaps in height point cloud data; Figure 10 This is a schematic diagram of the height point cloud data after processing and establishing a triangulated mesh; Figure 11 For any non-scanning (X ’’ , Y’’ Interpolate coordinates to obtain Z ’’ Schematic diagram of the spatial point after that located on the triangulation mesh surface; Figure 12 Schematic diagram of the principle of using the bilinear interpolation method to calculate the height data corresponding to the coordinates of any interpolation point; Figure 13 Schematic diagram of the mesh after triangulation of the point cloud data obtained by the high-precision displacement sensor scanning the surface of the measured sample, after removing gross errors and filling the removed points; Figure 14 Schematic diagram of the triangulation mesh obtained after correcting the motion stage jitter error of the point cloud data obtained by scanning the surface of the measured sample. Specific implementation manners

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1, as Figure 1 shown, a point-scanning profilometer includes a base 1, and the base can use a marble base as the support structure of the entire point-scanning profilometer. A gantry column 2 and a Y-direction direct-drive stage 12 are provided on the base 1, and the gantry column 2 is vertically arranged on the base. A vertical lead screw module 3 is provided on the gantry column 2, and a vertical motion component is provided on the vertical lead screw module 3; the vertical lead screw module drives the vertical motion component to move in the Z direction to adjust the height of the high-precision displacement sensor. In this embodiment, the vertical motion component includes a rotary table 5 and a swing table 6 connected to each other; a high-precision displacement sensor 8 is provided on the swing table 6; the rotary table 5 provides a rotational degree of freedom for the high-precision displacement sensor 8 in the vertical plane; the swing table 6 provides a swinging degree of freedom for the high-precision displacement sensor 8 in the vertical plane. In this embodiment, preferably, the high-precision displacement sensor is a spectral confocal probe, and its light-emitting mode is end-face light-emitting; it is used to measure the height information of the topography of the measured sample. An X-direction direct-drive stage 11 is provided on the Y-direction direct-drive stage 12; the Y-direction direct-drive stage 12 provides a degree of freedom for the Y-direction movement of the measured sample; the X-direction direct-drive stage 11 provides a degree of freedom for the X-direction movement of the measured sample. A leveling platform 10 for placing the measured sample is provided on the X-direction direct-drive stage 11; the leveling platform preferably uses a marble leveling platform; the vertical motion component and the leveling platform 10 are used to adjust the light-emitting angle of the high-precision displacement sensor relative to the measured sample; the Y-direction direct-drive stage and the X-direction direct-drive stage cooperate to move, so that the emitted light spot of the high-precision displacement sensor can perform an "S"-shaped point-scanning movement on the surface of the measured sample at a certain interval.

[0023] In this embodiment, the point scanning profiler effectively reduces the influence of the jumping error during the movement of the X-axis direct drive stage and the Y-axis direct drive stage on the measurement result of the sample height information by using a built-in high-precision displacement sensor; the non-contact measurement adopted avoids the friction and wear between the probe and the sample while ensuring the measurement efficiency, and effectively guarantees the accuracy of the sample topography measurement.

[0024] Embodiment 2, as Figure 2 and Figure 3 shown, a point scanning profiler is further optimized on the basis of Embodiment 1. In this embodiment, the Y-axis direct drive stage 12 includes a first linear guide rail 121 and a first platform 119. The first linear guide rail 121 is arranged symmetrically along the Y-axis on the base 1; that is, double guide rails are adopted to ensure the stability of the Y-axis movement. The first platform 119 is slidably connected to the first linear guide rail 121 through a first connecting slider 129. In this embodiment, four first connecting sliders are taken as an example, and two corresponding first connecting sliders are arranged on each linear guide rail. A matching first linear motor magnetic rail 122 and a first linear motor coil 123 are arranged between the two first linear guide rails 121 to form a linear motor; the first linear motor magnetic rail 122 is fixed at the bottom of the first platform 119, and the first linear motor coil 123 is fixed on the base 1. Preferably, the first linear motor coil 123 is fixed on the base through a first coil mounting seat 124 to ensure the stability of the installation. When the first linear motor coil is powered on, the first linear motor magnetic rail and the first platform move along the first linear guide rail, realizing the Y-axis stable adjustment of the X-axis direct drive stage and the adjustment platform. The linear motor directly generates linear motion without an intermediate transmission mechanism, greatly simplifies the structure, and significantly improves the dynamic response performance and positioning accuracy; the linear motor can achieve precise control at the micron or even nanometer level, is suitable for applications with high precision, high efficiency and high dynamic performance, and further improves the measurement accuracy.

