CN114253089B - Variable-magnification extreme ultraviolet lithography projection exposure optical system - Google Patents
Variable-magnification extreme ultraviolet lithography projection exposure optical system Download PDFInfo
- Publication number
- CN114253089B CN114253089B CN202210015194.7A CN202210015194A CN114253089B CN 114253089 B CN114253089 B CN 114253089B CN 202210015194 A CN202210015194 A CN 202210015194A CN 114253089 B CN114253089 B CN 114253089B
- Authority
- CN
- China
- Prior art keywords
- variable
- magnification
- light source
- compound eye
- imaging module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/20—Exposure; Apparatus therefor
- G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
- G03F7/2004—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70058—Mask illumination systems
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70058—Mask illumination systems
- G03F7/70091—Illumination settings, i.e. intensity distribution in the pupil plane or angular distribution in the field plane; On-axis or off-axis settings, e.g. annular, dipole or quadrupole settings; Partial coherence control, i.e. sigma or numerical aperture [NA]
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/70058—Mask illumination systems
- G03F7/7015—Details of optical elements
- G03F7/70183—Zoom systems for adjusting beam diameter
Abstract
The invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, which adopts a variable-magnification relay lens group to amplify a secondary light source with a circular outer envelope in the X direction and the Y direction at different magnifications to obtain an elliptical light source required by a variable-magnification imaging module of a next generation lithography machine; in other words, in order to obtain an elliptical light source required by a next generation lithography machine, the variable-magnification relay lens group is adopted for light source conversion, so that the conventional non-variable-magnification lighting assembly can be continuously used, namely, the conventional secondary light source with a circular outer envelope is used, and the research and development cost is greatly saved.
Description
Technical Field
The invention belongs to the technical field of optical design, and particularly relates to a variable-magnification extreme ultraviolet lithography projection exposure optical system.
Background
Photolithography, a process by which the structural pattern of an integrated circuit is transferred from a mask to the surface of a silicon wafer or other semiconductor substrate, is a critical technique in the manufacture of very large scale integrated circuits.
Theoretical resolution formula R = k of lithography system 1 λ/NA (where λ is the exposure wavelength, k1 is the process factor of lithography, and NA is the image-side numerical aperture of the projection objective), there are three ways to improve the resolution of the lithography system: the exposure wavelength lambda is shortened, the process factor k1 is reduced, and the image space numerical aperture NA of the projection objective is improved. At present, an extreme ultraviolet lithography machine adopts an exposure light source with the wavelength of 13.5nm for exposure, and because the exposure wavelength is greatly shortened, the extreme ultraviolet lithography can realize high resolution without a large numerical aperture. In the extreme ultraviolet band, almost all optical materials have extremely strong absorptivity, so that the extreme ultraviolet lithography optical system must adopt a reflective system and a reflective mask coated with a multilayer film, and the optical system should adopt as few reflectors as possible so as to ensure that the system has high transmittance. The most advanced existing industrialized lithography equipment is TWINSCAN NXE:3600D produced by ASML company, the lithography machine adopts a six-lens reflex objective system with the image space numerical aperture of 0.33 and the magnification ratio of 4 times, the resolution of a 13nm technical node can be realized by single exposure, and the production requirement of a 7nm-3nm technical node can be met by combining the technologies of resolution enhancement technology, multi-pattern multi-exposure and the like.
In order to realize the resolution of single exposure 8nm and higher technical node, under the condition that the k1 process factor is kept unchanged, the image-side numerical aperture of an objective lens system is required to be larger than 0.50, and under the condition of meeting the limitation of the incident angle of chief rays on the existing mask surface (less than 6 degrees), the incident beam and the emergent beam on the mask surface are overlapped by directly increasing the numerical aperture; if the incident angle of the chief ray is directly increased to avoid the beam overlapping, the shadow effect of the mask surface is aggravated, and the resolution of the actually exposed pattern is greatly reduced. Therefore, in order to increase the numerical aperture while avoiding the mask shadow effect, and taking into consideration various factors such as manufacturing process and cost, the next generation lithography machines will adopt variable magnification projection exposure optical systems, i.e., exposure optical systems having different miniatures in the scanning direction and the vertical scanning direction.
