JP2010140975A - Static eliminator for substrate, and method for eliminating static electricity of substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a static electricity elimination control system of a substrate for eliminating static electricity charged on a substrate by friction between the substrate and a carrier, before treating the substrate without reducing the equipment throughput. <P>SOLUTION: Static elimination to a substrate can be performed while the substrate is being conveyed in an EFEM (Equipment Front End Module) 1 by providing a static eliminator 3 and an FFU (Fan Filter Unit) 4 in the EFEM 1, thereby, the static elimination can be performed before treating the substrate without reducing the equipment throughput. Equipment controller 9 confirms an in-EFEM residence time taken until the substrate is conveyed to a treatment chamber 8, and controls the output from the static eliminator 3 and the flow rate of the FFU 4, by which the output from the static eliminator 3 and the flow rate of the FFU 4 can be controlled to complete the static elimination within the in-EFEM residence time, and hence the static elimination can be surely performed before treating the substrate while restricting inverse charging. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate static eliminator and a substrate static eliminator in an apparatus that processes and manufactures a substrate.

  Currently, semiconductor manufacturing processes have problems due to static electricity such as electrostatic attraction (ESA) and electrostatic breakdown (ESD) due to electrostatic force, which causes a reduction in product yield. Yes. In order to solve these problems, it can be said that a control technique for eliminating static electricity on the substrate is very important.

A control method used for static elimination of a conventional substrate, which is a countermeasure against these problems, will be described with reference to FIG.
FIG. 9 is a diagram showing a configuration of a control device used for static elimination of a conventional substrate.

As shown in FIG. 9, an electrode 301 for changing the surface potential of the substrate 101 is provided inside the stage 201 on which the processing substrate 101 is placed. The electrode 301 is connected to a high voltage power supply 401, and the high voltage power supply 401 is connected to a controller 701. Further, a surface potentiometer 501 for measuring the surface potential of the substrate 101 is provided, and a static eliminator 601 is provided above the stage 201. The surface potential meter 501 and the static eliminator 601 are connected to the controller 701. After a desired process is performed on the substrate 101 in the manufacturing apparatus having the stage 201, the surface potential of the substrate 101 is measured by the surface potential meter 501, and the voltage of the electrode 301 and the static eliminator are detected by the controller 701 based on the measurement result. By controlling the output of 601, the surface potential of the substrate 101 was controlled to a predetermined value (see, for example, Patent Document 1).
JP 2000-195934 A

  However, in the method in which the charge amount on the surface of the substrate 101 is measured by the surface potentiometer 501 on the stage 201 in the processing chamber and then the static elimination method is controlled according to the measured value, static electricity is removed only before and after the manufacturing process. I can't. On the other hand, the generation factor of static electricity includes friction between the substrate 101 and the carrier when the substrate transfer robot of the apparatus transfers the substrate 101 from the carrier to the apparatus processing chamber. While it is said that electrostatic breakdown can occur even when charging is 50V, the charge amount due to friction at this time is known to be 700V to 1800V (eigenvalue for each carrier), and the substrate transport before processing is known. It was necessary to take measures against charging the substrate 101 at the stage.

However, if a static elimination step is incorporated before processing, there is a problem that the apparatus throughput is reduced.
The present invention is directed to solving the above-described problems of the prior art, and eliminates the static electricity charged on the substrate due to friction between the substrate and the carrier before the substrate processing without reducing the apparatus throughput. The purpose is to provide a system.

  Note that EFEM is an abbreviation for Equipment Front End Module, and is a front module of a process apparatus. This is the front of the process equipment that processes wafers in a vacuum, and refers to the equipment that transfers wafers between the FOUP and the process equipment described below in a clean environment. In this case, it is a so-called preparation chamber in which the substrate is temporarily held in front of the processing chamber.