[0025] In this embodiment, a first grating scale 126 is provided along the Y direction at the bottom of the first platform 119. The first grating scale 126 is located on one side of one of the first linear guide rails 121. A first reading head 125 is provided on the side of the first grating scale 126 facing the first linear motor magnetic track 122. The first reading head 125 measures the first grating scale 126 in a non-contact manner, and then measures the moving distance of the first platform 119 in the Y direction. The grating scale, as a position feedback element, detects the engraved lines on the grating scale through an optical reading head and converts the physical displacement into an electrical signal for output. Its measurement accuracy is extremely high, usually reaching the micron or even sub-micron level. Two first fixed limit blocks 127 are also provided along the Y direction on the base 1. The two first fixed limit blocks 127 are located at two set limit positions. A first moving limit block 128 is provided at the bottom of the first platform 119. The first moving limit block 128 moves with the first platform 119 between the two first fixed limit blocks 127, which is used to limit the maximum displacement of the first platform 119 to ensure the effectiveness of the measurement. In addition, the first grating scale 126 cooperates with the reading head to measure and feedback the moving position in the Y direction. The fixed limit blocks and the moving limit block can prevent the Y-direction direct drive stage 12 from exceeding the predetermined range and causing accidents or damaging the equipment.

[0026] As a preferred implementation, as Figure 3 and Figure 4 shown, the X-direction direct drive stage 11 and the Y-direction direct drive stage 12 have similar structures. Specifically, the X-direction direct drive stage 11 includes second linear guide rails 111 and a second platform 103. The second linear guide rails 111 are arranged symmetrically along the X direction on the first platform 119, that is, double guide rails are adopted to ensure the stability of the X-direction movement. The second platform 103 is slidably connected to the second linear guide rails 111 through second connection sliders 109. Similarly, in this embodiment, four second connection sliders are taken as an example, and two corresponding second connection sliders are arranged on each linear guide rail. A second linear motor magnetic track 112 and a second linear motor coil 113 are provided between the two second linear guide rails 111 to form a linear motor. The second linear motor magnetic track 112 is fixed at the bottom of the second platform 103, and the second linear motor coil 113 is fixed on the first platform 119. Preferably, the second linear motor coil 113 is fixed to the base through a second coil mounting seat 114 to ensure the stability of the installation. When the second linear motor coil is energized, the second linear motor magnetic track and the second platform move along the second linear guide rails to realize the stable X-direction adjustment of the X-direction direct drive stage for the adjustment platform.

[0027] In this embodiment, a second grating scale 116 is provided at the bottom of the second platform 103 along the X direction. The second grating scale 116 is located on one side of one of the second linear guide rails 111. A second reading head 115 is provided on the side of the second grating scale 116 facing the second linear motor magnetic track 112. The second reading head 115 measures the second grating scale 116 in a non-contact manner, thereby measuring the moving distance of the second platform 103 in the X direction. Two second fixed limit blocks 117 are further provided on the first platform 119 along the X direction. The two second fixed limit blocks 117 are located at two set extreme positions. A second moving limit block 118 is provided at the bottom of the second platform 103. The second moving limit block 118 moves between the two second fixed limit blocks 117 along with the second platform 103, and is used to limit the maximum displacement of the second platform 103 to ensure the effectiveness of the measurement. At the same time, the second grating scale 116 cooperates with the reading head to realize the measurement and feedback of the moving position in the X direction. The fixed limit block and the moving limit block can prevent the X-direction direct drive stage 11 from exceeding the predetermined range and causing accidents or damaging the equipment. The Y-direction direct drive stage 12 and the X-direction direct drive stage 11 cooperate with each other to realize the point scanning movement of the outgoing light spot of the high-precision displacement sensor 8 on the surface of the measured topography.

