JP2006078303A - Control method of measuring apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the measurement time, required for simultaneously measuring a plurality of objects, to be measured. <P>SOLUTION: Measurement points indicating the destination of heads 20 and 22 are set, and on the basis of the coordinates of the set measuring points, a Y-axis driving part 26 is driven to move the whole heads 20 and 22 to the vicinity of the measurement points. Then images photographed by cameras mounted to the heads 20 and 22 are processed. On the basis of results of the processing, the heads 20 and 22 are each moved asymmetrically along a frame 12 for an X axis and moved slightly along a Y1S-axis or a Y2S-axis. The heads 20 and 22 are each positioned to the measuring positions. Then a PC30 processes the images imaged by the cameras 54 mounted to the heads 20 and 22, and micro-size of patterns of a flat panel 42 on a measuring table 18 are measured. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control method for a measuring apparatus that captures an image of an object to be measured as an object and processes an image obtained by the imaging to measure a minute dimension of the object to be measured.

  As an example of measuring the minute dimension of an object to be measured, for example, an X-axis frame slidably disposed on a guide rail extending in parallel, and this X-axis frame along the guide rail in the Y-axis direction. A Y-axis drive unit to be moved, a detection unit arranged to be slidable along the longitudinal direction of the X-axis frame, an X-axis drive unit to move the detection unit in the X-axis direction along the X-axis frame, A two-dimensional measuring machine has a light source unit that irradiates the object to be measured from below the detection unit and moves the detection unit in a two-dimensional direction to measure the line width of the pattern on the object to be measured. (See Patent Document 1).

Japanese Patent Laid-Open No. 7-12512 (pages 2 to 4, FIG. 1)

  In the conventional two-dimensional measuring machine, since the object to be measured is measured by one detection unit, even if a plurality of measurement parts are set on the object to be measured, a plurality of measurement parts can be measured simultaneously. Is not sufficient to shorten the measurement time.

  In order to shorten the measurement time, it is conceivable to employ a configuration in which a plurality of detection units are prepared and each detection unit is moved simultaneously to each measurement site. However, when preparing a plurality of detection units and simultaneously moving each detection unit to each measurement site, for example, simply configuring a drive system that drives each detection unit independently makes the configuration of the drive system complicated. However, depending on the configuration of the drive system, the detection units may interfere with each other, and may not be able to move the detection units to the measurement sites at the same time. In addition, it is necessary to sufficiently consider that a measurement part suitable for processing is extracted from a plurality of measurement parts (measurement points), and the extracted measurement parts are sequentially assigned as the movement destinations of the detection units.

  The present invention has been made in view of the above-mentioned problems of the prior art, and its purpose is to shorten the measurement time required to measure a plurality of measurement objects at the same time. When simultaneously measuring a plurality of measurement objects, measurement points suitable for movement are extracted from a plurality of measurement points indicating movement destinations of the plurality of heads, and are sequentially allocated to the respective heads.

  In order to achieve the object, in the control method of the measuring apparatus according to claim 1, a plurality of heads for imaging a pattern on the object to be measured, and a space facing the object to be measured are defined by the plurality of heads. As a moving region, a driving unit that moves the plurality of heads over the moving region, a control unit that controls driving of the driving unit, and an image obtained by imaging the plurality of heads, and a minute dimension related to the pattern When controlling a measuring apparatus including an image processing unit for calculating the measurement points, the measurement points indicating the movement destinations of the plurality of heads are set in association with the coordinates of the space, and the coordinates of the set measurement points are set. Based on this, the entire plurality of heads are moved along a one-dimensional direction in the space, and then the plurality of heads are moved along a one-dimensional or two-dimensional direction in the space. Each pattern is moved and positioned asynchronously, the pattern is imaged by the plurality of positioned heads, the pattern images obtained by the imaging of the plurality of heads are processed, and the minute dimension of each pattern is measured. The configuration.

  (Operation) When moving multiple heads to the specified measurement point, move the entire heads along a one-dimensional direction based on the coordinates of the measurement points, and then move the multiple heads to one or two dimensions. Since each head is moved asynchronously along the direction of positioning, the time required to move each head to the specified measurement point can be shortened. Measurement time (tact time Takt Time) required for measuring. In other words, the entire heads are moved to the vicinity of the measurement point, and then the heads are moved asynchronously and positioned at the position of the measurement point so that the heads can be quickly and accurately measured. Positioning can be performed, and the measurement time can be shortened.

  According to a second aspect of the present invention, there is provided a method for controlling the measuring apparatus according to the first aspect, wherein the plurality of heads are all one-dimensionally formed in the space based on the coordinates of the set measurement points. When moving along the direction, the plurality of heads pick up an image of the object to be measured and process an image of the picked-up image. The plurality of heads are positioned at positions corresponding to the set measurement points by moving the heads asynchronously along a two-dimensional direction.

