JP2003232901A - Optical device, illuminator and exposure device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device in which a surface to be irradiated is uniformly illuminated even by an illuminator using a lens array or a mirror array having a non-lens action part (including also the case it is a mirror) such as a micro-lens array and a micro-mirror array, and to provide the illuminator and an exposure device. <P>SOLUTION: The lens array where a plurality of lenses are formed in an array state has a prevention part for preventing the passing of incident luminous flux between the plurality of lenses. The mirror array where a plurality of concave and/or convex mirrors are formed in an array state has a prevention part for preventing the reflection of the incident luminous flux between the plurality of mirrors. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to optical elements, illuminators and exposure apparatus, and more particularly to manufacturing devices such as single crystal substrates for semiconductor wafers and glass substrates for liquid crystal displays (LCDs). The present invention relates to an optical element, an illuminating device, and an exposure device used in the.

[0002]

2. Description of the Related Art Due to recent miniaturization and high integration of circuit patterns, there is an increasing demand for higher resolution of projection exposure apparatuses used in lithography (printing) processes. A projection exposure apparatus generally has an illuminating device that illuminates a mask, and a projection optical system that is disposed between the mask and the object to be processed and projects the illuminated circuit pattern of the mask onto the object to be processed. In order to obtain a high-resolution circuit pattern, it is necessary to expose the surface of the object to be processed with a uniform light amount distribution. Therefore, in a lighting device that illuminates the mask, it is required to form a uniform lighting region.

The illuminator introduces a light beam from a light source into a fly-eye lens in which a large number of element lenses are arranged in an array,
A uniform illumination region is formed by using a condenser lens as a secondary light source surface for the exit surface to uniformly Koehler illuminate the mask surface.

In order to form a more uniform illumination area, it is effective to increase the number of element lenses of the fly-eye lens, but since the element lenses are independent lenses, the cost increases as the number increases. However, it is not easy in terms of work to arrange them with appropriate tolerances to form a fly-eye lens.

Therefore, it has been proposed to use the microlens array as a fly-eye lens. The microlens array is formed by directly forming minute element lenses having a lens function on a substrate and is formed by using optical lithography.

[0006] FIG. 16 is a schematic view of a main part of an illuminating device 1000 using microlens arrays 1300a and 1300b as fly-eye lenses (multi-beam forming means) 1300. The illuminating device 1000 arranges the light flux from the light source 1100 into a desired cross-sectional shape and light distribution by the light flux adjusting means 1200, and Koehler illuminates the illuminated surface 1500 with the multiple light flux forming means 1300 and the condenser lens 1400.

The multi-beam forming means 1300 comprises two groups of microlens arrays 1300a and 1300b, and the microlens array 130 on the light source 1100 side.
Each element lens 1300ar on the 0a surface is a surface to be illuminated 150.
It is arranged substantially conjugate with 0.

[0008]

However, between the element lenses 1300ar of the microlens array 1300a, there is a region 1300af having a very small lens action as compared with the microlens, and the light flux incident on the region 1300af is similar. In addition, the microlens array 1300b
But lens action (convergence and divergence action by optical power)
It goes straight through the multi-beam forming means 1300 without receiving the light.

In the Koehler illumination, the relationship between the angles on the incident side of the condenser lens 1400 is expressed by the irradiated surface 1
Since it is replaced with the positional relationship at 500, the straight light flux X that has passed through without being affected by the lens effect in the multi-beam forming means 1300 is a point on the irradiated surface 1500 regardless of the incident position on the condenser lens 1400. Focus on 1500a.

Therefore, the light intensity distribution of the irradiated area formed only by the element lenses 1300ar of the multi-beam forming means 1300 is as shown in FIG. 17, but in reality, the lens effect of the multi-beam forming means 1300 is extremely small. Area 1
Due to the presence of 300af, the light intensity distribution of the formed irradiation area becomes a distribution obtained by adding the intensity shown by the diagonal lines to the light intensity distribution shown in FIG. 17, and a uniform illuminance distribution cannot be obtained. . Further, when the light beam incident on the multi-beam forming means 1300 has a numerical aperture (NA), the hatched portion has a distribution that widens toward the bottom as shown in FIG. 19, which is not so bad as the light intensity distribution shown in FIG. However, the illuminance distribution is not uniform. Here, FIG. 17 shows the multi-beam forming means 13
00 is a graph showing the light intensity distribution of the irradiated area formed only by the element lens 1300ar, FIG. 18 is a graph showing the light intensity distribution of the irradiated area formed by the multi-beam forming means 1300, and FIG. 19 is NA. Is a graph showing the light intensity distribution of the illuminated area formed by the multi-beam forming means when using a light flux having Adopted the position of.

Such a problem similarly occurs in the illumination device 2000 using the two multi-beam forming means 2300 and 2500, as shown in FIG. Here, FIG. 20 shows a first multi-beam forming means 2300 composed of two groups of microlens arrays 2300a and 2300b, and a second multi-beam forming means 2500 composed of two groups of microlens arrays 2500a and 2500b. Lighting device 2 having
000 is a schematic configuration diagram of main parts.

The illuminating device 2000 is adjusted to a desired cross-sectional shape and light distribution by the light flux adjusting means 2200 from the light source 2100, and the first multi-beam forming means 2300 and a condenser lens 2400 form a plurality of two-dimensional light sources. The incident surface of the second multi-beam forming means 2500 is Koehler-illuminated, and the irradiated surface 2700 is Koehler-illuminated by the second multi-beam forming means 2500 and the condenser lens 2600.

