JP2009291911A - Lapping apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lapping apparatus having an abrasive particle embedding means for efficiently embedding abrasive particles in a surface plate forming a polishing face. <P>SOLUTION: The abrasive particle embedding means 6 includes an abrasive particle embedding mechanism 60 consisting of a thrust member 61 having a circular thrust face opposite to the surface of the surface plate and a mounting face on the opposite side to the thrust face, a supporting member 62 having a supporting portion on which the mounting face of the thrust member is mounted and a supporting shaft portion erected from the supporting portion, an ultrasonic vibrator 65 arranged on the supporting shaft portion of the supporting member 62, and a spindle member arranged on the supporting member 62, and an AC power supply means for applying AC power to the ultrasonic vibrator 65 of the abrasive particle embedding mechanism 60 to generate ultrasonic vibration. The thrust member 61 is formed so that its whole circular thrust face contacts the surface of the surface plate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lapping apparatus for polishing a workpiece such as a semiconductor wafer.

  In the semiconductor device manufacturing process, the surface of a substantially disk-shaped wafer is polished by a lapping apparatus, and devices such as IC and LSI are formed on the polished wafer surface. A lapping apparatus for polishing a workpiece such as a wafer includes a surface plate that is rotatably supported, an abrasive liquid supply means that supplies an abrasive liquid containing abrasive grains to the surface of the surface plate, and the abrasive liquid supply Abrasive embedding means for embedding abrasive grains contained in the abrasive liquid supplied by the means on the surface of the surface plate, and a work holding member for holding the work and contacting the surface of the surface plate Yes.

  In such a lapping apparatus, a workpiece held by a workpiece holding member is formed after a polishing surface is formed by embedding abrasive grains contained in the abrasive liquid supplied to the surface of the surface plate by the abrasive grain embedding means. Polishing is performed by bringing an object into contact with the polishing surface. When the polishing process is performed in this manner, the abrasive grains embedded in the surface plate are gradually worn out and the polishing function is deteriorated. Therefore, it is necessary to periodically perform the operation of embedding the abrasive grains in the surface plate.

  As a method of embedding abrasive grains on the surface plate, a method of sliding an abrasive embedding jig on the surface of the surface plate while supplying an abrasive liquid containing abrasive grains to the surface of the surface plate is generally performed. Yes. However, such an abrasive grain embedding method has a problem that the efficiency of embedding abrasive grains is low, and it takes a long time to embed a sufficient amount of abrasive grains on the surface of the surface plate.

In order to solve the above-described problems, a lapping apparatus has been proposed in which an abrasive grain embedding operation is performed while applying ultrasonic vibration to an abrasive grain embedding jig. (For example, see Patent Document 1)
Japanese Patent No. 3848643

  Therefore, the jig for embedding abrasive grains disclosed in Patent Document 1 is composed of a donut-shaped vibrating body, and the area of the pressing surface that presses the abrasive grains is small. It is not always satisfactory.

  The present invention has been made in view of the above-described facts, and a main technical problem thereof is to provide a lapping apparatus provided with abrasive grain embedding means capable of efficiently embedding abrasive grains on a surface plate that forms a polishing surface. There is.

In order to solve the main technical problem, according to the present invention, a surface plate that is rotatably supported, rotation driving means for rotating the surface plate, and a polishing liquid containing abrasive grains on the surface of the surface plate are supplied. An abrasive liquid supplying means, an abrasive embedding means for embedding abrasive grains contained in the abrasive liquid supplied by the abrasive liquid supplying means on the surface of the surface plate, and a workpiece to be held on the surface of the surface plate A workpiece holding member that is brought into contact with the lapping apparatus,
The abrasive grain embedding means includes a pressing member having a circular pressing surface facing the surface of the surface plate, a mounting surface opposite to the pressing surface, a support portion on which the mounting surface of the pressing member is mounted, A support member having a support shaft portion provided upright from the support portion; an ultrasonic vibrator disposed on the support shaft portion of the support member; and a weight member disposed on the support member. Provided with an abrasive embedding mechanism, and AC power supply means for applying AC power for generating ultrasonic vibration in the ultrasonic vibrator of the abrasive embedding mechanism,
The pressing member is formed so that the entire surface of the circular pressing surface is in contact with the surface of the surface plate.
A lapping apparatus is provided.

