TWI752045B - Polishing device - Google Patents

Abstract

A polishing device capable of polishing a wafer so as to have a target sectional shape according to a sectional shape of a wafer being polished. A polishing device 10 which includes an upper surface plate 21, a lower surface plate 22, a sun gear 23, an internal gear 24, and a carrier plate 30, and the carrier plate 30 is rotated and revolved by the sun gear 23 and the internal gear 24, and in which both surfaces of a wafer W placed in a work holding hole 30 A of a carrier plate 30 are polished. The polishing device 10 includes a shape measuring device 100 for measuring a cross-sectional shape of a wafer W being polished and a control device 300 for controlling polishing processing according to the cross-sectional shape measured by the shape measuring device 100.

Description

Grinding device

This invention relates to a polishing apparatus for polishing the surface of workpieces such as silicon wafers.

There is known a double-side polishing apparatus for polishing both sides of a wafer by rotating and revolving a planetary plate holding a wafer (refer to Patent Document 1).

Such a double-sided polishing device is provided with: a thickness measuring device, which can measure the thickness of the wafer being polished; the upper platen and the lower platen, which have through-holes for measurement; a sun gear; an internal gear; a planetary wheel plate, etc.; , While the upper plate and the lower plate clamp the pinwheel plate, the pinion plate is engaged with the sun gear and the inner gear, and the sun gear and the inner gear are rotated, thereby making the pinwheel plate rotate and revolve, and further By rotating the upper platen and the lower platen, both sides of the wafer held on the planetary plate are polished.

In addition, the double-sided polishing apparatus has: a polishing step of polishing both sides of the wafer only when the planetary wheel is rotated; wherein in the polishing step, there is a measuring step of measuring the thickness of the wafer at a predetermined position; and In the determination step, the polishing end time is determined according to the measurement result of the measurement step. Prior art documents Patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2015-47656

The problem to be solved by the invention

However, in such a polishing apparatus, since only the thickness of the wafer at a predetermined position is measured in the polishing step to determine the polishing end period, there is a possibility that the wafer cannot be polished to a target profile according to the cross-sectional shape of the wafer being polished. shape problem.

In the polishing process, not only the wafer is polished to a desired thickness, but it is also required to be polished to a desired cross-sectional shape to be targeted. The cross-sectional shape of a wafer is evaluated by indexes such as SFQR or GBIR, and by obtaining a wafer with a desired cross-sectional shape that satisfies these index conditions, the semiconductor device manufactured in the subsequent semiconductor device manufacturing steps can be improved. yield. However, it is not possible to judge whether the cross-sectional shape of the wafer is processed into a desired cross-sectional shape only by measuring the thickness of the wafer. Here, in order to obtain a wafer having a desired cross-sectional shape, a polishing apparatus such as the following is required, which can measure the cross-sectional shape of the wafer during the polishing process, and which can become the desired cross-sectional shape according to the measured cross-sectional shape of the wafer. The processing conditions are set according to the cross-sectional shape, and the wafer is polished.

In addition, the cross-sectional shape of the wafer is changed by the following factors, which can be set arbitrarily, such as the rotation speed of the upper surface plate, the lower surface plate, the sun gear and the internal gear, the processing load, the slurry supply amount, and the temperature. conditions; and the state of the machined surfaces such as the upper platen and lower platen (shape change due to temperature change or wear), the actual temperature of the polishing slurry, and the state of wafer rotation, which fluctuate at any time as polishing progresses. Therefore, even if the wafer is polished under the same processing conditions, the processing state is not necessarily the same. That is, even if the wafer is polished under the same processing conditions, a wafer having a desired cross-sectional shape cannot be stably obtained due to fluctuations in the processing state. Therefore, it is necessary to measure the cross-sectional shape of the wafer during the polishing process, and to change the processing conditions when the cross-sectional shape is not desired.

Here, in order to obtain a wafer having a desired cross-sectional shape, a polishing apparatus such as the following is required, which can measure the cross-sectional shape of the wafer during the polishing process, and which can become the desired cross-sectional shape according to the measured cross-sectional shape of the wafer. The processing conditions are set according to the cross-sectional shape, and the wafer is polished.

