JPH11291167A - Polishing device and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly polish the polishing object surface at a fast polishing speed by arranging the polishing pad vibrating part for applying vibrational motion to a polishing pad. SOLUTION: A wafer 1 being a polishing object member is installed in a wafer holding mechanism 2, the wafer holding mechanism 2 is lowered by depending on a lifting mechanism, and the polishing object surface of the wafer 1 is placed on a polishing pad 3 to be pressurized by a pressurizing mechanism. The wafer holding mechanism 2 is also connected to a wafer vibrating body for applying vibration in the horizontal direction 32 together with a rotary shaft 31 of the wafer rotating part to apply rotary motion and vibrational motion to the wafer 1. The polishing pad 3 has a plate shape, and is fixed to a platen 4 being a polishing pad holding mechanism. Vibrational motion is applied to the platen 4 by the polishing pad vibration part. During polishing, an abrasive 7 is dripped on the polishing pad 3 from a supply pipe 6 of the abrasive to polish the polishing object surface of the wafer 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polishing apparatus for flattening semiconductor devices on a wafer in a semiconductor process.

[0002]

2. Description of the Related Art In a semiconductor process for forming a semiconductor device on a wafer, a patterned electrode layer and a dielectric layer as an interlayer insulating film of the electrode layer are laminated. A step which is an influence is caused, and the existence of the step becomes a hindrance to a semiconductor process such as a subsequent exposure step. Therefore, a demand for flattening the step is increasing with a high definition of a semiconductor device pattern.
Further, there is a high demand for so-called inlay (plug, damascene) for embedding a metal electrode layer. In this case, removal and flattening of an extra metal layer after lamination of the metal layer are indispensable steps.

As a method of flattening the surface of a semiconductor device, a chemical mechanical polishing (Chemical Mechanical Polishing) method is used.
ng or Chemical Mechanical Planarization (hereinafter referred to as CMP) technology is considered a promising method. C
In a general MP method, a polishing pad having a polishing cloth or a polymer material is attached to a polishing platen, and a slurry-type polishing agent (hereinafter, simply referred to as a polishing agent) is dropped while the polishing platen is covered with the polishing pad. In this method, a polishing head holding a wafer as a polishing member is rotated and vibrated to polish a semiconductor device surface layer in the middle of the process.

FIG. 8 shows a conventional belt-type polishing apparatus. The polishing pad 105 has a belt shape and is fixed to a conveyor belt material. This is a polishing method in which a belt-shaped polishing pad is moved linearly in one direction, and the polishing is performed by rotating a polishing head 106 to which a wafer as a member to be polished is fixed. The polishing pad 105 moves linearly, and has a motion corresponding to the vibration.

FIGS. 7A and 7B show a conventional disk-shaped polishing apparatus. 100 is a polishing platen called a platen, 101 is a polishing pad, 102 is a wafer, 1
03 is a polishing head for holding a wafer, and 104 is a slurry supply mechanism. This polishing apparatus is an apparatus for rotating a platen and a polishing head in the same direction at substantially the same rotational speed while applying a load P to a surface to be polished of a wafer, and further oscillating to polish a semiconductor device surface on the wafer. FIG. 7B is a view of the disc-shaped polishing apparatus of FIG. 7A as viewed from above.

[0006]

The conventional CMP polishing apparatus has the following problems. The conventional belt-shaped polishing apparatus shown in FIG. 8 generally requires flexibility since the polishing pad 105 has a belt shape. Therefore, in the polishing state, when the polishing head 106 presses and presses the belt-shaped polishing pad surface, the surface where the belt comes into contact with the polishing head surface 108 so that the polishing pad surface does not deform from a planar shape. Provided a flat polishing platen 107.