  (Operation) When the whole of the plurality of heads is moved to the vicinity of the measurement point, the object to be measured is picked up by each head, and the image is processed. By moving along the direction or the two-dimensional direction, the plurality of heads can be accurately positioned at the positions of the measurement points, respectively. That is, when a plurality of heads move to the vicinity of the measurement point, the images picked up by the plurality of heads are processed, and each head is positioned by feeding back the processing results and positioning each head. Accurate positioning at the point.

  In order to achieve the other object, a measurement point distribution program according to claim 3 is a coordinate conversion for converting position information of a plurality of measurement points with respect to an object to be measured arranged in a moving area of a plurality of heads into machine coordinates. And a measurement point in which the distance from the origin of the machine coordinates changes along a straight line based on the coordinates of each measurement point coordinate-converted by the coordinate conversion means, sequentially extracted from the plurality of measurement points, First measurement point setting means for setting the extracted measurement point as a measurement point for one of the plurality of heads in association with a measurement order; and coordinates of each measurement point coordinate-converted by the coordinate conversion means On the basis of the measurement points, the measurement points existing at a position more than a certain distance from each measurement point sequentially set by the first measurement point setting means. A configuration for causing a computer to execute second measurement point setting means for sequentially extracting points from the plurality of measurement points and setting the extracted measurement points as measurement points for the other head in association with a measurement order; did.

  (Operation) Converts the position information of multiple measurement points with respect to the object to be measured into machine coordinates, and changes the distance from the origin of the machine coordinates along a straight line based on the coordinates of each measured measurement point. Sequentially extract from multiple measurement points, set the extracted measurement points as measurement points for one of the multiple heads in association with the measurement order, and then set a fixed distance from each set measurement point Since the measurement points that exist at the distant positions are sequentially extracted from a plurality of measurement points, and the extracted measurement points are set as measurement points for the other head in association with the measurement order, a plurality of measurement objects When measuring simultaneously, the measurement point with the shortest movement distance is extracted from multiple measurement points indicating the movement destinations of multiple heads Te, can be sequentially distributed to each of the heads, it is possible to contribute to shortening the measuring time.

  In a measurement point distribution program according to a fourth aspect, in the measurement point distribution program according to the third aspect, the first measurement point setting means is based on the coordinates of each measurement point transformed by the coordinate transformation means. The measurement point close to the origin of the machine coordinates or the measurement point close to the previously extracted measurement point is sequentially extracted from the plurality of measurement points, and the second measurement point setting means includes the first measurement point. Measurement points that exist within the maximum drive range of the other head and that are larger than the minimum distance that allows the proximity of the heads with reference to the coordinates of the measurement points sequentially set by the setting means Are sequentially extracted from the plurality of measurement points.

  (Operation) When setting the measurement point for one head, the measurement point close to the origin of the machine coordinates based on the coordinates of each coordinate point that has been transformed or multiple measurement points that are close to the previously extracted measurement point When the measurement points for the other head are set sequentially, the measurement points set for one head are within the maximum drive range of the other head and are close to each other. Since the measurement points that exist at a position larger than the minimum distance that allows the measurement are sequentially extracted from the multiple measurement points, each head can be quickly moved to the specified measurement point without interfering with each other. be able to.

  As is clear from the above description, according to the control method of the measuring apparatus according to the first aspect, it is possible to shorten the measurement time required to simultaneously measure a plurality of patterns.

  According to the second aspect, each head can be accurately positioned at a specified measurement point.

  According to the measurement point distribution program according to claim 3, the measurement point with the shortest moving distance can be extracted from a plurality of measurement points and can be sequentially distributed to each head, which contributes to shortening of the measurement time. Is possible.

  According to the fourth aspect of the present invention, each head can be quickly moved to a designated measurement point without interfering with each other.

  Next, embodiments of the present invention will be described based on examples. FIG. 1 is a perspective view showing an embodiment of a measuring apparatus according to the present invention, and FIG. 2 is a perspective view showing an embodiment of the measuring apparatus according to the present invention, showing a state when a head is omitted. FIG. 3 is a block diagram showing a measuring apparatus according to an embodiment of the present invention, FIG. 4 is a plan view of a flat panel, FIG. 5 is an enlarged plan view of a measurement pattern, and FIG. 6 is a fully closed view. FIG. 7 is a flow chart for explaining the operation of the measuring apparatus according to the present invention, FIG. 8 is an enlarged plan view when the center of the measurement pattern is deviated from the center of the image, and FIG. Is an enlarged plan view when the center of the measurement pattern is aligned with the center of the image, FIG. 10 is a flowchart for explaining the operation when the measurement points are rearranged in the measurement order, and FIG. 11 is an arrangement of a plurality of measurement points. It is a top view which shows an example of

