JP2001313246A - Method and apparatus for exposure and method for fabricating device and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for exposure in which exposure accuracy is enhanced while suppressing deformation of a substrate at the time of sucking the substrate, and the reliability of a device can be enhanced. SOLUTION: In the exposing method where a substrate P is sucked to a substrate stage 23 and the pattern of a mask R is transferred to the exposing region of the substrate P, the region to be sucked is specified for the substrate P depending on the exposing region and the specified region is sucked to the substrate stage 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exposure method and an exposure apparatus, and more particularly, to an exposure method and an exposure apparatus suitably used for a large-sized substrate.

[0002]

2. Description of the Related Art Conventionally, when a device (electronic device) such as a semiconductor element (integrated circuit) or a liquid crystal display panel is manufactured by a photolithography process, a mask or a reticle (hereinafter, collectively referred to as a reticle) by light from a light source. An exposure apparatus is used that illuminates a reticle pattern (circuit pattern) and transfers the reticle pattern (circuit pattern) to a substrate (a wafer coated with a photosensitive agent, a glass plate, or the like) via a projection optical system.

In the exposure apparatus, when transferring a circuit pattern, as shown in FIG. 11, a substrate P delivered from the upstream side is mounted on a substrate stage 90, and a suction mechanism 9 is provided.
1, the substrate P is sucked onto the holding surface 90a of the substrate stage 90. Further, alignment marks PM formed on substrate P by alignment detection systems 92 and 93 are provided.
Is detected while detecting the position of the substrate P. A device pattern as an integrated circuit is formed by repeatedly transferring (overlapping and exposing) a circuit pattern onto a substrate a plurality of times by such an exposure apparatus, and laminating wiring circuits.

[0004]

By the way, the substrate delivered to the exposure apparatus may be deformed such as warpage due to the influence of thermal stress or the like generated in the process up to that time. In recent years, thin and large-sized substrates tend to be used, and the above-described deformation of the substrates tends to further increase. Usually, such deformation of the substrate is eliminated when the substrate is attracted to the substrate stage and one surface of the substrate follows the holding surface of the substrate stage, but when the substrate size is large or thin, the entire surface of the substrate is removed. The substrate does not become smooth, and the deformation of the substrate is likely to partially remain. Deformation remaining on the substrate is likely to cause defocus such as a shift in the focal position.

FIG. 12 shows a state in which a partial deformation (warpage) remains on the substrate P during the suction of the substrate.
Assuming that the thickness of the substrate P at a predetermined location is t and the angle at which the location is tilted by the deformation is θ, the displacement of the substrate causes a positional shift represented by a positional shift amount d = t × θ in the substrate plane. (For example, t = 0.7 mm, θ = 1
mrad, the in-plane positional deviation amount d is 0.7 μm). When the position shift occurs in the substrate surface in this way,
An error occurs between the shape (line width or the like) of the pattern formed on the substrate P and the design value.

Further, when the substrate is forcibly suctioned with a strong suction force for the purpose of preventing the above-mentioned suction failure, the substrate is distorted due to the stress generated at that time.
In-plane dimensions locally change. For this reason, the positional relationship between the alignment mark and the circuit pattern is shifted, and it is difficult to accurately align the substrate. Furthermore, since the deformation of the substrate at the time of suction is considered to change for each suction operation, there is a possibility that the relative positional relationship between the patterns may be shifted between the layers to be stacked.

The present invention has been made in view of the above circumstances, and suppresses the deformation of a substrate that occurs at the time of substrate adsorption.
It is an object of the present invention to provide an exposure method and an exposure apparatus capable of improving exposure accuracy and improving device reliability.

[0008]

According to a first aspect of the present invention, a substrate (P) is adsorbed on a substrate stage (23) and a pattern of a mask (R) is formed on the substrate (P). In the exposure method of transferring to the exposure area (SA), an area to be suctioned with respect to the substrate (P) is specified according to the exposure area (SA), and the specified target area is suctioned to the substrate stage (23). It is characterized by doing.
In this exposure method, an area to be suctioned is specified according to the exposure area, and the target area is sucked to the substrate stage. Therefore, the area to be adsorbed is limited to be smaller than the entire substrate, and even when the substrate already has a deformation such as warpage, the substrate easily follows the substrate stage within the area to be adsorbed, and partially adheres to the substrate. Difficult deformation remains.

In this case, by changing the target area according to the change of the exposure area (SA), the exposure area can be changed within one substrate or between a plurality of substrates. Is changed, the substrate is attracted to the substrate stage in accordance with the change.

