JP4229406B2 - Conveying apparatus, grinding apparatus using the same, and conveying method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transport apparatus for grinding a workpiece such as a semiconductor wafer, a grinding apparatus using the transport apparatus, and a transport method.
[0002]
[Prior art]
In order to grind the surface of the semiconductor wafer, for example, a grinding apparatus as shown in FIG. 3 is used. In this grinding apparatus, first, the semiconductor wafer W is removed from the cassette 1 containing a plurality of semiconductor wafers W by the loading / unloading means 2. While carrying out one sheet at a time, it is conveyed onto the first standby table 3 and centered. Next, the semiconductor wafer on the first standby table 3 is sucked by the first transfer means 4 having a turning arm, transferred onto the chuck table 6 of the turntable 5 and sucked and held.
Thereafter, the turntable 5 is rotated so that the chuck table 6 is positioned under the rotating grindstone of the grinding means 7 and the semiconductor wafer surface is ground. In this case, the grinding means 7 includes a rough grinding means 7a and a finish grinding means 7b arranged side by side, and finish grinding after finishing the rough grinding.
After grinding, the turntable 5 is rotated and indexed to the carry-out position (transfer position), and the ground surface of the ground semiconductor wafer is cleaned by the cleaning means 8 while being held on the chuck table 6. After this cleaning, the semiconductor wafer on the chuck table 6 is sucked and transferred to the spinner cleaning means 10 by the second transfer means 9 having the same configuration as the first transfer means 4.
After spin cleaning and spin drying by the spinner cleaning means 10, they are sucked by the second transport means 9 and transported onto the second standby table 11, and finally sucked by the carry-in / out means 2 and stored in the cassette 1. Is housed in. This completes one cycle of the grinding process, and this cycle is repeated continuously with timing.
[0003]
[Problems to be solved by the invention]
In the above grinding process, contamination (cutting chips) is generated during grinding by the grinding means 7, and this contamination is not only mixed in the grinding liquid and adheres to the upper surface of the semiconductor wafer, but also a part of the outer periphery of the semiconductor wafer. Then, it goes around to the lower surface side through a slight gap with the chuck table 6 and is sucked into the chuck table 6.
After the grinding is completed, the upper surface (grind surface) of the semiconductor wafer is cleaned by the cleaning means 8, so that the contaminants adhering to the upper surface are removed, but the contaminants that have gone around to the lower surface side remain without being removed.
When the semiconductor wafer is adsorbed by the second transfer means 9 after the wafer cleaning, water is ejected from the inside of the chuck table 6 to lift and release the semiconductor wafer. The contamination sucked into the chuck table 6 is also Contrary to the above, the contamination is blown from the outer peripheral portion of the semiconductor wafer to the upper surface side, and is sucked into the suction pad of the second transfer means 9.
For this reason, not only the suction pad surface of the second transport means 9 is soiled, but also dirt is deposited in the vacuum piping within a relatively short period of time, and the life of the valves, piping, etc. is shortened. In addition, the contaminants adhering to the suction pad surface harden, causing damage to the semiconductor wafer when the semiconductor wafer is sucked and held. Further, when the semiconductor wafer cleaned by the spinner cleaning means 10 is transported to the second standby table, it is contaminated by the dirty suction pad surface. And since it was accommodated in the cassette 1 with dirt adhering, there existed a problem that a wafer crack etc. generate | occur | produced after that.
[0004]
The present invention has been made to solve such a conventional problem, and after cleaning the ground surface of the semiconductor wafer by the cleaning means, the contaminated ground surface accompanying the release of the chuck table when sucked by the second transport means. It is an object of the present invention to provide a conveying apparatus that prevents the wraparound from being squeezed and prevents contamination of the suction pad surface, a grinding apparatus using the conveying apparatus, and a conveying method.
[0005]
[Means for Solving the Problems]
As a technical means for achieving this object, the present invention provides a conveying apparatus comprising at least a holding means for sucking and holding a workpiece and a conveying means for conveying the workpiece held by the holding means. Because
The holding means is composed of a suction part and a shower part disposed on the outer periphery of the suction part and formed in a ring shape. When the workpiece is sucked and held by the suction part, water is supplied from the shower part. The gist of the transport device is to eject the water curtain .
Further, a chuck table for sucking and holding the workpiece, a grinding means for grinding the workpiece held on the chuck table, and a conveyance for carrying the ground workpiece from the chuck table to the next work area. And a grinding apparatus comprising at least the apparatus,
The gist of the present invention is that the above-described transport device is used.
Further, a conveying method using the grinding apparatus,
A grinding step of grinding the workpiece held on the chuck table by a grinding means;
A cleaning step of cleaning the ground surface of the workpiece that has been ground while being held by the chuck table;
A suction step in which the suction part of the holding means comes into contact with and sucks the ground surface of the cleaned workpiece;
In this suction step, water is ejected from the shower portion of the holding means in a state in which the workpiece is sucked to form a water curtain, and water or bubbles for floating the workpiece are ejected from the chuck table. A transfer step of transferring the workpiece from the chuck table to the holding means;
The gist of the present invention is a conveyance method comprising at least a conveyance step of conveying the workpiece transferred in the transfer step to the next work area by the conveyance means.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the same members as those described above are denoted by the same reference numerals.
