JP2009026977A - Projection optical system, and exposure apparatus with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve high quality exposure by facilitating liquid control while facilitating the eccentricity measurement of a final lens in an immersion exposure apparatus in which an exposure region on a second object side of the final lens does not include the optical axis of a projection optical system. <P>SOLUTION: The exposure apparatus is provided with the projection optical system for projecting the image of the pattern of a first object onto a second object and exposes the second object through liquid between a lens (final lens) arranged most on the second object side of the projection optical system and the second object, wherein the projection optical system is configured in such a manner that the surface on the first object side of the lens has refractive power, the exposure region (projection region) on the surface on the second object side of the lens does not include the optical axis of the projection optical system, and the surface on the second object side of the lens includes the optical axis and is smaller than an effective region on the surface on the first object side of the lens. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection optical system and an exposure apparatus having the projection optical system, and more particularly to an immersion exposure apparatus that exposes an object to be exposed through the liquid between the projection optical system and the object to be exposed and the projection optical system, and the projection optics thereof. It is about the system. The present invention, for example, is a projection optical system of an exposure apparatus that projects and exposes a reticle pattern onto a wafer, and is suitable for application to a catadioptric projection optical system using a reflecting mirror.

  Projection exposure apparatuses that transfer a circuit pattern by projecting a circuit pattern drawn on a mask or a reticle onto a wafer or the like by a projection optical system have been used in the past, and in recent years, the resolution required for the projection optical system has been increasing. . In order to meet this requirement, it is effective to increase the numerical aperture NA of the projection optical system, and immersion exposure is conventionally known as one means for realizing such a method. Immersion exposure is a process in which the space between the final surface of the projection optical system and the object to be exposed is filled with a liquid, and the numerical aperture and resolution are increased by using a substance having a higher refractive index than air for the liquid. Is.

  However, as the NA increases, the diameter of the glass material increases, which is a major factor in increasing the cost of the apparatus. This is one of the important issues particularly in an immersion optical system having a numerical aperture exceeding 1. Therefore, various proposals have been made to avoid the problem of increasing the diameter of the glass material by including a reflecting mirror in the optical system. For example, Patent Literature 1 and Patent Literature 2 disclose a catadioptric projection optical system that combines a reflective system and a refractive system.

  In immersion exposure, a nozzle for supplying and recovering liquid is arranged near the outer periphery of the final lens of the projection optical system, and a limited area between the final surface of the projection optical system and the object to be exposed is immersed in liquid. While circulating this. These nozzles are typically arranged along the outer diameter of the final lens of the projection optical system, and form a liquid flow path between the final surface of the projection optical system and the object to be exposed. If the flow path is long, it will be difficult to control the temperature and pressure of the liquid uniformly, and the non-uniformity of the temperature and pressure of the liquid will adversely affect the exposure light passing therethrough, making high-quality exposure difficult. To do. Thus, proposals for avoiding the problem of liquid control due to the length of the flow path are disclosed in Patent Document 3 and Patent Document 4.

For example, Patent Document 3 includes a projection optical system that projects and exposes a first object onto a second object, and a lens (final lens) that is disposed on the second object side that constitutes the projection optical system. An immersion exposure apparatus is described in which the first object side surface has refractive power. The immersion exposure apparatus of Patent Document 3 is further characterized in that it is smaller than the effective area on the first object side surface of the lens.
Patent Document 4 describes that the projection optical system is an off-axis visual field optical system in order to obtain flatness of an image. An off-axis visual field optical system is an optical system in which an effective visual field region and an effective projection region (effective exposure region) do not include an optical axis.
Also, Patent Document 5 and Patent Document 6 disclose proposals of an eccentricity measuring method and an eccentricity measuring apparatus for accurately measuring the eccentricity of each surface of the optical system.
JP 2005-037896 A WO2005 / 069055 JP 2005-286026 A WO2006 / 121009 publication JP-A-11-014306 JP 2000-193441 A

  As described above, as a means for facilitating liquid control, a method of arranging the liquid supply and recovery mechanism so that the length of the liquid flow path is short is effective. The inventor has repeatedly studied to apply the invention described in Patent Document 3 to the case where the off-axis visual field optical system described in Patent Document 4 is used. That is, a projection optical system that projects and exposes the first object onto the second object is provided, and the first object-side surface of the lens disposed on the second object side that constitutes the projection optical system has a refractive power. And the exposure area on the second object side surface does not include the optical axis of the projection optical system.