Further, in the exposure method according to the first or second aspect, after increasing the attraction force to the next target region as in the invention according to the third aspect, the attraction force to the original target region is reduced. By reducing the size, the suction state of the substrate is maintained in any region on the substrate, and the displacement of the substrate with respect to the substrate stage is suppressed even when the target region to be suctioned changes.

Further, in the exposure method according to any one of the first to third aspects, as in the invention according to the fourth aspect, the following method is performed so that the target area is adjacent to or at least partially overlaps the original target area. By specifying the target area of, the next area is adsorbed without separating from the already adsorbed area, so that even if the substrate already has a deformation such as warpage, the next target area is Adsorbed reliably.

According to a fifth aspect of the present invention, there is provided a substrate stage (23) for holding a substrate (P), and a pattern of a mask (R) is transferred to the substrate (P) via a projection optical system (PL).
A plurality of suction mechanisms (61) for adsorbing a specific area of the substrate (P) to the substrate stage (23), and an object to be adsorbed on the substrate (P). And a controller (24) for selectively controlling the plurality of suction mechanisms (61) according to the specified target area. In this exposure apparatus, the control unit specifies an area to be suctioned,
A plurality of suction mechanisms are selectively controlled according to the specified target area, and the target area of the substrate is suctioned to the substrate stage.
Therefore, similarly to the first aspect of the present invention, the area to be adsorbed is limited to be smaller than the entire substrate, and the substrate easily follows the substrate stage within the area to be adsorbed, and partial deformation hardly remains on the substrate. .

In this case, as in the invention described in claim 6, the plurality of suction mechanisms (61) may be arranged so that a plurality of suction mechanisms are suctioned to one exposure area (SA). . In this case, even when the size of the exposure region changes, the target region is easily specified according to the change.

Further, in the exposure apparatus according to the fifth or sixth aspect, the projection optical system (P) is used for positioning the substrate (P) as in the invention according to the seventh aspect.
L) and an alignment detection system (56) for detecting a mark formed on the substrate (P) via the alignment detection system (56). The alignment detection system (56) is configured to detect a mark (PM) in the target area. May be. In this case, the deformation of the substrate due to the suction is suppressed in the area where the mark is formed, and the mark is accurately detected.

An eighth aspect of the present invention is a device manufacturing method including a lithography step, wherein the lithography step uses the exposure method according to any one of the first to fourth aspects. Features. Also,
According to a ninth aspect of the present invention, there is provided a device having a predetermined pattern formed thereon, which is manufactured using the exposure apparatus according to any one of the fifth to seventh aspects.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an exposure apparatus according to the present invention will be described below with reference to FIGS. FIG.
1 schematically shows the entire configuration of the exposure apparatus 10 according to the present embodiment.

The exposure apparatus 10 includes a reticle R and a substrate P
In a stationary state, the circuit pattern formed on the reticle R is transferred to each exposure area (shot area) on the substrate P via the projection optical system PL, and the substrate P is sequentially moved stepwise. This is an exposure apparatus of an AND repeat system. Here, the projection optical system PL
In the plane perpendicular to the optical axis of FIG. 2, the direction perpendicular to the plane of FIG. 2 is the X direction, the direction perpendicular to the X direction in the plane is the Y direction, the direction parallel to the optical axis of the projection optical system PL is the Z direction, and the light is the same. A rotation direction about an axis parallel to the axis is defined as a θ direction.

The exposure apparatus 10 includes a light source 20 and the light source 20.
Illumination system 21 for illuminating reticle R with illumination light from
A reticle stage 22 for holding the reticle R, a projection optical system PL for projecting illumination light emitted from the reticle R onto the substrate P, a substrate stage 23 for holding the substrate P, and a control device for controlling the entire apparatus as a whole 24, etc.

As the light source 20, for example, a high-pressure mercury lamp, K
rF excimer laser light source, ArF excimer laser light source,
An F2 excimer laser light source, a light source that emits a harmonic of a metal vapor laser or a YAG laser, or the like is used.

The illumination system 21 is for shaping the illumination light from the light source 20 into a predetermined illumination area and uniformly emitting the illumination light to the reticle R. The reflection mirrors 32 and 33, the relay lens, and the fly-eye lens ( Or various lens systems 34 including a condenser lens and the like.
And a reticle blind 35 arranged at a position conjugate with the pattern surface of the reticle R.

On the reticle stage 22, the reticle R is held with the pattern forming surface on which the circuit pattern is formed facing downward, that is, toward the projection optical system PL, and an image defined by the reticle blind 35 is placed on the reticle R. An image is formed as a rectangular illumination area on the pattern formation surface. The reticle stage 22 is configured to finely move in a two-dimensional plane in the X, Y and rotational directions (θ direction) by a reticle stage drive system (not shown).

