JP3265574B2 - Exposure method and apparatus, and device manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure method and an exposure apparatus used for manufacturing, for example, a semiconductor device or a liquid crystal display device by using a photolithography technique.

[0002]

2. Description of the Related Art When manufacturing a semiconductor device or a liquid crystal display device using photolithography technology, an exposure apparatus for exposing a reticle pattern directly or at a predetermined ratio to a photosensitive material coated on a wafer by reducing the pattern at a predetermined ratio. Is used. In general, an appropriate exposure amount is determined for a photosensitive material applied to a wafer, and therefore, in a conventional exposure apparatus, a beam splitter is arranged in an illumination optical system of exposure light, and the exposure light branched by the beam splitter is used. By monitoring the amount of light, the amount of exposure on the wafer is monitored. Then, when the exposure amount on the wafer reaches the appropriate exposure amount, the exposure of the current shot area of the wafer is stopped, whereby the exposure amount is controlled.

[0003] In recent years, semiconductor devices and the like have been steadily miniaturized, and the minimum line width of a circuit pattern is about to reach a submicron region. For this reason, for example, in a reduction projection type exposure apparatus, a projection optical system having a larger numerical aperture has been developed, but in order to cope with further miniaturization of semiconductor devices and the like, the wavelength of exposure light is further reduced. It is necessary to wavelength.

Therefore, in place of exposing light such as g-ray (wavelength: 436 nm) and i-ray (wavelength: 365 nm) of a mercury lamp which is frequently used at present, excimer laser light which is light of shorter wavelength is expected to be used in the future. ing. Excimer laser light has different wavelengths depending on the type of gas of the oscillation medium of the laser light source. At present, for example, excimer laser light of 248 nm wavelength using krypton fluoride (KrF) as the oscillation medium or argon fluoride as the oscillation medium (Ar
Excimer laser light having a wavelength of 193 nm using F) is promising.

[0005]

However, when excimer laser light is used as the exposure light, the reflectance of the glass material and coating film of an optical component such as an illumination optical system or a beam splitter for the exposure light is reduced by the excimer laser light. It was found that the irradiation may change gradually. This is presumably because irradiation of the excimer laser beam changes the refractive index of the glass material and the coating film of the optical component.

In this case, the reflectivity of the beam splitter disposed in the illumination optical system for monitoring the amount of excimer laser light also changes, and the energy of the excimer laser light branched by the beam splitter reaches the wafer. The ratio with the energy of the excimer laser light also changes. Therefore, if the exposure amount control for the wafer is performed assuming that the ratio is constant, the difference between the actual exposure amount and the appropriate exposure amount may exceed a predetermined allowable value.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide an exposure method and an exposure apparatus capable of accurately monitoring an exposure amount on a wafer when a reticle pattern is transferred to a wafer under exposure light. . In addition, the present invention
Of high-performance device using exposure method such as
It also aims to provide.

[0008]

An exposure apparatus according to the present invention is an exposure apparatus for transferring an image of a pattern formed on a mask onto a substrate under exposure light from a light source.
First light receiving means ( 2) for receiving the exposure light on the light source side
9 ) and a second method for receiving the exposure light on the substrate side.
Light receiving means (20) and the height of the light receiving surface of the second light receiving means
Light receiving surface provided so as to substantially match
The plate side receives the exposure light, outputs a reference signal, and calibrates the light receiving sensitivity of the first light receiving unit based on the reference signal.

[0009]

Also, as an example, a stage (19) on which the substrate is mounted is provided , and the second light receiving means is provided with the stage (19) .
Stage, and the calibration means is located on the stage.
A third light receiving means provided in different positions (21) and the second light receiving means. Next, the exposure method according to the present invention comprises:
In an exposure method of transferring an image of a pattern formed on a mask onto a substrate via a projection optical system under exposure light from a light source, the substrate receives the exposure light and outputs a reference signal. The light receiving surface of the reference light receiving means is
A first light source arranged to receive the exposure light on the light source side;
The light receiving sensitivity of the light receiving means, calibrated on the basis of the reference signal, based on the output signal outputted from the calibrated the first light receiving means, and controls the exposure amount of the exposure light for the substrate. In this case, as an example, the criteria
The light receiving means is provided on the substrate side based on the reference signal.
Calibration of the light receiving sensitivity of the second light receiving means for receiving the exposure light of
You. Further, the method for manufacturing the first and second devices according to the present invention includes a step of performing exposure using the exposure apparatus and the exposure method according to the present invention, respectively.

