JPH0611067B2 - Mask storage device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thin plate storage device, and more particularly to a mask storage device suitable for storing a mask used in a semiconductor exposure process, which is reluctant to attach foreign matter.

[Conventional technology]

Since a mask used in a semiconductor exposure process is generally a circuit pattern drawn by a metal film on a glass substrate, when a foreign substance is present on the mask, it is transferred as a defect on the wafer.

Therefore, it is important to create an environment in which foreign matter does not adhere to the mask.

Therefore, conventionally, as described in, for example, JP-A-59-186320 and JP-A-57-39537, it has been proposed to keep the mask in a sealed state until it is conveyed to a predetermined position.

Further, as described in Japanese Patent Laid-Open No. 54-80082, for example, a foreign matter adhesion prevention film called a pellicle, which is a metal frame with a transparent thin film of nitrocellulose, is attached to the mask, and a new film on the mask is attached. It has been proposed that such foreign matter is less likely to be transferred onto the wafer due to the defocusing effect of the optical system of the exposure apparatus, and it becomes unnecessary to consider the adhesion of minute foreign matter.

[Problems to be solved by the invention]

The former prior art (Japanese Patent Laid-Open No. 59-186320 and Japanese Laid-Open Patent Publication No.
No. 7-39537) does not consider the naked state before the mask is housed in the case.

In general, fine foreign matter is likely to be attached to the surface of the mask in a naked state, so that it may not be possible to obtain a sufficient effect when the mask is taken in and out.

In the latter prior art (Japanese Patent Laid-Open No. 54-80082),
No consideration is given to the attachment of large foreign matter to the surface of the pellicle.

In the pellicle, a large foreign matter may be attached as a probability, and therefore, in consideration of this case, a sufficient effect may not be obtained.

Therefore, it is considered that the mask with the pellicle attached is housed in a case and transported between the apparatuses.

However, when the mask with the pellicle attached is housed in the case, the volume of the case becomes large, so that the storage space becomes a problem in the case of handling a large number of masks.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a mask storage that can store a mask in a clean state in a small storage space.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a storage shelf in which a shelf for holding a plurality of masks having pellicle film bodies mounted on both surfaces is arranged in a room maintained in a clean air flow atmosphere by a clean air unit. A transfer means for moving the mask into and out of the storage shelf, and a foreign material for removing foreign matter adhering to the pellicle film of the mask carried by the transport means and for inspecting the removal of the foreign matter. It is characterized by comprising: removal / inspection means, and case storage / removal means for storing the mask in which the pellicle film bodies are mounted on both surfaces from which the foreign matter has been removed by the foreign matter removal / inspection means in a case and take it out. It is a mask storage device.

[Action]

The present invention enhances the efficiency of the storage space by storing the thin plate in an upright state taken out from the case, while preventing the foreign matter from adhering to the thin plate by storing the thin plate in an atmosphere of a clean air flow. be able to.

Further, the steps of removing foreign matter adhering to the thin plate, inspecting for the presence of foreign matter, accommodating the thin plate in the case, taking it out, and moving it in and out of the chamber are performed in an atmosphere of air flow, so that the foreign matter is added by the intervention of a person. Probability can be suppressed extremely.

[Embodiment] Hereinafter, FIGS. 1 to 11 showing an embodiment of the present invention will be described. FIG. 1 is a sectional perspective view of a mask storage according to the present invention, FIG. 2 is an external perspective view of the mask storage, FIG. 3 is an enlarged sectional side view of the mask storage shelf shown in FIG. 1, and FIG. FIG. 3 is an enlarged perspective view of a sub-post portion of FIG. 3, FIG. 5 is an enlarged perspective view of the mask transport mechanism shown in FIG. 1, FIG. 6 is a partially enlarged perspective view of FIG. 5, and FIG. 8 is an enlarged perspective view of the mask holding mechanism shown in FIG. 8, FIG. 8 is a plan view of the foreign matter removing mechanism and foreign matter inspecting mechanism, FIG. 9 is a front view of an arrow A in FIG. 8, FIG. 10 is a front view of an arrow B in FIG. FIG. 11 is an enlarged perspective view of the case storage and removal mechanism shown in FIG.

