JPH0269955A - Mask loading mechanism - Google Patents

Abstract

PURPOSE:To prevent dusts from adhering onto a mask board and to simplify a loading mechanism by using means for opening or closing a mask substrate cassette when the cassette is loaded in a chamber for sealing from the atmosphere also as means for feeding it to a desired position in a chamber. CONSTITUTION:The door MCHD of a mask chamber MCH is opened, and a cassette of the state that a cassette body MCH is coupled to a cassette cover MCC to seal its interior is placed on a table. Then, the door MCHD is closed, the chamber MCC is evacuated in vacuum, He gas is filled therein, the table is raised by an elevator EA, and a mask substrate MF is moved to a desired position. Thus, the functions of a separating mechanism for separating the body MCM from the cover MCC and a selecting mechanism for the substrate MF are provided in a body chamber WMC, and a predetermined exposure is conducted in the chamber WMC. When it is finished, the door MCHD is opened by a reverse operation thereto to be opened with the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a mask cassette loading mechanism suitable for application to an X-ray exposure apparatus or the like.

[Prior Art] Conventionally, reticle substrates and mask substrates (transfer patterns) used in optical exposure apparatuses have generally been stored one by one in storage containers (hereinafter referred to as cassette cases) for dustproofing or storage.

The number of cassette cases containing reticle substrates and the like required for the exposure process is loaded into a reticle loader attached to the exposure apparatus.

When sequentially loading reticle substrates and the like from a reticle loader during exposure, the exposure apparatus first selects a desired cassette case of the reticle loader. The selected cassette case is extracted from the reticle loader by the reticle transport mechanism, and then the ejection port of the cassette case is opened by a part of the reticle transport mechanism. Furthermore, the desired reticle substrate in the opened cassette case is taken out from the cassette case by the reticle changer of the reticle transport mechanism and transported to a predetermined position. After a predetermined amount of exposure is completed, the reticle substrate is stored in a cassette case by a reticle transport mechanism, and the next cassette case is prepared.

At this time, the conventional reticle loader is driven in the atmosphere. Each reticle substrate is stored in each cassette case. Therefore, the reticle case containing the desired reticle is selected by the selection device, the door of the reticle cassette is opened by an opening device of a part of the transport mechanism, and the reticle substrate is opened by another device of the transport mechanism. It is taken out from the cassette case and transported to a predetermined position.

[Problem to be solved by the invention] However, in the conventional example described above, the exposure atmosphere of the exposure apparatus is normally in the atmosphere, and the exposure atmosphere is only controlled by temperature and humidity, and the pressure of the ambient air τ is equal to atmospheric pressure. dependent. However, among exposure devices, the exposure atmosphere of an X-ray exposure device is an inert gas in a low vacuum (or low pressure). Therefore, it has been difficult to apply the reticle transport mechanism of the conventional apparatus to the reticle transport mechanism of an X-ray exposure apparatus.

Furthermore, when a load lock mechanism for sample exchange in a conventional vacuum apparatus is combined with the reticle transport mechanism, the mechanism becomes complicated and the configuration becomes difficult.

Further, although it is relatively easy to manage dust and dust in a reduction optical exposure system, managing them becomes a very important issue in an X-ray exposure system.

The reason for this is as follows. In other words, in the case of a reduction optical system exposure device, the size of the transferred pattern on the reticle substrate is, for example, five times the burned size of the transferred object, and therefore the size to be controlled for dust and dust is relatively large. , management on the reticle substrate is easy. but,
The X-ray exposure apparatus transfers the pattern on the mask substrate at the same magnification, and the pattern size is thinner than the conventional printing size (on the transferred object), for example, as shown in the figure. Due to these factors, the dimensions at which dust and dirt can be managed are, for example, 1.
/20 is required. Therefore, it is no longer possible to ignore sources that were not a problem in the past.

For example, when loading reticles from a cassette case, the cassette case must be opened for each reticle. At this time, dust and the like may be deposited on the reticle due to dust being blown up near the dust opening from the hinge. The microscopic dirt and dust generated during this process also poses a problem.

The purpose of the present invention is to solve the problems in the conventional example described above.
A mask that allows loading of mask substrate cassettes with a simple configuration even in environments where the atmosphere is blocked, such as in an X-ray exposure device, and that also suppresses the generation of microscopic dirt and dust. The object of the present invention is to provide a cassette loading mechanism.

[Means for Solving the Problems] In order to achieve the above object, a mask cassette loading mechanism according to the present invention is a mechanism that loads a mask substrate cassette that stores a mask substrate in a chamber that blocks the atmosphere. , when a plurality of mask substrate cassettes can be stored, the means for opening and closing the mask substrate cassette and the means for transporting the mask substrates in the mask substrate cassette to a desired position within the chamber are the same. It is characterized by being

Further, the desired position of the mask substrate may be above a certain position of the mask substrate cassette before opening and closing the mask substrate cassette.

Furthermore, pressure measuring means and at least one gas inlet are provided within the chamber.

[Function] According to the above configuration, the mask substrate cassette can be loaded without exposing the mask substrate to the atmosphere during normal operation during storage and use.

Therefore, deterioration of the mask substrate due to reactive gases contained in the outside air is reduced.

In addition, a bulk storage type mask substrate cassette is used, and the same drive mechanism is used to open/close the mask substrate cassette, load it, and transport it to the desired position. It can be done without reducing
Cleanliness inside the chamber is maintained.

Furthermore, the gas pressure inside the mask substrate cassette can be easily controlled.

Furthermore, after opening and closing, the mask substrate cassette is located above its previous position, and is away from the loading section where dust or the like may occur at least. therefore,
Mask deterioration due to dust, dirt, etc. will be reduced.

[Example code] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a sectional view of a mask cassette portion and a mask loader portion of an X-ray exposure lid to which a mask cassette loading mechanism according to an embodiment of the present invention is applied.

In the figure, MF indicates a mask substrate (including a reticle substrate). The mask substrate MF consists of a ring-shaped support member and a thin film member attached to the ring member, and a transfer pattern is provided in the center of the thin film member. However, the shape of the mask substrate MF does not have to be circular.

MCM is a mask cassette body that accommodates the mask substrate MF. A plurality of mask substrates MF (for example, 20) are stored in the mask cassette main body MCM, and each mask is arranged vertically and radially. Further, the mask substrate MF is normally held and fixed by a magnetic unit provided in the mask cassette main body MCM. However, the mask substrate M
The arrangement method of F is not limited to this, and may be placed horizontally. Moreover, the fixing method may also be mechanical.

MCC is a cassette cover that covers and seals the mask cassette main body MCM. In FIG. 1, the mask cassette main body MCM and the cassette cover MCC are shown separated, but normally they are sealed and have an airtight structure. In this embodiment, the mask cassette has a cylindrical shape, but it may also be a rectangular parallelepiped or the like. Also, sealing is indicated by an O-ring or U-packet. Therefore, when the mask cassette is integrated, there is substantially no gas flow between the inside and the outside.

TT is a turntable connected to the mask cassette main body MCM and used to select a desired mask substrate MF.

Since the mask substrates MF are arranged radially on the mask cassette main body MCM, the mask cassette main body MCM is rotated in the direction of arrow A in order to sort the mask substrates MF. Therefore, the mechanism for selecting mask substrates MF differs depending on how the mask substrates MF are arranged.

ER is an elevator rod attached to the turntable TT, which separates the mask cassette main body MCM from the cassette cover MCC and moves the mask substrate MF to a desired position for receiving and passing.

In this embodiment, the mask cassette main body was moved upward and the cassette cover MCC was kept stationary, but since the separation method differs depending on the configuration of the mask cassette, it is not necessary to separate it in the vertical direction.

EA is an elevator that drives the elevator lot ER, and in this embodiment, an air cylinder is used. However, hydraulic or other drive mechanisms may also be used.

Furthermore, although in this embodiment the turntable TT is driven via the elevator rod ER, it is also possible to put the elevator EA into the mask chamber MCH (described later). MCH is a mask chamber for separating the mask cassette main body MCM and the cassette cover MCC from outside air when separating the mask cassette main body MCM and the cassette cover MCC.

WMC is a main body chamber for performing X-ray exposure.

Mask chamber MCH and elevator EA are taken into main body chamber WMC. However, the elevator EA may be attached to the mask chamber MCH.

MCHD is the door of mask chamber MCI.

Mask cassettes are taken in and out or replaced by opening and closing this door MCH. Generally, there is an interlock on the door MCH.

GPI and GP2 are gas ports attached to the mask chamber MCH. And Vl.

■2 is the gas port GPI, GP2 valve. The valve can be either manual or electric.

EP is an exhaust port of mask chamber MCH. The exhaust port MCH is connected to a vacuum pump (not shown).

Further, the EV is an exhaust valve and controls exhaust gas.

PG is a pressure gauge that monitors the pressure in the mask chamber MCH. GV is main body chamber WMC and mask chamber M
It is a gate valve between CH. The mask substrate MF passes through this gate valve GV and is carried into the main body chamber WMC.

MH is a mask hand for carrying the mask substrate MP into the main body chamber WCH or returning it to the mask cassette main body MCM. The shape of the mask hunt MH is not limited to the disclosed shape due to the shape of the mask substrate MF, etc.

Further, the mask substrate MF may be handled by mechanical clamping or by vacuum chuck. Further, the direction in which the mask hand MH moves differs depending on the shape and structure of the mask cassette.

FIG. 2 is a perspective view of the apparatus of this embodiment shown in FIG. 1.

Next, the operation of the apparatus of this embodiment will be explained in order with reference to FIGS. 1 and 2. In Figure 2(a),
First, open the door MCHD of the mask chamber MCH. Then, the mask cassette body MCM and the cassette cover MCC
The mask cassette connected to the mask chamber MC
Place it on turntable TT in H. At this time, the mask cassette main body MCM is fixed to the turntable TT,
Cassette cover MCC is fixed to mask chamber MCH. The fixing method may be by using an actuator or manually. Moreover, the method of fixing it does not matter.

In this embodiment, it is locked manually.

Next, the door MCHD is closed and sealed. Then, the exhaust valve EV shown in Fig. 1 is opened, and the mask chamber MC is opened using a vacuum pump.
Make a vacuum inside H. At this time, the degree of vacuum (pressure) is pressure i1
Monitor with PG. When the degree of vacuum reaches a predetermined value, the exhaust valve EV is closed.

Next, open the solenoid valve V2 and start flowing nitrogen N2.

Then, the pressure inside the mask chamber MCH is set to a predetermined pressure. In the case of this embodiment, this predetermined pressure is the same pressure as the pressure inside the mask cassette, for example, atmospheric pressure (760 Torr).
), and the inside of the mask cassette is exposed to a certain atmosphere. Therefore, the solenoid valve v2 is closed when the differential pressure between the mask chamber MCH and the mask cellar 1 becomes zero. This predetermined pressure can be any value, but
It is desirable that the pressure be close to atmospheric pressure. By setting the pressure near atmospheric pressure, the force required to hold the mask cassette cover MCC of the mask cassette can be reduced.

Next, drive the elevator EA to drive the elevator rod ER.
move upward. The stopping position is set in advance at elevator E.
It is adjusted by actuator A (air cylinder in this embodiment). When the elevator rod ER rises, the mask cassette main body MCM and the cassette cover MCC are separated as shown in FIG. 2(b), and the mask substrate MF is separated.
is guided to a position where it can be operated by Mask Hunt MH.

Next, the mask chamber MCH is filled with nitrogen N2.
To create a vacuum, the exhaust valve EV is opened and exhaust is performed using a vacuum pump (not shown) until a predetermined pressure is reached. The pressure gauge PG indicates that the inside of the mask chamber MCH has reached the predetermined pressure.
After confirming this, the exhaust valve EV is closed and the solenoid valve v1 is opened. Then, helium He is introduced into the mask chamber MCH. When the pressure in the mask chamber MCH becomes substantially equal to the pressure in the main body chamber WMC, the electromagnetic valve 1 is closed and the introduction of helium He is stopped.

After the series of operations described above is completed, gate valve GV that communicates main body chamber WMC and mask chamber MCH is opened. The mask hand MH in the main body chamber WMC enters the mask chamber MCH to carry in the mask substrate, and after gripping the mask substrate MP, the mask hand MH is transferred to the main body chamber WMC.
Take it inside.

Next, the procedure for taking out the mask cassette from the mask chamber MCH in order to exchange the mask cassette after the end of X-ray exposure or to shut down the apparatus will be described below.

After the mask substrate MF in the main body chamber WMC is returned to the predetermined mounting position of the mask cassette main body MCM, the gate valve GV communicating between the main body chamber WMC and the mask chamber MCH is closed.

Next, the exhaust valve EV is opened and the inside of the mask chamber MCH is evacuated by a vacuum pump (not shown).

When the pressure gauge PG reaches a predetermined pressure, close the exhaust valve EV, immediately open the solenoid valve ■2, and open the mask chamber MCI (
Nitrogen N2 is introduced into the tank. When the mask chamber MCH reaches a predetermined pressure, the solenoid valve (2) is closed. In this embodiment, this pressure value is atmospheric pressure, but it does not have to be atmospheric pressure.

Next, the elevator EA is driven to lower the elevator rod ER. By lowering the elevator lot ER, the mask cassette main body MCM and the cassette cover MCC are combined, and the inside of the mask cassette is sealed with nitrogen N2 atmosphere. Furthermore, mask chamber MCH
After making the inside pressure the same as the outside air pressure, open 5jMCHD.

In this embodiment, a purge valve is provided although not shown. Mask cassette body MCM and turntable TT lock, cassette cover MCC and mask chamber M
Each CH is unlocked and the mask cassette is taken out from the mask chamber MCH.

Operate the mask cassette using the above steps.

The gases used in this example are helium He and nitrogen N.
In particular, nitrogen N2 may be a plurality of active gases such as Ar. Further, it is also possible to use only helium He to create a single gas line and omit some of the configuration steps, but this is not so desirable since helium He is difficult to seal. In this embodiment, N2 is used in consideration of cost and risk.

By operating the mechanism and procedure of this embodiment as described above, the following effects can be obtained.

(1) The mask substrate MF has no contact with the atmosphere from beginning to end. This reduces deterioration of the mask substrate.

This is because the atmosphere becomes substantially free of water vapor, reactive gases, etc. contained in the atmosphere.

(2) The mask substrate MF is protected from dust, dirt, etc.

As mentioned above, the mask substrate MF must be reliably protected from dust and dirt. In this embodiment, a plurality of mask substrates MF are collectively managed in a mask cassette main body MCM. When accessing the mask substrate MF, in the past, each mask had a cassette, so the cassette had to be opened and closed each time, but in this embodiment, opening and closing is performed only when loading the mask cassette, and the cassette cannot be opened or closed midway. There is no. Therefore, waste generation is reduced. Therefore, the cleanliness inside the mask chamber MCH is maintained.

(3) The position where the mask hand MH receives and passes the mask substrate MF is located below the mechanism that loads the mask cassette cover MCC, and at least dust and dirt generated on the mask cassette cover MCC during loading of the mask hand MH are removed. is difficult to place on the mask substrate. Therefore, the possibility of deterioration of the mask substrate due to loading of the cassette cover MCC is reduced.

(4) By opening and closing the mask cassette according to the above-described procedure, the pressure and gas inside the mask cassette can be easily controlled.

Next, a cassette loading mechanism different from the mask cassette described above will be described.

FIG. 3 is a perspective view of a cassette loading mechanism according to a second embodiment of the present invention. MCH is a mask chamber, and this figure shows a cutaway view of this mask chamber MCH.

Hereinafter, the explanation will focus on the parts that are different from FIG. 1.

In FIG. 3, MCM indicates the mask cassette body.

In this embodiment, a plurality of mask substrates MF are held horizontally. The retention mechanism is mechanical. T is a table on which the mask cassette main body MCM is placed. E
R is an elevator rod, which is a support rod for moving the table T up and down. EA is an elevator and is a drive mechanism for the elevator rod ER. In this embodiment, a ball screw feeding mechanism is used, and this ball screw is driven by a stepping motor (not shown). BM is a motor board, and the above-mentioned stepping motor is attached here. In this embodiment, the main part of the elevator EA is located outside the mask chamber MCH, and the drive is transmitted into the mask chamber MCH via the elevator rod ER.

MH indicates a mask hand. In this embodiment, the mask band MH performs a gripping operation using a plunger to handle the mask substrate MF. WMC is the body chamber and G is the cage hole. The mask chamber MCH and the main body chamber WMC communicate with each other through the gate hole G. The mask substrate MF is transported into the main body WMC through this gate hole G. At this time, mask hand MH
is driven by a wire and interlocking guide.

Further, the gas boat GP, exhaust boat EP, pressure gauge PG, etc. shown in the previous embodiment (FIG. 1) are attached to the wall of the main body chamber WMC, but are not shown.

Next, the operating procedure of the mechanism shown in FIG. 3 will be explained, focusing on the differences from the previous embodiment.

First, the door MCHD of the mask chamber MCH is opened, and the mask cassette with the mask cassette main body MCM and the mask cassette cover MCC connected and sealed internally is placed on the table T. Thereafter, the door MCHD is closed and the main body chamber is evacuated to a predetermined pressure. mask chamber MC
Since C and main body MCH communicate through gate hole G,
The pressure is always maintained the same. Therefore, when the main body chamber MCH is evacuated, the mask chamber MCC is also evacuated. Thereafter, helium He gas is introduced through a gas inlet (not shown) until a predetermined pressure is reached. Thereafter, the table T is started to be driven upward by the elevator EA. At this time, the transfer position between the mask hand MH and the mask substrate receiver is at a predetermined height, and the desired mask substrate MF is driven to that position. In this embodiment, elevator E
Since A is a ball screw feed, it also serves as a positioning mechanism. Therefore, it has the functions of both a separating mechanism for the mask cassette main body MCM and the mask cassette cellar 1-cover MCC, and a selection mechanism for the mask substrate MF.

After the prescribed exposure is completed in the main body chamber WMC,
All mask substrates MF are stored in the mask cassette main body MCM. Thereafter, the mask cassette main body MCM is connected to the mask cassette cover MCC by the elevator EA. Then, the main body chamber WCH is opened to the atmosphere. The mask cassette of this embodiment is designed to withstand external pressure, and is substantially sealed after the mask cassette cover MCC and the mask cassette main body MCM are connected. Therefore, the inside of the mask cassette is maintained at a predetermined pressure with helium He. Thereafter, the door McHD of the mask chamber MCH is opened and the mask cassette is taken out. Load using the above steps.

In addition to the effects of the first embodiment, the second embodiment described above has the advantage that only one exhaust system gas introduction system is required because the main chamber WCH and the mask chamber MCH are in communication. In addition, since there is no gate valve, there are fewer places where dust and the like can occur.

In addition, since the elevator EA also serves as a mask substrate selection mechanism, the loading mechanism for the mask cassette is not located inside the mask chamber MCH, which saves the labor of the mechanism and reduces the number of places where dust can occur. The cleanliness inside the mask chamber MCH can be maintained at a high level.

[Effects of the Invention] As explained above, the cassette loading mechanism according to the present invention has the following effects.

(1) The possibility of dust, dirt, etc. adhering to the mask substrate can be reduced, which has the effect of preventing mask deterioration and extending the life of the mask.

(2) The loading mechanism of the mask substrate cassette is simplified in the chamber, which is effective in terms of space and cost.

[Brief explanation of the drawing]

1 is a side view of a mask cassette loading mechanism according to a first embodiment of the present invention, FIG. 2 is a perspective view for explaining a mask cassette loading procedure, and FIG. 3 is a side view of a mask cassette loading mechanism according to a first embodiment of the present invention. FIG. 2 is a perspective view of a mask cassette loading mechanism according to an embodiment of the present invention. MCH + mask chamber, TT, turntable, ER: elevator lot, EA: elevator, Vl, V2: solenoid valve, GPI, GP2: gas port, PG: pressure gauge, GV: gate valve, EP/exhaust boat, WMC: main body Djanba.

Claims (3)

[Claims] (1) A mechanism for loading a mask substrate cassette that stores mask substrates in a chamber shut off from the atmosphere, including a means for opening and closing the mask substrate cassette and a mechanism for loading the mask substrates in the mask substrate cassette in the chamber. A mask cassette loading mechanism characterized in that the means for transporting the mask cassette to a desired position are the same. (2) The mask cassette loading mechanism according to claim 1, wherein the position of the mask substrate after transportation is higher than the position of the mask substrate before opening and closing of the mask substrate cassette. (3) The mask cassette loading mechanism according to claim 1 or 2, wherein the chamber is provided with pressure measuring means and at least one gas inlet.