JP2001102293A - Aligner and method of exposure, and manufacturing method of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actualize higher precision exposure quantity control by suppressing the influence of variation in the transmissivity of an optical system. SOLUTION: A 1st optical sensor 46 detects the energy quantity of an energy beam EL passing through a lighting optical system 12, and a 2nd optical sensor 27 detects the energy quantity of an energy beam EL having passed through at least part of a projection optical system PL. Then a main controller 50 controls the integrated quantity of energy supplied to a substrate W during exposure according to both detection results. Here, if the transmissivity to the energy beam in the optical path from the 1st optical sensor to the substrate surface (image plane) varies, this variation is reflected nearly accurately on the value standardized, by dividing the detected value of the 2nd optical sensor by the detected value of the 1st optical sensor. The transmissivity variation of the optical system in the optical path is therefore substantially canceled, to enable high precision exposure quantity control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus, an exposure method, and a device manufacturing method.
The present invention relates to an exposure apparatus and an exposure method used in a lithography process when manufacturing a semiconductor element, a liquid crystal display element, and the like, and a device manufacturing method for manufacturing a device using the exposure method.

[0002]

2. Description of the Related Art Conventionally, in a lithography process for manufacturing an electronic device such as a semiconductor device or a liquid crystal display device, various exposure apparatuses for forming a device pattern on a substrate have been used. In recent years, along with the high integration of semiconductor elements and the like, a step-and-step method capable of forming a fine pattern with high throughput and high precision on a substrate such as a wafer or a glass plate (hereinafter collectively referred to as “wafer”).
Repeat type reduction projection exposure apparatus (so-called stepper)
A projection exposure apparatus such as a step-and-scan type scanning exposure apparatus (a so-called scanning stepper) obtained by improving this stepper is mainly used.

In this type of projection exposure apparatus, if the amount of exposure light irradiated on the wafer surface (integrated exposure amount) is too small or too small relative to the proper exposure amount, the line width of the formed pattern becomes small. As a result, the desired line width pattern cannot be obtained due to thickening or thickening, and as a result, the electronic device as the final product becomes defective. Therefore, in this type of projection exposure apparatus, it is necessary to control the integrated exposure amount applied to the wafer surface so as to be an appropriate exposure amount.

In a conventional projection exposure apparatus, the amount of energy of exposure light passing through the illumination optical system (hereinafter referred to as “energy amount in the illumination system” for convenience) and irradiation on the wafer surface, that is, the image surface, are determined in advance. Correlation with the amount of exposure light energy (hereinafter referred to as “image surface energy amount” for convenience)
Based on the correlation, a conversion coefficient (called an α value) for converting the energy amount in the illumination system into the image surface energy amount is determined. At the time of actual exposure, the amount of energy in the illumination system is detected using an optical sensor called an integrator sensor, and based on the detection result and the α value,
The amount of image plane energy is calculated, and based on the calculation result, exposure amount control is performed such that the integrated exposure amount applied to each point on the wafer surface becomes an appropriate exposure amount.

[0005]

As semiconductor elements and the like are becoming more and more highly integrated year by year, exposure apparatuses are required to have higher resolution. Typical methods for improving the resolving power of a projection exposure apparatus such as a stepper include a method of increasing the numerical aperture (NA) of a projection optical system and a method of shortening the exposure wavelength. Since an increase in the number causes a reduction in the depth of focus, it can be said that the most effective method for improving the resolving power is to shorten the exposure wavelength.

For these reasons, an argon fluoride excimer laser (ArF excimer laser) having an output wavelength of 193 nm has recently been receiving attention as an exposure light source following a krypton excimer laser (KrF excimer laser). . When this argon fluoride excimer laser is used as the exposure light source, the practical minimum line width (device rule)
It is said that mass production of micro devices having fine patterns ranging from 0.18 μm to 0.13 μm will be possible.

On the other hand, it has recently been confirmed that when short-wavelength light such as an ArF excimer laser is used as exposure light, the transmittance of an optical system such as a projection optical system changes at a time level that cannot be ignored. Have been. The reason for this is considered to be the so-called light cleaning effect.
The behavior has been clarified to some extent because it also occurred when an F excimer laser was used as a light source. However, as a practical problem, it is difficult to explain the above-described temporal variation of the transmittance when the ArF excimer laser is used as a light source only by the light cleaning effect. Therefore, at present, it is difficult to predict the transmittance variation with sufficient accuracy.

The fact that the transmittance variation of the projection optical system described above is confirmed means that the above-mentioned conventional exposure amount control method will fail in the near future. In the conventional exposure amount control using the detection value of the integrator sensor and the α value (constant value), the transmittance of the optical system (mainly the projection optical system) between the integrator sensor and the image plane (wafer surface) does not change. This is because it was established on the premise that there was something.

For these reasons, a new technology has been developed which can control the integrated exposure amount with high accuracy even in an exposure apparatus using light having a wavelength belonging to the vacuum ultraviolet region such as ArF excimer laser light as a light source. Is now urgently needed.

The present invention has been made under such circumstances, and a first object of the present invention is to provide an exposure apparatus and an exposure method that can realize more accurate exposure amount control.

A second object of the present invention is to provide a device manufacturing method capable of improving the productivity of highly integrated microdevices.

[0012]

According to a first aspect of the present invention, there is provided an exposure apparatus (10) for transferring a pattern formed on a mask (R) to a substrate (W). An illumination optical system (12) for illuminating; a projection optical system (PL) for projecting the energy beam emitted from the mask onto the substrate; and a detection of an energy amount of the energy beam passing through the interior of the illumination optical system. A first optical sensor (46); a second optical sensor (27) for detecting an energy amount of the energy beam having passed through at least a part of the projection optical system; and a first optical sensor (46). An exposure controller (50) for controlling an amount of integrated energy applied to the substrate during exposure based on the detected value.

According to this, the energy amount of the energy beam passing through the illumination optical system is detected by the first optical sensor, and the energy amount of the energy beam passing through at least a part of the projection optical system is detected by the second optical sensor. Is detected. Then, the amount of integrated energy applied to the substrate during exposure is controlled by the exposure amount control device based on the two detection results. Here, when the transmittance of the energy beam in the optical path from the first optical sensor to the substrate surface (image surface) fluctuates, this fluctuation is caused by the detection value of the second optical sensor being detected by the first optical sensor. The value normalized by dividing by the value is almost exactly reflected. That is, if the detection value of the second optical sensor fluctuates when the detection value of the first optical sensor is constant, the fluctuation reflects the fluctuation of the transmittance of the energy beam in the optical path almost directly. It was done. Therefore, according to the present invention, in which the exposure amount control device controls the integrated exposure amount given to the substrate during the exposure based on the detection values of the first and second optical sensors, as a result, the transmission in the optical path It is possible to perform high-precision exposure control by substantially canceling the rate fluctuation.

