HK1117271B - Method of adjusting lighting optical device, lighting optical device, exposure system, and exposure method - Google Patents

Description

Method for adjusting illumination optical device, exposure device, and exposure method

Technical Field

The present invention relates to an adjusting method of an illumination optical apparatus, an exposure apparatus, and an exposure method, and more particularly to an illumination optical apparatus suitable for an exposure apparatus or the like used for manufacturing microdevices such as semiconductor devices, imaging devices, liquid crystal display devices, thin film magnetic heads, and the like by an etching process.

Background

In such a typical exposure apparatus, a light beam emitted from a light source passes through a fly-eye lens (or a micro lens array) as a light integrator, and forms a secondary light source as a substantial surface light source composed of a plurality of light sources. The light beam from the secondary light source is condensed by a condenser lens, and then the light beam is superimposed on a mask on which a specific pattern is formed and illuminated.

The light transmitted through the pattern of the mask is imaged on the wafer by the projection optical system. In this way, the mask pattern is projection-exposed (transferred) on the wafer. In addition, the pattern formed on the mask is highly integrated, and it is essential to obtain a uniform illuminance distribution on the wafer in order to accurately transfer the fine pattern onto the wafer. In the past, as exposure light sources, a KrF excimer laser light source that supplies light having a wavelength of 248nm, an ArF excimer laser light source that supplies light having a wavelength of 193nm, and the like have been used.

In a conventional exposure apparatus, light supplied from such a light source is converted into linearly polarized light having a desired polarization direction by a wavelength plate according to a mask pattern, and the mask is illuminated (see, for example, patent document 1). Specifically, in the conventional exposure apparatus described in patent document 1, an 1/4 wavelength plate and a 1/2 wavelength plate made of quartz are disposed in an optical path between a light source and a diffractive optical element (beam conversion element).

[ patent document 1] WO2004/051717 pamphlet

However, it is difficult to accurately manufacture a wave plate such as the 1/4 wave plate or the 1/2 wave plate from 1 crystal plate. If the wavelength plate does not function properly due to a manufacturing error, the mask (and hence the wafer) cannot be illuminated with the desired linearly polarized light, and as a result, good exposure cannot be performed under the desired illumination conditions corresponding to the mask pattern.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to provide an illumination optical device capable of illuminating an irradiated surface with light in a desired polarization state without being substantially affected by manufacturing errors of an optical member functioning as a wavelength plate. It is another object of the present invention to provide an exposure apparatus and an exposure method capable of performing a good exposure under an appropriate illumination condition by using an illumination optical apparatus for illuminating a mask set on an irradiated surface with light in a desired polarization state.

In order to solve the above-described problems, a 1 st aspect of the present invention provides an illumination optical device for illuminating an illumination target surface in a desired polarization state based on light from a light source, the illumination optical device comprising:

a 1 st polarization changing device for locally changing a polarization state of light illuminating the irradiated surface; and

and a 2 nd polarization changing device for locally changing a polarization state at a position on or near a pupil plane of the illumination optical device.

The 2 nd aspect of the present invention provides an illumination optical device for illuminating an illuminated surface with light from a light source, the illumination optical device comprising:

has a polarization conversion element arranged on or near the illumination pupil surface for converting the polarization state of incident light into a specific polarization state,

the polarization conversion element locally changes the polarization state of light at a position on or near the pupil plane of the illumination optical device.

The 3 rd aspect of the present invention provides an illumination optical device for illuminating an illuminated surface with light from a light source, the illumination optical device comprising:

has a polarization conversion element arranged in the vicinity of the surface to be irradiated, at a position optically conjugate with the surface to be irradiated, or in the vicinity of the conjugate position, for converting the polarization state of incident light into a specific polarization state,

the polarization conversion element locally changes the polarization state of the illumination light on the illuminated surface.

The 3 rd aspect of the present invention provides an exposure apparatus, comprising: the illumination optical apparatus according to any one of the embodiments 1 to 3 is included, and a pattern of a mask illuminated by the illumination optical apparatus is exposed on a photosensitive substrate.

The 5 th aspect of the present invention provides an exposure method characterized by: the illumination optical apparatus according to any one of embodiments 1 to 3 exposes a pattern of a mask on a photosensitive substrate.

The 6 th aspect of the present invention provides a device manufacturing method, including:

an exposure step of exposing a pattern of a mask on a photosensitive substrate by using the illumination optical apparatus according to any one of embodiments 1 to 3; and

and a developing step of developing the photosensitive substrate exposed in the exposure step.

The 7 th aspect of the present invention provides an adjustment method for an illumination optical apparatus that illuminates an illuminated surface with light from a light source, the adjustment method comprising:

a first step of preparing a variable phase difference member for variably imparting a phase difference between incident light and emitted light;

a 2 nd step of setting the phase difference given by the variable phase difference member to a specific value; and

and a 3 rd step of disposing the variable phase difference member in an optical path between the light source and the irradiated surface.

An 8 th aspect of the present invention provides an adjustment method for an illumination optical apparatus that illuminates an illuminated surface with light from a light source, the adjustment method including:

a step of locally changing the polarization state of the illumination light on the irradiated surface; and

and a step of locally changing the polarization state of the light at a position on or near the pupil plane of the illumination optical device.

The 10 th aspect of the present invention provides an illumination optical apparatus characterized in that: the adjustment is performed according to the adjustment method of the 7 th or 8 th aspect.

The 10 th aspect of the present invention provides an adjustment method for an exposure apparatus for illuminating a specific pattern with an illumination optical device and exposing the specific pattern on a photosensitive substrate, the adjustment method comprising:

the illumination optical device is adjusted according to the adjustment method of the 7 th or 8 th aspect.

The 11 th aspect of the present invention provides an adjustment method for an exposure system including a 1 st exposure device and a 2 nd exposure device, wherein the 1 st exposure device has a 1 st illumination optical device for illuminating a 1 st pattern on a 1 st mask, and exposes the 1 st pattern of the 1 st mask on a photosensitive substrate, and the 2 nd exposure device has a 2 nd illumination optical device for illuminating a 2 nd pattern on a 2 nd mask, and exposes the 2 nd pattern of the 2 nd mask on the photosensitive substrate, the adjustment method comprising:

the 1 st and 2 nd illumination optical devices are adjusted according to the adjustment method of the 7 th or 8 th aspect.

The 12 th aspect of the present invention provides an exposure system characterized in that: the adjustment is performed according to the adjustment method of the 11 th aspect.

The 13 th aspect of the present invention provides a microdevice manufacturing plant, comprising: a manufacturing apparatus group for various processes including the 1 st exposure apparatus and the 2 nd exposure apparatus of the 12 th aspect, a local network for connecting the manufacturing apparatus group, and a gateway capable of connecting an external network outside a factory from the local network; information on at least 1 of the manufacturing apparatuses can be communicated.

The 14 th aspect of the present invention provides a method for manufacturing a microdevice, comprising: a step of installing a manufacturing apparatus group for various processes including the 1 st exposure apparatus and the 2 nd exposure apparatus according to the 12 th aspect in a microdevice manufacturing plant; and a step of manufacturing the microdevice by using the manufacturing apparatus group through a plurality of processing procedures.

In one aspect of the present invention, since the local polarization state on the pupil plane can be changed, for example, in the case where a pattern arranged on the surface to be irradiated is illuminated and exposure is performed on a photosensitive substrate, the most appropriate illumination condition can be formed. In addition, in another aspect of the present invention, since the local polarization state on the irradiation target surface can be changed, for example, when a pattern arranged on the irradiation target surface is illuminated and exposed on a photosensitive substrate, the in-plane variation in the pattern transfer state can be reduced.

In addition, in another aspect of the present invention, unlike the conventional technique in which a wavelength plate such as an 1/4 wavelength plate and a 1/2 wavelength plate is manufactured using 1 crystal plate, a variable phase difference member that variably imparts a phase difference between incident light and emitted light, such as a soleil compensator (soleil compensator) and a Babinet compensator (Babinet compensator), is used as an optical member that functions as a wavelength plate, and therefore, even if there is a certain degree of manufacturing error in an optical element constituting the variable phase difference member, the optical member can be used after being adjusted so that, for example, a 1/4 wavelength plate and a 1/2 wavelength plate function accurately.

Therefore, in the illumination optical device of the present invention, the mask serving as the irradiation surface can be irradiated with light in a desired polarization state substantially without being affected by manufacturing errors of the optical elements constituting the optical member functioning as the wavelength plate. As a result, in the exposure apparatus and the exposure method of the present invention, it is possible to perform favorable exposure under an appropriate illumination condition by using an illumination optical apparatus that illuminates a pattern set on an irradiated surface with light in a desired polarization state, and further to manufacture favorable microdevices.

Drawings

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

Fig. 2 is a schematic view showing an internal configuration of the polarization state measuring unit shown in fig. 1.

Fig. 3(a) to 3(b) are schematic diagrams showing the structure of each variable retardation member according to the present embodiment.

Fig. 4 is a schematic diagram showing the configuration of an exposure apparatus according to modification 1.

Fig. 5 is a schematic view showing the structure of a variable optical rotation unit according to modification 1.

Fig. 6(a) to 6(b) are schematic diagrams showing the structures of the respective variable optical rotation members constituting the variable optical rotation unit of fig. 5.

FIG. 7 is a diagram showing the optical rotation of a crystal.

Fig. 8 is a schematic view showing an annular secondary light source set to a circumferentially polarized state by the action of the variable optical rotation unit of fig. 5.

Fig. 9 is a schematic view of an annular secondary light source set to a radially polarized state by the action of the variable optical rotation unit of fig. 5.

Fig. 10 is a schematic diagram showing the configuration of the variable phase difference unit according to the present embodiment.

Fig. 11 is a schematic diagram illustrating the operation of the variable phase difference unit of fig. 10.

Fig. 12(a) to 12(b) are schematic views showing the structure of another variable phase difference means according to the present embodiment.

Fig. 13 is a schematic explanatory view showing the operation of the variable phase difference section shown in fig. 12(a) to 12 (b).

Fig. 14(a) to 14(b) are schematic diagrams showing the structure of the variable optical rotation unit according to modification 2.

Fig. 15 is a schematic view showing the configuration of a variable optical rotation unit according to a modification of the example shown in fig. 14(a) to 14 (b).

Fig. 16(a) to 16(c) are schematic diagrams showing the structure of the variable optical rotation/phase shift unit according to modification 3.

Fig. 17(a) shows a multipole secondary light source, and fig. 17(b) shows a positional relationship when a light flux for forming the multipole secondary light source shown in fig. 17(a) is emitted from a phase shifter of a phase shift unit.

Fig. 18 is a schematic diagram showing the operation of the configuration of the pair of aspherical optical rotators according to modification 4.

Fig. 19(a) to 19(d) are schematic diagrams showing examples of optical rotation amount (phase shift amount) distributions applied to a pair of aspherical optical rotators (phase shifters).

Fig. 20(a) to 20(d) are schematic diagrams showing another example of distribution of optical rotation amounts (phase shift amounts) given to a pair of aspherical optical rotators (phase shifters).

Fig. 21 is a schematic diagram showing a modification of 3 aspherical optical rotators (phase shifters) using a distribution of the amount of rotation (phase shift) that differs depending on the incident position.

Fig. 22(a) to 22(c) show cross sections of the on-axis light flux and the off-axis light flux passing through the aspherical optical rotator (phase shifter) in the modification of fig. 21.

Fig. 23 is a schematic flowchart showing steps of the method for adjusting the illumination optical device according to the present embodiment.

Fig. 24 is a schematic flowchart showing the respective steps of the adjustment method according to the modification of the present embodiment.

Fig. 25 is a diagram showing the entire system of the present embodiment separated from a certain angle.

Fig. 26 is a schematic diagram showing the entire system of the present embodiment separated from the perspective of fig. 25.

FIG. 27 is a diagram showing an example of a screen of a user interface provided to a display in the system of FIG. 26.

Fig. 28 a to 28 c are schematic diagrams showing the configuration of an aspherical optical rotator (phase shifter) used for correcting only a primary component (tilt component) of the distribution of the amount of rotation (phase shift).

Fig. 29 is a flowchart of a method for obtaining a semiconductor device as a microdevice.

Fig. 30 is a flowchart showing a method for obtaining a liquid crystal display element as a microdevice.

Detailed Description

Embodiments of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic diagram showing the configuration of an exposure apparatus according to an embodiment of the present invention. In fig. 1, a Z axis is set in a direction normal to a wafer W as a photosensitive substrate, a Y axis is set in a direction parallel to a paper surface of fig. 1 in a plane of the wafer W, and an X axis is set in a direction perpendicular to the paper surface of fig. 1 in the plane of the wafer W.

Referring to fig. 1, the exposure apparatus of the present embodiment includes a light source 1 for supplying exposure light (illumination light). As the light source 1, for example, an ArF excimer laser light source which supplies light having a wavelength of 193nm, a KrF excimer laser light source which supplies light having a wavelength of 248nm, or the like can be used. The light emitted from the light source 1 is expanded into a light beam having a desired cross-sectional shape by the shaping optical system 2, passes through the 1 st variable phase difference member 3 functioning as an 1/4 wavelength plate, the 2 nd variable phase difference member 4 functioning as a 1/2 wavelength plate, the depolarizer (non-polarizing element) 5, the diffractive optical element 6 for annular-band illumination, and enters the afocallens (afocallens) 7.

The 1 st variable retardation member 3, the 2 nd variable retardation member 4, and the depolarizer 5 constitute a polarization state switching device as will be described later, and the configuration and operation thereof will be described later. The afocal lens 7 is an afocal optical system (afocal system) that is set so that the front focal position of the front lens group 7a substantially coincides with the position of the diffractive optical element 6 and the rear focal position of the rear lens group 7b substantially coincides with the position of the specific surface 8 indicated by a broken line in the figure. In general, a diffractive optical element is configured by forming a step difference having a pitch of the order of the wavelength of exposure light (illumination light) on a substrate, and has an action of diffracting an incident beam at a desired angle.

Specifically, the diffractive optical element 6 for annular illumination has a function of forming an annular light intensity distribution in a far field (or a Fraunhofer diffraction (Fraunhofer diffraction) region) when a parallel light beam having a rectangular cross section is incident. Therefore, the substantially parallel light beams incident on the diffractive optical element 6 as the light beam conversion element form an annular light intensity distribution on the pupil surface of the afocal lens 7, and then exit the afocal lens 7 with an annular angular distribution. In the optical path between the front lens group 7a and the rear lens group 7b of the afocal lens 7, a variable phase difference unit 9 and a conical axicon system 10 are arranged on the pupil surface or in the vicinity thereof. The configuration and operation of the variable phase difference unit 9 and the axicon system 10 will be described later.

The light flux having passed through the afocal lens 7 passes through a variable focal length lens (zoom lens)11 and a variable optical rotation unit 12 for varying a σ value (σ value, which is a mask-side aperture of the illumination optical device/a mask-side aperture of the projection optical system), and enters a micro fly-eye lens (or fly-eye lens) 13. The configuration and operation of the variable optical rotation unit 12 will be described later. The micro fly-eye lens 13 is an optical element composed of a plurality of fine lenses having positive refractive power arranged in a vertically and horizontally dense manner. In general, a micro fly-eye lens is constructed by, for example, subjecting a parallel plane plate to an etching process to form a micro lens group.

Here, each microlens constituting the micro fly-eye lens is smaller than each lens element constituting the fly-eye lens. In addition, unlike a fly-eye lens formed of lens elements isolated from each other, a micro fly-eye lens is integrally formed with a plurality of micro lenses (micro refractive surfaces) without being isolated from each other. However, the micro fly-eye lens is a wavefront-dividing type light integrator similar to the fly-eye lens in that the lens elements having positive refractive power are arranged vertically and horizontally.

The position of the specific surface 8 is arranged in the vicinity of the front focal position of the variable focal length lens 11, and the incident surface of the micro fly-eye lens 13 is arranged in the vicinity of the rear focal position of the variable focal length lens 11. In other words, the variable focal length lens 11 has the specific surface 8 and the incident surface of the micro fly-eye lens 13 arranged substantially in a fourier transform relationship, and further has the pupil surface of the afocal lens 7 and the incident surface of the micro fly-eye lens 13 arranged substantially in a conjugate optically. The variable optical rotation unit 12 is disposed slightly in front of the micro fly's eye lens 13, and is further disposed substantially optically conjugate to the pupil plane (pupil face) of the afocal lens 7.

Therefore, an annular illumination region centered on the optical axis AX is formed on the entrance surface of the micro fly-eye lens 13, similarly to the pupil surface of the afocal lens 7. The overall shape of the annular illumination region is similarly varied depending on the focal length of the variable focusing lens 11. Each microlens constituting the micro fly-eye lens 13 has a rectangular cross section similar to the shape of the illumination region to be formed on the mask M (and further, the shape of the exposure region to be formed on the wafer W).

