JPH04294356A - Exposure controller - Google Patents

Abstract

PURPOSE:To prevent the unevenness of exposure and the defect of a wafer caused by dust generated from an exposure controller in an exposing device. CONSTITUTION:This exposure controller 20 is provided with a main shutter unit where a 1st dust cover groups 611 and 612 which seal both a bearing for a driving shaft which supports a driving shaft 171 and a driving drum 101, a 2nd dust cover groups 411, 412 and 413 which seal both respective bearings 21 and 22 which support a shaft 181 and an idler drum 11 are provided, and a 1st vacuum pump (not shown in figure) which sucks gas existing in the 1st dust cover groups 611 and 612, and the 2nd dust cover groups 411-413 through a suction pipe 5. Then, it is provided with an auxiliary shutter unit having the same constitution as the main shutter unit.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an exposure amount control device.
In particular, the present invention relates to an exposure amount control device that is optimal for use in an X-ray exposure apparatus that uses synchrotron radiation as a light source.

0002

2. Description of the Related Art As the capacity of semiconductor memories increases, improvements in miniaturization technology in semiconductor manufacturing equipment are required.

As one means of improving the miniaturization technology, there is an X-ray exposure apparatus that uses synchrotron radiation as a light source.

[0004] This X-ray exposure apparatus uses a reticle (mask)
One to several mask patterns shown above are projected onto a wafer, and the mask patterns are arrayed and printed on the entire surface of the wafer by step-and-repeat exposure. Unlike the conventional exposure apparatus, the wafer and reticle are exposed vertically (for example, Japanese Patent Laid-Open No. 2-100311).

[0005] Furthermore, in this X-ray exposure apparatus, since the synchrotron radiation light used as exposure light has an intensity distribution,
In order to keep the exposure amount of the entire exposure area constant, an exposure amount control device as described in, for example, Japanese Patent Laid-Open No. 2-90513 is provided.

FIG. 7 is a schematic diagram of an exposure amount control device described in Japanese Patent Application Laid-Open No. 2-90513.

This exposure amount control device includes a rectangular front exposure aperture 204, which is an opening through which synchrotron radiation light passes, and a rectangular rear exposure aperture 208, which is provided at a position opposite to the front exposure aperture 204. and a drive shaft 2 provided inside the endless belt 200.
20 is fixed to the drive drum 201 , and the drive drum 201 is configured to apply tension to the endless belt 200 .
inside the endless belt 200 parallel to each other,
An idler drum 202 rotatably provided around a shaft 221 and a drive drum 201 via a drive shaft 220
an actuator unit 203 that rotates the
and.

[0008] Here, the endless belt 200 is a thin plate belt made of metal such as stainless steel, and has a thickness sufficient to block synchrotron radiation.

In this exposure amount control device, the drive drum 20
1 is driven by the actuator unit 203, the endless belt 200 is driven by the drive drum 20.
A driving force is applied by the friction with the surface of the drum 1, and the drum is guided by the drive drum 201 and the idler drum 202 and moved in the direction of the arrow shown in the figure. At this time,
When the front edge 206 of the front exposure aperture 204 approaches the irradiation area of the synchrotron radiation light irradiated from the diagonally lower left side in the figure, exposure of the wafer (not shown) is started; When the rear edge 207 finishes passing through the irradiation area of the synchrotron radiation, the exposure of the wafer is completed. Note that the rear exposure aperture 208 is provided so that the synchrotron radiation light that has passed through the front exposure aperture 204 during exposure of the wafer is not blocked.

0010

[Problems to be Solved by the Invention] However, in the conventional exposure amount control device described above, the endless belt 200
is given driving force by friction with the surface of the drive drum 201 and is guided by the drive drum 201 and the idler drum 202 to move.
Dust generated when the endless belt 200 slides on the drive drum 201 and the idler drum 202 is diffused into the atmosphere, causing the following problems.

(a) This results in a decrease in the cleanliness within the exposure apparatus and a decrease in the purity of the atmospheric gas, and uneven exposure and defects occur on the wafer due to uneven exposure due to partial absorption of the synchrotron radiation. arise.

(b) If the dust adheres to the exposure control device and the mask that is disposed close to each other, it casts a shadow on the wafer during exposure and causes defects.

(c) When the dust particles adhere to the wafer, they block the synchrotron radiation and cause defects.

Similarly, a drive shaft bearing 210 supports the left end of the drive shaft 220 in the drawing, and bearings 2111 and 2112 (bearings 211 and 2112 support both ends of the shaft 221).
2 (not shown) causes a similar problem.