An object of the present invention is to provide a polishing apparatus capable of measuring the cross-sectional shape of a wafer during polishing, and polishing the wafer in such a manner that the cross-sectional shape of the wafer becomes a target according to the measured cross-sectional shape of the wafer. . means to solve the problem

The present invention provides a grinding device for grinding a workpiece by a grinding machine having a rotatable platen, comprising: a shape measuring device for measuring the cross-sectional shape of the workpiece during grinding; and a control device for measuring the shape according to the shape The cross-sectional shape of the workpiece measured by the apparatus controls the grinding process so that the above-mentioned cross-sectional shape becomes the target cross-sectional shape. Invention effect

According to the present invention, the cross-sectional shape of the wafer can be measured during the polishing process, and the wafer can be polished so that the desired cross-sectional shape can be obtained in accordance with the measured cross-sectional shape of the wafer. Therefore, the grinding process can be performed while grasping whether or not the cross-sectional shape of the workpiece is processed into the target cross-sectional shape, and the processing conditions can be changed during the grinding process when the workpiece is not in the target cross-sectional shape. Thereby, a workpiece having a target cross-sectional shape can be stably obtained.

Hereinafter, the Example concerning embodiment of the grinding|polishing apparatus of this invention is demonstrated based on drawing.

[First Embodiment] The polishing apparatus 10 shown in FIG. 1 includes a polishing machine 20, a shape measuring device 100, a control device 300, and the like, wherein the polishing machine 20 polishes a wafer (silicon wafer) W that is one of the workpieces. Both sides; the shape measuring device 100 measures the cross-sectional shape in the diameter direction of the wafer W being polished; the control device 300 makes the aforementioned cross-sectional shape as The drive devices M1 to M5 and the like, which will be described later, are controlled in accordance with the target cross-sectional shape. A 200-series storage unit stores a recipe indicating appropriate processing conditions for making the cross-sectional shape of the wafer W a target cross-sectional shape according to the cross-sectional shape in the diameter direction of the wafer W.

[Lapping Machine] The lapping machine 20 includes: an upper surface plate 21 and a lower surface plate 22; a sun gear 23, which is rotatably arranged at the center of the upper surface plate 21 and the lower surface plate 22; and an internal gear 24, which is arranged in The outer peripheral sides of the upper platen 21 and the lower platen 22 , and the pinwheel plate 30 are disposed between the upper platen 21 and the lower platen 22 and have workpiece holding holes 30A (see FIG. 2 ). Further, a grinding member 25 is provided on the lower surface of the upper surface plate 21 , and a grinding member 26 is provided on the upper surface of the lower surface plate 22 .

The pinwheel plate 30 is engaged with the sun gear 23 and the internal gear 24 as shown in FIG. 2 , and can rotate and revolve by the rotation of the sun gear 23 and the internal gear 24 . By the rotation and revolution of the star wheel plate 30 , both sides of the wafer W placed in the workpiece holding hole 30A of the star wheel plate 30 can be polished by the polishing members 25 and 26 .

The upper plate 21 is fixed to the rod 42 through the support stud 40 and the mounting member 41 as shown in FIG. 1 . The lever 42 is moved up and down by the drive device M1, and the upper platen 21 is moved up and down integrally by the up and down movement of the lever 42.

On the other hand, the upper portion 43A of the drive shaft 43 penetrates the hole 23A in the center portion of the sun gear 23 , the sun gear 23 is fixed to the upper portion 43A, and the sun gear 23 and the drive shaft 43 rotate integrally. The drive shaft 43 is rotated by the drive device M4, and the sun gear 23 is rotated integrally with the drive shaft 43 by the drive device M4.

In the hole of the drive shaft 43 , a drive shaft 44 , which is rotated by the drive device M2 , is inserted, and the upper end portion 44A of the drive shaft 44 protrudes from the upper end of the drive shaft 43 . A driver 45 is fixed to the upper end portion 44A, and the driver 45 rotates integrally with the drive shaft 44 . The hook 46 provided on the upper surface plate 21 is engaged with the outer peripheral surface of the driver 45 , and the upper surface plate 21 is integrally rotated by the rotation of the driver 45 . In addition, the hook 46 is movable in the up-down direction relative to the outer peripheral surface of the driver 45 , whereby the upper platen 21 can be moved in the up-down direction relative to the driver 45 .