[0011]

According to the present invention, even if the reflectance of the glass material or the coating film of the optical component changes due to the irradiation of the exposure light, for example, when the substrate W is replaced or the positioning stage ( when placing the predetermined substrate W on 19), the compare
The corrector receives the exposure light and outputs a reference signal.
The light receiving sensitivity of the first light receiving means is compared based on the reference signal.
Correct. The first thus calibrated just before the exposure
By using the output signal of the light receiving means, the absolute value of the exposure amount for the substrate W can be accurately monitored.
And perform exposure control with high accuracy based on the results.
Can be.

[0012] Further, there is provided a second light receiving means ( 20 ) for receiving the exposure light on the substrate side, and a third light receiving means serving as an illuminance reference in the calibrating means on a stage (19) on which the substrate is mounted. When means (21) is arranged, 1
The output signals of the first light receiving means ( 29 ) and the second light receiving means ( 20 ) are calibrated at a certain frequency such as once a month. Thereby, the first light receiving means ( 29 ) and the second light receiving means ( 20 )
Changes in sensitivity due to changes over time in the
It is possible to more accurately control the absolute value of the exposure amount for the substrate W. Further, according to the exposure method of the present invention, the absolute value of the exposure amount for the substrate can be accurately monitored. Further, according to the first and second device manufacturing methods of the present invention, since the exposure apparatus and the exposure method of the present invention are used, respectively, the exposure amount is accurately controlled, and a device such as a semiconductor element is manufactured. It can be manufactured with high precision.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exposure apparatus according to the present invention will be described below with reference to FIGS. In this embodiment, the present invention is applied to a projection exposure apparatus using excimer laser light as exposure light. FIG. 1 shows a configuration of a projection exposure apparatus of the present embodiment. In FIG. 1, reference numeral 1 denotes a laser light source of KrF excimer laser light, and Brewster windows 2 and 3 are attached to both ends of the laser light source 1. . A reflecting mirror 5 is disposed outside one Brewster window 2 via an etalon 4, and a semi-transmitting mirror 6 is disposed outside the other Brewster window 3.

The wavelength of the natural oscillation of the laser light source 1 is 248.
nm, the bandwidth is 300 pm, and this bandwidth is 3 pm
An etalon 4 is provided to narrow the band. In addition,
Although only the etalon 4 is shown here, the band may be narrowed by a grating, a prism, or the like. Further, since the Brewster windows 2 and 3 are substantially non-reflective for polarized light of a specific angle, only light of this polarized component is amplified between the reflecting mirror 5 and the semi-transmitting mirror 6. As a result, the laser light source 1 oscillates with linearly polarized light, and a substantially linearly polarized laser beam LB0 is emitted to the outside via the semi-transmissive mirror 6. The excimer laser light is a pulsed laser light, and the oscillation state of the laser light source 1 and the power of the emitted laser beam are controlled by a laser power supply 7.

The laser beam LB0 emitted from the semi-transmissive mirror 6 is shaped into a parallel beam having a desired cross-sectional shape by a beam shaping optical system including lenses 8 and 9, and the laser beam LB1 emitted from the beam shaping optical system. Is 1
The light is converted from linearly polarized light into circularly polarized light by the 波長 wavelength plate 10, reflected by the reflecting mirror 11, and then enters the fly-eye lens 12. The exit surface of the fly-eye lens 12 has a large number of 2
A secondary light source is formed, and laser beams from these many secondary light sources are incident on the beam splitter 13 in a superimposed manner, and the laser beam transmitted through the beam splitter 13 is transmitted to the first relay lens 14, the reticle blind 15, the second relay The reticle R is illuminated with a uniform illuminance distribution via the lens 16, the reflecting mirror 17, and the main condenser lens 18. The reticle blind 15 is conjugate with the reticle R with respect to the second relay lens 16 and the main condenser lens 18, and the reticle blind 15 sets an illumination field on the reticle R.

