JP6064910B2 - Shape measuring apparatus and shape measuring method - Google Patents

Description

  The present invention relates to a shape measuring device and a shape measuring method.

  In order to confirm the processing accuracy of a workpiece such as an optical element, it is necessary to measure the shape of the workpiece with high accuracy. For measuring the shape of the workpiece, a shape measuring device including a contact probe or an optical probe is used.

  As a technology related to this, the following Patent Document 1 describes, by using a plurality of laser length measuring devices, the position of the contact probe of the shape measuring device in the XYZ axis direction, the position of the stage in the XYZ axis direction, and the XY axis around Techniques for measuring tilt have been proposed. According to this technique, based on the measurement result of the laser length measuring device, the influence of the position deviation between the stage and the contact type probe due to the pitching and yawing of the stage and the position deviation between the stage and the contact type probe is reduced. Coordinates can be calculated with high accuracy.

  However, although this technique can provide sufficient accuracy for a shape measuring device equipped with a contact probe that measures a workpiece with a point, it can be used for a shape measuring device equipped with an optical probe that measures a workpiece on a surface. Is not enough. Since an optical probe measures a minute area (for example, 1 mm × 1 mm square) of a workpiece by one measurement operation, in a shape measuring apparatus equipped with an optical probe, only the relative position between the optical probe and the stage is used. First, it is necessary to correct the measurement data by detecting the relative attitude between the optical probe and the stage with high accuracy.

JP-A-5-209741

  The present invention has been made to solve the above-described problems, and can detect the relative position and posture error between the optical probe and the stage with high accuracy, and can measure the shape of the workpiece with high accuracy. An object is to provide a shape measuring apparatus and a shape measuring method.

  The above object of the present invention is achieved by the following means.

(1) have a mounting surface of the workpiece is placed, in a second direction parallel to the mounting surface before being perpendicular to the first direction and the first direction parallel to the mounting surface An optical stage that drives in a third direction orthogonal to the placement surface and has an orthogonal surface perpendicular to the optical axis and measures the shape of the workpiece placed on the placement surface. A first detection unit that detects an inclination of the mounting surface with respect to the reference surface and a distance from the reference surface to the mounting surface; A second detector for detecting an inclination of the orthogonal plane with respect to the reference plane and a distance from the reference plane to the orthogonal plane; and a third detector for detecting an inclination of the stage about an axis orthogonal to the reference plane A detector for detecting a tilt of the optical probe around the axis; Shape measuring apparatus having a detecting unit.

  (3) The first detection unit is provided on the reference surface, and includes three or more first length measuring devices for measuring a distance from the reference surface to the mounting surface, and the first length measurement. A first calculation unit that calculates an inclination of the placement surface with respect to the reference surface from a measurement result obtained by the measuring device, and the second detection unit is provided on the reference surface, From the measurement results obtained by three or more second length measuring devices for measuring the distance from the surface to the orthogonal surface, and the second length measuring device, the inclination of the orthogonal surface with respect to the reference surface is calculated. The shape measuring device according to (1) or (2), further including a second calculating unit that calculates.

  (4) The centroid position of the three or more first length measuring devices and the centroid position of the three or more second length measuring devices are respectively coincident with the optical axis. Shape measuring device.

  (5) a driving unit that moves the optical probe in the optical axis direction, and the third detection unit includes a first reflecting member having a first reflecting surface facing a side surface of the stage; Two third length measuring devices provided on the side surface of the stage so as to be spaced apart from each other along the longitudinal direction of the side surface, and measuring the distance from the side surface to the first reflecting surface; A third calculation unit that calculates the inclination of the stage around the axis from the measurement result obtained by the length measuring device, wherein the fourth detection unit is orthogonal to the orthogonal plane. A second reflecting member having a second reflecting surface facing the first side surface of the optical probe, and a third reflecting surface facing the second side surface of the optical probe orthogonal to the first side surface A third reflecting member having the first side surface provided on the first side surface; A fourth length measuring device for measuring the distance to the second reflecting surface, and a distance from the second side surface to the third reflecting surface provided on the second side surface. A fourth measuring unit for calculating an inclination of the optical probe about the axis from one fifth length measuring device, measurement results obtained by the fourth and fifth length measuring devices, and a center position of the driving unit; The shape measuring device according to (2), further comprising:

  (6) Relative position and posture errors between the stage and the optical probe from the inclination and distance of the placement surface and the orthogonal surface with respect to the reference surface detected by the first and second detection units, respectively. Obtained by measuring the surface of the work in units of a micro area by the optical probe based on the relative position and orientation error calculated by the fifth calculation unit. The shape measuring apparatus according to any one of (1) to (5), further including a stitching processing unit that performs a stitching process for correcting and joining a plurality of shape data.

