TWI579105B - Abrasive grain embedding device, polishing device and polishing method - Google Patents

Description

Abrasive grain embedding device, polishing device and polishing method Technical field

The present invention relates to an abrasive grain embedding device for embedding abrasive grains on a polishing plate used for polishing various workpieces such as semiconductor wafers, magnetic heads, electronic parts, and optical parts, including the abrasive grains. A polishing device for embedding a device, and a polishing method for polishing the workpiece using the polishing device.

Background technique

In the process of semiconductor wafers, magnetic heads, electronic parts, optical parts, and the like, the surface of the workpiece is polished by a polishing apparatus. Next, a device such as an LSI is formed on the surface of the workpiece to be polished, or the surface thereof is used as an optical surface.

The polishing apparatus used for the surface polishing of the workpiece includes a polishing plate supported by a rotatable state, a slurry supply mechanism for supplying a slurry containing abrasive grains (free abrasive grains) to the surface of the plate, and a workpiece to be held. It is brought into contact with the workpiece holding member of the surface of the plate. Then, the fixed disk is rotated, and the slurry containing the abrasive grains is supplied between the fixed plate and the workpiece, and the workpiece held by the workpiece holding member is pressed toward the fixed plate to perform the grinding process of the workpiece. . Further, in particular, when the quality of the surface to be ground is required to be high, the slurry containing no abrasive grains may be supplied and polished at a certain time before the end of the polishing process to reduce the damage of the free abrasive grains to the workpiece. Or damaged as a finishing process.

However, if the workpiece having a different hardness on the surface to be polished is ground using a slurry containing abrasive grains, the portion having a lower hardness is ground earlier than the portion having a higher hardness, so that the abrasive grains in the slurry are concentrated. The problem of partial over-grinding in the lower hardness portion is a problem. Therefore, there has been proposed a method in which abrasive grains are embedded in a fixed disk and polished using a polishing plate in a state in which one of the embedded abrasive grains is partially exposed (see, for example, Patent Document 1). The above grinding method is particularly suitable when the surface properties of the workpiece are required to be high.

When a grinding plate in which abrasive grains are embedded is formed, a lubricant (slurry) containing abrasive grains is applied to a polishing platen made of tin, and the grinding plate and the lubricant are pushed by a pressing force according to a predetermined force. At the same time, the pressing member and the polishing platen are slid, and the abrasive grains contained in the lubricant are embedded in the polishing platen (see Patent Document 1).

As described above, in order to perform the polishing process using only the slurry containing no free abrasive grains, it is necessary to embed the abrasive grains in the fixed plate before the polishing process, or to reduce the abrasive function by avoiding the abrasive grains embedded in the fixed plate. The operation of burying the abrasive grains in the fixed plate must be carried out regularly.

However, it takes a long time to embed a sufficient amount of abrasive grains on the surface of the polishing plate. Therefore, in order to shorten the time for embedding the abrasive grains in the fixed plate, a manufacturing apparatus for a polishing plate to which ultrasonic vibration is applied to the pressing member has been proposed (see, for example, Patent Document 2).

[First technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 7-299737

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-238398

Summary of invention

However, in the conventional polishing apparatus manufacturing apparatus disclosed in Patent Document 2, the slurry is efficiently supplied between the pressing member and the polishing platen, and the pressing member is formed with a groove. Therefore, once the ultrasonic vibration is applied to the pressing member and the polishing particles are buried, the abrasive grains are buried unevenly on the surface of the polishing plate, and the region where the abrasive grains are partially buried excessively is not buried. The area is a problem. As a result of the research conducted by the applicant, it was found that the unevenness of the above-mentioned abrasive grains was caused by the uneven fluid pressure of the slurry which was pressed by the pressing member. That is, since the pressing member is formed with a groove, the length of each pressing surface facing the sliding direction is different from each other. Therefore, the fluid pressure generated in the sliding direction due to the wedge effect will be uneven, resulting in uneven embedding of the abrasive grains.

In particular, if the intensity of the ultrasonic wave is increased, pitting corrosion occurs locally, and the surface of the fixing plate is damaged. To avoid this, even if you want to increase the ultrasonic intensity, you must use an ultrasonic intensity that is less than the value of the resulting pitting. Therefore, it is difficult to improve the embedding efficiency of the abrasive grains.

The present invention has been made in view of the above problems, and has an object of suppressing the unevenness of embedding of abrasive grains and efficiently embedding abrasive grains into a polishing platen.

According to the first aspect of the present invention, an abrasive grain embedding device can be provided, which can embed the abrasive particles contained in the slurry into the surface of the polishing plate. The utility model comprises: a pressing mechanism capable of pushing the polishing plate; a slurry supply mechanism capable of supplying a slurry containing abrasive grains to a surface of the polishing plate; and a sliding mechanism for performing the pressing mechanism and the polishing plate The pressing mechanism includes a pressing member, a weight member disposed above the pressing member and capable of pressing the pressing member toward the polishing platen, and ultrasonic waves can be applied to the pressing member. In the ultrasonic vibrator, the pressing member includes a pressing surface provided with a plurality of disk-shaped pressing pieces.

The pressing member should be disposed at a position that does not protrude from the use area of the polishing plate.

According to a second aspect of the present invention, there is provided a polishing apparatus comprising: a polishing plate comprising a grinding surface capable of grinding a workpiece, and being supported in a rotatable state; and a rotary driving mechanism for allowing said polishing plate to be carried out Rotating; the workpiece holding mechanism includes a holding surface that can hold the workpiece relative to the polishing surface of the polishing platen, and can hold the workpiece in contact with the polishing platen; and the slurry supply mechanism The slurry containing the abrasive grains and the slurry containing no abrasive grains may be selectively supplied to the surface of the polishing plate; and the abrasive grain embedding device may be supplied to the foregoing by the pressing mechanism and by the slurry supply mechanism Grinding the slurry of the abrasive grains on the surface of the plate to press the polishing plate, and sliding the pressing mechanism and the polishing plate to embed the abrasive grains contained in the slurry toward the surface of the polishing plate; The pressing mechanism includes a pressing member and a weight member disposed above the pressing member to press the pressing member toward the polishing plate. The pressing member applies an ultrasonic ultrasonic vibrator, and the pressing member includes a plurality of disc-shaped pressing The pushing surface of the piece.

According to a third aspect of the present invention, there is provided a polishing method for polishing a workpiece held by the workpiece holding mechanism using the polishing apparatus of claim 3, comprising the following steps: a first polishing step, a slurry containing abrasive grains is supplied to the surface of the polishing plate, and the polishing plate is pressed by the pressing mechanism to press the polishing plate, and the pressing mechanism and the polishing plate are slid toward the foregoing The surface of the polishing plate is embedded with the abrasive grains contained in the slurry, and the workpiece held by the workpiece holding mechanism is slid with the polishing plate to polish the surface of the workpiece; and the second polishing After the first polishing step is performed, a slurry containing no abrasive grains is supplied to the surface of the polishing platen, and the workpiece held by the workpiece holding mechanism is slid with the polishing platen to polish the foregoing The surface of the workpiece.

In the third aspect of the invention, the cleaning step of cleaning the polishing platen can be performed between the first polishing step and the second polishing step. The workpiece is selected from the group consisting of sapphire, SiC, GaN, and AlN.

In the abrasive grain embedding device according to the first aspect of the present invention, the pressing member includes a pressing surface provided with a plurality of disk-shaped pressing pieces, so that each pressing surface faces the pressing mechanism and the polishing platen. The sliding directions are the same length. Therefore, ultrasonic vibration can be used to promote the embedding of the abrasive grains, and the unevenness of the fluid stress can be suppressed, and the unevenness of the abrasive grains to the polishing plate can be suppressed.

Moreover, the pressing member is disposed in a use area that is not self-grinding the fixed platen The prominent position can make the pressure distribution caused by ultrasonic vibration uniform, without causing pitting corrosion, thus avoiding damage to the surface of the polishing plate.

In the polishing apparatus according to the second aspect of the present invention, the slurry containing the abrasive grains and the slurry containing no abrasive grains can be used, and the pressing mechanism and the workpiece holding member can be held, so that the function of the abrasive grain embedding device can be combined with The function of the polishing device. Moreover, when polishing the workpiece, the slurry containing the abrasive grains and the slurry containing no abrasive grains can be selected, so that the polishing particles can be polished while the polishing particles are embedded, and the free abrasive grains can be used as needed. Polishing with and without the use of free abrasive particles.

In the polishing method according to the third aspect of the present invention, after the first polishing step of polishing the surface of the workpiece using the slurry containing the abrasive grains, the second surface of the workpiece is polished using the slurry containing no abrasive grains. In the polishing step, the abrasive grains are embedded in the polishing plate in the first polishing step. Next, in the second polishing step, the polishing is performed by the polishing plate containing the embedded abrasive grains, so that the polishing efficiency can be improved.

Further, if the cleaning step of cleaning the polishing plate is performed between the first polishing step and the second polishing step, damage or damage of the workpiece due to the free abrasive grains can be reduced.

Simple illustration

Fig. 1 is a perspective view showing an abrasive particle embedding device.

Fig. 2 is an exploded perspective view showing a first example of the pressing mechanism.

Fig. 3 is a cross-sectional view showing a first example of the pressing mechanism.

Fig. 4 is a bottom view showing a pressing piece included in the pressing mechanism.

Figure 5 is a diagram showing the rotation support mechanism constituting the abrasive grain embedding device. Body map.

Fig. 6 is an explanatory view showing the relationship between the pressing member and the position and size of the polishing platen.

Fig. 7 is an explanatory view showing the relative sliding direction of the pressing mechanism and the polishing platen when the abrasive grains are buried.

Fig. 8 is an explanatory view showing the relationship between the conventional pressing mechanism and the position and size of the polishing platen.

Fig. 9 is a bottom plan view showing a second example of the pressing piece.

Fig. 10 is a bottom plan view showing a third example of the pressing piece.

Fig. 11 is a bottom plan view showing a fourth example of the pressing piece.

Fig. 12 is an exploded perspective view showing a second example of the pressing mechanism.

Fig. 13 is a cross-sectional view showing a second example of the pressing mechanism.

Fig. 14 is a bottom view showing a pressing member of a second example constituting the pressing mechanism.

Fig. 15 is an explanatory view showing the relationship between the pressing member and the position and size of the polishing platen.

Fig. 16 is a perspective view showing a polishing apparatus.

Figure 17 is a flow chart showing the steps of the polishing method 1.

Figure 18 is a flow chart showing the steps of the polishing method 2.

Figure 19 is a flow chart showing the steps of the polishing method 3.

Fig. 20 is a graph showing the processing efficiency of the polishing method 2 and the polishing method 3.

Form for implementing the invention

1. Structure of abrasive grain embedding device

In the abrasive grain embedding apparatus 1 shown in Fig. 1, in the apparatus base 2, a polishing platen 3 which is formed in a disk shape and is rotatable is supported. The polishing platen 3 is formed of a metal material such as tin, and a rotating shaft 31 is coupled to the lower portion thereof. A motor 32 as a rotation drive mechanism is coupled to the lower end of the rotary shaft 31, and the polishing platen 3 is configured to be rotatable by the motor 32. A center hole 33 is formed in a central portion of the polishing platen 3, and a surface (upper surface) 30 of a portion formed on the ring portion around the periphery thereof is a use region 34 of a region where the abrasive grains are actually buried and polished.

A slurry supply mechanism 4 for supplying the slurry 40 to the surface 30 of the polishing platen 3 is disposed in the front portion of the apparatus base 2. The slurry 40 may contain abrasive grains 40a and may also contain no abrasive particles 40a.

The slurry supply mechanism 4 includes a first slurry tank 41 such as a slurry for containing abrasive grains containing diamond abrasive grains having a particle diameter of 0.02 to 1 μm, and can be sprayed onto the upper surface 30 of the polishing platen 3 to include the first slurry tank 41. a nozzle 43a for arranging the slurry of the abrasive grains, a first pump 42 for supplying the slurry of the first slurry tank 41 to the nozzle 43a, and a second slurry tank 44 for accommodating the slurry containing no abrasive grains. The upper surface 30 of the polishing platen 3 discharges the nozzle 43b containing the slurry of the abrasive grains accommodated in the second slurry tank 44, and the second pump 44a capable of supplying the slurry of the second slurry tank 44 to the nozzle 43b, and the controllable portion 1 pump 42 and the second pump 44a actuated controller 45. Therefore, the slurry supply mechanism 4 can selectively supply the slurry containing the abrasive grains and the slurry containing no abrasive grains to the surface 30 of the polishing platen 3.

Above the grinding plate 3, it can be applied to the polishing plate 3 The pressing mechanism 6 for pushing the pressing force required for the abrasive grains. As shown in FIG. 2, the pressing mechanism 6 includes a plurality of (three in the illustrated example) pressing members 60 for embedding abrasive grains in the polishing platen 3, and is disposed above the pressing member 60. The weight member 63 that presses the pressing member 60 toward the polishing platen, and the ultrasonic vibrator 65 that can vibrate the pressing member 60 to vibrate. The ultrasonic vibrator 65 is provided with electrodes 652a and 652b as shown in FIG.

As shown in FIG. 2, the pressing member 60 includes a vibrating body 62 that can vibrate by the ultrasonic vibrator 65. The vibrating body 62 is provided with a disk-shaped supporting portion 621 at a lower portion thereof, and a large-diameter lower vibrating body 622 extending upward from the upper surface of the supporting portion 621, and a support extending upward from the upper end of the lower vibrating body 622. Shaft 622b. Below the support portion 621, a pressing action portion 61 is adhered by an adhesive. Further, the pressing action portion 61 may be attached to the support portion 621 by means of a screw and a fixing nut.

As shown in FIG. 2, the lower vibrating body 622 can be fitted to the ring-shaped urethane rubber band 8 and placed on the support portion 621. Further, the support shaft 622b is fitted to the ultrasonic vibrator 65 and placed on the lower vibrating body 622. Moreover, the upper vibrating body 66 is attached to the ultrasonic vibrator 65 in a state of being fitted to the support shaft 622b. The male shaft 622b is formed at the upper end portion of the support shaft 622b, and the fixed nut 67 is screwed to the male screw 622c to be fixed, so that the ultrasonic vibrator 65 can be fixed to the support shaft 622b. In this manner, the pressing action portion 61, the lower vibrating body 622, the ultrasonic vibrator 65, and the upper vibrating body 66 can be integrally formed to vibrate.

The rubber band 8 has an effect of insulating the vibration of the vibrating body 62 without moving the weight member 63, and maintains good vibration of the vibrating body 62. Enter Further, when the rubber band 8 is subjected to the operation of embedding the abrasive grains in the polishing platen 3 in the abrasive grain embedding apparatus 1 shown in Fig. 1, the state of the pressing mechanism 6 can be adjusted by elastic deformation so as to be formed in the grinding. The gap between the surface of the platen 3 and the pressing surface 611 below the pressing action portion 61 is uniformly formed on the pressing surface 611.

As shown in FIG. 2, the weight portion 63 is formed with a receiving hole 633 for accommodating the pressing member 60 in the same number as the pressing member 60. Further, an electrode terminal attaching portion 634 for connecting the common electrode to all of the pressing members 60 is protruded from the center portion of the upper surface of the weight member 63, and two slip rings are disposed on the outer peripheral surface of the electrode terminal mounting portion 634. 635a, 635b. The electrode terminal mounting portion 634 having the above configuration can be fitted to the rotary connector 692 of the AC power supply mechanism 69 shown in Fig. 1 . Next, the slip rings 635a and 635b disposed in the electrode terminal attaching portion 634 and the electrodes 652a and 652b of the vibrators 65 disposed on the three vibrating bodies 62 are electrically connected.

As shown in FIG. 3, the ultrasonic vibrator 65 is composed of a ring-shaped piezoelectric body 651 and annular electrodes 652a and 652b which are respectively mounted on the polarization surfaces on both sides of the piezoelectric body 651. The piezoelectric body 651 is formed of piezoelectric ceramics such as barium titanate (BaTiO ₃ ), lead zirconate titanate (PB(Zi, Ti)O ₃ ), lithium niobate (LiNbO ₃ ), or lithium niobate (LiTaO ₃ ). .

As shown in FIG. 4, in each of the pressing members 60 constituting the pressing mechanism 6, a plurality of pressing pieces 600 to which a pressing force can be applied to the polishing platen 3 are provided in each pressing action portion 61. Each of the pressing pieces 600 is formed in a disk shape by ceramics, and is fixed in a state in which it protrudes downward from the pressing surface 611. The plurality of pressing pieces 600 are formed in the same diameter, and their center positions are on the same arc and are arranged at equal intervals.

As shown in Fig. 1, a rotation support mechanism 5 capable of supporting the pressing mechanism 6 in a rotatable state is provided on the side after the polishing platen 3. The rotation support mechanism 5 includes a support mechanism that can support the pressing mechanism 6, that is, a support rod 51 that is movable in the horizontal direction and extends horizontally above the polishing platen 3.

The abrasive grain embedding apparatus 1 shown in Fig. 1 removes the pressing mechanism 6 as shown in Fig. 5 of the drawings, and the tip end of the support rod 51 is provided with the first branch formed by the support rod 51 and spaced apart by a predetermined interval. The roller support portion 511 and the second roller support portion 512. The first roller support portion 511 supports the rotatable drive roller 52, and the second roller support portion 512 supports the rotatable driven roller 53. Further, the support lever 51 is provided with a rotation drive mechanism 54 for rotating the drive roller 52. The rotation drive mechanism 54 is composed of an electric motor 541 and a conduction coupling mechanism 542 including a transmission belt that can connect the drive shaft of the electric motor 541 and the rotation shaft of the drive roller 52 to a driveable state.

Referring back to Fig. 1, the abrasive grain embedding apparatus 1 includes an AC power supply mechanism 69 that can supply AC power to the electrodes 652a and 652b of the vibrator 65 shown in Fig. 3. The AC power supply mechanism 69 can output AC power such as a frequency of 16 to 100 kHz and a voltage of 20 to 200V. The AC power outputted by the AC power supply unit 69 is passed through a wiring (not shown) disposed in the hose 691 and a rotary connector 692 disposed at the tip end of the hose 691 from the slip ring shown in FIG. 635a and 635b are supplied to the vibrator 65 via the wirings 682a and 682b.

