TWI438394B - Three-dimensional measurement method - Google Patents

Description

3-dimensional measurement method

The present invention relates to a three-dimensional measurement method for measuring a shape using a probe or the like. In particular, in the measurement of a wafer lens or the like in which a plurality of lenses are formed on a lower surface of a light-transmissive wafer, a positioning mark for positioning on a wafer is measured using a camera provided in a three-dimensional measuring machine. On the other hand, for the positioning mark measured by the camera, the three-dimensional measurement method of the lens center position measured by the measuring rod or the like is accurately obtained.

Camera functions are added to mobile devices such as mobile phones and PDAs, and the demand for small, inexpensive cameras is skyrocketing. The performance of the cameras used in such cameras is also increasing for the requirements of high pixelation. Previously, the lens used in these mobile machines was equipped with 10~15 lens molds in the molding machine, and 10 to 15 lenses were produced per shot. This method is not easy to cope with the increase in production quantity and low cost. Chemical. Therefore, in such fields that require low cost and a sharp increase in the number of productions, it is desired to form hundreds to thousands of lenses on one wafer, and laminate a plurality of the formed wafers, and then cut them after lamination. The technology of manufacturing wafer lens manufacturing.

The structure of the wafer lens is shown in FIG. It forms a lens 102 on the lower surface of the wafer 101, and forms a plurality of positioning marks 103 for positioning on the periphery of the upper surface. The wafer 101 is laminated so that the alignment marks 103 overlap, and the lens unit is completed.

If the center position of the lens 102 is deviated on the front and back surfaces of the wafer 101 which constitutes one lens unit of the lens unit, or the multilayer wafer 101 is laminated In the case where the center position of the mirror unit is deviated based on the positioning marks on the respective wafers 101, problems such as blurring of the image and inability to obtain optical performance are caused.

On the other hand, in the production of such a wafer lens, a method of matching the position of the glass substrate and the master mold for forming the photocurable resin is disclosed in Patent Document 1. FIG. 14 shows a procedure of the position matching method described in Patent Document 1.

In Fig. 14, reference numeral 104 is a positioning mark of the mother die 109, and reference numeral 105 is a positioning mark of the glass substrate 107. Symbol 106 is a camera that measures the position of the positioning mark.

The mother die 109 and the glass substrate 107 are superimposed so that the height of the camera 106 is moved up and down, and the positioning marks 104 and 105 on the upper and lower surfaces are focused to match the XY positions of the marks.

Specifically, as shown in FIG. 14 , in the camera 106 that can only move up and down, the focus is aligned with the positioning mark 105 from above the glass substrate 107 (see (1) in FIG. 14 ). Thereafter, the camera 106 is moved upward, and the mother die 109 is placed at a position between the camera 106 and the glass substrate 107, and the height position of the camera 106 is adjusted while the focus position thereof is positioned with the positioning mark 104 of the master 109 or It is identical in the vicinity (refer to (2) in Fig. 14).

In this case, for example, if it is assumed that the positioning mark 105 that is first aligned with the focus and the positioning mark 104 that is in focus with the focus are in the state shown in the upper stage of FIG. 15, the mother die 109 is moved in the horizontal direction (refer to FIG. 15). The lower stage) is to a position where the positioning mark 104 coincides with the positioning mark 105 of the glass substrate 107, and in this state, it is pressed against the glass substrate to which the photo-curing resin is applied in advance (see The mother mold 109 is irradiated with light according to (3) in Fig. 14 to form a lens.

[Prior technology] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2010-72665

As described above, if the center position of the lens 102 on the upper surface of the upper surface of the wafer 101 of the wafer lens is deviated or the center position of the lens based on the positioning mark on each wafer 101 is laminated, the optical performance is lowered. In order to eliminate or reduce such deviations, it is required to measure the center position of the lens based on the positioning mark with as high precision as possible.

However, even if the positioning method described with reference to FIGS. 14 and 15 is applied to the measurement of the center position of the lens based on the positioning mark, it is difficult to perform measurement with high precision. This point will be described below.

When the movement mechanism (not shown) for moving the camera 106 in the Z direction of the wafer surface is used, the Z direction of the camera is moved from the focus position of the registration mark 105 on the front side of (1) of FIG. 14 to (2) of FIG. The focus position of the positioning mark 104 on the back side causes a positional deviation of the unillustrated platform that moves the camera 106 in the Z direction with respect to the Y direction or the Y direction perpendicular to the paper surface. Therefore, if the Z height of the camera is changed, the position of the positioning mark cannot be measured with high precision.

In the case where the center position of the lens on the front and back sides of the wafer 101 shown in FIG. 13 is measured, for example, the posture of the wafer 101 is first set so that the front surface on which the positioning mark 103 is provided becomes the upper surface. To make the camera 106 on the wafer After adjusting the Z height by measuring the surface of the upper surface of 101 and measuring the positioning mark 103, the center position of the lens is measured by the probe based on the positioning mark. Thereafter, the posture of the wafer 101 is turned upside down, the Z height of the camera is changed, and the focus is changed to the Z height position of the positioning mark 103 on the lower surface of the wafer 101, and the probe is used as a reference. Determine the center position of the lens.

When the camera 106 is moved in the Z direction of the wafer surface by a moving mechanism (not shown), a positional deviation of the unillustrated platform that moves the camera 106 in the Z direction with respect to the X direction or the Y direction perpendicular to the paper surface is caused. Thus, an error in which the center position of the X direction or the Y direction of the camera 106 is slightly deviated is generated. As a result, the center position of the lens measured by the probe based on the measured positioning mark is deviated from the front side and the back side. Thus, when the center of the lens of the front side and the back side is calculated based on the positioning mark, the center position of the X or Y direction of the camera 106 slightly deviates from the error, and the front and back sides of the wafer 101 cannot be accurately measured. The center of the lens.

