JP2001015401A - Projection exposing method, projection aligner and manufacture of device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of exposure precision due to aberration of a projection optical system by performing exposure after correcting the error when variation of temperature of the projection optical system exceeds the predetermined threshold. SOLUTION: For performing exposure, the temperature of a projection optical system PL measured by a temperature sensor TS is observed by a lens control device LC. When the variation of temperature of the projection optical system PL exceeds the threshold, the main control apparatus C measures the nonlinear magnification, wavefront aberration, focal points or curvature of field of the projection optical system PL by using a projection magnification measuring system PM, a focal point measuring system or the like. Namely, the error of nonlinear magnification is corrected by driving a part of lenses in the projection optical system PL, change of pressure or the like and the curvature of field is corrected by driving the wafer stage WST in the direction Z (vertical direction) by controlling the driving mechanism to the measured correction position. The focal point is corrected by moving the wafer stage WST to the focusing position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure method, a projection exposure apparatus and a device manufacturing method used in an exposure step in the production of fine circuit patterns and the like such as semiconductor integrated circuits and liquid crystal displays.

[0002]

2. Description of the Related Art In general, a projection exposure apparatus is designed so that various optical aberrations become substantially zero under predetermined conditions when designing a projection optical system. The atmospheric pressure and temperature near the projection optical system change,
Alternatively, if there is heat absorption or the like due to irradiation of exposure illumination light, a change in the refractive index of the gas between the lenses constituting the projection optical system, lens expansion, a change in the refractive index of the lens, expansion of the lens barrel, and the like occur.

Therefore, when a reticle pattern is projected on a wafer, distortion occurs, which is a phenomenon that the projected image is shifted in a direction perpendicular to the optical axis of the projection optical system. As means for correcting a linear magnification error (a component in which the magnification changes linearly with respect to the image height) in the distortion, some lenses in the projection optical system have been conventionally driven, A lens control system that controls the gas pressure between the lenses has been used.

In addition to the distortion, the position (focus position) of the image plane (best focus plane) of the projection image in the direction of the optical axis of the projection optical system shifts, and the surface of the wafer deviates from the image plane. Defocus had also occurred. As means for correcting linear defocus (a component in which the defocus amount changes linearly with respect to the image height) of the defocus, the focus position of the wafer is conventionally controlled in the direction of the image plane. An automatic focusing mechanism is known.

[0005]

However, a change in magnification and a change in focus position of the projection optical system caused by the conventional irradiation of the illumination light for exposure require a temperature-magnification change characteristic and a temperature-focus change which are obtained in advance. The amount of change in magnification and change in focus is predicted and calculated based on the temperature actually measured from the characteristics and the like, and the projection optical system is corrected using the correction mechanism. However, in the above-described conventional method, when a measurement error or the like occurs in the relationship between the temperature and the aberration fluctuation amount (magnification change, focus change, and the like) characteristics obtained in advance, the error is not calculated in the aberration correction amount calculation of the projection optical system. Is caused, which causes a deterioration in the imaging performance of the pattern image exposed on the wafer. Further, the temperature-aberration fluctuation amount characteristic may be different from the one previously obtained due to aging or the like depending on the use situation. In this case, it is essential to previously obtain the relationship between the temperature-aberration fluctuation amount characteristic, and when the temperature sensor or the like is replaced, an error due to an individual difference of the measurement system is removed again to remove the error. There is a need to make measurements. Since the aberration amount calculation is generally represented by an approximation curve, the error between the calculated aberration amount and the actual aberration amount can be reduced by increasing the approximation order. There was a problem that caused it. In addition, since it is necessary to measure the aberration characteristics in advance, the adjustment workability has been reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a projection exposure method capable of preventing exposure accuracy from deteriorating due to aberration of a projection optical system and improving the adjustment work load of the projection optical system. It is an object of the present invention to provide a projection exposure apparatus and a method of manufacturing a device.

[0007]

The present invention has the following features to attain the object mentioned above. That is, with reference to FIGS. 1 to 3, in the projection exposure method according to the first aspect, the pattern on the mask (R) is transferred to the surface of the substrate (W) via the projection optical system (PL). In a projection exposure method, the temperature of the projection optical system is measured, and when the temperature variation does not exceed a preset threshold, an error in the optical characteristics of the projection optical system due to the temperature variation is not corrected. When exposure is performed and the fluctuation exceeds a threshold value, a technique of performing exposure after correcting the error is employed.

In the projection exposure apparatus according to the fourth aspect,
A projection exposure apparatus for transferring a pattern on a mask (R) onto a surface of a substrate (W) via a projection optical system (PL), comprising: a temperature sensor (TS) for measuring a temperature of the projection optical system;
A correction mechanism (C, STG, ALG, or the like) that measures an error in the optical characteristics of the projection optical system due to temperature fluctuation and corrects the error.
PM, FM) and when the temperature fluctuation measured by the temperature sensor does not exceed a preset threshold, exposure is performed without correcting the error, and when the fluctuation exceeds the threshold, And a control mechanism (LC) that controls the correction mechanism so as to perform exposure after correcting the error.

In the projection exposure method and the projection exposure apparatus, the temperature of the projection optical system (PL) is measured, and when the fluctuation of the temperature does not exceed a preset threshold, the projection optical system (PL) is caused by the temperature fluctuation. Exposure is performed without correcting the error of the optical characteristics, and when the fluctuation exceeds the threshold value, the exposure is performed after correcting the error, so it is necessary to measure the temperature-aberration fluctuation characteristics of the projection optical system in advance. When the temperature fluctuation does not exceed the threshold value, the exposure can be performed within a certain accuracy, and the exposure accuracy can be improved by correcting the error for the temperature fluctuation exceeding the threshold value. .

According to a fifth aspect of the present invention, there is provided a projection exposure method for transferring a pattern on a mask (R) onto a surface of a substrate (W) via a projection optical system (PL). Measure the temperature, when the fluctuation of the temperature does not exceed the preset threshold, do not measure the error of the optical characteristics of the projection optical system due to the temperature fluctuation, when the fluctuation exceeds the threshold, A technique for measuring the error is employed.

Further, in the projection exposure apparatus according to claim 6,
A projection exposure apparatus for transferring a pattern on a mask (R) onto a surface of a substrate (W) via a projection optical system (PL), comprising: a temperature sensor (TS) for measuring a temperature of the projection optical system;
A measuring mechanism (C, PM, FM) for measuring an error in the optical characteristics of the projection optical system due to a temperature change, and an error when the temperature change measured by the temperature sensor does not exceed a preset threshold value. Is not measured, and when the fluctuation exceeds a threshold value, a technique including a control mechanism (LC) that controls the measurement mechanism so as to measure the error is adopted.

In the projection exposure method and the projection exposure apparatus, the temperature of the projection optical system (PL) is measured, and when the fluctuation of the temperature does not exceed a preset threshold value, the projection optical system (PL) is caused by the temperature fluctuation. If the error exceeds the threshold value without measuring the error of the optical characteristic, the error is measured.Therefore, there is no need to measure the temperature-aberration variation characteristic of the projection optical system in advance, and the threshold value is exceeded. Exposure can be performed within a certain precision when there is no temperature fluctuation, and the exposure precision can be improved by measuring an error for a temperature fluctuation exceeding a threshold value.

According to a seventh aspect of the invention, there is provided a device manufacturing method,
A method for manufacturing a device, which is manufactured through a transfer step of transferring a pattern of a mask onto a photosensitive member, comprising:
A technique in which the transfer step is performed by the projection exposure method according to any one of 2, 3, and 5, is adopted.

According to this method of manufacturing a device,
Since the transfer step is performed by the projection exposure method described in any one of 2, 3, and 5, the adjustment work of the optical characteristics in the transfer step is improved and the transfer accuracy is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a projection exposure method, a projection exposure apparatus and a device manufacturing method according to the present invention will be described below with reference to FIGS.

FIG. 1 is a diagram schematically showing the overall configuration of a projection exposure apparatus according to the present embodiment, and particularly shows a projection magnification measurement system (correction mechanism, measurement mechanism) PM. The projection exposure apparatus uniformly illuminates the reticle (mask) R with exposure light IL from an exposure light source 1 such as an ArF laser while holding a reticle (mask) R on a reticle stage RST to project a pattern drawn on the reticle R. This is to form an image on a wafer (substrate) W coated with a photosensitive agent via an optical system PL.

In this projection exposure apparatus, the exposure light IL emitted from the exposure light source 1 is reflected by the mirror M and enters the illumination optical system 2. The illumination optical system 2 includes a relay lens, an optical integrator (such as a fly-eye lens) for equalizing the exposure light IL, and an exposure light IL.
An input lens that causes the light to enter the optical integrator, a relay lens that focuses the exposure light IL emitted from the optical integrator on the reticle R,
It has a plurality of lens elements such as a condenser lens.

Exposure light IL emitted from illumination optical system 2
Is incident on a reticle R on a reticle stage RST that can move two-dimensionally. Further, the exposure light IL transmitted through the reticle R enters the projection optical system PL,
The light passes through a plurality of lens elements constituting L and enters the wafer W, and a pattern image on the reticle R is formed on the surface of the wafer W.

The wafer W is placed on a wafer stage WST that can move in a three-dimensional direction (XYZ directions), and the position of the wafer stage WST in the XY plane is measured by a laser interferometer (not shown). ing. Wafer stage WST
Is stepped on the basis of the measurement value of the laser interferometer, and the stepping movement and exposure are repeated by a so-called stepping and repeat method, so that a pattern is sequentially exposed on the wafer W.

The projection optical system PL is provided with a temperature sensor TS for measuring the temperature of the projection optical system PL. The temperature information measured by the temperature sensor TS is stored in the lens controller L.
Transmitted to C and constantly monitored. The projection optical system PL is housed in a lens barrel (not shown), and a temperature sensor TS is installed in the lens barrel. The projection magnification measurement system PM has an imaging characteristic measurement sensor 3 fixed near the wafer W on the wafer stage WST. As shown in FIG. 2, the imaging characteristic measuring sensor 3 is a glass substrate which is set at the same height as the surface of the wafer W, has a light-shielding film 4a on the surface, and has a rectangular opening 4b. 4 and a photoelectric conversion element 5 that is provided below the glass substrate 4 and photoelectrically converts the exposure light IL that has passed through the opening 4b. The alignment control section ALG processes the detection signal S1 from the photoelectric conversion element 5. It is connected.

The processing result of the alignment control unit ALG is sent to the wafer stage control unit STG, and based on the processing result, the wafer stage control unit STG drives the wafer stage WST, whereby the projected image of the pattern of the reticle R is projected. To the opening 4b of the imaging characteristic measuring sensor 3.
, And the alignment control unit ALG calculates a non-linear magnification error and a field curvature of the projection optical system PL based on the detection signal S1 output from the photoelectric conversion element 5 at that time.

FIG. 3 shows a focus exposure system (correction mechanism, measurement mechanism) FM in the projection exposure apparatus according to the present embodiment. That is, as shown in FIGS. 3 and 4, the focus measurement system FM includes a fiducial plate 6 on which a predetermined opening pattern 6a is formed on a wafer stage WST, and an illumination light source 7, a glass fiber The illumination optical system including the cable 8 and the like and the detection optical system including the glass fiber cable 8, the light amount detector 9, the half mirror 10, and the like are connected.

Further, oblique incidence focus sensors 11a and 11b for detecting a wafer surface are fixed to the projection optical system PL, and the outputs of these sensors 11a and 11b and the detector 9 are input to the main controller C. The illuminating light output from the illuminating light source 7 is guided to the opening pattern 6a via the cable 8 and emitted upward, and forms a projection image of the opening pattern 6a on the pattern surface of the reticle R via the projection optical system PL. . The projected image can be moved to any position on the pattern of the reticle R by scanning the fiducial plate 6 within the range of the field of view of the projection optical system PL using the wafer stage control unit STG. Can be used to individually determine the focal point.

Further, optical information from the projected image of the pattern surface of the reticle R forms an image on a conjugate plane of the pattern with respect to the projection optical system PL by going back the optical path of the illumination light. At this time,
If the height of the reference surface is in a conjugate positional relationship with respect to the pattern surface and the projection optical system PL, the projected image of the pattern surface becomes clear at the in-focus boundary, and the projected image is reflected on the reference surface by the reflected light. The projected image of FIG. 2 also has a clear in-focus boundary.

Here, since the second projected image has the same shape, the same dimensions, and the same posture as the aperture pattern 6a,
The optical information from the projected image on the pattern surface enters the aperture pattern 6a to the maximum extent, proceeds through the above-described optical system for detection, and
And a peak of the amount of received light is given. On the other hand, when the height of the reference plane is shifted from the conjugate plane of the pattern plane, the reticle R
The projected image of the pattern surface and the second projected image on the reference surface are out of focus and have blurred boundaries. Therefore, the second projected image is incident on the aperture pattern 6a, and the amount of light received by the detector 9 is reduced.

Therefore, wafer stage control unit STG
The wafer stage WST is moved to position the projection image in order at a plurality of locations defined on the pattern surface of the reticle R. At each location, the main controller C causes the wafer stage control unit STG to detect The height of wafer stage WST is adjusted to a height at which a change in light amount is detected, and the height information is accumulated one after another. The optimum tilt angle of wafer stage WST is calculated from the height distribution information thus obtained, and the tilt of wafer stage WST is corrected by wafer stage control unit STG to this angle.

On the other hand, after the inclination is adjusted, the projected image is moved to the center of the pattern surface of the reticle R again, and again.
The height of the wafer stage WST is adjusted and corrected by the wafer stage control unit STG until the height of the fiducial plate 6 reaches the focal point (focus position). Thereafter, the origin adjustment of the oblique incidence focus sensors 11a and 11b is performed using the fiducial plate 6 adjusted to the height of the focal point.

That is, the height of the reflected beam spot on the fiducial plate 6 is stored as the origin, and thereafter, when the field of view of the projection optical system PL is scanned at an arbitrary position on the wafer stage WST, the oblique incidence focus The main controller C measures the exposure surface height of the wafer W based on the heights of the reflected beams and the spots at the sensors 11a and 11b, and sets the wafer stage controller ST so that the height becomes the height of the origin.
G adjusts the height of wafer stage WST.

Next, the projection exposure method according to the present embodiment will be described with reference to the flowchart of FIG.

First, when performing exposure, as shown in FIG. 5, the temperature of the projection optical system PL measured by the temperature sensor TS is observed by the lens controller LC (S).
1). Further, the lens controller LC determines whether the temperature fluctuation is greater than a threshold value (S
2). The threshold value at this time is determined according to the accuracy required for exposure, and in the present embodiment, the exposure accuracy is about 0.
The threshold value of the temperature fluctuation is set to 0.04 ° C., assuming that the focus is about 0.1 μm and the focus is about 0.1 μm.

At this time, if the temperature fluctuation of the projection optical system PL measured by the temperature sensor TS is less than the threshold value, the lens controller LC sets the optical characteristics (projection magnification, wavefront) of the projection optical system PL. An error of aberration, focal position or curvature of field) is not measured, and the main controller C is requested to execute exposure without correcting the error, and exposure is performed in the current state (S3).

If the temperature fluctuation of the projection optical system PL measured by the temperature sensor TS is equal to or larger than a threshold value,
The lens controller LC is provided with a projection optical system PL to the main controller C.
Is required to measure and execute the error of the optical characteristics. Then, the main controller C that has received the execution request measures the non-linear magnification (projection magnification), wavefront aberration, focal position, or field curvature of the projection optical system PL using the projection magnification measurement system PM and the focus measurement system FM. Execute (S4).

Further, the main controller C corrects the errors of the respective optical characteristics based on the measured error results of the optical characteristics of the projection optical system PL (S5). That is, the non-linear magnification error is corrected by driving a part of the lenses in the projection optical system PL, changing the pressure, and the like, and the curvature of field is controlled by the wafer stage WS via the wafer stage control unit STG.
By controlling the operation of the drive mechanism in the Z direction (height direction) within T, the drive mechanism is driven to the measured correction amount position. Further, at the focal position, correction is performed by moving wafer stage WST to the focal point through wafer stage control unit STG by the above-described method.

Therefore, only when a temperature fluctuation equal to or more than a predetermined threshold value occurs in the projection optical system PL, the actual non-linear magnification error, the field curvature or the focal position, etc. are measured, and the error is corrected. The projection optical system P
It is possible to improve exposure accuracy deterioration due to L aberration.
Further, two steps of a step of measuring each optical characteristic and a step of correcting an error thereof can be omitted when the temperature fluctuation does not exceed the threshold value, and the throughput can be improved. . Further, since it is not necessary to measure the temperature-aberration fluctuation characteristic, the burden of the adjustment operation process can be reduced. Then, a transfer step of transferring the pattern of the reticle R to the wafer W is performed by this projection exposure method, so that the transfer accuracy of the pattern is improved, and a semiconductor element can be formed with high accuracy and high productivity. become.

The present invention includes the following embodiments. The application of the exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor, and is, for example, an exposure apparatus for a liquid crystal that exposes a liquid crystal display element pattern to a square glass plate, and an exposure apparatus for manufacturing a thin film magnetic head. Widely applicable to equipment.

In this embodiment, the light source of the exposure apparatus is
g-line (436 nm), i-line (365 nm), KrF excimer laser (248 nm), ArF excimer laser (1
93 nm), an F2 laser (157 nm), or a light source having a shorter wavelength. The magnification of the projection optical system may be not only a reduction system but also an equal magnification and an enlargement system.

As the projection optical system, when far ultraviolet rays such as an excimer laser are used, a material which transmits the far ultraviolet rays such as quartz or fluorite is used as the glass material, and when a F2 laser or X-ray is used, a catadioptric system or a refracting system is used. If the reticle is of a reflection type, an electron optical system including an electron lens and a deflector may be used as the optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

When a linear motor (see US Pat. No. 5,623,853 or US Pat. No. 5,528,118) is used for a wafer stage or a reticle stage, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force is used. You can. The stage may be of a type that moves along a guide or a guideless type that does not have a guide.

The reaction force generated by the movement of the wafer stage may be mechanically released to the floor (ground) using a frame member (as described in US Pat. No. 5,528,118).
The reaction force generated by the movement of the reticle stage is (US S
As described in / N 416558, a frame member may be used to mechanically escape to the floor (ground).

If the transmittance of the optical member disposed between the light source and the substrate fluctuates with respect to the exposure light, irradiation unevenness may occur in the exposure area on the image plane side of the projection optical system. In that case, in order to prevent the influence of irradiation unevenness, the unevenness sensor may be moved in the two-dimensional direction within the exposure area and may be reciprocated. Then, the exposure amount of the exposure light to the exposure area may be controlled based on the representative value or the average value of the measurement results of the unevenness sensor.

As described above, the exposure apparatus of the present embodiment is
Each component (e) recited in the claims of the present application (claims)
It is manufactured by assembling various subsystems including lements) so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. To ensure these various precisions,
Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and adjustments to achieve electrical accuracy for various electrical systems Adjustments are made. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the manufacture of the exposure apparatus be performed in a clean room in which the temperature, cleanliness, and the like are controlled.

For the semiconductor device, a step of designing the function and performance of the device, a step of manufacturing a reticle based on the design step, a step of manufacturing a wafer from a silicon material, and a step of forming a reticle pattern by the exposure apparatus of the above-described embodiment. It is manufactured through a step of exposing a wafer, a device assembling step (including a dicing step, a bonding step, and a package step), an inspection step, and the like.

[0043]

According to the present invention, the following effects can be obtained.
According to the projection exposure method according to the first aspect and the projection exposure apparatus according to the fourth aspect, the temperature of the projection optical system is measured, and when the fluctuation of the temperature does not exceed a preset threshold value, the temperature fluctuation is measured. Exposure is performed without correcting the error in the optical characteristics of the projection optical system, and when the fluctuation exceeds a threshold, exposure is performed after correcting the error. The trouble of previously measuring the fluctuation characteristics becomes unnecessary, and when the fluctuation does not exceed the threshold value, the throughput can be improved by not performing the correction. In addition, the exposure accuracy is not degraded by correcting an error with respect to a large temperature fluctuation in which the fluctuation exceeds a threshold value. That is, it is possible to prevent the exposure accuracy from deteriorating due to the aberration of the projection optical system, and to reduce the adjustment work load of the projection optical system.

According to the projection exposure method of the present invention, since the threshold value is determined according to the precision required for exposure, it is necessary to maintain the minimum required exposure precision in consideration of throughput and the like. Can be.

According to the third aspect of the present invention, the optical characteristic is at least one of a projection magnification, a wavefront aberration, a focal position, and a field curvature. In addition, correction is performed for each of these characteristics that have a significant effect on exposure accuracy, and high exposure accuracy can be obtained.

According to the projection exposure method of the fifth aspect and the projection exposure apparatus of the sixth aspect, the temperature of the projection optical system is measured, and when the temperature fluctuation does not exceed a preset threshold value, The error of the optical characteristic of the projection optical system due to temperature fluctuation is not measured, and when the fluctuation exceeds a threshold value, the error is measured, so that the fluctuation characteristic of the optical aberration with respect to the temperature of the projection optical system is measured in advance. This eliminates the need for time and effort and does not perform measurement when the fluctuation does not exceed the threshold value, thereby improving the throughput.
Further, with respect to a large temperature fluctuation in which the fluctuation exceeds a threshold value, it is possible to accurately correct the temperature by measuring an actual error, thereby improving the exposure accuracy.

According to the device manufacturing method of the seventh aspect, the transfer step is performed by the projection exposure method of any one of the first, second, third, and fifth aspects, so that a semiconductor device, a liquid crystal device, or the like can be used. The transfer accuracy can be improved in the transfer step in the micro device, and the device can be manufactured with high accuracy and high productivity.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram illustrating an exposure apparatus in an embodiment of a projection exposure method, a projection exposure apparatus, and a device manufacturing method according to the present invention, and particularly illustrates a projection magnification measurement system. .

FIG. 2 is a plan view showing a configuration of an aperture shape on an imaging characteristic measuring sensor and a configuration of the imaging characteristic measuring sensor in one embodiment of a projection exposure method, a projection exposure apparatus, and a device manufacturing method according to the present invention. It is sectional drawing.

FIG. 3 is a schematic overall configuration diagram showing an exposure apparatus in an embodiment of a projection exposure method, a projection exposure apparatus, and a device manufacturing method according to the present invention, particularly showing a focus measurement system.

FIG. 4 is a plan view showing a fiducial plate in one embodiment of a projection exposure method, a projection exposure apparatus, and a device manufacturing method according to the present invention.

FIG. 5 is a flowchart illustrating a projection exposure method according to an embodiment of the projection exposure method, the projection exposure apparatus, and the device manufacturing method according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 exposure light source 2 illumination optical system ALG alignment controller C main controller (correction mechanism, measurement mechanism) FM focus measurement system (correction mechanism, measurement mechanism) IL exposure light LC lens controller (control mechanism) PL projection optical system PM projection Magnification measurement system (correction mechanism, measurement mechanism) R reticle (mask) TS temperature sensor W wafer (substrate)

Claims (7)

[Claims] 1. A projection exposure method for transferring a pattern on a mask onto a substrate surface via a projection optical system, wherein a temperature of the projection optical system is measured, and a change in the temperature is set to a predetermined threshold value. If not, exposure is performed without correcting an error in the optical characteristics of the projection optical system due to temperature fluctuation.If the fluctuation exceeds a threshold, exposure is performed after correcting the error. Characteristic projection exposure method. 2. The projection exposure method according to claim 1, wherein said threshold value is determined according to accuracy required for said exposure. 3. The optical characteristics include a projection magnification, a wavefront aberration,
3. The projection exposure method according to claim 1, wherein the projection exposure method is at least one of a focal position and a field curvature. 4. A projection exposure apparatus for transferring a pattern on a mask onto a substrate surface via a projection optical system, comprising: a temperature sensor for measuring a temperature of the projection optical system; A correction mechanism for measuring a characteristic error and correcting the error, and when the temperature fluctuation measured by the temperature sensor does not exceed a preset threshold value, perform exposure without correcting the error, A projection exposure apparatus, comprising: a control mechanism that controls the correction mechanism so as to perform exposure after correcting the error when the fluctuation exceeds a threshold value. 5. A projection exposure method for transferring a pattern on a mask onto a substrate surface via a projection optical system, wherein a temperature of the projection optical system is measured and a change in the temperature is set to a predetermined threshold value. A projection exposure method characterized in that an error in optical characteristics of the projection optical system due to a temperature change is not measured when the difference does not exceed the threshold, and the error is measured when the change exceeds a threshold value. 6. A projection exposure apparatus for transferring a pattern on a mask onto a substrate surface via a projection optical system, comprising: a temperature sensor for measuring a temperature of the projection optical system; A measurement mechanism for measuring a characteristic error, and when the temperature fluctuation measured by the temperature sensor does not exceed a preset threshold, the error is not measured, and when the fluctuation exceeds the threshold, And a control mechanism for controlling the measurement mechanism so as to measure the error. 7. A method of manufacturing a device, which is manufactured through a transfer step of transferring a pattern of a mask to a photosensitive member, wherein the transfer is performed by the projection exposure method according to claim 1, 2, 3, or 5. A method for manufacturing a device, wherein a process is performed.