JPH07142310A - Aligner and manufacture of semiconductor chip using the device - Google Patents

Abstract

PURPOSE:To correct the deviation of a mark image caused by a color generated on a detecting surface by lighting the second body with detecting light, whose wavelength is different from that of exposing light, detecting mark information on the second body, and aligning the relative positions of the first body and the second body. CONSTITUTION:A light source 14 is a light source for detecting an AA mark (alignment mark) and emits the luminous flux, whose wavelength is different from the wavelength of exposing light. The detecting light emitted from the light source 14 illuminates the AA mark 4 on a wafer 3 through a beam splitter 16, a mirror M1 and the like. The observed image information of the AA mark is formed on a CCD camera 22 through the mirror M1 and a mirror M2. Coma abberation generated in an observing microscope 11 is corrected with a lens group 13. Meanwhile, with respect to a reference mark 17, the image of the light emitted from a mark lighting light source is focused on the CCD camera 22 through a beam splitter 20 and the mirror M2. The accurate position information is obtained by comparing the positions of both images on the CCD camera 22, and alignment is performed in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus and a semiconductor chip manufacturing method using the same, and more particularly to a projection lens system for forming a fine electronic circuit pattern such as IC or LSI formed on a reticle (mask) surface. An exposure apparatus having a function of projecting light onto a wafer surface by a (projection optical system) and observing the state on the wafer surface through a projection lens system with light having a wavelength different from the light for this exposure, and The present invention relates to a method of manufacturing a semiconductor chip.

[0002]

2. Description of the Related Art In a minute projection type exposure apparatus for semiconductor manufacturing, a circuit pattern of a reticle as a first object is projected onto a wafer as a second object by a projection lens system and exposed. The alignment mark on the wafer is detected by observing the wafer surface using an observation device (detection means), and based on the detection result, the reticle and the wafer are aligned, that is, so-called alignment is performed.

The alignment accuracy at this time largely depends on the optical performance of the observation apparatus. Therefore, the performance of the observation device is an important factor in the exposure device.

Conventionally, in an exposure apparatus, the alignment mark formed on the wafer surface is often observed by an observation microscope system, and the position of the alignment mark is detected using the projected image signal to obtain wafer position information. Has been done.

Particularly in recent years, non-exposure light having a relatively wide wavelength range has been used as observation illumination light mainly for the following two reasons.

The first reason is that when observing the alignment mark formed on the wafer surface, in many cases, a photosensitive material (resist) for transferring an electronic circuit pattern is applied on the wafer surface. Since the resist usually absorbs a lot at the exposure wavelength, it becomes difficult to detect the alignment mark on the wafer through the resist film at the exposure wavelength. There is a problem that the resist is exposed to light and the detection of the alignment mark becomes unstable, or the detection becomes impossible. Therefore, a detection method using non-exposure light is desired.

The second reason is that, when light having a relatively wide wavelength range, such as a halogen lamp, is used as the illumination light for observing the non-exposure light, a monochromatic light source such as a He--Ne laser is used on the wafer. It is possible to reduce interference fringes, which tend to occur when observing the AA mark, due to film thickness unevenness of the resist film and various functional films used in the semiconductor process, and it is possible to perform better alignment.

For these reasons, the alignment mark observing microscope system can correct various aberrations with respect to the illumination light for observation having a relatively wide wavelength width by the non-exposure light, and can perform good alignment mark detection. I am trying to do it.

[0009]

However, when light with a wide wavelength width is used as the illumination light for observation in this way,
In order to correct the coma aberration occurring in the entire observation microscope, for example, when a lens for adjusting coma aberration is used and the lens is decentered from the optical axis, a color shift occurs due to the so-called prism effect, and a color shift occurs on the detection surface. The problem arises that the position of the projected image signal is projected at different positions depending on the color.

Further, when light having a wide wavelength width is used as the illumination light for observation, as shown in FIGS. 9A, 9B and 9C, a processing error or an assembly error of each element of the observation microscope system, etc. Error, specifically, the wedge component of the prism, the inclination with respect to the optical axis, and the eccentricity error of the lens, the position of the image signal projected on the detection surface is projected at different positions depending on the color. come. FIG. 9 (A),
(B) and (C) are the wedge components of the prism 91,
The figure shows how color deviation occurs on the projection screen due to the inclination of the prism 91 with respect to the optical axis and the eccentricity error of the lens.

As a result, the film thickness of the resist applied on the wafer surface and the film thickness of various functional films used in the semiconductor process,
When the film thickness of the alignment mark formed on the wafer surface changes, for example, as shown in FIG. 10, an image projected on the detection surface due to a change in the spectral characteristic of the alignment mark detection signal formed on the wafer surface. There is a problem in that the position of the signal changes to cause an alignment error, which deteriorates the alignment accuracy.

The present invention has been improved in that it is possible to detect the position of a mark image with high accuracy when detecting a mark through a projection lens system with detection light (alignment light) having a wavelength different from that of the exposure light. An object of the present invention is to provide an exposure apparatus having a mark detection function and a semiconductor chip manufacturing method using the same.

[0013]

In the exposure apparatus of the present invention, (1-1) the projection lens system for projecting the pattern of the first object onto the second object by the exposure light and the wavelength of the exposure light are different from each other. The second object is illuminated with the detection light, the mark information on the second object is detected, and the detection means performs relative alignment between the first object and the second object. The detecting means is characterized by correcting the coma aberration generated by the detecting means by decentering the optical element whose chromatic aberration has been corrected from the optical axis.

In particular, the optical element is characterized by being a cemented lens in which two lenses made of materials having different dispersions are cemented.

(1-2) A projection lens system for projecting the pattern of the first object on the second object with the exposure light, and the second object with the detection light having a wavelength different from that of the exposure light to illuminate the second object. A mark image based on a color generated on the detection surface, and a detection unit that detects mark information on the object and performs relative alignment between the first object and the second object based on the detected mark information. It is characterized by having an optical member for correcting the deviation of

In particular, it is characterized in that the optical member is constituted by a wedge plate or two wedge plates made of different dispersion materials or two lenses made of different dispersion materials.

Further, the method of manufacturing a semiconductor chip of the present invention is (2-1) a mark obtained based on the detection is detected by the detection means using the detection light which does not expose the wafer to the alignment mark on the wafer. The wafer is aligned according to the image position information, and the circuit pattern of the mask is illuminated with the exposure light that exposes the wafer to project and transfer the image of the circuit pattern onto the wafer through the projection lens system. When the semiconductor chip is manufactured, the detecting means corrects the coma aberration generated by the detecting means by decentering the optical element whose chromatic aberration has been corrected from the optical axis.

(2-2) The detection mark that does not expose the wafer to light is used to detect the alignment mark on the wafer by the detection means, and the alignment of the wafer is performed based on the position information of the mark image obtained based on the detection. When the semiconductor chip is manufactured, the image of the circuit pattern is projected and transferred onto the wafer through a projection lens system by illuminating the circuit pattern of the mask with exposure light that exposes the wafer. The means is characterized by having an optical member for correcting the deviation of the mark image due to the color generated on the detection surface.

[0019]

FIG. 1 is a schematic view of a main part of an optical system of Example 1 when the present invention is applied to an exposure apparatus for manufacturing a semiconductor device.

In the figure, numeral 8 is a reticle as a first object, which is mounted on the reticle stage 10. 3 is the second
It is a wafer as an object, and alignment marks (AA marks) 4 are provided on the surface thereof. Reference numeral 5 denotes a projection optical system including a projection lens system and a reticle (mask).
The circuit patterns on the 8th surface are projected on the 3rd surface of the wafer. The projection lens system 5 is a telecentric system on both the reticle 8 side and the wafer 3 side.

An illumination system 9 illuminates the reticle 8 with exposure light. Reference numeral 2 denotes a θ, Z stage on which the wafer 3 is placed, and θ rotation and focus adjustment of the wafer 3, that is, Z
We are adjusting the direction. The θ, Z stage 2 is mounted on the XY stage 1 for performing the step operation with high accuracy. An optical square (bar mirror) 6 that serves as a reference for measuring the stage position is placed on the XY stage 1.
The optical square 6 is monitored by a laser interferometer 7.

The alignment between the reticle 8 and the wafer 3 in this embodiment is performed indirectly by aligning each with a reference mark 17, which will be described later, whose positional relationship has been obtained. Alternatively, the resist image pattern or the like is actually aligned and exposed, the error (offset) is measured, and offset processing is performed in consideration of the value thereafter.

Next, each element of the detecting means 101 for detecting the position of the mark 4 on the surface of the wafer 3 will be described.

An observation microscope 11 observes the AA mark 4 on the surface of the wafer 3 with non-exposure light.

In this embodiment, an off-axis method is used in which alignment is performed without the projection lens 5.

A light source 14 for detecting the AA mark 4 is composed of a halogen lamp which emits a light flux (non-exposure light) having a wavelength different from the wavelength of the exposure light. 15 is a lens,
The light flux (detection light) from the light source 14 is condensed and made incident on the beam splitter 16 for illumination. Reference numeral 12 is an objective lens.

Reference numeral 13 denotes a lens group as an optical element,
In order to correct the coma aberration generated in the observation microscope 11, the optical axis S can be decentered.

In this embodiment, the lens group 13 is composed of two lenses, a positive lens and a negative lens, which are made of materials having different dispersions, and corrects chromatic aberration.

The detection light from the lens 15 reflected by the beam splitter 16 is reflected by the mirror M ₁ and the lens group 1
The light is guided to the AA mark 4 on the surface of the wafer 3 via 3 and the objective lens 12 to illuminate it.

Reference numeral 19 is a light source for illuminating the reference mark 17
It consists of ED etc. Reference numeral 18 is a lens. Light source 19
The light flux from is condensed by the lens 18, guided to the reference mark 17, and illuminated. Reference numeral 20 denotes a beam splitter for the reference mark, which reflects the light beam from the reference mark 17 and makes it enter the erector lens 21 via the mirror M ₂ . The erector lens 21 images the reference mark 17 and the AA mark 4 on the surface of the wafer 3 on the image pickup surface of the CCD camera 22, respectively. The detecting means 101 in this embodiment has each of the above elements.

In this embodiment, the non-exposure light (detection light) emitted from the light source 14 passes through the lens 15, the beam splitter 16, the mirror M ₁ , the lens group 13 and the objective lens 12 in this order, and the AA mark 4 on the wafer 3 is detected. Illuminate. Wafer 3
The observation image information of the upper AA mark 4 is the lens group 13,
Objective lens 12, mirror M ₁ , beam splitter 1
6, an image is formed on the CCD camera 22 through the beam splitter 20, the mirror M ₂ , and the erector lens 21.

In the present embodiment, the coma aberration generated in the observation microscope 11 is corrected by the lens group 13 which is decentered from the optical axis S as described later. This gives a good A
An observation image of the A mark 4 is formed on the CCD camera 22.

On the other hand, the reference mark 17 is obtained by illuminating light emitted from a light source 19 formed of an LED for illuminating the reference mark with a lens 18.
The light is condensed and illuminated by the laser beam and is focused on the CCD camera 22 through the beam splitter 20, the mirror M ₂ and the erector lens 21.

The position of the observed image of the AA mark 4 on the wafer 3 formed on the CCD camera 22 on the CCD camera 22 is measured by a signal processing device (not shown), and the CCD camera 22 is also measured by the signal processing device. Accurate position information of the XY stage 1 is obtained by comparing the position of the projected image of the reference mark 17 which is imaged on the upper side and is always fixed, and thereby highly accurate alignment is performed.

Next, the optical action of the lens group 13 for adjusting the coma aberration of this embodiment will be described with reference to FIG.

The lens group 13 of this embodiment has two different dispersions.
A cemented color correction lens that cements two lenses and corrects the chromatic aberration generated in the lens group 13 is configured to be decentered from the optical axis, and the entire observation microscope 11 does not generate an image shift due to color on the detection surface 22. The coma that is occurring can be corrected.

FIG. 2A shows a state in which an image is formed on the detection surface by the microscope imaging lens.
(B) shows a state in which a color shift due to a so-called prism effect occurs when one lens 13 is decentered from the optical axis.

FIG. 2C shows a state in which an image is formed on the detection surface by the cemented color correction lens 13 in which two lenses having different dispersions are cemented to correct chromatic aberration.

FIG. 2D shows that when the cemented color correction lens 13 of FIG. 2C is decentered from the optical axis, no color image shift occurs on the detection surface.

In the present embodiment, by composing the lens group 13 as described above, the coma aberration generated in the entire observation microscope 11 is corrected and the detection surface (the image pickup surface of the CCD camera 22).
A good image of the AA mark 4 is formed.

Further, in this embodiment, as the non-exposure light, a light source (for example, 633 ± 30 nm) having a central wavelength different from the wavelength of the exposure light from the halogen lamp and having a relatively wide wavelength is used, and a He-Ne laser like The interference fringes due to the resist film, which tend to occur when observing the AA mark on the wafer using a monochromatic light source, are reduced, and thereby good alignment is performed.

FIG. 3 is a schematic view of the essential parts of an optical system of Example 2 when the present invention is applied to an exposure apparatus for manufacturing semiconductor elements. In FIG. 3, the same members as those shown in FIG. 1 are designated by the same reference numerals.

The present embodiment is different from the embodiment 1 of FIG. 1 in that the AA mark 4 on the wafer 3 is observed by using the light passing through the projection lens 5, that is, the TTL method. The difference is that alignment is performed and the point that the optical system 24 is used, and other configurations are substantially the same.

In FIG. 3, the optical system 24 comprises a plane-parallel plate for correcting the aberration (eg, astigmatism) generated in the projection lens 5.

In this embodiment, the non-exposure light emitted from the halogen lamp 14 is the lens 15, the beam splitter 16, the lens group 13, the objective lens 12, the optical system 24, in that order.
The AA mark 4 on the wafer 3 is illuminated through the mirror 23 and the projection lens system 5.

The observation image information of the AA mark 4 on the wafer 3 is passed through the projection lens 5, the mirror 23, the optical system 24, the objective lens 12, the lens group 13, the beam splitter 16, the beam splitter 20, and the erector lens 21 in this order to the CC.
An image is formed on the D camera 22. At this time, the projection lens system 5
Shows the electronic circuit pattern drawn on the reticle 8 on the wafer 3
Since the image is projected on the upper side, the aberration is well corrected for the exposure light. Therefore, when the non-exposure light passes through the projection lens 5,
Aberration occurs.

In this embodiment, the spherical aberration and the axial chromatic aberration generated in the projection lens system 5 are corrected by the objective lens 12, and the coma aberration is also corrected by the lens group 13 which can be decentered from the optical axis. It is configured such that a good observation image of the AA mark 4 is formed on the CCD camera 22.

On the other hand, the reference mark 17 is illuminated by condensing the light emitted from the LED light source 19 for illuminating the reference mark by the lens 18, and forms an image on the CCD camera 22 through the beam splitter 20 and the objective erector lens 21. .

The position of the observed image of the AA mark 4 on the wafer 3 formed on the CCD camera 22 on the CCD camera 22 is measured by a signal processing device (not shown), and the CCD camera 22 is also measured by the signal processing device. Accurate position information of the stage is obtained by comparing the position of the projected image of the reference mark 17 which is imaged on the upper side and is always fixed, and thereby highly accurate alignment is performed.

As described above, in Examples 1 and 2, when the AA mark on the wafer is observed by the non-exposure light for alignment, an optical system element for correcting the coma aberration generated in the entire observation microscope. By constructing the optical system element whose chromatic aberration is corrected, the image shift due to color on the detection surface is prevented when the coma aberration generated in the entire observation microscope is corrected.

As a result, the film thickness of the resist applied on the wafer surface, the film thickness of various functional films used in the semiconductor process,
When the position of the image signal projected on the detection surface changes due to the change in the spectral characteristics of the alignment mark detection signal formed on the wafer surface, when the film thickness of the alignment mark formed on the wafer surface changes. The alignment error is reduced to improve the alignment accuracy.

FIG. 4 is a schematic view of the essential parts of an optical system of Example 3 when the present invention is applied to an exposure apparatus for manufacturing semiconductor elements. 4, the same members as those shown in FIG. 1 are designated by the same reference numerals.

Compared to the first embodiment shown in FIG. 1, this embodiment has CC
An optical member 41 composed of at least two transparent wedge prisms is arranged in front of the D camera 22 as described later, and an AA mark image of a color generated by an error or the like of each optical element of the observation microscope 11 is on the CCD camera 22 surface. Correcting the positional deviation at 1, and coma aberration correction lens group 1
3 is omitted, and other configurations are substantially the same.

Next, the structure of this embodiment will be described in order, although it partially overlaps with the description of FIG.

In this embodiment, the non-exposure light emitted from the halogen lamp 14 illuminates the AA mark 4 on the wafer 3 through the lens 15, the beam splitter 16, the mirror M ₁ and the objective lens 12 in order.

The observation image information of the AA mark 4 on the wafer 3 is transferred to the CCD camera 22 through the objective lens 12, the mirror M ₁ , the beam splitter 16, the beam splitter 20, the mirror M ₂ , the erector lens 21 and the optical member 41 in this order. Form an image.

On the other hand, the reference mark 17 is illuminated by condensing the light emitted from the LED light source 19 for illuminating the reference mark by the lens 18, and the beam splitter 20 and the mirror M.
₂ , CCD camera 22 through the objective erector lens 21
Image on top.

The position of the observed image of the AA mark 4 on the wafer 3 formed on the CCD camera 22 on the CCD camera 22 is measured by a signal processing device (not shown), and the CCD camera 22 is also measured by the signal processing device. Accurate position information of the stage is obtained by comparing the position of the projected image of the reference mark 17 which is imaged on the upper side and is always fixed, and thereby highly accurate alignment is performed.

In this embodiment, similarly to the first embodiment, a light source having a relatively wide wavelength width (for example, 633 ±
(30 nm) and a monochromatic light source such as a He-Ne laser is used to reduce interference fringes due to the resist film, which tends to occur when observing an AA mark on a wafer, thereby performing good alignment.

Next, the optical action of the optical member 41 of this embodiment will be described with reference to FIG.

In this embodiment, the optical member 41 uses two wedge plates 41a and 41b to correct the positional deviation of the projected image due to the color generated by the error of the optical system element of the observation microscope system 11.

FIG. 5A shows a state in which color shift occurs due to the so-called prism effect of one wedge plate 51.

FIG. 5B shows how the projected image is displaced due to a color generated by an error in the optical system elements of the observation microscope system 11.

FIG. 5C shows two wedge plates 41a, 41.
The positional deviation of the projected image shown in FIG. 5 (B) is corrected by using b. It is generated in an arbitrary direction and size by adjusting the set angles of the two wedge plates 41a and 41b. It is possible to correct the positional deviation of the projected image due to color.

FIGS. 6 and 7 are explanatory views related to a part of the optical member 41 of Examples 4 and 5 of the present invention.

The fourth and fifth embodiments are different from the third embodiment shown in FIG. 4 only in the structure of the optical member 41, and the other structures are the same.

In Example 4 of FIG. 6, two wedge plates 41a1 and 41a2 (41b) having different dispersions are used as the optical member 41.
1, 41b2) two parallel plane plates 41a, 4 joined together
1b is used to correct the positional deviation of the projected image (AA mark image) due to the color generated by the error of the optical system element of the observation microscope 11 shown in FIG.