(7) having a placement surface on which the workpiece is placed, in a first direction parallel to the placement surface and a second direction parallel to the placement surface while being orthogonal to the first direction; facing the mounting surface of the stage to be driven, and detects the distance to the mounting surface of the slope and the reference plane of the mounting surface relative to the reference surface of the reference member, and is mounted on the mounting surface In addition, the shape of the workpiece is measured, and the inclination of the orthogonal plane orthogonal to the optical axis of the optical probe that drives in the third direction orthogonal to the placement surface is from the reference plane to the orthogonal plane. A step (a) for detecting a distance; and a step (b) for detecting an inclination of the stage about an axis orthogonal to the reference plane and detecting an inclination of the optical probe about the axis. Shape measurement method.

  (9) In the step (a), the distance from the reference surface to the mounting surface is measured by three or more first length measuring devices provided on the reference surface, and the reference surface is A step (a1) of measuring a distance from the reference plane to the orthogonal plane by three or more provided second length measuring devices, and a measurement result obtained by the first and second length measuring devices; The shape measuring method according to (7) or (8), further including: (a2) calculating the inclination of the mounting surface and the inclination of the orthogonal surface with respect to the reference surface.

  (10) The centroid positions of the three or more first length measuring devices and the centroid positions of the three or more second length measuring devices respectively coincide with the optical axis. Shape measurement method.

  (11) In the step (b), the first reflecting member is formed from the side surface by two third length measuring devices provided on the side surface of the stage so as to be separated from each other along the longitudinal direction of the side surface. And measuring the distance to the first reflecting surface facing the side surface of the optical probe, and one fourth length measuring device provided on the first side surface of the optical probe orthogonal to the orthogonal surface, The distance from the first side surface to the second reflecting surface facing the first side surface of the second reflecting member is measured, and the second of the optical probe orthogonal to the first side surface is measured. A step (b1) of measuring a distance from the second side surface to a third reflecting surface facing the second side surface of the third reflecting member by one fifth length measuring device provided on the side surface; ) And the measurement result obtained by the third length measuring device, The tilt of the stage is calculated, and from the measurement results obtained by the fourth and fifth length measuring devices and the center position of the drive unit that moves the optical probe in the optical axis direction, (B2) calculating the inclination of the optical probe, The shape measuring method according to (8) above.

  (12) A step of calculating a relative position and an attitude error between the stage and the optical probe from the inclination and distance of the mounting surface and the orthogonal surface detected in the step (a) with respect to the reference surface ( c) and a plurality of shape data obtained by measuring the surface of the workpiece in units of a micro area by the optical probe based on the relative position and posture error calculated in the step (c). The shape measuring method according to any one of (7) to (11), further including a step (d) of performing stitching processing for joining together.

  According to the present invention, since the position and inclination of the optical probe and the stage are detected with reference to the reference plane, the relative position and posture error between the optical probe and the stage can be detected with high accuracy. As a result, the shape of the workpiece can be measured with high accuracy.

It is a schematic perspective view of the shape measuring apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows schematic structure of the shape measuring apparatus shown by FIG. It is a figure which shows arrangement | positioning of the laser length measuring device on a reference plane. It is a flowchart which shows the procedure of the position and orientation calculation process performed by the calculation part of a shape measuring apparatus. It is a figure for demonstrating the process which calculates the inclination around the Z-axis of a mounting stage. It is a figure for demonstrating the process which calculates the inclination around the Z-axis of an optical probe.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  FIG. 1 is a schematic perspective view of a shape measuring apparatus 1 according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a schematic configuration of the shape measuring apparatus 1.

  As shown in FIGS. 1 and 2, the shape measuring apparatus 1 according to the present embodiment includes a placement stage 10, an optical probe 20, an XY drive stage 30, a Z drive stage 40, a reference block 50, a reflection member 60, and a calculation. Part 70.