A region 2300af having a very small lens action exists between the element lenses 2300ar of the microlens array 2300a, and the light beam incident on the region 2300af goes straight without being subjected to the lens action by the first multi-beam forming means 2300. Then, as shown in FIG. 21, a light intensity distribution having a strong peak is formed on the incident surface of the second multi-beam forming means 2500. Therefore, the second multi-beam forming means 2
The effective light source formed by 500 becomes non-uniform, and a strong light beam enters only some of the element lenses 2500ar, so that the light intensity distribution on the irradiated surface 2700 deteriorates.

Further, the straight light from the area 2500af, which is present between the element lenses 2500ar of the microlens array 2500a and has a very small lens action, is a pre-stage multi-beam forming means 2300 and a condenser lens 2400.
NA is reduced by the Koehler illumination system consisting of
As a result, the number of luminous fluxes that have a large number is increased, so that a light intensity distribution having a high center and a wide skirt is formed as shown in FIG. The light intensity distribution shown in FIG. 22 is not so bad as the light intensity distribution shown in FIG. 21, but it does not provide a uniform illuminance distribution and directly causes illuminance unevenness. Here, FIG. 21 shows the first multi-beam forming means 2300.
22 is a graph showing the light intensity distribution on the incident surface of the second multi-beam forming means 2500, and FIG. 22 shows the irradiated surface 27 formed by the second multi-beam forming means 2500.
In each graph, the vertical axis represents the light intensity of the illuminated area and the horizontal axis represents the position of the illuminated area.

Further, the above-mentioned problem also occurs when a reflective microlens array in which minute elements having a reflecting action are directly formed on a substrate is used.

Therefore, it is an exemplary object of the present invention to provide an optical element, an illuminating device, and an exposing device capable of uniformly illuminating a surface to be illuminated even when a microarray lens is used as a fly-eye lens. .

[0017]

In order to achieve the above object, a lens array according to one aspect of the present invention is a lens array in which a plurality of lenses are formed in an array, and Has a prevention unit for preventing passage of an incident light beam. According to such a lens array, it is possible to remove an unnecessary light flux which has not been subjected to the lens action by the prevention portion provided between the plurality of lenses (a region having no lens action).

A lens array as another aspect of the present invention is a lens array in which a plurality of lenses having a refracting action are formed in array on both sides of a substrate, and an incident light beam passes between the plurality of lenses. It has a prevention part that prevents
The action of such a lens array also exhibits the same action as the above-mentioned lens array.

A lens array according to still another aspect of the present invention is a mirror array in which a plurality of concave and / or convex mirrors are formed in an array shape, and prevents reflection of an incident light beam between the plurality of mirrors. It has a prevention part. According to such a mirror array, an unnecessary light beam which is not subjected to the mirror action can be removed by the prevention portion provided between the plurality of concave and / or convex mirrors (region having no mirror action).

In the above array, the prevention part is a metal film and / or a dielectric film, or a diffusion surface for diffusing the incident light flux.

An illumination device as yet another aspect of the present invention is an illumination device that illuminates an illuminated area using a light beam emitted from a light source, and has a plurality of elements having refraction and / or reflection action in an array. A multi-beam forming means for forming a number of two-dimensional light sources using the light beams from the light source, and the light beams from between the plurality of elements are condensed in the illuminated area. And a preventive means for preventing this. According to such an illuminating device, by providing the light collecting prevention means, it is possible to remove an unnecessary light flux that is not refracted and / or reflected in the multi-beam forming means, and form a uniform illuminance distribution in the illuminated area. . The multi-beam forming means is configured such that the surfaces of the optical element on which the plurality of elements are formed face each other. The optical element may have the plurality of elements on both sides of a substrate. The optical element is a cylindrical lens array plate. The multi-beam forming means may include a plurality of sets of the cylindrical lens array plates arranged so that the sets are orthogonal to each other.
The preventing means is provided on a masking blade defining an illumination area for illuminating the illuminated area, which is disposed between the multi-beam forming means and the illuminated area, and is provided between a plurality of elements of the optical element. It is a filter that blocks the light flux that has passed through. The prevention means is a metal film and / or a dielectric multilayer film formed between the plurality of elements of the optical element and blocking the light flux passing between the plurality of elements. The prevention means is a diffusing surface formed between the plurality of elements of the optical element and diffusing the light flux. A plurality of multi-beam forming means may be provided.

An exposure apparatus as yet another aspect of the present invention has the above-mentioned illumination apparatus and an optical system for projecting a pattern formed on a reticle and / or a mask onto an object to be processed. According to such an exposure apparatus, it is possible to remove a light beam that has not been subjected to refraction or reflection and uniformly illuminate the mask to obtain a high-resolution pattern.

An exposure apparatus as still another aspect of the present invention has an optical system including the above-mentioned array. The operation of this exposure apparatus also has the same operation as the above-mentioned exposure apparatus.

A device manufacturing method as still another aspect of the present invention comprises the steps of exposing the object to be processed using the above-mentioned exposure apparatus and performing a predetermined process on the exposed object to be processed. Have. The claims of the device manufacturing method having the same operation as the above-described operation of the exposure apparatus extend to the devices themselves which are intermediate and final products. In addition, such devices include semiconductor chips such as LSI and VLSI, CCDs, LCDs, magnetic sensors, thin film magnetic heads, and the like.