Under the laser light, the pattern of the reticle R is imaged on the wafer W by the telecentric projection optical system PL on both sides (or one side), and the pattern of the reticle R is projected and exposed on the wafer W. The exit surface (secondary light source forming surface) of the fly-eye lens 12 and the pupil (entrance pupil) surface Ep of the projection optical system PL are conjugate. 19 is the wafer W
Indicates an XY stage for positioning the wafer W in a plane perpendicular to the optical axis of the projection optical system PL, and the wafer stage 19 for positioning the wafer W in the optical axis direction of the projection optical system PL. It is composed of a Z stage and the like.

In the vicinity of the wafer W on the wafer stage 19, an irradiation amount monitor 20 made of a photoelectric conversion element is arranged.
At another position on the wafer stage 19, a reference illuminometer 21 made of a photoelectric conversion element and capable of measuring an absolute value of illuminance with high accuracy is arranged. The height of the light receiving surface of each of the irradiation amount monitor 20 and the reference illuminometer 21 is provided so as to substantially coincide with the height of the surface of the wafer W. The reference illuminometer 21 is used for calibrating the irradiation amount monitor 20 and the like. In other cases, the reference illuminometer 21 is covered with a cover 22 so that the exposure light is not irradiated. Reference numeral 23 denotes a main control system for controlling the operation of the entire apparatus. The photoelectric conversion signal of the irradiation amount monitor 20 is supplied to the main control system 23 as a detection signal P1 via a variable amplifier 24, and the photoelectric conversion signal of the reference illuminometer 21 is provided. P2 is also the main control system 23
Supplied to

The movable mirror 2 is placed on the wafer stage 19.
5 is attached, and the laser interferometer 2 is
By reflecting the laser beam from 6, the laser interferometer 26 measures the coordinates of the wafer stage 19.
The main control system 23 controls the wafer stage 1 via a driving device 27 based on the coordinates and the like obtained by the laser
9 is performed.

The laser light reflected by the beam splitter 13 immediately after the fly-eye lens 12 enters a light receiving surface of an integrator sensor 29 composed of a photoelectric conversion element via a condenser lens 28. Due to the condenser lens 28, the light receiving surface of the integrator sensor 29 is arranged at a position conjugate with the reticle blind 15 as a field stop on the main optical path. Accordingly, the light receiving surface of the integrator sensor 29 is arranged on a surface conjugate with the exposure surface of the wafer W, and the photoelectric conversion signal of the integrator sensor 29 is converted into the detection signal P0 via the variable amplifier 30 as the main control system 23.
Is supplied to When performing exposure on the wafer W, the integrator sensor 29 generates a photoelectric conversion signal proportional to the power (peak output of the pulse light) of the pulse laser beam emitted from the laser light source 1, and the main control system 23 detects the signal. By integrating the signal P0, the integrated exposure amount for the wafer W can be monitored.

Incidentally, one of the important characteristics of the exposure apparatus is uneven illuminance on the wafer W. A method for measuring the uneven illuminance will be described with reference to FIG. FIG. 2 is a functional block diagram of the main control system 23 for measuring uneven illuminance. In FIG. 2, the main control system 23 drives the wafer stage 19 via the driving device 27 shown in FIG. The entire light exposure area of the projection optical system PL is scanned by the light receiving surface of the quantity monitor 20. At this time, the main control system 23 reads the two-dimensional coordinates (X, Y) of the irradiation amount monitor 20 via the laser interferometer 26. At the same time, the main control system 23 is connected to the laser power source 7 in FIG.
While the laser light source 1 is oscillated at a constant output (a constant discharge voltage) via the, the photoelectric conversion signals of the integrator sensor 29 and the irradiation amount monitor 20 are fetched.

The detection signal P0 fetched from the integrator sensor 29 via the variable amplifier 30 and the detection signal P1 fetched from the irradiation amount monitor 20 via the variable amplifier 24 are respectively peaked inside the main control system 23. It is supplied to the dividing means 33 via the hold circuits 31 and 32. Since the excimer laser light is pulsed light, the peak hold circuits 31 and 32 detect the peak values <P0> and <P1> of the corresponding detection signals, respectively. The dividing means 33 calculates the value <P1> / <P0> of the ratio of the two peak values, and
To supply. Further, the coordinates (X, Y) of the irradiation amount monitor 20 obtained by the laser interferometer 26 are converted into an address by the coordinate conversion means 35 in the main control system 23 and supplied to the processing means 34.

