Projection lens, projection exposure device, and projection exposure method

Abstract

A dioptic projection lens (PO) for imaging a pattern placed on the object plane (OS) of a dioptic projection lens onto the image plane (IS) of the dioptic projection lens by electromagnetic radiation at an operating wavelength in the ultraviolet range longer than 280 nm comprises a plurality of lens elements, the plurality of lens elements are positioned between the object plane (OS) and the image plane (IS) along the optical axis (AX) and are implemented so that a pattern placed on the object plane can be imaged onto the image plane by the lens elements, an aperture plane (BE) suitable for attaching an aperture aperture (AS) is located between the object plane and the image plane, and the main rays of imaging intersect the optical axis (AX) at this aperture plane. The projection lens is designed as a large field lens having an object field radius of at least 52 mm and has a structure having a 1:1 imaging scale that is mirror-symmetric with respect to the aperture plane (BE).

Description

Technology Field

[0001] The following disclosure is based on German patent application No. 102022201002.7 filed on January 31, 2022, which is incorporated by reference into this application.

[0002] The present invention relates to a dioptric projection lens for imaging a pattern placed on the object plane of a dioptric projection lens onto the image plane of the dioptric projection lens by electromagnetic radiation at an operating wavelength in the ultraviolet range longer than 280 nm, a projection exposure device equipped with the projection lens, and a projection exposure method that can be performed using the projection lens. Background Technology

[0003] Microlithographic projection exposure methods are currently widely used to manufacture semiconductor devices and other microstructured devices, such as masks for photolithography. Here, a mask (reticle) or other pattern-generating device is used, and this mask or device carries or forms a pattern of the structure to be imaged, such as a line pattern of a layer of a semiconductor device. This pattern is positioned in the area of ​​the object plane of the projection lens between the illumination system and the projection lens in a projection exposure device and is illuminated by illumination radiation provided by the illumination system. Radiation modified by the pattern travels through the projection lens as projection radiation, and this projection lens images the pattern onto the substrate to be exposed. The surface of the substrate is positioned on the image plane of the projection lens, and this image plane is optically conjugated with the object plane. The substrate is typically coated with a radiation-sensitive layer (resist, photoresist).

[0004] Typically, the demand from semiconductor device manufacturers differs for the exposure of critical and non-critical structures. Currently, critical structures, i.e., fine structures, are mostly fabricated using dioptic or reflective refractive immersion systems, which operate at wavelengths in the deep ultraviolet (DUV) range, specifically at approximately 193 nm. To date, the finest structures are exposed using EUV systems. These systems are projection exposure devices composed solely of reflective elements, which operate at wavelengths in the extreme ultraviolet (EUV) range between approximately 5 nm and 20 nm, for example, at approximately 13.4 mm.

[0005] Less important structures, that is, coarser structures, can be exposed using a simpler and therefore more cost-effective system.

[0006] For the purpose of manufacturing intermediate-important or non-important layers having typical structural dimensions significantly larger than 150 nm, work is conventionally performed using a projection exposure device configured for an operating wavelength greater than 280 nm. In this wavelength range, a dioptic (refractive) projection lens is commonly used, and the manufacturing of this lens can be easily controlled due to its rotational symmetry about the optical axis.

[0007] Projection exposure devices (so-called i-line systems) for operating wavelengths of 365.5 nm ± 2 nm are used particularly frequently for these applications. These devices utilize the i-line of a mercury vapor lamp, the natural maximum bandwidth of which is limited to a narrower usable bandwidth (Δλ)—e.g., approximately 4 nm or 5 nm—using filters or any other means. During projection, ultraviolet light with a relatively wide wavelength band is used, and the projection lens must cause relatively strong correction of chromatic aberration with even broadband projection light to ensure low-aberration imaging at the required resolution.

[0008] There have also been proposals in the past to design a projection lens so that the projection lens is corrected in a very broadband manner for all three mercury lines (e.g., WO2007 / 131161). If all Hg lines are used, more light becomes available for imaging, and as a result, exposure time can be shortened compared to conventional i-line systems, and thus throughput (number of exposed elements per unit time) can be increased. The problem to be solved

[0009] The object of the present invention is to provide a projection lens, a projection exposure apparatus, and a projection exposure method that operate with UV radiation at an operating wavelength longer than 280 nm and enable high throughput. means of solving the problem

[0010] To solve this problem, the present invention provides a dioptic projection lens having the characteristics of claim 1. Furthermore, a projection exposure apparatus having the characteristics of claim 15 and a projection exposure method having the characteristics of claim 18 are provided. Advantageous developments are specified in dependent claims. The wording of all claims is incorporated by reference in the content of the detailed description.

[0011] According to the wording of the claim, a dioptic projection lens is provided, which is implemented to image a pattern placed on the object plane of the dioptic projection lens onto the image plane of the dioptic projection lens by electromagnetic radiation at an operating wavelength in the ultraviolet range longer than 280 nm. All optical elements having refractive power are lens elements, i.e., refractive optical elements. The lens is placed between the object plane and the image plane along the optical axis and is implemented so that the whole causes this imaging. An aperture plane suitable for attaching an aperture is located between the object plane and the image plane, and the main ray of the imaging intersects the optical axis at this aperture plane.

[0012] According to the claimed invention, the projection lens is designed as a large field lens having an object field height of at least 52 mm and has a structure that is mirror-symmetric with respect to the aperture plane and has an imaging scale of 1:1. This corresponds to an imaging scale of |β|=1.

[0013] In this application, the phrase “large field lens” refers to a projection lens designed such that, due to the size of its available object field, the full width of at least a full 6” reticle (current standard size) can be exposed in a single exposure step. The available size of the object field is quantified in this case by the Object Field Height (OBH). This corresponds to the object field radius, that is, the radius of the minimum circle surrounding these object field points where the optical correction satisfies the specifications, i.e., is sufficiently good. This circle must contain the effective object field actually used for cursor imaging.

[0014] Preferably, the projection lens should be able to be used as a stepper lens. In this case, the stepper lens is up to 104 x 132 mm (corresponding to half a diagonal of 84 mm). 2 It is understood to mean an optical imaging system capable of imaging a 6" reticle with an object field onto a wafer with a single exposure without scanning. To this end, the projection lens must be corrected so that optical aberrations are corrected in an object field with an object field radius of 84 mm.

[0015] Depending on the development, the projection lens has an object field radius (OBH) of 84 mm or more. Due to the 1:1 imaging scale, 16 "dies" can be exposed simultaneously in a step-and-repeat process. This contributes to a high throughput of the process. However, aberration correction becomes more difficult as a result of the increased object field radius.

[0016] Scanner systems form an alternative to steppers. In this case, only a portion of the object field is imaged by the projection lens at any given time. Therefore, a scanning motion is required to perform a single exposure step while adjacent sections of the reticle are continuously transferred to the substrate. To transfer a complete pattern of a 6" reticle in a single exposure step with scanning, the effective object field must have a width of 104 mm. This advantage can be achieved with an object field radius of at least 52 mm, which significantly simplifies aberration correction. An object field radius of 55 mm will result in a maximum slit height of approximately 35 mm (measured in the scanning direction). However, the slit height should preferably be 56 mm; an object field radius of 59 mm is required for this. Sufficient light intensity on the wafer is obtained specifically using such slit dimensions.

[0017] First, the phrase "stepper system" merely specifies the size of the object field to be imaged. Furthermore, the imaging scale (β) of the system determines the size of the image field exposed at that time. In this case, the typical dimensions are 26 x 33 mm 2 It is provided by the dimensions of a single "die". If the (reducing) imaging scale is 4:1, a stepper with a 6" reticle can fully expose exactly one single "die" in one exposure. Due to the 1:1 imaging scale, 16 "dies" can eventually be exposed simultaneously in a single exposure step.

[0018] As a result, the throughput compared to conventional systems can be increased.

[0019] Significant difficulties in design problems are largely characterized by three dimensions, in particular (i) field size, that is, the field radius within which aberrations must be corrected, (ii) the same corresponding numerical aperture on the object side and the image side in the case of a 1:1 system, and (iii) the acquired aberration level.

[0020] The first two points are often combined with what is known as the geometric etendue (LLW). The geometric etendue (LLW) can be defined as the product of the object field size parameterized by the (dimensionless) object-side numerical aperture (NAO) and the object field height (OBH) (in mm). That is,

[0021] LLW = |OBH * NAO|

[0022] If the field size to be corrected changes, for example, if it increases from a scanner field to a stepper field, the numerical aperture must be appropriately adjusted (i.e., reduced) to succeed with the same number of correction means.

