Device, wire cutting equipment and method for repairing cutting lines

Abstract

An embodiment of the present invention discloses a device for repairing a cutting wire, characterized in that the device comprises: a cleaning module for cleaning the cutting wire segment that leaves the wire cutting area during wire cutting; a repair module for repairing the cleaned cutting wire segment by means of chemical vapor deposition.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of wafer processing technology, and in particular to a device, wire cutting equipment and method for repairing a cutting line. Background Art

[0002] As the carrier of semiconductor circuit manufacturing process, the quality of silicon wafer has a decisive influence on the formation of integrated circuits. At present, the main processes in the initial forming process of silicon wafers include: silicon rod cutting, physical and chemical grinding, chemical etching, physical and chemical polishing, etc. Silicon rod cutting is one of the core processes in the silicon wafer forming process, which mainly includes multi-wire slurry (SiC) cutting and inner circle cutting. The mainstream process currently used is multi-wire cutting, because compared with inner circle cutting, multi-wire cutting has the advantages of high efficiency, good quality and high wafer output rate.

[0003] Multi-wire cutting is an advanced slicing technology. Its principle is to wind the cutting wires sequentially into guide grooves formed on the circumferential surface of the spool at intervals to form an array of cutting wire segments. During the cutting operation of the silicon rod, the mortar is sprayed onto the cutting wire at a certain pressure, and the cutting wire and the mortar are reciprocated to cut the silicon rod. In addition to cutting the silicon rod, the mortar also plays the role of lubricating and cleaning the debris generated by cutting, and can also take away the heat generated by cutting.

[0004] During the online cutting process, the cutting wire will be worn by the mortar and silicon rods, and in severe cases, it may break. Since the cutting wire is a single wire that is wound on the spool multiple times, once it breaks at one point, the entire cutting wire cannot be used any longer, and the cutting operation must be interrupted by stopping. The problem of wire breakage can be solved by replacing the wire or repairing the broken wire. However, no matter which method is used, it is inevitable to realign the wire, that is, to realign the new cutting wire or the repaired cutting wire to the position where the last wire cutting operation was interrupted. If it is not aligned, it will seriously affect the flatness of the surface of the cut silicon wafer. Summary of the invention

[0005] In view of this, the embodiments of the present invention hope to propose a device, a wire cutting equipment and a method for repairing a cutting line; the cutting line performing a wire cutting operation can be repaired during the cutting operation to prevent the wire from breaking during the cutting operation, thereby avoiding the situation where the wire breaking and the wire replacement affect the surface flatness of the cut silicon wafer.

[0006] The technical solution of the embodiment of the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a device for repairing a cutting line, the device comprising:

[0008] A cleaning module, which is used to clean the cutting line segments leaving the wire cutting area during the wire cutting process;

[0009] A repair module, which is used to repair the cleaned cutting line segments by means of vapor deposition.

[0010] In a second aspect, an embodiment of the present invention provides a wire cutting device, which includes a device for repairing a cutting wire according to the first aspect.

[0011] In a third aspect, an embodiment of the present invention provides a wire cutting method, which is executed by using the wire cutting device according to the second aspect. Wherein, the method includes:

[0012] Cleaning the cutting line segments leaving the wire cutting area during the wire cutting process;

[0013] Repairing the cleaned cutting line segments by means of vapor deposition.

[0014] The embodiment of the present invention provides a device, a wire cutting device and a method for repairing a cutting wire. The device includes a cleaning module and a repair module. After the cleaning module cleans the cutting line segments leaving the wire cutting area to remove impurities on their surfaces, the repair module repairs the cleaned cutting line segments by means of vapor deposition, thereby achieving the purpose of repairing the cutting wire while performing wire cutting operations, avoiding wire breakage during wire cutting, and further avoiding the situation that wire breakage and wire replacement affect the flatness of the surface of the cut silicon wafer. Description of the Drawings

[0015] Figure 1 It is a schematic diagram of a conventional wire cutting device provided by an embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of another conventional wire cutting device provided by an embodiment of the present invention.

