JP2002343695A - Aligner and microdevice manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aligner, having an illumination optical system capable of dealing with the refining of the line width of the image of a mask pattern, which is projected on a photosensitive substrate to expose the substrate to the image. SOLUTION: The aligner has a surface light-source forming means 6 for subjecting luminous flux from a light source 1 to a wavefront division to form a surface light-source; a condenser optical system 4 for illuminating a mask pattern M, based on the surface light-source formed by the surface light-source forming means 6; and a projecting optical system for projecting the image of the mask pattern M on a photosensitive substrate W. In the aligner, the surface light-source forming means 6 has a plurality of elementary lenses disposed in parallel with each other, and the luminous flux from the light source 1 is projected on each elementary lens from the inclining direction to the optical axis of each elementary lens, so that it is reflected by the side surface of each elementary lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an exposure apparatus using an illuminating apparatus used for manufacturing a semiconductor integrated circuit and a method for manufacturing a micro device using the exposure apparatus.

[0002]

2. Description of the Related Art Conventionally, a projection exposure apparatus for projecting a mask pattern onto a wafer has a configuration in which the optical axis of an illumination optical system coincides with the optical axis of a projection optical system. First of all,
The transmittance unevenness of the projection optical system and the inclination of the principal ray on the mask surface occur rotationally symmetrically with respect to the optical axis at least in design. Further, the illuminance distribution of the illumination optical system and the inclination of the principal ray are also rotationally symmetric with respect to the optical axis. Therefore, in order to achieve high-precision uniformity of exposure amount and uniformity of spatial coherency, it is general to match the optical axes of the projection optical system and the illumination optical system.

If the entrance pupil of the projection optical system has no spherical aberration and the transmittance of the projection lens is uniform, it is not essential that the optical axes of the projection optical system and the illumination optical system coincide with each other. Designing and manufacturing an optical system is not feasible in terms of cost.

In recent years, as a projection exposure apparatus with a reduced number of lenses, a projection optical system using a mirror such as a concave mirror, that is, a catadioptric projection optical system has been developed. Since a mirror has no chromatic aberration, an optical system with extremely small chromatic aberration can be designed by using a mirror as a main lens of the optical system. Therefore, in a lithography apparatus using an F2 excimer laser (wavelength: 157 nm) as a light source, in which a glass material that can practically use only fluorite does not exist, it is considered that this catadioptric projection optical system is mainly used.

FIG. 13A shows a projection optical system using a conventional concave mirror. Luminous flux L from a lighting device (not shown)
Enters the mask M. Light flux L emitted from mask M
Is transmitted through the lenses 100, 101, and 102 and enters the concave mirror 103. The light beam L reflected by the concave mirror 103 is
The light again passes through the lens 102 and enters the mirror 104. The light beam L reflected by the mirror 104 passes through the lens 105 and enters the mirror 106. The light beam L reflected by the mirror 106 passes through the aperture stop 107 and the lens 108 and projects an image of a mask pattern on the wafer W. In a projection optical system using a concave mirror, a light beam incident on the concave mirror and
Since it is necessary to separate the reflected light beam from the concave mirror, the optical axis Z cannot be used. At this time, the positional relationship between the optical axis of the projection optical system and the exposure area is such that the exposure area 109 is shifted from the optical axis Z of the projection optical system as shown in FIG.

FIG. 13C is a view taken in the direction of the arrows CC in FIG. 13A. As shown in FIG. 13C, the illuminable range 111 is much larger than the The range that does not contribute to illumination (the hatched portion in the figure) is large. In order to increase the illumination efficiency, the optical axis of the illumination optical system should coincide with the center of the illumination area 110, that is, the optical axes of the projection optical system and the illumination optical system should be shifted, but it is difficult in design.

[0007]

By the way, in recent years, EUV
Exposure apparatuses for projecting and exposing a pattern image of a mask onto a photosensitive substrate using exposure light of a region around 10 nm in wavelength called (extreme ultra violet) have been put into practical use, and a mask pattern having a finer line width has been developed. Exposure apparatuses capable of obtaining an image of an image have been developed.

An object of the present invention is to provide an exposure apparatus having an illumination optical system capable of coping with a finer line width of a mask pattern image projected and exposed on a photosensitive substrate, and a micro device using the exposure apparatus. It is to provide a manufacturing method.

