KR20010051438A - Illumination optical apparatus, exposure apparatus having the same and micro device manufacturing method using the same - Google Patents

Abstract

PURPOSE: To provide an illumination optical device for adjusting the size of an illuminated region on an irradiated face and illumination (NA) to a desired level while a loss in light quantity is reduced adequately. CONSTITUTION: An illuminated face is irradiated by an illumination optical device. The illumination optical device includes a first variable magnification optical system 4 with variable focal distance or magnification for adjusting the number of illumination openings on the illuminated face, and a second variable magnification optical system 7 with variable focal distance or magnification for changing the size of the illumination region formed on the illuminated region.

Description

ILLUMINATION OPTICAL APPARATUS, EXPOSURE APPARATUS HAVING THE SAME AND MICRO DEVICE MANUFACTURING METHOD USING THE SAME}

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an illumination optical device and an exposure apparatus provided with the illumination optical device, and particularly preferably to an exposure apparatus for manufacturing microdevices such as semiconductor devices, imaging devices, liquid crystal display devices, thin film magnetic heads, etc. by lithography. It relates to an optical device.

In a typical exposure apparatus of this kind, the luminous flux emitted from the light source enters into an optical integrator such as a micro fly's eye, for example, and forms a secondary light source consisting of a plurality of light source images on the rear focal plane. The light beam from the secondary light source is limited through the aperture stop disposed in the vicinity thereof and then enters the condenser lens. The aperture stop limits the shape or size of the secondary light source to the desired shape or size, depending on the desired illumination conditions (exposure conditions). The light beam condensed by the condenser lens forms a rectangular illumination region on a predetermined surface that is conjugate with the mask. In the vicinity of this predetermined surface, a mask blind as an illumination field stop is arrange | positioned.

Therefore, the luminous flux from the rectangular illumination region formed on the predetermined surface is limited via the illumination field stop, and then illuminates the mask in which the predetermined pattern is formed via the relay lens. In this way, the image of the opening of the illumination field stop is formed as a rectangular illumination region on the mask. The light transmitted through the pattern of the mask is imaged on the wafer via the projection optical system. In this way, the mask pattern is subjected to projection exposure (transfer) on the wafer. In addition, the pattern formed on the mask is highly integrated, and in order to accurately transfer this fine pattern onto the wafer, it is essential to obtain a uniform illuminance distribution on the wafer.

In recent years, by changing the size of the opening (light transmitting part) of the aperture stop disposed on the exit side of the light integrator, the size of the secondary light source formed through the light integrator is changed to coherence σ of illumination. The technique of changing ((sigma) value = aperture diaphragm diameter / the pupil diameter of a projection optical system, or (sigma) value = the exit side aperture number of an illumination optical system / the incident side aperture number of a projection optical system) is attracting attention. Further, the shape of the secondary light source formed by the optical integrator is set by setting the shape of the opening of the aperture stop disposed on the exit side of the optical integrator to the annular band shape or the four hole shape (that is, the four-pole shape). Attention has been paid to a technique of improving the depth of focus and the resolution of the projection optical system by limiting to a ring-shaped or quadrupole shape.

By the way, in the exposure apparatus, depending on the characteristics of the microdevice to be manufactured, there is a case where it is desired to change the size of the illumination region, that is, the exposure region, formed on the photosensitive substrate such as a wafer. In other words, the size of the illumination region formed on the mask may be changed depending on the characteristics of the mask to be used. For example, when it is desired to form an illumination area smaller than a standard illumination area, a method of reducing the size of the opening of the illumination field stop described above can be considered. In this method, however, light loss occurs in the illumination field stop, resulting in a decrease in the throughput of the exposure apparatus.

On the other hand, in order to substantially avoid light loss in the illumination field stop, for example, a method of reducing the illumination area formed on the mask by changing the magnification of the relay lens and further reducing the exposure area formed on the photosensitive substrate. You can also think. However, in this method, the number of illumination apertures (hereinafter referred to as "lighting NA") changes in accordance with the change in the size of the illumination region formed on the mask, and hence, the optimally designed sigma value also changes.

As described above, in the exposure apparatus, there is a request to set the sigma value to a desired value similarly to the size of the exposure area according to the characteristics of the microdevice to be manufactured. In other words, in the illumination optical apparatus used for the exposure apparatus, there is a request that the illumination NA be set to a desired value as well as the size of the illumination region, depending on the characteristics of the mask to be used.

The microdevice according to the present invention includes a semiconductor element having a semiconductor integrated circuit and the like, an imaging device such as a high-definition flat panel display, a CCD, a magnetic head for a personal computer hard disk, a diffractive optical element, and the like.

In addition, in order to change exposure conditions or illumination conditions, the shape (for example, circular shape) which desires the light intensity distribution (light intensity distribution formed in the pupil position of the exposure apparatus or the vicinity) of the secondary light source formed by the optical integrator is changed. The number of illumination apertures in the mask as an object to be irradiated (NA, if changed to a shape, annular band shape or quadrupole shape) or a desired size (for example, circular, annular or quadrupole shape) ) Is changed, and there is a problem that a mask pattern which is satisfactorily made based on a desired exposure condition or a desired illumination condition cannot be exposed to a photosensitive substrate such as a wafer.

The objective of this invention was made in view of the above-mentioned subject, The illumination optical apparatus which can adjust the magnitude | size of the illumination area | region and illumination NA which are formed in a to-be-irradiated surface to a desired value, suppressing light loss satisfactorily, its illumination optics The exposure apparatus provided with the apparatus, and the microdevice manufacturing method using the exposure apparatus are provided.

In addition, another object of the present invention is an exposure apparatus and a micro-exposure apparatus capable of exposing a mask pattern formed satisfactorily on the basis of a desired exposure condition or a desired illumination condition to a photosensitive substrate such as a wafer even if the exposure condition or the illumination condition is changed. It is to provide a device manufacturing method.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically shows the configuration of a device with an illumination optical device according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view illustrating an internal configuration and an operation of the optical retardation unit 2 of FIG. 1;

3 shows the focal lengths of the zoom lens 4 and the zoom lens 7 according to the first embodiment, the size of the rectangular illumination area formed on a predetermined surface which is conjugate with the mask 10, and Drawings illustrating the relationship of illumination NA,

4 is a view for explaining the operation of the diffractive optical element 3a for annular band modified illumination,

5 is a view for explaining the operation of the diffractive optical element 3b for quadrupole modified illumination,

6 is a view schematically showing the configuration of an exposure apparatus with an illumination optical device according to Embodiment 2 of the present invention;

FIG. 7 shows the focal lengths of the zoom lens 4 and the micro fly eye group 50, the size of the rectangular illumination area formed on a predetermined surface conjugated with the mask 10, and the illumination NA in Example 2; Drawings illustrating the relationship,

8 is a diagram schematically showing a configuration of an exposure apparatus with an illumination optical device according to Embodiment 3 of the present invention;

FIG. 9 illustrates the relationship between the magnification of the zoom lens 41 and the zoom lens 71, the size of a rectangular illumination region formed on a predetermined surface conjugated with the mask 10, and the illumination NA in the third embodiment. Drawing,

10 is a diagram showing a flowchart of an example of a method of obtaining a semiconductor device as a micro device;

The figure which shows the flowchart about an example of the method at the time of obtaining the liquid crystal display element as a microdevice.

Explanation of symbols for the main parts of the drawings

1: light source 2: light delay unit

3: diffractive optical element 4: zoom lens

5: micro fly eye 6: aperture aperture

7: zoom lens 8: mask blind

9: relay optical system 10: mask

11 projection optical system 12 wafer

13 wafer stage 20 input means

21: control system 22-25: drive system

MEANS TO SOLVE THE PROBLEM In order to solve the said objective, in the 1st aspect of this invention, the illumination optical apparatus which illuminates a to-be-irradiated surface WHEREIN: The 1st variable-speed optical system whose focal length or magnification is variable in order to adjust the illumination aperture number in the said irradiated surface, And a second variable optical system having a variable focal length or magnification in order to change the size of the illuminated area formed on the irradiated surface.

According to a preferred aspect of the first aspect, the respective focal lengths or angular magnifications of the first and second variable optical systems are set to set the illumination numerical aperture and the size of the illumination region to desired values, respectively. It is preferable to have an adjustment system.

Further, according to a preferred aspect of the first aspect, the light source means for supplying illumination light, the plurality of light source formation means for forming a plurality of light fluxes based on the illumination light, and the light flux from the light source means in a predetermined cross section A light beam conversion optical system for converting the light beam into a light beam having a shape, wherein the first variable speed optical system guides the light beam having passed through the light beam converting optical system to the multi-light source forming means, and the second variable optical system is configured from the multi-light source forming means. It is preferable to induce a plurality of luminous fluxes of to the irradiated surface.

In this case, the multi-light source forming means has a wavefront split type optical integrator, and the first variable optical system converts the divergent light beam formed through the beam converting optical system into a substantially parallel beam flux, thereby inciting the wavefront split type optical integrator. Guided to the surface, the adjustment system changes the focal length of the second variable displacement optical system to adjust the size of the illumination region formed on the irradiated surface to a desired value, and changes the focal length of the second variable optical system It is preferable to change the focal length of the first variable speed optical system in order to adjust the illumination numerical aperture which changes according to the desired value.

Alternatively, the multi-light source forming means has an optical reflector of an inner surface reflection type, and the first variable displacement optical system focuses a divergent luminous flux formed through the beam converting optical system in the vicinity of an incident surface of the inner surface reflecting optical integrator, The adjusting system changes the magnification of the second variable magnification optical system to adjust the size of the illumination region formed on the irradiated surface to a desired value, and adjusts the number of illumination apertures that change according to the magnification change of the second variable magnification optical system. In order to adjust to a desired value, it is preferable to change the magnification of the said first variable optical system.

According to a preferred aspect of the first aspect, the apparatus includes a light source means for supplying illumination light and a light beam conversion optical system for converting the light beam from the light source means into a light beam having a predetermined cross-sectional shape, wherein the first variable The optical system guides the light beam in the light beam conversion optical system to the second variable optical system, and the second variable optical system includes multi-light source forming means for forming a plurality of light beams based on the light beams passing through the first variable optical system. The second variable speed optical system preferably guides the light beam from the first variable speed optical system to the irradiated surface.