  The placement stage 10 is for placing the workpiece W thereon. The placement stage 10 has a placement surface 11 on which the workpiece W is placed. The mounting surface 11 has a reflecting surface that reflects light from laser length measuring devices 52 to 54 described later. A laser length measuring device 13 is provided on the first side surface 12 of the mounting stage 10, and two laser length measuring devices 15 and 16 are provided on a second side surface 14 orthogonal to the first side surface 12. , And spaced apart from each other along the Y-axis direction. The laser length measuring devices 13, 15, 16 are arranged substantially evenly around the optical axis L of the optical probe 20 in order to reduce Abbe error.

  The optical probe 20 measures the shape of the workpiece W placed on the placement stage 10. The optical probe 20 is an optical interference probe, and measures the shape of a minute region (for example, 1 mm × 1 mm square) of the workpiece W by one measurement operation. The optical probe 20 is provided with an orthogonal member 22 having an orthogonal surface 21 orthogonal to the optical axis L. The orthogonal surface 21 has a reflection surface that reflects light from laser length measuring devices 55 to 57 described later. Laser length measuring devices 25 and 26 are provided on the first side surface 23 and the second side surface 24 orthogonal to the first side surface 23 of the orthogonal member 22, respectively. Similarly to the laser length measuring devices 13, 15, and 16, the laser length measuring devices 25 and 26 are arranged substantially evenly around the optical axis L of the optical probe 20 in order to reduce Abbe error.

  The XY drive stage 30 drives the mounting stage 10 in the horizontal direction. The XY drive stage 30 includes a first drive stage that moves the placement stage 10 in the X-axis direction and a second drive stage that moves the placement stage 10 in the Y-axis direction. The mounting stage 10 is moved in the direction.

  The Z drive stage 40 drives the optical probe 20 in the vertical direction. The Z drive stage 40 moves the optical probe 20 in the Z-axis direction.

  The reference block 50 is a reference member for detecting the positions and postures of the mounting stage 10 and the optical probe 20. The reference block 50 is disposed above the placement stage 10 and the optical probe 20 and has a reference surface 51 that faces the placement surface 11 and the orthogonal surface 21. The reference block 50 includes three laser length measuring devices 52, 53, and 54 for measuring the distance from the reference surface 51 to the mounting surface 11 of the mounting stage 10, and the orthogonality of the optical probe 20 from the reference surface 51. Three laser length measuring devices 55, 56, 57 for measuring the distance to the surface 21 are provided. As shown in FIG. 3, the three laser length measuring devices 52, 53, and 54 are arranged on the reference surface 51 so that the optical axis L of the optical probe 20 is located at the center of gravity. Similarly, the three laser length measuring devices 55, 56, and 57 are also arranged on the reference surface 51 so that the optical axis L of the optical probe 20 is located at the center of gravity. According to such a configuration, when calculating the inclinations of the stage 10 and the optical probe 20, the influence at each measurement point can be made uniform.

  The reflecting member 60 is for detecting the position of the mounting stage 10 in the XY direction and the inclination around the Z axis, and the position of the optical probe 20 in the XY direction and the inclination around the Z axis. The reflecting member 60 includes reflecting members 61 and 62 that face the first and second side surfaces 12 and 14 of the mounting stage 10 respectively, and first and second side surfaces 23 and 24 of the orthogonal member 22 of the optical probe 20. Have reflection members 63 and 64 facing each other. The reflection members 61 and 62 have reflection surfaces 61R and 62R facing the first and second side surfaces 12 and 14 of the mounting stage 10, and the laser length measuring devices 13 and 15 provided on the mounting stage 10. The light from 16 is reflected. The reflecting members 63 and 64 have reflecting surfaces 63R and 64R facing the first and second side surfaces 23 and 24 of the orthogonal member 22, and light from the laser length measuring devices 25 and 26 provided in the optical probe 20. To reflect. The reflection member 60 and the reference block 50 are fixed by a frame (not shown).

  The calculation unit 70 calculates the relative position and orientation error between the mounting stage 10 and the optical probe 20. The calculation unit 70 is, for example, a general PC (Personal Computer), and performs various arithmetic processes. The calculation unit 70 calculates the inclination of the mounting surface 11 with respect to the reference surface 51 from the measurement results obtained by the laser length measuring devices 52 to 54, and calculates the reference surface 51 from the measurement results obtained by the laser length measuring devices 55 to 57. The inclination of the orthogonal plane 21 with respect to is calculated. The calculation unit 70 calculates the inclination of the mounting stage 10 around the Z axis from the measurement results obtained by the laser length measuring devices 15 and 16, and the measurement results obtained by the laser length measuring devices 25 and 26 and The tilt of the optical probe 20 around the Z axis is calculated from the center position of the Z drive stage 40 on the XY plane. Further, the calculation unit 70 calculates the relative position and posture error between the mounting stage 10 and the optical probe 20 from the inclination and distance of the mounting surface 11 and the orthogonal surface 21 with respect to the reference surface 51. In addition, the calculation unit 70 has a plurality of shapes obtained by measuring the surface of the workpiece W in units of microscopic areas by the optical probe 20 based on the relative position and posture error between the mounting stage 10 and the optical probe 20. Perform stitching processing that corrects and stitches data together.