This polishing apparatus has the following problems. The first is the problem of deformation of the polishing pad surface shape due to frictional force. The polishing pad moves between the polishing platen and the polishing head surface against the frictional force generated by the pressing force of the polishing head, and is deformed by the frictional force generated by the pressing force. The amount of deformation is proportional to the magnitude of the frictional force, and the magnitude of the frictional force is proportional to the friction coefficient, the pressing force, and the moving speed of the polishing pad. This frictional force occurs more or less in all types of polishing equipment, but in this type of polishing equipment there is the problem that the polishing pad is generally flexible and therefore more strongly affected by this frictional force. . Even if the magnitude of the frictional force is the same, the shape of the polishing pad surface is more greatly deformed than in the case of a polishing apparatus in which the polishing pad is fixed to a hard polishing platen. Due to this deformation, there arises a problem that it is difficult to ensure the uniformity of the polishing rate in the wafer surface. The second problem is that the operation of replacing a new polishing pad into a belt when the polishing pad is worn out requires a long period of equipment downtime. Therefore, there is a problem that the throughput is reduced. The third problem is that this type of polishing apparatus has rollers 109 at both ends for movement of the polishing pad, so that the apparatus becomes large and the installation area of the apparatus becomes large. A fourth problem is that it is difficult for this type of polishing apparatus to make the polishing film thickness uniform at each point on the surface to be polished of the wafer. These lead to an increase in the cost of CMP polishing and a decrease in quality.

The conventional disk-shaped polishing apparatus shown in FIG. 7 has a problem that the weight of the apparatus is as heavy as 2 to 4 tons because the platen is thick and heavy, and the apparatus is large. Also,
With this type of polishing apparatus, it has been extremely difficult to make the polishing rate uniform at each point on the surface to be polished of the wafer, and hence to make the polishing film thickness uniform. These led to an increase in cost and quality in CMP polishing.

The present invention solves the above-mentioned problems. The polishing rate is high, uniform polishing is possible, and the operation rate is high.
An object of the present invention is to provide a compact CMP polishing apparatus having a high throughput.

[0010]

In order to solve the above problems, the surface shape of a polishing pad of a conventional polishing apparatus is made hard to be deformed by a pressing force, and the polishing pad can be easily regenerated or replaced. After examining whether it can be moved like a belt in a shape, if the polishing pad is fixed on a hard surface plate and this is vibrated by the polishing pad vibrating part, the polishing effect is almost equivalent to the belt-like movement I noticed that

In order to solve the above problems, the present invention firstly provides a polishing apparatus for polishing a member to be polished having a polishing pad portion and a member to be polished, wherein the member to be polished is A member-to-be-polished holding mechanism for holding the member-to-be-polished; and one of a member-to-be-polished rotating portion for giving a rotational motion to the member-to-be-polished or a member-to-be-polished vibrating portion for giving a vibration motion to the member-to-be-polished. A polishing apparatus comprising: a polishing pad holding mechanism for holding the polishing pad in the polishing pad unit; and a polishing pad vibrating unit for giving a vibration motion to the polishing pad. 1) ”.

Second, the polishing apparatus according to claim 1, wherein the direction of the vibration motion of the member to be polished and the direction of the vibration motion of the polishing pad are orthogonal to each other. I will provide a. Thirdly, "the polishing pad portion includes a polishing agent supply mechanism."
A polishing apparatus according to any one of claims (Claim 3) "is provided.

Fourth, the polishing apparatus according to any one of claims 1, 2, and 3, wherein the polishing pad portion is located below the holding portion of the member to be polished in the direction of gravity. Item 4) "is provided. Fifth, a polishing method for polishing using the polishing apparatus according to any one of claims 1, 2, 3, and 4, wherein the rotation speed of the rotational movement of the member to be polished is 10 rpm or more and 300 rpm or less and A polishing method comprising the steps of: polishing a member at a vibration frequency of 0.1 Hz or more and 10 KHz or less and a vibration frequency of a polishing pad at 0.1 Hz or more and 10 KHz or less. "I will provide a.

Sixth, a polishing method for polishing using the polishing apparatus according to any one of claims 1, 2, 3, and 4, wherein the rotational speed of the member to be polished and the vibration of the vibration of the polishing pad are performed. And polishing while keeping the number constant, and polishing while continuously changing the frequency of vibration of the polishing pad while keeping the rotation speed of the rotation of the member to be polished constant. A method (claim 6) is provided.