FIG. 3 is a plan view of the reticle R. The reticle R has a pattern area PA in which a circuit pattern to be transferred to the substrate P is formed. Outside the pattern area PA, a plurality (four in this case) of alignment marks A for alignment with the substrate P is provided in the field of view SHA of the projection optical system PL (see FIG. 2).
M1 to AM4 are provided. In the present embodiment, the alignment marks AM1 to AM4 (generally referred to as “alignment marks AM”) are located on both outer sides of the pattern area PA, that is, on both sides in the X and Y directions (outside each side of the pattern area PA). It is arranged in each. The circuit pattern and the alignment mark AM1
AM4 is transferred to a glass plate, which is a base material of the reticle R, based on design data by an apparatus such as a pattern generator or an EB exposure apparatus, and is formed as a light transmitting portion or a light shielding portion (a chrome film or the like). I have.

Returning to FIG. 2, as the projection optical system PL, an optical system which is telecentric on both sides and has a predetermined magnification is used. That is, when the reticle R is illuminated by the illumination light from the illumination system 21 in a state where the reticle R and the substrate P are aligned, an image of the circuit pattern of the reticle R is transmitted via the projection optical system PL. Projection exposure is performed on a substrate P having a surface coated with a photosensitive agent such as a photoresist.

The substrate stage 23 is moved in a horizontal direction along an XY plane (a plane perpendicular to the optical axis of the projection optical system PL) by a drive system 40 including, for example, a magnetic levitation type two-dimensional linear actuator (plane motor). It is configured to be driven freely. The position of the substrate stage 23 in the XY directions is adjusted by a laser interference system. This will be described in detail.
At the end on the Y side, an X moving mirror 41 composed of a plane mirror is extended in the X direction, and a length measuring beam from an X axis laser interferometer 42 is projected almost perpendicularly to the X moving mirror 41, and the reflected light Is received by a detector inside the X-axis laser interferometer 42, and the position of the X movable mirror 41, that is, the X position of the substrate P, is detected based on the position of the reference mirror inside the X-axis laser interferometer 42. I have. Similarly, although not shown, a Y moving mirror composed of a plane mirror extends in the Y direction at the + Y side end of the substrate stage 23. Then, the position of the Y moving mirror, that is, the position of the Y
The position is detected. The detected values (measured values) of the laser interferometers on the X axis and the Y axis, that is, the position information of the substrate P in the XY directions are sent to the control device 24.

In this embodiment, a substrate suction system 45 for sucking the substrate P onto the substrate stage 23 is provided. In addition, about this board | substrate adsorption system 45,
It will be described later.

The control unit 24 is constituted by a microcomputer (or minicomputer) including a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), etc., as described above. The position of the substrate stage 23 is controlled while monitoring the measurement value of the laser interferometer 42, and a substrate suction system 45 described later is controlled.

FIG. 4 shows an example of a device pattern for a liquid crystal display panel formed on the substrate P by a photolithography process. This device pattern (pattern) includes a pixel electrode 50, a gate line 51, a signal line 52, a drain 53, and a TFT (thin film transistor) 5.
Almost identical pixel pattern (partial pattern) 5 composed of 4
5 are arranged at a constant pitch in the X direction and the Y direction, respectively. The pixel electrodes 50, the gate lines 51, the signal lines 52, and the drains 53 are formed by superposing circuit patterns formed on a plurality of different reticles R layer by layer and exposing (overlapping exposure). is there.

In order to perform the overlay exposure, it is generally necessary to align the pattern of the reticle R and the pattern of the substrate P and to accurately overlay the next layer on the layer formed by the previous exposure. In the present embodiment, a substrate mark PM is formed in a gap located near each pixel pattern 55 as an alignment mark on the substrate side.

Further, above the reticle R, as shown in FIG. 2, a TTL (through through) for detecting the substrate mark PM is provided.
The (lens) type alignment detection system 56 is provided. The alignment detection system 56 is singly or plurally arranged so as to selectively irradiate the above-described alignment marks AM1 to AM4 on the reticle R, and is configured to detect the substrate mark PM on the substrate P through the projection optical system PL. Have been. In addition, the alignment detection system 56
Are any alignment marks AM1 to AM1 on the reticle R
It is configured to be movable to a position where the AM4 can be irradiated.
The TTL alignment detection system 56
Is the alignment mark AM1 formed on the reticle R.
ＡＭAM4 and the substrate mark PM are detected via the same projection optical system PL, so that errors due to differences in mark detection locations are less likely to occur, and there is an advantage that high-accuracy alignment can be easily realized.

