JP3854844B2 - Wafer edge polishing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wafer edge polishing apparatus .
[0002]
[Prior art]
As shown in FIGS. 11 and 12, the edge polishing of the wafer is performed by the edge polishing drums 2A, 2B, and 2C that are driven to rotate on the edges 1a, 1b, and 1c of the wafer 1 that are chucked and rotated by a spindle (not shown). The polishing is performed by pressing the compressible flexible polishing pads 3A, 3B, and 3C attached to the outer periphery. The edge polishing drum 2A contacts the wafer 1 at an angle θ1 (45 °) to polish the upper surface edge 1a, and the edge polishing drum 2B contacts the wafer 1 at an angle θ2 (90 °) to polish the side edge 1b. The edge polishing drum 2C contacts the wafer 1 at an angle θ3 (135 °) to polish the lower surface edge 1c. Examples of this type of wafer edge polishing method and apparatus include JP-A-10-328989, JP-A-11-33888, and JP-A-11-104942.
[0003]
[Problems to be solved by the invention]
In all of the known examples shown in the above publications, the wafer 1 is polished by pressing against the polishing pads 3A, 3B, 3C. For this reason, as shown in FIG. 11, when the entire circumference of the wafer 1 is polished at once with a plurality of polishing pads 3A, 3B, and 3C, there are the following problems. When the wafer 1 is urged in the direction of the arrow L, the polishing pad 3B faces the urging direction L, so that a constant contact pressure is obtained. However, since the polishing pads 3A and 3C are arranged with a certain angle with respect to the urging direction L, the contact pressure changes and a good polishing state cannot be obtained. Further, a polishing pad cannot be provided on the opposite side of the biasing direction L of the wafer 1, that is, on the left side of the wafer 1 in FIG. 11, and the arrangement of the polishing pad is limited.
[0004]
An object of the present invention is to always allow a plurality of edge polishing drums to contact a wafer with a constant contact pressure, to perform stable edge polishing, and the arrangement of the plurality of edge polishing drums is not limited. It is to provide a wafer edge polishing apparatus .
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides an edge polishing drum disposed opposite to the outer periphery of a wafer that is held horizontally and rotated, a rotation driving means that rotationally drives the edge polishing drum, and the edge Wafer edge provided with turning drive means for changing the inclination angle of the polishing drum, vertical drive means for moving the edge polishing drum up and down, and horizontal drive means for moving the edge polishing drum in the horizontal direction and applying pressure to the wafer A polishing unit, a flat polishing drum and a notch polishing drum disposed above and below corresponding to the outer periphery of the wafer, a rotation driving means for rotating and driving the flat polishing drum and the notch polishing drum, and a flat polishing drum and a notch polishing drum. A notch / planar edge polishing unit comprising a vertical drive means and a horizontal drive means for both vertical movement and horizontal movement. And a preparative, the wafer edge grinding unit is plural arranged around the wafer, and the horizontal movement direction of each edge grinding drum, characterized in that facing the center of the wafer, respectively.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. 1 to 4 show an edge polishing unit for polishing the edges 1a, 1b and 1c shown in FIGS. As shown in FIG. 1, a movable plate 10 that is movable in the vertical direction (arrow A, A ′ direction) and horizontal direction (arrow B, B ′ direction) and disposed horizontally is perpendicular to the wafer 1 side. The arranged rotation motor 11 is fixed, the edge polishing drum 2 (2A, 2B, 2C) is fixed to the output shaft of the rotation motor 11, and the outer periphery of the edge polishing drum 2 is compressible. A flexible polishing pad 3 (3A, 3B, 3C) is attached. Therefore, when the rotation motor 11 rotates, the polishing pad 3 rotates.
[0012]
As shown in FIGS. 1 and 3, a cover 12 is fixed to the movable plate 10 so as to cover the side surface of the polishing pad 3 excluding the wafer 1 side. A nozzle 13 is formed on the cover 12 toward the polishing surface of the polishing pad 3, and a polishing liquid is supplied to the nozzle 13 from a polishing liquid supply means (not shown).