An object of the present invention is to provide an exposure amount control device that can prevent exposure unevenness and defects caused on wafers due to dust generation.

[0016]

[Means for Solving the Problems] The exposure amount control device of the present invention controls the exposure amount by moving a shutter means having an opening through which exposure light passes by a driving means. The dust cover group includes a dust cover group that seals the dust generating part of the shutter means and the drive means, and a suction means that sucks gas present in the dust cover group.

Alternatively, an endless belt having a rectangular front exposure aperture, a rectangular rear exposure aperture provided at a position opposite to the front exposure aperture, and a drive shaft provided inside the endless belt. a fixed drive drum; an idler drum rotatably provided around an axis, parallel to the drive drum and inside the endless belt so as to apply tension to the endless belt; and an actuator unit that rotates the drive drum, and an exposure amount control device that controls the exposure amount by rotating the endless belt by rotating the drive drum with the actuator unit,
a first dust cover group that seals both the drive shaft bearing that pivotally supports the drive shaft and the drive drum; and a second dust cover that seals both the drive shaft bearing that pivotally supports the shaft and the idler drum. The dust cover includes a cover group, and suction means for sucking gas present in each of the first and second dust cover groups.

Alternatively, an endless belt having a rectangular front exposure aperture, a rectangular rear exposure aperture provided at a position opposite to the front exposure aperture, and a hollow drive shaft provided inside the endless belt. a hollow drive drum having a plurality of suction holes perforated over its entire surface, to which a hollow drive drum is fixed, and a hollow shaft centered on the hollow drive drum and inside the endless belt parallel to each other so as to provide tension to the endless belt. a hollow idler drum that is rotatably provided in the drum and has a large number of suction holes drilled all over its surface; an actuator unit that rotates the hollow drive drum via the hollow drive shaft; and an actuator unit that rotatably supports the hollow drive shaft. a first dust cover group that seals a bearing for a drive shaft that supports the hollow shaft; a second dust cover group that seals a bearing that supports the hollow shaft; the hollow drive shaft, the hollow drive drum, the hollow shaft, and the The dust cover includes a hollow idler drum and a suction means for sucking gas present in each of the first and second dust cover groups.

[0019] Here, the first dust cover group hermetically seals both the drive shaft bearing and the hollow drive drum, and the second dust cover group seals both the bearing and the hollow idler drum. May be closed tightly.

Alternatively, there is an exposure amount control device that controls the exposure amount by rotating a disk-shaped shutter plate with a rotating means, which has a drive shaft fixed at the center and has an exposure aperture on a part of its outer periphery. The apparatus includes a dust cover group for sealing a bearing that pivotally supports the drive shaft, and a suction means for sucking gas present in the dust cover group.

[0021]

[Function] In the exposure amount control device of the present invention, when the shutter means having an opening through which exposure light passes is moved by the driving means, even if dust is generated from the shutter means and the driving means, Since the dust-generating parts of the shutter means and the drive means are sealed with a group of dust covers,
The dust can be prevented from going out from the space inside the dust cover group, and the dust can be discharged to the outside space by sucking the gas existing inside the dust cover group with a suction means. be able to.

[0022]

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

FIG. 1 is a schematic diagram showing a first embodiment of the exposure amount control device of the present invention.

The exposure amount control device 20 is used in an X-ray exposure device that uses synchrotron radiation light (hereinafter referred to as "SOR light") as a light source.

The exposure amount control device 20 includes a box-shaped casing 1 and a box-shaped casing 1 provided with a front exposure beam window (not shown) for transmitting SOR light, which is indicated by an arrow in FIG. It consists of a main shutter unit and an auxiliary shutter unit that are housed inside.
Further, as shown in FIG. 2, it is housed in a shutter chamber 30 connected to an exposure unit (not shown).

Here, the pressure inside the shutter chamber 30 is determined by detecting the pressure inside the shutter chamber 30 with a pressure gauge 36 shown in FIG. A suction pipe 37 connecting the second vacuum pump 35 for suction and the shutter chamber 30
The pressure is maintained at P1 by controlling the opening and closing of a second valve 34 interposed therebetween.

Next, the configuration of the main shutter unit provided on the SOR light incident side will be explained using FIG. 1.

The main shutter unit has the same function as the conventional exposure amount control device shown in FIG. ,
It comprises an endless belt 121 having a rectangular rear exposure aperture 191. Note that the endless belt 121 functions as a shutter means having an opening through which the SOR light passes.