  In order to achieve the above object, a substrate static eliminator of the present invention includes a processing chamber that performs a manufacturing process on a substrate, a carrier that stores the substrate before the manufacturing process, and the carrier and the processing chamber. A preparatory chamber provided; a static eliminator disposed in the preparatory chamber; a blower disposed in the preparatory chamber; and a device controller that controls operations of the static eliminator and the blower during a static elimination process. It is characterized by that.

Further, the apparatus controller obtains a staying time of the substrate in the preparation chamber from a vacancy state of the processing chamber, and determines a discharging time of the substrate from the staying time.
In addition, the apparatus controller obtains the stay time of the substrate in the preparation chamber from the availability of the processing chamber, and sets the output of the charge removal apparatus and the air volume of the blower so that the charge removal is completed within the stay time. It is characterized by controlling.

The apparatus controller may reduce the output of the substrate neutralization apparatus to a predetermined value at the end of the neutralization of the substrate.
Furthermore, the substrate static elimination method of the present invention is performed when the substrate is neutralized by a manufacturing apparatus provided with a preparation chamber including a static elimination device and a blower in front of a processing chamber that performs a manufacturing process on the substrate. A step of obtaining a relationship between the output of the static eliminator, the wind force of the blower and the static elimination time, a step of obtaining a residence time of the substrate in the preparation chamber from an empty state of the processing chamber, and within the residence time The step of obtaining the output of the static eliminator and the wind force of the blower that completes static elimination, and the step of performing the static elimination process by controlling the output of the static eliminator and the wind force of the blower to the obtained values. It is characterized by that.

  In addition, the method further includes a step of reducing the output of the static eliminator and the wind force of the blower to a predetermined value after a time necessary for the static eliminator has elapsed.

  As described above, static electricity charged on the substrate due to friction between the substrate and the carrier can be eliminated before the substrate processing without reducing the apparatus throughput.

  As described above, the substrate static eliminator and the substrate static eliminator of the present invention can reduce the device throughput by providing the static eliminator and the FFU in the EFEM, so that the static eliminator can be discharged during the substrate transport in the EFEM. Therefore, it is possible to remove static electricity before processing the substrate. Furthermore, the device controller controls the stay time in the EFEM, which is the time until it is transferred to the processing chamber, and controls the output of the static eliminator and the FFU air volume, so that the static eliminating process is completed within the EFEM residence time. As a result, it is possible to control the output of the static eliminator and the FFU air volume, and it is possible to reliably eliminate static electricity before substrate processing. In addition, by obtaining in advance the static elimination time corresponding to the output of the static elimination device and the FFU air volume, the output of the static elimination device and the FFU air volume in the EFEM can be reduced when the static elimination time for completing static elimination has elapsed. Therefore, static electricity charged on the substrate can be completely removed, and reverse charging can be minimized.

Hereinafter, the board | substrate static elimination system of this invention is demonstrated, referring drawings.
First, an outline of the substrate neutralization system of the present invention will be described. A static eliminator and an FFU (Fan Filter Unit) are mounted on the EFEM portion of the apparatus, and the static elimination is performed at the timing when the substrate in the carrier is transported into the apparatus processing chamber in the EFEM part. With this configuration, the charge can be removed while the substrate is transported in the EFEM, so that the charge can be removed before the substrate processing without reducing the apparatus throughput.

  The control method is as follows. First, when the substrate in the carrier is transported into the apparatus processing chamber, the apparatus controller checks the availability of the processing chamber and determines whether the substrate can be directly input into the processing chamber without waiting in the EFEM.

  When a substrate can be directly loaded into the processing chamber, the static elimination time (residence time in the EFEM) of the substrate is short, so in many manufacturing equipment, the static elimination time is insufficient for the output of the normal static elimination device, and the static electricity on the substrate is completely eliminated. Therefore, when the neutralization time is insufficient for the output of the normal neutralization device, the device controller issues a command to switch the output of the neutralization device to a predetermined value (high output).