[0028] As Figure 4 shown, the leveling platform 10 is centrally arranged on the upper surface of the second platform 103, and at least three leveling screws 101 and at least two locking screws 102 are provided relative to the second platform 103. In this embodiment, three leveling screws 101 and two locking screws 102 are taken as examples. The three leveling screws 101 are distributed in an equilateral triangle along the central axis of the leveling platform 10. The two locking screws 102 are symmetrically distributed in the middle of the leveling platform 10. The three leveling screws 101 are used to adjust the level of the leveling platform 10, and the two locking screws 102 are used to lock and loosen the leveling platform 10. In this embodiment, three through holes are evenly provided in the leveling platform 10 along its central axis direction. Threaded sleeves are fixedly embedded in the three through holes. The leveling screws 101 are threadedly connected to the threaded sleeves. Positioning blind holes matching the leveling screws 101 are provided on the second platform 103. By respectively rotating the leveling screws 101 to change the length of the leveling screws 101 extending out of the leveling platform 10, the end surface of the leveling screw 101 presses against the bottom surface of the positioning blind hole, thereby adjusting the levelness of the leveling platform 10. Two vertical counterbore holes are symmetrically provided in the middle of the leveling platform 10. Two threaded holes corresponding to the vertical counterbore holes are provided on the second platform 103. The locking screws 102 pass through the vertical counterbore holes and are threadedly connected to the threaded holes. When the leveling platform 10 is in a suitable position, the locking screws 102 are tightened to lock the leveling platform 10.

[0029] As Figure 5As shown in the figure, in this embodiment, the vertical lead screw module 3 includes a vertical support 31 fixedly arranged on the gantry column 2. A vertically arranged first lead screw 32 and a first guide rail 33 are provided on the vertical support 31. The upper and lower ends of the first lead screw 32 are rotationally connected to the vertical support 31 through bearing members. A first slide block 34 is threadedly connected to the first lead screw 32. The first slide block 34 is fixedly connected to the slider of the first guide rail 33 and is slidably matched with the first guide rail 33. The upper end of the first lead screw 32 is connected to a first motor 35 arranged on the vertical support 31. The rotation of the first motor drives the rotation of the first lead screw, thereby driving the first slide block to move up and down along the first guide rail. The rotary table 5 is arranged on the front panel of the first slide block 34 and slides up and down synchronously with the first slide block. The swing table 6 is arranged on the front panel of the rotary table 5 and moves correspondingly with the rotary table 5. A clamping seat 7 for fixing the high-precision displacement sensor 8 is provided on the swing table 6. The clamping seat 7 clamps the high-precision displacement sensor 8. The rotary table 5 cooperates with the swing table 6 to adjust the light-emitting angle of the high-precision displacement sensor 8, ensuring that the emitted light of the high-precision displacement sensor 8 is perpendicular to the surface of the measured sample.

[0030] Embodiment 3, as Figure 6 As shown in the figure, a point-scanning profiler is further optimized on the basis of Embodiment 1. In this embodiment, the rotary table 5 is connected to the first slide block 34 through an adapter plate 4. The adapter plate 4 is connected to the first slide block through bolt members. The rotary table 5 includes a fixed seat 51 and a limit seat 54 rotatably arranged on the adapter plate 4. The fixed seat is fixed on the adapter plate. A graduated turntable 52 and an arc-shaped baffle 56 matched with the turntable 52 are rotatably arranged on the fixed seat 51. Two or three arc-shaped baffles can be provided to limit the turntable to ensure its stable rotation. Corresponding scales can also be set on the arc-shaped baffle. A rotating shaft 53 is arranged on the outer side of the turntable 52. A limit groove 55 is opened on the limit seat 54. The limit groove 55 is a vertically through groove. The end of the rotating shaft 53 extends into the limit groove 55. By tightening the rotating shaft 53, the position of the turntable can be limited. A driving screw 57 connected to the turntable 52 through a worm and worm gear is arranged on the limit seat 54. The driving screw 57 is threadedly connected to the limit seat. The driving screws 57 are symmetrically arranged on the upper and lower sides of the vertically through groove. By rotating the driving screw 57, the rotation of the turntable 52 is pushed. A corresponding handle is arranged on the driving screw 57 for easy manual adjustment.

[0031] In this embodiment, the swing table 6 includes a matching arc-shaped base 61 and an arc-shaped swing table 62. The arc-shaped base 61 is fixed on the turntable. An arc-shaped rail 63 is provided inside the arc-shaped base 61, and an arc-shaped groove is provided at the bottom of the arc-shaped swing table 62. The arc-shaped rail 63 is slidably matched with the arc-shaped groove, so that the arc-shaped swing table can only move along the arc-shaped rail. A driving worm 65 is provided on the arc-shaped base 61. The driving worm 65 is rotationally connected to the arc-shaped base through a bearing. A worm gear rack 66 is provided at the bottom of the arc-shaped swing table 62. The driving worm 65 is engaged with the worm gear rack 66 to form a structure similar to a worm and worm gear. A handle is provided at the end of the driving worm 65 for easy manual adjustment. The driving worm 65 is rotated forward and backward manually, and the driving worm 65 drives the worm gear rack and the arc-shaped swing table to swing, realizing the up and down swing of the arc-shaped swing table. A limiting rod 67 is provided on one side of the arc-shaped swing table 62, and a limiting plate 68 is provided on one side of the arc-shaped base 61. An arc-shaped limiting groove 69 is opened on the limiting plate 68. The limiting rod 67 is located in the arc-shaped limiting groove 69 and is used to lock the arc-shaped swing table 62 after it reaches the position.