The light flux incident on the micro fly-eye lens 13 is two-dimensionally divided by a plurality of micro lenses, and forms a secondary light source having substantially the same light intensity distribution as that of the illumination region formed by the incident light flux, that is, a secondary light source formed by a substantially annular surface light source centered on the optical axis AX, on the rear focal plane or in the vicinity thereof (and further, the illumination pupil). The light beam emitted from the secondary light source formed on the rear focal plane of the micro fly-eye lens 13 or in the vicinity thereof passes through the beam splitter 14a and the condensing optical system 15, and then, is superimposed on the mask shade 16 for illumination. The structure and operation of the polarization monitor 14 incorporating the spectroscope 14a will be described later.

In this way, a rectangular illumination area corresponding to the shape and focal length of each microlens constituting the micro fly-eye lens 13 is formed on the mask shade 16 as an illumination field stop. The light flux having passed through the rectangular aperture portion (light transmitting portion) of the mask curtain 16 receives the light converging action of the imaging optical system 17, and then superposes and illuminates the mask M on which the specific pattern is formed. That is, the imaging optical system 17 forms an image of the rectangular aperture portion of the mask curtain 16 on the mask M.

The light beam having passed through the pattern of the mask M held on the mask stage MS forms an image of the mask pattern on the wafer (photosensitive substrate) W held on the wafer stage WS by the projection optical system PL. In this way, the pattern of the mask M is sequentially exposed on each exposure area of the wafer W by performing the two-dimensional drive control of the wafer WS and the two-dimensional drive control of the wafer W in the plane (XY plane) orthogonal to the optical axis AX of the projection optical system PL, and performing the integral exposure or the scanning exposure.

Further, 4-pole illumination can be performed by setting a diffractive optical element (not shown) for 4-pole illumination in the illumination optical path instead of the diffractive optical element 6 for annular illumination. The 4-pole diffractive optical element for illumination has a function of forming a 4-pole light intensity distribution in a far field thereof when a parallel light beam having a rectangular cross section is incident thereon. Therefore, the light flux having passed through the diffractive optical element for 4-pole illumination forms a 4-pole illumination area, which is composed of 4 circular illumination areas centered on the optical axis AX, for example, on the incident surface of the micro fly-eye lens 13. As a result, the same 4-pole secondary light source as the illumination area formed on the incident surface thereof is also formed on the rear focal plane of the micro fly-eye lens 13 or in the vicinity thereof.

Further, by setting a diffractive optical element (not shown) for circular illumination in the illumination optical path instead of the diffractive optical element 6 for annular illumination, normal circular illumination can be performed. When a parallel light beam having a rectangular cross section is incident, the diffractive optical element for circular illumination has a function of forming a circular light intensity distribution in its far field. Therefore, the light flux passing through the circular illumination diffractive optical element forms a circular illumination area centered on the optical axis AX, for example, on the incident surface of the micro fly-eye lens 13. As a result, a circular secondary light source having the same illumination area as that formed on the incident surface thereof is also formed on the rear focal plane of the micro fly-eye lens 13 or its vicinity.

In addition, by setting a diffractive optical element (not shown) for multipole illumination in place of the diffractive optical element 6 for annular illumination in the illumination optical path, various multipole illuminations (2-pole illumination, 8-pole illumination, and the like) can be performed. Similarly, by setting a diffractive optical element (not shown) having appropriate characteristics in the illumination optical path instead of the diffractive optical element 6 for annular illumination, various forms of anamorphic illumination can be performed.

The axicon prism system 10 is constituted by, in order from the light source side, a 1 st prism member 10a having a plane facing the light source side and a concave conical refractive surface facing the mask side, and a 2 nd prism member 10b having a plane facing the mask side and a convex conical refractive surface facing the light source side. Further, the concave conical refractive surface of the 1 st prism member 10a and the convex conical refractive surface of the 2 nd prism member 10b are formed complementarily so as to be abuttable with each other. At least one of the 1 st prism member 10a and the 2 nd prism member 10b is configured to be movable along the optical axis AX, and the 1 st prism member 10a and the 2 nd prism member 10b are configured to have a variable interval between the concave conical refraction surface and the convex conical refraction surface. Next, the operation of the axicon system 10 and the operation of the variable focal length lens 11 will be described with attention paid to the annular band-shaped or 4-pole secondary light source.

Here, in a state where the concave conical refraction surface of the 1 st prism member 10a and the convex conical refraction surface of the 2 nd prism member 10b are in contact with each other, the axicon prism system 10 functions as a parallel plane plate, and does not affect the formed annular or 4-pole secondary light source. However, when the concave conical refraction surface of the 1 st prism member 10a and the convex conical refraction surface of the 2 nd prism member 10b are separated, the outer diameter (inner diameter) of the annular or 4-pole secondary light source is changed while maintaining the width of the annular or 4-pole secondary light source constant (1/2 for the difference between the outer diameter and the inner diameter of the annular secondary light source; 1/2 for the difference between the diameter (outer diameter) of the circle circumscribing the 4-pole secondary light source and the diameter (inner diameter) of the circle inscribed therein). That is, the annulus ratio (inner diameter/outer diameter) and the size (outer diameter) of the annular band-shaped or 4-pole-shaped secondary light source are changed.

The variable focal length lens 11 has a function of expanding or contracting the overall shape of the annular band-shaped or 4-pole-shaped secondary light source in a similar manner. For example, the focal length of the variable focal length lens 11 is increased from a minimum value to a specific value, whereby the overall shape of the annular band-shaped or 4-pole-shaped secondary light source is similarly increased. In other words, the variable focal length lens 11 is used to change the width and size (outer diameter) of the annular band-shaped or 4-pole secondary light source without changing the annular band ratio. In this way, the ring-to-band ratio and the size (outer diameter) of the annular band-shaped or 4-pole-shaped secondary light source can be controlled by the action of the axicon system 10 and the variable focal length lens 11.

The polarization monitor 14 includes a beam splitter 14a disposed in an optical path between the micro fly-eye lens 13 and the condensing optical system 15, and has a function of detecting a polarization state of incident light to the beam splitter 14 a. In other words, it is possible to detect whether or not the illumination light to the mask M (and hence the wafer W) reaches a desired polarization state (including a non-polarization state) at any time based on the detection result of the polarization monitor 14.

Fig. 2 is a schematic view showing an internal configuration of the polarization state measuring unit shown in fig. 1. In the present embodiment, as shown in fig. 2, a polarization state measurement unit 18 for measuring the polarization state of illumination light (exposure light) with respect to the wafer W is provided on the wafer stage WS for holding the wafer W. The polarization state measuring unit 18 includes a pinhole member 40 that is positioned two-dimensionally at a height position of the exposure surface of the wafer W. In addition, when the polarization state measuring unit 18 is used, the wafer W is retracted from the optical path.

The light having passed through the pinhole 40a of the pinhole member 40 is formed into a substantially parallel light flux by the collimator lens 41, reflected by the mirror 42, and then enters the relay lens system 43. The substantially parallel light flux having passed through the relay lens system 43 passes through a λ/4 plate 44 as a phase shifter and a polarization beam splitter 45 as a polarizer, and then reaches a detection surface 46a of a two-dimensional CCD 46. The output of the two-dimensional CCD 46 is supplied to a control unit (not shown). Here, the λ/4 plate 44 is configured to be rotatable about the optical axis, and a setting unit 47 for setting a rotation angle about the optical axis is connected to the λ/4 plate 44.

In this way, when the polarization degree of the illumination light with respect to the wafer W is not 0, the setting unit 47 rotates the λ/4 plate 44 around the optical axis, thereby changing the light intensity distribution on the detection surface 46a of the two-dimensional CCD 46. Therefore, the polarization state measuring unit 48 can rotate the λ/4 plate 44 around the optical axis by the setting unit 47, detect the change in the light intensity distribution on the detection surface 46a, and measure the polarization state (polarization degree; Stackers parameters for light S1, S2, S3) of the illumination light by the rotary phase shifter method from the detection result.

The rotary phase shifter method is described in detail in, for example, mitsubishi, "pencil of light-applied optics for optical technologists", new technology communications corporation, and the like. In practice, the pinhole member 40 (and hence the pinhole 40a) is moved two-dimensionally along the wafer surface, and the polarization state of the illumination light at a plurality of positions in the wafer surface is measured. At this time, since the polarization state measuring unit 18 detects a change in the light intensity distribution on the two-dimensional detection surface 46a, the distribution of the polarization state of the illumination light in the pupil can be measured based on the detection distribution information.

However, in the polarization state measurement unit 18, a λ/2 plate may be used instead of the/4 plate 44 as the phase shifter. In order to measure the polarization state of light, i.e., 4 schotter parameters of light, using either of the phase shifters, it is necessary to detect changes in the light intensity distribution on the detection surface 46a in at least 4 different states by changing the relative angle between the phase shifter and the polarizer (polarizing beam splitter 45) around the optical axis or by retracting the phase shifter or the polarizer from the optical path.

In the present embodiment, the λ/4 plate 44 as a phase shifter is rotated around the optical axis, but the polarization beam splitter 45 as a polarizer may be rotated around the optical axis, or both the phase shifter and the polarizer may be rotated around the optical axis. Instead of or in addition to this operation, one or both of the λ/4 plate 44 as a phase shifter and the polarizing beam splitter 45 as a polarizer may be inserted and removed from the optical path.

In the polarization state measurement unit 18, the polarization state of light may change depending on the polarization characteristics of the mirror 42. In this case, since the polarization characteristics of the mirror 42 are known in advance, the measurement result of the polarization state measurement unit 18 can be corrected based on the influence of the polarization characteristics of the mirror 42 on the polarization state by necessary calculation, and the polarization state of the illumination light can be accurately measured. Further, not only the mirror, but also the measurement result may be corrected in the same manner and the polarization state of the illumination light may be accurately measured when the polarization state is changed by another optical member such as a lens.

In this way, the polarization state measuring unit 18 measures the polarization state (polarization degree) of the illumination light to the wafer W in the pupil, and determines whether or not the illumination light reaches an appropriate polarization state in the pupil. In the above-described embodiment, the polarization state measurement unit 18 is shown as being attachable to the wafer stage WS, but the polarization state measurement unit 18 may be incorporated into the wafer stage WS or into a stage different from the wafer stage WS.

Fig. 3(a) to 3(b) are schematic diagrams showing the structure of each variable retardation member according to the present embodiment. In the present embodiment, the 1 st variable retardation member 3 and the 2 nd variable retardation member 4 are respectively configured as a solor compensator shown in fig. 3(a) or a babonet compensator shown in fig. 3 (b). The cord-lag compensator shown in fig. 3(a) is composed of a parallel plane plate 21a and a pair of angle-deflecting prisms 21b and 21c in this order from the light incident side.

Here, the parallel plane plate 21a, the 1 st deflection angle prism 21b, and the 2 nd deflection angle prism 21c are formed of crystal, which is a crystal material having birefringence. Further, the 1 st and 2 nd off-angle prisms 21b and 21c have wedge cross-sectional shapes complementary to each other. Further, the crystal optical axis of the parallel plane plate 21a and the crystal optical axes of the pair of deflection prisms 21b and 21c are set to be orthogonal to each other.

Further, a configuration is adopted in which the 1 st and 2 nd deflection prisms 21b, 21c are relatively moved in the Z direction, or the 1 st and 2 nd deflection prisms 21b, 21c are relatively moved in the direction of the intersecting line of the opposing inclined surface and the YZ plane, by a driving device (not shown) such as a micrometer head, for example. In the cord-accumulation compensators (21a to 21c) shown in fig. 3(a), a certain phase difference is variably given between incident light and emitted light depending on the relative positions of the 1 st deflection angle prism 21b and the 2 nd deflection angle prism 21c, regardless of the incident position of light.

On the other hand, the baviner compensator shown in fig. 3(b) is composed of a 1 st deflection prism 22a and a 2 nd deflection prism 22b in this order from the light incidence side. Here, the 1 st deflection prism 22a and the 2 nd deflection prism 22b are formed of crystal, which is a crystal material having birefringence, and have wedge-shaped cross-sectional shapes complementary to each other. The crystal optical axis of the 1 st deflection angle prism 22a and the crystal optical axis of the 2 nd deflection angle prism 22b are set so as to be orthogonal to each other.

Further, a configuration is adopted in which the 1 st deflection angle prism 22a and the 2 nd deflection angle prism 22b are relatively moved in the Z direction, or the 1 st deflection angle prism 22a and the 2 nd deflection angle prism 22b are relatively moved in the direction of the intersecting line of the opposing inclined surface and the YZ plane, by a driving device (not shown) such as a micrometer head, for example. In the cord-accumulation compensators (22a, 22b) shown in fig. 3(b), although depending to some extent on the incident position of light in the Z direction, a substantially constant phase difference is variably imparted between the incident light and the emitted light depending on the relative positions of the 1 st deflection angle prism 22a and the 2 nd deflection angle prism 22 b.

In the present embodiment, before mounting to the exposure apparatus, the phase difference between the incident light and the emitted light is measured by giving the phase difference between the incident light and the emitted light to the 1 st variable retardation member 3 alone, and the phase difference is 1/4 of the wavelength λ of the light, and even if the 1 st variable retardation member 3 functions correctly as a 1/4 wavelength plate, adjustment is performed in advance. Similarly, before mounting the exposure apparatus, the phase difference between the incident light and the outgoing light provided by the 2 nd variable retardation member 4 alone is measured, and the phase difference is adjusted in advance to 1/2 of the wavelength λ of the light, even if the 2 nd variable retardation member 4 functions correctly as a 1/2 wavelength plate.

Next, the 1 st variable phase difference member 3 that functions correctly as an 1/4 wavelength plate and is adjusted and the 2 nd variable phase difference member 4 that functions correctly as a 1/2 wavelength plate are positioned at specific positions on the optical path between the shaping optical system 2 and the depolarizer 5, and are set so as to be integrally rotatable about the optical axis AX. In this way, the 1 st variable phase difference member 3 as an 1/4 wavelength plate is configured to be rotatable about the optical axis AX, and converts incident elliptically polarized light into linearly polarized light. The 2 nd variable retardation member 4 as an 1/2 wavelength plate is configured to be rotatable about the optical axis AX, and changes the polarization direction of incident linearly polarized light.

On the other hand, the depolarizer 5 is a prism assembly formed by a crystal deflection angle prism having a wedge shape and a fluorite deflection angle prism (or a quartz deflection angle prism) having a wedge shape, which are complementary to each other, and is configured to be freely insertable into and removable from the illumination optical path. Further, for the detailed configuration and operation of the depolarizer 5, for example, international patent publication No. WO2004/051717 can be referred to.

When a KrF excimer laser light source and an ArF excimer laser light source are used as the light source 1, the light emitted from these light sources typically has a polarization degree of 95% or more, and substantially linearly polarized light enters the 1 st variable retardation member 3. However, if a right-angled prism as a back surface reflector is present in the optical path between the light source 1 and the 1 st variable phase difference member 3, if the polarization plane of the incident linearly polarized light does not coincide with the P-polarization plane or the S-polarization plane, the linearly polarized light is converted into elliptically polarized light by total reflection of the right-angled prism.

In the polarization state conversion devices (3-5), even if elliptically polarized light is incident due to, for example, total reflection by a rectangular prism, the 1 st variable phase difference member 3 as an 1/4 wavelength plate is set at a specific angular position around the optical axis AX with respect to the incident elliptically polarized light, and the elliptically polarized incident light is converted into linearly polarized light and guided to the 2 nd variable phase difference member 4. Then, by setting the 2 nd variable phase difference member 4 as an 1/2 wavelength plate at a desired angular position around the optical axis AX with respect to the incident linearly polarized light, the linearly polarized incident light is converted into linearly polarized light having a polarization direction in a desired direction, and is directly guided to the depolarizer 5 or the diffractive optical element 6.

Then, the depolarizer 5 is inserted into the illumination optical path, and the depolarizer 5 is set at a specific angular position around the optical axis AX with respect to the incident linearly polarized light, so that the linearly polarized incident light is converted into light in an unpolarized state (unpolarized) and enters the diffractive optical element 6. On the other hand, when the depolarizer 5 is removed from the illumination optical path, the linearly polarized light from the 2 nd variable retardation member 4 is directly incident on the diffractive optical element 6 without changing the polarization direction.

In this way, in the polarization state switching devices (3 to 5), the depolarizer 5 can be retracted from the illumination light path, and the 1 st variable phase difference member 3 as the 1/4 wavelength plate and the 2 nd variable phase difference member 4 as the 1/2 wavelength plate are set at specific angular positions around the optical axis AX, respectively, so that linearly polarized light having a polarization direction in a desired direction is incident on the diffractive optical element 6. The 1 st variable phase difference member 3 as an 1/4 wavelength plate and the 2 nd variable phase difference member 4 as an 1/2 wavelength plate are set at specific angular positions around the optical axis AX, respectively, and the depolarizer 5 is inserted into the illumination optical path and set at specific angular positions around the optical axis AX, respectively, so that the unpolarized light is incident on the diffractive optical element 6.

