JPH1012957A - Beam controller and aligner employing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sustain the performance of laser beam (beam quality) in good conditions constantly. SOLUTION: Detecting means 13, 14 detect the performance of a laser beam emitted from a laser light source 1. Based on the detection results, an arithmetic means 28 calculates the error of a detected performance with respect to the normal performance of laser beam. Based on the calculated error correcting means 29, 30-36 correct the performance of laser beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam control apparatus and an exposure apparatus using the same, and more particularly to a technique for controlling the performance of a laser beam used as exposure light of the exposure apparatus.

[0002]

2. Description of the Related Art In recent years, laser beams have been actively used and studied in various technical fields such as semiconductor manufacturing equipment. 2. Description of the Related Art In an exposure apparatus for manufacturing a semiconductor, a high resolution performance has been demanded with an increase in the density of an LSI to be manufactured. In order to improve the resolving power of the exposure device, it is necessary to shorten the wavelength of the exposure light. Historically, the light for exposure was g-line from a mercury lamp (wavelength 43
6 nm), i-line (365 nm wavelength), KrF excimer laser (248 nm wavelength), the wavelength of the exposure light is becoming shorter as the capacity of DRAM (dynamic random access memory) is increased. I have.
The use of an ArF excimer laser (wavelength: 193 nm) as a light source has been studied for the manufacture of 1GDRAM.

[0003]

However, while a high resolution can be obtained by shortening the wavelength of the exposure light, when the light source is used for a long time, the metal discharge electrode in the discharge chamber is scraped by the discharge. Sometimes. In particular, A
Since the rF excimer laser light has a shorter wavelength than the exposure light used so far, the electrodes are significantly worn. In the mercury lamp, the problem of wear of the discharge electrode does not occur much due to the structure of the light source. Also, KrF excimer laser is
By improving the discharge method (circuit) and the material and shape of the discharge electrode, deterioration of the electrode due to discharge can be suppressed to some extent.

When the discharge electrode of the light source wears, the emission position, beam size, beam divergence angle, and emission direction of the laser light output from the light source gradually change. As a result, in the exposure apparatus, the irradiation area of the optical integrator (fly-eye lens) changes, and the following problems (1) to (4) occur.

(1) Change in Beam Size When the cross-sectional area of the beam incident on the fly-eye lens increases, the amount of light blocked around the fly-eye lens increases, and the amount of light blocked on a photosensitive substrate such as a wafer is increased. Illuminance will decrease. Conversely, when the beam size is reduced, there are elements to which light does not enter among the lens elements in the fly-eye lens, and illuminance unevenness occurs on the wafer surface.

(2) Change in Beam Output Position When the output position of the beam emitted from the light source changes, the entire fly-eye lens is not irradiated with the beam, and the amount of light blocked around the fly-eye lens increases. The illuminance on the wafer will be reduced. In addition, as in the case where the beam size is reduced due to a change in the beam emission position, there is an element to which light does not enter among the lens elements in the fly-eye lens, and uneven illuminance on the wafer surface is reduced. Occurs.

(3) Change in beam divergence angle When the beam divergence angle emitted from the light source changes, the conjugate position in the illumination system of the exposure apparatus shifts, and the illuminated area on the incident surface of the fly-eye lens is shifted. The change causes a decrease in illuminance and uneven illuminance.

(4) Change in Beam Outgoing Direction When the outgoing direction (angle) of the beam emitted from the light source changes, illuminance lowering and illuminance non-uniformity occur at the incident end face of the fly-eye lens. , The position of the conjugate changes, which causes a shift in the telecentric system. In addition, there is a problem that a beam is projected out of the diameter of the optical member (so-called vignetting) on another optical member (a relay lens, a cylinder zoom, a zoom expander, or the like).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a beam control device capable of always maintaining good performance (beam quality) of a laser beam. .

Further, the performance (beam quality) of the laser beam
Another object of the present invention is to provide an exposure apparatus that can always perform an exposure operation in a good illumination state by maintaining the exposure apparatus in a good state.

[0011]

In order to solve the above-mentioned problems, a beam control device according to the present invention comprises detecting means (13, 14) for detecting the performance of a laser beam emitted from a laser light source (1). Calculating means (28) for calculating an error amount of the detected performance with respect to the normal performance of the laser beam based on the result of the detection; and a performance of the laser beam based on the calculated error amount. (29, 30 to 36, etc.). The detecting means (13, 14) is configured to detect at least one of the emission position, the beam size, the spread angle, and the emission direction of the laser beam emitted from the laser light source (1) as the performance. be able to.

Further, in the exposure apparatus of the present invention using the above-described beam control device, the detection means (13) detects the light traveling toward the mask (24) during the inspection mode for monitoring the performance of the laser light source (1). , 14) leading to the optical path switching means (8
8). At this time, it is desirable to provide an attenuating means (90) for attenuating the energy of the laser beam between the detecting means (13, 14) and the optical path switching means (88).

[0013]

In the present invention having the above structure, for example,
When a fly-eye lens (16) for uniformizing the illuminance distribution of a laser beam is used, a beam position / size monitor (13) is placed at a position where the optical distance from the light source (1) is the same as that of the fly-eye lens (16). ) To detect the position and size of the beam. Further, based on the information obtained from the monitor (13), the folding mirror (3, 3) in the illumination optical system is used.
5, 8), zoom expander (10), cylinder zoom lens (4), relay lens (2, 7), and other optical components are finely adjusted to minimize the beam displacement at fly-eye lens (16). Such control is performed.

Further, the light to the monitor system (13) for measuring the beam position and size is further divided, lenses are arranged on the optical paths of the divided light, and the focal point of the laser beam passing through the lens is focused. And the displacement of the focal point in a plane perpendicular to the optical path are measured. Then, based on such a measurement result, a deviation in the beam emission direction of the light source (1) and a change in the beam divergence angle (spread angle) are detected. Thereafter, based on the data thus detected, for example, the bending mirrors (3, 5, 8) in the illumination optical system,
Fine adjustment of optical components such as a zoom expander (10), a cylinder zoom lens (4), and a relay lens (2, 7) to minimize the angle deviation of the laser beam incident on the fly-eye lens (16). Perform control.

The detection and correction of the performance of the laser beam as described above are performed at the time of self-lock emission for confirming various performances of the light source (16). That is, by performing the performance control of the laser beam at a time other than the exposure operation and the alignment operation in the exposure apparatus, the fine adjustment of the optical system can be performed without lowering the throughput.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the following examples. In this embodiment, the present invention is applied to a projection exposure apparatus for manufacturing a semiconductor device.

[0017]

FIG. 1 shows the overall configuration of a projection exposure apparatus according to this embodiment, focusing on an illumination system. In this embodiment, the light source 1 that emits a laser beam for exposure is an ArF excimer laser. Laser light emitted from light source 1 is applied to reticle 2
The illumination optical system for guiding to the side 4 includes relay lenses 2 and 7 and mirrors 3 for changing the direction of a beam emitted from the laser light source 1.
5, 8, 11, 22; a cylinder zoom lens 4 for shaping a rectangular beam; a mesh filter 9 (or ND filter) as dimming means; and a zoom expander 10 for adjusting the beam size. Reticle 2
First fly-eye lens 16 for uniformly illuminating the area above 4
And a second fly-eye lens 17, a σ-stop 18 for forming an NA (numerical aperture) of an illumination system, a reticle blind 20 for regulating an irradiation range of a reticle 24, an exit of the second fly-eye lens 17, and a reticle. Relay systems 19 and 21 for conjugating blind 20 and reticle 24
And a condenser lens 23 for focusing on the reticle 24.

In the above-described illumination optical system, the exit of the laser light source 1 or the exit mirror (not shown) of the laser resonator and the first fly-eye lens 16 are conjugated by the relay lenses 2 and 7. Relationships are maintained. The cylinder zoom lens 4 shapes the laser beam emitted from the laser light source 1 into a rectangular shape that matches the shape of the first fly-eye lens 16. Further, the zoom expander 10 is configured to adjust the size of the beam to the size of the first fly-eye lens 16.

In this embodiment having the above-described configuration, the excimer laser light emitted from the laser light source 1 and guided into the illumination system passes through the relay lens 2 and is reflected by the mirror 3 before being reflected by the cylinder zoom lens 4. Incident on. In the cylinder zoom lens 4, the laser beam having a rectangular cross-sectional shape is applied to a mirror 5, a relay lens 7, a mirror 8,
The light enters the zoom expander 10 via the mesh filter 9. The light transmitted through the mirror 5 is detected by the energy monitor 6. The laser beam whose size has been adjusted by the zoom expander 10 is reflected by the mirror 11 and enters the first fly-eye lens 16. Meanwhile, mirror 1
The slight light transmitted through 1 is detected by the mirrors 12 and 15 at the emission position / size monitor 13 and the spread angle / emission direction monitor 14.

The light whose illuminance has been made uniform by the first fly-eye lens 16 passes through the second fly-eye lens 17, the σ-stop 18, the relay system 19, the reticle blind 20, the relay system 21, and the condenser lens 22. 23
Incident on. The laser light transmitted through the condenser lens 23 is irradiated onto the reticle 24 with a uniform illuminance distribution, and the image of the pattern formed on the reticle 24 is reduced to a predetermined magnification by the projection optical system (projection lens) 25, and the wafer Is projected on the photosensitive substrate 26. A photoresist having sensitivity to excimer laser light is applied on a photosensitive substrate 26 placed on the substrate stage 27, and is exposed with an image of a pattern formed on the reticle 24.

In the illumination system of this embodiment, in addition to the above-described optical configuration, an energy monitor 6 for measuring a variation in energy of the excimer laser light source 1 and an emission of a laser beam emitted from the laser light source 1 are provided. An emission position / size monitor 13 for measuring the position and size, a spread angle / emission direction monitor 14 for measuring the spread angle and emission direction (angle) of the laser beam, and an energy density irradiated on the reticle 24 are shown. A measurement system including an integrator sensor (not shown) for measurement is provided. In such a measurement system, the emission position / size monitor 13 and the spread angle / emission direction monitor 14 include a mirror 11 disposed between the zoom expander 10 and the first fly-eye lens 16.
The measurement is performed by using the transmitted light of. The emission position / size monitor 13 has an optical distance from a light receiving surface of the monitor 13 to an exit of the excimer laser light source 1 and an optical distance from an entrance of the first fly-eye lens 16 to an exit of the excimer laser light source 1. Are arranged so that are equal to each other.

As shown in FIG. 2, the energy monitor 6,
Output signals from the emission position / size monitor 13 and the spread angle / emission direction monitor 14 are supplied to the arithmetic processing unit 28. The arithmetic processing unit 28 performs a predetermined arithmetic operation on the drive amounts of the drive systems 30 to 36 based on the detection signals from the monitors (6, 13, 14). That is, an operation for correcting various performances (beam emission position, size, divergence angle, emission direction) of the laser beam emitted from the light source 1 to a normal state is performed. The normal state may be, for example, a state at the time of initial adjustment of the light source 1. The control device 29 controls the relay lens 2, mirror 3, cylinder zoom lens 4, mirror 5, relay lens 7, mirror 8, and zoom expander 1 based on the output signal of the arithmetic processing unit 28 via drive systems 30 to 36.
0 is drive-controlled.

Next, a method for detecting the emission position and size of the laser beam by the emission position / size monitor 13 and a correction method will be described with reference to FIGS. The excimer laser light immediately before entering the first fly-eye lens 16 after passing through the illumination optical system is a square beam 60 as shown in FIG. In FIG. 3A, the vertical direction indicates the direction between the cathode and the anode of the laser light source 1, and the horizontal direction corresponds to the direction in which the excimer laser gas flows. The intensity distribution of the beam 60 has a Gaussian function shape 64 in the horizontal direction and a top hat shape 62 in the vertical direction. The emission position / size monitor 13 is arranged for such a beam 60 as shown in FIG.

The emission position / size monitor 13 is composed of four two-divided sensors A, B, R, L arranged in a square shape and one non-divided sensor C arranged at the center thereof. . The two-divided sensors A, B, R, and L each include an inner light receiving unit (AI, BI, RI, LI) and an outer light receiving unit (A
O, BO, RO, LO). As shown in FIG. 3B, the direction of the division position (boundary line) between the inner light receiving portion and the outer light receiving portion of each sensor is such that the sensors A and B are in the horizontal direction and the sensors R and L are in the vertical direction. Place each. The sensor C measures the amount of light at the center of the beam 60 and represents the energy amount of the entire beam.

The position of the division line of the sensor A, the rotation angle, and the inclination of the sensor main body are determined by the detection value AI detected by the inner light receiving portion AI,
Adjustment is performed so that the value shown in the following expression (1) regarding the detection value AO by the outer light receiving unit AO is maximized.

(AI-AO) / C (1)

Here, the value shown in the above equation (1) becomes maximum so that the divided portion of the sensor A corresponds to the position where the gradient of the intensity distribution waveform 64 becomes maximum, that is, substantially near the center of the gradient. This is the case where the sensor is arranged.

Similarly, the sensors B, L, and R are similarly fine-adjusted so that the values shown in the following equations (2), (3), and (4) are maximized. Each sensor A, B, L,
By arranging R as described above, the emission position / size monitor 13 can detect changes in the beam emission position and the beam shape with the highest sensitivity.

(BI-BO) / C (2) (LI-LO) / C (3) (RI-RO) / C (4)

In the arithmetic processing unit 28, the sum (AI, AO, BI) of the divided light receiving portions of the sensors A, B, L, R
And BO, RI and RO, LI and LO) by the following equations (5) to
(8) As Aw, Bw, Lw, and Rw, respectively.

Aw = AI + AO (5) Bw = BI + BO (6) Lw = LI + LO (7) Rw = RI + RO (8)

Next, a description will be given of a method of measuring and correcting a laser beam emission position based on the output values of the sensors A, B, L, and R of the emission position / size monitor 13 as described above. The arithmetic processing unit 28 calculates the vertical position PV and the horizontal position PH of the beam by the following equations (9),
Expressed as (10).

PV = (Aw−Bw) / 2C (9) PH = (Lw−Rw) / 2C (10)

The arithmetic processing unit 28 sets the vertical and horizontal values PV0 and PH0 of the light incident on the first fly-eye lens 16 immediately after the adjustment of the optical axis of the exposure apparatus as initial values, using the following equations (11) and (11). 12) and is stored in advance as described above.

PV0 = (Aw−Bw) / 2C (11) PH0 = (Lw−Rw) / 2C (12)

FIG. 4 shows a state where the beam 60 in the state of the initial adjustment of the light source 1 (normal state) and the beam 66 shifted in the vertical direction are detected by the two-part sensors A and B. here,
In the beam 60 in the initial state, the values Aw (= AI + AO) and Bw (= BI +) detected by the sensors A and B are used.
BO) are substantially equal, so the value PV is about 0. On the other hand, in the laser beam 66 shifted vertically upward, the value Aw is larger than in the initial state, and the value Bw is smaller than in the initial state, so that the value PV (= (Aw−Bw) /
2C) is larger than in the initial state. Therefore, the arithmetic processing unit 28 calculates the difference between the vertical and horizontal values PV0 and PH0 of the beam 60 in the initial state (normal state) and the actual measured values PV and PH of the beam 66 shifted in the vertical direction. Ask. The difference is expressed by the following equations (13) and (14).
The mirror 3 of the illumination optical system is set to 0 as shown in FIG.
The positions (drive amounts) of 5 and 8 are calculated. Then, based on the data thus calculated, the control device 29 moves the mirrors 3, 5, 8 back and forth via the drive systems 35, 33, 31.

| PV−PV0 | → 0 (13) | PH−PH0 | → 0 (14)

Next, a method for detecting and correcting the size of the laser beam using the emission position / size monitor 13 will be described. In this embodiment, the vertical and horizontal magnitudes SV and SH of the laser beam are represented by the arithmetic processing unit 28 as in the following equations (15) and (16).

SV = (Aw + Bw) / 2C (15) SH = (Lw + Rw) / 2C (16)

The arithmetic processing unit 28 sets the vertical and horizontal values SV0 and SH0 of the light incident on the first fly-eye lens 16 immediately after the adjustment of the optical axis of the exposure apparatus as initial values, using the following equations (17) and (17). 18) and store it.

SV0 = (Aw + Bw) / 2C (17) SH0 = (Lw + Rw) / 2C (18)

FIG. 5 shows how the beam 60 in the initial state (normal state), the reduced beam 68 and the expanded beam 70 are detected by the two-part sensors A and B. Here, the value SV for the reduced beam 68 is smaller than the value SV0 of the beam 60 in the initial state. Also, the value SV for the expanded beam 70 is larger than the value SV0 of the beam 60 in the initial state. Therefore, the arithmetic processing unit 28 calculates the values SV0 and SH0 in the vertical direction and the horizontal direction of the beam in the initial state (normal state) and the value S0 actually measured.
Find the difference between V and SH. The difference is expressed by the following equation (1).
The drive amounts of the cylinder zoom lens 4 and the zoom expander 10 are calculated such that the drive amounts become 0 as in 9) and 20). Then, based on the data calculated in this way, the control device 29 drives and adjusts the cylinder zoom lens 4 and the zoom expander 10 via the drive systems 34 and 30.

| SV-SV0 | → 0 (19) | SH-SH0 | → 0 (20)

As described above, the method of measuring and correcting the emission position and the size of the laser beam emitted from the light source 1 in one direction (vertical direction) by the sensors A and B have been described. The measurement and correction operations (in the left-right direction) are performed in the same manner as the sensors A and B. Here, the description is omitted.

Next, a method of detecting and correcting a divergence angle and an emission direction (angle) of a laser beam according to the present embodiment will be described. FIG. 6 shows a configuration of the spread angle / emission direction monitor 14 for detecting the spread angle and the emission direction (angle) of the laser beam emitted from the laser light source 1. Spread angle
The emission direction monitor 14 splits the laser beam reflected by the mirror 15 (see FIG. 1) into two by a mirror 51, and uses the light reflected by the mirror 51 to detect the emission direction.
The light reflected at 2 is used for detecting the spread angle.

The system for detecting the divergence angle of the beam includes a condenser lens 54 disposed behind the mirror 52 and a lens 5.
And a pinhole sensor 56 arranged at the four focal positions. By oscillating the sensor 56 or the condensing lens 54 back and forth along the traveling direction of the laser beam, the spread angle of the laser beam emitted from the laser light source 1 is detected. That is, the divergence angle of the laser beam is measured by observing the focal position of the condenser lens 54 that changes according to the divergence angle of the laser beam.

First, the operation of detecting the spread angle by the pinhole sensor 56 will be described with reference to FIGS. If the spread angle of the laser beam emitted from the light source 1 is normal and the focal position of the condenser lens 54 and the position of the pinhole sensor 56 match as shown in FIG. 56 vibrates before and after the focal point of the condenser lens 54. Therefore, the light intensity waveform for two cycles is detected by the pinhole sensor 56 (FIG. 7).
(B)). Therefore, first, the pinhole sensor 56 is arranged at the focal position F0 of the condenser lens 54, and the initial calibration is performed. In FIG. 7A, a waveform C1 indicates the intensity of the laser beam detected when the pinhole sensor 56 is driven in one direction (outward) with respect to the initial focal position F0, and a waveform C2 indicates the intensity of the pinhole sensor 56. It shows the intensity of the laser beam detected when driving in the other direction (return path). FIG. 7B shows a waveform C3 for one cycle obtained by combining the waveforms C1 and C2 detected as described above.
Is shown. As can be seen from the waveform C3, when the spread angle of the laser beam emitted from the laser light source 1 is normal (initial state), the intensity distribution of the laser beam is detected as a periodic function for two periods.

Thereafter, the divergence angle of the laser beam emitted from the laser light source 1 changes, and as shown in FIG.
When the focus is in focus before the initial focus position F0, the intensity waveform detected when the pinhole sensor 56 is driven in one direction (from right to left) before and after the initial focus position F0 is indicated by C4. Become. Further, the intensity waveform detected when driving in the other direction (from left to right) is as indicated by C5.
FIG. 8B shows waveforms C4 and C5 detected as described above.
Shows a waveform C6 for one cycle in which is synthesized. As can be seen from the waveform C6, when the spread angle of the laser beam emitted from the laser light source 1 deviates from the normal state, the waveform C3 for two cycles as shown in FIG.
A waveform C6 as shown in FIG.

Therefore, a difference between the initial focal position F0 of the lens 54 and the actually measured focal position F is obtained. Also, the focal point F of the lens 54 is located at the initial focal position F0.
That is, the arithmetic processing unit 28 calculates the adjustment amounts of the relay systems 2, 7, the cylinder zoom 4, and the zoom expander 10 so as to satisfy the following conditional expression (21). Then, based on the output data of the arithmetic processing unit 28, the control system 29 controls the driving systems 36, 32, 34, 3
Drive adjustment of the relay systems 2 and 7, the cylinder zoom lens 4, and the zoom expander 10 is performed via 0.

| F−F0 | → 0 (21)

Next, the procedure for detecting and correcting the beam emission direction by the spread angle / emission direction monitor 14 will be described with reference to FIG. 9 in addition to FIG. The beam emission direction detection system includes a pinhole 55 and a condenser lens 53 disposed behind the mirror 51, and a four-division sensor 57 disposed at the focal position of the lens 53. As shown in FIG. 9, the four-divided sensor 57 includes four light receiving sections 80, 82, 8
4, 86, and these light receiving sections 80, 82, 8
The emission direction of the laser beam 85 is detected based on the ratio of the amount of light detected in the light sources 4 and 86.

Immediately after adjusting the optical axis of the exposure apparatus body,
The sensor 5 is located at a position B0 where the outputs of the light receiving sections 80, 82, 84, 86 of the four-divided sensor 57 are equal to each other.
7 for initial calibration. Even when the excimer laser 1 as a light source is started using the position B0 as an initial value, the position B of the laser beam 85 is always detected by the four-divided sensor 57, and a difference from the initial position B0 is obtained. Then, the angles of the mirrors 3, 5, 8 of the illumination system are adjusted so as to satisfy the following conditional expression (22).

| B−B0 | → 0 (22)

That is, the arithmetic processing unit 28 calculates the adjustment angles of the mirrors 3, 5, and 8 based on the signal from the four-divided sensor 57 (monitor 13), and supplies the calculated data to the control device 29. . The control device 29 controls the driving systems 35, 3 based on the data from the arithmetic processing unit 28.
Drive control of the mirrors 3, 5, 8 is performed via 3, 31.

In the above description, regarding the detection and correction of the performance of the laser beam, the emission position, size,
Although the description has been given in the order of the divergence angle and the emission direction, actually, the divergence angle and the emission direction of the beam are corrected first, and then the position and size of the beam are corrected. It is to be noted that moving or changing the position of the relay systems 2, 7 in the illumination optical system, the cylinder zoom lens 4, the zoom expander 10, and the mirrors 3, 5, 8 changes the performance of the beam (the emission position, (Size, divergence angle, emission direction) does not correspond one-to-one, and it is difficult to drive each to the ideal state by one operation. If it is not possible to achieve the predetermined performance by one operation, each correction is repeated alternately.

As described above, in the present embodiment, the emission position / size monitor 13 and the spread angle / emission direction monitor 14 measure and correct the beam performance due to wear of the electrodes of the ArF excimer laser 1 and the like. Therefore, the laser beam in a normal state always enters the first fly-eye lens 16. Therefore, uniformity of illuminance on the photosensitive substrate 26 is secured, and sufficient illuminance can be obtained. In addition, the conjugate position in the illumination system of the exposure apparatus is stabilized, and the telecentric system does not shift.

FIG. 10 shows a configuration of a main part of another embodiment of the present invention in which a part of the above embodiment is improved. In the above embodiment, the transmitted light of the mirror 11 is used in the measurement system (the emission position / size monitor 13, the divergence angle / the emission direction monitor 14), but in this embodiment, the optical path of the laser beam is An optical path conversion mirror 88 is inserted thereinto, and the measurement is performed by switching the optical path for exposure and the optical path for measurement. In this case, when the exposure apparatus does not use the laser light source 1, that is, in the self-lock mode in which the laser light source 1 oscillates to confirm the energy and the spectrum width of the output beam of the laser itself, the beam is emitted. The emission position, size, spread angle, and emission direction are each measured and corrected. This makes it possible to maintain the laser beam performance with high reliability without lowering the throughput of the exposure apparatus. In the case of switching and using the optical path for exposure and the optical path for measurement as in the present embodiment, since high-energy light may enter the optical path of the measurement system,
In order to extend the life of the optical element of the measurement system, a light reduction unit such as an ND filter 90 or a mesh filter is arranged in the optical path of the measurement system.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and does not depart from the gist of the technical idea of the present invention shown in the claims. Various changes are possible within the scope.
For example, a monitor 1 for detecting the size and position of a beam
For 3, a two-divided sensor (A, B, R, L) is used, but a sensor having a configuration in which a CCD element is arranged on the entire surface may be used. By using the CCD element, it is possible to detect a detailed change in the beam shape, for example, the resolution is improved and the shape of the entire beam can be grasped. In the above embodiment, the description has been made with the exposure apparatus of the static exposure type in mind. However, it is needless to say that the present invention can be applied to a scanning type exposure apparatus. In addition to an ArF excimer laser as a light source, a KrF excimer laser can be used when the electrodes become intense to take out a large output, and the use of the present invention is effective. The present invention is also effective in a case where an optical element for generating harmonics changes with time or changes with the number of pulses used in a device using harmonics of a solid-state laser or a YAG laser.

[0059]

As described above, according to the present invention, there is an effect that the performance (beam quality) of a laser beam can always be kept in a good state. In addition, this makes it possible to always perform the exposure operation in a good illumination state.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration of an exposure apparatus according to an embodiment of the present invention, focusing on an illumination system.

FIG. 2 is a block diagram illustrating a configuration of a control system according to the embodiment;

FIGS. 3A and 3B are an explanatory diagram and a plan view showing a configuration of a main part of the embodiment.

FIG. 4 is an explanatory diagram for explaining the operation of the embodiment.

FIG. 5 is an explanatory diagram for explaining the operation of the embodiment;

FIG. 6 is a conceptual diagram showing a configuration of a main part of the embodiment.

FIGS. 7A and 7B are explanatory diagrams showing the operation and operation of the embodiment.

FIGS. 8A and 8B are explanatory diagrams showing the operation and operation of the embodiment.

FIG. 9 is a conceptual diagram showing a configuration of a main part of the embodiment.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... ArF excimer laser light source 2,7 ... Relay lens 3,5,8,11 ... Mirror 4 ... Cylinder zoom lens 6 ... Energy monitor 10 ... Zoom expander 16,17 ... Fly eye lens 13 ... Outgoing position / size monitor 14 ... Spread angle / outgoing direction monitor 24 ... Reticle 25 ... Projection lens 26 ... Photosensitive substrate 28 ... Calculation processing unit 29 ... Control device 30-36 ... Drive system 53,54 ... Condenser lens 55 ... Pinhole 56 ... Pinhole sensor 57 ... 4 split sensor 88 ... Optical path switching mirror 90 ... ND filter

Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H01L 21/30 516D H01S 3/223 E

Claims (7)

[Claims] 1. A detecting means for detecting a performance of a laser beam emitted from a laser light source; and an arithmetic means for calculating an error amount of the detected performance with respect to a normal performance of the laser beam based on a result of the detection. And a correcting means for correcting the performance of the laser beam based on the calculated error amount. 2. The apparatus according to claim 1, wherein said detecting means detects at least one of an emission position, a beam size, a spread angle, and an emission direction of a laser beam emitted from said laser light source as said performance. Item 2. The beam control device according to item 1. 3. An exposure apparatus for irradiating a laser beam emitted from a laser light source onto a mask having a predetermined pattern formed thereon and transferring an image of the pattern onto a photosensitive substrate, wherein the performance of the laser beam emitted from the laser light source is measured. Detecting means for detecting; calculating means for calculating an error amount of the detected performance with respect to normal performance of the laser beam based on a result of the detection; and the laser beam based on the calculated error amount An exposure apparatus comprising: a correction unit configured to correct the performance of the exposure apparatus. 4. The apparatus according to claim 3, further comprising an optical path switching means for guiding a laser beam directed to said mask to said detection means during an inspection mode for monitoring the performance of said laser light source. Exposure equipment. 5. The apparatus according to claim 1, wherein said detecting means and said optical path switching means include:
5. The exposure apparatus according to claim 4, further comprising an attenuation unit that attenuates the energy of the laser beam. 6. The detecting means detects at least one of an emission position, a beam size, a spread angle, and an emission direction of a laser beam emitted from the laser light source as the performance. An exposure apparatus according to claim 3, 4 or 5. 7. The exposure apparatus according to claim 3, wherein said laser light source is an ArF excimer laser.