[0009]

According to the first aspect of the present invention, there is provided an exposure apparatus comprising: a plurality of light sources forming means for dividing a light beam from a light source into a wavefront to form a plurality of light sources; and a plurality of light sources formed by the multi light source forming means. In an exposure apparatus having a condenser optical system that illuminates a mask pattern based on a projection pattern, and a projection optical system that projects an image of the mask pattern onto a photosensitive substrate, the multiple light source forming unit includes a plurality of element lenses arranged in parallel. Wherein the luminous flux from the light source is incident on the element lens from an oblique direction with respect to the optical axis of the element lens, and is reflected on a side surface of the element lens.

[0010] The exposure apparatus according to claim 2 is characterized in that a side surface of the element lens is constituted by a total reflection surface. According to the exposure apparatus of claim 2,
The exposure apparatus according to claim 3, wherein the oblique direction with respect to the optical axis of the element lens corresponds to a scan direction in which the mask and the photosensitive substrate are moved relative to the projection optical system. It is characterized by being.

In the exposure apparatus according to the present invention, the effective diameter of the element lens in the Y direction is a, the focal length of the element lens is f, and the opening angle of the light beam incident on the element lens in the Y direction is α. When the angle between the center of the opening angle of the light beam incident on the element lens in the Y direction and the optical axis of the element lens is θy, and the number of reflections on the Y-side surface of the element lens is n, [n
a + (a−fα) / 2] / f>θy> [na− (a−f
α) / 2] / f, the effective diameter of the element lens in the Z direction is b, the focal length of the element lens is f, the opening angle of the light beam incident on the element lens in the Z direction is β, When the angle between the center of the opening angle of the light beam incident on the element lens in the Z direction and the optical axis of the element lens is θz, and the number of times of reflection on the Z side of the element lens is m, [mb + (b−fβ) / 2] / f>θz> [mb- (b
−fβ) / 2] / f.

According to the exposure apparatus of the present invention, when the light beam from the light source is incident on the element lens of the surface light source forming means, the light beam is oblique to the optical axis of the element lens. And the light is reflected on the side surface of the element lens, the effective range of the projection optical system can be formed at a position shifted from the optical axis without shifting the optical axes of the illumination optical system and the projection optical system. Therefore, with this exposure apparatus, high illumination efficiency can be obtained, and high exposure dose and uniformity of spatial coherency can be obtained.

According to a fifth aspect of the present invention, there is provided an exposure apparatus comprising: an illumination optical system for guiding a light beam from a light source onto a mask; and a projection optical system for projecting a pattern image of the mask onto a photosensitive substrate. The illumination optical system includes a reflective optical integrator that uniformly illuminates the mask, and the reflective optical integrator includes a multi-reflector including a plurality of element mirrors configured by a reflective Fresnel lens or a reflective diffractive optical element. It is characterized by comprising.

Further, the exposure apparatus according to the present invention is characterized in that the element mirror has a positive refractive power and has an arcuate outer shape.

According to the exposure apparatus of the fifth and sixth aspects, since the exposure apparatus includes the reflection type optical integrator including a plurality of element mirrors constituted by the reflection type Fresnel lens or the reflection type diffractive optical element, It is possible to efficiently and uniformly illuminate the pattern mask that is the surface to be irradiated.

According to a seventh aspect of the present invention, there is provided a method for exposing a transfer pattern of a reticle onto a photosensitive substrate using the exposure apparatus according to any one of the first to sixth aspects. And a developing step of developing the photosensitive substrate exposed in the exposing step.

According to the method of manufacturing a micro device described in claim 7, since the pattern image of the mask can be faithfully formed on the photosensitive substrate, the micro device can be manufactured with high throughput.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A projection exposure apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of a projection exposure apparatus according to the first embodiment, that is, an exposure apparatus of a step-and-scan method.

As shown in FIG. 1, a light beam L emitted from a light source 1 is collected by an elliptical mirror 2. That is, the light beam L emitted from the light source 1 disposed at the first focal position F ₁ of the elliptical mirror 2 is collected by the mirror 3 at the second focal position F ₂ of the elliptical mirror 2. The light beam L condensed at the _second focal position F ₂ is converted into a parallel light beam by the collector optical system 4 and enters the fly-eye lens 6 via the interference filter 5 for selecting an exposure wavelength. Here, the fly-eye lens 6 includes a number of optical elements.
An optical integrator having an (element lens). When a light beam enters the fly-eye lens 6, a light source image corresponding to the number of optical elements constituting the fly-eye lens 6 is provided on the exit side of the fly-eye lens 6. Is formed. That is, the fly-eye lens 6 functions as a surface light source forming unit (multi-light source forming unit) that divides the light side from the light source into a wavefront to form a surface light source (many light sources).

