JPH08321454A - Position detector and manufacture of semiconductor device using the detector - Google Patents

Abstract

PURPOSE: To improve the correction of a magnification and a chromatic aberration by installing, in the midway of an optical path, a correction optical device having one translucent member which is made by joining two glass materials of different dispersions and obtaining position information of a mark image on a plane of an image pick-up means using the correction optical device. CONSTITUTION: A mark 14 which is provided on a specified plane is illuminated by a plurality of light fluxes of different wavelengths from a light source through a projection lens 3. An image of the mark is formed on a plane of an image pick-up device 19 through the projection lens 3. In an optical path, a correction optical device 400 which has one translucent member which is made by joining two glass materials of different dispersions so that main light beams of a plurality of light fluxes of different wavelengths may coincide with each other on the plane of the image pick-up device 19. Using the correction otipcal device 400, positional information on the image of the mark on the plane of the image pick-up device 19 is obtained. By this method, the correction of a magnification and a chromatic aberration can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device and a method of manufacturing a semiconductor device using the position detecting device, and more particularly to a projection lens for forming a fine electronic circuit pattern such as IC or LSI formed on a reticle (mask) surface. When the system (projection optical system) projects and exposes on the wafer surface, the state (alignment mark) on the reticle surface or the wafer surface is observed, and the reticle and the wafer are aligned with each other to achieve high integration. It is suitable for manufacturing semiconductor devices.

[0002]

2. Description of the Related Art Conventionally, in a reduction projection type exposure apparatus for manufacturing semiconductor devices, a circuit pattern of a reticle as a first object is projected by a projection lens system onto a wafer as a second object to be exposed. At this time, the alignment mark on the wafer is detected by observing the wafer surface using an observation device (detection means) prior to the projection exposure, and the so-called alignment is performed on the reticle and the wafer based on the detection result. ing.

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. In particular, recently, various kinds of exposure apparatuses for manufacturing highly integrated semiconductor devices by using a phase shift mask, modified illumination, etc. have been proposed, and higher alignment accuracy is required for such exposure apparatuses.

Conventionally, in an exposure apparatus, the following three methods are mainly used as a method of observing a wafer alignment mark (wafer mark) for obtaining position information on the wafer surface.

(A). Method that uses non-exposure light and does not pass through the projection lens system (OFF-AXIS method) (b). Method using exposure light and passing through projection lens system (exposure light, TTL method) (C). A method that uses non-exposure light and passes through a projection lens system (non-exposure light, TTL method).

Among these methods, for example, the applicant of the present invention has proposed an alignment system using a non-exposure light TTL type observation apparatus in Japanese Patent Laid-Open No. 3-61802. In this publication, an optical image of an alignment mark (wafer mark) on the wafer surface is formed on an image pickup device such as a CCD camera,
The image information obtained from the image pickup device is processed to detect the position of the wafer mark.

Further, the present applicant has filed Japanese Patent Application Laid-Open No. 62-232504.
In the publication, an optical image of a wafer mark is formed by a CCD camera, image information obtained by the CCD camera is binarized,
A position detection device has been proposed which detects the position of a wafer mark by performing template matching processing using a template on the position coordinates of a specific image pattern in the binarized image.

[0008]

In recent years, the miniaturization of semiconductor devices has advanced, and in response to this, there is a demand for more accurate relative alignment between the reticle and the wafer. As the alignment method, the non-exposure light TT described above is used.
In the L method, an optical image of an alignment mark (hereinafter referred to as a wafer mark) formed on a wafer is imaged on an image pickup device such as a CCD camera through a projection optical system (TTL), and an electric signal of the image is processed to perform image processing of the wafer mark. The position is being detected.

The projection optical system has an exposure wavelength (for example, i-line 365).
nm and the oscillated light of the excimer laser (248 nm) are corrected. In this aberration correction, almost aberration-free level is corrected, and a narrower line width can be exposed in a wider range.

Generally, in optical design, an alignment wavelength (non-exposure light, for example, He-Ne laser oscillation light 63
3 nm), it is possible to correct the aberration of the projection optical system. However, this imposes a constraint on the specification of the exposure wavelength (NA, exposure range), and the total length of the projection optical system is lengthened and the number of constituent lenses is increased. Therefore, most of the projection optical systems currently existing are designed to have aberrations at the alignment wavelength.