Seventh, a polishing pad vibrator for causing the polishing pad vibrator to directly vibrate the polishing pad;
A polishing pad control unit for controlling one or both of the frequency and the amplitude of the polishing pad vibrating body, and the polished member vibrating body, wherein the polished member vibrating unit directly applies vibration to the polished member, 2. A polishing target member vibration control unit for controlling one or both of a frequency and an amplitude of the polishing target member vibrating body.
A polishing apparatus according to any one of claims 2, 3, and 4 (claim 7). "

Eighthly, "a polishing pad vibrator for causing the polishing pad vibrator to directly vibrate the polishing pad;
A polishing pad control unit for controlling one or both of the frequency and the amplitude of the polishing pad vibrating body, and the polished member vibrating body, wherein the polished member vibrating unit directly applies vibration to the polished member, A polishing mechanism for controlling one or both of a frequency and an amplitude of the polished member vibrating member, wherein the polished member rotating unit rotates the polished member continuously or in a fixed position. When,
A polishing apparatus (Claim 8) according to any one of claims 1, 2, 3, and 4, further comprising: a polishing target rotation control unit configured to control the polishing target rotation mechanism. .

Ninth, a polishing apparatus according to any one of claims 7 and 8, further comprising a phase difference control unit for controlling a phase difference between the vibration of the polishing pad and the vibration of the member to be polished. And a polishing apparatus (Claim 9). Tenthly, a polishing method for polishing using the polishing apparatus according to any one of claims 7, 8, and 9, wherein at least two or more selected from phase difference, frequency, amplitude, or rotation of a member to be polished. A polishing method characterized by having a step of polishing while controlling the polishing rate (claim 10). "

Eleventh, "the polishing apparatus according to any one of claims 1, 2, 3, 4, 7, 8, and 9 wherein the member to be polished is a wafer (claim 11)" I will provide a.
Twelfth, "the polishing method according to any one of claims 5 and 6, wherein the member to be polished is a wafer.
2) ”.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.
The present invention is not limited to this mode. FIG. 1A is a side view showing an outline of the polishing apparatus of the present invention, and FIG. 1B is a top view. The polishing apparatus of the present invention includes a polishing pad unit 20 and a wafer holding unit 30. The polishing pad section includes a polishing pad 3, a polishing pad holding mechanism 4, and a polishing pad vibrating section 5.
The wafer holding unit includes the wafer holding mechanism 2 and / or one or both of a wafer vibrating unit (in which the vibration direction 32 is indicated) and a wafer rotating unit (only the rotating shaft is shown). Further, the third embodiment includes a phase difference control unit. [First Embodiment] A polishing apparatus according to a first embodiment includes a wafer vibrating unit, a wafer rotating unit, and a polishing pad vibrating unit.

The present polishing apparatus operates as follows. A wafer 1 to be polished is attached to a wafer holding mechanism 2,
The wafer holding mechanism 2 is lowered by an elevating mechanism (not shown), and the surface to be polished of the wafer 1 is placed on the polishing pad 3 and pressed by a pressing mechanism (indicating a pressing direction 34). The wafer holding mechanism 2 is also connected to a wafer vibrator that vibrates in the horizontal direction 32 together with the rotation shaft 31 of the wafer rotation unit.
The wafer 1 is given a rotating motion and an oscillating motion.

The polishing pad 3 has a plate shape and is fixed to a platen 4 which is a polishing pad holding mechanism. The platen 4 is given a vibration motion (the vibration direction is shown in FIG. 21) by the polishing pad vibrator. An abrasive 7 is dropped on the surface of the polishing pad 3 from an abrasive (slurry) supply pipe 6.
During polishing, the abrasive (slurry) is supplied from the supply pipe 6 to the abrasive 7
Is dropped on the polishing pad 3 to polish the polished surface of the wafer.

As described above, in the present polishing apparatus, the rotational motion and the oscillating motion of the wafer and the oscillating motion of the polishing pad
Is polished. Second Embodiment A polishing apparatus according to a second embodiment includes a wafer rotating section and a polishing pad vibrating section. The polishing apparatus operates as follows. The wafer 1 to be polished is attached to the wafer holding mechanism 2, the wafer holding mechanism 2 is lowered by an elevating mechanism (not shown), and the surface to be polished of the wafer 1 is put on the polishing pad 3, and a pressing mechanism (pressing mechanism) Pressure direction 34)
And pressurized. The wafer holding mechanism 2 is connected to a rotating shaft 31 of a wafer rotating unit, and a rotating motion is given to the wafer 1. The polishing pad 3 has a plate shape and is fixed to a platen 4 which is a polishing pad holding mechanism. The platen 4 vibrates (shows a vibration direction 21) with a polishing pad vibrator. During polishing, an abrasive 7 is dropped onto the surface of the polishing pad 3 from an abrasive (slurry) supply pipe 6 to polish the surface to be polished of the wafer.