[0032] Embodiment 4, a method for correcting the height-direction runout error of a point-scanning profiler. Using the point-scanning profiler described in Embodiment 2 or 3, the steps are as follows: S1: Adjust the adjustment platform 10 to make it level; then adjust the height of the high-precision displacement sensor 8. The high-precision displacement sensor 8 is moved downward through the vertical lead screw module, so that the height change information of the overall surface of the adjustment platform 10 is within the range of the high-precision displacement sensor 8. Adjust the rotary table 5 and the swing table 6 on the vertical movement component to make the height measurement result of the high-precision displacement sensor 8 at a certain scanning point the smallest. The specific method of adjusting the adjustment platform 10 is to loosen the two locking screws 102 on the adjustment platform 10, and respectively adjust the three leveling screws 101 on the adjustment platform 10 to make the adjustment platform 10 level, and then lock the two locking screws 102.

[0033] S2: Control the movement of the X-direction direct drive stage 11 and the Y-direction direct drive stage 12, so that the outgoing light spot of the high-precision displacement sensor 8 is on the upper surface of the adjustment platform 10, and makes a point-scanning movement in an "S" shape at a certain interval relative to the adjustment platform 10, and makes the sampling points evenly distributed on the upper surface of the adjustment platform 10; the high-precision displacement sensor 8 obtains the height point cloud data at the corresponding sampling point (X ’ , Y ’ ), denoted as Z ’ , where, for the height point cloud data at the starting point (X1 ’ , Y1 ’ ), denoted as Z1 ’ , then the height-direction runout error of any subsequent point relative to the starting point (X1 ’ , Y1 ’ ) can be obtained: △Z ’ = Z ’ - Z1’ . Specifically, the X-axis direct drive stage 11 and the Y-axis direct drive stage 12 are controlled to move, so that the emitted light spot of the high-precision displacement sensor 8 makes an "S"-shaped point scanning movement on the upper surface of the adjustment platform 10. Among them, the distance between adjacent points in the X-axis and Y-axis directions is 0.5 mm, and the scanning range is a square area of 50 mm x 50 mm, and this area is located at the center of the upper surface of the adjustment platform 10. The obtained point cloud data is as Figure 7 shown. Due to the existence of factors such as the height direction runout error of the linear guide rail as Figure 8 shown, when the high-precision displacement sensor 8 scans the upper surface of the adjustment platform 10 after fine grinding, the obtained point cloud data still deviates from the same plane. The height direction runout error of the linear guide rail causes the runout errors of the X-axis direct drive stage 11 and the Y-axis direct drive stage 12 at different positions, which can be regarded as repeated errors and can be compensated or corrected by relevant methods. The high-precision displacement sensor 8 obtains the height point cloud data corresponding to the (X ’ , Y ’ ) coordinates, denoted as Z ’ . Among them, for the height point cloud data at the starting point (X1 ’ , Y1 ’ ) coordinates, it is denoted as Z1 ’ . Then, the height direction runout error of any subsequent point relative to the starting point (X1 ’ , Y1 ’ ) can be obtained: △Z ’ = Z ’ - Z1 ’ ; S3: Discrete point optimization and grid interpolation processing are performed on the height point cloud data Z ’ obtained in step S2 and denoted as Z ’’ . The specific steps for performing discrete point optimization and grid interpolation processing on the height point cloud data Z ’ obtained in step S2 are as follows: (a) Using the 3σ criterion to eliminate gross errors; specifically: calculate the mean and standard deviation of the 10,201 data points Z ’ obtained by the above scanning, denoted as μ and σ respectively. Traverse the above 10,201 data points Z ’ . When Z ’ is not within the interval (μ - 3σ, μ + 3σ), then this data point is eliminated.

