JP2008119785A - Grinding machine and grinding method of wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently remove undulation from a surface of a wafer by using the wafer having the undulation as it is. <P>SOLUTION: It is possible to remove the undulation by grinding a second surface Wb arranged on the side of a second supporting part 22 without applying unnecessary force to correct the undulation on the wafer W by making a grinding wheel 31b work on and grind the second surface Wb of the wafer W from a grinding wheel inserting groove 26 formed on the second supporting part 22 while actually supporting the wafer W with water 51 in a wafer supporting case body 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer grinding apparatus and a grinding method.

  A wafer on which devices such as IC and LSI are formed is formed by polishing the front and back surfaces of a wafer obtained by slicing a silicon ingot, for example.

  When a wafer is formed by slicing a silicon ingot or the like with an inner peripheral blade or a wire saw, undulation is generated on the front and back surfaces of the cut surface of the wafer. The other exposed surface is ground with a grinding wheel, and then the other ground surface is fixed to the support base and the exposed one surface is ground with a grinding wheel. Unery is removed from the front and back surfaces of the sliced wafer (see, for example, Patent Document 1).

JP 2000-5982 A

  However, according to the method disclosed in Patent Document 1, an extra process such as a pretreatment such as a coating process of the fluid member on the wafer, a pressing process on the plate, a solidifying process of the fluid member by cooling, etc. is required before grinding. In addition, there is a problem in that the workability of the sliced wafer cannot be used as it is because the step of removing the solidified fluid member is required even when grinding the surface side coated with the fluid member.

  The present invention has been made in view of the above, and an object of the present invention is to provide a wafer grinding apparatus and a grinding method capable of efficiently removing undulation from the surface of the wafer using the undulated wafer as it is. .

  In order to solve the above-described problems and achieve the object, a wafer grinding apparatus according to the present invention is a wafer grinding apparatus for grinding a wafer surface, wherein the first surface of the wafer is supported by water. A first support portion, a second support portion that supports a second surface that is the back surface of the first surface of the wafer with water, the first support portion, and the second support portion. A wafer support housing comprising an annular support portion surrounding the sandwiched wafer and supporting with water and forming a housing with the first support portion and the second support portion; A water supply means for supplying water to the first support portion and the second support portion of the wafer support housing; and a grinding wheel in which a grinding wheel is annularly arranged on an annular base, and the grinding Grinding means for rotatably supporting the wheel, and the grinding means supported by the wafer support housing Moving means that moves in a direction approaching and moving away from the wafer, and the grinding wheel of the grinding wheel is inserted into the second support portion of the wafer support housing to the wafer support housing. A grinding wheel insertion groove for grinding the second surface of the wafer from the center of the supported wafer toward the outer periphery is formed.

  Further, the wafer grinding apparatus according to the present invention is the above-described invention, wherein in the above invention, the first support portion and the first support portion, wherein the discharge direction with respect to the first surface and the second surface of the wafer is set obliquely, A water flow is formed by water supplied to the second support portion, and the wafer rotates.

  In addition, the wafer grinding method according to the present invention includes a first support portion that supports the first surface of the wafer with water, and a second surface that is a back surface with respect to the first surface of the wafer with water. A second supporting portion to be supported; and a side portion of the wafer sandwiched between the first supporting portion and the second supporting portion, and is supported by water to support the first supporting portion and the second supporting portion. A wafer support housing comprising an annular support portion forming a housing with the support portion; and a water supply means for supplying water to the first support portion and the second support portion of the wafer support housing. A grinding wheel in which a grinding wheel is annularly arranged on an annular base, a grinding means for rotatably supporting the grinding wheel, and the grinding means on a wafer supported by the wafer support housing Moving means for moving toward and away from the wafer, and the wafer supporting housing A wafer grinding method for grinding a surface of a wafer using a grinding device in which a grinding wheel insertion groove for inserting the grinding wheel of the grinding wheel is formed in the second support portion. Inserting the grinding wheel of the grinding wheel into the grinding wheel insertion groove formed in the support and rotating the second surface of the wafer from the center of the wafer supported by the wafer support housing toward the outer periphery It is characterized by grinding.