As shown in FIG. 6, each of the pressing members 60 is positioned above the use area 34 of the polishing platen 3. That is, the state in which the pressing surface 611 of all the pressing action portions 61 is accommodated in the range of the width 34a of the use region 34 is formed. applied area If the width 34a of 34 is, for example, 120 mm, the diameter of the pressing member 60 is about 115 mm. Further, the center of each pressing member 60 is positioned on an arc concentric with the outer diameter of the weight member 63.

2. The basic action of the abrasive grain embedding device

When the abrasive grains are embedded in the fixed plate 3, as shown in Fig. 1, the pressing member 60 constituting the pressing mechanism 6 is placed on the surface 30 of the polishing platen 3, and the outer peripheral surface of the weight member 63 is placed. The driving roller 52 and the driven roller 53 of the rotation support mechanism 5 are contacted. Next, the support rod 51 is moved in the direction of the arrow X as needed, and the pressing member 60 is positioned above the use area 34. Further, the position of the pressing mechanism 6 may be fixed and not moved. At this time, the size of the pressing member 60 is appropriately set to prevent the pressing member 60 from exceeding the range of the use region 34.

Further, the rotary connector 692 of the AC power supply mechanism 69 is fitted to the electrodes 652a and 652b shown in FIG. Then, by the driving of the electric motor 32, the polishing platen 3 is rotated in a direction indicated by an arrow 3a in FIG. 1 at a rotation speed of, for example, 30 to 60 rpm, and from the slurry supply mechanism 4 toward the surface 30 of the polishing platen 3. The slurry 40 containing the abrasive grains 40a is supplied.

Next, the drive roller 52 is rotated in the direction indicated by the arrow 52a by the driving of the electric motor 541 constituting the rotation support mechanism 5. In this manner, since the driving roller 52 is in contact with the outer peripheral surface of the weight member 63, the pressing member 60 is rotated in the direction indicated by the arrow 60a at a rotation speed of, for example, 15 to 30 rpm. As described above, by rotating the polishing platen 3 and rotating the pressing member 60, the slurry 40 containing the abrasive grains 40a supplied to the surface 30 of the polishing platen 3 can be brought into the pressing surface 611 of the pressing action portion 61. The surface 30 of the stationary plate 3 is ground.

Next, from the AC power supply mechanism 69 to constitute an ultrasonic vibrator AC electrodes 652a, 652b apply AC power. In this manner, the piezoelectric body 651 can be subjected to ultrasonic vibration, and the pressing action portion 61 can be ultrasonically vibrated in the vertical direction.

Thus, in the state where the slurry 40 containing the abrasive grains 40a enters between the pressing surface 611 of the pressing member 60 of the ultrasonic vibration and the surface 30 of the polishing platen 3 as described above, the pressing mechanism 6 and the grinding are performed. When the platen 3 is slid, the abrasive grains 40a contained in the slurry are pushed onto the surface 30 of the polishing platen 3 by the pressing surface 611 of the pressing member 60 to be embedded in the surface 30 of the polishing platen 3. Abrasive particles. Since the pressing member 60 presses the abrasive grains 40a in a full extent by the circular pressing surface 611, the abrasive grains 40a can be efficiently embedded in the surface 30 of the polishing platen 3.

The rotation direction of the polishing plate 3 shown by the arrow 3a in Fig. 1 is the same as the direction of rotation of the pressing member 60 indicated by the arrow 60a, and the relative sliding direction of the polishing plate 3 and the pressing member 60 is as shown. The direction of the arrow X' shown in 7. Further, since the lower surface of the pressing piece 600 as the pressing surface is formed in a circular shape, the relative sliding distance from the surface 30 of the polishing platen 3 can be made constant irrespective of the sliding position. Therefore, the pressure of the slurry 40 generated between the polishing platen 3 and the pressing surface 611 can be made constant regardless of the position on the polishing plate 3 to suppress the unevenness of the fluid stress. Therefore, the entire surface 30 of the polishing platen 3 can be embedded in the abrasive grains 40a in accordance with the uniform ultrasonic intensity, and the unevenness of the abrasive grains can be suppressed. Moreover, the abrasive grains can be efficiently embedded in the surface 30 by using ultrasonic waves.

When the ultrasonic wave is applied while the abrasive grains are embedded in the surface 30 of the polishing platen 3, if the pressing surface 611' of the pressing action portion 61' is beyond the range of the polishing platen 3 as shown in Fig. 8, the ultrasonic wave can be inferred. The pressure distribution caused by vibration is pushed The pressure surface 611' will be non-uniform in its entirety, and the local extreme pressure rise will cause pitting corrosion, which will locally damage the surface 30 of the polishing platen 3. However, as shown in FIG. 6, the pressing member 60 is disposed at a position that does not protrude from the use region 34 of the polishing platen 3 toward the outer peripheral side, so that the pressure distribution due to ultrasonic vibration will be uniform without causing pitting corrosion. Damage to the surface 30 of the polishing platen 3 can be avoided.

3. Change example of push piece

In the pressing member 60, if the sliding distance of each portion is made constant, the pressing action portions 61a to 61c shown in Figs. 9 to 11 may be used instead of the pressing action portion 61 shown in Figs. 4 and 7 . . The pressing action portion 61a shown in Fig. 9 is such that the pressing piece 600 is positioned on the outer peripheral side of the pressing surface 611a as compared with the example shown in Figs. 4 and 7, so that the push piece 600 is pushed in the outer periphery. The pressing surface 611 is outside the circumference. Moreover, the pressing action portion 61b shown in Fig. 10 constitutes a pressing piece 600b which is annularly arranged in an arc shape at equal intervals. The center of each of the pressing pieces 600b forms a circular groove 601, and the maximum pressure near the center of the pressing piece 600b can be lowered. Further, the pressing action portion 61c shown in Fig. 11 is configured such that each pressing piece 600c includes a plurality of pressing surfaces 602 having a circular small diameter, and shallow grooves 603 are formed around the pressing pieces 600c, and are arc-shaped at equal intervals. The above-mentioned pressing piece 600c is disposed.