Disclosure of Invention
In order to solve the problems, the invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, which adopts a variable-magnification relay lens group to amplify a secondary light source with a circular outer envelope in two different directions at different magnifications to obtain an elliptical light source required by a next generation lithography machine, can continuously use the existing commercialized extreme ultraviolet lithography illumination component, and saves the cost.
A variable-magnification extreme ultraviolet lithography projection exposure optical system comprises a variable-magnification illumination module and a variable-magnification imaging module, wherein the variable-magnification illumination module comprises an illumination assembly and a variable-magnification relay lens group;
the lighting assembly is used for providing a secondary light source with a circular outer envelope;
the variable-magnification relay lens group is used for imaging a secondary light source with a circular outer envelope on the entrance pupil surface on the exit pupil surface of the variable-magnification relay lens group in the X direction and the Y direction by using magnifications Mx _ ill and My _ ill respectively, and enabling the secondary light source with the elliptic outer envelope obtained on the exit pupil surface to be incident to a mask; wherein Mx _ ill and My _ ill satisfy: mx _ ill ≠ My _ ill and Mx _ ill/My _ ill = Mx/My, wherein Mx is the magnification of the variable-magnification imaging module in the X direction, and My is the magnification of the variable-magnification imaging module in the Y direction;
the variable-magnification imaging module is used for imaging the illuminated area of the mask on the silicon wafer surface.
Further, according to the light path transmission sequence, the illumination assembly sequentially comprises a light source, an ellipsoid collecting mirror, a field compound eye and a diaphragm compound eye, wherein the field compound eye is formed by arranging a plurality of field compound eye elements in a line-by-line or line-by-line mode, and an outer envelope line of an arrangement area is circular; the diaphragm compound eyes are arranged in a row-by-row or column-by-column mode through a plurality of diaphragm compound eye elements, and the outer envelope line of the arrangement area is circular.
Furthermore, the diaphragm compound eye is located at the entrance pupil of the variable-magnification relay lens group and is conjugated with the exit pupil surface of the variable-magnification relay lens group, the secondary light source with the circular outer envelope forms a secondary light source image with the elliptical outer envelope at the exit pupil surface of the variable-magnification relay lens group, and the size and the position of the elliptical secondary light source image are matched with the size and the position of the entrance pupil surface of the variable-magnification imaging module.
Furthermore, the secondary light source is an off-axis secondary light source, the positions and the inclination angles of each field compound eye element and each diaphragm compound eye element are different, and the off-axis degrees of the off-axis secondary light source are different.
Further, the field-of-view compound eye is located at a conjugate plane of the mask, and an image formed by the single field-of-view compound eye unit on the mask is matched with an object-side field of view of the variable-magnification imaging module.
Further, the out-of-pupil envelope of the variable-magnification imaging module is elliptical, the out-of-pupil envelope is circular, and the ratio of the long axis to the short axis of the elliptical in the X direction and the Y direction is Mx/My, and 1-Mx/My <5.
Further, when the diameter of the maximum photoetching element circumcircle of the variable-magnification lighting module is smaller than 1100mm, the aspect ratio of an actually used area of the optical surface of the variable-magnification relay lens group is larger than 2.2 and smaller than 4.
Further, the variable magnification relay lens group is composed of two anamorphic aspheric relay lenses, and the two anamorphic aspheric relay lenses have different magnifications in the X direction and the Y direction.
Furthermore, the variable magnification imaging module is composed of more than three free-form surface reflectors or more than two free-form surface reflectors and less than two aspheric mirrors.
Further, when the diameter of the maximum lithography element circumcircle of the variable-magnification imaging module is smaller than 1000mm, the aspect ratio of the actual using area of the optical surface of each lens of the variable-magnification imaging module is larger than 1 and smaller than 2.