In this case, the multi-light source forming means has an optical integrator group having a variable focal length including a plurality of wavefront split type optical integrators that are movable along an optical axis, and the first variable displacement optical system is divergent formed through the light beam conversion optical system. The luminous flux is converted into an almost parallel luminous flux and guided to the incidence plane of the optical integrator group, and the control system changes only the size of the illumination region formed on the irradiated surface to adjust to a desired value. It is preferable to change the focal length of the first variable optical system in order to change the focal length, change only the illumination numerical aperture, and adjust it to a desired value.

In this case, the optical integrator group includes a first optical integrator of positive refractive power that can move along the optical axis, a second optical integrator of negative refractive power that can move along the optical axis, in order from the light source side, A first optical integrator having a fixed refractive index third optical integrator along the optical axis, wherein the adjustment system continuously changes its focal length without substantially moving the rear focal plane of the optical integrator group; It is preferable to move the second optical integrator independently of one another along the optical axis.

Further, according to a preferred aspect of the first aspect, the luminous flux conversion optical system has a plurality of diffractive optical elements configured to be freely inserted and detached from the illumination optical path, and the plurality of diffractive optical elements differ from each other in substantially parallel luminous flux from the light source means. It is preferable to convert into the divergent light flux of cross-sectional shape.

Moreover, the 2nd characteristic of this invention is equipped with the illumination optical apparatus of a 1st characteristic, and the projection optical system for projecting and exposing the pattern of the mask arrange | positioned on the said to-be-exposed surface on a photosensitive board | substrate, The exposure apparatus characterized by the above-mentioned to provide.

In this case, it is preferable that the adjustment system adjusts each focal length or each magnification of the first variable displacement optical system and the second variable optical system based on the information on the pattern of the mask.

Further, in the third aspect of the present invention, the method includes illuminating the mask disposed on the irradiated surface by the illumination optical device of the first aspect, and transferring the pattern of the illuminated mask on the photosensitive substrate. A manufacturing method of a micro device is provided.

In this case, it is preferable to include the process of adjusting each focal length or each magnification of the said 1st displacement optical system and the said 2nd displacement optical system based on the information regarding the pattern of the said mask.

Moreover, in order to solve the said another object, in the 4th characteristic of this invention, the illumination optical apparatus which illuminates the pattern of the mask which has a predetermined pattern at the light beam for exposure, and project-exposes the pattern image of the said mask on the photosensitive board | substrate. An exposure apparatus having a projection system, comprising: input means for inputting information relating to an exposure condition on the photosensitive substrate or an illumination condition on the mask, wherein the illumination optical device is based on input information from the input means. Luminous flux converting means for converting the luminous flux for exposure into a luminous flux having a desired light intensity distribution, a first shift optical system for adjusting the number of illumination apertures in the mask based on input information from the input means, and the input means. Varying the size of the illumination area formed in the mask based on input information from the Provided is an exposure apparatus comprising a second variable optical system. In this case, the illumination optical device includes an optical integrator that illuminates the mask uniformly, the first shifting optical system is disposed on the incidence side of the optical integrator, and the second shifting optical system is the exit side of the optical integrator. It is preferably arranged in.

Moreover, in the 5th characteristic of this invention, the manufacturing of the microdevice containing the illumination process which illuminates the pattern of the mask which has a predetermined | prescribed pattern with the light beam for exposure, and the exposure process which project-exposes the pattern image of the said mask on the photosensitive board | substrate. In the method, the illuminating step includes an input step of inputting information relating to an exposure condition on the photosensitive substrate or an illumination condition on the mask, and a light that desires a light beam for exposure based on input information from the input step. On the basis of a light beam conversion step of converting to a light beam having an intensity distribution, an illumination area variable step of changing the size of an illumination area formed in the mask based on the input information from the input step, and an input information from the input means To adjust the number of illumination apertures in the mask. A manufacturing method of a micro device is provided. In this case, it is preferable that the adjustment process includes correcting the value of the illumination numerical aperture changed by the illumination region variable process to keep the value of the illumination numerical aperture almost constant.

Moreover, in the 6th aspect of this invention, in the exposure apparatus which has the illumination optical apparatus which illuminates the pattern of the mask which has a predetermined | prescribed pattern by the light beam for exposure, and the projection system which projects and exposes the pattern image of the said mask on the photosensitive board | substrate, And the illumination optical device is adapted to change the light intensity distribution at or near the pupil position of the illumination optical device, and to adjust the number of illumination apertures in the mask in accordance with the change in the light intensity distribution by the changing means. An exposure apparatus having an adjustment means is provided. In this case, the changing means preferably includes luminous flux converting means for selectively converting the luminous flux for exposure into one luminous flux among a plurality of luminous fluxes having different light intensity distributions. In this case, the luminous flux converting means includes a first diffractive optical member for forming a first light intensity distribution, and a second light different from the first light intensity distribution provided so as to be interchangeable with the first diffractive optical member for the optical path. It is preferred to have a second diffractive optical member forming an intensity distribution.

In addition, in the seventh aspect of the present invention, an illumination step of illuminating a pattern of a mask having a predetermined pattern using an illumination optical device and an exposure step of projecting and exposing the pattern image of the mask to a photosensitive substrate using a projection system. In the method of manufacturing a micro device, the illuminating step includes: a changing step of changing a light intensity distribution at or near a pupil position of the illumination optical device; and according to a change of light intensity distribution by the changing step. And a process for adjusting the number of illumination apertures in the mask.

The above and other objects, features, aspects, advantages, and the like of the present invention will become more apparent from the following detailed embodiments described with reference to the accompanying drawings.

(Example)

In the present invention, a first variable optical system for adjusting the illumination NA on the irradiated surface and a second variable optical system for changing the size of the illumination region formed on the irradiated surface are provided. In a typical embodiment of the present invention, there is provided a light beam conversion optical system for converting the light beam from the light source means into a divergent light beam having a predetermined cross-sectional shape, and the first shift optical system condenses the divergent light beam to form a multi-light source. Is guided to the irradiated surface, and the second variable displacement optical system collects light beams from a plurality of light sources formed by the multi-light source forming means and guides them to the irradiated surface.

Specifically, in the case of using a wavefront split type optical integrator such as a micro fly's eye or a fly's eye lens as the multi-light source forming means, the first variable displacement optical system converts the divergent luminous flux formed through the luminous flux converting optical system into a substantially parallel luminous flux. Induced on the plane of incidence. The second variable optical system focuses the luminous flux from the secondary light source formed on the rear focal plane of the optical integrator and guides it to the irradiated surface. In this case, the shape of each lens element (or microlens) constituting the micro fly's eye or fly's eye lens is different from the shape of the illumination region formed on the irradiated surface, the size of which depends on the focal length of the second variable optical system. .

Therefore, when the focal length of the second variable magnification optical system is changed, the size of the illumination region formed on the irradiated surface is changed, and the illumination NA on the irradiated surface is also changed. On the other hand, if the focal length of the first variable optical system is changed, the size of the illumination region formed on the incident surface of the optical integrator is changed, and as a result, only the illumination NA is changed without changing the size of the illumination region. In this way, by changing the focal length of the second variable magnification optical system, the size of the illumination region formed on the irradiated surface can be changed and adjusted to a desired value. By changing the focal length of the first variable optical system, the illumination NA changed in accordance with the change in the focal length of the second variable optical system can be adjusted to a desired value.

As described above, in the illumination optical apparatus of the present invention, by adjusting the focal lengths (or angular magnifications) of the first variable displacement optical system and the second variable optical system, the illumination NA and the illumination region can be suppressed while satisfactorily suppressing the amount of light loss. You can adjust the size to each desired value.

Therefore, in the exposure apparatus incorporating the illumination optical apparatus of the present invention, the size and sigma value of the exposure area can be adjusted to desired values while suppressing the loss of light amount in the aperture stop and the illumination field stop well. That is, in the exposure apparatus of this invention, according to the characteristic of the microdevice to manufacture, or the characteristic of the mask to be used, the magnitude | size and sigma value of an illumination area | region (exposure area) are set to a suitable value, respectively, and high exposure illuminance is carried out. And based on favorable exposure conditions, the favorable projection exposure with a high throughput can be performed.

Moreover, in the exposure method or the manufacturing method of a micro device which exposes the pattern of the mask arrange | positioned on the to-be-irradiated surface using the illumination optical apparatus of this invention, or the manufacturing method of a micro device, since projection exposure can be performed based on favorable exposure conditions, , A good micro device can be manufactured.

In addition, the present invention, in order to change the exposure conditions or illumination conditions, changing means or luminous flux converting means (for example, the diffractive optical member 3 for forming a circular luminous flux, the diffractive optical member 3a for forming a ring-band luminous flux, and Pupil position (secondary light source position formed by the optical integrator or optically conjugate position) of the illumination optical system by a mechanism for setting one of the diffraction optical members 3b for forming the four-pole beams to the illumination light path, or When the light intensity distribution in the vicinity of the position is changed, the number of illumination numerical apertures is changed, but the change in the number of illumination apertures can be corrected by adjusting (change) the magnification or the focal length of the first variable optical system as the adjusting means.

Therefore, the exposure apparatus and the manufacturing method of a micro device which can expose the mask pattern made favorable on the basis of desired exposure conditions or desired illumination conditions to a photosensitive substrate, such as a wafer, can be implement | achieved.

An embodiment of the present invention will be described based on the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows roughly the structure of the exposure apparatus provided with the illumination optical apparatus which concerns on Example 1 of this invention. In addition, in FIG. 1, the illumination optical apparatus is set to perform normal circular illumination.

The exposure apparatus of FIG. 1 is provided with the excimer laser light source which supplies wavelength light of 248 nm or 193 nm, for example as the light source 1 for supplying exposure light (lighting light). The nearly parallel luminous flux emitted from the light source 1 along the reference optical axis AX is shaped into a luminous flux having a desired rectangular cross section through a shaping optical system (not shown), and then enters the light retardation portion 2.

FIG. 2 is a perspective view illustrating the internal configuration and operation of the optical retardation unit 2 of FIG. 1.

As shown in FIG. 2, the optical retardation unit 2 includes a half mirror 200 that is 45 degrees private with respect to the optical axis AX. Therefore, the light beam incident on the half mirror 200 along the optical axis AX is divided into a light beam passing through the half mirror 200 and a light beam reflected in the + X direction from the half mirror 200. The light beam transmitted through the half mirror 200 is incident on the diffractive optical element (DOE) 3 for circular illumination along the optical axis AX.

