JPH07135148A - Illuminating equipment and aligner provided with said illuminating equipment - Google Patents

Abstract

PURPOSE:To improve the image quality of an illuminating equipment and an aligner, by irradiating a fly-eye lens with a plurality of lights arranged in the long side direction of a lens wherein a plurality of sections are almost rectangu lar. CONSTITUTION:A reticle 12 is illuminated with the light whose section constitutes a rectangular slit type, and a rectangular illumination region is formed on a reticle 12, so that the sectional form of each fine lens of a fly-eye lens 6 is a rectangle similar to the illumination region. The direction of the long side of the fine lens which constitutes the fly-eye lens 6 and has the rectangular section coincides with the arrangement direction of a light emitting part 1a and a focus 41 (image of the light emitting part 1a). The fly-eye lens is irradiated from different directions with two luminous fluxes from the light emitting part la and the focus 41. The intensity distribution of an effective light source formed by the fly-eye lens 6 becomes a distribution having a pair of light sources for each fine lens. As compared with the conventional effective light source, there is little difference between the X direction intensity distribution and the Y direction intensity distribution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device and an exposure apparatus including the illuminating device, and more particularly to an IC and an LS.
The present invention relates to an illuminator used for manufacturing a semiconductor device such as I, an image pickup device such as a CCD, a liquid crystal panel, a device such as a magnetic head, and a scanning projection exposure apparatus including the illuminator.

[0002]

2. Description of the Related Art FIG. 9 is a schematic view showing a conventional scanning projection exposure apparatus.

In FIG. 9, 1 is a light source that emits ultraviolet rays, such as an Hg lamp or Xe-Hg lamp, and 1a is its light emitting portion (electrode). Reference numeral 2 denotes an elliptical mirror, and the light emitting portion 1a of the light source 1 is placed near the first focal point thereof, and the elliptic mirror 2 forms an image of the light emitting portion 1a at its second focal point 4. A cold mirror 3 reflects ultraviolet rays and transmits infrared rays.

Light from the image of the light emitting portion 1a at the second focal point 4 of the elliptic mirror 2 is condensed by the condenser lens 5 on the light incident surface of the optical integrator composed of the fly-eye lens 6. The fly-eye lens 6 is an assembly of a plurality of minute lenses. 7 is an aperture stop.

In this apparatus, since the reticle 12 is illuminated with the slit-shaped light having a rectangular cross section to form a rectangular illumination area on the reticle 12, the cross-sectional shape of each minute lens of the fly-eye lens is equal to the illumination area. It is a similar rectangle.

Reference numeral 11 is a condenser lens, 10 is a masking blade which is a field stop, and a reticle 12 is located at a position conjugate with the masking blade 10.
A projection optical system 14 is composed of a refractive optical system, a catadioptric optical system, and the like. 15 is a wafer, and the reticle 12
And the wafer 15 are in an optically conjugate relationship with respect to the projection optical system 14. Drive devices 13 and 16 respectively move the reticle 12 and the wafer 15 in the scanning direction. The drive devices 13 and 16 move the reticle 12 and the wafer 15 to perform scanning exposure with slit-shaped light.

[0007]

Since the microlenses of the fly-eye lens 6 have a rectangular cross section in the above apparatus, the effective light source (secondary light source) produced by the fly-eye lens 6 has the intensity distribution shown in FIG. The illuminance distribution (intensity distribution) is different between the x direction and the y direction in FIG. Therefore, the quality of the image formed on the wafer-15 is different in the x direction and the y direction, so that there is a problem that the image quality is deteriorated.

The effective light source is a set of images of the aperture of the ellipsoidal mirror 2 which can be seen through the individual microlenses forming the fly-eye lens 6.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an illuminating device and an exposing device capable of improving image quality.

The illumination device of the present invention is a device for illuminating a surface to be illuminated with light from a fly-eye lens in which a plurality of lenses each having a substantially rectangular cross section are two-dimensionally arranged. It has a light irradiation means for irradiating the fly-eye lens with a plurality of lights.