As described above, in the present polishing apparatus, the wafer 1 is polished by the rotational motion of the wafer and the oscillating motion of the polishing pad. Third Embodiment A polishing apparatus according to a third embodiment controls a polishing pad vibrator for causing a polishing pad vibrator to directly vibrate a polishing pad, and controls one or both of a frequency and an amplitude of the polishing pad vibrator. A polishing pad control unit for controlling the wafer vibration unit to directly vibrate the wafer, and a wafer vibration control unit for controlling one or both of the frequency and the amplitude of the wafer vibration unit. The wafer rotating unit includes a rotation mechanism that enables continuous rotation of the wafer and rotation to a fixed position (for example, a position of 90 degrees or 180 degrees); a wafer rotation control unit that controls the rotation mechanism of the wafer; A phase difference controller for controlling a phase difference between the vibration of the pad and the vibration of the wafer.

The present polishing apparatus operates as follows. A wafer 1 to be polished is attached to a wafer holding mechanism 2,
The wafer holding mechanism 2 is lowered by an elevating mechanism (not shown), and the surface to be polished of the wafer 1 is placed on the polishing pad 3 and pressed by a pressing mechanism (indicating a pressing direction 34). The wafer holding mechanism 2 is also connected to a vibrating body that vibrates in the horizontal direction 32 together with the rotating shaft 31 of the wafer rotating unit, and the wafer 1 is given a rotating motion and a vibrating motion.

The polishing pad 3 has a plate shape and is fixed to a platen 4 which is a polishing pad holding mechanism. The platen 4 is vibrated by the polishing pad vibrating part (vibration direction 2).
1). An abrasive 7 is dropped on the surface of the polishing pad 3 from an abrasive (slurry) supply pipe 6. During polishing, an abrasive 7 is dropped onto the polishing pad 3 from an abrasive (slurry) supply pipe 6 to polish the surface to be polished of the wafer.

As described above, in the present polishing apparatus, the wafer 1 is polished by the vibration motion of the wafer and the vibration motion of the polishing pad. There are no particular restrictions on the frequency, amplitude, and wave shape of the vibration used here, but in particular, the wafer vibration control unit and the polishing pad vibration control unit operate at the same frequency in the direction orthogonal to the wafer and the polishing pad at the same time. When a sinusoidally oscillating vibration is applied, a specific point on the surface to be polished of the wafer corresponds to the phase difference (phase angle) between these two oscillating motions, as is well known in the theory of polarization in optics. The relative motion of the polishing pad in the first linear vibration (phase angle 0) → first elliptical motion → second linear vibration (phase angle π) → second elliptical motion → first linear motion ( Phase angle 2π) is repeated. Here, the phase angle 2π is a case where the two vibration motions are shifted by one period. This phase difference is controlled by a phase difference control unit.

If the two vibrations, that is, the amplitude of the wafer vibration and the amplitude of the polishing pad vibration (half the vibration width) are set to be equal by the wafer vibration control unit and the polishing pad vibration control unit, the first linear motion and the second linear motion The directions of the movements are orthogonal to each other, and the first and second elliptical movements are circular movements rotating in opposite directions.
This means that the fixed point on the polishing pad surface with respect to the fixed point on the polished surface of the wafer (the fixed point on the polished surface and the fixed point on the polishing pad surface overlap each other at the center of two vibrations. ) Means circular motion. This is shown in FIG. In FIG. 6, W1, W2, W3,
W4 is a specific point on the polished surface of the wafer, and T1 and T4
2, T3 and T4 denote the trajectories of one cycle of the vibration of the points on the polishing pad surface corresponding to the positions of W1, W2, W3 and W4 when the vibration of the wafer and the vibration of the polishing pad are at the center of the vibration, respectively. Show.