Has the advantages that:
1. the invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, which adopts a variable-magnification relay lens group to amplify a secondary light source with a circular outer envelope in the X direction and the Y direction at different magnifications to obtain an elliptical light source required by a variable-magnification imaging module of a next generation lithography machine; in other words, in order to obtain an elliptical light source required by the next generation of lithography machine, the variable-magnification relay lens group is adopted for light source conversion, so that the existing non-variable-magnification lighting assembly can be continuously used, namely the existing secondary light source with a circular outer envelope is used, and the research and development cost is greatly saved.
2. The invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, wherein a plurality of field compound eyes are distributed into a circular area by a plurality of field compound eye elements in a line-by-line or line-by-line mode, and a plurality of diaphragm compound eyes are distributed into a circular area by a plurality of diaphragm compound eye elements in a line-by-line or line-by-line mode, namely the invention adopts the circular field compound eye and circular diaphragm compound eye structure of the existing commercialized extreme ultraviolet lithography lighting module; in order to obtain an elliptical light source required by a next generation lithography machine, if the diaphragm compound eye is changed into an elliptical structure instead of the mode of using the variable-magnification relay lens group provided by the invention, the field compound eye needs to be matched with the elliptical diaphragm compound eye again, namely, the position and the inclination angle of each compound eye element of the field compound eye need to be adjusted again in addition to the position and the inclination angle of each compound eye element of the elliptical diaphragm compound eye, and the operation process is very complicated.
3. The invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, which enables diaphragm compound eyes to continuously use the existing non-variable-magnification circular structure and the control technology thereof, and enables the illuminance of a field compound eye element in a mask surface to be illuminated to be superposed after the matching constraint with a variable-magnification imaging module is considered, thereby enabling the illumination uniformity of an illumination module adopting the field compound eyes and the diaphragm compound eyes in a mask surface illuminated area to be greater than 99%.
4. The invention provides a variable-magnification extreme ultraviolet lithography projection exposure optical system, which adopts a free-form surface reflector and/or an aspheric mirror to construct a variable-magnification imaging module, fully considers the problem of mutual matching between an illumination module and an imaging module, ensures that the light paths between the illumination module and the imaging module are not blocked, and effectively ensures that the designed variable-magnification extreme ultraviolet lithography exposure optical system can meet the design requirement of 5nm-1nm technical nodes.
Drawings
FIG. 1 is a diagram of a variable magnification lithographic exposure optical system according to the present invention;
fig. 2 is a schematic diagram of a relay lens group of a variable magnification lighting module according to the present invention;
FIG. 3 is a structural diagram of a variable magnification lighting module provided by the present invention;
fig. 4 is an entrance pupil diagram of a deformable relay lens set of the variable magnification lighting module provided by the present invention;
FIG. 5 is an exit pupil diagram of an anamorphic relay lens set of the variable magnification lighting module according to the present invention;
FIG. 6 is a block diagram of a variable magnification imaging module according to the present invention;
FIG. 7 is an entrance pupil diagram of a variable magnification imaging module according to the present invention;
fig. 8 is an exit pupil diagram of a variable magnification imaging module provided by the present invention.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.
As shown in fig. 1, the variable magnification euv lithography projection exposure optical system mainly includes two parts, namely, a variable magnification illumination module and a variable magnification imaging module. The emergent light of the light source forms high-uniformity illumination light spots in an illuminated area of the mask through the variable-magnification illumination module, and the pattern of the illuminated area of the mask is imaged on a silicon wafer through the variable-magnification imaging module of the variable-magnification projection lithography system. Specifically, the variable-magnification illumination module is used for illuminating the mask surface and forming a specific secondary light source image, and comprises an illumination assembly and a variable-magnification relay lens group, wherein the illumination assembly sequentially comprises a light source, an ellipsoid collecting mirror, a field compound eye and a diaphragm compound eye along an optical path; the variable magnification imaging module is composed of more than three free-form surface reflectors or more than two free-form surface reflectors and less than two aspheric mirrors, as shown in figure 1, the invention adopts six free-form surface reflectors M1-M6 to form an imaging module part of a variable magnification projection lithography system, and is used for imaging mask patterns on the surface of a silicon wafer in a micro-shrinkage mode.
