JP4798480B2 - Semiconductor wafer manufacturing method, double-sided grinding method, and semiconductor wafer double-sided grinding apparatus - Google Patents

Description

  The present invention relates to a method including a step of grinding both sides of a semiconductor wafer or an apparatus for grinding both sides of a semiconductor wafer.

  The silicon single crystal ingot is cut by a cutting device such as a wire saw, and a silicon wafer is collected.

  One method for flattening both the front and back surfaces of a silicon wafer is to perform flattening by lapping both sides of the silicon wafer using a lapping apparatus. In the lapping process using such a lapping apparatus, the carrier rotates while the silicon wafer is inserted into the hole of the carrier. Therefore, the outer peripheral portion of the silicon wafer collides with the inner peripheral surface of the hole of the carrier during the lapping process. . For this reason, the load on the outer peripheral portion of the silicon wafer is large, and chipping and chipping are likely to occur at the outer peripheral portion of the silicon wafer.

  Therefore, in order to prevent chipping and chipping at the outer peripheral portion of the silicon wafer, it is essential to perform a chamfering process for chamfering the outer peripheral portion of the silicon wafer before the lapping step.

  That is, conventionally, a silicon wafer is manufactured from a cutting process through a chamfering process and a lapping process (further, through each process such as an etching process and a polishing process).

  However, in recent years, silicon wafers have become larger in diameter, and it has become necessary to highly flatten both sides of a silicon wafer having a diameter of 300 mm (12 inches) or more.

  However, in order to flatten both sides of a large-diameter silicon wafer, lapping using a lapping apparatus has a limit on the flatness of the wafer.

  Therefore, the flatness of a large-diameter silicon wafer is increased by performing double-sided grinding instead of lapping. Double-side grinding is a method in which both sides of a silicon wafer are simultaneously ground using a double-side grinding device (double-head grinding device).

  However, as before, when a double-sided grinding process as a flattening process is performed after the chamfering process, the wafer chamfering center plane that becomes the processing reference surface during the chamfering process and the thickness reference that becomes the processing reference surface during the double-side grinding process Due to the deviation from the surface, a part of the chamfered portion of the outer peripheral portion of the silicon wafer is ground, resulting in a problem that the chamfered shape deteriorates and the chamfered shape varies in the wafer circumferential direction.

  On the other hand, unlike the lapping apparatus, the double-side grinding apparatus has a small load on the outer periphery of the wafer during the flattening process, and it is considered that problems such as chipping and chipping at the outer periphery of the silicon wafer are unlikely to occur.

  Therefore, in view of such knowledge, the present applicant makes a patent application shown in Patent Document 1 to be described later, and performs chamfering after flattening to prevent chipping and chipping at the outer peripheral portion of the silicon wafer. While preventing the problem, the problem is that the chamfered shape deteriorates and the chamfered shape varies in the circumferential direction of the wafer.

On the other hand, Patent Document 2 described later describes an invention related to a double-side grinding apparatus. In this Patent Document 2, a silicon wafer in a vertical position is positioned between both pads, and the silicon wafer is rotated by a roller to rotate the silicon wafer so that both sides of the silicon wafer are attached to both pads. Both sides are ground simultaneously using a grinding wheel located in the notch.
Japanese Patent Laid-Open No. 11-154655 JP 2000-280155 A

  However, the present inventors have found that when the invention described in Patent Document 1 is actually implemented, chipping and chipping may occur at the outer peripheral portion of the silicon wafer. That is, when the silicon wafer is taken out from the double-side grinding apparatus after the double-side grinding process, the posture of the silicon wafer is inclined, and the outer peripheral portion of the wafer may come into contact with other members and cracks may occur.

  The present invention has been made in view of such a situation, and when performing double-side grinding in a state where the outer peripheral portion of the semiconductor wafer is not chamfered (or in a state where rough chamfering is performed), chipping or chipping at the outer peripheral portion of the wafer is performed. The problem to be solved is to prevent the deterioration of the chamfered shape and the variation in the chamfered shape in the circumferential direction of the wafer while preventing the above-described problem.

The first invention is
A cutting step of cutting a semiconductor ingot to obtain a semiconductor wafer;
After the cutting step, the semiconductor wafer is rotated by rotating the protective member in a state where the semiconductor wafer in the vertical position is positioned between both pads and the outer peripheral portion of the semiconductor wafer is protected by the protective member, A double-sided grinding process in which both sides of a semiconductor wafer are ground using a grinding wheel;
After the double-side grinding process, by supplying a fluid toward one surface of the semiconductor wafer, one surface of the semiconductor wafer is lifted from the pad, and at the same time , the other surface of the semiconductor wafer is grasped to take out the semiconductor wafer from the protective member. A semiconductor wafer removal process;
The semiconductor wafer manufacturing method includes a chamfering step of chamfering the outer peripheral portion of the semiconductor wafer after the semiconductor wafer removing step.

The second invention is the first invention ,
The double-sided grinding step is a step of roughly grinding both sides of a semiconductor wafer,
A step of further grinding both surfaces of the semiconductor wafer is performed after the chamfering step.

The third invention is the first invention ,
Before the double-side grinding step, a step of rough chamfering the outer periphery of the semiconductor wafer is performed.

The fourth invention is
The semiconductor wafer is rotated between the two pads of the semiconductor wafer by rotating the protective member in a state where the vertical position of the semiconductor wafer is positioned between both pads and the outer periphery of the semiconductor wafer is protected by the protective member. A double-sided grinding process in which both sides are ground using a grinding wheel;
After the double-side grinding process, by supplying a fluid toward one surface of the semiconductor wafer, one surface of the semiconductor wafer is lifted from the pad, and at the same time , the other surface of the semiconductor wafer is grasped to take out the semiconductor wafer from the protective member. A semiconductor wafer removal process;
A double-sided grinding method for a semiconductor wafer including

The fifth invention
A semiconductor wafer double-side grinding apparatus for grinding both sides of a semiconductor wafer,
Pads provided on both sides of a semiconductor wafer in a vertical position;
A protective member for protecting the outer periphery of the semiconductor wafer;
Rotation driving means for rotating the semiconductor wafer by rotating the protective member;
A grinding wheel for grinding both sides of the semiconductor wafer across both sides of the semiconductor wafer,
Fluid supply means for supplying fluid to the surface of the semiconductor wafer;
A take-out means for taking out the semiconductor wafer from the protective member by gripping the surface of the semiconductor wafer;
By controlling the fluid supply means and the take-out means to supply a fluid toward one surface of the semiconductor wafer after both-side grinding of the semiconductor wafer, the semiconductor wafer is lifted from the pad at the same time as the semiconductor wafer. And a control means for taking out the semiconductor wafer from the protective member by gripping the other surface.

According to the first invention, the fourth invention, and the fifth invention , since the double-side grinding is performed while the outer peripheral portion 1R of the silicon wafer 1 is protected by the carrier 13 as a protective member, No chipping or chipping occurs in the outer peripheral portion 1R of the silicon wafer 1. In addition, according to the first, fourth, and fifth inventions , the chamfering process is performed after the double-sided grinding process, so that the chamfered shape deteriorates at the wafer outer peripheral portion 1R and the chamfered shape varies in the wafer circumferential direction. Can be eliminated.

Further, according to the first invention, the fourth invention, and the fifth invention , the water is supplied to the one surface 1a of the silicon wafer 1 to float the one surface 1a of the silicon wafer 1 from the pad 11, while the silicon wafer 1 Since the silicon wafer 1 is taken out from the carrier 13 by gripping the other surface 1b, chipping and chipping do not occur in the outer peripheral portion 1R of the wafer by carrying it out.

According to the second invention , the double-sided grinding step is carried out as a step (primary surface grinding) for rough grinding both sides of the silicon wafer 1, and after the chamfering step, the both sides of the silicon wafer 1 are further finish ground (first step). Secondary surface grinding), the chamfering is performed in a state where rough irregularities of the silicon wafer 1 have already been removed by rough grinding, and even if further grinding is performed after the chamfering process, The chamfered shape is not impaired.

According to the third invention , the chamfering process is performed as a process of chamfering the wafer outer peripheral portion 1R, and the step of rough chamfering the outer peripheral portion 1R of the silicon wafer 1 is performed before the double-side grinding step. By rough chamfering, the outer peripheral portion 1R of the silicon wafer 1 is roughly chamfered, so that the possibility of chipping or chipping at the wafer outer peripheral portion 1R during the subsequent wafer transfer or the like becomes extremely low.

  Embodiments of the present invention will be described below with reference to the drawings.

  Fig.1 (a) is a side view which shows the structure of the double-sided grinding apparatus 10 used for embodiment, FIG.1 (b) is AA sectional drawing of Fig.1 (a).

  As shown in FIG. 1, a double-side grinding apparatus 10 protects pads 11 and 12 provided on both surfaces 1a and 1b of a silicon wafer 1 in a vertical position and an outer peripheral portion 1R of the silicon wafer 1, respectively. The carrier 13 as a protective member, the rotation roller 14 as the rotation driving means for rotating the silicon wafer 1 by rotating the carrier 13, and the notches 11a and 12a of the pads 11 and 12 are positioned on the silicon. Water is applied to both surfaces 1a and 1b of the silicon wafer 1 from the grinding wheels 15 and 16 for grinding the both surfaces 1a and 1b of the silicon wafer 1 and the holes formed in both the pads 11 and 12 with the both surfaces 1a and 1b of the wafer interposed therebetween. The silicon wafer 1 is loaded into the carrier 13 by gripping the one surface 1b of the silicon wafer 1 and the fluid supply means 17 for supplying (Carrying in) and controlling the hand 18 holding the one surface 1b of the silicon wafer 1 and taking it out from the carrier 13, and the fluid supply means 17 and the hand 18, and after the double-side grinding of the silicon wafer 1, the silicon wafer 1 Control is performed to take out the silicon wafer 1 from the carrier 13 by holding the other surface 1b of the silicon wafer 1 while floating the one surface 1a of the silicon wafer 1 from the pad 11 by supplying water to the one surface 1a. It comprises a controller 19 as control means for performing.

  The pad 12 is movable in the left-right direction in FIG. 1A by a cylinder (not shown). When the pad 12 is moved to the retracted position in the right direction in FIG. 1A, the hand 18 can be inserted between the pads 11 and 12. When the pad 12 is moved to the grinding position in the left direction of FIG. 1A, the grindstones 15 and 16 can be brought into contact with both surfaces 1a and 1b of the silicon wafer 1, respectively. At the grinding position, the distance from the pad 11 to the one surface 1a of the silicon wafer 1 and the distance from the pad 12 to the other surface 1b of the silicon wafer 1 are maintained at a predetermined distance for keeping the static pressure described later constant. Is done.

  The carrier 13 is a ring-shaped member on which the silicon wafer 1 is loaded, and is made of resin in order to protect the outer peripheral portion 1 </ b> R of the silicon wafer 1. The carrier 13 includes a protrusion 13 a having a shape corresponding to the notch 1 </ b> N of the silicon wafer 1 on the inner peripheral surface. By fitting the protrusion 13 a of the carrier 13 into the notch 1 N of the silicon wafer 1, the silicon wafer 1 can be positioned and held with respect to the carrier 13. The thickness of the carrier 13 is formed thinner than the thickness of the silicon wafer 1.

  The rotating roller 14 and the support roller 20 are in contact with the outer peripheral surface of the carrier 13. As a result, the carrier 13 is positioned in the double-side grinding apparatus 10.

  The rotation roller 14 and the support roller 20 are made of resin in order to protect the outer peripheral portion 1R of the silicon wafer 1.

  The grindstones 15 and 16 have rotation shafts 15a and 15b, respectively, and rotate in opposite directions. In addition, you may comprise so that the grindstones 15 and 16 may be rotated in the same direction.

  The grindstones 15 and 16 are positioned in the notches 11a and 12a so that the lower part below the center 1c of the silicon wafer 1 in the carrier 13 is ground. That is, when the rotating roller 1 is driven and the silicon wafer 1 is rotated together with the carrier 13, the grindstones 15, 16 are attached at positions where the surfaces 1 a, 1 b of the silicon wafer 1 can be surface ground by the grindstones 15, 16. ing.

  FIG. 2A is a configuration diagram of the hand 18. The hand 18 includes a suction pad 18 a that sucks one surface 1 b of the silicon wafer 1. The suction pad 18a of the hand 18 is made of resin in order to protect the silicon wafer 1.

  Hereinafter, a method for manufacturing the silicon wafer 1 using the double-side grinding apparatus 20 of FIG. 1 will be described.

(First embodiment)
First, a silicon ingot is pulled and grown by the CZ method.

(Cutting process)
The silicon ingot is cut by a wire saw device, and the silicon wafer 1 is obtained.

  The pad 12 of the double-sided grinding apparatus 10 is moved to the retracted position in the right direction in FIG. The hand 18 holding the silicon wafer 1 is inserted between the pads 11 and 12, and the silicon wafer 1 is loaded (loaded in) the carrier 13. At this time, the protrusion 13 a of the carrier 13 is fitted into the notch 1 N of the silicon wafer 1, and the silicon wafer 1 is positioned and held with respect to the carrier 13.

  When the carry-in of the silicon wafer 1 is finished, the pad 12 is moved to the grinding position in the left direction in FIG. 1A, and the grindstones 15 and 16 are brought into contact with both surfaces 1a and 1b of the silicon wafer 1, respectively.

(Double-side grinding process)
The grindstones 15 and 16 rotate in opposite directions, and the rotating roller 14 rotates. Thereby, the surfaces 1a and 1b of the silicon wafer 1 are surface ground by the grindstones 15 and 16 over the entire surface. During the surface grinding, the fluid supply means 17 supplies water to both surfaces 1a and 1b of the silicon wafer 1 from the holes formed in both pads 11 and 12, and the static pressure between both pads 11 and 12 is set to a predetermined value. Maintain and support the silicon wafer 1 in a non-contact state and hold it in a vertical position.

(Wafer unloading process (unloading process))
When the double-side grinding process is completed, the controller 19 controls the fluid supply means 17 and the hand 18 as follows to take out (carry out) the silicon wafer 1 from the surface grinding apparatus 10.

  That is, when the double-side grinding of the silicon wafer 1 is completed, the rotation of the rotating roller 14 is stopped. As a result, the rotation of the silicon wafer 1 is stopped once it has fallen down due to gravity. Thereafter, the pad 12 of the double-side grinding apparatus 10 is moved to the retracted position in the right direction in FIG. The hand 18 is inserted between the pads 11 and 12, and one surface 1 b of the silicon wafer 1 is sucked by the suction pad 18 a of the hand 18.

  As shown in FIG. 2 (c), the suction pad 18 a of the hand 18 is in a state of sucking the one surface 1 b of the silicon wafer 1, and at the same time, water is supplied from the hole of the pad 11 to the one surface 1 a of the silicon wafer 1. Is done. As a result, one surface 1a of the silicon wafer 1 is lifted from the pad 11, and the hand 18 grips the other surface 1b of the silicon wafer 1 in this state. The silicon wafer 1 is taken out from the carrier 13 by the hand 18, and the silicon wafer 1 is carried out above the surface grinding apparatus 1.

  FIG. 2B is a comparative example for comparison with FIG. 2C, and the surface 1 b of the silicon wafer 1 is gripped by the hand 18 with no water supplied from the fluid supply means 17, and is removed from the carrier 13. The case where the silicon wafer 1 is taken out is shown.

  In the case of the comparative example of FIG. 2B, the surface 1 b of the silicon wafer 1 is pressed against the pad 11 by the suction pad 18 a of the hand 18, while water is not supplied to the surface 1 a on the opposite side of the silicon wafer 1. Therefore, the upper part of the silicon wafer 1 is pressed against the pad 11 and the lower part of the silicon wafer 1 falls into the notch part 11a. For this reason, the lower part of the silicon wafer 1 may bite into the carrier 13. If the suction force by the suction pad 18a acts on the silicon wafer 1 while the lower part of the silicon wafer is biting into the carrier 13 in this way, there is a possibility that cracking may occur in the outer peripheral part 1R that bites into the carrier 13 below the silicon wafer. is there.

  On the other hand, in the case of FIG. 2C, the lower surface of the silicon wafer does not bite into the carrier 13 because one surface 1 a of the silicon wafer 1 is in a state of floating from the pad 11. For this reason, there is no possibility of chipping or chipping occurring at the outer peripheral portion 1R of the silicon wafer when the wafer is carried out.

  Further, since the members that directly contact the outer peripheral portion 1R of the silicon wafer 1, that is, the carrier 13 and the hand 18, are made of a material (for example, made of resin) that protects the outer peripheral portion 1R of the silicon wafer 1, the outer peripheral portion 1R of the silicon wafer 1 is formed. There is no risk of chipping or chipping. In addition, as long as the member (carrier 13 and hand 18) which contacts the outer peripheral part 1R of the silicon wafer 1 is a soft material below the hardness of the silicon wafer 1, arbitrary materials other than resin can be used.

(Chamfering process)
When the silicon wafer 1 is unloaded from the double-side grinding apparatus 1 as described above, the outer peripheral portion 1R of the silicon wafer 1 is then chamfered.

  FIG. 3 schematically shows a cross section of the silicon wafer 1 when the method of the present invention is carried out.

  3 (a), 3 (b), and 3 (c) respectively show the cross-sectional shapes of the silicon wafer 1 immediately after the cutting process, the double-side grinding process, and the chamfering process of this embodiment. e) and (f) respectively show warped states of the cross section of the silicon wafer 1 immediately after the cutting process, the double-side grinding process, and the chamfering process of the present embodiment.

  On the other hand, FIG. 4 is a comparative example with respect to the present embodiment, and schematically shows a cross section of the silicon wafer 1 when the double-side grinding step is performed after the chamfering step.

  4 (a), 4 (b), and 4 (c) show the cross-sectional shapes of the silicon wafer 1 immediately after the cutting process, immediately after the chamfering process, and immediately after the double-side grinding process, respectively. f) shows the warped state of the cross section of the silicon wafer 1 immediately after the cutting process, immediately after the chamfering process, and immediately after the double-side grinding process.

  In the case of the comparative example of FIG. 4, since the chamfering is performed in a state where the warp and undulation of the silicon wafer 1 after the cutting process is not removed, the warp and undulation of the silicon wafer 1 remain after chamfering. (FIGS. 4B and 4E). When double-side grinding is performed in this state, the outer peripheral portion 1R is ground unevenly, the chamfering shape of the outer peripheral portion 1R of the silicon wafer 1 after the double-side grinding step is deteriorated, and the chamfering shape in the wafer circumferential direction varies ( FIG. 4 (c)).

  On the other hand, in the case of the present embodiment of FIG. 3, warpage and undulation of the silicon wafer 1 are removed and the wafer surface is flattened by the double-side grinding process (FIGS. 3B and 3E). ), The chamfering shape of the outer peripheral portion 1R of the silicon wafer 1 after the chamfering process is good, and the chamfering shape in the wafer circumferential direction is uniform and has no variation (FIG. 3 ( c)).

  FIG. 5A is a diagram for explaining the top chamfering width A1 and the bottom chamfering width A2 that define the chamfering shape of the outer peripheral portion 1R of the silicon wafer 1. FIG. As shown in FIG. 5B, the values of the top chamfering width A1 and the bottom chamfering width A2 are uniform and uniform at each position in the circumferential direction of the silicon wafer 1, and the top chamfering width A1 and the bottom chamfering width A2 Ideally, a wafer with a small difference and uniform difference and no variation is ideal.

  FIGS. 6A and 6B are values of the top chamfering width A1 at each position in the circumferential direction of the silicon wafer 1 immediately after the chamfering process in the comparative example shown in FIG. The value of the bottom surface chamfering width A2 at each position in the circumferential direction of the silicon wafer 1 immediately after is shown by a graph.

  6 (c) and 6 (d) respectively show the value of the top chamfering width A1 at each circumferential position of the silicon wafer 1 immediately after the double-side grinding step in the comparative example shown in FIG. The value of the bottom surface chamfering width A2 at each position in the circumferential direction of the silicon wafer 1 immediately after the grinding process is shown by a graph.

  6A, 6B, 6C, and 6D show the measurement results of the top surface removal width A1 and the bottom surface removal width A2 for a plurality of silicon wafers 1. FIG.

  7A and 7B respectively show the values of the top chamfering width A1 at each position in the circumferential direction of the silicon wafer 1 immediately after the chamfering process in the case of the embodiment, and the silicon wafer just after the chamfering process in the case of the embodiment. The value of the bottom chamfering width A2 at each position in the circumferential direction 1 is shown by a graph. 7A and 7B show the measurement results of the top surface removal width A1 and the bottom surface removal width A2 for a plurality of silicon wafers 1. FIG.

  FIG. 8 shows the range (variation) between the upper limit value and the lower limit value of the top chamfering width A1 at each position in the circumferential direction of the silicon wafer 1 immediately after the double-side grinding step in the comparative example (FIGS. 6C and 6D). And the center value, the range (variation) of the upper limit value to the lower limit value of the bottom surface chamfering width A2, the center value thereof, and the top surface chamfering width A1 at each position in the circumferential direction of the silicon wafer 1 immediately after the chamfering process in the embodiment. It is the graph which contrasted the range (variation) of an upper limit value-a lower limit value, its center value, the range (variation) of the upper limit value-lower limit value of the bottom surface width A2, and its center value.

  As can be seen from FIGS. 6A and 6B, according to the comparative example, chamfering is performed in a state where warpage and undulation of the silicon wafer 1 after the cutting process is not removed. At each position in the circumferential direction of the wafer 1, the values of the top chamfering width A1 and the bottom chamfering width A2 vary, and the difference between the top chamfering width A1 and the bottom chamfering width A2 varies greatly.

  Further, as can be seen from FIGS. 6C and 6D, since the outer peripheral portion 1R of the silicon wafer 1 is unevenly ground, the top chamfering is performed at each position in the circumferential direction of the silicon wafer 1 immediately after the chamfering step. The values of the width A1 and the bottom chamfering width A2 vary, and the difference between the top chamfering width A1 and the bottom chamfering width A2 varies greatly (see Comparative Examples A1 and A2 in FIG. 8).

  On the other hand, as shown in FIGS. 7A and 7B, according to the present embodiment, the chamfering is performed in a state where the wafer surface is flattened. The values of the top chamfering width A1 and the bottom chamfering width A2 are uniform at each circumferential position, the difference between the top chamfering width A1 and the bottom chamfering width A2 is small, the difference is uniform, and there is little variation. (See Examples A1 and A2 in FIG. 8).

  As described above, according to the present embodiment, the double-side grinding is performed in a state where the outer peripheral portion 1R of the silicon wafer 1 is protected by the carrier 13 as a protective member. There is no occurrence of chipping or chipping at the outer peripheral portion 1R. In the wafer removal step, water is supplied to one surface 1a of the silicon wafer 1 so that the one surface 1a of the silicon wafer 1 is lifted from the pad 11 and the other surface 1b of the silicon wafer 1 is gripped. Since the silicon wafer 1 is taken out from the carrier 13, chipping or chipping does not occur in the wafer outer peripheral portion 1 </ b> R by carrying out the carrying-out operation. In addition, according to this embodiment, since the chamfering process is performed after the double-side grinding process, it is possible to eliminate the deterioration of the chamfered shape at the wafer outer peripheral portion 1R and the variation of the chamfered shape in the wafer circumferential direction.

(Second embodiment)
The above-described double-side grinding process of the first embodiment is carried out as a rough grinding process (primary surface grinding) on both sides of the silicon wafer 1, and after the chamfering process, the both sides of the silicon wafer 1 are further finish ground (first polishing). It is also possible to carry out (secondary surface grinding).

  According to the present embodiment, the chamfering is performed in a state where the rough unevenness of the silicon wafer 1 has already been removed by rough grinding. Therefore, even if the finish grinding is further performed after the chamfering, the chamfering shape of the wafer outer peripheral portion 1R is impaired. It will never be.

(Third embodiment)
In addition, the chamfering process of the first embodiment may be performed as a process of chamfering the outer peripheral part 1R of the wafer, and a process of roughing the outer peripheral part 1R of the silicon wafer 1 may be performed before the double-side grinding process. .

  According to the present embodiment, since the outer peripheral portion 1R of the silicon wafer 1 is roughly chamfered by rough chamfering, the possibility of occurrence of chipping or chipping at the wafer outer peripheral portion 1R at the time of subsequent wafer transfer or the like is extremely low.

  In the above description, the fluid supply means 17 has been described as supplying water, but it may supply liquid such as liquid other than water, air, and various gases.

  The present invention can be applied to chamfering and double-side grinding not only on silicon wafers but also on various semiconductor wafers such as gallium arsenide.

Fig.1 (a) is a side view which shows the structure of the double-sided grinding apparatus used for embodiment, FIG.1 (b) is AA sectional drawing of Fig.1 (a). FIG. 2A is a configuration diagram of a hand, and FIGS. 2B and 2C are diagrams showing a state in which a silicon wafer is taken out from a carrier. 3A to 3F schematically show a cross section of a silicon wafer when the method of the present invention is performed. 4A to 4F schematically show a cross section of a silicon wafer when the method of the comparative example is performed. FIG. 5 is a diagram for explaining the top and bottom chamfering widths that define the chamfering shape of the outer peripheral portion of the silicon wafer. 6 (a) and 6 (b) are values of the top chamfering width at each position in the circumferential direction of the silicon wafer immediately after the chamfering process in the comparative example shown in FIG. 4, respectively, just after the chamfering process in the comparative example. FIGS. 6C and 6D are graphs showing values of the bottom surface width at each circumferential position of the silicon wafer, and FIGS. 6C and 6D respectively show the silicon wafer immediately after the double-side grinding step in the comparative example shown in FIG. It is a figure which shows the value of the upper surface chamfering in each position of the circumferential direction of this, and the value of the chamfering width in each circumferential direction position of the silicon wafer immediately after the double-side grinding process in the case of a comparative example. FIGS. 7A and 7B are values of the top chamfering width at each position in the circumferential direction of the silicon wafer immediately after the chamfering process in the case of the example, respectively, and the circumference of the silicon wafer immediately after the chamfering process in the case of the example. It is a figure which shows the value of the bottom surface chamfering in each direction position with a graph. FIG. 8 shows the variation and center value of the top chamfering width value at each position in the circumferential direction of the silicon wafer immediately after the double-side grinding step in the comparative example, and the variation and center value of the bottom chamfering width value. 5 is a graph comparing the variation in the value of the top chamfering width at each position in the circumferential direction of the silicon wafer immediately after the chamfering step and the central value, and the variation in the value of the bottom chamfering width and the central value.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Silicon wafer 10 Double-sided grinding device 13 Carrier 17 Fluid supply means 18 Hand 19 Controller

Claims (6)

A cutting step of cutting a semiconductor ingot to obtain a semiconductor wafer;
After the cutting step, the semiconductor wafer is rotated by rotating the protective member in a state where the semiconductor wafer in the vertical position is positioned between both pads and the outer peripheral portion of the semiconductor wafer is protected by the protective member, A double-sided grinding process in which both sides of a semiconductor wafer are ground using a grinding wheel;
After the double-side grinding process, by supplying a fluid toward one surface of the semiconductor wafer, one surface of the semiconductor wafer is lifted from the pad, and at the same time , the other surface of the semiconductor wafer is grasped to take out the semiconductor wafer from the protective member. A semiconductor wafer removal process;
And a chamfering step of chamfering the outer peripheral portion of the semiconductor wafer after the semiconductor wafer removing step. The double-sided grinding step is a step of roughly grinding both sides of a semiconductor wafer,
The method of manufacturing a semiconductor wafer according to claim 1, further comprising a step of grinding both surfaces of the semiconductor wafer after the chamfering step. The method for manufacturing a semiconductor wafer according to claim 1, wherein a step of rough chamfering the outer peripheral portion of the semiconductor wafer is performed before the double-side grinding step. The semiconductor wafer is rotated between the two pads of the semiconductor wafer by rotating the protective member in a state where the vertical position of the semiconductor wafer is positioned between both pads and the outer periphery of the semiconductor wafer is protected by the protective member. A double-sided grinding process in which both sides are ground using a grinding wheel;
After the double-side grinding process, by supplying a fluid toward one surface of the semiconductor wafer, one surface of the semiconductor wafer is lifted from the pad, and at the same time , the other surface of the semiconductor wafer is grasped to take out the semiconductor wafer from the protective member. A semiconductor wafer removal process;
A method for double-sided grinding of a semiconductor wafer, comprising: A semiconductor wafer double-side grinding apparatus for grinding both sides of a semiconductor wafer,
Pads provided on both sides of a semiconductor wafer in a vertical position;
A protective member for protecting the outer periphery of the semiconductor wafer;
Rotation driving means for rotating the semiconductor wafer by rotating the protective member;
A grinding wheel for grinding both sides of the semiconductor wafer across both sides of the semiconductor wafer,
Fluid supply means for supplying fluid to the surface of the semiconductor wafer;
A take-out means for taking out the semiconductor wafer from the protective member by gripping the surface of the semiconductor wafer;
By controlling the fluid supply means and the take-out means to supply a fluid toward one surface of the semiconductor wafer after both-side grinding of the semiconductor wafer, the semiconductor wafer is lifted from the pad at the same time as the semiconductor wafer. And a control means for taking out the semiconductor wafer from the protective member by gripping the other surface of the semiconductor wafer.   6. The double-side grinding apparatus for a semiconductor wafer according to claim 5, wherein at least one of the protective member and the take-out means is formed of a soft material having a hardness equal to or lower than the hardness of the semiconductor wafer.

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