JP2011077288A - Carrying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carrying device capable of suppressing deterioration in carrying precision even if a carrying speed is increased. <P>SOLUTION: The carrying device includes: a carrying arm 16 configured to expand and contract, and swivel; a pick 17 provided on a top of the carrying arm 16, and mounted with a carrier W; an electrostatic adsorption mechanism 30 including an internal electrode 31 provided in the pick 17, and electrostatically adsorbing the carrier W to the pick 17; a gas discharge mechanism 40 including a gas flow passage 41 formed in the pick 17, and discharging gas to an adsorption surface 42 of the formed W for the pick 17; and a control unit 50 controlling the electrostatic adsorption mechanism 30 and the gas discharge mechanism 40 to cancel the electrostatic adsorption by the electrostatic adsorption mechanism 30, and then carrying out an electrostatic discharge sequence for the carrier W and the pick 17 and the discharge of the gas to the adsorption surface 42 in parallel. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transfer device.

  In manufacturing a semiconductor device, when a wafer is transferred, for example, a transfer device having a transfer arm is used as described in Patent Document 1. A pick is attached to the tip of the transfer arm, and the wafer is placed on the pick and transferred.

JP 2006-351484 A

  However, if the transfer speed of the transfer device is increased to improve the throughput, the wafer placed on the pick is likely to be displaced, and the transfer accuracy is lowered.

  The present invention has been made in view of the above circumstances, and provides a transport device that can suppress a decrease in transport accuracy even when the transport speed is increased.

  In order to solve the above-described problem, a transport apparatus according to a first aspect of the present invention is a transport apparatus that transports a transport body, and is provided at a transport arm configured to be extendable and retractable, and provided at a tip of the transport arm. An electrostatic adsorption mechanism for electrostatically adsorbing the conveyance body to the pick, and a gas provided in the pick, the pick including the pick on which the conveyance body is placed, an internal electrode provided in the pick A gas discharge mechanism that discharges gas to an adsorption surface of the transport body including the flow path and the pick; and the electrostatic adsorption mechanism and the gas discharge mechanism are controlled to perform electrostatic adsorption by the electrostatic adsorption mechanism. And a controller that executes, in parallel, a charge removal sequence for the carrier and the pick and gas discharge to the adsorption surface.

  According to this invention, it is possible to provide a transport apparatus that can suppress a decrease in transport accuracy even when the transport speed is increased.

The top view which shows roughly an example of the semiconductor manufacturing system which can utilize the conveying apparatus which concerns on one Embodiment of this invention The top view which shows roughly the pick of the conveying apparatus which concerns on one Embodiment of this invention Side view of pick of transport apparatus shown in FIG. Timing chart showing an example of the operation of the transport device

  Embodiments of the present invention will be described below with reference to the drawings. Note that common parts are denoted by common reference numerals throughout the drawings.

  FIG. 1 is a plan view schematically showing an example of a semiconductor manufacturing system that can use a transfer apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the semiconductor manufacturing system includes four vacuum processing units 1, 2, 3, and 4 that perform high-temperature processing such as film formation processing. It is provided corresponding to each of the four sides of the transfer chamber 5 having a hexagonal shape. Load lock units 6 and 7 are provided on the other two sides of the transfer chamber 5, respectively. A loading / unloading chamber 8 is provided on the opposite side of the load lock units 6 and 7 to the transfer chamber 5, and a wafer W as an object to be processed is placed on the loading / unloading chamber 8 on the opposite side of the load lock units 6 and 7. Ports 9, 10, and 11 for attaching three FOUP (Front Opening Unified Pod) that can be accommodated are provided. The vacuum processing units 1, 2, 3, and 4 are configured to perform a predetermined vacuum process, for example, a film forming process or an etching process, with a target object placed on a processing plate.