[0034] (b) Using the neighborhood interpolation method to fill in the gaps; specifically: as Figure 9 shown, the collected data points are observed from a top-down perspective, with the horizontal right direction as the X-axis direction, the vertical upward direction as the Y-axis direction, and the direction perpendicular to the X-Y plane and outward as the Z-axis direction. For the data points that may be eliminated, four cases are listed: ① As Figure 9 shown in (a), when there is 1 eliminated point inside the point cloud data, use (Za1 ’ +Z a2 ’ +Z a3 ’ +Z a4 ’ ) / 4 is used to represent the height value at this point; ② As shown in (b) of Figure 9 When there are 2 culling points inside the point cloud data, (Z b1 ’ +Z b2 ’ +Z b3 ’ ) / 3 is used to represent the height value of the previous point, and (Z b4 ’ +Z b5 ’ +Z b6 ’ ) / 3 is used to represent the height value of the next point; ③ As shown in (c) of Figure 9 When there is 1 culling point on the boundary of the point cloud data, (Z c1 ’ +Z c2 ’ +Z c3 ’ ) / 3 is used to represent the height value at this point; ④ As shown in (d) of Figure 9 When there is 1 culling point at the corner of the point cloud data, (Z d1 ’ +Z d2 ’ ) / 2 is used to represent the height value at this point. And so on for other cases. The height value of the culling point is filled with the average of the height values of the adjacent points. If there are multiple culling points in a certain area, filling starts from the edge of the area where there are adjacent points.

[0035] (c)Use the regular grid triangulation method to establish a cell grid, and divide each quadrilateral grid cell into two triangles in the way of the upper right diagonal and the lower left diagonal; As shown in Figure 10 and Figure 11 shown.

[0036] (d)According to the triangulation result, use the bilinear interpolation method to calculate the height data corresponding to the coordinates of any interpolation point, and denote it as Z ’’ . Specifically: As shown in Figure 12As shown in the figure, the collected data points are observed from a top-down perspective. The horizontal right direction is the X direction, the vertical upward direction is the Y direction, and the direction perpendicular to the X-Y plane and outward is the Z direction. For any point specified within the above scanning area, in Case 1: The point is located inside the triangle in the lower left diagonal of the triangular grid. From the grating rulers (encoders) of the X-axis direct drive stage and the Y-axis direct drive stage, as well as the high-precision displacement sensor (spectral confocal probe), the vertex coordinates of the triangle in the lower left diagonal can be read. Let them be (X1 ’ , Y1 ’ , Z1 ’ ), (X1 ’ , Y1 ’ + 0.5, Z2 ’ ), and (X1 ’ + 0.5, Y1 ’ + 0.5, Z3 ’ ). The X and Y coordinates of the arbitrarily specified point are (X1 ’ + dX, Y1 ’ + dY). These coordinates are read from the grating rulers (encoders) of the X-axis direct drive stage and the Y-axis direct drive stage. Therefore, dX and dY are known. Then the height value Z ’’ = Z1 ’ + (Z2 ’ - Z1 ’ ) × dY / 0.5 + (Z3 ’ - Z2 ’ ) × dX / 0.5; In Case 2: The point is located inside the triangle in the upper right diagonal of the triangular grid. From the grating rulers (encoders) of the X-axis direct drive stage and the Y-axis direct drive stage, as well as the high-precision displacement sensor (spectral confocal probe), the vertex coordinates of the triangle in the upper right diagonal can be read. Let them be (X1 ’ , Y1 ’ , Z1 ’ ), (X1 ’ + 0.5, Y1 ’ , Z4 ’ ), and (X1 ’ + 0.5, Y1 ’ + 0.5, Z3 ’ ). The X and Y coordinates of the arbitrarily specified point are still assumed to be (X1 ’ + dX, Y1 ’ + dY). Similarly, dX and dY are known. Then the height value Z ’’ = Z1 ’ + (Z4 ’ - Z1 ’ ) × dX / 0.5 + (Z3 ’ - Z4 ’) × dY / 0.5. After taking points for verification, the obtained spatial points are on the triangulated grid surface, as Figure 11 shown.

[0037] S4: Height point cloud data Z ’ After processing, the coordinates of any point within the point scan boundary can be obtained (X ’’ , Y ’’ ), and the corresponding height data Z ’’ and the height jump error of this point relative to the starting point (X1 ’ , Y1 ’ ) in the height direction: △Z ’’ = Z ’’ - Z1 ’ . In this example, through discontinuous point scanning, the height point cloud data of a finite number of coordinate points (10,201) can be obtained. After being processed by the above methods (a) to (d), the coordinates of any point (X ’’ , Y ’’ ) within the 50mm x 50mm point scan area can be obtained, and the corresponding height data Z ’’ can also be obtained. The height jump error of this arbitrary point relative to the starting point (X1 ’ , Y1 ’ ) in the height direction: △Z ’’ = Z ’’ - Z1 ’ , which lays a foundation for correcting or compensating the height jump error of the guide rail at this arbitrary point.