Meanwhile, the light beam reflected in the + X direction from the half mirror 200 is reflected in the -Y direction by the first reflection mirror 201, and is reflected in the -X direction by the second reflection mirror 202, and the third reflection mirror After reflection in 203 in the + Y direction and reflection in the fourth reflection mirror 204 in the + X direction, the flow returns to the half mirror 200. The light beam returned to the half mirror 200 is divided into a light beam passing through the half mirror 200 and a light beam reflected from the half mirror 200 in the -Z direction. The light beam reflected from the half mirror 200 in the -Z direction is incident on the diffractive optical element 3 along the optical axis AX. On the other hand, the light beam passing through the half mirror 200 passes back through the first reflection mirror 201 to the fourth reflection mirror 204, and then returns to the half mirror 200 again.

As described above, the light beam incident on the optical retardation unit 2 along the optical axis AX is divided into a light beam passing through the half mirror 200 as a beam splitter and a light beam reflected by the half mirror 200. The light beams reflected by the half mirror 200 are sequentially deflected in the four reflection mirrors 201 to 204 arranged to form a rectangular delay optical path, and then return to the half mirror 200. At this time, the incidence position of the light beam incident on the half mirror 200 along the optical axis AX and the reentry position of the light beam returning to the half mirror 200 through the rectangular delayed optical path coincide with each other. Reflective mirrors 201 to 204 are arranged.

Therefore, after passing through the delay optical path once, the light beam P1 reflected from the half mirror 200 in the -Z direction is emitted along the same optical axis AX as the light beam P0 transmitted through the half mirror 200 without passing through the delay light path. An optical path length difference equal to the optical path length of the delayed optical path is provided between P0 and the light beam P1. Similarly, after passing through the retardation optical path twice, the light beam P2 reflected by the half mirror 200 is emitted along the same optical axis AX as the light beam P0 or the light beam P1. At this time, an optical path length difference equal to twice the optical path length of the delayed optical path is provided between the light beams P0 and the light beam P2, and an optical path length difference equal to the optical path length of the delayed light path is provided between the light beams P1 and the light beam P2. That is, the optical retardation unit 2 converts the light beam incident along the optical axis AX into a plurality of light beams in time (in theory, an infinite number of light beams, but in practically a finite number of light beams, ignoring the influence of light beams with small energy). By dividing, an optical path length difference equal to the optical path length of the delayed optical path is provided at two instantaneous optical moments.

In general, the reflectance of the reflection mirror is different in P-polarized light incident and S-polarized light incident, and the S-polarized light incident side can ensure higher reflectance than P-polarized light incident. Therefore, in the optical retardation unit 2, in order to prevent light loss in the delayed optical path, it is preferable to configure the light beams to enter the four reflective mirrors 201 to 204 in the S polarization state. In the present embodiment, as shown in FIG. 2, the incident light beam is incident on the half mirror 200 in the P polarization state, so that the S polarized light incident on the four reflection mirrors 201 to 204 is possible.

As described above, the light beam incident along the optical axis AX is divided by the light retardation unit 2 into a plurality of light beams in time, and an optical path length difference equal to the light path length of the delayed light path is provided at two time instants in succession. do. Here, the optical path length difference to be provided is set to be equal to or larger than the temporal interference distance of the light beam from the coherent light source 1. Therefore, coherence (coherence) in the division divided by the optical retardation unit 2 can be reduced, and the occurrence of interference fringes and speckles on the surface to be illuminated can be satisfactorily suppressed. Can be. More detailed configurations and actions relating to this kind of optical retardation means are described, for example, in Japanese Patent Application Laid-Open No. 11-174365, Japanese Patent Application Laid-Open No. 10-117434, and Japanese Patent Application Laid-Open No. 11-21591. , Japanese Patent Application Laid-Open No. 11-25629, the drawings and the like.

As described above, a substantially parallel light beam having a rectangular shape passing through the light retardation unit 2 is incident on the diffractive optical element 3. In general, a diffractive optical element is constituted by forming a step having a pitch about the wavelength of exposure light (illumination light) on a glass substrate, and has a function of diffracting an incident beam at a desired angle. Specifically, the diffractive optical element 3 for circular illumination converts the substantially parallel light beam of the rectangular shape incident along the optical axis AX into the divergent light beam which has a circular cross section. In this manner, the diffractive optical element 3 constitutes a light beam conversion optical system for converting the light beam from the light source 1 into a divergent light beam having a predetermined cross-sectional shape (in this case, a circular shape).

The circular diverging light beam passing through the diffractive optical element 3 passes through the zoom lens 4 as the first condenser optical system (first variable optical system), and then enters into the micro fly's eye 5 as a multi-light source forming means or an optical integrator. do. In this way, a circular illumination region is formed on the incident surface of the micro fly's eye 5. The size of the illumination region to be formed (that is, its diameter or radius) is changed depending on the focal length of the zoom lens 4 as described later.

In addition, the micro fly's eye 5 is an optical element composed of a microlens (microlens element) having a large number of rectangular-shaped positive refractive powers arranged longitudinally and densely. Generally, a micro fly's eye is comprised by performing an etching process to a parallel plane glass plate, for example, and forming a microlens group.

Here, each micro lens constituting the micro fly's eye is smaller than each lens element constituting the fly's eye lens. In addition, the micro fly's eye is different from the fly's eye lens composed of lens elements that are abolished with each other, and a plurality of micro lenses are formed integrally without being abolished with each other. However, the micro fly's eye is the same as the fly's eye lens in that the lens elements having the refractive power are arranged vertically and horizontally. 3, 6 and 7 show the number of the micro lenses constituting the micro fly's eye very much smaller than the actual ones in order to enlarge the drawing.

Therefore, the light beams incident on the micro fly's eye 5 are divided two-dimensionally by a plurality of micro lenses, so that one light source image is formed on each of the rear focal planes (i.e., near its exit surface) of each micro lens. . In this manner, a plurality of light sources (hereinafter referred to as "secondary light sources") having the same circular shape as the illumination region formed by the light flux incident on the micro fly eyes 5 are formed on the rear focal plane of the micro fly eyes 5. do. In this way, the micro fly's eye 5 is a wave integrating light integrator, and constitutes a multi-light source forming means for forming a plurality of light sources (large luminous fluxes) based on the luminous flux from the light source 1.

In addition, the zoom lens 4 continuously changes the focal length so that its front focal plane coincides with the diffractive plane of the diffractive optical element 3 and its rear focal plane coincides with the incident plane of the micro fly's eye 5. It is preferable. Therefore, it is preferable that the zoom lens 4 is provided with three lens groups which can be moved independently of each other along the optical axis.

The light beam from the circular secondary light source formed on the rear focal plane of the micro fly's eye 5 enters the aperture stop 6 for circular illumination disposed in the vicinity thereof. The aperture stop 6 has a circular opening (light transmitting portion) corresponding to a circular secondary light source formed on the rear focal plane of the micro fly's eye 5.

Moreover, the diffraction optical element 3 is comprised freely with respect to an illumination optical path, and is comprised switchable with the diffraction optical element 3a for ring-band modified illumination, and the diffraction optical element 3b for quadrupole modified illumination. The structure and effect | action of the diffraction optical element 3a for ring-band modified illumination, and the diffraction optical element 3b for four-pole modified illumination are mentioned later. As described above, the zoom lens 4 is configured to continuously change the focal length in a predetermined range. The aperture diaphragm 6 is freely detachable from the illumination light path, and also includes a plurality of aperture diaphragms for circular illumination having different sizes of the apertures, a plurality of aperture diaphragms for annular band-modified illumination having different sizes of the apertures, and It is comprised so that switching is possible with the aperture stop for several 4-pole modified illumination which differs in size.

Here, the switching between the diffractive optical element 3 for circular illumination and the diffractive optical element 3a for annular band modified illumination and the diffractive optical element 3b for quadrupole modified illumination operates based on the command from the control system 21. The first drive system 22 is used.

In addition, the change of the focal length of the zoom lens 4 is performed by the second drive system 23 operating based on the command from the control system 21.

In addition, switching between the aperture stop 6 for circular illumination and a different aperture stop is performed by the 3rd drive system 24 which operates based on the instruction | command from the control system 21. As shown in FIG.

In addition, switching between the aperture stop 6 for circular illumination and another aperture stop is switched by a suitable method, such as a turret system and a slide system, for example. The aperture stop may be fixedly mounted in the illumination optical path without being limited to the aperture stop such as the turret method or the slide method. The aperture stop capable of appropriately changing the size and shape of the light transmitting area may be used. Instead of the plurality of circular aperture diaphragms, an iris diaphragm capable of continuously changing the circular aperture diameter may be provided.

The light from the secondary light source passing through the aperture diaphragm 6 having a circular opening is subjected to the light condensing action of the zoom lens 7 as the second condenser optical system (second variable optical system), and then the mask 10 to be described later and Overlapping illuminates optically conjugate surfaces. In this way, a rectangular illumination region similar to the shape of each microlens constituting the micro fly's eye 5 is formed on this predetermined surface. The size and illumination NA of the rectangular illumination region formed on the predetermined surface are changed depending on the focal length of the zoom lens 7 as described later.

It is preferable that the zoom lens 7 continuously change the focal length such that the front focal plane and the rear focal plane of the micro fly's eye 5 coincide with each other and the rear focal plane coincides with the predetermined surface described above. Therefore, the zoom lens 7 preferably includes three lens groups that can move independently of one another along the optical axis, similarly to the zoom lens 4. As described above, the zoom lens 7 is configured to continuously change the focal length in a predetermined range, and the change of the focal length is applied to the fourth drive system 25 operating based on the command from the control system 21. Is done by.

Moreover, the mask blind 8 as an illumination field stop is arrange | positioned at the predetermined surface optically conjugate with the mask 10. As shown in FIG. The light beam passing through the opening (light transmitting part) of the mask blind 8 receives the condensing action of the relay optical system 9, and then uniformly illuminates the mask 10 in which a predetermined pattern is formed. In this way, the relay optical system 9 forms an image of the rectangular opening of the mask blind 8 on the mask 10.