Further objects or other features of the present invention are:
It will be apparent from the preferred embodiments described below with reference to the accompanying drawings.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION An exposure apparatus 1 and an illumination apparatus 100 according to the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to these examples, and each constituent element may be substituted instead as long as the object of the present invention is achieved. Here, FIG.
FIG. 1 is a schematic configuration diagram of an exemplary exposure apparatus 1 of the present invention.

The exposure apparatus 1 is, as shown in FIG. 1, an illumination apparatus 100 for illuminating a mask or reticle 200 (which are used interchangeably in the present application) 200 on which a circuit pattern is formed, and an illumination apparatus 100. Projection optical system 300 for projecting diffracted light generated from a mask pattern onto a plate 400
And a stage 450 that supports the plate 400.

The exposure apparatus 1 is, for example, a mask 20 using a step-and-repeat method or a step-and-scan method.
It is a projection exposure apparatus that exposes a circuit pattern formed on the plate 400 onto the plate 400. Such an exposure apparatus is suitable for a sub-micron or quarter-micron lithography process, and in the present embodiment, a step-and-scan type exposure apparatus (also referred to as a “scanner”) will be described below as an example. Here, "step and scan method"
Is an exposure method in which the wafer is continuously scanned with respect to the mask to expose the mask pattern on the wafer, and after the exposure of one shot is completed, the wafer is step-moved to the exposure area of the next shot. The “step-and-repeat method” is an exposure method in which the wafer is moved stepwise for each batch exposure of a shot of the wafer and moved to the exposure area of the next shot.

The illuminating device 100 illuminates the mask 200 on which the transfer pattern is formed. The illumination device 100 includes a light source unit 110 and an illumination optical system 120, as shown in FIG. Here, FIG. 2 is a schematic configuration diagram of a main part of an illuminating device 100 which is a part of the exemplary exposure apparatus 1 of the present invention.

The light source section 110 uses, for example, a laser as a light source. The laser has a Kr of about 248 nm.
An F excimer laser, an ArF excimer laser having a wavelength of about 193 nm, an F ₂ laser having a wavelength of about 157 nm, or the like can be used, but the type of laser is not limited to the excimer laser, and for example, a YAG laser may be used,
The number of lasers is not limited either. For example, if two solid-state lasers that operate independently are used, there is no mutual coherence between the solid-state lasers, and speckle due to the coherence is significantly reduced. Further, the optical system may be swung linearly or rotationally to reduce speckle. The light source that can be used for the light source unit 110 is not limited to a laser, and one or more lamps such as a mercury lamp or a xenon lamp, or an EUV light source can also be used. When an EUV light source is used, no lens can be used in the optical system, so each element of the optical system is a mirror.

The illumination optical system 120 is an optical system for irradiating the mask 200, and has a light flux adjusting means 122, a multiple light flux forming means 124, a condenser lens 126, and an image forming optical system 128.

The light flux adjusting means 122 is means for adjusting the light flux from the light source section 110 into a desired cross-sectional shape and light distribution. As the light flux adjusting unit 122, for example, a light flux shaping optical system, an incoherent optical system, or the like can be considered. The light flux shaping optical system can use, for example, a plurality of cylindrical lenses, a beam expander, or the like, and converts the aspect ratio of the cross-sectional dimension of the parallel light flux from the laser light source into a desired value. The incoherent optical system makes a coherent laser light beam incoherent, for example, splits an incident light beam into at least two light beams (for example, p-polarized light and s-polarized light) on a light splitting surface, and then uses one of the light beams as an optical member. An optical system having at least one folding system in which an optical path length difference equal to or larger than the coherence length of the laser beam is given to the other light flux through the other light flux, and then the light is re-induced to the split surface so as to be superposed and emitted with the other light flux. Systems can be used.

The multi-beam forming means 124 uses the light beams emitted from the light source section 110 to form a large number of two-dimensional light sources (that is, in order to have a fly-eye lens function), the microlens array 124a. And 124b of 2
It is composed of groups.

In the microlens array 124a, a plurality of elements 124ap having a lens action are arranged in an array on the substrate S.
It is formed integrally with 1. Micro lens array 12
A prevention part 124as is formed between a plurality of elements 124ap of 4a (that is, a region having no lens action) 124an. The prevention unit 124as allows the light flux from the light source 110 to pass through the plurality of elements 12 of the microlens array 124a.
Between 4 ap (that is, a region having no lens effect) 124
prevent passing through an.

Similarly, the microlens array 124b has the same structure.
A plurality of elements 124bp having a lens action are integrally formed with the substrate S1 'in an array, and the plurality of elements 124bp
Between bp (that is, a region having no lens effect) 124b
The prevention part 124bs is formed in n. Preventing part 124
bs prevents the light flux that has passed through the microlens array 124a from passing between the plurality of elements 124bp (that is, a region having no lens effect) 124bn. However, in the present embodiment, the prevention portions 124as and 124bs are provided on both the microlens arrays 124a and 124b. However, at least one of them, more preferably the front group located at a position conjugate with the irradiated surface T, that is, the microlens array. 1
You may provide only in 24a.