[0013]
As shown in FIGS. 1 and 4, a horizontal guide 14 extending in the radial direction of the wafer 1 is disposed below the movable plate 10. The horizontal guide 14 is fixed to the lower surface of the movable plate 10. A horizontal slider 15 is slidably inserted. The horizontal guide 14 is fixed to a support plate 16, and a motor bracket 17 is fixed to the upper surface of the support plate 16. A horizontal drive cylinder 18 having pressure control means is fixed to the motor bracket 17. The operating rod of the horizontal driving cylinder 18 is connected to the rising portion 10 a of the movable plate 10. Accordingly, when the horizontal drive cylinder 18 is operated, the horizontal slider 15 slides along the horizontal guide 14, and the polishing pad 3 moves together with the movable plate 10 in the direction of the arrow B or B ′ that contacts or separates from the wafer 1. .
[0014]
As shown in FIGS. 1 to 4, a vertical guide 20 is vertically disposed below the movable plate 10, and a vertical slider 21 is slidably fitted into the vertical guide 20. The vertical slider 21 is fixed to the front surface portion of the support plate 16. The vertical guide 20 is fixed to the front support plate 22, and the front support plate 22 is provided with an opening 22 a so that the movable plate 10 can move up and down and turn. A vertical movement motor 23 is fixed to the vertical support plate 22, and a pinion 24 is fixed to the output shaft of the vertical movement motor 23. The pinion 24 meshes with a rack 25 arranged vertically, and the rack 25 is fixed to the front support plate 22. Therefore, when the vertical movement motor 23 rotates, the pinion 24 moves up and down by the rack 25 while rotating. That is, the vertical slider 21 moves up and down along the vertical guide 20, and the movable plate 10 and the polishing pad 3 move up and down in the direction of arrow A or A ′ through the support plate 16 together with the vertical slider 21.
[0015]
A side support plate 30 arranged vertically is fixed to the front support plate 22, and an arcuate gear 31 is fixed to the side support plate 30. The center of the gear 31 is an arc having an edge arc center 1d (see FIG. 12A) of the wafer 1 when the polishing pad 3 is in contact with the wafer 1 and the side edge 1b. A turning slider 32 is fixed to the side support plate 30, and the turning slider 32 is slidably inserted into a turning guide 33 formed concentrically with the gear 31. The turning guide 33 is fixed to the base plate 34, and a turning motor 35 is fixed to the base plate 34. A gear 36 that meshes with the gear 31 is fixed to the output of the turning motor 35. Therefore, when the turning motor 35 rotates, the side support plate 30 and the turning slider 32 are turned along the turning guide 33 together with the gear 31 by the gear 36. As a result, the entire apparatus turns around the edge arc center 1d, that is, the polishing pad 3 turns around the edge arc center 1d (see FIG. 12).
[0016]
Therefore, three units of this apparatus are installed around the wafer 1 chucked by a spindle (not shown). In this case, the respective edge polishing drums 2 </ b> A, 2 </ b> B, and 2 </ b> C of each apparatus are arranged so as to move toward the center of the wafer 1. That is, the horizontal movement directions B and B ′ of the edge polishing drums 2A, 2B, and 2C are the center direction of the wafer 1. Then, the angles θ1, θ2, and θ3 of the edge polishing drums 2A, 2B, and 2C of the three apparatuses are set as shown in FIG. That is, the first edge polishing drum 2A is set at an angle θ1 (45 °) with respect to the wafer 1 as shown in FIG. The second edge polishing drum 2B is set at an angle θ2 (90 °) with respect to the wafer 1 as shown in FIG. The third edge polishing drum 2C is set at an angle θ3 (135 °) with respect to the wafer 1 as shown in FIG.
