JP2019169536A - Substrate transport system and substrate neutralization method - Google Patents

Abstract

To effectively neutralize a substrate to prevent adhesion of particles even when the transport height of the substrate changes.SOLUTION: A substrate transport system 100 according to the present embodiment includes a substrate transport unit that transports a substrate, and a static eliminator 120 that neutralizes the substrate. The substrate transfer unit changes the transfer height of the substrate. The static eliminator 120 changes the static elimination output on the basis of the transport height of the substrate. The static eliminator 120 is provided above the substrate transported by the substrate transport unit, and weakens the neutralization output as the conveyance height of the substrate is higher.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a substrate transfer system and a substrate charge removal method.

  In order to prevent adhesion of particles due to charging of the substrate, a static eliminator is provided in a transfer unit serving as a passage for carrying the substrate in and out of the processing chamber. For example, a corona discharge type static eliminator is installed above the transport unit, and an electric field is concentrated on the discharge electrode to cause corona discharge and generate ions. The ionized air hits the substrate by the downward flow formed by the fan filter unit (FFU), and the substrate is discharged.

  Conventionally, the static elimination output of the static eliminator has always been constant. For this reason, when the transport height of the substrate changes in the transport unit, the substrate can be neutralized at one transport height, but the other transport height cannot be neutralized or the substrate may be charged.

Japanese Unexamined Patent Publication No. 2011-159834 JP 2000-183132 A Japanese Patent Laid-Open No. 2017-111241 JP-A-9-251936 JP-A-2015-146349

  The present invention has been made in view of the above-described conventional situation, and provides a substrate transfer system and a substrate charge removal method that can effectively eliminate the substrate even when the substrate transfer height changes and prevent the adhesion of particles. This is the issue.

  A substrate transport system according to an aspect of the present invention is a substrate transport system including a substrate transport unit that transports a substrate and a static eliminator that neutralizes the substrate, wherein the substrate transport unit has a transport height of the substrate. In other words, the static eliminator changes the static elimination output based on the transport height of the substrate.

  In the substrate transport system according to one aspect of the present invention, the static eliminator is provided above the substrate transported by the substrate transport unit, and the higher the transport height of the substrate, the weaker the static elimination output.

  In the substrate transfer system according to an aspect of the present invention, the substrate transfer system further includes a delivery fan that sends the air that has flowed in through the introduction portion downward, and the static eliminator is a corona discharge static eliminator, and ions generated by the corona discharge are It moves downward by the air delivered by the delivery fan.

  In the substrate transport system according to one aspect of the present invention, the substrate transport unit transports the substrate at a first height and a second height higher than the first height, and the static eliminator has the substrate The substrate is neutralized while being transported at the first height, and is turned off while the substrate is transported at the second height.

  A substrate neutralization method according to an aspect of the present invention is a substrate neutralization method in a substrate conveyance system including a substrate conveyance unit that conveys a substrate and a static eliminator that neutralizes the substrate, according to the conveyance height of the substrate. Thus, the static elimination output of the static eliminator is changed.

  According to the present invention, it is possible to effectively neutralize the substrate even when the transport height of the substrate changes, and to prevent adhesion of particles.

It is a top view of the electron beam drawing apparatus which concerns on embodiment of this invention. It is a partial cross section figure of the electron beam drawing apparatus concerning the embodiment. It is a schematic diagram of a substrate conveyance system concerning the embodiment. It is the schematic of the board | substrate conveyance system by a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view of an electron beam drawing apparatus provided with a substrate transfer system according to an embodiment of the present invention, and FIG. 2 is a writing chamber (W chamber) 400 and an electron beam column that are part of the electron beam drawing apparatus. FIG. As shown in FIGS. 1 and 2, the electron beam lithography apparatus includes a substrate transfer system 100, a load / unload (I / O) chamber 200, a robot chamber (R chamber) 300, a W chamber 400, an electron beam column 500, a control. A device 600 and gate valves G1 to G3 are provided. In FIG. 1, the electron beam column 500 is not shown.

  The substrate transfer system 100 includes a transfer robot (transfer arm) 110 that transfers the mask substrate W, receives the mask substrate W from the outside, and transfers the mask substrate W to a chamber on the rear stage side while removing electricity. Further, the substrate transfer system 100 carries the mask substrate W to the outside while performing neutralization of the mask substrate W after drawing. The detailed configuration of the substrate transfer system 100 will be described later.