Here, the rear exposure aperture 191 is
Front exposure aperture 13 when exposing a wafer (not shown)
The endless belt 121 is made of a thin metal belt such as stainless steel, and has a thickness sufficient to block the SOR light. .

The main shutter unit has a drive drum 101 to which a drive shaft 171 is fixed, which is provided inside the endless belt 121 in the upper part of the casing 1 as shown in the figure, as a drive means for moving the endless belt 121, and an endless belt. In order to apply tension to the endless belt 121 , a shaft 1 is installed inside the endless belt 121 parallel to the drive drum 101 in the downward direction shown in the casing 1 and parallel to each other.
Idler drum 1 rotatably provided around 81
11 and an actuator unit 161 that is attached to the outside of the right side of the casing 1 and rotates the drive drum 101 via a drive shaft 171 . Here, the left end of the drive shaft 171 in the drawing is supported by a drive shaft bearing (not shown) provided on the left side surface of the casing 1 in the drawing. Further, both ends of the shaft 181 are connected to respective bearings 21 and 2 provided on both sides of the casing 1 in the drawing.
2 (only the bearing 21 provided on the left side surface of the casing 1 is shown). Regarding the above points,
This is similar to the conventional exposure amount control device shown in FIG.

However, the main shutter unit
This device differs from the conventional exposure amount control device in that it includes first and second dust cover groups and suction means as described below.

(a) First dust cover group This group is for sealing both the drive shaft bearing and the drive drum 101, and includes a first drum dust cover 611 and a first bearing dust cover 612. It consists of

As shown in FIG. 1, the first drum dust cover 611 is located at the upper side of the casing 1 as shown in the drawing, and the first bearing dust cover 612 (see FIG. 2) is located on the left side of the casing 1 as shown in the drawing. It is located on the outside and above. Here, on the illustrated lower surface of the first drum dust cover 611,
Two slits 311 and 312 (slit 312 not shown) are provided for passing the endless belt 121 through.

Furthermore, in the upper left side of the casing 1 in the drawing, there is a communication hole 821 (see FIG. 2) that communicates the space inside the first drum dust cover 611 and the space inside the first bearing dust cover 612. is drilled.

(b) Second dust cover group bearings 21,
22 and the idler drum 111, and consists of a second drum dust cover 411, a second left bearing dust cover 412, and a second right bearing dust cover 413.

The second drum dust cover 411 is located inside the casing 1 at the lower side in the figure, and the second left bearing dust cover 412 is located at the outer lower side of the left side surface of the casing 1 in the figure. The dust cover 413 (see FIG. 2) is provided on the outer lower side of the right side surface of the casing 1 in the drawing. Here, two slits 313 and 314 are provided on the illustrated upper surface of the second drum dust cover 411 for passing the endless belt 121 therethrough.

Note that a communication hole 811 is bored in the lower left side of the casing 1 in the drawing to communicate the space inside the second drum dust cover 411 and the space inside the second left bearing dust cover 412. Further, at the lower right side of the casing 1 in the drawing, there is a communication hole 812 (see FIG. 2) that communicates the space inside the second drum dust cover 411 and the space inside the second right bearing dust cover 413. ) are drilled.

(c) Suction means As shown in FIG. 2, the first dust cover group 611,
612 and the second dust cover group 411 to 413
In order to suck the gas existing inside, a space inside the first bearing dust cover 612 provided above the outer side of the left side surface of the casing 1 as shown in the figure, and a space provided below the outer side of the left side surface of the casing 1 as shown in the figure. The space inside the second left bearing dust cover 412 refers to the space inside the suction pipe 5 and the first valve 31.
The first vacuum pump 32 is connected to the first vacuum pump 32 via the respective first vacuum pumps.

Here, the first valve 31 detects the pressure difference P1-P2 between the pressure P1 inside the shutter chamber 30 and the pressure P2 inside the suction pipe 5 on the side of the shutter chamber 30 from the first valve 31. Opening/closing is controlled by a differential pressure gauge 33.

Next, the auxiliary shutter unit included in this exposure amount control device 20 will be explained.

As shown in FIG. 1, the auxiliary shutter unit is provided on the side opposite to the incidence of the SOR light of the main shutter unit, and after the exposure of the wafer by the main shutter unit is completed, forward exposure is performed. This is to prevent the wafer from being irradiated with SOR light when the aperture 131 is returned to the exposure starting position.