  According to the wafer grinding apparatus and the grinding method of the present invention, the grinding wheel is removed from the grinding wheel insertion groove formed in the second support portion while substantially supporting the wafer with water in the wafer supporting housing. Since grinding is performed by acting on the second surface, the second surface disposed on the second support portion side is ground without unnecessary force acting on the wafer to correct the undulation. As a result, it is possible to remove undulation efficiently from the surface of the wafer by using the wafer with undulation as it is. In particular, by grinding with a grinding wheel while rotating the wafer with a water flow formed by the water supplied while supporting the wafer with water in the wafer support housing, the undulation of the second surface of the wafer is more efficiently performed. There is an effect that it can be removed.

  A wafer grinding apparatus and grinding method that are the best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic perspective view showing a configuration example of a grinding apparatus according to the present embodiment. The grinding apparatus 10 of the present embodiment includes a wafer support housing 20 that supports the wafer W, and a grinding means 30 that rotatably supports a grinding wheel 31 that grinds the wafer W supported by the wafer support housing 20. The grinding means 30 is provided with a moving means 40 that moves in a vertical direction that approaches and separates from the wafer W supported by the wafer support housing 20.

  First, the grinding means 30 includes a grinding wheel 31, a housing 32, a mount 34 that is attached to the lower end of the housing 32 by a bolt 33 and supports the grinding wheel 31 that is rotatable counterclockwise, and supports and rotates the mount 34. A spindle 35 that rotates, a motor 36 that rotationally drives the spindle 35, and a moving base 37 on which the housing 32 is mounted. The moving base 37 has a guided rail 37a, and the grinding means 30 moves in the vertical direction by fitting the guided rail 37a to the guide rail 13 provided on the support plate 12 of the housing 11 so as to be movable. Supported as possible. Further, as shown in FIG. 4, the grinding wheel 31 has an annular base 31a formed in a downward cup shape, and is disposed annularly at equal intervals on the lower surface of the base 31a. And a plurality of grinding wheels 31b exhibiting cutting action.

  Further, the moving means 40 moves the moving base 37 of the grinding means 30 along the guide rails 13 so that the grinding wheel 31 approaches and separates from the wafer W supported by the wafer support housing 20. This is for moving so as to feed in the grinding direction (Z-axis direction). The moving means 40 includes a male screw rod 41 that is disposed on the support plate 12 in parallel with the guide rail 13 in the vertical direction and is rotatably supported, a pulse motor 42 for rotationally driving the male screw rod 41, and a moving base 37. And an internal thread block (not shown) that is engaged with the external thread rod 41.

  On the other hand, as shown in FIGS. 2 to 5, the wafer support housing 20 includes a first support portion 21, a second support portion 22, and an annular support portion 23, and supports the wafer W inside. Is the body. 2 is an exploded perspective view showing the wafer support housing, FIG. 3 is a perspective view showing the wafer support housing, FIG. 4 is a schematic cross-sectional view showing the vicinity of a grinding portion, and FIG. It is a schematic diagram which shows the positional relationship etc. of a wafer support housing | casing and a grinding wheel in a top view.

  The first support portion 21 is formed to be slightly larger than the wafer W and supports the first surface Wa which is the lower surface side of the wafer W with water. The first support portion 21 is positioned immediately below the grinding means 30 and the standby shown in FIG. It is fixedly disposed on a movable base 14 that is movable in the X-axis direction between the positions. The second support portion 22 is paired with the first support portion 21 and has a second surface Wb that is a back surface (upper surface) with respect to the first surface Wa of the wafer W and receives a grinding action by the grinding wheel 31b. It is supported by water. The annular support portion 23 is formed on the outer peripheral portion of the first support portion 21 so as to surround and support the side portion Wc of the wafer W sandwiched between the first support portion 21 and the second support portion 22 with water. It is formed in a wall shape. That is, the first support portion 21 and the annular support portion 23 are formed as an annular body having a recess capable of accommodating the wafer W, and the annular support body and the second support portion 22 detachably covering the upper surface of the annular body. A housing capable of supporting the wafer W with water in the recess is configured. Here, on the annular support portion 23, it is connected to a suction source (not shown) in order to keep the second support portion 22 in close contact with the first support portion 21 against water pressure when the wafer W is supported. A suction groove 24 is formed. Further, a positioning pin 25 for positioning the second support portion 22 with respect to the first support portion 21 is formed on the annular support portion 23, and the positioning pin 25 is fitted on the second support portion 22 side. A matching positioning hole (not shown) is formed.