  In these drawings, a multi-head length measuring machine 10 is a three-dimensional measuring apparatus, and includes an X-axis frame 12 arranged in parallel with the X-axis of XY coordinates (machine coordinates), and XY coordinates (machine coordinates). ) Are moved asynchronously (independently) to the pair of Y-axis frames 14, the base 16, the measurement table 18 fixed on the base 16, and the X-axis frame 12. A plurality of heads (detectors) 20 and 22 arranged as possible, an X-axis drive unit 24 for moving the heads 20 and 22 asynchronously (independently) along the X-axis direction, and the heads 20 and 22 A Y-axis drive unit 26 for moving the whole along the Y-axis direction, a Z-axis drive unit 28 for moving the heads 20 and 22 along the Z-axis direction asynchronously (independently), and each drive Two personal computers that perform calculations to control the drive Computers (hereinafter referred to as PCs) 30, 32, a display device 34 for displaying the processing results of the PCs 30, 32, a keyboard 36 for inputting various information to the PCs 30, 32, and driving units. And a control box 38 for indicating the driving direction of the camera.

  Sliding portions (not shown) are formed at both axial ends of the X-axis frame 12, and each sliding portion is configured to be slidable along each Y-axis frame 14. The X-axis frame 12 can be moved along the Y-axis direction by driving the Y-axis drive unit 26. The Y-axis drive unit 26 includes a plurality of Y-axis linear motor magnets 26a and Y-axis linear. It is comprised with the linear motor provided with the coil 26b for motors. When the coil 26b of the linear motor is energized and the energization amount and energization direction to the coil 26b are controlled by the PC 30, the X-axis frame 12 moves along the Y-axis direction (Y-axis frame 14). . That is, by driving the Y-axis drive unit 26, the entire heads 20 and 22 can move along the Y-axis direction as the X-axis frame 12 moves. In this case, the Y-axis drive unit 26 constitutes a main drive unit that moves the heads 20 and 22 along the Y-axis direction.

  The X-axis frame 12 is provided with an X-axis drive unit 24 for moving the heads 20 and 22 asynchronously (independently) along the X-axis direction (X-axis frame 12). The X-axis drive unit 24 includes a plurality of X-axis linear motor magnets 24 a arranged along the X-axis frame 12 and X-axis linear motor coils 24 b mounted on the heads 20 and 22. It is configured. The heads 20 and 22 can be moved asynchronously (independently) along the X-axis direction by controlling the energization amount and the energization direction for each coil 24b by the PC 30. In this case, the X-axis drive unit 24 constituted by a linear motor constitutes an X-direction auxiliary drive unit that moves the heads 20 and 22 asynchronously along the X-axis direction.

  The base 16 to which the X-axis frame 12 and the Y-axis frame 14 are fixed is supported by a plurality of frame bodies 40 fixed on the base, and the multi-head length measuring machine 10 is mounted on the base 16. A measurement table 18 constituting the machine coordinates (XY coordinates) is arranged. Both ends of the measurement table 18 are supported by table frames 18a, and a flat panel 42 as an object to be measured is mounted on the measurement table 18, for example, as shown in FIG. The flat panel 42 is formed in a substantially rectangular shape, and a plurality of liquid crystal monitors 44 are formed on the flat panel 42. Alignment marks M1 and M2 are formed on the upper and lower portions of the flat panel 42 on the left end side. In addition, measurement points (management points) P1 to P4 are set in each liquid crystal monitor 44, and as shown in FIG. 5, patterns PT1, PT2,. Is formed.

  The heads 20 and 22 are arranged so as to be movable along the three-dimensional direction in the moving region, with the space facing the liquid crystal monitor 44 arranged in the measured region of the flat panel 42 as the moving region of the heads 20 and 22. . Each of the heads 20 and 22 includes a reference camera unit 46 and a subordinate camera unit 48 as a head body. Each of the reference camera unit 46 and the subordinate camera unit 48 includes a lens barrel 50. In each lens barrel 50, the liquid crystal monitor 44 on the flat panel 42 is used as an object, and a pattern on the liquid crystal monitor 44 is imaged. As imaging means, an objective lens 52 and a camera 54 are accommodated. The objective lens 52 and the camera 54 have a function as an electron microscope, magnify and capture a pattern on the liquid crystal monitor 44, and transfer a signal related to the captured image to the PC 30 via a cable (not shown). It has become. Further, as the camera 54, for example, two 1 million pixel digital cameras are provided as a high magnification camera and a medium magnification camera, and two color cameras, a low magnification camera and a high field of view are provided. It is provided as a camera. The four cameras 54 are housed in the lens barrel 50, the cameras 54 in the reference camera unit 46 are connected to the image board 56 of the PC 30, and the cameras 54 in the subordinate camera unit 48 are respectively connected to the image board 58 of the PC 32. It is connected.