[0023] Preferably, the projection lens is designed so that the numerical aperture (NA) (object-side and image-side) is less than 0.3, particularly NA = 0.25 or less. For example, the numerical aperture may be between 0.1 and 0.2, particularly at 0.18. Due to the very intermediate NA, the Rayleigh unit (RU = λ / NA) that specifies the measurement for depth of field 2 ) is very large, so the remaining second spectrum can generally be ignored. Ultimately, this simplifies the correction of aberrations.

[0024] A projection lens that is very compact in the axial direction can be realized within the scope of the present invention. Depending on the deployment, the projection lens has an installation length (TT) ("total track length") measured between the object plane and the image plane, an object field radius (OBH), and an object-side numerical aperture (NAO), and the following condition applies: (OBH * NAO) / TT > 0.01

[0025] The installation length is preferably about 1 meter, for example, in the range between 800 mm and 1200 mm, particularly at 1000 mm.

[0026] Compared to the prior art, the projection lens of the type presented herein may achieve a very high geometric etendu value. Depending on the development, the projection lens has a geometric etendu of at least 10 mm (LLW = OBH * NAO), and the geometric etendu is preferably 15 mm or more. The etendu can be considered as a measure of the performance of the imaging system. As the etendu increases, the system can image "more," for example, a larger field (if the OBH increases) or a finer structure (if a larger NA is used).

[0027] What is common to all exemplary embodiments is that these embodiments are purely dioptic designs. Ultimately, only lens elements are required. This advantage particularly simplifies manufacturing. For example, the use of mirrors, as known from catadioptric offner systems (see, e.g., US 3,748,015, US 4,293,188 or US 2004 / 0001191 A1), is intentionally eliminated, even though this simplifies the correction of aberrations, such as field curvature or longitudinal chromatic aberration.

[0028] The projection lens according to the claimed invention has resulting mirror symmetry with respect to the aperture plane. The aperture plane is positioned midway between the object field (reticle) and the image field (wafer). This means that all lens elements occurring in the first lens portion upstream of the aperture (between the object plane and the aperture plane) have identically designed corresponding portions that are positioned in a mirror-symmetric manner in the second lens portion downstream of the aperture.

[0029] Symmetrical structures offer advantages, particularly when correcting aberrations. Transverse chromatic aberrations, such as distortion, coma, and chromatic variation, are inherently corrected by the symmetry of the structure. Therefore, separate correction methods are not required for this purpose.

[0030] Preferably, only the UV radiation of the Hg i-line is used. This is a significant difference from conventional systems, which are corrected in a very broadband manner for all three mercury lines. If all Hg lines are used, more light becomes available for imaging, but it appears difficult to correct aberrations over a relatively large object field radius.

[0031] A preferred exemplary embodiment is provided or designed for use with an optical wavelength of approximately 365.5 nm and / or a bandwidth of several nm (up to 5 nm). Therefore, longitudinal correction of the primary spectrum (longitudinal chromatic aberration) is sufficient.

[0032] In the case of dioptic projection lenses operating in a broadband manner, different lens element materials with sufficiently different dispersion properties are used for color correction (i.e., chromatic aberration correction), and these lens element materials are distributed within the projection lens into regions with different ray height ratios. Transparent materials used in conventional i-line projection lenses include specialty glasses and synthetic fused silica (SiO2), which are commercially available under the designations FK5, LF5, and LLF, manufactured particularly by SCHOTT (Mainz, Germany). Among these optical glasses, synthetic fused silica and FK5 glass typically represent relatively low-dispersion glass (crown glass), whereas glasses (LF5 and LLF1) typically represent relatively high-dispersion glass (flint glass). Other manufacturers use different designations for their respective types of glass.

[0033] Accordingly, within this application, a lens element made of crown glass is referred to as a "crown lens element," and a lens element made of flint glass is also referred to as a "flint lens element."

[0034] Longitudinal chromatic aberration can be corrected, for example, by using a combination of at least one crown lens element with positive refractive power and at least one flint lens element with negative refractive power. This pair of lens elements should be placed in an area of ​​the optical imaging system where the peripheral rays of the image have a possible large ray height (peripheral ray height). Generally, this is the case in the aperture area near the system aperture.

[0035] As a result of the symmetry of the structure, an exemplary embodiment is characterized in that the lens elements on both sides of the aperture plane comprise at least one flint lens element made of a first material having a relatively low Abbe number and a plurality of crown lens elements made of a second material having a higher Abbe number than the first material. At least one flint lens element is required to correct chromatic aberration and must be used in the design. If a material having anomalous partial dispersion is not used as the flint material, the secondary spectrum is automatically set longitudinally. For example, this is the case for available materials such as LF5 or LLF1 or comparable glass.

[0036] The present invention recognizes that flint materials possess some disadvantageous properties. For example, flint glass exhibits reduced light transmission when used conventionally, and this advantage is equivalent to increased absorption. This may lead to unwanted side effects such as lens heating and / or compression of the material. Furthermore, current flint materials that are transparent in the wavelength range greater than 280 nm (e.g., approximately 365 nm) all contain significant proportions of lead and additional heavy metals, and such use of these glasses is permitted only with special certification. Equivalent lead-free alternative glasses are not actually available at this time. Therefore, the development of projection lenses with reduced use of flint lens elements compared to the prior art is considered advantageous.

[0037] The use of flint lens elements is reduced in some exemplary embodiments to a target manner, preferably in such a way that up to two flint lens elements are placed on each side of the aperture plane. In some embodiments, the use of flint lens elements may be reduced to a range in which only a single flint lens element, particularly a flint lens element having negative refractive power, is used in each lens part.

[0038] Some exemplary embodiments are characterized in that at least one crown lens element having a positive refractive power, at least one flint lens element having a negative refractive power, and up to two flint lens elements having a negative refractive power are disposed on each side of the aperture plane in the aperture region around the aperture plane, and the condition │CRH / MRH│ < 1 applies to the ray height ratio (CRH / MRH) between the main ray height (CRH) and the peripheral ray height (MRH) of the imaging. Preferably, only a single flint lens element having a negative refractive power is provided in the aperture region on each side of the aperture plane.

[0039] Further details regarding options for correcting aberrations, particularly longitudinal chromatic aberration (CHL), will be described in conjunction with exemplary embodiments. Brief explanation of the drawing

[0040] Further advantages and aspects of the present invention are obvious from the description of exemplary embodiments of the present invention and from the claims, which will be described below with reference to the drawings. FIG. 1 illustrates a schematic example of a projection exposure device according to one exemplary embodiment. FIG. 2 illustrates a schematic meridional lens of a projection lens according to a first exemplary embodiment. FIGS. 3 to 6 illustrate schematic cross-sectional views of meridian lens elements of a projection lens according to the second, third, fourth, and fifth exemplary embodiments. Specific details for implementing the invention

[0041] FIG. 1 illustrates an example of a microlithographic projection exposure device (WST), which can be used for the manufacture of semiconductor devices and other finely structured devices and operates using electromagnetic radiation or light from ultraviolet (UV) light to achieve resolution down to a fraction of a micrometer. A mercury vapor lamp serves as the primary radiation source or light source (LS). This lamp emits a broad spectrum with relatively high intensity (I) emission lines in a wavelength range having centroid wavelengths at approximately 436 nm (visible, blue, g-line), approximately 405 nm (visible, violet, h-line), and approximately 365.5 nm (near-ultraviolet, UV-A, i-line). This part of the spectrum is illustrated by a schematic (I(λ)) diagram.

[0042] A projection exposure device is an i-line system that uses only light from the i-line, that is, UV light around a central operating wavelength of approximately 365.5 nm. The natural full bandwidth of the i-line is limited to a narrower bandwidth (Δλ) of, for example, approximately 5 nm by using a filter or any other method.

[0043] At the emission surface (ES), the illumination system (ILL) positioned downstream of the light source (LS) generates a large, clearly demarcated, and substantially uniformly illuminated illumination field, and this illumination field is aligned with the telecentrity requirements of the projection lens (PO) positioned downstream in the optical path. The illumination system (ILL) has a device for setting different illumination modes (illumination settings) and can switch, for example, between conventional on-axis illumination and off-axis illumination having different coherence degrees (σ).