The applicant of the present invention has proposed a method of correcting the aberration at this alignment wavelength, for example, in Japanese Patent Laid-Open No. 3-61802. The publication proposes a method of correcting the following aberrations generated in the projection optical system.

[0012]. Spherical aberration: The lens of the detection system generates and corrects the reverse spherical aberration. Coma aberration: Tilt the plane parallel plate to generate the opposite coma and correct it. Astigmatism aberration: Inclination of the plane parallel plate generates the opposite astigmatism and corrects it. Axial chromatic aberration: The lens of the detection system generates the opposite axial chromatic aberration and corrects it. Chromatic astigmatism: With the bonded cylindrical lenses, the opposite chromatic astigmatism is generated and corrected. Lateral chromatic aberration: Corrects by causing color shift by selecting glass material of parallel plane plate for ascoma correction

Of these, when the alignment wavelength is polychromatic light, the correction of the lateral chromatic aberration is related to the performance and the material of the optical element that performs the ascoma correction, and it is generally difficult to correct all wavelengths independently. . For example, it may be difficult to correct lateral chromatic aberration at all wavelengths depending on the aberration of the projection optical system, and in such a case, it is necessary to redesign the projection optical system. This is a constraint in the design of the projection optical system.

The present invention eliminates various aberrations such as coma, astigmatism, and chromatic aberration of magnification that occur in the projection optical system when light beams of different wavelengths (including continuous spectrum) are used as exposure light as alignment light. By using a correction optical element having at least one translucent member in which a plurality of glass materials having mutually different dispersions are bonded, chromatic aberration of magnification is satisfactorily corrected without being largely affected by ascoma aberration of the projection optical system, A position detection device which detects position information of an alignment mark provided on a substrate with high accuracy and relatively accurately aligns a reticle and a wafer with high accuracy to facilitate manufacturing of a highly integrated semiconductor device, and a semiconductor using the position detecting device. It is intended to provide a method for manufacturing a device.

[0015]

The position detecting device of the present invention comprises:
When a mark provided on a predetermined surface is illuminated through a projection lens system with a plurality of light beams having different wavelengths from a light source means and the mark image is formed on the surface of the image pickup means through the projection lens, the wavelength is changed. A correction optical element having at least one translucent member, in which at least two glass materials having different dispersions are joined, is provided in the optical path so that principal rays of a plurality of different luminous fluxes substantially match each other on the image pickup means surface, The position information of the mark image on the surface of the image pickup means is detected by using the correction optical element.

The projection exposure apparatus of the present invention is an exposure apparatus which projects and exposes a pattern on the first object plane illuminated by the exposure light from the illumination means onto the second object plane by the projection lens system. When a mark provided on the second object plane is illuminated with a plurality of different light fluxes through the projection lens system and the mark image is formed on the image pickup means surface through the projection lens, a plurality of different wavelengths are used. A correction optical element having at least one translucent member, in which at least two glass materials having different dispersions are joined, is provided in the optical path so that the principal rays of the light flux are substantially coincident with each other on the surface of the image pickup means. It is characterized in that the position information of the mark image on the surface of the image pickup means is detected using an element.

According to the method of manufacturing a semiconductor device of the present invention, the pattern on the reticle surface illuminated by the exposure light from the illuminating means is projected and exposed on the wafer surface by the projection lens system, and then the wafer is subjected to a developing treatment to perform the semiconductor device processing. In the method of manufacturing the, a mark on the wafer surface is illuminated through the projection lens system with a plurality of light beams having different wavelengths from a light source means,
When forming the mark image on the surface of the image pickup means through the projection lens, at least two glass materials having different dispersions such that the chief rays of a plurality of light fluxes having different wavelengths substantially match each other on the surface of the image pickup means. A correction optical element having at least one light-transmissive member bonded to each other is provided in the optical path, and the correction optical element is used to detect the position information of the mark image on the surface of the imaging means. I am trying.

[0018]

Embodiment 1 FIG. 1 is a schematic view of the essential portions of Embodiment 1 of the present invention, showing an exposure apparatus for semiconductor manufacturing. In the figure, reference numeral 1 denotes a reticle as a first object, which is mounted on the reticle stage 28. The reticle 1 is a lighting unit 31.
It is illuminated with exposure light from. Reference numeral 2 is a wafer as a second object, and an alignment mark 1 is provided on the surface thereof.
4 are provided. A projection optical system 3 is composed of a projection lens system and projects a circuit pattern or the like on the surface of the reticle 1 onto the surface of the wafer 2.

