JP2001093808A - Exposure method and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure method and an aligner which have high accuracy and satisfactory productivity and workability. SOLUTION: An aligner 1 has an illumination optical system 2 which illuminates a mask M with a light beam from a light source 21, a projection optical system 3 which projects the image of the pattern of the mask M illuminated by the exposure light EL upon a substrate W, a substrate stage 7 with a plurality of substrate holders 6, and a control unit 9 which integrally controls all the movements of the exposure apparatus 1. The control unit 9 controls the substrate stage 7, so as to be expose the substrate W after the lapse of a waiting time, until the temperature difference between one of the substrate holder among the plurality of substrate holders 6 and the substrate W placed on the substrate holder becomes almost zero. Here, the thicknesses of the plurality of substrate holders 6 can be set different from each other.

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 used in, for example, an exposure step in manufacturing a thin-film magnetic head.

[0002]

2. Description of the Related Art Conventionally, various types of exposure apparatuses have been used to manufacture thin-film magnetic heads, semiconductor elements, liquid crystal display elements, and the like by a photolithography process. )
An exposure apparatus that projects an image of a pattern formed on a substrate having a surface coated with a photosensitive agent such as a photoresist through a projection optical system is generally used.

In such an exposure apparatus, a substrate to be exposed is placed on a substrate holder arranged in a projection area of a projection optical system by a substrate loader. The substrate placed on the substrate holder is moved in the optical axis direction (Z direction) of the projection optical system by operating a substrate stage that supports the substrate holder, and is stored within the focal depth of the focal position of the projection optical system. Exposure processing is performed one by one.

[0004]

The movable range of the substrate stage in the Z direction is set with respect to a certain reference substrate thickness. Therefore, when performing exposure processing on each of the substrates having greatly different thicknesses by using such an exposure apparatus, the movable range of the substrate stage in the Z direction is required to keep the substrates within the depth of focus of the projection optical system. In some cases, the height adjustment by moving the substrate stage in the Z direction is not sufficient. Accordingly, in order to keep each of these substrates within the depth of focus of the projection optical system, the substrate holder is replaced with a thick one or a thin one corresponding to the thickness of the substrate during the exposure processing. However, the substrate holder and the substrate stage are usually screwed, and replacement of the substrate holder is troublesome.

In some cases, the substrate supplied to the substrate holder is heated in a resist process, a transfer process, or the like. If the substrate is placed on the substrate holder in this state, the substrate may be deformed due to a change in temperature. In this case, accurate focus / leveling adjustment and exposure processing become difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has as its object to provide an exposure method and an exposure apparatus which are highly accurate and have good productivity and workability.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following structure corresponding to FIGS. 1 to 7 shown in the embodiment. According to the exposure method of the present invention, in a method of exposing a substrate (W) by projecting a pattern of a mask (M) onto the substrate (W), the substrate (W) is provided on one of a plurality of substrate holders (6). W)
After the elapse of a waiting time (t) until the temperature difference between the substrate holder (6) and the substrate (W) placed on the substrate holder (6) almost disappears, the substrate (W) is subjected to exposure processing. It is characterized by.

According to the present invention, when performing the exposure processing, a waiting time (t) for eliminating a temperature difference between the substrate holder (6) and the substrate (W) placed on the substrate holder (6) is provided. Thus, stable exposure processing is performed after the deformation of the substrate (W) due to the temperature change stops.

During the waiting time (t), the substrate (W) held by another substrate holder (6) of the plurality of substrate holders (6) can be subjected to exposure processing, so that productivity is improved. I do.

A waiting time (t) required from the time when the substrate (W) is placed on the substrate holder (6) until the temperature difference with the substrate holder (6) almost disappears is measured in advance, and a plurality of substrates (W) are measured. It is determined whether or not the waiting time (t) has elapsed for each of the substrates (W) sequentially held in the holder (6),
By performing exposure processing on the substrate (W) after the elapse of the waiting time (t), accurate and stable exposure processing can be performed in a state in which the deformation of the substrate (W) due to the temperature change is reliably stopped.

For one substrate (W) to be exposed,
By holding two or more substrates (W) in the substrate holder (6), exposure processing on one substrate (W) and temperature stabilization of another substrate (W) can be performed simultaneously, Productivity and workability are improved.

During the waiting time (t), the substrate holder (6) sucks the substrate (W) by vacuum, and after the waiting time (t) elapses, the substrate (W) is exposed before the substrate (W) is exposed. Is released, and the vacuum suction is performed again, whereby the stress generated when the substrate (W) expanded and contracted by the heat radiation returns to the original position is released. Therefore, the exposure processing for the substrate (W) is performed with high accuracy in a state where the distortion of the substrate (W) due to expansion and contraction is removed.

The exposure apparatus of the present invention projects a pattern of a mask (M) onto a substrate (W) by projecting the pattern on the substrate (W).
An exposure apparatus for exposing a plurality of substrate holders (6)
The substrate (W) was placed on at least one substrate stage (7) having one or more of the plurality of substrate holders (6), and was placed on the substrate holder (6) and the substrate holder (6). After a lapse of a waiting time (t) until the temperature difference with the substrate (W) substantially disappears, a control means (9) for controlling the substrate stage (7) so as to perform exposure processing on the substrate (W) is provided. It is characterized by the following.

According to the present invention, in the exposure processing, the temperature difference between the plurality of substrate holders (6) on the substrate stage (7) and the substrate (W) mounted on the substrate holder (6) is substantially eliminated. It is done after. Therefore, stable and accurate exposure processing is performed after the deformation of the substrate (W) caused by the temperature change stops.

[0015] The control means (9) is provided during the waiting time (t).
Another substrate holder (6) of the plurality of substrate holders (6)
Since the substrate stage (7) is controlled so as to perform exposure processing on the substrate (W) held in the substrate, exposure processing on the substrate (W) and temperature stabilization of the substrate (W) can be performed simultaneously. Therefore, productivity and workability are improved.

Since the plurality of substrate holders (6) have at least two substrate holders (6) having different thicknesses from each other, even if the thickness of the substrate (W) to be exposed is greatly different. The substrate (W) can be arranged within the depth of focus of the projection optical system (3) with a simple configuration without replacing the substrate holder (6). Therefore, accurate and stable exposure processing can be performed.

For each of the substrates (W) sequentially held by the plurality of substrate holders (6), the control means (9) places the substrate (W) on the substrate holder (6) and then sets the substrate holder (6). It is determined whether or not the waiting time (t) required until the temperature difference with the temperature substantially disappears has elapsed, and an instruction is given to perform exposure processing on the passed substrate (W). Accurate and stable exposure processing can be performed in a state where the deformation of W) is reliably stopped.

An exposure apparatus for exposing a substrate (W) by projecting a pattern of a mask (M) onto the substrate (W) has at least one substrate holder (6).
A plurality of substrate holders (6) having different thicknesses provided on the substrate stage (7) and having a plurality of substrate holders (6) having different thicknesses. The substrate (W) is accommodated within the depth of focus of the projection optical system (3) with a simple configuration. Therefore, accurate exposure processing is performed efficiently.

In this case, the difference in thickness between the plurality of substrate holders (6) is set according to the difference in thickness between the plurality of substrates (W) to be processed. It is surely arranged within the depth of focus of (3).

[0020]

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

In FIG. 1, an exposure apparatus 1 includes an illumination optical system 2 for illuminating a light beam from a light source 21 such as a mercury lamp onto a mask M held by a mask holder 5, and an illumination optical system 2.
A blind portion 4 that adjusts the area of an opening S that is arranged in the inside and allows the exposure illumination light (exposure light) EL to pass therethrough to define an illumination range of the mask M by the exposure light EL, and a mask illuminated by the exposure light EL A projection optical system 3 for projecting an image of the pattern of M onto the substrate W, and a substrate holder 6 for holding the substrate W
A substrate stage 7 having a plurality of the substrate holders 6;
The exposure apparatus 1 includes a control unit (control means) 9 that controls the entire operation of the exposure apparatus 1.

The illumination optical system 2 includes an elliptical mirror 22 for condensing a light beam emitted from the light source 21, a wavelength filter 23 for passing only a wavelength necessary for exposure in the light beam from the light source 21, and a wavelength filter 23. The light beam passing through 23 is adjusted to a light beam having a substantially uniform illuminance distribution, is converted into exposure light EL, and is guided to the blind unit 4. An illumination range is defined by the blind unit 4, and is guided by the reflection mirror 25. And a main condenser lens 26 for illuminating the exposure light EL onto the mask M with uniform illuminance.

The blind portion 4 includes, for example, a pair of blades 41A and 41B which are bent in a plane L shape and are combined in a plane orthogonal to the optical axis AX of the exposure light EL to form a rectangular opening S. These blades 41A, 4
Light-shielding unit displacement devices 42A and 42B for displacing 1B in a plane orthogonal to the optical axis AX based on an instruction from the control unit 9 are provided. At this time, the size of the opening S is the blade 41A,
The aperture S changes according to the displacement of the exposure light 41 </ b> B, and the aperture S transmits only the passed exposure light EL out of the exposure light EL incident from the fly-eye integrator 24 to the main condenser lens 26 via the reflection mirror 25. The exposure light EL defined by the opening S illuminates a specific area (pattern area) PA of the mask M held by the mask holder 5 via the main condenser lens 26 with substantially uniform illuminance. These optical members and the blind portion 4 are arranged in a predetermined positional relationship, and the blind portion 4 is arranged on a surface conjugate to the pattern surface of the mask M.

The mask holder 5 has vacuum suction portions 12 at four corners on the upper surface thereof, and the mask M is held on the mask holder 5 via the vacuum suction portions 12. The mask holder 5 has an opening (not shown) corresponding to a pattern area PA which is an area where a pattern on the mask M is formed, and is driven in an X direction and a Y direction by a driving mechanism (not shown).
Fine movement in the direction and the θ direction (rotational direction around the Z axis), thereby positioning the mask M such that the center (mask center) of the pattern area PA passes through the optical axis AX of the projection optical system 3. It has a possible configuration.

The projection optical system 3 forms an image of a pattern existing in the illumination range of the mask M defined by the opening S by the exposure light EL on the substrate W, and forms the pattern in a specific area (shot area) of the substrate W. Exposure of the image. The projection optical system 3 includes a plurality of optical members such as a lens and a reflector formed of a fluoride crystal such as fluorite or lithium fluoride. In the present embodiment, as the projection optical system 3,
A reduction optical system having a projection magnification of, for example, 1/4 or 1/5 is used. For this reason, the pattern formed on the mask M is reduced and projected onto the shot area on the substrate W by the projection optical system 3, and a reduced image of the pattern formed on the mask M is transferred and formed on the substrate W.

On the substrate stage 7, a plurality of substrate holders 6 for holding the substrate W are provided. In the present embodiment, the substrate stage 7 has two substrate holders 6A,
6B. The substrate stage 7 includes a base 71,
An X stage 72 that can reciprocate in the X direction in FIG. 1 on the base 71, a Y stage 73 that can reciprocate in the Y direction orthogonal to the X direction on the X stage 72, and a Y stage 73 are provided on the Y stage 73. And a substrate table 74 provided. That is, the substrate holder 6 fixed to the substrate stage 7 is supported movably in the horizontal direction along the XY plane (in the direction perpendicular to the optical axis AX of the projection optical system 3). At this time, the optical axis AX of the projection optical system 3 coincides with the Z direction orthogonal to the XY plane. That is, the XY plane is orthogonal to the optical axis AX of the projection optical system 3. Further, the substrate table 74 is mounted on the Y stage 73 so as to be positioned in the XY directions and to be allowed to move and tilt in the Z-axis direction.

Each substrate holder 6 (6A, 6B)
As shown in FIG. 2, the suction grooves 62, 64,
66 are provided. At the bottom of the suction groove 62, a suction hole 62A,
62B are formed. Further, suction holes 64A and 64B are formed at the bottom of the suction groove 64. At the bottom of the suction groove 66, a suction hole 66A is formed. The substrate holders 6 (6A, 6B) are configured to be able to independently hold the substrate W by vacuum suction.

The thickness (width in the Z direction) of each of the substrate holders 6A and 6B can be set to be different from each other. In this case, the thickness difference between the respective substrate holders 6 is such that the respective pattern transfer surfaces of the substrates W are substantially the same in the Z direction according to the thickness difference between the respective substrates W placed on the respective substrate holders 6. Set to position.

Further, in order to make the respective pattern transfer surfaces of the plurality of substrates W have substantially the same height in the Z direction, at least one of the plurality of substrate holders 6 has the pattern transfer surface of the substrate W at a predetermined height. A height adjustment mechanism for setting the height position (position in the Z direction). The height adjusting mechanism is configured by an adapter 8 that can be inserted into and removed from the space between the substrate W and the substrate holder 6 as shown in FIG.

In this case, the adapter 8 is provided with the suction grooves 82 and 86.
And a groove 84, and a suction hole 8 is provided at the bottom of the suction groove 82.
2A and 82B are formed. A suction hole 86A is formed at the bottom of the suction groove 86. The suction holes 82A, 82B, and 86A on the adapter 8 side communicate with the suction holes 62A, 62B, and 66A on the substrate holder 6 so as to correspond to the suction holes 62A, 62B, and 66A, respectively. (Open / close valve) 82 is connected to a substrate suction vacuum source (not shown). On the other hand, the other suction holes 64A and 64B of the substrate holder 6 are connected to an adapter vacuum source (not shown) via a suction path 84 and a valve 86. That is, the substrate holder 6 is provided with suction grooves and suction holes for sucking the substrate and suction grooves and suction holes for sucking the adapter alternately. Thus, the suction of the substrate holder 6 is constituted by two systems, one for sucking the substrate and the other for sucking the adapter. The valves 82 and 86 may be manually operated valves, for example, or may be electrically controllable valves such as electromagnetic valves.

The position of the substrate stage 7 in the XY directions is adjusted by a laser interferometer system.
In detail, the substrate stage 7 (substrate table 7)
4) An X movable mirror 75 composed of a plane mirror is provided at the end on the -X side.
X extends in the Y direction. A measuring beam from the X-axis laser interferometer 76X is projected almost perpendicularly to the X moving mirror 75X, and the reflected light is received by a detector inside the X-axis laser interferometer 76X.
The position of the X movable mirror 75X, that is, the X position of the substrate W, is detected based on the position of the reference mirror inside 6X. Similarly, although not shown, a Y moving mirror, which is a plane mirror, extends in the Y direction at the + Y side end of the substrate stage 7. And, through this Y moving mirror,
The position of the Y movable mirror, that is, the Y position of the substrate W is detected by the axial laser interferometer in the same manner as described above. 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 W in the XY directions are sent to the control unit 9.

On the other hand, the position of the substrate W arranged in the projection area of the projection optical system 3 in the Z direction is detected by a multipoint focus position detection system which is one of the oblique incidence type focus detection systems. It is to be adjusted based on. To explain this in detail, the multipoint focus position detection system
Optical fiber bundle 81, condenser lens 82, pattern forming plate 8
3, a beam irradiation system 13 including a lens 84, a mirror 85, and an irradiation objective lens 86, and a beam reception system 14 including a condenser objective lens 87, an imaging lens 89, and a light receiver 90 having a plurality of photosensors as light reception sensors. A beam having a wavelength that is different from that of the exposure light EL and that does not expose the photoresist on the substrate W is guided from an unillustrated illumination light source via the optical fiber bundle 81. The beam emitted from the optical fiber bundle 81 illuminates the pattern forming plate 83 via the condenser lens 82. Pattern forming plate 83
Is transmitted through the lens 84, the mirror 85, and the irradiation objective lens 86 to be projected onto the surface of the substrate W, and the image of the pattern on the pattern forming plate 83 is projected and formed on the surface of the substrate W. The reflected light of the beam reflected by the substrate W is projected on the light receiving surface of the light receiver 90 via the condenser objective lens 87 and the imaging lens 89. Detection signals (photoelectric conversion signals) from a large number of photosensors of the light receiver 90 are supplied to a signal processing device 10, and the signals processed by the signal processing device 10 are:
That is, the position information of the substrate W in the Z direction is sent to the control unit 9. The control unit 9 detects the position of the substrate W in the Z direction based on the signal from the signal processing device 10.

The controller 9 monitors the positional information of the substrate W in the XY and Z directions obtained by the laser interference system and the multipoint focus position detecting system, and via the substrate stage driving device 78 as a driving system. X stage 7
2. The Y stage 73 and the substrate table 74 are driven so that the pattern surface of the mask M and the surface of the substrate W are conjugate with respect to the projection optical system 3, and the imaging surface of the projection optical system 3 matches the substrate W. In such a manner, the positioning operation of the substrate W in the XY direction, the Z direction, and the tilt direction is performed. When the pattern area PA of the mask M is illuminated by the exposure light EL emitted from the illumination optical system 2 with substantially uniform illuminance in the state where the positioning is performed in this manner, the image of the pattern of the mask M is projected. Is imaged on a substrate W having a surface coated with a photoresist.

A method of transferring the image of the pattern of the mask M onto the substrate W using the exposure apparatus 1 having the above-described configuration will be described with reference to FIG. FIG. 5 is a diagram illustrating a relationship between the temperature and the time of the plurality of substrates W sequentially placed on the plurality of substrate holders 6.

First, the control unit 9 instructs a substrate loader (not shown) to supply the substrate W1 to be exposed to the substrate holder 6A. The substrate W1 is placed on the substrate holder 6A by the substrate loader (Step S1). At this time, the substrate W1 is heated in the resist process, the transport process, and the like, and is held by suction on the substrate holder 6A in this heated state.

Next, the substrate W2 is placed on the substrate holder 6B by the substrate loader (Step S2). At this time, the substrate W1 previously held by the substrate holder 6A is maintained in the held state. By maintaining the holding state of the substrate W1, the temperature thereof approaches the temperature of the substrate holder 6A, as shown in FIG. That is, the substrate W1
The temperature difference between the substrate W1 and the substrate holder 6A is reduced by heat exchange between the substrate W1 and the substrate holder 6A and heat radiation of the substrate W1 itself.

The substrate W1 is held in the substrate holder 6A for a predetermined time t as a processing waiting time, so that the temperature difference between the substrate W1 and the substrate holder 6A is substantially eliminated. This waiting time t is required after the substrate W is placed on the substrate holder 6 until the temperature difference between the substrate W and the substrate holder 6 is substantially eliminated due to heat radiation of the substrate W itself or heat exchange with the substrate holder 6. The data relating to the waiting time t is stored in the control unit 9 in advance.

The data relating to the waiting time t has been obtained experimentally in advance. That is, the time required from the time when the substrate W is placed on the substrate holder 6 to the time when the temperature difference with the substrate holder 6A substantially disappears is obtained experimentally in advance, and the controller 9 stores data relating to this time. Have been. That is, the control unit 9 includes the substrate W and the substrate holder 6.
The relationship between the temperature difference and the waiting time t is stored. At this time, when there are a plurality of types of substrates W placed on the substrate holder 6, the control unit 9 stores a plurality of data corresponding to each type of the substrates W. The control unit 9 determines based on this data whether or not the temperature difference has almost disappeared, that is, whether or not the temperature difference has become equal to or less than a predetermined value.

Since the temperature of the substrate W1 is stabilized by eliminating the temperature difference between the substrate W1 and the substrate holder 6A, the deformation of the substrate W1 due to the temperature change is stopped. Accordingly, by determining whether the waiting time t has elapsed for the substrate W held by the substrate holder 6, the substrate W1
It can be determined whether or not the deformation has almost stopped.
Therefore, by performing the exposure processing on the substrate W for which the waiting time t has elapsed, the exposure processing can be performed on the substrate W whose deformation caused by the temperature change is stopped.

In this manner, the control unit 9 determines whether or not the preset waiting time t has elapsed for the substrate W1 held in the substrate holder 6A. First, the substrate holder 6A once releases the vacuum suction of the substrate W, and performs the vacuum suction again. by this,
Since the stress generated when the stretched substrate W returns to its original state is released, the distortion generated in the substrate W is removed.

Next, the control section 9 controls the substrate stage 7 using the laser interference system and the multipoint focus position detection system described above in order to position the substrate W1.
Perform focus position adjustment and leveling adjustment. Control unit 9
The substrate held by the substrate stage driving device 78 in the substrate holder 6A so that the position of the pattern transfer surface of the substrate W is located at the focal position of the projection optical system 3 based on the calculation result of the signal processing device 10. W is the optical axis A of the projection optical system 3
The focus position is adjusted by moving in the X direction. In this case, after performing the focus position adjustment, the control unit 9 performs the leveling adjustment. Then, an exposure process is performed on the positioned substrate W1 (Step S).
3).

For a substrate having such a characteristic that the deformation does not stop even when the temperature difference with the substrate holder 6 disappears, the substrate W is placed on the substrate holder 6 using a shape measuring instrument or the like. After that, the waiting time required until the deformation of the substrate W due to the temperature difference from the substrate holder 6 substantially stops is measured in advance, and it is determined whether or not the waiting time has elapsed for the substrate W held by the substrate holder 6. However, the exposure process may be performed when the waiting time has elapsed.

As shown in FIG. 3, while the exposure process is being performed on the substrate W1, the substrate W2 is held by the other substrate holder 6B. That is, during the waiting time t of the substrate W2 for eliminating the temperature difference with the substrate holder 6B, the exposure processing is performed on the substrate W1 held by the substrate holder 6A.

When the exposure processing for the substrate W1 is completed,
The substrate stage 7 is moved, and the substrate holder 6A holding the substrate W1 is arranged at a place where the substrate holder 6A is transferred to a substrate unloader (not shown). At this time, the substrate W2 held by the substrate holder 6B is arranged in the projection area of the projection optical system 3.
The substrate W1 that has been subjected to the exposure processing is transported to the next step by the substrate unloader. At the same time, the next substrate W3 to be exposed is supplied to the substrate holder 6A by a substrate loader (not shown) (step S4).

The control section 9 determines whether or not the substrate W2 arranged in the projection area of the projection optical system 3 has passed the waiting time t. When it is determined that the waiting time t has elapsed, the substrate W2 is once released and re-adsorbed by the substrate holder 6B, and then positioned and subjected to an exposure process. On the other hand, when it is determined that the waiting time t has not elapsed, the suction holding of the substrate W2 by the substrate holder 6B is maintained until the waiting time t elapses. Then, when the waiting time t has elapsed, the substrate W2 is subjected to the exposure process through the temporary release of the vacuum suction, the re-suction, and the positioning (step S5). While the exposure process is being performed on the substrate W2, the substrate W3 is held by the substrate holder 6A.

Thus, the substrates W1, W2,..., W4 are sequentially supplied to the substrate holders 6A and 6B provided on the substrate stage 7 alternately, as shown in FIG. Then, the control unit 9 determines whether or not the waiting time t has elapsed for each of the substrates W1, W2,..., W4 held in the substrate holders 6A and 6B. Then, an exposure process is performed.

When the thickness of the substrate W to be exposed is largely different, the thicknesses of the substrate holders 6A and 6B are set to be different as shown in FIG. By the substrate holders 6A and 6B having different thicknesses, the pattern transfer surface of the substrate W held by each of the substrate holders 6A and 6B has a depth of focus of the projection optical system 3 within a movable range of the substrate stage 7 in the Z direction. You can put it inside. Alternatively, as described above, the adapter 8 is provided according to the thickness of each of the plurality of substrates W.

As described above, the plurality of substrate holders 6A, 6B
, The exposure processing waiting time t is set for each of the substrates W1, W2,..., Which are sequentially placed, and the exposure processing is performed on the substrate W after the waiting time t has elapsed. It is performed accurately and stably with the deformation caused by the temperature change of the substrate W suppressed. That is, the substrate W may be heated and expanded in the resist process, the transport process, and the like, but in this state, accurate focus position adjustment, leveling adjustment, and exposure processing are not performed. However, by leaving the substrate W held in the substrate holder 6 for a predetermined time,
The heated substrate W is dissipated and no longer changes in temperature. Therefore, accurate positioning and exposure processing is performed on the substrate W in a state where deformation due to temperature change is eliminated.

At this time, since a plurality of substrate holders 6 are installed on the substrate stage 7, one of the substrate holders 6A
The exposure process for the substrate W held in (6B) and the temperature stabilization of the substrate held in the other substrate holder 6B (6A) are performed simultaneously. Therefore, productivity and workability are improved. That is, the productivity per unit time in this embodiment is the same as that of one substrate holder 6 as shown in FIG.
The substrate W1 is supplied to the substrate W (step T1), a waiting time t is provided for the substrate W1, exposure processing is performed after the elapse of the waiting time t (step T2), and the exposed substrate W1 is replaced with a new substrate W2. (Step T3), and this is replaced with W2, W3,
.. Is better than a method of sequentially repeating for. As described above, the waiting time t for one substrate W is set using the exposure processing time of the other substrate W, so that productivity is improved.

In this embodiment, different substrates W1,
.., Is provided with a waiting time for each substrate W. However, the waiting time may be provided for each exposure of one substrate W. That is, the pattern formed on the substrate W is usually formed by a plurality of layers (layers), and the pattern of the substrate W is manufactured by a plurality of exposures using a plurality of masks M. The time from to the next exposure can be set as the waiting time. That is, when the next exposure processing is performed immediately after performing the exposure processing on one substrate W, the next exposure processing is performed on the substrate W heated by the first exposure processing. Therefore, the overlay accuracy of the layers is degraded, but the overlay accuracy of the layers is improved by setting a waiting time from the end of exposure to one substrate W to the start of the next exposure. Note that, besides the mode in which the waiting time can be set for the exposure step of overlapping the layers, for example, from the end of exposure of a shot area of a plurality of shot areas on one substrate W to the next shot area It is of course possible to set the time until the start of the exposure. In this case, as described above, it is preferable to set the waiting time between the two exposure processings, radiate the heat of the substrate W, and then perform the focus position adjustment and the leveling adjustment. As described above, the setting of the waiting time can be applied to each shot area or each substrate.

During the waiting time t, the substrate holder 6 vacuum-adsorbs the substrate W, and after the lapse of the waiting time t, the substrate W
Before performing the exposure processing on the substrate W, the vacuum suction of the substrate W is released, and the substrate W expanded and contracted by heat radiation is released by vacuum suction again.
The stress that occurs when returning to the original position is released. Therefore, accurate positioning and exposure processing can be performed in a state where distortion generated in the substrate W is removed. That is, the substrate W
Is held by the substrate holder 6 by suction for a predetermined time to stabilize the temperature, but expands and contracts due to heat radiation. Therefore, the stress applied to the substrate W is released by releasing the vacuum suction once after the substrate W is sufficiently dissipated.

The substrate stage 7 has a plurality of substrate holders 6, and the thicknesses of the substrate holders 6 can be set to be different from each other. That is, when the thicknesses of the plurality of substrates W to be subjected to the exposure processing are largely different, the conventional exposure apparatus has only one substrate holder 6, and therefore, only the movement of the substrate stage 7 in the Z direction is sufficient. If not, the substrate holder 6 was replaced each time the exposure position of the substrate W was set at a predetermined position. Alternatively, a normal exposure apparatus is, for example, 0.5 mm
When performing exposure processing on a ceramic substrate, which is a substrate for a thin-film magnetic head having a thickness of about 1 to 3 mm, using this exposure apparatus, the alignment accuracy is checked. For example, the accuracy of the entire apparatus is usually checked at the normal time by using the silicon wafer. Therefore, after confirming the accuracy of the silicon wafer, the exposure process is often performed after replacing the silicon wafer substrate holder with the ceramic substrate substrate holder. However, a plurality of substrate holders 6 can be set on the substrate stage 7, and the thickness difference between the substrate holders 6 is set according to the thickness difference between the plurality of substrates W to be subjected to exposure processing. The pattern transfer surface of the substrate W can be efficiently provided at a predetermined height position without exchanging 6.
At this time, as shown in the present embodiment, by adjusting the height position by the adapter 8 as a height adjustment mechanism,
The height position of the exposure surface of the substrate W is adjusted with a simple configuration.

The number of the substrate holders 6 provided on the substrate stage 7 is not limited to two, and three or more substrate holders can be provided. At this time, the plurality of substrate holders 6 can be configured to include at least two substrate holders having different thicknesses.

Further, a configuration may be employed in which a plurality of substrate stages 7 are independently provided for each of the plurality of substrate holders 6. In this case, of the plurality of substrates W held by the plurality of substrate holders 6,
Can be removed from the substrate holder 6 while performing the exposure processing on the next substrate W, and the substrate holder 6 can hold a new substrate W. This means that during the exposure processing on one of the substrates W held by the plurality of substrate holders 6, the other substrate W is removed from the substrate holder 6 and a new substrate W is held by the substrate holder 6. This is realized by a substrate exchange device. An exposure apparatus having two such stages is disclosed in, for example, JP-A-10-16
No. 3097 is disclosed. Further, the substrate holder in the above-described embodiment may be a pin chuck holder that supports the substrate with a large number of pins.

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

The exposure apparatus is not limited to a step-and-repeat type exposure apparatus (stepper) that exposes the pattern of the mask M while the mask M and the substrate W are stationary and sequentially moves the substrate W step by step. The present invention can also be applied to a step-and-scan type scanning exposure apparatus (scanning stepper) for exposing the pattern of the mask M onto the substrate W by synchronously moving the mask M and the substrate W.

The types of the exposure apparatus include not only the above-described exposure apparatus for manufacturing a thin-film magnetic head, but also an exposure apparatus for manufacturing a semiconductor wafer, an exposure apparatus for manufacturing a liquid crystal display device, and the like.
The present invention can be widely applied to an exposure device for manufacturing an imaging device (CCD) or a mask M and the like.

As the light source 21 of the illumination optical system 2, a bright line (g-line (436 nm), h-line (40 nm) generated from a mercury lamp is used.
4.7 nm), i-line (365 nm)), KrF excimer laser (248 nm), and 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.

The magnification of the projection optical system 3 may be not only a reduction system but also an equal magnification system or an enlargement system.

As far as the projection optical system 3 is concerned, if far ultraviolet rays such as an excimer laser are used, a material which transmits far ultraviolet rays such as quartz or fluorite is used as the glass material. A system or a refraction type optical system (a reflection type mask is used as the mask M). When an electron gun is used, an electron optical system including an electron lens and a deflector may be used as the optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

The optical path of the beam for position detection is
The container may be covered with light transmitting windows at both ends, and the temperature, pressure, and the like of the gas inside the container may be controlled.
Alternatively, the inside of the container may be evacuated. As a result, it is possible to reduce a length measurement error caused by air fluctuation on the external optical path. Such details are disclosed, for example, in Japanese Patent Application Laid-Open No. 10-105241.

When a linear motor is used for the substrate stage or the mask stage, either an air floating type using an air bearing or a magnetic floating type using Lorentz force or reactance force may be used. Further, the substrate stage and the mask stage may be of a type that moves along a guide, or may be of a guideless type without 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 stage moving surface side. (Base).

It is to be noted that a reference mirror (fixed mirror) for a laser interferometer is fixed to a projection optical system, and the positions of the X movable mirror and the Y movable mirror are measured relatively frequently based on the reference mirror. In this case, an optical element ahead of the polarizing beam splitter (prism) for separating the reference beam and the measurement beam may be housed inside the substrate chamber, and a laser light source, a detector, and the like may be arranged outside the substrate chamber.

The reaction force generated by the movement of the substrate stage may be mechanically released to the floor (ground) by 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.

As described in JP-A-8-330224, the reaction force generated by the movement of the mask stage may be mechanically released to the floor (ground) using a frame member. 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. 7, in the semiconductor device, as shown in FIG. 7, 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. a step 203 of manufacturing a substrate (wafer) from a silicon material; a substrate processing step 204 of exposing a mask pattern to the substrate by the exposure apparatus of the above-described embodiment;
The device is manufactured through a device assembling step (including a dicing step, a bonding step, and a package step) 205, an inspection step 206, and the like.

[0069]

The exposure method and exposure apparatus of the present invention have the following effects. (1) When performing the exposure processing, a waiting time is provided until the temperature difference between the substrate holder and the substrate placed on the substrate holder disappears, so that the exposure processing starts after the deformation of the substrate due to the temperature change stops. Since it is performed, accurate and stable exposure processing is performed. By providing a plurality of substrate holders, during this waiting time, a substrate held by another substrate holder among the plurality of substrate holders can be subjected to exposure processing, so that productivity and workability are improved. You. (2) Since the plurality of substrate holders have at least two substrate holders having different thicknesses from each other, even if the thicknesses of the substrates are greatly different, the substrate holder can be easily replaced without replacing the substrate holders. It can be located within the depth of focus of the projection optics. Therefore, accurate and stable exposure processing can be performed. In this case, the thickness difference between the plurality of substrate holders is set according to the thickness difference between the plurality of substrates to be processed.

[Brief description of the drawings]

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

FIG. 2 is a side sectional view illustrating a substrate holder.

FIG. 3 is a diagram illustrating a substrate stage including a plurality of substrate holders.

FIG. 4 is a diagram illustrating a substrate stage including a plurality of substrate holders.

FIG. 5 is a diagram illustrating a relationship between exposure processing of a substrate by an apparatus having a plurality of substrate holders and time.

FIG. 6 is a diagram illustrating a relationship between exposure processing of a substrate by an apparatus having one substrate holder and time.

FIG. 7 is a flowchart illustrating an example of a semiconductor device manufacturing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Illumination optical system 3 Projection optical system 6 Substrate holder 7 Substrate stage 9 Control part (control means) M Mask W Substrate t Wait time

Claims (11)

[Claims] An exposure method for exposing the substrate by projecting a mask pattern onto the substrate, wherein the substrate is placed on one of a plurality of substrate holders, and the substrate holder and the substrate holder are placed on the substrate holder. An exposure method, wherein an exposure process is performed on the substrate after a lapse of a waiting time until the temperature difference between the substrate and the mounted substrate substantially disappears. 2. The exposure method according to claim 1, wherein during the waiting time, a substrate held by another one of the plurality of substrate holders is subjected to exposure processing. 3. The exposure method according to claim 1, wherein a waiting time required from when the substrate is placed on the substrate holder to when the temperature difference with the substrate holder substantially disappears is measured in advance. Determining whether or not the waiting time has elapsed for each of the substrates sequentially held by the substrate holder, and performing an exposure process on the substrate after the waiting time has elapsed. 4. The exposure method according to claim 1, wherein two or more substrates are held by the substrate holder with respect to one substrate on which the exposure processing is performed. Exposure method. 5. The exposure method according to claim 1, wherein the substrate holder vacuum-sucks the substrate during the waiting time, and after the waiting time elapses, before exposing the substrate. An exposure method, wherein the vacuum suction of the substrate is released and vacuum suction is performed again. 6. An exposure apparatus for exposing the substrate by projecting a pattern of a mask onto the substrate, comprising: at least one substrate stage having a plurality of substrate holders; A control for controlling the substrate stage so as to perform an exposure process on the substrate after a lapse of a waiting time until a temperature difference between the substrate holder and the substrate mounted on the substrate holder is substantially eliminated; An exposure apparatus comprising: 7. The exposure apparatus according to claim 6, wherein the control unit performs an exposure process on a substrate held by another one of the plurality of substrate holders during the waiting time. An exposure apparatus for controlling a substrate stage. 8. The exposure apparatus according to claim 6, wherein the plurality of substrate holders include at least two substrate holders having different thicknesses. 9. The exposure apparatus according to claim 6, wherein the control unit places the substrate on the substrate holder for each of the substrates sequentially held by the plurality of substrate holders. An exposure apparatus for determining whether or not a waiting time required until the temperature difference with the substrate holder substantially disappears has elapsed, and instructing the exposure processing to be performed on the elapsed substrate. 10. An exposure apparatus for exposing the substrate by projecting a pattern of a mask onto the substrate, comprising: at least one substrate stage having a plurality of substrate holders; An exposure apparatus comprising: a plurality of different substrate holders. 11. The exposure apparatus according to claim 10, wherein a difference in thickness between the plurality of substrate holders is set according to a difference in thickness between a plurality of substrates to be processed. .