In other words, in the polarization state switching devices (3 to 5), the polarization state of the incident light to the diffractive optical element 6 (and further, the polarization state of the light illuminating the mask M and the wafer W) can be switched between the linearly polarized state and the unpolarized state. Also, in the case of the linearly polarized state, it is possible to switch between, for example, polarized states orthogonal to each other (between the Z-direction polarized light and the X-direction polarized light).

As described above, in the present embodiment, unlike the conventional technique in which wavelength plates such as the 1/4 wavelength plate and the 1/2 wavelength plate are manufactured using 1 crystal plate, the variable phase difference members (3, 4) that variably impart a phase difference between incident light and emitted light, such as the soley compensator and the babonet compensator, are used as optical members that exhibit the functions of wavelength plates such as the 1/4 wavelength plate and the 1/2 wavelength plate. Therefore, even if there is a certain degree of manufacturing error in the optical elements (the parallel plane plate and the deflection prism) constituting the variable retardation members (3, 4), the optical elements can be adjusted to function correctly as the 1/4 wavelength plate and the 1/2 wavelength plate, and then applied.

Therefore, in the illumination optical devices (1-17) of the present embodiment, the mask M, which is the surface to be illuminated, can be illuminated with light in a desired polarization state without being substantially affected by manufacturing errors of the optical elements (21 a-21 c; 22a, 22b) constituting the optical members (3, 4) functioning as wavelength plates. As a result, in the exposure apparatuses (1 to WS) of the present embodiment, favorable exposure can be performed under appropriate illumination conditions by the illumination optical apparatuses (1 to 17) that illuminate the mask M set on the surface to be illuminated with light in a desired polarization state.

In the above description, the phase difference caused by the variable phase difference members (3, 4) alone is measured, and the phase difference is adjusted in advance so as to have a specific value (1/4 or 1/2 of the wavelength λ of light), and the variable phase difference members (3, 4) are incorporated into the illumination light path. However, the present invention is not limited to this, and the variable retardation members (3, 4) may be adjusted so as to function accurately as the 1/4 wavelength plate and the 1/2 wavelength plate, respectively, based on the measurement result of the polarization state measuring unit 18 after the variable retardation members (3, 4) are incorporated into the illumination optical path, as shown in the modification 1 of fig. 4. Further, the variable retardation members (3, 4) can be more actively fine-adjusted from the state of being adjusted to function correctly as the 1/4 wavelength plate and the 1/2 wavelength plate, so that the mask M, which is the surface to be irradiated, and further the wafer W can be illuminated with light in a plurality of polarization states.

In fig. 4, the control unit CR receives the measurement result from the polarization state measurement unit 18, controls the driving unit DR3 for changing the relative positions between the optical elements (21a to 21 c; 22a, 22b) in the variable retardation members (3, 4), and adjusts the amount of phase difference formed by the variable retardation members (3, 4) so that the polarization state on the mask M or the wafer W as the surface to be irradiated is in a desired state.

In the above description, the optical elements constituting the variable retardation members (3, 4) are formed of crystal, but the present invention is not limited thereto, and the optical elements of the variable retardation members (3, 4) may be formed of a birefringent crystal material such as magnesium fluoride and calcite.

Fig. 5 is a schematic view showing the structure of the variable optical rotation unit according to the present embodiment. Fig. 6(a) to 6(b) are schematic diagrams showing the structures of the respective variable optical rotation members constituting the variable optical rotation unit of fig. 5. The variable optical rotation unit 12 according to the present embodiment is disposed slightly in front of the micro fly's eye lens 13, that is, at or near the pupil of the illumination optical system (2 to 17). Therefore, in the case of the annular illumination, a light beam having a substantially annular cross section centered on the optical axis AX can be incident on the variable optical rotation unit 12.

Referring to fig. 5, the variable optical rotation unit 12 is composed of 8 variable optical rotation members 12a, 12b, 12c, 12d, 12e, 12f, 12g, and 12h arranged in the circumferential direction of a circle centered on the optical axis AX. Each of the variable optical rotation members 12a to 12h has a fan-shaped outer shape obtained by dividing an annular band-shaped region centered on the optical axis AX by 8 times in the circumferential direction, and has the same basic configuration as each other. Referring to fig. 6(a) to 6(b), each of the optically variable members 12a to 12h is constituted by a pair of deflection prisms 23a and 23b formed of crystal as an optical material having optical rotation.

The 1 st deflection prism 23a and the 2 nd deflection prism 23b have wedge-shaped cross-sectional shapes complementary to each other, and the crystal optical axis of the 1 st deflection prism 23a and the crystal optical axis of the 2 nd deflection prism 23b are both arranged parallel to the optical axis AX (i.e., parallel to the Y direction). Further, a configuration is adopted in which the 1 st and 2 nd deflection prisms 23a and 23b are relatively moved in a diameter direction of a circle centered on the optical axis AX, or the 1 st and 2 nd deflection prisms 23a and 23b are relatively moved in an intersecting line direction of opposing inclined surfaces and a plane including the optical axis AX, by a driving device (not shown) such as a micrometer head, for example.

In this way, in the variable optical rotation members 12a to 12h shown in fig. 6(a) to 6(b), the rotation angle is variably given to the incident linearly polarized light depending on the relative positions of the 1 st deflection angle prism 23a and the 2 nd deflection angle prism 23 b. Hereinafter, the optical rotation of the crystal will be briefly described with reference to FIG. 7. Referring to fig. 7, a parallel-plane plate-like optical member 100 made of quartz crystal having a thickness d is disposed so that its crystal optical axis coincides with the optical axis AX. In this case, the incident linearly polarized light is emitted in a state where the polarization direction is rotated by θ around the optical axis AX by the optical rotation of the optical member 100.

In this case, the rotation angle θ of the polarization direction due to the optical rotation of the optical member 100 can be represented by the thickness d of the optical member 100 and the optical rotation energy ρ of the crystal, as shown in the following formula (a).

θ＝d·ρ (a)

In general, the optical rotation energy ρ of crystal has wavelength dependence (property of optical rotation energy values differing depending on the wavelength of light used: optical dispersion), and specifically, tends to increase as the wavelength of light used becomes shorter. The optical rotation energy ρ of the crystal with respect to light having a wavelength of 250.3nm is 153.9 degrees/mm as described on page 167 of "applied optics II".

Fig. 8 is a schematic view showing an annular secondary light source set to a polarization state in the circumferential direction by the action of the variable optical rotation unit of fig. 5. In the present embodiment, when linearly polarized light having a polarization direction in the Z direction is incident on the variable optical rotation members 12a and 12e facing each other with the optical axis AX interposed therebetween, the relative positions of the 1 st deflection angle prism 23a and the 2 nd deflection angle prism 23b are set so as to emit linearly polarized light having a polarization direction in the X direction, which is a direction in which the Z direction is rotated by +90 degrees around the Y axis. Therefore, in this case, in the annular secondary light source 31 shown in fig. 8, the polarization direction of the light beams in the pair of fan-shaped regions (or circular arc-shaped regions) 31a and 31e formed by the light beams subjected to the optical rotation action of the variable optical rotation members 12a and 12e forms the X direction.

When linearly polarized light having a polarization direction in the Z direction is incident, the relative positions of the 1 st deflection prism 23a and the 2 nd deflection prism 23b are set so as to emit linearly polarized light having a polarization direction in a direction in which the Z direction is rotated by +135 degrees around the Y axis, even in a direction in which the Z direction is rotated by-45 degrees around the Y axis. Therefore, in this case, in the annular secondary light source 31 shown in fig. 8, the polarization direction of the light beams in the pair of sector-shaped regions 31b and 31f formed by the light beams subjected to the optical rotation action of the variable optical rotation members 12b and 12f forms a direction in which the Z direction is rotated by-45 degrees around the Y axis.

When linearly polarized light having a polarization direction in the Z direction is incident, the relative positions of the 1 st deflection prism 23a and the 2 nd deflection prism 23b are set so as to emit linearly polarized light having a polarization direction in a direction of rotating the Z direction by +180 degrees around the Y axis, that is, in the X direction. Therefore, in this case, in the annular secondary light source 31 shown in fig. 8, the Z direction is formed by the polarization direction of the light beams in the pair of fan-shaped regions 31c and 31g formed by the light beams subjected to the optical rotation action of the variable optical rotation members 12c and 12 g.

When linearly polarized light having a polarization direction in the Z direction is incident, the relative positions of the 1 st deflection prism 23a and the 2 nd deflection prism 23b are set so as to emit linearly polarized light having a polarization direction in a direction in which the Z direction is rotated by +45 degrees around the Y axis, by the variable optical rotation members 12d and 12h facing each other with the optical axis AX interposed therebetween. Therefore, in this case, in the annular secondary light source 31 shown in fig. 8, the polarization direction of the light beams in the pair of fan-shaped regions 31d and 31h formed by the light beams subjected to the optical rotation action of the variable optical rotation members 12d and 12h forms a direction in which the Z direction is rotated by +45 degrees around the Y axis.

In this way, the variable optical rotation unit 12 is disposed on or near the illumination pupil surface, and constitutes a polarization conversion element for converting the polarization state of incident light into a specific polarization state. In the present embodiment, in order to perform normal circular illumination without retracting the variable optical rotation unit 12 from the optical path, a circular central region 12j having a radial dimension of the effective region of the variable optical rotation unit 12 of not less than 3/10, preferably not less than 1/3, and having no optical rotation is provided. Here, the central region 12j may be formed of an optical material having no optical rotation, such as quartz or fluorite, or may simply have a circular aperture. However, the central region 12j is not an essential element for the variable optical rotation unit 12.

In the case of circumferential polarization annular illumination (deformed illumination in which the light beam passing through the annular secondary light source is set to the circumferential polarization state) in the present embodiment, the linearly polarized light having the polarization direction in the Z direction is incident on the variable optical rotation unit 12 by the action of the polarization state switching devices (3 to 5). As a result, an annular secondary light source (annular illumination pupil distribution) 31 is formed on the rear focal plane of the micro fly-eye lens 13 or in the vicinity thereof as shown in fig. 8, and the light beam passing through the annular secondary light source 31 is set to a polarization state in the circumferential direction by the action of the variable optical rotation unit 12. In the circularly polarized state, the light fluxes passing through the fan-shaped regions 31a to 31h constituting the annular secondary light source 31 form a linearly polarized state having a polarization direction substantially coincident with a tangential direction of a circle centered on the optical axis AX at a central position in the circumferential direction of each of the fan-shaped regions 31a to 31 h.

In this way, in the present embodiment, the annular secondary light source (illumination pupil distribution) 31 in the circumferentially polarized state can be formed by the optical rotation action of the variable optical rotation unit 12 without substantially causing a loss of light amount. In the circumferential polarization zone illumination based on the annular illumination pupil distribution in the circumferential polarization state, the light irradiated on the wafer W as the final irradiated surface forms a polarization state having S-polarized light as the main component. Here, the S-polarization refers to a linear polarization having a polarization direction in a direction perpendicular to the incident surface (a polarization in which an electric vector vibrates in a direction perpendicular to the incident surface). However, the incidence plane is defined as a plane including a normal line of the boundary plane at the point and the incidence direction of light when the light reaches the boundary plane (irradiated surface: surface of the wafer W) of the medium.

As a result, in the circumferential polarized zone illumination, the optical performance (e.g., depth of focus) of the projection optical system PL can be improved, and a mask pattern image with high contrast can be obtained on the wafer (photosensitive substrate) W. That is, in the exposure apparatus of the present embodiment, since the illumination optical apparatus is used which can favorably suppress the loss of the light amount and form the annular illumination pupil distribution in the polarization state in the circumferential direction, the fine pattern can be transferred faithfully and with high productivity under the appropriate illumination condition.

In the present embodiment, the linearly polarized light having the polarization direction in the X direction is incident on the variable optical rotation unit 12 by the action of the polarization state switching devices (3 to 5), and as shown in fig. 9, the light beam passing through the annular secondary light source 32 is set to the radial polarization state, and the radial polarized annular illumination (the deformed illumination in which the light beam passing through the annular secondary light source 32 is set to the radial polarization state) is performed. In the radially polarized state, the light fluxes passing through the fan-shaped regions 32a to 32h constituting the annular secondary light source 32 form a linearly polarized state having a polarization direction substantially coincident with a radial direction of a circle centered on the optical axis AX at a central position along the circumferential direction of the fan-shaped regions 32a to 32 h.

In the radial polarized zone illumination based on the annular illumination pupil distribution in the radial polarized state, the light irradiated on the wafer W as the final irradiated surface is in the polarized state having P-polarized light as the main component. Here, the P-polarized light refers to a linearly polarized light having a polarization direction in a direction parallel to the incident surface defined as described above (a polarized light in which an electric vector is vibrated in a direction parallel to the incident surface). As a result, in the radial polarized zone illumination, the light reflectance of the photoresist applied to the wafer W can be suppressed to be small, and a good mask pattern image can be obtained on the wafer (photosensitive substrate) W.

However, the present applicant has proposed, for example, in WO2005/076045 pamphlet of the international patent, a configuration in which a plurality of types of crystal plates having different thicknesses (lengths in the optical axis direction) in the light transmission direction are arranged as optical rotation members in the circumferential direction as polarization conversion elements arranged on or near the illumination pupil surface to convert the polarization state of incident light into a specific polarization state. In the polarization conversion element proposed in the above application, it is difficult to accurately manufacture 1 crystal plate from each optically active member for imparting a desired angle of polarization to incident linearly polarized light. When the respective optically active members function incorrectly due to manufacturing errors, the desired circumferential polarization state and radial polarization state cannot be achieved.

In contrast, in the present embodiment, the variable optical rotation unit 12 as a polarization conversion element is configured by a plurality of variable optical rotation members 12a to 12h that variably impart a rotation angle to linearly polarized light incident in accordance with the relative positions of the 1 st and 2 nd deflection prisms 23a and 23 b. Therefore, even if there is a certain degree of manufacturing error in the optical elements (a pair of deflection prisms) constituting the respective variable optical rotation members 12a to 12h, the respective variable optical rotation members 12a to 12h can be adjusted to function accurately as optical members for providing a desired rotation angle, and then the variable optical rotation unit 12 can be reused.

Specifically, before mounting the variable optical rotation unit 12 on the exposure apparatus, the optical rotation angles formed by the variable optical rotation members 12a to 12h are measured, the optical rotation angles are adjusted to a specific value by adjusting the variable optical rotation members 12a to 12h (and further the relative positions of the 1 st deflection prism 23a and the 2 nd deflection prism 23b), and then the variable optical rotation unit 12 is incorporated into the illumination optical path. Alternatively, after the variable optical rotation unit 12 is incorporated into the illumination optical path, the relative positions of the 1 st deflection prism 23a and the 2 nd deflection prism 23b may be adjusted based on the measurement result of the polarization state measurement unit 18, so that the variable optical rotation members 12a to 12h function accurately. Further, by further actively fine-adjusting each of the variable optical rotation members 12a to 12h from a state adjusted to function correctly as the variable optical rotation unit 12, the mask M, which is the irradiated surface, and further the wafer W, may be illuminated with light in a plurality of polarization states (for example, a deformed circumferential polarization state slightly different from a complete circumferential polarization state).

In this case, as shown in fig. 1, the control unit CR receives the measurement result from the polarization state measurement unit 18, controls the drive unit DR1 that changes the relative positions of the optical elements (12a to 12h) in the variable optical rotation unit 12, and adjusts the distribution of the amount of rotation light formed by the variable optical rotation unit 12 so that the polarization state of the light beam on the mask M or the wafer W directed to the surface to be irradiated is in a desired state.

Thus, in the illumination optical devices (1 to 17) of the present embodiment, the mask M, which is the surface to be illuminated, can be illuminated with light in a desired polarization state substantially without being affected by manufacturing errors of the optical elements (12a to 12 h; 23a, 23b) constituting the variable optical rotation unit 12. As a result, in the exposure apparatuses (1 to WS) of the present embodiment, favorable exposure can be performed under appropriate illumination conditions by the illumination optical apparatuses (1 to 17) that illuminate the mask M set on the surface to be illuminated with light in a desired polarization state.

In the above description, the light beam incident on the variable optical rotation unit 12 can be switched between the linearly polarized state having the polarization direction in the Z direction and the linearly polarized state having the polarization direction in the X direction, thereby realizing the circumferential polarized zone illumination and the radial polarized zone illumination. However, the present invention is not limited to this, and the circumferential polarization zone illumination and the radial polarization zone illumination may be realized by switching the variable optical rotation unit 12 between the 1 st state shown in fig. 5 and the 2 nd state rotated by 90 degrees around the optical axis AX with respect to an incident beam in a linearly polarized state having a polarization direction in the Z direction or the X direction.

In the above description, the variable optical rotation unit 12 is disposed slightly in front of the micro fly-eye lens 13. However, the present invention is not limited to this, and the variable optical rotation unit 12 may be disposed at or near the pupil of the illumination optical devices (1 to PL), for example, at or near the pupil of the projection optical system PL, at or near the pupil of the imaging optical system 17, slightly in front of the conical axicon system 10 (at or near the pupil of the afocal lens 7), or the like.

