JP4283919B2 - Substrate transfer method, substrate transfer machine, and substrate processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate transfer method , a substrate transfer machine, and a substrate processing apparatus for transferring a substrate such as a wafer or a glass substrate by a substrate transfer machine in semiconductor manufacturing, and in particular, on a substrate mounting surface of a boat or a cassette. A substrate transfer method , a substrate transfer machine, and a substrate transfer device for controlling the extraction of the substrate holder after confirming whether the substrate is separated from or in close contact with the substrate holder holding the substrate The present invention relates to a substrate processing apparatus .
[0002]
[Prior art]
A wafer transfer machine used in a semiconductor manufacturing apparatus will be described with reference to FIG. The wafer transfer device 10 has an elevating mechanism (not shown). A slide mechanism 12 is rotatably provided on an elevating platform 11 of the elevating mechanism, and a chucking head 13 slides horizontally on the slide mechanism 12. It is possible. The chucking head 13 is provided with tweezers 14 for holding the wafer 1 in a plurality of stages (five stages in the illustrated example) in the vertical direction. The wafer transfer device 10 has a wafer vacuum suction mechanism (not shown) for vacuum-sucking the wafer 1, and a suction hole (not shown) of the wafer vacuum suction mechanism is opened on the upper surface of the tweezer 14. ing.
[0003]
The wafer transfer operation by the wafer transfer machine 10 will be described. The lifting mechanism 11 is moved up and down by the lifting mechanism and the slide mechanism 12 is rotated to move the chucking head 13 to the cassette stocker 15 in front of the position of the wafer 1 to be transferred. 13 is advanced and the tweezer 14 is inserted into the cassette 16. Next, the chucking head 13 is lifted slightly, the wafer 1 is lifted by the tweezers 14 and held by vacuum suction, and then the chucking head 13 is moved backward to take out the wafer 1 to be transferred from the cassette 16.
[0004]
Next, the slide mechanism 12 is rotated by 180 °, the chucking head 13 is opposed to the boat 17, the chucking head 13 is moved up and down by the lifting and lowering of the lifting platform 11, and the chucking head 13 is moved to the wafer transfer position of the boat 17. Move forward. Further, the chucking head 13 is advanced, the wafer 1 held by the tweezer 14 is inserted into the boat 17, the vacuum suction is released, the chucking head 13 is slightly lowered, and the wafer 1 is transferred to the boat 17. The chucking head 13 is moved backward. Thereby, one wafer transfer operation from the cassette stocker 15 to the boat 17 is completed. By repeating this transfer operation, a desired number of wafers 1 can be transferred from the cassette stocker 15 to the boat 17. Further, the transfer of the wafer 1 from the boat 17 to the cassette stocker 15 is performed in the reverse order of the above operation.
[0005]
[Problems to be solved by the invention]
By the way, when the wafer 1 is transferred on the wafer transfer surface such as the slits and slots in the boat 17 and the cassette 16 by the wafer transfer device 10, the wafer 1 is warped. There was a possibility that the tweezers 14 would not adhere to each other. If the chucking head 13 is pulled back in this close contact state, the wafer 1 is dragged out. Therefore, the boat 17 is dragged down or the wafer 1 is left on the tweezers 14 while the wafer 1 is placed on the boat 17 or the cassette 16. However, there is a possibility that an accident such as breakage of the wafer 1 and the tweezer 14 may occur. In order to prevent such an accident, the operator needs to adjust the wafer suction pressure by the wafer vacuum suction mechanism. However, this adjustment operation is very difficult, and the wafer 1 and the tweezer 14 are completely brought into close contact with each other. It was difficult to prevent.
[0006]
The object of the present invention is to solve the above-mentioned problems of the prior art, and it is possible to confirm whether or not the substrate and the substrate holding part are separated when the substrate is transferred, thereby preventing the substrate from being damaged. An object of the present invention is to provide a method for transferring a substrate.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the substrate transfer method of the present invention transfers a substrate onto a substrate mounting surface of a boat or a cassette by a substrate transfer machine, and then transfers the substrate to the substrate holding unit of the substrate transfer machine. It is characterized in that it is confirmed that the substrate and the substrate holding part are separated by detecting the suction pressure by the substrate vacuum suction mechanism capable of vacuum suction.
[0008]
When the substrate is transferred onto the substrate mounting surface of the boat or the cassette, if the substrate and the substrate holding unit are separated from each other, even if the vacuum pump of the substrate vacuum suction mechanism is operated, the substrate and the substrate holding unit Since the atmospheric gas is sucked through the gap, the adsorption pressure (detected by the pressure sensor or the like) of the substrate vacuum adsorption mechanism is not in a vacuum (low pressure) state, and the substrate and the substrate holder are separated from each other. I can confirm. On the other hand, when the substrate and the substrate holding part are in close contact, if the substrate vacuum suction mechanism sucks, the suction pressure of the substrate vacuum suction mechanism is in a vacuum (low pressure) state, and the substrate and the substrate holding part are not separated. I can confirm.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. The substrate transfer method according to the present invention is used for transferring and transporting substrates (semiconductor wafers, glass substrates for LCDs, etc.) in various substrate processing apparatuses or semiconductor manufacturing apparatuses such as CVD apparatuses, diffusion apparatuses, and oxidation apparatuses. It can be used. 1 and 2 show an embodiment of a substrate transfer method according to the present invention, and a transfer operation when a wafer 1 as a substrate is transferred to a cassette (or boat) 3 by a wafer transfer device 2. It is explanatory drawing explaining these.
