JP3214494B2 - Holder and exposure system, device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for manufacturing a semiconductor element, a liquid crystal display element, and the like, and more particularly to an apparatus for controlling environmental conditions in a chamber for accommodating the exposure apparatus while substantially blocking the exposure apparatus from the outside air. It is.

[0002]

2. Description of the Related Art In recent years, in a lithography process for manufacturing a semiconductor device or a liquid crystal display device, a mask or a reticle (hereinafter, referred to as a "reticle") has been used.
The pattern of a reticle is simply called a photosensitive substrate (a semiconductor wafer or glass plate with a resist layer formed on the surface).
A projection exposure apparatus (stepper) of a step-and-repeat method is frequently used as an apparatus for transferring the image onto the upper surface. For example, in a stepper for manufacturing a liquid crystal display element, an image of each reticle pattern is exchanged at an equal magnification via a projection optical system while exchanging a plurality of reticles, and sequentially connected and transferred onto a glass plate while stepping a plate stage. Go. This makes it possible to form a large-area circuit pattern synthesized (joined) on the glass plate.

A stepper of this type includes a projection optical system for forming and projecting an image of a reticle pattern on a glass plate, and a plate stage which holds the glass plate and is two-dimensionally movable within an image plane of the projection optical system. Having at least one holding member capable of holding a glass plate, carrying the glass plate held by the holding member into the exposure processing unit, and performing the exposure processing in the exposure processing unit. And a substrate transport unit that transports the glass plate to the same or different holding members. As a holding member, for example, a plate storage carrier capable of storing a plurality of (about 10 to 20) glass plates, or a stepper and a coater / developer in-line to adjust a plate transport cycle time. There is a buffer cassette or the like for temporarily storing a glass plate.

In the stepper having the above-described structure, an image of the projection optical system is formed by a change in environmental conditions (atmospheric pressure, temperature, humidity, etc.) around the projection optical system, and a change in temperature due to absorption of exposure light by the projection optical system. Characteristics (focal position, projection magnification, etc.) may fluctuate. Therefore, the entire apparatus (the exposure processing section and the substrate transport section) is maintained at a constant temperature (for example, 23 ° ± 0.1 ° C.)
It is housed in a chamber controlled to a certain degree of cleanliness (for example, class 10) while being substantially shielded from outside air. In addition, a technique has been proposed to efficiently prevent fluctuations in the imaging characteristics by controlling the temperature of only the projection optical system that has an important effect on the imaging characteristics using a fluid whose temperature is highly controlled. I have.

[0005]

In the prior art as described above, a stepper is used in a chamber whose temperature is controlled with an accuracy of about ± 0.1 ° C. Alternatively, when the glass plates are carried into the chamber one by one, the glass plates equilibrate to a temperature substantially equal to the temperature in the chamber. However, the plate stage (especially a holder) of the exposure processing unit is used to transfer heat energy to the stage through the glass plate during pattern exposure on the glass plate and to store the thermal energy, or a driving system of the plate stage (for example, a feed screw mechanism). In the case of (1), the temperature in the chamber is equilibrated to a temperature different from the temperature in the chamber due to heat or the like generated from the nut screwed to the feed screw. Therefore, the temperature difference between the glass plate taken out of the plate carrier by the substrate transfer device (plate loader) and placed on the plate stage (holder) of the exposure processing unit becomes almost zero. Until the temperature of the plate stage reaches a temperature substantially equal to the temperature of the plate stage.

Accordingly, until the temperature of the glass plate reaches an equilibrium state, the glass plate continues to undergo dimensional changes. If pattern exposure is performed on the glass plate during this time, a plurality of reticle patterns on the glass plate are exposed. There is a problem that the joining accuracy or the accuracy of overlaying (aligning) the projected image of the reticle pattern on the pattern already formed on the glass plate is reduced. In order to prevent this, the temperature difference between the glass plate and the plate stage (holder) becomes negligible or almost zero (in other words, a decrease in the joining accuracy or alignment accuracy due to a dimensional change of the glass plate is determined. The exposure operation needs to be stopped until the allowable value (a value determined by the pattern line width or the like) is reached, but there is a problem that the stop time reduces the throughput of the exposure apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and the alignment accuracy (or joining accuracy) and throughput due to dimensional change of a photosensitive substrate in an exposure processing unit until the photosensitive substrate is thermally equilibrated. It is an object of the present invention to obtain an exposure apparatus capable of preventing the reduction.

