JP4899473B2 - Imaging optical system, exposure apparatus, and device manufacturing method - Google Patents

Description

The present invention relates to, for example, an imaging optical system used for transferring a pattern onto a substrate in a lithography process for manufacturing a device such as a semiconductor element, an imaging element (CCD, etc.), a liquid crystal display element or a thin film magnetic head , a method for manufacturing a device using the exposure apparatus and exposure apparatus having the imaging optical system.

  In lithography processes for manufacturing devices such as semiconductor elements and liquid crystal display elements, a projection exposure apparatus that transfers a mask pattern onto a substrate via a projection optical system is used. Examples of the projection exposure apparatus include a step-and-repeat type reduction projection type exposure apparatus (stepper), a step-and-scan type projection exposure apparatus that performs exposure by synchronously scanning a mask and a substrate, and the like.

  In recent years, there has been proposed an immersion projection exposure apparatus that performs exposure in a state where a space between a projection optical system and a substrate is filled with a predetermined liquid (see, for example, Patent Document 1). The resolution of the projection exposure apparatus increases as the exposure wavelength λ used decreases and as the numerical aperture NA (brightness of the projection optical system) of the projection optical system increases. This resolution A is represented by A = n (refractive index of a medium through which exposure light passes) × sin θ (ray incident angle of exposure light). Since exposure in the projection exposure apparatus other than immersion is performed in the atmosphere, n = 1, whereas in the immersion projection exposure apparatus, n is larger than 1, and the light incident angle θ of the exposure light is changed. The numerical aperture NA of the projection optical system can be increased without any problem. That is, the resolution of the projection exposure apparatus can be improved to 1 / n times (the refractive index of the liquid is usually about 1.2 to 1.6). On the other hand, in the immersion projection exposure apparatus, when the numerical aperture NA is set to be the same as that of the projection exposure apparatus other than immersion, the beam incident angle θ of the exposure light can be reduced. Improvement).

International Publication No. 99/49504 Pamphlet

  By the way, the liquid generally has a property of taking heat away from the surroundings when vaporized, and the heat taken away at this time is generally referred to as heat of vaporization. A lens that constitutes the projection optical system of the above-described immersion projection exposure apparatus and is in contact with the interface between the liquid and air is cooled by the heat of vaporization. When the lens is cooled, a change in refractive index based on a temperature change due to cooling occurs according to the physical property value of the lens, and the aberration changes. In addition, when the lens is partially cooled to give a temperature distribution to the lens and the temperature distribution given to the lens is changed, various aberrations are generated as aberrations of the lens. Among these various aberrations, there is included center astigmatism that cannot be corrected by moving or decentering the lens constituting the projection optical system in the optical axis direction.

An object of the present invention is an imaging optical system in which a predetermined liquid is interposed between at least an image surface side lens and an image surface, and the aberration can be adjusted by utilizing the heat of vaporization of the liquid. image optical system, is to provide a device manufacturing method using the exposure apparatus and exposure apparatus having the imaging optical system.

The imaging optical system according to the present invention includes a lens (LS6) in contact with the liquid in the imaging optical system (PL) that forms an image of the first surface (R) on the second surface (W) via the liquid. The cooling suppression member (6a), which is provided in a part of the region in contact with the liquid in) and suppresses partial cooling of the lens by the heat of vaporization of the liquid, and the cooling suppression member is provided A setting position changing unit (4b) for changing a part of the area within the area in contact with the liquid is provided.
The imaging optical system according to the present invention includes a lens that contacts the liquid in the imaging optical system (PL) that forms an image of the first surface (R) on the second surface (W) via the liquid. A cooling suppression member (6a) that is provided in a part of the region in contact with the liquid in (LS6) and suppresses partial cooling of the lens due to heat of vaporization of the liquid, and the cooling suppression member is provided. And an area variable unit for changing the area of the partial region.

In the exposure apparatus of the present invention, in the exposure apparatus (11) for exposing a pattern to the substrate (W), the image of the pattern on the first surface (R) is disposed on the second surface (W) ( In order to form an image on (W), the image forming optical system (PL ) of the present invention is provided.

  Further, the device manufacturing method of the present invention uses the exposure apparatus (11) of the present invention to expose the pattern (W) to the substrate (W), and develops the substrate (W) exposed by the exposure step. And a developing step.

  According to the imaging optical system of the present invention, since the control means for controlling the influence of the heat of vaporization of the liquid is provided, the image is formed by adjusting the aberration of the lens contacting the liquid generated by the heat of vaporization of the liquid. The aberration of the entire optical system can be adjusted. Therefore, the image of the first surface can be favorably formed on the second surface.

  Further, according to the exposure apparatus of the present invention, a pattern is formed using the imaging optical system of the present invention, the imaging optical system manufactured by the manufacturing method of the present invention, or the imaging optical system adjusted by the adjusting method of the present invention. Is exposed on the substrate, the pattern can be exposed on the substrate with high resolution.

  Further, according to the device manufacturing method of the present invention, since exposure is performed using the exposure apparatus of the present invention, a predetermined pattern can be exposed on the substrate with high resolution, and a good device can be obtained. .

  The exposure apparatus according to the first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the exposure apparatus 11 of the present embodiment synchronously moves a reticle R as a mask and a wafer W as a substrate in a one-dimensional direction (here, left and right in the drawing in FIG. 1). The circuit pattern formed on the reticle R is transferred to each shot area on the wafer W through the projection optical system PL. That is, the exposure apparatus 11 of the present embodiment is a step-and-scan type scanning exposure apparatus, a so-called scanning stepper.

  The exposure apparatus 11 includes an exposure light source (not shown), an illumination optical system 12, a reticle stage RST, a projection optical system PL, a wafer stage WST, and the like. Reticle stage RST holds reticle R, and wafer stage WST holds wafer W. The exposure light source of the present embodiment uses a light source that emits ArF excimer laser light (wavelength 193 nm) as exposure light EL.

  The illumination optical system 12 includes an optical integrator (not shown) such as a fly-eye lens and a rod lens, various lens systems such as a relay lens and a condenser lens, an aperture stop, and the like. The exposure light EL emitted from an exposure light source (not shown) is adjusted so as to uniformly illuminate the pattern on the reticle R by passing through the illumination optical system 12.

  In order to improve the resolution and depth of focus, a polarized illumination optical unit is disposed in the illumination optical system when guiding polarized light that vibrates in the direction of the exposure pattern (longitudinal direction of the exposure pattern) from the illumination optical system. The polarized illumination optical unit may be provided so as to be detachable from the illumination optical path in polarized illumination and non-polarized illumination. This polarized illumination optical unit is described in, for example, WO / 2005 / 076045A1.

  Reticle stage RST is arranged between illumination optical system 12 and projection optical system PL so that the mounting surface of reticle R is substantially orthogonal to the optical path. That is, reticle stage RST is arranged on the object plane side of projection optical system PL (on the exposure light EL incident side, which is the upper side in FIG. 1).

  The projection optical system PL includes a plurality of lens elements LS1, LS2, LS3, LS4, LS5, LS6 and LS7 (only seven are shown in FIG. 1). Among these lens elements LS1 to LS7, lens elements LS1 to LS6 other than the lens element LS7 closest to the wafer W are held in the lens barrel 13. A space between the lens elements LS1 to LS6 in the lens barrel 13 is filled with a purge gas (for example, nitrogen). A lens holder 14 for holding the lens element LS7 is disposed at the lower end of the lens barrel 13. Each of the lens elements LS1 to LS7 has a light incident surface on which the exposure light EL is incident and a light emission surface on which the incident exposure light EL is emitted. The lens elements LS <b> 1 to LS <b> 7 are arranged so that the optical axes thereof coincide with each other and an optical path space is formed on each light incident surface side and light emission surface side.

  Wafer stage WST is arranged on the image plane side of projection optical system PL so that the mounting surface of wafer W is substantially orthogonal to the optical path of exposure light EL. Then, the pattern image on reticle R illuminated by exposure light EL is projected and transferred onto wafer W on wafer stage WST while being reduced to a predetermined reduction magnification through projection optical system PL. An aberration measuring device 40 that measures the wavefront aberration of the projection optical system PL is provided on wafer stage WST.