The present invention has been made in view of the above problems, and an object thereof is to provide a three-dimensional measurement method for measuring the shape of an object to be measured with high precision.

In order to achieve the above object, a three-dimensional shape measuring method according to the present invention is a three-dimensional measuring method for obtaining surface shape data of an object to be measured by two or more surface detecting means, which is characterized in that it is provided separately from the object to be measured. The height in the Z direction of the calibration positioning mark that does not move relative to the object to be measured in the XY direction is equal to the surface height of the object to be measured; and the height is consistent by the two or more surface detecting means. The calibration positioning mark; the result of the measurement described above is used to correct the offset in the XY direction of the two or more surface detecting means; and the surface shape data and the surface of the object to be measured measured by the two or more surface detecting means are used. The above-described offset of the correction is performed to obtain the surface shape of the object to be measured.

Preferably, the surface detecting mechanism includes a measuring rod for surface shape measurement provided on a first Z-direction moving mechanism that moves in the Z direction on an XY stage that moves in the XY direction, and moves in the Z direction on the XY stage. a camera that measures an image in the XY plane provided in the second Z-direction moving mechanism; and the calibration positioning mark that matches the surface height of the object to be measured is captured by the camera, and is measured by the probe, and the photographing is performed according to the photographing And correcting the deviation between the measuring rod and the center position of the camera by the measurement result; measuring the surface shape of the object to be measured by the measuring rod; and using the measurement result obtained by using the measuring rod and the corrected offset, The surface shape of the above-mentioned object to be measured is obtained.

More preferably, the surface shape of the object to be measured by the measuring rod is measured once in the X direction of the lens surface so as to pass near the vertex position of each lens surface on the object to be measured, and further The measurement is performed once in the Y direction by the vicinity of the vertex position of the lens surface; and according to the above-described measurement data, the measurement data is divided for each lens according to the X-direction and the Y-direction distance of the lens, and The lens segmentation data is used to evaluate the shape and the XYZ position and orientation of the lens center.

For example, the object to be measured is a wafer lens in which a plurality of lenses are formed on a thin plate.

According to the three-dimensional measurement method of the present invention, the shape of the object to be measured can be measured with high precision. For example, the center position of the lens of the front and back of the wafer lens can be measured with high precision by positioning the mark as a reference. That is, a positioning mark is formed on the back side of the wafer, and the camera is used to measure the position mark on the front side of the wafer without unevenness, or the wafer is measured on the wafer based on the positioning mark measured only by the camera on the wafer. In the case of the center of the lens, the position of the lens can be measured based on the positioning mark by using the corrected offset value between the center position of the camera and the measuring rod, and the positioning mark for high-precision assembly is used as a reference. Measurement of the position of the lens on the wafer.

Thereby, by measuring the lens shape of the upper surface of the upper surface of the wafer on the wafer, and calculating the positional deviation under the reference mark, the lens on the wafer can be accurately measured with the positioning mark as a reference. The position of the center of the optical axis is deviated.

Further, since the deviation from the central axis of each of the upper and lower surfaces of the positioning mark can be calculated individually, the deviation of the central axes of the respective lenses on the upper and lower surfaces can be measured with high precision.

Further, by separating the primary measurement data in the X direction and the Y direction near the vertex positions of the respective lens faces on the object to be measured into the respective data of the lenses, the ternary shape can be evaluated with high accuracy and speed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)

1) Description of the device configuration of the 3-dimensional measuring machine used

Fig. 1 is a perspective view showing a schematic configuration of a shape measuring device as an embodiment for carrying out the shape measuring method of the present invention. In Fig. 1, a frequency-stabilized He-Ne laser 4 for measuring the position of the XYZ coordinate is placed on the stone plate 14 on the XY stage 3, and the probe is attached to the stone plate 14 via the Z1 axis platform 2, and stabilized by the vibration frequency. The He-Ne laser light reflects the X reference mirror surface 5, the Y reference mirror surface 6, and the Z reference mirror surface 7 having a fixed flatness of the nanometer level, whereby the XYZ coordinates can be measured with high precision on the nanometer level.

These units are controlled by a computer 41 as a control calculation unit, and are combined with a three-dimensional measuring machine to perform automatic operation.

Further, the shape measuring device is constituted by a camera 8 that measures the position of the positioning mark, a Z2-axis stage 9 that moves the camera 8 in the Z-axis direction, and a center position of the front end of the correction probe 1 and a center position of the image of the camera 8. The offset distance correction positioning mark 10; the Z3 axis stage 11 for moving the correction positioning mark 10 in the Z-axis direction; the wafer lens 12 as a measuring object; and the wafer chuck 13 of the wafer lens 12. In Fig. 1, the clockwise rotation in the + direction of the X-axis is taken as A, the clockwise rotation in the + direction of the Y-axis is taken as B, and the clockwise rotation in the + direction of the Z-axis is made as C. Description.

The configuration of the probe used in the shape measuring device is shown in Fig. 2 . In Fig. 2, the spindle 18 is supported by a micro air slider 15, and the movable portion of the micro air slider 15 is supported by a microspring 16. The deflection of the microspring is measured by the focus detecting laser 19 irradiated onto the mirror surface of the micro air slider 15, and the weak interatomic force acting on the front end of the measuring object 17 and the measuring rod 18 becomes a certain manner. The probe unit 20 is controlled by a linear motor (not shown) on the Z side. Towards the location. At the same time, the above-described frequency-stabilized He-Ne laser light 21 is irradiated onto the mirror surface 22 by displacement in the Z direction, and the position in the Z direction is measured. In this state, the entire probe unit was scanned in the XY direction, and the shape of the measurement surface was measured. According to this configuration, the weight of the movable portion of the micro air slider 15 which is the movable portion to which the measuring rod 18 is attached can be reduced, and the high inclined surface having a maximum height of 75° can be measured with high precision.