In the present embodiment, the set angles of the two sets of wedge plates can be adjusted to correct the positional deviation of the projected image due to the color generated in any direction and size. Particularly in this embodiment, two wedge plates 41a1 and 41a having different dispersions are used.
If the glass materials forming the a2 (41b1, 41b2) have the same refractive index but different dispersion at one wavelength (for example, the central wavelength λ ₀ ) of the illumination wavelength used for alignment, these two wedge plates will have different wavelengths. Since it has no refractive power with respect to λ ₀ , when the wedge plate is inserted in the optical path to correct the positional deviation of the projected image due to color, the CCD camera 2
2 has the feature that the optical axis of the observation image formed on the image does not change.

In Example 5 of FIG. 7, as the optical member 41,
Two lenses 41c and 41d made of materials having different dispersions
Is used to form a plane-parallel plate as a whole, thereby correcting the positional deviation of the projected image due to the color caused by the error of the optical system element of the observation microscope system 11 shown in FIG. I am trying to do it.

In this embodiment, the eccentricity of the lens and the amount of eccentricity can be adjusted to correct the positional deviation of the projected image due to the color generated in any direction and size.

Particularly in this embodiment, the glass materials forming the two lenses 41c and 41d made of materials having different dispersions have the same refractive index at one wavelength (for example, the central wavelength λ ₀ ) of the illumination wavelength used for alignment. If they have different dispersions, they have no refractive power with respect to these two lens wavelengths λ ₀ , so when the lens is inserted in the optical path to correct the positional deviation of the projected image due to color, the CCD
It has a feature that the optical axis of the observation image formed on the camera 22 does not change.

FIG. 8 is a schematic view of the essential parts of an optical system of Example 6 when the present invention is applied to an exposure apparatus for manufacturing semiconductor devices. 8, the same members as those shown in FIG. 4 are designated by the same reference numerals.

The present embodiment is different from the third embodiment in FIG. 4 in that the AA mark 4 on the wafer 3 is observed by using the light passing through the projection lens 5, that is, the TTL method. The difference is that alignment is performed, and other configurations are almost the same.

In this embodiment, the non-exposure light emitted from the halogen lamp 14 illuminates the AA mark 4 on the wafer 3 through the lens 15, the beam splitter 16, the objective lens 12, the mirror M ₁ and the projection lens system 5 in this order.

The observation image information of the AA mark 4 on the wafer 3 passes through the projection lens 5, the mirror M ₁ , the objective lens 12, the beam splitter 16, the beam splitter 20, the erector lens 21, the optical member 41, and the CCD camera 22 in order.
Image on top.

On the other hand, the reference mark 17 is illuminated by condensing the light emitted from the LED light source 19 for illuminating the reference mark by the lens 18, and passes through the beam splitter 20, the objective elector lens 21, the optical member 41, and the CCD camera 22.
Image on top.

The position of the observed image of the AA mark 4 on the wafer 3 formed on the CCD camera 22 on the CCD camera 22 is measured by a signal processing device (not shown), and the CCD camera 22 is also measured by the signal processing device. Accurate position information of the stage is obtained by comparing the position of the projected image of the reference mark 17 which is imaged on the upper side and is always fixed, and thereby highly accurate alignment is performed.

As described above, in Examples 3 to 6, when the AA mark on the wafer surface is observed by non-exposure light for alignment, an optical member for correcting the image shift due to the color generated on the detection surface is provided. When the resist applied on the wafer surface, various functional films used in the semiconductor process, and the film thickness of the alignment mark formed on the wafer surface are changed,
The alignment error is reduced when the position of the image signal projected on the detection surface changes due to the change in the spectral characteristic of the alignment mark detection signal formed on the wafer surface, thereby improving the alignment accuracy.