  It is desirable that a plurality of grooves be formed on the circular pressing surface of the pressing member.

  In the lapping apparatus according to the present invention, the abrasive grain embedding mechanism constituting the abrasive grain embedding means for embedding abrasive grains contained in the abrasive liquid supplied by the abrasive liquid supplying means on the surface of the surface plate faces the surface of the surface plate. A support having a pressing member having a circular pressing surface, a mounting surface opposite to the pressing surface, a support portion on which the mounting surface of the pressing member is mounted, and a support shaft portion provided upright from the support portion A member, an ultrasonic transducer disposed on the support shaft portion of the support member, and a weight member disposed on the support member, the pressing member contacting the entire surface of the circular pressing surface to the surface of the surface plate Therefore, abrasive grains can be embedded efficiently on the surface of the surface plate.

Preferred embodiments of a lap device constructed according to the present invention will be described below in more detail with reference to the accompanying drawings.
FIG. 1 shows a perspective view of a lapping apparatus constructed in accordance with the present invention. The lap device shown in FIG. 1 includes a device housing generally indicated by numeral 2. A disk-shaped surface plate 3 is rotatably supported on the table plate 21 constituting the device housing 2. The surface plate 3 is made of a metal material such as tin, and a rotating shaft 31 is provided on the lower surface thereof. The surface plate 3 configured as described above is rotated by an electric motor 32 serving as a rotation driving means connected to the rotation shaft 31 by transmission.

  The table plate 21 constituting the apparatus housing 2 is provided with a polishing liquid supply means 4 for supplying a polishing liquid containing abrasive grains to the surface (upper surface) 30 of the surface plate 3. The abrasive liquid supply means 4 includes, for example, an abrasive liquid tank 41 that contains an abrasive liquid containing diamond abrasive grains having a particle diameter of 0.05 to 1 μm, and a pump that feeds the abrasive liquid contained in the abrasive liquid tank 41. 42 and a nozzle 43 that ejects the abrasive liquid fed from the pump 42 onto the surface (upper surface) 30 of the surface plate 3.

  The lapping apparatus in the illustrated embodiment includes an abrasive grain embedding means and a workpiece to be described later for embedding abrasive grains contained in the abrasive liquid supplied by the abrasive liquid supply means 4 in the surface (upper surface) 30 of the surface plate 3. And a rotary support means 5 for rotatably supporting a workpiece holding member, which will be described later, for holding the workpiece and bringing it into contact with the surface (upper surface) 30 of the surface plate 3. The rotary support means 5 includes a support lever 51 disposed so as to be movable in parallel with the surface (upper surface) 30 of the surface plate 3. The support lever 51 can be moved in a direction indicated by an arrow X in FIG. 1 by operating means (not shown). A first roller support portion 511 and a second roller support portion 512 are provided at the tip of the support lever 51 so as to be spaced apart from each other. First, the driving roller 52 is rotatably supported by the roller support portion 511, and the driven roller 53 is rotatably supported by the second roller support portion 512. The support lever 51 is provided with a rotation driving means 54 for rotating the driving roller 52. The rotation drive unit 54 includes an electric motor 541 and a transmission connection unit 542 including a transmission belt that transmits and connects the drive shaft of the electric motor 541 and the rotation shaft of the drive roller 52.