For the prevention portions 124as and 124bs, vapor deposition of a metal film of chromium (Cr) or coating of a dielectric multilayer film can be considered. However, the prevention parts 124as and 124b
s is not limited to these, and any structure known in the art can be applied as long as it shields a region of the microlens array having no lens action.

Therefore, the multi-beam forming means 124 has the prevention part 124a in the areas 124an and 124bn of the microlens arrays 124a and 124b which do not have the lens action.
By providing s and 124bs, it is possible to eliminate unnecessary light fluxes that are not subjected to the lens action and to make the illuminated surface T a uniform illuminance distribution.

In the Koehler illumination, the condenser lens 126 shows the relationship of angles on the incident side with respect to the illuminated surface T.
Replace with the positional relationship in. Therefore, the condenser lens 126 illuminates the illuminated surface T by Koehler illumination using the light flux that has undergone the lens effect by the multiple light flux forming means 124.

The imaging optical system 128 enlarges the uniform illumination area formed on the surface to be illuminated T to a desired size and mask 2
00 is Koehler illuminated.

Here, FIGS. 3 to 5, FIG. 8, FIG. 9, and FIG.
With reference to FIG. 2, illumination devices 100A to 100F, which are modified examples of the illumination device 100, will be described. The same members as those of the lighting device 100 are designated by the same reference numerals, and a duplicate description will be omitted. Here, FIG. 3 is a schematic configuration diagram of a main part of an illuminating device 100A having a multi-beam forming means 130 which is a modified example of the multi-beam forming means 124 shown in FIG. 2, and FIG. 4 is a multi-beam forming shown in FIG. Illumination device 100 having multi-beam forming means 140 which is a modification of forming means 124
FIG. 5 is a schematic configuration diagram of a main part of B, and FIG.
FIG. 8 shows a cylindrical lens array plate 170a, which is a schematic configuration diagram of a main part of an illuminating device 100C having 50 and 160.
9 is a schematic diagram showing the main part of an illuminating device 100D having a multi-beam forming means 170 composed of a plurality of parts 170 to 170d.
8A is a YZ plane sectional view of the lighting device 100D, FIG.
9B is a cross-sectional view taken along the XZ plane of the lighting device 100D, FIG.
FIG. 12 is a schematic configuration diagram of a main part of an illuminating device 100E having a multi-beam forming means 180 formed of a reflective microlens array plate. FIG. 12 shows an illuminating device 100F in which a masking blade 192 is provided with a light collecting prevention means 194. It is a schematic diagram of a main part.

The illumination device 100A will be described below. With reference to FIG. 3, the illuminating device 100A differs from the illuminating device 100 with respect to the multi-beam forming means 130.
The multi-beam forming means 130 includes a microlens array 130.
A plurality of two-dimensional light sources are formed by using the light flux emitted from the light source unit 110, which is composed of one group a.

In the microlens array 130a, a plurality of elements 130ap having a lens action are arranged in an array on the substrate S.
It is directly formed on both surfaces of 2 (that is, the incident side and the emitting side of the microlens array 130a). Between the plurality of elements 130ap of the microlens array 130a (that is, a region having no lens action) 130an, the prevention unit 13 is provided.
0as is formed. The prevention unit 130as is the light source 1
The light flux from 10 is prevented from passing through a plurality of elements 130ap of the microlens array 130a (that is, a region having no lens action) 130an. In this embodiment as well, the preventing portions 130as are provided on the incident side and the emitting side (both sides of the substrate S2) of the microlens array 130a, but are provided only on at least one side, more preferably on the incident side at a position conjugate with the irradiated surface T. May be.

Therefore, the multi-beam forming means 130 has a region 1 of the microlens array 130a having no lens action.
By providing 30as, it is possible to eliminate the unnecessary light flux that has not been subjected to the lens action and make the illuminated surface T a uniform illuminance distribution.

The illumination device 100B will be described below. With reference to FIG. 4, the illuminating device 100B differs from the illuminating device 100 with respect to the multi-beam forming means 140.
The multi-beam forming unit 140 forms a number of two-dimensional light sources using the light beams emitted from the light source unit 110 (that is,
In order to have the function of a fly-eye lens), it is composed of two groups of microlens arrays 140a and 140b.

In the microlens array 140a, a plurality of elements 140ap having a lens function are arranged in an array on the substrate S.
It is formed integrally with 3. Micro lens array 14
A diffusion surface 140as is formed between the multiple elements 140ap of 0a (that is, a region having no lens effect) 140an. The diffusion surface 140as is formed by performing patterning by a lithography technique or the like. Diffusion surface 1
40as diffuses the light flux from the light source unit 110 so that the light flux is present between the plurality of elements 140ap of the microlens array 140a (that is, a region having no lens action).
Prevents passing 40 an.

In the microlens array 140b, a plurality of elements 140bp having a lens function are arrayed on the substrate S.
It is formed integrally with 3 '. In the present embodiment, the diffusion surface is not formed between the plurality of elements 140bp of the microlens array 140b (that is, the area having no lens action) 140bn, but the formation of the diffusion surface is not hindered.

Therefore, the multi-beam forming means 140 is provided in the area 1 of the microlens array 140a which does not have the lens function.
By providing the diffusion surface 140as on 40an, it is possible to eliminate unnecessary light fluxes that are not subjected to the lens action and to make the illuminated surface T a uniform illuminance distribution.

The illumination device 100C will be described below. Referring to FIG. 5, the illuminating device 100C includes a first multi-beam forming means 150 and a second multi-beam forming means 160.