Further, the lighting assembly is used for providing a secondary light source with a circular outer envelope; specifically, the ellipsoidal collector mirror is used for guiding light emitted by the light source; the field compound eyes are arranged in a row-by-row or column-by-column mode by a plurality of rectangular or arc field compound eyes, the envelope line of the arrangement area is circular, meanwhile, the field compound eyes are positioned at the conjugate plane of the mask, the image formed by the single field compound eye element on the mask is matched with the object field of the variable magnification imaging module, namely the size of the image formed by the single field compound eye element on the mask in the scanning direction is 4-16 mm, the size vertical to the scanning direction is 104mm, and the field compound eyes can be arc-shaped or rectangular; the diaphragm compound eye consists of a plurality of rectangular or oval field diaphragm compound eye elements, the plurality of diaphragm compound eye elements are arranged in a row-by-row or row-by-row mode, an outer envelope line of an arrangement area is circular, meanwhile, the diaphragm compound eye is positioned at an entrance pupil of the variable magnification relay lens group and is conjugated with an exit pupil surface of the variable magnification lighting module, the circular outer envelope of the diaphragm compound eye is arranged on the exit pupil surface of the whole variable magnification lighting module, namely the exit pupil surface of the variable magnification relay lens group is imaged to be oval, a secondary light source image with the oval outer envelope is obtained on the exit pupil surface, and the size position of the oval is matched with the size position of the entrance pupil surface of the variable magnification imaging module.
The variable magnification relay lens group images the diaphragm compound eye on the exit pupil of the whole variable magnification lighting module so as to image compound eye elements of each field of view on the lighted area of the mask, and the variable magnification relay lens group has different magnifications in the X direction and the Y direction; specifically, an entrance pupil surface and an exit pupil surface of the variable-magnification relay lens group are a pair of conjugate surfaces, and the variable-magnification relay lens group is used for imaging a secondary light source with a circular outer envelope on the entrance pupil surface onto the exit pupil surface of the variable-magnification relay lens group in the X direction and the Y direction respectively by using magnifications Mx _ ill and My _ ill, and enabling the secondary light source with an elliptical outer envelope on the exit pupil surface to be incident on the mask; wherein Mx _ ill and My _ ill satisfy: mx _ ill ≠ My _ ill and Mx _ ill/My _ ill = Mx/My, wherein Mx is the magnification of the variable-magnification imaging module in the X direction, and My is the magnification of the variable-magnification imaging module in the Y direction; as shown in fig. 2, the variable power relay lens group of the present invention is composed of two anamorphic aspheric relay lenses, and the two anamorphic aspheric relay lenses have different magnifications in the X direction and the Y direction, and meanwhile, the entrance pupil of the variable power relay lens group is circular and matched with the circular diaphragm compound eye, and the exit pupil is elliptical and matched with the variable power imaging module.
It should be noted that the secondary light source is an off-axis secondary light source, and the positions and the inclination angles of each field compound eye element and each diaphragm compound eye element are different, and the off-axis degrees of the off-axis secondary light source are different; that is, the variable-magnification illumination module can image the light source at the entrance pupil of the variable-magnification imaging module as a plurality of off-axis secondary light sources, and the formation of the secondary light sources is realized by adjusting the positions and the inclination angles of the compound eye elements of each field of view and the compound eye elements of each diaphragm.