In the shape measuring apparatus, the probe 1 is scanned in the XY direction on the surface of the measuring object 17, and the XYZ coordinate data line on the measuring object is obtained, and the computer 41 is used as a control computing unit (not shown). The shape of the Z-coordinate data at the XY coordinate position of the needle 1 is measured, and the shape of the measurement object 17 is measured.

2) Principle of measurement method

Figure 3 is a schematic diagram showing the principle of the measurement mode of the present invention. In FIG. 3, in order to measure the probe 1 in the Z direction with high precision, the Z1 axis stage 2 which drives the probe 1 in the Z-axis direction is provided in the XY stage 3 which scans the probe 1 in the XY direction. Further, on the XY stage 3, a Z2-axis stage 9 for driving the camera 8 for positioning marker measurement in the Z-axis direction is provided. The camera 8 for positioning mark measurement is disposed at a position shifted in the XY direction with respect to the probe 1. The distance (center-to-center distance) Xo from the center of the probe 1 and the center of the camera 8 according to the offset is the XY direction caused by the movement of the camera 8 in the Z-axis direction caused by the position on the Z2-axis stage 9. The position of the position changes slightly.

Further, the shape measuring device is configured by a wafer card 12 (refer to FIG. 4 together) which is a measuring object of a circular substrate having a diameter of about 200 mm. a disk 13; a gamma stage 23 for rotating the entire wafer chuck 13 about the Z axis; and an alignment mark 29 for XY position on the wafer lens 12 specifically disposed on the wafer chuck 13 and marking Identification device not shown in the pattern detection.

Further, the calibration positioning mark 10 for shifting the center position of the probe 1 for calibration measurement to the center of the camera 8 is placed on the Z3 axis stage 11 which is movable in the Z direction on the stone plate 24 of FIG. As will be described later in detail, the correction is performed by measuring the calibration positioning mark 10 with the probe 1 and the camera 8.

A wafer lens 12 as an object to be measured is shown in FIG. On the wafer lens 12, the lens 34 is formed in a lattice shape at substantially a certain predetermined distance in the respective directions of X and Y. Specifically, a lens 34 is formed at the same position on both the A surface and the B surface of the wafer lens 12. Further, two or more positioning marks 29 are formed at specific positions on the A side of the wafer lens 12.

The correction positioning marks 10 are shown in Figs. 5(a) and (b). In the present embodiment, the alignment mark 10 for correction is used for the chrome mask substrate for semiconductor production in which a chromium film 26 of about 0.1 μm is vapor-deposited on the glass substrate 25. In the center of the chrome film 26, a etched portion 27 having a square shape having a size of about 1 mm square is provided. The chrome film 26 is removed by the etching portion 27 to expose the glass substrate 25.

3) Summary of measurement methods

Fig. 6 shows the overall flow of the measurement of the 3-dimensional measurement method according to the present invention.

The measurement is started in step 201, and a processing program is set in the computer 41, that is, a computer program for automatically performing a series of measurement procedures. In the processing program, input the design shape of the wafer lens 12 to be measured. Shape, wafer size, design of the lens 34 on the wafer lens 12, the pitch between the centers of the lenses in the X and Y directions, the lens arrangement on the wafer lens 12, and the measurement speed of the probe 1 during the measurement, 2 The information required for measurement such as the position of the positioning mark 29 is measured, and measurement preparation such as setting of measurement conditions is performed, and measurement is started thereafter.

The wafer lens 12 measured in step 202 is placed on the wafer chuck 13 of the shape measuring device so as to be on the side of the A surface (the surface on which the positioning mark 29 is provided). The wafer lens 12 is manually positioned on the wafer chuck 13 of the shape measuring device and fixed, and is adsorbed by a vacuum suction mechanism (not shown).

Thereafter, in accordance with step 203, the XY position of the camera 8 is moved by a drive mechanism (not shown) of the XY stage 3 so as to be positioned above the positioning mark 29 of the A side of the wafer lens 12 provided in step 202. Thereafter, the focus of the camera 8 is such that the height L1 of the positioning mark 29 on the wafer on the front side of the wafer lens 12 as the object to be measured shown in FIG. 3 is displayed on the monitor of the computer 41 (not shown). The image of the camera 8 is monitored and adjusted in the Z direction to match the height of the Z2 axis platform 9 for camera height adjustment.

In step 204, the focus height position of the camera 8 adjusted in step 203 is continuously maintained, and the camera 8 is moved by the XY stage 3 to be positioned above the correction positioning mark 10. Next, the state in which the fixed camera 8 is not moved in either of the XYZ directions is continuously maintained, so that the height of the Z3 axis stage 11 is adjusted so that the focus of the camera 8 is aligned with the correction positioning mark 10. As a result of this adjustment, the height L2 of the marking surface of the correction positioning mark 10 coincides with the height L1 of the positioning mark 29 of the front surface (A surface) of the wafer lens 12 as the object to be measured.

In step 205, the calibration positioning mark 10 is measured by the camera 8 adjusted by the procedures of the above steps 201 to 204, and the calibration positioning mark 10 is also measured by the probe 1, and the probe 1 and the camera 8 are executed based on the measurement result. The measurement of the distance Xx between the centers (correction of the center position of the probe 1 and the camera 8).

In step 206, the position of the two positioning marks 29 provided on the wafer lens 12 is measured using the camera 8 and the XY stage 3, and the center position of the positioning mark 29 is memorized. The rotation deviation angle γ of the wafer lens 12 with respect to the coordinates of the shape measuring device (fixed XYZ coordinate system) was measured based on the two positioning mark positions measured as described above.