The auxiliary shutter unit has the same structure as the main shutter unit described above, and includes an auxiliary drive drum 102 (not shown) and an auxiliary idler drum 112 (not shown) driven by an auxiliary actuator unit 162. During the exposure of the wafer by the main shutter unit, the SOR light is passed through using an aperture (not shown) in the auxiliary endless belt 122 stretched between the main shutter unit and the auxiliary endless belt 122 (not shown). After this is completed, it operates to block the SOR light.

The auxiliary shutter unit also includes a first auxiliary drum dust cover 621 for sealing the auxiliary drive drum 102, and a first auxiliary drum dust cover 621 for sealing the auxiliary drive drum 102.
a first auxiliary bearing dust cover 622 for sealing an auxiliary drive shaft bearing (not shown) that pivotally supports an auxiliary drive shaft (not shown) fixed to the auxiliary idler drum 112;
Dust cover 4 for the second auxiliary drum to seal the
21, and a second auxiliary left bearing dust cover 422 and a second auxiliary right bearing for sealing each auxiliary bearing that pivotally supports an auxiliary shaft (not shown) provided on the auxiliary idler drum 112. dust cover 423 (not shown)
are provided similarly to the main shutter unit.

[0044] Also, the first auxiliary bearing dust cover 62
2 and the second left bearing dust cover 422 are also connected to the suction pipes 5, respectively, and the first auxiliary drum dust cover 621 and the first auxiliary bearing dust cover 622
, the gas present in the second auxiliary drum dust cover 421, the second auxiliary left bearing dust cover 422, and the second auxiliary right bearing dust cover 423 is
It is designed so that suction can be performed using a vacuum pump 32.

Next, the operation of this exposure amount control device 20 will be explained.

[0046] When the exposure operation to the wafer is started,
Auxiliary drive drum 102 of the auxiliary shutter unit
is rotated by the auxiliary actuator unit 162, the auxiliary endless belt 122 moves with the rotation of the auxiliary drive drum 102 due to friction with the auxiliary drive drum 102, and the aperture is
It is moved to a position that allows the R light to pass through. Thereafter, the drive drum 101 of the main shutter unit is rotated by the actuator unit 161 in the direction of the arrow shown in FIG. 1, and the endless belt 121 moves due to friction with the drive drum 101 as the drive drum 101 rotates. The exposure of the wafer starts from the moment the front edge 141 of the front exposure aperture 131 enters the SOR light irradiation area.
The exposure of the wafer ends at the moment the rear edge 151 of the wafer leaves the irradiation area of the SOR light. At this time, by changing the rotational speed of the drive drum 101 according to the intensity distribution of the SOR light, it is possible to equalize the amount of exposure over the entire exposure area of the wafer.

Also in this exposure amount control device 20, during the exposure operation to the wafer, the contact surface between the drive drum 101 of the main shutter unit and the endless belt 121, and the contact between the idler drum 111 and the endless belt 121 are controlled. The drive shaft bearing and shaft 181 that support the drive shaft 171 generate dust from the surface.
Dust is also generated from the bearings 21 and 22 that support the shaft. The same applies to the auxiliary shutter unit.

However, in this exposure amount control device 20, as described above, the drive drum 101, the idler drum 111, the drive shaft bearing, and each bearing 21, 22 of the main shutter unit are connected to the first dust cover. groups 611, 612 and the second dust cover group 41
Since the dust cover groups 611, 612, and 413 are respectively sealed, the dust is generated in the first and second dust cover groups 611, 612, and 41.
As shown in FIG. can be discharged into the external space. The same applies to the auxiliary shutter unit.

Furthermore, since this exposure amount control device 20 is used by being housed in a shutter chamber 30 connected to the exposure unit, the first vacuum pump 32 is started to close each of the dust covers 611, 612, 621,622
, 411 to 413, and 421 to 423 are lower than the pressure in the shutter chamber 30, the atmospheric gas in the shutter chamber 30 is reduced to the respective dust covers 611, 612, 621, 622, 411 to 413.
, 421 to 423, respectively.
1 to 314, 321 to 324 (two slits 321,
322 is the first auxiliary drum dust cover 621;
The two slits 323 and 324 are respectively provided in the second auxiliary drum dust cover 421).
Each dust cover 611, 612, 621, 622, 4
11 to 413 and 421 to 423, it is possible to further prevent the dust from scattering in the optical path of the SOR light.