[0017] Figure 3 It is a schematic diagram of a wire cutting device provided by an embodiment of the present invention.

[0018] Figure 4 It is a schematic diagram of a wire cutting device provided by another embodiment of the present invention.

[0019] Figure 5 It is a flowchart of the wire cutting method provided by an embodiment of the present invention. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] See Figure 1 , which shows a schematic diagram of a conventional wire cutting device 1. Understandably, Figure 1 the structure shown is only for illustrative purposes of the principle, and it does not mean that those skilled in the art will not add or subtract components based on the specific implementation status on Figure 1 the shown composition structure. The embodiments of the present invention do not make specific limitations in this regard. As Figure 1 shown, the wire cutting device 1 may include a wire cutting unit 11 and a carrying unit 12; the wire cutting unit 11 may be placed below the carrying unit 12 in the vertical direction as Figure 1 shown in some examples, or may be placed above the carrying unit 12 in the vertical direction as Figure 2 shown in some examples. Specifically, the wire cutting unit 11 may include a plurality of wire spools 111 and a cutting wire 112, and the cutting wire 112 is wound around the wire spools 111 to form an array composed of mutually parallel cutting line segments; in Figure 1 , the number of wire spools 111 is taken as an example of 2, and the reciprocating movement directions of the wire spools 111 and the cutting wire 112 towards and away from the carrying unit 12 are as Figure 1 shown by the solid arrows in, and the reciprocating movement speed can be exemplarily 10 m / s to 15 m / s. The carrying unit 12 is used to load and fix the silicon rod 2 to be processed. In the examples shown in Figure 1 and Figure 2 , the carrying unit 12 may include a base 121 and an intermediate member 122, and the intermediate member 122 can fix the silicon rod 2 to be processed to the base 121. For example, the silicon rod to be processed can be fixed to the lower surface ( Figure 1 ) or the upper surface ( Figure 2 ) of the base by resin bonding on its circumferential surface so as to be fixed to the base.

[0022] For Figure 1 , 2 in the wire cutting device 1 shown, the wire cutting unit 11 or the carrying unit 12 can be moved to make the cutting wire 112 and the silicon rod 2 to be processed move towards each other in the vertical direction. After the cutting wire 112 and the silicon rod 2 to be processed come into contact with each other, the cutting of the silicon rod 2 to be processed is realized by the movement of the cutting wire 112 along its extending direction. In the example shown in Figure 1 , the wire cutting unit 11 can be moved along the direction shown by the black arrow, or the carrying unit 12 can be moved along the direction of the dotted white arrow to realize the movement of the cutting wire 112 and the silicon rod 2 to be processed towards each other in the vertical direction. In the example shown in Figure 2In the illustrated example, the carrier unit 12 can be moved in the direction indicated by the black arrow, or the wire cutting unit 11 can be moved in the direction of the dashed white arrow to achieve the relative movement in the vertical direction between the cutting wire 112 and the silicon rod 2 to be processed. It should be noted that in the embodiment of the present invention, a lifting device (not shown in the figure) is added to realize the movement of the wire cutting unit 11 or the carrier unit 12. Understandably, those skilled in the art can also realize the movement of the wire cutting unit 11 or the carrier unit 12 in other ways according to actual needs and implementation scenarios. It should be pointed out that during wire cutting operation, the diameter of the wire spool is larger than the diameter of the silicon rod, so that the distance between the cutting wire segment arrays on the upper and lower sides of the wire spool is larger than the diameter of the silicon rod. In this way, only the cutting wire segment array on one side of the wire spool will cut the silicon rod, while the cutting wire segment array on the other side of the wire spool will not contact the silicon rod. For Figure 1 example, after the cutting wire leaves the incoming wire wheel IW, it winds around the wire spool 11 and travels around the wire spool 111. Among them, only the cutting wire segment array above the wire spool 111 will cut the silicon wafer. Therefore, the wire cutting area CA is also located on the upper side of the wire spool. The cutting wire segment leaving the wire cutting area CA will travel to the lower side of the wire spool. After traveling a certain distance without load, it winds around the wire spool 111 again and returns to the upper side of the wire spool and enters the wire cutting area CA again to participate in the cutting operation, and so on until it travels away from the wire spool and is taken up by the take-up wire wheel OW. Similarly, in Figure 2 the embodiment, the wire cutting area CA is located on the lower side of the wire spool. During wire cutting, the cutting wire brings the mortar to the cutting position through reciprocating movement. Therefore, it will be continuously worn by the mortar and the silicon rod, and the cutting wire always bears a certain tension. Considering these factors, the cutting wire may break during the cutting process. As mentioned in the "Background Art" section, if the cutting wire breaks at one place, the entire cutting wire cannot continue to be used and the cutting operation must be interrupted. It is particularly pointed out here that since the entire cutting wire bears a certain tension during wire cutting operation, any part of the cutting wire that has experienced wire cutting operation may break. For example, the break may occur in the cutting area or outside the cutting area, that is to say, the position of the break point is uncertain.