In step 207, the wafer lens 12 is rotated by the gamma stage 23 disposed at the lower portion of the wafer chuck 13 by the amount of the rotation deviation angle γ measured so as to be parallel to the X reference mirror 5 and the Y reference mirror of the shape measuring device. 7 ways to adjust.

In step 208, it is confirmed whether or not the value of the rotational deviation angle γ is within a predetermined range with respect to a predetermined value set in advance. If it is within the range, the process proceeds to step 209. If it is outside the range, the process from step 206 is repeated.

In step 209, the entire area of the A face of the wafer lens 12 is measured in one continuous direction in the X direction and the Y direction in a continuous shape so that the probe 1 passes through the center of each lens on the wafer lens 12.

In step 210, the measurement data in the two directions of the X direction and the Y direction measured in step 209, the position of the two positioning marks 29 obtained by the step of step 206, and the probe 1 obtained in step 205 are used. The center-to-center distance of the camera 8 is calculated based on the positioning mark 29 to calculate the center of each lens 34 on the wafer lens 12.

In steps 211 to 219, the same is repeated for the B plane of the wafer lens 12. Reason.

First, in step 211, the wafer chuck 12 is mounted on the wafer chuck 13 so that the front and back of the wafer lens 12 measured in the above-described steps are reversed with the Y axis as the rotation axis and the B surface is placed thereon.

According to step 212, the focus height of the camera 8 is adjusted by the Z2 axis platform 9 at the position of the positioning mark 29 on the lower side.

According to step 213, the Z3 axis stage 11 is adjusted to maintain the focus of the camera 8 in alignment with the correction positioning mark 10 while maintaining the focus height position of the camera 8 adjusted by the Z2 axis stage 9 in the step of 212.

In step 214, by using the calibration positioning mark 10, the procedure of steps 211 to 213 is adjusted to measure the distance XoB between the center of the camera 8 and the center of the probe 1 which is slightly deviated in the XY direction.

In steps 215 to 218, the same processing as steps 206 to 209 is performed in the above-described setting state.

In step 219, the measurement data in the two directions of the X direction and the Y direction measured in step 218, the positions of the two positioning marks 29 obtained in the step of step 215, and the probe and camera obtained in step 214 are used. The center-to-center distance of 8 is calculated based on the positioning mark 29 to calculate the center of each lens 34 on the wafer lens 12.

In step 220, the center deviation of the wafer lens 12 from the opposite side of the lens 34 is calculated by the calculation process based on the center position of each lens 34 on the A side and the center position of each lens 34 on the B side.

The measurement is ended at step 221 .

2) Details of the measurement method

Hereinafter, the details of the procedure described in FIG. 6 will be described in order.

In step 205, based on the positional relationship between the positioning mark 29 on the wafer lens 12 and the correction positioning mark 10 adjusted by the procedures of steps 201 to 204, the center of the probe 1 and the camera 8 are measured using the calibration positioning mark 10. The distance is XoA.

Hereinafter, details of the correction procedure for correcting the center position of the probe and the camera using the above-described calibration positioning mark will be described.

First, the center position (Xc, Yc) of the correction positioning mark 10 is calculated by the following procedure using the camera 8.

After the adjustment of the Z3 axis stage 11 of step 204, the camera 8 is moved by the XY stage 3 at the mark center position of the correction positioning mark 10.

Thereafter, the image shown in FIG. 7 is obtained by the camera 8 as the etching portion 27 for the correction positioning mark 10.

Here, the center position of the square-shaped etching portion 27 is calculated by the following procedures 1 to 5.

In the X-axis direction of the etching unit 27, the intersection position X1L and X1R of the etching portion 27 is obtained from the data of the X measurement line 30, and the intersection position X2L with the etching portion 27 is obtained from the data of the X measurement line 31, X2R.

In the Y-axis direction of the etching unit 27, the intersection position Y1D and Y1U with the etching unit 27 is obtained based on the information of the Y measurement line 32, and the intersection position Y2D with the etching portion 27 is obtained based on the information of the Y measurement line 33, Y2U.

Procedure 3: The center line 35 is measured in the Y direction, that is, the longitudinal line connecting the longitudinal direction of the etching portion 27 of the intersection position X1L and the intersection position X2L and the longitudinal line of the etching portion 27 connecting the intersection position X1R and the intersection position X2R. .

Procedure 4: Determine the X-direction measurement center line 34, that is, the average line connecting the horizontal line of the etching portion 27 of the intersection position Y1D and the intersection position Y2D and the transverse line connecting the intersection portion Y1U and the etching portion 27 of the intersection position Y2U. .

Procedure 5: The mark center position (Xc, Yc) is obtained, that is, the intersection of the center line 34 and the Y direction measurement center line 35 is measured in the X direction.

Hereinafter, details of the calculation procedure of the center position of the etching portion 27, that is, the mark center position (Xc, Yc) will be described. In the following calculation, the gradation image of the chrome film 6 including the entire etched portion 5 is extracted based on the CCD data of the camera 8.

Here, the measurement data are extracted from the two measurement sections on the X-axis as the X measurement line 30 and the X measurement line 31. The data shown in Fig. 8 is the concave-convex shape generated by the shading, and the central portion of the unevenness of the shading image is used as a threshold value, and the position in the Y direction of the edge position is captured, that is, the XY shown in Fig. 7. The position of the vector table of the direction, the intersection of the thresholds of the X measurement line 30 is expressed as X1L = (X1Lx, X1y), and X1R = (X2Lx, X2y). Similarly, the intersection vector of the threshold values on the X measurement line 32 is represented as X2L, X2R. Similarly, the intersection positions Y1U, Y1D, Y2U, and Y2D of the thresholds of the total of four points of the Y measurement line 32 and the Y measurement line 33 in the two directions in the Y-axis direction are obtained in the same manner.