According to the present invention, the amount of energy of the energy beam can be always detected by the first and second optical sensors even during the transfer of the pattern to the substrate. Since the above-described control of the integrated exposure amount can be performed based on the result, the control of the integrated exposure amount can be performed with higher accuracy than in the case where the change in the optical system transmittance is predicted during the exposure and the integrated exposure amount control is performed. Becomes possible.

In this case, as in the second aspect of the present invention, the exposure amount control device (50) is configured to control the exposure amount based on the detection values of the first and second optical sensors (46, 27). A conversion coefficient for converting a detection value of the first optical sensor into an energy amount on the substrate may be corrected. In such a case, as described above, when the transmittance of the energy beam in the optical path from the first optical sensor to the substrate surface (image surface) fluctuates, this fluctuation causes the detection value of the second optical sensor to change to the second value. 1
Since the value is almost accurately reflected on the value normalized by dividing by the detection value of the optical sensor, by using this value to correct the conversion coefficient, a complicated operation can be performed in the same manner as in the above-described conventional technique. It is possible to accurately calculate the amount of energy on the substrate without performing the operation, and it is possible to accurately control the integrated exposure amount using the detection value of the first optical sensor and the conversion coefficient after the correction. .

In the exposure apparatus according to each of the first and second aspects of the present invention, as in the third aspect of the present invention, the second
The optical sensor (27) corresponds to an energy beam applied to an optical element optically closest to the image plane of the projection optical system in the optical element group constituting the projection optical system (PL). The energy amount may be detected. In such a case, there is no optical element contributing to the change in the energy beam transmittance on the optical path between the second optical sensor and the image plane. The value normalized by dividing by the detection value of the first optical sensor is a value that more accurately reflects the change in the transmittance of the energy beam in the optical path from the first optical sensor to the image plane, and is more accurate. Control of the integrated exposure amount becomes possible.

According to a fourth aspect of the present invention, a mask (R) on which a pattern is formed is illuminated by an energy beam via an illumination optical system (12), and the pattern is projected onto a substrate via a projection optical system (PL). In the exposure method for transferring to (W), when the pattern is transferred to the substrate via the projection optical system, at least a first energy amount of an energy beam passing through the illumination optical system and at least the projection optical system. While monitoring the second energy amount of the energy beam passing through a part thereof, the integrated energy amount applied to the substrate is controlled based on the monitoring result.

According to this, when the pattern is transferred to the substrate via the projection optical system, the energy amount of the energy beam passing through the illumination optical system and the energy amount of the energy beam passing through at least a part of the projection optical system And the amount of integrated energy applied to the substrate is controlled based on the monitoring result, so that the illumination optical system is consequently controlled for the same reason as described in the first aspect of the present invention. Highly accurate exposure amount control can be performed by substantially canceling the transmittance fluctuation of the energy beam in the optical path from the inside to the substrate surface (image surface).

In this case, the detection of the third energy amount of the energy beam applied to the image plane of the projection optical system is performed by the first and second detection means.
Is performed almost at the same time as the detection of the energy amount, and a calibration for calibrating a conversion coefficient for converting the detection result of the first energy amount during exposure to the energy amount given on the image plane based on the detection result. , May be further repeated at a predetermined timing. In such a case, since the calibration for calibrating the conversion coefficient is repeated at a predetermined timing, it cannot be corrected based on the correlation between the detection results of the first and second energy amounts generated in a long term. In addition, the integrated energy amount can be adjusted in consideration of the change over time of the conversion coefficient, and more accurate exposure amount control can be realized.

According to a sixth aspect of the present invention, there is provided a device manufacturing method including a lithography step. In the lithography step, a device pattern is formed on a substrate by using the exposure method according to any one of the fourth and fifth aspects. It is characterized by transferring.

According to this, in the lithography step, the device pattern is transferred onto the substrate using the exposure method according to each of the fourth and fifth aspects of the present invention. Exposure is performed accurately while controlling. Therefore, it is possible to improve the yield of highly integrated microdevices and improve the productivity.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG.

FIG. 1 shows a schematic configuration of an exposure apparatus 10 of the present embodiment. The exposure apparatus 10 uses an argon fluoride excimer laser light source (output wavelength 193) as an exposure light source.
nm) and a step-and-scan type scanning projection exposure apparatus, that is, a so-called scanning stepper.

The exposure apparatus 10 includes an illumination system including a light source 16 and an illumination optical system 12, and exposure light EL from the illumination system.
A reticle stage RST for holding a reticle R as a mask illuminated by a reticle, a projection optical system PL for projecting exposure light EL emitted from the reticle R onto a wafer W as a substrate, and a Z tilt stage 58 for holding the wafer W A wafer stage WST as a mounted substrate stage,
And a control system for them.

The light source 16 is actually used in the illumination optical system 1.
2 is installed in a low-clean service room separate from the clean room in which the chamber 11 in which the exposure apparatus main body including the reticle stage RST, the projection optical system PL, and the wafer stage WST is housed. The chamber 11 is connected to a chamber 11 via a drawing optical system (not shown) including at least a part of an optical axis adjusting optical system called a beam matching unit. The light source is a KrF excimer laser light source (output wavelength 248 n).
m) or an F ₂ laser light source (output wavelength: 157 nm), or another pulsed light source that emits vacuum ultraviolet light.

FIG. 2 shows the inside of the light source 16 together with the main controller 50. The light source 16 includes a laser resonator 16a, a beam splitter 16b, an energy monitor 16
c, an energy controller 16d, a high voltage power supply 16e, and the like.

The laser beam LB emitted in a pulse form from the laser resonator 16a enters a beam splitter 16b having a high transmittance and a small reflectance, and the laser beam LB reflected by the beam splitter 16b is converted into a photoelectric conversion element. And the photoelectric conversion signal from the energy monitor 16c is supplied to the energy controller 16d as an output ES via a peak hold circuit (not shown).

