JP2002110511A - Exposure method and exposure apparatus - Google Patents

Abstract

(57) Abstract: When exposing a plurality of patterns having different depth shapes to a substrate by a projection optical system, an exposure method and exposure capable of exposing all patterns to obtain a desired shape with high accuracy. It is intended to provide a device. An exposure apparatus (EX) includes a projection optical system (P) during exposure.
Substrate stage PST for moving substrate P in the optical axis direction of L
And the substrate P for each exposure of the plurality of patterns PA
And a controller CONT for setting at least one of a position in the Z direction and a movement amount for moving the position during exposure. Therefore, when each of the plurality of patterns PA having different depth shapes is formed on the substrate P, the pattern P
Since the exposure is performed by setting the focus position or the depth of focus corresponding to A to an arbitrary value, all the patterns PA
Can be accurately formed into desired shapes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure method and an exposure apparatus for exposing a plurality of patterns to a substrate by a projection optical system.

[0002]

2. Description of the Related Art Conventionally, when a device such as a liquid crystal display element or a semiconductor element is manufactured by a photolithography process, a photomask or a reticle (hereinafter, referred to as a "mask") is used.
An exposure apparatus is generally used which exposes a pattern formed on a substrate having a surface coated with a photosensitive agent such as a photoresist through a projection optical system. In this exposure apparatus, the mask and the substrate are kept stationary, and the mask is irradiated with exposure light, an image of the pattern of the mask is exposed on the substrate via the projection optical system, and the substrate is sequentially moved step by step. Exposing each of a plurality of patterns to different regions (shot regions) of one substrate;
There is an and repeat type exposure apparatus.

When a plurality of patterns are exposed on a substrate by the step-and-repeat type exposure apparatus, conventionally, the position of the substrate in the optical axis direction of the projection optical system (hereinafter referred to as "focus position") is For example, one piece of data is set for exposure processing, and each pattern in the substrate is exposed according to this value.

[0004]

However, even if one data can be set for the exposure process, when each pattern in the substrate is exposed, the difference in the surface condition and the resist thickness due to the respective pattern shape of the substrate is not sufficient. The focus detection light for detecting the focus position is affected by the detection error, and a difference in resist thickness affects the exposure light, so that a plurality of patterns exposed on the substrate are not accurately formed in a desired shape. There are cases.

Further, when it is desired to form a pattern requiring a predetermined depth shape, such as a pixel pattern or a contact hole pattern in a liquid crystal display element, with high precision, it is preferable to perform exposure with a deep focal depth. However, when a pattern requiring a predetermined depth shape and another pattern not requiring a predetermined depth shape are formed on the same substrate, a focus position detected by focus detection light is set as in the related art. In other words, even if the other pattern can be formed into a desired shape, a pattern requiring a predetermined depth shape may not be formed into a desired shape.

The present invention has been made in view of such circumstances. For example, when each of a plurality of patterns having different depth shapes is exposed on a substrate by a projection optical system, all the patterns are precisely formed in a desired shape. It is an object of the present invention to provide an exposure method and an exposure apparatus capable of performing exposure so as to obtain an image.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following structure corresponding to FIGS. 1 to 6 shown in the embodiments. According to the exposure method of the present invention, a plurality of patterns (PAa-PA) are formed by a projection optical system (PL).
In the exposure method of exposing each of d) to the substrate (P), the position of the substrate (P) with respect to the image plane of the projection optical system (PL) in the optical axis direction of the projection optical system (P), At least one of the amount of movement in the optical axis direction during exposure is set for each of a plurality of patterns (PAa to PAd).

An exposure apparatus according to the present invention comprises a projection optical system (PL)
Moving the substrate (P) in the direction of the optical axis of the projection optical system (PL) during exposure in the exposure apparatus (EX) that exposes each of the plurality of patterns (PAa to PAd) to the substrate (P) via For each exposure of the apparatus (PST, PSTD) and the plurality of patterns (PAa to PAd), the projection optical system (P) in the optical axis direction of the projection optical system (PL) is used.
A control device (CONT) for setting at least one of a position of the substrate (P) with respect to the image forming plane of L) and a movement amount for moving the position during exposure.

According to the present invention, a plurality of patterns (PAa
To PAd), the projection optical system (PL)
At least one of the position of the substrate (P) with respect to the image plane of the projection optical system (PL) in the optical axis direction and the amount of movement of the position during the exposure is set. A plurality of patterns having different shapes (PAa ~
When each of the PAd) is formed on the substrate (P), the exposure is performed by setting the focus position or the focal depth according to the pattern (PAa to PAd) to an arbitrary value.
All the patterns (PAa to PAd) can be precisely formed into desired shapes.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an exposure method and an exposure apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an exposure apparatus of the present invention.