Next, in general, the polishing speed is affected not only by the polishing pressure and the relative speed of the polishing pad, but also by the planar shape error of the polishing pad. For example, a concave portion of the polishing pad functions to reduce the polishing rate, and a convex portion functions to increase the polishing rate. Returning to the previous stage, what should be noted here is the vibration motion of the wafer,
The direction of the relative movement of the polishing pad on the surface to be polished of the wafer can be freely changed in a two-dimensional plane according to the phase angle with the vibration motion of the polishing pad. The speed of the relative movement is completely uniform over the entire polished surface of the wafer. Complete uniformity of this relative motion over the entire surface of the wafer,
Due to the fact that the direction of the relative motion can be freely controlled by changing the magnitude of the phase angle of the two vibrations,
Not only can the polishing rate, that is, the uniformity of the polishing film thickness, be ensured, but also the polishing pad can be completely isotropically polished without any deviation in the direction of the relative speed of the polishing pad. Further, by controlling the magnitude of the two amplitudes and the ratio of the amplitudes of the two vibrations in conjunction with the control of the phase difference between the two vibrations during polishing, the polishing pad passing through a specific point on the surface to be polished of the wafer is controlled. Points can be freely selected. Thus, by continuously changing all or a part selected from the phase difference of the two vibrations or the magnitude of the two amplitudes or the ratio of the amplitudes of the two vibrations during polishing, the wafer area is substantially reduced. To prevent transfer of a planar shape error of the polishing pad (specifically, a concave portion, a convex portion, or a concave portion of the lattice groove of the polishing pad having a smaller area than the wafer area) onto the surface to be polished of the wafer in a small area. Can be.

It should be further noted that if the wafer rotating unit is operated and the wafer is evenly polished at the 0-degree position and the 180-degree rotation position, the point of the planar shape error in a region larger than the wafer area of the polishing pad surface is obtained. The transfer of the target component onto the surface to be polished of the wafer can be offset, and the point-symmetric plane shape error of the polishing pad surface has no effect on the surface to be polished of the wafer.

The above invention is particularly effective for improving the polishing quality when the semiconductor pattern is further miniaturized. In the polishing of a crystal having anisotropic mechanical properties, anisotropy can be given in the opposite direction to the polishing direction. The scope of the present embodiment also includes a mode of controlling at least one selected from phase difference control, amplitude control, or waveform control,
A mode that does not use a wafer rotating unit is appropriately used in accordance with use conditions.

There is no particular limitation on the polishing pad used in the polishing apparatus according to the first, second and third embodiments of the present invention, and a hard, soft, multi-layer or composite structure polishing pad is selected according to the type of the member to be polished. Is done. Even if the polishing pad is soft, the overall rigidity is maintained by the rigidity of the platen for fixing the polishing pad. The polishing agent may be supplied from the polishing pad side or from the wafer side. The frequency of the wafer vibration, the rotation speed of the wafer rotation, and the frequency of the polishing pad vibration are the stability of the vibration, the uniformity of the polishing, the required polishing speed, and the conditions for preventing the transfer of the polishing pad pattern to the surface to be polished. The frequency of the vibration of the wafer is preferably 0.1 Hz or more and 10 KHz or less, and the rotation speed of the rotation of the wafer is preferably 10 rpm or more and 300 rpm or less. The frequency of the vibration of the polishing pad is preferably 0.5.
It is 1 Hz or more and 10 KHz or less. Above operating frequency,
Depending on the amplitude used, the polishing pad vibrator and wafer vibrator have ball screws, cam mechanisms, etc., as well as hydraulic, compressed air, ultrasonic motors, electromagnetic motors, ultrasonic linear motors, etc.
A means selected from one or more actuators such as an electromagnetic linear motor, a piezo element, a voice coil and the like is preferably used.

In the polishing apparatuses according to the first, second and third embodiments of the present invention, since the polishing pad 3 has a plate shape, the platen for fixing the polishing pad 3 also has a plate shape. Since the roller unit 109 for rotating the polishing pad is not required, the size of the entire apparatus can be reduced. In addition, since the polishing pad and the platen are plate-shaped and have high rigidity, the pressing force that determines the polishing pressure of the wafer is increased, and the relative speed of the polishing pad on the surface to be polished of the wafer is increased. Therefore, the polishing speed can be greatly increased as compared with a conventional belt-conveying polishing apparatus. In addition, since the polishing pad is plate-shaped, replacement of the polishing pad 3 is also facilitated.