  Here, the exposure apparatus 11 according to the present embodiment is a so-called immersion exposure in which the immersion method is applied in order to substantially shorten the wavelength of the exposure light EL to improve the resolution and substantially widen the depth of focus. Device. Therefore, a first liquid supply for individually supplying a predetermined liquid (for example, pure water) to the exposure device 11 to the light path space 15 on the light exit surface side and the light path space 16 on the light incident surface side of the lens element LS7. A device 17 and a second liquid supply device 18 are provided. Further, the exposure device 11 is provided with a first liquid recovery device 19 and a second liquid recovery device 20 for individually recovering a predetermined liquid (for example, pure water) supplied to the optical path space 15 and the optical path space 16. It has been.

  In the optical path space 15 between the lens element LS7 and the wafer W, a liquid is supplied from the first liquid supply device 17, whereby a liquid immersion region LT1 is formed. Then, the liquid forming the liquid immersion region LT1 is recovered from the optical path space 15 based on the driving of the first liquid recovery device 19. In addition, in the optical path space 16 between the lens element LS6 and the lens element LS7, a liquid is supplied from the second liquid supply device 18, whereby a liquid immersion region LT2 is formed. Then, the liquid forming the liquid immersion region LT2 is recovered from the optical path space 16 based on the driving of the second liquid recovery device 20.

  In the present embodiment, the aberration of the projection optical system PL is adjusted by controlling the influence of the heat of vaporization on the lens element LS6 in contact with the liquid. FIG. 2 is a diagram for explaining the influence on the lens LS caused by the heat of vaporization of the liquid, that is, the heat taken away from the surroundings when the liquid is vaporized. As shown in FIG. 2, when the liquid 2 is vaporized (indicated by an arrow in the figure), a cooling phenomenon occurs at a portion of the lens LS that is in contact with the interface between the liquid and air. The liquid 2 is cooled by the heat of vaporization. When the lens LS is cooled and the temperature is lowered, the refractive index is changed by the temperature change according to the physical property value of the lens LS, and the aberration is changed.

  Here, for example, as shown in FIG. 3, when only the region A of the lens LS is cooled by the heat of vaporization of the liquid 2, center ass is generated. Center astigmatism is astigmatism at an image height of 0 mm and cannot be corrected by moving a predetermined lens constituting the optical system along the optical axis or decentering the optical axis as an axis. .

  In this embodiment, a protective member (for example, aluminum foil) is used to control the influence of the liquid vaporization heat on the lens element LS6 in contact with the liquid. The lens element LS6 and the lens element LS7 have shapes as shown in FIG. 1 to be supported by the lens barrel 13 and the lens holder 14, respectively. However, for convenience, they have shapes as shown in FIG. The protection member included in the lens element LS6 will be described.

  FIG. 5 is a diagram illustrating an example of the configuration of the lens element LS6. As shown in FIG. 5, the lens element LS6 includes a protective member (for example, an aluminum foil) 6a on a part of the side surface of the lens element LS6. The protective member 6a functions as a heat retaining means (or heat insulating means) that suppresses cooling due to the vaporization heat of the liquid in the region B of the lens element LS6. That is, the cooling due to the vaporization heat of the liquid in the region B of the lens element LS6 is suppressed, and the region C of the lens element LS6 is cooled by the heat of vaporization of the liquid. Therefore, a temperature change occurs in the region B and the region C of the lens element LS6, and as described above, center ass is generated.

  FIG. 6 is a graph showing the field aberration of the lens element LS6 when the temperature in the region B is 0.05 ° C. higher than the temperature in the region C. As shown in FIG. 6, the center element is generated in the lens element LS6. Accordingly, when the projection optical system PL is center-assured when the projection optical system PL is assembled, exposed to exposure light, or after long-term use, the influence of cooling by the heat of vaporization of each region in the lens element LS6 is controlled. The center ass in the projection optical system PL can be corrected by intentionally generating the center ass of the opposite component to the center ass of the system PL.

  For example, when the protection member 6a is attached to a half of the side surface of the lens element LS6 as shown in FIG. 7, the region D of the lens element LS6 is caused by the heat of vaporization of the liquid. Cooling is suppressed. As a result, a temperature change occurs between the region D and the region E of the lens element LS6, and coma aberration occurs in the lens element LS6. Therefore, when coma aberration occurs in the projection optical system PL, the effect of cooling by the heat of vaporization of each region in the lens element LS6 is controlled, and the coma aberration having the opposite component to the coma aberration of the projection optical system PL is generated. The coma aberration in the optical system PL can be corrected.