That is, the upper surface plate 21 is moved up and down by the up and down movement of the lever 42 , and is rotated by the rotation of the drive shaft 44 . That is, the upper surface plate 21 rotates integrally with the drive shaft 44 by the drive device M2.

A drive shaft 49 is formed at the lower part of the central portion of the lower surface plate 22 , and a rotatable drive shaft 43 is arranged in the drive shaft 49 . The drive shaft 49 is rotated by the drive device M3, and the lower platen 22 is rotated by the drive device M3 integrated with the drive shaft 49.

A drive shaft 47 is formed on the internal gear 24 , and a rotatable drive shaft 49 is arranged in the drive shaft 47 . The drive shaft 47 is rotated by the drive device M5, and the internal gear 24 is rotated integrally with the drive shaft 47 by the drive device M5.

On the upper surface plate 21 , measurement holes 50 are formed at positions spaced apart by a predetermined distance in the diameter direction from the center of the upper surface plate 21 . The measurement hole 50 is formed through the upper surface plate 21 and the polishing member 25, and a window member 51 that is transparent to infrared laser as measurement light is attached. In addition, the upper surface plate 21 is provided with a supply hole (not shown) for supplying the polishing slurry.

[Shape Measuring Apparatus] As shown in FIG. 1, the shape measuring apparatus 100 includes an optical head 101 that irradiates an infrared laser as measuring light toward the wafer W through a window member 51 attached to the measuring hole 50 of the upper platen 21, At the same time, it receives the reflected light from the wafer W; the laser oscillator 102 is used for irradiating the infrared laser from the optical head 101; In addition, the optical head 101 is installed on the upper surface plate 21 and rotates together with the upper surface plate 21 .

The calculation device 110 includes: a thickness calculation unit 111, which obtains the measured thickness of the wafer W from the reflected light received by the optical head 101; The in-plane position when the measured thickness is obtained; and the cross-sectional shape calculation unit 113 obtains the wafer W from the measured thickness of the wafer W obtained by the thickness calculation unit 111 and the in-plane position obtained by the position calculation unit 112 sectional shape in the diametrical direction.

[Thickness Calculation Unit] The thickness calculation unit 111 is a device that performs measurement by, for example, optical reflection interferometry, and obtains the wavelength-tunable laser beam on the surface of the wafer W for high-speed wavelength scanning according to the reflected light received by the optical head 101 The measured thickness of the wafer W is obtained by reconstructing the wavelength dispersion of the reflection (the state of interference of light reflected on the surface and the back surface of the wafer W) from the reflection intensity on the wafer W, and analyzing the frequency.

[Position Calculation Unit] The position calculation unit 112 obtains the position and rotation number of the pinion plate 30 from the rotational positions of the sun gear 23 and the internal gear 24 . That is, the revolution position and the autorotation position of the pinwheel plate 30 are obtained, and the in-plane position of the wafer W is obtained from the revolution position and the autorotation position. Thereby, the in-plane position measured by the measured thickness of the wafer W determined by the thickness calculation unit 111 can be obtained.

[Cross-sectional shape calculation unit] The cross-sectional shape calculation unit 113 obtains the wafer W based on the measured thickness of the wafer W obtained by the thickness calculation unit 111 and the in-plane position of the wafer W obtained by the position calculation unit 112 sectional shape in the diametrical direction.

The cross-sectional shape in the diameter direction of the wafer W can be obtained by any method. Here, for example, as shown in FIG. 5 , when the diameter of the wafer W is 300 mm, the shape of the portion of 0 to 150 mm (equivalent to the radius of the wafer W) is obtained, and the shape of the portion of 150 mm is taken as the center. The shape of the part is mirror-inverted, and the cross-sectional shape in the diameter direction of the wafer W is obtained. In addition, without performing mirror inversion, the shape of the portion (corresponding to the diameter of the wafer W) from 0 to 300 mm may be obtained and taken as the cross-sectional shape of the wafer W in the diameter direction. Next, the judgment shape and P-V value of the wafer W are obtained from the obtained cross-sectional shape of the wafer W in the diameter direction. The "judgment shape" of the wafer W refers to a type of classification based on the tendency of the cross-sectional shape of the wafer W in the diameter direction. In the obtained cross-sectional shape in the diameter direction of the wafer W, the cross-sectional shape of the radial portion of the wafer W is divided into arbitrary parts, and according to the tendency of the cross-sectional shape of the divided part, as shown in FIG. Select the corresponding type in combination with the inverted V shape, W shape, M shape, U shape, etc., and use this type as the "judgment shape" of the wafer W. The P-V value refers to the difference between the maximum measured thickness P and the minimum measured thickness V of the wafer W shown in FIG. 5 . In addition, the P-V value may also be obtained by the control device 300 .