Reference numeral 21 denotes a θ, Z stage on which the wafer 2 is placed, and the θ rotation of the wafer 2 and focus adjustment, that is, adjustment in the Z direction are performed. The θ and Z stage 21 is mounted on an XY stage 22 for performing a step operation with high accuracy. An optical square 23, which serves as a reference for measuring the stage position, is placed on the XY stage 22, and the optical square 23 is monitored by a laser interferometer 24.

The alignment between the reticle 1 and the wafer 2 in this embodiment is performed indirectly by aligning the reference marks whose positional relationship is determined in advance. Alternatively, an actual resist image pattern or the like is aligned and exposed to measure the error (offset), and thereafter, the offset processing is performed in consideration of the value.

Next, a method for detecting the position of the mark 14 on the surface of the wafer 2 will be described. 63 is a light source (light source means)
And is composed of a white light source such as a halogen lamp.
Of the light flux from the light source 63, a predetermined wavelength width (for example, the wavelength 63
A light beam having a polarization plane of 3 ± 20 nm and a half width of 40 nm) is passed through the condenser lens 62, and a linearly polarized light beam having a polarization plane in a predetermined direction is reflected by the polarization beam splitter 67. The light source 63 emits a light flux having a predetermined half-width.

In the present embodiment, the light source 63 may be composed of a plurality of light emitting means (lasers or the like) that emit light beams having different wavelengths.

The light beam reflected by the polarization beam splitter 67 is converted into circularly polarized light by the λ / 4 plate 65, and a correction lens 18 for correcting spherical aberration and chromatic aberration and an optical property described later are provided and are dispersed in a predetermined shape. After being reflected by the mirror M1 via the correction optical element 400 made of a translucent member in which a plurality of different glass materials are joined, the light is incident on the projection lens system 3.

Here, the correction optical element 400 is arranged so that its entrance end and exit end are inclined at a predetermined angle with respect to the optical axis in the meridional section of the projection lens system 3, thereby exposing as will be described later. Astigmatism, coma and chromatic aberration generated from the projection lens system 3 due to the difference in wavelength between the light and the detection light (alignment light), in particular, lateral chromatic aberration and the like are corrected in good balance over all alignment wavelengths. The light flux incident on the projection lens system 3 illuminates the mark 14 on the surface of the wafer 2 after emission.

The reflected light from the mark 14 on the surface of the wafer 2 is, in order, the projection lens system 3, the mirror M1, the correction optical element 400,
Then, the correction optical system 18 and the original optical path are returned to the λ / 4 plate 65.
Incident on. The light flux that has passed through the λ / 4 plate 65 becomes linearly polarized light with its polarization plane rotated by 90 degrees from before, and this time it passes through the polarization beam splitter 67 and enters the CCD (imaging device) 19, and the mark 14 An image (mark image) is formed.

At this time, the positional relationship of the wafer 2 is obtained by observing (measuring) the position of the mark image formed on the surface of the CCD 19. For example, the deviation of the mark image from the reference position (reference mark) on the CCD 19 surface is obtained.

Thus, in this embodiment, the elements 63, 66,
The deviation of the mark on the surface of the wafer 2 from the reference mark is detected via the projection lens system 3 by the detection means having 62, 67, 65, 18, 400, M1, and 19. Then, the detection of the mark image at this time is performed by forming the mark image on the surface of the CCD 19 by the image forming means having the elements M1, 400 and 18.

Next, a method of aligning the mark 1a provided on the reticle 1 with the reference mark 64 provided on the main body will be described.

Of the light flux from the light source 63a, the wavelength selection filter 68 allows a light flux having a predetermined wavelength width to pass through, is condensed by the condenser lens 62a, and is reflected by the half mirror 61. Then, the light is reflected by the half mirror, and the correction lens 1
The mark 1a and the reference mark 64 are illuminated by the light flux passing through 8a and the mirror 17. Mark 1a and reference mark 64
The reflected light from the mirror 17 returns to the original optical path through the correction lens 18a, passes through the half mirror 61, and then the CCD 19
It is incident on the surface a and both mark images are formed on the surface. Based on the positional relationship between both mark images at this time, the reticle 2 is aligned with the main body.