The first multi-beam forming means 150 includes the light source section 1
In order to form a large number of two-dimensional light sources using the light flux emitted from 10 (that is, in order to have a function of a fly-eye lens), it is composed of two groups of microlens arrays 150a and 150b.

In the microlens array 150a, a plurality of elements 150ap having a lens function are arranged in an array on the substrate S.
It is formed integrally with 4. Micro lens array 15
The prevention part 150as is formed between the plurality of elements 0aap of 0a (that is, a region having no lens action) 150an. The prevention part 150as is formed by vapor deposition of a metal film of chromium (Cr) or the like, coating of a dielectric multilayer film, a diffusion surface, etc., and the light flux from the light source part 110 is present between a plurality of elements 150ap of the microlens array 150a (that is, , An area having no lens action) 150an is prevented.

As shown in FIG. 6, the plurality of elements 150ap of the microlens array 150a are generally constituted by hexagonal element lenses, and the prevention portions 150as are formed around them. Here, FIG. 6 is a schematic front view showing an example of the microlens array 150a. The illumination σ (coherency) is required to be close to a circle, which is equivalent to circularly illuminating the second multi-beam forming means 160 in the subsequent stage. Even if a hexagonal lens element is used for the plurality of elements 150ap of the first multi-beam forming means 150, the light illuminating the second multi-beam forming means 160 does not become a circle, but the light of the second multi-beam forming means 160 does not. When cutting out, such as placing a circular diaphragm in the latter stage, there is little reduction in light efficiency.

Further, as shown in FIG. 7, the preventing portion 150 is previously formed so that the transmitting portions of the plurality of elements 152ap (hexagonal element lenses) of the microlens array 150a are circular.
You may provide as. Here, FIG. 7 is a schematic front view showing an example of the microlens array 150a.

In the microlens array 150b, a plurality of elements 150bp having a lens function are arrayed on the substrate S.
It is formed integrally with 4 '. It should be noted that the prevention portion may be formed at least only on the incident side microlens array 150a, and in this embodiment, the microlens array 150a is provided.
The prevention part is not formed in the region 150bn having no lens action of b.

The second multi-beam forming means 160 forms a number of two-dimensional light sources using the light beams from the first multi-beam forming means 150 and the condenser lens 126 (that is, the function of a fly-eye lens). In order to have the above), it is composed of two groups of microlens arrays 160a and 160b.

In the microlens array 160a, a plurality of elements 160ap having a lens action are arranged in an array on the substrate S.
It is formed integrally with 5. Micro lens array 16
A prevention part 160as is formed between the plurality of elements 160ap of 0a (that is, a region having no lens action) 160an. The prevention unit 160as is formed by vapor deposition of a metal film such as chromium (Cr), coating of a dielectric multilayer film, a diffusion surface, and the like, and the light flux from the first multi-beam forming means 150 and the condenser lens 126 is microlens array 160a. Between the plurality of elements 160ap (that is, a region having no lens effect) 160an is prevented.

In the microlens array 160b, a plurality of elements 160bp having a lens function are arrayed on the substrate S.
It is formed integrally with 5 '. It should be noted that the prevention section may be formed at least only on the incident side microlens array 160a. In the present embodiment, the microlens array 160a is formed.
The prevention part is not formed in the region 160bn having no lens action of b.

Therefore, the first multi-beam forming means 150 forms the effective light source flat, and the second multi-beam forming means 160 uses the effective light source to illuminate the illuminated surface T uniformly without unevenness in illuminance. be able to.

The illumination device 100D will be described below. Referring to FIG. 8, the lighting device 100D includes cylindrical microlens array plates 170a to 170d. The multi-beam forming means 170 is formed by arranging the cylindrical lens array plates 170a and 170c and the cylindrical lens array plates 170b and 170d so as to be orthogonal to each other. The multi-beam forming means 170 is arranged such that a set of cylindrical lens array plates 170a and 170c and a set of cylindrical lens array plates 170b and 170d illuminate the illuminated surface T via the condenser lens 126 by Koehler illumination. The illumination shape of the irradiation surface T has a rectangular shape (slit shape).

In the cylindrical lens array plates 170a and 170c, a plurality of elements 170ap and 170cp having a lens action in the YZ section are formed integrally with the substrates S6a and S6c in an array. In the cylindrical lens array plates 170b and 170d, a plurality of elements 170bp and 170dp having a lens action in the XZ section are integrally formed with the substrates S6b and S6d in an array.

Between the plurality of elements 170cp and 170dp of the cylindrical lens array plates 170c and 170d (that is, a region having no lens action) 170cn and 1
Preventing portions 170cs and 170ds are formed at 70dn.

The preventive portions 170cs and 170ds are formed by vapor deposition of a metal film of chromium (Cr) or the like, coating of a dielectric multilayer film, etc., and the luminous flux is between the plurality of elements 170cp and 170dp of the cylindrical lens array plates 170c and 170d. (That is, the area having no lens effect) 1
Prevent passage through 70cn and 170dn. Since the prevention portions 170cs and 170dn are linear, they can be provided more easily than the microlenses formed of square element lenses.

Further, since the multi-beam forming means 170 is constructed by arranging the cylindrical lens array plates 170a to 170d alternately, the cylindrical lens array plates 170a and 170b other than the cylindrical lens array plates 170c and 170 are prevented. When formed, vignetting will occur.