Thereafter, the midpoint is calculated based on the following equation using the symbol shown in FIG.

[Number 1] X1C=(X1L+X1R)/2 X2C=(X2L+X2R)/2

Also, define the following vector XV.

[Number 2] XV=X1C-X2C

Using this vector XV, if t is a scalar, the equation of the X measurement center line 34 becomes the following equation (1).

[Number 3] XL = t ^* XV + X1C... (1)

Similarly, the equation for the Y measurement center line 35 is expressed using the scalar s as shown in the following equation (2).

[Number 4] YL=s ^* YV+Y1C.........(2)

YV=YUC-YDC

YUC=(Y1U+Y2U)/2

YDC=(Y1D+Y2D)/2

Since the mark center is the intersection of the lines 34 and 35 represented by the equations XL and YL, if t and s are calculated according to the formula (1)=(2), the mark center is obtained.

The equation XL, that is, the equation (1) and the equation YL, that is, the equation (2), can be changed to the following equations (1)', (2)', respectively.

[Number 5] XLX=t ^* XVX+X1CX, XLY=t ^* XVY+X1CY... (1), YLX=s ^* YVX+Y1CX, YLY=s ^* YVY+Y1CY... (2), according to ( 1) The equations (3) and '(2)' give the following equations (3) and (4).

[Number 6] t ^* XVX + X1CX = s ^* YVX + Y1CX... (3) t ^* XVY + X1CY = s ^* YVY + Y1CY... (4)

The following equation (5) is obtained for the equations (3) and (4) of the t solution.

[Equation 7] t={(Y1CX ^* YVY-Y1CY ^* YVX)-(X1CX ^* YVY-X1CY ^* YVX)}/(XVX ^* YVY-XVY ^* YVX).........(5)

Substituting the value of t obtained by the equation (5) into the equation (1) to find the intersection point, that is, the marker center (Xc, Yc) = Xc = t * XV + X1C. Further, even if the value of s obtained by the equations (3) and (4) is substituted into the equation (2), the marker center (Xc, Yc) can be obtained.

The position of the positioning mark in the range of the image of the camera is calculated by detecting the edges of the two directions in the X-axis direction and the Y-axis direction by the above-described calculation program.

By calculating the center of the X position and the Y direction of the edge position of the positioning mark 10, even if the correction positioning mark is slightly inclined with respect to the X or Y direction of the measuring machine, the positioning mark for correction can be accurately obtained. Center (Xc, Yc).

Next, the probe is moved to the position of the calibration positioning mark, and the probe is the same as the four lines of the X measurement line 30, the X measurement line 31, the Y measurement line 32, and the Y measurement line 33 measured by the camera. Each of the two lines in the X direction and the Y direction is scanned, and the X measurement line 30, the X measurement line 31, the Y measurement line 32, and the Y measurement line 33 of the step shape portion of the calibration mark are respectively arranged in the respective directions. The center position of the height is sequentially calculated as the intersection position X1L, X1R, X2L, X2R, Y1U, Y1D, Y2U, Y2D. In the same manner as the above-described calculation program of the camera, two X-measurement center lines 34 and Y-measurement center lines 35 passing through the points in the X-direction and the Y-direction are calculated, and the calculated X-direction Y direction is calculated. The coordinates of the intersection of the center line of the straight line in the two directions are calculated, and the position of the positioning mark (Xa, Ya) measured by the probe is calculated by the same calculation formula as that of the above-described camera.

Based on the measurement results, the offset position (XoA, YoA) = (Xc, Yc) - (Xa, Ya) of the camera under the probe reference when measuring the A surface of the wafer lens 12 is calculated.

The value of the offset position of the probe 1 with respect to the camera 8 under the lens measurement on the wafer lens 12 surface is referred to later, and the position of the positioning mark obtained by the camera 8 is converted into the probe reference by The offset value is subtracted and calculated.

Thus, when the height of the positioning mark 29 on the wafer lens 12 is changed, the camera 8 and the probe 1 are measured by aligning the calibration positioning mark 10 with the height of the positioning mark on the wafer. With the same mark, the correct offset value of the camera 8 and the probe 1 can be found.

Thereby, even if the straightness of the XY direction of the Z-axis stage adjusted by the Z-axis adjustment adjusted at the focus adjustment of the camera 8 is deviated, the measurement error of the optical center position deviation due to the deviation of the focus height of the camera is not caused. The impact can still be measured with high precision.

In Fig. 9, Xw and Yw are coordinate systems of the wafer lens. Xm and Ym are coordinate systems in which the shape measuring device of the wafer lens 12 is provided. However, in this state, as shown in FIG. 9, the coordinate system of the wafer lens 12 of the Xw and Yw and the coordinate system of the shape measuring apparatus of Xm and Ym cannot be arranged in parallel, and there is a state of being somewhat deviated.

In step 206, the position of the two positioning marks 29 provided on the wafer lens 12 is measured using the camera 8 and the XY stage 3, and the center positions XaA1 and XaA2 of the positioning marks are memorized. The rotational position of the wafer lens 12 is measured with respect to the coordinates of the 3-dimensional measuring machine based on the two positioning mark positions measured as described above. Deviate from γ. The above calculated program can be calculated based on the positioning mark center calculation program of the camera 8 described in step 205.

The two positioning marks on the wafer are as shown in Fig. 9, and the two positioning marks 29 are described as being arranged on the Y-axis. The difference between the XY position vectors of the two positioning marks 29 is obtained, and as shown in FIG. 9, the distance between the two positioning marks 29 in the Y direction is YLd, and the deviation of the X marks in the X direction is set to dX. Then, the rotational position of the measuring machine about the Z axis is calculated as γ = atan (dX / YLd).