The exposure apparatus of the present invention is an apparatus for exposing a substrate through a mask with light from a fly-eye lens in which a plurality of lenses each having a substantially rectangular cross section are two-dimensionally arranged.
It has a light irradiation means for irradiating the fly-eye lens with a plurality of lights arranged in the long side direction of the lens.

According to the illumination device and the exposure device of the present invention,
By including the light irradiation means, an image having substantially constant image quality can be produced regardless of the direction, and the image quality can be improved.

In a preferred form of the illuminating device and the exposing device of the present invention, the light irradiating means divides the light from the light source to form the plurality of lights, and is parallel to the long side of the substantially rectangular lens and has an optical axis. The maximum angle that the ray incident on the substantially rectangular lens makes with the optical axis in the section cut along the plane including the angle θa, the substantially rectangular lens in the section cut along the plane parallel to the short side of the substantially rectangular lens and including the optical axis When the maximum angle with respect to the optical axis of the light ray that can be taken by is θbc, the plurality of lights are incident on the substantially rectangular lens at an incident angle satisfying θa> θbc.

Further, a preferred embodiment of the exposure apparatus of the present invention is characterized by having a projection optical system for forming an image of the pattern of the mask on the substrate.

By using the exposure apparatus of the present invention, semiconductor devices such as IC and LSI, image pickup devices such as CCD, liquid crystal panels, devices such as magnetic heads can be accurately manufactured.

[0016]

1 is a schematic configuration diagram showing an embodiment of the present invention, which is a scanning type for manufacturing a semiconductor device such as an IC or an LSI, an image pickup device such as a CCD, a liquid crystal panel, a magnetic head or the like. 1 shows a projection exposure apparatus.

Although the folding mirror and the cold mirror shown in FIG. 8 are omitted in FIG. 1 for simplification, these mirrors may be provided at positions indicated by broken lines.

In FIG. 1, 1 is a light source that emits ultraviolet rays such as an Hg lamp or Xe-Hg lamp, 1a is a light emitting portion (electrode) thereof, and 21 is a spherical mirror, which is orthogonal to the optical axis from the center of curvature of the spherical mirror 2. The light emitting part 1a of the light source 1 is slightly displaced in the direction of
Is placed, and the spherical mirror 21 places the light emitting portion 1a at its focal point 41.
Image on. Therefore, two light sources, that is, a light source including the light emitting unit 1a and a light source including an image of the light emitting unit 1a, are provided across the optical axis.

Light from the two light sources of the light emitting portion 1a and the focal point 41 (the image of the light emitting portion 1a thereof) is condensed by the condenser lens 5 on the light entrance surface of the optical integrator composed of the fly-eye lens 6. 7 is an aperture stop. A special diaphragm for annular illumination or quadrupole illumination is placed instead of the aperture diaphragm 7.

In this embodiment, since the reticle 12 is illuminated with the slit-shaped light having a rectangular cross section to form a rectangular illumination area on the reticle 12, the cross-sectional shape of each minute lens of the fly-eye lens 6 is as shown in FIG. As shown in 1, the rectangle is similar to the illumination area. As the fly-eye lens, a combination of spherical lenses is usually used, but a combination of cylindrical lenses or a combination of toric lenses may be used.

Reference numerals 8 and 11 are condenser lenses, and
0 is a masking blade, masking blade 1
The reticle 12 is placed at a position conjugate with 0. A projection optical system 14 is composed of a refractive optical system and a catadioptric optical system. Reference numeral 15 is a wafer, which is a reticle 12 and a wafer 1.
Reference numeral 5 has an optically conjugate relationship with the projection optical system 14. Reference numerals 13 and 16 denote driving devices for moving the reticle 12 and the wafer 15 in the scanning direction, respectively.
The reticle 12 and the wafer 15 are moved by 3 and 16 to perform scanning exposure with slit-shaped light.

In this embodiment, the direction of the long side of the minute lens having a rectangular cross-section forming the fly-eye lens 6 and the direction in which the light emitting portion 1a and the focal point 41 (image of the light emitting portion 1a) are aligned are aligned. Since the fly-eye lens is illuminated from two directions different from each other by the two light fluxes from the light emitting unit 1a and the focal point 41, the intensity distribution of the effective light source made by the fly-eye lens 6 is, as shown in FIG. The distribution has a pair of light sources, and the difference between the intensity distributions in the x direction and the y direction is smaller than that in the conventional effective light source of FIG.

From FIG. 1, the relationship between the directions of the spherical mirror 21, the lamp 1 and the long-side direction of each minute lens of the fly-eye lens 6 becomes clear.

The effective light source shown in FIG. 2 produced by the apparatus of this embodiment through the fly-eye lens 6 has a smaller difference between the intensity distributions in the x and y directions than the conventional effective light source shown in FIG. . Therefore, according to the apparatus of this embodiment, the difference in the resolution of the image on the wafer 15 in the x direction and the y direction is small.

FIG. 3 is an explanatory view showing a minute lens forming the fly-eye lens of this embodiment. As shown in FIG. 3A, the microlens has a rectangular cross section, and the long side has a length a and the short side has a length b.

A cross-sectional view of the microlens cut along a plane parallel to its long side and including the optical axis is taken as a section A in FIG. 3B. The microlens is cut along a plane parallel to its short side and including the optical axis. A cross-sectional view is shown as a cross-section B in FIG.

Now, in the section A shown in FIG. 3 (B), the maximum angle formed with the optical axis of the light beam incident on the minute lens is θa.
, The maximum angle formed with the optical axis of the ray incident on the microlens in section B shown in FIG. 3C is θb, and the maximum angle formed with the optical axis of the ray that can be taken in by the microlens in section A is θac, In the case of the conventional example of FIG. 10, when the maximum angle formed with the optical axis of the light beam that can be captured by the microlens in the cross section B is θbc,

[0028]

[Outer 1] In the cross section B, a light ray having an angle close to the maximum angle θbc at which the light ray is eclipsed is incident,
In the cross section A, a light ray having an angle smaller than the maximum angle θac at which the incident light ray is eclipsed is incident, and therefore, the distribution method of the effective light source is different in the x and y directions.

On the other hand, in the case of this embodiment shown in FIGS. 1 to 3,

[0030]

[Outside 2] Therefore, the distribution of effective light sources is made uniform in the x and y directions.

The fly-eye lens and the incident light ray are given by (Equation 2)
There is a great effect if the relationship like

[0032]

[Outside 3] If the relationship like above is satisfied, it is sufficiently effective. That is,
The distribution of the effective light sources in the x and y directions is made uniform, and the difference in the image quality between the x direction and the y direction of the image formed on the wafer 15 is reduced. Further, since the light beam is less eclipsed, the illuminance is also high, and therefore, the throughput at the time of producing a semiconductor element is also improved.

Although the light from the lamp 1 is divided into two in this embodiment, it may be divided into any number.

FIG. 4 is a schematic configuration diagram showing a second embodiment of the present invention, which is a semiconductor device such as IC or LSI, CC.
1 shows a scanning projection exposure apparatus for manufacturing an image pickup device such as D, a liquid crystal panel, a device such as a magnetic head.

In FIG. 4, reference numeral 1 is a light source that emits ultraviolet rays, such as an Hg lamp or Xe-Hg lamp, and 1a is a light emitting portion (electrode) thereof. Lenses 51 and 52 are placed on the left and right of the light source 1, and the respective lights emitted from the light emitting unit 1a to the left and right are collimated by the lenses 51 and 52 on the left and right of the light source 1, and then the plane mirrors 23 and 24, respectively. Is reflected by the condenser lens 5
To the fly-eye lens 6 from different directions.

The ellipsoidal mirror 2 is provided to direct light that cannot be captured by the lenses 51 and 52 to the condenser lens 5.
It is 2, and it may or may not be placed. The position of the first focal point of the elliptical mirror 22 and the position of the light emitting portion 1a of the light source 1 are substantially aligned,
The light emitted upward from the light source 1 is reflected and made incident on the condenser lens 5. 3 by placing the elliptical mirror 22
The individual light beams are made incident on the fly-eye lens 6 from different directions.

Reference numeral 7 is an aperture stop. A special diaphragm for annular illumination or quadrupole illumination is placed instead of the aperture diaphragm 7.

Also in this embodiment, since the reticle 12 is illuminated with the slit-shaped light having a rectangular cross section to form a rectangular illumination area on the reticle 12, the cross-sectional shape of each minute lens of the fly-eye lens 6 is as shown in FIG. As shown in 1, the rectangle is similar to the illumination area. As the fly-eye lens, a combination of spherical lenses is usually used, but a combination of cylindrical lenses or a combination of toric lenses may be used.

Denoted at 8 and 11 are condenser lenses.
0 is a masking blade, masking blade 1
The reticle 12 is placed at a position conjugate with 0. A projection optical system 14 is composed of a refractive optical system and a catadioptric optical system. Reference numeral 15 is a wafer, which is a reticle 12 and a wafer 1.
Reference numeral 5 has an optically conjugate relationship with the projection optical system 14. Reference numerals 13 and 16 denote driving devices for moving the reticle 12 and the wafer 15 in the scanning direction, respectively.
The reticle 12 and the wafer 15 are moved by 3 and 16 to perform scanning exposure with slit-shaped light.

In the apparatus of this embodiment, the arrangement direction of a plurality of light beams obtained by division and the direction of the long side of the minute lens having a rectangular cross section which constitutes the fly-ear lens 6 are the same as the apparatus of the above-mentioned embodiment. Match.

The apparatus of the present embodiment also exhibits the same effect as the apparatus of the above-mentioned embodiment, the distribution of the effective light sources in the x and y directions is made uniform, and the image formed on the wafer 15 in the x and y directions. The difference in quality is reduced.

Although the light from the light source is divided into two in this embodiment, it may be divided into any number.

FIG. 5 is a schematic configuration diagram showing a third embodiment of the present invention, which is a semiconductor device such as IC or LSI, CC.
1 shows a scanning projection exposure apparatus for manufacturing an image pickup device such as D, a liquid crystal panel, a device such as a magnetic head.

In FIG. 5, reference numeral 1 is a light source that emits ultraviolet rays, such as an Hg lamp or Xe-Hg lamp, and 1a is a light emitting portion (electrode) thereof. Reference numerals 2'and 2 '' are respective parts obtained by dividing an ordinary elliptical mirror into two. The elliptic mirror 2'has a second focal point of 4'and the elliptic mirror 2 "has a second focal point of 4". By arranging one elliptic mirror separately, the light from the light source is substantially divided. However, the second focus forms an image of the light emitting portion 1a at each of 4'and 4 ''. The light from each image of the light emitting unit 1a at the second focal points 4 ′ and 4 ″ is condensed on the light incident surface of the fly-eye lens 6 by the condenser lens 5.

Reference numeral 7 is an aperture stop. A special diaphragm for annular illumination or quadrupole illumination is placed instead of the aperture diaphragm 7.

Also in this embodiment, since the reticle 12 is illuminated with the slit-shaped light having a rectangular cross section to form a rectangular illumination area on the reticle 12, the cross-sectional shape of each minute lens of the fly-eye lens 6 is as shown in FIG. As shown in 1, the rectangle is similar to the illumination area. As the fly-eye lens, a combination of spherical lenses is usually used, but a combination of cylindrical lenses or a combination of toric lenses may be used.

Reference numerals 8 and 11 are condenser lenses, and
0 is a masking blade, masking blade 1
The reticle 12 is placed at a position conjugate with 0. A projection optical system 14 is composed of a refractive optical system and a catadioptric optical system. Reference numeral 15 is a wafer, which is a reticle 12 and a wafer 1.
Reference numeral 5 has an optically conjugate relationship with the projection optical system 14. Reference numerals 13 and 16 denote driving devices for moving the reticle 12 and the wafer 15 in the scanning direction, respectively.
The reticle 12 and the wafer 15 are moved by 3 and 16 to perform scanning exposure with slit-shaped light.

