JPH10202497A - Drive restarting method at time of wire cutting of semiconductor slice device and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a pitch of a wire fitting groove constant by restraining thermal contraction of a roller caused by thermal contraction of a bearing housing by supplying a heat exchanging medium to restrict thermal contraction to a passage of the heat exchanging medium. SOLUTION: A wire 6 is extracted from a slit of semiconductor ingot by stopping a roller drive device by a controller 23 in accordance with a change of a detected value S of a distance measuring sensor 22 at the time of cutting the wire. A high temperature heat exchanging medium is supplied to passages 15a, 15b of the heat exchanging medium of a bearing part 4 of each of rollers 2, 3, etc., to restrict thermal contraction by changing change-over valves 16, 17 over to each other, and a pair of cutting points of the wire 6 is drawn out of a tail roller 3 and connected by winding up the wire 6 by control of the roller drive device while restricting thermal expansion of each of the rollers 2, 3, etc., in a state at the time of cutting the wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor slicing apparatus for cutting a semiconductor ingot by pressing a semiconductor ingot while supplying slurry to a wire, and more particularly to a method of restarting operation of the semiconductor slicing apparatus at the time of cutting a wire and the apparatus. .

[0002]

2. Description of the Related Art As a single crystal ingot slicing apparatus, a well-known inner peripheral blade slicer for moving a work b of a single crystal ingot relative to an inner peripheral blade in a direction perpendicular to an axis and slicing the same, as shown in FIG. Rollers b, c, and d having a spiral groove (see FIG. 3) for the wire a on the outer peripheral surface are arranged at the apexes of the inverted triangle, respectively, and these rollers b, c, and d are fitted. A wire row e is formed between the recessed grooves, and a semiconductor ingot h is supplied to the wire row e while slurry g containing abrasive grains of a cutting material is supplied from a slurry supply nozzle f.
(Wire saw) is used to cut the semiconductor ingot by lapping of abrasive grains by pressing the wire. However, the former inner peripheral blade slicer has less material loss and higher precision than the latter wire saw. Although it has the advantage of being able to perform slice cutting, it has a drawback that it is necessary to cut out wafers one by one structurally, which is not suitable for cutting large-diameter semiconductor ingots due to poor mass productivity. Therefore, in recent years, a wire saw type has been increasingly used as a slicing apparatus for a semiconductor ingot having a large diameter.

[0003]

The wire of the wire saw is made of a wire material having high wear resistance and tensile strength and high hardness, such as a special piano wire.
As the roller, a resin roller having a predetermined hardness is used to prevent the wire from being damaged.However, the wire is cut and entangled with the roller when the semiconductor ingot is sliced and cut due to aging of the wire or fatigue due to fatigue. In some cases, the cut portion causes damage to the fitting groove on the outer periphery of the roller, and the cutting of the wafer cannot be continued.

[0004] In such a case, conventionally, after performing a detaching operation for detaching the cut of the semiconductor ingot from the wire, the wire is manually or pulled out, or the roller driving device is manually operated so that the cut portion of the wire is one side. Pull out to the outside of the roller as appropriate, connect the cut parts, and then perform the drawing work to pull out again to the position where the connection part of the wires is not directly involved in cutting the semiconductor ingot, or in the unusable state Replacement work was performed to replace the wire with a new one. Then, after such a wire repairing process, a return operation is performed in which each cut of the semiconductor ingot is engaged with each row of the wire in a corresponding manner, and the cutting of the semiconductor ingot is restarted, whereby the slice cutting of the semiconductor ingot is performed. The restoration work that completed was done.

However, when the time required from the start of the wire recovery to the resumption of the cutting of the semiconductor ingot is extremely short,
For example, a long time (1 to 3 hours) is required for the wire repair process unless the wire process can be completed only by connecting the wires, such as a case where the wire is cut out of engagement with the roller. If it is necessary, the roller that has thermally expanded due to frictional heat with the bearing portion and the wire of the roller cools down, and the pitch of the wire insertion groove into which the wire is inserted becomes narrow. When the cutting of the semiconductor ingot is restarted in the state, there is a problem that an uncorrectable step is generated on both the cut wafer and the cut surface of the semiconductor ingot.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wire saw type semiconductor slicing apparatus so that the heat shrinkage of a roller immediately after a wire is cut can be restricted to connect or replace a wire. It is another object of the present invention to provide a method of connecting or replacing wires of a novel semiconductor slice device and a device therefor.

[0007]

According to the first aspect of the present invention,
A wire insertion groove is formed at a predetermined winding pitch on the outer peripheral surfaces of the rollers arranged in parallel with each other, and the wire wound between the roller insertion grooves is moved within a predetermined range by forward and reverse rotation of the roller. In the operation method of the semiconductor slicing apparatus, in which the semiconductor ingot is pressed and sliced while supplying the slurry containing the cutting material to the reciprocating portion of the wire, heat exchange is performed in advance in the bearing housing and other supporting portions of the rollers. A passage for introducing a medium is formed, and when the wire is cut, the forward and reverse rotation of the roller and the supply of the slurry are stopped, and heat shrinkage (generally, heat shrinkage, rarely) occurs in the passage of the heat exchange medium. After introducing a heat exchange medium which regulates the thermal expansion when the room temperature is high, the pair of cut portions of the wire is not directly used for cutting the semiconductor ingot. Position rewinding connected to, a cut of the semiconductor ingot in the state pressed against the wire, characterized in that to resume the normal and reverse rotation of the supply and the roller of the slurry.

In other words, immediately after the wire is cut, the forward and reverse rotation of the roller is stopped, and the supply of the slurry is stopped, so that the entanglement of the wire and the damage of the roller due to the cut portion of the wire are prevented. By supplying a heat exchange medium, such as water or oil, for restricting heat shrinkage to the passages, the heat shrinkage of the roller caused by the heat shrinkage of the bearing housing is suppressed, and the pitch of the wire fitting groove is kept constant. is there.

Then, a pair of cut portions of the wire is extended and connected to a position not directly involved in cutting of the semiconductor ingot, and in this state, the cut of the semiconductor ingot is pressed against the wire in this state, and the slurry is removed. By restarting the supply and the forward and reverse rotation of the roller,
Enables slice cutting without steps.

According to a second aspect of the present invention, a wire insertion groove is formed at a predetermined winding pitch on the outer peripheral surfaces of rollers arranged side by side, and the wire wound between the insertion grooves of these rollers is provided. Is reciprocated within a predetermined range by forward and reverse rotation of the roller, and the semiconductor ingot is pressed and sliced while supplying a slurry containing a cutting material to the reciprocating portion of the wire. A heat exchange medium passage for introducing a heat exchange medium and restricting thermal expansion and contraction thereof, a low-temperature heat exchange medium passage and a high-temperature heat exchange medium which are selectively connected to the passage via a switching valve. Passage and thermal expansion of the roller
It is characterized by comprising a detecting means for detecting thermal shrinkage, and a controller for switching the switching valve based on a detection signal from the detecting means for restricting thermal expansion and thermal shrinkage of the roller. That is, when the wire is cut, the controller switches the switching valve in accordance with the thermal expansion / thermal contraction by the detecting means, so that the thermal contraction of the roller caused by the thermal contraction of the bearing housing is maintained in a state immediately after the cutting. For this reason,
If the wires are connected and exchanged as in the first aspect of the present invention, even if the cutting is restarted, the pitch shift of the wires can be suppressed, and a wafer free from cutting defects can be obtained. The semiconductor slicing apparatus according to claim 3, wherein the detecting means is provided in a fixed system, and detects a change in a distance from a detection surface thereof to a detection surface of the roller as a change amount of the thermal expansion and thermal contraction. Is input to the controller.

If the thermal expansion / contraction of the roller is detected in a non-contact manner as described above, the reliability of sensing can be maintained, and correct control of the thermal expansion / contraction of the roller can be performed.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the constituent members described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely described. It is only an example.

FIG. 1 is a structural view of a semiconductor slicing apparatus according to one embodiment of the present invention, FIG. 2 is a block diagram of a control system for controlling thermal expansion of a roller, and FIG. 3 is a semiconductor ingot cutting invitation and slurry supply apparatus. 3 shows a schematic configuration showing the relationship between

First, the main configuration of the slice apparatus will be described in detail with reference to FIGS. A head roller 2 and a tail roller 3 are rotatably supported via bearings 4 at an upper portion of the main body substrate 1 serving as a fixed system and are spaced apart from each other. At the bottom,
A driving roller 5 is supported in parallel with the head roller 2 and the tail roller 3. These rollers 2, 3, 5
A fitting groove 7 is formed on the outer peripheral surface at a predetermined spiral pitch from one end to the other end, and one wire 6 is wound around the fitting groove 7 of these rollers 2, 3, 5. 6, the head roller 2 and the tail roller 3
Are simultaneously rotated in the same rotation direction.

As shown in FIG. 2, the wire 6 cooperates with a slurry containing an abrasive to cut the semiconductor ingot 12 pressed against the slurry by the lapping action of abrasive grains. It is made of a wire having high tensile strength and high hardness, for example, a special piano wire. Both ends of the wire 6 extend outwardly of the head roller 2 and the tail roller 3 and are once guided upward by a fixed pulley 8 and a moving pulley 9 which are supported by a fixed system, and then are separated by another fixed pulley. The wire 6 is folded downward again (not shown), and a constant tension is applied to the wire 6 by the weight of a weight (not shown) attached to the front end and the rear end thereof.

The traveling of the wire 6 is performed by, for example, a driving device 11 which transmits a forward / reverse rotational driving force to the driving roller 5 and causes the driving roller 5 to reciprocate in a predetermined range, and presses the semiconductor ingot 12 against the wire 6. Is the wire 6
Of the semiconductor ingot 12 disposed above the device.

An object of the present invention is to eliminate the irregularity of the pitch of the wire 6 due to the heat shrinkage of the rollers 2, 3, and 5 from the time when the wire 6 is cut to the time when the wire 6 is restarted, and to reduce the step of the wafer caused by this. It is to suppress the occurrence.

Therefore, in this embodiment, the parts directly involved in the thermal expansion and contraction of the head roller 2, the tail roller 3, and the drive roller 5, that is, as shown in FIG. , 5 and a supply passage 15a and a discharge passage 15b for a heat exchange medium, for example, water and oil, are formed in a bearing housing 4a in a bearing portion 4 which is in heat transferable contact with the supply passage 15a and the discharge passage 15b. On the other hand, the supply passage 18a and the discharge passage 18b for the low-temperature heat exchange medium and the supply passage 19a and the discharge passage 1 for the high-temperature heat exchange medium via the switching valves (two-way switching valves) 16 and 17, respectively.
9b, the slurry is supplied by the slurry nozzle 20 and the supply passage 15a and the discharge passage 15b of each of the rollers 2, 3, and 5 are supplied in a normal state, that is, during normal ingot cutting without wire cutting. Supply passage 18a and discharge passage 1 for the heat exchange medium having a low temperature with respect to
The switching valves 16 and 17 are switched so as to communicate with the rollers 8, 8 b, and their thermal expansion is regulated. The switching valves 16 and 17 are switched so that communication between the supply passage 18a of the low-temperature heat exchange medium and the supply passage 19a and the discharge passage 19b of the high-temperature heat exchange medium passage is interrupted and the communication between the supply passage 15a and the discharge passage 15b is interrupted. Roller 2,
It is configured to regulate 3,5 heat shrinkage.

In this case, in order to correctly perform the switching between the normal state and the abnormal state, and to correctly set the temperature and the flow rate of the heat exchange medium at the time of the switching, the switching timing of the switching valves 16 and 17 is accurately determined. At the same time, it is preferable to accurately detect the temperature of the heat exchange medium to be supplied and accurately set the flow rate.

For this reason, in the embodiment of the present invention, as shown in FIG. 1, an end face 21a of an end face plate 21 integrated with each of the rollers 2, 3, and 5 is used as a non-detection face as a fixed system, for example, A distance measuring sensor 22 is attached to the substrate 1 so that the distance between the end surface 21a and the roller 2, 3, 5 can be interpreted as a displacement at the time of thermal expansion or thermal contraction, and the output of the distance measuring sensor 22 is measured. A temperature sensor 24 configured to input to a controller (CPU or the like) 23 and detecting an outlet temperature to a discharge passage 18b of a low-temperature heat exchange medium as shown in the block diagram of FIG. A temperature sensor 25 for detecting the outlet temperature is provided in the medium discharge passage 19b. And the controller 23
The distance S to the end face 21a of the end face plate 21 detected at the time of cutting the normal semiconductor ingot 12 is stored as a reference value (for example, 0). When the difference on the + side from the distance S1 detected by the distance measuring sensor 22 exceeds a predetermined value, it is determined that the wire has been cut, and the reference value S and the current value detected by the distance measuring sensor 22 are determined. When the difference on the negative side from the distance S1 is less than a predetermined value, it is determined that the ingot is cut normally. Further, based on the outlet temperatures detected by the temperature sensors 24 and 25, each roller 2, After calculating the heat loads of 3, 5, the capacities of the cooling device 26 and the heating device 27 for the heat loads are adjusted, and the flow rates corresponding to the respective capacities are calculated to supply the low-temperature heat exchange medium supply device 28 and the high-temperature Heat exchange medium It has become the supply amount of the supply device 29 so as to regulate respectively. In this case, when an optical sensor is used as the distance measuring sensor 22, a reflector (reflecting plate) is provided on the end face 21a. It is preferable to gradually increase the control of the supply amount and temperature of the heat exchange medium for restricting shrinkage.

In the wire repairing method according to the present embodiment, when the wire is cut, the roller driving device 11 is stopped manually or by the controller 23 based on a change in the detection value S of the distance measuring sensor 22 and the semiconductor ingot is cut. The wire 6 is withdrawn from the notch 12 and the switching valves 16 and 1 are removed.
7, a high-temperature heat exchange medium is supplied to the heat exchange medium passage 15 of the bearing portion 4 of each of the rollers 2, 3, 5 so as to restrict heat shrinkage. While restricting the expansion to the state at the time of cutting the wire, the wire 6 is wound up by manual operation or manual control of the roller driving device 11, and a pair of cut portions of the wire 6 are pulled out, for example, out of the tail roller 3 and connected. I do. Then, after the position of the connection portion is pulled out to a position that is not directly used for cutting the semiconductor ingot 12, each cut of the semiconductor ingot 12 before cutting is engaged with each wire row 10 and pressed. Thereafter, in this state, the wire 6 is driven by the roller driving device 11 and the slurry is supplied by the slurry supply nozzle 20 while the wire 6 is driven to rotate forward and backward by the roller driving device 11 to complete the slice cutting of the semiconductor ingot 12. I do. In this case, when the wire is damaged in a place where the cut portion is not directly involved in the cutting of the semiconductor ingot 12, it is not necessary to wind the wire 6 in order to draw out the cut portion of the wire 6. If the condition is bad due to entanglement of the wire, the wire 6 is replaced. If the condition of the fitting groove 7 of each of the rollers 2, 3, 5 is bad and there is a strong possibility that the cutting of the semiconductor ingot 12 is adversely affected. , The low and high temperature heat exchange medium passages 18a, 18b,
Once all of 19a and 19b are shut off and the roller is replaced,
A high-temperature heat exchange medium is supplied to each of the rollers 2, 3, and 5 so as to return to the state immediately after cutting.

When the control is performed by the controller, when the signal from the distance measuring sensor 22 is processed and the wire cutting is determined, the roller driving device 11 is automatically stopped and the slurry is supplied to the slurry supply nozzle 20. A stop signal is output to a pump (not shown) that supplies the slurry, and when cutting of the semiconductor ingot is restarted by a manual button or the like, the roller driving device 11 and the slurry supply pump to the slurry supply nozzle are driven. like,
If the feeding device 13 of the semiconductor ingot 12 is configured to be slowly started to press the semiconductor ingot 12 against the wire 6, it is possible to further promote labor saving.

Therefore, according to the method and the apparatus according to the present embodiment, each of the rollers 2 and
A low-temperature heat exchange medium for restricting thermal expansion is supplied to the supply passages 15a and 15b of the heat exchange mediums 3 and 5, so that the pitch of the wires 6 is kept constant, and the slice of the semiconductor ingot 13 during the normal operation further increases. When the wire is cut, the switching valves 16 and 17 are switched according to the heat shrinkage by the distance measuring sensor 22.
That is, since the high-temperature heat exchange medium for controlling the heat shrinkage is supplied, the pitch of the wire 10 is set to be almost the same as the state before the cutting, and even if the cutting of the semiconductor ingot 12 is restarted, the pitch of the wire 6 is shifted. Thus, the formation of steps on the wafer due to the above is suppressed, and a wafer comparable to a wafer obtained by cutting the semiconductor ingot 12 can be obtained. In the description of this embodiment, the supply passage 15a for the heat exchange medium is provided in the bearing housing 4a.
The reason why the discharge passage 15b is formed is that the rollers 2, 3, and 5 are thermally expanded by using this as a heat source. Therefore,
When the flow rate of the heat exchange medium is large and sufficient, the supply path 15a and the discharge path 15b of the direct heat exchange medium are formed in each of the rollers 2, 3, and 5 without such a configuration.
The switching valves 16 and 17 may be connected to these.

(Embodiment) FIG. 4 shows an embodiment of the semiconductor slicing apparatus according to the present invention. As shown, the end surface 21a of the end plate 21 integral with the rollers 2, 3, and 5 is used as a non-detection surface in a fixed system, for example, the end surface 21a on the substrate 1.
Distance measuring sensor 2 so that the distance between the rollers 2, 3, and 5 can be regarded as the displacement at the time of thermal expansion or thermal contraction.
2 was attached, and the output of the distance measuring sensor 22 was input to the controller 23. In this case, the bearing portion 4 is composed of the core 30 of the rollers 2, 3, and 5 and the inner shaft 31.
And the inner ring 32 is fitted to the inner shaft 31 to form a bearing 33.
And the outer ring 34 of each bearing 33 is fitted on the inner surface of a cylindrical outer shaft 35, and the outer shaft 35 is connected to the bearing housing 4.
a. Then, the inner surface of the bearing housing 4a is depressed radially outward to form a spiral groove 36, and the two ports 3 formed in the bearing housing 4a are formed in the spiral groove 36.
7 and 38, respectively, which are used as a supply passage 15a and a discharge passage 15b for the heat exchange medium such as water and oil. The switching valve (two-way) is connected to the supply passage 15a and the discharge passage 15b for the heat exchange medium. The supply passage 18a and the discharge passage 18b for the low-temperature heat exchange medium and the supply passage 19a and the discharge passage 19b for the high-temperature heat exchange medium via the switching valves 16 and 17.
And can be switched freely. And the controller 23
By controlling the cutting of the wire, the cutting of the semiconductor ingot was resumed by the above method after the cutting of the wire 6 and the step of the obtained wafer was measured. However, the defective rate was 0%.

[0025]

As has been described above, according to the present invention, it is possible to suppress the formation of a step on a wafer due to a wire pitch shift even if the semiconductor ingot is restarted after the wire is cut. Thus, an excellent effect that a wafer having a quality comparable to that of a wafer obtained by cutting a semiconductor ingot can be obtained.

[Brief description of the drawings]

FIG. 1 is a detailed view of a main part showing an embodiment of a semiconductor slicing apparatus according to the present invention.

FIG. 2 is a perspective view showing one embodiment of a semiconductor slicing apparatus according to the present invention.

FIG. 3 is a block diagram showing one embodiment of a semiconductor slicing apparatus according to the present invention.

FIG. 4 is a detailed sectional view of a main part showing one embodiment of the present invention.

FIG. 5 is a schematic diagram for explaining a configuration of a conventional slice device.

[Explanation of symbols]

 2, 3, 5 Roller 4 Bearing 6 Wire 7 Fitting groove 10 Wire row 15a Heat exchange medium supply path 15b Heat exchange medium discharge path 16, 17 Switching valve 18a Low temperature heat exchange medium supply path 18b Low temperature heat Exchange medium discharge path 19a Supply path of high-temperature heat exchange medium path 19b Low-temperature heat exchange medium discharge path 22 Distance sensor 23 Controller

Claims (3)

[Claims] 1. A wire insertion groove is formed at a predetermined winding pitch on an outer peripheral surface of rollers arranged in parallel with each other, and a wire wound between the insertion grooves of the rollers is forwardly or reversely mounted on the roller. A method of operating a semiconductor slicing apparatus in which a semiconductor ingot is pressed and sliced while supplying a slurry containing a cutting material to a reciprocating portion of the wire by reciprocating within a predetermined range by rotation, wherein a bearing housing of each of the rollers is previously prepared. A passage for introducing the heat exchange medium is formed in the roller support portion, and when the wire is cut, the forward / reverse rotation of the roller and the supply of the slurry are stopped, and the heat contraction / expansion is restricted in the passage of the heat exchange medium. After introducing the heat exchange medium to be cut, the pair of cut portions of the wire are pulled out to a position not directly used for cutting the semiconductor ingot and connected. Wherein in a state pressed against the notch of the semiconductor ingot to the wire, the method of resuming the operation during the wire cutting of the semiconductor slice and wherein the resuming forward and reverse rotation of the supply and the roller of the slurry. 2. A wire insertion groove is formed at a predetermined winding pitch on the outer peripheral surfaces of rollers arranged side by side, and the wire wound between the insertion grooves of the rollers is rotated forward and backward of the roller. A semiconductor slicing apparatus which reciprocates within a predetermined range by rotation and presses a semiconductor ingot while supplying a slurry containing a cutting material to a reciprocating portion of the wire to perform slice cutting, wherein a heat exchange medium formed in a bearing housing of the roller A low-temperature heat exchange medium path and a high-temperature heat exchange medium path that are selectively connected to the path via a switching valve; Detecting means for detecting thermal expansion and thermal contraction; and a controller for switching and operating the switching valve based on a detection signal of the detecting means for restricting thermal expansion and thermal contraction of the roller. The semiconductor slice apparatus comprising the and. 3. The semiconductor slicing apparatus according to claim 2, wherein said detecting means is provided in a fixed system, and a change in a distance from a detecting surface of the detecting means to a detecting surface of the roller is determined by the thermal expansion / deceleration.
A semiconductor slicing device comprising a non-contact type sensor which detects a change in heat shrinkage and inputs the same to the controller.