The processing means 34 receives the supplied ratio value <P
1> / <P0> is supplied to the data terminal DA of the memory 36, and the corresponding address is stored in the address terminal AD of the memory 36.
To supply. Thus, the ratio value <P1> / <P0> is stored in the memory 36 in a format corresponding to the coordinates (X, Y). The main control system 34 reads the ratio value <P1> / <P0> stored in the memory 36 and displays it on the display means 37 in a format corresponding to the coordinates (X, Y). When measuring the illuminance unevenness, a reticle without a pattern is put on the entire surface as the reticle R in FIG. 1 or the measurement is performed in a state where the reticle R is not placed. Thereby, the illuminance unevenness on the wafer W can be accurately measured.

Next, a method of monitoring the exposure amount on the wafer W during the exposure on the wafer W will be described. In FIG. 1, since the exposure amount on the wafer W cannot be directly measured by the irradiation amount monitor 20 during the exposure on the wafer W, the detection signal P0 obtained from the integrator sensor 29 through the variable amplifier 30 is used. Measure. In this case, the dose monitor 20 is calibrated in advance using the reference illuminometer 21 with the cover 22 removed or using another illuminometer as a reference. Further, a ratio value between the detection signal P1 obtained from the dose monitor 20 via the variable amplifier 24 before the exposure is started and the detection signal P0 obtained from the integrator sensor 29 via the variable amplifier 30, more precisely, A ratio value <P1> / <P0> between a peak value <P1> of the detection signal P1 and a peak value <P1> of the detection signal P0 is obtained and stored.

At this time, as the reticle R, in addition to the reticle R actually exposed, a test reticle in which only a certain portion does not have a pattern may be used. Further, the measurement may be performed in a state where reticle R does not exist. Assuming that the transmittance of the reticle R to be actually exposed is T, the ratio of the two peak values obtained when no reticle is present is converted into <P1> .T / <P0> and stored.

Next, when exposing the pattern of the reticle R to be exposed on the wafer W, the main control system 23 uses the peak value <0 of the detection signal P0 obtained from the integrator sensor 29 via the variable amplifier 30. Monitor only P0>. From this peak value, a peak value <P1> (or <P1> · K) corresponding to the exposure amount on the wafer W can be obtained by calculation. First, the main control system 23 controls the output of the laser light source 1 via the laser power supply 7 to obtain a peak value <P indicating the amount of light received by the integrator sensor 29.
0> is set to a predetermined value. When the exposure is completed in one pulse, the exposure amount is controlled by this. When exposure is performed with a plurality of pulses for each shot on the wafer W, the main control system 23 detects the integrated exposure amount to each shot area of the wafer W by integrating the peak value <P0> for each pulse. When the integrated exposure reaches the appropriate exposure, the exposure of the shot area is stopped. Thereby, the total exposure amount per shot is set to an appropriate exposure amount.

However, when the exposure is continued, the reflectance of the glass material or the coating film of the optical components from the beam splitter 13 to the projection optical system PL changes due to the accumulation of irradiation energy or the like. The ratio value <P1> / <P0> stored first may change. Therefore,
In this example, the ratio value <P1> / <P0> of the output of the integrator sensor 29 and the output of the irradiation amount monitor 20 is actually measured when the reticle R is replaced or periodically. If the value of the ratio fluctuates, the ratio value <P
1> / <P0> is stored. That is, the ratio is set by changing the ratio value stored first to the ratio value measured this time. Thereafter, by monitoring the exposure amount based on the output signal of the integrator sensor 29,
It is possible to secure an appropriate exposure amount on the wafer W.

In this embodiment, since the reference illuminometer 21 serving as the illuminance reference is provided on the wafer stage 19, three kinds of calibration procedures using the illuminance meter will be described below. [First Calibration Procedure] First, the light receiving surface of the reference illuminometer 21 is moved to the image plane of the projection optical system PL, and the output signal P2 of the reference illuminometer 21 is measured.
Then, the output signal P0 of the integrator sensor 29 is measured, and the gain of the output signal of the integrator sensor 29 is automatically adjusted using a predetermined fixed coefficient α so that the following equation is satisfied. P0 × α = P2

Next, the irradiation amount monitor 20 is connected to the projection optical system P.
Move to the position of the image plane of L and measure the output signal P1 of the dose monitor 20. And integrator sensor 2
9, the gain of the output signal of the irradiation amount monitor 20 is automatically adjusted so that the following equation is satisfied. P0 × α = P1

[Second Calibration Procedure] As in the first calibration procedure, a predetermined fixed coefficient α is used, but first, the output signal of the reference illuminometer 21 is used to calibrate the output signal of the dose monitor 20. Then, the output signal of the integrator sensor 29 is calibrated using the output signal of the reference illuminometer 21.