Note that in this exposure amount control device 20, the first
When the vacuum pump 32 is started, the atmospheric gas in the shutter chamber 30 is also sucked through the slits 311 to 314 and 321 to 324, as described above.
This causes changes in the cleanliness, purity, pressure, temperature, etc. of the atmospheric gas within the shutter chamber 30 and the exposure unit. As a result, a distribution occurs in the amount of attenuation of the SOR light when passing through the shutter chamber 30 and the exposure unit, which causes fluctuations in the exposure amount and causes uneven exposure on the wafer. Measures are being taken.

(a) When a change in the cleanliness and purity is detected, the atmospheric gas is evacuated (for example, by the second vacuum pump 35 shown in FIG. 2), and the supply amount is adjusted according to the change. While controlling
supply within.

(b) At this time, the pressure inside the shutter chamber 30 is monitored by, for example, the pressure gauge 36 shown in FIG. 2, and the opening and closing of the second valve 34 is controlled according to the pressure. and exhausting and supplying the atmospheric gas while keeping the pressure inside the exposure unit constant.

(c) Also, by monitoring the temperature of the atmospheric gas with a thermometer (not shown) and controlling the temperature of the supplied atmospheric gas according to the temperature, the temperature inside the shutter chamber 30 and the exposure unit can be controlled. keep the temperature constant.

(d) When starting the first vacuum pump 32, the differential pressure P1-P2 between the pressure P1 in the shutter chamber 30 and the pressure P2 in the suction tube 5 is monitored by the differential pressure gauge 33, and the difference is constantly monitored. The opening and closing of the first valve 31 is controlled so that the pressure P1-P2 is positive or constant. At this time, each of the dust covers 611, 612, 621, 622, 4 passes through each of the slits 311 to 314, 321 to 324.
By determining in advance the optimum amount of the atmospheric gas to be introduced into the slits 311-413, 421-423, the optimum amount and each of the slits 311-314, 321-324
The optimum value of the differential pressure P1-P2 can be determined from the opening area of .

FIG. 3 is a schematic diagram showing another structure of the suction means.

This suction means has a third valve 38 interposed between the shutter chamber 30 and the second valve 34, and the suction pipe 5 is inserted between the second valve 34 and the third valve 38. By branching, the second vacuum pump 35
is shared.

Here, the third valve 38 adjusts the pressure P1 in the shutter chamber 30 and the pressure P1 of the exposure amount control device 20 by adjusting the line resistance of the suction pipe 37 in which the third valve 38 is provided. Each dust cover 611, 612,
621, 622, 411 to 413, and 421 to 423 to make the differential pressure P1-P2 with respect to the pressure P2 to a positive or predetermined value. As a modification of the exposure amount control device of this embodiment, for example, as described in Japanese Patent Laid-Open No. 2-100311, a rectangular exposure aperture is opened instead of the endless belt 121 of the main shutter unit. It is conceivable to use a belt with both ends wrapped around the drive drum 101 and the idler drum 111, respectively.

In this modification, when exposing a wafer, the actuator unit 161 drives the drive drum 101 at a variable speed to move the exposure aperture upward to adjust the exposure amount. By driving the drive drum 101 in the opposite direction with the actuator unit 161, an operation is performed to move the exposure aperture downward and return the exposure aperture to its original position.

FIG. 4 is a schematic diagram showing a second embodiment of the exposure amount control device of the present invention.

This exposure amount control device 60 is composed of a main shutter unit and an auxiliary shutter unit like the exposure amount control device 20 shown in FIG. 1, but the main shutter unit has the following points. It is different from the main shutter unit of the exposure amount control device 20.

(a) In place of the driving drum 101, a hollow driving drum 501 having a large number of suction holes 6111 formed over its entire surface is used.

(b) Instead of the idler drum 111, a hollow idler drum 511 having a large number of suction holes 6112 drilled over its entire surface is used.

(c) A hollow drive shaft 571 and a hollow shaft 581 are used instead of the drive shaft 171 and the shaft 181.

(d) As the first dust cover group, a first bearing inner dust cover 4611 (not shown) is used to seal the drive shaft bearing (not shown) that supports the left end of the hollow drive shaft 571 in the drawing. ) and a first bearing outer dust cover 4612 (not shown) are provided above the inner side and above the outer side of the left side surface of the casing 41, respectively. In addition, the hollow drive shaft 571 and the actuator unit 5
61 The third dust cover 46 seals the connection part with
3 is provided inside and above the right side surface of the casing 41 in the drawing.