1 and 2 show an embodiment of a conveying device 21 according to the present invention. A vertical rotating shaft 23 is disposed on a cylindrical base body 22, and conveying means 24 is disposed at the upper end of the vertical rotating shaft 23. A rear end portion is attached so that the conveying means 24 can freely turn in a horizontal plane by forward and reverse rotation of the vertical rotation shaft 23.
[0007]
The conveying means 24 has an arm 25 fixed to the vertical rotating shaft 23, a long hole 25 a is formed in the middle part of the arm 25, and a ring-shaped plate 26 is fixed to the tip part, A plurality (three in the figure) of through holes 26a are arranged at regular intervals along the direction. A cover 27 is attached to the upper portion of the arm 25.
[0008]
Reference numeral 28 denotes a holding unit, which includes a suction part 29 and a shower part 30 disposed on the outer periphery of the suction part 29. The suction part 29 is made of a porous member, is attached to the lower part of a disk-shaped support 31 and communicates with an appropriate suction source. The shower portion 30 is formed in a ring shape along the outer peripheral portion of the support 31, a large number of obliquely downward slit holes 30 a are formed along the circumferential direction, and a connection valve 30 b is provided at an important point. Yes.
[0009]
The support 31 is provided with three support columns 31a extending in the circumferential direction so as to correspond to the through holes 26a of the plate 26. The support members 31a are inserted through the through holes 26a, respectively, and the upper end portions thereof are formed. The holding means 28 is suspended and held at the tip of the conveying means 24 by tightening with the adjusters 32 with slits.
The adjuster 32 adjusts the tightening force of the tightening screw 32a so that the holding means 28 can be moved up and down, and a coil spring 33 is interposed between the support 31 and the arm 25, respectively. That is, an appropriate cushioning property is given to the holding means 28.
[0010]
Inside the vertical rotating shaft 23, an air passage 23a and a water passage 23b are juxtaposed along the axial direction, and these open to the upper surface of the arm 25 through communication holes 25b formed in the arm 25, respectively. Connection valves 34 and 35 are respectively attached to the openings. A cover 36 protects the vertical rotation shaft 23.
[0011]
One end of a vent pipe 37 is connected to the connection valve 34, and the vent pipe 37 passes through the cover 27 and is drawn downward from the long hole 25a of the arm 25, and the other end is the support body. It is connected to a connection valve 31b attached to the center of 31. As a result, the air passage 23 a and the suction part 29 communicate with each other through the air pipe 37.
[0012]
Similarly, one end of a water conduit 38 is connected to the connection valve 35 of the water passage 23b. The water conduit 38 passes through the cover 27 and is drawn downward from the long hole 25a of the arm 25. The other end is connected to the connection valve 30 b of the shower unit 30. Thereby, the water flow path 23b and the shower part 30 are connected via the water flow pipe 38.
[0013]
The transport device 21 configured in this way is used in place of the second transport means 9 in FIG. In this grinding apparatus, the semiconductor wafer W as a workpiece is unloaded from the cassette 1, ground by the grinding means 7, indexed to the unloading position after grinding, and the ground surface is cleaned by the cleaning means 8. Is the same as above.
[0014]
The cleaning process by the cleaning unit 8 is performed in a state where the semiconductor wafer is held on the chuck table 6 in the same manner as described above. After the cleaning, the semiconductor wafer is adsorbed by the suction unit 29 of the holding unit 28 of the transfer device 21 and the above described. It is conveyed to the spinner cleaning means 10.
[0015]
In the suction process of the semiconductor wafer by the suction part 29, water or bubbles for ejecting water from the shower part 30 in a state where the semiconductor wafer is sucked to form a water curtain, and floating the semiconductor wafer from the chuck table 6. A step of transferring the semiconductor wafer from the chuck table 6 to the holding means 28 is performed.
When water is ejected from the shower section 30, water is supplied to the water passage 23b of the vertical rotating shaft 23. This water passes through the water pipe 38 and flows into the shower section 30 and is obliquely formed from the slit hole 30a. This is done by radiating downward. In the suction process by the suction unit 29, the air inside is sucked by a suction source (not shown) disposed in the transport device 21 through the ventilation path 23 a and the ventilation pipe 37 of the vertical rotation shaft 23. Is made by
[0016]
Therefore, in the transfer process from the chuck table 6 to the holding means 28, contamination that tends to go around to the upper surface side by water radiated from the shower unit 30 can be prevented. This contamination is the contamination caused by the grinding process as described above, and when it is cleaned by the post-grinding cleaning means 8, it goes around from the outer peripheral portion of the semiconductor wafer to the lower surface side and is sucked into the chuck table 6 and remains. At the time of release of the semiconductor wafer, it is intended to go around to the upper surface side of the semiconductor wafer together with water ejected from the chuck table 6.