Here, the substrate suction system 45 will be described with reference to FIGS. The substrate suction system 45 of the present embodiment includes a vacuum generator 60 such as a vacuum pump, a plurality of suction mechanisms 61 for sucking the substrate P to the substrate stage 23, and the control device 24 for controlling these collectively. It is comprised including.

The suction mechanism 61 includes a plurality of suction nozzles 65 as suction holes having openings in the holding surface 23 a of the substrate stage 23, a pipe 66 for connecting the suction nozzle 65 and the vacuum generator 60, It has a plurality of valves 67 as a switching device for controlling the flow, and a detecting device 68 for detecting the state of gas in the pipe 66. By switching the valve 67, any one of the suction nozzle 65 and the vacuum generating device 6
0, the holding surface 23a of the substrate stage 23 is partially brought into a negative pressure state through the opening of the suction nozzle 65, whereby a specific area of the substrate P is suctioned to the substrate stage 23. Have been.

Here, the holding surface 23a of the substrate stage 23
Is divided into a plurality of block areas BA as shown in FIG. 6, and the suction mechanism 6 is provided for each block area BA.
1 are assigned one by one, and each block area B
In A, the openings of the plurality of suction nozzles 65 are respectively provided. The size and arrangement of the block areas BA are determined according to the exposure areas (shot areas) SA on the substrate P. Here, a plurality of (for example, four) block areas BA ( Or part of it)
Is defined to be included. The exposure area SA
The number and arrangement position of the block areas BA with respect to
It goes without saying that the number and arrangement position of the suction nozzles 65 in the block area BA are arbitrary and are not limited to those shown in the drawing.

The control device 24 shown in FIG. 5 selects one of the plurality of block areas BA based on the control data at the time of exposure, and selects the valve 67 of the suction mechanism 61 based on this. By performing the control, a region to be sucked to the substrate P (target region) is specified. Here, the substrate P is sucked by opening the valve 67, and the control device 2
When the target area is specified, the selected block area B
A control is performed to open the valve 67 of the suction mechanism 61 assigned to A and close the valve 67 of the suction mechanism 61 assigned to another block area BA. The detection device 68 is configured to detect information (such as pressure) for determining whether or not the substrate P is normally sucked in each block area BA, and to supply the detection result to the control device 24. ing.

That is, the substrate suction system 45 controls the respective suction mechanisms 61 individually and independently for the local block area BA divided in the holding surface 23a of the substrate stage 23, and A specific target area in the area is adsorbed.

Next, the exposure apparatus 1 configured as described above
The operation of 0 will be described. Here, an active matrix type liquid crystal display panel is manufactured. Therefore, in order to form an active element, it is necessary to expose a plurality of pattern layers in a manufacturing process. Further, a plurality of reticles serving as an original plate (mask) are prepared, and a pattern layer is superposed and exposed while exchanging reticles. In addition, here, it is assumed that a liquid crystal display panel is manufactured using a so-called screen combining method in which a screen formed in one exposure region is combined to form one panel. Therefore, the exposure apparatus divides one panel area into a plurality of exposure areas adjacent to each other and performs exposure (division exposure).

First, a substrate P coated with a photosensitive agent (resist or the like) is exposed to an exposure apparatus 10 by a substrate transport system (not shown).
After being pre-aligned, it is mounted on the holding surface 23 a of the substrate stage 23. When the substrate P is mounted on the substrate stage 23, the control device 24 of the exposure apparatus 10 starts the suction of the substrate P by the substrate suction system 45.

In adsorbing the substrate P, the substrate adsorbing system 4
Reference numeral 5 designates, by the control device 24, a target area to be suctioned to the substrate P according to the exposure area on the substrate P. Here, as shown in FIG. 7A, the area includes a first exposure area SA1 and predetermined marks PM formed in exposure areas SA2 and SA3 adjacent to the first exposure area SA1. Next, the block areas BA1 to BA9 are selected from the plurality of block areas BA in the holding surface 23a, and the target area (the hatched area shown in FIG. 7A) is specified. In this example, as described above, since exposure is performed using the screen combining method, a plurality of (here, four) exposure areas SA (for example, the exposure areas SA
1 to SA4) are arranged adjacent to each other.

Subsequently, the substrate suction system 45 is shown in FIG.
As shown in (a), the valve 67 is selected and opened according to the specified target area. As a result, the suction nozzle 65 is connected to the vacuum generating device 60, the gas is suctioned from the opening of the suction nozzle 65, and the target area of the substrate P is suctioned to the holding surface 23 a of the substrate stage 23.