However, in such an immersion exposure apparatus, when the above-described means for facilitating liquid control is applied, it becomes difficult to realize high-quality exposure.
Hereinafter, an example in which a liquid supply and recovery mechanism is arranged in the above-described projection optical system so as to shorten the length of the flow path will be described with reference to the schematic diagram of FIG. FIG. 10 is a partial cross-sectional view showing an example of the configuration on the second object side of the projection optical system 100 described above. The projection optical system 100 includes a plurality of optical elements (not shown) and a lens barrel 120 that holds the optical elements. The final lens 110 is held on the lens barrel 120 by the holding unit 112. As described above, the first object-side surface 110R1 of the final lens 110 has a refractive power, and the exposure region 110EF of the second object-side surface 110R2 of the final lens 110 includes the optical axis 101 of the projection optical system 100. Absent. The liquid LW is supplied from the liquid supply mechanism between the second object and the final lens 110 by the supply nozzle 131, and is recovered by the recovery nozzle 141 to the liquid recovery mechanism. The arrangement of the supply nozzle 131 and the recovery nozzle 141 is exemplary, and the positions can be interchanged. If the second object-side surface 110R2 is minimized to a region smaller than the first object-side surface 110R1 for the purpose of shortening the length of the liquid flow path as in the prior art, the second object The side surface 110R2 does not include the optical axis.

  FIG. 11 is a schematic plan view of the final lens 110 of FIG. 10 as viewed from the second object-side surface 110R2. The reference numeral 301 represents the rotation of the lens to be measured when the eccentricity measuring method described in Patent Document 5 is performed. It is a locus of a measuring beam. FIG. 12 is a schematic diagram of the projection optical system 100 and the final lens 110 of FIG. Here, the eccentricity measurement method disclosed in Patent Document 5 is used to measure the eccentricity of the second object-side surface 110R2 for a lens in which the second object-side surface 110R2 does not include the optical axis. Think. According to Patent Document 5, high-precision eccentricity measurement can be performed by rotating a lens to be measured. When a lens having a configuration that does not include the optical axis is applied to this lens, only the locus of the light beam represented by 301 in FIG. 11 can be measured, and high-precision measurement cannot be realized. As a result, as shown in a conceptual example in FIG. 12, it becomes difficult to match the optical axis 101 of the projection optical system and the optical axis 101A of the final lens 110 with a desired accuracy, thereby realizing high-quality exposure. You can't do it.

  In the present invention, the first object side surface 110 </ b> R <b> 1 of the final lens 110 has refractive power, and the second object side exposure area 110 </ b> EF of the final lens 110 does not include the optical axis 101 of the projection optical system 100. The present invention relates to an exposure apparatus. In such an immersion exposure apparatus, an exemplary object is to provide an exposure apparatus that facilitates liquid control while facilitating the decentration measurement of the final lens and can realize high-quality exposure.

  In order to achieve the above object, a projection optical system of the present invention is a projection optical system that projects an image of a pattern of a first object onto a second object, and is disposed closest to the second object side. The first object side surface of the lens (final lens) has a refractive power, and the projection area on the second object side surface of the lens does not include the optical axis of the projection optical system; The second object side surface of the lens includes the optical axis, and is smaller than an effective area on the first object side surface of the lens.

  The exposure apparatus of the present invention includes a projection optical system that projects an image of a pattern of a first object onto a second object, and a lens (mostly disposed on the second object side of the projection optical system). An exposure apparatus that exposes the second object through a liquid between a final lens and the second object, wherein the projection optical system has a refractive power at a surface on the first object side of the lens. The exposure area (projection area) on the second object side surface of the lens does not include the optical axis of the projection optical system, the second object side surface of the lens includes the optical axis, The lens is smaller than the effective area on the first object side surface of the lens.

  According to the present invention, it is possible to easily suppress the deviation between the optical axis of the final lens and the optical axis of the projection optical system in a so-called off-axis visual field optical system. In addition, by applying the projection optical system of the present invention to an immersion exposure apparatus, the liquid can be easily controlled and high-quality exposure can be realized.