In the above description, the variable optical rotation unit 12 is configured by 8 fan-shaped variable optical rotation members 12a to 12h corresponding to 8 divisions of the annular effective region. However, the present invention is not limited to this, and the variable optical rotation unit 12 may be configured by, for example, 8 sector-shaped variable optical rotation members corresponding to 8 divisions of a circular effective region, 4 sector-shaped variable optical rotation members corresponding to 4 divisions of a circular or annular effective region, or 16 sector-shaped variable optical rotation members corresponding to 16 divisions of a circular or annular effective region. That is, various modifications are possible with respect to the shape of the effective region of the variable optical rotation unit 12, the number of divisions of the effective region (the number of variable optical rotation members), and the like.

In the above description, each optically variable member (and thus the optically variable unit 12) is formed of crystal. However, the present invention is not limited to this, and each variable optical rotation member may be formed of another suitable optical material having optical rotation. In this case, an optical material having optical rotation energy of 100 degrees/mm or more with respect to light of a wavelength to be used is preferable. That is, if an optical material having small optical rotatory power is used, the thickness required for obtaining the required rotation angle in the polarization direction is too large, which is not preferable because it causes a loss of light amount.

In the above description, the variable optical rotation unit 12 is fixedly provided to the illumination optical path, but the variable optical rotation unit 12 may be provided to the illumination optical path so as to be insertable and removable. In the above description, the S-polarized light and the annular illumination for the wafer W are combined, but the S-polarized light and the multipolar illumination such as 2-pole, 4-pole, and 8-pole illumination and the circular illumination for the wafer W may be combined.

Fig. 10 is a schematic diagram showing the configuration of the variable phase difference unit according to the present embodiment. The variable phase difference unit 9 according to the present embodiment is disposed at or near the pupil plane of the afocal lens 7, that is, at or near the pupil of the illumination optical systems (2 to 17). Therefore, in the case of annular illumination, a light flux having a substantially annular cross section centered on the optical axis AX can be incident on the variable phase difference unit 9. In the case of 8-pole illumination, a light flux having, for example, 8 substantially circular cross sections centered on the optical axis AX can be incident on the variable phase difference unit 9. Next, the case of 8-pole illumination will be described for the sake of simplicity of description.

Referring to fig. 10, the variable phase difference unit 9 is composed of 8 circular variable phase difference members 9a, 9b, 9c, 9d, 9e, 9f, 9g, and 9h arranged in the circumferential direction of a circle centered on the optical axis AX. Each of the variable phase difference members 9a to 9h has the same basic configuration as each other, and specifically, is configured separately as a solor compensator shown in fig. 3(a) or as a barvint compensator shown in fig. 3 (b).

Each of the variable phase difference members 9a to 9h is configured to be rotatable about an axis parallel to the optical axis AX (parallel to the Y direction) through the center of a circular outer shape, for example. For example, when 8-pole illumination is performed in the above-described circumferentially polarized state, as shown in fig. 11, the 8 circular light fluxes 33a to 33h constituting the 8-pole light flux 33 entering the variable phase difference unit 9 should all be linearly polarized in the Z direction by the action of the polarization state conversion devices (3 to 5).

However, due to the influence of the polarization characteristics of the optical members disposed in the optical path between the 2 nd variable phase difference member 4 and the variable phase difference unit 9, and the like, the polarization state of the light beam reaching the variable phase difference unit 9 may be changed from the linearly polarized state having the polarization direction in the Z direction. As a simple specific example, as shown in fig. 11, for example, a circular light flux 33a incident on the variable phase difference member 9a of the variable phase difference unit 9 is formed in an elliptically polarized state, or a circular light flux incident on the variable phase difference member 9h is formed in a linearly polarized state having a polarization direction in a direction inclined with respect to the Z direction.

In this case, in the variable phase difference unit 9 of the present embodiment, in order to allow the variable phase difference member 9a to function correctly as an 1/4 wavelength plate, the relative positions of the 1 st declined prism 21b and the 2 nd declined prism 21c (or the relative positions of the 1 st declined prism 22a and the 2 nd declined prism 22b) are adjusted. In order to allow the variable phase difference member 9h to function correctly as an 1/2 wavelength plate, the relative positions of the 1 st declination prism 21b and the 2 nd declination prism 21c (or the relative positions of the 1 st declination prism 22a and the 2 nd declination prism 22b) are adjusted.

Then, by setting the variable phase difference member 9a at a specific angular position around the central axis, the incident light of the elliptically polarized light is converted into the light of the linearly polarized light having the polarization direction in the Z direction. By setting the variable phase difference member 9h at a specific angular position around the central axis, the incident light of the linearly polarized light is converted into the linearly polarized light having the polarization direction in the Z direction. In this way, the polarization state of the incident light can be converted into a desired polarization state (in a specific example, a linearly polarized state having a polarization direction in the Z direction) by the action of the variable retardation unit 9 as a polarization conversion element disposed on or near the illumination pupil plane, and the mask M and the wafer W can be illuminated in the desired polarization state (for example, a circumferential polarization state, a diametric polarization state, a linearly polarized state having a polarization direction in the Z direction, and the like). That is, by locally changing the polarization state at the illumination pupil plane or at a position near the illumination pupil plane by the variable phase difference unit 9 according to the present embodiment, not only can the mask M and the wafer W be illuminated with illumination light having a desired distribution of polarization states at the illumination pupil plane or near the illumination pupil plane, but also the desired resolution and depth of focus can be improved, and the occurrence of asymmetric errors in, for example, the left-right direction and the up-down direction of the pattern can be suppressed.

In the above description, attention is focused on the case of performing 8-pole illumination, but the present invention is not limited to this, and for example, in the case of performing multipole illumination such as 2-pole or 4-pole illumination and zone illumination, the polarization state of incident light may be converted into a desired polarization state by the function of the variable phase difference element 9 serving as a polarization conversion element in the same manner. In the above description, the variable phase difference unit 9 is disposed on or near the pupil surface of the afocal lens 7, but the present invention is not limited thereto, and may be disposed on or near the pupil surface of the illumination optical systems (2 to 17) in general. Incidentally, the variable phase difference unit 9 may be provided so as to be removable from the illumination optical path, or may be provided so as to be fixed to the illumination optical path.

In the above description, the 8-pole light fluxes 33a to 33h after passing through the variable phase difference unit 9 are all adjusted to be in the linearly polarized state having the polarization direction along the Z direction, but the adjustment is not limited to this, and the adjustment may be performed so that the light fluxes after passing through the variable phase difference unit 9 are in various polarized states.

Further, by further actively and finely adjusting the variable retardation members 9a to 9h from a certain adjustment state based on the measurement result of the polarization state measuring unit 18, the mask M, which is the surface to be irradiated, and further the wafer W can be illuminated with light in a more varied polarization state. In this case, the control unit CR adjusts the variable phase difference elements 9a to 9h of the variable phase difference unit 9 by the driving unit DR2 shown in fig. 1.

In addition, the variable optical rotation means 12 shown in fig. 5 and the variable phase difference means 9 shown in fig. 10 may be used in combination. In this case, it is preferable that the variable phase difference unit 9 controls the ellipticity of the illumination light, and the variable optical rotation unit 12 controls the polarization direction (the major axis direction in the case of elliptically polarized light). In this case, the variable phase difference unit 9 and the variable optical rotation unit may be disposed in a state of being adjacent to each other, or the relay optical systems (7b, 11) may be interposed between these units, and these units 9, 12 may be disposed so as to be conjugate to each other.

Fig. 12(a) to 12(b) are schematic views showing the structure of another variable phase difference means according to the present embodiment. As shown in fig. 12(a), the variable phase difference unit 19 shown in fig. 12(a) to 12(b) is disposed in the vicinity of the mask blind 16, that is, at or near a position optically conjugate with the surface to be irradiated of the illumination optical devices (1 to 17). Therefore, the variable phase difference unit 19 is incident with a rectangular light beam substantially similar to the illumination region on the mask M and the exposure region on the wafer W (stationary exposure region in the case of scanning exposure) regardless of the ring-shaped illumination, the multi-pole illumination, the circular illumination, and the like.

Referring to fig. 12(b), the variable phase difference unit 19 is configured by a plurality of circular variable phase difference members 19a, 19b, 19c, 19d, 19e, and … arranged substantially densely in a rectangular region centered on the optical axis AX. Each of the variable phase difference members (19a to 19e, …) has the same basic configuration as each other, and specifically, is configured separately as a solor compensator shown in fig. 3(a) or as a babonet compensator shown in fig. 3 (b).

The variable phase difference members (19a to 19e, …) are configured to be rotatable about an axis parallel to the optical axis AX (parallel to the Y direction) through the center of a circular outer shape, for example. For example, when the mask M and the wafer W are illuminated in a linearly polarized state having a polarization direction along the Y direction, the light beams incident on the variable phase difference members (19a to 19e, …) of the variable phase difference unit 19 should all be linearly polarized along the Z direction by the action of the polarization state switching devices (3 to 5), as shown in fig. 13.

However, due to the influence of the polarization characteristics of the optical members disposed in the optical path between the 2 nd variable phase difference member 4 and the variable phase difference unit 19, the polarization state of the light beam reaching the variable phase difference unit 19 may be changed from the linearly polarized state having the polarization direction in the Z direction. As a simple specific example, as shown in fig. 13, for example, the light beam incident on the variable phase difference member 19a of the variable phase difference unit 19 is in an elliptically polarized state, or the light beam incident on the variable phase difference member 19e is in a linearly polarized state having a polarization direction in a direction oblique to the Z direction.

In this case, in the variable phase difference unit 9 shown in fig. 12(a) to 12(b), the relative positions of the 1 st declination prism 21b and the 2 nd declination prism 21c (or the relative positions of the 1 st declination prism 22a and the 2 nd declination prism 22b) are adjusted so that the variable phase difference member 19a functions as an 1/4 wavelength plate accurately. In order to allow the variable phase difference member 19e to function accurately as an 1/2 wavelength plate, the relative positions of the 1 st declination prism 21b and the 2 nd declination prism 21c (or the relative positions of the 1 st declination prism 22a and the 2 nd declination prism 22b) are adjusted.

Then, by setting the variable phase difference member 19a at a specific angular position around the central axis, the incident light of the elliptically polarized light is converted into the light of the linearly polarized light having the polarization direction in the Z direction. By setting the variable phase difference member 19e at a specific angular position around the central axis, the incident light of the linearly polarized light is converted into the linearly polarized light having the polarization direction in the Z direction. In this way, the polarization state of the incident light can be converted into a desired polarization state (in a specific example, a linearly polarized state having a polarization direction along the Z direction) by the action of the variable phase difference unit 19 as a polarization conversion element disposed at a position optically conjugate with the surface to be irradiated or in the vicinity thereof, and the mask M and the wafer W can be illuminated in the desired polarization state (for example, a linearly polarized state having a polarization direction along the Y direction). That is, by locally changing the polarization state of the light illuminating the surface to be irradiated (mask M, wafer W) by the other variable phase difference unit 19 according to the present embodiment, the mask M and the wafer W can be illuminated by the illumination light having a desired distribution of polarization states on the surface to be irradiated, and further, the line width of the pattern formed on the wafer W can be suppressed from varying at every position in the exposure region, and the occurrence of a so-called line width difference in the magnetic field can be suppressed.

In addition, the variable optical rotation unit of fig. 5 and the variable optical rotation unit of fig. 10, or the variable phase difference unit of fig. 10 and the variable phase difference units of fig. 12(a) to 12(b) may be used in combination. In this case, by locally and continuously changing the polarization state of the illumination pupil plane or its vicinity and locally and continuously changing the polarization state of the light illuminating the surface to be irradiated (mask M, wafer W), the mask M and the wafer W can be illuminated with the illumination light having a desired distribution of polarization states at or near the illumination pupil plane and having a desired distribution of polarization states at the surface to be irradiated, and further, the occurrence of asymmetric errors in the pattern, the occurrence of line width differences in the magnetic field, and the like can be suppressed.

In the above description, the variable phase difference unit 19 is disposed in the vicinity of the mask blind 16. However, the present invention is not limited to this, and may be arranged in the vicinity of the surface to be irradiated of the illumination optical devices (1 to 17) (for example, in the vicinity of the mask M), in the vicinity of the position optically conjugate with the surface to be irradiated, or in the vicinity of the position conjugate with the surface to be irradiated, in addition to the vicinity of the mask shade 16. Incidentally, the variable phase difference unit 19 may be provided so as to be removable from the illumination optical path, or may be provided so as to be fixed to the illumination optical path. In addition, when scanning exposure is performed, it is preferable that a plurality of circular variable phase difference members are arranged in the non-scanning direction, and the arrangement in the non-scanning direction is preferably staggered (or zigzag).

In the above description, the adjustment is performed so that all the light fluxes having passed through the variable phase difference unit 19 are in the linearly polarized state having the polarization direction in the Z direction, but the adjustment is not limited thereto, and the adjustment may be performed so that the light fluxes having passed through the variable phase difference unit 19 are in various polarized states. Further, by further actively and finely adjusting the variable retardation members (19a to 19e, …) from a certain adjustment state based on the measurement result of the polarization state measurement unit 18, the mask M, which is the surface to be irradiated, and further the wafer W can be illuminated with light in a more varied polarization state.

In this case, as shown in fig. 12(a) to 12(b), the control unit CR receives the measurement result from the polarization state measurement unit 18, controls the driving unit DR4 for driving the variable phase difference members 19a to 19e in the variable phase difference unit 19, and adjusts the distribution of the phase difference amount formed by the variable phase difference unit 19 so that the polarization state distribution of the light beam on the mask M or the wafer W as the irradiation target surface becomes a desired distribution.

In the above-described embodiment, the variable phase difference means 19 is disposed at or near the position optically conjugate with the surface to be irradiated of the illumination optical devices (1 to 17), but a plurality of variable optical rotation means may be disposed instead of the variable phase difference means. In this case, the shape of each variable optical rotation member is not a sector as shown in fig. 5, but a circular shape is preferable. With this configuration, the linearly polarized illumination can be performed by the illumination light having a desired distribution of polarization directions on the illuminated surface. Further, polarized illumination can be performed by illumination light having a desired distribution of polarization states on the illuminated surface. In addition, such a variable optical rotation unit and a variable phase difference unit may be used in combination. In this case, it is preferable that the variable phase difference unit controls the ellipticity of the illumination light, and the variable optical rotation unit controls the polarization direction (the major axis direction in the case of elliptically polarized light).

As shown in fig. 14(a) to 14(b) as a 2 nd modification, optically variable members 81a to 81f made of an optically active material (e.g., crystal) in a wedge shape may be arranged as the optically variable unit 80 in a direction corresponding to the non-scanning direction (X direction). These variable optical rotation members 81a to 81f are movable in a direction (Z direction) corresponding to the scanning direction, and their movement amounts can be controlled by the control unit CR and adjusted by the drive units 82a to 82f connected to the respective variable optical rotation members 81a to 81 f.

The operation of each of the optically variable members 81a to 81f will be described with reference to fig. 14 (b). Here, the variable optical rotation member 81f will be described as a representative. In FIG. 14(b), a plurality of positions 83f 1-83 f5 in the moving direction (Z direction) of the variable optical rotation member 81f are considered. At this time, the polarization states of the light fluxes passing through the positions 83f1 to 83f5 in the aperture portion 16a of the shade 16 are represented by 84f1 to 84f 5. The polarization states 84f1 to 84f3 of the light beam not passing through the variable optical rotation member 81f, the polarization states 84f4 and 84f5 of the light beam passing through the variable optical rotation member 81f are rotated around the optical axis in the polarization direction of the incident linearly polarized light according to the thickness of the variable optical rotation member 81f in the optical axis direction (Y direction).

Here, considering the scanning exposure, the polarization state of the beam reaching one point on the wafer W can be regarded as the average polarization state of the beam group in the scanning direction. In embodiment 2, the average polarization state of the polarization states 84f1 to 84f5 of the light beam in the Z direction can be changed according to the Z-direction position of the variable optical rotation member 81f, and therefore the polarization state of the light beam reaching one point on the wafer W can be changed. By changing the Z-direction positions of the variable optical rotation members 81a to 81f in the non-scanning direction, the distribution of the polarization state of the light beam in the non-scanning direction can be changed. As shown in fig. 15, wedge-shaped optical members 85a to 85f (only 85f is illustrated in fig. 15) made of an amorphous material (e.g., quartz) for optical axis correction may be provided on the variable optical rotation members 81a to 81f of the variable optical rotation unit, and may be formed in a parallel planar plate shape as a whole.

Fig. 16(a) to 16(c) are schematic diagrams showing the structure of the variable optical rotation/phase shift unit according to modification 3. The 3 rd modification is to control the polarization direction of linearly polarized light (the length in the major axis direction of elliptically polarized light) by a variable optical rotator and to control the ellipticity of the polarized light by a variable phase shifter. Referring to the side view shown in FIG. 16(a), the top view shown in FIG. 16(b), and the bottom view shown in FIG. 16(c), the optical rotators 51 to 55 are each formed of crystal having a crystal optical axis oriented in the optical axis direction, and the phase shifters 61 to 66 are each formed of crystal having a crystal optical axis oriented in the direction orthogonal to the optical axis.