In FIGS. 1 and 2, reference numeral 1 is a mask storage, and a mask storage rack 2 in the chamber 10, a mask transfer mechanism 3 , a mask holding mechanism 4, and two vertical casings 510 are installed respectively. A foreign matter removing mechanism 5 (not shown) and a foreign matter inspecting mechanism 6 (not shown) are installed, and a case storing / extracting mechanism 7 is installed, and an opening / closing door 10b is provided in the opening 10a on the opposite side of the mask storage shelf 2. was placed, and foreign matter on the mask 13 of the mask storage shelf 2 chambers, especially the mask storage in the shelf 2 10. the upper position
A clean air unit 11 is installed to reduce the probability that 14 will adhere.

As shown in FIGS. 3 and 4, the mask storage shelf 2 is
A plurality of vertical columns 201 fixed to the floor plate 101, a plurality of main columns 202 horizontally fixed to the vertical columns 201 at intervals in the vertical direction, and the length of each of the main columns 202. Formed from a plurality of sub-posts 203 that are fixed at intervals in the direction and project in a horizontal direction at a right angle, and two V-shaped claws 204 that are fixed at intervals in the longitudinal direction of each sub-post 203. Then, for each of the two claws 204, one mask 13 having two velicles 12 mounted on both sides is held upright.

As shown in FIG. 1, FIG. 3, FIG. 5, and FIG. 6, the mask transfer mechanism 3 includes the mask storage rack on the floor plate 101.
2 , a guide rail 301 fixed parallel to the guide rail 301, and a base on which a Y-direction drive mechanism (not shown) and a Z-direction drive mechanism (not shown) are movably supported on the guide rail 301 and installed therein. A base 302, a post 303 fixed in an upright state on the base 302, and a post 303 slidably supported in the vertical direction (Z direction), and an X-direction drive mechanism (not shown) internally. The X-direction driving unit 304 to be installed is vertically penetrated through the X-direction driving unit 304, and the post 303 is surrounded in the vertical direction to be connected to the Z-direction driving mechanism.
A metal tape 305 for moving the X-direction drive unit 304 in the Z-direction when the Z-direction is moved by the drive of the direction drive mechanism.
And an L-shaped X-direction drive arm 306 that is movably supported in the X-direction by the X-direction drive unit 304 and is connected to the X-direction drive mechanism, and a tip upright wall body of the X-direction drive arm 306.
Installed at both upper and lower ends of 306a, the lower part is fixedly supported,
The upper part is supported by a motor 308 so as to be vertically movable, and two rods 309 for fixing four claws 310 and 311 for respectively holding the upper and lower ends of the mask 13 in the longitudinal direction of the inner facing surface, respectively. Bar code 1 drawn on the mask 13
Bar code reader 312 that reads 2a and confirms that it matches the mask 13 to be taken out from the mask storage rack 2
It is formed from and.

Therefore, in the mask transfer mechanism 3, the Y-direction drive mechanism drives the base 302 to move in the right Y-direction along the guide rail 301, and the Z-direction drive mechanism drives the metal tape 305.
The X-direction drive unit 304 moves in the Z-direction through the two, and the upper and lower two rods 309 are used for the mask 1 to be taken out from the mask storage rack 2.
Move to a position (horizontal and vertical position) that is slightly offset from the position parallel to 3.

Then, the X-direction drive mechanism is driven in advance with the upper rod 309 positioned above by driving the motor 308, and the two upper and lower rods 309 are advanced to predetermined positions via the X-direction drive arm 306.

Then, the Y-direction driving mechanism is driven again to move the base 302 to the guide rail 301 and further move in the Y-direction to move the upper and lower parts 2 above.
When the rods 309 reach the upper and lower opposite end positions of the mask 13, the Z-direction drive mechanism and the motor 308 are driven, and one end portion of the two claws 311 of the lower rod 309 is located behind the mask 13. The upper end of the mask 13 is clamped by the two claws 310 of the upper rod 309 descending while the upper end of the mask 13 is clamped by being inserted above the gap between the end face and the sub-main pillar 203. Get

Then, when the Z-direction drive mechanism is driven and the four claws 310 and 311 lift up the mask 13 via the two upper and lower rods 309 to separate it from the claw 204 of the mask storage rack 2 , the X-direction drive is performed. The mechanism is driven, and the four claws 310 and 311 are retracted in the front X direction with respect to FIG. 5 while holding the mask 13 via the X direction drive arm 306.

Then, when the mask 13 moves backward and the bar code 12a reaches a position opposite to the bar code reader 312, the bar code reader 312 reads the bar code 12a which is moving backward to determine whether or not the mask 13 should be taken out. To detect.

In this case, if the mask 13 detected by the barcode reader 13 is different from the mask 13 to be taken out, the operation of the entire apparatus is stopped by a command mechanism (not shown).

When the mask 13 detected by the barcode reader 13 coincides with the mask 13 to be taken out, the four claws 310 and 311 holding the mask 13 continuously retreat in the front X direction with respect to FIG. When the original position is reached, the Y-direction drive mechanism drives in the opposite direction to the above-mentioned mask 13
There is transfer to the mask holding mechanism 4 reaches transfer position is transported the mask holding mechanism 4 to the left with respect to Figure 5 and so the guide rails 301.

When the transfer of the mask 13 to the mask holding mechanism 4 is completed in this way, the Y-direction drive mechanism drives in the opposite direction to the above case, and the base 302 moves backward in the right Y direction with respect to FIG. After that, the above operation is repeated.

As shown in FIGS. 1 and 7, the mask holding mechanism 4 is a mask holding guide fixed on the floor plate 101 at a position opposite to the mask foreign matter removing mechanism 5 , foreign matter inspecting mechanism 6 and case storing / extracting mechanism 7. A rail 401, a mask holding base 402 that is movably supported on the mask holding guide rail 401, and has a longitudinal (Y direction) drive mechanism (not shown) installed therein, and a mask holding base 402. A mask holding post 403 fixed upright on a base 402 and a mask holding post 403 are rotatably and reciprocally supported by an inner surface of an upper portion of the mask holding post 403 at an angle of 90 ° (between the horizontal direction and the vertical direction). A rotating arm 405 connected to a motor 404 fixed to the opposite side of the mask holding post 403, and this rotating arm.
The rotary arm 4
Two arms 406 that move in a longitudinal direction (Y direction) of the rotary arm 405 and a direction (X direction) perpendicular thereto by a drive mechanism (not shown) installed in the 05,
When the two arms 406 are diagonally spaced from the inner facing portions of the arms 406, that is, when the two arms 406 are at the positions shown in FIG. 7, the facing tips are respectively the two arms 406.
It is formed of four V-shaped claws 407 that are inclined and fixed to the mounting portion in a slanting direction.

The reason for inclining the four claws 407 obliquely is as follows.
As shown in FIG. 6, the four claws 407 are two upper and lower parts for fixing the 310, 311 when holding the upper and lower ends of the mask 13 held by the four claws 310, 311 of the mask transfer mechanism 3. This is to prevent the rod 309 from hitting.

Therefore, the mask holding mechanism 4 is driven by the Y-direction driving mechanism so that the mask holding guide rail 401 moves to the mask holding guide rail 401.
When moving to the right in the Y direction with respect to the drawing and reaching the position for preparation for receiving the mask 13 from the mask transport mechanism 3 , the motor 40
4 is driven, and the rotary arm 405 is rotated 90 ° from the position shown in the figure to be in an upright state.

Then, by driving the driving mechanism in the rotary arm 405, the two arms 406 respectively project in the outer longitudinal direction, and by driving the driving mechanism in the rotary arm 405, the two arms 406 move away from each other. After the movement, when the mask holding mechanism 4 as a whole moves in the right Y direction by the driving of the Y-direction driving mechanism to reach the opposing positions of the upper and lower end portions of the mask 13, the driving mechanism in the rotating arm 406 moves. When driven, the two arms 406 move toward each other, and four claws 407, which are installed on the two arms 406 in a slanting direction, respectively grip the upper and lower ends of the mask 13. .

Then, the motor 308 of the mask transfer mechanism 3 drives the upper rod 309 to move upward, and the Z-direction drive mechanism drives the lower rod 309 to move downward so that the upper and lower rods 309 are installed. 4 nails 3
01 and 311 are separated from the upper and lower ends of the mask 13.

Next, when the motor 404 is driven in the opposite direction to the above case and the rotary arm 405 is rotated 90 ° leftward with respect to FIG. 7 to reach the position shown in the figure (horizontal position), the Y-direction drive is performed. The mechanism drives the two rods 406 and the four claws 4
With the mask 13 held by 07, the mask 13 is moved in the left Y direction with respect to FIG. 7 and inserted between the foreign matter removing mechanism 5 and the foreign matter inspecting mechanism 6 .

After that, the driving mechanism in the rotary arm 405 drives in the opposite direction to pull the two rods 406 inward in the longitudinal direction, and the mask 13 held by the four claws 407 is held. The two pellicles 12 reach the opposite positions of the foreign matter removing mechanism 5 and the foreign matter inspection mechanism 6 , respectively.

Next, when the foreign matter 14 attached to the pellicle 12 is removed by the foreign matter removing mechanism 5 and the absence of foreign matter is inspected by the foreign matter inspecting mechanism 5, the mask 13 is held by the driving of the Y direction drive mechanism 2 The individual rod 406 further moves in the left Y direction with respect to FIG. 7.

After that, the mask 13 is used for the case storage and removal mechanism.
When the upper case 702 of the lower case 16 is reached, the upper and lower stages 702 of the case storing / extracting mechanism 7 are lifted to mount the mask 13 on the four pins 16a on the lower case 16.

Then, when the driving mechanism in the rotary arm 405 is driven in the opposite direction to the above case, the two arms 406 are driven outward from each other, and the four claws 407 are separated from both ends of the mask 13. Then, the transfer to the case storage and removal mechanism 7 is completed.

Then, the upper and lower stages 702 of the case storing / extracting mechanism 7 are lowered and the Y-direction driving mechanism is driven in the opposite direction to move the two arms 406 to the right Y direction with respect to FIG. Move to and return to the original position.

As shown in FIGS. 1, 8 and 9, the foreign matter removing mechanism 5 includes two containers which are vertically spaced from each other.
Nozzles 502 that are installed in the respective 501 and eject N ₂ gas 504 obliquely downward toward the reticle 12 across the reticle 12, and a nozzle 502 inclined at an angle corresponding to the nozzle 502, It is formed of an intake port 503 that absorbs the foreign matter 14 scattered by the N ₂ gas 504 on the reticle 12.

As shown in FIGS. 1, 8 and 10, the foreign matter inspection mechanism 6 is opened in the two containers 501 in a direction orthogonal to the foreign matter removing mechanism 5 in a diagonally downward position toward the reticle 12. And a high-intensity illumination 601 which irradiates the reticle 12 with high-intensity illumination light.
Foreign matter on the pellicle 12 illuminated by the illumination light from
14 is formed using a TV camera (not shown) or the like.

The high-intensity illumination 601 and the detection unit 602 are automatically or manually driven to detect the presence or absence of the foreign matter 14.

As shown in FIGS. 1 and 11, the case accommodating / extracting mechanism 7 has an L shape including a horizontal wall 701a and a vertical wall 701b, and a frame 701 fixed to the floor surface 101 and the horizontal wall 701a. An up-and-down stage 702 which is moved in the up-and-down direction (Z direction) by a drive mechanism (not shown) which has a platform 703 fixed to the upper surface and fixed to the upper surface and which is installed on the upper and lower ends of the vertical wall 701b. Two rotating arms 705 that are rotatably supported in the direction of the arrow and are connected to motors 704 that are fixed to opposite sides of the vertical wall 701b, respectively.
Two case arms fixed to the rotary end of each rotary arm 705 so as to project in the X direction perpendicular to the longitudinal direction thereof.
And 706.

The upper case 15 shown in FIG.
As described in No. 18, it is formed in a box shape with an opening at the lower part, and the two case arms 706 are provided on both end faces thereof.
, The four receivers 15a are fixed so as to be mounted on the upper surface of the receiver. Also, the lower case 16 is the base 70
3 is formed into a raised shape so as to engage with the upper side, and the two case arms 706 are mounted on the upper surface when the two case arms 706 are rotated 90 ° downward from the position shown in the figure to the outer position. The flat plate-shaped protrusion 16a is fixed to one body, and four pins 16b protruding upward at the center of the upper surface and mounting the mask 13 on the upper end are fixed.

Therefore, the case accommodating / extracting mechanism 7 drives the two motors 704 in advance to rotate the two case arms 706 through the two rotating arms 705 to the outer positions 90 ° below the illustrated position. To move.

Then, when the upper and lower stages 702 rise, the upper case 1
5 and lower case 16 are vertically stacked and the outlet 1
The protrusion 16a of the lower case 16 is held so as to be mounted on the table 703 from the position 7.

Then, when the upper and lower stages 702 descend, the two motors 704 are driven at the same time, and the two case arms 706 are further inwardly rotated via the two rotating arms 705. The lower case 16 and the upper case 15 are separated from each other by lifting the receiver 15a provided on the.

Then, the upper and lower stages 702 mount only the lower case 16 on the table 703 and descend to the position shown in the figure.

In this state, the mask holding mechanism 4 is used to remove the foreign matter removing mechanism 5.
And when the mask 13 from the foreign matter inspection mechanism 6 is mounted on the four pins 16a on the lower case 16, the upper and lower stages 702 are raised in the opposite direction to the above, and the two motors 704 are Since the two case arms 706 rotate downward by driving in the opposite direction to the above case, the lower case 16 is stacked on the upper lower case 15 and is used for the two cases. The arm 706 separates from the receiver 15a of the upper case 15.

Further, when the upper and lower stages 702 continue to rise, the upper case 15 and the lower case 16 are taken out from the taking-out port 17 in a stacked state.

Then, when the upper case 15 and the lower case 16 are taken out to the outside, the next upper case 15 and the lower case 16 are mounted on the table 703, the upper and lower stages 702 descend, and the above-described operations are repeated. .

When the mask 13 is stored in the mask storage rack 2 , the above steps can be performed in reverse.

However, during storage, a procedure for registering the mask 13 stored by the barcode reader 312 is added.

The clean air unit 11 discharges clean air from the air outlet 12 toward the mask storage shelf 2 .

Since the mask storage 1 according to the present invention is configured as described above, the air outlet 102 of the clean air unit 11 is provided inside the chamber 10.
A clean atmosphere is maintained by discharging clean air.

In this state, the mask 13 to be taken out, which is held upright by the two claws 204 in the mask storage shelf 2 , is to be taken out.
When the four claws 301 and 311 of 3 are gripped, the mask 13 is conveyed in the Y direction by the guide rail 301 of the mask conveying mechanism 3 . At this time, if it is different whether or not the mask 13 should be taken out even if the bar code reader 213 reads the bar code 12a installed on the mask 13, the entire apparatus stops.

Therefore, the mask to be taken out from the mask storage shelf 2
13 is surely taken out.

Then, when the mask 13 reaches the delivery position between the mask holding mechanism 4, the rotary arm 405 of the mask holding mechanism 4
Is rotated 90 ° upward from the position shown in FIG. 7 and is in an upright state, that is, the mask 13 held by the mask transfer mechanism 3
The four claws 407 held in parallel with the rotary arm 405 via the two loads 406 grip the upper and lower end portions of the mask 13, and at this time, the mask transfer mechanism 3 has four pins.
The individual claws 310 and 311 move outward to be separated from the upper and lower end portions of the mask 13, and move toward the original mask storage rack 2 by the guide rail 301.

Then, when the rotating arm 405 of the mask holding mechanism 4 rotates in the opposite direction, that is, downward by 90 ° in the above case and becomes horizontal, the four pawls 407 are passed through the two loads 406.
Moves the mask 13 in the left Y direction with respect to FIG. 7 to insert the mask 13 between the foreign matter removing mechanism 5 and the foreign matter inspecting mechanism 6 .

Then, when the two loads 406 are pulled inward in the longitudinal direction, the two pellicles 12 installed on the upper and lower surfaces of the mask 13 reach the positions facing the foreign matter removing mechanism 5 and the foreign matter inspecting mechanism 6 , respectively. In this state, the foreign matter removing mechanism 5
Spouts N ₂ gas 504 from the nozzle 502 to cause the pellicle 12
The foreign matter 14 on the top is scattered, and the scattered foreign matter 14 is absorbed by the intake port 503. Further, the foreign matter inspection mechanism 6 irradiates the pellicle 12 with high-intensity illumination light from the high-intensity illumination and
The detection unit 602 detects the presence or absence of the foreign matter 14 on the surface 12. In this way, when the detection unit 602 detects that there is no foreign matter 14 on the pellicle 12, the mask holding mechanism 4 is driven to mask the mask.
13 further moves in the left Y direction with respect to FIG.

Then, the mask 13 reaches between the upper case 15 preliminarily mounted on the two case arms 706 of the case accommodating / removing mechanism 7 and the lower case 16 preliminarily mounted on the base 703. When the two pellicles 12 installed on the upper and lower surfaces of the mask 13 face the upper case 15 and the lower case 16, the upper and lower stages 702 move upward to move the lower case 1
The mask 13 is mounted on the four pins 16b in the pin 6.

Further, as the upper and lower stages 702 move up,
When the case arms 706 rotate outward, the upper case 15 is mounted on the lower case 16 and the four case arms 15a of the upper case 15 are used to move the two case arms.
After the 706 are separated, the upper case 15 and the lower case 16 are
Is taken out from the take-out port 17.

Therefore, foreign matter that adheres to the pellicle of the mask is removed and detected in a room with clean air, and after detecting that there is no foreign matter, it is housed in the case and discharged to the outside, so foreign matter adheres to the pellicle. It is possible to prevent this from happening, and it is possible to store a large amount of masks in a small space and remove the foreign substances on the pellicle to store the masks in the case.

Needless to say, the structure of the case storage / removal mechanism in the above-described embodiment is not limited to this, and may be changed at any time depending on the type and storage / removal method of the mask and case. .

〔The invention's effect〕

As described above, according to the present invention, many masks are always kept in a clean state in a small space, and after the foreign matter on the pellicle is removed, the mask is housed in the case and taken out to the outside. The yield in the semiconductor exposure process can be improved.

[Brief description of drawings]

1 is a sectional perspective view of the present invention applied to a mask storage, FIG. 2 is an external perspective view, FIG. 3 is an enlarged sectional side view of the mask shelf shown in FIG. 1, and FIG. FIG. 5 is an enlarged perspective view of the auxiliary column portion of the figure, FIG. 5 is an enlarged perspective view of the mask transport mechanism shown in FIG. 1, FIG. 6 is a partially enlarged perspective view of FIG. 5, and FIG. 7 is shown in FIG. 8 is an enlarged perspective view of the mask holding mechanism, FIG. 8 is a plan view of the foreign matter removing mechanism and foreign matter inspecting mechanism in the container shown in FIG. 1, FIG. 9 is a front view of an arrow A in FIG. 8, and FIG.
FIG. 11 is a front view of the arrow B, FIG. 11 is a case storage shown in FIG.
It is an expansion perspective view of an extraction mechanism. 1 ... Mask storage cabinet, 2 ... Mask storage rack, 3 ... Mask transport mechanism, 4 ... Mask holding mechanism, 5 ... Foreign matter removing mechanism, 6 ... Foreign matter inspection mechanism, 7 ... Case storage, take-out mechanism, 10 ... Chamber, 11 ...
Clean air unit, 12 ... Pellicle, 13 ... Mask, 14
… Foreign matter, 15… Upper case, 16… Lower case.

Claims (1)

[Claims] 1. A storage shelf in which a shelf for holding a plurality of masks having pellicle membranes mounted on both surfaces is arranged in a room maintained in a clean air flow atmosphere by a clean air unit, and the mask is provided by the storage shelf. Transporting means for loading and unloading and transporting the foreign matter, foreign matter removing / inspecting means for removing foreign matter adhering to the pellicle film of the mask transported by the transporting means, and for inspecting the removal of the foreign matter; A mask storage device comprising: a case storing / removing unit that stores a mask having pellicle film bodies mounted on both sides from which foreign substances have been removed by the foreign substance removing / inspecting unit and stores the mask in the case.