  The mounting position of the protection member 6a may be changed after the lens element LS6 is removed from the lens barrel 13, that is, the exposure apparatus 11 main body, or may be changed by, for example, a rotary drive unit using a motor or the like. FIG. 8 is a diagram showing the configuration of the rotation drive portion of the protection member 6a, and FIG. 9 is a top view thereof. As shown in FIGS. 8 and 9, on the side surface of the lens element LS6, a protection member support 4a that supports the protection member 6a and a rotation drive unit that rotates the protection member 6a around the optical axis of the lens element LS6 (for example, Motor) 4b is provided. The mounting position of the protection member 6a is changed by driving the rotation drive part 4b and rotating the protection member support part 4a along the side surface of the lens element LS6.

  8 and 9 show an example in which the setting position of the protection member 6a on the side surface of the lens element 6 is changed, the present invention is not limited to this. It is also possible to control the aberration by changing the area of the protective member 6a that contacts the side surface of the lens element 6. For example, the protective member 6a has a folding structure, and the area of the protective member 6a is reduced via a drive system (not shown). It can be expanded or folded to be narrowed. Further, a roller around which the protection member 6a is wound is disposed at the end of the protection member 6a, and this roller is rotated along the side surface of the lens element 6 via a drive system (not shown), thereby reducing the area of the protection member 6a. It is also possible to make it variable. Further, by combining the means for changing the area of the protection member 6a and the means for changing the position of the protection member 6a as shown in FIG. 8, not only the installation position of the protection member 6a but also the area can be changed simultaneously. It is also possible.

  In the projection optical system PL of the present embodiment, a liquid is supplied to the second optical path space 16 from the wafer W side between the lens barrel 13 and the lens holder 14 (hereinafter referred to as an annular nozzle member). (Referred to as “second nozzle member”) 21 is arranged so as to surround the optical path of the exposure light EL. The second nozzle member 21 is supported by a support member (not shown) so as not to contact the lens element LS6 and the lens element LS7. The second nozzle member 21 is connected to the second liquid supply device 18 via the liquid supply pipe 22. A liquid supply passage (not shown) communicating with the liquid supply pipe 22 is formed in the second nozzle member 21, and the liquid flowing through the liquid supply pipe 22 and the liquid supply passage is inside the second nozzle member 21. It flows into the optical path space 16 through a supply opening (not shown) formed in the above.

  The second nozzle member 21 is connected to the second liquid recovery device 20 via the liquid recovery pipe 25. A liquid recovery passage (not shown) communicating with the liquid recovery pipe 25 is formed in the second nozzle member 21. The liquid forming the liquid immersion region LT2 in the optical path space 16 passes through a recovery opening (not shown) formed on the inner side of the second nozzle member 21 on the side facing the supply opening (not shown). Then, it is recovered by the second liquid recovery device 20.

  Further, an annular nozzle member (hereinafter referred to as “first nozzle member”, which supplies liquid to the first optical path space 15 from the wafer W side) between the lens holder 14 and the wafer W. ) 30 is disposed so as to surround the optical path of the exposure light EL. The first nozzle member 30 is supported by a support member (not shown) so as not to contact the first specific lens element LS7 and the lens holder 14. The first nozzle member 30 is connected to the first liquid supply device 17 via the liquid supply pipe 31. A liquid supply passage (not shown) communicating with the liquid supply pipe 31 is formed in the first nozzle member 30, and a supply opening communicating with the liquid supply passage 32 is formed on the lower surface side of the first nozzle member 30. (Not shown) is formed in an annular shape.

  The first nozzle member 30 is connected to the first liquid recovery device 19 via the liquid recovery pipe 34. A liquid recovery passage (not shown) communicating with the liquid recovery pipe 34 is formed in the first nozzle member 30, and a recovery opening communicating with a liquid recovery passage (not shown) is formed on the lower surface side of the first nozzle member 30. The part (not shown) is formed so as to form an annular shape. The collection opening is formed outside the supply opening (not shown) so as to surround the supply opening.

  Next, an operation when a liquid is supplied to each of the optical path spaces 15 and 16 of the exposure apparatus 11 of the present embodiment will be described. When wafer W placed on wafer stage WST is placed on the optical path of exposure light EL, first liquid supply device 17 and second liquid supply device 18 start driving. Then, a liquid is supplied from the first liquid supply device 17, and this liquid is supplied into the optical path space 15 via the liquid supply pipe 31. At the same time, a liquid is supplied from the second liquid supply device 18, and this liquid is supplied into the optical path space 16 through the liquid supply pipe 22.