[Control Device] The control device 300 compares the obtained cross-sectional shape of the wafer W in the diameter direction with the target cross-sectional shape of the wafer W. That is, the determined shape and PV value of the obtained wafer W are compared with the determined shape and PV value of the target wafer W, and the values stored in the storage unit 200 are read in Table 1 of FIG. 3 . According to the prescription of the comparison result, the processing conditions corresponding to the prescription read out are further read out from Table 2 shown in FIG. It is control of the driving of each of the drive devices M1 to M5, and the like. In addition, the control device 300 also controls the computing device 110 .

[Storage Unit] As shown in FIG. 3 , the storage unit 200 stores Table 1 showing the most suitable recipes, and the result is to compare the obtained cross-sectional shape in the diameter direction of the wafer W with the target cross-sectional shape. And get.

Moreover, as shown in FIG. 4, the storage part 200 stores Table 2 which shows the processing conditions of each prescription.

The processing conditions are the rotation speeds of the upper and lower surface plates 21 and 22, the rotation speeds of the sun gear 23 and the internal gear 24, the processing load and unit pressure of the upper surface plate 21, the load slope, and the acceleration of the upper surface plate 21 and the lower surface plate 22. time, the deceleration time of the upper surface plate 21 and the lower surface plate 22, the rotation speed of the rotation and revolution of the planetary wheel plate 30, and the like.

The most suitable processing conditions are obtained in advance through experiments, and it is possible to efficiently grind the obtained cross-sectional shape of the wafer W in the diameter direction into a target cross-sectional shape. In addition, the processing conditions may also include the type, supply amount, temperature, and the like of the abrasive slurry. The grinding process can be controlled by changing these processing conditions during the grinding process.

[Operation] Next, the operation of the polishing apparatus 10 configured as described above will be described based on the flowcharts shown in FIGS. 6 to 8 . Basic machining conditions are selected in step S1. The basic processing conditions refer to the processing conditions that are the basis for performing the polishing during the period from the start of the polishing of the wafer W until the feedback processing is performed based on the measurement results described later. First, the polishing process of the wafer W is started based on the basic basic process conditions set in advance.

In step S2 , the wafer W is loaded into the workpiece holding hole 30A of the planetary plate 30 (see FIG. 2 ). Then, the upper platen 21 located at the position to be avoided is lowered, and the wafer W is sandwiched between the lower platen 22 and the upper platen 21 .

In step S3, the double-sided polishing process is started under the basic machining conditions. In step S4, the initial processing step operation is performed. That is, the upper surface plate 21 and the lower surface plate 22 are rotated at a low speed by controlling the driving devices M2 and M3 by the control device 300, and the upper surface plate 21 is pressed downward with a low load by controlling the driving device M1. Accordingly, the upper surface plate 21 presses the wafer W with a low load. In addition, by controlling the driving devices M4 and M5 by the control device 300, the sun gear 23 and the internal gear 24 are rotated at a low speed, and the pinwheel plate 30 is rotated and revolved at a low speed.

Both sides of the wafer W are polished by the low-speed rotation of the upper surface plate 21 and the lower surface plate 22 and the low load of the upper surface plate 21 . In addition, both sides of the wafer W are polished by the planetary plate 30 rotating and revolving at a low speed. In addition, while polishing is being performed, the polishing slurry is supplied at a predetermined timing from a supply hole (not shown) provided in the upper surface plate 21 .