The light beam passing through the pattern of the mask 10 forms a mask pattern image on the wafer (or plate) 12 which is a photosensitive substrate via the projection optical system 11. In addition, the wafer 12 is held on the wafer stage 13 which can be moved two-dimensionally in a plane orthogonal to the optical axis AX of the projection optical system 11. In this way, the pattern of the mask 10 is applied to each exposure area (shot area) of the wafer 12 by performing batch exposure or scan exposure (scan exposure) while driving control of the wafer 12 in two dimensions. This is sequentially exposed.

In the batch exposure method, the mask pattern is collectively exposed to each exposure area of the wafer in accordance with a so-called step and repeat method. In this case, the shape of the illumination area | region on the mask 10 is a rectangular shape near a square, and the cross-sectional shape of each micro lens of the micro fly eye 5 also becomes a rectangular shape near a square.

On the other hand, in the scanning exposure method, a mask pattern is scanned and exposed to each exposure area of the wafer while moving the mask and the wafer relative to the projection optical system in accordance with a so-called step and scan method. In this case, the shape of the illumination region on the mask 10 is a rectangular shape having a ratio of short side to long side, for example, 1: 3, and the cross-sectional shape of each micro lens of the micro fly's eye 5 is similar to this. It becomes a shape.

FIG. 3 is a view for explaining the relationship between the focal length of the zoom lens 4 and the zoom lens 7, the size of the rectangular illumination area formed on a predetermined surface conjugated with the mask 10, and the illumination NA.

In FIG. 3A, the light beam 30 emitted at the maximum exit angle θ1 from the intersection of the diffractive surface of the diffractive optical element 3 and the optical axis AX passes through the zoom lens 4 set to the maximum focal length f11. It becomes parallel to AX and enters into the micro fly eye 5. The micro fly's eye 5 is composed of a micro lens having a focal length of fm. Here, the size of each micro lens shown in FIG. 3 is d.

The outermost light ray 31 emitted from the micro fly eye 5 in parallel with the optical axis AX passes through the zoom lens 7 set at the maximum focal length f21, and then the predetermined surface which is conjugate with the mask 10 at an incident angle θ21 ( 32) and the intersection of the optical axis AX. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the shape of the microlens. The size of the illumination region 33 according to the drawing of FIG. 3 is Φ1.

Here, as shown in FIG. 3B, the focal length of the zoom lens 4 is changed from the maximum focal length f11 to the minimum focal length f12, and the focal length of the zoom lens 7 is changed to the maximum focal length. Change from f21 to the minimum focal length f22. In this case, the light beam 30 emitted at the maximum exit angle θ1 from the intersection of the diffraction surface of the diffractive optical element 3 and the optical axis AX is parallel to the optical axis AX via the zoom lens 4 set at the minimum focal length f12, It enters into the micro fly eye 5.

The outermost ray 31 emitted from the micro fly eye 5 in parallel with the optical axis AX passes through the zoom lens 7 set to the minimum focal length f22, and then a predetermined plane that is conjugate with the mask 10 at an incident angle θ22. 32) and the intersection of the optical axis AX. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the shape of the microlens. Here, the size of the illumination region 33 according to the drawing of FIG. 3 is Φ2.

In Fig. 3A, the relationship shown in the following expressions (1) and (2) is established.

In addition, in FIG.3 (b), the relationship shown to following formula (3) and (4) is established.

Referring to Equations 2 and 4 above, the illumination region 33 is a projection of the microlenses by the zoom lens 7, so that the size? Of the illumination region 33 is the focal length f2 of the zoom lens 7. It can be seen that it is proportional to. That is, it can be seen that the size? 1 of the illumination region 33 in FIG. 3A is the maximum size, and the size? 2 of the illumination region 33 in FIG. 3B is the minimum size.

Further, referring to Equations 1 and 3 above, since θ1 is an intrinsic value of the diffractive optical element 3, the sinusoidal value sinθ of the incident angle θ2 on the predetermined surface 32 is determined by the zoom lens 4. It can be seen that it depends on the ratio between the focal length f1 and the focal length f2 of the zoom lens 7, that is, f1 / f2. In other words, the illumination NA of the illumination region 33 in FIG. 3A is proportional to f11 / f21, and the illumination NA of the illumination region 33 in FIG. 3B is f12 / f22. It can be seen that it is proportional.

3 (a) and 3 (b), the size of the circular illumination area formed on the incident surface of the micro fly's eye 5 is determined by the size of the zoom lens 4. It is proportional to the focal length f1. That is, the illumination area formed in the incident surface of the micro fly's eye 5 is the largest in FIG. 3 (a), and the illumination formed in the incident surface of the micro fly's eye 5 in FIG. 3 (b). It can be seen that the size of the region is minimum.

As described above, when the focal length f2 of the zoom lens 7 is changed, the size of the illumination region formed on the predetermined surface 32, and furthermore, the size of the illumination region formed on the pattern surface of the mask 10, and the wafer ( The size of the exposure area formed on the exposure surface of 12) is changed. In addition, according to the change of the focal length f2 of the zoom lens 7, the illumination NA on the predetermined surface 32 changes, and the illumination NA on the pattern surface of the mask 10 changes. More specifically, when the focal length f2 of the zoom lens 7 is increased, the illumination area on the mask 10 becomes large, and the illumination NA becomes large. In this way, the zoom lens 7 constitutes a second variable displacement optical system for changing the size of the illumination region formed on the mask 10 (the wafer 12, which is the surface to be irradiated).

On the other hand, when the focal length f1 of the zoom lens 4 is changed, the size of the illumination region formed on the pattern surface of the mask 10 does not change, but the size of the illumination region formed on the incident surface of the micro fly's eye 5 is changed. The size is changed, and the illumination NA on the mask 10 is changed. More specifically, when the focal length f1 of the zoom lens 4 is made small, only the illumination NA on the mask 10 is reduced without changing the size of the illumination region on the mask 10. In this way, the zoom lens 4 constitutes a first variable optical system for changing only the illumination NA on the mask 10 which is the irradiated surface.

Therefore, in this embodiment, by setting the focal length of the zoom lens 7 to a predetermined value, it is possible to obtain an illumination area of a desired size on the mask 10 without substantially losing light in the mask blind 8. have. Further, by setting the focal length of the zoom lens 4 to a predetermined value with respect to the focal length of the zoom lens 7 set to a predetermined value, the aperture diaphragm 6 can be used on the mask 10 without substantially losing light. In the present invention, an illumination NA of a desired size can be obtained.

As described above, the diffractive optical element 3 has a configuration that can be inserted and detached from the illumination optical path, and the diffraction optical element 3b for polar deformation illumination and the diffraction optical element 3a or 4 for annular band modified illumination. It is configured to be switchable.

Hereinafter, the annular band modified illumination obtained by setting the diffractive optical element 3a in the illumination optical path instead of the diffractive optical element 3 will be described.

4 is a view for explaining the operation of the diffractive optical element 3a for annular band modified illumination.

As shown in FIG. 4, the diffraction optical element 3a for annular band modified illumination diffracts a circular beam having a circular beam cross section perpendicularly incident along the optical axis AX along all directions at equal angles with respect to the optical axis AX. And a ring beam having a ring beam cross section. Therefore, when the parallel light beam of circular cross section enters into this diffraction optical element 3a along the optical axis AX, it becomes a ring-shaped divergent light flux as shown in FIG. As described above, the diffractive optical element 3a constitutes a light beam conversion optical system for converting the light beam from the light source 1 into a substantially annular diverging light beam.

The annular diverging light beam passing through the diffractive optical element 3a enters the micro fly's eye 5 after passing through the zoom lens 4. In this way, an annular strip-shaped illumination region is formed on the incident surface of the micro fly's eye 5. As a result, in the rear focal plane of the micro fly's eye 5, a secondary light source having the same annular band shape as the illumination region formed on the incident surface is formed. As described above, based on the luminous flux from the light source 1, the annular secondary light source is formed in the rear focal plane of the micro fly's eye 5 with almost no loss of light.

In addition, in response to the switching from the diffractive optical element 3 to the diffractive optical element 3a, the switching from the circular aperture diaphragm to the annular aperture diaphragm is performed. Here, the annular aperture opening diaphragm positioned in the illumination light path is an aperture diaphragm having an annular annular opening corresponding to the annular annular secondary light source. In this way, by using the diffractive optical element 3a for annular band modified illumination, an annular band-shaped secondary light source can be formed on the basis of the luminous flux from the light source 1 with almost no loss of light. Annular strip deformation | transformation illumination can be performed, suppressing the light quantity loss in the aperture stop which limits the luminous flux from a light source favorably.

Next, the four-pole strain illumination obtained by setting the diffraction optical element 3b in the illumination optical path instead of the diffraction optical element 3 is demonstrated, for example. 5 is a view for explaining the operation of the diffractive optical element 3b for quadrupole modified illumination.

The diffraction optical element 3b for quadrupole modified illumination diffracts a circular beam having a circular beam cross section perpendicularly incident along the optical axis AX as shown in FIG. 5 according to four directions specified at an equiangular angle about the optical axis AX. This converts the four fine beams. Therefore, when the parallel light beam of circular cross section enters into the diffraction optical element 3b according to the optical axis AX, it becomes a 4-pole divergent light flux as shown in FIG. As described above, the diffractive optical element 3b constitutes a light beam conversion optical system for converting the light beam from the light source 1 into four divergent light beams eccentric with respect to the optical axis AX.

The 4-pole divergent light beam passing through the diffractive optical element 3b enters the micro fly's eye 5 after passing through the zoom lens 4. In this way, a quadrupole-shaped illumination region is formed on the incident surface of the micro fly's eye 5. As a result, a quadrupole-shaped secondary light source identical to the illumination region formed on the incident surface is formed on the rear focal plane of the micro fly's eye 5. As described above, the quadruple secondary light source is formed on the rear focal plane of the micro fly's eye 5 with almost no loss of light based on the luminous flux from the light source 1.

In addition, in response to the switching from the diffractive optical element 3 to the diffractive optical element 3b, the switching from the circular aperture stop to the four-pole aperture stop is performed. Here, the four-pole opening diaphragm positioned in the illumination light path is an opening diaphragm having four openings corresponding to the four-pole secondary light source. In this way, by using the diffractive optical element 3b for quadrupole modified illumination, a quadrupole secondary light source can be formed on the basis of the luminous flux from the light source 1 with almost no loss of light. Four-pole deformed illumination can be performed while suppressing the loss of light quantity in the aperture stop which limits the luminous flux from a light source.