Further, in the polishing apparatus according to the third embodiment of the present invention, FIG. 3 shows an example of the polishing pad used in the present invention. Basically, not only the one shown in FIG. 3 but also an IC-1000 manufactured by Rodale, which is used as a conventional polishing pad, is possible. In the present invention, the pitch p as shown in FIG.
Since the plate-like polishing pad 3 having the groove structure described above is reciprocated using the vibrator 5, the required width of the reciprocating motion is at least one pitch, so that the vibration or the width of the vibration can be reduced. Polishing is performed by the vibration of the polishing pad 5 and the workpiece (wafer)
It is performed with only one rotation. When polishing is performed with a polishing pad having a fixed groove structure, the groove structure in which the final polishing state is fixed may be transferred, and in order to remove the groove structure from the state, as shown in FIG. The method is shifted in the direction perpendicular to the direction or the method of vibrating the polishing pad is changed at the end of polishing.

Further, the polishing apparatus according to the third embodiment of the present invention controls the vibration amplitude, the vibration frequency and the phase difference between the polishing pad and the wafer so that the polishing rate is completely uniform at each point on the surface to be polished of the wafer. In addition, it is possible to perform isotropic polishing, and it is also possible to remove a point target component of a planar shape error of the polishing pad surface. Although the polishing apparatus of the present invention has been described centering on a polishing apparatus for polishing a wafer in which the member to be polished is a wafer, the present invention relates to a case where the member to be polished is another member, for example, an optical element for an optical component. It goes without saying that the present invention can be preferably applied not only to a polishing apparatus, but also to a polishing apparatus in which the surface to be polished has a curved surface as well as a planar shape.

Hereinafter, the present invention will be described with reference to examples.

[0036]

[Example 1] Based on an epoxy resin,
A sheet-shaped member having a size of 300 mm x 300 mm and a thickness of 5 mm is formed, and spiral grooves having a pitch of 0.5 mm and lattice grooves having a pitch of 1 mm are formed on the surface of the member in order to provide abrasive holding and fluidity. Was designated as a polishing pad 3. The hardness of the polishing pad was 90 with AskerC. The polishing pad was attached to the platen 4, and a voice coil for converting an electric signal into mechanical vibration was used as an actuator of a polishing pad vibrator for reciprocating the platen. As a member to be polished, a 6-inch wafer having a thermal oxide film formed with a thickness of 1 μm was used. A backing film was used for holding the wafer, and the wafer was applied with water.

The polishing conditions were such that the load on the wafer surface was 350 g / cm ² ,
The amplitude of the vibration of the polishing head is ± 10 mm and the frequency is 35H
z. The number of rotations of the wafer was 60 rpm. The polishing agent used was SS12 from Cabot, supplied at 50 ml / min. A polishing rate of 300 nm / min was obtained, and a uniformity of ±
Within 5% was obtained. [Embodiment 2] FIG. 2 is a view showing a mechanism for supplying the polishing slurry of this embodiment from the polishing pad side. The supply of the polishing agent is preferably performed from below the apparatus when the vibration width (twice the vibration amplitude) is equal to or less than half the wafer diameter. The polishing agent is supplied to the surface of the polishing pad 3 from the polishing agent tank 9 via the polishing agent supply system 8, the platen 4 and the polishing pad 3 using a pump or the like. When the vibration width is half or more of the wafer diameter, a method in which the polishing agent is supplied from above the apparatus as shown in FIG. 1 can be adopted. [Embodiment 3] As shown in FIG. 4, a wafer vibrating part is newly added to the mechanism of Embodiment 1, and a stroke (twice the amplitude) in a direction perpendicular to the vibration direction of the polishing pad is 10 reciprocations per 10 mm.
A minute (0.16 Hz) vibration of the wafer was newly added.
The polishing conditions were the same as in Example 1, and the polishing rate was 300 nm / min as in Example 1. However, the transfer of the structure corresponding to the pitch of the lattice grooves of the polishing pad was eliminated due to the effect of the vibration of the wafer. Example 4 300 mm based on epoxy resin
A sheet-shaped member having a size of 300 mm and a thickness of 5 mm was prepared, and spiral grooves having a pitch of 0.5 mm and lattice grooves having a pitch of 1 mm were formed on the surface of the member in order to provide abrasive holding and fluidity. Polishing pad 3 was obtained. The hardness of the polishing pad was 90 with AskerC. This polishing pad,
A voice coil was used as a vibrator for an actuator of a polishing pad vibrator attached to the platen 4 to reciprocate the platen. As a member to be polished, a 6-inch wafer having a thermal oxide film formed with a thickness of 1 μm was used. The wafer was held in water using a backing film.