In addition, the total length of the variable-magnification illumination module is 2000 mm-5000 mm, the illumination uniformity in the mask illumination area is more than 99%, wherein if the diameter of the maximum photoetching element circumcircle of the variable-magnification illumination module is less than 1100mm, the aspect ratio (X/Y) of the actually used area of the optical surface of the deformable relay lens group is more than 2.2 and less than 4; the variable magnification imaging module is of an off-axis structure, the off-axis quantity is 400-600 mm, the object distance is 200-1000 mm, the total length is 1800-2500 mm, the maximum caliber of a reflector is 800-1200 mm, the image space numerical aperture of the variable magnification imaging module is 0.45-0.8, if the diameter of the maximum photoetching element circumcircle of the variable magnification imaging module is less than 1000mm, the transverse-longitudinal ratio (X/Y) of the actual use area of the optical surface of each lens of the variable magnification imaging module, such as free-form surface reflectors (M1-M6), is more than 1 and less than 2; if the diameter of the maximum photoetching element circumcircle of the variable-magnification lighting module is smaller than 1000mm, the transverse-longitudinal ratio (X/Y) of an actually used area of the optical surface of the variable-magnification relay lens group is larger than 1 and smaller than 2; meanwhile, the external pupil envelope of the variable-magnification imaging module is elliptical, the external exit pupil envelope is circular, the ratio of the long axis to the short axis of the elliptical entrance pupil in the X direction and the Y direction is Mx/My, and 1-Mx/My <5.
It should be noted that, the outer envelope of the field-of-view compound eye of the conventional lithography machine is circular, the outer envelope of the diaphragm compound eye is also circular, the relative position and inclination angle between each compound eye element are adjusted, if the diaphragm compound eye is changed into an ellipse instead of using the variable magnification relay lens provided by the present invention, the field-of-view compound eye needs to be re-matched with the elliptical diaphragm compound eye, that is, each compound eye unit of the elliptical diaphragm compound eye needs to be adjusted, and each compound eye unit of the field-of-view compound eye needs to be re-adjusted, which is very complicated.
The variable-magnification euv lithography projection exposure optical system is further described below by taking the surface type parameters of each optical element of the variable-magnification euv lithography projection exposure optical system as an example.
Firstly, the definition principle of the positive and negative signs of the structural parameters of the optical system is given as follows:
the positive and negative signs of the curvature radius are defined as follows: the direction from the curvature center of the lens surface to the vertex of the lens surface is defined as negative when the direction is the same as the direction of the light path, and vice versa;
the positive and negative signs of the interval are defined as follows: if the direction from the intersection point of the current surface and the reference axis to the intersection point of the next surface and the reference axis is positive along with the direction of the light path, otherwise, the direction is negative;
wherein the XYZ coordinate system is defined as: the Z axis is parallel to the reference axis and is in the same direction with the direction of the light path, the Y axis is vertical to the Z axis, and the X axis is vertical to a plane formed by the Y axis and the Z axis.
The XY free-form surface used in the embodiment of the invention has the following surface formula:
wherein r is 2 ＝x 2 +y 2 (ii) a z is the rise of the XY free-form surface parallel to the z axis; c is the curvature of the top point of the XY free-form surface; k is a conic constant; c j Is x m y n The coefficient of the term.
The variable magnification relay lens group is realized by adopting a deformed aspheric surface relay lens, and the expression of the used deformed aspheric surface is as follows:
where Kx, ky denote conic constants along the x and y axes; AR, BR, CR and DR represent 4 th, 6 th, 8 th and 10 th order rotationally symmetric coefficients of the anamorphic aspheric surface; AP, BP, CP and DP represent 4 th, 6 th, 8 th and 10 th order non-rotational symmetry coefficients of the deformed aspheric surface; c. C x And c y Is the curvature in the X and Y directions;
the NA0.55 variable magnification lithography exposure optical system is shown in fig. 1, the design result of the variable magnification illumination system is shown in fig. 3, the specific position coordinates and the inclination angle of each element of the variable magnification illumination system are shown in table 1, and the surface type parameter data of each element are shown in table 2;
TABLE 1 position and Tilt of various optical elements in NA0.55 variable magnification lighting systems
TABLE 2 surface shape parameters of optical elements in NA0.55 variable magnification lighting system
The variable power illumination module can provide uniform illumination with uniformity of more than 99% at the illuminated area of the mask surface, and can provide multiple illumination forms at the exit pupil of the illumination module (at the entrance pupil of the imaging module), the entrance pupil and the exit pupil of the variable power relay lens group being shaped as shown in fig. 4 and 5, respectively. The variable-magnification illumination module meets the design requirement that an illumination system not only keeps a circular diaphragm compound eye, but also meets the design requirement matched with an entrance pupil of a variable-magnification imaging system.