Hereinafter, the operation | movement adjustment of the magnitude | size of illumination region, illumination NA, etc. in this embodiment are demonstrated concretely.

First, information on various masks to be sequentially exposed in accordance with the step-and-repeat method or the step-and-scan method, information on lighting conditions of various masks or exposure conditions of wafers to be sequentially exposed, and the like is used as an input means such as a keyboard ( It is input to the control system 21 via 20). The control system 21 stores information on various masks and wafers such as a desired size of the illumination area (exposure area), an optimal illumination NA, an optimal line width (resolution), a desired depth of focus, and the like. It is stored in the memory unit, and an appropriate control signal is supplied to the first drive system 22 to the fourth drive system 25 in response to the input from the input means 20.

That is, when the ordinary circular illumination is performed based on the illumination area of the desired size, the optimum illumination NA, the optimal resolution, and the desired depth of focus, the first drive system 22 is circular based on the instruction from the control system 21. The illumination diffraction optical element 3 is positioned in the illumination optical path. And in order to obtain the illumination area | region which has a desired magnitude | size on the mask 10, the 4th drive system 25 sets the focal length of the zoom lens 7 based on the command from the control system 21. As shown in FIG. In addition, in order to obtain a desired illumination NA on the mask 10, the second drive system 23 sets the focal length of the zoom lens 4 based on the command from the control system 21. In addition, in order to limit the circular secondary light source formed on the rear focal plane of the micro fly's eye 5 to a state in which light loss is satisfactorily suppressed, the third drive system 24 commands from the control system 21. Based on this, a desired circular aperture stop is positioned in the illumination light path.

If necessary, the mask may be changed by changing the focal length of the zoom lens 4 by the second drive system 23 or by changing the focal length of the zoom lens 7 by the fourth drive system 25. The size and illumination NA of the illumination region formed on (10) can be appropriately changed independently of each other. In this case, the desired circular aperture stop is selected and positioned in the illumination optical path in accordance with the change in the size of the circular secondary light source in accordance with the change in the focal length of the zoom lens 4.

As mentioned above, the input means 20, the control system 21, the 2nd drive system 23, and the 3rd drive system 24 consist of a 1st variable speed optical system, and in order to set illumination NA and the magnitude | size of an illumination area to a desired value, respectively. An adjusting system for adjusting each focal length of the second variable optical system is configured.

In this way, the optimal circular illumination can be performed by setting the size of the illumination region formed on the mask 10 and the illumination NA to desired values with almost no loss of light amount.

In addition, in the case of annular band-deformed illumination based on an illumination area of a desired size, an optimal illumination NA, an optimal resolution, and a desired depth of focus, the first drive system 22 is based on a command from the control system 21. The diffractive optical element 3a of the band-deformed illumination is positioned in the illumination optical path. And in order to obtain the illumination area | region which has a desired magnitude | size on the mask 10, the 4th drive system 25 sets the focal length of the zoom lens 7 based on the command from the control system 21. As shown in FIG. In addition, in order to obtain a desired illumination NA on the mask 10, the second drive system 23 sets the focal length of the zoom lens 4 based on the command from the control system 21. Often, in order to limit the annular band-shaped secondary light source formed on the rear focal plane of the micro fly's eye 5 to a state in which the amount of light loss is satisfactorily suppressed, the third drive system 24 is provided from the control system 21. Based on the instruction, the desired annular aperture stop is positioned in the illumination light path.

If necessary, the mask may be changed by changing the focal length of the zoom lens 4 by the second drive system 23 or by changing the focal length of the zoom lens 7 by the fourth drive system 25. The size and illumination NA of the illumination region formed on (10) can be appropriately changed independently of each other. In this case, according to a change in the size of the annular stripe-shaped secondary light source (that is, the size of a circle circumscribed to the annular stripe-shaped secondary light source) according to the change in the focal length of the zoom lens 4, An annular aperture aperture is selected and positioned in the illumination light path.

In this way, an optimal annular band-deformed illumination can be performed by setting the size of the illumination region formed on the mask 10 and the illumination NA to desired values with almost no loss of light amount.

In addition, when 4-pole deformation illumination is performed on the basis of an illumination area of a desired size, an optimum illumination NA, an optimal resolution, and a desired depth of focus, the first drive system 22 is based on a command from the control system 21. The diffractive optical element 3b of the annular band modified illumination is positioned in the illumination optical path. And in order to obtain the illumination area | region which has a desired magnitude | size on the mask 10, the 4th drive system 25 sets the focal length of the zoom lens 7 based on the command from the control system 21. As shown in FIG. In addition, in order to obtain a desired illumination NA on the mask 10, the second drive system 23 sets the focal length of the zoom lens 4 based on the command from the control system 21. In addition, in order to limit the quadrupole-shaped secondary light source formed on the rear focal plane of the micro fly's eye 5 to a state in which light loss is satisfactorily suppressed, the third drive system 24 is controlled from the control system 21. Based on the instruction, the desired four-pole aperture stop is positioned in the illumination light path.

If necessary, the mask may be changed by changing the focal length of the zoom lens 4 by the second drive system 23 or by changing the focal length of the zoom lens 7 by the fourth drive system 25. The size and illumination NA of the illumination region formed on (10) can be appropriately changed independently of each other. In this case, the desired four-pole according to the change of the size of the quadrupole-shaped secondary light source (that is, the size of the circle circumscribed to the quadrupole-shaped secondary light source) according to the change of the focal length of the zoom lens 4 An aperture stop is selected and positioned in the illumination light path.

In this way, the optimum four-pole deformation illumination can be performed by setting the size of the illumination region and illumination NA formed on the mask 10 to desired values, with almost no loss of light amount.

As described above, in the present embodiment, the aperture stop 6 and the illumination field stop 8 are controlled by controlling the focal length of the zoom lens 4 as the first variable optical system and the zoom lens 7 as the second variable optical system. Is a desired value of the illumination NA and the illumination area on the mask 10, and the size and the sigma value of the exposure area on the wafer 12. Can be adjusted. That is, in the exposure apparatus of this embodiment, the size and sigma value of the illumination region (exposure region) are set to optimal values in accordance with the characteristics of the micro device to be manufactured or the characteristics of the mask 10 to be used. Based on high exposure illuminance and good exposure conditions, good projection exposure with high throughput can be performed.

Further, in the above-described embodiment, modified illumination such as annular band modified illumination and quadrupole modified illumination and ordinary circular illumination can be performed while satisfactorily suppressing light loss in the aperture stop for limiting the secondary light source. Therefore, the kind of modified illumination can be changed suitably, and the resolution and depth of focus of the projection optical system suitable for the fine pattern which should be projected by exposure can be obtained. As a result, good projection exposure with high throughput can be performed based on high exposure illuminance and good exposure conditions.

In addition, in order to change the exposure condition or the illumination condition, the changing means or the light beam converting means (for example, the diffractive optical member 3 for forming the circular light beam, the diffractive optical member 3a for forming the annular beam beam, and the diffraction for forming the 4-pole beam Light at the pupil position (secondary light source position formed by the optical integrator or position optically conjugate with it) of the illumination optical system by a mechanism for setting one of the optical members 3b to the illumination light path, or the vicinity thereof When the intensity distribution is changed, the illumination numerical aperture NA may change. The change in the number of illumination apertures according to the change of the exposure condition or the illumination condition can be corrected by adjusting (change) the magnification or the focal length of the first variable optical system 4 as the adjustment means.

In that case, the control system 21 sends an appropriate control signal to the first drive system 22 and the second drive system based on the exposure conditions or illumination conditions of each mask or wafer stored in the internal memory unit via the input means 20. Output to 23 and the 3rd drive system 24, respectively. That is, the first diffraction optical elements 3, 3a, and 3b are set in the illumination optical path by the first drive system 22, and the aperture diaphragm having an opening having an appropriate shape or an appropriate size is illuminated by the third drive system 24. In order to correct the change in the number of illumination apertures while being set in the optical path, the first drive optical system is adjusted (changed) to an appropriate magnification or an appropriate focal length by the second drive system 23.

Thereby, the favorable mask pattern can be exposed to photosensitive board | substrates, such as a wafer, based on a desired exposure condition or a desired illumination condition, and the manufacturing method of the exposure apparatus and microdevice obtained can be realized.

FIG. 6 is a diagram schematically showing a configuration of an exposure apparatus with an illumination optical device according to Embodiment 2 of the present invention. FIG.

Example 2 has a structure similar to Example 1. However, in Example 1, as the multi-light source forming means, a focal length composed of one micro fly's eye 5 uses an invariant optical integrator, and a condenser optical system uses a zoom lens 7 having a variable focal length. In Example 2, a condenser lens having a variable focal length consisting of three micro fly's eyes 51 to 53 having a variable focal length as a multi-light source forming means and a condenser optical system having a constant focal length ( Only the point using 70) is basically different.

Therefore, in Fig. 6, the same reference numerals as those in Fig. 1 are assigned to elements having the same functions as those in the first embodiment. The second embodiment will be described below focusing on differences from the first embodiment.

In addition, although the illumination optical apparatus is set so that ordinary circular illumination may be performed also in FIG. 6, ring-band deformed illumination and 4-pole deformed illumination are possible by switching a diffraction optical element similarly to Example 1, In this point, Overlapping descriptions are omitted.

In Embodiment 2, the first micro fly's eye 51 made of the fine lens of positive refractive power and the second micro fly's eye made of the micro lens of negative refractive power in order from the light source side. 52 and a micro fly's eye group 50 composed of a third micro fly's eye 53 made of a microlens with a refractive power. Here, each of the micro lenses constituting the micro fly eyes 51 to 53 has a rectangular cross section, and the size is the same.

The first micro fly's eye 51 and the second micro fly's eye 52 are movable independently of each other along the optical axis AX, and the third micro fly's eye 53 is fixed along the optical axis AX. Then, by moving the first micro fly eye 51 and the second micro fly eye 52 independently of each other along the optical axis AX so that the rear focal plane of the micro fly eye group 50 does not move, the micro fly eye group ( 50) is configured to continuously change from the maximum focal length f501 to the minimum focal length f502. In addition, the change of the focal length of the micro fly eye group 50 is performed by the drive system which operates based on the command from a control system similarly to Example 1. As shown in FIG.

FIG. 7 is a view for explaining the relationship between the focal length of the zoom lens 4 and the micro fly eye group 50, the size of the rectangular illumination region formed on a predetermined surface in conjugate with the mask 10, and the illumination NA.

In FIG. 7A, the light beam 30 emitted at the maximum exit angle θ1 from the intersection of the diffraction surface of the diffractive optical element 3 and the optical axis AX passes through the zoom lens 4 set to the maximum focal length f11. It becomes parallel to AX and injects into the micro fly eye group 50. The micro fly eye group 50 is set to the maximum focal length f501. Here, in each of the micro fly's eyes 51 to 53 constituting the micro fly's eye group 50, the size of the temporary microlens according to the drawing of FIG. 7 is d.

The outermost light ray 31 emitted in parallel with the optical axis AX from the micro fly eye group 50 passes through the condenser lens 70 having the focal length f70, and then a predetermined surface which is conjugate with the mask 10 at an incident angle θ21 ( 32) and the intersection of the optical axis AX. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the shape of the microlens. Incidentally, the size of the illumination region 33 shown in FIG. 7 is φ3.

Here, as shown in FIG. 7B, the focal length of the zoom lens 4 is changed from the maximum focal length f11 to the minimum focal length f12, and the focal length of the micro fly eye group 50 is maximized. Change from distance f501 to minimum focal length f502. In this case, the light beam 30 emitted at the maximum exit angle θ1 from the intersection of the diffraction surface of the diffractive optical element 3 and the optical axis AX is parallel to the optical axis AX via the zoom lens 4 set to the minimum focal length f12, It enters the micro fly eye group 50 set to the minimum focal length f502.

The outermost ray 30 emitted from the micro fly eye group 50 in parallel with the optical axis AX passes through the condenser lens 70 having the focal length f70, and then a predetermined plane conjugated with the mask 10 at an incident angle θ22. 32) and the intersection of the optical axis AX. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the shape of the microlens. Here, according to the drawing of FIG. 7, the size of the illumination region 33 is φ4.

In Fig. 7A, the relationship shown in the following expressions (5) and (6) is established.

In Fig. 7B, the relationship shown in the following expressions (7) and (8) is established.

Referring to Equations 6 and 8 described above, it can be seen that the size? Of the illumination region 33 is inversely proportional to the focal length f50 of the micro fly eye group 50. That is, it can be seen that the size φ 3 of the illumination region 33 in FIG. 7A is the minimum size, and the size φ 4 of the illumination region 33 in FIG. 7B is the maximum size.

In addition, referring to Equations 5 and 7 described above, since the value of θ1 and the value of f70 are invariant, the sinusoidal value sinθ2 of the incident angle θ2 on the predetermined surface 32 is the focal length f1 of the zoom lens 4. You can see that it depends on. In other words, the illumination NA of the illumination region 33 in FIG. 7A is the maximum in proportion to f11, and the illumination NA of the illumination region 33 in FIG. 7B is proportional to f12. It can be seen that the minimum.

As described above, when the focal length f50 of the micro fly eye group 50 is changed, the size of the illumination region formed on the predetermined surface 32, and furthermore, the size of the illumination region formed on the pattern surface of the mask 10 is changed. More specifically, when the focal length f50 of the micro fly eye group 50 is increased, only the size of the illumination region on the mask 10 is reduced without changing the illumination NA on the mask 10. As described above, the micro fly eye group 50 constitutes a multi-light source forming means, and at the same time, a second for changing the size of the illumination area formed on the mask 10 (the wafer 12, which is the irradiated surface). It constitutes a part of the variable speed optical system.

On the other hand, when the focal length f1 of the zoom lens 4 is changed, the size of the illumination region formed on the incident surface of the micro fly eye group 50 is changed, and the illumination NA on the mask 10 is changed. More specifically, when the focal length f1 of the zoom lens 4 is made small, only the illumination NA on the mask 10 is reduced without changing the size of the illumination region formed on the mask 10. In this way, the zoom lens 4 constitutes a first variable optical system for changing only the illumination NA on the mask 10 which is the irradiated surface.

Therefore, in Embodiment 2, by setting the focal length of the micro fly eye group 50 to a predetermined value, the mask blind 8 is provided with an illumination area of a desired size on the mask 10 without substantially losing light. You can get it. Further, by setting the focal length of the zoom lens 4 to a predetermined value, the illumination NA of the desired size can be obtained on the mask 10 without substantially losing light in the aperture stop 6.

8 is a diagram schematically showing a configuration of an exposure apparatus with an illumination optical device according to Embodiment 3 of the present invention.

The third embodiment has a configuration similar to that of the first embodiment. However, in Example 1, the micro fly's eye 5, which is a wavefront split type optical integrator, is used as a means for forming a multi-light source, whereas in Example 3, a lot integrator which is an optical integrator of inner surface reflection type is used. Only using 500 is basically different.

Therefore, in Fig. 8, the same reference numerals as those in Fig. 1 are assigned to elements having the same functions as those in the first embodiment. The third embodiment will be described below focusing on differences from the first embodiment. In addition, also in FIG. 8, although the illumination optical apparatus is set to perform normal circular illumination, similarly to Example 1, by switching a diffractive optical element, annular band distortion illumination and quadrupole distortion illumination are possible, Overlapping descriptions are omitted.

In Embodiment 3, the first imaging optical system (first variation) in the optical path between the diffractive optical element 3 and the lot integrator 500 corresponds to using the lot integrator 500 in place of the micro fly's eye 5. A zoom lens 41 as an optical system is provided, and a zoom lens 71 as a second imaging optical system (second variable speed optical system) is provided in place of the zoom lens 7 and the relay optical system 9. In addition, the mask blind 8 as an illumination visual aperture is arrange | positioned in the vicinity of the exit surface of the lot integrator 500. As shown in FIG.

Here, the zoom lens 41 is configured to continuously change the imaging magnification m1 while optically maintaining the diffractive plane of the diffractive optical element 3 and the incident plane of the lot integrator 500 in airspace. In addition, the zoom lens 71 is configured to continuously change the imaging magnification m2 while keeping the exit surface of the lot-type integrator 500 and the pattern surface of the mask 10 in air space. In addition, the change of the magnification of the zoom lens 41 and the zoom lens 71 is performed by the drive system which operates based on the command from a control system similarly to Example 1, respectively.

The lot integrator 500 is an inner reflection glass lot made of a glass material such as quartz glass or fluorite, and uses a total reflection at the interface between the inside and the outside, that is, the inner surface. ) Forms a number of light source images according to the number of inner surface reflections along a plane parallel to the lot incidence plane. Here, most of the light source image formed is a virtual image, but only the light source image of a center (condensing point) becomes a real image. That is, the luminous flux incident on the lot integrator 500 is divided in the angular direction by the inner surface reflection, so that a secondary light source is formed of a plurality of light sources along the plane parallel to the incidence plane through the condensing point.

The luminous flux from the secondary light source formed on the incident side by the lot integrator 500 superimposes on the exit surface, and then uniformly illuminates the mask 10 in which the predetermined pattern is formed via the zoom lens 71. . As described above, the zoom lens 71 optically connects the exit surface of the lot integrator 500 and the mask 10 (the wafer 12 to be advanced) almost optically. Thus, a rectangular illumination region similar to the cross-sectional shape of the lot integrator 500 is formed on the mask 10.

FIG. 9 is a diagram for explaining the relationship between the magnification of the zoom lens 41 and the zoom lens 71, the size of the rectangular illumination region formed on a predetermined surface which is conjugate with the mask 10, and the illumination NA.

In FIG. 9A, the light beam 30 emitted at the maximum emission angle θ1 from the intersection of the diffractive surface of the diffractive optical element 3 and the optical axis AX passes through the zoom lens 41 set to the maximum magnification m11, An incident angle θ11 is incident on the intersection point of the optical axis AX and the incident surface of the lot integrator 500. Here, the size of the exit surface of the lot integrator 500 according to the drawing of FIG. 9 is d5.

The light beam 31 emitted at the injection angle θ11 from the intersection of the optical axis AX and the exit surface of the lot integrator 500 passes through the zoom lens 71 set at the maximum magnification m21, and then enters the mask 10 at the incident angle θ21. The intersection of the predetermined plane 32, which is airspace, and the optical axis AX is reached. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the exit surface of the lot integrator 500 (and strictly similar to the shape of the opening of the mask blind 8). The size of the illumination region 33 according to the drawing of FIG. 9 is φ5.

Here, as shown in Fig. 9B, the magnification of the zoom lens 41 is changed from the maximum magnification m11 to the minimum magnification m12, and the magnification of the zoom lens 71 is changed from the maximum magnification m21 to the minimum magnification m22. Change. In this case, the light beam 30 emitted at the maximum exit angle θ1 from the intersection of the diffractive surface of the diffractive optical element 3 and the optical axis AX passes through the zoom lens 41 set to the minimum magnification m12, and then the optical axis AX and the lot integrator. An incident angle θ12 is incident on the intersection with the incident surface of 500.

The light rays 31 emitted at the injection angle θ12 from the intersection of the optical axis AX and the exit surface of the lot integrator 500 pass through the zoom lens 71 set to the minimum magnification m22, and then enter the mask 10 at the incident angle θ22. The intersection of the predetermined plane 32, which is airspace, and the optical axis AX is reached. In this way, the predetermined surface 32 is formed with a rectangular illumination region 33 similar to the exit surface of the lot integrator 500. Here, the size of the illumination region 33 according to the drawing of FIG. 9 is φ6.

In Fig. 9A, the relationship shown in the following expressions (9) and (10) is established.

In Fig. 9B, the relationship shown in the following expressions (11) and (12) holds.

Referring to Equations 10 and 12 described above, it can be seen that the size? Of the illumination region 33 is proportional to the magnification m2 of the zoom lens 71. That is, it can be seen that the size φ5 of the illumination region 33 in FIG. 9A is the maximum size, and the size φ6 of the illumination region 33 in FIG. 9B is the minimum size.

In addition, referring to Equations 9 and 11 described above, since the value of θ1 is invariant, the incident angle θ2 on the predetermined surface 32 is determined by the magnification m1 of the zoom lens 4 and the magnification m2 of the zoom lens 71. It can be seen that it depends on the ratio of m1 / m2. In other words, the illumination NA of the illumination area 33 in FIG. 9 (a) depends on m11 / m21, and the illumination NA of the illumination area 33 in FIG. 9 (b) is set to m21 / m22. You can see that it depends.