  In the shape measuring apparatus 1 of the present embodiment configured as described above, the shape of the workpiece W is continuously measured in units of minute regions while intermittently changing the relative position between the workpiece W and the optical probe 20. The shape data of the entire workpiece W is acquired. At this time, due to the influence of pitching, yawing, and rolling of the XY drive stage 30 and the Z drive stage 40, a positional shift and a posture shift between the mounting stage 10 and the optical probe 20 occur.

  In the shape measuring apparatus 1 of the present embodiment, the positions and postures of the mounting stage 10 and the optical probe 20 are detected by a plurality of laser length measuring devices, respectively. Then, based on the position and orientation information of the placement stage 10 and the optical probe 20, the relative position and orientation error between the placement stage 10 and the optical probe 20 are calculated. Based on the calculated relative position and posture error information, the coordinates of the shape data obtained by measuring the shape of the minute region of the workpiece W by the optical probe 20 are corrected. Hereinafter, with reference to FIGS. 4 to 6, a process for calculating the relative position and orientation error between the mounting stage 10 and the optical probe 20 by the shape measuring apparatus 1 will be described.

  FIG. 4 is a flowchart showing the procedure of the position / orientation calculation process executed by the calculation unit 70 of the shape measuring apparatus 1. Note that the algorithm shown in the flowchart of FIG. 4 is stored as a program in the storage unit of the calculation unit 70 and is executed by the CPU. Prior to the execution of the position / orientation calculation process, the distances between the mounting stage 10 and the optical probe 20, the reference block 50, and the reflecting members 61, 62, 63, 64 are measured by a plurality of laser length measuring devices. ing.

  In step S01, distance data from the reference surface 51 of the reference block 50 to the placement surface 11 of the placement stage 10 measured by the laser length measuring devices 52 to 54 is acquired.

  In step S02, the inclination of the mounting surface 11 with respect to the reference surface 51 and the distance on the optical axis L are calculated based on the distance data acquired in the process shown in step S01.

  Specifically, when the XY coordinates of the laser length measuring devices 52 to 54 on the reference plane 51 are (x1, y1), (x2, y2), and (x3, y3), respectively, the laser length measuring devices 52 to 54 are used. Based on the measurement results in the Z-axis direction, the coordinates of three points on the mounting surface 11 irradiated with light from the laser length measuring devices 52 to 54 are ZS1 (x1, y1, z1) and ZS2 (x2), respectively. , Y2, z2) and ZS3 (x3, y3, z3).

  Therefore, if the placement surface 11 including these three points is expressed as the following equation (1), each component a, b, and c of the normal vector of the placement surface 11 is expressed by the following equation (2). Is calculated by

  Accordingly, the inclination of the mounting surface 11 with respect to the reference surface 51 is a tilt angle of the normal vector (a, b, c) of the mounting surface 11 in the X-axis direction with respect to the Z-axis (= π / 2−normal and X An angle formed with the axis θx (yawing) and a tilt angle in the Y-axis direction (= π / 2−angle formed between the normal and the Y axis) θy (pitching) are calculated by the following equation (3).

  Further, the center of gravity positions of these three points ZS1, ZS2, and ZS3 are on the placement surface 11, and assuming that the displacement in the optical axis L direction (x = 0, y = 0) is z0, z0 is expressed by the following equation (4). Is calculated by

  In step S03, distance data from the reference surface 51 of the reference block 50 to the orthogonal surface 21 of the optical probe 20 measured by the laser length measuring devices 55 to 57 is acquired.

  In step S04, the inclination of the orthogonal plane 21 with respect to the reference plane 51 and the distance on the optical axis L are calculated based on the distance data acquired in the process shown in step S03. Note that the process of calculating the inclination of the orthogonal surface 21 with respect to the reference surface 51 is the same as the process of calculating the inclination of the placement surface 11 with respect to the reference surface 51 in step S02, and thus the description thereof is omitted.