Therefore, the multi-beam forming means 170 provides the preventing portions 170cs and 170ds in the areas 170cn and 170dn having no lens action of the cylindrical lens array plates 170c and 170d, respectively, so that unnecessary light beams not having a lens action are generated. The irradiation target surface T can be deleted to have a uniform illuminance distribution.

The illumination device 100E will be described below. The lighting device 100E has an extreme ultraviolet ray (EUV).
The mask 200 on which the transfer pattern is formed is illuminated using ultraviolet light. Lighting device 100E
Is an EUV light source 110E, a multi-beam forming means 180,
And a condenser optical system 182.

As the EUV light source 110E, for example, a laser plasma light source is used. The laser plasma light source irradiates a high-intensity pulsed laser beam on a target material placed in a vacuum to generate high-temperature plasma. Then, the EUV light having a wavelength of about 13.4 nm emitted from this is used. As the target material, a metal thin film, an inert gas, a droplet, or the like is used. In order to increase the average intensity of the emitted EUV light, the pulse laser preferably has a high repetition frequency and is usually operated at a repetition frequency of several kHz. Alternatively, the EUV light source 110E uses a discharge plasma light source. The discharge plasma light source emits a gas around the electrode placed in a vacuum and applies a pulse voltage to the electrode to cause a discharge to generate high temperature plasma. The EU with a wavelength of about 13.4 nm emitted from now on
It utilizes V light. However, the EUV light source 110E
Are not limited to these, and any technique known in the art can be applied.

The multi-beam forming means 180 includes the EUV light source 11
In order to form a large number of two-dimensional light sources by using EUV light emitted from 0E (that is, to have a function of a fly-eye lens), a reflective microlens array 180a (convex curved surface micromirror array or concave Curved micro mirror array).

The microlens array 180a has a plurality of reflective elements 180ap formed integrally with the substrate S7. Between a plurality of elements 180ap of the microlens array 180a (that is, a region having no reflection effect)
A prevention portion 180as is formed on 180an.
The prevention unit 180as is formed of a non-reflective member, and EUV light from the EUV light source unit 110E receives the microlens array 1.
It prevents reflection at 180 an between the plurality of elements 180 ap of 80 a (that is, a region having no reflection effect).

In the case where the multi-beam forming means 180 is a microlens array 180a in which the cylindrical reflecting surfaces are arranged in an array in a direction perpendicular to the generatrix thereof, a linear preventing portion 180as is provided as shown in FIG. The multi-beam forming means 180 is a microlens array 18 of square element lenses.
In the case of 0a, as shown in FIG. 11, the prevention portions 180as are provided in a grid pattern. Here, FIG. 10 is a schematic front view showing an example of a microlens array 180a in which cylindrical reflecting surfaces are arranged in an array in a direction perpendicular to the generatrix, and FIG. 11 is an example of a microlens array 180a of square element lenses. It is a schematic front view shown.

When EUV light is hardly reflected by a normal material and a multilayer film of 40 layers needs to be applied for reflection, the prevention portion 180as is not formed by a non-reflective member, but is formed by a reflection layer. A certain multilayer film may be intentionally not attached or may be peeled off. Furthermore, the prevention unit 180a
If s is processed into a diffusing surface, then a multilayer film may be attached to the entire surface, which facilitates production.

The condenser optical system 182 is arranged at a position optically conjugate with the multi-beam forming means 180 and the surface to be irradiated T, and reflects the EUV light from the multi-beam forming means 180 to illuminate the surface to be irradiated T. .

Therefore, the multi-beam forming means 180 has a region 18 of the microlens array 180a which does not have a reflecting action.
By providing the prevention unit 180as at 0an, it is possible to eliminate unnecessary luminous flux and make the illuminated surface T a uniform illuminance distribution.

The illumination device 100F will be described below. Referring to FIG. 12, the illumination device 100F includes a multi-beam forming unit 190, a masking blade 192, a light collection preventing unit 194, and an image forming optical system 196.

The multi-beam forming means 190 uses the light beams emitted from the light source section 110 to form a large number of two-dimensional light sources (that is, in order to have a fly-eye lens function), and the microlens array 190a. And 190b of 2
It is composed of groups.

Microlens arrays 190a and 190
b is a plurality of elements 190ap and 1 having a lens action.
90 bp is formed integrally with the substrates S8 and S8 'in an array. However, between the plurality of elements 190ap and 190bp of the microlens arrays 190a and 190b (that is, a region having no lens action) 190an and 1
90bn is not provided with a prevention part for preventing passage of a light beam. Therefore, on the first irradiated surface T ′, a portion having high illuminance is generated at the center by the light flux passing through the regions 190an and 190bn having no lens action of the microlens arrays 190a and 190b.

Therefore, as shown in FIG. 13, a masking blade 192 for restricting the illuminated area is arranged on the first illuminated surface T ', and the masking blade 192 has a light-shielding (or dimming) function at the center thereof. A light collecting prevention means 194 such as a filter having The light collection prevention unit 194 prevents the light flux that has passed through the areas 190an and 190bn having no lens action of the microlens arrays 190a and 190b from collecting (that is, reaching) the second irradiation surface T ″. To do. Here, FIG. 13 shows the light collecting prevention means 1.
FIG. 9 is a schematic front view of a masking blade 192 having 94.

The imaging optical system 196 determines the image of the masking blade 192 as a conjugate image on the second irradiation surface T ″.

Therefore, in the illuminating device 100F, by providing the masking blade 192 with the light collecting preventing means 194,
The light flux passing through the regions 190an and 190bn having no lens action of the microlens arrays 190a and 190b can be deleted to make the second illuminated surface T ″ have a uniform illuminance distribution.

Returning to FIG. 1 again, the mask 200 is made of, for example, quartz, on which a circuit pattern (or image) to be transferred is formed, and is supported and driven by a mask stage (not shown). The diffracted light emitted from the mask 200 passes through the projection optical system 300 and is projected onto the wafer 400. The wafer 400 is an object to be processed and is coated with a resist. The pattern of the mask 200 is transferred onto the wafer 400 by scanning the mask 200 and the wafer 400. In the case of a stepper (step-and-repeat type exposure apparatus), exposure is performed while the mask 200 and the wafer 400 are stationary.

The projection optical system 300 reduces and projects the circuit pattern of the mask 200 onto the wafer 400 at a desired magnification.
The projection optical system 300 includes an optical system including only a plurality of lens elements, an optical system including a plurality of lens elements and at least one concave mirror (catadioptric optical system), a plurality of lens elements and at least one kinoform. An optical system having a diffractive optical element such as, an all-mirror type optical system, or the like can be used. If you need to correct chromatic aberration,
A plurality of lens elements made of glass materials having mutually different dispersion values (Abbe values) are used, or the diffractive optical element is configured to generate dispersion in the direction opposite to that of the lens elements.

The wafer 400 is coated with a photoresist. The photoresist coating process includes a pretreatment, an adhesion improver coating treatment, a photoresist coating treatment, and a prebake treatment. The pretreatment includes washing, drying and the like. The adhesion improving agent coating treatment is a surface modification treatment (that is, hydrophobic treatment by applying a surfactant) for enhancing the adhesion between the photoresist and the base, and HMDS (Hexam)
An organic film such as ethyl-dilazane) is coated or vapor-treated. Prebaking, which is a baking (baking) step, is softer than that after development, and removes the solvent.

The stage 450 supports the wafer 400. Since the stage 450 may have any configuration known in the art, detailed description of its structure and operation will be omitted here. For example, the stage 450 can move the wafer 400 in XY directions using a linear motor. The mask 200 and the wafer 400 are, for example, synchronously scanned, and the positions of the stage 450 and a mask stage (not shown) are monitored by, for example, a laser interferometer, and both are driven at a constant speed ratio. The stage 450 is provided, for example, on a stage surface plate supported on a floor or the like via a damper, and the mask stage and the projection optical system 300 are, for example, a damper or the like on a base frame placed on the floor or the like. It is provided on a lens barrel surface plate (not shown) that is supported via.

In the exposure, the luminous flux emitted from the light source section 110 uniformly illuminates the mask 200 by Koehler illumination by the illumination optical system 120. The light that passes through the mask 200 and reflects the mask pattern is imaged on the wafer 400 by the projection optical system 300.

Since the exposure apparatus 1 using the illuminating devices 100A to 100F can illuminate with a uniform light intensity distribution, the pattern transfer to the resist can be performed with high accuracy and a high quality device (semiconductor element, LCD element, image pickup device). Element (CC
D) and thin film magnetic heads).

Next, with reference to FIGS. 14 and 15, an embodiment of a device manufacturing method using the above-described exposure apparatus 1 will be described. FIG. 14 is a flowchart for explaining the manufacture of devices (semiconductor chips such as IC and LSI, LCDs, CCDs, etc.). Here, manufacturing of a semiconductor chip will be described as an example. In step 1 (circuit design), the device circuit is designed. In step 2 (mask manufacturing), a mask having the designed circuit pattern is manufactured. In step 3 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by a lithography technique using the mask and the wafer. Step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer created in Step 4, and an assembly process (dicing,
Bonding), packaging process (chip encapsulation), etc. are included. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

FIG. 15 is a detailed flowchart of the wafer process in Step 4. In step 11 (oxidation), the surface of the wafer is oxidized. Step 12 (CV
In D), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), electrodes are formed on the wafer by vapor deposition or the like. In step 14 (ion implantation),
Implant ions into the wafer. In step 15 (resist processing), a photosensitive agent is applied to the wafer. Step 16
In (exposure), the exposure apparatus 1 exposes the circuit pattern of the mask onto the wafer. In step 17 (development), the exposed wafer is developed. Step 18 (Etching)
Then, parts other than the developed resist image are scraped off. In step 19 (resist peeling), the unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. According to the manufacturing method of this embodiment, it is possible to manufacture a higher quality device than the conventional one.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these, and various modifications and changes can be made within the scope of the gist thereof.

[0087]

According to the present invention, even in an illumination device using a lens array or a mirror array having a non-lens acting portion (including a mirror) such as a microlens array or a micromirror array, the illuminated surface is uniform. Can be illuminated. An exposure apparatus having such an illuminating device can achieve high resolution and can provide a high quality device.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an exemplary exposure apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of a main part of an illumination device which is a part of an exemplary exposure apparatus of the present invention.

3 is a schematic configuration diagram of a main part of an illuminating device having a multi-beam forming means which is a modification of the multi-beam forming means shown in FIG.

4 is a schematic configuration diagram of a main part of an illuminating device having a multi-beam forming means which is a modification of the multi-beam forming means shown in FIG.

FIG. 5 is a schematic configuration diagram of a main part of an illumination device having two multi-beam forming means.

6 is a schematic front view showing an example of the microlens array shown in FIG.

7 is a schematic front view showing an example of the microlens array shown in FIG.

FIG. 8 is a schematic configuration diagram of a main part of an illuminating device having a multi-beam forming unit configured by a cylindrical lens array plate.

FIG. 9 is a schematic configuration diagram of a main part of an illuminating device having a multi-beam forming unit configured by a reflective microlens array.

FIG. 10 is a schematic front view showing an example of the cylindrical microlens array shown in FIG.

11 is a schematic front view showing an example of a microlens array of the square element lenses shown in FIG.

FIG. 12 is a schematic configuration diagram of a main part of an illuminating device in which a masking blade is provided with a light collecting prevention unit.

13 is a schematic front view of a masking blade having the light-collecting preventing means shown in FIG.

FIG. 14 is a flowchart for explaining a device manufacturing method having the exposure apparatus of the present invention.

FIG. 15 is a detailed flowchart of Step 4 shown in FIG.

FIG. 16 is a schematic configuration diagram of a main part of a conventional lighting device using a microlens array as a fly-eye lens.

FIG. 17 is a graph showing a light intensity distribution of an illuminated area formed only by the element lenses of the multi-beam forming means shown in FIG.

FIG. 18 is a graph showing a light intensity distribution of an irradiation area formed by the multi-beam forming means shown in FIG.

FIG. 19 is a graph showing a light intensity distribution of an illuminated region formed by the multi-beam forming means shown in FIG. 16 when a light beam having NA is used.

FIG. 20 is a schematic configuration diagram of a main part of a conventional lighting device having two multi-beam forming means.

21 is a graph showing the light intensity distribution on the incident surface of the second multi-beam forming means formed by the first multi-beam forming means shown in FIG.

22 is a graph showing the light intensity distribution on the illuminated surface formed by the second multi-beam forming means shown in FIG.

[Explanation of symbols]

1 exposure apparatus 100, 100A to 100F illumination apparatus 124 multi-beam forming means 124a, 124b microlens array 124ap, 124bp element (lens) 124as, 124bs prevention section S1 substrate 140 multi-beam forming means 140a, 140b microlens array 140ap, 140bp element (Lens) 140as Diffusion surface S3 Substrate 180 Multi-beam forming means 180a Reflective microlens array 180ap Element (mirror) 180as Preventing part S7 Substrate 190 Multi-beam forming means 190a, 190b Microlens array 190ap, 190bp Element (lens) 192 Masking blade 194 Condensing prevention means S8 Substrate

Claims (17)

[Claims] 1. A lens array in which a plurality of lenses are formed in an array, and a lens array having a prevention unit for preventing passage of an incident light beam between the plurality of lenses. 2. A lens array in which a plurality of lenses having a refracting action are formed on both surfaces of a substrate in an array form, and a lens array having a prevention unit for preventing passage of an incident light beam between the plurality of lenses. 3. A mirror array in which a plurality of concave and / or convex mirrors are formed in an array form, and a mirror array having a prevention unit for preventing reflection of an incident light beam between the plurality of mirrors. 4. The array according to claim 1, wherein the prevention unit is a metal film and / or a dielectric film. 5. The array according to claim 1, wherein the prevention unit is a diffusion surface that diffuses the incident light flux. 6. An illumination device for illuminating an illuminated area using a light beam emitted from a light source, comprising: an optical element in which a plurality of elements having a refracting and / or reflecting action are formed in an array. Illumination having a multi-beam forming means for forming a large number of two-dimensional light sources by using a light beam from a light source, and a preventing means for preventing the light beam from between the plurality of elements from converging on the illuminated region. apparatus. 7. The illumination device according to claim 6, wherein the multi-beam forming means is configured such that surfaces of the optical element on which the plurality of elements are formed face each other. 8. The illumination device according to claim 6, wherein the optical element has the plurality of elements on both surfaces of a substrate. 9. The illumination device according to claim 6, wherein the optical element is a cylindrical lens array plate. 10. The illuminating device according to claim 9, wherein the multi-beam forming means has a plurality of sets of the cylindrical lens array plates arranged so that the sets are orthogonal to each other. 11. The prevention means is provided on a masking blade defining an illumination area for illuminating the illuminated area, which is disposed between the multi-beam forming means and the illuminated area, and the preventing means is provided on the masking blade. The lighting device according to claim 6, which is a filter that blocks the light flux that has passed between a plurality of elements. 12. The prevention means is a metal film and / or a dielectric multilayer film formed between the plurality of elements of the optical element and blocking the light flux passing between the plurality of elements. The illumination device according to item 6 or 11. 13. The illumination device according to claim 6, wherein the prevention unit is a diffusing surface formed between the plurality of elements of the optical element and diffusing the light flux. 14. The lighting device according to claim 6, further comprising a plurality of the multi-beam forming means. 15. An exposure apparatus having an optical system including the array according to claim 1. Description: 16. An illumination system according to claim 6, and an optical system for projecting a pattern formed on a reticle and / or a mask illuminated by the illumination system onto a target object. An exposure apparatus having. 17. A device manufacturing method comprising: exposing an object to be processed using the exposure apparatus according to claim 15 or 16; and performing a predetermined process on the exposed object to be processed.