  Each lens barrel 50 has a Z-axis servo as a Z-direction auxiliary drive unit for moving the image pickup means along the Z-axis direction in accordance with control signals from the PCs 30 and 32 for focusing of the image pickup means. The motors 60 and 62 are connected to each other. In this case, one Z-axis servomotor 60 functions as a Z1-axis servomotor, the other Z-axis servomotor 62 functions as a Z2-axis servomotor, the objective lens 52 in one lens barrel 50 and a plurality of cameras. 54 can reciprocate along the Z1 axis, and the objective lens 52 and the plurality of cameras 54 in the other lens barrel 50 can reciprocate along the Z2 axis. The height of each head 20, 22 in the Z-axis direction, that is, the height from the measurement table 18 is detected by the scale 64, and the detected value is output to the PC 30 via the counter board 66 of the PC 30. ing.

  A plurality of autofocus devices 68 and 70 are provided in order to perform focusing by processing an image captured by each camera 54, and each autofocus device 68 and 70 is connected to the PC 30 via a connection terminal 72. Has been.

  Further, each head 20, 22 is responsive to a control signal from the PC 30, a Y-axis servo motor 74 as a Y-direction auxiliary drive unit that moves each head 20, 22 asynchronously along the Y-axis direction, 76 is provided. As a Y1S servomotor, the Y-axis servomotor 74 can reciprocate the head 20 by a minute range along the Y1S axis parallel to the Y-axis frame 14. The other Y-axis servomotor 76 is a Y2S servomotor, and can reciprocate the head 22 by a minute range along the Y2S axis parallel to the Y-axis frame 20.

  Here, in order to position the heads 20 and 22 in the X-axis direction with high accuracy, the X-axis drive unit 24 is configured with a full closed loop control system as shown in FIG. ing.

  Specifically, a plurality of magnets 24a are arranged in parallel with the X axis (X axis frame 12), and a linear guide 78 and glass for guiding the movement of each head 20, 22 in parallel with the X axis. A scale 80 is arranged. Each head 20, 22 is equipped with a position sensor (linear sensor) 82. Each position sensor 82 detects the scale of the glass scale 80 and outputs a detection signal to the scale counter 84. . The scale counter 84 counts the number of scales on the glass scale 80 in response to the detection signal of the position sensor 82, and outputs the count value to the monitor driver 86. The monitor driver 86 outputs position information of the heads 20 and 22 to the linear motor (24a) and the PC 30, and the PC 30 energizes the coil 24b on the heads 20 and 22 based on the position information of the heads 20 and 22. The amount and the energization direction can be controlled, and the positioning of the heads 20 and 22 in the X-axis direction can be controlled with high accuracy.

  Also, in the Y-axis drive unit 26, similarly to the X-axis drive unit 24, a full-closed loop control system is configured using a position sensor or the like, thereby positioning the heads 20 and 22 in the Y-axis direction with high accuracy. Can be done.

  On the other hand, the PC 30 and the PC 32 are connected to each other via a LAN (local area network). The PC 30 has a function as a control unit that controls driving of the X-axis drive unit 24, the Y-axis drive unit 26, and the Z-axis drive unit 28, and an image captured by the camera 54 mounted on the heads 20 and 22. And a function as an image processing unit that calculates a minute dimension related to the pattern on the liquid crystal monitor 44 based on the processing result. The PC 32 is configured to process an image captured by the camera 54 mounted on the head 22 and transfer the processing result to the PC 30.

  Further, when controlling the movement of the heads 20 and 22, the PC 30 sets the measurement points indicating the movement destinations of the heads 20 and 22 in association with the coordinates of XY, respectively, and based on the coordinates of the set measurement points. The heads 20 and 22 are moved along the one-dimensional direction, that is, the Y-axis direction, and when the heads 20 and 22 reach the vicinity of each measurement point, the heads 20 and 22 are moved in a one-dimensional direction, for example, X The heads 20 and 22 are respectively measured at measuring points by moving them asynchronously along the axial direction or the Y-axis direction, or moving asynchronously along two-dimensional directions, for example, the X-direction and the Y-axis direction, respectively. To the heads 20 and 22 that are positioned, process images processed by the cameras 54 mounted on the heads 20 and 22, and process the results. The minute dimension of the pattern on the liquid crystal monitor 44 is measured based on the result.