As shown in FIG. 1, an exposure apparatus EX includes an illumination optical system IL for illuminating a light beam from a light source 1 onto a mask M (Ma to Md) held on a mask stage MST, and an illumination optical system IL. The mask M (Ma) by the exposure light EL is adjusted by adjusting the area of the opening through which the exposure light EL passes.
And a projection optical system PL for projecting an image of a pattern PA (PAa to PAd) of a mask M (Ma to Md) illuminated with the exposure light EL onto a substrate P. It has. The operation of the entire exposure apparatus EX is performed based on an instruction from the control unit CONT.

As the light source 1, a mercury lamp is used.
As the exposure light EL, a g-line (436 nm) and an h-line (40
5 nm), i-line (365 nm) and the like.

The exposure light EL emitted from the light source 1 is condensed by the elliptical mirror 2, passes through a shutter S for controlling the passage and blocking of the exposure light EL, and reflects off the return mirror 3a of the illumination optical system IL. The light enters the optical unit IU that constitutes the illumination optical system IL. The optical unit IU includes a relay lens, an optical integrator for equalizing the exposure light EL, an input lens for inputting the exposure light EL to the optical integrator, and a light source for condensing the exposure light EL emitted from the optical integrator on the mask M. It has a plurality of lenses (optical elements) such as a relay lens and a condenser lens.

As shown in FIG. 1, patterns PAa-PA
The masks Ma to Md each provided with d are mounted on the mask changer 7. The mask changer 7 is movably disposed above the mask stage MST, and can load and unload each of the masks Ma to Md with respect to the mask stage MST.

The mask M to be mounted on the mask changer 7 is stored in a mask library (not shown).
To mount the mask M in the mask library on the mask changer 7, the mask M is loaded onto the mask stage MST by a loader (not shown) from the mask library, and the mask changer 7 receives the mask M on the mask stage MST. Mask M is mask changer 7
Mounted on On the other hand, in order to return the mask M mounted on the mask changer 7 into the mask library, the mask M is loaded from the mask changer 7 onto the mask stage MST, and the mask M on the mask stage MST is masked by the loader (not shown). Return to library.

Exposure light E emitted from the optical unit IU
L is reflected by the return mirror 3b and is reflected in the two-dimensional direction (XY
Direction) mask M on movable mask stage MST
(Ma to Md). Further, the exposure light EL transmitted through the mask M is incident on the projection optical system PL, is transmitted through a plurality of lenses (optical elements) constituting the projection optical system PL and is incident on the substrate P, and the image of the pattern of the mask M is formed. Is formed on the surface of the substrate P.

The substrate P has a surface coated with a photosensitive agent and is held by a substrate holder PH. The substrate holder PH for holding the substrate P is a substrate stage (moving device) PST
It is installed above. The substrate stage PST is provided so as to be movable in the XYZ directions, and is provided so as to be rotatable around the Z axis. Further, the optical axis A of the exposure light EL
By providing a mechanism that can also move in the tilt direction with respect to X, the leveling of the substrate P may be adjusted when the substrate P is supported.

The position of the substrate stage PST in the XY plane is detected by the laser interferometer 5. On the other hand, the position of the substrate stage PST in the Z direction (the optical axis direction of the projection optical system PL) is detected by a focus position detection system 6 including a light projection system 6a and a light receiving system 6b. The detection results of the laser interferometer 5 and the focus position detection system 6 are output to the control device CONT, and the substrate stage PST is moved via the drive mechanism PSTD based on an instruction from the control device CONT. The focus position detection system 6 detects the position (focus position) of the surface (exposure processing surface) of the substrate P held by the substrate holder PH in the direction of the optical axis of the projection optical system PL, and outputs information on the position. Output to CONT. When performing the exposure processing, the control device CONT controls the substrate via the drive mechanism PSTD based on the detection result of the focus position detection system 6 so that the surface position of the substrate P matches the image forming position of the projection optical system PL. Stage PST
To move.

The exposure apparatus EX according to the present embodiment
Is a step-and-repeat type exposure apparatus that exposes the pattern of the mask M while keeping the mask M and the substrate P stationary, and sequentially moves the substrate P step by step. Each of PAa to PAd is exposed. And each pattern PA
a to PAd are formed on each of the plurality of masks Ma to Md, and the exposure apparatus EX controls the masks Ma to Md.
While exchanging d, the patterns PAa to PAd are respectively exposed to different regions of the substrate P.

With the exposure apparatus EX having the above-described configuration, a plurality of patterns P are formed by the projection optical system PL.
A method of exposing each of Aa to PAd to the substrate P will be described.

In the present embodiment, the substrate P with respect to the image forming plane of the projection optical system PL in the optical axis direction of the projection optical system PL is used.
And at least one of the amount of movement of this position in the optical axis direction during exposure is determined by a plurality of patterns PAa to PAa.
It is set for each d. And
Data relating to the exposure processing as shown in Table 1 is registered in advance in the control device CONT, and the exposure apparatus EX performs the exposure processing based on this data. In the following description, for convenience, a case where the pattern PAa and the pattern PAb of the plurality of patterns PAa to PAd are exposed will be described.

[0022]

[Table 1]

Here, Table 1 will be described. In Table 1, the pattern size is the length (unit: μm) of each of the patterns PAa, PAb,. The pattern position is defined as the center O of the masks Ma and Mb on the masks Ma and Mb.
The center position of the pattern with respect to m (unit: μm).
That is, the pattern size and the pattern position are as shown in FIG.
(A) Center Om of masks Ma and Mb as shown in (b)
Are set based on a coordinate system (mask coordinate system) with reference to. The arrangement in Table 1 means how many patterns PAa and PAb are arranged in the XY directions on the substrate P in a coordinate system (substrate coordinate system) based on the center Op of the substrate P as shown in FIG. Is the numerical value of. The arrangement pitch is the distance (unit: μm) between the center positions of each pattern when a plurality of patterns are arranged in the substrate coordinate system. The arrangement positions are the patterns PAa, P
The position (unit: μm) of the center of the pattern arrangement with respect to the center Op when a plurality of Abs are arranged on the substrate P.

In Table 1, the exposure energy is the energy (unit: mJ) of the exposure light when exposing each of the patterns PAa and PAb. The AF value is the position (unit: μm) of the substrate P with respect to the image plane of the projection optical system PL in the optical axis direction of the projection optical system PL. The AF swing width is a movement amount (unit: μm) for moving the position of the substrate P in the optical axis direction of the projection optical system PL during exposure. At this time, the center of the AF swing width is set to the AF value. That is, when the AF value is a and the AF swing width is b, the surface (exposure processing surface) of the substrate P is (ab-2) to (a + b / 2) due to the movement of the substrate stage PST in the Z direction. Is continuously moved in the range of.

The AF value is a value previously obtained by an experiment or the like. Specifically, first, test exposure is performed in a state where the position of the image forming surface of the projection optical system PL and the position of the exposure processing surface of the substrate P are matched based on the detection result of the focus position detection system 6. The position of the substrate P (the value obtained by the focus position detection system 6) at this time is set as a reference value of the AF value. Then
A development process is performed on the exposed substrate P, and the shape of the actually formed pattern is measured. If a pattern shape having the desired accuracy is not obtained, test exposure is performed while adjusting the position of the substrate P until a pattern shape having the desired accuracy is obtained, and the position at which the desired pattern shape is obtained is determined by AF. Set as a value. Therefore, for example, the AF value of the pattern PAa in Table 1 is set to 0.
The value of 5 μm is a deviation amount from the reference value.

In this case, since the AF swing width is 2 μm, the substrate P moves in the Z direction around the AF value of 0.5 μm.
The substrate is continuously moved in the range of 0.5 to 1.5 μm by the substrate stage PST. The AF swing width in this case is also set in advance by an experiment or the like in accordance with the pattern to be formed. That is, for example, when a pattern requiring a predetermined depth shape such as a contact hole pattern is formed, a desired shape can be obtained by varying the AF value within a predetermined range. A pattern having a predetermined shape is formed by setting the AF swing width in accordance with the depth of focus of the projection optical system PL, for example, by setting the depth within the focus depth or outside a predetermined amount range from the depth of focus. can do.

As described above, the setting of the AF value and the setting of the AF swing width are set according to the image forming position or the depth of focus of the projection optical system PL.

The exposure energy is set in advance for each pattern. This exposure energy is also set to an optimum value obtained by an experiment in advance according to the pattern. Specifically, as shown in Table 1, the pattern PAa is exposed at an exposure energy of 40 mJ, and the pattern PAb is exposed at an exposure energy of 50 mJ.

Then, based on the preset data in Table 1, the position of the substrate P with respect to the imaging plane of the projection optical system PL in the optical axis direction of the projection optical system PL and the amount of movement of the substrate P in the optical axis direction Are set for each pattern, and exposure processing is performed, whereby patterns PAa and PAb are formed on the substrate P. Specifically, as shown in FIG. 3, the pattern PAa is formed in two columns and two rows with the size and position shown in Table 1, and the pattern PAb is formed in three columns and one row with the size and position shown in Table 1. Is done.

Next, a procedure for exposing a plurality of patterns to the substrate P based on preset data as shown in Table 1 will be described with reference to FIG.

First, the control unit CONT instructs the exposure apparatus EX to start the exposure processing (step S1). 1
The first pattern data (n = 1) is read, the mask Ma on which the pattern PAa as the first exposure pattern is drawn is selected and loaded on the mask stage MST, and the mask is masked by the blind portion B according to the pattern size of the pattern PAa. Set the illumination range of Ma (step S
2). Then, the control device CONT instructs to perform an exposure process using the mask Ma (step S3).

Next, among the preset data, data relating to the AF value is input to the control device CONT (step S4). The controller CONT adjusts the position of the substrate stage PST holding the substrate P based on the AF value. Specifically, as shown in Table 1, the substrate P
Is moved in the + Z direction (optical axis direction) at a position of 0.5 μm with respect to the image forming plane of the projection optical system PL.

The data relating to the AF swing width is stored in the control unit CO.
Input to NT. The control unit CONT receives the input AF.
It is determined whether the value of the swing width is 0 (step S5).
At this time, the AF swing width in the pattern PAa is 2 μm (≠ 0) as shown in Table 1.

If it is determined that the value of the inputted AF swing width is not 0, it is determined whether or not the exposure energy is individually set for each pattern (step S6). In this case, the exposure energy is individually set to 40 mJ for the pattern PAa and 50 mJ for the pattern PAb for each pattern.

If it is determined that the exposure energy is individually set for each pattern, the control unit CONT adjusts the output of the light source 1 so as to have the set exposure energy of 40 mJ, and sets the AF value to 0.5 μm. Is instructed to move the substrate stage PST in the direction of the optical axis of the projection optical system PL with the AF swing width of 2 μm with respect to the center value. The substrate P on the substrate stage PST is exposed (FLEX exposure) while being moved in the optical axis direction of the projection optical system PL (Step S7). in this case,
The control device CONT performs continuous movement control of the substrate stage PST supporting the substrate P in the optical axis direction of the projection optical system PL based on the set AF swing width. For example,
While irradiating the substrate P with the exposure light, the substrate P is reciprocated continuously in the optical axis direction, for example, at a sine curve speed. Then, as shown in FIG.
Exposure is performed at four positions shown in FIG.

When the first exposure processing of the pattern PAa is completed, the control unit CONT determines whether the exposure processing of all the patterns is completed (step S8). When it is determined that the exposure processing for all the patterns has been completed, an instruction is given to the exposure apparatus EX to terminate the processing (step S14). On the other hand, if it is determined in step S8 that the exposure processing for all the patterns has not been completed, the next pattern data is read. If the next pattern data belongs to the same mask as the previous pattern, the same mask is used as it is and the mask Mb having a different pattern PAb as in the present embodiment.
In this case, the mask on the mask stage MST (in this case, the mask Ma) is unloaded, and the next mask (in this case, the mask Mb) is loaded on the mask stage MST. The setting of the blind portion B is performed (step S9). Next, the process of step S3 is performed, and thereafter, the above-described procedure is repeated until it is determined that the exposure process of all the patterns has been completed. Then, as shown in FIG. 3, the pattern PAb is exposed at three positions shown in Table 1.

In step S6, when it is determined whether or not the exposure energy is individually set for each pattern, and if it is determined that the exposure energy is not individually set for each pattern, the control device CONT preliminarily sets The exposure energy value of the set representative value (predetermined value) is used. At this time, the exposure energy applied during the opening time of the shutter S is integrated so that the exposure energy set to the representative value is obtained, and the shutter S is closed when the target exposure energy value is reached. At this time, in accordance with the opening time of the shutter S, the substrate stage driving unit PSTD is instructed to move the substrate stage PST in the optical axis direction of the projection optical system PL by the AF swing width with the set AF value as the center value. I do. The substrate P on the substrate stage PST is exposed while being moved in the optical axis direction of the projection optical system PL (Step S).
10). When the exposure processing in step S10 ends, the process proceeds to step S8.

In step S5, when it is determined whether the value of the AF swing width is 0 or not, if it is determined that the value of the AF swing width is 0, then it is determined whether the exposure energy is individually set for each pattern. (Step S1)
1).

When it is determined that the exposure energy is individually set for each pattern, the control unit CONT controls the substrate stage driving unit PSTD so that the set AF value is obtained.
Is driven to adjust the position of the substrate stage PST. Then, exposure is performed by controlling the opening time of the shutter S so that the exposure energy becomes a preset exposure energy. In this way, the substrate P on the substrate stage PST is exposed (normal exposure) while the position is fixed (Step S1).
2). When the exposure processing in step S12 ends, the process proceeds to step S8.

In step S11, when it is determined whether or not the exposure energy is individually set for each pattern, if it is determined that the exposure energy is not individually set for each pattern, the control device CONT sets the set value. The position of the substrate stage PST is adjusted by driving the substrate stage PSTD so that the AF value is obtained. Then, exposure energy is set to a preset representative value (predetermined value), and exposure is performed by controlling the opening time of the shutter S so that the exposure energy is set to the representative value. In this way, the substrate P on the substrate stage PST is exposed while the position is fixed (Step S13). When the exposure processing in step S13 ends, the process proceeds to step S8.

The above description has been made by taking as an example the case where the two patterns PAa and PAb are exposed.
It is needless to say that data relating to all patterns of Ad is registered, and exposure processing of the patterns PAa to PAd can be performed based on the registered data.

As described above, when each of the plurality of patterns PAa to PAd is exposed on one substrate P, the optical axis of the projection optical system PL is set for each exposure of the plurality of patterns PAa to PAd. At least one of the position (AF value) of the substrate P with respect to the image forming plane of the projection optical system PL in the direction and the amount of movement (AF swing width) for moving this position during exposure is set. Even if the target depth shape to be formed on the substrate P of each of the patterns PAa to PAd is different, exposure can be performed by setting the focus position or the focal depth according to the pattern PAa to PAd to an arbitrary value. Therefore, all the patterns PAa to PAd can be accurately formed into desired shapes.

That is, when a pattern requiring a predetermined depth shape, such as a contact hole pattern or a pixel pattern in a liquid crystal display element, is desired to be formed with high precision, it is preferable that the exposure is performed with a deep focal depth. However, the numerical aperture NA of the projection optical system PL has been set to be large in accordance with recent demands for finer patterns, and accordingly, the depth of focus has become shallower. In this case, a pattern that does not require a predetermined depth shape is exposed with high accuracy, but a pattern that requires a predetermined depth shape has to be exposed using a projection optical system PL with a shallow depth of focus. In some cases, a desired depth shape cannot be obtained. However, since the exposure is performed while moving the substrate P in the direction of the optical axis of the projection optical system PL according to the pattern to be formed, even when a projection optical system having a small depth of focus is used, a desired depth shape is obtained. Necessary patterns can be formed with high accuracy.

In the present embodiment, the control device CONT is provided with a substrate stage PST holding the substrate P.
Is controlled continuously in the optical axis direction of the projection optical system PL, but it may be configured not to move continuously.

Table 2 (a) shows one pattern PA while continuously controlling the movement of the substrate stage PST in the optical axis direction of the projection optical system PL as in the embodiment based on Table 1 described above.
(E.g., PAa). In this case, the exposure energy is 40 mJ, AF
The value is set to 0 μm, and the AF swing width is set to 8 μm. Then, the control device CONT is -4 μm to +4 μm so that, for example, the moving speed of the projection optical system PL in the optical axis direction changes in a sine curve shape around the AF value of 0 μm.
The substrate P is continuously moved within the range of m. On the other hand, Table 2
(B) shows one pattern PA while controlling the movement of the substrate stage PST stepwise in the optical axis direction of the projection optical system PL.
This is data related to exposure processing when exposing (PAa). Then, at the time of exposure, the positioning operation of the substrate P with respect to the imaging plane of the projection optical system PL is performed twice, and exposure is performed at each of the two positioned positions. In this case, at the time of the first exposure, the exposure energy is 20 mJ, the AF value is +4 μm, and the AF swing width is 0.
μm (that is, the substrate P is not moved during the exposure). In the second exposure, the exposure energy is 20 mJ, the AF value is −4 μm, and the AF swing width is 0 μm (that is, the substrate P is not exposed during the exposure). Is not moved). Then, exposure is performed twice at each AF value.

[0046]

[Table 2]

As described above, when exposing the substrate P by moving it in the direction of the optical axis of the projection optical system PL, the exposure may be performed while moving the substrate P continuously. And exposure may be performed at each position. When the substrate P is moved stepwise, exposure light reaching the substrate P is blocked by a shutter or the like during the movement.

When exposing a plurality of patterns PAa and PAb to one substrate P, the substrate P is exposed while moving the substrate P continuously in the optical axis direction of the projection optical system PL when exposing the pattern PAa. During exposure of PAb, substrate P
May be moved stepwise in the optical axis direction of the projection optical system PL to perform exposure a plurality of times.

When exposing while moving the substrate P in the direction of the optical axis of the projection optical system PL, the exposure energy is set to be larger than when exposing without moving the substrate P. The shape of the pattern formed under the conditions can be made uniform. This is the substrate P
Is moved, the image of the pattern is defocused by an amount corresponding to the movement, that is, in a blurred state. Therefore, when the substrate P is moved and exposed, compared to when the substrate P is not moved and exposed. This is because high exposure energy is required to obtain the same pattern shape. Therefore, by individually setting the exposure energy depending on whether or not the substrate P is moved in the optical axis direction,
A pattern having a desired shape can be formed.

Therefore, in Table 2, (a) the exposure energy is 40 mJ, and in Table 2 (b), each exposure energy is 20 mJ, and the exposure is performed twice, and the total exposure energy is as shown in Table 2 (a). The exposure energy in Table 2 (a) is increased (for example, Table 2
(The exposure energy in (a) is 41 mJ). That is, when performing exposure once while continuously moving the substrate P, the setting is changed so as to increase the exposure energy, as compared with when performing exposure a plurality of times while moving the substrate P stepwise.

Similarly, when exposing the substrate P while moving it in the direction of the optical axis of the projection optical system PL, it is preferable to set the exposure energy to increase as the AF swing width is increased. In other words, even if the image is blurred by increasing the AF swing width, the exposure is performed with high exposure energy. Therefore, the shape of the pattern exposed with the small AF swing width and the exposure with the AF swing width larger than this swing width are performed. And the shape of the pattern can be made uniform.

The numerical values shown in Tables 1 and 2 are merely examples, and it is needless to say that any numerical values can be set. Also, the pattern is not limited to four, PAa to PAd,
Of course, any number of patterns can be exposed.

In the above embodiment, when the exposure energy is individually set for each pattern exposure, the exposure energy is set by adjusting the exposure time while keeping the illuminance constant. At this time, for example, when it is desired to increase the exposure energy, the exposure time is lengthened.
As another method, the output of the light source 1 (that is, the illuminance)
May be adjusted to set the exposure energy to an arbitrary value.

Various settings such as the AF value, the AF swing width, and whether the substrate P is to be moved continuously or stepwise in the optical axis direction of the projection optical system PL are previously stored as data in the memory of the control unit CONT. Although it is stored, for example, selection of continuous movement or stepwise movement of the substrate P, various settings such as the number of steps at the time of stepping can be input from an operation display unit connected to the control device CONT, The operator may be configured to input various settings from the operation display unit.

In the present embodiment, a plurality of patterns are respectively exposed to different regions (shot regions) in the same layer of the substrate P. However, the patterns are overlapped on the same shot region. At the time of exposure, at least one of the AF value and the AF swing width may be set for each pattern exposed on a different layer. For example, when manufacturing a semiconductor device, the AF swing width is set to a predetermined value in order to obtain a deep depth of focus in the contact hole pattern, and the substrate P is projected onto the projection optical system PL.
Exposure is performed while moving in the optical axis direction, and the exposure is performed while fixing the position of the substrate P in the wiring pattern.

Further, a plurality of substrates P to be subjected to the exposure processing may be set as one lot, and at least one of the AF value and the AF swing width may be set for each exposure to a different substrate P in the lot.

In the present embodiment, each of the plurality of patterns is exposed to a different region of the substrate P. However, each of the plurality of patterns is connected on the substrate P (screen connection is performed). It is also possible to form one composite pattern by exposure. in this case,
For example, when joining and exposing a substrate P having poor flatness to form one combined pattern, the combined pattern can be formed with high accuracy. When performing this screen joining, the required accuracy differs for each pattern, and it is conceivable to set the AF value and the AF swing width accordingly. Therefore, the pattern may be divided for each required accuracy and exposed.

To perform the screen splicing, a blind portion B as shown in FIG. 5 is used. The blind part B is shown in FIG.
As shown in (a), a blind B1 is provided with a light source side blind B1 and a projection optical system side blind B2.
Reference numerals 1 and B2 each include a glass blind Bg and a normal blind Bn provided integrally. At the time of exposure processing for performing screen splicing, a glass blind Bg is used. The glass blind Bg has a light transmitting portion 15a formed of a transparent glass substrate.
Is a light shielding portion 16. Further, the light transmitting portion 15
At the end of “a”, there is provided a dimming section 15b set so that the dimming rate increases from the light transmitting section 15a toward the light shielding section 16. Then, when performing the screen splicing, as shown in FIG.
An illumination area for the mask M is set by combining a predetermined amount of each of the light transmitting portions 15a, 15a of g and Bg. Then, the exposure is performed so as to overlap the light-reduced area on the substrate P corresponding to the light-reduced portion 15b, so that the exposure amount can be made uniform in all the areas of the combined pattern. In FIG. 5, the dimming unit 15b is provided in the upper and lower parts and not in the horizontal part. However, at the time of performing the exposure processing, at least one of the glass blinds Bg on the light source side or the projection optical system side is used. Exposure while moving in the Y direction generates a light quantity distribution, and a darkened area is formed in the projection area. By superimposing this darkened area on the substrate P, the light exposure in all areas of the composite pattern is increased. Can be made uniform. Then, using the blind portion B (glass blind Bg), a plurality of patterns are joined together on the substrate P to form one composite pattern.

In this embodiment, a plurality of patterns P
Aa to PAd are provided on a plurality of masks Ma to Md,
When exposing a plurality of patterns PAa to PAd, it has been described that a plurality of masks Ma to Md are exchanged for exposure. However, a plurality of patterns PAa to PAd are formed on one mask M, and each pattern is formed. A configuration in which exposure is performed by setting an AF value and an AF swing width may also be employed.
In this case, for the pattern on the mask M to be exposed, the openings 14, 14 of the two normal blinds Bn, Bn of the blind portion B shown in FIG.
To set the size of the opening through which the exposure light EL passes, so that only the pattern to be exposed is illuminated with the exposure light, and the light-shielding portion 16
To block exposure light. When switching between the glass blind Bg and the normal blind Bn during the exposure processing, the respective blinds B1 and B2 (entire blind portion B) are moved in the Y direction in FIG.

In the present embodiment, the exposure apparatus EX is a step-and-repeat type exposure apparatus, while simultaneously moving the mask M and the substrate P relative to the illumination optical system IL and the projection optical system PL. The present invention can also be applied to a scanning type exposure apparatus that performs exposure. In this case, while the substrate P is continuously moved in the optical axis direction of the projection optical system PL, the scanning speed is switched for each pattern while the mask M and the substrate P are reciprocally scanned, so that each exposure of a plurality of patterns is performed. Exposure energy can be set individually. In the case of a scan type exposure apparatus, an AF value and an AF swing width are set for each pattern in order to scan the slit-shaped exposure area with respect to the substrate P, and the pattern changes during scanning. Thus, the operating state of the AF value and the AF swing width can be continuously switched.

In the above embodiment, the illumination condition of the illumination optical system is changed for each exposure of a plurality of patterns, so that an aperture stop with a normal circular aperture, an aperture stop for reducing the σ value, Alternatively, a switching aperture may be provided by providing a ring-shaped aperture stop or a modified aperture stop having a configuration in which a plurality of apertures for a deformed light source are eccentrically arranged.

By applying the method described in the present embodiment at the time of test exposure, that is, by changing the AF value and the AF swing width at the time of test exposure and performing exposure, optimization of exposure processing conditions with one substrate Can be performed efficiently.

The application of the exposure apparatus EX is not limited to an exposure apparatus for a liquid crystal for exposing a liquid crystal display element pattern to a square glass plate. For example, an exposure apparatus for manufacturing a semiconductor or a thin film magnetic head may be manufactured. It can be widely applied to an exposure apparatus for performing the above.

The light source 1 of the exposure apparatus EX of this embodiment includes a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), and an F ₂ laser (157 n).
m), Kr ₂ laser (146 nm), Ar ₂ laser (1
26 nm) can also be used.

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

As far as the projection optical system PL is concerned, a material that transmits far ultraviolet rays such as quartz or fluorite is used as a glass material when far ultraviolet rays such as an excimer laser is used, and a catadioptric system is used when an F ₂ laser or X rays is used. Alternatively, a refraction optical system is used (a reflection type mask is used as the mask).

The substrate stage PST and the mask stage MS
When a linear motor is used for T, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. Also,
The stage may be a type that moves along a guide or a guideless type that does not have a guide.

When a plane motor is used as the stage driving device, one of the magnet unit (permanent magnet) and the armature unit is connected to the stage, and the other of the magnet unit and the armature unit is connected to the moving surface of the stage. (Base).

The reaction force generated by the movement of the substrate stage PST may be mechanically released to the floor (ground) using a frame member as described in Japanese Patent Application Laid-Open No. 8-166475. The present invention is also applicable to an exposure apparatus having such a structure.

The reaction force generated by the movement of the mask stage MST is mechanically moved to the floor (ground) using a frame member as described in Japanese Patent Application Laid-Open No. 8-330224.
You may escape to The present invention is also applicable to an exposure apparatus having such a structure.

As described above, the exposure apparatus according to the embodiment of the present invention converts various subsystems including the components described in the claims of the present application into predetermined mechanical accuracy, electrical accuracy,
It is manufactured by assembling to maintain optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. 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.

As shown in FIG. 6, in the semiconductor device, a step 201 for designing the function and performance of the device, and a step 20 for manufacturing a mask based on this design step
2. Step 203 of manufacturing a substrate (wafer, glass plate) serving as a base material of the device; substrate processing step 204 of exposing a mask pattern to the substrate by the exposure apparatus of the above-described embodiment; device assembling step (dicing step, bonding) (Including a process and a package process) 205, an inspection step 206, and the like.

[0073]

The exposure method and exposure apparatus of the present invention have the following effects. According to the exposure method according to the first aspect and the exposure apparatus according to the seventh aspect, each time a plurality of patterns are exposed, the substrate is moved with respect to the image plane of the projection optical system in the optical axis direction of the projection optical system. location and,
Since at least one of the movement amount to move this position during the exposure is set, for example, when each of a plurality of patterns having different depth shapes is formed on the substrate, a focus position or a focus depth according to the pattern is set. Since the exposure is performed by setting the respective values to arbitrary values, all the patterns can be accurately formed into desired shapes.

According to the second aspect of the present invention, the position of the substrate with respect to the image plane of the projection optical system and the position of the substrate are projected in accordance with at least one of the imaging position of the projection optical system and the depth of focus. Since the amount of movement of the optical system in the optical axis direction is set, accurate exposure processing can be performed without greatly blurring the pattern image.

According to the third aspect of the present invention, since each of the plurality of patterns is exposed to a different region of the substrate, a plurality of devices can be accurately formed from one substrate.

According to the exposure method of the present invention, since a plurality of patterns are exposed so as to be connected, for example, a substrate having a large flatness is connected and exposed to form one composite pattern. In this case, the composite pattern can be formed with high accuracy.

According to the exposure method of the present invention, since the exposure energy is individually set for each exposure of a plurality of patterns, each pattern can be formed into a desired shape. In addition, since the exposure energy can be set individually when the substrate is moved in the optical axis direction of the projection optical system during exposure and when the substrate is not moved, the shapes of the plurality of patterns can be made uniform. .

According to the exposure method of the present invention, a plurality of patterns are provided on a plurality of masks, and a plurality of patterns are exposed by exchanging a plurality of masks. Exposure can be carried out efficiently while setting to.

According to the exposure apparatus of the present invention, since the control device controls the continuous movement of the substrate in the direction of the optical axis of the projection optical system, for example, it exposes a pattern requiring a predetermined depth shape. In this case, accurate exposure processing can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining an embodiment of an exposure apparatus of the present invention.

FIG. 2 is a diagram for explaining an arrangement of a pattern formed on a mask.

FIG. 3 is a diagram for explaining an arrangement of a pattern formed on a substrate.

FIG. 4 is a flowchart for explaining an embodiment of the exposure method of the present invention.

FIG. 5 is a schematic diagram for explaining a blind unit.

FIG. 6 is a flowchart illustrating an example of a semiconductor device manufacturing process.

[Explanation of symbols]

 6 Focus position detection system CONT control device EX Exposure device M (Ma to Md) Mask P substrate PA (PAa to PAd) Pattern PL Projection optical system PST Substrate stage (moving device) PSTD Substrate stage driving section (moving device)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 516D F-term (Reference) 2H097 AA20 AB09 BA01 DA03 GB00 KA03 KA29 KA38 LA10 LA12 5F046 AA13 BA04 CC01 CC02 CC05 DA02 DA06 DA08 DA14 DD06

Claims (8)

[Claims] 1. An exposure method for exposing each of a plurality of patterns to a substrate by a projection optical system, the method comprising: determining a position of the substrate with respect to an imaging plane of the projection optical system in an optical axis direction of the projection optical system; An exposure method, wherein at least one of a movement amount to be moved in the optical axis direction during exposure is set for each of the plurality of patterns. 2. The exposure method according to claim 1, wherein the setting is performed in accordance with at least one of an imaging position and a depth of focus of the projection optical system. 3. The exposure method according to claim 1, wherein the plurality of patterns are respectively exposed to different regions of the substrate. 4. The exposure method according to claim 1, wherein the plurality of patterns are exposed so as to be connected. 5. The exposure method according to claim 1, wherein exposure energy is individually set for each of the plurality of patterns. 6. The exposure method according to claim 1, wherein the plurality of patterns are provided on a plurality of masks, and the plurality of masks are exchanged when exposing the plurality of patterns. Exposure method characterized by the above-mentioned. 7. An exposure apparatus for exposing each of a plurality of patterns onto a substrate via a projection optical system, comprising: a movement device for moving the substrate in an optical axis direction of the projection optical system during exposure; A control device for setting at least one of a position of the substrate with respect to an imaging plane of the projection optical system in an optical axis direction of the projection optical system, and a movement amount for moving the position during the exposure for each exposure An exposure apparatus comprising: 8. The exposure apparatus according to claim 7, wherein the control device performs continuous movement control of the substrate in the optical axis direction based on the movement amount.