[0017]
The angles θ1, θ2, and θ3 of the edge polishing drums 2A, 2B, and 2C are set by rotating the turning motor 35 as described above. When the turning motor 35 is rotated, the side support plate 30 and the turning slider 32 are turned along the turning guide 33 together with the gear 31 by the gear 36. As a result, the entire apparatus turns around the edge arc center 1d, that is, the polishing pad 3 turns around the edge arc center 1d. That is, the edge polishing drum 2B shown in FIG. 12B is in the state shown in FIG. The edge polishing drum 2A shown in FIG. 12A can be set by rotating the gear 36 in the direction of arrow C and rotating the gear 31 in the direction of arrow D from the state shown in FIG. The edge polishing drum 2C of FIG. 12C can be set by rotating the gear 36 in the direction of arrow C ′ and rotating the gear 31 in the direction of arrow D ′ from the state of FIG.
[0018]
Next, the operation will be described. Before the wafer 1 is chucked on a spindle (not shown), the polishing pads 3A, 3B, and 3C are in a retracted position so as not to interfere with the wafer 1. When the wafer 1 is chucked by the spindle and rotated, the rotation motor 11 rotates and the polishing pads 3A, 3B, and 3C rotate. In this state, the horizontal driving cylinder 18 is driven, and the polishing pads 3A, 3B, 3C are advanced as described above and are brought into pressure contact with the edges 1a, 1b, 1c of the wafer 1 by the pressure control means of the horizontal driving cylinder 18. After a certain period of time, the horizontal drive cylinder 18 operates in the opposite direction to that described above, the polishing pad 3 moves away from the edges 1a, 1b, and 1c of the wafer 1, and the rotation of the rotation motor 11 and the turning motor 35 stops. Thereby, the entire circumferences of the edges 1a, 1b, and 1c of the wafer 1 are polished at a time.
[0019]
As described above, a plurality of wafer edge polishing apparatuses are arranged around the wafer 1 held horizontally, and the horizontal movement directions of the edge polishing drums 2A, 2B, and 2C are respectively directed toward the center of the wafer 1, Since the wafer 1 is pressed by the edge polishing drums 2A, 2B, and 2C toward the center of the wafer for polishing, the plurality of edge polishing drums 2A, 2B, and 2C can always be brought into contact with the wafer 1 with a constant contact pressure. In addition, stable edge polishing can be performed, and the arrangement of the plurality of edge polishing drums 2A, 2B, and 2C is not limited.
[0020]
5 to 10 show another embodiment of the present invention. As shown in FIGS. 11 and 12 (d1) and (d2), the present embodiment shows a notch / planar polishing unit that polishes the notch 1e of the wafer 1 and the plane 1f around the upper surface edge 1a. As shown in FIGS. 6, 8, and 10 (refer to FIG. 10 in particular), a drum support block 51 is fixed to the horizontal moving plate 50, and a shaft portion 52 a of a flat polishing drum 52 is disposed above and below the drum support block 51. Shaft portions 53a of the notch polishing drum 53 are rotatably supported, and polishing pads 54 and 55 are attached to the flat polishing drum 52 and the notch polishing drum 53, respectively. Timing pulleys 56 and 57 are fixed to the shaft portion 52a of the flat polishing drum 52 and the shaft portion 53a of the notch polishing drum 53, respectively, and a timing belt 58 is wound around the timing pulleys 56 and 57. An output shaft of a drum rotation motor 59 is connected to the shaft portion 52 a, and the drum rotation motor 59 is fixed to the horizontal moving plate 50 via a motor bracket 60.
[0021]
As shown in FIGS. 5 and 6, a U-shaped support plate 65 is fixed to the horizontal movement plate 50, and a slider 66 is fixed to the support plate 65. The slider 66 is slidably inserted into a guide 67 disposed vertically, and the guide 67 is fixed to a vertical plate 68. A vertical driving air cylinder 69 for switching between the flat polishing drum 52 and the notch polishing drum 53 is fixed below the vertical plate 68, and the operation rod of the vertical driving air cylinder 69 is flat polished on the wafer 1. An air cylinder 70 for pressing the drum 52 or the notch polishing drum 53 is fixed. The operating rod of the air cylinder 70 is fixed to a connecting plate 71 fixed to the support plate 65.