At this time, the substrate suction system 45 locally sucks the substrate by limiting the range to the target area. Therefore, even when the substrate P is large, thin, and has already been deformed (warped) due to heat or the like, the substrate P easily follows the holding surface 23a of the substrate stage 23 and becomes smooth in the suction range. Almost no partial deformation remains.

When the valves 67 are selectively controlled, all of the valves 67 (see FIG. 5) corresponding to the target region may be simultaneously opened, or one or a plurality of valves 67 may be sequentially opened. Open the valves 67 in order,
By controlling the suction range to gradually widen, the distortion of the substrate P due to the suction is further suppressed, and the substrate P
Is less likely to remain.

When the substrate P is adsorbed, the pressure in the pipe 66 is detected by the detecting device 68, and the result is supplied to the control device 24. The control device 24 determines whether or not the suction of the substrate P has been completed based on the detection result (pressure data) from the detection device 68, and when the suction has been completed, shifts to a positioning operation of the next substrate P.

The alignment of the substrate P is performed by detecting the substrate mark PM formed on the substrate P by the alignment detection system 56 via the projection optical system PL (TT
L method). That is, the alignment light from the alignment detection system 56 is applied to the substrate P through the reticle R and the projection optical system PL, and the reflected light from the substrate P is detected again by the alignment detection system 56 through the projection optical system PL, so that the reticle R Mark AM formed on
And the substrate mark PM formed on the substrate P is measured, and based on the measurement result, the substrate stage 23 is moved to align the substrate P with the reticle R. When the substrate stage 23 moves, the laser interferometer 42 emits a laser toward the movable mirror 41 on the substrate stage 23, measures the distance based on the interference between the reflected light and the incident light, and The control device 24 controls the drive system 40 based on the result of the accurate detection of the position 23.

At this time, as the alignment mark on the substrate P side, as shown in FIG. 7A, the exposure area SA adjacent to the current exposure area (exposure area SA1) is used.
2, a plurality of substrate marks PM1 to PM provided on SA3
4 is used. In the positioning operation, the control device 24 sequentially selects and uses the substrate mark PM and the corresponding alignment mark AM on the reticle R from a plurality. As described above, since the alignment mark AM is arranged outside each side of the pattern area PA,
The control device 24 efficiently selects and uses a mark close to a predetermined substrate mark PM from the plurality of alignment marks AM.

At this time, the substrate mark PM to be detected is
1 to PM4 are located in the target area smoothly sucked without distortion, and hardly have an error such as a displacement due to the suction. Therefore, the substrate marks PM1 to PM4 are accurately detected by the alignment detection system 56, and the substrate P
Is performed.

Further, the substrate marks PM1 to PM4 correspond to the exposure areas SA adjacent to the current exposure area SA1.
2, because of being provided in SA3, a stepwise error of the screen combining unit that is likely to occur when performing exposure using the screen combining method as in the present example, that is, in the boundary portion of the pattern formed by the divided exposure. A phenomenon in which a minute shift occurs and the performance of the element changes in this portion, and the brightness appears uneven on the completed liquid crystal panel is suppressed. Moreover, since the substrate marks PM1 to PM4 are located relatively close to the exposure area SA1, even if the substrate P is slightly distorted due to suction, there is almost no influence on the alignment.

When the alignment of the substrate P is completed, the exposure apparatus 10 proceeds to the next exposure processing. In the exposure process, the circuit pattern formed in the pattern area PA of the reticle R is projected with the reticle R and the substrate P stationary.
Is transferred to each exposure area (shot area) on the substrate P through the step (step and repeat). In this exposure processing, the illumination light incident on the illumination system 21 is defined by the reticle blind 35 into a rectangular illumination area, and then illuminates the pattern area PA of the reticle R. The image of the circuit pattern including the pixel pattern 55 in the pattern area PA is
An image is formed on the exposure area SA1 of the substrate P via the projection optical system PL.

At this time, the exposure area SA1 is located within the target area smoothly sucked, and has almost no displacement due to the suction. Further, since no partial deformation remains on the substrate P, phenomena such as a focus shift and a defocus hardly occur. Thereby, the image of the circuit pattern is accurately transferred into the exposure area SA1 of the substrate P. Therefore, an error between the shape (line width or the like) of the circuit pattern formed on the substrate P and the design value is small.

When the exposure processing for the exposure area SA1 is completed, the exposure apparatus 10 executes the above-described series of processing for the next exposure area (the exposure area SA5 shown in FIG. 7B).