  Specifically, as shown in FIG. 3, the PC 30 includes a CIM application (computer integrated production application) 88, control software 90, control software 92, and system interface (SCAM) 94 as functions necessary for image processing and measurement. The PC 32 includes a system interface (SCAM) 96 as a function necessary for image processing and measurement. As a client for the control software 90, the CIM application 88 exchanges information with a host server, captures various information related to the production line system, and transfers information related to recipe specification and board number to the control software 90. The control software 90 is controlled remotely. The control software 90, as a client for each system interface (SCAM) 94, 96, outputs a measurement instruction for performing measurement by assigning a teaching macro to a measurement point, to each system interface (SCAM) 94, 96. An instruction for assigning one of the four cameras to the point is output to each system interface (SCAM) 94, 96. Further, the control software 90 is configured as a client for the control software 92, and outputs an operation instruction for instructing operations to the X-axis drive unit 24 and the Y-axis drive unit 26 to the control software 92.

  The system interface (SCAM) 94 outputs a command for selecting any one of the cameras 54 mounted on the head 20 to the reference camera unit 46 and displays an image from the selected camera 54 on the image board. 56, the captured image is processed, and a micro dimension regarding the pattern is calculated based on the processing result, and the head 20 is feedback-controlled based on the processing result. Operation support for the servo motor 62 is output to the control software 92. The system interface (SCAM) 96 outputs a command for selecting one of the cameras 54 mounted on the head 22 to the subordinate camera unit 48 and captures an image from the selected camera 54. In order to output the processing result to the control software 92 and feedback control of the head 22 based on the processing result, operation instructions for the X-axis drive unit 24 and the Y-axis servo motor 64 are sent to the control software 92. It is designed to output.

  The control software 92 is a control signal for driving the X-axis drive unit 24, the Y-axis drive unit 26, and the Z-axis drive unit 28 based on operation instructions from the control software 90 and system interfaces (SCAM) 94 and 96. And the generated control signal is output to the X-axis drive unit 24, the Y-axis drive unit 26, the Z-axis drive unit 28, and the like via the controller 98. Further, information on the height of the cameras in the heads 20 and 22 is acquired from the scale 64, an autofocus control signal is output to the autofocus device 68 or the autofocus device 70, and a control signal for performing autofocus is sent to the controller 98. Are output to the Z-axis servomotors 60 and 62. Further, the control software 92 generates an illumination control signal for the illumination device 100 provided in the heads 20 and 22, and outputs the illumination control signal to the illumination device 100 via the controller 98. The lighting device 100 mounted on each head 20, 22 illuminates the heads 20, 22 from below the heads 20, 22. In addition, between the system interface (SCAM) 94 and 96 and the control software 92, information for performing autofocus, information for controlling the illumination device 100, information for controlling each drive unit, and the like are sockets. It is done by communication.

  Next, a control method of the multihead length measuring machine 10 will be described with reference to the flowchart of FIG. First, when the operator performs an operation for opening a recipe file (step S1), the recipe file stored in the hard disk of the PC 30 is opened (step S2), and the contents of the recipe file are read into the control software 90. That is, information on a plurality of measurement points and measurement methods indicating the movement destinations of the heads 20 and 22 is read.

  Next, when the operator presses the execute button (step S3), the alignment measurement is performed in the control software 90 prior to moving the heads 20 and 22 to the first measurement point as an alignment process (step S4). ). In this alignment measurement, as shown in FIG. 4, in order to detect the positions of the alignment marks M1, M2 formed on the flat panel 42, for example, the head 20 is arranged at a position corresponding to the alignment marks M1, M1. Then, the Y-axis drive unit 26 is driven to move the X-axis frame 12 along the Y-axis direction, and the alignment marks M1 and M2 are sequentially imaged by the camera 54 mounted on the head 20, and an image obtained by this imaging is captured by the PC 30. The position of the flat panel 42 is determined based on the processing result.

  Then, a schedule process for rearranging the plurality of measurement points in the order of measurement is executed (step S5). When the measurement points related to the heads 20 and 22 are sequentially selected in the order of measurement, the position of the first measurement point and the teaching macro are first extracted (step S6). The position of the first measurement point and the teaching macro name are the control software. The data is transferred from the software 90 to the system interface (SCAM) 94 (step S7). In the system interface (SCAM) 94, a teaching macro is created based on the position of the first measurement point and the teaching macro name (step S8). That is, a process for converting the position of the first measurement point into XY coordinates is performed. When the processing for creating the teaching macro is completed, creation completion is transmitted from the system interface (SCAM) 94 to the control software 90 (step S9). The origin of the XY coordinates is provided on the lower left side of FIG. 1 for convenience, but may be the XY movement center.

  Next, as a process for moving the heads 20 and 22 to the vicinity of the first measurement point, the control software 90 determines the difference between the current position of the camera 54 mounted on the heads 20 and 22 and the first measurement point. Based on the above, a process for calculating the movement amount and the movement direction is executed (step S10), and the processing result is output to the control software 92. When the control software 92 executes the processing according to the processing result, the Y-axis drive unit 26 is driven as the coarse movement of the heads 20 and 22, and the entire heads 20 and 22 move along the X-axis frame 12. 20 and 22 move to the vicinity of the first measurement point (step S11).