[0023] After a wire break occurs, one solution is to replace the cutting wire, that is, remove the broken wire and replace it with a new one. However, when removing the broken wire, the cutting wire remaining in the half-cut silicon rod may cause damage to the surface of the cut silicon wafer due to factors such as the mortar adhered to it and the accumulation of silicon slag generated by the previous cutting operation. Another solution is wiring, that is, if the wire break position is not in the wire cutting area, the broken cutting wire segment can be reconnected by, for example, tying a knot. However, the knotted segment cannot continue to participate in the cutting operation and can only travel on the spool until the cutting operation ends. Moreover, no matter which of the above two methods is adopted, before restarting the cutting operation, the cutting wire needs to be restored to the position in the silicon rod before the wire break occurred. However, in actual operation, it is very difficult to accurately reposition the cutting wire to this position, which will cause the surface of the silicon wafer cut after the wire cutting operation is restarted to not be in the same plane as the surface of the silicon wafer cut before, and the surface of the silicon wafer cut in this way has poor flatness and cannot meet the product requirements.

[0024] Based on this, the embodiments of the present invention propose a device, a wire cutting device and a method for repairing a cutting wire; it can repair the cutting wire performing the wire cutting operation while the cutting operation is in progress to prevent a wire break from occurring during the cutting operation, and further avoid the situation that the wire break and wire replacement affect the flatness of the surface of the cut silicon wafer.

[0025] See Figure 3 , which shows a device 20 for repairing a cutting wire 112 provided by an embodiment of the present invention. It is characterized in that the device 20 includes:

[0026] A cleaning module 201, which is used to clean the cutting wire segment SS that leaves the wire cutting area CA during the wire cutting process;

[0027] A repair module 202, which is used to repair the cleaned cutting wire segment SS by means of chemical vapor deposition.

[0028] As Figure 3As shown, the device 20 includes a cleaning module 201 and a repair module 202. After the cutting line segment SS that has undergone the wire cutting operation leaves the wire cutting area CA, it continues to leave the cutting area along the advancing direction, and then travels to the cleaning module 201. The cleaning module 201 sprays a cleaning liquid onto the surface of the advancing cutting line segment SS, for example, by spraying, to remove impurities adhering to its surface. The impurities may include, for example, mortar, silicon slag, impurities, etc. After being cleaned, the cutting line segment SS continues to travel to the repair module 202 and is repaired by the repair module 202 by means of vapor deposition while traveling, so as to compensate for the worn amount of the cutting line segment SS, so that it can withstand the tension and / or wear brought by subsequent wire cutting operations without breaking until the end of a wire cutting operation. It should be noted that the method of vapor deposition refers to: using the reaction between gases to deposit a single layer or multiple layers of metal films on the surface of the cutting line segment SS, thereby compensating for the worn amount of the cutting line segment SS.

[0029] An embodiment of the present invention provides a device 20 for repairing a cutting wire 112; the device 20 includes a cleaning module 201 and a repair module 202. After the cleaning module 201 cleans the cutting line segment SS that leaves the wire cutting area CA to remove impurities left on its surface by the previous operation, the repair module 202 repairs the cleaned cutting line segment SS by means of vapor deposition, thereby achieving the purpose of repairing the cutting wire 112 while performing the wire cutting operation, so that the worn cutting line segment after the wire cutting operation can be repaired in time, avoiding wire breakage during the wire cutting process, and further avoiding the situation that wire breakage and wire replacement affect the flatness of the surface of the cut silicon wafer.

[0030] According to a preferred embodiment of the present invention, as Figure 3 shown, the cutting line segment SS that leaves the wire cutting area CA is the cutting line segment SS that leaves the wire spool 111 and has not reached the take-up reel OW.

[0031] Specifically, in the preferred embodiment shown in Figure 3 , the device 20 is arranged downstream of the wire spool 111 along the advancing direction of the cutting wire, and is arranged upstream of the take-up reel OW. In this case, the device 20 repairs the cutting line segment SS that no longer participates in the wire cutting operation and only travels idly, that is, the cutting line segment SS that is no longer wound around the wire spool and has not been wound onto the take-up reel OW. As mentioned above, the entire cutting wire 112 always bears tension during the cutting operation, and the wear degree of the cutting line segment SS that leaves the wire spool 111 is often the largest, so the possibility of wire breakage in this part is also relatively large. Arranging the device 20 downstream of the wire spool 111 not only helps to prevent wire breakage, but also facilitates the transformation of existing wire cutting equipment.

[0032] According to another preferred embodiment of the present invention, as Figure 4 shown, the cutting segment SS leaving the wire cutting area CA is one or more cutting segments SS that are about to enter the wire cutting area CA again.

[0033] Specifically, in the Figure 4 illustrated embodiment, the silicon rod 2 moves downward from above the spool 111 towards the cutting segment array, so the wire cutting area CA is located on the upper side of the spool 111. As Figure 4 shown, the device 20 is arranged between the two spools 111 on the lower side of the spools 111. The cutting segment SS that leaves the wire cutting area CA and travels around the spool 111 from the upper side of the spool 111 to the lower side is first cleaned by the cleaning module 201 of the device 20 after reaching the lower side of the spool 111, then repaired by the repair module 202, and then travels around the other spool 111 again to return to the wire cutting area CA and participate in the wire cutting operation again. That is to say, the cutting segment that has just participated in the wire cutting operation can be repaired immediately, greatly reducing the risk of wire breakage. It can be understood that a part of the cutting segments SS in the cutting segment array can be selected for repair according to the situation, or as Figure 4 shown, all the cutting segments SS can be repaired.

[0034] In order to be able to properly repair the cutting wire, preferably, referring to Figure 3 and Figure 4 , the device 20 further includes: a detection module 203 for obtaining the actual diameter of the cutting segment SS located between the cleaning module 201 and the repair module 202;

[0035] a processing module 204 communicating with the detection module 203 and the repair module 202, the processing module 204 is used to determine the repair amount according to the difference between the target diameter and the actual diameter and send the repair amount to the repair module 202, and the repair module 202 repairs the cutting segment according to the repair amount. Since the wear degree of each part of the cutting wire 112 is not the same, the degree of compensation required is also not the same. By obtaining the actual diameter of the cutting segment SS through the detection module 203 and performing corresponding repairs, the repaired cutting wire can still have a uniform diameter, which is very necessary for the situation where the repaired cutting segment SS still has to participate in the cutting operation, because maintaining the diameter of the cutting wire can ensure that the cut silicon wafer has a uniform thickness and good flatness.

[0036] According to the preferred embodiment of the present invention, referring to Figure 4The device 20 further includes a trimming module 205. The trimming module 205 is used to trim the cut line segment SS repaired by the repair module 202 so that the diameter of the repaired cut line segment SS is the target diameter. When the trimming module 205 is provided, the diameter of the repaired cut line segment SS can be made slightly larger than the target diameter, and then the trimming module 205 can remove the redundant radial part of the cut line segment SS by means such as grinding, so as to finally reach the target diameter. This can better ensure that the cut line segment SS trimmed by the device 20 can consistently have the target diameter.