  Further, the grinding apparatus 10 according to the present embodiment includes water supply means 50 for supplying water 51 to the first support portion 21 and the second support portion 22 of the wafer support housing 20. The water supply means 50 is formed so as to penetrate the first support portion 21 in the front and back direction and a plurality of water supply nozzles 52 formed so as to penetrate in the front and back direction. And a plurality of water supply nozzles 53 and piping paths formed so as to connect the water supply nozzles 52 and 53 and the water supply source.

  Here, one of the plurality of water supply nozzles 52 is formed perpendicularly to the center of the first support portion 21, but the remaining plurality are arranged in the same circumference in the first support portion 21. The discharge direction of the water 51 with respect to the first surface Wa of the wafer W is arranged at equal intervals on the top, and the counterclockwise circumferential direction as shown by arrows in FIGS. 4 and 2 Is set to be diagonally upward. In addition, the plurality of water supply nozzles 53 are arranged at equal intervals on the same circumference in the second support portion 22, and the discharge direction of the water 51 with respect to the second surface Wb of the wafer W is As shown in FIGS. 4 and 2, it is set to be obliquely downward along the counterclockwise circumferential direction. By setting the discharge direction as described above, a water flow in the counterclockwise direction is formed by the water 51 supplied to the first support portion 21 and the second support portion 22 and is supported by the water 51 in the wafer support housing 20. The wafer W is rotated counterclockwise by this water flow.

  Further, a grinding wheel that exposes a part of the second surface Wb of the wafer W supported by the water 51 in the wafer support housing 20 is provided in the second support portion 22 constituting the wafer support housing 20 described above. An insertion groove 26 is formed. The grinding wheel insertion groove 26 is configured to rotatably insert the grinding wheel 31 b so that a part of the grinding wheel 31 b of the grinding wheel 31 overlaps the second surface Wb of the wafer W in the wafer support housing 20. And is formed in an arc shape having a size corresponding to the radius of the grinding wheel 31. The grinding wheel insertion groove 26 is formed at a position where a part of the grinding wheel 31b of the inserted grinding wheel 31 can rotate through the center O (see FIG. 5) of the second surface Wb of the wafer W. Yes. Here, the first support portion 21 and the second support portion 22 are fitted so that the position of the grinding wheel insertion groove 26 in the X-axis direction is a predetermined position and the both are detachably fitted. Step portions 27 and 28 are formed. The fitting step 28 is set so as to close the end of the suction groove 24 in a state where the first support 21 and the second support 22 are fitted.

  Further, the supply amount of the water 51 supplied from each of the water supply nozzles 52 and 53 is configured to be individually controllable, and the strength of the water flow is set according to the positional relationship with the grinding wheel insertion groove 26. This will be described with reference to FIG. In FIG. 5, the solid thick arrow indicates the supply amount on the water supply nozzle 53 side of the second support portion 22, the broken thick arrow indicates the supply amount on the water supply nozzle 52 side of the first support portion 21, The length indicates the strength of the water flow. The water flow from the water supply nozzle 52 is weak and the water flow from the water supply nozzle 53 is strong on the upstream side in the counterclockwise direction (right side in FIG. 5) of the grinding wheel insertion groove 26 which is the upstream side portion of the grinding wheel 31 in the rotation direction. The water flow from the water supply nozzle 52 is stronger on the upstream side (left side in FIG. 5) counterclockwise than the grinding wheel insertion groove 26 that is the downstream side portion of the grinding wheel 31 in the rotational direction. The water flow from the water supply nozzle 53 is set to be weak, and the strength of the water flow from the other water supply nozzles 52 and 53 is set to an intermediate level. Due to the setting of the strength relationship of the water flow, the wafer W supported by the water 51 in the wafer support housing 20 is not in a horizontal state, but is upstream of the rotational direction of the grinding wheel 31 in the arc-shaped grinding wheel insertion groove 26 portion. The side portion rotates in the counterclockwise direction while being supported in an oblique state so that the lower side portion is lower and the downstream side portion in the rotation direction of the grinding wheel 31 is higher.

