CN216400146U

CN216400146U - Device for cutting silicon single crystal rod

Info

Publication number: CN216400146U
Application number: CN202123091731.6U
Authority: CN
Inventors: 王明
Original assignee: Xian Eswin Material Technology Co Ltd
Current assignee: Xian Eswin Material Technology Co Ltd
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-04-29
Anticipated expiration: 2031-12-09

Abstract

The utility model discloses a device for cutting a single crystal silicon rod, which comprises: cutting a line; a driver for driving the single crystal silicon rod to move, so that the cutting line cuts the single crystal silicon rod along the cutting surface of the single crystal silicon rod; a controller for controlling the speed of the driver for driving the single crystal silicon rod to move, so that the cutting line cuts the part with the same area in the cutting surface in unit time.

Description

Device for cutting silicon single crystal rod

Technical Field

The utility model relates to the field of silicon wafer production, in particular to a device for cutting a silicon single crystal rod.

Background

Silicon wafers can be obtained after the single crystal silicon rod drawn by the czochralski method is cut, and at present, the single crystal silicon rod is generally cut by a multi-wire cutting process. In the multi-wire cutting process, a plurality of cutting wires which are in the same plane and are parallel to each other are reciprocated at high speed in the extending direction thereof with slurry-like abrasive adhered thereto, while a silicon rod is driven in such a manner that the longitudinal axis thereof is parallel to the plane in which the plurality of cutting wires are located and perpendicular to the cutting wires to generate a feeding motion with respect to the plurality of cutting wires, whereby the silicon rod is cut into several thin pieces by the grinding action of the abrasive.

In the above-described multi-wire cutting process, friction between the cutting wire and the silicon rod, friction between the slurry abrasive and the cutting wire, and friction between the slurry abrasive and the silicon rod all cause a large amount of frictional heat to be generated at the cut position of the silicon rod.

Since the silicon rod has a circular cross section, the contact length between the cutting line and the silicon rod may vary during the cutting of the silicon rod, for example, the contact length may be small when cutting the radial edge of the silicon rod, at which the silicon rod may be easily cut and the increase in the temperature of the silicon rod due to frictional heat may be small, and the contact length may be large when cutting the radial center of the silicon rod, at which the silicon rod may be difficult to cut and the increase in the temperature of the silicon rod due to frictional heat may be large, or, the temperature of the silicon rod may vary during the entire cutting of the silicon rod, which may cause warpage of the finally cut silicon wafer.

SUMMERY OF THE UTILITY MODEL

In order to solve the above technical problems, embodiments of the present invention desirably provide an apparatus for cutting a single crystal silicon rod into silicon wafers, which is capable of improving the condition of the difference in the temperature of the silicon rod during the entire cutting process, thereby cutting silicon wafers with improved warpage conditions.

The technical scheme of the utility model is realized as follows:

the embodiment of the utility model provides a device for cutting a silicon single crystal rod, which comprises:

cutting a line;

a driver for driving the single crystal silicon rod to move, so that the cutting line cuts the single crystal silicon rod along the cutting surface of the single crystal silicon rod;

a controller for controlling the speed of the driver for driving the single crystal silicon rod to move, so that the cutting line cuts the part with the same area in the cutting surface in unit time.

Embodiments of the present invention provide an apparatus for slicing a single crystal silicon rod, in which portions of a same area in a slicing surface are sliced in a unit time, so that heat generated by friction in the whole slicing process is the same in the unit time, thereby reducing a temperature change of the single crystal silicon rod, and improving flatness of sliced sections formed after slicing, or improving warpage of a silicon wafer in a case where the single crystal silicon rod is sliced into silicon wafers with a plurality of sliced sections.

Drawings

FIG. 1 is a schematic view of an apparatus for slicing a single crystal silicon rod according to an embodiment of the present invention;

FIG. 2 is a schematic view of a cutting face according to the present invention divided into different portions of equal area;

FIG. 3 is a schematic view of an apparatus for slicing a single crystal silicon rod according to a further embodiment of the present invention;

fig. 4 is a schematic view of an apparatus for slicing a single crystal silicon rod according to another embodiment of the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Considering that, for example, during the cutting of the silicon rod, when the silicon rod is cut to the diameter position of the cross section of the silicon rod, the driving of the silicon rod is stopped so that the feeding movement of the silicon rod relative to the plurality of cutting lines is no longer generated, friction is no longer generated between the cutting lines and the silicon rod, between the slurry-like abrasive and the cutting lines, and between the slurry-like abrasive and the silicon rod, and thus no friction heat is generated, so that the situation that the silicon rod has a high temperature, which would otherwise occur when the silicon rod is cut to the position, can be improved. It is thereby possible to take into account that the feed rate of the single crystal silicon rod is reduced when cutting to a diameter position of the silicon rod cross section in order to generate less heat per unit time. It is further considered that, during the cutting of the silicon rod, the amount of heat generated due to friction should be proportional to the amount of silicon rod removed, while the width of the kerf is substantially equal to the diameter of the cutting line or does not change, and therefore, the amount of heat generated due to friction is in fact proportional to the area of the silicon rod that has been cut. It can be seen that, as long as the area cut per unit time is the same, the amount of heat generated per unit time is the same, and the temperature of the silicon rod is kept constant on the assumption that the amount of heat dissipated from the silicon rod per unit time is constant.

Based on this, referring to fig. 1, an embodiment of the present invention provides an apparatus 1 for slicing a single crystal silicon rod SR, where the apparatus 1 may include:

a cutting line 10;

a driver 20 for driving the single crystal silicon rod SR to move, for example, in the direction of the hollow arrow shown in fig. 1, such that the cutting line 10 cuts the single crystal silicon rod SR along a cutting surface 10F of the single crystal silicon rod SR;

a controller 30 for controlling the speed at which the driver 20 drives the single crystal silicon rod SR to move so that the cutting wire 10 cuts a portion of the same area in the cutting surface 10F per unit time.

Specifically, as shown in fig. 2, the above-described cutting surface 10F is exemplarily divided into 8 portions, and the 8 portions have the same area and are cut by the cutting line 10 at the same time by moving the single crystal silicon rod SR shown in fig. 1, that is, the cutting surface 10F, in the direction of the hollow arrow. More specifically, as can be seen from fig. 2, when the cutting line 10 cuts the radial edge portion of the single crystal silicon rod SR, that is, the cutting surface 10F moves faster, the movement speed of the cutting surface 10F gradually slows as the cutting line cuts a portion of the cutting surface 10F closer to the radial center portion, and the movement speed of the cutting surface 10F is slowest when the cutting line 10 cuts the radial center portion of the cutting surface 10F.

In this way, since the same area portion of the cut surface 10F is cut per unit time, the amount of heat generated by friction per unit time is the same throughout the cutting process, so that the temperature variation of the single crystal silicon rod SR is reduced, and the flatness of the cut surfaces formed after cutting is improved, or the warpage of the silicon wafer can be improved in the case where the number of cut surfaces is plural and the single crystal silicon rod SR is cut into the silicon wafer.

It can be understood that, assuming that the moving speed of the single crystal silicon rod SR is the same when the cutting line 10 cuts each portion of the cutting surface 10F, dividing the cutting surface 10F into more portions having the same area in the manner shown in fig. 2, the more timely the moving speed of the single crystal silicon rod SR can be adjusted, and the more the variation range of the amount of heat generated by friction can be reduced throughout the cutting process. Therefore, in a preferred embodiment of the present invention, the unit time may be not more than one tenth of the total time for the cutting wire 10 to cut off the single crystal silicon rod SR, or the cutting surface 10F may be divided into not less than 10 parts having the same area in the manner shown in fig. 2, thereby limiting the variation width of the heat generated by friction within a certain range.

In order to cut the single crystal silicon rod SR into several thin slices during a single movement of the single crystal silicon rod SR to obtain silicon wafers, the cutting wire 10 may comprise a plurality of cutting wire strands 10T to cut at a corresponding plurality of locations of the single crystal silicon rod SR, see fig. 3.

Still referring to fig. 3, the strands of string 10T may lie in the same plane and may be parallel to one another. When the plurality of strand of cutting wires 10T are in the same plane, the single crystal silicon rod SR can be cut at the shortest moving distance, and when the plurality of strand of cutting wires 10T are parallel to each other, the cut silicon wafer can have a uniform thickness.

The plurality of strands of cutting wire 10T as shown in fig. 3 may be reciprocated along their own extension direction, as schematically shown by black arrows in fig. 3, thereby facilitating cutting of the single crystal silicon rod SR.

Still referring to fig. 3, during the driving of the single crystal silicon rod SR, the longitudinal axis X of the single crystal silicon rod SR may be parallel to the plane in which the plurality of strands of cutting wire 10T lie and may be perpendicular to the plurality of strands of cutting wire 10T. In the case where the longitudinal axis X of the single crystal silicon rod SR is parallel to the plane in which the plurality of strand of cutting wires 10T are located, the single crystal silicon rod SR can be cut with the shortest moving distance, and in the case where the longitudinal axis X of the single crystal silicon rod SR is perpendicular to the plurality of strand of cutting wires 10T, a silicon wafer having a circular surface can be cut.

With the plurality of strands 10T reciprocating, still referring to figure 3, the apparatus 1 may also comprise a supply 40 for supplying the plurality of strands 10T with slurry abrasive as schematically illustrated by the small black dots in figure 3. This makes it possible to cause the slurry-like abrasive to exert an abrasive action on the single crystal silicon rod SR by the reciprocating motion of the strand of cutting wire 10T, and to perform material removal on the single crystal silicon rod SR by the abrasive action to effect cutting.

Preferably, as shown in fig. 3, the number of the supplies 40 may be two and two supplies 40 may be disposed at different sides of the single crystal silicon rod SR.

With respect to the reciprocating movement of the strands of string 10T, see figure 4, the strands 10T can be wound on the opposite driving wheel 50 and the reciprocating movement is generated by rotation of the driving wheel 50.

Still referring to fig. 4, the apparatus 1 further includes a clamp 60 for clamping the single crystal silicon rod SR, and the driver 20 moves the single crystal silicon rod SR by driving the clamp 60.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. An apparatus for slicing a single crystal silicon rod, the apparatus comprising:

cutting a line;

2. The apparatus of claim 1 wherein the unit time is no greater than one tenth of the total time the cutting wire severs the single crystal silicon rod.

3. The apparatus of claim 1 or 2, wherein the cutting wire comprises a plurality of strands of cutting wire to cut at a corresponding plurality of locations of the single crystal silicon rod.

4. Device according to claim 3, characterized in that said strands are in the same plane and parallel to each other.

5. Device according to claim 4, characterized in that said plurality of strands reciprocates along its own extension.

6. The device as recited in claim 4 wherein a longitudinal axis of the single crystal silicon rod is parallel to a plane in which the plurality of strands of cutting wire lie and perpendicular to the plurality of strands of cutting wire during driving of the single crystal silicon rod.

7. The apparatus of claim 5, further comprising a supply for supplying slurry abrasive to the plurality of strand of cutting wires.

8. Device according to claim 5, characterized in that said plurality of strands is wound on opposite driving wheels and said reciprocating movement is generated by rotation of said driving wheels.

9. The apparatus of claim 7 wherein the number of supplies is two and two of the supplies are disposed on different sides of the single crystal silicon rod.

10. The apparatus of claim 1, further comprising a clamp for holding the single crystal silicon rod, and wherein the driver moves the single crystal silicon rod by driving the clamp.