Fig. 6 shows the design results of the variable magnification imaging module in the NA0.55 variable magnification lithography exposure optical system. The structural parameters of the variable-magnification imaging module are shown in table 3, and the surface shape parameters of each reflecting surface in the variable-magnification imaging module are shown in table 4.
TABLE 3 NA0.55 variable magnification imaging Module construction parameters
| Surface name | Surface type | Radius/mm | Distance/mm | Catadioptric form |
| Mask surface | 0.00 | 1298.57 | ||
| M1 | XY polynomial | -10982.99 | -974.40 | Reflection |
| M2 | XY polynomial | 1922.98 | 466.16 | Reflection |
| M3 | XY polynomial | 530.95 | -430.18 | Reflection |
| M4 | XY polynomial | 907.85 | 1680.73 | Reflection |
| M5 | XY polynomial | 1200.76 | -600.08 | Reflection |
| M6 | XY polynomial | 745.56 | 628.84 | Reflection |
| Silicon wafer surface | 0.00 |
TABLE 4 surface type coefficient of XY free-form surface of NA0.55 variable magnification imaging module
The NA0.55 variable-magnification imaging module is a rectangular view field, the requirement of a 5nm-1nm technical node can be well met, the entrance pupil and the exit pupil of the NA0.55 variable-magnification imaging module are respectively shown in figures 7 and 8, the entrance pupil of the variable-magnification imaging module is matched with the exit pupil of the variable-magnification lighting module, and the exit pupil of the variable-magnification imaging module is circular, so that the design requirement of designing the variable-magnification imaging module is met.
In summary, the variable-magnification euv lithography exposure optical system disclosed in the present invention includes a variable-magnification illumination module and a variable-magnification imaging module. The objective lens in the variable-magnification extreme ultraviolet lithography imaging module has high numerical aperture, large field of view and high resolution; the variable-magnification illumination module adopts the variable-magnification relay lens group, so that the diaphragm compound eye can continuously use the existing non-variable-magnification circular structure and the control technology thereof, and after the matching constraint with the variable-magnification imaging module is considered, the illumination uniformity of the illumination module in the illuminated area of the mask surface is more than 99%. The design example shows that the performance of the variable-magnification extreme ultraviolet lithography exposure system can meet the design requirement of a 5nm-1nm technical node.
The present invention is capable of other embodiments, and various changes and modifications can be made by one skilled in the art without departing from the spirit and scope of the invention.
Claims (8)
1. A variable-magnification extreme ultraviolet lithography projection exposure optical system is characterized by comprising a variable-magnification illumination module and a variable-magnification imaging module, wherein the variable-magnification illumination module comprises an illumination assembly and a variable-magnification relay lens group; according to the light path transmission sequence, the illumination component sequentially comprises a light source, an ellipsoid collecting mirror, a field compound eye and a diaphragm compound eye, wherein the field compound eye is formed by arranging a plurality of field compound eye elements in a line-by-line or line-by-line mode, and an envelope curve of an arrangement area is circular; the diaphragm compound eyes are arranged by a plurality of diaphragm compound eye elements in a line-by-line or line-by-line mode, and the outer envelope curve of the arrangement area is circular; the variable-magnification relay lens group consists of two deformed aspheric relay lenses, the two deformed aspheric relay lenses have different magnifications in the X direction and the Y direction, meanwhile, the entrance pupil of the variable-magnification relay lens group is circular and is matched with the diaphragm compound eye with the circular outer envelope line, the exit pupil is elliptic and is matched with the entrance pupil of the variable-magnification imaging module, and the exit pupil of the variable-magnification imaging module is circular;
the lighting assembly is used for providing a secondary light source with a circular outer envelope;
the variable-magnification relay lens group is used for imaging a secondary light source with a circular outer envelope on the entrance pupil surface on the exit pupil surface of the variable-magnification relay lens group in the X direction and the Y direction by using magnifications Mx _ ill and My _ ill respectively, and enabling the secondary light source with the elliptic outer envelope obtained on the exit pupil surface to be incident to a mask; wherein Mx _ ill and My _ ill satisfy: mx _ ill ≠ My _ ill and Mx _ ill/My _ ill = Mx/My, wherein Mx is the magnification of the variable-magnification imaging module in the X direction, and My is the magnification of the variable-magnification imaging module in the Y direction;
the variable-magnification imaging module is used for imaging the illuminated area of the mask on the silicon wafer surface.