[0022]
As shown in FIGS. 7 to 8, an L-shaped support plate 75 is fixed below the horizontal moving plate 50, and a slider 77 is fixed to the support plate 75 via a connecting plate 76. The slider 77 is slidably fitted into a guide 78 disposed at right angles to the central axis of the shaft portion 52 a of the flat polishing drum 52, and the guide 78 is fixed to the vertical plate 79 a of the frame 79. . A screw shaft 80 disposed in parallel with the guide 78 is rotatably supported on the frame 79, and a female screw block 81 fixed to the connecting plate 76 is screwed onto the screw shaft 80. A horizontal driving motor 83 is fixed to the frame 79 via a motor bracket 82. A timing pulley 84 fixed to the output shaft of the horizontal driving motor 83 and a timing pulley 85 fixed to the screw shaft 80 are attached to the frame 79. The timing belt 86 is stretched over. 5, 8, and 9, reference numeral 5 denotes a spindle 5 that vacuum-sucks the wafer 1.
[0023]
The notch / planar polishing unit having such a configuration is disposed on the outer periphery of the wafer 1 in the same manner as the edge polishing unit. In this case, the flat polishing drum 52 and the notch polishing drum 53 are arranged so as to move toward the center of the wafer 1 by the rotation of the horizontal drive motor 83. Either the polishing of the notch 1e or the polishing of the flat surface 1f may be performed first. Here, the case where the polishing of the flat surface 1f is performed after the polishing of the notch 1e will be described.
[0024]
FIG. 8 shows a state before notch polishing. During polishing of the notch 1e (see FIGS. 110 and 12D1), the wafer 1 is stopped with the notch 1e corresponding to the notch polishing drum 53. When the drum rotation motor 59 rotates, the flat polishing drum 52 rotates, and the notch polishing drum 53 rotates via the timing pulley 56, the timing belt 58, and the timing pulley 57. Next, when the operating rod of the air cylinder 70 is retracted from the state shown in FIG. 8, the rotating polishing pad 54 comes into pressure contact with the notch 1e and polishes the notch 1e. After a certain time, the operating rod of the air cylinder 70 protrudes, the polishing pad 54 is separated from the wafer 1, and the rotation of the drum rotating motor 59 is stopped.
[0025]
Next, the horizontal drive motor 83 rotates. As a result, the screw shaft 80 rotates via the timing pulley 84, the timing belt 86, and the timing pulley 85, and the female screw block 81, the connecting plate 76, and the slider 77 move along the guide 78 in the direction of arrow E in FIGS. Moving. As a result, the support plate 75, the vertical plate 68, the guide 67, the slider 66, the support plate 65, and the horizontal movement plate 50 all move in the direction of arrow E, and the planar polishing drum 52 and the notch polishing drum 53 move away from the wafer 1. It moves and is located outside the wafer 1. Next, the operating rod of the air cylinder 69 for vertical driving retracts. As a result, the notch polishing drum 53 and the flat polishing drum 52 are lowered, the notch polishing drum 53 is positioned on the lower side of the wafer 1, and only the flat polishing drum 52 is positioned on the upper side of the wafer 1.
[0026]
Next, the horizontal drive motor 83 moves in the opposite direction, the female screw block 81 moves in the direction of arrow E ', and the flat polishing drum 52 corresponds to the flat surface 1f of the wafer 1 as shown in FIG. The rotation motor 59 rotates and the polishing pads 54 and 55 rotate. Further, the spindle 5 rotates and the wafer 1 rotates. Next, the operating rod of the air cylinder 70 is retracted, the polishing pad 54 is pressed against the flat surface 1 f of the wafer 1, and the flat surface 1 f is polished by the polishing pad 54. The flat surface 1f is polished simultaneously with the polishing of the edges 1a, 1b, and 1c. After a certain period of time, the operating rod of the air cylinder 70 protrudes, the polishing pad 54 is separated from the wafer 1, and the rotation of the drum rotating motor 59 stops. Thereafter, the horizontal driving motor 83 is rotated so that the planar polishing drum 52 and the notch polishing drum 53 move away from the wafer 1 and are positioned outside the wafer 1. Subsequently, the operating rod of the air cylinder 69 for vertical driving protrudes to raise the flat polishing drum 52 and the notch polishing drum 53, and the notch polishing drum 53 moves to the upper side of the wafer 1 to the original initial position.