  The I / O chamber 200 is a so-called load lock chamber for carrying in and out the mask substrate W while keeping the inside of the R chamber 300 in a vacuum (low atmospheric pressure). The I / O chamber 200 includes a vacuum pump 210 and a gas supply system 220, and a gate valve G1 is provided between the I / O chamber 200 and the substrate transfer system 100. The vacuum pump 210 is, for example, a dry pump or a turbo molecular pump, and evacuates the I / O chamber 200. The gas supply system 220 supplies venting gas (for example, nitrogen gas or CDA) into the I / O chamber 200 when the I / O chamber 200 is set to atmospheric pressure.

  When the inside of the I / O chamber 200 is evacuated, the vacuum pump 210 connected to the I / O chamber 200 is evacuated. Further, when the inside of the I / O chamber 200 is returned to the atmospheric pressure, the venting gas is supplied from the gas supply system 220, and the inside of the I / O chamber 200 becomes the atmospheric pressure. Note that when the inside of the I / O chamber 200 is evacuated and at atmospheric pressure, the gate valves G1 and G2 are closed.

  The R chamber 300 includes a vacuum pump 310, an alignment chamber 320, a mask cover storage chamber 330, and a transfer robot 340. The R chamber 300 is connected to the I / O chamber 200 via the gate valve G2.

  The vacuum pump 310 is, for example, a cryopump or a turbo molecular pump. The vacuum pump 310 is connected to the R chamber 300, and the inside of the R chamber 300 is evacuated to maintain a high vacuum. The alignment chamber 320 is a chamber for positioning (alignment) the mask substrate W.

  The mask cover storage chamber 330 is a chamber for storing the mask cover H. The mask cover H has conductivity, and a frame-shaped frame having an opening at the center is provided with a plurality of ground mechanisms. The size of the frame is slightly larger than the mask substrate W. The mask cover H is for discharging charges accumulated on the mask substrate W by irradiation with an electron beam.

  The transfer robot 340 transfers the mask substrate W among the I / O chamber 200, the alignment chamber 320, the mask cover storage chamber 330, and the W chamber 400.

  The W chamber 400 includes a vacuum pump 410, an XY stage 420, and drive mechanisms 430A and 430B, and is connected to the R chamber 300 via a gate valve G3.

  The vacuum pump 410 is, for example, a cryopump or a turbo molecular pump. The vacuum pump 410 is connected to the W chamber 400 and evacuates the W chamber 400 to maintain a high vacuum. The XY stage 420 is a table on which the mask substrate W is placed. The drive mechanism 430A drives the XY stage 420 in the X direction. The drive mechanism 430B drives the XY stage 420 in the Y direction.

  As shown in FIG. 2, an electron beam column 500 includes an electron gun 510, a blanking aperture 520, a first aperture 522, a second aperture 524, a blanking deflector 530, a shaping deflector 532, an objective deflector 534, and a lens. 540 (illumination lens (CL), projection lens (PL), objective lens (OL)) and the like are provided, and an electron beam is applied to the mask substrate W placed on the XY stage 420. Irradiate. Although the mask cover H is set on the mask substrate W irradiated with the electron beam, the mask cover H is not shown in FIG.

  An electron beam 502 as an example of a charged particle beam emitted from the electron gun 510 illuminates the entire first aperture 522 having a rectangular, for example, square hole, by the illumination lens CL. Here, the electron beam 200 is first shaped into a rectangle, for example, a square. The electron beam of the first aperture image that has passed through the first aperture 522 is projected onto the second aperture 524 by the projection lens PL. The position of the first aperture image on the second aperture 524 is controlled by the shaping deflector 532, and the beam shape and size can be changed. Then, the electron beam of the second aperture image that has passed through the second aperture 524 is focused by the objective lens OL, deflected by the objective deflector 534, and the mask substrate on the XY stage 420 that is movably disposed. The desired position of W is irradiated. Application of a deflection voltage to the shaping deflector 532 and the objective deflector 534, movement of the XY stage 420, and the like are controlled by the control device 600. The electron beam drawing apparatus is a variable shaping type drawing apparatus.

  The electron beam 502 emitted from the electron gun 510 is controlled by the blanking deflector 530 so as to pass through the blanking aperture 520 when the beam is on, and when the beam is off, the entire beam is shielded by the blanking aperture 520. To be deflected. An electron beam that has passed through the blanking aperture 520 before the beam is turned off from the beam-off state becomes one electron beam shot. The irradiation amount per shot of the electron beam irradiated to the mask substrate W is adjusted depending on the irradiation time of each shot.

  The control device 600 is, for example, a computer or the like, and has a function of controlling each chamber, gate valve, and the like.