[0010]
As shown in the figure, the wafer transfer machine 2 is provided with tweezers 4 as substrate holding portions in five stages in the vertical direction, and the wafer 1 is held on each tweezer 4 by vacuum suction by a wafer vacuum suction mechanism. Can be transported. A suction path 5 is formed in each tweezer 4, and one end side of the suction path 5 opens to the upper surface of the tweezer 4 to form a suction hole. Further, the other end side of each suction path 5 is communicated with a pipe 6, and these pipes 6 are assembled into a pipe 7 and connected to a vacuum pump (not shown). Each pipe 6 is provided with a vacuum sensor (adsorption sensor) 8 and an electromagnetic valve 9. Further, the wafer transfer device 2 is provided with control means (not shown) for controlling the movement amount, the operation of the vacuum pump, the opening and closing of the electromagnetic valve 9 and the like. The vacuum sensor 8 detects the pressure in each pipe 6, and when the detected pressure is below a predetermined pressure (in a vacuum state), the ON signal is sent to the control means as a detection signal. Entered. 1 and 2, the vacuum sensor 8 is shown only in the pipe 6 for the uppermost and lowermost tweezers 4.
[0011]
The vacuum pump of the wafer vacuum suction mechanism is kept in an operating state, the electromagnetic valve 9 is opened, the wafer 1 is vacuum-sucked and held on the tweezer 4 and transferred to the cassette 3, and the tweezer 4 is inserted into the cassette 3. . Next, as shown in FIG. 1A, all the solenoid valves 9 are closed to stop the vacuum suction of all the tweezers 4, and the tweezers 4 are slightly lowered to transfer each wafer 1 to the target slot of the cassette 3. .
[0012]
After the wafer transfer, the tweezers 4 are extracted from the cassette 3. Before that, the operation of confirming whether or not the respective wafers 1 and the tweezers 4 are separated is performed. In this embodiment, this confirmation operation is performed one by one from the lowermost tweezer 4 to the uppermost tweezer 4 in order. That is, first, as shown in FIG. 1B, only the solenoid valve 9 of the pipe 6 communicating with the suction path 5 of the lowermost tweezer 4 is opened, and only the lowermost tweezer 4 is brought into a vacuum suction operation state. After maintaining this state for a predetermined time, the ON / OFF state of the vacuum sensor 8 is detected. If the wafer 1 and the tweezer 4 are separated from each other, the pressure in the pipe 6 does not decrease, and the vacuum sensor 8 is in an OFF state. On the other hand, if the wafer 1 and the tweezer 4 are in close contact, the pressure in the pipe 6 is The vacuum sensor 8 is turned on. Therefore, if all the vacuum sensors 8 are in the OFF state, it can be determined that the lowermost tweezer 4 that is the current confirmation target tweezer and the wafer 1 are reliably separated from each other, and the second stage tweezer 4 from the bottom. Move on to confirmation.
[0013]
In this case as well, as shown in FIG. 1C, only the electromagnetic valve 9 corresponding to the tweezer 4 in the second stage from the bottom is opened, and all the vacuum sensors 8 are in the OFF state. By detecting, it is confirmed that the tweezers 4 in the second stage from the bottom is away from the wafer 1. Thus, the confirmation operation is performed one by one up to the topmost tweezers 4, and after confirming that all the tweezers 4 are separated from the wafer 1, the wafer transfer operation is normal by removing the tweezers 4 from the cassette 3. (FIG. 1 (d)).
[0014]
However, even when the wafer 1 is transferred to the slot of the cassette 3, as shown in FIG. 2A, there is a case where the wafer 1 is warped and the wafer 1 and the tweezer 4 are in close contact without being separated. is there. In such a case, when the suction pressure confirmation operation by the wafer vacuum suction mechanism is performed, the vacuum sensor 8 for the tweezer 4 to which the wafer 1 is in close contact is turned on, so that the wafer 1 and the tweezer 4 are separated. I can confirm that it is not. Therefore, when any one of the vacuum sensors 8 is in the ON state, a warning to that effect is issued, all the solenoid valves 9 are opened, all the tweezers 4 are brought into the vacuum suction operation state, and the tweezers 4 are slightly raised. All the wafers 1 are scooped up from the slots and held, and the wafer transfer operation is stopped (FIG. 2B).