When the processing action of step S4 is performed for a predetermined time, the process proceeds to step S5. In step S5, the upper platen 21 and the lower platen 22 rotating at a low speed gradually increase the rotation speed and enter into a medium speed rotation. In addition, the upper surface plate 21 is further pressed downward with a medium load. Thereby, the upper surface plate 21 presses the wafer W with a moderate load. In addition, the sun gear 23 and the internal gear 24 that are rotating at a low speed gradually increase the rotational speed to enter a medium speed rotation, and the pinwheel plate 30 rotates and revolves at a medium speed. Then, both sides of the wafer W are polished by the middle-speed rotation of the upper surface plate 21 and the lower surface plate 22 and the middle load of the upper surface plate 21 . In addition, both sides of the wafer W are polished by the spinner plate 30 rotating and revolving at a moderate speed. Then, as in step S4, when the processing operation of step S5 has been performed for a predetermined time, the process proceeds to step S20.

The step S20 is to perform the main processing step processing, and the main processing step processing is performed by the processing actions of the step S21 to the step S26 as shown in FIG. 7 , that is, the feedback processing is performed. Hereinafter, the processing operation of each of steps S21 to S26 will be described.

In step S21, the upper platen 21 and the lower platen 22 rotating at a medium speed gradually increase the rotation speed and enter into a high speed rotation. In addition, the upper surface plate 21 is pressed downward with a high load. Thereby, the upper surface plate 21 presses the wafer W with a high load. In addition, the sun gear 23 and the internal gear 24 in the middle-speed rotation gradually increase the rotation speed to enter the high-speed rotation, and the pinwheel plate 30 rotates and revolves at a high speed. Then, both sides of the wafer W are polished by the high-speed rotation of the upper surface plate 21 and the lower surface plate 22 and the high load of the upper surface plate 21 . In addition, both sides of the wafer W are polished by the spinner plate 30 rotating and revolving at high speed.

On the other hand, the infrared laser is irradiated downward from the optical head 101 by the laser oscillator 102 , and irradiates the wafer W through the window member 51 of the measurement hole 50 , and the reflected light reflected by the surface and the back of the wafer W is transmitted therethrough. The window member 51 of the measurement hole 50 is incident on the optical head 101 .

In step S22, every time the optical head 101 receives the reflected light, the thickness calculation unit 111 obtains the measured thickness of the wafer W according to the interference light of the received reflected light from the front and back surfaces of the wafer W. On the other hand, the position calculation unit 112 of the calculation device 110 obtains the in-plane position of the wafer W when the measured thickness is obtained, respectively.

The cross-sectional shape calculation unit 113 of the calculation device 110 obtains the wafer W based on the individual measured thicknesses of the wafer W obtained by the thickness calculation unit 111 and the individual in-plane positions of the wafer W when the measured thicknesses are obtained. The cross-sectional shape of W in the diametrical direction. That is, the cross-sectional shape in the diameter direction of the wafer W is obtained from the measured thickness of the individual in-plane positions of the wafer W. FIG. In addition, the P-V value was obtained from the obtained cross-sectional shape of the wafer W in the diameter direction. Furthermore, the thickness of the wafer W is obtained from the obtained measured thickness of the wafer W. Here, the "measured thickness of the wafer W" refers to each measured thickness, and the number of data is plural and used to describe the cross-sectional shape. In addition, "thickness of wafer W" refers to the representative value (moving average, etc.) of the measured thickness of wafer W at the time obtained from the measured thickness of wafer W to be measured, and the number of data is single and used for Comparison with target thickness.

That is, in step S22, the cross-sectional shape in the diameter direction of the wafer W, the P-V value shown in FIG.

In step S221 , the obtained sectional shape in the diameter direction of the wafer W is compared with the judgment shape of the predetermined reference, and it is determined which judgment shape the obtained sectional shape in the diameter direction of the wafer W corresponds to. That is, the obtained cross-sectional shape of the radial portion of the wafer W is divided into arbitrary blocks, for example, the outer peripheral portion of the wafer W, the inner peripheral portion, the intermediate peripheral portion between the outer peripheral portion and the inner peripheral portion, and the like. , according to the tendency of the cross-sectional shape of the divided blocks, as shown in FIG. 5, the corresponding type is determined as the judgment shape of the wafer W from the combination of the concavity and convexity and the inverted V shape, W shape, M shape, U shape, etc. .

In step S23, it is determined whether the cross-sectional shape in the diameter direction of the wafer W obtained in steps S22 and S221 has reached the target cross-sectional shape. That is, it is judged whether the judged shape of the wafer W obtained in steps S22 and S221 has reached the target judged shape, and whether the P-V value has reached the target P-V value is judged, and if it is judged "No", the process proceeds to step S24.