[Third Calibration Procedure] First, the reference illuminometer 21
Is moved to the image plane of the projection optical system PL, and the output signal P2 is measured. Then, the output signal P of the integrator sensor 29
By measuring 0, the value of the coefficient α is changed so that the following equation is satisfied. P0 × α = P2 Next, the irradiation amount monitor 20 is moved to the image plane of the projection optical system PL, and its output signal P1 is measured. Then, by using the changed coefficient α, the gain of the output signal of the dose monitor 20 is automatically adjusted so that the following equation is satisfied. P0 × α = P1

In accordance with any of the above-described calibration procedures, the dose monitor 20 and the integrator sensor 29 on the wafer stage may be calibrated using the reference illuminometer 21 at a constant frequency such as once a month. Good. This allows
The change with time due to the irradiation of the laser light from the irradiation amount monitor 20 and the integrator sensor 29 can be corrected.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 3, in which parts corresponding to those in FIG.
2, a depolarizing element 38 is arranged. This depolarizing element 38 is configured by disposing a wedge-shaped quartz plate 39 and a wedge-shaped quartz plate 40 along the optical axis, and rotating the quartz plate 39 and the quartz plate 40 to convert the excimer laser light into a straight line. Converts polarized light to random polarized light. Therefore, in this example, 1/4 of FIG.
The wave plate 10 is not required. Also, the depolarizing element 3 of the present example
8, a function similar to that of the variable amplifier 30 of FIG. 1 can be achieved. Other configurations are the same as those in FIG.

Also in this embodiment, the irradiation amount monitor 20 is used before the exposure starts.
From the detection signal P1 obtained from the integrator sensor 29 via the variable amplifier 30 (or simply an amplifier) from the detection signal P1 obtained through the variable amplifier 24,
More precisely, the value <P1> / <P of the ratio between the peak value <P1> of the detection signal P1 and the peak value <P1> of the detection signal P0.
0> is obtained and stored. When the reticle R is replaced, the ratio value <P1> / <P0> is actually measured. If the ratio value fluctuates, the ratio between the quartz plate 39 and the quartz plate 40 of the depolarizing element 38 is changed. The polarization state of the laser light is changed by adjusting the relative rotation angle. As a result, the reflectivity of the beam splitter 13 changes, and the amount of light received by the integrator sensor 29, and thus the peak value <P0> can be calibrated.

In the above embodiment, for example, a portable illuminometer may be used instead of the irradiation amount monitor 20 on the wafer stage 19. Similar effects can be obtained even when the present invention is applied to a proximity type exposure apparatus that does not use a projection optical system. As described above, the present invention is not limited to the above-described embodiment, and can take various configurations without departing from the gist of the present invention.

[0035]

According to the present invention , illumination light is provided in the optical path of the exposure light.
By arranging the calibration means serving as a degree reference, there is an advantage that the exposure amount on the substrate (wafer) can be accurately monitored. Further, a third means in which the calibration means is provided on the stage
More accurate monitoring of the exposure
Can be

[Brief description of the drawings]

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

FIG. 2 is a functional block diagram of a main control system 23 when measuring an illuminance distribution on a wafer stage in the embodiment.

FIG. 3 is a configuration diagram showing a main part of another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser light source 2, 3 Brewster window 4 etalon 6 semi-transmissive mirror 7 laser power supply 10 1/4 wavelength plate 12 fly eye lens 13 beam splitter 15 reticle blind 18 main condenser lens R reticle PL projection optical system W wafer 19 wafer stage 20 Irradiation dose monitor 21 Reference illuminometer 23 Main control system 26 Laser interferometer 27 Drive device 29 Integrator sensor 30 Variable amplifier 38 Depolarization element 39 Quartz plate 40 Quartz plate

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20 521

Claims (18)

(57) [Claims] [Claim 1] Under the exposure light from a light source, an exposure apparatus for transferring onto a substrate an image of a pattern formed on a mask, a first light receiving means for receiving the exposure light at the light source side, the Second light receiving means for receiving the exposure light on the substrate side
And the height of the light receiving surface of the second light receiving means is substantially coincident with the height of the light receiving surface.
And a calibration means for receiving the exposure light on the substrate side, outputting a reference signal, and calibrating the light receiving sensitivity of the first light receiving means based on the reference signal. Exposure equipment. 2. The method according to claim 1, wherein the calibrating unit is configured to perform a
2. The exposure apparatus according to claim 1 , wherein the light receiving sensitivity of the second light receiving unit is calibrated. 3. The calibrating means according to claim 2, wherein said calibrating means comprises :
Based on the output signal output from the optical means, the second reception
2. The light receiving sensitivity of the light means is calibrated.
3. The exposure apparatus according to claim 1. 4. The apparatus according to claim 1 , wherein said calibration means receives the first light receiving means.
As the light sensitivity, an output signal output from the first light receiving means is used.
Signal gain and adjusting the light receiving
An output signal output from the second light receiving means as sensitivity;
4. The gain according to claim 2 or 3, wherein
Exposure apparatus according to the above. 5. The calibration means according to claim 1 , wherein:
The output signal output from the first light receiving means will be the same
Thus, the output signal of the first light receiving means is multiplied by a predetermined coefficient.
The exposure apparatus according to claim 1, wherein: 6. The calibration means according to claim 1 , wherein:
The output signal of the second light receiving means is multiplied.
Item 6. An exposure apparatus according to Item 5. 7. A stage on which the substrate is mounted, wherein the second light receiving means is provided on the stage, and wherein the calibrating means is at a different position on the stage from the second light receiving means. The exposure apparatus according to claim 1, further comprising a third light receiving unit provided. 8. An image of a pattern formed on the mask,
Has a projecting projection optical system for transferring onto a substrate, said stage, each light receiving surface and the light-receiving surface of the third light receiving means of the second light receiving means to the image plane of the projection optical system
The exposure apparatus according to claim 7 , wherein the exposure apparatus moves . 9. A changing means for changing a relation between an output signal from the first light receiving means and an output signal from the second light receiving means after a predetermined time, and the relation changed by the changing means ; The first light receiving hand
The exposure apparatus according to any one of claims 1 to 8 , further comprising: an exposure amount control unit configured to control an exposure amount of the exposure light to the substrate based on an output signal from a stage . 10. An output signal from the first light receiving means and an output signal from the second light receiving means for receiving and outputting the exposure light before transferring the image of the pattern onto the substrate. When the ratio between the output signal from the first light receiving means and the output signal from the second light receiving means, which receives and outputs the exposure light after the predetermined time has elapsed, changes the The exposure apparatus according to claim 9, wherein the relationship is changed. 11. Calibration of the first light receiving unit and the second light receiving means, an exposure apparatus according to any one of claim 1 to 10, characterized in that performed periodically. 12. The exposure apparatus according to claim 7 , wherein the third light receiving unit is of a portable type. 13. An exposure method for transferring an image of a pattern formed on a mask onto a substrate through a projection optical system under exposure light from a light source , wherein the exposure light is received on the substrate side. A light receiving surface of a reference light receiving unit that outputs a reference signal is disposed on an image plane of the projection optical system, and a light receiving sensitivity of the first light receiving unit that receives the exposure light on the light source side is calibrated based on the reference signal. An exposure method, comprising: controlling an exposure amount of exposure light to the substrate based on a calibrated output signal output from the first light receiving unit. 14. The reference light receiving means, based on the reference signal, claim 13, characterized in that calibrating the light receiving sensitivity of the second light receiving means for receiving the exposure light by the substrate side
Exposure method according to 1. 15. The exposure method according to claim 14 , wherein the light receiving sensitivity of the second light receiving unit is calibrated based on an output signal from the first light receiving unit calibrated with the reference signal. . . 16. After the light-receiving sensitivity of the first and second light receiving means is calibrated, the output signals 及 from the first light receiving means
And a relationship between an output signal from the second light receiving means and the first signal .
The exposure amount of the exposure light to the substrate is controlled based on an output signal from a light receiving unit.
16. The exposure method according to 14 or 15 . 17. The device manufacturing method comprising the step of performing exposure using an exposure apparatus according to any one of claims 1 to 12. 18. The device manufacturing method comprising the step of performing exposure by using the exposure method according to any one of claims 13 to 16.