The polishing conditions were as follows: the load on the wafer surface was 350 g / cm ² ,
The polishing agent used was SS12 from Cabot, supplied at 50 ml / min. Polishing is performed for 2.5 minutes with the rotational speed of the wafer rotating motion at 60 rpm, the amplitude of the vibration motion of the polishing pad ± 10 mm, and the frequency of 35 Hz, and then the rotational speed of the wafer rotating motion at 60 rpm and the polishing pad. ± 1 amplitude of vibration motion
Polishing was performed for 30 seconds while gradually lowering the frequency of the vibration motion of the polishing pad from 35 Hz to 10 Hz while maintaining the thickness at 0 mm. The transfer of the structure corresponding to the pitch of the lattice groove of the polishing pad was eliminated by the effect of the change in the frequency. [Embodiment 5] FIG. 5 is a view showing an embodiment 5, in which the wafer holding mechanism 2 can be moved to a plurality of places, so that another place can be used without being replaced when the polishing pad is exhausted. FIG. In this way, the life of the polishing pad can be further extended, the replacement cycle can be extended, and the operation rate of the polishing apparatus can be improved, and the throughput can be extended. [Embodiment 6] FIG. 3 is a view showing a polishing pad according to Embodiment 6, which is described in connection with the transfer of the lattice groove structure of the polishing pad described in Embodiments 3 and 4. The polishing pad 3 is a plate-shaped polishing pad member in which lattice grooves 40 having a pitch p are formed. When this polishing pad 3 is used,
Necessary minimum stroke (2 of amplitude) of the vibration motion of the polishing pad 3 for preventing the structure of the lattice groove from being transferred to the surface to be polished of the wafer.
Is the length p of one pitch as a result of the experiment, which was consistent with the result obtained from geometric considerations. This condition was applicable to periodic grooves having a pitch p of not only a lattice shape but also any other shape.

[0039]

As described above, in the polishing apparatuses according to the first, second and third embodiments of the present invention, since the polishing pad 3 has a plate shape, the size of the entire apparatus can be reduced. Further, since the polishing pad and the platen are plate-shaped and have high rigidity, the polishing rate can be increased. In addition, since the polishing pad is plate-shaped, replacement of the polishing pad 3 is also facilitated.

Further, with the polishing apparatus according to the third embodiment of the present invention, it is possible to carry out polishing with a completely uniform polishing rate over the entire surface of the wafer, a completely isotropic or inversely controlled anisotropy. As a result, the polishing apparatus of the present invention provides low production cost and high polishing quality not only in CMP polishing but also in polishing of optical elements and the like.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a polishing apparatus according to the present invention.

FIG. 2 is a diagram illustrating an abrasive supply mechanism according to a second embodiment.

FIG. 3 is a view showing a polishing pad of Example 6.

FIG. 4 is a schematic diagram illustrating a wafer according to a third embodiment in which a vibration motion and a rotation motion are performed.

FIG. 5 is a view showing that the wafer of Example 5 is moved to a plurality of positions on a polishing pad and polished.

FIG. 6 is a diagram illustrating an example of a trajectory of a point on the polishing pad when the phase difference between the vibration of the polishing pad and the vibration of the wafer is π / 2.

FIG. 7 is a view showing a conventional disk-shaped polishing apparatus.