In this embodiment, a plurality of detecting means for detecting marks on the surface of the wafer 2 and an optical system for aligning the reticle with the main body are provided symmetrically with respect to the optical axis of the projection lens system 3.

In this embodiment, as described above, the exposure light and the detection light are provided by providing the group of the correction optical elements 400 in the optical path of the detection optical system for detecting the mark 15 on the surface of the wafer 2. The astigmatism, coma, and chromatic aberration generated by the projection lens system 3 due to the difference in the wavelength of are corrected in both the sagittal plane and the meridional plane, and the mark 14 on the wafer 2 can be detected satisfactorily. The relative alignment between the reticle 1 and the wafer 2 is performed with high accuracy. After that, the pattern on the surface of the reticle 1 is projected and exposed on the surface of the wafer 2 by the projection lens system 3, and the semiconductor chip is manufactured through known development processing and the like.

Next, the correction optical element 400 used in this embodiment
The optical action of the will be described. First, correction of lateral chromatic aberration will be described with reference to FIG. In FIG. 2, for simplification, one light-transmissive member 100 constituting the correction optical element is set so that the light incident end 100a and the light emission end 100b are perpendicular to the optical axis 103.

In FIG. 2, reference numeral 100 denotes two glass materials 101 and 102 having different dispersions from each other, and an angle θ with respect to the optical axis 103.
It is a translucent member joined by. Now, this translucent member 10
Consider the case where the monochromatic light 104 having the wavelength λ enters 0. The refractive indexes of the glass materials 101 and 102 at the wavelength λ are n
₁ and n ₂ . Since the glass materials 101 and 102 have different dispersions, the refractive index before and after the bonding surface 105 is n ₁ ≠ n ₂ (1). Therefore, with respect to the optical path that enters the glass material 101, exits from the glass material 102 through the bonding surface 105, and reaches the observation image plane 106, the following relational expression is established from “Snell's law”.

N ₁ sin (90 ° -θ) n ₂ sin θ ‥‥‥‥ (2) θ ₂ = 90 ° -θ-θ ₁ ‥‥‥ (3) n ₂ sin θ ₂ = sin θ ₃ ‥‥‥‥ (4) Y = Ltan θ ₂ + Dtan θ ₃ (5) where θ is the angle between the cemented surface 105 and the optical axis 103 θ ₁ : The angle of refraction of the ray of wavelength λ at the cemented surface 105 θ ₂ : The cemented surface Angle between light ray 104 of wavelength λ after transmission of 105 and optical axis 103 θ ₃ : Angle between light ray 104 of wavelength λ and the normal line of emission end face 100 b L: Emission from the intersection point of joint surface 105 and light ray 104 of wavelength λ Distance to the end face 100b D: Distance from the emission end face 100b to the observation image plane 106 Y: Position of the light ray from the optical axis 103 of the wavelength λ on the observation image plane 106

The above equations (2) to (5) are similarly established for other wavelengths. However, if the wavelengths are different, the glass material 1
Since the refractive indexes at 01 and 102 vary depending on the wavelength, n ₁ = N ₁ (λ) (6) n ₂ = N ₂ (λ) (7) Therefore, when a plurality of lights having different wavelengths pass through the translucent member 100, the positions Y of the respective wavelengths on the observation image plane 106 have different values.

For example, when two kinds of glass materials 1 n _d = 1.72600 ν _d = 53.5 and 2 n _d = 1.72825 ν _d = 28.5 are joined at θ = 45 °, L = 2
5, D = 21.78881, at wavelength 632.8 nm and wavelength 613 nm, λ = 632.8 nm n ₁ = 1.7231493 θ ₁ ＝ 45.00181557 n ₂ = 1.7230947 θ ₂ ＝ -0.00181557 θ ₃ ＝ -0.00312840 Y ₆₃₃ ＝ -0.001982mm λ = 613 nm n ₁ = 1.7243238 θ ₁ = 44.97096755 n ₂ = 1.7251982 θ ₂ = 0.02903245 θ ₃ = 0.05008673 Y ₆₁₃ = 0.031715 mm.