[0079]

According to the present invention, by setting each element as described above, the mark can be detected through the projection lens system with the detection light (alignment light) having a wavelength different from that of the exposure light. It is possible to achieve an exposure apparatus having an improved mark detection function, which can detect the position of an image with high accuracy, and a semiconductor chip manufacturing method using the exposure apparatus.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of an optical system according to a first embodiment of an exposure apparatus of the present invention.

2 is an explanatory diagram of an embodiment for correcting coma aberration of the observation microscope of FIG.

FIG. 3 is a schematic view of a main part of an optical system according to a second embodiment of the exposure apparatus of the present invention.

FIG. 4 is a schematic view of a main part of an optical system according to a third embodiment of an exposure apparatus of the present invention.

FIG. 5 is an explanatory diagram showing correction of positional deviation of the AA mark image by the colors of FIG.

6 is an explanatory diagram showing correction of positional deviation of the AA mark image by the colors of FIG.

FIG. 7 is an explanatory diagram showing correction of positional deviation of the AA mark image by the colors of FIG.

FIG. 8 is a schematic view of a main part of an optical system of Example 4 of the exposure apparatus of the invention.

FIG. 9 is an explanatory diagram of positional deviation of an AA mark image due to color in a conventional device.

FIG. 10 is an explanatory diagram showing a change in spectral reflectance with film thickness.

[Explanation of symbols]

1 XY stage 2 θ stage 3 Wafer 4 Alignment mark (AA mark) on the wafer 5 Projection lens 6 Bar mirror 7 Laser interferometer for measuring XY stage position 8 Reticle 9 Exposure illumination system 10 Reticle stage 11 Color projection Optical system for correcting image displacement 12 Objective lens 13 Observation optical system for observing AA mark on wafer by non-exposure light 14 Halogen lamp light source for illumination 15 Illumination lens 16 Beam splitter for illumination 17 Reference mark 18 Reference Lens for mark illumination 19 LED light source for reference mark illumination 20 Beam splitter for reference mark 21 Erector lens 22 CCD camera

Claims (6)

[Claims] 1. A projection lens system for projecting a pattern of a first object onto a second object with exposure light, and a second object illuminated with detection light having a wavelength different from that of the exposure light, And a detection unit that detects the mark information and performs relative alignment between the first object and the second object, and the detection unit decenters the chromatic-aberration-corrected optical element from the optical axis. By so doing, the coma aberration generated by the detecting means is corrected. 2. The exposure apparatus according to claim 1, wherein the optical element is composed of a cemented lens in which two lenses made of materials having different dispersions are cemented. 3. A detection means detects a position alignment mark on the wafer using detection light that does not expose the wafer, and the position of the wafer is aligned based on the position information of the mark image obtained based on the detection. By illuminating the circuit pattern of the mask with the exposure light that exposes the wafer, the image of the circuit pattern is projected and transferred onto the wafer through the projection lens system, and when the semiconductor chip is manufactured, the detection means uses chromatic aberration. A method of manufacturing a semiconductor chip, wherein the corrected optical element is decentered from the optical axis to correct the coma aberration generated by the detection means. 4. A projection lens system for projecting a pattern of a first object onto a second object with exposure light, and a second object illuminated with detection light having a wavelength different from that of the exposure light. It has a detection means for detecting the mark information and for performing the relative alignment between the first object and the second object from the mark information, and the detection means detects the deviation of the mark image due to the color generated on the detection surface. An exposure apparatus having an optical member for correction. 5. The optical member is composed of a wedge plate or two wedge plates made of different dispersion materials or two lenses made of different dispersion materials.
Exposure equipment. 6. A detection mark is used to detect alignment marks on the wafer by using detection light that does not expose the wafer, and the alignment of the wafer is performed based on the position information of the mark image obtained based on the detection. By illuminating the circuit pattern of the mask with the exposure light that exposes the wafer, the image of the circuit pattern is projected and transferred onto the wafer through the projection lens system, and when the semiconductor chip is manufactured, the detection means detects A method of manufacturing a semiconductor chip, comprising: an optical member for correcting the deviation of the mark image due to the color generated on the surface.