At the time of normal light emission, the energy controller 16d sets the output ES of the energy monitor 16c to a value corresponding to the target value of energy per pulse in the control information TS supplied from the main controller 50. The power supply voltage of the high-voltage power supply 16e is feedback-controlled. Further, the energy controller 16d includes a laser resonator 16d.
The oscillation frequency is also changed by controlling the energy supplied to a through the high-voltage power supply 16e. That is, the energy controller 16d sets the oscillation frequency of the light source 16 to the frequency specified by the main control device 50 according to the control information TS from the main control device 50, and
The feedback control of the power supply voltage of the high-voltage power supply 16e is performed so that the energy per pulse in the above becomes the value instructed by the main controller 50. Further, a shutter 16f for shielding the laser beam LB in accordance with control information from the main controller 50 is also provided outside the beam splitter 16b in the light source 16.

The illumination optical system 12 includes a beam shaping optical system 18, an energy rough adjuster 20, a fly-eye lens 22 as an optical integrator (homogenizer), an illumination system aperture stop plate 24, a beam splitter 26, and a first relay lens 28A. , A second relay lens 28B, a fixed reticle blind 30A, a movable reticle blind 30B,
A mirror M for bending the optical path and a condenser lens 32 are provided. Note that a rod lens as an optical integrator may be used instead of the fly-eye lens 22.

The beam shaping optical system 18 includes the chamber 1
1, and is connected to a beam matching unit (not shown) via a light transmission window 17 provided in the light emitting device. The beam shaping optical system 18 efficiently inserts the cross-sectional shape of the laser beam LB that is pulsed by the light source 16 and enters through the light transmission window 17 into the fly-eye lens 22 provided behind the optical path of the laser beam LB. It is formed of, for example, a cylinder lens and a beam expander (both not shown).

The energy rough adjuster 20 is disposed on the optical path of the laser beam LB behind the beam shaping optical system 18.
Here, a plurality (for example, six) of ND filters (for example, six) having different transmittances (1-dimming rate) around the rotating plate 34 (two of the ND filters 36A and 36B are shown in FIG. 1). And by rotating the rotary plate 34 with the drive motor 38, the transmittance for the incident laser beam LB can be switched from 100% in geometric progression in a plurality of steps. Drive motor 38
Is controlled by a main controller 50 described later. Note that a rotary plate similar to the rotary plate 34 may be arranged in two stages so that the transmittance can be more finely adjusted by a combination of two sets of ND filters.

The fly-eye lens 22 is disposed on the optical path of the laser beam LB emitted from the energy rough adjuster 20, and includes a number of point light sources at its exit end to illuminate the reticle R with a uniform illuminance distribution. A surface light source (secondary light source) is formed. Hereinafter, the laser beam emitted from the secondary light source is referred to as “exposure light EL”.

In the vicinity of the exit surface of the fly-eye lens 22,
An illumination system aperture stop plate 24 made of a disk-shaped member is arranged. This illumination system aperture stop plate 24 is provided at equal angular intervals,
For example, an aperture stop composed of a normal circular aperture, an aperture stop composed of small circular apertures for reducing the σ value which is a coherence factor, a ring-shaped aperture stop for annular illumination, and a plurality of apertures for a modified light source method. A modified aperture stop which is eccentrically arranged (only two types of aperture stops are shown in FIG. 1) and the like are arranged. The illumination system aperture stop plate 24 is configured to be rotated by a drive device 40 such as a motor controlled by a main control device 50 described later.
It is selectively set on the optical path of L.

Exposure light EL emitted from illumination system aperture stop plate 24
A beam splitter 26 having a small reflectance and a large transmittance is arranged on the optical path of the first relay lens 28A and the second relay lens 28A and the second relay lens 28B on the optical path behind the fixed reticle blind 30A and the movable reticle blind 30B.
A relay optical system including a relay lens 28B is provided.

The fixed reticle blind 30A is arranged on a plane slightly defocused from a conjugate plane with respect to the pattern plane of the reticle R, and has a rectangular opening defining an illumination area IAR on the reticle R. Further, a movable reticle blind 30B having an opening whose position and width in the scanning direction are variable near the fixed reticle blind 30A.
Is arranged at the start and end of the scanning exposure so as to further limit the illumination area IAR via the movable reticle blind 30B, thereby preventing exposure of unnecessary portions.

On the optical path of the exposure light EL behind the second relay lens 28B constituting the relay optical system, a bending mirror M for reflecting the exposure light EL passing through the second relay lens 28B toward the reticle R is arranged. And this mirror M
A condenser lens 32 is arranged on the optical path of the rear exposure light EL.

The operation of the illumination system 12 configured as described above will be briefly described. A laser beam LB pulse-emitted from an excimer laser light source 16 enters a beam shaping optical system 18 where a rear fly-back beam is emitted. After its cross-sectional shape is shaped so as to efficiently enter the eye lens 22,
The light enters the energy rough adjuster 20. Then, the laser beam LB that has passed through one of the ND filters of the energy rough adjuster 20 enters the fly-eye lens 22. Thus, the secondary light source is formed at the exit end of the fly-eye lens 22. Exposure light EL emitted from this secondary light source
After passing through one of the aperture stops on the illumination system aperture stop plate 24, the light reaches a beam splitter 26 having a large transmittance and a small reflectance. The exposure light EL transmitted through the beam splitter 26 passes through the first relay lens 28A, the rectangular opening of the fixed reticle blind 30A and the movable reticle blind 30B, and then the second relay lens 28B
, The optical path is bent vertically downward by the mirror M, and then passes through the condenser lens 32 to illuminate the rectangular illumination area IAR on the reticle R held on the reticle stage RST with a uniform illuminance distribution.

On the other hand, the exposure light EL reflected by the beam splitter 26 is received via a condenser lens 44 by an integrator sensor 46 as a first optical sensor comprising a light receiving element having a silicon photodiode or a GaN-based crystal. The photoelectric conversion signal (electric signal corresponding to the detected energy amount) of the integrator sensor 46 is output via a peak hold circuit (not shown) and an A / D converter to output DS [digit / pu].
[lse] to the main controller 50.