  In step S05, distance data from the second side surface 14 of the mounting stage 10 to the reflecting surface 62R of the reflecting member 62, which is measured by the laser length measuring devices 15 and 16, is acquired.

  In step S06, based on the distance data acquired in the process shown in step S05, the inclination of the mounting stage 10 about the Z axis and the distance to the mounting stage 10 at the optical axis position are calculated.

  Specifically, as shown in FIG. 5, the distances from the second side surface 14 to the reflecting surface 62R measured by the laser length measuring devices 15 and 16 are XS1 and XS2, respectively. When the distance between 16 is d, the inclination θz (rolling) around the Z axis of the mounting stage 10 is calculated by the following equation (5).

  In step S07, distance data from the first side surface 23 of the optical probe 20 to the reflecting surface 63R of the reflecting member 63, which is measured by the laser length measuring device 25, is acquired.

  In step S08, distance data from the second side surface 24 of the optical probe 20 to the reflecting surface 64R of the reflecting member 64, which is measured by the laser length measuring device 26, is acquired.

  In step S09, based on the distance data acquired in the processing shown in step S07 or step S08 and the center position of the XY plane of the Z drive stage 40, the inclination of the optical probe 20 around the Z axis and the optical probe 20 An XY shift amount is calculated.

  As shown in FIG. 6, the rotation center around the Z axis of the optical probe 20 is at the center T of the Z drive stage 40 that is shifted by a certain distance S from the Z axis. Therefore, the inclination φ (rolling) around the Z-axis of the optical probe 20 is geometric from one of Xp and Yp obtained from the length measurement results of the laser length measuring devices 25 and 26 and the reference positions X0 and Y0. Is calculated automatically.

  In step S10, distance data from the first side surface 12 of the mounting stage 10 to the reflecting surface 61R of the reflecting member 61, which is measured by the laser length measuring device 13, is acquired.

  In step S11, the relative position and orientation error between the mounting stage 10 and the optical probe 20 are calculated. Specifically, the relative position between the mounting stage 10 and the optical probe 20 is calculated from the distance data acquired in the processes shown in steps S01, S03, S05, S07, S08, and S10. Then, the tilt (pitching, yawing, rolling) of the mounting stage 10 and the optical probe 20 calculated in the processes shown in S02, S04, S06, and S09, the distance on the optical axis L, and the mounting at the optical axis position, respectively. From the distance to the stage 10 and the amount of XY deviation of the optical probe 20, the relative position and orientation error between the mounting stage 10 and the optical probe 20 are calculated.

  As described above, according to the processing of the flowchart shown in FIG. 4, the relative position and orientation error between the mounting stage 10 and the optical probe 2 are calculated based on the length measurement result by the laser length measuring device.

  Based on the calculated relative position and orientation error information, the coordinates of the shape data obtained by measuring the shape of the minute region of the workpiece W by the optical probe 20 are corrected. After the coordinates (position and orientation) of all the shape data in the measurement area are corrected, stitching processing for joining these shape data is performed, and the shape data of the entire workpiece is acquired.

  As described above, according to the present embodiment, the positions and postures of the mounting stage 10 and the optical probe 20 are detected by a plurality of laser length measuring devices. In particular, since the inclination of the mounting surface 11 and the orthogonal surface 21 around the X-axis and Y-axis and the position in the Z-axis direction are detected based on the common reference surface 51, the mounting stage 10 and the optical probe 20 are detected. Relative position and posture error are detected with high accuracy. As a result, the shape of the workpiece can be measured with high accuracy.

  Since the laser length measuring device is easily affected by airflow and environmental fluctuations (temperature, atmospheric pressure, and humidity), the shape measuring device 1 may be provided with a shielding structure for stabilizing the airflow. Furthermore, control may be performed in which environmental factors are simultaneously measured and fed back to relative position and attitude errors.

  Further, in the above equation (4), when s1, s2, and s3 are defined as in the following equation (6), the displacement z0 in the optical axis L direction is calculated by the following equation (7).

  Since the displacement z0 in the direction of the optical axis L is expressed by the above equation (7), the best measurement condition that minimizes the variation in z0 due to variations in the length measuring devices ZP1 to ZP1 is s1 = s2. It is given when = s3. In the above equation (6), s1 is equal to twice the area of the small triangle formed by the optical axis position and the three points ZP2 and ZP3. Similarly, s2 and s3 are each equal to twice the area of the corresponding small triangle. Therefore, it can be seen that the best measurement condition is the condition that the areas of the three small triangular regions are equal, and it is desirable that the optical axis position be in the center of gravity. Therefore, the three-point coordinates ZS1, ZS2, and ZS3 on the mounting surface 11 irradiated with the light from the laser length measuring devices 52 to 54, and the orthogonal surface 21 irradiated with the light from the laser length measuring devices 55 to 57. The upper three coordinates ZP1, ZP2, and ZP3 are arranged in the center of gravity with the optical axis L as the center (see FIG. 3). Although FIG. 3 is represented as an equilateral triangle, the optical axis position only needs to be the center of gravity, and does not need to be an equilateral triangle.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, in the above-described embodiment, the inclinations of the mounting surface 11 and the orthogonal surface 21 with respect to the reference surface 51 are detected by three laser length measuring devices. However, the inclination of the mounting surface 11 and the orthogonal surface 21 may be detected by a laser interferometer, respectively. In this case, in order to measure the positions of the mounting surface 11 and the orthogonal surface 21 in the Z-axis direction, one laser length measuring device is used separately from the laser interferometer.

  In the above-described embodiment, the inclination of the optical probe 20 around the Z axis is based on the measurement results of the laser length measuring devices 25 and 26 provided on the two side surfaces 23 and 24 and the center of the Z drive stage on the XY plane. Calculated based on position. However, similarly to the method of calculating the inclination of the mounting stage 10 around the Z axis, the calculation may be performed by two laser length measuring devices provided on one side surface so as to be separated from each other.

  In the embodiment described above, a laser length measuring device is used to measure the distance between the objects. However, the means for measuring the distance is not limited to the laser length measuring device, and for example, an ultrasonic length measuring device may be used.

  In the above-described embodiment, three laser length measuring devices 52 to 54 and 55 to 57 are used to measure the distance from the reference surface 51 to the placement surface 11 or the orthogonal surface 21, respectively. However, the laser length measuring device is not limited to three, and four or more laser length measuring devices may be used.

  The means and method for performing various processes in the shape measuring apparatus according to the present embodiment can be realized by either a dedicated hardware circuit or a programmed computer. The program may be provided by a computer-readable recording medium such as a flexible disk and a CD-ROM, or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. The program may be provided as a single application software, or may be incorporated into the software as a function of the shape measuring apparatus.

1 shape measuring device,
10 Placement stage,
11 Placement surface,
13, 15, 16, 25, 26, 52, 53, 54, 55, 56, 57 Laser length measuring device,
20 optical probe,
21 orthogonal plane,
30 XY drive stage,
40 Z drive stage,
50 reference blocks,
51 reference plane,
60, 61, 62, 63, 64 reflective member,
70 Calculation unit.

Claims (10)