2. The variable-magnification euv lithography projection exposure optical system according to claim 1, wherein the diaphragm compound eye is located at the entrance pupil of the variable-magnification relay lens group and is conjugate to the exit pupil surface of the variable-magnification relay lens group, the secondary light source whose outer envelope is circular is provided by the diaphragm compound eye, and forms a secondary light source image whose outer envelope is elliptical at the exit pupil surface of the variable-magnification relay lens group, and the size position of the elliptical secondary light source image matches the size position of the entrance pupil surface of the variable-magnification imaging module.
3. The variable magnification euv lithography projection exposure optical system according to claim 1, wherein said secondary light source is an off-axis secondary light source, and the positions and tilt angles of each field compound eye element and each diaphragm compound eye element are different, and the off-axis degrees of the off-axis secondary light source are different.
4. The variable magnification euv lithographic projection exposure optical system of claim 1, wherein the field-of-view compound eye is located at a conjugate plane of the mask, and the image formed by a single field-of-view compound eye element on the mask matches the object field of view of the variable magnification imaging module.
5. The variable-magnification euv lithography projection exposure optical system according to any one of claims 1 to 4, wherein the outer envelope of the entrance pupil of said variable-magnification imaging module is elliptical, the outer envelope of the exit pupil is circular, and the ratio of the major axis to the minor axis of the elliptical entrance pupil in the X direction and the Y direction is Mx/My, and 1< -Mx My <5.
6. The projection exposure optical system according to any one of claims 1 to 4, wherein when the maximum lithography element circumcircle diameter of the variable magnification illumination module is less than 1100mm, the aspect ratio of the actual use area of the optical surface of the variable magnification relay lens group is greater than 2.2 and less than 4.
7. The variable magnification euv lithography projection exposure optical system according to any one of claims 1 to 4, wherein the variable magnification imaging module is composed of more than three free-form surface mirrors or more than two free-form surface mirrors and less than two aspherical mirrors.
8. The variable magnification euv lithography projection exposure optical system according to claim 7, wherein when the maximum lithography element circumcircle diameter of the variable magnification imaging module is less than 1000mm, the aspect ratio of the actual use area of the optical surface of each lens of said variable magnification imaging module is greater than 1 and less than 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210015194.7A CN114253089B (en) | 2022-01-07 | 2022-01-07 | Variable-magnification extreme ultraviolet lithography projection exposure optical system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210015194.7A CN114253089B (en) | 2022-01-07 | 2022-01-07 | Variable-magnification extreme ultraviolet lithography projection exposure optical system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114253089A CN114253089A (en) | 2022-03-29 |
| CN114253089B true CN114253089B (en) | 2023-02-17 |
Family
ID=80796247
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210015194.7A Active CN114253089B (en) | 2022-01-07 | 2022-01-07 | Variable-magnification extreme ultraviolet lithography projection exposure optical system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114253089B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003178971A (en) * | 2002-10-24 | 2003-06-27 | Nikon Corp | Projection light exposure apparatus, and projection light exposure method |
| CN102629082A (en) * | 2012-04-28 | 2012-08-08 | 北京理工大学 | Design method of extreme ultra-violet lithography compound eye lighting system |
| WO2015051587A1 (en) * | 2013-10-09 | 2015-04-16 | 北京理工大学 | Adjustment and design method of lighting system of extreme ultraviolet lithography machine with multiple matching objective lenses |