In step S24, it is determined whether or not the thickness of the wafer W obtained in step S22 is below the lower limit of the target thickness. And it progresses to step S6, and it progresses to the process step of finishing the grinding|polishing process. When the thickness of the wafer W is not equal to or less than the lower limit of the target thickness, the determination in step S24 is NO, and the process proceeds to step S25 .

In step S25, the control device 300 compares the cross-sectional shape in the diameter direction of the wafer W obtained in the steps S22 and S221 with the cross-sectional shape of the target wafer W, and stores the result of the comparison in the storage unit. Table 1 (refer to FIG. 3 ) of 200 reads the recipe, reads the machining conditions indicated by the read out recipe from Table 2 (refer to FIG. 4 ), and controls each drive device M1 based on the read out machining conditions to the operation of the M5, etc. Then, it returns to step S22.

In step S22 , the cross-sectional shape in the diameter direction of the wafer W, that is, the judgment shape of the wafer W, the P-V value, and the like are obtained again in the above-mentioned manner. The processing operations from Step S22 to Step S25 are repeated until the obtained cross-sectional shape in the diameter direction of the wafer W reaches the target cross-sectional shape. Since both sides of the wafer W are polished, the processing conditions (recipe) will vary. Since the cross-sectional shape in the diameter direction of the wafer W is changed, the cross-sectional shape in the diameter direction of the wafer W can be polished to a target cross-sectional shape with certainty.

If the cross-sectional shape of the wafer W in the radial direction reaches the target cross-sectional shape, the determination in step S23 is YES, and the process proceeds to step S26 . In step S26, it is determined whether the thickness of the wafer W is below the upper limit of the target thickness, and if "No", the process returns to step S21, and the processing operations from steps S21 to S26 are repeated until the thickness of the wafer W is below the upper limit of the target thickness until. When the thickness of the wafer W is equal to or less than the upper limit of the target thickness, the determination is YES, and the process proceeds to step S6.

In step S6, a deceleration processing step operation is performed, that is, the control device 300 controls the operation of the driving devices M1 to M5 to decelerate the upper platen 21 and the lower platen 22, the sun gear 23, and the inner gear 24 that are rotating at a high speed to the middle. At the same time, the load on the lower side of the upper surface plate 21 is reduced to a medium load. The process proceeds to step S7 after the processing operation of this step S6 is performed for a predetermined time.

In step S7, the pure water washing step operation is performed. That is, while the pure water is supplied from the supply hole provided in the upper platen 21, the upper platen 21, the lower platen 22, the sun gear 23, and the internal gear 24 are decelerated and rotated at a low speed. In addition, the lower load of the upper surface plate 21 is reduced to a low load. Then, both sides of the wafer W are washed with pure water. After the processing operation of this step S7 has been performed for a predetermined time, the process proceeds to step S8, and the machining operation is terminated.

In step S9, the upper platen 21 is raised to collect the polished wafer W, and in step S10, the cross-sectional shape of the wafer W is measured by an external measuring device.

As described above, in the present invention, the cross-sectional shape of the wafer W being polished is measured, and the processing conditions (recipes) are changed so that the cross-sectional shape becomes the desired cross-sectional shape, so that the wafer W can be efficiently polished to the desired cross-sectional shape. sectional shape. In addition, as described above in step S24 , the thickness can be compared with the target thickness, so that the wafer W can be reliably prevented from being over-polished, resulting in defective products.

Furthermore, since the present invention measures the cross-sectional shape of the wafer W and changes the processing conditions according to the cross-sectional shape, it is possible to prevent only a part of the wafer W from becoming too thin or too thick. In addition, since it is possible to determine whether the cross-sectional shape of the wafer W being polished has been processed into the target cross-sectional shape at the same time as the grinding process, and if the cross-sectional shape is not the target, the processing conditions can be changed during the grinding process, so that it is possible to stably perform the grinding process. A wafer W having a target cross-sectional shape is obtained.

[Second Embodiment] FIG. 8 is a flowchart showing a second embodiment. In this second embodiment, after step S5, a step S20' for performing the main processing step process 1 and a step S30 for performing the main processing step process 2 are added.