A reticle R is mounted on the reticle stage RST, and is held by suction via a vacuum chuck (not shown). The reticle stage RST can be finely driven in a horizontal plane (XY plane), and is scanned by a reticle stage driving unit 49 in a predetermined stroke range in a scanning direction (here, the Y direction which is the horizontal direction in FIG. 1). It is supposed to be. The position of reticle stage RST during scanning is measured by external laser interferometer 54R via movable mirror 52R fixed on reticle stage RST, and the measured value of laser interferometer 54R is supplied to main controller 50. It is supposed to be.

The material used for the reticle R needs to be properly selected depending on the light source (exposure wavelength) used. That is, when a light source of KrF excimer laser light source or the ArF excimer laser light source can be used synthetic quartz, the case of using the F ₂ laser light source, fluorite,
Alternatively, it must be formed of fluorine-doped quartz or the like.

The projection optical system PL is composed of a plurality of lens elements having a common optical axis AX in the Z-axis direction arranged in a telecentric optical arrangement on both sides. As the projection optical system PL, one having a projection magnification of, for example, 1/4 or 1/5 is used. For this reason, when the illumination area IAR on the reticle R is illuminated by the exposure light EL as described above, the image formed on the reticle R is reduced in size by the projection optical system PL at the projection magnification by the projection optical system PL. Resist (photosensitive agent)
Is projected and transferred to the slit-shaped exposure area IA on the wafer W on which is coated.

A beam splitter BS having a transmittance of, for example, about 97 to 99% is provided at a position which is not a conjugate point with respect to an image plane near the lower end of the inside of the lens barrel of the projection optical system PL. A sub-integrator sensor 27 as a second optical sensor is provided on the reflected optical path of the splitter BS. Various types of sensors can be used as the sub-integrator sensor 27. Here, the sub-integrator sensor 27 includes a light receiving element similar to the integrator sensor 46, similarly receives the exposure light EL, performs photoelectric conversion, and performs photoelectric conversion. A signal (electric signal corresponding to the detected energy amount) is supplied to the main controller 50 via a peak hold circuit (not shown) and an A / D converter.

In this case, as is clear from FIG. 1, similarly to the integrator sensor 46, the sub-integrator sensor 27 is provided in the projection optical system PL even when the pattern is being transferred onto the wafer W. It is possible to always detect the energy amount of the exposure light EL that passes through most of the light toward the wafer W (substantially equal to the energy amount of the exposure light EL on the image plane).

[0044] In the case of using an ArF excimer laser beam, KrF excimer laser light as exposure light EL, it is possible to use synthetic quartz and fluorite as the lens elements constituting the projection optical system PL, F ₂ laser When light is used, fluorite is used as the material of the lenses used in the projection optical system PL.

The wafer stage WST is two-dimensionally driven by a wafer stage driving section 56 in the Y-axis direction, which is the scanning direction, and the X-axis direction, which is orthogonal thereto. On the wafer stage WST, a Z tilt stage 58 is mounted, and the wafer W is held on the Z tilt stage 58 by vacuum suction or the like via a wafer holder (not shown). The Z tilt stage 58 adjusts the position (focus position) of the wafer W in the Z direction and
It has a function of adjusting the tilt angle of the wafer W with respect to the Y plane. Further, the position of wafer stage WST is measured by an external laser interferometer 54W via movable mirror 52W fixed on Z tilt stage 58, and the measured value of laser interferometer 54W is supplied to main controller 50. It has become so.

On the Z tilt stage 58 (or wafer stage WST), an irradiation amount monitor 59 for detecting the energy amount of the exposure light EL that passes through the projection optical system PL and irradiates the image plane is provided. The light receiving surface is set to be substantially the same height as the surface of the wafer W. This irradiation dose monitor 5
As 9, an optical sensor having a light receiving element similar to the integrator sensor 46 is used. The photoelectric conversion signal of the irradiation amount monitor 59 is supplied to the main controller 50 in the same manner as the photoelectric conversion signal DS of the integrator sensor 46 and the photoelectric conversion signal CS of the sub-integrator sensor 27.

The control system is mainly constituted by the main control device 50 as a control device in FIG. Main controller 5
0 is a CPU (Central Processing Unit), ROM (Read
And a so-called microcomputer (or workstation) including a memory (only memory), a random access memory (RAM), and the like. For example, synchronous scanning of the reticle R and the wafer W is performed so that the exposure operation is performed accurately. , Stepping of the wafer W, exposure timing, and the like. Further, in the present embodiment, main controller 50 also controls the integrated exposure amount for wafer W during scanning exposure, as described later.

More specifically, the main controller 50 controls the reticle R to move the reticle stage RS
In synchronization with scanning at a speed V _R = V in the + Y direction (or −Y direction) via T, the wafer W is moved relative to the exposure area IA in the −Y direction (or + Y direction) via the wafer stage WST.
Reticle stage driving unit 49 and wafer stage driving based on the measured values of laser interferometers 54R and 54W so that scanning is performed in the direction (direction) at a speed V _W = β · V (β is a projection magnification from reticle R to wafer W). The position and speed of the reticle stage RST and the wafer stage WST are controlled via the units 56, respectively. At the time of stepping, main controller 50 controls the position of wafer stage WST via wafer stage driving unit 56 based on the measurement value of laser interferometer 54W.

Further, the main controller 50 supplies control information TS to the light source 16 in order to provide the wafer W with the integrated exposure amount determined according to the exposure condition and the resist sensitivity at the time of the above scanning exposure. By controlling the oscillation frequency (light emission timing) and light emission power of the light source 16 or controlling the energy rough adjuster 20 via the motor 38, the light amount of the exposure light EL applied to the reticle R can be adjusted. Do. The control of the integrated exposure amount applied to the wafer W will be further described later. In the main control device 50, the illumination system aperture stop plate 24 is connected to the drive device 40.
, And further controls the opening and closing operation of the movable reticle blind 30B in synchronization with the operation information of the stage system.

As described above, in this embodiment, the main controller 5
0 also has a role of an exposure controller (exposure amount control device) and a stage controller (stage control device). It is needless to say that these controllers may be provided separately from main controller 50.

Next, a flow of the exposure operation by the above-described exposure apparatus 10 will be briefly described with reference to FIG.

First, under the control of main controller 50, a reticle loader and a wafer loader (not shown) perform reticle loading and wafer loading, and a reticle microscope, a reference mark plate on wafer stage WST, off-axis alignment, and the like. Preparatory operations such as reticle alignment and baseline measurement (measurement of the optical axis distance of the projection optical system PL from the detection center of the alignment detection system) are performed by a predetermined procedure using a detection system (both not shown).

Thereafter, main controller 50 performs EGA on wafer W using an alignment detection system (not shown).
An alignment measurement such as (enhanced global alignment) is performed. When movement of wafer W is necessary in such an operation, main controller 50 moves wafer stage WST (wafer W) in a predetermined direction. After the completion of such alignment measurement, the exposure operation of the step-and-scan method is performed as follows.

In this exposure operation, first, the wafer W
The wafer stage WST is moved so that the XY position of the wafer stage becomes the scanning start position for exposing the first shot area (first shot) on the wafer W. at the same time,
The XY position of the reticle R becomes the scanning start position,
Reticle stage RST is moved. Then, main controller 50 controls reticle R based on position information of wafer W measured by wafer interferometer 54W and position information of reticle R measured by reticle interferometer 54R.
Scanning exposure is performed by synchronously moving (reticle stage RST) and wafer W (wafer stage WST).

When the transfer of the reticle pattern to one shot area is completed, wafer stage WST is stepped by one shot area, and scanning exposure is performed for the next shot area.
In this way, the stepping and the scanning exposure are sequentially repeated, and the required number of shot patterns are transferred onto the wafer W. Then, each time the wafer W is replaced, the exposure of a large number of wafers is performed by repeatedly performing the step-and-scan exposure on the replaced wafer.

During the exposure as described above, the integrated light amount of the exposure light EL given to each point on the wafer W, that is, the integrated exposure amount is controlled by the main controller 50 as described later. Controlled.

Here, a method of controlling the integrated exposure amount performed during the scanning exposure by the main controller 50 will be described.

As a premise, the output DS of the integrator sensor 46 is calibrated (calibrated) with respect to the output of a reference illuminometer (not shown) mounted on the image plane in advance, and the integrator sensor 46 after this calibration is completed. Sub-integrator sensor 27 for output DS
And the output of the dose monitor 59 are also calibrated in advance. Therefore, it is assumed that a conversion coefficient α value for calculating the amount of light (energy amount) given on the image plane based on the output of the integrator sensor 46 is obtained in advance and stored in the memory 51. It is also assumed that the output of the energy monitor 16c in the light source 16 is also calibrated in advance with respect to the output DS of the integrator sensor 46. Also,
Here, from the viewpoint of simplifying the description, the pattern exists in the pattern region of the reticle R with a substantially uniform distribution,
It is assumed that the transmittance of the reticle R is partially unbiased.
Even with this assumption, it is considered that there is no particular problem in a reticle for manufacturing a general memory or the like.

In the main controller 50, the first wafer W
Immediately before the scanning for exposure of the first shot area starts, the reticle R is irradiated with the exposure light EL in a state where the wafer is not directly below the projection optical system PL, and the output DS of the integrator sensor 46 at this time is output. _0, detects the output CS ₀ of the sub integrator sensor 27, they stores in memory 51 as the initial value for each sensor output, calculates the ratio of the two gamma ₀ by the following equation (1) in the memory 51 Store. γ ₀ = CS ₀ / DS ₀ (1)

Then, the above-described scanning exposure is started, and thereafter, the output DS of the integrator sensor 46 and the output CS of the sub-integrator sensor 27 are fetched at predetermined sampling intervals for each exposure of each shot area.
In each case, a value γ obtained by normalizing the output CS with the output DS is calculated by the following equation (2). γ = CS / DS (2)

[0061] Here, the ratio gamma / gamma ₀ of gamma and gamma _0, sub integrator sensor 27 from the integrator sensor 46
, That is, the variation of the transmittance (optical system transmittance) of the exposure light EL in the optical path from the beam splitter 26 to the beam splitter BS is reflected almost as it is. Further, in this embodiment, since the beam splitter BS is provided near the lower end inside the lens barrel of the projection optical system PL, the transmittance of the optical path from the integrator sensor 46 to the sub-integrator sensor 27 is determined by the integrator sensor Since the transmittance is almost equal to the transmittance of the optical path from 46 to the image plane, the ratio γ / γ ₀
Are sequentially calculated, the integrator sensor 46
It is possible to monitor the temporal change in the transmittance of the optical path from to the image plane.

Accordingly, the main controller 50 monitors the temporal change of the transmittance of the optical path from the integrator sensor 46 to the image plane during the exposure as described above, and sequentially corrects the α value by the equation (3). At the same time, the integrator sensor 46 is calculated by the equation (4) using the corrected α value α ′.
, That is, the amount of exposure light EL (average pulse energy density) P [mJ / (cm ² · p) on the image plane indirectly obtained from the output of the integrator sensor 46.
ulse)] is calculated. α ′ = α × γ / γ ₀ (3) P = DS × α ′ (4)

The exposure light EL on the image plane is obtained indirectly by the output of the integrator sensor 46.
The amount of integrated energy to be given to each point on the image plane (that is, the wafer W), that is, the amount of integrated exposure applied to each point on the wafer W, is controlled in the following manner based on the light amount P.

That is, in a scanning type exposure apparatus having a laser light source (pulse light source) such as the exposure apparatus 10 of the present embodiment, the scanning speed (scanning speed) of the wafer W is set to V _W , and the slit-shaped exposure on the wafer W is performed. If the width (slit width) of the region IA in the scanning direction is D and the repetition frequency of the pulse of the laser light source is F, the interval at which the wafer W moves between pulse emission is V _W / F. The number of pulses (number of exposure pulses) N of the exposure light IL to be irradiated per is expressed by the following equation (5).

N = D / (V _W / F) (5)

Since the average pulse energy density is P,
The energy amount to be given per one point on the wafer, that is, the integrated exposure amount (integrated energy amount) S is given by the following equation (6).
It is represented by

S = N × P = P × D / (V _W / F) (6)

Therefore, the main controller 50 sets the slit width D so that the integrated exposure amount S expressed by the above equation (6) at the time of scanning exposure coincides with the preset exposure amount set in advance according to the resist sensitivity and the like. By controlling at least one of the scan speed V _W , the pulse repetition frequency F of the laser light source, and the amount of exposure light EL on the image plane indirectly obtained from the output of the integrator sensor 46, that is, the average pulse energy density P. It is possible to make the integrated exposure amount given to each point on the wafer W substantially coincide with the set exposure amount. Since there is a difficulty in adjusting the slit width D during scanning exposure due to the problem of the response speed, the scanning speed V _W , the pulse repetition frequency F of the laser light source, and the average pulse energy density of the exposure light EL on the image plane Any one of P or an arbitrary combination thereof may be controlled.

Here, in order to clarify the features of the present embodiment, the amount of processing by the output DS of the integrator sensor 46, that is, the amount of exposure light EL on the image plane indirectly obtained from the output of the integrator sensor 46 (the amount of exposure) : Calculation of the above average pulse energy density) P will be described using a specific example while comparing with the conventional technique.

For example, as an initial condition, it is assumed that when the output of the integrator sensor DS is a [digit / pulse], the conversion coefficient is α [mJ / (cm ² · digit)].
Then, it is assumed that the transmittance of the optical element in the optical path from the integrator sensor 46 to the image plane during the exposure temporarily changes to １ ／. In such a case, the exposure amount (pulse energy density) P ₁ actually given on the image plane is determined assuming that the output of the integrator sensor 46 is, for example, 2a.
P ₁ = 2a × (１ ／) × α = aα (= A)

In this case, in the case of the prior art, since the control is performed with the α value kept constant, the exposure amount P _{2 on} the image plane is P ₂ = 2a × α = 2aα (= 2A). As a result of the above-described control of the integrated exposure amount, the integrated exposure amount S ′ on the image plane is given by S ′ = S × A / (2A) = S /
It is controlled to be 2.

On the other hand, in the case of the present embodiment, the above-mentioned ratio γ / γ ₀ is γ / γ ₀ = １ ／, and as a result, the transmittance is surely changed to １ ／. Is detected, and according to the above equations (3) and (4), α ′ = α × 1/2 = α / 2 (3) ′ P = 2a × α / 2 = aα = A = P ₁ (4) ) ′, The exposure amount on the image surface after the transmittance change can be accurately calculated as the processing amount P of the integrator sensor 46, and as a result, the integrated exposure amount on the image surface becomes equal to the set exposure amount. Controlled to match.

As described above, according to the present embodiment, main controller 50 controls integrator sensor 46.
And the output of the sub-integrator sensor 27 is constantly monitored. Based on these monitoring results, the exposure amount P on the image plane corresponding to the change in the transmittance of the exposure light EL in the optical path from the integrator sensor 46 to the image plane is easily determined. It is accurately calculated by a simple calculation. Then, since the control of the integrated exposure amount for each point on the wafer W is performed based on the exposure amount P, as a result, the effect of the transmittance fluctuation in the optical path is substantially cancelled, and the high-precision exposure amount is achieved. Control will be performed. The outputs of the integrator sensor 46 and the sub-integrator sensor 27 need not always be monitored, but may be monitored periodically (at relatively short intervals). In this case, for example, the sub-integrator sensor 27 can be moved in and out of the optical path.

Further, in the present embodiment, even while the pattern of the reticle R is being transferred onto the wafer W, the light amount (energy amount) of the exposure light EL is always controlled by the integrator sensor 46 and the sub-integrator sensor 27. It is possible to detect and control the integrated exposure amount described above based on these detection results, so that compared with the case where the integrated exposure amount control is performed by predicting a change in the optical system transmittance during exposure. It is possible to control the integrated exposure amount with higher accuracy.

In the above embodiment, the projection optical system PL
A beam splitter BS is disposed near the lower end of the lens barrel, and the exposure light EL split by the beam splitter BS is provided.
Although the case in which the light amount is detected by the sub-integrator sensor 27 has been described, it is a matter of course that the present invention is not limited to this. For example, a mirror or the like is arranged between the optical element optically closest to the image plane and the image plane among the optical elements (lenses and the like) constituting the projection optical system PL, and the mirror is arranged on the reflection optical path of the mirror. Two optical sensors may be provided, and the second optical sensor may detect an energy amount corresponding to an energy beam applied to an optical element optically closest to the image plane. With this configuration, there is no optical element contributing to the change in the energy beam transmittance on the optical path between the second optical sensor and the image plane. The value normalized by dividing by the detection value of the optical sensor (integrator sensor 46) is
This value more accurately reflects the change in the transmittance of the energy beam in the optical path from the optical sensor to the image plane, and the integrated exposure amount can be controlled with higher accuracy. However, in this case,
Simply between the optical element optically closest to the image plane and the image plane,
When a mirror or the like is arranged, a shadow of the mirror or the like itself is reflected on an image plane, which may cause a deterioration in exposure accuracy.Therefore, a predetermined opening is provided outside the pattern area of the reticle, and the opening is inserted into the projection optical system PL. It is desirable to adopt a configuration in which the light is reflected by a mirror disposed at a position other than the exposure region on the wafer W on the optical path of the incident exposure light EL. Thus, the exposure light E incident from the opening outside the pattern region of the reticle is
According to the method of detecting L, for example, even when the distribution of the pattern of the reticle R or the transmittance thereof varies depending on the position, it is not affected as much as possible.
The energy amount of the exposure light EL can be accurately detected by the second optical sensor.

Alternatively, instead of the beam splitter BS and the subintegrator sensor 27 in the above embodiment,
A photomultiplier tube (photomultiplier) and other detectors that convert light energy into electrical signals, and a diamond thin-film light amount detector that detects reflected and scattered light from the lens surface are provided. May be used to detect the amount of energy corresponding to the energy beam applied to the lens element optically closest to the image plane. When the output from these detectors is small, it is also effective to perform phase-sensitive detection with the light source pulse.

However, the second optical sensor is not limited to the vicinity of the lower end of the projection optical system PL, but may be provided in other parts. In short, any configuration may be used as long as the energy amount of the exposure light EL that has passed through at least a part of the inside of the projection optical system can be detected. Even in such a case, the variation of the transmittance in the optical path from the first optical sensor (integrator sensor 46) to the second optical sensor can be monitored by the method described in the above embodiment, so that the transmittance is constant. When controlling the integrated exposure amount given on the substrate on the assumption that
Alternatively, it is possible to control the integrated exposure amount with higher accuracy than in the case where the fluctuation of the optical system transmittance during the exposure is predicted.

Although not specifically described above, the integrator sensor 4 described in the above embodiment is not described.
6. α based on the output of the subintegrator sensor 27
The correction of the value and the calculation of the exposure amount on the image plane using the α value after the correction are clearly more accurate than the case of the prediction control for predicting the variation of the transmittance, Is not directly measured. Therefore, some errors occur in the long term. For this reason,
In the exposure apparatus 10 of the above embodiment, the simultaneous measurement of the exposure light EL by the integrator sensor 46, the sub-integrator sensor 27, and the irradiation amount monitor 59 is repeated at a predetermined timing as shown in FIG. Then, based on the measurement results A ₁ , A ₂ , A ₃ (see FIG. 3), the correlation between the sensor outputs is calibrated,
A conversion coefficient for converting the output of the integrator sensor 46 during exposure into the amount of energy given on the image plane is calibrated. Therefore, it cannot be corrected based on the correlation between the detection results of the integrator sensor 46 and the sub-integrator sensor 27, and occurs when viewed in the long term.
The integrated energy amount can be adjusted in consideration of the change over time of the conversion coefficient, and more accurate integrated exposure amount control can be realized. The predetermined timing may be each time exposure of a predetermined number of wafers is completed, or each time the ratio γ / γ ₀ becomes equal to or more than a predetermined value.

Although not specifically described above,
In the case of an apparatus that performs exposure with an exposure wavelength of 200 nm or less as in this embodiment, the light beam passing portion has a small absorption of exposure light such as N ₂ gas or an inert gas such as helium, argon, or krypton. It is necessary to take measures such as filling or flowing gas (low-absorbing gas), and vacuuming the light beam passage portion.

In the above embodiment, the case where a refraction optical system is used as the projection optical system PL has been described. However, the present invention is not limited to this, and a reflection system consisting of only a reflection optical element or a reflection optical element and a refraction optical element may be used. A catadioptric system (catadioptric system) may be employed. Wavelength 200
In an exposure apparatus using vacuum ultraviolet light (VUV light) of about nm or less, a catadioptric system may be used as the projection optical system. Examples of the catadioptric projection optical system include, for example, Japanese Patent Application Laid-Open Nos. 8-170154 and 10-201.
No. 95, etc., a catadioptric system having a beam splitter and a concave mirror as a reflection optical element, or JP-A-8-33469 and JP-A-10-3039.
A catadioptric system having a concave mirror or the like can be used as a reflective optical element without using a beam splitter as disclosed in Japanese Patent Application Laid-Open Publication No. H10-163,036.

In addition, US Pat. No. 5,031,976
No. 5,488,229 and 5,717,51
No. 8 discloses a plurality of refractive optical elements and two mirrors (a primary mirror that is a concave mirror, and a sub-mirror that is a back mirror in which a reflective surface is formed on the side opposite to the incident surface of the refractive element or the parallel flat plate). ) May be arranged on the same axis, and a catadioptric system may be used in which an intermediate image of the reticle pattern formed by the plurality of refractive optical elements is re-imaged on the wafer by the primary mirror and the secondary mirror. In this catadioptric system, a primary mirror and a secondary mirror are arranged following a plurality of refractive optical elements, and illumination light is reflected through a part of the primary mirror in the order of a secondary mirror and a primary mirror. Part to reach the wafer.

The catadioptric projection optical system has, for example, a circular image field, is telecentric on both the object side and the image side, and has a projection magnification of 1/4 or 1/5. A double reduction system may be used. Further, in the case of a scanning exposure apparatus having this catadioptric projection optical system, the irradiation area of the illumination light is substantially centered on its optical axis within the field of view of the projection optical system, and is substantially in the scanning direction of the reticle or wafer. It may be of a type defined in a rectangular slit shape extending along the orthogonal direction. According to a scanning exposure apparatus provided with such a catadioptric projection optical system, for example, a high accuracy 100 Nml / S pattern about fine patterns using a F ₂ laser beam having a wavelength of 157nm as exposure illumination light on the wafer Can be transferred to

In the above embodiment, the present invention uses ArF excimer laser light (wavelength 193) as the exposure illumination light EL.
nm) or an exposure apparatus using laser light such as F ₂ laser light (wavelength 157 nm). However, the present invention is not limited to this. For example, an infrared region oscillated from a DFB semiconductor laser or a fiber laser, Alternatively, a single-wavelength laser beam in the visible region is amplified by, for example, a fiber amplifier doped with erbium (or both erbium and yttrium), and a harmonic converted from a wavelength into ultraviolet light using a nonlinear optical crystal is used as exposure illumination light. The present invention can be suitably applied to the exposure apparatus described above.

For example, the oscillation wavelength of a single-wavelength laser is set to 1.
When the wavelength is in the range of 51 to 1.59 μm, the generated wavelength is 18
An eighth harmonic having a wavelength in the range of 9 to 199 nm or a tenth harmonic having a generation wavelength in the range of 151 to 159 nm is output. Especially the oscillation wavelength is 1.544 to 1.553 μm
m, an 8th harmonic having a generation wavelength in the range of 193 to 194 nm, that is, ultraviolet light having substantially the same wavelength as the ArF excimer laser light is obtained, and the oscillation wavelength is set to 1.57.
When it is within the range of 1.58 μm, the generated wavelength is 157 to
The 10th harmonic within the range of 158 nm, that is, ultraviolet light having substantially the same wavelength as the F ₂ laser light is obtained.

The oscillation wavelength is set to 1.03 to 1.12 μm
, A 7th harmonic whose output wavelength is in the range of 147 to 160 nm is output.
When the wavelength is in the range of 099 to 1.106 μm, a 7th harmonic having a generated wavelength in the range of 157 to 158 μm, that is, ultraviolet light having substantially the same wavelength as the F ₂ laser light is obtained. In this case, as the single-wavelength oscillation laser, for example, an ytterbium-doped fiber laser can be used.

In the above embodiment, the case where the present invention is applied to a step-and-scan type scanning exposure apparatus has been described. However, the scope of the present invention is not limited to this. The present invention can be suitably applied to a static exposure apparatus such as the one described above.

In the projection exposure apparatus of the above embodiment, the illumination optical system composed of a plurality of lenses and the projection optical system are incorporated in the main body of the exposure apparatus for optical adjustment, and a reticle stage and a wafer stage composed of many mechanical parts are provided. Can be manufactured by attaching wires and pipes to the exposure apparatus main body, and performing overall adjustment (electrical adjustment, operation confirmation, etc.). In this case, it is desirable to manufacture the exposure apparatus in a clean room in which temperature and cleanliness are controlled.