[0044] These optical elements, which receive light from a light source (LS) and form illumination radiation from the light, and to which the illumination radiation is sent to a reticle (M), are part of the illumination system (ILL) of a projection exposure device.

[0045] A device (RS) for maintaining and manipulating a mask (M) (reticle) in such a way that the pattern placed on the reticle is on the object plane (OS) of the projection lens (PO)—which coincides with the exit plane (ES) of the lighting system and is also referred to here as the reticle plane (OS)—is placed downstream of the lighting system.

[0046] Downstream of the reticle plane (OS) there is a projection lens (PO), i.e., an imaging system, which images an image of a pattern placed in a mask (M) having a defined imaging scale (β) onto a substrate (W) coated with a photoresist layer, and the photosensitive substrate surface (SS) of the substrate is in the region of the image plane (IS) of the projection lens (PO).

[0047] In an exemplary case, the substrate to be exposed, which is a semiconductor wafer (W), is held by a device (WS) also referred to as a "wafer stage".

[0048] The illumination field generated by the illumination system (ILL) defines the effective object field (OF) used during projection exposure. In an exemplary case, the effective object field is rectangular, and the height (A) measured parallel to the y-direction * It has ), and the width (B) measured perpendicular to it (x-direction). * * It has an aspect ratio (AR=B * / A * The effective object field is approximately 104 / 132. The effective object field is centered on the optical axis (on-axis field). With a system having this field size, a typical 6" reticle can be taken to imaging in a single exposure step.

[0049] ​An effective image field located in the image area (IS) and optically conjugated to the effective object field has the same shape as the effective object field and an aspect ratio between the same height (B) and width (A). In the case of the illustrated 1:1 system (imaging scale |β|=1), the image field has the size of the effective object field.

[0050] Some comments are made regarding the field size. If the field size of the image field is 26×33 mm, the entire "die" can be exposed in a single exposure step without scanning. The term "die" refers to a single, unpackaged semiconductor wafer in semiconductor and microsystem technology. Accordingly, the projection exposure device can be designed as a wafer stepper for a step-and-repeat process. A device to perform the scanning operation for the exposure of the die may not be required. The projection exposure device can also be designed as a wafer scanner for a step-and-scanning process. In this case, a device to perform the scanning operation for the exposure of the die must be provided.

[0051] In a rotationally symmetric system, a circle centered on the optical axis (OA) that encloses the effective object field (OF) and touches its corners specifies the size of the object field, and within this object field, optical correction at every field point must satisfy the specifications. This also applies to all field points within the effective object field. The correction of aberrations becomes more complex as the object field becomes larger. In this case, the size of the circle is parameterized by the object field radius (OBH) (i.e., half the object field diameter), and at the same time, this object field radius corresponds to the maximum field height of the object field point.

[0052] An exemplary embodiment is a stepper system having 1:1 imaging—as a result, 16 dies can be exposed simultaneously.

[0053] To better understand the important aspects of the exemplary embodiments to be described later, some explanations regarding chromatic aberration and its correction in dioptric (refractive) optical systems are provided first to clarify the terms and their meanings used in this application.

[0054] Chromatic aberration is an imaging aberration in an optical system caused by the refractive index (n) of a transparent optical material varying as a function of wavelength (λ). This dependence (dn / dλ) is referred to as the dispersion of the optical material. Generally, the refractive index of an optical material is greater for shorter wavelengths than for longer wavelengths.

[0055] Chromatic aberration can be subdivided into several categories. The first category of chromatic aberration takes into account that dedicated images occur for each wavelength in the paraxial region (on the optical axis) and that these images may vary in position, shape, and / or size along the optical axis. Chromatic aberrations of the first category include longitudinal chromatic aberration (CHL) (axial chromatic aberration, axial color, AX) and chromatic magnification aberration or chromatic magnification aberration (CHV) (lateral color, LAT).

[0056] Longitudinal chromatic aberration is the longitudinal aberration of the paraxial focal position as a function of wavelength. If the refractive index for a shorter wavelength is greater than that for a longer wavelength, the shorter wavelength is refracted more strongly at each optical plane, for example in the case of a simple positive lens element, so that light rays of the relatively shorter wavelength are focused at a focal position closer to the lens element than at the focal point of the relatively longer wavelength. The paraxial distance along the optical axis of the lens element between the two focal points is the longitudinal chromatic aberration. If light rays with shorter wavelengths are focused closer to the imaging system than light rays with longer wavelengths, the longitudinal chromatic aberration is usually referred to as "under-corrected" or "negative."

[0057] If an imaging system forms images of different sizes for different wavelengths, or if images at off-axis points form color fringes, then chromatic aberration or chromatic aberration (CHV) is present. Chromatic aberration can be quantified by the lateral distance between the heights of paraxial images of different wavelengths.

[0058] The dispersion of the optical material used, that is, the chromatic variation of the refractive index, may also result in changes in monochromatic aberrations, and such changes may be combined in the second category of chromatic aberrations. For example, these include changes in spherical aberrations, changes in field curvature, etc.

[0059] Regarding additional features of possible aberrations, imaging of light from a broadband radiation source is considered, where the broadband radiation source emits light with different wavelengths around a central wavelength (λ), and the radiation distribution is characterized by a spectral bandwidth (Δλ) (full width at half maximum). Typically, the range of chromatic aberration increases as the spectral bandwidth (Δλ) increases. Chromatic aberration can be characterized by the focal positions for different wavelengths along the optical axis for three wavelengths within the spectral bandwidth. The three wavelength components have wavelengths (λ1, λ2, λ3), where λ1 < λ2 < λ3.

[0060] The magnitude of longitudinal chromatic aberration (CHL) corresponds to the maximum length of the focal range along the optical axis—where different wavelengths are focused. Typically, one of the wavelengths is focused closer to the imaging system than the other. The distance between the nearest focal position of a wavelength and the farthest focal position of a wavelength corresponds to the magnitude of the longitudinal chromatic aberration of the imaging system for a broadband light source. The focal position of the central wavelength (λ) along the optical axis can be considered as the image plane within the focal range.

[0061] The change in the paraxial focal position due to wavelength is usually extended in a power series. In this case, the linear part is called the "first-order spectrum," the second part is called the "second-order spectrum," and furthermore, the "third-order spectrum" can also be defined by the third part (cubic portion).

[0062] The first-order spectrum can be corrected by combining converging and diverging lens elements composed of different optical materials having different degrees of dispersion. More specifically, longitudinal chromatic aberration can be corrected so that the paraxial focal planes for two different wavelengths, e.g., the minimum wavelength (λ1) and the maximum wavelength (λ2) of the spectral range, coincide on the optical axis. Such an optical imaging system is also referred to in this application as "achromatized" or "achromat."

[0063] Generally, the remainder of longitudinal chromatic aberration remains for other wavelengths that are not captured by correction. This remainder of longitudinal chromatic aberration is usually the "secondary spectrum."

[0064] In some cases, this second spectrum can also be corrected by appropriate selection of optical material, lens element dimensions, distance and refractive power, etc. The second spectrum may be corrected to the extent that the focal positions of all three wavelengths (λ1, λ2, λ3) of the wavelength range under consideration are in the same axial position; only the "third spectrum" now remains. In this application, an optical system in which the second spectrum is also corrected is also referred to as "apochromatically corrected" or "apochromatic."

[0065] In other words, longitudinal chromatic aberration for two separated wavelengths becomes very small (probably down to a value of 0) in the case of a chromatic imaging system. Longitudinal chromatic aberration for three spectrally separated wavelengths becomes very small (probably down to a value of 0) in the case of a chromatic desensitization optical imaging system.

[0066] In dioptic projection lenses intended to function as spectrally broadband light sources, different lens element materials with the largest possible difference in Abbe numbers are used for chromatic aberration correction. The Abbe number (v) facilitates the characterization of the dispersion properties of the material over a corresponding wavelength range. For example, the Abbe number of a material can be calculated using the following mathematical formula:

[0067] v=(n2-1) / (n1-n3)

[0068] Here, n1, n2, and n3 are the refractive indices of the material at wavelengths λ1, λ2, and λ3, respectively, and λ1 < λ2 < λ3 applies. Generally, a low Abbe number indicates a material with relatively strong dispersion, while a high Abbe number indicates a material with relatively weak dispersion. Therefore, the Abbe number is often also referred to as "reciprocal relative dispersion."