  The first liquid supply device 17 stops driving when a predetermined volume of liquid is supplied into the optical path space 15. As a result, a liquid immersion region LT1 made of a liquid is formed in the optical path space 15. The second liquid supply device 18 stops driving when a predetermined volume of liquid is supplied into the optical path space 16. As a result, a liquid immersion region LT2 made of a liquid is formed in the optical path space 16.

  According to the exposure apparatus of the first embodiment, since the protection member 6a is used for the lens element LS6 in which a part of the lens is in contact with the liquid, the influence of the liquid vaporization heat can be controlled. By adjusting the aberration of the lens element LS6 generated by the heat of vaporization, the aberration of the entire projection optical system PL can be adjusted. Therefore, the pattern image of the reticle R can be favorably formed on the wafer W, and the pattern can be exposed on the wafer W with high resolution.

  In the first embodiment, the protective member 6a formed of, for example, an aluminum foil for controlling the heat of vaporization of the liquid is provided. However, the liquid around the lens element LS6 is used instead of the protective member 6a. The heat of vaporization of the liquid may be controlled by partially stretching an oil film on the surface of the liquid. That is, the oil film functions as a heat retaining means or a heat insulating means for suppressing the cooling of the lens element LS6 due to the vaporization heat of the liquid, and a region that is cooled and a region that is not cooled are generated in the lens element LS6 by partially stretching the oil film. As a result, a temperature change occurs in the lens element LS6, and aberration occurs. When an aberration occurs in the projection optical system PL, the effect of cooling due to the heat of vaporization in each region in the lens element LS6 is controlled by applying an oil film, and projection is performed by generating an aberration opposite to the aberration of the projection optical system PL. Aberrations in the optical system PL can be corrected. Further, in the above embodiment, the protective member 6a has been described mainly having a function as a heat insulating means. However, a means that can be maintained at a predetermined constant temperature so that there is no fluctuation in temperature may be used. It is also possible to use a material that can positively impart a predetermined temperature distribution.

  In the first embodiment, an example of correcting the center astigmatism and coma aberration of the projection optical system PL has been described. However, the cooling effect by the heat of vaporization of the liquid on the entire lens element LS6 is positively used. Accordingly, it is also possible to correct the rotation target aberration of the projection optical system PL. That is, when an aberration to be rotated occurs in the projection optical system PL, the influence of the cooling due to the heat of vaporization of the entire area in the lens element LS6 is controlled, and the aberration to be rotated whose rotation component is opposite to that of the projection optical system PL. By intentionally generating the aberration, it is possible to correct the aberration to be rotated in the projection optical system PL.

Next, an exposure apparatus according to the second embodiment of the present invention will be described. The exposure apparatus according to the second embodiment does not include the protective member 6a that protects the lens element LS6 included in the exposure apparatus 11 according to the first embodiment. Further, the exposure apparatus according to the second embodiment does not include the annular second nozzle member 21 included in the exposure apparatus 11 according to the first embodiment, and as shown in FIG. Nozzle member that supplies liquid in the scanning direction (direction of arrow a in the figure) to the immersion region LT2, nozzle member that supplies liquid in the direction opposite to the scanning direction (direction of arrow b in the figure), orthogonal to the scanning direction The nozzle member which supplies a liquid in the direction (arrow c and d direction in a figure) to perform is provided. In addition, a nozzle member that collects liquid in the scanning direction (direction of arrow f in the drawing), a nozzle member that collects liquid in the direction opposite to the scanning direction (direction of arrow e in the drawing), and an orientation (in the drawing, orthogonal to the scanning direction) The configuration of the exposure apparatus according to the second embodiment, which includes a nozzle member that collects liquid in the directions of arrows g and h), other than the above-described points, is the configuration of the exposure apparatus 11 according to the first embodiment. Is the same. Therefore, in the description of the second embodiment, a detailed description of the same configuration as that of the exposure apparatus according to the first embodiment is omitted. In the description of the exposure apparatus according to the second embodiment, the same reference numerals as those used in the first embodiment are assigned to the same components as those of the exposure apparatus according to the first embodiment. Will be explained.