  Next, with reference to FIG. 2 and FIG. 3, an abrasive grain embedding means for embedding abrasive grains contained in the abrasive liquid supplied by the abrasive liquid supply means 4 in the surface (upper surface) 30 of the surface plate 3 will be described with reference to FIGS. explain. 2 and 3 show an abrasive grain embedding mechanism 60 constituting the abrasive grain embedding means 6. The abrasive grain embedding mechanism 60 shown in FIGS. 2 and 3 includes a pressing member 61 for pressing abrasive grains contained in the abrasive liquid supplied to the surface (upper surface) 30 of the surface plate 3, and the pressing member 61. A support member 62 is provided for support. In the illustrated embodiment, the pressing member 61 is formed in a circular shape having a diameter of, for example, 40 mm using ceramics, and has a pressing surface 611 on the lower surface thereof and an attachment surface 612 on the upper surface opposite to the pressing surface 611. is doing. The pressing surface 611 is preferably formed with a plurality of grooves for storing the abrasive liquid containing the abrasive grains supplied by the abrasive liquid supply means 4. Examples of the plurality of grooves formed on the pressing surface 611 include a plurality of radial grooves 611a as shown in FIG. 4, a plurality of annular grooves 611b as shown in FIGS. 5A and 5B, and FIG. As shown in FIG. 7, a plurality of radial grooves 611a and a plurality of annular grooves 611b, and a plurality of lattice-like grooves 611c as shown in FIG. The width of the radial grooves 611a, the annular grooves 611b, or the plurality of lattice-shaped grooves 611c may be 1 to 2 mm.

  2 and 3, the support member 62 includes a support portion 621 on which the mounting surface 612 of the pressing member 61 is attached by an adhesive, and a support portion 621 that is erected from the support portion 621. The support shaft portion 622 is provided. The support part 621 is formed in a circular shape having an outer diameter larger than that of the pressing member 61, and four bolt insertion holes 621 a are provided at equiangular positions on the outer peripheral part. The mounting surface 612 of the pressing member 61 is fixed to the lower surface of the support portion 621 with an appropriate adhesive. The support shaft portion 622 constituting the support member 62 includes a large-diameter weight member loose fitting portion 622a extending upward from the upper surface of the support portion 621 and a weight member loose fitting portion extending upward from the upper end of the weight member loose fit portion 622a. A vibrator mounting portion 622b having a smaller diameter than 622a and an electrode terminal mounting portion 622c having a smaller diameter than the vibrator mounting portion 622b extending upward from the upper end of the vibrator mounting portion 622b are provided.

  A weight member 63 is disposed on the support member 62 configured as described above. The weight member 63 is formed in an annular shape from a metal material such as stainless steel. The weight member 63 is formed with a loosely fitting hole 631 loosely fitted in the weight member loosely fitting portion 622a of the support shaft portion 622 constituting the support member 62 in the center portion, and on the lower surface thereof the support member 62. Four female screw holes 632 are formed at positions corresponding to the four bolt insertion holes 621 a provided in the support portion 621. The weight member 63 configured in this manner is loosely fitted to the weight member loosely fitting portion 622a of the support shaft portion 622 constituting the support member 62 and placed on the upper surface of the support portion 621. The fastening bolt 64 is inserted into the bolt insertion hole 621 a from the lower side of the portion 621 and screwed into the female screw hole 632, so that the mounting portion 621 of the support member 62 is mounted. The weight member 63 may have a weight of about 5 kg.

  An ultrasonic transducer 65 is disposed on the transducer mounting portion 622b of the support member 62. The ultrasonic vibrator 65 includes an annular piezoelectric body 651 and annular electrodes 652a and 652b mounted on both side polarization surfaces of the piezoelectric body 651, respectively. The piezoelectric body 651 is formed of piezoelectric ceramics such as barium titanate (BaTiO3), lead zirconate titanate (PB (Zi, Ti) O3), lithium niobate (LiNbO3), lithium tantalate (LiTaO3), and the like. The ultrasonic transducer 65 configured as described above is fitted into the transducer mounting portion 622b of the support shaft portion 622 constituting the support member 62, and is placed on the upper surface of the weight member loose fitting portion 622a. In this manner, the annular spacer 66 fitted to the vibrator mounting portion 622b is placed on the ultrasonic vibrator 65 placed on the upper surface of the weight member loosely fitting portion 622a. The ultrasonic vibrator 65 is attached to the vibrator mounting portion 622b by screwing the fastening nut 67 into the male screw portion 622d formed at the upper end portion of the vibrator mounting portion 622b.

  Two slip rings 681a and 681b are disposed on the outer periphery of the electrode terminal mounting portion 622c of the support member 62. The slip rings 681a and 681b are connected to the electrodes 652a and 652b constituting the ultrasonic transducer 65 via wirings 682a and 682b.