In the apparatus of this embodiment, the fly-ear lens 6 and the arrangement direction of a plurality of light beams obtained by division (the arrangement direction of the second focal points 4 ', 4'') and the fly-ear lens 6 are configured as in the apparatus of the above-mentioned embodiment. The direction of the long side of the minute lens having a rectangular cross section is the same.

The apparatus of the present embodiment also exhibits the same effect as the apparatus of the previous embodiment, uniformizes the distribution of the effective light sources in the x and y directions, and the image formed on the wafer 15 in the x and y directions. The difference in quality is reduced.

Further, since the vignetting of light rays is small, the illuminance is high, and therefore, the throughput at the time of producing a semiconductor element is also improved.

Although the light from the light source is divided into two in this embodiment, it may be divided into any number.

FIG. 6 is a schematic configuration diagram showing a fourth embodiment of the present invention, which is a semiconductor device such as IC or LSI, CC.
1 shows a scanning projection exposure apparatus for manufacturing an image pickup device such as D, a liquid crystal panel, a device such as a magnetic head.

In FIG. 6, reference numeral 100 is a laser light source such as an excimer laser. Reference numerals 101 and 102 are half mirrors, and 103 is a mirror. The plurality of mirrors divide the laser light from the laser light source 100 into three, and the three laser lights are fly-eye. It is incident on the lens 6.

Also in this embodiment, since the reticle 12 is illuminated with the slit-shaped light having a rectangular cross section to form a rectangular illumination area on the reticle 12, the cross-sectional shape of each minute lens of the fly-eye lens 6 is as shown in FIG. As shown in 1, the rectangle is similar to the illumination area. As the fly-eye lens, a combination of spherical lenses is usually used, but a combination of cylindrical lenses or a combination of toric lenses may be used.

Reference numerals 8 and 11 are condenser lenses, and
0 is a masking blade, masking blade 1
The reticle 12 is placed at a position conjugate with 0. A projection optical system 14 is composed of a refractive optical system and a catadioptric optical system. Reference numeral 15 is a wafer, which is a reticle 12 and a wafer 1.
Reference numeral 5 has an optically conjugate relationship with the projection optical system 14. Reference numerals 13 and 16 denote driving devices for moving the reticle 12 and the wafer 15 in the scanning direction, respectively.
The reticle 12 and the wafer 15 are moved by 3 and 16 to perform scanning exposure with slit-shaped light.

In the apparatus of this embodiment, the arrangement direction of a plurality of light beams obtained by division and the direction of the long side of the minute lens having a rectangular cross section which constitutes the fly-ear lens 6 are the same as the apparatus of the above-mentioned embodiment. Match.

The apparatus of the present embodiment also exhibits the same effect as the apparatus of the above-mentioned embodiment, uniformizes the distribution of the effective light sources in the x and y directions, and images of the image formed on the wafer 15 in the x and y directions. The difference in quality is reduced.

Although the light from the light source is divided into two in this embodiment, it may be divided into any number.

According to the present invention, by dividing a light source in a scan-type projection exposure apparatus having a rectangular illumination range using a fly-eye lens composed of a plurality of rectangular microlenses, the effective light source distribution There is an effect that the method is the same vertically and horizontally, and there is no difference in image performance between the reticle pattern vertically and horizontally.

Further, since the vignetting of light rays is small, the illuminance is high, and therefore, the throughput at the time of producing a semiconductor element is also improved. This is particularly effective when using modified illumination such as annular illumination or quadrupole illumination.

Next, an embodiment of a method of manufacturing a semiconductor device using the scanning type exposure apparatus of FIGS. 1 to 6 will be described. FIG. 7 shows a manufacturing flow of semiconductor elements (semiconductor chips such as IC and LSI, liquid crystal panels and CCDs). In step 1 (circuit design), the circuit of the semiconductor device is designed. Step two
In (mask manufacturing), a mask (reticle 304) on which the designed circuit pattern is formed is manufactured. On the other hand, step 3
In (wafer-manufacturing), a wafer (wafer-306) 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 the lithography technique using the mask and the wafer prepared above. The next step 5 (assembly) called a post-process, Step 4 thus wafer created - a step of chip the, assembly process (dicing, Bonde _b ring), package - managing step (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).
To be done.

FIG. 8 shows a detailed flow chart of the wafer process. In step 11 (oxidation), the surface of the wafer (wafer 306) 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. In step 14 (ion implantation), ions are implanted in the wafer. Step 15 (resist processing)
Then, a resist (sensitive material) is applied to the wafer. In step 16 (exposure), the scanning exposure apparatus exposes the wafer with an image of the circuit pattern of the mask (reticle 304). In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist are scraped off. In step 19 (resist stripping), the resist that is no longer needed after etching is removed. By repeating these steps, a circuit pattern is formed on the wafer.

By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device.

[0064]

As described above, according to the present invention, an image having substantially constant image quality can be produced regardless of the direction, and the image quality can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a fly's eye lens of the apparatus of FIG. 1 and a light intensity distribution of an effective light source.

FIG. 3 is a diagram showing a structure of a minute lens of a fly-eye lens of the apparatus shown in FIG.

FIG. 4 is a partial schematic view showing another embodiment of the present invention.

FIG. 5 is a partial schematic view showing another embodiment of the present invention.

FIG. 6 is a partial schematic view showing another embodiment of the present invention.

FIG. 7 is a flowchart showing a manufacturing process of a semiconductor device.

FIG. 8 is a flowchart showing details of the wafer process during the process of FIG.

FIG. 9 is a schematic configuration diagram showing a conventional scanning projection exposure apparatus.

10 is a diagram showing the fly-eye lens and the light intensity distribution of an effective light source of the apparatus of FIG.

[Explanation of symbols]

 1 Lamp 1a Light Emitting Part 4 Second Focus (Position) 6 Fly-Eye Lens 12 Mask 14 Projection Optical System 15 Wafer 21 Spherical Mirror 41 Focus of Spherical Mirror

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03F 7/20 521 9122-2H

Claims (6)

[Claims] 1. A device for illuminating a surface to be illuminated with light from a fly-eye lens in which a plurality of lenses each having a substantially rectangular cross section are two-dimensionally arranged, An illuminating device comprising a light irradiating means for irradiating the fly-eye lens. 2. The light irradiating means divides light from a light source to form the plurality of lights, and the substantially rectangular lens in a cross section cut along a plane parallel to the long side of the substantially rectangular lens and including the optical axis. The maximum angle that the ray incident on the optical axis makes with the optical axis is θa
When the maximum angle formed with the optical axis of the light beam that can be captured by the substantially rectangular lens is θbc in a cross section that is cut by a plane that is parallel to the short side of the substantially rectangular lens and that includes the optical axis, then the plurality of lights are , Θa> θbc, the light is incident on the substantially rectangular lens at an incident angle.
Lighting equipment. 3. An apparatus for exposing a substrate through a mask with light from a fly-eye lens in which a plurality of lenses each having a substantially rectangular cross section are two-dimensionally arranged, and a plurality of lenses arranged in a long side direction of the lenses are exposed. An exposure apparatus comprising a light irradiation means for irradiating the fly-eye lens with light. 4. The light irradiating means splits light from a light source to form the plurality of lights, and the substantially rectangular lens is formed in a cross section taken along a plane parallel to a long side of the substantially rectangular lens and including an optical axis. The maximum angle that the ray incident on the optical axis makes with the optical axis is θa
When the maximum angle formed with the optical axis of the light beam that can be captured by the substantially rectangular lens is θbc in a cross section that is cut by a plane that is parallel to the short side of the substantially rectangular lens and that includes the optical axis, then the plurality of lights are , Θa> θbc, the light is incident on the substantially rectangular lens at an incident angle.
Exposure equipment. 5. The exposure apparatus according to claim 4, further comprising a projection optical system for forming an image of the pattern of the mask on the substrate. 6. A device manufacturing method comprising manufacturing a device using the exposure apparatus according to claim 4.