In a preferred embodiment of the present invention, the present invention is applied to an immersion exposure apparatus. The immersion exposure apparatus includes a projection optical system that projects an image of a pattern of a first object onto a second object, the lens disposed closest to the second object side of the projection optical system, and the second An exposure apparatus that exposes the second object via a liquid between the objects.
In this embodiment, in the projection optical system, the first object side surface of the lens has refractive power, and the second object side surface of the lens is the first object side of the lens. It is smaller than the effective area in the surface. The exposure area (projection area) on the second object side surface of the lens does not include the optical axis of the projection optical system. Furthermore, the second object side surface of the lens includes the optical axis.

  Further, it is preferable that the projection optical system is a catadioptric projection optical system having one or a plurality of lenses including the final lens and at least one reflecting mirror. Moreover, it is preferable that the surface on the second object side of the final lens has an area of ¼ or less of an effective area on the first object side. In addition, an outer diameter major radius of the second object side surface of the lens is preferably less than an outer diameter radius of the lens on the first object side surface, and the first object side surface It is more preferable that the radius be less than or equal to the effective radius. In addition, it is preferable that an outer diameter short radius of the second object side surface of the lens is less than an outer diameter long radius of the second object side surface and is 0.1 mm or more.

Further, the exposure apparatus according to the present embodiment includes a supply nozzle that supplies the liquid between the lens and the second object. The distance between the supply port of the supply nozzle and the optical axis is preferably less than the outer radius of the first object side surface of the lens, and is less than or equal to the effective radius of the first object side surface. Some are more preferable.
In addition, the exposure apparatus according to the present embodiment includes a recovery nozzle that recovers the liquid between the lens and the second object. The distance between the recovery port of the recovery nozzle and the optical axis is preferably less than the outer radius of the surface on the first object side of the lens, and is less than or equal to the effective radius of the surface on the first object side. Some are more preferable.

[Example of projection optical system]
Hereinafter, embodiments of the present invention will be described in more detail based on examples shown in the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted. FIG. 1 is a partial cross-sectional view showing an example of the configuration on the second object side of the projection optical system 100. The projection optical system 100 includes a plurality of optical elements (not shown) other than the lens 110 disposed on the second object side, and a lens barrel 120 that holds the optical elements.

  FIG. 2 is a partial cross-sectional view showing an example of the configuration of the lens 110. On the first object-side surface 110R1 of the lens 110, the distance between the exposure light A and the optical axis 101 farthest from the optical axis 101 is defined as an effective radius 200, and the effective radius 200 is defined as the radius centering on the optical axis 101. This area is referred to as an effective area 200EF. The distance between the optical axis 101 and the part farthest from the optical axis 101 on the first object-side surface 110R1 of the lens 110 is referred to as an outer diameter radius 201. On the second object-side surface 110R2α of the lens 110, the distance between the portion farthest from the optical axis 101 and the optical axis 101 is referred to as an outer diameter major radius 110L. On the second object-side surface 110R2α of the lens 110, the distance between the portion closest to the optical axis 101 and the optical axis 101 is referred to as an outer diameter short radius 110L '.

  In the projection optical system 100, the first object-side surface 110R1 of the lens 110 has a positive refractive power. In the projection optical system 100, an exposure area (projection area) 110EF of exposure light for projecting an image of the pattern of the first object onto the second object on the second object side surface 110R2α of the lens 110 is light. The shaft 101 is not included. Furthermore, the second object-side surface 110R2α includes the optical axis 101 and is formed smaller than the effective region 200EF. As a result, the eccentricity measurement of the lens 110 can be performed with high accuracy, and the optical axis 101 of the projection optical system 100 and the optical axis 101 of the lens 110 can be easily matched within a desired accuracy. In addition, liquid control can be facilitated, and thus, high-quality exposure can be realized.

  As an example of the projection optical system in which the exposure area 110EF does not include the optical axis 101, a catadioptric projection optical system including at least one reflecting mirror can be cited (for example, FIG. 12 of Patent Document 1 and FIG. 17 of Patent Document 2). ). The present invention is suitable for such a catadioptric projection optical system. Hereinafter, examples of the catadioptric projection optical system will be introduced with reference to FIGS. 3 to 6 are schematic views of examples of the catadioptric projection optical system.