  Returning to FIG. 1 and continuing the description, the abrasive grain embedding means 6 in the illustrated embodiment supplies AC power to the electrodes 652a and 652b of the ultrasonic vibrator 65 constituting the abrasive grain embedding mechanism 60. Means 69 are provided. The AC power supply means 69 outputs AC power having a frequency of 10 to 50 kHz and a voltage of 20 to 100 V, for example. The AC power output from the AC power supply means 69 is supplied to the slip ring 681a via a wiring (not shown) provided in the flexible pipe 691 and a rotary connector 692 provided at the tip of the flexible pipe 691. And 681b are supplied to the ultrasonic transducer 65 via wirings 682a and 682b. The rotary connector 692 is configured to fit into the electrode terminal mounting portion 622c of the support member 62, and brushes that are in sliding contact with the slip rings 681a and 681b are disposed on the inner peripheral surface thereof. Accordingly, by fitting the rotary connector 692 to the electrode terminal mounting portion 622c of the support member 62, the AC power supply means 69 and the electrodes 652a and 652b of the ultrasonic transducer 65 are electrically connected.

  Next, a workpiece holding member for holding the workpiece and bringing it into contact with the surface (upper surface) 30 of the surface plate 3 will be described with reference to FIG. A workpiece holding member 7 shown in FIG. 8 is formed in a cylindrical shape from a metal material such as stainless steel, and a wafer W as a workpiece is attached to the lower surface of the workpiece holding member 7 by wax.

The lap device in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
First, an abrasive embedding operation for embedding abrasive grains on the surface (upper surface) 30 of the surface plate 3 will be described with reference to FIG. In order to carry out the abrasive grain embedding work, the abrasive grain embedding mechanism 60 constituting the abrasive grain embedding means 6 is placed on the surface (upper surface) of the surface plate 3, and the outer peripheral surface of the weight member 63 is driven by the rotary support means 5. The roller 52 and the driven roller 53 are brought into contact with each other. If the abrasive burying mechanism 60 is supported by the driving roller 52 and the driven roller 53 of the rotary support means 5 in this way, the AC power supply means is applied to the electrode terminal mounting portion 622c of the support member 62 constituting the abrasive burying mechanism 60. 69 rotary connectors 692 are fitted. Next, the electric motor 32 as the rotation driving means of the surface plate 3 is operated to rotate the surface plate 3 in the direction indicated by the arrow 3a at a rotation speed of, for example, 10 rpm, and the abrasive liquid supply means 4 is operated to turn the abrasive grains. A polishing liquid 40 containing 40 a is supplied to the surface (upper surface) 30 of the surface plate 3. Then, the electric motor 541 of the rotary support means 5 is operated to rotate the drive roller 52 in the direction indicated by the arrow 52a. As a result, the abrasive embedding mechanism 60 in which the driving roller 52 and the outer peripheral surface of the weight member 63 are in contact is rotated in the direction indicated by the arrow 60a. The abrasive liquid 40 including the abrasive grains 40a supplied to the surface (upper surface) 30 of the surface plate 3 is obtained by operating the abrasive liquid supply means 4 and rotating the surface plate 3 and rotating the abrasive grain embedding mechanism 60 in this manner. Enters between the pressing surface 611 of the pressing member 61 constituting the abrasive grain embedding mechanism 60 and the surface (upper surface) of the surface plate 3.

  Next, the AC power supply means 69 is operated, and AC power is applied to the electrodes 652a and 652b constituting the ultrasonic vibrator 65 as described above. As a result, the piezoelectric body 651 vibrates ultrasonically, and the ultrasonic vibration is transmitted to the pressing member 61 via the support member 62 of the abrasive grain embedding mechanism 60, and the pressing member 61 is ultrasonically vibrated in the vertical direction. According to experiments by the present inventors, when AC power having a frequency of 10 to 50 kHz and a voltage of 20 to 100 V is applied to the electrodes 652a and 652b constituting the ultrasonic vibrator 65, the pressing member 61 has a frequency of 10 to 50 kHz. Vibrated in the vertical direction with an amplitude of 0.5 to 5 μm.