As described above, when the magnification m2 of the zoom lens 71 is changed, the size and illumination NA of the illumination region formed on the pattern surface of the mask 10 are changed. More specifically, when the magnification m2 of the zoom lens 71 is increased, the illumination area on the mask 10 becomes large, and the illumination NA becomes small. In this way, the zoom lens 71 constitutes a second variable displacement optical system for changing the size of the illumination region formed on the mask 10 as the irradiated surface.

On the other hand, when the magnification m1 of the zoom lens 41 is changed, the size of the illumination region formed on the incident surface of the micro fly's eye 5 is changed, and the illumination NA on the mask 10 is changed. More specifically, when the magnification m1 of the zoom lens 41 is increased, only the illumination NA on the mask 10 is increased without changing the size of the illumination region formed on the pattern surface of the mask 10. In this way, the zoom lens 41 constitutes a first variable-speed optical system for changing only the illumination NA on the mask 10 as the irradiated surface.

Therefore, in this embodiment, by setting the magnification of the zoom lens 71 to a predetermined value, the mask blind 8 obtains an illumination area of a desired size on the mask 10 without substantially losing light. Can be. Further, by setting the magnification of the zoom lens 41 to a predetermined value with respect to the magnification of the zoom lens 7 set to a predetermined value, the illumination NA of a desired size can be obtained on the mask 10. .

Moreover, also in Example 3 shown in FIG. 8, in order to change exposure conditions or illumination conditions similarly to Example 1 shown in FIG. 1, a change means or a light beam conversion means (for example, the diffraction optical member 3 for circular beam formation) ), The pupil position of the illumination optical system (by an optical integrator) is formed by a mechanism for setting one of the diffraction optical member 3a for ring-shaped beam forming and the diffraction optical member 3b for forming 4-pole beam in the illumination optical path. When changing the secondary light source position or the position optically conjugate with it) or the light intensity distribution in the vicinity of the position, the illumination numerical aperture NA may change. The change of the number of illumination numerical apertures according to the change of the exposure condition or the illumination condition can be corrected by the adjustment (change) of the magnification or the focal length of the first variable optical system 41 as the adjustment means.

As mentioned above, in the Example shown to FIG. 1 and FIG. 8, the change of the value of the illumination numerical aperture according to the change of the illumination visual field by the 2nd variable optical system 7 and 71 is made into the 1st variable optical system 4, 41. FIG. By adjusting (change) of the magnification or the focal length, the value of the illumination numerical aperture can be kept substantially constant. Therefore, projection exposure can also be performed based on high lighting efficiency even under such specific conditions.

However, one of the changing means or the luminous flux converting means (e.g., the diffractive optical member 3 for forming a circular beam, the diffractive optical member 3a for forming a band-shaped beam, and the diffractive optical member 3b for forming a four-pole beam is provided with an illumination light path. Illuminance distribution on the mask or on the wafer may be changed by a mechanism to be set to the surface of the mask), resulting in uneven illuminance. In that case, a method of moving a part of optical elements (lens, etc.) of the second condenser optical system (variation optical systems 7 and 70) or the relay optical system (imaging optical system 9), or the optical integrator 5, 50, 500 The illuminance distribution on the mask or on the wafer can be uniformly performed by a method in which a plurality of filters having predetermined angular characteristics for illuminance distribution adjustment are exchangeable in the optical path between the mask 10 and the mask 10. However, since the illumination numerical aperture may change with this illuminance correction, the change of the illumination numerical aperture according to the correction of the illuminance distribution by said illuminance correction means is made into the 1st variable optical system (1st condenser optical system 4, It can correct | amend by adjustment (change) of the magnification or focal length of the 1st imaging optical system 41. FIG.

The luminous flux converting means (change means) shown in each of the above embodiments selectively converts into a luminous flux having a desired luminous intensity distribution among one of a plurality of luminous fluxes having different luminous intensity distributions based on the luminous flux for exposure. The lower surface has a function of converting the exposure luminous flux into a luminous flux having any one of a luminous flux having a predetermined first luminous intensity distribution and a luminous flux having a predetermined second luminous intensity distribution different from the first luminous intensity distribution. The light intensity distribution in the pupil position of the illumination optical system (the position of the secondary light source formed by the optical integrator or the position optically conjugate with it) or the vicinity thereof can be changed to the desired light intensity distribution. In this way, the luminous flux converting means (modifying means) for changing the light intensity distribution at or near the pupil position of the illumination optical system is configured to switch the diffractive optical elements 3, 3a and 3b forming the desired divergent luminous flux. Not only the convex conical refracting surface prism capable of forming annular beams (or prisms having concave conical refracting surfaces), but the convex quadrangular pyramidal refracting surface prism capable of forming four-pole beams ( Alternatively, the concave prism having a conical quadrangular refraction surface) may be replaced.

In this way, the light beam converting means (modifying means) can convert into a divergent light in a desired state by selectively placing one of the optical members having a diffraction action or a refractive action in the illumination optical path. In addition, suppose that the light beam conversion means (change means) is a combination of three interchangeable diffractive optical elements and a shift optical system, the annular band ratio (ring band) of the annular light beam formed at or near the pupil position of the illumination optical system. Ratio between the inner diameter of the inner ring and the outer diameter of the annular band), the size of the circular light beam, and the distance from the center of the four-pole light beam can be continuously changed. Similarly, the light beam converting means (modifying means) can also be configured by combining the replaceable prism (refractive optical element) and the variable speed optical system.

Moreover, since each optical member, each stage, etc. in each example shown to FIGS. 1-9 are electrically, mechanically or optically connected so that the above-mentioned function may be achieved, the exposure apparatus which concerns on this invention can be implemented. have.

Next, an example of a method of obtaining a semiconductor device as a micro device is formed by forming a predetermined circuit pattern on a wafer as a photosensitive substrate using the exposure apparatus in each example shown in FIGS. 1 to 9. The flowchart of 10 is demonstrated.

First, in step 301 of FIG. 10, a metal film is deposited on one lot of wafers. In the next step 302, a photoresist is applied onto the one-lot wafer-like metal film. Subsequently, in step 303, the image of the pattern on the mask (reticle) is passed through the projection optical system (projection optical unit) using the projection exposure apparatus of any of the drawings shown in Figs. Exposure is transferred sequentially to each shot region of the image. Thereafter, in step 304, the photoresist on the one lot of wafers is developed, and then in step 305, the resist pattern is etched as a mask on the one lot of wafers, thereby forming a circuit corresponding to the pattern on the mask. A pattern is formed in each shot region on each wafer. Thereafter, by forming the circuit pattern of the layer thereon and the like, a device such as a semiconductor element is manufactured.

According to the semiconductor device manufacturing method described above, throughput can be obtained satisfactorily for a semiconductor device having an extremely fine circuit pattern.

In addition, in the above-mentioned exposure apparatus shown in FIGS. 1-9, the liquid crystal display element as a microdevice can also be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, with reference to the flowchart of FIG. 11, an example of the method at this time is demonstrated.

In FIG. 11, in a pattern formation process (step 401), what is called a photolithography process which transfer-exposes the pattern of a reticle to a photosensitive substrate (glass substrate etc. to which resist was apply | coated) is performed using the exposure apparatus of a present Example. By this optical lithography process, a predetermined pattern including a plurality of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate is subjected to each step such as a developing step, an etching step, a reticle peeling step, or the like to form a predetermined pattern on the substrate, and the process proceeds to the next color filter forming step (step 402).

Next, in the color filter formation step (step 402), a color filter in which a plurality of sets of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix form is formed. Then, after the color filter forming step (step 402), the cell assembling step (step 403) is executed.

In the cell assembly step (step 403), a liquid crystal panel (liquid crystal cell) is assembled using a substrate having a predetermined pattern obtained by the pattern forming step (step 401) and a color filter obtained by the color filter forming step (step 402). . In the cell granulation step (step 403), for example, a liquid crystal is injected between a substrate having a predetermined pattern obtained by the pattern forming step (step 401) and a color filter obtained by the color filter forming step (step 402) to form a liquid crystal. A panel (liquid crystal cell) is produced.

Thereafter, in the module assembly step (step 404), components such as an electric circuit and a backlight for performing the display operation of the assembled liquid crystal panel (liquid crystal cell) are assembled and completed as a liquid crystal display element.

According to the manufacturing method of the liquid crystal display element mentioned above, the liquid crystal display element which has an extremely fine circuit pattern can be obtained with good throughput.

In the above-described embodiment, the diffractive optical element as the light beam conversion optical system can be configured to be positioned in the illumination optical path by, for example, a turret method. For example, the above-mentioned diffraction optical element can be removed and switched using a known slider mechanism. By the way, the detailed description of the diffractive optical element that can be used in the present invention is disclosed in US Patent No. 5,850,300.

In addition, although the diffraction optical element is used as a light beam conversion optical system in the above-mentioned embodiment, it is also possible to use a wavefront split type optical integrator such as a fly's eye lens or a micro fly's eye, for example.

In addition, in the above-described embodiment, although a micro fly's eye or a lot integrator is used as the means for forming a multi-light source, other suitable optical components such as a fly's eye lens and a diffractive optical element can also be used.

In addition, in Example 1 and Example 2 mentioned above, after forming an illumination area | region once on the predetermined surface which is conjugate with the mask 10, and restricting the light beam from this illumination area to the mask blind 8, the relay optical system 9 The illumination region is formed on the mask 10 via (). However, it is also possible to omit the relay optical system 9 and to form the illumination region directly on the mask 10 arranged at the position of the mask blind 8 via the zoom lens 7 or 70.

In the third embodiment described above, the circular integrator 500 is incident on the lot integrator 500 having a rectangular cross-section. However, in order to increase the filling rate of the incident luminous flux, it is converted into an elliptic luminous flux. It is preferable. The lot integrator may be a single solid glass rod, or may be a form in which a reflective mirror is assembled into a tunnel shape. When forming a lot integrator by a reflection mirror, the cross-sectional size d5 can be comprised so that change is possible as needed.