[0069] In this case, Abe number ( ) must be related to the range of the ultraviolet spectral range. To this end, the refractive indices (n1, n2, n3) of the mercury spectral lines at 365.0 nm (i-line for n1), 404.7 nm (h-line for n2), and 435.8 nm (g-line for n3) are used. The Abbe numbers for the glass used are listed in Table 10.

[0070] Lens element materials for the operating wavelength in the emission line of a mercury vapor lamp can be divided into three different groups depending on their refractive index and their Abbe number. The first group includes these materials with an Abbe number in the range of 40 to 70. Here, the Abbe numbers are calculated for wavelengths λ1=365.01 nm, λ2=404.65 nm, and λ3=435.84 nm—corresponding to the wavelengths of the i-, h-, and g-emission lines of the mercury vapor lamp. Materials in the first group have a conventional refractive index in the range of 1.46 to 1.56 in the mercury i-line. Materials in the first group include, in particular, synthetic fused silica (SiO2) and various borosilicate glasses—BK7 glass or glass (K5, K7, or FK5).

[0071] Group 2 includes materials with an Abbe number greater than 70. Some materials in Group 2, such as crystalline calcium fluoride (fluorine or CaF2), have a refractive index of less than 1.46.

[0072] The third group includes materials with an Abbe number of less than 40. These materials have a refractive index greater than approximately 1.56. The materials of the third group include, in particular, ordinary flint glasses such as LLF-6 glass, LLF-1 glass, or LF-5 glass.

[0073] For the purpose of reducing chromatic aberration by means of a refractive means, the optical system must have lens elements made of at least two materials having different degrees of dispersion or different Abbe numbers. Accordingly, a first optical element made of a first material having a relatively low Abbe number and a second optical element made of a second material having a higher Abbe number than the first material must be combined.

[0074] Generally, the materials of the second group are used as relative crown materials. Generally, the materials of the third group are used as relative flint materials. The materials of the first group can function as relative crown materials when combined with materials from the third group, and can function as relative flint materials when combined with materials from the second group. For example, synthetic fused silica (SiO2) functions as a relative crown material when combined with materials from the third group (e.g., LF5, LLF1, LLF6). In contrast, if synthetic fused silica is combined with materials of the second group (B), e.g., CaF2, the synthetic fused silica functions as a relative flint material.

[0075] Within the scope of this application, a first material having a relatively low Abbe number is also referred to as a "relative flint material," and a second material having a relatively higher Abbe number is also referred to as a "relative crown material." For brevity, in exemplary embodiments further specific to this application, a lens element made of the relative crown material is also referred to as a "crown lens element," and a lens made of the relative flint material is also referred to as a "flint lens element." Generally, materials from the first and third material groups are used.

[0076] In the following description of a preferred embodiment of a projection lens, the term "optical axis" refers to a straight line passing through the center of the curvature of the surface of a curved lens element. In the example, the object is a mask (reticle) having a pattern of an integrated circuit; it may also be related to a different pattern, such as a grating. In the example, an image is projected onto a wafer having a photoresist layer, and this wafer acts as a substrate. Other substrates, such as a substrate for an optical grating or an element for a liquid crystal display, are also possible.

[0077] Some characteristics will be described based on the relationship and profile between the chief ray and the peripheral ray of the image. In this case, the chief ray (CR) refers to a ray that starts from an edge point of the object field and intersects the optical axis in the region of the pupil plane, that is, in the region of the aperture plane (BE) suitable for attaching the aperture (AS). Within the meaning of this application, the peripheral ray (MR) passes from the center of the object field to the edge of the aperture. The perpendicular distance of these rays from the optical axis gives rise to the corresponding ray height. In the sense that this application refers to "Marginal Ray Height" (MRH) or "Chief Ray Height" (CRH), the advantages refer to the paraxial marginal ray height and the paraxial chief ray height, respectively.

[0078] The term "aperture region" (BB) refers to the area around the aperture plane (BE) (i.e., upstream and downstream of the aperture plane), where the ratio of the ray height between the main ray height (CRH) and the peripheral ray height (MRH) of the image (│CRH / MRH│) is less than 1. Consequently, a relatively large peripheral ray height occurs in the aperture region.

[0079] In the drawings, crown lens elements, in particular fused silica lens elements or lens elements made of FK5, are represented as open lens elements, and flint lens elements, in particular LF5 or LLF1, are represented as oblique lens elements. Aspherical surfaces are indicated by short aspherical dashed lines.

[0080] The specifications of the projection lenses illustrated in the drawings are listed in a table compiled at the end of the detailed description, and the numbers in this table correspond to the corresponding numbers of the drawings.

[0081] Tables 2 through 6 summarize the specifications of each design in table form. In this case, column "SURF" indicates the number of a refractive surface or a surface distinguished in some other way, column "RADIUS" indicates the radius (r) of the surface (in mm), column "THICKNESS" indicates the distance (d) between a surface and a subsequent surface (in mm)—indicated as thickness—and column "MATERIAL" indicates the material of the optical element. Columns "INDEX1", "INDEX2", and "INDEX3" indicate the refractive indices of the material at wavelengths 365.5 nm (INDEX1), 364.5 nm (INDEX2), and 366.5 nm (INDEX3). Column "SEMIDIUM" indicates the available free radius or free optical semi-diameter (in mm) of the lens element or optical element. (In column, "Radius") The radius (r=0) corresponds to a planar surface. Some optical surfaces are aspherical. Tables marked with "1" represent the corresponding aspherical data, and aspherical surfaces are calculated according to the following standards:

[0082]

[0083] In this case, the reciprocal of the radius ( ) represents the surface curvature, and h represents the distance between the surface point and the optical axis (i.e., the ray height). Ultimately, p(h) represents the sagittal height, that is, the distance between the surface point and the surface vertex in the z-direction (the direction of the optical axis). The coefficients (K, C1, C2,...) are shown in the table marked with "1".

[0084] Table 7 provides a clear overview of important design parameters of an exemplary embodiment, such as numerical aperture (NA), object field radius (OBH), and imaging scale.

[0085] In the following description of exemplary embodiments, the same reference numerals are used in all drawings for identical or corresponding characteristics. Lens elements are numbered in order from the object plane to the image plane; thus, for example, lens element (L1) is the first lens element immediately following the object plane. Not all lens elements are provided with reference numerals for the sake of clarity.

[0086] FIG. 2 illustrates a schematic meridional lens element cross-sectional view of a first exemplary embodiment of a dioptic projection lens (200) by a selected beam to describe the imaging beam path or projection beam path of the projection radiation passing through the projection lens during operation.

[0087] The projection lens is provided as a 1:1 imaging system to image the pattern of the mask placed on the object plane (OS) directly onto the image plane (IS) aligned parallel to the object plane, that is, without generating an intermediate image and without changing the size, particularly at a scale of -1:1 (the imaging scale is -1).

[0088] Between the object plane and the image plane, there is a unique pupil plane (PUP) of the imaging system, where the principal ray (CR) of the optical imaging intersects the optical axis (OA). The aperture (AS) of this system is attached to the region of the pupil plane. Therefore, the location or plane suitable for attaching the aperture is also referred to here as the aperture plane (BE).

[0089] The aperture region (BB) extends around the aperture plane, and the condition (│CRH / MRH│<1) is applied to the ratio of the ray height between the main ray height (CRH) and the peripheral ray height (MRH) of the image within this aperture region (BB). Accordingly, the peripheral ray height is higher than the main ray height. The optical structure can be characterized as follows:

[0090] In the object-side first lens portion (OP1), immediately following the object plane (OS) comes a front lens element group (NV) ("negative group") having negative refractive power, and this element group is provided by an object-side concave meniscus lens element (L1) having negative refractive power.

[0091] A first group of lens elements (LG1) having positive refractive power and a total of three lens elements (L2 to L4) follow immediately thereafter. This first group of lens elements concentrates light rays incident from the front negative group, consequently forming a bulge in the projection beam path.

[0092] A second group of lens elements (LG2) having negative refractive power comes immediately after the first group of lens elements (LG1). This second group of lens elements includes five lens elements (L5 to L9) and creates a waist around a local minimum of peripheral ray height between the object plane (OS) and the aperture plane (BE) in the projection beam path.

[0093] A third lens element group (LG3) having positive refractive power and a total of three lens elements (L10 to L12) follow immediately after the second lens element group (LG2). The lens elements of the third lens element group are positioned between the aperture plane suitable for attaching the aperture aperture (AS) and the second lens element group (LG2).