That is, as shown in FIG. 1B, the control device 24 moves the substrate stage 23 in a predetermined direction by the drive system 40, and simultaneously moves the substrate stage 23 with respect to the substrate P in accordance with the next exposure area SA5. The target area (block areas BA10 to BA18 shown in FIG. 7B) is specified, and the valve 67 is selectively controlled with respect to this target area. As a result, the suction nozzle 65 corresponding to the next target area is connected to the vacuum generator 60, and that area is sucked on the holding surface 23 a of the substrate stage 23. When the substrate P is sucked, the exposure apparatus 10 performs a series of operations of the above-described positioning of the substrate P and exposure processing.

At this time, since the area to be suctioned is specified according to the change in the exposure area SA, the area is also suctioned in the next exposure area SA5 in a smooth state without distortion. That is, even when a plurality of exposure areas SA are arranged in the substrate P as in this example, the area of the suction target is specified for each exposure area SA, so that the image of the circuit pattern is repeatedly transferred with high accuracy. Is done.

In the substrate suction system 45, when the next target area is sucked, the valve corresponding to the next target area is opened, and then the valve corresponding to the original target area is closed. For this reason, since the suction state is always maintained in any region on the substrate P, the displacement of the substrate P with respect to the substrate stage 23 is suppressed, the time required for the alignment of the substrate P is reduced, and the position of the substrate P is reduced. A decrease in exposure accuracy due to a displacement is avoided.

As described above, according to the exposure apparatus 10 of the present embodiment, even when the substrate P delivered from the upstream side has a deformation such as a warp, the range of adsorption is locally limited. Thereby, the exposure area SA can be sucked in a smooth state without deformation. Further, by using the substrate mark PM arranged in the target area, the substrate P can be accurately positioned by the TTL method.
Further, even in the overlay exposure, the relative positional relationship of the circuit patterns between the layers to be laminated hardly shifts, and a plurality of pattern layers are accurately overlapped. For these reasons, in the exposure apparatus 10, errors caused by poor suction can be reduced, and exposure accuracy can be easily improved.

In the embodiment described above, a step-and-repeat type exposure apparatus for transferring a circuit pattern formed on the reticle R onto the substrate P while the reticle R and the substrate P are stationary will be described. But
The present invention is not limited to this, and is also applicable to a scanning type exposure apparatus that transfers a circuit pattern onto a substrate while moving the substrate relative to the projection optical system. FIG. 8 shows a state in which the substrate is locally attracted by such a scanning type exposure apparatus. Here, a plurality of projection areas S1 to S5 are formed on the substrate P by a plurality of projection optical systems, and the projection area S
The circuit pattern is transferred onto the substrate P by integrally scanning 1 to S5 in a predetermined direction.

In this case, when the projection areas S1 to S5 are scanned on the substrate P, as shown in FIGS. Is moved in the scanning direction (the shaded area shown in FIG. 8).
That is, the projection areas S1 to S5 are moved by scanning with respect to the substrate P, and the block areas B1 to B8 divided in the scanning direction are sequentially selected, so that the selected block areas (for example, the block areas B1 to B3) are moved. The substrate P is locally absorbed. As described above, by sequentially switching the area to be suctioned in the scanning direction, it is possible to locally limit the area to be suctioned with respect to scanning exposure (scanning exposure). In addition, as the actual control, for example, based on a program input in advance or the position information of the substrate stage from the above-mentioned laser interferometer or the like, the area to be suctioned with respect to the movement (scanning movement) of the substrate stage is determined. Synchronize.

Here, the next area to be adsorbed is specified so as to be adjacent to or at least partially overlap the original target area. That is, in the example of FIG. 8, three block areas B1 to B
3 is selected, one of the block areas B1 to B3 in the scanning direction is excluded from the next selection, and the block area B4 adjacent to the other block area B3 is set as the next target area. Selected as one. In this way, by specifying the next target area so as to be adjacent to or at least partially overlap the original target area, the next area is adsorbed without being separated from the area already adsorbed. Even if the substrate already has the deformation described above, the following effect can be obtained in that the next target region can be easily sucked.

This effect is not limited to the scanning type exposure apparatus, but is also applicable to the above-described step-and-repeat type exposure apparatus. That is, as shown in FIG. 9, when exposing a substrate in which the next exposure area SA5 is spaced apart from the original exposure area SA1 by the step-and-repeat method, the original adsorption target The next target area is specified so as to be adjacent to or at least partially overlap with the area (the shaded area shown in FIG. 9),
By sequentially moving the suction area to the next exposure area SA5, the same effect as described above can be obtained. At this time, as described in the above-described embodiment, if one exposure area SA1 or SA5 is suctioned by a plurality of suction mechanisms, the target area can be flexibly specified according to the change of the exposure area. can do.