[0015]
As described above, after the wafer 1 is placed on the cassette or the like from the tweezer 4 and before the tweezer 4 is pulled back to the original position, it is confirmed whether or not the wafer 1 and the tweezer 4 are separated. Since the wafer transfer operation was stopped urgently, the wafer 1 was damaged by removing the tweezer 4 from the cassette or the like while holding the wafer 1 on the tweezer 4 or taking the wafer into the cassette or the like. Accidents such as doing can be prevented in advance.
[0016]
In addition, after the wafer 1 is transferred, the wafer 1 is peeled off from the tweezer 4 by using a wafer vacuum suction mechanism that vacuum-sucks the wafer 1 to the tweezer 4. In a wafer transfer machine having an adsorption mechanism, it is not necessary to provide a detection means for confirming wafer peeling, and can be easily implemented.
[0017]
In the above-described embodiment, it is confirmed that the wafer 1 is separated from the tweezers 4 with respect to all the tweezers 4. However, the wafers 1 are loaded from the storage data of the wafers stored in a cassette or the like. For the tweezers 4 known not to exist, the peeling confirmation operation after the transfer may be omitted. In the above embodiment, a tweezer is used as the substrate holding unit, but a substrate transport plate or the like may be used.
[0018]
【The invention's effect】
As described above in detail, according to the present invention, after the substrate is transferred to the cassette or the like, the substrate and the substrate holding unit are detected by detecting the suction pressure by the substrate vacuum suction mechanism that can vacuum-suck the substrate to the substrate holding unit. Because it is configured to confirm that the board is separated from the board, it is possible to prevent damage to the board and the board holding part due to the close contact between the board and the board holding part, and improve the safety and reliability of the board transfer operation. can do.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a substrate transfer method according to the present invention, and is an explanatory view for explaining a transfer operation when a wafer is transferred to a cassette or the like by a wafer transfer machine.
FIG. 2 shows an embodiment of a substrate transfer method according to the present invention, and is an explanatory view for explaining a transfer operation when a wafer is transferred to a cassette or the like by a wafer transfer machine.
FIG. 3 is a schematic configuration diagram for explaining a wafer transfer method by a conventional wafer transfer machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wafer 2 Wafer transfer machine 3 Cassette 4 Tweezer 5 Suction path 6 Piping 7 Piping 8 Vacuum sensor 9 Solenoid valve

Claims (8)

  The vacuum suction operation state of the substrate placed on the substrate holding unit of the substrate transfer machine is stopped by a substrate vacuum suction mechanism capable of vacuum suction, and the substrate holding unit is lowered to place the substrate on the substrate of the boat or cassette. After transferring on the mounting surface, by detecting the suction pressure as the vacuum suction operation state again by the substrate vacuum suction mechanism, it is confirmed whether the substrate and the substrate holder are separated or in close contact with each other, 2. A substrate transfer method according to claim 1, wherein the substrate holding unit is controlled to be extracted from the boat or the cassette based on a confirmation result.   The vacuum suction operation state of the substrate placed on the substrate holding unit of the substrate transfer machine is stopped by a substrate vacuum suction mechanism capable of vacuum suction, and the substrate holding unit is lowered to place the substrate on the substrate of the boat or cassette. After transferring on the mounting surface, by detecting the adsorption pressure as the vacuum adsorption operation state again by the substrate vacuum adsorption mechanism, confirm whether the substrate and the substrate holding part are separated or in close contact, A substrate transfer machine comprising control means for controlling the extraction of the substrate holding part from the boat or the cassette based on a confirmation result.   The substrate transfer machine according to claim 2, wherein the substrate holding unit is a tweezer or a substrate transport plate.   The vacuum suction operation state of the substrate placed on the substrate holding unit of the substrate transfer machine is stopped by a substrate vacuum suction mechanism capable of vacuum suction, and the substrate holding unit is lowered to place the substrate on the substrate of the boat or cassette. After transferring on the mounting surface, by detecting the suction pressure as the vacuum suction operation state again by the substrate vacuum suction mechanism, it is confirmed whether the substrate and the substrate holder are separated or in close contact with each other, A substrate processing apparatus comprising a substrate transfer machine having a control means for controlling the extraction of the substrate holding unit from the boat or the cassette based on a confirmation result. Check whether the substrate and the substrate holding part are separated or in close contact,
When the substrate and the substrate holding part are separated, the substrate holding part is extracted from the boat or the cassette,
5. The substrate processing apparatus according to claim 4, wherein when the substrate and the substrate holding part are in close contact with each other, a warning is issued and the substrate holding part is raised to hold and stop the substrate. When having a plurality of the substrate holding portion,
When all the substrate holding parts are separated from the substrate, the substrate holding part is extracted from the boat or the cassette,
6. The substrate processing apparatus according to claim 4, wherein, when at least one substrate holding unit is in close contact with the substrate, the substrate holding unit is raised to hold and stop the substrate.   The substrate processing apparatus according to claim 4, wherein it is not confirmed whether the substrate and the substrate holding unit are separated from each other or are in close contact with each other with respect to the substrate holding unit on which the substrate is not placed. .   The substrate processing apparatus according to claim 4, wherein the substrate holding unit is a tweezer or a substrate transport plate.

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