The main processing step Process 1 of Step S20' is to perform the processes of Steps S21 to S26 shown in Fig. 7, but the "achieve target cross-sectional shape" in step S23 is changed to "achieve the first target cross-sectional shape". This first target cross-sectional shape indicates the cross-sectional shape at a stage before reaching the target cross-sectional shape. The rest is the same as that of the first embodiment, and the description is omitted.

The main processing step Process 2 of step S30 is performed in the same manner as the processing operations of steps S21 to S26 shown in FIG. 7 , and the description thereof is omitted.

According to the second embodiment, by adding steps S20' and S30, the polishing process can be divided into a plurality of stages to obtain the target cross-sectional shape, so that the cross-sectional shape of the wafer W can be more reliably ground into the target cross-sectional shape. That is, it is possible to more reliably prevent the occurrence of defective products due to excessive polishing of the wafer W, and to reliably prevent only a part of the wafer W from becoming too thin or too thick. In addition, since it is possible to determine whether the cross-sectional shape of the wafer W being polished has been processed into the target cross-sectional shape at the same time as the grinding process, and if the cross-sectional shape is not the target, the processing conditions can be changed during the grinding process, so that it is possible to stably perform the grinding process. A wafer W having a target cross-sectional shape is obtained.

Although the measurement holes 50 are provided in the upper surface plate 21 in the above-mentioned embodiment, the lower surface plate 22 may also be provided with measurement holes to measure the cross-sectional shape of the wafer W by irradiating infrared lasers to the lower surface of the wafer W from below.

In addition, although the case where one wafer W is polished using one pinwheel plate 30 has been described, it is also applicable to simultaneous polishing by disposing a plurality of pinwheel boards 30 between the upper surface plate 21 and the lower surface plate 22 In the case of a plurality of wafers W, or in the case of arranging a plurality of wafers W on one planetary plate 30 .

Furthermore, although the optical head 101 is arranged on the upper platen 21 in the above-mentioned embodiment, the optical head can also be arranged above the position spaced by a predetermined distance in the diameter direction from the center of the upper platen 21. When the upper surface plate 21 is rotated directly under the optical head, the infrared laser irradiated from the optical head is irradiated on the wafer W through the window member 51, and the cross-sectional shape of the wafer W is measured. At least one measurement hole 50 is sufficient, but a plurality of the measurement holes 50 may be formed at equal intervals along the circumferential direction of the positions spaced apart by the above-mentioned predetermined distances. When a plurality of measurement holes 50 are formed, a window member 51 is attached to each measurement hole 50 .

Any one of the above-mentioned embodiments is described with respect to a polishing apparatus for polishing both sides of the wafer W, but it can also be applied to a polishing apparatus for polishing only one side of the wafer W. FIG.

In addition, although in the above-mentioned embodiment, when steps S20, S20', and S30 are performed, the processing operations from steps S21 to S26 are performed, but this is not a limitation. S26 is the same processing operation. In addition, although the case of polishing a silicon wafer has been described in the above-mentioned embodiment, it is not limited to this, and may be a thin plate-shaped workpiece such as glass, ceramics, crystal, or the like.

The present invention is not limited to the above-mentioned embodiments, and design changes or additions are allowed as long as they do not deviate from the gist of the invention as claimed in the scope of the patent application.

10‧‧‧grinding device 20‧‧‧grinding machine 21‧‧‧Fixed Order (Fixed Order) 22‧‧‧Fixing Order (Fixing Order) 23‧‧‧Sun Gear 23A‧‧‧hole 24‧‧‧Internal gear 25, 26‧‧‧Abrasive components 30‧‧‧Star Wheel Plate 30A‧‧‧Workpiece holding hole 40‧‧‧Support Stud 41‧‧‧Installation components 42‧‧‧Rod 43, 44, 47, 49‧‧‧Drive shaft 43A‧‧‧Top 44A‧‧‧Top 45‧‧‧Drive 46‧‧‧Hook 50‧‧‧Measuring hole 51‧‧‧Window Components 100‧‧‧Shape measuring device 101‧‧‧Optical head 102‧‧‧Laser oscillator 110‧‧‧Calculator 111‧‧‧Thickness Calculation Department 112‧‧‧Location Calculation Department 113‧‧‧Cross-section Shape Calculation Department 200‧‧‧Storage 300‧‧‧Controls M1-M5‧‧‧Driver W‧‧‧Wafer (Workpiece)