  When the heads 20 and 22 are positioned near the first measurement point, the control software 92 commands the control software 90 to complete the movement (step S12).

  The control software 90 instructs the system interface (SCAM) 94 to perform a process for feedback control of the positions of the heads 20 and 22 (step S13). The system interface (SCAM) 94 processes the image from the camera 54 mounted on the head 20 to finely move the head 20, and the current position of the camera 54 on the X axis and the Y axis and the first measurement point. An operation instruction (operation command) for setting each difference to 0 is output to the control software 92 (step S14). At this time, the system interface (SCAM) 96 also processes the image from the camera 54 mounted on the head 22 in order to finely move the head 22, and the current position of the camera 54 on the X axis and the Y axis, the measurement point, An operation instruction (operation command) is output to the control software 92 in order to make each difference zero. The control software 92 generates a control signal for positioning the camera 54 mounted on the heads 20 and 22 at the first measurement point on the basis of an operation instruction from the system interface (SCAM) 94 and 96, and performs control. A signal is output to the X-axis drive unit 24 and the Y-axis servomotors 74 and 76, and the camera 54 mounted on the heads 20 and 22 is positioned at the first measurement point by fine movement of the heads 20 and 22 (step S15). .

  When the cameras 54 mounted on the heads 20 and 22 are positioned at the first measurement point, focusing is performed by moving the heads 20 and 22 in the Z-axis direction by driving the Z-axis servomotors 60 and 62. . When this focusing is performed, the pattern at the first measurement point is imaged by the cameras 54 of the heads 20 and 22, and the image obtained by this imaging is processed by the PC 30. In this case, as shown in FIG. 8, pattern matching between a pattern obtained by imaging and a registered pattern registered in advance is performed, and the center of the pattern (circle pattern) obtained by imaging is not at the center of the image. Then, the Y-axis servo motors 74 and 76 are driven and positioned so that the circle pattern becomes the center of the image as shown in FIG. Thereafter, the camera 54 captures the pattern of the first measurement point again, and processes the image obtained by the imaging. For example, as shown in FIG. 5, the micro-sized patterns PT1, PT2 at the measurement points P1, P2 The line width (line width on the order of several μm) is measured.

  When the measurement related to the first measurement points P1 and P2 is completed, a measurement completion is transmitted from the system interface (SCAM) 94 to the control software 90 (step S16). The control software 90 that has received the notification of the measurement completion determines whether or not the measurement for all the measurement points is completed (step S17), and when the measurement for all the measurement points is not completed, for example, the first After the measurement for the measurement point is completed, the process returns to step S5 as the process for measuring the second measurement point, and the processes from step S6 to step S17 are repeated. When the measurement for all the measurement points is completed, a signal for displaying the measurement completion is transmitted from the control software 90 to the display device 34 (step S18), and the processing in this routine is terminated (step S19). ).

  Next, schedule processing for rearranging measurement points in the order of measurement will be described with reference to the flowchart of FIG. First, alignment processing (processing similar to step S4) is performed (step S20), and then the measurement points P1 to Pn registered in the recipe file are converted into machine coordinates (step S21). Thereafter, the measurement point closest to the origin of the machine coordinates is registered in the rearrangement list as the first measurement point of the head 20 (step S22), and n = 1 is set (step S23). Thereafter, it is determined whether or not there is a measurement point that is not registered in the rearrangement list (step S24). In this case, as shown in FIG. 11, only the measurement point P1 among the measurement points P1 to Pn is registered in the first measurement point of the head 20, and the other measurement points are not registered in the rearrangement list. In step S25, the measurement point belonging to the maximum drive range in which the Y-axis servomotor 74 can finely move in the Y-axis direction is extracted with reference to the nth (first) measurement point P1 of the head 20. Thereafter, it is determined whether or not a measurement point satisfying the condition in step S25 has been extracted, that is, whether or not there is a measurement point serving as the first measurement point of the head 22 (step S26). When there is a measurement point, the minimum distance at which the head 20 and the head 22 can be brought close to each other in the X-axis direction with reference to the coordinates of the first measurement point P1 of the head 20 (proximity between the heads 20 and 22 is allowed. Measurement points existing in a range larger than (minimum distance) (step S27). Thereafter, it is determined whether or not a measurement point that satisfies the condition in step S27 has been extracted, that is, whether or not there is a measurement point that is the first measurement point of the head 22 (step S28).

  Next, when it is determined that there is a measurement point serving as the first measurement point of the head 22, it is determined whether there are an odd number of measurement points (step S29). For example, when three measurement points P2, P3, and P4 are extracted as existing measurement points, the center measurement point P3 among the three measurement points is the nth (first) measurement point of the head 22. Is registered in the rearrangement list (step S30).