The optical rotatory plate 51 and the phase shifter 61 are formed in a quadrangular pyramid shape, and the optical rotatory plates 52 to 55 and the phase shifters 62 to 65 are formed in a wedge shape in cross section (in a plane including the optical axis) and in a quadrangular circle shape when viewed from the optical axis direction. In order to eliminate the optical rotation of the phase shifters 61 to 65, the crystal optical axis directions of the phase shifters 61 to 65 and the crystal optical axis direction of the phase shifter 66 are orthogonal to each other. The optical rotators 52 to 55 are provided to the optical rotator 51 so as to be movable in the radial direction with respect to the optical axis, and the phase shifters 62 to 65 are provided to the phase shifter 61 so as to be movable in the radial direction with respect to the optical axis. In this case, it is preferable that the optical rotators 52 to 55 are movable along the inclined surface of the quadrangular pyramid-shaped optical rotator 51, and the phase shifters 62 to 65 are movable along the inclined surface of the quadrangular pyramid-shaped phase shifter 61.

The thickness of the optical rotator in the optical axis direction is locally changed as the whole optical rotator according to the radial position of the optical rotators 52-55. The thickness of the entire phase shifter in the optical axis direction is partially changed in accordance with the radial position of the phase shifters 62 to 65. Therefore, the amounts of rotation and phase shift imparted to the 1 st light beam passing through the optical rotators 51 and 52 and the phase shifters 61, 62, and 66, the 2 nd light beam passing through the optical rotators 51 and 53 and the phase shifters 61, 63, and 66, the 3 rd light beam passing through the optical rotators 51 and 54 and the phase shifters 61, 64, and 66, and the 4 th light beam passing through the optical rotators 51 and 55 and the phase shifters 61, 65, and 66 can be independently adjusted, and thus the respective polarization states (polarization directions and ellipticities) of the 1 st to 4 th light beams can be independently adjusted.

In addition, in order to effectively adjust (correct) the phase shift amount, it is preferable to arrange variable optical rotation units (51-55) on the incident side of the variable phase shift units (61-66) as in the present modification. Here, if the variable optical rotation units (51-55) are disposed on the exit side of the variable phase shift units (61-66), there is a possibility that the crystal axis orientations of the phase shifters of the variable phase shift units (61-66) and the polarization direction of light incident on the variable phase shifters 61-66 are parallel or perpendicular, and at this time, no phase shift effect is imparted to incident light. In this case, it is preferable to provide a phase shifter rotating mechanism for rotating the crystal axes of the phase shifters 61 to 66 of the variable phase units 61 to 66 in an arbitrary direction within the orthogonal plane of the optical axis, or to provide them so as to be interchangeable with phase shifters having crystal axes of different azimuths. The arrangement in this manner is made in the order of the variable optical rotation means and the variable phase shift means from the light incident side, and is effective not only in the present embodiment but also in the modified examples and embodiments described later.

The variable optical rotation/phase shift units (51 to 55; 61 to 66) may be disposed on or near the pupil surface of the illumination optical device, instead of the variable optical rotation unit 12 shown in FIG. 5 or the variable phase unit 9 shown in FIG. 10. In this case, as the secondary light sources formed on the pupil plane of the illumination optical device, for example, multipolar secondary light sources 35a to 35d as shown in fig. 17(a) can be applied. FIG. 17(b) shows the positional relationship when the light fluxes of the multi-pole secondary light sources 35a to 35d are emitted from the phase shifters 62 to 65 of the phase shifting units (61 to 65). In the example of fig. 17(a) to 17(b), the azimuth angle around the optical axis at the off-point in the circumferential direction of the secondary light sources 35a to 35d is 10 degrees or more. Thereby, it is possible to eliminate the need for consuming light for forming the secondary light sources 35a to 35d at the boundaries of the divided phase shifters (optical rotators). Instead of the variable phase difference means 19 shown in fig. 12(a) to 12(b), it may be disposed on the surface to be irradiated of the illumination optical apparatus, the vicinity of the surface to be irradiated, or a conjugate surface thereof.

In the above example, the optical rotation amount and the phase shift amount of the light flux passing through the 4 regions are independently controlled, but the number of the regions is not limited to 4, and may be 6 or 8. Here, when the wavelength of the illumination light (exposure light) is 193nm, the crystal has a rotational energy of 90 degrees/228 μm and a phase shift amount of 180 degrees/7 μm. When the variable of the linear polarization direction formed by the optical rotatory plate is, for example, +/-20 degrees and the phase adjustment amount formed by the phase shifter is + -10 degrees, the radial stroke required for the optical rotatory plates 52 to 55 is + -1 mm when the wedge angle of the optical rotatory plate is 7.2 degrees, and the radial stroke required for the phase shifters 62 to 65 is 100 μm when the wedge angle of the phase shifter is 0.35 degrees.

Fig. 18 is a schematic diagram showing the configuration and operation of a pair of aspherical optical rotators according to modification 4. In the present modification, as shown in fig. 18, a 1 st pair of aspherical optical rotators 58 is disposed on the front side (light source side) of the mask curtain 16, and a 2 nd pair of aspherical optical rotators 59 is disposed on the rear side (mask side) of the mask curtain 16. The 1 st pair of aspherical optical rotators 58 includes a combination of an optical rotator 58a having a YZ section in a concave shape and an optical axis correcting plate 58b having a convex surface complementary to the concave surface of the optical rotator 58a, and the 2 nd pair of aspherical optical rotators 59 includes a combination of an optical rotator 59a having a YZ section in a convex shape and an optical axis correcting plate 59b having a concave surface complementary to the convex surface of the optical rotator 59 a. These 1 st aspherical optical rotator pair 58 and 2 nd aspherical optical rotator pair 59 are configured such that the thicknesses of the optical rotators are different depending on the incident position of the light beam.

Specifically, the 1 st pair of aspherical optical rotators 58 has, as shown in fig. 19(a), an optical rotation amount distribution of a quadratic concave pattern in which the optical rotation amount is minimized at the center of the effective area in the Y direction, and the optical rotation amount increases toward the periphery without change (monotony) according to a quadratic function of the distance from the center, for example. On the other hand, the 2 nd aspherical optical rotator pair 59 has, as shown in fig. 19(b), an optical rotation amount distribution of a quadratic convex pattern in which the optical rotation amount is maximized at the center of the effective area in the Y direction, for example, and the optical rotation amount decreases as a quadratic function of the distance from the center without change to the periphery.

In the present modification, the difference between the maximum value of the optical rotation amounts in the periphery of the effective region of the 1 st pair of aspherical optical rotators 58 and the minimum value of the optical rotation amounts in the center is set to be equal to the difference between the maximum value of the optical rotation amounts in the center and the minimum value of the optical rotation amounts in the periphery of the effective region of the 2 nd pair of aspherical optical rotators 59. That is, the 1 st pair of aspherical optical rotators 58 has a quadratic optical rotation amount distribution in a concave pattern, and the 2 nd pair of aspherical optical rotators 59 has a quadratic optical rotation amount distribution in a convex pattern. As a result, the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 can be made to have complementary optical rotation amount distributions.

In the present modification, the distance between the 1 st pair of aspherical optical rotators 58 (strictly, the concave surfaces thereof) and the mask curtain 16 is set to be equal to the distance between the 2 nd pair of aspherical optical rotators 59 (strictly, the convex surfaces thereof) and the mask curtain 16. Next, attention is paid to a light ray reaching a center point P1 intersecting the optical axis AX on the mask M as an irradiated surface (or the wafer W as a final irradiated surface), a light ray reaching a point P2 apart from the center point P1 by a certain distance in the + Y direction, and a light ray reaching a point P3 apart from the center point P1 by a certain distance in the-Y direction.

Here, a case where only the 1 st aspherical optical rotator pair 58 having the optical rotation amount distribution of the quadratic concave pattern is interposed is considered. In fig. 18, 3 plots (a) between the 1 st pair of aspherical optical rotators 58 and the mask curtain 16 show the distribution of the amounts of internal rotation in the respective apertures of the light beams with respect to the points P1, P2, P3 traveling in the optical path between the 1 st pair of aspherical optical rotators 58 and the mask curtain 16, and 3 plots (B) between the mask curtain 16 and the 2 nd pair of aspherical optical rotators 59 show the distribution of the amounts of internal rotation in the respective apertures of the light beams with respect to the points P1, P2, P3 traveling in the optical path between the mask curtain and the 2 nd pair of aspherical optical rotators 59.

Further, 3 plots (C) between the 2 nd aspherical optical rotator pair 59 and the imaging optical system 17 (or the imaging optical system 17 and the projection optical system PL) represent distributions of the amounts of internal rotation in the respective apertures of the light beams with respect to the points P1, P2, P3, which travel in the optical path between the 2 nd aspherical optical rotator pair 59 and the imaging optical system 17 (or the imaging optical system 17 and the projection optical system PL), 3 plots (D) between the imaging optical system 17 (or the imaging optical system 17 and the projection optical system PL) and the irradiated surfaces (M, W), which travel in the optical path between the imaging optical system 17 (or the imaging optical system 17 and the projection optical system PL) and the irradiated surfaces (M, W), and represent distributions of the amounts of internal rotation in the respective apertures of the light beams with respect to the points P1, P2, P3. In these plots (A) to (D), the optical rotation amount is plotted on the vertical axis and the numerical aperture NA is plotted on the horizontal axis.

Here, according to the plot (a), between the 1 st pair of aspherical optical rotators 58 and the mask blind 16, the in-aperture rotated amount with respect to the center point P1 forms a concave pattern, the in-aperture rotated amount distribution with respect to the point P2 forms an oblique pattern, and the in-aperture rotated amount distribution with respect to the point P3 forms an oblique pattern opposite to the oblique pattern of the point P2 in the oblique direction. As shown in the plot (B), after passing through the mask blind 16 (intermediate imaging point), the in-aperture rotated light amount distribution with respect to the center point P1 maintains a concave pattern, but the in-aperture rotated light amount distribution with respect to the point P2 and the in-aperture rotated light amount distribution with respect to the point P3 form an oblique pattern whose oblique directions are opposite.

In addition, if the 2 nd pair of aspherical optical rotators 59 having the optical rotation amount distribution with the quadratic convex pattern is interposed in addition to the 1 st pair of aspherical optical rotators 58, the optical rotation amount distribution with respect to the center point P1 is returned from the concave pattern to a uniform pattern by the action of the 2 nd pair of aspherical optical rotators 59, and the degree of the inclination pattern with respect to the optical rotation amount distribution at the point P2 and the point P3 is changed to be more emphasized as shown in plots (C) and (D) of fig. 18.

In other words, the cooperative action of the 1 st pair of correcting aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 causes the optical rotation amount distribution with respect to the center point P1 (and the point having the same Y coordinate as P1) not to change, the optical rotation amount distribution with respect to the point P2 (and the point having the same Y coordinate as P2) to change into a linear inclination pattern, and the optical rotation amount distribution with respect to the point P3 (and the point having the same coordinate as P3) to change into a linear inclination pattern which is opposite to the inclination pattern of the point P2 in the inclination direction and has the same inclination degree. The degree of the linear inclination adjustment of the optical rotation amount distribution at the point P2 and the point P3 depends on the distance in the Y direction between the point P2 and the center point P1 and the point P3.

That is, the farther from the center point P1 in the Y direction, the greater the degree of linear inclination adjustment of the optical rotation amount distribution with respect to that point. As is clear from fig. 18, the larger the distance between the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 from the mask curtain 16 becomes, the size of a region (hereinafter referred to as "partial region") where light rays reaching each point on the surface to be irradiated pass through the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59, respectively, and the degree of linear inclination adjustment of the optical rotation amount distribution at each point also increases. Of course, if the degree of change in the optical rotation amount distribution of the 1 st pair of aspherical optical rotators 59 and the 2 nd pair of aspherical optical rotators 59 is set to be larger, the degree of linear inclination adjustment of the optical rotation amount distribution at each point also increases.

As described above, in the present modification, since the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 have complementary optical rotation amount distributions, and the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 sandwich the mask curtain 16 and set at equal distances, the positions and sizes of partial regions of respective points on the irradiated surface are substantially matched with each other on the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59. As a result, the optical rotation amount distribution at each point on the surface to be irradiated is adjusted for each point due to the cooperative action of the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59, but the optical rotation amount distribution on the surface to be irradiated is not substantially changed.

As described above, in the present embodiment, the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 constitute adjusting means for independently adjusting the distribution of the amount of optical rotation for each point on the irradiated surface (M, W), in other words, in the present modification, the 1 st pair of aspherical optical rotators 58 and the 2 nd pair of aspherical optical rotators 59 constitute adjusting means for independently adjusting the polarization state in the aperture of the light flux reaching each point on the irradiated surface (M, W). As a result, in the exposure apparatus of the present modification, since the distribution of the amount of light rotation on the irradiated surfaces (M, W) can be maintained substantially uniformly and the polarization state distribution of each point on the irradiated surfaces can be adjusted to a desired distribution, the fine pattern of the mask M can be faithfully transferred to the wafer W with a desired line width over the entire exposure area.

In the above description, the 1 st aspherical optical rotator pair 58 and the 2 nd aspherical optical rotator pair 59 are set at equal distances with the mask shade 16 interposed therebetween, but the mask shade may be set at equal distances with the conjugate plane optically conjugate to the final irradiated surface, i.e., the wafer W interposed therebetween, specifically, with the mask M interposed therebetween, for example, and the same effects as those of the above-described embodiments may be obtained. In the above description, the 1 st pair of aspherical optical rotators 58 has the optical rotation amount distribution of the secondary concave pattern and the 2 nd pair of aspherical optical rotators 59 has the optical rotation amount distribution of the secondary convex pattern, but the same effects as those of the above-described modification can be obtained even when the 1 st pair of aspherical optical rotators 58 has the optical rotation amount distribution of the secondary convex pattern and the 2 nd pair of aspherical optical rotators 59 has the optical rotation amount distribution of the secondary concave pattern.

In the above description, the 1 st aspherical optical rotator pair 58 and the 2 nd aspherical optical rotator pair 59 use optical rotators made of crystals having crystal axes aligned parallel to the optical axis in order to provide a specific pattern of optical rotation amount distribution, but instead, for example, phase shifters made of crystals having crystal axes aligned perpendicular to the optical axis and optical axis correction plates may be combined to use the 1 st aspherical phase shifter pair and the 2 nd aspherical phase shifter pair. In this case, for example, the 1 st aspheric phase shifter pair includes a combination of a phase shifter having a YZ section in a concave shape and an optical axis correction plate having a convex surface complementary to the concave surface of the phase shifter, and the 2 nd aspheric phase shifter pair includes a combination of a phase shifter having a YZ section in a convex shape and an optical axis correction plate having a concave surface complementary to the convex surface of the phase shifter. These 1 st aspheric phase shifter pair and 2 nd aspheric phase shifter pair are configured such that the phase shifters have different thicknesses depending on the incident position of the light beam.

Specifically, the 1 st aspherical phase shifter pair has, for example, a phase shift amount distribution in which the phase shift amount is minimized at the center of the effective region in the Y direction and the phase shift amount is increased without changing toward the periphery according to a quadratic function of the distance from the center, as shown in fig. 19 (c). On the other hand, the 2 nd aspherical phase shifter pair has a phase shift amount distribution in which, for example, the phase shift amount is maximized at the center of the effective region in the Y direction and the phase shift amount is reduced to the periphery without changing the phase shift amount as a quadratic function of the distance from the center, as shown in fig. 19 (d). With these 1 st and 2 nd aspherical phase shifter pairs, the phase shift amount distribution with respect to each point on the irradiated surface can be adjusted independently. In other words, the polarization state in the aperture of the light beam reaching each point on the surface to be irradiated (M, W) can be adjusted independently by the 1 st aspheric phase shifter pair and the 2 nd aspheric phase shifter pair. Further, the pair of aspherical phase shifters and the pair of aspherical optical rotators may be combined.

In the above description, the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59 have optical rotation amount (phase shift amount) distributions of the quadratic pattern, but are not limited thereto, and various modifications are possible with respect to the patterns of the optical rotation amount (phase shift amount) distributions given to the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59. Specifically, for example, as shown in fig. 20 a and 20 c, the 1 st pair of aspherical optical rotators (phase shifters) 58 may have a distribution of optical rotation amounts (phase shift amounts) in an M-shaped pattern of four times, in which the transmittance is once increased from the center toward the periphery in accordance with a quartic function of the distance in the Y direction from the center of the effective region, for example, as a modification 5.