Therefore, the difference ΔY between the positions on the observed image plane 104 is ΔY = Y ₆₁₃ −Y ₆₃₃ = 33.6 μm. On the contrary, if a color misregistration of -33.6 μm occurs between the wavelength 632.8 nm and the wavelength 613 nm by utilizing this, the color misregistration can be removed by passing the light flux through the translucent member 100. Is shown.

In the above example, calculation was performed for two wavelengths, but even in the case of a light flux having a continuous spectrum, it is established in the wavelength region where the refractive index of the glass material becomes a substantially linear function of wavelength.
Therefore, by changing the above parameters,
A plurality of chief rays of different wavelengths can be made to substantially match on the observation image plane.

In the case of the first embodiment shown in FIG. 1, in addition to the correction of the lateral chromatic aberration generated in the projection lens 3 by the correction optical element 400 of the transparent member 100 as shown in FIG. Also correct. The aberration correction at this time will be described below with reference to FIG.

In FIG. 3, reference numeral 200 denotes a translucent member in which glass materials 201 and 202 similar to those shown in FIG. 2 are arranged at a predetermined angle θ with respect to the optical axis 203 in the meridional section. In order to simplify the model, in FIG. 3, the two bonded glass materials 201 and 202 having different dispersions have the same refractive index (n ₁ = n ₂ ) with respect to the fundamental wavelength λ. Then, with respect to the fundamental wavelength λ, since the light flux is not refracted at the joint surface 205 in the translucent member 200,
The translucent member 200 is equivalent to a mere parallel plane plate.

Generally, as shown in FIG. 3, thickness d and refractive index N
It is assumed that a light beam having a divergence angle μ is incident on the plane-parallel plate 200 such that the principal ray PR thereof has an angle θ. At this time, the astigmatism AS and the coma aberration CM generated from the plane-parallel plate 200 are “Modern Optical Engineer” by W. Smith.
AS = d · θ ² (N ² −1) / N ³ (8) CM = d · μ ² · θ (N ² -1) / (2N ³ ). It becomes (9).

That is, the astigmatism AS is proportional to the square of the incident angle θ, and the coma aberration CM is proportional to the incident angle θ. Similarly, both the astigmatism AS and the coma aberration CM are proportional to the thickness d.

Therefore, in this embodiment, by utilizing this property, the incident angle θ and the thickness d for canceling the astigmatism and the coma aberration at the fundamental wavelength of the alignment generated in the projection lens system 3 of FIG. 1 are set to (8). , (9) are solved by solving the simultaneous equations, and astigmatism and coma are well corrected at the fundamental wavelength. However, if the sign of the thickness d becomes negative at this time, there is no practical solution.

Therefore, in the present embodiment, the projection lens system is designed so that the incident angle θ to the correction optical element 400 and the thickness d can be realized by controlling the aberration at the alignment fundamental wavelength of the projection lens system. I'm designing.

The farther the alignment wavelength is from the basic wavelength, the larger the refraction angle of the light beam at the cemented surface of the correction optical element 400 becomes, and the coma aberration and astigmatism increase the residual aberration, but this is within the allowable range for alignment measurement. If the degree is, it is possible to sufficiently widen the wavelength band.

As described above, in this embodiment, the correction optical element 40 of the first group is configured by controlling the aberration amount of the projection lens system in advance.
At 0, various aberrations caused by the projection lens system 3 due to the difference in wavelength are corrected, and the mark 14 on the wafer 2 surface is satisfactorily observed.

4 to 7 are schematic views of the essential portions of Embodiments 2 to 5 of the present invention. In the figure, the same elements as those shown in FIG. 1 are designated by the same reference numerals.

The second embodiment shown in FIG. 4 is different from the first embodiment shown in FIG. 1 in that when the correction optical element 400 is constructed by joining two glass materials having different dispersions, two refractive indexes at respective alignment fundamental wavelengths. n _1, n ₂ merely is different in that in the n ₁ ≠ n ₂ by estimating a case that can not be realized n ₁ = n ₂ for the convenience or the like of the glass material, and other configurations are the same .