  Also, if t1 is the transfer time when the substrate is transferred directly from the carrier to the processing chamber (the EFEM stay time of the substrate), the charge removal device can be completed in a state where the output of the charge removal device is high and within t1. When the static elimination completion time t4 (t4 <t1) has been reached, the output of the static eliminator is switched to a predetermined value (output lower than the normal output) to minimize reverse charging.

When the neutralization cannot be completed within t1 in a state where the output of the static eliminator is high, the FFU wind (air volume) in the EFEM is switched to a predetermined value (strong wind).
The wind power is switched to the normal value and the output of the static eliminator is switched to the minimum value when t3 when the neutralization is completed when the FFU wind is in a strong wind state.

  If the substrate cannot be loaded directly into the processing chamber, the static eliminator remains at its normal output, and when neutralization is completed, the output of the static eliminator is switched to the minimum value when t2 is reached, and the substrate is loaded when the processing chamber is empty. To do.

  As described above, by controlling the output of the static eliminator and the air volume of the FFU from the EFEM stay time and the static elimination time, it is possible to surely eliminate the static electricity before processing the substrate and minimize the reverse charging.

Next, a specific configuration of the substrate neutralization system of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic cross-sectional view showing a configuration of a substrate static eliminator of the present invention.

  As shown in FIG. 1, there is a substrate transport robot 2 inside an EFEM 1 (portion surrounded by a dotted line in FIG. 1) that transports a substrate from a carrier called FOUP to a processing chamber. A static eliminator 3 for neutralizing the charge, and an FFU 4 is provided at the top. The substrate 7 in the carrier 6 installed in the apparatus load port 5 is transferred to the processing chamber 8 by the substrate transfer robot 2. The transfer robot 2, the charge removal device 3, the FFU 4, and the processing chamber 8 are connected to the device controller 9.

  Here, FOUP is an abbreviation of “Front-Opening Unified Pod”, which is a kind of carrier (wafer carrier), and is a so-called front-opening cassette-integrated conveyance / storage box. In this embodiment, the FOUP can store 25 substrates.

  FFU is an abbreviation for “Fan Filter Unit”, which is a fan / filter integrated clean device. Specifically, it is a device for cleaning the inside of the apparatus by sending the wind of a fan through a filter.

  Here, a static eliminator was installed immediately below the FFU. By doing so, the down flow of the FFU promotes ion irradiation to the wafer by the static eliminator, and the static elimination time of the wafer can be shortened.

In the present embodiment, a processing chamber 8 that can store five substrates 7 at a time will be described as an example.
In the manufacturing apparatus having the configuration shown in FIG. 1, while the substrate 7 in the carrier 6 is transferred to the processing chamber 8 by the substrate transfer robot 2, the charge removal of the substrate 7 is performed by the charge removal device 3 in the EFEM 1.

As described above, by removing the charge using the substrate transport time before processing, the charge removal of the substrate 7 can be completed without reducing the apparatus throughput.
Next, the state of static elimination when the above static elimination method is used will be described with reference to FIGS.

  FIG. 3 is a graph showing the relationship between the charge removal time and the charge amount, and is a graph showing the transition of the charge removal time and the substrate charge amount when the charge removal method is used. FIG. 4 is a diagram showing the EFEM stay time of the substrate for each slot position, and the EFEM 1 stay time when the substrate 7 in the carrier 6 is transported to the processing chamber 8 by the substrate transport robot 2 in a certain apparatus ( It is a graph which shows the time which can be neutralized by the static elimination apparatus 3). Here, the measurement conditions are that the neutralizer output is a normal output (applied voltage is pulsed AC ± 7000 V), the FFU wind speed is 0.3 m (0.3 m / s) per second, and the substrate charge is −700 V.

  As shown in FIG. 3, when neutralization is performed under the above conditions, it takes 22 seconds to complete the neutralization. However, if the output of the static eliminator continues after the charge amount reaches 0V, the charge is reversed to the + side.

  FIG. 4 is a graph showing the relationship between the slot position of the substrate and the EFEM residence time. Here, the slot is a unit representing the position of the wafer in the carrier. In this embodiment, since 25 wafers are included in the FOUP, there are 1 to 25 slots, the bottom is 1 slot, and the top is 25 slots. Normally, the substrates are processed in order from the lowest slot number.

  As shown in FIG. 4, the EFEM 1 staying time (the time during which static elimination can be performed by the static elimination device 3) is different for each slot position of the substrate. It is 8 to 9 seconds for 1 to 5 slots, and 38 seconds or more after the 6th slot. This is because whether the substrate 7 in the carrier 6 is directly put into the processing chamber 8 or waits in the EFEM 1 depends on whether the processing chamber 8 is vacant. As described above, in this apparatus, the charge removal time is insufficient in 1 to 5 slots, and reverse charging is performed after 6 slots.

  Here, the charge removal time is insufficient in 1 to 5 slots, and the reverse charging after 6 slots is caused by the fact that up to five substrates in the processing chamber 8 can be stored at a time. In the case of 1 to 5 slots, the substrate is immediately loaded into the processing chamber 8 from the substrate loading port. However, since the processing chamber 8 is already filled with the wafer after 6 slots, the processing chamber 8 is already waited in the EFEM 1. . That is, there is almost no waiting time of the substrate in the EFEM 1 in 1 to 5 slots, but the EFEM 1 is waited after 6 slots. In this case, since there is almost no waiting time in EFEM1 for 1 to 5 slots, the charge removal time is insufficient, and after 6 slots, the waiting time in EFEM1 is too long. It will be done.

  FIG. 5 is a diagram showing the relationship between the output of the static eliminator and the static elimination completion time, FIG. 6 is a diagram showing the relationship between the air volume of the FFU and the static elimination completion time, and FIG. 7 is the static elimination time when the output of the static eliminator is changed. Is a graph showing the relationship between the charge amount and the charge amount, and the charge removal time and charge amount when the output of the charge removal device 3 is changed (lower output than normal) when the charge removal is completed (the charge amount of the substrate is 0 V). It is a graph which shows.

  In FIG. 5, the measurement conditions were such that the output of the static eliminator was pulsed AC ± 4000V to 22000V, the FFU wind power was 0.3 m / s, and the substrate charge was −1800V, −700V, and −400V.

  In FIG. 6, the measurement conditions are: the neutralizer output is a normal output (applied voltage: pulse AC ± 7000 V), the FFU wind speed is 0.2 m / s to 0.3 m / s, the substrate charge is −1800 V, −700 V, −400V.

In FIG. 7, the output of the static eliminator was an applied voltage of pulse AC ± 7000 V, pulse AC ± 14000 V, FFU wind speed of 0.3 m / s, and substrate charge amount of −700 V.
As shown in FIGS. 5 and 6, the larger the output of the static eliminator 3 and the larger the air volume of the FFU 4, the shorter the static elimination completion time, and even if the EFEM 1 stay time is 8 to 9 seconds as in 1 to 5 Slots, the static elimination is performed. It becomes possible to complete. Moreover, as shown in FIG. 7, reverse charging can be suppressed by reducing the output of the static eliminator 3 after the completion of static elimination.

  By utilizing this feature and using a control method as shown in FIG. 2, neutralization can be completed in the EFEM 1 while suppressing reverse charging. FIG. 2 is a diagram showing a control flow in the substrate static eliminator of the present invention.

  As shown in FIG. 2, when the substrate 7 in the carrier 6 is first transported to the apparatus processing chamber 8, the apparatus controller 9 confirms the availability of the processing chamber 8 (step 1), and the carrier 6 starts the EFEM 1. It is confirmed whether or not the substrate 7 can be loaded into the processing chamber 8 without waiting (step 2).

When the substrate 7 can be loaded into the processing chamber 8 without waiting in the EFEM 1 from the carrier 6, the following control is performed.
Assuming that the transfer time (the stay time of the substrate 7 in the EFEM 1) when the substrate 7 is transferred from the carrier 6 to the processing chamber 8 without waiting in the EFEM 1 is t1, the output of the static eliminator 3 is in a normal state and within t1. (Step 3), and if the charge removal cannot be completed within t1, the device controller 9 sets the output of the charge removal device 3 to a predetermined value (higher than normal). A command to change is issued (step 4). If the neutralization can be completed within the normal state and within t1, the neutralization device 3 maintains the output of the neutralization device 3 as it is and performs the neutralization process (step 5). After confirming that the completion time (t2) has elapsed (step 6), a command is issued to change the output of the static eliminator 3 to a predetermined value (lower output than normal) (step 7).

  Even if the output of the static eliminator 3 is in a high output state, it is confirmed whether or not the static eliminator is completed within t1 (step 8). If not, the device controller 9 determines the air volume of the FFU 4 by a predetermined value ( A command to change to a higher wind power than normal is issued and the charge removal process is performed (step 9). Then, it is confirmed that the time (t3) for completing static elimination has elapsed (step 10), and the device controller 9 issues a command to change the output of the static elimination device 3 to a predetermined value (lower output than normal). (Step 7). In addition, when the output of the static eliminator 3 is in a high output state and the static eliminator can be completed within t1, the device controller 9 performs the static eliminating process while maintaining the air volume of the FFU 4 at the normal air volume, and the static erasure is completed. (Step 11), and the device controller 9 issues a command to change the output of the static eliminator 3 to a predetermined value (lower output than normal) (step 11). 7). Thereafter, the process waits until the substrate 7 can be loaded into the processing chamber 8 (step 12). When the loading becomes possible, the substrate 7 is loaded into the processing chamber 8 (step 13).

If the substrate 7 cannot be loaded from the carrier 6 into the processing chamber 8 without waiting in the EFEM 1 (NO in step 2), the neutralization process is performed with the output of the static eliminator 3 kept at the normal output (step 5). 9 is a time (t2) at which static elimination is completed, and issues a command to change the output of the static elimination device 3 to a predetermined value (lower output than normal) (step 7). Then, when the processing chamber 8 is empty, the substrate 7 is loaded.
Note that t1 to t4 are eigenvalues for each device and are registered in advance in the device.

t1: EFEM1 stay time of the substrate 7 when directly transporting from the carrier 6 to the processing chamber 8 t2: Static elimination device 3 normal output, static elimination completion time when FFU4 is normal wind t3: Static electricity removal device 3 high output, FFU4 strong wind Static elimination completion time t4: Static elimination device 3 high output, FFU4 normal electricity neutralization time for normal wind FIG. 8 is a diagram showing the effect of changing the output of the static elimination device and the wind power of the FFU, and introduction of the static elimination control described above It is a graph which shows the average number of particles on a board | substrate for every slot position before and behind (before introduction, static elimination apparatus 3 and FFU4 always a normal output). Here, particles having a particle size of 0.12 μm or more were measured as measurement conditions.

As shown in FIG. 8, by introducing the charge removal control, an effect of reducing the number of particles attached to the substrate in almost all slots can be seen.
As described above, by providing the static eliminator and the FFU in the EFEM, it is possible to eliminate static electricity while the substrate is transported in the EFEM, so that it is possible to eliminate static electricity before substrate processing without reducing the apparatus throughput. It becomes. In addition, the device controller controls the stay time in the EFEM, which is the time until it is transferred to the processing chamber, and the control of the output of the static eliminator and the FFU air volume in the EFEM. It is possible to control the output of the static eliminator and the FFU air volume in the EFEM so that the processing is completed, and it is possible to reliably eliminate static electricity before the substrate processing. Furthermore, by obtaining in advance the static elimination time corresponding to the output of the static eliminator and the FFU air volume in the EFEM, the static electricity output and the FFU air volume in the EFEM are reduced when the static elimination time has elapsed. Therefore, it is possible to completely eliminate static electricity charged on the substrate and to minimize reverse charging.