In this 5 th modification, the 2 nd aspherical optical rotator (phase shifter) pair 59 has an optical rotation amount (phase shift amount) distribution of a W-shaped pattern which is increased four times from the center toward the periphery in accordance with a quadratic function of the distance in the Y direction from the center of the effective region as shown in fig. 20(b) and (d). In this case, the same effects as those of the above-described modified example can be obtained by setting the optical rotation amount (phase shift amount) distribution of the 1 st pair of aspherical optical rotators (phase shifters) 58 and the optical rotation amount (phase shift amount) distribution of the 2 nd pair of aspherical optical rotators (phase shifters) 59 in a complementary manner. However, since the optical rotation amount (phase shift amount) distribution of the 1 st pair of aspherical optical rotators (phase shifters) 58 and the optical rotation amount (phase shift amount) of the 2 nd pair of aspherical optical rotators (phase shifters) 59 have a pattern of four times, a tilt adjustment effect of not a linear tilt adjustment but a cubic function can be obtained. The distribution of the optical rotation amounts (phase shift amounts) of the patterns of the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59 may be four or more.

In the above description, the optical rotatory power (phase shift amount) in the Y direction is given to the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59, that is, the optical rotators (phase shifters) are cylindrical lenses, but various modifications are possible with respect to the direction of change of the distribution of the one-dimensional optical rotatory power (phase shift amount). Further, a two-dimensional distribution of the optical rotation amount (phase shift amount) may be given to the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59. The distribution of the amounts of rotation (phase shift amounts) to be given to the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59 may be defined by another appropriate function. As an example, by defining the distributions of the amounts of rotation (phase shift amounts) of the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59 by, for example, Zernike polynomials (Zernike polynomials) which will be described later, it is possible to adjust the distributions of the in-aperture polarized light states at each point on the irradiated surface in a plurality of forms, respectively at each point.

However, in the above-described modification, the crystal is oriented with the crystal axis perpendicular to the optical axisThe phase shifters constituted by the 1 st and 2 nd aspherical phase shifter pairs are not limited to crystal, and magnesium fluoride (MgF) may be used as the phase shifter₂) And the phase shifters formed of crystal materials exhibiting birefringence, the phase shifters formed of light-transmitting materials having stress deformation distribution, the phase shifters formed of light-transmitting materials including patterns having structural birefringence, and the like.

In the above-described modification, the transmittance distribution of the 1 st pair of aspherical optical rotators (phase shifters) 58 and the light amount (phase shift amount) distribution of the 2 nd pair of aspherical optical rotators (phase shifters) 59 are set to be complementary to each other, but the present invention is not limited to this, and a modification may be made in which a light amount (phase shift amount) distribution substantially different from a light amount (phase shift amount) distribution complementary to the light amount (phase shift amount) distribution of the 1 st pair of aspherical optical rotators (phase shifters) 58 is given to the 2 nd pair of aspherical optical rotators (phase shifters) 59. In this modification, the distribution of the polarization state on the irradiation surface can be adjusted based on the difference between the distribution of the amounts of rotation (phase shift amounts) complementary to the distribution of the amounts of rotation (phase shift amounts) of the 1 st pair of aspherical optical rotators (phase shifters) 59 and the distribution of the amounts of rotation (phase shift amounts) of the 2 nd pair of aspherical optical rotators (phase shifters) 59, and the distribution of the polarization state in each aperture of each point on the irradiation surface can be adjusted substantially uniformly while maintaining the distribution of the polarization state on the irradiation surface substantially constant.

Similarly, as a modification for actively adjusting the distribution of the polarization state on the irradiated surface, the 1 st pair of aspherical optical rotators (phase shifters) 58 and the 2 nd pair of aspherical optical rotators (phase shifters) 59 may be set at different distances from each other with the mask shade 16 interposed therebetween. In this case, the distribution of the polarization state on the irradiated surface can be adjusted according to the difference between the distance between the mask curtain 16 and the 1 st pair of aspherical optical rotators (phase shifters) 58 and the distance between the mask curtain 7 and the 2 nd pair of aspherical optical rotators (phase shifters) 59, and further, the distribution of the polarization state on the irradiated surface can be maintained substantially constant, and the distribution of the polarization state in the aperture of each point on the irradiated surface can be adjusted substantially uniformly.

In the above description, the distribution of the polarization state on the irradiation surface is maintained or adjusted substantially uniformly by the pair of aspherical optical rotators (phase shifters) (58, 59), and the distribution of the polarization state in the aperture of each point on the irradiation surface is adjusted substantially uniformly. However, the present invention is not limited to this, and the effects of the present invention can be obtained by using an adjusting device constituted by a plurality of aspherical optical rotators or aspherical phase shifters having a specific optical rotation amount distribution or phase shift amount distribution. That is, various modifications are possible for the number and arrangement of the aspherical optical rotators (phase shifters) constituting the adjustment device.

Specifically, for example, as shown in fig. 21, a 6 th modification example may be used in which 3 aspherical optical rotators (phase shifters) 71a to 71c having different distributions of the amounts of rotation (phase shift amounts) depending on the incident positions are used. In the 6 th modification of fig. 21, the 1 st aspherical optical rotator (phase shifter) and the 2 nd aspherical optical rotator (phase shifter) 71b are disposed in this order from the light source side in the optical path of the condensing optical system 15 between the micro fly-eye lens 13 and the mask curtain 16, and the 3 rd aspherical optical rotator (phase shifter) 71c is disposed in the optical path between the condensing optical system 15 and the mask curtain 16.

In this case, as shown in fig. 22(a) to 22(c), the on-axis light beams (light beams reaching the intersection of the mask curtain 16 and the optical axis AX) pass through the regions of the aspherical optical rotators (phase shifters) 71a to 71c, that is, the on-axis partial regions 71aa, 71ba, and 71ca, respectively, and are different for each of the aspherical optical rotators (phase shifters) 71a to 71 c. Similarly, the off-axis light flux (light flux reaching a point on the mask curtain 16 away from the optical axis A X) passes through the off-axis regions 71ab, 71bb, and 71cb, which are regions of the aspheric optical rotators (phase shifters) 71a to 71c, respectively, and is different for each of the aspheric optical rotators (phase shifters) 71a to 71 c.

In the 6 th modification, by setting the distribution of the amount of rotation (amount of phase shift) of each of the aspherical optical rotators (phase shifters) 71a to 71c and the positions and sizes of the axially partial region and the axially outer partial region on each of the aspherical optical rotators (phase shifters) 71a to 71c as appropriate, the distribution of the polarization state on the irradiated surface can be adjusted substantially uniformly, and the distribution of the polarization state in the aperture of each point on the irradiated surface can be adjusted substantially uniformly. In addition, the effect of the present invention can be obtained by setting the optical rotation amount (phase shift amount) distribution of each aspherical optical rotator (phase shifter), the position and the size of the axially upper portion region and the axially outer portion region of each aspherical optical rotator (phase shifter), and the like as appropriate by using an adjusting device including a plurality of aspherical optical rotators (phase shifters) each having a specific optical rotation amount (phase shift amount) distribution in which the optical rotation amount (phase shift amount) changes depending on the incident position.

Next, a description will be given of an illumination optical apparatus for illuminating a wafer W having a light source 1 to a projection optical system PL as an illuminated surface, and a method for adjusting the illumination optical apparatus (1 to PL). In addition, in the present embodiment, in order to simplify the explanation of the adjustment method, it is possible to substantially uniformly adjust the distribution of the polarization state on the irradiation surface (the surface on which the wafer W is set) and to substantially uniformly adjust the distribution of the polarization state in the aperture at each point on the irradiation surface, respectively, by using a plurality of (2 or more) aspherical optical rotators (phase shifters) having a specific distribution of the amount of rotation (phase shift amount).

Fig. 23 is a schematic flowchart showing steps of the method for adjusting the illumination optical device according to the present embodiment. As shown in fig. 23, in the adjustment method for the illumination optical devices (1 to PL) according to the present embodiment, a distribution (pupil polarization state distribution) of polarization states in apertures at a plurality of points on the irradiated surface and a distribution of polarization states on the irradiated surface are obtained (S11). Specifically, in the distribution obtaining step S11, the distribution of the polarization state in the apertures of the plurality of points on the irradiated surface and the distribution of the polarization state on the irradiated surface are calculated based on the design data of the illumination optical devices (1 to PL).

Here, as design data of the illumination optical devices (1 to PL), for example, data of optical systems (15 to PL) from a position just behind the micro fly's eye lens 13 to a position just before the wafer W, that is, data of a curvature radius of each optical surface, an on-axis interval of each optical surface, a refractive index and a kind of an optical material forming each optical member, a wavelength of used light, a rotation amount (phase shift amount) of each optical member, incident angle characteristics (rotation amount and phase shift (retardation) amount) of the antireflection film and the reflection film, and the like are used. For example, U.S. Pat. No. 6,870,668 discloses a method for calculating the distribution of polarization states in apertures at a plurality of points on an irradiated surface from design data.

Alternatively, in the distribution obtaining step S11, the distribution of the polarization state in the apertures of the plurality of points on the irradiation surface and the distribution of the polarization state on the irradiation surface may be measured for each device manufactured in practice. Specifically, the distribution of the polarization state in the apertures of the plurality of points on the irradiated surface and the distribution of the polarization state on the irradiated surface can be measured by, for example, the polarization state measuring unit 18 shown in fig. 2.

In the present embodiment, the distribution of polarization states in the apertures of the plurality of points on the irradiated surface (in the pupils of the plurality of points on the irradiated surface) can be determined from the steckel parameter (S)₀，S₁，S₂，S₃) Specified degree of polarization (DSP)₁，DSP₂，DSP₃) Distribution of (2). Here, a specific degree of polarization DSP₁From the Steckey parameter S for light rays that pass through a point on the pupil to a point on the image plane₁For Stecke' S parameter S₀Ratio of (S)₁/S₀As indicated. Also, a specific degree of polarization DSP₂From the Steckey parameter S for light rays that pass through a point on the pupil to a point on the image plane₂For Stecke' S parameter S₀Ratio of (S)₂/S₀Expressed, specific degree of polarization DSP₃From the Steckey parameter S for light rays that pass through a point on the pupil to a point on the image plane₃For Stecke' S parameter S₀Ratio of (S)₃/S₀As indicated. Here, S₀Is full strength, S₁Subtracting the vertical linear polarization intensity from the level linear polarization intensity, S₂Subtracting the intensity of the 135 degree linear polarization from the intensity of the 45 degree linear polarization, S₃The right-rotated circular polarization intensity is subtracted from the right-rotated circular polarization intensity.

Next, in the adjustment method of the present embodiment, it is determined whether or not the distribution of the polarization states in the apertures of the plurality of points on the irradiation surface and the distribution of the polarization states of the irradiation surface, which are obtained by calculation based on the design data or measurement by the polarization state measurement unit 18, are substantially uniform to a desired degree (S12). If it is determined in the determination step S12 that at least one of the distribution of the polarization states and the distribution of the polarization states in the aperture is not substantially uniform to a desired extent (in the case of no in the figure), the process proceeds to a step S13 of designing an aspherical optical rotator (phase shifter). On the other hand, if it is determined in the determination step S12 that both the distribution of the polarization states in the aperture and the distribution of the polarization states are substantially uniform to a desired extent (in the case of yes in the figure), the process proceeds to a shape determination step S15 of the aspherical optical rotator (phase shifter).

In the second design step S13, in order to adjust the distribution of the polarization state in the apertures for the plurality of points on the irradiated surface independently from each other and adjust the distribution of the polarization state in the irradiated surface as needed so that both the distribution of the polarization state in the apertures and the distribution of the polarization state become substantially uniform to a desired degree, a desired distribution of the amount of rotation (phase shift amount) to be applied to each of the plurality of aspherical optical rotators (phase shifters) is determined (calculated). Specifically, the number and positions of the aspherical optical rotators (phase shifters) to be used are set in advance with reference to the calculated or measured information on the distribution of polarization states in the apertures and the information on the distribution of polarization states, and the distribution of the amount of rotation (phase shift amount) to be applied to each aspherical optical rotator (phase shifter) is determined so that the distribution of polarization states in the apertures at each point on the irradiated surface is maintained or adjusted substantially uniformly.

Next, in a state where a plurality of aspherical optical rotators (phase shifters) to which the distribution of the amount of rotation (phase shift amount) determined in the designing step S13 is added are arranged at the set positions, that is, in a state where the aspherical optical rotators (phase shifters) are mounted, the distribution of the polarization state in the apertures at a plurality of points on the irradiated surface (pupil polarization state distribution) and the distribution of the polarization state on the irradiated surface are calculated (S14). Specifically, in the distribution calculating step S14, the distribution of the polarization states and the distribution of the polarization states in the aperture are calculated with reference to the information on the distribution and the position of the optical rotation amount (phase shift amount) of each aspherical optical rotator (phase shifter) in addition to the above-mentioned design information.

Next, it is determined whether or not the distribution of the polarization states in the apertures of the plurality of points on the irradiation surface and the distribution of the polarization states on the irradiation surface, which are calculated in the distribution calculating step S14, are substantially uniform to a desired extent (S12). If it is determined in the determination step S12 that at least one of the distribution of polarization states and the distribution of polarization states in the aperture is not substantially uniform to a desired extent (in the case of NO in the figure), the process returns to the design step S13 of the aspherical optical rotator (phase shifter). On the other hand, if it is determined in the determination step S12 that both the distribution of the polarization states in the aperture and the distribution of the polarization states are substantially uniform to a desired degree (YES in the figure), the process proceeds to a shape determination step S15 of the aspherical optical rotator (phase shifter).

For example, in the shape determining step S15 in which the designing step S13 and the distribution calculating step S14 are repeated in a trial and error manner, the surface shape of the aspherical optical rotator (phase shifter) necessary for realizing the required optical rotation amount (phase shift amount) distribution (optical rotation amount (phase shift amount) distribution to be given to each aspherical optical rotator (phase shifter) calculated in the designing step S13 is determined. Finally, a plurality of aspherical optical rotators (phase shifters) having the surface shape determined in the shape determining step S15 and an optical axis correction plate having a surface shape complementary to the surface shape are manufactured, and the manufactured aspherical optical rotators (phase shifters) are incorporated at specific positions in the optical system (S16). As described above, the shape determining step S15 and the manufacturing and mounting step S16 constitute an adjusting step of forming and arranging a plurality of aspherical optical rotators (phase shifters) each having a desired distribution of the amount of rotation (phase shift amount). Thus, the adjustment method of the present embodiment is ended.

Next, as a modification of the present embodiment, an adjustment method capable of easily and accurately obtaining a required distribution of the amount of rotation (phase shift amount) to be applied to each aspherical optical rotator (phase shifter) without trial and error will be described. Fig. 24 is a schematic flowchart showing the respective steps of the adjustment method according to the modification of the present embodiment. In the adjustment method of the modification shown in fig. 24, as in the adjustment method shown in fig. 23, distribution of polarization states in the pupil (intra-pupil polarization state distribution or pupil polarization state distribution) and distribution of polarization states on the irradiated surface with respect to a plurality of points on the irradiated surface are obtained (S21). Specifically, in the distribution obtaining step S21, the distribution of the pupil polarization states with respect to the plurality of points on the irradiated surface and the distribution of the polarization states on the irradiated surface are calculated based on the design data of the illumination optical devices (1 to PL). Alternatively, the polarization measurement unit 18 described above measures the distribution of the intra-pupil polarization state at a plurality of points on the irradiation surface and the distribution of the polarization state at the irradiation surface for each device actually manufactured.

Next, similarly to the adjustment method shown in fig. 23, it is determined whether or not the distribution of the intra-pupil polarization states of the plurality of points on the irradiation surface and the distribution of the polarization states of the irradiation surface, which are obtained by calculation based on the design data or measurement by the polarization state measurement unit 18, are substantially uniform to a desired degree (S22). If it is determined in the determination step S22 that at least one of the distribution of the intra-pupil polarized light state and the distribution of the polarized light state is not substantially uniform to a desired extent (no in the figure), the process proceeds to an approximation step S23 of the intra-pupil polarized light state distribution. On the other hand, if it is determined in the determination step S22 that both the distribution of the pupil polarization state and the distribution of the polarization state are substantially uniform to a desired extent (in the case of yes in the figure), the process proceeds to a shape determination step S27 of the aspherical optical rotator (phase shifter).

In the in-pupil polarized light state distribution approximating step S23, the in-pupil polarized light state distribution for each point on the illuminated surface obtained in the distribution obtaining step S21 is approximated by a specific polynomial which is a function of the pupil coordinates of the illumination pupil surface. For example, in the present embodiment, when 2-pole illumination and Annular illumination are performed, for example, distribution of the polarization state of illumination light in the pupil is performed by using a Zernike Annular polynomials polynomial, and a specific degree of polarization DSP (DSP) is used₁，DSP₂，DSP₃) The distribution of (a) is expressed. This is because, in the annular illumination, the shape of the effective light source region in the pupil is a circular ring (annular shape), and in the 2-pole illumination, the 2-pole effective light source region in the pupil occupies a part of the circular ring. In the expression of the nintend's ring polynomial for expressing the distribution in the pupil of a specific polarization degree DSP, the pupil polar coordinates (ρ, θ) are used as a coordinate system, and the cylindrical function of the nintend's ring is used as an orthogonal function system.

That is, the specific polarization degree DSP (ρ, θ) is developed as the following expression (b) by the cylindrical function AZi (ρ, θ) of the ninx ring.

DSP(ρ，θ)＝∑Ci·AZi(ρ，θ)

＝C1·AZ1(ρ，θ)+C2·AZ2(ρ，θ)

…+Cn·AZn(ρ，θ) (b)

Here, Ci is a coefficient of each term of the nintend cyclic polynomial. In the functional system AZi (ρ, θ) of each term of the ninx cyclic polynomial, the following table (1) shows only the functions AZ1 to AZ16 of the 1 st to 16 th terms. Further, [ epsilon ] included in the functions AZ2 to AZ16 is an annulus ratio of an annular region in which the effective light source region occupies a part or the whole of the effective light source region within the pupil (inner diameter/outer diameter of the annular region ═ σ inner diameter/σ outer diameter).

TABLE 1

Watch (1)

AZ11

AZ2

AZ3

AZ4

AZ5

AZ6

AZ7

AZ8

AZ9

AZ10

AZ11

AZ12

AZ13

AZ14

AZ15

AZ16

On the other hand, in the case of circular illumination, for example, the distribution of the polarization state of illumination light in the pupil is calculated by edge zernike polynomials (fringe zernike polynomials), and a specific degree of polarization DSP (DSP) is used₁、DSP₂、DSP₃) The distribution of (a) is expressed. This is because, in circular illumination, the shape of the effective light source region in the pupil is circular. In the expression of the edge nintendue polynomial for expressing the distribution in the pupil of a specific polarization degree DSP, the pupil polar coordinates (ρ, θ) are used as a coordinate system, and the cylindrical function of the edge nintendue is used as an orthogonal function system.

That is, the specific polarization degree DSP (ρ, θ) is developed as the following expression (c) by the cylindrical function FZi (ρ, θ) of edge tenick e.

DSP(ρ，θ)＝∑Bi·FZi(ρ，θ)

＝B1·FZ1(ρ，θ)+B2·FZ2(ρ，θ)

…+Bn·FZn(ρ，θ) (c)

Here, Bi is a coefficient of each term of the edge nintendo polynomial. In the following, in the function system FZi (ρ, θ) of each term of the edge nintendo polynomial, only the functions FZ1 to FZ16 concerning the 1 st to 16 th terms are shown in the following table (2).

Watch (2)

FZ1：1

FZ2：ρcosθ

FZ3：ρsinθ

FZ4：2ρ²-1

FZ5：ρ²cos2θ

FZ6：ρ²sin2θ

FZ7：(3ρ²-2)ρcosθ

FZ8：(3ρ²-2)ρsinθ

FZ9：6ρ⁴-6ρ²+1

FZ10：ρ³cos3θ

FZ11：ρ³sin3θ

FZ12：(4ρ²-3)ρ²cos2θ

FZ 13：(4ρ²-3)ρ²sin2θ

FZ 14：(10ρ⁴-12ρ²+3)ρcosθ

FZ15：(10ρ⁴-12ρ²+3)ρsinθ

FZ16：20ρ³-30ρ⁴+12ρ²-1

Next, in the adjustment method of the present modification, the distribution of the polarization state with respect to each point is evaluated by a polarization state distribution polynomial which is a function of the image plane polar coordinates (h, α) and the pupil polar coordinates (ρ, θ) based on the coefficients Ci of the terms in the nintendo polynomial obtained in the approximation step S23 (S24). Specifically, in the evaluation step S24, a polarization state distribution polynomial is set that represents the distribution of the polarization states at each point as a function of the image plane polar coordinates (h, α) and the pupil polar coordinates (ρ, θ). Further, as for the setting of the polarization state distribution polynomial, reference is made to US2003/0206289 and to JP 2005-12190.

In the above-mentioned publication, an aberration polynomial (aberration polynomial) is set which expresses the wavefront aberration of the projection optical system as a function of the image plane polar coordinates (h, α) and the pupil polar coordinates (ρ, θ), but it is obvious that the polarization state distribution polynomial can be set by the same method. In this way, in the evaluation step S24, the coefficients of the terms in the polarization state distribution polynomial are determined from the tenick coefficients Ci of the terms in the tenick polynomial obtained in the approximation step (S23), and the distribution of the polarization state at each point is expressed by the polarization state distribution polynomial and evaluated.

Specifically, as disclosed in the above-mentioned publication, focusing on the nintend function Zi of a specific term, for example, the coefficient of the specific term in the polarization state distribution polynomial is determined by a least square method, for example, from the distribution of the corresponding nintend coefficients Ci in the image plane (the distribution of the coefficients Ci at each point). Note that focusing on the other specific terms of the nintend function Zi, the coefficients of the other terms in the polarization state distribution polynomial are sequentially determined by, for example, the least square method from the in-plane distribution of the corresponding nintend coefficients Ci.

In this way, in the evaluation step S24, a polarization state distribution polynomial for simultaneously expressing the distribution in the pupil and the distribution in the image plane of the polarization state distribution is finally obtained. In this way, by using the polarization state distribution polynomial which simultaneously expresses the intra-pupil distribution and the intra-image-plane distribution of the polarization state distribution, the polarization state distribution can be resolved analytically, and the optical adjustment solution can be calculated quickly and accurately, as compared with a method of performing numerical optimization by trial and error using a computer. That is, since the characteristics of the polarization state distribution state are easily grasped by the polarization state distribution polynomial, prediction of optical adjustment is easily proposed.

Next, in the design step S25 of the aspherical optical rotators (phase shifters), in order to adjust the distribution of the polarization state at each of the plurality of points on the irradiated surface independently and adjust the distribution of the polarization state at the irradiated surface as necessary so that both the pupil polarization state and the distribution of the polarization state in the irradiated surface become substantially uniform to a desired degree, a desired distribution of the amount of rotation (phase shift amount) to be applied to each of the plurality of aspherical optical rotators (phase shifters) is determined (calculated). Specifically, first, the distribution of the polarization state of the irradiated surface (image plane) obtained in the distribution obtaining step S21 is approximated in advance by an ninx polynomial which is a function of the image plane polar coordinates (h, α), as necessary.

Then, the distribution of the optical rotation amount (phase shift amount) to be given to each aspherical optical rotator (phase shifter) is expressed by, for example, a ninx polynomial using polar coordinates on the optical surface of the aspherical optical rotator (phase shifter). Then, a 1 st table T21 showing the relationship between the coefficients of the terms of the ninx polynomial for expressing the distribution of the optical rotation amount (phase shift amount) of each aspherical optical rotator (phase shifter) and the change in the distribution of the pupil polarization state with respect to each point on the irradiated surface, and a 2 nd table T22 showing the relationship between the coefficients of the terms of the ninx polynomial for expressing the distribution of the optical rotation amount (phase shift amount) of each aspherical optical rotator (phase shifter) and the distribution of the polarization state on the irradiated surface are prepared.

In this way, in the designing step S25, an optimization method is obtained by using a linear combination of the polarization state distribution information obtained in the evaluating step S24 and approximated by the ninx polynomial according to need, the correlation between the distribution of optical amounts (phase shift amounts) of the respective aspherical optical rotators (phase shifters) and the change in the distribution of pupil polarization states in table 1T 21, and the correlation between the distribution of optical amounts (phase shift amounts) of the respective aspherical optical rotators (phase shifters) and the change in the distribution of polarization states in table 2T 22, based on the polarization state distribution evaluating result (specifically, the polarization state distribution polynomial expressing both the distribution of polarization states and the distribution of polarization states in the image plane), the optical amounts to be applied to the respective aspherical optical rotators (phase shifters) to maintain or adjust the distribution of polarization states of the irradiated surface substantially uniformly, and to adjust the distribution of pupil polarization states of the respective points on the irradiated surface substantially uniformly (phase shift) distribution.

Next, in a state where a plurality of aspherical optical rotators (phase shifters) to which the distribution of the amount of rotation (phase shift amount) determined in the designing step S25 is added are arranged at the set positions, that is, in a state where the aspherical optical rotators (phase shifters) are mounted, pupil polarization state distributions at a plurality of points on the surface to be irradiated and polarization state distributions on the surface to be irradiated are calculated (S26). Then, it is determined whether the pupil polarization state distribution of the plurality of points on the irradiated surface and the polarization state distribution on the irradiated surface calculated in the distribution calculating step S26 are substantially uniform to a desired extent (S22). Since the desired distribution of the optical rotation amounts (phase shift amounts) can be easily and accurately obtained without trial and error by the optimization method based on the linear coupling, the determination step S22 determines that both the distribution of the pupil polarization state and the distribution of the polarization state are substantially uniform to a desired extent, and the process proceeds to the shape determination step S27 of the aspherical optical rotator (phase shifter).

In the shape determining step S27, the surface shape of the aspherical optical rotator (phase shifter) necessary for realizing the required optical rotation amount (phase shift amount) distribution calculated in the designing step S25 is determined. Finally, a plurality of aspherical optical rotators (phase shifters) having the surface shape determined in the shape determining step S27 and an optical axis correction plate having a surface shape complementary to the surface shape are manufactured, and the pairs of aspherical optical rotators (phase shifters) thus manufactured are incorporated at specific positions in the optical system (S28). Thus, the adjustment method of the modification is ended.

The adjustment method according to each of the embodiments and the modifications described above can be used for adjusting a plurality of exposure apparatuses installed in a semiconductor manufacturing factory, for example. In this case, it is preferable to adjust the polarization states of the plurality of exposure devices to be the same as each other. This makes it possible to share OPC (optical proximity effect correction) of a mask used by a user of an exposure apparatus among a plurality of exposure apparatuses, thereby reducing the mask cost.

Next, an example of a production system of a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a microcomputer, or the like) using an exposure system having a plurality of exposure devices will be described. The maintenance service such as the trouble-handling and the periodic maintenance of the manufacturing apparatus installed in the semiconductor manufacturing factory, the software provision, etc. is performed by using a computer network outside the manufacturing factory.

Fig. 25 shows the entire system of the present embodiment divided from a certain angle. In the figure, 301 is a business of a vendor (device supplier) that provides a manufacturing apparatus for semiconductor devices. Examples of the manufacturing apparatus include various semiconductor manufacturing apparatuses for processing used in a semiconductor manufacturing plant, for example, a pre-process apparatus (a photolithography apparatus such as an exposure apparatus, a resist processing apparatus, and an etching apparatus, a heat treatment apparatus, a film formation apparatus, and a planarization apparatus), and a post-process apparatus (an assembly apparatus, an inspection apparatus, and the like). The enterprise 301 includes a main management system 308 for providing a maintenance database of the manufacturing apparatus, a plurality of operation terminal computers 310, and a Local Area Network (LAN)309 for connecting them to construct an internal network. The master management system 308 has a gateway for connecting the LAN 309 to the internet 305, which is an external network of a business, and a security function for restricting connection from the outside.

Meanwhile, reference numerals 302 to 304 denote manufacturing plants of semiconductor manufacturers as users of manufacturing apparatuses. The manufacturing plants 302 to 304 may be plants belonging to different factories, or may be plants belonging to the same factory (for example, a factory for a previous process, a factory for a subsequent process, or the like). Each of the factories 302 to 304 is provided with a plurality of manufacturing apparatuses 306 including the exposure system (a plurality of exposure apparatuses) described above, a Local Area Network (LAN)311 for constructing an intranet by connecting them, and a main management system 307 as a monitoring apparatus for monitoring the operating state of each manufacturing apparatus 306. The master management system 307 provided in each of the plants 302 to 304 has a gateway for connecting the LAN 311 in each plant to the internet 305, which is an external network of the plant. This makes it possible to connect the master management system 308 of the vendor 301 side from the LAN 311 of each factory via the internet 305, and to obtain a connection permission only for a user limited by the security function of the master management system 308.

Specifically, through the internet 305, in addition to the state information indicating the operation status of each manufacturing apparatus 306 (for example, the symptoms of the manufacturing apparatus having a failure) being notified from the factory side to the vendor side, maintenance information such as response information (for example, information indicating a method of handling a failure, software and data for handling), the latest software, and help information corresponding to the notification can be received from the vendor side. A communication protocol (TCP/IP) commonly used in the Internet is used for data communication between each of the factories 302-304 and the vendor 301 and data communication on the LAN 311 in each factory. As an external network outside the plant, a highly secure private line network (ISDN or the like) that does not allow a connection from a third party may be used instead of the internet. The master management system is not limited to the one provided by the vendor, and may be configured by the user, installed on an external network, and allow connection from a plurality of factories of the user to the database.

Fig. 26 is a conceptual diagram showing the entire system of the present embodiment divided from a different angle from that of fig. 25. In the example of fig. 25, a plurality of customer plants each having a manufacturing apparatus and a management system of a vendor of the manufacturing apparatus are connected by an external network, and production management of each plant and information of at least 1 manufacturing apparatus are communicated via the external network. In contrast, in this example, a factory having a plurality of manufacturing apparatuses of vendors and a management system of each vendor of the plurality of manufacturing apparatuses are connected by an external network outside the factory, and maintenance information of each manufacturing apparatus is communicated by data. In the drawing, reference numeral 201 denotes a manufacturing plant of a manufacturing apparatus user (semiconductor device manufacturer), and manufacturing apparatuses for performing various processes, which are exemplified by the 1 st and 2 nd exposure apparatuses 202, the resist processing apparatus 203, and the film formation processing apparatus 204 according to the above embodiments, are introduced into a manufacturing line of the manufacturing plant. In fig. 26, only 1 manufacturing plant 201 is shown, but actually, a plurality of plants are networked in the same manner. Each device in the factory is connected by a LAN 206 to form an internal network, and the operation management of the manufacturing line is performed by a master management system 205.

Meanwhile, each enterprise of vendors (apparatus suppliers), such as the exposure apparatus manufacturer 210, the photoresist processing manufacturer 220, and the film forming apparatus manufacturer 230, has a master management system 211, 221, and 231 that remotely maintains the supplied apparatuses, and these systems include a maintenance database and a gateway (gateway) of an external network as described above. The master management system 205 for managing each device in the manufacturing plant of the user and the management systems 211, 221, and 231 of the vendors of each device are connected by an internet network or a dedicated network as the external network 200. In this system, when a failure occurs in any one of a series of manufacturing machines in the manufacturing line, the operation of the manufacturing line is stopped, but by receiving remote maintenance via the internet 200 from a vendor of the failed machine, it is possible to quickly respond to the failure and to minimize the stoppage of the manufacturing line.

Each manufacturing apparatus installed in a semiconductor manufacturing plant includes a display, a network interface, and a computer for executing network connection software and apparatus operation software stored in a storage device. The storage device may be a built-in memory, a hard disk, a network archive server, or the like. The software suite for network connection includes a dedicated or general-purpose web browser, and provides a user interface such as a screen shown as an example in fig. 27 to a display.

An operator who manages a manufacturing apparatus in each factory inputs information such as a model (401), a serial code (402), an event name (403) of a trouble, a date of occurrence (404), an emergency degree (405), a symptom (406), a processing method (407), and a history (408) of the manufacturing apparatus to an input project on a screen while referring to the screen. The entered information is sent to a maintenance database via the Internet, and the resulting maintenance information is sent back from the maintenance database and is presented on a display. The user interface provided by the web browser also realizes hyperlink functions (410-412) as shown in the figure, so that the operator can link more detailed information of each item, or can extract the latest version of software used in the manufacturing device from a software library provided by a vendor, or can extract an operation manual (help information) referred by the operator of the factory.

The information on the polarization state measured by the polarization measurement unit 18 in the above-described embodiment may be included in the above-described state information, and the information on the adjustment amounts of the variable phase difference member and the variable optical rotation member may be included in the above-described response information.

In the above-described aspherical optical rotator, if only the primary component (tilt component) of the distribution of the amount of light rotation can be corrected by the aspherical optical rotator, a wedge-shaped optical rotator can be used as shown in fig. 28 (a). In this case, when the wedge angle of the wedge-shaped optical rotator is extremely shallow (for example, in the range of 0.5 'to 10'), the optical axis correction plate may not be provided.

In the above-described aspherical phase shifter, if only the primary component (tilt component) of the phase shift amount distribution is corrected by the aspherical phase shifter, a light transmitting member having a stress deformation distribution (stress birefringence distribution) of the primary component may be used instead of the aspherical phase shifter as shown in fig. 28 b. As shown in the phase shift amount distribution diagram 28(c) of the light transmitting member shown in fig. 28(b), a phase shift amount distribution of the primary component (oblique component) is formed.

Further, according to the adjustment method of each of the above embodiments, even when the light transmitting member constituting the mask has a birefringence distribution, for example, the mask can be illuminated with illumination light having a polarization distribution that compensates for the birefringence distribution inside the mask, so that it is possible to correct deterioration of the polarization state caused by the mask and reduce line width abnormality of the pattern formed on the photosensitive substrate. Further, even when the projection optical system has a specific retardation distribution, the mask can be illuminated with illumination light having a polarization distribution that compensates for the retardation distribution, so that it is possible to correct deterioration of the polarization state by the projection optical system and reduce line width abnormality of the pattern formed on the photosensitive substrate.