[0037] Preferably, the vapor deposition method includes a physical deposition method and a chemical deposition method. Among them, the physical deposition method includes a magnetron sputtering method, and the chemical deposition method includes a plasma gas deposition method.

[0038] Further preferably, refer to Figure 3 The repair module includes: a reaction chamber 2021. The cut line segment SS is repaired during the process of traveling through the reaction chamber 2021. Thus, the repair process will not hinder or affect the travel of the cutting wire at all, nor will it hinder or affect the wire cutting operation, effectively preventing wire breakage during the wire cutting operation.

[0039] It should be understood that, as Figure 3 shown, an inlet 2022 for introducing an inert gas and an outlet 2023 for discharging the inert gas can be provided in the reaction chamber 2021. For the magnetron sputtering method, as an example, refer to Figure 3 In the reaction chamber 2022, a magnet 2024 and a copper target 2025 are further provided. By introducing an inert gas into the reaction chamber 2021, copper can be plated on the surface of the cutting wire with a clean surface by the coaxial magnetron sputtering method, so as to achieve the purpose of repairing the cut line segment.

[0040] Refer to Figure 3 The embodiment of the present invention further provides a wire cutting device 3. The wire cutting device 3 includes the device 20 for repairing the cutting wire according to the above.

[0041] Refer to Figure 5 The embodiment of the present invention further provides a wire cutting method. The wire cutting method is executed by using the wire cutting device 3 according to the above. Among them, the method includes:

[0042] S101. Clean the cut line segment that leaves the wire cutting area during the wire cutting process;

[0043] S102. Repair the cleaned cut line segment by a vapor deposition method.

[0044] Preferably, the cutting line segment leaving the wire cutting area is the cutting line segment that has left the wire spool and has not yet reached the wire take-up reel; or,

[0045] the cutting line segment leaving the wire cutting area is one or more cutting line segments that are about to re-enter the wire cutting area.

[0046] It should be noted that: among the technical solutions described in the embodiments of the present invention, any combination can be made without conflict.

[0047] As mentioned above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A device for repairing a cutting line, characterized in that, The device includes: a cleaning module for cleaning the cutting wire segments that leave the wire cutting area during the wire cutting process; a repair module for repairing the cleaned cutting wire segments by means of vapor deposition; wherein, the method of vapor deposition includes a physical deposition method, and the physical deposition method includes a magnetron sputtering method.

2. The device according to claim 1, wherein The cutting wire segments that leave the wire cutting area are the cutting wire segments that leave the wire spool and have not reached the take-up reel.

3. The device according to claim 1, wherein The cutting wire segments that leave the wire cutting area are one or more cutting wire segments that are about to enter the wire cutting area again.

4. The device according to claim 3, wherein The device further includes: a detection module for obtaining the actual diameter of the cutting wire segment located between the cleaning module and the repair module; a processing module in communication with the detection module and the repair module, the processing module for determining the repair amount according to the difference between the target diameter and the actual diameter and sending the repair amount to the repair module, and the repair module repairing the cutting wire segment according to the repair amount.

5. The device according to claim 4, characterized in that The device further includes a trimming module for trimming the cutting wire segment repaired by the repair module so that the diameter of the repaired cutting wire segment is the target diameter.

6. The device according to any one of claims 1 to 5, characterized in that The repair module includes: a reaction chamber, and the cutting wire segment is repaired during the process of traveling through the reaction chamber.

7. A wire cutting device, characterized in that, The wire cutting equipment includes the device for repairing the cutting wire according to any one of claims 1 to 6.

8. A wire cutting method, characterized in that, The wire cutting method is performed by using the wire cutting equipment according to claim 7, wherein the method includes: cleaning the cutting wire segments that leave the wire cutting area during the wire cutting process; repairing the cleaned cutting wire segments by means of vapor deposition.

9. The method according to claim 8, wherein The cutting wire segments that leave the wire cutting area are the cutting wire segments that leave the wire spool and have not reached the take-up reel; or, The cutting wire segments that leave the wire cutting area are one or more cutting wire segments that are about to enter the wire cutting area again.

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