In the above-described embodiment, the exposure region S
Since the substrate mark PM adjacent to A is used, there is an advantage that areas including the exposure area SA and the substrate mark PM can be collectively sucked in one area, but the present invention is not limited to this. Instead, for example, as shown in FIG. 10, the substrate P may be aligned with respect to a predetermined exposure area SA using a substrate mark PM provided at a specific location. In this case, the target area (B1 to B4) to be sucked is specified according to the substrate mark PM, and the target area is sucked for the alignment of the substrate P, so that the substrate mark PM can be accurately obtained as described above. Can be detected. In this case, the area may be sucked for each substrate mark PM, or a plurality of target areas may be sucked at once to shorten the processing time.

In the above-described embodiment, the case where a plurality of exposure regions having substantially the same area are arranged in the substrate P has been described. However, the present invention is not limited to this.
The present invention can be applied to a case where a plurality of exposure regions having different areas are arranged in a substrate, and a case where the position and the area of the exposure region are different for each substrate. In such a case, the block area BA is finely divided in the holding surface 23a of the substrate stage 23, and each of the suction mechanisms 61 is independently controlled for each of the block areas BA, thereby changing the exposure area. More flexibly.

The various shapes, combinations, procedures, and the like of the components shown in the above-described embodiment are merely examples, and can be variously modified based on design requirements without departing from the gist of the present invention. The present invention includes the following modifications.

In the above-described embodiment, only the target area is sucked by opening and closing the valve.
The suction operation may be performed even in a region different from the target region as a structure in which the suction force of each suction mechanism can be adjusted. In this case, the suction force in the other area is set, for example, to an extent that the substrate is held auxiliary, and is set lower than the pressure in the target area. In this case, when the entire substrate has a large warp, by locally adsorbing the end of the substrate, the other end is prevented from leaving a large distance from the substrate stage, and poor adsorption of the substrate is prevented. Further reduction can be achieved. Further, the suction force may be changed according to the thickness and size of the substrate, or the suction force may be changed according to the area to be suctioned (for example, when suctioning the outer peripheral portion of the substrate compared to when suctioning the central portion). For example, the suction force may be increased).

In parallel with the efforts to reduce the suction failure by the exposure apparatus, efforts to reduce the deformation of the substrate, such as improving the material of the substrate and reviewing the process in other processing steps, are carried out. Needless to say.

The substrate according to the present invention is not limited to a glass plate for a liquid crystal display device, but may be a semiconductor wafer for a semiconductor device or a ceramic wafer for a thin-film magnetic head.

The types of the exposure apparatus include not only the above-described liquid crystal display device manufacturing but also semiconductor manufacturing exposure apparatuses, thin-film magnetic heads, image pickup devices (CCD), masks M and the like. It can be widely applied to such applications.

As the light source of the illumination system, bright lines (g-line (436 nm), h-line (404.
7 nm), i-line (365 nm)), KrF excimer laser (248 nm), ArF excimer laser (193n)
m), F2 laser (157 nm), as well as charged particle beams such as X-rays and electron beams. For example, when an electron beam is used, thermionic emission type lanthanum hexaborite (LaB6) or tantalum (Ta) can be used as the electron gun. Alternatively, a high frequency such as a YAG laser or a semiconductor laser may be used. Further, when an electron beam is used, a structure using a mask may be used, or a pattern may be formed directly on a substrate without using a mask.

In the case where far ultraviolet rays such as an excimer laser are used as the projection optical system, a material that transmits far ultraviolet rays such as quartz or fluorite is used as the glass material.
When a line is used, a catadioptric or refractive optical system is used (a reticle of a reflective type is used). When an electron beam is used, an electron optical system including an electron lens and a deflector is used as the optical system. You can use it. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

The magnification of the projection optical system may be not only a reduction system but also an equal magnification system or an enlargement system.

When a linear motor is used for the reticle stage or the substrate stage, any of an air levitation type using an air bearing and a magnetic levitation type using Lorentz force or reactance force may be used. Further, the mask stage and the substrate stage may be of a type that moves along a guide, or may be of a guideless type without a guide.

Also, as a stage driving device, a planar motor
When using a magnet, one of the magnet unit (permanent magnet) and the armature unit may be connected to the stage, and the other of the magnet unit and the armature unit may be provided on the moving surface side (base) of the stage.

Further, the reaction force generated by the movement of the wafer stage is mechanically moved to the floor (ground) by using a frame member, as described in JP-A-8-166475.
You may escape to The present invention is also applicable to an exposure apparatus having such a structure.