  As described above, the abrasive liquid 40 including the abrasive grains 40a enters between the pressing surface 611 of the pressing member 61 that vibrates ultrasonically and the surface (upper surface) of the surface plate 3, as described above. As shown, the abrasive grains 40 a are pressed and embedded in the surface (upper surface) 30 of the surface plate 3 by the pressing surface 611 of the pressing member 61. At this time, the operating means (not shown) of the rotary support means 5 that rotatably supports the abrasive grain embedding mechanism 60 is operated to move the support lever 51 in the direction indicated by the arrow X, so ) 30 can be embedded with abrasive grains 40a. In addition, since the pressing member 61 presses the abrasive grains 40a over the entire surface of the circular pressing surface 611, the abrasive grains 40a can be efficiently embedded in the surface (upper surface) 30 of the surface plate 3. In the illustrated embodiment, the pressing surface 611 of the pressing member 61 is formed with a plurality of radial grooves 611a, a plurality of annular grooves 611b, or a plurality of lattice-shaped grooves 611c as shown in FIGS. Therefore, the abrasive liquid 40 containing the abrasive grains 40a is stored in the plurality of radial grooves 611a or the plurality of annular grooves 611b, and therefore, between the pressing surface 611 and the surface (upper surface) 30 of the surface plate 3. The abrasive liquid 40 containing the abrasive grains 40a can always be held. According to the experiments by the inventors, when the abrasive grains 40a are embedded in the surface (upper surface) 30 of the surface plate 3 having a diameter of 600 mm using the pressing member 61 having the pressing surface 611 having a diameter of 40 mm, as described above, The required amount of abrasive grains 40a could be embedded in the surface (upper surface) 30 of the surface plate 3 in about 10 minutes.

Next, the lapping work performed using the surface plate 3 in which the abrasive grains 40a are embedded as described above will be described with reference to FIG.
To perform the lapping work, the abrasive liquid supply means 4, the abrasive grain embedding mechanism 60 and the AC power supply means 69 used for the abrasive grain embedding work are removed as shown in FIG. A workpiece holding member 7 on which a wafer W as a workpiece is mounted is placed on the surface (upper surface) of the surface plate 3 on the wafer W side, and the outer peripheral surface of the workpiece holding member 7 is driven by the rotary support means 5. The roller 52 and the driven roller 53 are brought into contact with each other. When the workpiece holding member 7 is supported by the drive roller 52 and the driven roller 53 of the rotary support means 5 in this way, the electric motor 32 as the rotation drive means of the surface plate 3 is operated to move the surface plate 3 to the arrow. For example, while rotating at a rotational speed of 10 rpm in the direction indicated by 3a, the electric motor 531 of the rotary support means 5 is operated to rotate the drive roller 52 in the direction indicated by the arrow 52a, and the workpiece holding member 7 is indicated by the arrow 7a. Rotate in the direction. At this time, the operating means (not shown) of the rotary support means 5 that rotatably supports the workpiece holding member 7 is operated to move the support lever 51 in the direction indicated by the arrow X. As a result, the wafer W as the workpiece mounted on the lower surface of the workpiece holding member 7 is polished by the abrasive grains 40a having the polished surface embedded in the surface (upper surface) 30 of the surface plate 3.

Next, another embodiment of the abrasive grain embedding mechanism 60 will be described with reference to FIGS. 12 and 13.
The abrasive embedding mechanism 60 shown in FIGS. 12 and 13 is configured by mounting a plurality of (three in the illustrated embodiment) support members 62 each having a pressing member 61 mounted on a weight member 63. The pressing member 61 and the supporting member 62 have substantially the same configuration although the diameter is smaller than that of the pressing member 61 and the supporting member 62 shown in FIG. 2 and FIG. The description is omitted. In addition, the bolt insertion hole 621a formed in the support part 621 of the support member 62 shown in FIGS. 2 and 3 is not provided in the support part 621 of the support member 62 shown in FIGS. On the other hand, the weight member 63 is provided with three fitting holes 633 for disposing the three support members 62, respectively. A common electrode terminal mounting portion 634 protrudes from the center of the upper surface of the weight member 63, and two slip rings 635 a and 635 b are disposed on the outer peripheral surface of the common electrode terminal mounting portion 634. Has been. The rotary connector 692 of the AC power supply means 69 is fitted to the common electrode terminal mounting portion 634 configured as described above. As shown in FIG. 13, the support member 62 of the abrasive grain embedding mechanism 60 is fitted into the fitting hole 633 of the weight member 63 configured as described above from the lower surface side, and the upper surface of the support portion 621 constituting the support member 62 and the weight The urethane rubber ring 8 is interposed between the lower surface of the member 63 and the support portion 621 is attached to the lower surface of the weight member 63 with an appropriate adhesive. The slip rings 635a and 635b disposed on the common electrode terminal mounting portion 634 and the electrodes 652a and 652b constituting the ultrasonic transducers 65 disposed on the three support members 62 are electrically connected. Connect to.