| CN105652439A (en) * | 2016-03-25 | 2016-06-08 | 北京理工大学 | Combined power-amplification imaging objective lens system design method |
| CN112162468A (en) * | 2020-10-14 | 2021-01-01 | 北京理工大学 | Ultrahigh numerical aperture combined variable-magnification extreme ultraviolet lithography illumination system |
| CN112305863A (en) * | 2019-07-25 | 2021-02-02 | 上海微电子装备（集团）股份有限公司 | Illumination system, pupil ellipticity compensation method and photoetching machine |
-
2022
- 2022-01-07 CN CN202210015194.7A patent/CN114253089B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003178971A (en) * | 2002-10-24 | 2003-06-27 | Nikon Corp | Projection light exposure apparatus, and projection light exposure method |
| CN102629082A (en) * | 2012-04-28 | 2012-08-08 | 北京理工大学 | Design method of extreme ultra-violet lithography compound eye lighting system |
| WO2015051587A1 (en) * | 2013-10-09 | 2015-04-16 | 北京理工大学 | Adjustment and design method of lighting system of extreme ultraviolet lithography machine with multiple matching objective lenses |
| CN105652439A (en) * | 2016-03-25 | 2016-06-08 | 北京理工大学 | Combined power-amplification imaging objective lens system design method |
| CN112305863A (en) * | 2019-07-25 | 2021-02-02 | 上海微电子装备（集团）股份有限公司 | Illumination system, pupil ellipticity compensation method and photoetching machine |
| CN112162468A (en) * | 2020-10-14 | 2021-01-01 | 北京理工大学 | Ultrahigh numerical aperture combined variable-magnification extreme ultraviolet lithography illumination system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114253089A (en) | 2022-03-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7471456B2 (en) | Optical integrator, illumination optical device, exposure device, and exposure method | |
| US11467501B2 (en) | Image-forming optical system, exposure apparatus, and device producing method | |
| KR101309880B1 (en) | A six-mirror euv projection system with low incidence angles | |
| US8908151B2 (en) | Illumination optical system, exposure apparatus, device manufacturing method, compensation filter, and exposure optical system | |
| US10345708B2 (en) | Light source apparatus, optical apparatus, exposure apparatus, device manufacturing method, illuminating method, exposure method, and method for manufacturing optical apparatus | |
| US7403262B2 (en) | Projection optical system and exposure apparatus having the same | |
| US9280054B2 (en) | Illumination optical system, exposure apparatus, and method of manufacturing device | |
| JP2012519951A (en) | Illumination optical system and optical system for microlithography | |
| KR101158159B1 (en) | Illumination System With Zoom Objective | |
| WO2003050856A1 (en) | Diffraction optical device, refraction optical device, illuminating optical device, exposure system and exposure method | |
| US5891806A (en) | Proximity-type microlithography apparatus and method | |
| US20190025574A1 (en) | Method for Designing Imaging Objective Lens System of Anamorphic Magnification | |
| TW536735B (en) | Optical condenser system, optical illumination system provided with the same, and exposure system | |
| JP2004022708A (en) | Imaging optical system, illumination optical system, aligner and method for exposure | |
| KR101892766B1 (en) | Reflective imaging optical system, exposure apparatus, and method for producing device | |
| CN114253089B (en) | Variable-magnification extreme ultraviolet lithography projection exposure optical system | |
| TWI701458B (en) | Catadioptric optical system, illumination optical system, exposure device and article manufacturing method | |
| JP2005315918A (en) | Reflection type projection optical system and exposure device having the reflection type projection optical system | |
| US10976669B2 (en) | Reflective image-forming optical system, exposure apparatus, and device manufacturing method | |
| US8743342B2 (en) | Reflective imaging optical system, exposure apparatus, and method for producing device | |
| CN114217512B (en) | Extreme ultraviolet photoetching projection exposure optical system | |
| CN112859543A (en) | Design method of catadioptric deep ultraviolet lithography objective system | |
| JPH03101708A (en) | Reflected image forming optical device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |