JP3173589B2 - Semiconductor ingot cutting system and cutting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor ingot cutting system and method, and more particularly, to a semiconductor ingot cutting system and method for cutting a semiconductor ingot, which is a single crystal material, into a large number of wafers by using wires running on the semiconductor ingot.

[0002]

2. Description of the Related Art When a semiconductor ingot, which is a single crystal material, is cut with a wire saw, it is necessary to cut the semiconductor ingot after setting the cutting direction so that the cut surface is equal to the crystal orientation. Therefore, when cutting the semiconductor ingot, first, the crystal orientation of the semiconductor ingot is detected by irradiating the surface of the semiconductor ingot with X-rays and detecting the reflection angle. Then, the semiconductor ingot is attached to the tilting unit provided on the work feed table, and the semiconductor ingot is inclined horizontally and vertically by the tilting unit so that the semiconductor ingot is cut along the crystal orientation. Set the cutting direction. Thereafter, the semiconductor ingot is pressed against the wire row by feeding the work feed table toward the wire row, and the semiconductor ingot is cut into a number of wafers.

[0003]

However, in the conventional wire saw, one semiconductor ingot can be cut in accordance with its crystal orientation, but the crystal orientation of this semiconductor ingot differs from that of this semiconductor ingot. Since other semiconductor ingots cannot be cut at the same time, there is a disadvantage that production efficiency is poor.

[0004] If the length of the semiconductor ingot is extremely shorter than the width of the wire row, there is a large portion of the wire row that does not contribute to cutting, resulting in a problem that the production efficiency deteriorates. The present invention has been made in view of such circumstances, and has as its object to provide a semiconductor ingot cutting system and a cutting method capable of cutting a plurality of semiconductor ingots simultaneously.

[0005]

According to the present invention, in order to achieve the above object, a running wire is wound around a plurality of grooved rollers to form a wire row, a semiconductor ingot is mounted on a work table, and a semiconductor ingot is mounted on the work table. In a semiconductor ingot cutting system having a wire saw for pressing an ingot against a row of wires and cutting the semiconductor ingot into a plurality of thin wafers, each tilting is performed outside the wire saw.
Semiconductor ingots whose crystal orientations have been aligned using a tilting unit are tilted in the direction of their axes.
With a single setting base being retained in series at intervals through the unit, the attach the setting base in the work table of the wire saw to cut a plurality of semiconductor ingots fixed to setting base simultaneously It is characterized by the following.

According to the present invention, in order to achieve the above object, a running wire is wound around a plurality of grooved rollers to form a wire row, a semiconductor ingot is mounted on a work table, and the semiconductor ingot is connected to the wire row. In a method of cutting a semiconductor ingot provided with a wire saw for cutting the semiconductor ingot into a number of thin wafers by pressing the semiconductor ingot, the crystal orientation of a plurality of semiconductor ingots is adjusted in advance using the respective tilting units outside the wire saw .
There performed each, each semiconductor ingot the crystal orientation is combined, the respective tilting unit in the direction of the axis
A plurality of semiconductor ingots are cut at the same time by being detachably held on a single setting base in series with a space therebetween, and attaching the setting base to the work table.

According to the present invention, the crystal orientations of a plurality of semiconductor ingots are respectively adjusted beforehand outside the wire saw, and the plurality of semiconductor ingots whose crystal orientations are aligned are fixed side by side on a single setting base. And
Attach the setting base to the worktable, and cut multiple semiconductor ingots simultaneously.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a semiconductor ingot cutting system and a cutting method according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of a wire saw applied to the semiconductor ingot cutting system of the present invention, and FIG. 2 is a front view of the wire saw shown in FIG. According to the wire saw 10 shown in FIG. 1, the wire 14 wound on the wire reel 12 has a large number of guide rollers 1.
Are wound around three grooved rollers 18A, 18B, 18C through a wire running path formed by 6, 16,... To form a horizontal wire row 20. The wire 14 having the wire row 20 formed thereon is wound on a wire reel (not shown) via a wire running path on the other side formed symmetrically with respect to the wire row 20.

A wire guide device 22, a dancer roller 24, and a wire cleaning device 26 are provided on each of the wire running paths formed on both sides of the wire row 20 (only one side is shown). The wire 14 is guided from the wire reel 12 at a constant pitch. Also,
The dancer roller 24 has a predetermined weight (not shown).
Is provided, and a constant tension is applied to the traveling wire 14 by this weight. The wire cleaning device 26 sprays the cleaning liquid supplied from the cleaning liquid tank 29 onto the wire 14 to remove the slurry attached to the wire 14 from the wire 14.

The pair of wire reels 12 and the grooved rollers 18C are connected to motors (not shown) which can rotate forward and backward, respectively. It reciprocates between the reels 12 at high speed. A work feed table 28 that moves vertically with respect to the wire row 20 is installed above the wire row 20. Work feed table 2
As shown in FIG. 2, three tilting units 30, 30, 30, which will be described later, are detachably attached to the mounting unit 8 via a setting base 31, and the lower part of these tilting units 30, 30, 30 is The semiconductor ingots 32, 32, 32 are set and held at arbitrary inclination angles. These semiconductor ingots 32, 32, 32
Have different crystal orientations, and are individually set to a predetermined inclination angle by the respective tilting units 30, 30, 30.

In the wire saw 10 configured as described above, the cutting of the ingots 32, 32, 32 is performed by lowering the work feed table 28 toward the wire row 20 so that the ingots 32, 3
2 and 32 are pressed simultaneously. On this occasion,
Slurry is supplied to the wire row 20 from a slurry tank 34 via a nozzle (not shown), and an ingot 32
Is cut into wafers by the lapping action of abrasive grains contained in the slurry.

The slurry used for processing the ingot 32 is supplied to an oil pan 3 provided below the wire row 20.
8, the slurry is collected in the slurry tank 34, and is recycled while replenishing the shortage. At this time, the temperature of the slurry is increased by absorbing heat generated during processing, and the recovered slurry is cooled to a constant temperature by the heat exchanger 36. The ingot 32 is cut in the housing 40 as shown by a two-dot broken line in FIG. 1 to prevent the supplied slurry from scattering around.

Next, the mounting relationship between the setting base 31, the tilting unit 30, and the semiconductor ingot 32 will be described with reference to FIGS. FIG.
Is the setting unit 31 and the tilting unit 30
FIG. 4 is a front view showing a state in which the semiconductor ingot 32 is attached via the connector, and FIG. 4 is a partial perspective view of FIG. In FIG. 4, the setting base 31 and the tilting unit 30 are inserted into
By inserting the dovetail part 44 formed on the upper surface of the
Tilting units 30 and 3
0 and 30 are attached. The dovetail groove 42 and the dovetail part 44
As shown in FIG. 5, a pressing plate 46 having a wedge-shaped cross section
Is arranged. The pressing plate 46 is pivotally supported at an end of a screw rod 48, and the screw rod 48 is attached to the setting base 3.
The lever 52 is fixed to the other end by being screwed into the screw hole 50 formed at the other end.

Therefore, when the lever 52 is rotated in the direction in which the screw rod 48 is pushed in, the pressing plate 46 is pushed by the screw rod 48 and moves in the direction of the arrow in FIG. It is sandwiched between the pressing plate 46. Thereby, the tilting unit 30 is fixed to the setting base 31. When the lever 52 is rotated in the reverse direction, the pressing plate 46 is retracted from the dovetail part 44, and the above-described holding force is released. At this time, if the tilting unit 30 is moved along the dovetail groove 42, the position of the tilting unit 30 with respect to the setting base 31 can be changed. In FIG. 4, the tilting unit 30 and the semiconductor ingot 32 are inserted into a dovetail groove 54 formed in a longitudinal direction on the lower surface of the tilting unit 30.
By inserting the dovetail portion 56 on the semiconductor ingot 32 side, the semiconductor ingot 32 is inserted into the tilting unit 30.
Is attached. The dovetail portion 56 is formed on an upper surface of a mounting plate 58. The slice base 60 of the semiconductor ingot 32 is fixed to the lower surface of the mounting plate 58, and the semiconductor ingot 32 is held on the mounting plate 58. Also, dovetail groove 5
A pressing plate 62 having a wedge-shaped cross section is disposed between the dovetail part 4 and the dovetail part 56. The pressing plate 62 is used to pinch or release the dovetail portion 56 by rotating the lever 64. Since the details are the same as those of the mechanism shown in FIG.

Next, the structure of the tilting unit 30 will be described with reference to FIGS. FIG. 6 is a longitudinal sectional view of the tilting unit 30, and FIG. 7 is a plan view of the tilting unit 30. As shown in FIG. 6, the tilting unit 30 includes a mounting block 66, a horizontal swing block 68, and a vertical swing block 70 as main constituent members, each of which is integrally connected by bolts 72. .

The mounting block 66 is formed in a rectangular shape, and the dovetail portion 44 is formed on an upper surface thereof. This ant part 4
The upper surface 44 </ b> A of 4 is a reference surface in the horizontal direction with respect to the wire row 30. As shown in FIG. 7, guide holes 74, 74 formed in an arc shape are formed on the mounting block 66 concentrically with respect to the bolt 72 and at symmetrical positions. Guide nuts 76 are inserted into the guide holes 74, 74,. The guide nut 76 is formed so as to be slidable along the guide hole 74, and a bolt 78 disposed at the center thereof is screwed into the nut 82 through the through hole 80 of the horizontal swing block 68. ing.

Therefore, the bolt 72 and the bolt 7
8 and 78, the guide hole 74 and the guide nut 7
6, the horizontal swing block 68 can be rotated in the horizontal direction with respect to the mounting block 66. If the bolt 72 and the bolts 78, 78 are tightened, the horizontal tilt angle of the horizontal swing block 68 can be reduced. Can be set. The horizontal swing block 68 slides along the lower surface of the mounting block 66, is fixed to the mounting block 66 by tightening the bolts 78, 78, and swings about the bolt 72 in the horizontal direction by loosening.

At the lower portion of the horizontal swing block 68, a concave curved surface 84 is formed. The curved surface 84 is a vertical reference surface for the wire row 20. On the other hand, a convex curved surface 86 conforming to the shape of the curved surface 84 is formed on the upper part of the vertical swing block 70. In the center of the upper part of the vertical swing block 70, an arc-shaped long hole 88 is formed along the shape of the curved surface 86. This long hole 88
The nut 72 is screwed into the bolt 72.

The vertical swing block 70 slides on the concave curved surface 84 (vertical reference plane) of the horizontal swing block 68,
When the bolt 72 is tightened, it is fixed to the mounting block 66 via the horizontal rocking block 68, and when it is loosened, it rocks vertically with respect to the mounting block 66.
In the lower part of the vertical swing block 70, the aforementioned dovetail 54
The dovetail groove 54 is formed in parallel with the horizontal reference plane.

Next, a procedure for adjusting the cutting direction of the semiconductor ingot 32 by the tilting unit 30 will be described. The crystal orientation of the semiconductor ingot 32 is confirmed in advance by an X-ray irradiator. The horizontal tilt angle and the vertical tilt angle of the semiconductor ingot 32 with respect to the wire row 20 are set by the tilting unit 30 in order to cut along the crystal orientation.

First, the dovetail portion 56 of the mounting plate 58 to which the semiconductor ingot 32 is fixed is inserted into the dovetail groove 54 on the tilting unit 30 side. Then, the levers 64 are rotated to fix the semiconductor ingot 32 to the tilting unit 30. Next, the bolt 72 and the bolts 78, 78 are loosened so that the horizontal swing block 68 and the vertical swing block 70 can swing with respect to the mounting block 66. Then, the horizontal rocking block 68 and the vertical rocking block 70 are each rocked in the horizontal direction, and when the horizontal crystal orientation of the semiconductor ingot 32 matches the wire row 20, the bolts 72 and 7
8 and 78 are fastened to fix the horizontal swing block 68 and the vertical swing block 70 to the mounting block 66.

Next, the bolt 72 is loosened so that the vertical swing block 70 can swing with respect to the mounting block 66. Then, the vertical rocking block 70 is rocked in the vertical direction with respect to the horizontal rocking block 68, and when the crystal orientation in the vertical direction of the semiconductor ingot 32 matches the wire row 20, the bolt 72 is fastened. 70 is fixed to the mounting block 66.

Thus, the positioning operation of the semiconductor ingot 32 in the cutting direction is completed. Then, the other two semiconductor ingots 32, 32 are similarly aligned by the tilting units 30, 30. Since these semiconductor ingots 32, 32, 32 have different crystal orientations, their cutting directions are naturally set to different directions.

Next, these semiconductor ingots 32, 3
A procedure for attaching the work feeders 2 and 32 to the work feed table 28 shown in FIG. 2 will be described. First, the three tilting units 30, 30, 30 whose orientations of the semiconductor ingots 32, 32, 32 are completed are fixed to the setting base 31 at predetermined intervals as shown in FIG.

Next, the setting base 31 is transferred to the position of the work feed table 28, and shoulders 31A, 31A formed on both ends of the setting base 31 are provided.
To the hooks 28A and 28 of the work feed table 28.
Place on A. And the work feed table 28
Rods 94, 9 of hydraulic cylinders 92, 92 provided in
4 to extend the shoulder 31 of the setting base 31.
A, 31A with the hooks 28A, 28A and the rod 94,
Secure with the tip of 94. This completes the work of mounting the semiconductor ingots 32, 32, 32.

The semiconductor ingots 32, 3
When cutting 2 and 32, work feed table 2
8 is sent out to the wire row 20 and the semiconductor ingots 32, 32, 32 are pressed against the wire row 20 to cut the wafer into wafers. Therefore, in the present embodiment, the semiconductor ingots 32, 32,
Since 32 can be cut at the same time, production efficiency can be improved.

In this embodiment, the method of cutting the semiconductor ingots 32, 32, 32 having different crystal orientations has been described, but the present invention is not limited to this. For example, a single semiconductor ingot differs in specific resistance and impurity concentration depending on its axial position, and the semiconductor ingot at that position is selected according to the semiconductor product to be manufactured. In such a case, one semiconductor ingot 32 is divided into a plurality of pieces, and these pieces are attached to the work feed table 28 via the tilting units 30, 30, and cut at the same time. In this case, the crystal orientation is the same.

FIG. 8 is a side view showing a second embodiment of the tilting unit. As shown in the figure, the tilting unit 96 is formed of a cylindrical body, and the cylindrical body has a surface F ₁ perpendicular to the axis L and two surfaces F ₂ and F inclined at a predetermined angle with respect to the axis L. It is divided into four by _three . Each of the divided bodies 98, 100,
102, 104 are rotatably connected to each other along the respective bonding surfaces F ₁ to F _2.

The tilting operation is performed by adjusting the angle in the horizontal direction with the divided body 100 rotating on the horizontal plane F ₁ ,
Adjust the angle in the vertical direction in the divided body 102, 104 rotate on _2, F _3. By combining the two directions of inclination, the ingot 32 can be inclined at an arbitrary angle with respect to the surface of the wire row 20.

[0030]

As described above, according to the semiconductor ingot cutting system and the cutting method according to the present invention, the crystal orientations of a plurality of semiconductor ingots are respectively adjusted beforehand outside the wire saw, and the plurality of semiconductor ingots having the aligned crystal orientations are adjusted. Semiconductor ingots are arranged in series on a single setting base.
Since the setting base is fixed to the work table, a plurality of semiconductor ingots can be cut at the same time.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wire saw according to an embodiment of the present invention.

FIG. 2 is a front view of the wire saw shown in FIG. 1;

FIG. 3 is a front view showing a state where the semiconductor ingot is mounted on a setting base via a tilting unit.

FIG. 4 is a perspective view of a main part of FIG. 3;

FIG. 5 is a partial sectional view showing an engagement state between the setting base and the tilting unit.

FIG. 6 is a longitudinal sectional view of the tilting unit.

FIG. 7 is a plan view of a tilting unit.

FIG. 8 is a side view showing a second embodiment of the tilting unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Wire saw 14 ... Wire 20 ... Wire row 28 ... Work feed table 31 ... Setting base 30, 96 ... Tilting unit 32 ... Semiconductor ingot

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-99261 (JP, A) JP-A-49-111290 (JP, A) JP-A-8-25208 (JP, A) JP-A-8-208 39415 (JP, A) JP-A-10-100139 (JP, A) JP-A-7-308920 (JP, A) JP-A-2-43156 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B28D 5/04 B24B 27/06 H01L 21/304

Claims (2)

(57) [Claims] 1. A running wire is wound around a plurality of grooved rollers to form a row of wires, a semiconductor ingot is mounted on a work table, and the semiconductor ingot is pressed against the row of wires to form the semiconductor ingot into a plurality of thin plates. of the cutting system for a semiconductor ingot having a wire saw for cutting a wafer, a plurality of semiconductor ingots <br/> crystal orientation with each of the tilting units outside the wire saw has joined together is, its
The distance between each tilting unit in the direction of the shaft center
With a single setting base being retained in series at a, and attaching the setting base in the work table of the wire saw, characterized by cutting a plurality of semiconductor ingots fixed to setting base simultaneously Semiconductor ingot cutting system. 2. A running wire is wound around a plurality of grooved rollers to form a row of wires, a semiconductor ingot is mounted on a work table, and the semiconductor ingot is pressed against the row of wires to form the semiconductor ingot into a plurality of thin plates. In the method for cutting a semiconductor ingot provided with a wire saw for cutting into wafers, alignment of crystal orientations of a plurality of semiconductor ingots is performed in advance using the respective tilting units outside the wire saw, and each semiconductor in which the crystal orientation is aligned is Ingot ,
In the direction of the axis, insert the respective tilting units.
Attach / detach to a single setting base in series at a distance
Capable holding, cutting method of a semiconductor ingot, characterized by cutting said setting based a plurality of semiconductor ingots mounted on the work table at the same time.