JP2001300845A - Polishing device and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a defective, and to reduce polishing time while repeatedly measuring the thickness without taking out workpiece from a polishing device. SOLUTION: This polishing device is composed of a workpiece installing part 5, a surface plate rotating mechanism 6 for rotating a surface plate 16, an abrasive grain spraying mechanism 9 for spraying an abrasive grain on a surface plate surface 26 and a polishing device control part 1 for controlling polishing by a plate thickness signal from a thickness meter 3. The workpiece installing part 5 is composed of a pressurizing mechanism 4 for applying pressure to the workpiece 27, a workpiece fixing part 2 for bringing the workpiece 27 into close contact with the surface plate surface 26 and the thickness meter 3 mounted on the polishing object fixing part 2. Plate thickness measured data from the thickness meter 3 is transferred to the polishing device control part 1 via a signal passage 7, and is transferred to the pressurizing mechanism 4 from the polishing device control part 1 via a signal passage 8. Since the polishing device control part 1 controls a surface plate rotating speed, pressurization to the workpiece and the grain size of the abrasive grain with a plate thickness as a parameter, there is no need to measure the thickness by taking out the workpiece from the polishing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing apparatus and a polishing method suitable for producing a semiconductor wafer or the like.

[0002]

2. Description of the Related Art Usually, a polishing process is included in a process for manufacturing a semiconductor wafer or the like. The basic configuration of a polishing apparatus that has been used conventionally includes a support that attaches a wafer to a surface plate to which an abrasive is applied and presses the wafer against the surface plate. The platen is rotated by the power of the motor. Further, the support is rotated by being pulled by the rotation of the surface plate. When the size of the device is large, the support may rotate by the force of the motor. Polishing is continued until the wafer reaches the desired thickness. When the target thickness is reached, polishing is stopped.

[0003] In the case of a material which has been polished or has been repeatedly polished, the timing of stopping is when a polishing time obtained by estimating the polishing speed has elapsed. The polishing is completed without actually measuring the thickness. Confirmation of the plate thickness is performed by taking out the wafer from the polishing apparatus. Further, in the case of a new material, since the polishing rate is unknown, a preliminary experiment for estimating the polishing rate was necessary.

[0004]

However, in the conventional polishing apparatus and the conventional polishing method, the steps of polishing, taking out the object to be polished from the polishing apparatus, and measuring the thickness (division of the polishing step) are repeatedly performed. However, it took a long time to finish the polishing. Also, the polishing accuracy is not high. Further, if the measured value when the object to be polished is taken out from the polishing apparatus and measured is smaller than the plate thickness, the wafer becomes unusable. Therefore, defective products are generated in the polishing process, and a long polishing time is required.

[0005] In order to polish efficiently, pressure control may be performed so that a large pressure is applied to the object to be polished when the plate thickness is large, and a small pressure is applied to the object to be polished when the plate thickness is small. In this case, too, the operator monitored the plate thickness and controlled this pressure. Further, the rotation speed of the platen may be high when the plate thickness is large, and may be low when the plate thickness is small. In this case as well, the operator monitors the plate thickness and controls the pressing unit of the polishing apparatus. Furthermore, it is necessary to change the particle size of the abrasive used for polishing. When the plate thickness is large, the polishing speed is increased by coarsening the grain size. When the plate thickness is small, it is necessary to increase the flatness by reducing the grain size and to suppress damage to the object to be polished. In this case as well, the operator similarly changed the abrasive grains.

The reason why polishing must be performed in such a state is that a thickness gauge capable of measuring a plate thickness during polishing is not mounted. Even if it is mounted, visual observation is impossible unless the rotation, revolution, or planetary rotation of the polishing apparatus is stopped. An operator is required for this visual inspection. That is, it is necessary for an operator to stick to the polishing apparatus during polishing, which is a factor that increases the man-hour value of polishing. The reason that the conventional polishing apparatus has such a structure is that the electric signal of the thickness gauge cannot be taken out to the outside because the support for the object to be polished is a rotating body.

The present invention has been made in view of the above points, and has a low polishing accuracy and a large number of man-hours in a polishing process (a preliminary experiment for estimating a polishing speed, a division of a polishing process for obtaining accuracy). Time loss), low yield in polishing, inadequate pressure control on the object to be polished, damage to the object to be polished due to improper selection of platen rotation speed and improper selection of abrasive size and reduction in polishing efficiency It is another object of the present invention to provide a polishing apparatus and a polishing method capable of solving problems such as an increase in man-hours due to the necessity of monitoring personnel during the polishing operation.

[0008]

In order to achieve the above object, the present invention relates to a method for mounting a polishing object on a support for a fixing portion of a polishing object, the method comprising: Have a mechanism that can take out to the outside, timely pressure control on the object to be polished by feeding back the signal to the polishing device, automatic selection of polishing abrasive grains, control of the number of revolutions of the platen, and target The main feature is that the polishing apparatus can be stopped at the same time as the plate thickness is increased. The thickness gauge and its electric signal extraction mechanism are different from the conventional technology.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, a polishing apparatus of the present invention has a polishing object 27 brought into close contact with a surface plate 16 having a surface to which an abrasive is applied or a surface having file-like irregularities. A polishing apparatus for polishing the object to be polished 27 by a relative movement between the object to be polished 27 and the platen 16,
Mechanism 4 for applying pressure to the platen, and the object to be polished 27
6, a polished work fixing portion 2 to be brought into close contact with 6, and a polished work mounting portion 5 including a thickness gauge 3 for measuring the thickness of the polished work 27;
It is composed of a platen rotating mechanism 6 for rotating the platen 16, an abrasive spraying mechanism 9 for spraying abrasive grains on the platen surface 26, and a polishing apparatus controller 1 for controlling the polishing by a thickness signal from the thickness gauge 3. It is characterized by being done.

The polishing apparatus according to the present invention is characterized in that the thickness signal from the thickness gauge 3 is transmitted to the polishing apparatus control unit 1 by radio.

Further, the polishing apparatus of the present invention is characterized in that the thickness signal from the thickness gauge 3 is transferred to the polishing apparatus control section 1 via the signal extraction terminal 40 of the workpiece fixing section 2. Have.

Further, the polishing apparatus of the present invention has an actuator 36 for pressing the vacuum suction portion 28 for sucking the workpiece 27 to the pressing mechanism 4 downward with reference to one end of the workpiece fixing portion 2. Has features.

In order to solve the above-mentioned problem, the polishing method of the present invention is characterized in that the pressing mechanism 4 is controlled by a thickness signal from the thickness gauge 3 sent from the polishing apparatus controller 1. I have.

Further, the polishing method of the present invention uses the thickness signal from the thickness gauge 3 sent from the polishing device control unit 1 to
It is characterized in that the platen rotating mechanism 6 is controlled.

Further, the polishing method according to the present invention is characterized in that the abrasive spray mechanism 9 is controlled by a thickness signal from the thickness gauge 3 sent from the polishing apparatus control section 1.

The polishing method of the present invention is characterized in that polishing is performed by repeating the thickness measurement after the rotation of the surface plate 16 is stopped and the polishing after the measurement.

Further, the polishing method of the present invention is characterized in that the thickness is measured a plurality of times and polishing is performed based on an average value thereof.

Further, the polishing method of the present invention is characterized in that the thickness is measured at predetermined time intervals during polishing, and polishing is performed by setting the polishing time and polishing conditions based on the relationship between the obtained time and the change in thickness. have.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a polishing apparatus according to the present invention, a thickness gauge is mounted on a support portion of an object-to-be-polished fixed portion, and a thickness signal thereof can be taken out even while the object-to-be-polished fixed portion is rotating. Is fed back to the polishing apparatus, and the polishing apparatus can be stopped at the same time when the target plate thickness is obtained. In addition, the polishing method according to the present invention automatically measures the thickness in real time during polishing, and the signal is fed back to the rotation mechanism of the polishing platen to control and stop the rotation speed of the platen. is there. Therefore, a preliminary experiment for estimating the polishing rate is unnecessary even for a new material. By feeding the signal back to the pressurizing mechanism, optimal pressurization of the object to be polished is possible. Also, by feeding back the thickness signal from the thickness gauge to the abrasive spraying mechanism capable of selecting the particle size of the abrasive to be sprayed, it is possible to select the optimal abrasive.

Next, a polishing apparatus according to an embodiment of the present invention will be described. The embodiment is merely an example, and it goes without saying that various changes or improvements can be made without departing from the spirit of the present invention.

(Embodiment 1) FIG. 1 is a block diagram of a polishing apparatus according to the present invention. The configuration of the polishing apparatus is as follows: the polishing apparatus control section 1, the workpiece fixing section 2, the thickness gauge 3, the pressing mechanism 4, the workpiece mounting section 5, the platen rotating mechanism 6, and the thickness gauge 3. , A signal path 8 from the polishing apparatus controller 1 to the pressurizing mechanism 4, and an abrasive spray mechanism 9.

The measurement data from the thickness gauge 3 is transferred to the polishing apparatus controller 1 via the signal path 7. In the polishing apparatus controller 1, in order to efficiently perform high-quality polishing, the rotation speed of the platen, the pressure applied to the workpiece,
In addition, control having a program mechanism for the grain size of the abrasive grains is possible. The board thickness signal from the thickness gauge 3 is transferred from the polishing apparatus controller 1 to the pressing mechanism 4 via the signal path 8. Further, control signals from the polishing apparatus controller 1 to the platen rotating mechanism 6 and the abrasive grain rotating mechanism 9 are transferred by a generally used electric signal cable.

FIG. 2 shows the structure of a polishing apparatus according to the present invention. The polishing apparatus according to the present invention includes an object to be polished 2 that is detachable from the polishing apparatus and a vacuum exhaust hose outlet 1 for a vacuum chuck.
1. Thickness gauge 3, auxiliary rotation mechanisms 13 and 14 for rotation of object-to-be-polished fixed part 2, support arms 15 for auxiliary rotation mechanisms 13 and 14, platen 16, polishing machine stand 17, platen surface forming ring 18,
Auxiliary rotation mechanism 19, 2 for rotation of platen surface forming ring 18
0, the support arms 21 of the auxiliary rotation mechanisms 19 and 20, the polishing apparatus control unit 1, the abrasive material A ejection portion 23, and the abrasive material B ejection portion 2
4 and an ejection portion 25 of the abrasive C.

Next, the mechanism of each part will be described. Surface plate 16
Rotates in the direction of the arrow in the figure. The workpiece fixing portion 2 is rotated by the rotation of the platen 16 in the direction of the arrow in the drawing. Here, the evacuation hose outlet 11 is not fixed. An auxiliary rotation mechanism 13 for rotating the object-to-be-polished
Reference numeral 14 denotes a fixing jig for preventing the object-to-be-polished fixing portion 2 from moving on the surface plate 16, and the object-to-be-polished fixing portion 2 being fixed to the surface
It also serves to assist the self-rotation by the rotation of 6. In addition, the auxiliary rotation mechanisms 13 and 14 respectively rotate in the direction of the arrow in the drawing as the polished work fixing portion 2 rotates. Signal transmission between the thickness gauge 3 mounted on the polished-substrate fixing unit 2 of the polished-substrate mounting unit 5 and the polishing-apparatus controller 1 was performed by radio. As the thickness gauge 3, a dial gauge was used. Thereby, even if the relative positional relationship between the workpiece mounting unit 5 and the polishing apparatus control unit 1 changes, or even if the workpiece mounting unit 5 rotates with respect to the polishing apparatus control unit 1. , Signals can be exchanged.

The object to be polished is fixed to the object-to-be-fixed part 2 by vacuum suction. The evacuation for this purpose is performed by a vacuum evacuation hose provided at the center of the object-to-be-polished fixed part 2. Was. A commercially available vacuum secret rotary port was used for connection of this hose. For this reason, even if the workpiece fixing part 2 rotates, the hose does not rotate and the evacuation can be continued, and the workpiece can be stably fixed to the workpiece fixing part 2. The surface of the platen surface forming ring 18 used here that is in contact with the platen 16 is formed by a vapor phase diamond, and is mounted on the platen throughout the polishing, and rotates with the rotation of the platen 16. During this time, the platen surface is polished by the gas phase diamond of the platen surface forming ring 18 to maintain its flatness.

Here, a signal path 7 for transferring a thickness signal from the thickness gauge 3 of the workpiece mounting section 5 to the polishing apparatus control section 1 and a signal path from the polishing apparatus control section 1 to the pressing mechanism 4. Although the wireless communication is used as 8, an infrared light widely used for connection to a personal computer or a printer at present may be used.

(Embodiment 2) In Embodiment 1, a signal path 7 from the thickness gauge 3 to the polishing apparatus control section 1 for transferring a signal between the workpiece mounting section 5 and the polishing apparatus control section 1 and polishing are performed. Although wireless was used as the signal path 8 from the device control unit 1 to the pressurizing mechanism 4, in this embodiment, the polished work fixing unit 2 on which the thickness gauge 3 is mounted has an electrode, and Thickness meter 3 via an electrode terminal installed in an area other than polishing object fixing portion 2
Is transferred to the polishing apparatus control unit 1.
Hereinafter, this will be described.

FIG. 3 is a view showing the fixing portion 2 of the object to be polished in FIG.
FIG. 2 is a vertical cross-sectional view taken through the evacuation hose outlet 11 and the center of the thickness gauge 3, and shows a state in which an object-to-be-polished fixing portion 2 on which an object-to-be-polished 27 is fixed is mounted on a surface 26 of a surface plate 16. Is shown. That is, the object to be polished 27 is vacuum-adsorbed and fixed at the vacuum suction port 29 of the vacuum suction section 28. The object-to-be-polished fixing portion 2 is composed of a vacuum suction portion 28, a vacuum suction port 29, and a support portion 32 in which these are provided. The vacuum suction section 28 is evacuated from a vacuum pump inlet 31 via a vacuum rotary connector 30 provided above. Since the vacuum rotary connector 30 is used, the vacuuming hose is not twisted even when the polished work fixing portion 2 rotates. The vacuum suction unit 28
It is contained in the support portion 32 of the fixed portion 2 of the object to be polished. A gap is maintained between the vacuum suction part 28 and the support part 32 of the object-to-be-polished fixing part 2 by a sliding ring 33 so that they slide.

The thickness of the object to be polished 27 is
The probe 37 is disposed so that the tip of the probe 37 is in contact with the upper surface of the vacuum suction unit 28. The signal from the thickness gauge 3 is applied to the insulator 3 on the outer periphery of the support portion 32 of the workpiece fixing portion 2.
Signal take-out terminal 4 of thickness gauge attached via 9
It is led to 0. The insulator 39 and the signal extraction terminal 40
Extends around the outer periphery of the support portion 32 of the fixed portion 2 of the object to be polished. The thickness gauge 3 and the signal extraction terminal 40 may be connected by an electric cable (not shown). Since the thickness gauge 3 and the signal extraction terminal 40 are both mounted on the support portion 32, the relative position does not change even if the support portion 32 rotates, so that the electric cable is not twisted. The anti-polishing part 3
Numeral 8 is made of cemented carbide, is much harder than the object to be polished 27, and hardly wears.

Next, a mechanism for extracting a signal from the thickness gauge signal extraction terminal 40 to the outside of the support portion 32 of the workpiece fixing portion 2 will be described with reference to FIGS. FIG. 4 is a plan view, and FIG. 5 is an elevation view. The signal extraction terminals 40 of the thickness gauge are insulated from each other by the insulator 39,
Further, it is also insulated from the support portion 32 of the polishing object fixing portion 2. Auxiliary rotation mechanism 13, 1 for rotating the object-to-be-polished fixed part 2
4. Support arm 1 for supporting auxiliary rotation mechanisms 13 and 14
By 5, the object-to-be-polished fixing portion 2 having the support portion 32 of the object-to-be-polished fixing portion 2 as a main component is swung on the surface plate 16. An actuator 46, a support spring 47, an electrode support 48, and an electrode 49 attached to the electrode support 48 are mounted on the support arm 15. A lead wire 50 extends from the electrode 49, and a signal of the thickness gauge 3 can be taken out from the lead wire 50.

In the drawing, reference numeral 51 denotes the rotation direction of the platen 16, reference numeral 52 denotes the rotation direction of the workpiece fixing portion 2, and reference numeral 53 denotes the swing direction of the swing mechanism. Actuator 4 used here
6 functions to press the electrode 49 against the signal extraction terminal 40. The actuator 46 has a pressure sensor (not shown) so that a force exceeding a certain level is not applied from the electrode 49 to the signal extraction terminal 40. In order to increase the contact area between the signal extraction terminal 40 and the electrode 49 and not to apply a lateral force to the polished-piece fixing portion 2, the electrode support 48 and the electrode 4
9 is made to be less rigid. actually,
A plastic sheet was used for the electrode support 48, and phosphor bronze having a thickness of 0.1 μm was used for the electrodes 49.

Embodiment 3 Returning to FIG. 3, the pressurizing mechanism will be described. A pressure spring 34 provided on the outer circumference of the pipe and a pressing plate 35 for pressing the pressure spring 34 downward are incorporated in the vacuum suction unit 28. This pressing plate 35
An actuator 36 is disposed between the support portion 32 of the workpiece fixing portion 2 and the support portion 32. That is, the actuator 36 extends with the support portion 32 as a fulcrum, and presses the pressing plate 35 downward to press the workpiece 27. The actuator 36 has a pressure sensor (not shown) so that an arbitrary pressure can be applied from the outside.

Further, a polishing method according to an embodiment of the present invention will be described with reference to a flowchart. FIG. 6 is a flowchart illustrating a polishing process based on a thickness signal from the thickness gauge 3. As an example, a sapphire substrate having a thickness of 330 μm is polished to a target thickness of 50 μm.

Polishing device operation: The polishing device is started manually. Thickness gauge: First, the thickness of the sheet is automatically measured by the operation of the polishing apparatus. Plate thickness> 100 μm: A polycrystalline diamond having an abrasive size of 9 μm is sprayed onto the platen 16 together with a dispersant from a jet portion of the abrasive material A of the abrasive grain spray mechanism according to a program. next,
A pressure of 2 kg / cm ² is applied to the sapphire substrate from the pressing mechanism, and the platen 16 rotates at a speed of 20 rpm by the platen rotating mechanism. This series of operations is automatically performed by the polishing apparatus controller. Thus, polishing starts. During the polishing, the fixed part of the object to be polished and the plate thickness of the surface plate molding tool are constantly measured.

Plate thickness> 60 μm: When the plate thickness reaches 100 μm, the pressure applied to the sapphire substrate is 0 kg
/ Cm ² , and water flows on the surface of the surface plate 16, and diamond particles on the surface of the surface plate are removed by the surface surface forming ring. This time was set to 10 minutes in this embodiment.
Thereafter, the water stops, and a polycrystalline diamond having an abrasive size of 3 μm is sprayed onto the platen 16 together with the dispersant from the ejection portion of the abrasive B. A pressure of 1 kg / cm ² is applied to the sapphire substrate, and the platen 16 rotates at a speed of 15 rpm. Thus, polishing is restarted.

Plate thickness> 50 μm: When the plate thickness reaches 60 μm, the pressure applied to the sapphire substrate is 0 kg /
cm ² , water flows on the surface of the surface plate 16, and diamond particles on the surface of the surface plate are removed by the surface surface forming ring. This time was set to 10 minutes in this embodiment. After that, the water stops and the abrasive grain size 1
A polycrystalline diamond of μm is sprayed on the platen 16 together with a dispersant. A pressure of 0.5 kg / cm ² is applied to the sapphire substrate, and the platen 16 rotates at a speed of 10 rpm.
Thus, polishing is restarted.

Stopping of the polishing apparatus: When the plate thickness became 50 μm, the pressure applied to the sapphire substrate was reduced to 0 kg / c.
m ² , the rotation of the platen 16 stops, and the polishing is completed. The above series of operations are automatically performed. As a result, a desired plate thickness can be obtained by polishing in a short time. Further, since the polishing is not excessively performed, the yield of the process is high. Further, since an appropriate rotation speed of the platen and an appropriate pressure to the object to be polished 27 are applied according to the thickness of the object to be polished,
Is not damaged. This further increases the yield.

FIG. 7 is a flowchart showing a polishing process based on the repetition of the measurement of the thickness after stopping the rotation of the surface plate and the subsequent polishing. When polishing a new material which has not been polished so far, the polishing rate is unknown. Therefore, it is necessary to measure the polishing rate several times and carefully carry out the polishing, so that a long time of several tens of hours may occur. On the other hand, if the polishing is performed with carelessness for a long time, the plate thickness may be too thin or the workpiece 27 may be damaged. In this embodiment, when the object to be polished 27 without polishing data is polished for the first time, the polishing is efficiently performed while setting the optimum polishing conditions. As an example, plate thickness 33
A 0 μm sapphire substrate is polished to a target thickness of 50 μm.

Polishing apparatus surface plate stopped state: This is the initial state when the polishing apparatus is manually started. Thickness measurement: Thickness measurement: The thickness of the sapphire substrate is measured when the surface plate 16 of the polishing apparatus is in a stopped state. Plate thickness> 100 μm: A polycrystalline diamond having an abrasive size of 9 μm is sprayed onto the platen 16 together with a dispersant from a jet portion of the abrasive material A of the abrasive grain spraying mechanism according to a program. next,
A pressure of 2 kg / cm ² is applied to the sapphire substrate from the pressing mechanism, and the platen 16 rotates at a speed of 20 rpm by the platen rotating mechanism. Polishing device operation: Polishing device platen stopped after polishing for 10 minutes → thickness measurement of thickness gauge → polishing at plate thickness> 100 μm →
After polishing for 10 minutes, the polishing apparatus surface plate stop state is repeated.

Plate thickness> 60 μm: When the plate thickness reaches 100 μm, the pressure applied to the sapphire substrate is 0 kg
/ Cm ² , and water flows on the surface of the surface plate 16, and diamond particles on the surface of the surface plate are removed by the surface surface forming ring. This time was set to 10 minutes in this embodiment.
Thereafter, the water stops, and a polycrystalline diamond having an abrasive size of 3 μm is sprayed onto the platen 16 together with the dispersant from the ejection portion of the abrasive B. A pressure of 1 kg / cm ² is applied to the sapphire substrate, and the platen 16 rotates at a speed of 15 rpm. Thus, polishing is restarted. Polishing device operation: after polishing for 10 minutes, polishing device surface plate stopped → Thickness gauge thickness measurement → Thickness> 100 μm → Thickness> 60 μ
Polishing at m → After polishing for 10 minutes, the polishing apparatus surface plate stop state is repeated.

Plate thickness> 50 μm: When the plate thickness reaches 60 μm, the pressure applied to the sapphire substrate is 0 kg /
cm ² , water flows on the surface of the surface plate 16, and diamond particles on the surface of the surface plate are removed by the surface surface forming ring. This time was set to 10 minutes in this embodiment. After that, the water stops, and the abrasive grain size 1
A polycrystalline diamond of μm is sprayed on the platen 16 together with a dispersant. A pressure of 0.5 kg / cm ² is applied to the sapphire substrate, and the platen 16 rotates at a speed of 10 rpm.
Thus, polishing is restarted. Polishing device operation: after polishing for 10 minutes, polishing device surface plate stopped → Thickness gauge thickness measurement → Thickness> 100 μm → Thickness> 60 μ
m → polishing at plate thickness> 50 μm → after polishing for 10 minutes, the polishing apparatus surface plate is stopped repeatedly.

Stopping of the polishing apparatus: When the plate thickness became 50 μm, the pressure applied to the sapphire substrate was reduced to 0 kg / c.
m ² , the rotation of the platen 16 stops, and the polishing is completed. The above series of operations are automatically performed, and a desired plate thickness can be obtained. Further, since the polishing is not excessively performed, the yield of the process is high. In addition, since an appropriate platen rotation speed and pressure on the object to be polished are applied according to the plate thickness,
The object to be polished 27 is not damaged. This further increases the yield.

FIG. 8 is a flowchart for calculating the average value of the sheet thickness from a plurality of sheet thickness measurements. n = 0: n is set to 0 as an initial value. n = n + 1: Each time n = n + 1 is passed, the value of n is incremented by one. n ≦ 5: Check whether n is 5 or less. Here, the value of n is one less than the actual number of thickness measurements. Polishing device surface plate stopped state: When n is 5 or less, the surface plate 16 is stopped. Thickness gauge thickness measurement d (n): The thickness is measured. Polishing device platen rotation: Polishing is performed for 1 minute by platen rotation → n
= N + 1 → n ≤ 5 → polishing machine base plate stopped state → thickness gauge thickness measurement d (n) → polishing machine base plate rotation is repeated until n reaches 6. Thickness gauge, thickness calculation, D = ｛d (1) + d (2) + d
(3) + d (4) + d (4)｝ / 5: 5 by thickness meter 3
The average thickness is calculated from the measured thickness values.

FIG. 9 is a flowchart for obtaining polishing conditions by performing plate thickness measurement at predetermined time intervals. Initial setting conditions: platen rotation speed 20 rpm, pressurization 2 kg /
cm ² and abrasive grains are 9 μm. Polishing start: Polishing is started. Thickness gauge: First thickness measurement d (1) is performed 10 minutes after the start of polishing. Thickness gauge: Second thickness measurement d (2) 20 minutes after the start of polishing
I do. Estimation of polishing rate: V = {d (1) + d (2)} / 30 is calculated. Output polishing rate: Output the calculated value from the equation as the polishing rate. The polishing conditions are output to the polishing apparatus from the correspondence table between the speed and the polishing conditions.

When the thickness is measured by the thickness gauge 3, noise may be generated due to vibration or the like, and the data may vary. The source of noise is often due to the vibration of the platen 16 or the distribution of abrasive grains. In other words, the vibration of the surface plate 16 is a vibration in the plane of the surface plate 16 or a vibration in a direction perpendicular to the surface due to the deflection of the surface plate surface 26. In addition, when abrasive grains are the cause,
6 due to the non-uniform distribution. The greater the size of the abrasive grains and the lower the concentration of the abrasive grains, the greater the effect. In this embodiment,
How to use the thickness gauge 3 in such a case will be described.

When the surface plate is a cause of noise, the surface plate 16 is temporarily stopped, and thereafter, the thickness is measured. Thereby, noise due to vibration can be prevented. in this case,
If a microprocessor is mounted on the thickness gauge 3 and the procedure of this measurement is programmed, the measurement can be performed automatically. When there is a bend that impairs the flatness of the platen surface 26, the above measurement is repeated, and the average value of the obtained data is used as the measured value.

If the abrasive grains cause noise, the measurement is repeated, and the average value is used as the measured value. The thickness is measured by the method described above, the value is transferred to the polishing device controller, and the pressurizing mechanism, the platen rotating mechanism, and the abrasive spraying mechanism are controlled, and the processing is performed efficiently and with high accuracy. Polishing with less damage can be performed.

[0048]

As described above, when the polishing is performed using the polishing apparatus and the polishing method of the present invention, the thickness of the object to be polished is sequentially measured and added to the object to be polished depending on the thickness. Pressure adjustment, control of the rotation speed of the platen, and selection of abrasive grains can be performed. In particular, if the thickness gauge and these functions are linked, optimal polishing can be performed in a fully automatic manner and in the shortest time while minimizing processing damage to the object to be polished. From the above advantages,
Improvement of polishing efficiency by the polishing apparatus and the polishing method,
It is possible to reduce manpower, improve polishing accuracy, and improve yield. In particular, it exhibits the best performance for polishing materials that have no polishing experience. This has a great effect on industry and materials / parts research.

[Brief description of the drawings]

FIG. 1 is a block diagram of a polishing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a polishing apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view of a polishing apparatus according to an embodiment of the present invention.

FIG. 4 is a plan view showing a mechanism for extracting a thickness gauge signal of the polishing apparatus according to the embodiment of the present invention.

FIG. 5 is an elevational view showing a mechanism for extracting a thickness gauge signal of the polishing apparatus according to the embodiment of the present invention.

FIG. 6 is a flowchart illustrating a polishing step based on a thickness signal from a thickness gauge in the polishing method according to one embodiment of the present invention.

FIG. 7 is a flowchart showing a polishing process based on repetition of the measurement of the thickness after stopping the rotation of the surface plate and the subsequent polishing in the polishing method of one embodiment of the present invention.

FIG. 8 is a flowchart for calculating an average value of sheet thickness from a plurality of sheet thickness measurements in the polishing method according to one embodiment of the present invention.

FIG. 9 is a flowchart for obtaining a polishing condition by performing a thickness measurement at predetermined time intervals in the polishing method according to one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polishing apparatus control part 2 Polishing object fixing part 3 Thickness gauge 4 Pressurizing mechanism 5 Polishing object mounting part 6 Surface plate rotation mechanism 7 Signal path 8 Signal path 9 Abrasive spray mechanism 11 Vacuum exhaust hose outlet 13 Auxiliary rotation mechanism 14 Auxiliary rotation mechanism 15 Support arm 16 Surface plate 17 Mount 18 Surface plate forming ring 19 Auxiliary rotation mechanism 21 Auxiliary rotation mechanism 21 Abrasive material A ejection part 24 Abrasive material B ejection part 25 Abrasive material C ejection part 26 Constant Board surface 27 Polished object 28 Vacuum suction part 29 Vacuum suction port 30 Vacuum rotary connector 31 Vacuum pump inlet 32 Support part 33 Slip ring 34 Pressing spring 35 Pressing plate 36 Actuator 37 Probe 38 Polishing part 39 Insulator 40 Signal Take-out terminal 46 Actuator 47 Support spring 48 Electrode support 49 Electrode 50 Lead wire 51 Rotation direction of platen 52 Cover Swinging direction of rotation 53 swinging mechanism Migakubutsu fixing portion

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/304 622 H01L 21/304 622S

Claims (10)

[Claims] An object to be polished (2) is placed on a surface plate (16) having an abrasive-applied surface or a surface having file-like irregularities.
7) is a polishing apparatus for polishing the object to be polished (27) by bringing the object to be polished (27) into close contact with the object to be polished (27) by relative movement of the object to be polished (27) and the platen (16). A pressure mechanism (4), an object-to-be-fixed part (2) for bringing the object (27) into close contact with the surface plate (26), and a thickness gauge (3) for measuring the thickness of the object (27). A workpiece mounting portion (5) composed of: a surface plate rotating mechanism (6) for rotating a surface plate (16); and an abrasive grain spraying mechanism (9) for spraying abrasive grains onto a surface (26) of the surface plate.
A polishing apparatus, comprising: a polishing apparatus control section (1) for controlling polishing by a thickness signal from a thickness gauge (3). 2. The polishing apparatus according to claim 1, wherein a thickness signal from the thickness gauge (3) is wirelessly transmitted to the polishing apparatus control section (1). 3. The polishing apparatus according to claim 1, wherein a thickness signal from the thickness gauge is transferred to the polishing apparatus control section via the signal extraction terminal of the workpiece fixing section. A polishing apparatus, characterized in that: 4. The pressing mechanism (4) according to claim 1, wherein the pressing mechanism (4) includes a vacuum suction unit (28) for suctioning the workpiece (27) and one end of the workpiece fixing unit (2). A polishing apparatus comprising an actuator (36) for pressing downward with respect to a reference. 5. The polishing method according to claim 4, wherein the pressing mechanism (4) is controlled by a thickness signal from a thickness gauge (3) sent from the polishing apparatus controller (1). . 6. The polishing machine according to claim 1, wherein the platen rotating mechanism (6) is controlled by a thickness signal from a thickness gauge (3) sent from the polishing apparatus control section (1). Method. 7. The polishing method according to claim 1, wherein the abrasive spray mechanism (9) is controlled by a thickness signal from a thickness gauge (3) sent from the polishing apparatus control section (1). Method. 8. The polishing method according to claim 1, wherein the polishing is performed by repeating the thickness measurement after the rotation of the platen (16) is stopped and the polishing after the measurement. 9. The polishing method according to claim 1, wherein the thickness is measured a plurality of times, and polishing is performed based on an average value thereof. 10. The polishing method according to claim 1, wherein the thickness is measured during polishing at predetermined time intervals, and polishing is performed by setting a polishing time and polishing conditions based on a relationship between the obtained time and a change in thickness. Polishing method.