[0017]
In this way, contamination is prevented from adhering to the upper surface of the semiconductor wafer in order to prevent contamination that goes around to the upper surface side of the semiconductor wafer, and contamination is not attracted from the suction surface of the suction part 29 and may be contaminated by contamination. Absent.
[0018]
The semiconductor wafer adsorbed by the suction unit 29 is transported to the spinner cleaning means 10 as described above, subjected to spin cleaning and spin drying, and then again adsorbed by the suction unit 29 of the transport device 21 to obtain a second standby table. 11 is conveyed. At this time, since the suction surface of the suction part 29 is not contaminated by contamination, the upper surface of the semiconductor wafer is not soiled.
[0019]
The semiconductor wafer transferred onto the second standby table 11 is adsorbed by the carry-in / out means 2 and accommodated in the cassette 1. Therefore, the semiconductor wafer accommodated in the cassette 1 is not contaminated by contamination, and an abnormality such as a wafer crack does not occur later.
[0020]
The cleaning means 8 may be used not only for cleaning the upper surface of the semiconductor wafer after grinding, but also for cleaning the upper surface of the chuck table 6 after the semiconductor wafer is transferred to the spinner cleaning means 10. .
The route of the grinding process is not limited to that of the present embodiment. For example, as shown in FIG. 3, another cassette 1 'is placed at the opposite position of the cassette 1, and the semiconductor wafer is finally placed in this cassette 1'. It is possible to make a change such as storing the unprocessed semiconductor wafer in the cassette 1 'and setting the grinding route in two ways at the opposing positions. Furthermore, the cassette mounting location may be a position indicated by a virtual line. These can be appropriately selected depending on the type of workpiece, grinding conditions, and the like.
[0021]
【The invention's effect】
As described above, according to the present invention, in grinding a workpiece such as a semiconductor wafer, the shower unit is provided in the suction unit of the transport device that transports the workpiece cleaned after grinding to the next work area, that is, the spinner cleaning means. In the state where the workpiece is sucked, water is sprayed from the shower unit to prevent contamination that goes around to the upper surface side of the workpiece, so that contamination of the suction unit can be prevented in advance. Therefore, the semiconductor wafer is not contaminated when the semiconductor wafer is adsorbed by the suction unit and transferred to the standby table after the spinner cleaning process. Thereby, there exists an effect which prevents the crack etc. of the semiconductor wafer resulting from contamination.
In addition, the suction path is not contaminated, and it is possible to save the trouble of cleaning the transfer device and to prolong the service life.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an essential part showing an embodiment of a conveying apparatus according to the present invention. FIG. 2 is a top view partially omitted. FIG. 3 is an overall perspective view showing an example of a grinding apparatus.
DESCRIPTION OF SYMBOLS 1 ... Cassette 2 ... Carry-in / out means 3 ... 1st standby table 4 ... 1st conveyance means 5 ... Turntable 6 ... Chuck table 7 ... Grinding means 8 ... Cleaning means 9 ... 2nd conveyance means 10 ... Spinner washing means DESCRIPTION OF SYMBOLS 11 ... 2nd standby table 21 ... Conveying device 22 ... Base | substrate 23 ... Vertical rotating shaft 24 ... Conveying means 25 ... Arm 26 ... Plate 27 ... Cover 28 ... Holding means 29 ... Suction part 30 ... Shower part 31 ... Support body 32 ... Adjuster 33 ... Coil springs 34, 35 ... Connection valve 36 ... Cover 37 ... Vent pipe 38 ... Water pipe

Claims (3)

A conveying device comprising at least holding means for sucking and holding a workpiece and conveying means for conveying the workpiece held by the holding means,
Said holding means comprises a suction unit is disposed on the outer periphery of the suction unit is composed of a shower unit which is formed in a ring shape, when sucking and holding the workpiece by the suction unit, the water from the shower unit A transfer device that forms a water curtain by jetting . A chuck table for sucking and holding the workpiece, a grinding means for grinding the workpiece held on the chuck table, a conveying device for carrying the ground workpiece from the chuck table to the next work area, and In a grinding device comprising at least
Grinding device the transport device, characterized in that the conveying apparatus according to claim 1 Symbol placement. It is a conveyance method in the grinding device according to claim 2 ,
A grinding step of grinding the workpiece held on the chuck table by a grinding means;
A cleaning step of cleaning the ground surface of the workpiece that has been ground while being held by the chuck table;
A suction step in which the suction part of the holding means comes into contact with and sucks the ground surface of the cleaned workpiece;
In this suction step, water is ejected from the shower portion of the holding means in a state in which the workpiece is sucked to form a water curtain, and water or bubbles for floating the workpiece are ejected from the chuck table. A transfer step of transferring the workpiece from the chuck table to the holding means;
A transfer method comprising at least a transfer step of transferring the workpiece transferred in the transfer step to the next work area by the transfer means.

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