[0038] S5: Place the sample to be measured 9 on the adjustment platform 10, and the high-precision displacement sensor 8 performs point scanning on the sample to be measured, so that its scanning range is within the boundary of the above-mentioned adjustment platform point scanning range (50mm x 50mm), and make the coordinates of its first scanning point (X1 ’’’ , Y1 ’’’ ) consistent with the starting point coordinates (X1 ’ , Y1 ’ ). After that, the coordinates of any subsequent scanning point are recorded as (X ’’’ , Y ’’’ ), and the height data measured by the high-precision displacement sensor 8 is recorded as Z ’’’ ; the obtained height point cloud data Z ’’’ After being processed by the methods (a), (b), and (c) in S3, the height data without the sample to be measured corresponding to this arbitrary scanning point (X ’’’ , Y ’’’ ) is calculated by the bilinear interpolation method in S3(d) and recorded as Z ’’ . Then the original height jump error of this arbitrary scanning point relative to the starting point (X1 ’ , Y1 ’ ): △Z’’’ =Z ’’ -Z1 ’ , then the height point cloud data of the measured sample 9 after correcting the original height jump error is obtained: Z R =Z ’’’ -△Z ’’’ Specifically: perform point scanning on the sample 9 to make its scanning range (measurement area) within the boundary of the above-mentioned 50mmx50mm scanning area, and make its first scanning point coordinate (X1 ’’’ , Y1 ’’’ ) and the above starting point coordinates (X1 ’ , Y1 ’ ) is consistent, and then the coordinates of any scanning point are marked as (X ’’’ , Y ’’’ ), the height data measured by the high-precision displacement sensor 8 is recorded as Z ’’’ The obtained point cloud data is (a) removed from the gross errors and (b) filled with the removed points, and then (c) meshed triangulated, as shown in Figure 13 As shown; By the above (d) bilinear interpolation method, the arbitrary point (X ’’’ , Y ’’’ ) in the height direction: Z ’’ and the arbitrary point relative to the starting point (X1 ’ , Y1 ’ ) of the original height direction runout error: △Z ’’’ =Z ’’ -Z1 ’ (caused by the rail runout), then the height point cloud data of the measured sample 9 after correcting the original height runout error is obtained: Z R =Z ’’’ -△Z ’’’ ,like Figure 14 shown.

[0039] In summary, the present invention utilizes the high-precision displacement sensor provided by the point scanning topography instrument to effectively reduce the influence of the guide rail runout error during the movement of the X-axis and Y-axis direct-drive motion stages on the measurement results of the sample height information; the non-contact measurement avoids the friction and wear between the probe and the sample while ensuring the measurement efficiency; and effectively ensures the accuracy of the sample topography measurement.

[0040] It should be noted that the present invention is an improvement on equipment components and measurement methods, and does not involve improvements on circuits and control programs. The present invention only controls the operation and stop of various electronic devices through a PLC control system. Since the PLC control system is a mature automatic control system in industry, the present invention will not repeat the circuit and control program content.