In this embodiment, the fundamental wavelength correcting optical element 40 is also used.
Since the light is refracted at the cemented surface within 0, the mirror M2 is arranged with a predetermined inclination so that the optical axis of the optical system after the correction optical element 400 (from the correction optical element 400 to the CCD 19 side) and the principal ray of the light beam coincide with each other. are doing. However, if the optical axis of the optical system after the correction optical element 400 is tilted, it is not necessary to adjust the tilt of the mirror in the optical system.

In Example 3 of FIG. 5, there is almost no coma and astigmatism generated in the projection lens system 3 at the alignment wavelength as compared with Example 1 of FIG. 1, and refraction of the glass material forming the correction optical element 500 is performed. Index is n _{1 at the} fundamental wavelength
The difference is that n = n ₂ and other configurations are the same.

In this embodiment, since only the chromatic aberration of magnification needs to be corrected by the correction optical element 500, only the correction optical element as shown in FIG. 2 is inserted in the optical path.

Compared to the first embodiment shown in FIG. 1, the fourth embodiment shown in FIG. 6 is such that the aberrations produced by the projection lens system 3 at the alignment wavelength are only astigmatism and lateral chromatic aberration, and that coma is not produced. The only difference is that the other configurations are the same.

Aberrations corrected by the correction optical element 600 in this embodiment are astigmatism and lateral chromatic aberration. On the other hand, since the coma aberration is 0, there is no need to correct it. In this case, however, astigmatism and lateral chromatic aberration are corrected and coma aberration is reduced to zero with only one group of translucent members as in the above-described embodiment.
It is difficult to correct the aberration without changing the value. This is because the astigmatism generated in the projection lens system 3 when the thickness d of the correction optical element and the incident angle θ is other than 0 is canceled by the equations (8) and (9), so that a predetermined amount is generated and the coma aberration is generated. This is because the solution for CM = 0 does not actually exist.

Therefore, in the case of this embodiment, the correction optical element 6
6, as shown in FIG. 6, a transparent member 602 for correcting lateral chromatic aberration and a transparent member 602 composed of a pair of identical plane-parallel plates arranged in a V-shape opposed to each other in a sagittal section. , 603 corrects the astigmatism. By these translucent members 601, 602, 603, astigmatism and lateral chromatic aberration are corrected and coma aberration is kept unchanged at 0.

As compared with the first embodiment shown in FIG. 1, the fifth embodiment shown in FIG. 7 is such that the aberrations produced by the projection lens system 3 at the alignment wavelength are only coma and chromatic aberration of magnification, and no astigmatism is produced. The only difference is that the other configurations are the same.

In this embodiment, the aberrations corrected by the correction optical element 700 are coma and chromatic aberration of magnification. On the other hand, since the astigmatism is 0, it is not necessary to correct it. But,
Also in this case, it is difficult to correct the coma aberration and the chromatic aberration of magnification only by the first group of translucent members as in the first to third embodiments described above, and it is difficult to correct the astigmatism.

This is because, similarly to the fourth embodiment, the coma aberration generated in the projection lens system 3 is canceled by the equations (8) and (9) when the thickness d of the transparent member and the incident angle θ are other than 0. Therefore, there is no actual solution that produces astigmatism CM = 0 by a predetermined amount.

Therefore, in this embodiment, the correction optical element 70
As shown in FIG. 7, the translucent member 701 is inserted into the optical path with a predetermined amount tilted in the meridional section as 0, and chromatic aberration of magnification and coma aberration generated in the projection lens system 3 are corrected.

In this case, however, astigmatism occurs due to the translucent member 701 being tilted. Therefore, in order to correct this astigmatism, the translucent members 702 and 703 composed of a pair of parallel flat plates having the same “C” shape facing each other in the sagittal cross section after the translucent member 701.
Has been arranged. These three translucent members 701, 70
2, 703 corrects coma aberration and chromatic aberration of magnification, and corrects astigmatism generated in the translucent member 701 to realize highly accurate alignment.

Next, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described.

FIG. 8 shows a flow of manufacturing a semiconductor device (semiconductor chip such as IC or LSI, or liquid crystal panel, CCD or the like). In step 1 (circuit design), the circuit of the semiconductor device is designed. In step 2 (mask manufacturing), a mask having the designed circuit pattern is manufactured.

On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4
The (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by a lithography technique using the mask and the wafer prepared above.

The next step 5 (assembly) is called a post-process, and is a process of forming a semiconductor chip by using the wafer manufactured in step 4, an assembly process (dicing, bonding), a packaging process (chip encapsulation). Etc. are included. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).