  On the other hand, when there are a plurality of existing measurement points, for example, when there are four measurement points P2, P3, P4 and P5, the measurement point closer to the head 22 among the two central measurement points P3 and P4. Are registered in the rearrangement list as the nth (first) measurement point of the head 22 (step S31).

  On the other hand, when it is determined in step S26 that there is no measurement point that is the first measurement point of the head 22, that is, when a measurement point that satisfies the condition in step S25 is not extracted, or in step S28. When it is determined that there is no measurement point that is the first measurement point of the head 22, that is, when the measurement point that satisfies the condition in step S27 is not extracted, the measurement point for the head 22 is not extracted, and the head Assuming that simultaneous measurement using 20 and 22 is impossible, the nth (first) measurement point column of the head 22 is emptied (step S32).

  Next, it is determined whether or not all the measurement points are registered in the rearrangement list (step S33). When the first measurement point is registered, the process proceeds to step S34, where n = 2. Next, the measurement point closest to the (n-1) th point of the head 20 is set as the nth measurement point of the head 20 (step S35). That is, a measurement point whose distance from the origin of the machine coordinates changes along a straight line, and a measurement point closest to the first measurement point P1 of the head 20 is set as a second measurement point of the head 20. . For example, the measurement point P2 or the measurement point P6 is registered in the rearrangement list as the second measurement point of the head 20, and the process returns to step S24.

  In step S24, in this case, only the first measurement point of the heads 20 and 22 among the measurement points P1 to Pn is registered, and the other measurement points are not registered in the rearrangement list. Then, using the nth (second) measurement point of the head 20 as a reference, a measurement point belonging to the maximum drive range in which the Y-axis servomotor 74 can finely move in the Y-axis direction is extracted. Thereafter, the same processing is repeated until step S35, and when all the measurement points are registered in the rearrangement list, the processing in this routine is terminated.

  In the present embodiment, the position information of the plurality of measurement points P1 to Pn is converted into machine coordinates, and the distance from the origin of the machine coordinates is along a straight line based on the coordinates of the measurement points P1 to Pn that have been coordinate-converted. The changing measurement points are sequentially extracted from a plurality of measurement points, the extracted measurement points are set as measurement points relating to the head 20 in association with the measurement order, and then fixed from each measurement point set for the head 20. Since the measurement points existing at positions separated by more than the distance are sequentially extracted from the plurality of measurement points P1 to Pn, the extracted measurement points are set as measurement points related to the head 22 in association with the measurement order. The measurement point with the shortest movement distance is extracted from the plurality of measurement points P1 to Pn indicating the movement destinations of the heads 20 and 22. Can be sequentially distributed to each of the heads 20 and 22, it is possible to contribute to shortening the measuring time.

  In the PC 30 in the present embodiment, when performing the rearrangement process of the plurality of measurement points P1 to Pn, the coordinate conversion means for converting the position information of the plurality of measurement points P1 to Pn into machine coordinates, and the coordinates by the coordinate conversion means. Based on the converted coordinates of each measurement point, measurement points whose distance from the origin of the machine coordinates changes along a straight line are sequentially extracted from the plurality of measurement points P1 to Pn, and the extracted measurement points are extracted from one head. First measurement point setting means that is set as a measurement point related to 20 in association with the measurement order, and sequentially set by the first measurement point setting means based on the coordinates of each measurement point coordinate-converted by the coordinate conversion means. A measurement point existing at a position more than a certain distance from each measurement point is selected from a plurality of measurement points P1 to Pn. Next, a measurement point distribution program is executed to cause a PC (computer) 30 to execute second measurement point setting means that extracts and sets the extracted measurement points as measurement points relating to the other head 22 in association with the measurement order. Will be.

  In this case, as the first measurement point setting means, a plurality of measurement points close to the origin of the machine coordinates based on the coordinates of each measurement point coordinate-converted by the coordinate conversion means or a plurality of measurement points close to the previously extracted measurement point are used. The second measurement point setting means is configured to sequentially extract from the measurement points P1 to Pn, and the other head 22 is used as the second measurement point setting means with reference to the coordinates of the respective measurement points sequentially set by the first measurement point setting means. The measurement points that exist within the maximum drive range and that exist at a position larger than the minimum distance that allows the heads 20 and 22 to approach each other are sequentially extracted from the plurality of measurement points P1 to Pn. Can do. As a result, the heads 20 and 22 can be quickly moved to designated measurement points without the heads 20 and 22 interfering with each other.

  In this embodiment, when the heads 20 and 22 are moved to the respective measurement points, the heads 20 and 22 are moved along the Y-axis direction to the vicinity of the respective measurement points, and then the camera 54 mounted on the heads 20 and 22 is used. Since the heads 20 and 22 are moved asynchronously along the X-axis direction based on the image of the above-described imaging, and the heads 20 and 22 are moved and positioned asynchronously along the Y1S axis or the Y2S axis, respectively, Each head 20, 22 can be quickly moved to a specified measurement point. When the measurement point is reached, the tact time can be shortened by simultaneously measuring the minute dimensions of the pattern at each measurement point using the heads 20 and 22, respectively.

  Further, in the pattern matching between the pattern obtained by processing the captured image using the camera 54 mounted on the heads 20 and 22 and processing the captured image, there is a slight deviation between the two. In some cases, the deviation can be corrected by moving the head 20 or the head 22 in which the deviation is detected along the Y1S axis or the Y2S axis by driving the Y axis servo motor 74 or 76 by a minute range.

It is a perspective view which shows one Example of the measuring apparatus which concerns on this invention. It is a perspective view which shows one Example of the measuring apparatus which concerns on this invention, Comprising: It is a perspective view which shows a state when a head is abbreviate | omitted. It is a block block diagram which shows one Example of the measuring apparatus which concerns on this invention. It is a top view of a flat panel. It is an enlarged plan view of a measurement pattern. It is a block diagram of a fully closed loop control system. It is a flowchart for demonstrating the effect | action of the measuring apparatus which concerns on this invention. It is an enlarged plan view when the center of the measurement pattern is shifted from the center of the image. It is an enlarged plan view when the center of the measurement pattern is aligned with the center of the image. It is a flowchart for demonstrating an effect | action when rearranging a measurement point in order of a measurement. It is a top view which shows an example of the arrangement | sequence of several measurement points.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Multihead length measuring machine 12 X-axis frame 14 Y-axis frame 16 Base 18 Measurement table 20, 22 Head 24 X-axis drive part 26 Y-axis drive part 28 Z-axis drive part 30, 32 PC
42 Flat panel 44 LCD monitor 54 Camera 60, 62 Z-axis servo motor 74, 76 Y-axis servo motor

Claims (4)

  A plurality of heads for imaging a pattern on the object to be measured, and a drive unit that moves the plurality of heads over the movement area, with a space facing the object to be measured as a movement area of the plurality of heads; In controlling a measuring apparatus including a control unit that controls driving of the driving unit and an image processing unit that processes images captured by the plurality of heads to calculate a minute dimension related to the pattern, the plurality of heads The measurement points indicating the movement destinations are respectively set in association with the coordinates of the space, and the plurality of heads are moved along a one-dimensional direction of the space based on the coordinates of the set measurement points. Thereafter, the plurality of heads are moved and positioned asynchronously along one-dimensional or two-dimensional directions in the space, respectively, and the plurality of heads are positioned. The pattern is imaged, respectively, by processing the image of the pattern by imaging the plurality of heads respectively, a control method of a measuring device and measuring the critical dimension of the respective patterns.   2. The control method of the measurement apparatus according to claim 1, wherein the plurality of heads are moved along a one-dimensional direction in the space based on the coordinates of the set measurement points. The image of the object to be measured is picked up by a head and an image by the picking up is processed, and the plurality of heads are moved asynchronously along a one-dimensional direction or a two-dimensional direction in the space based on the processing result. A method of controlling a measuring apparatus, wherein the plurality of heads are positioned at positions corresponding to the set measurement points.   Based on the coordinate conversion means for converting the position information of the plurality of measurement points with respect to the object to be measured arranged in the movement areas of the plurality of heads into machine coordinates, and the coordinates of each measurement point coordinate-converted by the coordinate conversion means A measurement point whose distance from the origin of the machine coordinate changes along a straight line is sequentially extracted from the plurality of measurement points, and the extracted measurement point is used as a measurement point for one of the plurality of heads in the measurement order. Based on the first measurement point setting means to be set in association with each other and the coordinates of each measurement point coordinate-converted by the coordinate conversion means, it is fixed from each measurement point sequentially set by the first measurement point setting means. The measurement points present at positions that are more than or equal to the distance are sequentially extracted from the plurality of measurement points, and the extracted measurement points are Measurement points sorting program for executing a second measuring point setting means for setting in association with the measurement order as the measurement point for the other of the head to the computer.   4. The measurement point distribution program according to claim 3, wherein the first measurement point setting means is a measurement point close to the origin of the machine coordinates based on the coordinates of each measurement point coordinate-converted by the coordinate conversion means or the previous time. Measurement points close to the extracted measurement points are sequentially extracted from the plurality of measurement points, and the second measurement point setting unit is configured to coordinate the measurement points sequentially set by the first measurement point setting unit. The measurement points that are within the maximum driving range of the other head and are located at a position that is larger than the minimum distance allowing the proximity of each head are sequentially extracted from the plurality of measurement points. A measurement point distribution program characterized by

Images