[0041] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "vertical", "horizontal", "upper", "lower", "front", "rear", "left", "right", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of simplifying the description of the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0042] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for correcting the height-direction jumping error of a point-scanning profilometer, characterized in that: The steps are as follows: S1: Adjust the adjustment platform (10) to keep it horizontal; then adjust the height of the high-precision displacement sensor (8) so that the height change information of the overall surface of the adjustment platform (10) is within the range of the high-precision displacement sensor (8). Adjust the rotary table (5) and the swing table (6) on the vertical movement component to minimize the height measurement result of the high-precision displacement sensor (8) at a certain scanning point. S2: Control the movement of the X-axis direct drive stage (11) and the Y-axis direct drive stage (12) so that the outgoing light spot of the high-precision displacement sensor (8) is on the upper surface of the adjustment platform (10), and perform an "S"-shaped point scanning movement with a certain spacing relative to the adjustment platform (10), and make the scanning points evenly distributed on the upper surface of the adjustment platform (10); the high-precision displacement sensor (8) obtains the height point cloud data corresponding to the scanning points (X ’ , Y ’ ), denoted as Z ’ . Among them, for the height point cloud data at the coordinates of the starting point (X1 ’ , Y1 ’ ), denoted as Z1 ’ , then the height direction runout error of any subsequent scanning point relative to the starting point (X1 ’ , Y1 ’ ) can be obtained: △Z ’ = Z ’ - Z1 ’ ; S3: Perform discrete point optimization and grid interpolation on the height point cloud data Z obtained in step S2, and denote it as Z ’ ; ’’ ; S4: Height point cloud data Z ’ After discrete point optimization and grid interpolation processing, the coordinates of any point (X ’’ , Y ’’ ) within the point scan boundary can be obtained, along with the corresponding height data Z ’’ and the jump error of this point relative to the starting point (X1 ’ , Y1 ’ ) in the height direction: △Z ’’ = Z ’’ - Z1 ’ ; S5: Place the sample under test (9) on the adjustment platform (10). The high-precision displacement sensor (8) performs point scanning on the sample under test (9), making its scanning range within the boundary of the point scanning range of the above adjustment platform, and making the coordinates of its first scanning point (X1 ’’’ , Y1 ’’’ ) coincide with the coordinates of the starting point (X1 ’ , Y1 ’ ). After that, the coordinates of any scanning point are denoted as (X ’’’ , Y ’’’ ), and the height data measured by the high-precision displacement sensor (8) is denoted as Z ’’’ ; the obtained height point cloud data Z ’’’ , after being processed by the methods (a), (b), and (c) in S3, the height data without the sample under test corresponding to any scanning point (X ’’’ , Y ’’’ ) is calculated by the bilinear interpolation method (d) in S3 and denoted as Z ’’ . Then, the original height jump error of this arbitrary scanning point relative to the starting point (X1 ’ , Y1 ’ ) is: △Z ’’’ = Z ’’ - Z1 ’ . After that, the height point cloud data of the sample under test (9) after correcting the original height jump error is obtained: Z R = Z ’’’ - △Z ’’’ .

2. The correction method for the height-direction runout error of the point-scanning profiler according to claim 1, wherein: In step S3, for the height point cloud data Z obtained in step S2 ’ The specific steps for discrete point optimization and grid interpolation processing are as follows: (a) Use the 3σ criterion to eliminate gross errors; (b) Use the neighborhood interpolation method to fill in the gaps; (c) Use the regular grid triangulation method to establish a unitized grid, and divide each quadrilateral grid cell into two triangles in the way of the upper right diagonal and the lower left diagonal; (d) According to the triangulation result, use the bilinear interpolation method to calculate the height data corresponding to the coordinates of any interpolation point, and denote it as Z ’’ .

3. The method for correcting the height-direction runout error of the point-scanning profiler according to claim 1 or 2, characterized in that: The point scanning profilometer used includes a base (1). A gantry column (2) and a Y-direction direct drive moving table (12) are provided on the base (1). A vertical lead screw module (3) is provided on the gantry column (2), and a vertical movement component is provided on the vertical lead screw module (3). The vertical movement component includes a connected rotary table (5) and a swing table (6); a high-precision displacement sensor (8) is provided on the swing table (6); an X-direction direct drive moving table (11) is provided on the Y-direction direct drive moving table (12); an adjustment platform (10) for placing the sample to be measured is provided on the X-direction direct drive moving table (11); the vertical movement component and the adjustment platform (10) are used to adjust the light-emitting angle of the high-precision displacement sensor (8) relative to the sample to be measured. The Y-direction direct drive moving table (12) and the X-direction direct drive moving table (11) cooperate to move so that the emitted light spot of the high-precision displacement sensor (8) can perform an "S"-shaped point scanning movement on the surface of the sample to be measured at a certain interval.

4. The method for correcting the height-direction runout error of the point-scanning profiler according to claim 3, wherein: The adjustment platform (10) uses a marble adjustment platform; the Y-direction direct drive moving table (12) includes a first linear guide rail (121) and a first platform (119). The first linear guide rail (121) is arranged symmetrically along the Y-direction on the base (1); the first platform (119) is slidably connected to the first linear guide rail (121) through a first connecting slider (129). A matching first linear motor magnetic rail (122) and a first linear motor coil (123) are provided between the two first linear guide rails (121). The first linear motor magnetic rail (122) is fixed at the bottom of the first platform (119), and the first linear motor coil (123) is fixed on the base (1). A first grating scale (126) is provided along the Y-direction at the bottom of the first platform (119). The first grating scale (126) is located on one side of one of the first linear guide rails (121). A first reading head (125) is provided on the side of the first grating scale (126) facing the first linear motor magnetic rail (122); two first fixed limit blocks (127) are also provided along the Y-direction on the base (1). A first movement limit block (128) is provided at the bottom of the first platform (119), and the first movement limit block (128) moves between the two first fixed limit blocks (127) along with the first platform (119).