  Next, a method for grinding the wafer W by the grinding apparatus 10 of the present embodiment will be described. For example, a wafer W to be ground by being cut out from a silicon ingot or the like is placed on the first support portion 21 positioned at the standby position, and the fitting step portions 27 and 28 are fitted to each other. At this time, positioning is performed by fitting positioning pins 25 and positioning holes (not shown). Then, a suction source (not shown) is operated to integrate the second support body 22 with the first support body 21 in close contact via the suction groove 24. In this state, by supplying water 51 from the water supply nozzles 52 and 53 to the first support portion 21 and the second support portion 22, the wafer W floats in the water 51 in the wafer support housing 20. Support with. In this state, water 51 is interposed around the first surface Wa, the second surface Wb, and the side portion Wc of the wafer W, and the wafer W has the first support portion 21 and the second support portion 22. In addition, it does not directly contact the annular support portion 23. Further, the wafer W rotates counterclockwise while floating on the water 51 in the wafer support housing 20 due to the water flow of the water 51 supplied in an oblique direction to the wafer W from the water supply units 52 and 53. . At this time, the wafer W is set such that the upstream portion in the rotational direction of the grinding wheel 31 is low and the downstream portion in the rotational direction of the grinding wheel 31 is high in the grinding wheel insertion groove 26 portion by setting the strength relationship of the water flow for each place. Supported in an oblique state.

  Then, by moving the movable base 14 in the X-axis direction, the wafer support housing 20 that supports the wafer W is moved to the lower side of the grinding means 30, and the grinding wheel insertion groove 26 is directly below the grinding wheel 31. The wafer support housing 20 is positioned as follows. Therefore, while the grinding wheel 31 is rotated counterclockwise by the motor 36, the grinding means 30 is lowered by the moving means 40 in a direction approaching the wafer W, and a part of the grinding wheel 31b of the rotating grinding wheel 31 is inserted into the grinding wheel. The second surface Wb of the wafer W is brought into contact with the second surface Wb of the wafer W that is inserted into the groove 26 and exposed by the grinding wheel insertion groove 26 portion, and the second surface Wb is ground with the grinding wheel 31b.

  At this time, the wafer W and the grinding wheel 31 (grinding wheel 31b) rotate counterclockwise as indicated by an arrow in FIG. 5, but the wafer W is set to the grinding wheel insertion groove 26 portion by setting the strength of water flow. In FIG. 5, the grinding wheel 31 is supported in an oblique state so that the upstream portion in the rotational direction is low and the downstream portion in the rotational direction of the grinding wheel 31 is high. Therefore, only the portion indicated by hatching in FIG. Becomes the actual grinding region A that contacts the second surface Wb of the wafer W, and the second surface Wb is ground by a substantially radial amount from the center O of the wafer W toward the outer periphery on the downstream side in the rotation direction of the grinding wheel 31. Is done. By continuing such a grinding operation passing through the center O of the wafer W, the second surface Wb of the wafer W is ground flat over the entire surface, and undulation is removed.

  After the grinding of the second surface Wb of the wafer W is completed, the grinding means 30 is raised in the direction away from the wafer W by the moving means 40, and then the wafer support housing 20 is returned to the standby position, and the suction source is used. The suction state is released, the second support portion 22 is removed from the first support portion 21, the front and back surfaces of the wafer W are replaced, and the wafer W is set in the first support portion 22 again. After fitting 22, as in the case described above, while supplying water 51 by the water supply means 50 to the first support portion 21 and the second support portion 22, the grinding wheel 31 b is inserted into the grinding wheel insertion groove 26. Is inserted, and the grinding operation of the new second surface Wb that has not been ground on the wafer W is executed, whereby the grinding of the both surfaces of the wafer W is completed.