  In the present embodiment, as in the first embodiment, the aberration of the projection optical system PL is adjusted by controlling the influence of the heat of vaporization of the liquid on the lens element in contact with the liquid. That is, in this embodiment, instead of the lens element LS6 protected by the protection member 6a according to the first embodiment, a lens element (hereinafter referred to as a lens element LS50) is provided, and the lens element LS50 is provided. A liquid control device (not shown) for controlling the flow of the liquid on the wafer W side, that is, the liquid in the liquid immersion region LT2 is provided.

  The amount of heat of vaporization of the liquid varies depending on the flow of the liquid. Therefore, as the liquid flow changes, the temperature of the lens element 50 also changes, so the aberration in the lens element LS50 also changes. The liquid control device (not shown) corrects the influence of the heat of vaporization of the liquid by controlling the direction of the liquid flow in the liquid immersion region LT2, the flow speed of the liquid (including the stopped state), the distribution of the flow speed, the flow rate, and the like. .

  That is, the liquid control device outputs a control signal including information on the flow direction, flow rate, flow rate, and the like of the liquid to be supplied to the second liquid supply device 18 and the second liquid recovery device 20, and supplies the second liquid supply. The device 18 and the second liquid recovery device 20 start driving based on the control signal of the liquid control device. The second liquid supply device 18 supplies the liquid from any one of the arrows a, b, c, and d shown in FIG. 10 based on the control signal of the liquid control device, and the flow velocity of the supplied liquid and the distribution of the flow velocity. Then, the flow rate or the like is changed to form the liquid immersion region LT2. The second liquid recovery apparatus 20 also recovers the liquid from any one of the arrows e, f, g, and h shown in FIG. 9 based on the control signal of the liquid control apparatus, and the flow velocity of the liquid to be recovered and the distribution of the flow velocity. Change the flow rate.

  FIG. 11 shows the lateral aberration of the lens element LS50 when the temperature of the entire lens element LS50 is decreased by 0.5 ° C. due to the influence of heat of vaporization by controlling the entire flow of the liquid in the liquid immersion region LT2. It is a graph. Y represents the image height. As shown in FIG. 11, the in-plane lateral aberration of the lens element LS50 changes. Accordingly, when the projection optical system PL is assembled, subjected to exposure light irradiation, or after long-term use, if aberrations to be rotated occur in the projection optical system PL, the entire flow of the liquid in the liquid immersion region LT2 is made the same. By controlling the flow of the liquid and generating an aberration that is a rotation object having a component opposite to the rotation object of the projection optical system PL, the rotation object aberration in the projection optical system PL can be corrected.

  Further, for example, when coma occurs in the projection optical system PL, the difference between the temperature of one region and the temperature of the other region that occurs in the plane including the optical axis of the lens element LS50 is generated. The flow of liquid in contact with the other region and the flow of liquid in contact with the other region are controlled. In this way, by controlling the flow of the liquid, it is possible to correct the coma aberration in the projection optical system PL by generating the coma aberration opposite to the coma aberration of the projection optical system PL.

  According to the exposure apparatus of the second embodiment, since the influence of the heat of vaporization of the liquid can be controlled by controlling the flow of the liquid, the refractive index change of the lens element LS50 generated by the heat of vaporization of the liquid. By adjusting this, it is possible to adjust the aberration of the entire projection optical system PL. Therefore, the pattern image of the reticle R can be favorably formed on the wafer W, and the pattern can be exposed on the wafer W with high resolution.

  Next, a method for adjusting the projection optical system (imaging optical system) PL included in the exposure apparatus according to each of the above embodiments will be described with reference to the flowchart shown in FIG.

  First, the influence of the aberration due to the heat of vaporization of the liquid is obtained for the lens element (lens in contact with the liquid) LS6 or LS50 (step S10). Specifically, before assembling the projection optical system PL, the aberration due to the vaporization heat of the liquid is measured in advance with respect to the lens element LS6 or LS50 using an aberration measuring device (not shown) or the like. For example, the center ass when the temperature distribution as shown in FIG. 5 is generated by the heat of vaporization of the liquid, the coma aberration generated when the temperature distribution as shown in FIG. These are stored in a storage unit (not shown).

  Next, the aberration generated by long-term use of the projection optical system PL is measured using the aberration measuring device 40 provided in the exposure apparatus 11 (step S11). Next, the aberration generated in the projection optical system PL is adjusted so as to cancel out the influence of the aberration due to the heat of vaporization of the liquid (step S12). Specifically, the aberration generated by the temperature change of the lens element LS6 or LS50 generated by the heat of vaporization of the liquid measured in step S10, and the aberration of the projection optical system PL measured by the aberration measuring device 40 in step S11. Based on the above, the vaporization heat of the liquid partially generated for the lens element LS6 or LS50 is obtained. The lens element LS6 or LS50 is partially cooled by generating the obtained vaporization heat of the liquid, and the aberration of the projection optical system is adjusted by generating an aberration opposite to the aberration of the projection optical system PL.

  In the first embodiment, the attachment position of the protection member 6a is obtained, and the protection member 6a is attached to the side surface of the lens element LS6 based on the obtained attachment position. In the second embodiment, the liquid control device obtains a liquid flow and outputs a control signal to the second liquid supply device 18 and the second liquid recovery device 20 based on the obtained liquid flow.

  According to the adjustment method of the projection optical system (imaging optical system) PL according to this embodiment, in order to adjust the aberration generated in the projection optical system PL so as to cancel the influence of the aberration due to the heat of vaporization of the liquid, The aberration of the projection optical system PL can be adjusted by adjusting the aberration of the lens element LS6 or LS50 generated by the heat of vaporization of the liquid. Therefore, the pattern image of the reticle R can be projected onto the wafer W satisfactorily.

  In addition, when the projection optical system PL is manufactured, the same process as the above-described adjustment method of the projection optical system PL can be performed to adjust the aberration of the projection optical system PL generated during the manufacturing, which is favorable. The projection optical system PL with adjusted aberration can be manufactured.

  In each of the above-described embodiments, the exposure apparatus in which liquid is interposed between the lens element LS6 (LS50) and the lens element LS7 and between the lens element LS7 and the wafer W has been described as an example. However, the present invention can also be applied to an exposure apparatus in which a liquid is interposed only between the lens element LS7 and the wafer W. In this case, a protective member is provided on the side surface of the lens element LS7, or the flow of the liquid interposed between the lens element LS7 and the wafer W is controlled, so that the lens element LS7 and the wafer W are interposed. Controls the heat of vaporization of the intervening liquid.

  In the exposure apparatus according to each of the above-described embodiments, a micropattern (exposure process) is performed by exposing a photosensitive pattern (wafer) to a transfer pattern formed by a reticle (mask) using a projection optical system. Semiconductor elements, imaging elements, liquid crystal display elements, thin film magnetic heads, etc.) can be manufactured. FIG. 13 shows an example of a technique for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a wafer or the like as a photosensitive substrate using the exposure apparatus according to each of the embodiments described above. This will be described with reference to a flowchart.

  First, in step S301 in FIG. 13, a metal film is deposited on one lot of wafers. In the next step S302, a photoresist is applied on the metal film on one lot of wafers. Thereafter, in step S303, using the exposure apparatus according to each of the above-described embodiments, the image of the reticle pattern is sequentially exposed and transferred to each shot area on the wafer of one lot via the projection optical system. Thereafter, in step S304, the photoresist on one lot of wafers is developed, and then in step S305, etching is performed on the one lot of wafers using the resist pattern as a mask, thereby corresponding to the reticle pattern. A circuit pattern is formed in each shot area on each wafer.

  Thereafter, an upper layer circuit pattern is formed, and the wafer is cut into a plurality of devices to manufacture devices such as semiconductor elements. According to the semiconductor device manufacturing method described above, since exposure is performed using the exposure apparatus according to each of the above-described embodiments, exposure can be performed with high resolution, and a good semiconductor device can be obtained. In steps S301 to S305, a metal is vapor-deposited on the wafer, a resist is applied on the metal film, and exposure, development, and etching processes are performed. Prior to these processes, on the wafer. It is needless to say that after forming a silicon oxide film, a resist may be applied on the silicon oxide film, and steps such as exposure, development, and etching may be performed.

  In the exposure apparatus according to each of the above-described embodiments, a liquid crystal display element as a micro device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). . Hereinafter, an example of the technique at this time will be described with reference to the flowchart of FIG. First, in FIG. 14, in the pattern forming step S401, so-called photolithography, in which a mask pattern is transferred and exposed to a photosensitive substrate (such as a glass substrate coated with a resist) using the exposure apparatus according to each of the above embodiments. The process is executed. By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step S402.