1 is a perspective view of a lap device constructed in accordance with the present invention. The perspective view which decomposes | disassembles and shows the abrasive grain embedding mechanism which comprises the abrasive grain embedding means with which the lapping apparatus shown in FIG. 1 is equipped. Sectional drawing of the abrasive grain embedding mechanism which comprises the abrasive grain embedding means with which the lapping apparatus shown in FIG. 1 is equipped. FIG. 4 is a bottom view showing a first embodiment of a pressing member constituting the abrasive grain embedding mechanism shown in FIGS. 2 and 3. The bottom view which shows 2nd embodiment of the press member which comprises the abrasive grain embedding mechanism shown in FIG. 2 and FIG. The bottom view which shows 3rd embodiment of the press member which comprises the abrasive grain embedding mechanism shown in FIG. 2 and FIG. The bottom view which shows 4th embodiment of the press member which comprises the abrasive grain embedding mechanism shown in FIG. 2 and FIG. The perspective view of the workpiece holding member with which the lapping apparatus shown in FIG. 1 is equipped. Explanatory drawing of the abrasive grain embedding operation implemented using the lapping apparatus shown in FIG. Explanatory drawing which shows the state by which an abrasive grain is embed | buried on the surface of a surface plate by the abrasive grain embedment work shown in FIG. Explanatory drawing of the lapping operation implemented using the lap | wrap apparatus shown in FIG. The disassembled perspective view which shows other embodiment of the abrasive grain embedding mechanism which comprises the abrasive grain embedding means with which the lapping apparatus shown in FIG. 1 is equipped. FIG. 12 is a cross-sectional view of the abrasive grain embedding mechanism.

Explanation of symbols

2: Device housing 21: Table plate 3: Surface plate 4: Abrasive liquid supply means 41: Abrasive liquid tank 42: Pump 43: Pump 5: Rotary support means 51: Support lever 52: Drive roller 53: Drive roller 54: Rotation drive Means 6: Abrasive embedding means 60: Abrasive embedding mechanism 61: Press member 62: Support member 63: Weight member 65: Ultrasonic vibrator 66: Spacer 69: AC power supply means 692: Rotary connector 8: Workpiece holding Element
W: Wafer

Claims (2)

A surface plate supported rotatably, a rotation driving means for rotating the surface plate, an abrasive liquid supply means for supplying an abrasive liquid containing abrasive grains to the surface of the surface plate, and an abrasive liquid supply means. In a lapping apparatus comprising: an abrasive grain embedding means for embedding abrasive grains contained in an abrasive liquid on the surface of the surface plate; and a workpiece holding member that holds the workpiece and contacts the surface of the surface plate. ,
The abrasive grain embedding means includes a pressing member having a circular pressing surface facing the surface of the surface plate, a mounting surface opposite to the pressing surface, a support portion on which the mounting surface of the pressing member is mounted, A support member having a support shaft portion provided upright from the support portion; an ultrasonic vibrator disposed on the support shaft portion of the support member; and a weight member disposed on the support member. Provided with an abrasive embedding mechanism, and AC power supply means for applying AC power for generating ultrasonic vibration in the ultrasonic vibrator of the abrasive embedding mechanism,
The pressing member is formed so that the entire surface of the circular pressing surface is in contact with the surface of the surface plate.
A lap device characterized by that.   The lapping apparatus according to claim 1, wherein a plurality of grooves are formed on a circular pressing surface of the pressing member.

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