(E) The second dust cover group includes a second left bearing inner dust cover 4411 that seals the bearing 421 that pivotally supports the left end of the hollow shaft 581 in the figure;
The outer dust cover 4412 for the left bearing of the casing 4
A second right bearing inner dust cover 4413 and a second right bearing inner dust cover 4413 are respectively provided on the inner lower side and the outer lower side of the left side of A second right bearing outer dust cover 4414 is provided on the inner lower side and the outer lower side of the right side surface of the casing 41 in the figure, respectively.

(F) A fourth dust cover 464 that communicates the space inside the third dust cover 463 and the space inside the second right bearing inner dust cover 4413 is provided inside the right side surface of the casing 41 in the drawing. It is being

The auxiliary shutter unit of this exposure control device 60 has the same structure as the main shutter unit described above.

In this exposure amount control device 60, when exposure of a wafer (not shown) is started, the hollow drive drum 501 of the main shutter unit and the endless belt 52
1 and the contact surface between the hollow idler drum 511 and the endless belt 521 , dust is generated from the contact surfaces between the hollow idler drum 511 and the endless belt 521 , and the drive shaft bearings that support the hollow drive shaft 571 and the bearings 21 that support the hollow shaft 581 . ,22
It also generates dust. The same applies to the auxiliary shutter unit.

However, the entire surface of the hollow drive drum 501 and the hollow idler drum 511 of the main shutter unit have a large number of suction holes 6111,
6112, and the space inside the hollow drive drum 501 is used for the hollow drive shaft 571, the first dust cover group 4611, 4612 and the suction pipe 4.
5 to a vacuum pump (not shown), and the space inside the hollow idler drum 511 is also connected to the hollow shaft 5.
81, the second dust cover group 4411 to 4414
and the vacuum pump via the suction pipe 45, the dust generated from each contact surface passes through the suction holes 6111 and 6112 together with the atmospheric gas into the space inside the hollow drive drum 501 and the hollow space. idler drum 51
1 is sucked into the internal space and discharged to the external space by the vacuum pump. Further, dust generated from the drive shaft bearing and each of the bearings 21 and 22 is also removed from the dust cover 461.
1 to 4613 and 4411 to 4414, the SOR light is discharged to the external space by the vacuum pump without being diffused into the optical path of the SOR light. The same applies to the auxiliary shutter unit.

Note that even if there is a slight gap between the second left bearing inner dust cover 4411 and the hollow shaft 581,
Due to the suction by the vacuum pump, the pressure inside the second left bearing inner dust cover 4411 becomes lower than the pressure inside the casing 41, which prevents dust from the bearing 421 from diffusing into the optical path of the SOR light. . However, bearing 421
In order to improve the degree of sealing, a seal structure such as a dynamic O-ring, mechanical seal, lip packing, or labyrinth may be provided in the small gap between the second left bearing inner dust cover 4411 and the hollow shaft 581. good. The same applies to the drive shaft bearing and the bearing 422.

Furthermore, the contact surface between the hollow drive drum 501 and the endless belt 521 and the contact surface between the hollow idler drum 511 and the endless belt 521 are
Each may be made of a porous material. In this case, by applying an adhesive to each surface of the hollow drive drum 501 and the hollow idler drum 511 other than the contact surfaces, or by making each surface of the hollow drive drum 501 and the hollow idler drum 511 from a material other than a porous material, the vacuum pump can be Efficiency may be improved by preventing unnecessary suction.

FIG. 5 is a schematic diagram showing a third embodiment of the exposure amount control device of the present invention.

This exposure amount control device 90 differs from the exposure amount control device 60 shown in FIG. 4 in the following points.

(a) As the first dust cover group, a first drum is used to seal both the hollow drive drum 801 and the drive shaft bearing (not shown) that supports the left end of the hollow drive shaft 871 in the drawing. and a first bearing dust cover 7612 (not shown). In addition,
The first drum dust cover 7611 is the casing 71
The first bearing dust cover 7612 is provided above the outside of the left side surface of the casing 71 in the drawing.

(b) As the second dust cover group, bearings 721 and 722 pivotally support both ends of the hollow shaft 881 as shown in the figure.
(The bearing 7 provided below the right side of the casing 71 in the figure)
22 (not shown) and the hollow idler drum 811, a second drum dust cover 7411 is installed.
, a second left bearing dust cover 7412, and a second right bearing dust cover 7413. The second drum dust cover 7411 is provided inside the casing 71 at the lower side in the figure, and the second left bearing dust cover 7412 is provided at the outer lower side of the left side surface of the casing 71 in the figure. The right bearing dust cover 7413 is provided on the outer lower side of the right side surface of the casing 71 in the drawing.