In the above-described embodiment, an aperture stop for restricting the luminous flux of the secondary light source is disposed near the rear focal plane of the micro fly's eye. However, in some cases, by setting the cross-sectional area of each microlens constituting the micro fly's eye sufficiently small, it is also possible to omit the arrangement of the aperture stop and to limit the luminous flux of the secondary light source at all.

In addition, although the example which forms a 4-pole secondary light source is shown in the above-mentioned embodiment, for example, a secondary pole light source of a 2 pole (second) shape, or a multipole like 8-pole (8th) shape. It is also possible to form a secondary shape light source.

In addition, in the above-mentioned embodiment, although this invention was demonstrated using the projection exposure apparatus provided with the illumination optical apparatus as an example, it is clear that the present invention can be applied to the general illumination optical apparatus for uniformly illuminating an irradiated surface other than a mask. Do.

In this embodiment, since the wavelength of 180 nm or more exposure light, such as KrF excimer laser (wavelength: 248 nm) and ArF excimer laser (wavelength: 193 nm), is used as a light source, a diffraction optical element is used, for example. It can be formed from quartz glass.

In the case where a wavelength of 200 nm or less is used as the exposure light, the diffractive optical element is composed of fluorite, fluorine-doped quartz glass, fluorine and hydrogen-doped quartz glass, and a structure crystal temperature of 1200 K or less, and an OH group concentration. Quartz glass with 1000 ppm or more, quartz glass with a structure crystal temperature of 1200 K or less, and hydrogen concentration of 1 × 10 ¹⁷ molecules / cm ³ or more, quartz glass with a structure crystal temperature of 1200K or less, and chlorine concentration of 50 ppm or less, and structure crystal temperature It is preferred to form a material selected from the group of quartz glass having a molecular weight of 1200 K or less, and at a hydrogen molecule concentration of 1 × 10 ¹⁷ molecules / cm ³ or more and a chlorine concentration of 50 ppm or less.

Moreover, about quartz glass whose structure crystal temperature is 1200K or less and OH group concentration is 1000 ppm or more, it is disclosed by Unexamined-Japanese-Patent No. 2770224 by the applicant of this application, The structure crystal temperature is 120 OK or less, and also the hydrogen molecule concentration is Quartz glass with 1x10 ¹⁷ molecules / cm ³ or more, structure crystal temperature of 120 OK or less, quartz glass with chlorine concentration of 50 ppm or less and structure crystal temperature of 1200K or less, and hydrogen molecule concentration of 1 × 10 ¹⁷ molecules / cm ³ or more Moreover, about the quartz glass whose chlorine concentration is 50 ppm or less, it is disclosed by Unexamined-Japanese-Patent No. 2936138 by this applicant.

As described above, in the illumination optical apparatus of the present invention, by controlling the focal length or the magnification of the first variable displacement optical system and the second variable displacement optical system, the illumination NA and the size of the illumination region are respectively controlled while suppressing light loss. You can adjust it to the desired value. Therefore, in the exposure apparatus incorporating the illumination optical apparatus of the present invention, the size and sigma value of the exposure area can be adjusted to desired values while suppressing light loss at the aperture stop and the illumination field stop well. As a result, in the exposure apparatus of the present invention, according to the characteristics of the microdevice to be manufactured or the characteristics of the mask to be used, the size and sigma value of the illumination region (exposure region) are set to optimal values, respectively, and high exposure is achieved. Good projection exposure with high throughput can be performed based on illuminance and good exposure conditions.

Moreover, in the exposure method which exposes the pattern of the mask arrange | positioned on the to-be-exposed surface on the photosensitive board | substrate or the manufacturing method of a micro device using the illumination optical apparatus of this invention, since projection exposure can be performed based on favorable exposure conditions, Good microdevices can be manufactured.

Further, according to the exemplary embodiment of the present invention, modified illumination such as annular band modified illumination or quadrupole modified illumination and ordinary circular illumination can be performed while satisfactorily suppressing light loss in the aperture stop for limiting the secondary light source. Can be. Therefore, in the exposure apparatus which assembled the illumination optical apparatus of this invention, the kind of modified illumination can be changed suitably, and the resolution and focus depth of the projection optical system suitable for the fine pattern to carry out exposure projection can be obtained. As a result, good projection exposure with high throughput can be performed based on high exposure illuminance and good exposure conditions.

Even if the number of illumination apertures is changed by converting the exposure luminous flux into a luminous flux having a desired light intensity distribution by the luminous flux converting means (modifying means) in order to set it to a desired exposure condition or a desired illumination condition, the adjustment means Since the illumination numerical aperture can be adjusted, the manufacturing method of the exposure apparatus and microdevice which can always expose a favorable mask pattern to photosensitive substrates, such as a wafer, based on a desired exposure condition or a desired illumination condition can be realized.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

Claims (16)

In the illumination optical device for illuminating the surface to be irradiated, A first variable optical system having a variable focal length or magnification in order to adjust the number of illumination apertures on the irradiated surface; Second variable optical system whose focal length or magnification is variable to change the size of the illumination area formed on the irradiated surface Illumination optical device comprising a. The method of claim 1, And an adjusting system for adjusting respective focal lengths or angular magnifications of the first and second variable optical systems to set the illumination numerical aperture and the size of the illumination region to a desired value, respectively. Lighting optical device. The method of claim 1, Light source means for supplying illumination light, Multi-light source forming means for forming a plurality of light beams based on the illumination light; A light beam conversion optical system for converting the light beam from the light source means into a light beam having a predetermined cross-sectional shape, The first variable displacement optical system guides the light beam passing through the light beam conversion optical system to the multi-light source forming means, And said second variable optical system guides a plurality of light beams from said multi-light source forming means to said irradiated surface. The method of claim 1, Light source means for supplying illumination light, A light beam conversion optical system for converting the light beam from the light source means into a light beam having a predetermined cross-sectional shape, The first variable displacement optical system guides the luminous flux in the luminous flux conversion optical system to the second variable optical system, The second variable optical system includes multi-light source forming means for forming a plurality of light beams based on the light beams passing through the first variable optical system, and guides the light beams from the first variable optical system to the irradiated surface. Lighting optical device. The method of claim 2, Light source means for supplying illumination light, Multi-light source forming means for forming a plurality of light beams based on the illumination light; A light beam conversion optical system for converting the light beam from the light source means into a light beam having a predetermined cross-sectional shape, The first variable displacement optical system guides the light beam passing through the light beam conversion optical system to the multi-light source forming means, And said second variable optical system guides a plurality of light beams from said multi-light source forming means to said irradiated surface. The method of claim 2, Light source means for supplying illumination light, A light beam conversion optical system for converting the light beam from the light source means into a light beam having a predetermined cross-sectional shape, The first variable displacement optical system guides the luminous flux in the luminous flux conversion optical system to the second variable optical system, The second variable optical system includes multi-light source forming means for forming a plurality of light beams based on the light beams passing through the first variable optical system, and guides the light beams from the first variable optical system to the irradiated surface. Lighting optical device. The illumination optical device as described in any one of Claims 1-6, And an optical system for projecting and exposing the pattern of the mask disposed on the irradiated surface onto a photosensitive substrate. The process of illuminating the mask arrange | positioned at the said irradiated surface by the illumination optical apparatus as described in any one of Claims 1-6, Transferring the pattern of the illuminated mask onto a photosensitive substrate Micro device manufacturing method comprising a. In the exposure apparatus which has the illumination optical apparatus which illuminates the pattern of the mask which has a predetermined pattern by the light beam for exposure, and the projection system which projects and exposes the pattern image of the said mask on the photosensitive board | substrate, Input means for inputting information on an exposure condition on the photosensitive substrate or an illumination condition on the mask, The illumination optical device, Luminous flux converting means for converting the exposure luminous flux into a luminous flux having a desired light intensity distribution based on input information from the input means; A first variable optical system for adjusting the number of illumination apertures in the mask based on input information from the input means, A second variable optical system for changing the size of an illumination region formed in the mask based on input information from the input means Exposure apparatus comprising a. The method of claim 9, The illumination optics device comprises an optical integrator for uniformly illuminating the mask, The first variable optical system is disposed on the incidence side of the optical integrator, The second variable optical system is disposed on the exit side of the optical integrator. In the manufacturing method of a micro device containing the illumination process which illuminates the pattern of the mask which has a predetermined pattern by the light beam for exposure, and the exposure process which project-exposes the pattern image of the said mask on the photosensitive board | substrate, The lighting process, An input step of inputting information on an exposure condition on the photosensitive substrate or an illumination condition on the mask; A light beam conversion step of converting the light beam for exposure to a light beam having a desired light intensity distribution based on the input information in the input step; An illumination region variable process of changing the size of an illumination region formed in said mask based on input information in said input process; An adjusting step of adjusting the number of illumination apertures in the mask based on the input information from the input means Micro device manufacturing method comprising a. The method of claim 11, And the adjusting step corrects the value of the illumination numerical aperture that is changed by the illumination region variable process to keep the value of the illumination numerical aperture almost constant. In the exposure apparatus which has the illumination optical apparatus which illuminates the pattern of the mask which has a predetermined pattern by the light beam for exposure, and the projection system which projects and exposes the pattern image of the said mask on the photosensitive board | substrate, The illumination optical device, Changing means for changing the light intensity distribution at or near the pupil position of the illumination optical device; Adjusting means for adjusting the number of illumination apertures in the mask in accordance with the change in the light intensity distribution by the changing means An exposure apparatus characterized by the above-mentioned. The method of claim 13, And said changing means includes luminous flux converting means for selectively converting said exposure luminous flux into one luminous flux among a plurality of luminous fluxes having different luminous flux distributions. The method of claim 14, The luminous flux converting means includes a first diffraction optical member for forming a first light intensity distribution and a second light intensity distribution different from the first light intensity distribution provided so as to be interchangeable with the first diffraction optical member for an optical path. It has a 2nd diffraction optical member to form, The exposure apparatus characterized by the above-mentioned. An illumination step of illuminating a pattern of a mask having a predetermined pattern using an illumination optical device, and an exposure step of projecting and exposing the pattern image of the mask to a photosensitive substrate using a projection system. , The lighting process, A changing step of changing the light intensity distribution at or near the pupil position of the illumination optical device; An adjusting step of adjusting the number of illumination apertures in the mask in accordance with the change of the light intensity distribution by the changing step. Micro device manufacturing method comprising a.