  The substrate referred to in the present invention is not limited to a glass substrate or a semiconductor substrate constituting a liquid crystal display device, and is not particularly limited as long as it is a plate-like body transported by a transport robot or the like. .

  Further, the present invention can be used for a film forming apparatus, an exposure apparatus, an alignment film forming apparatus, a rubbing apparatus, a seal forming apparatus, a bonding apparatus, a cutting apparatus, and the like, and is particularly limited as long as it is an apparatus equipped with EFEM. It is not a thing.

  The present invention can discharge static electricity charged on a substrate due to friction between the substrate and a carrier before the substrate processing without reducing the device throughput, and the substrate discharging device and the substrate in an apparatus that processes and manufactures the substrate It is useful for static elimination methods.

Schematic sectional view showing the configuration of the substrate static eliminator of the present invention The figure which shows the control flow in the board | substrate static elimination apparatus of this invention Diagram showing the relationship between static elimination time and charge amount The figure which shows the EFEM residence time of the board | substrate for every slot position The figure which shows the relation between the output of the static eliminator and the static elimination completion time The figure which shows the relationship between the air volume of FFU and the static elimination completion time The figure which shows the relationship between the static elimination time and the amount of charge when changing the output of the static eliminator The figure which shows the effect of changing the output of a static elimination apparatus, and the wind power of FFU The figure which shows the structure of the control apparatus used for the static elimination of the conventional board | substrate

Explanation of symbols

1 EFEM
2 Robot 3 Static eliminator 4 FFU
DESCRIPTION OF SYMBOLS 5 Load port 6 Carrier 7 Board | substrate 8 Processing chamber 9 Apparatus controller 101 Board | substrate 201 Stage 301 Electrode 401 High voltage power source 501 Surface potential meter 601 Static elimination apparatus 701 Controller

Claims (6)

A processing chamber for manufacturing the substrate;
A carrier for storing the substrate before the manufacturing process;
A preparation chamber provided between the carrier and the processing chamber;
A static eliminator disposed in the preparation room;
A blower arranged in the preparation room;
A substrate static eliminator, comprising: a device controller that controls the operation of the static eliminator and the blower during the neutralization process.   2. The substrate neutralization apparatus according to claim 1, wherein the apparatus controller obtains a staying time of the substrate in the preparation chamber from a vacancy state of the processing chamber, and determines a discharging time of the substrate from the staying time. .   The apparatus controller obtains the residence time of the substrate in the preparation chamber from the availability of the processing chamber, and controls the output of the static elimination apparatus and the air volume of the blower so that the static elimination is completed within the residence time. The substrate static eliminator according to claim 1.   4. The substrate static eliminator according to claim 3, wherein the apparatus controller reduces the output of the substrate static eliminator to a predetermined value at the end of static elimination of the substrate. When performing neutralization processing of the substrate in a manufacturing apparatus provided with a preparation chamber provided with a static elimination device and a blower on the front surface of a processing chamber that performs manufacturing processing on the substrate,
Obtaining the relationship between the output of the static eliminator, the wind force of the blower and the static elimination time;
Obtaining the residence time of the substrate in the preparation chamber from the availability of the processing chamber;
Obtaining the output of the static eliminator and the wind force of the blower that completes the static elimination within the stay time;
A method of neutralizing a substrate, comprising the step of performing a neutralization process by controlling the output of the neutralization device and the wind force of the blower to the obtained value.   6. The substrate neutralization according to claim 5, further comprising a step of reducing the output of the static eliminator and the wind force of the blower to a predetermined value after a time necessary for the static eliminator has elapsed. Method.

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