(c) The third and fourth dust covers 463 and 464 shown in FIG. 4 are not provided.

The configuration of the auxiliary shutter unit of this exposure amount control device 90 is similar to the configuration of the main shutter unit described above.

In this exposure amount control device 90, the hollow drive drum 801 is hermetically sealed with the first drum dust cover 7611, and the hollow idler drum 811 is hermetically sealed with the second drum dust cover 7411. It is possible to obtain an even greater dust prevention effect than the exposure control device shown.

Each of the exposure amount control devices 20, 60, and 90 shown in FIGS. 1, 4, and 5 described above includes a main shutter unit and an auxiliary shutter unit having similar configurations. The auxiliary shutter unit is not necessarily necessary, and other means for blocking SOR light, such as a shutter that can be opened and closed, may be used.

FIG. 6 is a schematic diagram showing a fourth embodiment of the exposure amount control device of the present invention.

This exposure amount control device 100 includes a casing 110 in which a front exposure beam window 111 and a rear exposure beam window 112 are provided on the front side and the rear side in the figure, respectively, and a center window provided on the front side in the casing 110 in the figure. A disk-shaped shutter plate 101 having an exposure aperture 102 on a part of its outer periphery has a drive shaft 109 fixed thereto, and the shutter plate 101 is rotated via the drive shaft 109 provided in a casing 110 . The actuator unit 115 , an inner dust cover 1211 and an outer dust cover 1212 that seal the drive shaft bearing 106 that pivotally supports the front end of the drive shaft 109 provided on the inner and outer sides of the front surface of the casing 110 , respectively; Dust cover 1212
Suction pipe 1 that communicates the internal space with a vacuum pump (not shown)
09. Note that the front surface of the casing 110 has a communication hole 108 that communicates the space inside the inner dust cover 1211 with the space inside the outer dust cover 1212.
1,1082 are drilled.

[0082] In this exposure amount control device 100, SOR
The optical axis of the light is set to coincide with an imaginary line connecting the center of the front exposure beam window 111 and the center of the rear exposure beam window 112.

[0083] When exposure of a wafer (not shown) is started,
The shutter plate 101 is the actuator unit 115
The exposure aperture 1 is rotated in the direction of the arrow shown by
Exposure of the wafer begins when the leading edge 103 of 02 passes the lower end of the front exposure beam window 111 in the drawing. Also, the rear edge 104 of the exposure aperture 102
When the beam has passed through the upper end of the front exposure beam window 111 in the drawing, the exposure of the wafer is completed. At this time, by changing the rotational speed of the actuator unit 115 according to the intensity distribution of the SOR light, it is possible to equalize the exposure amount over the entire exposure area of the wafer.

[0084] Also in this exposure amount control device 100,
During the exposure operation to the wafer, the drive shaft bearing 106
Dust is generated. However, as described above, since the drive shaft bearing 106 is sealed by the dust covers 1211 and 1212, the dust is removed from the dust covers 1211 and 1212.
211, 1212 from going outside, and each of the dust covers 1211, 12
By suctioning and discharging the gas existing in the space inside the vacuum pump 12 using the vacuum pump, the dust can be discharged to the external space.

[0085]

[Effects of the Invention] Since the present invention is constructed as described above, it produces the following effects.

[0086] The exposure amount control device of the present invention includes a dust cover group for sealing the dust generating part of the shutter means and the driving means, and a suction means for sucking the gas existing in the dust cover group. Even if dust is generated from the shutter means and the driving means when the shutter means is moved by the driving means, the dust is prevented from going out from the space within the dust cover group. At the same time, the generated dust can be discharged to the outside space, which has the effect of preventing uneven exposure and defects caused on the wafer due to the generated dust.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an exposure amount control device of the present invention.

FIG. 2 is a schematic configuration diagram of a suction means of the exposure amount control device shown in FIG. 1;

FIG. 3 is a schematic configuration diagram showing another configuration of the suction means of the exposure amount control device shown in FIG. 1;

FIG. 4 is a schematic configuration diagram showing a second embodiment of the exposure amount control device of the present invention.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the exposure amount control device of the present invention.

FIG. 6 is a schematic configuration diagram showing a fourth embodiment of the exposure amount control device of the present invention.

FIG. 7 is a schematic configuration diagram showing the configuration of an exposure amount control device described in Japanese Patent Application Laid-Open No. 2-90513.

[Explanation of symbols]

1,41,71,110 casing 21,
421,721 Bearing 311,3
13,314,9513 Slit 411,74
11 Second drum dust cover 41
2,7412 Second left bearing dust cover 413, 7413 Second right bearing dust cover 421 Second auxiliary drum dust cover 422 Second auxiliary left bearing dust cover 5, 37, 45, 75, 107
Suction pipe 611, 7611 First drum dust cover 612 First bearing dust cover 621 First auxiliary drum dust cover 622 First auxiliary bearing dust cover 811, 812, 821, 5811
,5812,5821,8811,8812,8821
, 1081, 1082 Communication hole 10
1 Drive drum 111 Idler drum 121, 521, 821 Endless belt 122, 522, 822 Auxiliary endless belt 131, 531, 831
Front exposure aperture 141, 541, 841, 103 Front edge 151, 551, 851, 104 Rear edge 161, 561, 861 Actuator unit 162, 562, 862
Auxiliary actuator unit 115 Actuator unit 171, 109 Drive shaft 181 Axis 191, 591, 891
Rear exposure aperture 20, 60, 90, 100 Exposure amount control device 30 Shutter chamber 31
First valve 32 First vacuum pump 33
Differential pressure gauge 34 Second valve 35 Second vacuum pump 36
Pressure gauge 38 Third valve 4411 Second inner dust cover for left bearing 4412 Second outer dust cover for left bearing 4413 Second inner dust cover for right bearing 4414 Second outer dust cover for right bearing 463 Third dust cover 464
Fourth dust cover 501, 502, 801
Hollow drive drum 511, 811
Hollow idler drum 571,8
71 Hollow drive shaft 581
,881 hollow shaft 611
1,6112,9111,9112 Suction hole 101
Shutter plate 102 Exposure aperture 106 Drive shaft bearing 111 Front exposure beam window 112 Back exposure beam window 1211 Inner dust cover 1212 Outer dust cover

Claims (5)

[Claims] 1. In an exposure amount control device that controls the exposure amount by moving a shutter means having an opening through which exposure light passes by a driving means, a part of the shutter means and the driving means where dust is generated is sealed. A group of dust covers,
An exposure amount control device comprising: suction means for suctioning gas present within the dust cover group. 2. An endless belt having a rectangular front exposure aperture, a rectangular rear exposure aperture provided at a position opposite to the front exposure aperture, and a drive shaft provided inside the endless belt. a fixed drive drum; an idler drum rotatably provided around an axis, parallel to the drive drum and inside the endless belt so as to apply tension to the endless belt; and an actuator unit that rotates the drive drum, the exposure amount control device controlling the exposure amount by rotating the endless belt by rotating the drive drum with the actuator unit, wherein the drive shaft is rotated. a first dust cover group that seals both a bearing for a drive shaft that supports the shaft and the drive drum; a second dust cover group that seals both the bearing that supports the shaft and the idler drum; An exposure amount control device comprising: suction means for suctioning gas present in each of the first and second dust cover groups. 3. An endless belt having a rectangular front exposure aperture, a rectangular rear exposure aperture located opposite to the front exposure aperture, and a hollow drive shaft provided inside the endless belt. a hollow drive drum having a plurality of suction holes perforated over its entire surface, to which a hollow drive drum is fixed, and a hollow shaft centered on the hollow drive drum and inside the endless belt parallel to each other so as to provide tension to the endless belt. a hollow idler drum that is rotatably provided in the drum and has a large number of suction holes drilled all over its surface; an actuator unit that rotates the hollow drive drum via the hollow drive shaft; and an actuator unit that rotatably supports the hollow drive shaft. a first dust cover group that seals a bearing for a drive shaft that supports the hollow shaft; a second dust cover group that seals a bearing that supports the hollow shaft; the hollow drive shaft, the hollow drive drum, the hollow shaft, and the An exposure amount control device comprising a hollow idler drum and suction means for suctioning gas present in each of the first and second dust cover groups. 4. The first dust cover group seals both the drive shaft bearing and the hollow drive drum, and the second dust cover group seals both the bearing and the hollow idler drum. The exposure amount control device according to claim 3. 5. An exposure amount control device that controls the exposure amount by rotating a disk-shaped shutter plate, which has a drive shaft fixed at the center and has an exposure aperture on a part of its outer periphery, using a rotating means. An exposure amount control device characterized in that it comprises a dust cover group for sealing a bearing that pivotally supports the drive shaft, and a suction means for sucking gas present in the dust cover group.