In this regard, in step 207, the gamma deviation of the wafer lens 12 is rotated by the gamma stage 23 disposed at the lower portion of the wafer chuck 13 so that the XY coordinates of the wafer lens are parallel to the 3-dimensional measurement. The X reference mirror 5 and the Y reference mirror 7 are adjusted.

In step 208, it is confirmed whether or not the deviation of the value of γ with respect to a predetermined specific value is within a predetermined range. If it is within the range, the process proceeds to step 209. If it is outside the range, the process from step 206 is repeated.

In step 209, all of the wafer lenses are measured in one continuous direction in the X direction and the Y direction in a continuous shape so that the probe 1 passes through the center of each lens on the wafer lens 12.

Calculating the center position of the wafer lens 12 based on the positions of the two positioning marks 29 measured as described above, and establishing an NC path of the measurement path measured in one continuous shape in the X direction and the Y direction for all the lenses 34 to be measured, and The X direction, the Y direction and the probe 1 are sequentially scanned in a continuous shape by the vicinity of the vertex positions of the comprehensive lenses 34 on the wafer lens 12 as shown in FIG. 10 to obtain all the lenses on the wafer. Measurement on the XY axis material.

The arrangement of the lenses 34 of the wafer lens 12 measured here needs to be arranged in a grid shape at equal intervals in the X direction and the Y direction. The lens 34, which is arranged in a grid shape, is measured by continuous scanning. The design of all lens shapes is the same.

In step 210, the measurement data in the two directions of the X direction and the Y direction measured in step 209, the positions XaA1 and XaA2 of the two positioning marks 29 obtained by the step of step 206, and the probe 1 and the camera 8 are used. The center-to-center distance XoA is calculated from the positioning marks 29 to calculate the center of each lens on the wafer lens 12.

The procedure is described below. In the continuous shape of one of the pens shown in FIG. 10, the lens is measured in the X direction, and the lens is measured in the Y direction. After the scanning of the probe is completed, the scanning data of each XY is used according to the design of the pre-input. The distance between the X direction and the Y direction of the lens arrangement is divided into measurement data of the X direction and the Y direction for each lens based on the coordinates of the measuring machine.

Here, the relationship between the lens position (i, j) and the index i, j indicating the position of the lens is shown in FIG. The index of i, j is set to (i, j) = (0, 0) in the center of the wafer lens, and the first lens in the X + direction is defined as i = +1, the first in the Y + direction The lenses are defined as j=+1.

The procedure for data segmentation is illustrated in FIG. The continuous measurement data is set to the virtual center position X[i]=i*Xp for each of the integer multiples of the design pitch, and the range of ±Xp/2 of one half distance of the arrangement pitch of the lenses from the center The data is used as the data of the i-th lens, and is segmented according to the original one of the strokes.

Similarly, the virtual center position Y[j]=j*Yp in the Y direction is set, and the data of the range of ±Yp/2 which is one half distance of the arrangement pitch of the lenses from the center is used as the data of the jth lens, and according to Originally one piece of continuous data was segmented.

Further, the data of one set of the X direction and the Y direction having the same point as the same point is used as the measurement data of one lens, and is stored in the memory of a computer not shown. Using the segmented data, the cut data is aligned for each lens and evaluated as the maximum deviation from the center position, shape deviation, design, ie PV (Peak to Valley), RMS (Root Mean Square) : RMS) and so on.

Using the data of each of the divided lenses 34, based on the XZ and YZ profiles on the XY axis of the measuring lens 34, the measurement data and design of each measuring point are determined with respect to the center position of the lens of the measuring machine. The sum of the squares of the difference of the shapes is the smallest, and the coordinate system of the measurement data point difference design is moved in the X direction, the Y direction, the Z direction, the A rotation direction around the X axis, and the B rotation direction around the Y axis. The amount of movement is sequentially calculated for all the lenses 34 on the wafer lens 12, and the lens center positions of all the lenses 34 on the wafer lens 12 are calculated. On the one side of the wafer surface, the design of each lens shape is the same.

Figure 12 shows the measured data point rows (Xk, Yk, Zk) and the design shape of the (i, j) position on the wafer. In Fig. 12, for the sake of easy explanation, the measurement data dot row and design shape on the XZ section are displayed.

In Fig. 12, the data of each point of the measurement data point row and the design shape expressed by Z = f (x, y) are used, and Zfk = f (Xk, Yk) according to each position of the (Xk, Yk) of the measurement data. Calculate Zfk, calculate the difference between this value and Zk of the above-mentioned measurement data, and Zdk=Zk-Zfk, and calculate the square sum of all the measured data, the rotation dBa around the Y-axis with the smallest ΣZdk ² , and the X-axis direction. The movement amount dZa in the movement amount dXa and the Z-axis direction.

In the description of Fig. 12, although the description is on the XZ plane, the case of all the data of the XZ profile and the YZ profile is also determined by the same procedure using the XYZ3 dimension measurement data (Xk, Yk, Zk). The amount of movement in which the sum of squares of Z=f(Xk, Yk) is the smallest is calculated as dXa, dYa, dZa, dAa, and dBa, and the deviation dXa and dYa from the center position of the lens are calculated from the measurement data line in the XY2 direction. According to the deviation from the continuous shape of one of the lenses, the center position of the lens at the (i, j) position is used as the following equation, and the values of i and j are changed for all the lenses, and sequentially calculated to be divided one by one corresponding to each lens. The sum of the above virtual center positions determined by 4-4).

[Number 8] Xf[i,j]=X[i]+dXa Yf[i,j]=Y[i]+dYa

The center position data point of the above lens is taken as (Xf[i,j], Yf[i,j]) (i, j is an integer value indicating the grid position of the lens of the XY plane on the wafer) and is memorized Memory of a computer not shown.