[0027]
【The invention's effect】
In the present invention, a plurality of edge polishing drums are disposed around a horizontally held wafer, and the wafer is pressed by each edge polishing drum toward the center of the wafer while the wafer is rotated, so that the plurality of edge polishing drums are polished. Any of the polishing drums can always be brought into contact with the wafer with a constant contact pressure, stable edge polishing can be performed, and the arrangement of the plurality of edge polishing drums is not limited.
[Brief description of the drawings]
FIG. 1 is a partial sectional front view showing an embodiment of a wafer edge polishing unit of the present invention.
FIG. 2 is a plan view.
FIG. 3 is a bottom view.
FIG. 4 is a rear view.
FIG. 5 is a front view showing an embodiment of the nodge / planar polishing unit of the present invention.
FIG. 6 is a plan view.
7 is a cross-sectional view taken along line FF in FIG.
FIG. 8 is a right side view showing a state before polishing the nudge.
FIG. 9 is a right side view showing a state before surface polishing.
10 is a cross-sectional view taken along line GG in FIG.
FIG. 11 is an explanatory view of polishing of a wafer edge portion.
12A is a cross-sectional view taken along line HH in FIG. 11, FIG. 12B is a cross-sectional view taken along line II in FIG. 11, FIG. 12C is a cross-sectional view taken along line JJ in FIG. (D2) is the KK sectional view taken on the line of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wafer 1a Upper surface edge 1b Side surface edge 1c Lower surface edge 1d Edge circular arc center 1e Nodge 1f Plane 2 (2A, 2B, 2C) Edge polishing drum 3 (3A, 3B, 3C) Polishing pad 10 Movable plate 11 Motor 14 for rotation Horizontal guide 15 horizontal slider 16 support plate 17 motor bracket 18 horizontal drive cylinder 20 vertical guide 21 vertical slider 22 front side support plate 23 vertical movement motor 24 pinion 25 rack 30 side support plate 31 gear 32 swing slider 33 swing guide 34 base plate 35 Rotating motor 36 Gear 50 Horizontal moving plate 51 Drum support block 52 Flat polishing drum 53 Notch polishing drums 54 and 55 Polishing pads 56 and 57 Timing pulley 58 Timing belt 59 Drum rotation motor 65 Support plate 66 Slider 67 Guide 68 Vertical plate 69 Vertical drive air cylinder 70 Air cylinder 75 Support plate 77 Slider 78 Guide 79 Frame 80 Screw shaft 81 Female screw block 83 Horizontal drive motors 84 and 85 Timing pulley 86 Timing belt

Claims (1)

  An edge polishing drum disposed facing the outer periphery of the wafer held horizontally and rotated; a rotation driving means for rotating the edge polishing drum; and a turning driving means for changing an inclination angle of the edge polishing drum; A wafer edge polishing unit comprising a vertical drive means for moving the edge polishing drum up and down, a horizontal drive means for moving the edge polishing drum in the horizontal direction and applying pressure to the wafer, and corresponding to the outer periphery of the wafer A planar polishing drum and a notch polishing drum disposed above and below, a rotation driving means for rotationally driving the planar polishing drum and the notch polishing drum, a vertical driving means for vertically moving and horizontally moving the planar polishing drum and the notch polishing drum, and A notch / planar edge polishing unit having a horizontal driving means, and the wafer edge polishing unit. Unit, a plurality of arranged around the wafer, and the horizontal movement direction of each edge grinding drum, wafer edge grinding apparatus, characterized in that facing the center of the wafer, respectively.

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