[0094] Due to mirror symmetry with respect to the aperture plane, a mirrored refractive power sequence occurs on the other side of the aperture plane (BE) in the image-side second lens section (OP2). Each lens element (Lx) of the first lens section (OP1) between the object plane (OS) and the aperture plane (BE) has an identical corresponding section (Lx') that is mirrored in the second lens section (OP2) between the aperture plane and the image plane (IS).

[0095] For example, three positive lens elements are placed right next to the aperture plane on two sides. According to conventional lessons, it would be more advantageous to attach a flint negative lens element next to the aperture plane, because the height of the peripheral rays is higher there, and this flint lens element would ultimately have a better effect with respect to longitudinal chromatic aberration. However, it is currently assumed that for the purpose of obtaining excellent correction in large object fields, it would be more advantageous to place at least two, and optionally three, positive lens elements right next to the aperture plane.

[0096] The projection lens is characterized by a refractive power sequence, NPNPPNPN, where "P" represents a group of lens elements with positive refractive power and "N" represents a group of lens elements with negative refractive power. In the region of the negative third lens element group (LG3), there is only a single prominent waist on each side of the aperture plane.

[0097] The first exemplary embodiment includes a stepper field of OBH=84mm when the image-side numerical aperture (NA=0.18) is -1; the imaging scale is LLW=15.12.

[0098] This exemplary embodiment has a plurality (2×12) of lens elements having relatively low refractive power. A plurality of lens elements (L1, L2, L5 to L8, L10 to L12) are made of fused silica. Longitudinal chromatic aberration is corrected by diverging flint lens elements (L9, made of LF5 material).

[0099] In the front section, the two flint lens elements (L2 and L3) have positive refractive power and cause adverse effects on the correction of longitudinal chromatic aberration, but this advantage is negligible due to the significantly smaller peripheral ray height of the lens elements compared to L9: the contribution of the lens elements to the correction of longitudinal chromatic aberration is proportional to the square of the peripheral ray height. The reason for using flint material in this regard can be seen in the following two properties: (i) Flint lens elements have a higher refractive index. This advantage helps correct monochromatic aberrations such as spherical aberration and astigmatism. (ii) Flint lens elements contribute to the total flint refractive power of this system, which ultimately corrects the color change of Petzval sum.

[0100] It can be shown that the color change of the Petsval sum disappears whenever the sum of the individual refractive powers across the various materials disappears. Therefore, to correct the color change of the Petsval sum, in addition to at least one negative lens element made of flint material required to correct longitudinal chromatic aberration, at least one flint lens element having a positive refractive power is also required.

[0101] The design features a prominent waist structure. Accordingly, the negative refractive power of L1 enables the formation of a significant bulge of the positive lens elements (L2, L3, L4). Next is a long waist with mostly negative refractive power (L5, L7, L9) and individually weak positive lens elements (L6, L8). The beam is then weakly collimated by the lens elements (L10, L11, L12) and guided through the central aperture. Collimation of the beam is a prerequisite for focusing of the image plane—which follows from the symmetry of the structure.

[0102] Correction of aberrations is further aided by the use of 2×4 asphericals. The asphericals are located only on the quartz lens elements.

[0103] The overall design has an installation length (TT) (axial distance between the object plane and the image plane) of 1000 mm, and thus the condition ((OBH·NAO) / TT > 0.01) is observed. There is only a slight deviation from telecentrity on both the object side and the image side.

[0104] The same reference numerals are used for corresponding or similar characteristics in the following exemplary embodiments, but for clarity, these reference numerals are not mentioned again separately. Each of the second to fifth exemplary embodiments includes a stepper field having OBH=84mm when the image-side numerical aperture (NA=0.18); in each case, the imaging scale is -1 and the installation length is 1000mm.

[0105] A second exemplary embodiment (projection lens (300) in FIG. 3) has a structure very similar to that of the first exemplary embodiment in the aperture region (BB). One difference is that each lens part is composed of a double aspherical element specifically positioned as the lens element (L1 and L1') closest to the field, each of which is designed as a negative meniscus lens element, with its concave side pointing toward the nearest field plane. This advantage contributes to the number of lens elements being reduced by one lens element to only 11 lens elements per lens part. Similarly, the number of flint lens elements is reduced to two flint lens elements per lens part. As in the first exemplary embodiment, each lens part includes only a single flint lens element (L8 or L8') designed as a double concave lens element within the aperture region (BB). Additionally, as in the first exemplary embodiment, an additional positive flint lens element (L3 or L3') is positioned in the region closer to the field.

[0106] Compared to the second exemplary embodiment, the third exemplary embodiment (projection lens (400) in FIG. 4) is differentiated in that the number of lens elements (L3) made of the flint material of the second exemplary embodiment are replaced by lens elements made of fused silica. Consequently, the exemplary embodiment has only a single flint lens element per lens part, specifically L8 or L8'. Consequently, the color change of the Petzval sum can no longer be completely corrected in principle. However, this advantage appears to be relatively insignificant with respect to imaging performance due to the relatively medium numerical aperture (NA=0.18) and the accompanying relatively large depth of field.

[0107] The projection lens (500) of FIG. 5 (fourth exemplary embodiment) is an additional example of minimal use of flint lens elements, in which only one flint lens element is provided per lens part. Furthermore, progressing from the previous exemplary embodiment, the number of lens elements utilized could be further reduced. A key contribution to this purpose was achieved by the use of additional asphericals. In this case, all lens elements not composed of flint glass are designed as aspherical lens elements having a single aspherical lens element surface. Consequently, the number of asphericals increased from 2×4 (third exemplary embodiment) to 2×6, and consequently, the number of lens elements could be reduced to 2×8.

[0108] In the fifth exemplary embodiment (projection lens (600) of FIG. 6), the number of lens elements could be further reduced by using a field-near double aspherical (lens element (L1 or L1')) per lens part, and this number is now reduced to 7 lens elements per lens part in each case.

[0109] An example of a symmetric 1:1 lithography system for the mercury i-line (365.5 nm) intended for use as a stepper is presented. That is, the entire 6" reticle can be imaged using a single exposure without scanning. However, 104×132 mm 2 Smaller than, for example, only 104×28mm 2 Scanning systems with in-object fields can also be used.

[0110] surface radius thickness subject matter Refractive index 1 Refractive index 2 Refractive index 3 Half diameter 0 0.000 55.489 1 -200.653 6.999 SILUV 1.474477 1.474623 1.474332 90.2 2 -1010.698 13.566 97.5 3 981.347 46.056 SILUV 1.474477 1.474623 1.474332 108.5 4 -211.180 1.000 109.8 5 723.111 31.131 LLF1 1.579164 1.579477 1.578854 110.0 6 -390.169 10.634 109.6 7 226.903 24.328 LF5 1.619068 1.619457 1.618683 96.5 8 1049.072 18.797 94.1 9 147113.888 7.000 SILUV 1.474477 1.474623 1.474332 86.3 10 129.093 65.380 75.7 11 -295.363 12.745 SILUV 1.474477 1.474623 1.474332 70.0 12 -149.865 31.821 69.7 13 -148.623 6.999 SILUV 1.474477 1.474623 1.474332 62.4 14 211.535 29.110 62.5 15 -670.286 15.987 SILUV 1.474477 1.474623 1.474332 65.5 16 -225.414 19.748 66.2 17 -98.051 6.999 LF5 1.619068 1.619457 1.618683 66.1 18 1454.493 6.703 77.1 19 -4835.846 31.764 SILUV 1.474477 1.474623 1.474332 79.6 20 -146.129 1.000 82.3 21 -1139.947 25.367 SILUV 1.474477 1.474623 1.474332 88.4 22 -196.150 1.000 89.9 23 1706.555 27.385 SILUV 1.474477 1.474623 1.474332 91.4 24 -243.157 2.999 91.6 25 0.000 2.999 88.2 26 243.157 27.385 SILUV 1.474477 1.474623 1.474332 91.6 27 -1706.555 1.000 91.4 28 196.150 25.367 SILUV 1.474477 1.474623 1.474332 89.9 29 1139.947 1.000 88.4 30 146.129 31.764 SILUV 1.474477 1.474623 1.474332 82.3 31 4835.846 6.703 79.6 32 -1454.493 6.999 LF5 1.619068 1.619457 1.618683 77.1 33 98.051 19.748 66.1 34 225.414 15.987 SILUV 1.474477 1.474623 1.474332 66.2 35 670.286 29.110 65.5 36 -211.535 6.999 SILUV 1.474477 1.474623 1.474332 62.5 37 148.623 31.821 62.4 38 149.865 12.745 SILUV 1.474477 1.474623 1.474332 69.7 39 295.363 65.380 70.0 40 -129.093 7.000 SILUV 1.474477 1.474623 1.474332 75.7 41 -147113.888 18.797 86.3 42 -1049.072 24.328 LF5 1.619068 1.619457 1.618683 94.1 43 -226.903 10.634 96.5 44 390.169 31.131 LLF1 1.579164 1.579477 1.578854 109.6 45 -723.111 1.000 110.0 46 211.180 46.056 SILUV 1.474477 1.474623 1.474332 109.8 47 -981.347 13.566 108.5 48 1010.698 6.999 SILUV 1.474477 1.474623 1.474332 97.5 49 200.653 55.489 90.2 50 0.000 0.000 84.0