The present invention is not limited to an exposure apparatus for manufacturing a semiconductor, but is also applicable to an exposure apparatus for transferring a device pattern used for manufacturing a display including a liquid crystal display element onto a glass plate and a thin film magnetic head. The present invention can also be applied to an exposure apparatus for transferring a device pattern to be transferred onto a ceramic wafer, an exposure apparatus used for manufacturing an imaging device (such as a CCD), and the like. Also, not only micro devices such as semiconductor elements, but also light exposure devices, E
The present invention can also be applied to an exposure apparatus that transfers a circuit pattern onto a glass substrate or a silicon wafer for manufacturing a reticle or a mask used in a UV exposure apparatus, an X-ray exposure apparatus, an electron beam exposure apparatus, and the like. .

<< Device Manufacturing Method >> Next, an embodiment of a device manufacturing method using the above-described lithography system (exposure apparatus) and exposure method in a lithography process will be described.

FIG. 4 shows a flow chart of an example of manufacturing devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). As shown in FIG. 4, first, step 401
In the (design step), a function / performance design of the device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. Continued
In step 402 (mask manufacturing step), a mask on which the designed circuit pattern is formed is manufactured. on the other hand,
In step 403 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

Next, in step 404 (wafer processing step), using the mask and the wafer prepared in steps 401 to 403, an actual circuit or the like is formed on the wafer by lithography or the like, as described later. . Next, in step 405 (device assembly step), device assembly is performed using the wafer processed in step 404. In this step 405,
Steps such as a dicing step, a bonding step, and a packaging step (chip encapsulation) are included as necessary.

Finally, step 406 (inspection step)
In step S405, inspections such as an operation check test and a durability test of the device created in step 405 are performed. After these steps, the device is completed and shipped.

FIG. 5 shows a detailed flow example of step 404 in the semiconductor device. FIG.
In step 411 (oxidation step), the surface of the wafer is oxidized. In step 412 (CVD step), an insulating film is formed on the wafer surface. In step 413 (electrode forming step), electrodes are formed on the wafer by vapor deposition. In step 414 (ion implantation step), ions are implanted into the wafer. Each of the above steps 411 to 414 constitutes a pre-processing step in each stage of wafer processing.
At each stage, it is selected and executed according to necessary processing.

In each stage of the wafer process, when the above-mentioned pre-processing step is completed, the post-processing step is executed as follows. In this post-processing step, first, in step 4
In 15 (resist forming step), a photosensitive agent is applied to the wafer. Subsequently, in step 416 (exposure step), the circuit pattern of the mask is transferred onto the wafer by the lithography system (exposure apparatus) and the exposure method described above. Next, in step 418 (etching step), the exposed members other than the portion where the resist remains are removed by etching. Then, in step 419 (resist removing step), unnecessary resist after etching is removed.

By repeating these pre-processing and post-processing steps, multiple circuit patterns are formed on the wafer.

If the device manufacturing method of the present embodiment described above is used, the exposure apparatus and the exposure method of the above embodiment are used in the exposure step (step 416), so that the integrated exposure amount on the wafer can be controlled with high precision. Meanwhile, exposure can be performed with a high resolution by an energy beam having a short wavelength in an ultraviolet region or a vacuum ultraviolet region. Therefore, it is possible to improve the productivity of a highly integrated microdevice having a fine pattern.

[0097]

As described above, according to each of the first to third aspects of the present invention, the effect of the change in the transmittance of the optical system in the exposure light path is substantially canceled to control the exposure amount with high accuracy. There is an excellent effect that can be realized.

Further, according to each of the fourth and fifth aspects of the present invention, it is possible to realize high-precision exposure control by substantially canceling out the influence of the transmittance change of the optical system in the exposure light path. An exposure method is provided.

According to the invention described in claim 6, the productivity of a highly integrated microdevice can be improved.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an internal configuration of the light source of FIG.

FIG. 3 is a diagram for explaining calibration between optical sensors in the exposure apparatus of FIG. 1;

FIG. 4 is a flowchart for explaining a device manufacturing method according to the present invention.

FIG. 5 is a flowchart illustrating an example of a detailed process of step 404 in FIG. 4;

[Explanation of symbols]

10 Exposure device, 12 Illumination optical system, 27 Sub-integrator sensor (second optical sensor), 46 Integrator sensor (first optical sensor), 50 Main control device (exposure amount control device), PL Projection optical system, R: reticle (mask), W: wafer (substrate).

Claims (6)

[Claims] 1. An exposure apparatus for transferring a pattern formed on a mask onto a substrate, comprising: an illumination optical system for illuminating the mask with an energy beam; and projecting the energy beam emitted from the mask onto the substrate. A first optical sensor for detecting an energy amount of the energy beam passing through the illumination optical system; a second optical sensor for detecting an energy amount of the energy beam passing at least partially in the projection optical system; An exposure apparatus comprising: a second optical sensor; and an exposure controller that controls an integrated amount of energy applied to the substrate during exposure based on detection values of the first and second optical sensors. 2. The exposure control device according to claim 1, wherein
2. The exposure apparatus according to claim 1, wherein a conversion coefficient for converting a detection value of the first optical sensor into an amount of energy on the substrate is corrected based on a detection value of the optical sensor. 3. The second optical sensor corresponds to an energy beam applied to an optical element optically closest to an image plane of the projection optical system in an optical element group forming the projection optical system. The exposure apparatus according to claim 1, wherein an amount of energy is detected. 4. An exposure method for illuminating a mask on which a pattern is formed with an energy beam via an illumination optical system and transferring the pattern to a substrate via a projection optical system, wherein the pattern is transmitted via the projection optical system. Monitoring the first energy amount of the energy beam passing through the illumination optical system and the second energy amount of the energy beam passing through at least a part of the projection optical system when transferring the image onto the substrate. And controlling the amount of integrated energy applied to the substrate based on the monitoring result. 5. The detection of a third energy amount of the energy beam applied to the image plane of the projection optical system is performed substantially simultaneously with the detection of the first and second energy amounts, and the detection result is obtained. The method further comprises: repeating, at a predetermined timing, calibration for calibrating a conversion coefficient for converting the detection result of the first energy amount to the energy amount given on the image plane during exposure based on the first energy amount. The exposure method according to claim 4, wherein 6. A device manufacturing method including a lithography step, wherein in the lithography step, a device pattern is transferred onto a substrate by using the exposure method according to claim 4 or 5. .