4. Structural change example of the pressing mechanism

Instead of the pressing mechanism 6 shown in FIGS. 2 and 3, the pressing mechanism 6a shown in FIGS. 12 and 13 can be used. The pressing mechanism 6a includes a pressing member 61a for pressing the abrasive grains contained in the slurry supplied to the surface 30 of the polishing platen 3, and a supporting member 70 for supporting the pressing member 61a. The pressing member 61a is formed into a disk shape by ceramics, and a pressing surface 611a is provided on the lower surface thereof, and the pressing surface is provided. The upper surface of the opposite side of 611a is provided with a mounting surface 612a.

As shown in FIG. 14, the pressing surface 611a is provided with a disk-shaped pressing piece 600a on a double arc. The pressing piece 600a protrudes downward more than the pressing surface 611a.

As shown in FIG. 12, the support member 70 includes a support portion 71 on which the attachment surface 612a of the pressing member 61a can be attached by an adhesive, and a support shaft portion 72 that is erected from the support portion 71. The support portion 71 is formed in a disk shape having an outer diameter larger than the pressing member 61a, and the outer peripheral portion has an arc shape and four bolt insertion holes 710 are provided at equal intervals.

The support shaft portion 72 includes a weight member sliding fitting portion 720 having a large diameter extending upward from the upper surface of the support portion 71, and an upper end of the weight member sliding fitting portion 720 extending upward and having a smaller diameter than the weight member sliding fitting portion. The vibrator mounting portion 721 of the 720 is formed with an electrode terminal attaching portion 722 having a diameter smaller than the vibrator mounting portion 721 and extending upward from the upper end of the vibrator mounting portion 721.

The weight member sliding fitting portion 720 is slidably fitted to the outer peripheral side to form a ring-shaped weight member 73 by a metal material such as stainless steel. The weight member 73 is formed with a slide fitting hole 730 that is slidably fitted to the weight member sliding fitting portion 720 at the center portion, and the lower surface thereof is located at a position corresponding to the four bolt insertion holes 710 provided in the support portion 71. Four female screw holes 731 are formed. The weight member 73 is configured such that the slide fitting hole 730 is slidably fitted to the weight member sliding fitting portion 720 and placed on the upper surface of the support portion 71, and is directed from the lower side of the support portion 71 toward the bolt insertion hole 710. The fixing bolt 64 is inserted and screwed into the female screw hole 731 to be attached to the support portion 71.

The vibrator mounting portion 721 of the support portion 71 can be inserted into the ultrasonic vibrator 65. The ultrasonic vibrator 65 is composed of a ring-shaped piezoelectric body 651 and annular electrodes 652a and 652b which are respectively mounted on the split surface of the piezoelectric body 651. The piezoelectric body 651 is formed of piezoelectric ceramics such as barium titanate (BaTiO ₃ ), lead zirconate titanate (PB(Zi, Ti)O ₃ ), lithium niobate (LiNbO ₃ ), or lithium niobate (LiTaO ₃ ). . The ultrasonic vibrator 65 configured as described above can be fitted to the vibrator mounting portion 721 of the support shaft portion 72 and placed on the upper surface of the weight member sliding fitting portion 720. In this way, the ultrasonic vibrator 65 placed on the upper surface of the weight member sliding fitting portion 720 is placed on the annular spacer 66 fitted to the vibrator mounting portion 721. Next, the consolidating nut 67 is screwed to the male screw portion 723 formed at the upper end portion of the vibrator mounting portion 721, whereby the vibrator mounting portion 721 can be provided with the ultrasonic vibrator 65.

As shown in FIG. 13, two slip rings 681a and 681b are disposed on the outer circumference of the electrode terminal mounting portion 722. The slip rings 681a and 681b are connected to the electrodes 652a and 652b constituting the ultrasonic vibrator 65 via the wirings 682a and 682b.

As shown in Fig. 14, the pressing mechanism 6a shown in Figs. 12 and 13 has a circular shape on the lower surface of the pressing piece 600a. Therefore, the sliding distance from the polishing platen 3 can be made constant regardless of the sliding position. Therefore, the pressure of the slurry 40 generated between the polishing platen 3 and the pressing member 61a can be made constant regardless of the position on the polishing plate 3, so that the entire surface 30 of the polishing platen 3 is uniformly supersonic. The abrasive grains 40a are embedded in strength.

Moreover, as shown in FIG. 15, all of the pressing pieces 600a are positioned inside the use area 34 of the fixed plate 3, so that the pressure distribution caused by the ultrasonic vibration can be uniform, and no pitting occurs to avoid grinding. The surface 30a of the platen 3 is damaged.

5. Polishing device comprising abrasive particle embedding device

The polishing apparatus 9 shown in Fig. 16 is provided with the workpiece holding mechanism 90 attached to the abrasive grain embedding apparatus 1 shown in Fig. 1, and the abrasive grains can be embedded in the polishing platen 3, and the polishing plate 3 can be used. Grinding (polishing) of the workpiece is performed. In the polishing apparatus 9, the same components as those of the abrasive grain embedding apparatus 1 shown in Fig. 1 are assigned the same reference numerals as in Fig. 1, and the detailed description thereof will be omitted.

The workpiece holding mechanism 90 includes a holding member 91 that is formed in a cylindrical shape. A holding surface 91a for holding a workpiece is provided on the lower surface of the holding member 91. The holding surface 91a faces the surface 30 of the polishing surface of the polishing platen 3, and the workpiece held by the holding surface 91a can be held while being in contact with the surface 30 of the polishing platen 3.

The workpiece holding mechanism 90 includes a support rod 92 that is movable in the horizontal direction. The tip end of the support rod 92 is provided with a first roller support portion 921 and a second roller support portion 922 which are branched from the support rod 92 and are spaced apart from each other by a predetermined interval. The first roller support portion 921 supports the rotatable drive roller 93, and the second roller support portion 922 supports a rotatable driven roller (not shown). Further, the support lever 92 is provided with a rotation drive mechanism 94 for rotating the drive roller 93. The rotation drive mechanism 94 is composed of an electric motor 941 and a conduction coupling mechanism 942 including a transmission belt that can connect the drive shaft of the electric motor 941 and the rotation shaft of the drive roller 93 to a driveable state.

6. Polishing of processed objects

Hereinafter, the operation of the polishing apparatus 9 when the workpiece is polished using the polishing apparatus 9 shown in Fig. 16 will be described. When the workpiece is polished, the workpiece, such as the wafer W, is held on the holding surface 91a of the workpiece holding mechanism 90. At this time, the surface to be polished of the wafer W is opposed to the surface 30 of the polishing platen 3. its Then, the outer peripheral surface of the holding member 91 constituting the workpiece holding mechanism 90 is brought into contact with the driving roller 93 and the driven shaft, and the support rod 92 is moved in the direction indicated by the arrow X to position the wafer W on the polishing platen. 3 is above the use area 34.

In this manner, once the wafer W is positioned and the workpiece holding mechanism 90 is supported by the driving roller 93 and the driven shaft, the slurry is supplied from the slurry supply mechanism 4 to the surface 30 of the polishing platen 3 and the wafer W. At the same time, the fixed motor 3 is rotated by the electric motor 32 in the direction indicated by the arrow 3a, and the driving roller 93 is rotated by the electric motor 941 to rotate the holding member 91 in the direction indicated by the arrow 91b. Thus, the abrasive particles 40a and the slurry which have been embedded in the surface 30 of the fixed plate 3 are polished under the surface to be polished of the wafer W disposed under the holding member 91.

In the polishing apparatus 9, a slurry containing the abrasive grains 40a and a slurry containing no abrasive grains 40a are used depending on the purpose. For example, any of the first pump 42 or the second pump 44a may be actuated by the controller 45 of the slurry supply mechanism 4 to control whether the slurry supplied to the upper surface 30 of the polishing plate contains abrasive particles 40a. . Hereinafter, an example of a step of polishing using the polishing apparatus 9 will be described with reference to the flowcharts of FIGS. 17 to 19.

(1) Polishing method 1

As shown in Fig. 17, first, abrasive grains are embedded in the surface 30 of the polishing platen 3 (step S11). In step S11, the pressing member 60 is placed on the surface 30 of the polishing platen 3, and the pressing mechanism 6 is supported by the rotation support mechanism 5. Further, the workpiece holding mechanism 90 first removes the holding member 91.

Then, the polishing platen 3 is rotated in the direction indicated by the arrow 3a, and supplied to the surface 30 of the polishing platen 3 from the slurry supply mechanism 4 The slurry 40 of the abrasive grains 40a (free abrasive grains) is rotated in the direction indicated by the arrow 52a, and the pressing member 60 is rotated in the direction indicated by the arrow 60a. Further, the AC power is applied from the AC power supply means 69, and the pressing action portion 61 is subjected to ultrasonic vibration. Thus, the slurry 40 containing the abrasive grains 40a can be brought between the pressing surface 611 of the pressing member 60 and the surface 30 of the polishing platen 3, and the abrasive grains 40a can be embedded in the surface 30 of the polishing platen 3. Further, the slurry 40 is used such as a hydrocarbon oil, ethylene glycol or the like.

As described above, the lower surface of the pressing piece 600 as the pressing surface forms a circular shape, and the pressure of the slurry 40 generated between the polishing platen 3 and the pressing action portion 61 can be made constant, so that the abrasive grains can be suppressed. Buried unevenly.

Next, in order to remove the slurry 40, the abrasive grains 40a, and the sludge contained in the slurry 40 (the processing powder of the fixing plate 3 and the pressing piece 600, etc.) remaining on the polishing platen 3, for example, by rotating the polishing plate 3 At the same time, the high-pressure cleaning liquid is ejected from a nozzle (not shown) to clean the polishing platen 3. Then, the polishing platen 3 is rotated while discharging high-pressure gas from the nozzle (not shown) toward the polishing platen 3 to perform drying processing (step S12).

In this manner, polishing of the workpiece can be performed in a state where the abrasive grains have been buried on the surface 30 of the polishing platen 3 and the surface 30 is cleaned (step S13). At the time of polishing, as shown in Fig. 16, the workpiece, such as the wafer W, is held on the holding surface 91a of the holding member 91. Next, the holding member 91 is brought into contact with the driving roller 93 and the driven roller to be supported by the same, and the wafer W is placed on the surface 30 of the polishing platen 3, and the driving roller 93 is moved in the X direction as needed. The wafer W is positioned within the use area 34 of the surface 30 of the polishing platen 3.

Thus, once the wafer W is placed in the use area of the polishing platen 3 In the field 34, polishing is carried out by supplying a slurry containing no abrasive particles from the slurry supply mechanism 4 to the surface 30 of the polishing platen 3 and the wafer W. By the cleaning of step S12, the abrasive grains (free abrasive grains) remaining on the surface 30 of the polishing platen 3 used in the step S11 can be removed, so that the polishing marks such as scratches caused by the free abrasive grains are not generated during the polishing. A good processing surface can be obtained and the surface roughness of the wafer W can be improved.

(2) Polishing method 2

As shown in Fig. 18, the polishing of the wafer was carried out initially using a slurry containing abrasive grains. First, as shown in FIG. 16, the pressing mechanism 67 is held by the rotation support mechanism 5, and the holding member 91 holding the wafer W is held in the workpiece holding mechanism 90, and the pressing mechanism 6 and the wafer W are carried. It is placed on the use area 34 of the polishing platen 3.

Next, the polishing table 3 is rotated in the direction of the arrow 3a shown in Fig. 16, and the pressing mechanism 6 is rotated in the direction of the arrow 60a, and the holding member 91 is rotated in the direction of the arrow 91b, and the polishing plate 3 is made. The surface 30 slides with the pressing surface 611 of the pressing member 60, and slides the surface 30 and the wafer W. At this time, the AC power is applied from the AC power supply means 69, and the pressing action portion 61 is subjected to ultrasonic vibration. Further, the slurry supply mechanism 4 supplies a slurry containing the abrasive grains 40a (free abrasive grains) between the surface 30 of the polishing platen 3 and the wafer W, and between the surface 30 and the pressing surface 611 of the pressing mechanism 6. . Thus, the wafer W can be polished by the abrasive grains embedded in the surface 30 of the polishing platen 3 and the abrasive grains (free abrasive grains) supplied from the slurry supply mechanism 4, and the free abrasive grains can be pushed by the pressing mechanism 6. It is buried in the surface 30 of the polishing platen 3 (step S21, the first polishing process).

Next, the slurry supply mechanism 4 supplies the slurry containing no abrasive grains 40a between the surface 30 of the polishing platen 3 and the wafer W, and slides the rotating surface 30 and the rotating wafer W to perform the wafer W. Grinding. At this time, the AC power may be applied from the AC power supply means 69, and the pressing action portion 61 may be subjected to ultrasonic vibration or ultrasonic vibration. Thus, the free abrasive grains remaining on the surface 30 of the polishing platen 3 used in the step S21 and the abrasive grains (fixed abrasive grains) embedded in the surface 30 of the polishing platen 3 can be ground. On the other hand, the polishing method 1 for removing the free abrasive grains can improve the polishing efficiency (step S22, second polishing process).

The above method is a method which is effective when a further finishing process such as CMP (Chemical Mechanical Polishing) or a polishing method using only the above-mentioned abrasive grains is not required, and the processing time of the CMP can be shortened. Even if the polishing process with smaller abrasive grains is not added, the processed surface with higher quality than the free abrasive grains can be obtained, and the process cost can be reduced.

(3) Polishing method 3

In the above polishing method 2, the polishing is performed by the free abrasive grains in step S22, so that damage or damage caused by the free abrasive grains may occur on the processed surface of the wafer W. Therefore, in order to reduce the above damage or damage, as shown in FIG. 19, polishing by the slurry containing the abrasive grains (step S31, the first polishing process) and polishing by the slurry containing no abrasive grains (step S33, Between the second polishing process, cleaning of the surface 30 of the cleaning polishing plate 3 is performed (step S32). The cleaning step may employ a method of spraying a liquid containing no abrasive particles toward the surface 30 of the polishing platen 3, and pressing the cloth or the porous material toward the surface 30 of the polishing platen 3. The method of polishing the pad, the method of removing the residue from the polishing plate 3 by a rubber wiper, etc., can be selected according to the desired quality. Once the cleaning is performed, the discharge of the free abrasive grains can be promoted. Therefore, the polishing efficiency in the step S33 is lower than that in the step S22, but the processing quality of the wafer W can be improved. Further, step S31 is executed in the same manner as step S21, and step S33 is executed in the same manner as step S22.

As described above, in the polishing method 2 and the polishing method 3, when polishing is performed by supplying a slurry containing no abrasive grains, the reduction in processing efficiency can be suppressed, so that it can be removed by processing which is not affected by the free abrasive grains. The volume will increase. That is, the area where the polishing marks can be removed when polishing using the free abrasive grains will increase. Therefore, the diameter of the workpiece in the shape of the wafer can be increased. In particular, it is more effective in polishing a hard substrate such as sapphire, SiC (gallium carbide), GaN (gallium nitride), or AlN (aluminum nitride).

[First Embodiment]

For the block of AlTiC (alumina-titanium carbide ceramic) used for the magnetic head, the polishing apparatus 9 of the present invention is used for polishing by the above-described polishing method 2 and polishing method 3, and general polishing using a function of embedding without abrasive grains is used. In the same manner as the polishing method 2 and the polishing method 3 described above, the polishing efficiency after polishing by the slurry containing the abrasive grains and polishing by the slurry containing no abrasive grains is shown in Fig. 20 .

It can be seen that both of the polishing methods 2 and 3 have higher polishing efficiency when using the polishing apparatus 9 of the present invention than when using a general polishing apparatus. It can be inferred that the polishing device 9 having the abrasive grain embedding function can embed the abrasive grains on the surface 30 of the polishing platen 3 when polishing with the free abrasive grains, and can be lifted. The efficiency of polishing of the abrasive grains is not used.

Further, comparing the polishing method 2 and the polishing method 3, it is understood that the polishing efficiency of the polishing method 2 is higher than that of the polishing method 3 when either device is used. It can be inferred that the ratio of removing the free abrasive grains by the polishing method 3 is high, so that the polishing efficiency is correspondingly lowered.

Further, among the four methods, it has been confirmed that the polishing apparatus 9 of the present invention is used for polishing by the polishing method 2, and the polishing efficiency is the highest.