[0111] SRF 1 3 12 15 35 K 0 0 0 0 0 C1 1.556817E-07 -7.751526E-08 1.152818E-07 1.106397E-07 -1.106397E-07 C2 -3.056346E-11 2.390564E-11 1.738212E-12 2.636125E-12 -2.636125E-12 C3 1.297670E-15 -2.332133E-15 3.881138E-16 2.560794E-17 -2.560794E-17 C4 8.491171E-20 1.084662E-19 -6.298423E-20 5.839551E-21 -5.839551E-21 C5 -1.895677E-23 -2.295160E-24 1.244399E-23 -2.068605E-24 2.068605E-24 C6 1.221464E-27 1.168621E-29 -1.244426E-27 2.626725E-28 -2.626725E-28 SRF 38 47 49 K 0 0 0 C1 -1.152818E-07 7.751526E-08 -1.556817E-07 C2 -1.738212E-12 -2.390564E-11 3.056346E-11 C3 -3.881138E-16 2.332133E-15 -1.297670E-15 C4 6.298423E-20 -1.084662E-19 -8.491171E-20 C5 -1.244399E-23 2.295160E-24 1.895677E-23 C6 1.244426E-27 -1.168621E-29 -1.221464E-27

[0112] surface radius thickness subject matter Refractive index 1 Refractive index 2 Refractive index 3 Half diameter 0 0.000 56.960 1 -152.507 19.482 SILUV 1.474477 1.474623 1.474332 90.6 2 -299.336 1.000 98.5 3 330.750 46.756 SILUV 1.474477 1.474623 1.474332 106.2 4 -266.521 36.322 106.6 5 205.579 26.444 LF5 1.619068 1.619457 1.618683 95.1 6 1122.671 67.004 93.1 7 -486.776 6.997 SILUV 1.474477 1.474623 1.474332 69.0 8 227.711 11.969 64.5 9 1387.683 18.089 SILUV 1.474477 1.474623 1.474332 63.7 10 -170.878 15.194 62.8 11 -105.571 6.999 SILUV 1.474477 1.474623 1.474332 60.9 12 188.530 33.004 62.0 13 -682.872 20.113 SILUV 1.474477 1.474623 1.474332 66.9 14 -178.054 28.329 67.8 15 -97.114 6.998 LF5 1.619068 1.619457 1.618683 67.7 16 4591.627 6.761 79.5 17 -1604.813 31.793 SILUV 1.474477 1.474623 1.474332 82.0 18 -148.650 0.993 84.9 19 -963.024 27.129 SILUV 1.474477 1.474623 1.474332 91.5 20 -188.861 0.998 93.0 21 2122.290 27.687 SILUV 1.474477 1.474623 1.474332 94.9 22 -252.641 2.991 95.1 23 0.000 2.991 91.8 24 252.641 27.687 SILUV 1.474477 1.474623 1.474332 95.1 25 -2122.290 0.998 94.9 26 188.861 27.129 SILUV 1.474477 1.474623 1.474332 93.0 27 963.024 0.993 91.5 28 148.650 31.793 SILUV 1.474477 1.474623 1.474332 84.9 29 1604.813 6.761 82.0 30 -4591.627 6.998 LF5 1.619068 1.619457 1.618683 79.5 31 97.114 28.329 67.7 32 178.054 20.113 SILUV 1.474477 1.474623 1.474332 67.8 33 682.872 33.004 66.9 34 -188.530 6.999 SILUV 1.474477 1.474623 1.474332 62.0 35 105.571 15.194 60.9 36 170.878 18.089 SILUV 1.474477 1.474623 1.474332 62.8 37 -1387.683 11.969 63.7 38 -227.711 6.997 SILUV 1.474477 1.474623 1.474332 64.5 39 486.776 67.004 69.0 40 -1122.671 26.444 LF5 1.619068 1.619457 1.618683 93.1 41 -205.579 36.322 95.1 42 266.521 46.756 SILUV 1.474477 1.474623 1.474332 106.6 43 -330.750 1.000 106.2 44 299.336 19.482 SILUV 1.474477 1.474623 1.474332 98.5 45 152.507 56.960 90.6 46 0.000 0.000 84.0

[0113] SRF 1 2 10 13 33 K 0 0 0 0 0 C1 3.879678E-07 2.680864E-07 1.554667E-07 1.332664E-07 -1.332664E-07 C2 -3.856109E-11 -3.432170E-11 6.188552E-14 1.528943E-12 -1.528943E-12 C3 -9.892283E-16 5.170746E-16 5.909591E-16 -2.362353E-16 2.362353E-16 C4 5.011228E-19 1.752725E-19 -3.913635E-19 4.583681E-20 -4.583681E-20 C5 -5.478951E-23 -1.610997E-23 8.348405E-23 -8.184644E-24 8.184644E-24 C6 2.692253E-27 5.340503E-28 -1.142445E-26 6.330550E-28 -6.330550E-28 SRF 36 44 45 K 0 0 0 C1 -1.554667E-07 -2.680864E-07 -3.879678E-07 C2 -6.188552E-14 3.432170E-11 3.856109E-11 C3 -5.909591E-16 -5.170746E-16 9.892283E-16 C4 3.913635E-19 -1.752725E-19 -5.011228E-19 C5 -8.348405E-23 1.610997E-23 5.478951E-23 C6 1.142445E-26 -5.340503E-28 -2.692253E-27

[0114] surface radius thickness subject matter Refractive index 1 Refractive index 2 Refractive index 3 Half diameter 0 0.000 57.800 1 -139.359 23.493 SILUV 1.474477 1.474623 1.474332 90.6 2 -317.928 0.999 100.4 3 324.384 47.144 SILUV 1.474477 1.474623 1.474332 108.2 4 -284.373 29.328 108.6 5 152.215 47.512 SILUV 1.474477 1.474623 1.474332 97.6 6 -898.785 38.018 95.3 7 -224.903 6.999 SILUV 1.474477 1.474623 1.474332 77.2 8 211.078 19.405 70.2 9 363.178 20.330 SILUV 1.474477 1.474623 1.474332 68.1 10 -234.067 24.784 67.0 11 -135.545 6.997 SILUV 1.474477 1.474623 1.474332 61.6 12 170.803 38.010 60.7 13 -1050.726 13.849 SILUV 1.474477 1.474623 1.474332 64.7 14 -305.455 22.876 65.2 15 -95.190 6.998 LF5 1.619068 1.619457 1.618683 65.3 16 -10858.385 6.731 76.4 17 -1032.176 31.098 SILUV 1.474477 1.474623 1.474332 78.8 18 -136.299 1.014 81.6 19 -1050.186 26.605 SILUV 1.474477 1.474623 1.474332 88.1 20 -184.274 1.048 89.5 21 1483.193 25.695 SILUV 1.474477 1.474623 1.474332 90.8 22 -264.183 3.281 90.9 23 0.000 3.281 87.8 24 264.183 25.695 SILUV 1.474477 1.474623 1.474332 90.9 25 -1483.193 1.048 90.8 26 184.274 26.605 SILUV 1.474477 1.474623 1.474332 89.5 27 1050.186 1.014 88.1 28 136.299 31.098 SILUV 1.474477 1.474623 1.474332 81.6 29 1032.176 6.731 78.8 30 10858.385 6.998 LF5 1.619068 1.619457 1.618683 76.4 31 95.190 22.876 65.3 32 305.455 13.849 SILUV 1.474477 1.474623 1.474332 65.2 33 1050.726 38.010 64.7 34 -170.803 6.997 SILUV 1.474477 1.474623 1.474332 60.7 35 135.545 24.784 61.6 36 234.067 20.330 SILUV 1.474477 1.474623 1.474332 67.0 37 -363.178 19.405 68.1 38 -211.078 6.999 SILUV 1.474477 1.474623 1.474332 70.2 39 224.903 38.018 77.2 40 898.785 47.512 SILUV 1.474477 1.474623 1.474332 95.3 41 -152.215 29.328 97.6 42 284.373 47.144 SILUV 1.474477 1.474623 1.474332 108.6 43 -324.384 0.999 108.2 44 317.928 23.493 SILUV 1.474477 1.474623 1.474332 100.4 45 139.359 57.800 90.6 46 0.000 0.000 84.0