  FIG. 3 is a schematic diagram of the substrate transfer system 100. In FIG. 3, the illustration of the transfer robot 110 is omitted. The mask substrate W is carried into and out of the outside through the carry-in / out port 142 of the substrate carrying system 100. The mask substrate W is transferred in a state of being accommodated in a case (not shown) outside the drawing apparatus. Therefore, the case containing the mask substrate W is carried into the substrate transport system 100 from the carry-in / out port 142. The mask substrate W is lowered by the elevating unit 140, and the mask substrate W is removed from the case.

  The mask substrate W that has moved down the elevating unit 140 is moved in the horizontal direction by the transfer robot 110 toward the I / O chamber 200 at the subsequent stage.

  As shown in FIG. 3, the height H <b> 1 of the mask substrate W after being lowered by the elevating unit 140 is different from the height H <b> 2 of the connection portion between the substrate transfer system 100 and the I / O chamber 200. More specifically, the loading / unloading port 150 for loading / unloading the mask substrate W between the substrate transfer system 100 and the I / O chamber 200, to which one end of the gate valve G1 is connected, is a mask substrate that has been lowered by the elevating unit 140. It is provided at a position higher than the position of W.

  Therefore, the transfer robot 110 raises the mask substrate W that has moved down the elevating unit 140 in the vertical direction to the height H2 of the loading / unloading port 150 while moving in the horizontal direction toward the subsequent I / O chamber 200 side, Thereafter, the movement in the horizontal direction is resumed.

  When carrying out the mask substrate W after the drawing process to the outside, the transfer robot 110 moves the mask substrate W loaded from the I / O chamber 200 side through the loading / unloading port 150 in the horizontal direction to the lifting unit 140 side. The transfer robot 110 lowers the mask substrate W in the vertical direction on the way, and then resumes movement in the horizontal direction and carries it into the elevating unit 140. The mask substrate W ascends the elevating unit 140, is accommodated in the case, and is carried out from the loading / unloading port 142 to the outside.

  The position where the mask substrate W is moved up and down between the height H1 and the height H2 is not particularly limited. The position where the mask substrate W is raised from the height H1 to the height H2 may be different from the position where the mask substrate W is lowered from the height H2 to the height H1.

  The substrate transfer system 100 is provided with a fan filter unit (hereinafter referred to as FFU) that forms a downward flow of air. The FFU includes a delivery fan 130 that sends air introduced from the introduction part 134 in the upper part of the casing downward, and a filter (not shown) that collects dust in the air that has passed through the delivery fan 130.

  The FFU flows into the substrate transfer system 100 through the introduction unit 134, forms a downward flow of air flowing out from the discharge unit 136 through the substrate transfer unit provided with the transfer robot 110, and enters the air. Collect and remove contained dust. Thereby, the air inside the housing | casing of the board | substrate conveyance system 100 is cleaned.

  A static eliminator 120 is provided between the transport route of the mask substrate W transported by the transport robot 110 and the delivery fan 130 and the filter, that is, above the transport route of the mask substrate W and below the filter. .

  The static eliminator 120 is, for example, a corona discharge type static eliminator, and includes a high-voltage power source, an electrode needle, and a ground electrode. By applying a high voltage to the electrode needle, corona discharge is generated at the tip of the electrode needle. When corona discharge occurs, the air existing around the electrode needle is electrically decomposed to generate ions. The ions generated by the corona discharge move downward by the downward flow formed by the FFU, and the mask substrate W transported by the transport robot 110 is neutralized.

  As described above, since the height is different between the position where the mask substrate W descends the lifting unit 140 and the loading / unloading port 150, the transfer height changes during the transfer of the mask substrate W. When the static elimination output (voltage applied to the electrode needle) of the static eliminator 120 is constant, when the static elimination output is adjusted to the height H1 at which the mask substrate W descends the elevating part 140, the mask substrate W becomes high at the loading / unloading port 150. There is a risk of charging when it is at H2. On the other hand, if the discharge output is matched with the height H2 of the loading / unloading port 150, the mask substrate W may not be sufficiently discharged when the mask substrate W is at the height H1.

  Therefore, in the present embodiment, the static elimination output of the static eliminator 120 is changed according to the transport height of the mask substrate W. Specifically, when the mask substrate W is moving at a height H2 of the loading / unloading port 150 rather than the first static elimination output when the mask substrate W is moving at a height H1 lowered from the elevating unit 140. Reduce the second static elimination output.