  In FIG. 3, the exposure light emitted from the first object 501 passes through the lens group 191A, is reflected by the mirror 192A, is reflected by the concave mirror M1, and forms an intermediate image 180A of the real image, and passes through the imaging system G1 and passes through the second. It is the structure which reaches | attains the object 502 of this. The lens group 191A may include a mirror. Furthermore, a reciprocating optical system may be included between the mirror 192A and the concave mirror M1. The reciprocating optical system is, for example, a reciprocating optical system having at least one lens having a negative refractive power. Of course, the catadioptric projection optical system is not limited by the number of intermediate imaging operations from the first object 501 to the second object 502. Therefore, the schematic diagram may be configured as shown in FIG.

  In FIG. 4, the light beam emitted from the first object 501 forms at least one intermediate image, passes through the lens group 191B, is reflected by the mirror 192B, is reflected by the concave mirror M1, and the real image intermediate image 180B is obtained. In this configuration, the second object 502 is reached through the imaging system G1. The lens group 191B may include a mirror. Furthermore, a reciprocating optical system may be included between the mirror 192B and the concave mirror M1. The reciprocating optical system is, for example, a reciprocating optical system having at least one lens having a negative refractive power. The catadioptric projection optical system may be an optical system including a plane mirror as shown in FIG.

  In FIG. 5, the light beam emitted from the first object 501 passes through the lens group 191C (which may include a mirror) and is reflected by the mirror 193C having no refractive power. Further, an intermediate image 181C of the real image is formed, reflected by the concave mirror M1, and formed by an intermediate image 180C of the real image, reflected by the mirror 194C having no refractive power, and reaches the second object 502 through the imaging system G1. It is the structure of doing. In this case, the intermediate image of the real image exists after the reflection of the mirror 193C. However, the position of the intermediate image of the real image may be before the reflection of the mirror 193C. Further, it is assumed that the intermediate image of the real image exists before the reflection of the mirror 194C. However, the position of the intermediate image of the real image may be after the reflection of the mirror 194C. Furthermore, a reciprocating optical system may be included between the mirror 193C and the concave mirror M1. The reciprocating optical system is, for example, a reciprocating optical system having at least one lens having a negative refractive power. Further, the catadioptric projection optical system may be an optical system in which the optical axis on the first object side does not coincide with the optical axis on the second object side as shown in FIG.

In FIG. 6, the light beam emitted from the first object 501 forms at least one intermediate image, passes through the lens group 191D (which may include a mirror), is reflected by the concave mirror M1, and has a refractive power. It is reflected by the mirror 193D that it does not have. Furthermore, a real image intermediate image 180D is formed, reflected by a mirror 194D having no refractive power, and reaches the second object 502 through the imaging system G1. Furthermore, a reciprocating optical system may be included between 191D and the concave mirror M1. The reciprocating optical system is, for example, a reciprocating optical system having at least one lens having a negative refractive power.
As mentioned above, although the example of the catadioptric projection optical system suitable for implementing this invention was given, naturally, it is not limited to these structures.

  Further, in FIGS. 1 and 2, the second object-side surface 110R2α is preferably formed to ¼ or less of the effective area 200EF. Thereby, the outer diameter radius 201 of the first object side surface 110R1 and the outer diameter major radius 110L and the outer diameter minor radius 110L ′ of the second object side surface 110R2α are often almost the same. Compared to the optical system, the flow rate of the liquid LW can be smaller than that of the conventional projection optical system. As a result, it is easier than ever to control the temperature and pressure of the liquid LW flowing through the flow path, so that high-quality exposure can be realized. In addition, since the time for controlling the temperature and pressure of the liquid LW can be shortened, the throughput can be improved. Further, since the contact area between the lens 110 and the liquid LW is reduced, the lens 110 is dissolved in the liquid LW, or the additional optical material provided on the second object-side surface 110R2α is dissolved in the liquid LW. It is possible to reduce the mixing of impurities into the liquid LW. The additional optical material is, for example, a protective film or an antireflection film. As a result, it is possible to prevent high-quality exposure by preventing deterioration and unevenness of the transmittance of the liquid due to the mixing of impurities.

  As an example of the shape of the second object-side surface 110R2α, FIGS. 7 to 9 will be introduced. 7 to 9 are schematic plan views of the lens 110 viewed from the second object-side surface 110R2α side. Naturally, the second object-side surface 110R2α is not limited to the rectangular shape as shown in FIG. For example, in order to facilitate manufacture, a shape in which the exposure region 110EF is not present after the shape is formed in a rotationally symmetric shape about the optical axis 101 as shown in FIG. 8 may be cut off. Further, the exposure area 110EF is not limited to the rectangular shape as shown in FIG. 7, but may be an arc shape as shown in FIG. 9 selected for easy design. Of course, the second object-side surface 110R2α is not limited to these shapes.

  1 and 2, it is desirable to shorten the flow path of the liquid LW from the viewpoint of controlling the temperature and pressure of the liquid LW, and the length of the outer diameter major radius 110L of the second object-side surface 110R2α is: The outer diameter radius 201 of the first object-side surface 110R1 is less than 201. Furthermore, it is more preferable that the length of the outer diameter major radius 110L of the second object-side surface 110R2α is equal to or less than the effective radius 200 of the first object-side surface 110R1. Thereby, the supply nozzle 131 and the recovery nozzle 141 for the liquid LW can be brought closer to the exposure area 110EF, and the flow path for the liquid LW can be shortened. As a result, it is easier than ever to control the temperature and pressure of the liquid LW flowing through the flow path, so that high-quality exposure can be realized. In addition, since the time for controlling the temperature and pressure of the liquid LW can be shortened, the throughput can be improved.

  The outer short radius 110L ′ of the second object side surface 110R2α is less than the outer long radius 110L of the second object side surface 110R2α. Further, from the viewpoint of measuring the eccentricity of the lens 110, the outer diameter minor radius 110L 'of the second object-side surface 110R2α must be larger than zero and is at least 0.1 mm or more. Furthermore, it is more preferable that it is 1 mm or more from the viewpoint of measurement accuracy. As a result, the eccentricity of the lens 110 can be measured with a desired accuracy, and high-quality exposure can be realized by suppressing the deviation from the optical axis 101.

  The distance between the supply port of the supply nozzle 131 and the optical axis is less than the outer diameter radius 201 of the first object-side surface 110R1. Furthermore, it is more preferable that the distance between the supply port of the supply nozzle 131 and the optical axis is equal to or less than the effective radius 200 of the first object-side surface 110R1. As a result, the supply port of the supply nozzle 131 for the liquid LW approaches the exposure area 110EF, and the flow path for the liquid LW is shortened. As a result, it is easier than ever to control the temperature and pressure of the liquid LW flowing through the flow path, so that high-quality exposure can be realized. In addition, since the time for controlling the temperature and pressure of the liquid LW can be shortened, the throughput can be improved.

  The distance between the recovery port of the recovery nozzle 141 and the optical axis is less than the outer diameter radius 201 of the first object-side surface 110R1. Furthermore, it is more preferable that the distance between the recovery port of the recovery nozzle 141 and the optical axis is equal to or less than the effective radius 200 of the first object-side surface 110R1. Accordingly, the recovery port of the recovery nozzle 141 for the liquid LW approaches the exposure area 110EF, and the flow path for the liquid LW is shortened. As a result, it is easier than ever to control the temperature and pressure of the liquid LW flowing through the flow path, so that high-quality exposure can be realized. In addition, since the time for controlling the temperature and pressure of the liquid LW can be shortened, the throughput can be improved.

  As mentioned above, although the preferable Example of this invention was described, it cannot be overemphasized that this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary. For example, the present invention can be applied even if the second object-side surface 110R2α is not a flat exposure apparatus.

[Example of exposure apparatus]
Hereinafter, an exemplary immersion exposure apparatus to which the projection optical system of the present invention is applied will be described. As shown in FIG. 13, the exposure apparatus 1 includes an illumination device 10, a reticle stage 30 on which a reticle (first object) 20 is mounted, a projection optical system 100, and a wafer stage 60 on which a wafer (second object) 50 is mounted. Have. Then, the circuit pattern formed on the reticle 20 is transferred to the wafer in a step-and-scan manner via the liquid LW supplied to at least a part between the final surface of the projection optical system 100 closest to the wafer 50 and the wafer 50. 50 exposure.
The second object is a wafer in this embodiment, but widely includes liquid crystal substrates and other objects to be processed. A photoresist is applied to the wafer 50.

The illumination device 10 illuminates a reticle 20 on which a transfer circuit pattern is formed, and includes a light source unit 12 and an illumination optical system 14. For example, the light source unit 12 uses a laser as a light source. As the laser, an ArF excimer laser with a wavelength of about 193 nm, a KrF excimer laser with a wavelength of about 248 nm, an F ₂ excimer laser with a wavelength of about 153 nm, or the like can be used. However, the type of laser is not limited to the excimer laser, and for example, a YAG laser may be used, and the number of lasers is not limited. Furthermore, in order to reduce speckles, an optical system (not shown) arranged in the optical path may be swung linearly or rotationally. Further, when a laser is used as the light source unit 12, a light beam shaping optical system that shapes a parallel light beam from the laser light source into a desired beam shape and an incoherent optical system that makes a coherent laser beam incoherent are used. It is preferable to do. The light source that can be used for the light source unit 12 is not limited to a laser, and one or a plurality of lamps such as a mercury lamp and a xenon lamp can be used.

The illumination optical system 14 is an optical system that illuminates the reticle 20 with light from the light source unit 12, and includes a lens, a mirror, an optical integrator, a diaphragm, and the like.
The projection optical system 100 can use an optical system composed only of a plurality of lens elements, or an optical system (catadioptric optical system) having a plurality of lens elements and at least one concave mirror. An optical system having a plurality of lens elements and at least one diffractive optical element such as a kinoform, an all-mirror optical system, and the like can also be used.

  The reticle stage 30 and the wafer stage 60 can be moved by, for example, a linear motor. Since the exposure apparatus 1 is a step-and-scan projection exposure method (scanner), each stage moves synchronously. Further, in order to align the pattern of the reticle 20 on the wafer 50, at least one of the wafer stage 60 and the reticle stage 30 is provided with a separate actuator.

  The liquid supply mechanism 130 has a supply nozzle 131 and supplies the liquid LW between the projection optical system 100 and the wafer 50. The liquid supply mechanism 130 includes, for example, a tank that stores the liquid LW, a pressure feeding device that sends out the liquid LW, and a flow rate control device that controls the supply flow rate of the liquid LW. It is preferable that the liquid supply mechanism 130 further includes a temperature control device for controlling the supply temperature of the liquid LW.

The liquid recovery mechanism 140 has a recovery nozzle 141 and recovers the liquid LW supplied between the final lens 110 and the wafer 50 via the recovery nozzle 141. The liquid recovery mechanism 140 includes, for example, a tank that temporarily stores the recovered liquid LW, a suction device that sucks out the liquid LW, and a flow rate control device that controls the recovery flow rate of the liquid LW.
Note that the arrangement of the liquid supply mechanism 130 and the liquid recovery mechanism 140 is exemplary, and the respective positions can be interchanged.
Such an exposure apparatus can be used for manufacturing a semiconductor device such as a semiconductor integrated circuit or a device on which a fine pattern such as a micromachine or a thin film magnetic head is formed.

[Example of device manufacturing method]
Next, with reference to FIGS. 14 and 15, an embodiment of a device manufacturing method using the above-described exposure apparatus will be described. FIG. 14 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, and the like). Here, a semiconductor chip manufacturing method will be described as an example.
In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask production), a mask (also referred to as an original plate or a reticle) is produced based on the designed circuit pattern. In step 3 (wafer manufacture), a wafer (also referred to as a substrate) is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer using the mask and the wafer by the above exposure apparatus using the lithography technique. Step 5 (assembly) is referred to as a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4. including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, a semiconductor device is completed and shipped (step 7).

  FIG. 15 is a detailed flowchart of the wafer process in Step 4. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the exposure apparatus to expose a circuit pattern on the mask onto the wafer. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.