FIG. 1 is an explanatory diagram showing the structure of an embodiment of the polishing apparatus according to the present invention. FIG. 2 is an explanatory diagram showing the positional relationship of the sun gear, the internal gear, and the pinion plate shown in FIG. 1 . FIG. 3 is an explanatory diagram showing a table that is most suitable for a recipe based on the result of comparing the cross-sectional shape of the wafer to be measured and the cross-sectional shape of the target wafer. FIG. 4 is an explanatory diagram showing a table of processing conditions for each recipe. 5 is an explanatory diagram showing a cross-sectional shape of a wafer, a shape determined from the cross-sectional shape, and a P-V value. Fig. 6 is a flowchart showing the operation of the first embodiment. FIG. 7 is a flowchart showing the processing of the main processing steps of FIG. 6 . Fig. 8 is a flowchart showing the operation of the second embodiment.

10‧‧‧grinding device

20‧‧‧grinding machine

21‧‧‧Fixing (Fixing)

22‧‧‧Fixing Order (Fixing Order)

23‧‧‧Sun Gear

23A‧‧‧hole

24‧‧‧Internal gear

25, 26‧‧‧Abrasive components

30‧‧‧Star Wheel Plate

40‧‧‧Support Stud

41‧‧‧Installation components

42‧‧‧Rod

43, 44, 47, 49‧‧‧Drive shaft

43A‧‧‧Top

44A‧‧‧Top

45‧‧‧Drive

46‧‧‧Hook

50‧‧‧Measuring hole

51‧‧‧Window Components

100‧‧‧Shape measuring device

101‧‧‧Optical head

102‧‧‧Laser oscillator

110‧‧‧Calculator

111‧‧‧Thickness Calculation Department

112‧‧‧Location Calculation Department

113‧‧‧Cross-section Shape Calculation Department

200‧‧‧Storage

300‧‧‧Controls

M1-M5‧‧‧Driver

W‧‧‧Wafer (Workpiece)

Claims (3)

A grinding device for grinding a workpiece by a grinding machine having a rotatable plate, comprising: a shape measuring device for measuring the cross-sectional shape of the workpiece during grinding; and a control device for measuring the workpiece according to the shape measuring device The cross-sectional shape of the workpiece is controlled so that the cross-sectional shape becomes the target cross-sectional shape. When the cross-sectional shape of the workpiece measured by the shape measuring device does not reach the target cross-sectional shape, the control device changes the prescription according to the cross-sectional shape of the workpiece. , the prescription shows the appropriate machining conditions for making the cross-sectional shape the target cross-sectional shape, and the grinding process is repeatedly controlled according to the machining conditions of the changed prescription, when the cross-sectional shape of the workpiece measured by the shape measuring device reaches the target cross-sectional shape , if the thickness of the workpiece is not below the upper limit of the target thickness, the control device repeats the control of the grinding process without changing the prescription. When the cross-sectional shape of the workpiece measured by the shape measuring device reaches the target cross-sectional shape, if the thickness of the workpiece When the target thickness is equal to or less than the upper limit of the target thickness, the control device controls the next machining operation of the polishing process without changing the recipe. The polishing apparatus according to claim 1 of the scope of claim 1 is provided with: a storage unit for storing the prescription; wherein, when the control device controls the polishing process according to the machining conditions of the changed prescription, the control device measures the shape according to the shape. The cross-sectional shape of the workpiece measured by the device reads the prescription from the storage unit, and controls the grinding process according to the processing conditions of the read prescription. For example, the grinding device according to Item 1 or 2 of the scope of the application is provided with: The optical head receives the reflected light reflected by the workpiece while the shape measuring device irradiates the measuring light toward the workpiece through the measuring hole arranged on the platen; the thickness calculation device obtains the The measured thickness of the workpiece; a position calculation device for obtaining the in-plane position when the measured thickness of the workpiece is obtained; and a cross-sectional shape calculation device for obtaining the measured thickness of the workpiece according to the thickness calculation device and the position calculation device The obtained in-plane position is obtained, and the cross-sectional shape of the workpiece is obtained.

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