  In such a grinding operation, the grinding wheel 31b is inserted into the grinding wheel 31b from the grinding wheel insertion groove 26 formed in the second support portion 22 while the wafer W is substantially supported by the water 51 in the wafer support housing 20. Since the grinding is performed by acting on the second surface Wb, the second surface Wb disposed on the second support portion 22 side is ground without unnecessary force acting on the wafer W to correct the undulation. Unery can be removed, and it is possible to efficiently remove unery from the surface of the wafer W by using the wafer W with unery as it is. In particular, the grinding wheel 31b is rotated counterclockwise while rotating the wafer W counterclockwise by the water flow formed by the water 51 supplied while supporting the wafer W with the water 51 in the wafer support housing 20. By grinding, the undulation of the second surface Wb of the wafer W can be removed more efficiently. Furthermore, since the grinding wheel 31b is ground while supplying the water 51 to the first support part 21 and the second support part 22 by the water supply means 50, the grinding operation is performed using the grinding water. Similarly, the grinding wheel 31b can be cooled and the grinding waste can be discharged at the grinding wheel insertion groove 26 portion.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, the example in which both surfaces of the wafer W cut out from the silicon ingot are ground has been described. However, in the present invention, the wafer is ground while being substantially supported by water. It can also be applied to the case where the back surface of a wafer on which a device such as LSI is formed is ground as the second surface. At this time, it is necessary to attach a protective tape to the front surface (first surface) of the wafer. It can be ground without tape.

  In the present embodiment, the grinding wheel 31b is rotated counterclockwise to grind the grinding region A of the second surface Wb of the wafer W in the outward direction from the center O toward the outer periphery. The grinding wheel 31b is rotated clockwise to grind the grinding region A of the second surface Wb of the wafer W inward from the center O toward the outer periphery so as to be directed from the outer periphery toward the center O. It may be. The direction of the water flow that rotates the wafer W may be reversed, and the wafer W may be rotated clockwise.

It is a schematic perspective view which shows the structural example of the grinding apparatus of embodiment of this invention. It is a disassembled perspective view which shows a wafer support housing | casing. It is a perspective view which shows a wafer support housing | casing. It is a schematic sectional drawing which shows the grinding location vicinity. It is a schematic diagram which shows the positional relationship etc. of a wafer support housing | casing and a grinding wheel in a top view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Wafer support housing | casing 21 1st support part 22 2nd support part 23 Annular support part 30 Grinding means 31 Grinding wheel 31a Base 31b Grinding wheel 40 Moving means 50 Water supply means 51 Water W Wafer Wa 1st surface Wb Second side Wc Side

Claims (3)

A wafer grinding device for grinding a wafer surface,
A first support portion that supports the first surface of the wafer with water, a second support portion that supports the second surface that is the back surface of the wafer with respect to the first surface, and the first An annular support portion that surrounds a side portion of the wafer sandwiched between the support portion and the second support portion and supports the wafer with water, and forms a housing with the first support portion and the second support portion. A wafer support housing composed of
Water supply means for supplying water to the first support portion and the second support portion of the wafer support housing;
A grinding means having a grinding wheel in which a grinding wheel is annularly arranged on an annular base, and rotatably supporting the grinding wheel;
Moving means for moving the grinding means in a direction approaching and separating from the wafer supported by the wafer support housing;
With
The grinding wheel of the grinding wheel is inserted into the second support portion of the wafer support housing, and the second surface of the wafer is moved from the center of the wafer supported by the wafer support housing toward the outer periphery. A grinding apparatus for a wafer, wherein a grinding wheel insertion groove for grinding is formed.   A water flow is formed by the water supplied to the first support portion and the second support portion from the water supply means in which the discharge direction with respect to the first surface and the second surface of the wafer is set obliquely. 2. The wafer grinding apparatus according to claim 1, wherein the wafer rotates. A first support portion that supports the first surface of the wafer with water, a second support portion that supports the second surface that is the back surface of the wafer with respect to the first surface, and the first support portion; An annular support portion that surrounds a side portion of the wafer sandwiched between the support portion and the second support portion and supports the wafer with water, and forms a housing with the first support portion and the second support portion. A wafer support housing composed of: a water supply means for supplying water to the first support portion and the second support portion of the wafer support housing; and a grinding wheel in an annular base Grinding means having a disposed grinding wheel and rotatably supporting the grinding wheel, and moving means for moving the grinding means in a direction approaching and separating from the wafer supported by the wafer support housing And the second support portion of the wafer support housing includes a grinding wheel. Serial using a grinding device grinding wheel insertion groove is formed for inserting the grinding wheel, a grinding method of the wafer to grind the surface of the wafer,
The grinding wheel of the grinding wheel is inserted into the grinding wheel insertion groove formed in the second support portion and rotated to rotate from the center of the wafer supported by the wafer support housing toward the outer periphery. A method for grinding a wafer, comprising grinding the second surface.

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