5. The method for correcting the height-direction runout error of the point scanning profiler according to claim 4, wherein: The X-direction direct drive stage (11) includes a second linear guide rail (111) and a second stage (103). The second linear guide rail (111) is arranged symmetrically along the X-direction on the first stage (119); the second stage (103) is slidably connected to the second linear guide rail (111) through a second connecting slider (109). A second linear motor magnetic rail (112) and a second linear motor coil (113) which cooperate with each other are arranged between the two second linear guide rails (111). The second linear motor magnetic rail (112) is fixed to the bottom of the second stage (103), and the second linear motor coil (113) is fixed to the first stage (119).

6. The correction method for the height-direction runout error of the point-scanning profilometer according to claim 5, characterized in that: A second grating scale (116) is arranged along the X-direction at the bottom of the second stage (103). The second grating scale (116) is located on one side of one of the second linear guide rails (111). A second reading head (115) is arranged on the side of the second grating scale (116) facing the second linear motor magnetic rail (112); two second fixed limit blocks (117) are further arranged along the X-direction on the first stage (119). A second moving limit block (118) is arranged at the bottom of the second stage (103). The second moving limit block (118) moves between the two second fixed limit blocks (117) along with the second stage (103).

7. The method for correcting the height-direction runout error of the point-scanning profilometer according to claim 6, characterized in that: The leveling stage (10) is centrally arranged on the upper surface of the second stage (103), and at least three leveling screws (101) and at least two locking screws (102) are provided relative to the second stage (103); at least three through holes are uniformly arranged along the central axis direction of the leveling stage (10), and threaded sleeves are fixedly arranged in the through holes; leveling screws (101) are threadedly connected in the threaded sleeves, and positioning blind holes which cooperate with the leveling screws (101) are arranged on the second stage (103); at least two vertical countersunk holes are symmetrically arranged in the middle of the leveling stage (10), threaded holes corresponding to the vertical countersunk holes are arranged on the second stage (103), and the locking screws (102) are threadedly connected with the threaded holes after passing through the vertical countersunk holes.

8. The method for correcting the height-direction runout error of the point-scanning profilometer according to any one of claims 4 to 7, characterized in that: The vertical lead screw module (3) includes a vertical support (31) arranged on the gantry column (2). A vertically arranged first lead screw (32) and a first guide rail (33) are arranged on the vertical support (31). A first slider (34) is threadedly connected to the first lead screw (32). The first slider (34) is slidably matched with the first guide rail (33). The upper end of the first lead screw (32) is connected to a first motor (35) arranged on the vertical support (31); a rotary table (5) is arranged on the front panel of the first slider (34), and a swing table (6) is arranged on the front panel of the rotary table (5); a clamping seat (7) for fixing a high-precision displacement sensor (8) is arranged on the swing table (6).

9. The correction method for the height-direction runout error of the point-scanning profiler according to claim 8, wherein: The rotary table (5) is connected to the first sliding seat (34) through an adapter plate (4). The rotary table (5) includes a fixed seat (51) and a limit seat (54) rotatably arranged on the adapter plate (4). A graduated turntable (52) and an arc-shaped baffle (56) matching the turntable (52) are rotatably arranged on the fixed seat (51). A rotating shaft (53) is arranged on the outer side of the turntable (52). A limit groove (55) is formed in the limit seat (54). The end of the rotating shaft (53) extends into the limit groove (55). A driving screw (57) connected to the turntable (52) through a worm and worm gear is arranged on the limit seat (54).

10. The method for correcting the height-direction runout error of the point-scanning profilometer according to claim 9, characterized in that: The swing table (6) includes a matching arc-shaped base (61) and an arc-shaped swing table (62). An arc-shaped rail (63) is arranged in the arc-shaped base (61). An arc-shaped groove is formed at the bottom of the arc-shaped swing table (62). The arc-shaped rail (63) is slidably matched with the arc-shaped groove. A driving worm (65) is arranged on the arc-shaped base (61). A worm gear rack (66) is arranged at the bottom of the arc-shaped swing table (62). The driving worm (65) is meshed with the worm gear rack (66). A limit rod (67) is arranged on one side of the arc-shaped swing table (62). A limit plate (68) is arranged on one side of the arc-shaped base (61). An arc-shaped limit groove (69) is formed in the limit plate (68). The limit rod (67) is located in the arc-shaped limit groove (69).

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