  Next, in the color filter forming step S402, a large number of groups of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction. Then, after the color filter formation step S402, a cell assembly step S403 is executed. In the cell assembly step S403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step S401, the color filter obtained in the color filter formation step S402, and the like. In the cell assembly step S403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step S401 and the color filter obtained in the color filter formation step S402, and a liquid crystal panel (liquid crystal cell ).

  Thereafter, in a module assembly step S404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the method for manufacturing a liquid crystal display element described above, since exposure is performed using the exposure apparatus according to each of the embodiments described above, exposure can be performed with high resolution, and a good liquid crystal display element can be obtained. Can do.

It is a figure which shows the structure of the exposure apparatus concerning 1st Embodiment. It is a figure for demonstrating the influence on the lens by the heat of vaporization of a liquid. It is a figure for demonstrating the influence on the lens by the heat of vaporization of a liquid. It is a figure for demonstrating the shape for the convenience of a lens element. It is a figure which shows the structure of the lens element and protection member concerning 1st Embodiment. It is a graph which shows the image surface aberration of a lens element in case there exists an area | region of a 0.05 degreeC temperature difference. It is a figure which shows the structure of the protection member in case a coma aberration generate | occur | produces in a lens element. It is a figure which shows the structure of the rotation drive part of a protection member. It is a top view which shows the structure of the rotation drive part of a protection member. It is a figure for demonstrating the supply direction and collection | recovery direction of the liquid by the nozzle member with which the exposure apparatus concerning 2nd Embodiment is provided. It is a graph which shows the lateral aberration of a lens element in the case of giving a temperature fall of 0.5 degreeC. It is a flowchart for demonstrating the adjustment method of the projection optical system concerning embodiment. It is a flowchart which shows the manufacturing method of the semiconductor device as a microdevice concerning embodiment of this invention. It is a flowchart which shows the manufacturing method of the liquid crystal display element as a microdevice concerning embodiment of this invention.

Explanation of symbols

  6a ... protective member 11 ... exposure device 13 ... lens barrel 14 ... lens holder 15 ... light path space 16 ... light path space 17 ... first liquid supply device 18 ... second liquid supply device 19 ... first Liquid recovery device, 20 ... second liquid recovery device, 21 ... second nozzle member, 30 ... first nozzle member, 40 ... aberration measuring device, EL ... exposure light, LS1 to LS7 ... lens elements, LT1, LT2 ... immersion Region, PL ... projection optical system, R ... reticle, W ... wafer.

Claims (9)

In an imaging optical system that forms an image of the first surface on the second surface via a liquid,
A cooling suppression member that is provided in a part of a region in contact with the liquid in the lens that contacts the liquid and suppresses partial cooling of the lens due to heat of vaporization of the liquid ;
An imaging optical system comprising: a setting position changing unit configured to change the partial area in which the cooling suppression member is provided in an area in contact with the liquid .   The imaging optical system according to claim 1, wherein the cooling suppression member controls a generation amount of center ass in the imaging optical system.   The imaging optical system according to claim 1, wherein the cooling suppression member controls the amount of coma aberration generated in the imaging optical system.   The imaging optical system according to any one of claims 1 to 3, further comprising an area variable unit for changing an area of the partial region in which the cooling suppression member is provided. In an imaging optical system that forms an image of the first surface on the second surface via a liquid,
A cooling suppression member that is provided in a part of a region in contact with the liquid in the lens that contacts the liquid and suppresses partial cooling of the lens due to heat of vaporization of the liquid;
An imaging optical system, characterized in that it comprises a variable area section for changing the area of the said part of the region where the cooling suppression member is provided. The imaging optical system according to claim 5, wherein the cooling suppression member controls a generation amount of center ass in the imaging optical system. The imaging optical system according to claim 5, wherein the cooling suppression member controls an amount of coma generated in the imaging optical system. In an exposure apparatus that exposes a pattern onto a substrate,
To form an image of the pattern of the first surface on the substrate placed on the second surface, and characterized in that it comprises an imaging optical system according to any one of claims 1 to 7 Exposure equipment to do. An exposure step of exposing the pattern to the substrate using the exposure apparatus according to claim 8 ;
A development step of developing the substrate exposed by the exposure step;
A device manufacturing method comprising:

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