The measurement center of each of the above lenses is previously provided by rotating the γ-axis platform so that the coordinates of the positioning marks on the wafer are as close as possible to the coordinates of the measuring machine, but the positioning of the γ-axis motor is performed. In order to limit the accuracy, it is difficult to rotate and position the γ-axis so that the position of the two positioning marks in the X direction deviates from the dX to 1 μm or less.

In this regard, using the values of the deviations YL2 and dX2 of the position of the positioning marks measured by the camera, all the center XY position data points of the lens are made with respect to the center position of all the lenses calculated above, based on the positioning marks (Xf). [i, j], Yf[i, j]) (i, j is an integer value indicating the grid position of the lens on the XY plane on the wafer) rotation angle γ2 = atan (dX2 / YLd2), and the positioning is calculated Mark the center position of the lens of the reference. According to the above procedure, the lens center position can be accurately obtained with respect to the positioning mark coordinates obtained by the camera.

Here, FIG. 9 shows the relationship between the lens center position (Xf[i, j], Yf[i, j]) and the indices i and j indicating the lens position. The position of the lens center is represented by (Xf[i, j], Yf[i, j]) as a position based on the positioning mark on the wafer. The index of i, j of the arrangement has the center of the wafer lens as (i, j) = (0, 0), the first lens in the X + direction is defined as i = +1, and the first lens in the Y + direction Defined as j=+1.

In step 211, the wafer lens 12 measured in the above-described step is flipped forward and backward with the Y axis as a rotation axis, and the B surface is attached to the wafer chuck 13 by using the measurement side of the probe 1.

Then, according to step 212, the front side of the wafer lens 11 disposed in the step of 202 is placed on the Y-axis as a rotation axis to reverse the wafer, and then the substrate formed on the transparent wafer lens is measured. In the case of the positioning mark on the back side, by the opposite rotation of the wafer, in the measurement of steps 202 to 210, the positioning mark 29 on the side of the probe 1 is moved to the position on the wafer chuck 13 side, and The focus height of the camera 8 is adjusted by the Z-axis stage 9 to the position of the positioning mark 29 on the wafer chuck side.

Thereafter, according to step 213, the camera 8 is moved to the position of the correction positioning mark 10 while maintaining the focus height position of the camera 8 adjusted by the Z-axis stage 9 in the step of 212, and the wafer is positively performed by the step of 212 described above. Instead, the Y-axis is set to be reversed by the rotation axis, whereby the Z3 axis stage 11 is adjusted by an amount corresponding to the Z height of the changed wafer thickness in such a manner that the focus of the camera 8 is aligned with the correction positioning mark 10.

In step 214, the center distance between the probes 10 and the camera 8 is measured using the calibration positioning mark 10 for the center position of the camera 8 which is slightly shifted in the XY direction by the procedure of the above-described steps 211 to 213, and the center distance XoB between the probe 1 and the camera 8 is measured.

The calibration procedure is corrected using the same calibration procedure as the calibration procedure shown in the description of step 205 above.

In steps 215 to 218, the same processing as steps 206 to 209 is performed in the above-described setting state.

In step 219, the measurement data of the two directions of the X direction and the Y direction measured by 218, the positions XaB1 and XaB2 of the two positioning marks 29 obtained by the step of 215, and the distance between the centers of the probe 1 and the camera 8 are used. XoB calculates the center of each lens on the wafer lens 12 based on the positioning mark 29.

This calculation program is calculated by the same calculation program as the calculation program shown in the above description of step 210.

In step 220, the position marks 29 obtained in step 219 are set based on the center positions of the lenses on the A side under the reference mark 29 obtained in step 210 and the front and back of the wafer being reversed with the Y axis as the rotation axis. The center position of each lens of the B surface under the reference is calculated by calculation processing to calculate the deviation of the center of the wafer lens 12 from the center of the lens.

If the lens center XY position data point line on the front side of the wafer obtained by the above step 210 is set to (Xf[i, j], Yf[i, j]) (i, j is the XY on the wafer) The integer value of the grid position of the lens on the plane is rotated 180 degrees on the Y-axis and set and measured. The lens center XY position data point line of the back surface of the same wafer lens obtained by the above procedure of step 219 is obtained. Set to (Xb[i,j], Yb[i,j]) (i, j is an integer value indicating the position of the grid of the lens on the XY plane on the wafer), and the left and right direction of the back side of the front side The data index is the value of i. If the value of the polarity inversion is inverted by flipping on the back side, the lens position can be specified, and the center position of the lens between the front and the back is deviated from the point group, and the lens on the back side. The center position deviation of each lens on the front side of the reference is calculated by the following equation.

[9] (dX[i, j], dY[i, j]) = Xf[i, j], Yf[i, j]) - (Xb[-i, j], Yb[-i, j ])

i, j is an integer value indicating the position of the grid of the lens on the XY plane on the wafer

According to the above procedure, the lens center positional deviation corresponding to the front and back sides of all the lenses on the wafer at the opposite position can be found.

The characteristics of the wafer lens 12 are evaluated based on the results of the lens center position data on the front side of the step 220, the lens center position data on the back side of the step 219, and the deviation of the center of the lens from the step 220.

The measurement is ended at step 221 .

Moreover, since the wafer lens of a plurality of thicknesses is present in the manufacture of the actual wafer lens, and the mark height on the wafer varies depending on the type, the camera height adjustment Z2 is adjusted by the above-described correction program according to the replacement of the variety. The height of the shaft platform 9 and the Z3 axis platform 11 for adjusting the positioning mark height.

Further, the case where the lens position is repeatedly measured on the one side (the A side or the B side) of the wafer lens 12 of the same type with the positioning mark 29 as a reference can be measured according to the procedures of steps 201 to 210. In this case, when the measurement of the wafer lens 12 after the second sheet is performed in the repeated measurement, the measurement is performed by skipping the steps 203 to 205, and the measurement time can be shortened and measured.