The light beam emitted from the fly-eye lens 6 sequentially passes through an aperture stop 7, a collimator lens 8, a field stop 9, and a condenser lens front group 10, and then passes through a mirror 1
Incident on 1. The light beam L reflected by the mirror 11 passes through the condenser lens rear group 12 and enters the mask M. The light beam L emitted from the mask M enters the projection optical system PL, and the pattern image of the mask M is transferred onto the wafer W by the projection optical system PL.

That is, the light beam L emitted from the mask M passes through the lens 13 and enters the concave mirror 14. The light beam L reflected by the concave mirror 14 passes through the lens 13 again and enters the mirror 15. The light beam L reflected by the mirror 15 is incident on the mirror 16, and the light beam L reflected by the mirror 16 is
Through the lens 17, the aperture stop 18, and the lens 19,
The pattern image of the mask M is transferred onto the wafer W.

Here, on the aperture stop 7, a surface light source (a large number of light sources) by a fly-eye lens 6 is formed. Further, a field stop 9 is arranged between the collimator lens 8 and the condenser lens front group 10, and the field stop 9 is optically conjugate with the mask M. Further, the fly-eye lens 6 and the collimating lens 8 uniformly illuminate the opening of the field stop 9 at a position optically conjugate with the mask M.
Further, the entrance surface of the fly-eye lens 6 is arranged at a position optically conjugate with the mask M.

As shown in FIG. 2A, the fly-eye lens 6 has a plurality of optical elements (element lenses) 6a arranged in parallel, and a side surface of each element lens 6a has a polished surface ( When the light beam L formed as a total reflection surface and converted into a parallel light beam by the collector optical system 4 is incident on the fly-eye lens 6, the light beam L is obliquely incident on the optical axis of the fly-eye lens 6. ing. By employing this configuration, a fly-eye lens equivalent to an eccentric fly-eye lens as shown in FIG. 2B is realized using a normal fly-eye lens having an optical axis in the lens plane. Can be.

FIG. 3 is a view for explaining the range of the incident direction of light incident obliquely with respect to the optical axis of the element lens 6a when the light beam is incident on the element lens 6a of the fly-eye lens 6. is there. Here, the direction in which the incident light is inclined with respect to the optical axis of the fly-eye lens 6 depends on the fact that the exposure apparatus according to this embodiment is a step-and-scan type exposure apparatus. (Photosensitive substrate) The direction (direction indicated by an arrow in FIG. 1) corresponds to the scan direction which is a direction in which the W is moved relatively to the projection optical system PL. Note that FIG.
3A, the element lens 6 of the fly-eye lens 6 is shown.
The optical axis direction of a is the X direction, the direction perpendicular to X (the vertical direction in the figure) is the Y direction, and the direction perpendicular to X (the direction perpendicular to the paper).
Is the Z direction. In FIG. 3B, the optical axis direction of the element lens 6a of the fly-eye lens 6 is the X direction,
Is defined as a Y direction, and a direction perpendicular to X (horizontal direction in the drawing) is defined as a Z direction.

As shown in FIGS. 3A and 3B, the effective diameter of the element lens 6a of the fly-eye lens 6 in the Y direction is a, the effective diameter of the element lens 6a in the Z direction is b, and the element lens 6a is incident on the element lens 6a. The opening angle in the Y direction of the light beam to be emitted is α, and the center of the opening angle in the Y direction of the light beam incident on the element lens 6a is the element lens 6a.
Is defined as θy, the focal length of the element lens 6a is f, and the number of reflections on the Y-side surface of the element lens 6a is n, the condition of Expression 1 is satisfied. (Equation 1) [na + (a−fα) / 2] / f>θy> [na− (a
−fα) / 2] / f

The effective diameter of the element lens 6a in the Z direction is b, the opening angle of the light beam incident on the element lens 6a in the Z direction is β (not shown), and the opening angle of the light beam incident on the element lens 6a in the Z direction is β. The angle between the center of the angle and the optical axis of the element lens 6a is θz
(Not shown), when the focal length of the element lens 6a is f and the number of reflections on the Z-side surface of the element lens 6a is m, the condition of Expression 2 is satisfied. (Equation 2) [mb + (b−fβ) / 2] / f>θz> [mb− (b
−fβ) / 2] / f