1‧‧‧Abrasive grain embedding device

2‧‧‧ device base

3‧‧‧ Grinding plate

3a, 52a, 60a, 91b, X, X’‧‧‧ arrows

4‧‧‧Slurry supply mechanism

5‧‧‧Rotary support organization

6, 6a‧‧‧ Pushing mechanism

8‧‧‧ Rubber band

9‧‧‧ polishing device

30, 30a‧‧‧ surface

31‧‧‧Rotary axis

32‧‧‧Electric motor

33‧‧‧ center hole

34‧‧‧Use area

34a‧‧‧Width

40‧‧‧Slurry

40a‧‧‧Abrasive grain

41‧‧‧1st slurry tank

42‧‧‧1st pump

43a, 43b‧‧‧ nozzle

44‧‧‧Second slurry tank

44a‧‧‧2nd pump

45‧‧‧ Controller

51‧‧‧Support rod

52, 93‧‧‧ drive roller

53‧‧‧ driven roller

54‧‧‧Rotary drive mechanism

60, 61a‧‧‧ Pushing members

61, 61', 61a~61c‧‧‧ pushing action

62‧‧‧ vibrating body

63, 73‧‧‧heavy hammer components

64‧‧‧Consolidated bolts

65‧‧‧Supersonic vibrator

66‧‧‧Upper vibrating body, spacer

67‧‧‧Consolidated nut and pushing mechanism

69‧‧‧AC power supply agency

70‧‧‧Support components

71, 621‧‧‧ Support Department

72‧‧‧Support shaft

90‧‧‧Processed object retention mechanism

91‧‧‧ Keeping components

91a‧‧‧ Keep face

92‧‧‧Support rod

94‧‧‧Rotary drive mechanism

511, 921‧‧‧1st roller support

512, 922‧‧‧2nd roller support

541‧‧‧Electric motor

542‧‧‧Transduction link mechanism

600, 600a, 600b, 600c‧‧‧ push tablets

601‧‧‧ trench

602, 611, 611', 611a‧‧‧ push surface

603‧‧‧ shallow groove

612a‧‧‧Installation surface

622‧‧‧lower vibrating body

622b‧‧‧Support shaft

622c‧‧‧ male thread

633‧‧‧ accommodating holes

634‧‧‧Electrode terminal mounting

635a, 635b, 681a, 681b‧‧‧ slip rings

651‧‧‧piezoelectric body

652a, 652b‧‧‧ electrodes

682a, 682b‧‧‧ wiring

691‧‧‧Hose

692‧‧‧Rotary connector

710‧‧‧Bolt insert hole

720‧‧‧heavy hammer member sliding fitting

721‧‧‧ vibrator installation department

722‧‧‧Electrode terminal mounting

723‧‧‧ Male thread

730‧‧‧Sliding fitting hole

731‧‧‧Female threaded holes

941‧‧‧Electric motor

942‧‧‧Transmission link mechanism

S11~S33‧‧‧ Process steps

W‧‧‧ wafer

Fig. 1 is a perspective view showing an abrasive particle embedding device.

Fig. 2 is an exploded perspective view showing a first example of the pressing mechanism.

Fig. 3 is a cross-sectional view showing a first example of the pressing mechanism.

Fig. 4 is a bottom view showing a pressing piece included in the pressing mechanism.

Fig. 5 is a perspective view showing a rotation support mechanism constituting the abrasive grain embedding device.

Fig. 6 is an explanatory view showing the relationship between the pressing member and the position and size of the polishing platen.

Fig. 7 is an explanatory view showing the relative sliding direction of the pressing mechanism and the polishing platen when the abrasive grains are buried.

Fig. 8 is an explanatory view showing the relationship between the conventional pressing mechanism and the position and size of the polishing platen.

Fig. 9 is a bottom plan view showing a second example of the pressing piece.

Fig. 10 is a bottom plan view showing a third example of the pressing piece.

Fig. 11 is a bottom plan view showing a fourth example of the pressing piece.

Fig. 12 is an exploded perspective view showing a second example of the pressing mechanism.

Fig. 13 is a cross-sectional view showing a second example of the pressing mechanism.

Fig. 14 is a bottom view showing a pressing member of a second example constituting the pressing mechanism.

Fig. 15 is an explanatory view showing the relationship between the pressing member and the position and size of the polishing platen.

Fig. 16 is a perspective view showing a polishing apparatus.

Figure 17 is a flow chart showing the steps of the polishing method 1.

Figure 18 is a flow chart showing the steps of the polishing method 2.

Figure 19 is a flow chart showing the steps of the polishing method 3.

Fig. 20 is a graph showing the processing efficiency of the polishing method 2 and the polishing method 3.

6‧‧‧Pushing mechanism

60‧‧‧ Pushing members

61‧‧‧Pushing action department

63‧‧‧heavy hammer components

600‧‧‧Pushing tablets

611‧‧‧ pushing surface

Claims (6)

An abrasive grain embedding device having at least a pressing mechanism for pushing a polishing plate, the abrasive grain embedding device supplying a slurry containing abrasive grains to a surface of the polishing plate, and by the pressing mechanism Pressing the polishing plate by the slurry, and sliding the pressing mechanism and the polishing plate to embed the abrasive particles contained in the slurry into the surface of the polishing plate, wherein the pressing mechanism comprises: a plurality of pressing members and a weight member disposed above the plurality of pressing members to press the plurality of pressing members and the ultrasonic vibrator on the polishing platen, respectively, and the plurality of pressing members may be respectively The ultrasonic particle embedding device includes: a power supply mechanism that supplies electric power to the ultrasonic vibrator, wherein each of the plurality of pressing members has a pressing surface, and the pressing surface is provided with a plurality of discs Push the piece. In the abrasive grain embedding apparatus of the first aspect of the invention, the pressing member is disposed at a position that does not protrude from a use region of the polishing platen. A polishing apparatus comprising: a polishing plate having a grinding surface capable of grinding a workpiece, and being supported to be rotatable; a rotary driving mechanism for rotating the polishing plate; and a workpiece holding mechanism having the same grinding The polishing surface of the fixed plate is opposite to the holding surface of the workpiece, and the workpiece can be held in contact with the polishing platen; a slurry supply mechanism for selectively supplying a slurry containing abrasive grains and a slurry containing no abrasive grains to the surface of the polishing platen; and an abrasive grain embedding device which can be supplied to the polishing plate by the slurry supply mechanism a slurry containing abrasive grains on the surface thereof to press the polishing plate, and the pressing mechanism and the polishing plate are slid to embed the abrasive grains contained in the slurry into the surface of the polishing plate; the abrasive grains are buried The injecting device includes: a pressing mechanism, comprising: a plurality of pressing members and a weight member disposed above the plurality of pressing members to press the plurality of pressing members and the ultrasonic vibrator on the polishing platen An ultrasonic wave may be applied to each of the plurality of pressing members; and a power supply mechanism that supplies electric power to the ultrasonic vibrator, wherein the plurality of pressing members respectively have pressing surfaces, and the pressing surfaces are provided with a plurality of pressing surfaces Disc-shaped push piece. A polishing method for polishing a workpiece held by the workpiece holding mechanism by using a polishing apparatus according to item 3 of the patent application, comprising the steps of: a first polishing step of supplying a surface of the polishing plate comprising abrasive grains And the slurry is pressed by the pressing mechanism to press the polishing plate by the slurry containing the abrasive grains, and the pressing mechanism is slid with the polishing plate to embed the abrasive grains contained in the slurry into the polishing process. a surface of the disk, and the workpiece held by the workpiece holding mechanism is slid with the polishing plate to polish the surface of the workpiece; and In the second polishing step, after the first polishing step is performed, a slurry containing no abrasive grains is supplied to the surface of the polishing platen, and the workpiece held by the workpiece holding mechanism is slid with the polishing platen. Polishing the surface of the aforementioned workpiece. The polishing method of claim 4, further comprising a cleaning step of cleaning the polishing plate between the first polishing step and the second polishing step. In the polishing method of claim 4 or 5, the workpiece is sapphire, SiC, GaN or AlN.