  The vacuum processing units 1 to 4 are connected to the respective sides of the transfer chamber 5 through gate valves G, which are communicated with the transfer chamber 5 by opening the corresponding gate valves G and close the corresponding gate valves G. As a result, the transfer chamber 5 is cut off. The load lock units 6 and 7 are connected to the remaining sides of the transfer chamber 5 via the first gate valve G1 and connected to the loading / unloading chamber 8 via the second gate valve G2. Has been. The load lock chambers 6 and 7 are communicated with the transfer chamber 5 by opening the first gate valve G1, and are shut off from the transfer chamber by closing the first gate valve G1. The second gate valve G2 is opened to communicate with the loading / unloading chamber 8, and the second gate valve G2 is closed to shut off the loading / unloading chamber 8.

  In the transfer chamber 5, a transfer device 12 that loads and unloads the wafer W with respect to the vacuum processing units 1 to 4 and the load lock units 6 and 7 is provided. The transfer device 12 is disposed substantially at the center of the transfer chamber 5, and has two support arms 14a and 14b that support the wafer W at the tip of a rotatable / extensible / retractable portion 13 that can be rotated and extended. These two support arms 14a and 14b are attached to the rotating / extending / contracting portion 13 so as to face opposite directions. The inside of the transfer chamber 5 is maintained at a predetermined degree of vacuum.

  Each of the load lock units 6 and 7 is configured as a vacuum container capable of reducing the inside to a predetermined vacuum level, and is configured to be capable of pressure conversion between the predetermined vacuum level and atmospheric pressure or almost atmospheric pressure. ing. As a result, the environment around the wafer W is mutually converted into the environment inside the transfer chamber 5 and the environment inside the load / unload chamber 8. The load lock units 6 and 7 are each connected to the transfer chamber 5 via the gate valve G1, and are connected to the loading / unloading chamber 8 via the gate valves G2 and G2.

  Shutters (not shown) are provided in the three ports 9, 10, 11 for attaching the FOUP F, which are wafer storage containers in the loading / unloading chamber 8, respectively, and the wafers W are accommodated in these ports 9, 10, 11 or An empty hoop F is directly attached, and when it is attached, the shutter is released to communicate with the carry-in / out chamber 8 while preventing intrusion of outside air. An alignment chamber 15 is provided on the side surface of the loading / unloading chamber 8, and the wafer W is aligned there.

  A transfer device 16 is provided in the carry-in / out chamber 8. The conveyance device 16 is configured to be able to travel on rails 18 provided along the direction in which the FOUPs F are arranged. The transfer device 16 of the present example has a pair of transfer arms 16a and 16b that are arranged to be arranged in two upper and lower stages at different heights. The transfer arms 16a and 16b have an articulated arm structure, and are configured to be able to expand and contract and turn around a rotation axis. Picks 17a and 17b are provided at the tips of the transfer arms 16a and 16b, and the wafer W is placed on the picks 17a and 17b, and between the FOUP F, the load lock units 6 and 7, and the alignment chamber 15. Be transported.

  This vacuum processing system has a process controller 20 composed of a microprocessor (computer) that controls each component, and each component is connected to and controlled by the process controller 20. Also connected to the process controller 20 is a user interface 21 comprising a keyboard for an operator to input commands for managing the vacuum processing system, a display for visualizing and displaying the operating status of the plasma processing apparatus, and the like. ing.

  In addition, the process controller 20 causes each component of the vacuum processing system to execute processing according to a control program for realizing various types of processing executed by the vacuum processing system under the control of the process controller 20 and processing conditions. For example, a storage unit 22 that stores a program for forming a film, a film forming recipe related to film forming processing, a transfer recipe related to wafer transfer, a purge recipe related to pressure adjustment in the load lock chamber, and the like is connected. Such various recipes are stored in a storage medium in the storage unit 22. The storage medium may be a fixed one such as a hard disk or a portable one such as a CD-ROM, DVD, or flash memory. Moreover, you may make it transmit a recipe suitably from another apparatus via a dedicated line, for example.

  2 is a plan view schematically showing the pick 17a (17b) of the transport device 16 according to one embodiment of the present invention, and FIG. 3 is a side view of the pick 17a (17b) shown in FIG.

  As shown in FIGS. 2 and 3, the transfer device 16 includes an electrostatic attraction mechanism 30 that electrostatically attracts the wafer W having the internal electrode 31 in the pick 17a (17b) to the pick 17a (17b), and the pick 17a. The gas discharge mechanism 40 that discharges gas onto the suction surface 42 of the wafer W having the gas flow path 41 in (17b) and the pick 17a (17b), and the electrostatic suction mechanism 30 and the gas discharge mechanism 40 are controlled. And a control unit 50.

  The pick 17a (17b) of this example is made of a dielectric. Examples of the dielectric include silicon carbide ceramic and aluminum nitride ceramic.

  The electrostatic attraction mechanism 30 of this example includes the above-described internal electrode 31 provided in the pick 17a (17b), a voltage variable positive power source 32 that applies a positive voltage to the internal electrode 31, and a negative voltage to the internal electrode 31. The voltage variable negative power source 33 for applying the voltage of V and the switch 34 for selecting whether the internal electrode 31 is connected to the voltage variable positive power source 32 or the voltage variable negative power source 33, or the positive / negative voltage can be switched. Consists of a variable power supply.

  The gas discharge mechanism 40 of this example includes a gas flow path 41 provided in the pick 17a (17b), a gas supply source 43 for supplying a gas, for example, an inert gas, into the gas flow path 41, and a gas supply source. 43 and a variable flow rate valve 44 provided between the gas flow path 41 and the gas flow path 41.

  The control unit 50 of this example controls the voltage of the voltage variable positive power supply 32, the voltage of the voltage variable negative power supply 33, and the switch 34 of the electrostatic adsorption mechanism 30 based on an instruction from the process controller 20, for example. To do. At the same time, the flow rate of the flow rate variable valve 44 of the gas discharge mechanism 40 is controlled.

  Next, operations up to the electrostatic chucking, chucking release, and charge removal of the wafer W by the transfer device 16 will be described.

  FIG. 4 is a timing chart showing an example of the operation of the transport device 16. Operation control according to this timing chart is performed by the control unit 50.

  As shown in FIG. 4, at time t0, the wafer W is placed on the pick 17a (17b) (wafer placement). Next, at time t1, a positive voltage is applied from the voltage variable positive power source 32 or a negative voltage from the voltage variable negative power source 33 to the internal electrode 31 to start electrostatic adsorption. FIG. 4 shows an example in which a negative voltage is applied from the voltage variable negative power source 33 to the internal electrode 31. The transfer device 16 transfers the wafer W to the transfer destination while electrostatically attracting the wafer W to the pick 17a (17b).

  When it arrives at or approaches the transport destination, the static elimination sequence is started as shown at time t2. At the same time, gas discharge is started using the gas discharge mechanism 40. In the static elimination sequence of this example, a positive voltage from the voltage variable positive power source 32 or a negative voltage from the voltage variable negative power source 33 is alternately applied to the internal electrode 31 of the electrostatic adsorption mechanism 30 and the voltage level is sequentially changed. Give while lowering. In this example, since a negative voltage is applied to the internal electrode 31 during electrostatic attraction, in the static elimination sequence, first, the positive voltage + V1 is applied to the internal electrode 31 in a pulse shape. Next, the negative voltage −V2 is applied to the internal electrode 31 in a pulse shape. Next, a positive voltage + V3 is applied to the internal electrode 31 in a pulsed manner, and a negative voltage −V4 is applied to the internal electrode 31 in a pulsed manner.

  In addition, the absolute value of the voltage is | + V1 |> | −V2 |> | + V3 |> | −V4 |, and the voltage level is gradually lowered while finally decreasing the voltage to zero.

  In this way, by gradually lowering the voltage level and finally reducing the voltage to zero, the charge accumulated in the pick 17a (17b) is removed when the voltage is applied to the internal electrode 31 in the static elimination sequence. Can do. Thereby, the adsorption | suction force with respect to the wafer W of the pick 17a (17b) can be eliminated.

Furthermore, in this example, it is assumed that the suction force of the pick 17a (17b) to the wafer W cannot be eliminated by only the above-described static elimination sequence. For example, an inert gas, specifically nitrogen gas (N ₂ gas) is discharged. Thus, the wafer W that has been electrostatically attracted to the pick 17a (17b) can be more easily separated from the pick 17a (17b).

  As described above, according to the transfer device 16 according to the embodiment, the wafer W is transferred by being electrostatically attracted to the pick 17a (17b) during transfer of the wafer W. Therefore, even if the transfer speed of the transfer device 16 is increased. Since the wafer W can be prevented from shifting, a decrease in the conveyance accuracy can be suppressed.

  Further, before the wafer W is detached from the pick 17a (17b), the electrostatic attraction by the electrostatic attraction mechanism 30 is released, and then the static elimination sequence for the wafer W and the pick 17a (17b) and the gas to the attraction surface 42 are released. The discharge is executed in parallel. For this reason, when the wafer W is detached, it is possible to suppress the wafer W and the pick 17a (17b) from being adsorbed, and it is possible to suppress the deviation of the wafer W at the time of separation.

  Therefore, according to the transfer device 16 according to the embodiment, the wafer W can be prevented from being displaced not only during the transfer of the wafer W but also when the wafer W is detached, and a decrease in transfer accuracy can be further suppressed. The advantage that can be obtained.

  The present invention has been described according to the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the invention. In the embodiment of the present invention, the above-described embodiment is not the only embodiment.

  For example, in the above-described embodiment, only electrostatic adsorption is used, but a vacuum adsorption mechanism for vacuum-adsorbing the wafer W to the pick 17a (17b) is further provided in the pick 17a (17b), and electrostatic adsorption is performed. And vacuum adsorption can be used in combination.

  Further, when electrostatic adsorption and vacuum adsorption are used in combination, the adsorption immediately after placing the wafer W on the pick 17a (17b) is electrostatic adsorption, and the adsorption just before the wafer W is detached from the pick 17a (17b). Is preferably vacuum suction. In this case, the wafer W is vacuum-adsorbed to the pick 17a (17b) after the neutralization sequence and gas discharge are completed.

Further, the vacuum adsorption can be performed using the gas flow path 41 of the processing gas discharge mechanism 40. For example, after the discharge of the gas from the gas flow path 41 is completed, the connection destination of the gas flow path 41 is switched from the gas supply source 43 to the exhaust device to exhaust the gas flow path 41. Thereby, the wafer W can be vacuum-sucked to the pick 17a (17b) through the gas flow path 41 whose pressure has been reduced.
In addition, the present invention can be modified as appropriate without departing from the spirit of the present invention.

  1-4; Vacuum processing unit, 5; Transfer chamber, 6, 7; Load lock unit, 8; Loading / unloading chamber, 12, 16; Transfer device, 20; Process controller, 30; Electrostatic adsorption mechanism, 40; Mechanism, 50; control unit

Claims (4)

A transport device for transporting a transport body,
A transfer arm configured to be extendable and rotatable, and
A pick provided at a tip of the transfer arm, on which the transfer body is placed;
An electrostatic adsorption mechanism that includes an internal electrode provided in the pick, and that electrostatically attracts the carrier to the pick;
A gas discharge mechanism that includes a gas flow path provided in the pick, and discharges gas onto an adsorption surface of the carrier with the pick;
After controlling the electrostatic adsorption mechanism and the gas discharge mechanism and canceling the electrostatic adsorption by the electrostatic adsorption mechanism, the charge removal sequence for the carrier and the pick and the discharge of the gas to the adsorption surface are performed in parallel. A control unit to be executed
A conveying apparatus comprising:   The transport apparatus according to claim 1, wherein the static elimination sequence is to apply positive and negative voltages to the internal electrode of the electrostatic adsorption mechanism alternately while sequentially decreasing the voltage level.   The transport apparatus according to claim 1, wherein the gas is an inert gas. A vacuum suction mechanism provided in the pick for vacuum-sucking the carrier to the pick;
4. The transport apparatus according to claim 1, wherein the transport body is made to suck the pick vacuum after completion of the charge removal sequence and the discharge of the gas. 5.

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