FIG. 9 shows a detailed flow of the wafer process. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface.

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
In (resist processing), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), parts other than the developed resist image are removed. In step 19 (resist peeling), the resist that has become unnecessary due to etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer.

By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device which has been difficult to manufacture in the past.

[0067]

As described above, according to the present invention, coma aberration, astigmatism, chromatic aberration of magnification, etc., which occur in the projection optical system when light fluxes having different wavelengths are used as exposure light as alignment light. By using a correction optical element having at least one translucent member in which a plurality of glass materials having different dispersions are bonded to each other, the lateral chromatic aberration is corrected for all wavelengths without being largely affected by the ascoma aberration of the projection optical system. Position that facilitates the manufacture of highly integrated semiconductor devices by accurately detecting the position information of the alignment marks provided on the wafer surface and by performing the relative alignment between the reticle and the wafer with high accuracy. It is possible to achieve a detection apparatus and a semiconductor device manufacturing method using the detection apparatus.

In particular, according to the present invention, lateral chromatic aberration, coma and astigmatism occurring in the projection optical system can be corrected well,
Changes in chromatic aberration in the vicinity of the alignment fundamental wavelength, which was a constraint when designing a projection lens system, can be greatly mitigated, facilitating the design of the projection lens and obtaining a good alignment signal for highly accurate position. The effect that matching can be achieved is obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a first embodiment of the present invention.

FIG. 2 is a schematic view of a correction optical element according to the present invention.

FIG. 3 is a schematic view of a correction optical element according to the present invention.

FIG. 4 is a schematic view of the essential portions of Embodiment 2 of the present invention.

FIG. 5 is a schematic view of the essential portions of Embodiment 3 of the present invention.

FIG. 6 is a schematic view of the essential portions of Embodiment 4 of the present invention.

FIG. 7 is a schematic view of the essential portions of Embodiment 5 of the present invention.

FIG. 8 is a flowchart of a method for manufacturing a semiconductor device according to the present invention.

FIG. 9 is a flowchart of a method for manufacturing a semiconductor device of the present invention.

[Explanation of symbols]

1 reticle (first object) 2 wafer (second object) 3 projection optical system 4,400, 500, 600, 700 correction optical element 14 alignment mark 18, 18a correction lens 19 image sensor 63 light source means 100, 200, 601, 602,603,701,7
02,703 Translucent member

Claims (3)

[Claims] 1. A mark provided on a predetermined surface is illuminated via a projection lens system with a plurality of light beams having different wavelengths from a light source means, and the mark image is formed on the surface of an imaging means via the projection lens. At this time, a correction optical element having at least one translucent member in which at least two glass materials having different dispersions are joined so that the principal rays of a plurality of light fluxes having different wavelengths substantially match with each other on the surface of the imaging means. A position detecting device which is provided in an optical path and detects position information of the mark image on the surface of the image pickup means by using the correction optical element. 2. An exposure apparatus which projects and exposes a pattern on a first object plane illuminated by exposure light from an illuminating means onto a second object plane by a projection lens system, using a plurality of light beams having different wavelengths from a light source means. When the mark provided on the second object plane is illuminated through the projection lens system and the mark image is formed on the image pickup means surface through the projection lens, the principal rays of a plurality of light beams having different wavelengths are A correction optical element having at least one translucent member, in which at least two glass materials having different dispersions are bonded to each other on the surface of the image pickup means, is provided in the optical path, and the correction optical element is used to An exposure apparatus which detects position information of the mark image on the surface of the image pickup means. 3. A method for manufacturing a semiconductor device by projecting and exposing a pattern on a reticle surface illuminated by exposure light from an illuminating means onto a wafer surface by a projection lens system, and then developing the wafer to produce a semiconductor device. When a mark on the wafer surface is illuminated through the projection lens system with a plurality of light beams having different wavelengths from and the mark image is formed on the image pickup means surface through the projection lens, a plurality of different wavelengths are emitted. A correction optical element having at least one translucent member, in which at least two glass materials having different dispersions are joined, is provided in the optical path so that the principal ray of the light flux of A method of manufacturing a semiconductor device, characterized in that position information of the mark image on the surface of the image pickup means is detected by using an optical element.