Stage the workpiece is to have a mounting surface to be mounted, is driven in a second direction parallel to the mounting surface before being perpendicular to the first direction and the first direction parallel to the mounting surface When,
An optical probe that drives in a third direction orthogonal to the placement surface, has an orthogonal surface perpendicular to the optical axis, and measures the shape of the workpiece placed on the placement surface;
A reference member having a reference surface facing the mounting surface;
A first detector that detects the inclination of the placement surface with respect to the reference surface and a distance from the reference surface to the placement surface;
A second detection unit that detects the inclination of the orthogonal surface with respect to the reference surface and the distance from the reference surface to the orthogonal surface;
A third detector for detecting the tilt of the stage around an axis orthogonal to the reference plane;
A fourth detector for detecting an inclination of the optical probe around the axis;
A shape measuring apparatus. The first detection unit includes:
Three or more first length measuring devices provided on the reference surface and measuring a distance from the reference surface to the mounting surface;
A first calculation unit that calculates an inclination of the placement surface with respect to the reference surface from a measurement result obtained by the first length measuring device;
The second detection unit includes:
Three or more second length measuring devices provided on the reference plane for measuring the distance from the reference plane to the orthogonal plane;
The shape measuring apparatus according to claim 1, further comprising: a second calculation unit that calculates an inclination of the orthogonal plane with respect to the reference plane from a measurement result obtained by the second length measuring device.   The shape measuring apparatus according to claim 2, wherein a gravity center position of the three or more first length measuring devices and a gravity center position of the three or more second length measuring devices respectively coincide with the optical axis. A drive unit that moves the optical probe in the optical axis direction;
The third detection unit includes:
A first reflecting member having a first reflecting surface facing the side surface of the stage;
Two third length measuring devices provided on the side surface of the stage so as to be separated from each other along the longitudinal direction of the side surface and measuring the distance from the side surface to the first reflecting surface;
A third calculation unit for calculating an inclination of the stage around the axis from a measurement result obtained by the third length measuring device,
The fourth detection unit includes:
A second reflecting member having a second reflecting surface facing the first side surface of the optical probe orthogonal to the orthogonal surface;
A third reflecting member having a third reflecting surface facing the second side surface of the optical probe orthogonal to the first side surface;
One fourth length measuring device provided on the first side surface for measuring the distance from the first side surface to the second reflecting surface;
One fifth length measuring device provided on the second side surface for measuring the distance from the second side surface to the third reflecting surface;
A fourth calculation unit for calculating an inclination of the optical probe around the axis from a measurement result obtained by the fourth and fifth length measuring devices and a center position of the drive unit;
The shape measuring apparatus according to claim 1, comprising: Relative position and posture errors between the stage and the optical probe are calculated from the inclination and distance of the placement surface and the orthogonal surface with respect to the reference surface detected by the first and second detection units, respectively. A fifth calculation unit;
Based on the relative position and orientation errors calculated by the fifth calculation unit, the optical probe is used to correct and connect a plurality of shape data obtained by measuring the surface of the workpiece in units of minute regions. The shape measuring apparatus according to claim 1, further comprising a stitching processing unit that performs a stitching process. A stage having a placement surface on which a workpiece is placed and driven in a first direction parallel to the placement surface and a second direction parallel to the placement surface while being orthogonal to the first direction facing the mounting surface of, detecting a distance from the slope and the reference plane of the mounting surface to the mounting surface with respect to the reference surface of the reference member and the workpiece placed on the mounting surface Measure the shape of the optical probe and detect the inclination of the orthogonal plane orthogonal to the optical axis of the optical probe driven in the third direction orthogonal to the mounting surface with respect to the reference plane and the distance from the reference plane to the orthogonal plane Step (a)
Detecting the tilt of the stage about an axis orthogonal to the reference plane, and detecting the tilt of the optical probe about the axis;
A shape measuring method comprising: The step (a)
The distance from the reference surface to the mounting surface is measured by three or more first length measuring devices provided on the reference surface, and three or more second measuring devices provided on the reference surface. Measuring a distance from the reference plane to the orthogonal plane by a length measuring device (a1);
The step (a2) of calculating the inclination of the mounting surface and the inclination of the orthogonal surface with respect to the reference surface from the measurement results obtained by the first and second length measuring devices. Shape measurement method.   The shape measuring method according to claim 7, wherein a gravity center position of the three or more first length measuring devices and a gravity center position of the three or more second length measuring devices respectively coincide with the optical axis. The step (b)
A first reflection facing the side surface of the first reflecting member from the side surface by two third length measuring devices provided on the side surface of the stage so as to be separated from each other along the longitudinal direction of the side surface. A second reflection is measured from the first side surface by one fourth length measuring device provided on the first side surface of the optical probe that measures the distance to the surface and is orthogonal to the orthogonal surface. One fifth member provided on the second side surface of the optical probe that measures the distance to the second reflecting surface facing the first side surface of the member and is orthogonal to the first side surface. A step (b1) of measuring a distance from the second side surface to a third reflecting surface facing the second side surface of the third reflecting member by a length measuring device;
From the measurement result obtained by the third length measuring device, the inclination of the stage around the axis is calculated, and the measurement result obtained by the fourth and fifth length measuring devices and the optical probe The shape measuring method according to claim 6, further comprising a step (b2) of calculating an inclination of the optical probe around the axis from a center position of a driving unit that moves the optical probe in the optical axis direction. (C) calculating a relative position and posture error between the stage and the optical probe from the inclination and distance of the mounting surface and the orthogonal plane with respect to the reference plane detected in the step (a); ,
Based on the relative position and orientation errors calculated in the step (c), the stitches are obtained by correcting and joining a plurality of shape data obtained by measuring the surface of the workpiece in units of minute regions by the optical probe. The shape measuring method according to claim 6, further comprising a step (d) of performing a bending process.

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