FIG. 8 is a view showing a conventional belt-shaped polishing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Polished member (wafer) 2 Wafer holding mechanism 3 Polishing pad 4 Polishing pad holding mechanism (platen) 5 Polishing pad vibrating part 6 Abrasive supply mechanism 7 Abrasive 8 Abrasive supply system 9 Abrasive tank 10 Wafer holding mechanism up 20 shows the polishing direction of the polishing pad. Reference Signs List 30 Wafer holding unit 31 Rotation axis (of wafer rotating unit) 32 Indicates the direction of vibration of wafer 33 Indicates the direction of rotation of wafer field 34 Indicates the pressure on the surface to be polished 40 Lattice groove 41 Abrasive supply hole 50 Vibration of polishing pad Indicates the width 60 Indicates the vibration width of the wafer 70 Indicates the trajectory of the angle of the polishing pad due to relative movement of the polishing pad 100 Platen 101 Polishing pad 102 Wafer 103 Polishing head for holding the wafer 104 Abrasive supply mechanism 105 Belt polishing Pad P Grid groove pitch

Claims (12)

[Claims] 1. A polishing apparatus for polishing a member to be polished, comprising a polishing pad portion and a member to be polished, wherein the member to be polished holds the member to be polished; The polishing pad includes one or both of a rotating member to be polished to apply a rotational motion to the member to be polished and a vibration member to be polished to apply a vibration motion to the member to be polished, and the polishing pad unit holds the polishing pad. A polishing pad holding mechanism for polishing the polishing pad, and a polishing pad vibrating section for giving a vibration motion to the polishing pad. 2. The polishing apparatus according to claim 1, wherein a direction of the vibration motion of the member to be polished is perpendicular to a direction of the vibration motion of the polishing pad. 3. The polishing apparatus according to claim 1, wherein said polishing pad section includes a polishing agent supply mechanism. 4. The polishing apparatus according to claim 1, wherein said polishing pad portion is located below said holder to be polished in the direction of gravity. 5. A polishing method for polishing using the polishing apparatus according to claim 1, wherein the rotational speed of the rotational movement of the member to be polished is 10 rpm or more and 300 rpm or less, and A polishing method comprising the steps of: polishing at a vibration frequency of the polishing member of 0.1 Hz to 10 KHz and a vibration frequency of the polishing pad of 0.1 Hz to 10 KHz. 6. A polishing method for polishing using the polishing apparatus according to claim 1, wherein the rotation speed of the member to be polished, the vibration frequency of the polishing pad, and A polishing method comprising the steps of: polishing while maintaining a constant value; and polishing while maintaining the rotation speed of rotation of the member to be polished constant and continuously changing the frequency of vibration of the polishing pad. 7. A polishing pad vibrator for causing the polishing pad vibrator to directly vibrate the polishing pad, and a polishing pad controller for controlling one or both of a frequency and an amplitude of the polishing pad vibrator. A vibration member to be polished in which the vibration member to be polished directly applies vibration to the member to be polished; and a vibration member to be polished to control one or both of a frequency and an amplitude of the vibration member to be polished. And a control unit.
The polishing apparatus according to claim 1. 8. A polishing pad vibrator for causing the polishing pad vibrator to directly vibrate the polishing pad, and a polishing pad controller for controlling one or both of a frequency and an amplitude of the polishing pad vibrator. A vibration member to be polished in which the vibration member to be polished directly applies vibration to the member to be polished; and a vibration member to be polished to control one or both of a frequency and an amplitude of the vibration member to be polished. A control unit, wherein the polished member rotating unit includes a rotation mechanism for continuously rotating or rotating the polished member at a fixed position, and a polished member rotation control unit for controlling the polished member rotation mechanism. The polishing apparatus according to any one of claims 1, 2, 3, and 4, wherein: 9. The polishing apparatus according to claim 7, further comprising a phase difference control section for controlling a phase difference between vibration of said polishing pad and vibration of said member to be polished. Polishing equipment characterized in that 10. A polishing method for polishing by using the polishing apparatus according to claim 7, wherein at least two selected from a phase difference, a frequency, an amplitude, and rotation of a member to be polished. A polishing method comprising the step of polishing while controlling the above. 11. The polishing apparatus according to claim 1, wherein the member to be polished is a wafer. 12. The polishing method according to claim 5, wherein said member to be polished is a wafer.