[0008]

Means for Solving the Problems The invention according to claim 1
Is a holding device for holding a substrate,
The substrate is positioned to transfer turns onto the substrate
Separate from the stage that holds the substrate at the exposure position
And a holder for holding a substrate to be exposed at the exposure position.
In the holding device, the temperature of the held substrate is directly adjusted.
Knot means are provided.

[0009]

According to the first aspect of the present invention, the putter on the mask is provided.
Exposure where the substrate is positioned to transfer the pattern onto the substrate
The substrate to be exposed at the position is the substrate at the exposure position.
Adjusting means for a holding device provided separately from the stage for holding
Temperature is controlled directly by So, on stage
The temperature of the substrate can be adjusted outside.

Therefore, the temperature of the photosensitive substrate before being carried into the exposure processing section can be set substantially equal to the temperature of the stage (holder) in the exposure processing section. Therefore, it is not necessary to stop the exposure operation until the photosensitive substrate is thermally equilibrated in the exposure processing unit, and the throughput of the exposure apparatus can be improved without lowering the alignment (or joining) accuracy. It becomes possible.

[0011]

FIG. 1 is a view showing a schematic overall configuration of an exposure apparatus according to an embodiment of the present invention. Here, an exposure apparatus housed in a chamber is viewed from above. As shown in FIG. 1, in the present embodiment, the entire apparatus is housed in two sets of chambers MC and SC, almost insulated from outside air. The main chamber (first chamber of the present invention) MC is an exposure processing section P having a projection optical system 7 for forming and projecting a reticle pattern on a glass plate.
The sub-chamber (second chamber of the present invention) SC includes two sets of plate carriers PC1 and PC2, and carries the glass plate stored in the carrier PC1 (or PC2) into the exposure processing unit PE. And a substrate transporter (plate loader) PL for carrying out the glass plate exposed by the exposure processor PE to the carrier PC1 or PC2.

In this embodiment, the glass plate to be carried into the exposure processing unit PE is stored in the carrier PC1, and the glass plate taken out of the carrier PC1 and having the pattern transferred by the exposure processing unit PE is transferred to the carrier by the plate loader PL. It shall be stored in PC2. Also,
As shown in FIG. 1, the glass plate can be transferred between the main chamber MC and the sub-chamber SC.
An opening AP is formed at a part of the boundary.

The plate carriers PC1 and PC2 can be raised and lowered, that is, a supporting member E that can move in a direction perpendicular to the plane of the drawing.
V1 and EV2, the supporting members EV1 and EV
2 is lowered to support members EV1 and EV2 and carrier transport wagon PW via doors SD1 and SD2.
And the carriers PC1 and PC2 are exchanged. In FIG. 1, an environmental sensor for detecting environmental conditions (temperature, atmospheric pressure, etc.) in the sub-chamber SC, particularly in the present embodiment, around a plate carrier PC1 holding a glass plate to be carried into the exposure processing unit PE. 26 are arranged.

In this embodiment, it is sufficient that only the temperature of the glass plate in the carrier PC1 or the temperature around the glass plate can be detected. For example, the glass plate (or the carrier PC1)
May be measured directly or indirectly by a temperature sensor. Since the glass plate in the plate carrier PC2 may be carried into the exposure processing unit PE in some cases, it is desirable to dispose an environment sensor near the carrier PC2.

FIG. 5 is a perspective view showing a specific structure of the plate loader PL. The glass plate PT in the carrier PC1 is taken out by vacuum-adsorbing the back surface of the glass plate PT by a transfer member (arm) 70. Each of the plurality of glass plates in the carrier PC1 moves the carrier PC1 and the transfer arm 70 relative to each other in the Z direction. That is, in this embodiment, the carrier PC1 is moved up and down by the support member EV1 (FIG. 1). It is taken out of PC1 by the transfer arm 70.

After the transfer arm 70 holding the glass plate PT is rotated by 90 ° in the XY plane, the glass plate PT is moved to the transfer arm 70 by a pre-alignment mechanism 71 attached to an arm turning portion (not shown). Alignment. The pre-aligned glass plate PT is transferred to a load arm 73 via a transfer table 72 movable in the Z direction, and the plate stage PS waiting at a predetermined position in the exposure processing unit PE by the load arm 73. And is adsorbed by the holder PH. The transfer table 72 can transfer the glass plate PT to the load arm 73 by rotating the glass plate PT by 90 ° when necessary.

The glass plate PT on which the pattern has been transferred by the exposure processing unit PE is taken out by the transport arm 70 entering the plate stage PS.
After being rotated by °, it is stored in the carrier PC2 (FIG. 1).
In order to speed up the exchange of the glass plate, the next glass plate may be held by the load arm 73 during the exposure operation of the glass plate.

Next, the configuration of the exposure processing unit PE will be briefly described with reference to FIG. In the apparatus shown in FIG. 4, at least the projection optical system 7 and the plate stage PS are arranged in the chamber room MR. In FIG. 4, a reticle stage RS holds four reticles R1 to R4, and each reticle is set above a projection optical system 7 by a laser interferometer 5 and a motor 6. Reticle R
Each of 1 to R4 is X, Y, θ on the reticle stage RS.
(Revolution) direction, and three sets of reticle alignment systems 3X, 3Y, 3θ (3X is a mirror 4
By finely moving the reticle using X only), the reticle is positioned such that the center point of the pattern area to be transferred substantially coincides with the optical axis AX of the projection optical system 7.

The illumination light having passed through the reticle R2 is incident on a projection optical system 7 which is telecentric on both sides, and the projection optical system 7 has an equal magnification of the projected image of the reticle pattern, and a resist layer is formed on the surface. An image is formed and projected on a glass plate PT held so as to substantially coincide with the image forming plane of the projection optical system 7. The glass plate PT is mounted on a plate stage PS via a plate holder (not shown). The plate stage PS is configured to be two-dimensionally movable by a motor 9 in a step-and-repeat manner. When the transfer exposure of the reticle R2 to the glass plate PT is completed, the plate stage PS is stepped to the next shot position. The two-dimensional position of the plate stage PS is always detected by the interferometer 8 with a resolution of, for example, about 0.01 μm. Further, a temperature sensor 30 for measuring the temperature of the stage or the holder is provided on the plate stage PS. Further, FIG. 4 shows a T-band as disclosed in, for example, Japanese Patent Application Laid-Open No. 60-130742.
An alignment system 31 of a TL (Through The Lens) system is also provided. The control device 50 includes a reticle stage RS
And the position of the plate stage PS, as well as overall control of the entire apparatus.

Returning to the description of FIG. 1, in the main chamber MC, the exposure processing unit PE is disposed in a chamber room MR surrounded by a HEPA filter 12, a partition (wall) 14, a return duct 15, and the like. The environmental conditions in the chamber room MR, especially the air temperature, are different from the air conditioner room 1
The temperature (10) of the gas (air) in the main chamber MC is controlled and circulated by a temperature controller 10, a fan 11, a refrigerator 13 and the like provided in the 7 to obtain a predetermined temperature (2
(About 3 ° C.). At this time, for example, an environment (or temperature) sensor 16 arranged near the projection optical system 7
Chamber controller 100 based on the detection result of
By controlling the temperature controller 10 (FIG. 3), the air temperature in the chamber room MR is maintained at a predetermined temperature.

The arrows shown in FIG. 1 indicate the direction of air flow (circulation path) in the main chamber MC.
In the chamber room MR, the air flows substantially along the boundary with the sub-chamber SC. The flow direction of the air in the chamber room MR may be arbitrary, but it is naturally preferable to flow the air so as not to face the sub-chamber SC, that is, the opening AP. Note that the pressure of the gas flowing into the chamber room MR and the like may be controlled together with the temperature.

Next, referring to FIG.
An example of the specific configuration will be described. FIG. 2 shows the sub-chamber SC shown in FIG. 1 as viewed from the front (the direction of the wagon PW), and shows two sets of plate carriers PC1.
, PC2 (not shown) and the plate loader PL
The gas (air) whose temperature is controlled at least through the EPA filter 22 and the return duct 25 is housed in the chamber SR in which the gas is circulated. Environmental conditions in the chamber room SR, in particular, a plate carrier PC1 containing a glass plate to be carried into the exposure processing unit PE.
Is controlled at a predetermined temperature by controlling and circulating the temperature of gas (air) in the sub-chamber SC by a temperature controller 20, a fan 21, a refrigerator 23 and the like provided in the air conditioner room 27. Can be set to Similar to the main chamber MC, the temperature of the chamber room SR is set based on the detection results of the environment (or temperature) sensor 26 and the temperature sensor 30 (described later) provided on the plate stage (holder) PS in the exposure processing unit PE. On the basis of,
The chamber controller 100 (FIG. 3) uses the temperature controller 2
This is performed by controlling 0.

The arrow shown in FIG.
The flow direction (circulation path) of air whose temperature is controlled in C is shown. In the chamber room SR, the air flows from the boundary (opening AP) with the main chamber MC toward the return duct 25. In this embodiment, because of its configuration, the openings (the entrances and exits of the glass plates) of the two sets of plate carriers PC1 and PC2 in the chamber room SR are substantially parallel to the direction in which the air flows, and are therefore housed inside. In order to improve the efficiency of controlling the temperature of the glass plate, for example, a plurality of holes (openings) are formed in the side portions (surfaces substantially perpendicular to the direction in which the air flows) of the carriers PC1 and PC2, and the air whose temperature is controlled is Carrier PC1,
It is desirable to have a structure that flows substantially along each glass plate in PC2. In addition, chamber room SR
The direction in which the air flows may be arbitrary. For example, the air may flow from the carrier PC1 to the carrier PC2 in FIG. However, it is desirable to flow the air from the HEPA filter 22 so as not to go to the main chamber MC, that is, the opening AP.

Now, in the apparatus having the above configuration, as shown in FIG.
It is possible to independently control each of the temperature controllers 10 and 20 based on the detection results of the temperature sensors 6 and 26 and the temperature sensor 30 to arbitrarily set the respective temperatures of the gas circulating in the chambers MR and SR. ing. Accordingly, the glass plate in the plate carrier PC1 stored in the sub-chamber SC for performing the exposure processing is stored as stock, and at the same time, the air temperature in the chamber room SR,
That is, the temperature is equilibrated to a temperature substantially equal to the temperature of the plate stage (more precisely, the plate mounting surface (holder surface)) in the exposure processing unit PE. For this reason, when loading the glass plate in the plate carrier PC1 onto the plate stage, the temperature difference between the glass plate and the plate stage (holder) is already almost zero, and the size of the glass plate on the plate stage Since no change occurs, the exposure operation can be started immediately.

In the above embodiment, the two sets of plate carriers PC1, PC2 and the plate loader PL are stored in the sub-chamber SC. However, only the carrier storing the glass plate to be carried into the exposure processing unit PE is used. It may be stored in the sub-chamber SC. For example, the glass plate housed in the carrier PC1 is moved to the exposure processing unit PE.
Is transferred to the same carrier PC1 again.
In this case, only the carrier PC1 may be stored in the sub-chamber SC. At this time,
The components other than the carrier PC1 are stored in the main chamber MC. When the stepper and the coater developer are inlined, the glass plate having the resist layer formed on the surface may be carried into the main chamber via the sub-chamber. In the case of in-line as described above, a holding member (for example, a buffer cassette or the like) for adjusting the transfer time of the glass plate is provided in the transfer path, so that the buffer cassette is stored in the sub-chamber. Just do it.

Further, in this embodiment, the temperature of the glass plate is controlled in accordance with the temperature of the plate stage (holder). For example, when the temperature change of the plate stage is small, the temperature of the glass plate is kept at a constant value. That is, the temperature may be constantly controlled to a predetermined temperature within the range of the temperature change of the plate stage. Further, it is not necessary to control the temperature of the glass plate so as to be substantially equal to the temperature of the plate stage. For example, the amount of dimensional change of the glass plate caused by the temperature difference between the glass plate and the plate stage is a predetermined allowable value ( What is necessary is just to control the temperature of the glass plate within a temperature range that is within a value which is uniquely determined by the alignment accuracy and the joining accuracy.

In the above embodiment, the temperature-controlled air is circulated in the sub-chamber SC in order to control the temperature of the glass plate to a desired temperature. However, other methods such as the exposure processing unit PE The temperature may be controlled by heating (or cooling) a plate carrier (or a buffer cassette) containing a glass plate to be carried in or a glass plate by a temperature adjusting means such as a Peltier element. When such a configuration is adopted, it is not particularly necessary to provide a sub-chamber, and the plate carrier PC1 together with the exposure processing unit PE is used.
Can be stored in the main chamber. However, considering the temperature control accuracy of the glass plate,
It is desirable to arrange at least the carrier PC1 in the sub-chamber. The gas circulating in the sub-chamber SC may be other than air, such as helium. In addition to the method of circulating the gas whose temperature is controlled, in a case where only the temperature of the glass plate is directly or indirectly controlled, a fluid (water or the like) may be used in addition to the gas.

Further, when a sequence in which the next glass plate is made to stand by in the loader arm 73 during the exposure operation in order to speed up the exchange of the glass plate is adopted, the waiting time in the loader arm 73 is reduced. in view of,
It is desirable to set the temperature of the glass plate in the sub-chamber SC to a higher temperature in advance. In the above embodiment, the temperature of the glass plate PT is equilibrated with the temperature of the plate stage PS by setting the temperature in the sub-chamber SC to be substantially equal to the temperature of the plate stage PS. The temperature inside the sub-chamber SC (that is, the temperature of the circulating air) is positively controlled so that the temperature of the sub-chamber SC becomes equal to the temperature of the plate stage PS. For example, a plate carrier (or a glass plate) is housed in the sub-chamber. Immediately after, the temperature is set higher than the temperature of the plate stage PS, and when the temperature of the glass plate PT becomes substantially equal to the temperature of the plate stage PS, the temperature is set substantially equal to the temperature of the plate stage PS. good.

Further, a temperature adjusting mechanism may be provided on the plate stage PS to control, for example, the temperature of the stage to be always constant. In this case, there is an advantage that the temperature control in the sub-chamber SC (more precisely, the temperature control of the glass plate) becomes very easy. More positively, the temperature of the plate stage may be controlled in accordance with the temperature of the glass plate placed on the plate stage so that the temperature difference between the two becomes substantially zero. At this time, the temperature of the glass plate placed next on the plate stage may be controlled to a predetermined value by a subchamber or the like, or may not be controlled at all without providing a subchamber or the like.

Although the above embodiment focuses on the temperature difference between the glass plate and the plate stage, a completely similar problem may occur between the reticle and the reticle stage. Alternatively, the temperature of the reticle may be controlled to a predetermined value. At this time, the storage unit (including the reticle case and the like) for storing the reticle before being transported to the reticle stage is almost isolated from the outside air separately from the main chamber MC in the same manner as in the above embodiment. And the temperature may be controlled to a predetermined value. Alternatively, even if the temperature of the reticle is directly controlled, if the stock system and the stepper capable of storing hundreds of reticles are inlined, the reticle temperature is controlled within the stock system. It does not matter.

In the present invention, the configuration of the main chamber (first chamber) and the temperature adjusting mechanism thereof may be arbitrary, and the exposure processing unit PE may be of a type other than the projection type, such as a proximity type. In addition, the present invention can be applied to an exposure apparatus for manufacturing a semiconductor in a completely similar manner.

[0032]

According to the first aspect of the present invention, on the mask
The substrate is positioned to transfer the pattern onto the substrate
The substrate to be exposed at the exposure position
Adjusting means of the holding device installed separately from the stage that holds the plate
Temperature is controlled directly by the stage. Because of this, on stage
The temperature of the substrate can be adjusted in other cases. The invention of claim 1
For example, the temperature of the substrate to be exposed
Adjust the stage according to the temperature of the stage
The substrate was placed on the stage by placing it on the top
It is also possible to suppress later deformation of the substrate. Ma
Also, since the temperature of the substrate is directly controlled, the fluid (eg, circulation)
The equipment is simpler than the one that controls the environment by using
It is possible to simplify and reduce the size.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic overall configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a specific configuration of a sub-chamber (second chamber) shown in FIG.

FIG. 3 is a block diagram showing an example of a configuration of a control system for an exposure apparatus, particularly two sets of chambers, according to an embodiment of the present invention.

FIG. 4 is a plan view showing a specific configuration of an exposure processing unit.

FIG. 5 is a perspective view showing a specific configuration of a substrate transport unit (plate loader).

[Explanation of symbols]

 10, 20 Temperature controller 11, 21 Fan 12, 22 HEPA filter 16, 26 Environmental sensor (temperature sensor) 30 Temperature sensor PE Exposure processing unit PL Substrate transport unit PC1, PC2 Plate carrier 100 Chamber controller

Claims (15)

(57) [Claims] 1. A method for transferring a pattern on a mask onto a substrate.
Hold the substrate in the exposure position where the substrate is positioned for
The stage is installed separately from the stage
A holding device for holding a substrate to be provided, Adjustment means for directly adjusting the temperature of the held substrate
And a holding device. 2. The holding device according to claim 1, The adjusting means includes a Peltier element, and the Peltier element
Heating or cooling the substrate by
Holding device. 3. The holding device according to claim 1, The adjusting means heats or cools the substrate using a liquid.
A holding device. 4. The holding device according to claim 1, Temperature near the stage that holds the substrate at the exposure position
Detecting means for detecting information about the degree, The adjusting unit is configured to be detected by the detecting unit.
Adjusts the temperature of the held substrate according to the information.
A holding device to mark. 5. The holding device according to claim 4, wherein The adjusting means includes a Peltier element, and the Peltier element
Wherein the temperature of the substrate is adjusted by
Place. 6. The holding device according to claim 4, The adjusting means heats or cools the substrate using a liquid.
A holding device. 7. The holding device according to claim 4, wherein The adjusting means is configured to control the temperature of the held substrate
The temperature of the substrate is adjusted to be equal to the temperature near
A holding device characterized by knotting. 8. The holding device according to claim 4, wherein The adjusting unit is configured to control the temperature of the held substrate by the stage.
So that the temperature of the substrate is higher than the temperature near
A holding device characterized by adjusting. 9. The holding device according to claim 4, wherein The adjusting means determines that the temperature of the held substrate is within a predetermined range.
Adjusting the temperature of the substrate so that
Holding device. 10. The holding device according to claim 9, wherein The predetermined range is determined according to a temperature change of the stage.
A holding device, wherein 11. The holding device according to claim 1, A holding device characterized by being disposed in a chamber.
Place. 12. The holding device according to claim 11, The transfer means for transferring the substrate to the stage,
A holding device characterized by being disposed in a chamber.
Place. 13. A holding device according to claim 1, wherein:
An exposure system, comprising: an exposure system. 14. An exposure system according to claim 13, Characterized by including at least a coater developer
Exposure system. 15. Exposure by the exposure system according to claim 14.
A device manufactured using a substrate.