By measuring the calibration positioning mark by the camera in this way, the lens shape and the lens center position are measured by the probe, and the corrected offset value is used, and the height of the wafer or the positioning mark on the wafer is attached to the front or attached. The height of the back surface is independent of the influence of the linearity deviation of the Z-axis stage in the XY direction, which is adjusted when the focus of the camera 8 is adjusted, and the optical center position deviation due to the deviation of the focus height of the camera. The influence of the measurement error is measured, and the measurement with high precision is performed.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, regarding the center distance between the probe 1 and the camera 8 in the measurement of the A side of the wafer lens 12 provided with the positioning mark 29, it is not necessary to use the calibration positioning mark as shown in steps 204 and 205 of FIG. The same processing as in steps 204 and 205 is performed using the positioning marks 29 of the wafer lens 12, and the center distance between the probe 1 and the camera 8 is corrected.

[Industrial availability]

In the third-order measurement method of the present invention, the third-order element of the ternary shape is measured with high precision, and the camera accurately measures the position of the positioning mark with respect to the position of the positioning mark, thereby accurately measuring the position relative to the probe. Since the offset is applied, a plurality of lenses formed on one substrate such as a wafer lens or a lens array can be applied to a three-dimensional measurement in which measurement is performed at high speed and with high precision.

Further, in the above embodiments, the wafer lens is used as the measuring object, but the wafer lens is used as a measuring object, but it may be applied to a mold for manufacturing a wafer lens or a lens array instead of the wafer lens.

1‧‧‧ probe

2‧‧‧Z1 axis platform

3‧‧‧XY platform

8‧‧‧ camera

9‧‧‧Z2 axis platform

10‧‧‧Alignment marker

11‧‧‧Z3 axis platform

12‧‧‧ wafer lens

29‧‧‧ Positioning Mark

Fig. 1 is a view showing the entire apparatus of the three-dimensional measurement method according to the first embodiment of the present invention.

Fig. 2 is a view showing the configuration of a probe of a three-dimensional measurement method according to the first embodiment of the present invention.

Fig. 3 is a detailed view showing a three-dimensional measurement method according to the first embodiment of the present invention.

Fig. 4 is a view showing the configuration of a wafer lens and a positioning mark in the first embodiment of the present invention.

Figs. 5(A) and 5(B) are views showing the configuration of a positioning index mark for correction according to the first embodiment of the present invention.

Fig. 6 is a flow chart showing the entire measurement of the first embodiment of the present invention.

A cross-sectional view of an edge portion of the alignment mark for correction according to the first embodiment of the present invention.

Fig. 7 is a detailed view showing the positional relationship of the positioning marks in the first embodiment of the present invention.

Fig. 8 is a detailed view showing the measurement of the positioning mark for correction in the first embodiment of the present invention.

Figure 9 is a view showing the positional relationship of the wafer lens in the first embodiment of the present invention. Figure.

Fig. 10 is a detailed view showing a wafer lens measurement scanning path according to the first embodiment of the present invention.

Fig. 11 is a detailed view of measurement data measured by the probe of the first embodiment of the present invention.

Fig. 12 is a detailed view showing the calculation of the lens center position in the first embodiment of the present invention.

FIG. 13 is a configuration diagram of a wafer lens described in Patent Document 1.

Fig. 14 is a view showing a method of measuring a previous three-dimensional method described in Patent Document 1.

Fig. 15 is a view showing a method of measuring a previous three-dimensional method described in Patent Document 1.

1‧‧‧ probe

2‧‧‧Z1 axis platform

3‧‧‧XY platform

8‧‧‧ camera

9‧‧‧Z2 axis platform

10‧‧‧Alignment marker

11‧‧‧Z3 axis platform

12‧‧‧ wafer lens

13‧‧‧ wafer chuck

23‧‧‧γ platform 23

24‧‧‧stone plate

29‧‧‧ Positioning Mark

Claims (4)

A three-dimensional measurement method for obtaining a surface shape data of an object to be measured by two or more surface detecting means, wherein the position in the XY direction provided separately from the object to be measured is not relative to the above The height of the calibration positioning mark moving in the Z direction is the same as the height of the surface of the object to be measured; and the two or more surface detecting means measure the positioning mark for matching the height; As a result, the offset in the XY direction of the two or more surface detecting means is corrected, and the surface shape data of the object to be measured measured by the two or more surface detecting means and the corrected offset are used to obtain the above-mentioned The surface shape of the object was measured. The third dimension measuring method of claim 1, wherein the surface detecting means includes a measuring rod for surface shape measurement provided on a first Z-direction moving mechanism that moves in the Z direction on an XY stage that moves in the XY direction, and the above-mentioned XY a camera that measures an image in the XY plane provided in the second Z-direction moving mechanism that moves in the Z direction on the platform; and the calibration positioning mark that matches the surface height of the object to be measured is captured by the camera, and the measurement is performed Measuring the rod, correcting a deviation of the center position of the measuring rod from the camera according to the result of the photographing and measuring; and measuring a surface shape of the object to be measured by the measuring rod; The surface shape of the object to be measured is obtained by using the measurement result obtained by the above-described measuring rod and the corrected offset. The third dimension measuring method according to claim 2, wherein the surface shape of the object to be measured by the measuring rod is measured in the X direction of the lens surface so as to pass near the vertex position of each lens surface on the object to be measured The last measurement is performed once in the Y direction so as to pass near the vertex position of the lens surface. According to the above measurement data, the measurement data is divided for each lens according to the X-direction and the Y-direction distance of the lens. And the XYZ position and posture of the shape and the center of the lens are evaluated for the data divided by each lens. The three-dimensional measurement method according to any one of claims 1 to 3, wherein the object to be measured is a wafer lens in which a plurality of lenses are formed on a thin plate.