It is a schematic fragmentary sectional view which shows an example of the structure by the side of the 2nd object of the projection optical system used for the immersion exposure apparatus as one side of this invention. It is a schematic fragmentary sectional view which shows an example of the lens arrange | positioned at the 2nd object side of the projection optical system shown in FIG. It is a schematic sectional drawing which shows the 1st structural example of the catadioptric projection optical system used for the immersion exposure apparatus as one side of this invention. It is a schematic sectional drawing which shows the 2nd structural example of the catadioptric projection optical system used for the immersion exposure apparatus as one side of this invention. It is a schematic sectional drawing which shows the 3rd structural example of the catadioptric projection optical system used for the immersion exposure apparatus as 1 side surface of this invention. It is a schematic sectional drawing which shows the 4th structural example of the catadioptric projection optical system used for the immersion exposure apparatus as one side of this invention. FIG. 3 is a schematic plan view showing an example of a lens disposed on the second object side shown in FIG. 2. FIG. 6 is a schematic plan view showing another example of the lens arranged on the second object side shown in FIG. 2. FIG. 10 is a schematic plan view showing still another example of the lens disposed on the second object side shown in FIG. 2. It is a schematic fragmentary sectional view which shows an example of a 2nd object side structure of the projection optical system used for the immersion exposure apparatus used as the subject of this invention. It is a schematic plan view which shows an example of the lens arrange | positioned at the 2nd object side of the projection optical system used for the immersion exposure apparatus used as the subject of this invention. It is a schematic sectional drawing which shows an example of the structure by the side of the 2nd object of the projection optical system used for the immersion exposure apparatus used as the subject of this invention. It is a schematic block diagram of the immersion exposure apparatus to which the projection optical system of FIG. 1 is applied. It is a flowchart for demonstrating manufacture of the device using an exposure apparatus. It is a detailed flowchart of the wafer process of step 4 in the flowchart shown in FIG.

Explanation of symbols

100 Projection optical system 101 Optical axis 110 Lens (final lens)
110EF exposure area (projection area)
110L outer radius major radius 110L 'outer radius minor radius 110R1 first object side surface 110R2 second object side surface (not including optical axis)
110R2α Second object side surface (including optical axis)
112 Holding Unit 131 Supply Nozzle 141 Recovery Nozzle 200 Effective Radius 200EF Effective Area 201 Outer Diameter Radius 501 First Object 502 Second Object

Claims (12)

A projection optical system that projects an image of a pattern of a first object onto a second object,
The first object-side surface of the lens disposed closest to the second object side has a refractive power,
The projection area on the second object side surface of the lens does not include the optical axis of the projection optical system,
The projection optical system according to claim 1, wherein the second object side surface of the lens includes the optical axis and is smaller than an effective area on the first object side surface of the lens.   The projection optical system according to claim 1, wherein the projection optical system is a catadioptric projection optical system having at least one reflecting mirror.   3. The projection optical system according to claim 1, wherein a surface of the lens on the second object side has an area of ¼ or less of an effective area on the first object side.   4. The outer diameter major radius of the second object side surface of the lens is less than the outer radius of the first object side surface of the lens. 5. The projection optical system described.   The projection optical system according to claim 4, wherein an outer diameter major radius of the second object side surface of the lens is equal to or less than an effective radius of the lens on the first object side surface.   The outer diameter minor radius of the second object side surface of the lens is less than the outer diameter major radius of the second object side surface, and is 0.1 mm or more. 5. The projection optical system according to 4. A projection optical system that projects an image of a pattern of a first object onto a second object, and a liquid between a lens disposed closest to the second object of the projection optical system and the second object An exposure apparatus for exposing the second object via
An exposure apparatus, wherein the projection optical system is the projection optical system according to any one of claims 1 to 6. A supply nozzle for supplying the liquid between the lens and the second object;
8. The exposure apparatus according to claim 7, wherein the distance between the supply port of the supply nozzle and the optical axis is less than the outer radius of the surface of the lens on the first object side.   9. The exposure apparatus according to claim 8, wherein a distance between the supply port of the supply nozzle and the optical axis is equal to or less than an effective radius of the surface of the lens on the first object side. A recovery nozzle for recovering the liquid between the lens and the second object;
10. The exposure according to claim 7, wherein a distance between the recovery port of the recovery nozzle and the optical axis is less than an outer radius of the surface of the lens on the first object side. apparatus.   11. The exposure apparatus according to claim 10, wherein a distance between the recovery port of the recovery nozzle and the optical axis is equal to or less than an effective radius of the surface of the lens on the first object side.   12. A device manufacturing method comprising: exposing a substrate using the exposure apparatus according to claim 7; and developing the exposed substrate.

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