FIG. 4 is a diagram showing the positional relationship between the number of reflections of the light beam incident obliquely with respect to the optical axis on the side surface of the element lens 6a of the fly-eye lens 6 and the illumination area. As shown in this figure, when the number of reflections on the Y side of the element lens 6a is n and the direction Y of the illumination range defined by the fly-eye lens 6 is A, the number of reflections on the Y side of the element lens 6a is 0. In the position in contact with the illumination range (indicated by the broken line in the drawing), the number of reflections on the Y-side surface of the element lens 6a is 1
An illumination range (shown by a solid line in the figure) is formed, and an illumination range (shown by a two-dot chain line in the figure) in which the number of reflections on the Y-side surface of the element lens 6a is 2 is formed. It is formed at a position spaced by A on the opposite side of the illumination range where the number of reflections is one. That is, the displacement amount (Dy) from the optical axis based on the number of reflections is Dy = nA.

In the projection exposure apparatus according to the first embodiment, when the light beam converted into a light beam substantially parallel by the collector optical system 4 from the oblique direction to the optical axis enters the fly-eye lens 6, the element The light side reflected by the side surface of the lens 6a is emitted from the element lens 6a. The light beam emitted from the fly-eye lens 6 passes through the aperture stop 7, the collimating lens 8, the field stop 9, and the condenser lens front group 10 in order, and then enters the mirror 11. The light beam reflected by the mirror 11 passes through the condenser lens rear group 12 and illuminates the mask M. In this case, the illumination area is formed at a position deviated from the optical axis according to the number of reflections on the side surface of the element lens 6a of the fly-eye lens 6.

A predetermined circuit pattern is formed on the mask M, and the mask M is held on a mask stage (not shown) that can move two-dimensionally along a horizontal plane. The light beam transmitted through the mask M is transmitted to the projection optical system P
An image is formed on wafer W coated with a resist as a photosensitive substrate via L, and a pattern image of mask M is projected and transferred onto wafer W. The wafer W is held on a substrate stage (not shown) that can move two-dimensionally along a horizontal plane.

Here, by moving the mask stage and the substrate stage in directions opposite to each other (in the direction of the arrow), the entire pattern formed on the mask M is scanned and exposed on the wafer W via the projection optical system PL. You.

In the projection exposure apparatus according to the first embodiment, when a light beam is incident on the element lens 6a of the fly-eye lens 6, the light beam is incident obliquely with respect to the optical axis of the element lens 6a. The light source 1, the elliptical mirror 2, the mirror 3, the collector optical system 4, the interference filter 5, the fly-eye lens 6, the aperture stop 7, the collimator lens 8, the field stop 9, and the condenser lens front group 10 are reflected on the side surface of the lens 6 a. The effective exposure range of the projection optical system PL can be formed at a position shifted from the optical axis without shifting the optical axes of the illumination optical system constituted by the mirror 11 and the condenser lens rear group 12 and the projection optical system PL. . Therefore, in this projection exposure apparatus, high illumination efficiency can be obtained, and further, high exposure dose and uniformity of spatial coherency can be obtained.

Next, with regard to the fly-eye lens 6 of the projection exposure apparatus according to the first embodiment, it will be described that the ranges indicated by the mathematical expressions 1 and 2 are appropriate by increasing specific numerical values. .

The effective diameter a of the element lens 6a in the Y direction is 6 m.
m, the effective diameter b of the element lens 6a in the Z direction is 6 mm, the focal length f of the element lens 6a is 15 mm, the opening angle α of the light beam incident on the element lens 6a in the Y direction is 0.08 rad, and the light beam enters the element lens 6a. The opening angle β of the light beam in the Z direction is set to 0.
3 rad, the number of reflections n on the Y-side surface of the element lens 6a is 1
Assuming that the number m of reflections on the Z-side surface of the element lens 6a is 0, the ranges of θy and θz expressed by Expressions 1 and 2 are 0.16>θy> 0.10666 (rad) 0.05>θz> −0.05 (rad).

Here, ray tracing is performed using actual lens data. Since the number of reflections on the side surface in the Z direction is 0, only the confirmation of θy is performed. θy = 0.10666
(Rad), the range of the luminous flux at the exit surface of the fly-eye lens (with the effective diameter center as the reference position) is 1.00 mm>a> −0.20 mm, and θy = 0.16 (rad) ), The range of the luminous flux on the exit surface of the fly-eye lens (with the effective diameter center as the reference position) is 0.20 mm>a> −1.00 mm. Therefore, it was confirmed that the luminous flux did not protrude beyond the effective diameter of the fly-eye lens, and the allowable range of θy and θz was appropriate.

In the first embodiment, the side surface of the element lens is a total reflection surface (polished surface). However, a reflection film is formed on the side surface of the element lens, and the reflection film is formed on this side surface. A fly-eye lens may be constituted by the element lenses described above, and when a light beam is incident on the fly-eye lens, the light beam may be incident on the fly-eye lens obliquely with respect to the optical axis of the fly-eye lens.

In the first embodiment, the light from the light source 1 is guided to the collector optical system 4 by the elliptical mirror 2 and the mirror 3, and is converted into a substantially parallel light beam through the collector optical system 4. A configuration is adopted in which the luminous flux incident on the fly-eye lens 6 is obliquely incident on the optical axis of the fly-eye lens 6.
When a light beam is incident on the fly-eye lens of the illumination optical device disclosed in Japanese Patent Application Laid-Open No. 82933, a configuration may be adopted in which the light beam is incident obliquely with respect to the optical axis of the fly-eye lens.

That is, the illumination optical device disclosed in Japanese Patent Application Laid-Open No. 2000-182933 has an excimer laser light source. Incident. The light beam incident on the diffractive optical element is converted into an annular light beam, and is incident on the second fly-eye lens via the afocal zoom lens, the first fly-eye lens, and the zoom lens. The incident direction when the light beam enters the second fly-eye lens is, as in the case of the first embodiment, a predetermined oblique direction with respect to the optical axis of the element lens constituting the second fly-eye lens. That is, the direction satisfies Expressions 1 and 2 used in the description of the first embodiment.

Next, a projection exposure apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a configuration diagram of a projection exposure apparatus according to the second embodiment.

This projection exposure apparatus is provided with a light source 30 for emitting exposure light having a wavelength (about 10 nm). The light source 30 condenses laser light emitted from a YAG laser light source 31 using an optical system 32 and applies it to a high-concentration gas target supplied from a nozzle 33 to obtain a point-like EUV (extreme ultra-light). violet) light source.
Since the EUV light emitted from the EUV light source cannot pass through the atmosphere, the entire apparatus is covered by the vacuum chamber 34.

The light beam emitted from the light source 30 is condensed by the focusing optical system 3.
The light beams are converted into substantially parallel light beams by passing through
The light enters a multi-reflector (reflection type first optical integrator) 37. The light beam reflected by the multi-reflector 37 is incident on a second multi-reflector (reflection type second optical integrator) 39 via a stop 38. The light beam reflected by the multi-reflector 39 enters the condenser mirror 40 via the stop 38.

The light beam reflected by the first multi-reflector 37 and the second multi-reflector 39 enters the condenser mirror 40 in a state of being divided into a large number of light beams, and the light beam reflected by the condenser mirror 40 passes through the mirror 41. Over the pattern mask 42 via Aperture 3
Numeral 8 determines the exposure NA of the light beam, and a mirror 41 is a plane mirror for changing the traveling direction of the light beam.

The pattern mask 42 having received light in the exposure range
Transfers the pattern via the projection optical system 43 to the photosensitive substrate 44 coated with the light receiving resin. Here, since the projection optical system 43 is a reflection optical system, the aberration is corrected only at a very small image height. Therefore, since an arc-shaped region having the same image height needs to be used for exposure, the outer shape (outline) of the element mirror 37a of the first multi-reflector 37 has an arc shape. Therefore, the contour shape (arc shape) of the element mirror 37a is similar to the shape of the arc-shaped illumination area (exposure range) formed on the pattern mask 42 as the irradiation surface.

FIG. 6 is a diagram showing the structure of the first multi-reflector 37. As shown in this figure, the first multi-reflector 37 is configured by a plurality of element mirrors 37a having a reflection surface whose contour (outer shape) is formed in an arc shape, which are two-dimensionally densely arranged. The first multi-reflector 37 has six rows of element mirrors 37a arranged in a large number, and the six rows of element mirrors 37a are:
They are arranged so as to be substantially circular as a whole.

FIG. 7 is a diagram for explaining details of the configuration of each element mirror 37a. As shown in this figure, each element mirror 37a is obtained by cutting a disk-shaped reflection type Fresnel lens (Fresnel mirror) 50 so that the contour (outer shape) becomes an arc shape. The first multi-reflector 37 can be formed by arranging a plurality of element mirrors 37a cut out from the disc-shaped Fresnel mirror 50 two-dimensionally and densely. In addition, a disk-shaped reflective Fresnel lens
The (Fresnel mirror) 50 is formed with a plurality of grooves such that the gap between the grooves is large inside the disc and the gap between the grooves is small outside the disc. Therefore, the interval between the grooves at each position of the element mirror 37a can be made different depending on how the element mirror 37a is cut out. This element mirror 37a
The reflection direction of the light beam incident on each element mirror 37a can be controlled by changing the interval between the grooves at the respective positions.

FIG. 8 is a diagram showing the configuration of the second multi-reflector 39. Since the light source 1 has a substantially circular shape,
It is desirable that the second multi-reflector 39 has an outer shape as close to a circle as possible from the viewpoint of efficiency. Therefore, the second multi-reflector 39 is configured to have a rectangular outer shape close to a square.

Here, since each element mirror 37a of the first multi-reflector 37 and each element mirror 39a of the second multi-reflector 39 must correspond one to one, as shown in FIG. The reflection direction of each element mirror 37a of the reflector 37 is controlled. That is,
By making the intervals of the grooves provided in each element mirror 37a of the first multi-reflector 37 different, the reflection direction of the incident light beam is made to be the direction of the corresponding element mirror 39a of the second multi-reflector 39. .

FIG. 10 shows a reflection type Fresnel lens on the surface.
It shows a part of a first multi-reflector 37 in which element mirrors 37a constituted by (Fresnel mirrors) are two-dimensionally arranged. Since the first multi-reflector 37 can have a surface shape close to a plane, it can be easily manufactured by pattern etching using photolithography.

In this projection exposure apparatus, when a substantially parallel light beam enters the first multi-reflector 37, the light is split into a circular arc by a number of element mirrors 37a to form a second light beam.
The light enters the multi-reflector 39. The light beam reflected by the second multi-reflector 39 illuminates the pattern mask 42 as the surface to be illuminated in an arc shape in a superimposed manner via the condenser mirror 40 and the mirror 41.

A predetermined circuit pattern is formed on the surface of the pattern mask 42.
Is held on a mask stage (not shown) that can move two-dimensionally along a horizontal plane. The light beam reflected by the pattern mask 42 is imaged via a projection optical system 43 on a photosensitive substrate 44 coated with a resist. Then, the pattern image of the arc-shaped pattern mask 42 is projected and transferred onto the photosensitive substrate 44. The photosensitive substrate 44 is held on a substrate stage (not shown) that can move two-dimensionally along a horizontal plane.

Here, by moving the mask stage and the substrate stage in directions opposite to each other (in the direction of the arrow), the entire pattern formed on the pattern mask 42 is placed on the photosensitive substrate 44 via the projection optical system 43. It is scanned and exposed.

According to the projection exposure apparatus of the second embodiment, the first multi-reflector 37 as a reflection type optical integrator has a large number of element mirrors formed by reflection type Fresnel lenses which divide the wavefront into an arc shape. 3
7a, the mask 42 which is the surface to be irradiated
Can be efficiently and uniformly illuminated in a circular arc pattern.

In the second embodiment, a multi-reflector 37 as a reflection type optical integrator is formed by cutting out a disk-shaped reflection type Fresnel lens into an arc shape and arranging it two-dimensionally. However, the multi-reflector 37 may be configured by cutting out a disk-shaped reflection type diffractive optical element into an arc shape and arranging it two-dimensionally.

In the projection exposure apparatus according to the second embodiment, all of the element mirrors of the multi-reflectors 37 and 39 are constituted by reflection type Fresnel lenses, but all of the multi-reflectors 37 and 39 are reflected. It may be constituted by a type diffractive optical element.

In the projection exposure apparatus according to the second embodiment, all of the element mirrors of the multi-reflectors 37 and 39 are constituted by reflection type Fresnel lenses or reflection type diffractive optical elements. , 3
A part of the nine element mirrors may be constituted by a reflective Fresnel lens or a reflective diffractive optical element.

Hereinafter, referring to the flow chart of FIG. 11, manufacturing of a semiconductor device as a micro device for forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the projection exposure apparatus shown in FIGS. The method will be described.

First, in step S301 in FIG. 11, a metal film is deposited on one lot of wafers. In the next step S302, a photoresist is applied on the metal film on the wafer of the lot. Then, in step S303, using the projection exposure apparatus shown in FIGS. 1 and 5, the image of the pattern on the mask is transferred through the projection optical system (projection optical module) to each shot area on the wafer of the lot. Are sequentially exposed and transferred. afterwards,
After the development of the photoresist on the wafer of the lot in step S304, the process proceeds to step S305.
In the above, a circuit pattern corresponding to the pattern on the mask is formed in each shot region on each wafer by performing etching on the wafer of the lot using the resist pattern as a mask. Thereafter, a device such as a semiconductor element is manufactured by forming a circuit pattern of an upper layer and the like. According to the above-described semiconductor device manufacturing method, a semiconductor device having an extremely fine circuit pattern can be obtained with high throughput.

In the projection exposure apparatus shown in FIGS. 1 and 5, a predetermined pattern (circuit pattern, electrode pattern, etc.) is formed on a plate (glass substrate).
A liquid crystal display element as a micro device can also be obtained. Hereinafter, a method of manufacturing a liquid crystal display device will be described with reference to the flowchart of FIG. In FIG. 12, in a pattern forming step S401, a so-called photolithography step of transferring and exposing a mask pattern onto a photosensitive substrate (a glass substrate coated with a resist or the like) using the projection exposure apparatus shown in FIGS. Be executed. By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate is subjected to various processes such as a developing process, an etching process, and a reticle peeling process, so that a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming process S402.

Next, in the color filter forming step S402, three colors corresponding to R (Red), G (Green), and B (Blue)
Many sets of dots are arranged in a matrix,
Alternatively, a color filter in which a set of three stripe filters of R, G, and B are arranged in a plurality of horizontal scanning line directions is formed. Then, after the color filter forming step S402,
The cell assembling step S403 is performed. In the cell assembling step S403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern forming step S401, the color filter obtained in the color filter forming step S402, and the like. In the cell assembling step S403, for example, a liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern forming step S401 and the color filter obtained in the color filter forming step S402, and a liquid crystal panel (liquid crystal cell) is formed. ) To manufacture.

Thereafter, a module assembling step S404
Then, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display device, a liquid crystal display device having an extremely fine circuit pattern can be obtained with high throughput.

[0060]

According to the exposure apparatus of the present invention, when the light beam from the light source is incident on the element lens of the surface light source forming means, the light beam is incident obliquely with respect to the optical axis of the element lens. Therefore, the effective range of the projection optical system can be formed at a position shifted from the optical axis without shifting the optical axes of the illumination optical system and the projection optical system. Therefore, in the exposure apparatus of the present invention, a high illumination efficiency can be obtained, and a high exposure amount and uniformity of spatial coherency can be obtained.

According to the exposure apparatus of the present invention, the illumination optical system is a multi-reflector forming an arc-shaped illumination area, and is at least one element mirror constituted by a reflective Fresnel lens or a reflective diffractive optical element. , It is possible to efficiently and uniformly illuminate the pattern mask, which is the irradiated surface, in an arc shape.

Further, according to the method of manufacturing a micro device of the present invention, a pattern image of a mask can be faithfully formed on a photosensitive substrate, so that a micro device can be manufactured with high throughput.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a projection exposure apparatus according to a first embodiment.

FIG. 2 is a diagram for explaining an incident direction of light incident on a fly-eye lens of the projection exposure apparatus according to the first embodiment.

FIG. 3 is a diagram for explaining a range of an incident direction of light incident on a fly-eye lens of the projection exposure apparatus according to the first embodiment.

FIG. 4 is a diagram showing a positional relationship between the number of reflections and the illumination area on the side surface of the element lens of the fly-eye lens according to the first embodiment.

FIG. 5 is a schematic configuration diagram of a projection exposure apparatus according to a second embodiment.

FIG. 6 is a diagram illustrating a configuration of a multi-reflector according to a second embodiment.

FIG. 7 is a diagram illustrating details of a configuration of a multi-reflector according to a second embodiment.

FIG. 8 is a diagram illustrating a configuration of a multi-reflector according to a second embodiment.

FIG. 9 is a diagram illustrating a state of reflection on an element mirror of the multi-reflector according to the second embodiment.

FIG. 10 is a diagram illustrating a part of a multi-reflector according to a second embodiment.

FIG. 11 is a flowchart illustrating a method for manufacturing a micro device according to an embodiment of the present invention.

FIG. 12 is a flowchart illustrating a method for manufacturing a micro device according to an embodiment of the present invention.

13A is a schematic diagram of a conventional projection optical system, FIG. 13B is a diagram illustrating a positional relationship between an optical axis and an exposure region, and FIG. 13C is a diagram illustrating a positional relationship of an illumination region.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 4 ... Collector optical system, 6 ... Fly eye lens, 6a ... Element lens, 7 ... Aperture stop, 8 ... Collimate lens, 9 ... Field stop, 10 ... Condenser lens front group,
12: Rear group of condenser lenses, M: Mask, PL: Projection optical system, W: Wafer, 30: Light source, 37, 39: Multi-reflector, 40: Condenser mirror, 42: Pattern mask, 43: Projection optical system, 44: Photosensitive substrate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G02B 19/00 G03F 7/20 521 G03F 7/20 521 H01L 21/30 515D 527 F Term (Reference) 2H042 DD02 DE00 2H049 AA07 AA08 AA13 AA14 AA50 AA55 AA65 AA66 2H052 BA02 BA03 BA09 BA12 2H087 KA21 RA26 RA32 TA01 TA04 TA05 5F046 BA05 CB01 CB03 CB13 CB23

Claims (7)

[Claims] 1. A multi-light source forming means for dividing a light beam from a light source into a wavefront to form a plurality of light sources, a condenser optical system for illuminating a mask pattern based on the plurality of light sources formed by the multi-light source forming means, An exposure apparatus having a projection optical system for projecting an image of the mask pattern onto a photosensitive substrate, wherein the multiple light source forming unit has a plurality of element lenses arranged in parallel, and emits a light beam from the light source to the element. An exposure apparatus, wherein the light is incident on the element lens from an oblique direction with respect to the optical axis of the lens and is reflected on a side surface of the element lens. 2. The exposure apparatus according to claim 1, wherein a side surface of the element lens is formed by a total reflection surface. 3. An oblique direction with respect to an optical axis of the element lens is a direction corresponding to a scan direction in which the mask and the photosensitive substrate are moved relative to the projection optical system. 3. The exposure apparatus according to claim 1, wherein: 4. The effective diameter of the element lens in the Y direction is a,
The focal length of the element lens is f, the opening angle of the light beam incident on the element lens in the Y direction is α, and the angle between the center of the opening angle of the light beam incident on the element lens in the Y direction and the optical axis of the element lens is Is defined as θy and the number of reflections on the Y side surface of the element lens is defined as n, and the following condition is satisfied: [na + (a−fα) / 2] / f>θy> [na− (a
−fα) / 2] / f The effective diameter of the element lens in the Z direction is b, the focal length of the element lens is f, the opening angle of the light beam incident on the element lens in the Z direction is β, and the light beam is incident on the element lens. The angle formed by the center of the opening angle of the luminous flux in the Z direction with the optical axis of the element lens is θ.
4. The exposure apparatus according to claim 1, wherein the following condition is satisfied, where z is the number of reflections on the Z-side surface of the element lens. [Mb + (b−fβ) / 2] / f>θz> [mb− (b
−fβ) / 2] / f 5. An exposure apparatus having an illumination optical system for guiding a light beam from a light source onto a mask and a projection optical system for projecting a pattern image of the mask onto a photosensitive substrate, wherein the illumination optical system makes the mask uniform. An exposure apparatus, comprising: a reflection type optical integrator for illuminating a light source; and the reflection type optical integrator includes a plurality of element mirrors each including a reflection type Fresnel lens or a reflection type diffractive optical element. 6. An exposure apparatus according to claim 5, wherein said element mirror has a positive refractive power and an arc-shaped outer shape. 7. An exposure step of exposing a transfer pattern of a reticle onto a photosensitive substrate using the exposure apparatus according to claim 1, and the photosensitive element exposed by the exposure step. And a developing step of developing the conductive substrate.