  Accordingly, the mask substrate W moving at the height H1 can be sufficiently discharged, and when the mask substrate W is moving at the height H2, the amount of ions generated is suppressed to prevent the mask substrate W from being charged. It is possible to prevent particles from adhering to W.

  For example, when the mask substrate W to be drawn is carried into the substrate transfer system 100 and descends the elevating unit 140, the static eliminator 120 starts generating ions with the first static elimination output. While the mask substrate W is moving at the height H1, the static eliminator 120 continues to generate ions with the first static elimination output.

  When the transfer robot 110 raises the mask substrate W in the vertical direction from the height H1 to the height H2, the static eliminator 120 weakens the static elimination output from the first static elimination output to the second static elimination output. After the mask substrate W is carried out to the I / O chamber 200, the second static elimination output may be maintained, or the operation of the static eliminator 120 may be turned off.

  When the drawn mask substrate W is carried into the substrate transfer system 100 from the I / O chamber 200, the static eliminator 120 starts generating ions with the second static elimination output. While the mask substrate W is moving at the height H2, the static eliminator 120 continues to generate ions with the second static elimination output.

  When the transfer robot 110 lowers the mask substrate W from the height H2 to the height H1 in the vertical direction, the static eliminator 120 increases the static elimination output from the second static elimination output to the first static elimination output. After the mask substrate W has moved up the elevating unit 140, the operation of the static eliminator 120 is turned off.

  In the above-described embodiment, an example in which the second static elimination output when the mask substrate W moves the height H2 is smaller than the first static elimination output when the mask substrate W moves the height H1 has been described. 2 The static elimination output may be zero. That is, the static eliminator 120 is turned on only when the mask substrate W moves the height H1, and the static eliminator 120 is turned off when the mask substrate W moves the height H2. Thereby, the operation time of the static eliminator 120 can be shortened, and the maintenance cycle such as electrode cleaning and potential measurement can be extended.

  In the above embodiment, an example in which there are two types of conveyance heights, height H1 and height H2, has been described, but there may be three or more types of conveyance heights. The static elimination output of the static eliminator 120 is changed according to the conveyance height, and the static elimination output is increased as the conveyance height is lower, that is, the distance from the static eliminator 120 is increased.

  As shown in FIG. 4, the mask substrate W that has descended the elevating unit 140 may be linearly moved obliquely upward to the loading / unloading port 150. In this case, it is preferable to continuously change (gradually weaken) the static elimination output of the static eliminator 120 in accordance with the height of the mask substrate W. When the drawn mask substrate W is carried into the substrate transfer system 100 from the I / O chamber 200, the mask substrate W is linearly moved obliquely downward from the loading / unloading port 150 to the lift unit 140. In this case, it is preferable to gradually increase the static elimination output of the static eliminator 120 in accordance with the height of the mask substrate W.

  In the above-described embodiment, an example in which the substrate transport system 100 provided in the electron beam lithography apparatus transports the mask substrate W has been described. However, the substrate transport system 100 is not limited to the lithography apparatus, but includes various apparatuses such as an etching apparatus and a CVD apparatus. Can be applied to. Moreover, the board | substrate to convey is not limited to a mask board | substrate, Other board | substrates, such as a silicon wafer and a metal substrate, may be sufficient.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 100 Substrate transfer system 110 Transfer robot 120 Static eliminator 140 Lifting unit 200 Loading / unloading chamber 300 Robot chamber 400 Writing chamber 500 Electron beam column 600 Control device

Claims (5)

A substrate transport section for transporting the substrate;
A static eliminator for neutralizing the substrate;
A substrate transfer system comprising:
The substrate transport unit changes the transport height of the substrate,
The static eliminator changes the static elimination output based on the conveyance height of the substrate.   2. The substrate transfer system according to claim 1, wherein the static eliminator is provided above a substrate transferred by the substrate transfer unit and weakens the discharge output as the transfer height of the substrate increases. It further comprises a delivery fan that sends the air that has flowed in through the introduction portion downward,
3. The substrate transfer system according to claim 2, wherein the static eliminator is a corona discharge type static eliminator, and ions generated by the corona discharge move downward by the air sent out by the sending fan. The substrate transport unit transports the substrate at a first height and a second height higher than the first height,
The static eliminator performs neutralization of the substrate while the substrate is transported at the first height, and is turned off while the substrate is transported at the second height. The substrate transfer system according to claim 2 or 3. A substrate discharge method in a substrate transfer system, comprising: a substrate transfer unit that transfers a substrate; and a static eliminator that neutralizes the substrate,
A substrate static elimination method, wherein the static elimination output of the static eliminator is changed in accordance with the transport height of the substrate.

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