The reaction force generated by the movement of the reticle stage may be mechanically released to the floor (ground) by using a frame member as described in JP-A-8-330224. The present invention is also applicable to an exposure apparatus having such a structure.

Further, the exposure apparatus of the embodiment of the present invention controls various subsystems including each component listed in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. It is manufactured by assembling. Before and after this assembly, in order to ensure these various precisions, adjustments to achieve optical precision for various optical systems,
Adjustments are made to achieve mechanical accuracy for various mechanical systems, and adjustments are made to achieve electrical accuracy for various electrical systems. The assembling process from various subsystems to the exposure apparatus involves mechanical connection between various subsystems,
Wiring connection of an electric circuit, piping connection of an air pressure circuit, and the like are included. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the manufacture of the exposure apparatus be performed in a clean room in which the temperature, cleanliness, and the like are controlled.

Devices (electronic devices) such as semiconductor elements (integrated circuits) and liquid crystal display panels are provided with a step of designing the function and performance of the device, a step of manufacturing a reticle based on the design step, a glass plate, and the like. It is manufactured through a wafer manufacturing step, a device assembling step (including a dicing step, a bonding step, and a package step), an inspection step, and the like.

[0073]

As described above, according to the first to seventh aspects of the present invention, an area to be suctioned is specified according to an exposure area, and the area to be suctioned is suctioned to a substrate stage. Accordingly, it is possible to suppress the deformation of the substrate that occurs when the substrate is attracted, to improve the exposure accuracy, and to improve the reliability of the device. According to each of the inventions described in claims 8 and 9, a device in which the accuracy of the formed pattern is improved can be provided.

[Brief description of the drawings]

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

FIG. 2 is a schematic configuration diagram illustrating an overall configuration of the exposure apparatus of FIG.

FIG. 3 is a plan view of the reticle R shown in FIG.

FIG. 4 is a layout view of a device pattern in which a substrate mark is formed in a pattern area of a reticle R;

FIG. 5 is a block diagram showing a configuration of a substrate suction system 45 shown in FIG.

FIG. 6 is a plan view showing a substrate P mounted on the substrate stage 23.

FIG. 7 is a diagram showing a state in which a target area of a substrate P is attracted to a substrate stage 23 according to an exposure area SA.

FIG. 8 is a view showing another embodiment of the present invention, showing a state in which a substrate is sucked at the time of scanning exposure.

FIG. 9 is a view showing another embodiment of the present invention, and is a view showing how a target area to be sucked moves.

FIG. 10 is a diagram showing another embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing a conventional exposure apparatus.

FIG. 12 is a view showing a state in which deformation is left on a substrate due to a suction failure in a conventional exposure apparatus.

[Explanation of symbols]

 R reticle (mask) P substrate PL projection optical system PA pattern area PM substrate mark (mark) AM, AM1 to AM4 alignment mark BA block area SA exposure area 10 exposure apparatus 22 reticle stage 23 substrate stage 24 controller 40 drive system 45 substrate Suction system 56 Alignment detection system 60 Vacuum generator 61 Suction mechanism 23a Holding surface 65 Suction nozzle 66 Piping 67 Valve

Claims (9)

[Claims] 1. An exposure method for adsorbing a substrate on a substrate stage and transferring a mask pattern to an exposure area of the substrate, wherein an area to be adsorbed on the substrate is specified according to the exposure area, and the specified object is specified. An exposure method, wherein an area is attracted to the substrate stage. 2. The exposure method according to claim 1, wherein the target area is changed according to the change of the exposure area. 3. The exposure method according to claim 1, wherein the attraction force for the original target region is reduced after the attraction force for the next target region is increased. 4. The exposure method according to claim 1, wherein a next target area is specified so as to be adjacent to or at least partially overlap the original target area. 5. An exposure apparatus, comprising: a substrate stage for holding a substrate; and transferring a pattern of a mask onto an exposure region of the substrate via a projection optical system. An exposure apparatus comprising: a plurality of suction mechanisms; and a control device that specifies an area to be suctioned with respect to the substrate and selectively controls the plurality of suction mechanisms according to the specified target area. 6. The exposure method according to claim 5, wherein the plurality of suction mechanisms are arranged so that a plurality of suction mechanisms suction one exposure area. 7. An alignment detection system for detecting a mark formed on the substrate via the projection optical system for aligning the substrate, wherein the alignment detection system detects a mark in a target area. The exposure apparatus according to claim 5 or 6, wherein 8. A device manufacturing method including a lithography step, wherein the lithography step uses the exposure method according to any one of claims 1 to 4. 9. A device having a predetermined pattern formed thereon, the device being manufactured using the exposure apparatus according to claim 5. Description: