JPH0427681B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a comparative method of an exposure dose control device for exposing a pattern on, for example, a wafer or a photomask.

(Background of the invention) In recent years, in the manufacture of semiconductor devices, especially ICs, there has been a demand for miniaturization of circuit patterns.
It is desirable for the so-called tepid exposure equipment, which is a device that prints patterns with line widths as follows, to always give a constant amount of exposure to the photosensitive material (photoresist) coated on the wafer, and for this reason, highly accurate exposure control is required. It has become rare.

FIG. 1 schematically shows an exposure apparatus that exposes a circuit pattern image onto a wafer or a photomask.

In FIG. 1, light from a light source for exposure, such as a mercury lamp 1, is focused by a condenser lens 2, and then passes through a condenser lens 5 and a projection lens 8 via a rotary plate 3, which serves as a shutter. , wafer 9
(A photomask may also be used.) (The same applies to exposure apparatuses of other types.) The rotary plate 3 is divided into four parts, for example.
A light-shielding part and a transmitting part are provided alternately, and the shutter is rotated by a rotation drive mechanism, for example, a pulse motor 4, and functions as a rotary shutter. Glass substrate 7 with a circuit pattern (reticle or photomask)
is placed between the condenser lens 5 and the projection lens 8, and the pattern on the glass substrate 7 is imaged onto the wafer 9. The photodetector 6 is a photoelectric conversion element for measuring the light intensity of the light source, measures the light that has passed through the shutter, and its output is used for exposure control. In such devices, the opening and closing time of the shutter is mechanically long, ranging from several milliseconds to several tens of milliseconds.
Extensive. In addition, the light intensity (detector 6
FIG. 2 shows the changes in the values detected in the wafer 9 or the values measured on the wafer 9. In Figure 2, the horizontal axis represents exposure time and the vertical axis represents light intensity, and trapezoidal broken lines A and B
represents the difference due to deterioration of the light source lamp.
When the lamp is new and the light intensity is high, the exposure time becomes longer, as shown by broken line A, and when the lamp deteriorates and the light intensity decreases, as shown by broken line B, the exposure time becomes longer. Note that the light intensity at the top of the trapezoid, that is, when the shutter is fully open, is
Let L _N and L _p be. Thus, the trapezoidal light intensity characteristic is based on the opening/closing operation time of the shutter. This occurs due to the time it takes for the rotary plate 3 to rotate 1/4 as shown in FIG.
The time it takes for the rotating plate 3 to rotate 1/4 of a turn from the state where the light shielding part of the rotating plate 3 blocks light to the state where the rotating plate 3 completely transmits the light (shutter opening time)
is the time ta-to in FIG. In addition, rotating plate 3
The start of rotation is defined as to. And time (ta
-to), the light completely passes through the rotary plate 3 (hereinafter referred to as fully opening the shutter), so the light intensity becomes stable at L _N or L _p . and,
After a predetermined exposure time, that is, from time tb or time td, the rotating plate 3 rotates another 1/4 rotation, and the light is blocked by the light blocking portion. The time when the light is completely blocked is time tc or te. Note that due to the structure of the shutter, the opening operation time and the closing operation time are approximately equal, so the time (tc-tb) and the time (te-td) are both equal and also approximately the same as the time (ta-to).

As shown in this light intensity characteristic, in such a device, the exposure time is usually changed depending on the brightness of the lamp in order to keep the exposure amount constant. This conventional exposure control will be explained with reference to FIG. In FIG. 3, the photoelectric output of the photoelectric detector 6 is amplified by an amplifier 11 and then input to an integrator comprising a resistor 12, a capacitor 14, and an amplifier 13.
The output of the integrator is a value proportional to the exposure amount, a so-called light amount integral value. The output of this integrator is compared by a comparator 15 with a reference voltage Es indicating a predetermined target value. On the other hand, the flip-flop circuit 16 is set at the start of the exposure operation, and the shutter drive circuit 17 drives a motor etc. to open the shutter. After the shutter is opened, when the integral value of the light amount reaches the reference voltage Es as described above, the output of the comparator 15 is inverted and the flip-flop circuit 16 is reset. By this reset, the drive circuit 17 further rotates the motor etc. and closes the shutter. In this way, the shutter is controlled so that the integrated value of the amount of light remains constant even if the brightness of the lamp changes. here,
The exposure amount at that time is shown in the graph of FIG. In the graph of Figure 4, the horizontal axis is the same time axis as Figure 2,
The vertical axis represents the exposure amount, that is, the integrated value of the light amount. As shown in FIG. 2, the period from the exposure start time to to the time ta is the shutter opening operation time, and the integrated value of the light amount gradually increases. The period from time ta to time tb or time td is the shutter fully open period. still,
As shown in FIG. 2, A and B indicate when the light intensity of the light source is high and when it is low. When the integral value of the light amount of A or B reaches the reference voltage Es, the shutter closing operation begins. However, the exposure will occur during the time (fc-tb) or (fe-td) until the shutter is completely closed, and as a result, the total exposure amount will be Eo or Eo', and the predetermined target value E It will exceed by (Eo-Es) or (Eo′-Es).

If the light intensity of the light source is always constant, the excess amount can be predicted and the total exposure amount can be determined, but in reality, the brightness of the light source changes significantly as the lamp deteriorates.
Therefore, as shown in Figure 4, time (tc - tb)
Even though the time (te−td) is the same, the excess amount changes. This excess change (Eo - Eo') can be ignored if the light intensity of the light source is small and the exposure time is sufficiently long. However, if the light intensity of the light source increases and the exposure amount during the shutter closing time increases as a proportion of the total exposure amount, the total exposure amount will fluctuate due to the change in excess (Eo − Eo'). is an important issue. Generally, to control the exposure amount,
The fluctuation in the total exposure amount must be within a few percent, but the conventional exposure equipment mentioned above does not take into account excess amounts, so it is not possible to obtain a stable exposure amount over a long period of time. It had

In order to solve this drawback, as disclosed in Japanese Unexamined Patent Publications No. 57-71132 and No. 57-101839, the amount of overexposure due to the delay in the shutter closing operation is measured, and the Control is being considered to correct the start time of.

If this correction control is performed in an analog manner, the circuit size is small and simple, but it requires high-precision parts such as an integrator and a capacitor that stores the correction amount, making it expensive, and it is not suitable for repeated long-term exposure. In this case, problems such as capacitor leakage occur, making accurate correction impossible. Furthermore, in this case, the dynamic range of photometry is narrow, and it is disadvantageous that the brightness of the light source changes significantly.

On the other hand, if this correction control is performed digitally, a photoelectric signal corresponding to the exposure intensity is converted into pulses using a voltage/frequency converter, and in addition to a counter that counts the pulses, a correction timer, a correction counter, etc. are required. Therefore, the disadvantage was that the circuit scale was larger than that of the analog system.

Furthermore, regardless of whether it is an analog method or a digital method, in conventional technology, the exposure amount is controlled based only on the output signal of the photoelectric detector 6. , 11-1
4) Sensitivity change over time or photoelectric detector 6
There has been a problem in that when various optical systems from the wafer 9 to the wafer 9 change over time, the actual exposure amount given to the wafer 9 becomes out of order.

(Object of the Invention) The present invention aims to solve such problems and to always stabilize the amount of exposure obtained on a photosensitive material (wafer, etc.) to a target value, and in particular, to solve the problem by stabilizing the amount of exposure obtained on a photosensitive material (wafer, etc.). The purpose of this invention is to stabilize the photometric sensitivity in an exposure control device that does not require the following.

(Summary of the Invention) A method for calibrating an exposure amount control device of the present invention includes an exposure system comprising an illumination system for irradiating a photosensitive material with light from a light source and a light amount control means for controlling the amount of exposure to the photosensitive material. In the apparatus, an illuminance measuring device is provided on the stage on which the photosensitive material is placed, and the light amount control means is compared based on the output of the illuminance measuring device.

Preferably, the light amount control means includes an integrated light amount measuring device that integrates a signal corresponding to the intensity of light from the light source, and calibrates the integral sensitivity of the integrated light amount measuring device based on the output of the illuminance measuring device. do.

(Example) Next, the present invention will be explained based on an example. FIG. 5 shows an embodiment of an exposure amount control device for carrying out the present invention. In FIG. 5, light from a light source 1 provided at a first focal point of an elliptical reflector 20 is focused by an elliptical reflector 20, and a shutter 3 provided at a second focal point, which is the convergence point, is focused by the elliptical reflector 20. The light beam passes through a first condenser lens 21 and is converted into a parallel beam, passes through an optical kintegrator 22 using a Fryan lens, and then passes through a second condenser lens 5,
A glass substrate 7 having a circuit pattern is exposed onto a wafer 9 through a projection lens 8. Note that an interference filter is provided in the optical path leading to the second condenser lens 5, which transmits almost all of the light of the exposure wavelength.

The photometry means consists of a photoelectric detector 6 and a filter 23, and is provided at a position off the optical axis l for exposure, and directly receives the light from the light source 1, and sends a photoelectric signal corresponding to the light intensity to the exposure control means 24. Output to.
The shutter 3 is arranged at an angle of 45 degrees with respect to the optical axis l of the exposure light, and the light reflected by the shutter 3 is also used as illumination light for a microscope, etc. for device alignment. It also has the advantage of preventing errors in the photoelectric signal caused by the light traveling backwards and entering the light source detector 6. 6 is a detailed view of the shutter 3, and FIG. 7 is a plan view of the shape of the shutter blade of the shutter 3 shown in FIG. As shown in FIG. 6, the shutter 3 is made up of a front reflecting plate 30 and a light blocking plate 31 having a larger diameter than the reflecting plate 30, and as shown in FIG. The cutout portions 3b are equally divided in the circumferential direction. Four slit openings 31b are provided in a portion of each blade portion 3a of the light shielding plate 31 at an angle of 90 degrees. This slit opening 31b is a status mark provided to detect the position of the blade portion 3a of the shutter 3. That is, the light irradiated onto the shutter 3 from the floodlight 25 provided on the back side of the shutter 3 is reflected on the back side of the reflecting plate 30 through the slit opening 31b.
By entering the light receiver 26, the position of the blade portion 3a of the shutter 3 is detected. This shutter 3
The opening and closing operations are performed by rotating the pulse motor 4 through an angle θ, that is, 1/8 rotation.

The operation of the present invention in which the photometric means is disposed upstream of the shutter 3 regardless of the opening/closing operation of the shutter 3 will be explained with reference to FIGS. 8 and 9. 8th
9A and 9B, A indicates the integral value of the light amount from the start of the opening operation of the shutter 3 until the completion of the closing operation, and C
represents the integrated value of the light amount at the photoelectric detector 6, and D represents the integrated value of the light amount at the wafer 9. B shows the light intensity distribution of exposure on the wafer 9, and C shows the light intensity distribution of the photoelectric detector 6. Note that Figure 8 shows when the lamp is new and the light intensity is high, and Figure 9 shows when the lamp has deteriorated.
This shows a case where the light intensity decreases.

As shown in FIGS. 8 and 9A, the output of the photoelectric detector 6 is integrated at the same time as the opening operation of the shutter 3 starts, and this integrated light amount value reaches the reference voltage Es corresponding to the target exposure value. The closing operation of the shutter 3 is started at time tb or td. Wafer 9 during this tb or td
Although the integrated value of the actual exposure amount on the surface is slightly insufficient with respect to the reference voltage Es, the exposure amount up to the time tc or te when the shutter 3 completes closing corresponds to this shortage. In other words, by using a rotary shutter as the shutter 3, the characteristic that the operating delay when opening the shutter (ta-to) is equal to the operating delay when closing the shutter (tc-tb) or (te-td) is utilized. Thus, the actual lack of exposure on the wafer 9 due to the delay in opening the shutter is compensated for by the amount of exposure due to the delay in closing the shutter. Therefore, the target exposure amount can be controlled with high precision regardless of the exposure intensity and shutter driving time.

FIG. 10 shows a block diagram of the exposure control means 24 of this embodiment which controls the exposure amount. 10th
In the figure, 100 is an amplifier that amplifies the photoelectric signal from the photoelectric detector 6 and outputs it as a voltage signal S ₁ . 101 is a voltage/frequency converter that converts the voltage signal S ₁ from the amplifier 100 into a pulse signal S ₂ . 102 counts this pulse signal _S2 and comparator 1
This is a counter that outputs the light amount count value _S4 at 04.
The light intensity count value _S4 counted by the counter 102 is calculated by the microcomputer (CPU) when the shutter starts to be opened.
It is returned to zero by the clear signal _S3 of 103. 1
05 is a target value set register which inputs a set signal _S7 from the CPU 103 and outputs the number of pulses _S5 corresponding to the appropriate exposure amount to the comparator 104. The comparator 104 compares this pulse number S ₅ with the light amount count value S ₄ from the counter 102 and outputs a shutter close signal S ₆ to the CPU 103 if these values match.
106 is a drive circuit for the pulse motor 4 that rotates the shutter 3. In addition, 107 is shutter 3
This amplifier is placed at the rear of the photodetector 24 and outputs the photoelectric signal _S3 to the comparator 108.The comparator 108 inputs this photoelectric signal _S3 and sends a status signal to the CPU 103.
Output S ₉ .

Next, the operation of the exposure control means 24 shown in FIG. 10 will be explained. Figures 11 and 12 show CPU1
FIG. 11 is a flowchart of a subroutine for setting the initial position of the shutter 3, which is included in the initialization program when the power is turned on for the exposure control device of this embodiment. , FIG. 11 is a sub-routine flowchart for the exposure operation.

Since the blade portion 3a of the shutter 3 is in an arbitrary position when the power of the exposure control device is turned on, it is necessary to position the blade portion 3a. In Figure 10, when the power to the exposure control device is turned on,
The CPU 103 is at step 200 and the shutter 3 is at an angle of 2θ.
In other words, the number of pulses N2θ required to rotate 90 degrees
The pulse motor ₄ is controlled by the drive circuit 106 and starts rotating at a low speed. Note that N is the number of pulses for rotating a unit angle. at the same time
The CPU 103 uses the comparator 108 in step 201.
monitor the status signal S ₉ from the receiver 2.
4 detects the slit opening 31b on the rear surface of the shutter 3, and when the status signal _S9 changes from "L" to "H", the output of the motor drive data _S10 is stopped in step 202, and the rotation of the pulse motor 4 is stopped. let
In this state, one of the four blade portions 3a of the shutter 3 is positioned so as to block the optical axis l, and the shutter 3 is in the closed state. Here, the number of pulses of the motor drive data _S10 is set to N2θ because the slit opening 31b provided in the shutter 3 is 90
This is because the slit opening 31b is always detected if the shutter 3 is rotated at least 90 degrees since the openings are provided at different angles. After the shutter 3 is closed in this manner, the exposure operation of the wafer 9 is performed.

In FIG. 12, when the exposure operation is started,
In step 210, the CPU 103 outputs the set signal _S7 to the target value set register 105, and the target value set register 105 outputs the number of pulses _S5 corresponding to the appropriate exposure amount to the comparator 104. Next step
At 211, a clear signal _S3 is output to the counter 102,
The light quantity count value _S4 remaining in the counter 102 is made zero. Step at a certain timing with this
212, motor drive data S ₁₀ , number of pulses to rotate shutter 3 by angle θ, that is, 1/8 rotation.
The pulse motor 4 is driven by outputting Nθ to the drive rotation 106, and the shutter 3 starts rotating.
This time corresponds to to in FIGS. 8 and 9.

The counter 102 counts the pulse signal _S2 from the voltage/frequency converter 101 at the same time as the shutter 3 starts rotating.

When the step motor 4 rotates at high speed and the shutter 3 rotates 1/8, the step motor 4 stops rotating, the shutter 3 becomes fully open, and the integrated value of the light amount becomes the value at time ta in FIGS. 8 and 9. becomes. Even after the step motor 4 stops rotating, the counter 102 counts the pulse signal S ₂ from the voltage/frequency converter 101 and outputs the light quantity count value S ₄ to the comparator 104. Also, the CPU 103 inputs the comparator 10 at step 212.
The closing signal S ₆ from 4 is monitored, and the integrated light amount value becomes the value at tb in FIG. ₈ or td in _FIG. It is detected when they match and the closing signal _S6 changes from "L" to "H". When the closing signal _S6 becomes "H", the motor drive data _S10 of pulse Nθ for rotating the step motor 4 again is output in step 214, and the step motor 4 starts closing the shutter 3 by the number of pulses Nθ. When the shutter 3 rotates and stops, the shutter 3 becomes fully closed. At this time, the integrated value of the exposure amount for the 9th wafer surface is shown in Figure 8 tc or Figure 9.
The value at te is the appropriate exposure amount.

In the embodiment of the exposure control means 24 shown in _FIG .
The counter 103 may be configured to execute interrupt processing for closing the shutter, and the counter 1
02, comparator 104 and target value set register 1
05 can also be similarly configured by a program inside the CPU 103.

In addition, a gate circuit is provided between the voltage/frequency converter 101 and the counter 102. Then, to help start exposure, a value corresponding to the appropriate exposure amount is set in the counter, and at the start of exposure, the gate circuit is opened and the number of pulses of the pulse signal _S2 is set to the counter 10.
Subtract it from the value of 2. Then, when the value of the counter 102 becomes zero, the shutter may be closed by outputting the closing signal _S6 .

FIG. 13 shows a block diagram of an embodiment of the exposure control means 24, which has a relatively short shutter control time and can be applied with analog control. In FIG. 13, the same symbols as in FIG. 3 indicate the same configurations. However, the position of the photoelectric detector 6 is as shown in FIG. Also the third
Unlike the example shown in the figure, a switch 40 is provided in parallel with the capacitor 14 forming an integrator.

When the exposure start signal is input, the switch 40 opens and starts integrating the light amount, and the comparator 15 compares the light amount integral value with the target value, and when the light amount integral value reaches the target value after the shutter is fully open, An appropriate amount of exposure can be obtained by closing the shutter.

FIG. 14 shows a part of another embodiment,
Some other variations of the measuring means are shown.

The first is when the photoelectric detector 6a is installed at the opening of the elliptical reflector 20 around the holder 20a that holds the elliptical reflector 20, and the second is when the photoelectric detector 6b is installed above the elliptical reflector 2. , when the light source 1 is provided to receive light emitted from the opening through which the upper electrode 1a passes, the third image of the light source 1 is formed on one end surface of the fiber bundle 52 by the lens 51, and the image of the fiber bundle 52 is This is a case where the amount of light is detected by the photoelectric detector 6c at the other end.
According to this third photometric means, the photoelectric detector 6c can be placed at a location away from the light source 1.
c is not exposed to high temperature from light source 1,
A stable photoelectric signal can be obtained. Furthermore, when the light source 1 is a high-pressure mercury discharge tube, the photoelectric detector 6c can be maintained even in case of an explosion accident that rarely occurs. In addition, by providing a filter 23 or a heat shielding filter that selectively transmits light of a wavelength for exposure between the photoelectric detectors 6, 6a, 6b, and 6c and the light source 1, the light source 1 can transmit light of a wavelength other than that for exposure. Even if light of the same wavelength is generated, an appropriate exposure amount can be detected, and it is not affected by heat rays from the light source.

FIG. 15 shows another embodiment of the present invention. 15th
The optical system shown in the figure is disclosed in Japanese Patent Application Laid-Open No. 57-85019, and when the lamp for light source 1 is replaced, the position of the bright spot of light source 1 is changed to the first focal point of elliptical reflector 20. A monitor optical system is added for accurate positioning. Exposure light emitted from the light source 1 is reflected by an elliptical reflector 20, further reflected by a dichroic mirror 54 installed obliquely between the second focus F ₂ ' of the ellipse reflector 20, and includes an interference filter and an integrator. Passing through the optical member 55 and reflecting mirror 54
and is guided to the condenser lens 5.

If the dichroic mirror 54 is made to have spectral characteristics such that about a few percent of the light at the exposure wavelength and light at wavelengths other than the exposure wavelength is transmitted, the dichroic mirror 54 will transmit almost all of the light at the exposure wavelength. is reflected, and an image of the light source is formed at the second focal point _F2 .
A shutter is provided at this second focal point _F2 . Further, a part of the light having the exposure wavelength and light having a wavelength longer than this wavelength is transmitted through the dichroic mirror 54 to form an image of the light source 1 at the second focal point F ₂ '. This transmitted light is transmitted through a positive lens 5 provided outside the optical axis l of the optical system.
7a, a reflecting mirror 58a, and an index plate 59a.
The light source position detection system and the positive lens 57b, reflecting mirror 58a, and index plate 59b, which are also provided outside the optical axis l of the optical system, are arranged so as to be replaceable with the photometry means consisting of the filter 24 and the photoelectric detector 6d. In this embodiment, when replacing the lamp for the light source 1, the index plate 59b is placed, the light source 1 is aligned,
After this alignment is completed, a photometry means is inserted at the position of the index plate 59b to perform photometry for exposure control.

Each embodiment of the present invention has been described above, but in short, the photoelectric detector for photometry is provided so as to always detect the intensity of light from the light source regardless of the shutter, and the shutter opening time (ta-to ) and the closing time (tc-tb) and (te-td) are equal, an extremely accurate exposure amount can be obtained. Further, if this condition is met, the shutter does not need to be a rotary type, and a reciprocating linear type shutter may be driven by a solenoid.

In the case of a reduction projection type exposure apparatus with a built-in exposure control device as in the above embodiment, a stage on which a photosensitive substrate is placed and moved two-dimensionally is used to measure the illuminance distribution of illumination light and to project a reticle. Japanese Patent Laid-Open No. 117238/1983 discloses the provision of a photoelectric detector having a minute aperture (slit) for detecting images. Therefore, if such an on-stage photoelectric detector can be used, the actual exposure amount can be monitored by the photoelectric detector, and the gain of the photometric amplifier 100 and the conversion ratio of the voltage/frequency converter 101 can be adjusted using the photoelectric detector. etc. can be adjusted to appropriate values. That is, it becomes possible to calibrate the sensitivity of so-called light amount integral.

(Effects of the Invention) As described above, according to the present invention, an illuminance detector is provided on the stage to detect the intensity of illumination light,
Since the exposure amount control means is calibrated based on the output, the actual exposure amount to the photosensitive material can be maintained at the target value over a long period of time despite the simple configuration. Moreover, when the light intensity of the light source changes significantly, for example, even immediately after replacing the light source lamp with a new one as explained in FIG. 15, the appropriate exposure amount can be reliably obtained. In addition, in the case of a projection exposure apparatus, the photometric photodetector of this type of exposure amount control means is installed closer to the light source than the mask that transfers the pattern to the photosensitive material, so the amount of illumination light lost due to the projection optical system is However, according to the present invention, the amount of illumination light that has passed through the projection optical system is detected by the illuminance measuring device on the stage, so the exposure amount control means can detect the amount of illumination light that has passed through the projection optical system. It also has the advantage of being calibrated taking losses into account.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional exposure apparatus, Figure 2 is an exposure intensity distribution diagram, Figure 3 is a block diagram of conventional exposure control, Figure 4 is a distribution diagram of integrated light quantity values, and Figure 5 is a diagram of the present invention. Fig. 6 is a structural diagram of the shutter used in the embodiment shown in Fig. 5;
Figure 7 is a plan view of the shutter blade shape, Figures 8 and 9 A are distribution diagrams of integrated light amount values, B are light intensity distribution diagrams, and Figure 10 is the exposure of the embodiment shown in Figure 5. Block diagram of control means, Fig. 11, Fig. 1
2 is a flowchart of a program of the exposure control means shown in FIG. 10, FIG. 13 is a block diagram of another embodiment of the exposure control means, and FIG. 14 is a block diagram of another embodiment of the present invention. FIG. 15 is a block diagram of another embodiment of the present invention. 1... Light source, 2... Focusing lens, 3... Shutter, 4... Pulse motor, 5... Board, 6, 6
a, 6b, 6c, 6d...Photoelectric detector, 7...Substrate, 8...Projection resin, 9...Wafer, 11...
Amplifier, 12...Resistor, 13...Amplifier, 14...
... Capacitor, 15 ... Comparator, 16 ... Flip-flop circuit, 17 ... Drive circuit, 20 ... Elliptical reflector, 21 ... Condenser lens, 22 ...
Optical integrator, 100...amplifier,
101...Voltage/frequency converter, 102...Counter, 103...CPU, 104...Comparator, 1
05...Target value set register, 106...Drive circuit.

Claims (1)

[Scope of Claims] 1. In an exposure apparatus equipped with an illumination system for irradiating the photosensitive material with light from a light source and a light amount control means for controlling the amount of exposure to the photosensitive material, the photosensitive material is placed. 1. A method for calibrating an exposure amount control device, characterized in that an illuminance measuring device is provided on a stage, and the light amount controlling means is calibrated based on the output of the illuminance measuring device. 2. The light amount control means includes an integrated light amount measuring device that integrates a signal according to the intensity of light from the light source,
2. The method for calibrating an exposure amount control device according to claim 1, wherein the integral sensitivity of the integrated light amount measuring device is calibrated based on the output of the illuminance measuring device. 3. an illumination optical system for irradiating the mask substrate with light from a light source; a projection optical system for forming and projecting an image of the pattern formed on the mask substrate by the irradiation of the illumination light onto the photosensitive substrate; A stage on which the photosensitive substrate is placed and moved; and a light amount control means that detects the intensity of the illumination light before reaching the mask substrate and controls the amount of exposure given to the photosensitive substrate to a target value. 1. A method for calibrating an exposure amount control device, wherein a photoelectric detector for measuring illuminance is provided on the stage, and the light amount control means is calibrated based on the output of the photoelectric detector.