In the exposure apparatus according to the above-described embodiment, a microdevice (such as a semiconductor device, an image pickup device, a liquid crystal display device, or a thin film magnetic head) can be manufactured by illuminating a mask (reticle) with an illumination optical device (illumination step) and exposing a transfer pattern formed on the mask onto a photosensitive substrate with a projection optical system (exposure step). Next, an example of a method for obtaining a semiconductor device as a microdevice by forming a specific circuit pattern on a wafer or the like as a photosensitive substrate by using the exposure apparatus according to the above-described embodiment will be described with reference to a flowchart of fig. 29.

First, in step 301 of fig. 29, a metal film is evaporated on 1 lot of wafers. In a next step 302, a photoresist is coated on the metal film on the 1 lot of wafers. Then, in step 304, the image of the pattern on the mask is sequentially subjected to exposure transfer onto the respective shot areas on the 1 lot of wafers by the exposure apparatus of the above-described embodiment through the projection optical system. Then, after developing the photoresist on the 1 lot of wafers in step 304, a circuit pattern corresponding to the pattern on the mask is formed on each shot region on each wafer by etching the photoresist pattern as a mask on the 1 lot of wafers in step 305. Then, by forming a circuit pattern in a layer higher than the above, a device such as a semiconductor device is manufactured. As described above, the semiconductor device having an extremely fine circuit pattern can be obtained with high productivity.

In the exposure apparatus of the above embodiment, a liquid crystal display device as a microdevice can be obtained by forming a specific pattern (circuit pattern, electrode pattern, or the like) on a plate material (glass substrate). An example of this method will be described below with reference to the flowchart of fig. 30. In fig. 30, in a pattern forming step 401, a so-called photolithography step is performed in which the exposure apparatus of the above-described embodiment is used to transfer and expose the pattern of the mask onto a photosensitive substrate (e.g., a glass substrate coated with a photoresist). By this photolithography step, a specific pattern including a plurality of electrodes and the like is formed on the photosensitive substrate. Then, the exposed substrate is subjected to various processes such as a developing process, an etching process, and a photoresist stripping process to form a specific pattern on the substrate, and then is subjected to a next color filter forming process 402.

Next, in the color filter forming step 402, a plurality of groups of 3 dots corresponding to R (red), G (green), and B (blue) are arranged in a matrix, or a plurality of groups of R, G, B of 3 stripe-type color filters are arranged in the horizontal scanning line direction. Then, after the color filter forming step 402, a device assembling step 403 is performed. In the element assembling step 403, a liquid crystal panel (liquid crystal element) is assembled using the substrate having the specific pattern obtained in the pattern forming step 401, the color filter obtained in the color filter forming step 402, and the like.

In the element assembling step 403, for example, a liquid crystal panel (liquid crystal element) is manufactured by injecting liquid crystal between the substrate having the specific pattern obtained in the pattern forming step 401 and the color filter obtained in the color filter forming step 402. Then, in the module assembling step 404, the liquid crystal display device is completed by mounting various components such as a circuit for performing a display operation of the assembled liquid crystal panel (liquid crystal device) and a backlight. As described above, the liquid crystal display element having an extremely fine circuit pattern can be obtained with high productivity.

In the above-described embodiment, the ArF excimer laser (wavelength: 193nm) and the KrF excimer laser (wavelength: 248nm) are used as the exposure light, but the present invention is not limited to this, and can be applied to other suitable light sources, for example, a F2 laser light source for supplying a laser beam having a wavelength of 157 nm.

In the above-described embodiment, the present invention is applied to an illumination optical apparatus for illuminating a mask in an exposure apparatus, but the present invention is not limited to this, and may be applied to a general illumination optical apparatus for illuminating an illumination target surface other than a mask and an adjustment method thereof.

Claims (58)

1. An illumination optical device for illuminating an illuminated surface in a desired polarization state based on light from a light source, comprising:

a 1 st polarization changing device for locally changing a polarization state of light illuminating the illuminated surface;

and a 2 nd polarization changing device for locally changing a polarization state at a position on or near a pupil plane of the illumination optical device.

2. The illumination optical apparatus according to claim 1, wherein: at least one of the 1 st and 2 nd polarization changing devices has a phase member for locally changing the phase of the light passing therethrough.

3. The illumination optical apparatus according to claim 2, wherein:

the phase member has a pair of optical members formed of a biaxial crystalline material and disposed close to each other in an optical axis direction;

a pair of optical members, the pair of optical members being positioned such that a crystal optical axis of one optical member and a crystal optical axis of the other optical member are substantially orthogonal to each other;

the pair of optical members are formed in such a manner that differences between the thickness of the one optical member and the thickness of the other optical member along a plurality of straight lines parallel to the optical axis are different from each other.

4. The illumination optical apparatus according to claim 2, wherein: the phase member has a plurality of phase change adjusting portions which are arranged corresponding to the plurality of regions on the pupil surface, respectively, and which can adjust a phase change of the light beam passing therethrough.

5. The illumination optical apparatus according to claim 4, wherein: the phase change adjusting portion has a Barviny wavelength plate or a Soxhlet wavelength plate.

6. The illumination optical apparatus according to claim 1, wherein: at least one of the 1 st and 2 nd polarization changing devices has a polarization changing member for locally adjusting the polarization state of incident light.

7. The illumination optical apparatus according to claim 6, wherein: the polarization-variable member has a plurality of polarization-variable elements for independently adjusting the polarization state of incident light in a plurality of local regions.

8. The illumination optical apparatus according to claim 1, wherein:

a polarization state measuring device for measuring the polarization state of the light reaching the irradiated surface;

at least one of the 1 st and 2 nd polarization changing devices is adjusted based on the measurement result of the polarization state measuring device.

9. The illumination optical apparatus according to claim 1, wherein:

the 1 st polarization changing device is disposed at any one of the irradiated surface, a position in the vicinity of the irradiated surface, a position optically conjugate to the irradiated surface, and a position in the vicinity of the position optically conjugate to the irradiated surface,

the 2 nd polarization changing device is disposed at a position on or near a pupil plane of the illumination optical device.

10. An illumination optical device for illuminating an irradiation surface with light from a light source, comprising:

a polarization conversion element disposed on or near the illumination pupil surface for converting the polarization state of incident light into a specific polarization state;

the polarization conversion element locally changes the polarization state of light at a position at or near the pupil plane of the illumination optical device.

11. The illumination optics of claim 10, wherein: the polarization conversion element has a plurality of variable optical rotation members for variably imparting a rotation angle to incident linearly polarized light.

12. The illumination optical apparatus according to claim 11, wherein: each of the plurality of variable optical rotation members is formed of an optical material having optical rotation, and has 2 deflection prisms relatively movable in a direction intersecting with an optical axis of the illumination optical device.

13. The illumination optics of claim 12, wherein: the 2 off-angle prisms are arranged such that a crystal optical axis is substantially parallel to the optical axis.

14. The illumination optics of claim 13, wherein: the 2 off-angle prisms have wedge-shaped cross-sectional shapes that are complementary to each other.

15. The illumination optical apparatus according to claim 11, wherein: the plurality of variable optical rotation members are arranged in a circumferential direction of a circle centered on an optical axis of the illumination optical device.

16. The illumination optics of claim 15, wherein: each of the plurality of variable optical rotation members has a substantially fan-like shape.

17. The illumination optical apparatus according to claim 11, wherein:

and a polarization state measuring device for measuring the polarization state of the light reaching the irradiated surface,

the plurality of variable optical rotation members are adjusted based on the measurement result of the polarization state measuring device.

18. The illumination optics of claim 10, wherein: the polarization conversion element has a plurality of variable phase difference members for variably imparting a phase difference between incident light and emitted light.

19. The illumination optics of claim 18, wherein: each of the plurality of variable phase difference members has a Bakini compensator or a Soxhlet compensator which is configured to be rotatable about an axis substantially parallel to the optical axis of the illumination optical device.

20. The illumination optics of claim 18, wherein: the plurality of variable phase difference members are arranged in a circumferential direction of a circle having an optical axis of the illumination optical device as a center.

21. The illumination optics of claim 18, wherein:

a polarization state measuring device for measuring the polarization state of the light reaching the irradiated surface;

the plurality of variable retardation members are adjusted based on the measurement result of the polarization state measuring device.

22. The illumination optics of claim 10, wherein:

a polarization conversion element which is disposed in the vicinity of the surface to be irradiated, at a position optically conjugate with the surface to be irradiated, or in the vicinity of the conjugate position, and which converts the polarization state of incident light into a specific polarization state;

the other polarization conversion element locally changes the polarization state of the illumination light on the illuminated surface.

23. An illumination optical device for illuminating an irradiation surface with light from a light source, comprising:

a polarization conversion element disposed in the vicinity of the surface to be irradiated, at a position optically conjugate with the surface to be irradiated, or in the vicinity of the conjugate position, for converting the polarization state of incident light into a specific polarization state;

the polarization conversion element locally changes the polarization state of the illumination light on the illuminated surface.

24. The illumination optics of claim 23, wherein: the polarization conversion element has a plurality of variable phase difference members for variably imparting a phase difference between incident light and emitted light.

25. The illumination optics of claim 24, wherein: each of the plurality of variable phase difference members has a Bakini compensator or a Soxhlet compensator which is configured to be rotatable about an axis substantially parallel to the optical axis of the illumination optical device.

26. The illumination optics of claim 24, wherein:

a polarization state measuring device for measuring the polarization state of the light reaching the irradiation surface;

the plurality of variable retardation members are adjusted based on the measurement result of the polarization state measuring device.

27. The illumination optics of claim 23, wherein: the polarization conversion element has a plurality of variable optical rotation members for variably imparting a rotation angle to incident linearly polarized light.

28. The illumination optics of claim 27, wherein:

a polarization state measuring device for measuring the polarization state of the light reaching the irradiation surface;

the plurality of variable optical rotation elements are adjusted individually based on the measurement result of the polarization state measuring device.

29. The illumination optics of claim 23, wherein: the polarization conversion element includes:

a 1 st polarization conversion element;

and a 2 nd polarization conversion element disposed at a position between the first polarization conversion element and the irradiated surface.

30. The illumination optics of claim 29, wherein:

the 1 st polarization conversion element is configured to be away from the conjugate position by a 1 st distance, and the 2 nd polarization conversion element is configured to be away from the conjugate position by a 2 nd distance or from the conjugate position and the optical conjugate position, wherein the 1 st distance and the 2 nd distance are equal.

31. The illumination optics of claim 29, wherein:

the 1 st polarization conversion element is disposed at a 1 st distance from the conjugate position, and the 2 nd polarization conversion element is disposed at a 2 nd distance from the conjugate position or from the conjugate position and the optically conjugate position, wherein the 1 st distance and the 2 nd distance are different distances.

32. The illumination optics of claim 29, wherein:

further comprises a mask blind disposed at a position optically conjugate to the irradiated surface,

the 1 st polarization conversion element is disposed in an optical path between the light source and the mask blind,

the 2 nd polarization conversion element is disposed in an optical path between the mask blind and the irradiated surface.

33. The illumination optics of claim 32, wherein:

the optical system further includes a light integrator, and the 1 st polarization conversion element and the 2 nd polarization conversion element are disposed in an optical path between the light integrator and the irradiated surface.

34. An exposure apparatus characterized in that: the optical device according to any one of claims 1 to 33, wherein the specific pattern illuminated by the optical device is exposed on a photosensitive substrate.

35. An exposure method characterized by comprising: the illumination optical device according to any one of claims 1 to 33, wherein a specific pattern is exposed on a photosensitive substrate.

36. A component manufacturing method, comprising:

an exposure step of exposing a specific pattern on a photosensitive substrate by using the illumination optical device according to any one of claims 1 to 33; and

and a developing step of developing the photosensitive substrate exposed in the exposure step.

37. An adjustment method of an illumination optical apparatus for illuminating an illuminated surface with light from a light source, the adjustment method comprising:

a first step of locally changing the polarization state of illumination light on the irradiation target surface; and

and a 2 nd step of locally changing a polarization state of light at a position on or near a pupil plane of the illumination optical device.

38. The adjustment method of claim 37, characterized in that: at least one of the steps 1 and 2 includes a step 3 of locally changing the phase of the light passing therethrough.

39. The adjustment method of claim 38, characterized in that: at least one of the steps 1 and 2 includes a step 4 of variably applying a twilight angle to incident linearly polarized light.

40. The adjustment method of claim 37, characterized in that:

a polarization state measuring step for measuring a polarization state of the light reaching the irradiated surface;

in at least one of the steps 1 and 2, the adjustment is performed based on the measurement result in the polarization state measurement step.

41. The adjustment method of claim 37, characterized in that:

in the step 1, the polarization state of any one of the irradiated surface, a position in the vicinity of the irradiated surface, a position optically conjugate with the irradiated surface, and a position in the vicinity of the position optically conjugate with the irradiated surface is locally changed;

in the step 2, the polarization state at a position on or near the pupil plane of the illumination optical device is locally changed.

42. An illumination optical apparatus characterized by: adjustment is performed according to the adjustment method of claim 37.

43. An adjustment method for an exposure apparatus for illuminating a specific pattern by an illumination optical device and exposing the specific pattern on a photosensitive substrate,

the method is characterized in that:

adjusting the illumination optics according to the adjustment method of claim 37.

44. An adjustment method according to claim 43, characterized in that:

a polarization state measurement step for measuring the polarization state of light that reaches the photosensitive substrate;

in at least one of the steps 1 and 2, the adjustment is performed based on the measurement result in the polarization state measurement step.

45. An exposure apparatus characterized in that: the adjustment is made according to the adjustment method of claim 44.

46. An adjusting method of an exposure system comprising a 1 st exposure device and a 2 nd exposure device, wherein

The 1 st exposure device has a 1 st illumination optical device for illuminating the 1 st pattern on the 1 st mask, and exposes the 1 st pattern of the 1 st mask on the photosensitive substrate,

a 2 nd exposure device having a 2 nd illumination optical device for illuminating a 2 nd pattern on a 2 nd mask, and exposing the 2 nd pattern of the 2 nd mask on the photosensitive substrate;

the method is characterized in that:

the 1 st and 2 nd illumination optical devices are adjusted according to the adjustment method of claim 37.

47. The adjustment method of claim 46, further comprising:

measuring the polarization state of light to the photosensitive substrate of the 1 st and 2 nd exposure devices; and

the variable phase difference members of the 1 st and 2 nd exposure apparatuses are adjusted in accordance with the measured polarization states.

48. An adjustment method according to claim 47, characterized in that: in the step of adjusting the variable phase difference member, the polarization state of light to the photosensitive substrate of the 1 st exposure device and the polarization state of light to the photosensitive substrate of the 2 nd exposure device are adjusted to substantially match each other.

49. An adjustment method according to claim 48, characterized in that: the step of adjusting the variable retardation member includes at least one of a step of locally changing a polarization state of the illumination light of the irradiation target surface and a step of locally changing a polarization state of the light at a position on or near a pupil surface of the illumination optical device.

50. An exposure system characterized by: the adjustment method according to claim 46.

51. A microdevice manufacturing plant comprising:

a manufacturing apparatus group for various processes including the 1 st exposure apparatus and the 2 nd exposure apparatus according to claim 50, a local network for connecting the manufacturing apparatus group, and a gateway capable of connecting an external network outside a factory from the local network; and

information on at least 1 of the manufacturing apparatuses can be communicated.

52. A method of fabricating a micro-device, comprising:

a step of installing a manufacturing apparatus group for various processes including the 1 st exposure apparatus and the 2 nd exposure apparatus according to claim 50 in a microdevice manufacturing plant; and

and a step of manufacturing the microdevice by using the manufacturing apparatus group through a plurality of processing procedures.

53. The method of manufacturing a microcomponent of claim 52 further comprising:

connecting the manufacturing apparatus group by using a local area network; and

and communicating information on at least 1 manufacturing apparatus of the manufacturing apparatus group between the local area network and an external network outside the microdevice manufacturing plant.

54. An adjustment method of an illumination optical apparatus for illuminating an illuminated surface with light from a light source, the adjustment method comprising:

a first step of preparing a variable phase difference member for variably imparting a phase difference between incident light and emitted light;

a 2 nd step of setting the phase difference given by the variable phase difference member to a specific value; and

and a 3 rd step of disposing the variable phase difference member in an optical path between the light source and the surface to be irradiated.

55. An adjustment method according to claim 54, characterized in that: the 3 rd step is to provide the variable phase difference member in which the phase difference in the 2 nd step is set to the specific value in an optical path between the light source and the surface to be irradiated.

56. An adjustment method according to claim 54, characterized in that: the 2 nd step includes a 4 th step of measuring light passing through the variable phase difference providing member disposed in an optical path between the light source and the irradiation target surface, and a 5 th step of setting the phase difference of the variable phase difference providing member to a specific value based on a measurement result in the 4 th step.

57. An adjustment method according to claim 56, characterized in that: in the 4 th step, the polarization state of the light reaching the irradiated surface is measured.

58. An adjustment method according to claim 56, characterized in that: the method includes a 6 th step of rotating the variable phase difference member around an optical axis of the illumination optical device.