[0115] SRF 1 2 10 13 33 K 0 0 0 0 0 C1 4.502414E-07 2.926858E-07 1.351396E-07 9.457687E-08 -9.457687E-08 C2 -4.134066E-11 -3.546123E-11 4.038608E-12 2.360083E-12 -2.360083E-12 C3 -1.009207E-15 4.957139E-16 -2.487710E-16 -1.110830E-16 1.110830E-16 C4 5.203906E-19 1.734823E-19 1.551639E-20 9.206137E-21 -9.206137E-21 C5 -5.751903E-23 -1.529489E-23 -1.405004E-23 -1.990656E-24 1.990656E-24 C6 2.870459E-27 4.714738E-28 3.258394E-29 2.678650E-28 -2.678650E-28 SRF 36 44 45 K 0 0 0 C1 -1.351396E-07 -2.926858E-07 -4.502414E-07 C2 -4.038608E-12 3.546123E-11 4.134066E-11 C3 2.487710E-16 -4.957139E-16 1.009207E-15 C4 -1.551639E-20 -1.734823E-19 -5.203906E-19 C5 1.405004E-23 1.529489E-23 5.751903E-23 C6 -3.258394E-29 -4.714738E-28 -2.870459E-27

[0116] surface radius thickness subject matter Refractive index 1 Refractive index 2 Refractive index 3 Half diameter 0 0.000 66.365 1 -199.533 15.802 SILUV 1.474477 1.474623 1.474332 90.4 2 -126.741 1.533 93.5 3 848.271 36.096 SILUV 1.474477 1.474623 1.474332 103.3 4 -367.658 19.010 103.9 5 407.500 21.070 SILUV 1.474477 1.474623 1.474332 91.3 6 4053.676 85.043 89.6 7 -187.800 18.098 SILUV 1.474477 1.474623 1.474332 62.9 8 123.553 64.319 60.6 9 356.148 11.492 SILUV 1.474477 1.474623 1.474332 73.3 10 463.241 39.181 73.5 11 -108.121 7.128 LF5 1.619068 1.619457 1.618683 74.0 12 1824.505 1.404 89.3 13 1376.122 44.363 SILUV 1.474477 1.474623 1.474332 92.8 14 -157.381 4.552 95.6 15 443.299 56.019 SILUV 1.474477 1.474623 1.474332 107.9 16 -163.323 0.498 108.7 17 0.000 0.498 104.2 18 163.323 56.019 SILUV 1.474477 1.474623 1.474332 108.7 19 -443.299 4.552 107.9 20 157.381 44.363 SILUV 1.474477 1.474623 1.474332 95.6 21 -1376.122 1.404 92.8 22 -1824.505 7.128 LF5 1.619068 1.619457 1.618683 89.3 23 108.121 39.181 74.0 24 -463.241 11.492 SILUV 1.474477 1.474623 1.474332 73.5 25 -356.148 64.319 73.3 26 -123.553 18.098 SILUV 1.474477 1.474623 1.474332 60.6 27 187.800 85.043 62.9 28 -4053.676 21.070 SILUV 1.474477 1.474623 1.474332 89.6 29 -407.500 19.010 91.3 30 367.658 36.096 SILUV 1.474477 1.474623 1.474332 103.9 31 -848.271 1.533 103.3 32 126.741 15.802 SILUV 1.474477 1.474623 1.474332 93.5 33 199.533 66.365 90.4 34 0.000 0.000 84.0

[0117] SRF 1 4 6 7 9 K 0 0 0 0 0 C1 -3.865767E-08 1.477249E-07 -2.970278E-07 -4.029114E-07 1.507906E-07 C2 -1.676923E-11 -3.793500E-11 4.747555E-11 4.815137E-11 -1.584248E-11 C3 -1.780786E-16 1.545914E-15 -4.137536E-15 2.983414E-15 8.832833E-16 C4 1.791800E-19 9.815092E-20 3.652948E-19 -1.759165E-18 5.232436E-20 C5 -2.730495E-23 -1.120480E-23 -2.909069E-23 2.561074E-22 -9.661947E-24 C6 1.396583E-27 2.974752E-28 1.237502E-27 -1.281065E-26 7.970738E-28 SRF 13 16 18 21 25 K 0 0 0 0 0 C1 2.119515E-08 3.831308E-08 -3.831308E-08 -2.119515E-08 -1.507906E-07 C2 -3.529856E-13 1.194220E-12 -1.194220E-12 3.529856E-13 1.584248E-11 C3 3.632528E-16 3.596652E-17 -3.596652E-17 -3.632528E-16 -8.832833E-16 C4 -4.860291E-20 1.645053E-21 -1.645053E-21 4.860291E-20 -5.232436E-20 C5 2.514316E-24 -7.774899E-26 7.774899E-26 -2.514316E-24 9.661947E-24 C6 -4.975080E-29 2.819935E-30 -2.819935E-30 4.975080E-29 -7.970738E-28 SRF 27 28 30 33 K 0 0 0 0 C1 4.029114E-07 2.970278E-07 -1.477249E-07 3.865767E-08 C2 -4.815137E-11 -4.747555E-11 3.793500E-11 1.676923E-11 C3 -2.983414E-15 4.137536E-15 -1.545914E-15 1.780786E-16 C4 1.759165E-18 -3.652948E-19 -9.815092E-20 -1.791800E-19 C5 -2.561074E-22 2.909069E-23 1.120480E-23 2.730495E-23 C6 1.281065E-26 -1.237502E-27 -2.974752E-28 -1.396583E-27

[0118] surface radius thickness subject matter Refractive index 1 Refractive index 2 Refractive index 3 Half diameter 0 0.000 75.810 1 -245.191 20.980 SILUV 1.474477 1.474623 1.474332 94.1 2 -139.596 27.771 96.1 3 171.276 42.632 SILUV 1.474477 1.474623 1.474332 97.1 4 8532.088 87.623 95.7 5 -196.785 6.999 SILUV 1.474477 1.474623 1.474332 64.6 6 144.025 71.168 62.4 7 276.899 11.318 SILUV 1.474477 1.474623 1.474332 72.3 8 358.279 41.122 72.2 9 -102.925 6.998 LF5 1.619068 1.619457 1.618683 72.4 10 1685.182 4.768 87.2 11 4395.516 47.601 SILUV 1.474477 1.474623 1.474332 92.3 12 -168.929 0.998 97.1 13 423.713 53.723 SILUV 1.474477 1.474623 1.474332 108.2 14 -161.935 0.498 108.7 15 0.000 0.498 104.3 16 161.935 53.723 SILUV 1.474477 1.474623 1.474332 108.7 17 -423.713 0.998 108.2 18 168.929 47.601 SILUV 1.474477 1.474623 1.474332 97.1 19 -4395.516 4.768 92.3 20 -1685.182 6.998 LF5 1.619068 1.619457 1.618683 87.2 21 102.925 41.122 72.4 22 -358.279 11.318 SILUV 1.474477 1.474623 1.474332 72.2 23 -276.899 71.168 72.3 24 -144.025 6.999 SILUV 1.474477 1.474623 1.474332 62.4 25 196.785 87.623 64.6 26 -8532.088 42.632 SILUV 1.474477 1.474623 1.474332 95.7 27 -171.276 27.771 97.1 28 139.596 20.980 SILUV 1.474477 1.474623 1.474332 96.1 29 245.191 75.810 94.1 30 0.000 0.000 84.0

[0119] SRF 1 2 4 5 7 K 0 0 0 0 0 C1 2.678285E-07 3.168599E-07 -1.933666E-07 -3.602011E-07 1.249264E-07 C2 -4.180387E-11 -3.046929E-11 3.098033E-11 4.075956E-11 -1.419538E-11 C3 -3.200353E-15 -4.385053E-15 -4.010763E-15 -1.397169E-15 8.232973E-16 C4 7.607847E-19 9.452445E-19 3.681612E-19 1.006822E-19 3.296397E-20 C5 -3.738705E-23 -6.704496E-23 -1.951021E-23 -4.108267E-23 -1.351250E-23 C6 6.471811E-28 1.926133E-27 4.511682E-28 3.968684E-27 1.789603E-27 SRF 11 14 16 19 23 K 0 0 0 0 0 C1 4.486274E-08 4.340755E-08 -4.340755E-08 -4.486274E-08 -1.249264E-07 C2 -1.534573E-12 1.330151E-12 -1.330151E-12 1.534573E-12 1.419538E-11 C3 4.347996E-16 3.621365E-17 -3.621365E-17 -4.347996E-16 -8.232973E-16 C4 -4.481159E-20 1.688777E-21 -1.688777E-21 4.481159E-20 -3.296397E-20 C5 1.473479E-24 -8.437869E-26 8.437869E-26 -1.473479E-24 1.351250E-23 C6 -3.605964E-30 2.740874E-30 -2.740874E-30 3.605964E-30 -1.789603E-27 SRF 25 26 28 29 K 0 0 0 0 C1 3.602011E-07 1.933666E-07 -3.168599E-07 -2.678285E-07 C2 -4.075956E-11 -3.098033E-11 3.046929E-11 4.180387E-11 C3 1.397169E-15 4.010763E-15 4.385053E-15 3.200353E-15 C4 -1.006822E-19 -3.681612E-19 -9.452445E-19 -7.607847E-19 C5 4.108267E-23 1.951021E-23 6.704496E-23 3.738705E-23 C6 -3.968684E-27 -4.511682E-28 -1.926133E-27 -6.471811E-28

[0120] design N336a N342a N343a N344a N345a NA 0.18 0.18 0.18 0.18 0.18 OBH 84 84 84 84 84 Maßstab -1 -1 -1 -1 -1 LLW 15.12 15.12 15.12 15.12 15.12

Claims

Claim 1 A dioptric projection lens (PO) for imaging a pattern placed on the object plane (OS) of a dioptric projection lens onto the image plane (IS) of the dioptric projection lens by electromagnetic radiation at an operating wavelength in the ultraviolet range longer than 280 nm, comprising a plurality of lens elements disposed between the object plane (OS) and the image plane (IS) along an optical axis (AX), wherein the pattern (PAT) placed on the object plane is implemented to be imaged within the image plane by the lens elements, wherein an aperture plane (BE) suitable for attaching an aperture aperture (AS) is located between the object plane and the image plane, and the main ray of the imaging intersects the optical axis (AX) at the aperture plane, wherein (i) the projection lens is designed as a large field lens having an object field radius (OBH) of at least 52 mm and has a structure having a 1:1 imaging scale that is mirror-symmetric with respect to the aperture plane (BE); and (ii) the lens elements are relatively more A projection lens comprising at least one flint lens element made of a first material having a low Abbe number and at least one crown lens element made of a second material having a higher Abbe number than the first material; (iii) at least two positive lens elements are positioned on each side of the aperture plane (BE) right next to the aperture plane (BE). Claim 2 A projection lens according to claim 1, characterized in that up to two flint lens elements are disposed on each side of the aperture plane. Claim 3 A projection lens according to claim 2, characterized in that only a single flint lens element is disposed on each side of the aperture plane (BE). Claim 4 A projection lens according to claim 3, characterized in that the single flint lens element (L6, L8) has a negative refractive power and is positioned in the aperture area (BB) in an area where the ray height ratio (│CRH / MRH│) is less than 0.

5. Claim 5 A projection lens according to claim 1 or claim 2, wherein the projection lens comprises at least one flint lens element (L21, L1) having a positive refractive power on each side of the aperture plane (BE). Claim 6 A projection lens according to claim 5, characterized in that the flint lens elements (L21, L1) having positive refractive power are positioned optically near the field plane in an area where the ray height ratio of the imaging satisfies the condition (│CRH / MRH│>0.7). Claim 7 A projection lens according to claim 1 or claim 2, characterized in that at least one of the following conditions is satisfied: (i) the object field radius (OBH) is at least 84 mm, (ii) the object-side and image-side numerical apertures are less than 0.3, and (iii) the projection lens has an object field radius (OBH), an object-side numerical aperture (NAO), and a geometric etendue (LLW=0BH·NAO) of at least 10 mm. Claim 8 A projection lens according to claim 1 or claim 2, characterized in that the projection lens has an installation length (TT), an object field radius (OBH), and an object-side numerical aperture (NAO) measured between the object plane (OS) and the image plane (IS), and the condition ((OBH·NAO) / TT > 0.01) is applied. Claim 9 A projection lens according to claim 1 or claim 2, characterized in that at least one of the lens elements on each side of the aperture plane (BE) is an aspherical having at least one rotationally symmetric aspherical lens element surface. Claim 10 A projection lens according to claim 9, characterized in that at least one of the aspherical surfaces is configured as a double aspherical surface, and the incident surface and the exit surface are designed as rotationally symmetric aspherical lens surfaces. Claim 11 A projection lens according to claim 10, characterized in that the lens element closest to the object plane (OS) and closest to the image plane (IS) is a double aspherical. Claim 12 A projection lens according to claim 1 or claim 2, wherein the projection lens is characterized by a refractive power sequence, NPNPPNPN, where "P" represents a group of lens elements having positive refractive power and "N" represents a group of lens elements having negative refractive power, and there is only a single pronounced waist on each side of the aperture plane in the region of the third group of negative lens elements. Claim 13 A projection lens according to claim 1 or claim 2, wherein the projection lens has a prominent waist structure in which the negative refractive power of a first lens group adjacent to the object plane enables the formation of a bulge of positive lens elements (L2, L3, L4), and then a long waist having negative refractive power (L5, L7, L9) and positive lens elements (L6, L8), and the light ray is then collimated by a lens element having positive refractive power so as to be guided as a beam collimated through a central aperture. Claim 14 A projection lens according to claim 1 or claim 2, characterized in that the projection lens is designed for at least one of the UV radiation of the i-line of a mercury vapor lamp (LS) and UV radiation having a bandwidth of up to 5 nm. Claim 15 A projection exposure apparatus (WST) for exposing a radiation-sensitive substrate disposed in an area of ​​the image plane (IS) of a projection lens (PO) to at least one image of a pattern disposed in an area of ​​the object plane (OS) of the projection lens, comprising: a light source (LS) for emitting electromagnetic radiation at an operating wavelength in the ultraviolet range longer than 280 nm; an illumination system (ILL) for receiving light from the light source and forming illumination radiation sent to the pattern; and a projection lens (PO) for imaging the structure of the pattern onto a radiation-sensitive substrate (W); wherein the projection lens (PO) is implemented according to claim 1 or claim 2. Claim 16 A projection exposure apparatus according to claim 15, characterized in that the projection exposure apparatus (WST) is designed as a wafer stepper for a step-and-repeat process. Claim 17 A projection exposure apparatus according to claim 15, characterized in that the light source is a mercury vapor lamp (LS) for emitting electromagnetic radiation of the i-line of the mercury vapor lamp (LS) and the radiation has a bandwidth of up to 5 nm. Claim 18 A projection exposure method for exposing a radiation-sensitive substrate to at least one image of a pattern of a mask, comprising the following steps: providing said pattern between a projection lens of a projection exposure device and an illumination system such that the pattern is placed in an area of ​​the object plane of the projection lens; holding said substrate such that the radiation-sensitive surface of said substrate is placed in an area of ​​the image plane of said projection lens which is optically conjugated to said object plane; illuminating an illuminated area of ​​said mask with illumination radiation provided by said illumination system at an operating wavelength in the ultraviolet range longer than 280 nm; and projecting a portion of said pattern in said illuminated area onto an image field on said substrate using said projection lens, wherein all rays of said projection radiation contributing to image generation in said image field form a projection beam path, and wherein the projection lens described in claim 1 or claim 2 is used. Claim 19 A projection exposure method according to claim 18, characterized in that the substrate is exposed in a step-and-repeat process without scanning, that the i-line illumination radiation of a mercury vapor lamp is used, and that the illumination radiation having a bandwidth of less than 5 nm is used.

Images