JP2012231046A - Optical apparatus, exposure apparatus, and device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection optical system, an exposure apparatus, an exposure method, and a device manufacturing method, capable of enhancing exposure accuracy.SOLUTION: An exposure apparatus 10 comprises a projection apparatus 14 equipped with a plurality of mirrors 17 held inside a lens barrel 16. A periphery of the lens barrel 16 of the projection apparatus 14 is provided with: a metallic material 19, having a physical property of phase transitioning between a liquid phase and a solid phase, in which the liquid phase and the solid phase coexist; and a metal holding member 18 which is provided in a periphery of the lens barrel 16 and holds the metallic material 19.

Description

  The present invention relates to an optical apparatus having a lens barrel that houses an optical member used when manufacturing a microdevice such as a semiconductor element, a liquid crystal display element, and a thin film magnetic head using photolithography technology, and the optical apparatus And a device manufacturing method including a step of performing exposure using the exposure apparatus.

  In recent years, with the demand for miniaturization and high integration of devices such as semiconductor devices, circuit patterns formed on devices have been highly refined. As one of exposure apparatuses that achieve such high definition, an EUV exposure apparatus that uses extreme ultraviolet light (EUV light: Extreme Ultraviolet Light) as exposure light has attracted attention.

  In general, the exposure apparatus includes a projection optical system having a plurality of optical members such as a mirror, a lens, and a field stop. And when the board | substrate which is exposure object is exposed, the exposure light inject | emitted from the light source is irradiated to a board | substrate via a projection optical system. At this time, in addition to the mirror that reflects the exposure light or the lens that transmits the exposure light, heat of the exposure light is also given to the lens barrel that holds these optical members. On the other hand, since the outer periphery of the lens barrel is exposed to the external atmosphere in which the lens barrel is placed, heat is given or taken away depending on the temperature difference between the temperature of the lens barrel and the external atmosphere. . Because of these various factors, the temperature of the lens barrel tends to change.

  Therefore, for example, in the technique described in Patent Document 1, a refrigerant pipe is provided so as to be in contact with the outer peripheral portion of the lens barrel. And the temperature change of a lens-barrel is suppressed by circulating the inside of piping by the refrigerant | coolant by which temperature was adjusted.

JP 2004-304145 A

  However, with the configuration in which the pipe is brought into direct contact with the outer periphery of the lens barrel and the refrigerant circulates inside the pipe, the vibration accompanying the circulation of the refrigerant is transmitted to the lens barrel and the optical member inside the pipe. . Such vibration causes positional deviation of the image projected on the substrate and fluctuations in the distance between the optical members.

  An aspect of the present invention has been made in view of such circumstances, and an object thereof is to provide an optical apparatus, an exposure apparatus, and a device manufacturing method that can improve exposure accuracy.

  In order to solve the above-mentioned problems, the following configuration corresponding to FIGS. 1 to 10 shown in the embodiments described later is employed in the aspect of the present invention.

  An optical device according to an aspect of the present invention is an optical device (14) including an optical member (17) held inside a lens barrel (16), and has physical properties that undergo phase transition between a liquid phase and a solid phase. And a metal material (19) in which the liquid phase and the solid phase coexist, and a first holding part (18) that is provided on an outer peripheral part of the lens barrel and holds the metal material. Is the gist.

  According to the above configuration, the metal material held by the first holding unit receives the heat of the lens barrel or gives heat to the lens barrel in accordance with the temperature change of the lens barrel, thereby causing the temperature of the lens barrel. Adjust. For this reason, since the temperature of the lens barrel is maintained within a predetermined range, it is possible to suppress thermal expansion and contraction of the lens barrel, and consequently the position of the optical member. Therefore, the accuracy of exposure through the optical device is improved.

  In addition, in order to explain the aspect of the present invention in an easy-to-understand manner, the configuration of the present invention and the reference numerals attached to the drawings used for the description of the embodiment have been described in association with each other. However, the aspect of the present invention is limited to the embodiment. Is not to be done.

1 is a diagram showing a schematic configuration of a scanning exposure apparatus in a first embodiment. The figure which shows the cross-section of the metal holding member periphery in 1st Embodiment. Binary eutectic phase diagram. The graph which shows the relationship between heating time and the temperature of a metal material. The graph which shows the relationship between the liquid level height of a metal material, and the state of a metal material. The figure which shows the cross-section of the metal holding member periphery in 2nd Embodiment. The figure which shows the cross-section of the metal holding member periphery in 3rd Embodiment. The figure which shows the cross-section of the metal holding member periphery in 4th Embodiment. The flowchart which shows the procedure of the process in the manufacture example of a device. The flowchart which shows the board | substrate process process in the manufacture example of a device in detail.

[First Embodiment]
Hereinafter, a first embodiment of an optical apparatus and an exposure apparatus according to an aspect of the present invention will be described with reference to FIGS.
[Exposure equipment]
First, the overall configuration of the exposure apparatus will be described with reference to FIG. As shown in FIG. 1, an exposure apparatus 10 of the present embodiment uses extreme ultraviolet light, ie, EUV (Extreme Ultraviolet) light, which is a soft X-ray region having a wavelength of about 100 nm or less, emitted from a light source device 11 as exposure light. This is a scanning EUV exposure apparatus used as an EL. The exposure apparatus 10 includes an exposure chamber C that is set in a predetermined temperature region within a vacuum atmosphere whose pressure is lower than that of the atmosphere. The light source device 11 is connected to the exposure chamber C via a connecting portion 11a. In the exposure chamber C, an illumination device 12 that illuminates a reflective reticle R on which a predetermined pattern is formed by the exposure light EL supplied from the light source device 11 into the exposure chamber C, and a pattern formation surface Ra are provided. A reticle stage 13 that holds the reticle R is provided. Further, in the exposure chamber C, a projection device 14 as an optical device that irradiates a wafer W coated with a photosensitive material such as a resist by exposure light EL through a reticle R, and a wafer stage 15 that holds the wafer W. And are provided.

  The light source device 11 is a device that outputs EUV light having a wavelength of 5 to 20 nm as exposure light EL, and includes a laser excitation plasma light source (not shown). In this laser-excited plasma light source, plasma is generated by irradiating a high-density EUV light generating substance (target) with a high-power laser such as a YAG laser or excimer laser using semiconductor laser excitation, and EUV light is emitted from the plasma. Is emitted as exposure light EL. Such exposure light EL is condensed by a condensing optical system (not shown) and output into the exposure chamber C.

  The illumination device 12 includes a housing 12a in which the inside is set to a vacuum atmosphere, similarly to the inside of the exposure chamber C. In the casing 12a, a plurality of reflection mirrors (not shown) that can reflect the exposure light EL incident from the light source device 11 into the casing 12a are provided. The exposure light EL sequentially reflected by the respective reflecting mirrors enters the reflecting mirror RM, is reflected by the reflecting mirror RM, and is guided to the reticle R held on the reticle stage 13.

  The reticle stage 13 is disposed on the object plane side of the projection device 14 and includes an electrostatic chuck holding device (not shown) that electrostatically chucks the reticle R. The reticle stage 13 can be moved relative to the projection device 14 by driving a reticle stage drive unit (not shown).

  The projection device 14 is an optical system that reduces an image of a pattern formed by illuminating the pattern forming surface Ra of the reticle R with exposure light EL to a predetermined reduction magnification such as 1/4. Similar to the inside of the exposure chamber C, the projection device 14 includes a lens barrel 16 whose inside is set to a vacuum atmosphere. A plurality of reflective mirrors 17 are accommodated in the lens barrel 16. The number of mirrors 17 accommodated in the lens barrel 16 is, for example, six, and only one is shown in FIG. 1 for convenience of illustration. Then, the exposure light EL guided from the reticle R side, which is the object plane side, is sequentially reflected by each mirror 17 and guided to the exposure surface Wa of the wafer W held on the wafer stage 15.

  A plurality of metal holding members 18 that hold liquid metal are connected to the outer periphery of the lens barrel 16. Each metal holding member 18 holds a metal material 19 that undergoes a phase transition between a liquid phase and a solid phase. The metal material 19 adjusts the temperature of the lens barrel 16 to a predetermined range by exchanging heat with the lens barrel 16 through the contact surface of the lens barrel 16.

  The wafer stage 15 includes an electrostatic chucking holding device (not shown) for electrostatically chucking the wafer W. The wafer stage 15 can be moved relative to the projection device 14 by a wafer stage driving unit (not shown).

When using the exposure apparatus 10 to form a circuit pattern of the reticle R on one shot area of the wafer W, first, the reticle stage driving unit performs the reticle R while the illumination area is formed on the reticle R by the illumination apparatus 12. The wafer stage drive unit moves the wafer W in synchronization with the movement direction of the reticle R at a speed ratio corresponding to the reduction magnification of the projection apparatus 14 with respect to the movement of the reticle R. Let When the formation of the circuit pattern in one shot area is completed, the circuit pattern is continuously formed in another shot area.
[Metal holding member]
Next, details of the metal holding member 18 and the surrounding structure will be described with reference to FIG. As shown in FIG. 2, the metal holding member 18 is an annular member formed of a heat insulating material such as various synthetic resins, and has an annular bottom wall portion 18 a having the same inner diameter as the outer diameter of the lens barrel 16. Have. A cylindrical peripheral wall portion 18b extending toward the reticle stage 13 is integrally formed on the outer peripheral edge of the bottom wall portion 18a over the entire periphery of the bottom wall portion 18a. A cylindrical connecting portion 18c extending toward the wafer stage 15 is formed integrally with the bottom wall portion 18a on the inner peripheral edge of the bottom wall portion 18a. An O-ring 18e is sandwiched between the bottom wall portion 18a and the lens barrel 16, and an O-ring 18f is also sandwiched between the connection portion 18c and the lens barrel 16.

  Then, the connecting portion 18c is screwed to the lens barrel 16 with a screw 18d, thereby sealing between the bottom wall portion 18a and the lens barrel 16 and between the connecting portion 18c and the lens barrel 16. Further, in the space sandwiched between the peripheral wall portion 18b and the lens barrel 16, an annular recess having the bottom wall portion 18a as the bottom is formed by the metal holding member 18 and the lens barrel 16, which is the first groove. The metal material 19 is held in the holding space S as the holding portion. In addition, since the metal holding member 18 is formed of a heat insulating material, it is possible to suppress the influence of the metal holding member 18 on the transfer of heat between the lens barrel 16 and the metal material 19.

  The metal material 19 is, for example, a binary alloy and an alloy having a eutectic composition. The metal material 19 is a solid-liquid coexisting phase in which the liquid phase and the solid phase coexist at a reference temperature that is the temperature of the lens barrel 16 when the exposure apparatus 10 is used.

Above the metal material 19, there is a measuring device M that measures the liquid level height H of the metal material 19 in the holding space S, that is, the distance between the surface of the bottom wall 18a on the holding space S side and the liquid level 19s. It is arranged. The measuring device M is a device that measures the height of the liquid surface 19s in a non-contact manner. For example, the emitted light directed to the surface of the metal material 19 is reflected by the liquid surface 19s of the metal material 19, and the measurement is performed. Based on the time until the detection by the apparatus M, the height of the liquid surface 19s of the metal material 19 is measured. From the height of the liquid surface 19s measured by the measuring device M, it is determined whether the metal material 19 is a liquid phase, a solid-liquid coexisting phase in which the liquid phase and the solid phase coexist, or a solid phase. can do. That is, the measuring device M of the present embodiment is a detection device that detects the ratio between the solid phase and the liquid phase in the metal material 19.
[Metal material]
Hereinafter, the characteristics of the metal material 19 will be described with reference to FIGS. As described above, the metal material 19 is a binary alloy composed of the metal A and the metal B, and as shown in FIG. 3, the melting point of the metal material 19 is the melting point Tma of the metal A alone and This is the eutectic point Tm which is lower than the melting point Tmb of the single metal B and which is the melting point when the metal A and the metal B are in the eutectic composition E. That is, the metal material 19 is a eutectic alloy that is an alloy having an eutectic composition E, and phase transition is performed between a liquid phase and a solid phase in the same manner as a single metal.

  That is, when the solid-phase metal material 19, for example, the metal material 19 at the temperature T1, is heated, as shown in FIG. 4, the temperature of the metal material 19 is equal to the eutectic point Tm from the timing t0 when the heating starts. Until the timing t1, the temperature of the metal material 19 continues to rise. At the timing t1, when the temperature of the metal material 19 reaches the eutectic point Tm, the metal material 19 that is a solid phase starts melting, and the metal material 19 becomes a solid-liquid coexisting phase. When the metal material 19 becomes a solid-liquid coexistence phase at the timing t1, the thermal energy given to the metal material 19 is consumed as latent heat until the timing t2 when all of the metal material 19 becomes a liquid phase. The temperature of the material 19 is kept constant. Then, when all of the metal material 19 becomes a liquid phase at the timing t2, the temperature of the metal material 19 starts to rise again.

  Thus, while the metal material 19 that is a eutectic alloy is in a solid-liquid coexisting phase, the temperature of the metal material 19 is kept constant even if heat dissipation and heat absorption of the metal material 19 occur. Therefore, for example, when the lens barrel 16 receives heat from the outside and its temperature becomes higher than the reference temperature, the metal material 19 receives the heat corresponding to the temperature rise of the lens barrel 16 and thus receives the heat. Consumes heat as latent heat. Thereby, the ratio of the liquid phase to the total amount of the metal material 19 becomes larger than before the heat from the lens barrel 16 is received. On the other hand, when the temperature of the lens barrel 16 is reduced to be lower than the reference temperature, the metal material 19 gives heat corresponding to the temperature drop of the lens barrel 16. Thereby, the ratio of the solid phase in the total amount of the metal material 19 becomes larger than before the heat is applied to the lens barrel 16.

Examples of combinations of metals constituting the metal material 19, eutectic compositions of the combinations, and eutectic points are given below.
Ga—In alloy Ga: In = 84: 16 (at%) Eutectic point 15.7 ° C.
Ga—Sn alloy Ga: Sn = 92: 8 (at%) Eutectic point 20.5 ° C.
Ga—Zn alloy Ga: Zn = 94: 6 (at%) Eutectic point 25 ° C.
Ga—Al alloy Ga: Al = 91: 9 (at%) Eutectic point 26.4 ° C.
Hg-Na alloy Hg: Na = 15: 85 (at%) Eutectic point 21 ° C.
Among the combinations described above, a combination of metals that become a solid-liquid coexistence phase at a reference temperature set in the lens barrel 16, for example, a temperature at which the thermal expansion of the lens barrel 16 or the mirror 17 falls within a predetermined range, Selected as material 19. For convenience of explanation and illustration, FIG. 3 shows a phase diagram of a two-component system in which the metal A and the metal B are dissolved regardless of the mixing ratio if they are liquids, but the solids are hardly dissolved. Show.

  Further, as shown in FIG. 5, the liquid level height H measured by the measuring device M is a height HS when all of the metal material 19 is in a solid phase, and the metal material 19 is a solid-liquid. When the phase is a coexisting phase, the liquid surface height H increases as the proportion of the liquid phase in the total amount of the metal material 19 increases. The height HL is reached when all of the metal material 19 is in a liquid phase.

Here, when the metal material 19 is in a solid-liquid coexisting phase, as described above, even if the temperature of the lens barrel 16 rises and falls, the temperature of the lens barrel 16 is maintained substantially constant due to heat absorption and heat dissipation by the metal material 19. Is done. However, if the metal material 19 is in a liquid phase or a solid phase, the temperature of the metal material 19 also increases and decreases as the temperature of the lens barrel 16 increases and decreases. As a result, the distance between the mirrors 17 varies due to thermal expansion and contraction of the lens barrel 16, and the accuracy of exposure by the exposure apparatus 10 decreases. Therefore, in the exposure apparatus 10, when the liquid level height H is in the following range, the exposure is stopped because the exposure accuracy cannot be sufficiently obtained.
When the height of the metal material 19 is less than the height H1 that is larger than the height HS when the metal material 19 is a solid phase by a predetermined distance.
When the height H2 that is smaller by a predetermined distance than the height HL when all of the metal material 19 is in the liquid phase is exceeded.

  As described above, according to the first embodiment of the optical apparatus and the exposure apparatus according to the aspect of the present invention, the effects listed below can be obtained.

  (1) A metal holding member 18 is provided on the outer periphery of the lens barrel 16 and a metal material 19 is held in the metal holding member 18. Therefore, the metal material 19 exchanges heat with the lens barrel 16 through the contact surface of the lens barrel 16 to adjust the temperature of the lens barrel 16 to a predetermined range. Therefore, the temperature of the lens barrel 16 can be kept at a predetermined temperature. In addition, the accuracy of exposure by the exposure apparatus 10 can be increased.

  (2) An alloy having a eutectic composition that is a solid-liquid coexisting phase at the reference temperature of the lens barrel 16 is used as the metal material 19. Therefore, even when the temperature of the lens barrel 16 is higher or lower than the reference temperature, the metal material 19 is easily maintained at a constant temperature while absorbing or radiating heat by the temperature change of the lens barrel 16. . Therefore, the temperature of the lens barrel 16 can be kept at a predetermined temperature. In addition, the accuracy of exposure by the exposure apparatus 10 can be increased.

  (3) When the liquid level height H of the metal material 19 is less than the height H1 that is a predetermined distance larger than the height HS when all of the metal material 19 is a solid phase, and all of the metal material 19 When the height H2 is smaller by a predetermined distance than the height HL when the liquid is in the liquid phase, the exposure by the exposure apparatus 10 is stopped. For this reason, exposure by the exposure apparatus 10 is not performed in a temperature range where the thermal expansion or contraction of the lens barrel 16 occurs, so that it is possible to suppress a reduction in exposure accuracy on the wafer W.

(4) The metal holding member 18 is formed of a heat insulating material. Therefore, it is possible to suppress the metal holding member 18 from affecting the transfer of heat between the lens barrel 16 and the metal material 19. Therefore, it becomes easy to keep the temperature of the lens barrel 16 constant.
[Second Embodiment]
A second embodiment of the optical apparatus and exposure apparatus according to an aspect of the present invention will be described below with reference to FIG. In addition, this embodiment differs in the structure of the metal holding member periphery provided in the outer periphery of the lens-barrel 16 compared with the said 1st Embodiment. Therefore, in the following, the periphery of the metal holding member of the optical device and the exposure device will be described in detail.
[Metal holding member]
As shown in FIG. 6, the metal holding member 21 is an annular member formed of a heat insulating material such as various synthetic resins as in the first embodiment, and has a circle having the same inner diameter as the outer diameter of the lens barrel 16. It has an annular bottom wall 21a. A cylindrical peripheral wall portion 21b extending toward the reticle stage 13 is formed integrally with the bottom wall portion 21a at the outer peripheral edge of the bottom wall portion 21a, and the wafer stage is provided at the inner peripheral edge of the bottom wall portion 21a. A cylindrical connecting portion 21c extending to the 15 side is formed integrally with the bottom wall portion 21a. An O-ring 21 e is fitted between the bottom wall portion 21 a and the lens barrel 16, and an O-ring 21 f is fitted between the connection portion 18 c and the lens barrel 16. Then, the connection portion 21c is screwed to the lens barrel 16 with a screw 21d, thereby sealing between the bottom wall portion 21a and the lens barrel 16 and between the connection portion 21c and the lens barrel 16.

  A heat conducting portion 21g having a cylindrical shape concentric with the outer peripheral edge and the inner peripheral edge of the bottom wall 21a is disposed at the approximate center. The heat conducting portion 21g includes a partition portion 21h having a cylindrical shape concentric with the peripheral wall portion 21b, and a flange portion 21i orthogonal to the partition portion 21h. The flange portion 21i is screwed to the bottom wall portion 21a by a screw 21j disposed so as to sandwich the partition portion 21h. The heat conducting part 21g is formed of a heat conductive material such as metal.

  In the space between the heat conducting portion 21g and the lens barrel 16, an annular recess having the bottom wall portion 21a as the bottom is formed by a part of the metal holding member 21 and the lens barrel 16. A metal material 19 similar to that of the first embodiment is held in a first holding space S1 as a certain first holding portion.

  Above the metal material 19, as in the first embodiment, the liquid level height H of the metal material 19 in the first holding space S1, that is, the surface of the bottom wall portion 21a on the first holding space S1 side, A measuring device M for measuring the distance from the liquid level 19s is provided.

Further, in the space sandwiched between the peripheral wall portion 21b and the heat conducting portion 21g, an annular concave portion having the bottom wall portion 21a as a bottom portion is formed by a part of the metal holding member 21, and the second holding portion is the concave portion. The thermally conductive liquid material 22 is held in the second holding space S2 as a part. One end of the metal block 23 is immersed in the liquid material 22, and the other end of the metal block 23 is connected to the refrigerant pipe 26. For example, the end of the metal block 23 on the wafer stage 15 side is immersed in the liquid material 22, and the end of the metal block 23 on the reticle stage 13 side is interposed via a Peltier element 24 and a pipe connection portion 25. And connected to the refrigerant pipe 26.
[Liquid material]
As the liquid material 22 held in the second holding space S2, Ga, an alloy containing Ga, and a liquid metal such as mercury can be used. When an alloy containing Ga is selected as the liquid material 22, an alloy having a eutectic composition may be used as in the case of the metal material 19. As the liquid material 22, it is preferable to select a material having a melting point lower than the reference temperature of the lens barrel 16 and the eutectic point of the metal material 19. Thereby, it can suppress that the liquid material 22 turns into a solid phase.

Further, as the liquid material 22, a magnetic fluid in which magnetic powder is dispersed in oil or liquid metal can be used. In this case, by applying an external magnetic field to the liquid material 22, the liquid material 22 is easily held in the second holding space S2.
[Adjustment device]
In the present embodiment, the metal block 23, the Peltier element 24, the pipe connecting portion 25, and the refrigerant pipe 26 adjust the transfer of heat to the metal material 19 held in the first holding space S1, thereby the metal material. The adjustment apparatus which maintains 19 in the state of a solid-liquid coexistence phase is comprised. Hereinafter, the adjustment device will be described in detail.

  The metal block 23 is formed of a material having a relatively high thermal conductivity such as copper, copper alloy, aluminum, aluminum alloy, and molybdenum. When the forming material of the metal block 23 is corroded by the liquid material 22, the surface of the metal block 23 may be protected from the liquid material 22 by plating or the like. The metal block 23 is provided over the entire circumferential direction of the lens barrel 16.

  The heat absorption side of the Peltier element 24 is thermally connected to the metal block 23, and the heat dissipation side of the Peltier element 24 is thermally connected to the refrigerant pipe 26 via the pipe connection part 25. The Peltier element 24 is electrically connected to a control device that controls the degree of heat absorption. And the Peltier device 24 maintains the temperature of the metal block 23 substantially constant by adjusting the degree of heat absorption with respect to the metal block 23 according to the control signal from a control apparatus.

  In the refrigerant pipe 26, the refrigerant maintained at a constant temperature by a temperature adjusting device (not shown) flows. And the refrigerant | coolant piping 26 maintains the temperature of the thermal radiation side in the Peltier device 24 substantially constant by removing the heat of the thermal radiation side in the Peltier device 24 via the piping connection part 25. FIG.

  According to the metal holding member 21 and the adjusting device of the present embodiment, the temperature of the lens barrel 16 is maintained substantially constant in the following manner. That is, when the temperature of the lens barrel 16 becomes higher than the reference temperature, the metal material 19 in contact with the outer periphery of the lens barrel 16 increases the heat received from the lens barrel 16. Since the metal material 19 is a solid-liquid coexistence phase at the reference temperature of the lens barrel 16 as described above, the temperature is maintained at the eutectic point by consuming heat from the lens barrel 16 as latent heat. However, the ratio of the liquid phase to the whole metal material 19 is increased.

  When the liquid level height H of the metal material 19 measured by the measuring device M exceeds the height H2, the control device outputs a control signal for increasing the heat absorption side output in the Peltier element 24. Output for. Thereby, in the Peltier element 24, the heat absorption by the liquid material 22 through the metal block 23, that is, the heat absorption to the metal material 19 through the liquid material 22 and the heat conducting portion 21g is strengthened. At this time, since the refrigerant continues to circulate in the refrigerant pipe 26, the temperature on the heat dissipation side of the Peltier element 24 is maintained constant, and accordingly, the temperature on the heat absorption side of the Peltier element 24 is also maintained at a predetermined temperature. Become so. Note that most of the vibration generated by the circulation of the refrigerant is absorbed by the liquid material 22 and the metal material 19, so that transmission of vibration to the lens barrel 16 is suppressed. As a result, since the ratio of the liquid phase to the whole metal material 19 becomes small, the liquid level height H of the metal material 19 measured by the measuring device M becomes smaller than the height H2.

  On the other hand, when the lens barrel 16 is cooled and its temperature becomes lower than the reference temperature, the metal material 19 radiates heat to the lens barrel 16. When the metal material 19 dissipates heat, the ratio of the solid phase in the entire metal material 19 increases while the temperature is maintained at the eutectic point.

  When the liquid level height H measured by the measuring device M becomes less than the height H1, the control device outputs a control signal to the Peltier element 24 for reducing the heat absorption side output of the Peltier element 24. . Thereby, in the Peltier element 24, the heat absorption by the liquid material 22 through the metal block 23, that is, the heat absorption by the metal material 19 through the liquid material 22 and the heat conducting portion 21g is weakened. At this time, since the refrigerant continues to circulate in the refrigerant pipe 26, the temperature on the heat dissipation side of the Peltier element 24 is maintained constant, and accordingly, the temperature on the heat absorption side of the Peltier element 24 is also maintained at a predetermined temperature. Become so. Since most of the vibration generated by the circulation of the refrigerant is absorbed by the liquid material 22 and the metal material 19 as described above, transmission of vibration to the lens barrel 16 is suppressed. As a result, since the ratio of the solid phase to the whole metal material 19 is reduced, the liquid level height H of the metal material 19 measured by the measuring device M is larger than the height H1.

  Thus, in the present embodiment, when the liquid surface height H of the metal material 19 exceeds the height H2 and less than the height H1, heat absorption or heat dissipation by the Peltier element 24, In addition, by circulating the refrigerant, the metal material 19 is prevented from deviating from the solid-liquid coexistence phase.

  As described above, according to the second embodiment of the optical apparatus and the exposure apparatus according to the aspect of the present invention, in addition to the effects obtained by the first embodiment, the following effects can be obtained.

  (5) One end of the metal block 23 is immersed in the liquid material 22 held in the second holding space S2 of the metal holding member 21, and the other end of the metal block 23 is connected to the Peltier element 24 and the pipe connecting portion 25. The refrigerant pipe 26 is connected via Then, when the liquid level height H of the metal material 19 held in the first holding space S1 is less than the height H1 and exceeds the height H2, the refrigerant flowing through the Peltier element 24 and the refrigerant pipe 26 The liquid surface height H of the metal material 19 is set to be not less than the height H1 and not more than the height H2. For this reason, even if the metal material 19 applies heat to the lens barrel 16 or receives heat from the lens barrel 16, the metal material 19 is maintained in a solid-liquid coexistence state. Therefore, since the temperature of the metal material 19 is kept constant, the temperature of the lens barrel 16 is also kept constant. Therefore, the accuracy of exposure by the exposure apparatus 10 is improved.

(6) The vibration generated by the refrigerant flowing in the refrigerant pipe 26 is absorbed by the liquid material 22 and the metal material 19. Therefore, even if the circulation of the refrigerant is used to maintain the temperature of the metal material 19, the vibration caused by the circulation of the refrigerant is not easily transmitted to the lens barrel 16. Therefore, it is possible to suppress a reduction in exposure accuracy by the exposure apparatus 10.
[Third Embodiment]
A third embodiment of the optical apparatus and the exposure apparatus according to an aspect of the present invention will be described below with reference to FIG. In addition, this embodiment differs in the structure of the metal holding member periphery provided in the outer periphery of the lens-barrel 16 compared with the said 1st Embodiment and 2nd Embodiment. Therefore, in the following, the periphery of the metal holding member of the optical device and the exposure device will be described in detail.
[Metal holding member]
As shown in FIG. 7, the metal holding member 18 is an annular member formed of a heat insulating material such as various synthetic resins as in the first embodiment, and includes a bottom wall portion 18a, a peripheral wall portion 18b, and a connection. It has a portion 18c. An O-ring 18e is sandwiched between the bottom wall portion 18a and the lens barrel 16, and an O-ring 18f is also sandwiched between the connecting portion 18c and the lens barrel 16. Then, the connecting portion 18c is screwed to the lens barrel 16 with a screw 18d, thereby sealing between the bottom wall portion 18a and the lens barrel 16 and between the connecting portion 18c and the lens barrel 16.

  Further, in the space sandwiched between the peripheral wall portion 18b and the lens barrel 16, an annular recess having the bottom wall portion 18a as the bottom is formed by the metal holding member 18 and the lens barrel 16, and this is the first recess. The metal material 19 is held in the holding space S as a holding portion. Above the metal material 19, a measuring device M for measuring the liquid level height H is disposed.

  In the holding space S, while being immersed in the metal material 19, a refrigerant pipe 31 as an adjusting device is provided so as not to contact the bottom wall portion 18a, the peripheral wall portion 18b, and the lens barrel 16 that form the holding space S. It is provided over the entire holding space S which is the concave portion. A refrigerant maintained at a constant temperature by a temperature control device (not shown) flows in the refrigerant pipe 31. As in the second embodiment, the circulation of the refrigerant is performed when the liquid level height H measured by the measuring device M becomes less than the height H1 and exceeds the height H2.

  Thereby, even if the metal material 19 receives heat from the lens barrel 16 or gives heat to the lens barrel 16 by the temperature of the lens barrel 16 becoming higher or lower than the reference temperature, the inside of the refrigerant pipe 31 is maintained. The circulating refrigerant gives heat to the metal material 19 or receives heat from the metal material 19, whereby the metal material 19 is maintained in a solid-liquid coexisting phase. Therefore, since the temperature of the metal material 19 is kept constant, the temperature of the lens barrel 16 is also kept constant, and as a result, the accuracy of exposure by the exposure apparatus 10 is improved.

  In the present embodiment, the refrigerant circulating in the refrigerant pipe 31 receives heat directly from the metal material 19, or heat is directly applied to the metal material 19. Therefore, transfer of heat between the metal material 19 and the refrigerant is performed in a shorter period of time than through another member or liquid material. Therefore, the metal material 19 is more easily maintained in a solid-liquid coexisting phase.

  In addition, the vibration generated by the circulation of the refrigerant in the refrigerant pipe 31 is absorbed by the metal material 19, so that it is difficult to be transmitted to the lens barrel 16. Therefore, even if heat is transferred to the metal material 19 by circulating the refrigerant, it is possible to suppress a decrease in exposure accuracy by the exposure apparatus 10.

  According to the present embodiment, in addition to the effects obtained by the first embodiment, the following effects can be obtained.

  (7) The refrigerant pipe 31 is immersed in the metal material 19, and when the liquid surface height H of the metal material 19 is less than the height H1 and exceeds the height H2, the refrigerant pipe 31 is used. Heat is transferred between the metal material 19 and the refrigerant by circulating the refrigerant therein. Thereby, since the metal material 19 is maintained in the solid-liquid coexisting phase, the temperature of the lens barrel 16 is also maintained constant. Therefore, the accuracy of exposure by the exposure apparatus 10 can be improved.

(8) The refrigerant pipe 31 in which the refrigerant circulates is immersed in the metal material 19. For this reason, the vibration generated by the circulation of the refrigerant is absorbed by the metal material 19, and is thus difficult to be transmitted to the lens barrel 16. Therefore, even if heat is transferred to the metal material 19 by circulating the refrigerant, it is possible to suppress a decrease in exposure accuracy by the exposure apparatus 10.
[Fourth Embodiment]
Hereinafter, a fourth embodiment of an optical apparatus and an exposure apparatus according to an aspect of the present invention will be described with reference to FIG. In addition, this embodiment differs in the structure of the adjustment apparatus provided in the holding space holding a metal material compared with the said 3rd Embodiment. Therefore, in the following, the adjustment apparatus included in the optical apparatus and the exposure apparatus of the present embodiment will be described in detail.
[Metal holding member]
As shown in FIG. 8, similar to the third embodiment, the bottom wall portion 18 a of the metal holding member 18 is a bottom portion, and a recess formed in a space between the peripheral wall portion 18 b and the lens barrel 16. Thus, the metal material 19 is held in the holding space S as the first holding portion. A measuring device M that measures the liquid level height H of the metal material 19 is disposed above the metal material 19.

  A first adjusting device is configured so that the holding space S is immersed in the metal material 19 but does not come into contact with the bottom wall portion 18a, the peripheral wall portion 18b, and the lens barrel 16 that form the holding space S. A refrigerant pipe 41 is provided over the entire holding space S which is the concave portion. In the first refrigerant pipe 41, a refrigerant maintained at a constant temperature by a temperature control device (not shown) flows, and the second refrigerant pipe is connected via a Peltier element 42 disposed in the first pipe connection portion 41a. 43 2nd piping connection parts 43a are connected. Similarly to the first refrigerant pipe 41, the refrigerant maintained at a constant temperature by the temperature controller flows through the second refrigerant pipe 43. That is, in this embodiment, the adjustment apparatus is comprised by the 1st refrigerant | coolant piping 41, the 1st piping connection part 41a, the Peltier element 42, the 2nd refrigerant | coolant piping 43, and the 2nd piping connection part 43a.

  In the present embodiment, when the liquid level height H measured by the measuring device M is less than the height H1 and exceeds the height H2, heat dissipation or heat absorption by the Peltier element 42, and the first refrigerant The refrigerant is circulated in the pipe 41 and the second refrigerant pipe 43. Thereby, the state of the metal material 19 is maintained in a solid-liquid coexisting phase.

According to the present embodiment, the effect obtained by the first embodiment and the effect obtained by the third embodiment can be obtained.
[Other Embodiments]
In addition, the said embodiment can also be suitably changed and implemented as follows.

  Although the metal holding members 18 and 21 are provided over the entire circumferential direction of the lens barrel 16, the metal holding members 18 and 21 may be provided in a part of the lens barrel 16 in the circumferential direction. Moreover, you may provide in the multiple places of the lens-barrel 16. For example, the metal holding members 18 and 21 may be provided in a portion of the lens barrel 16 where the temperature of the lens barrel 16 is likely to change. Further, the metal holding members 18 and 21 are not limited to the outer peripheral portion of the lens barrel 16, and may be provided in the inner portion or the inner peripheral portion of the lens barrel 16.

  Although the bottom wall portions 18a and 21a, the peripheral wall portions 18b and 21b, and the connection portions 18c and 21c of the metal holding members 18 and 21 are formed of various resin materials, they are more thermally conductive than the lens barrel 16 and the metal material 19. You may make it form using material with low property.

  The metal material 19 may be an alloy having no eutectic composition as long as it is a solid-liquid coexisting phase at the reference temperature of the lens barrel 16.

  The metal material 19 is not limited to the combination of the above metals, but includes gallium (Ga), indium (In), tin (Sn), zinc (Zn), aluminum (Al), sodium (Na), and mercury (Hg). What is necessary is just an alloy containing at least one. For example, not only a binary alloy but also an alloy containing three or more metals may be used.

  The metal material 19 is not limited to the above-described alloy, but may be a single metal of gallium (Ga) or cesium (Cs). The freezing point of Ga is 29.8 ° C., and the freezing point of Cs is 28.4 ° C. Therefore, since it has a freezing point near the temperature generally set as the reference temperature of the lens barrel 16, it is easy to maintain a solid-liquid coexisting phase state during use of the exposure apparatus 10.

  The metal material 19 is not limited to gallium and cesium as long as it is a solid-liquid coexisting phase at the reference temperature of the lens barrel 16, but may be other single metals.

  The O-rings 18e and 18f may not be provided between the metal holding members 18 and 21 and the lens barrel 16. The metal holding members 18 and 21 and the lens barrel 16 may be in close contact so that the metal material 19 does not leak.

  Although the lens barrel 16 and the metal holding members 18 and 21 are separately formed, the lens barrel 16 and the metal holding member 18 may be formed integrally. For example, a metal holding member may be formed on the lens barrel. This eliminates the need for the O-rings 18e and 18f and the screw 18d, and prevents the metal material 19 from leaking out. Further, the projection device 14 according to the aspect of the present invention is simplified.

  Although the metal holding members 18 and 21 are formed of a heat insulating material, the metal holding members 18 and 21 may not be a heat insulating material. For example, you may comprise with a low thermal expansion material and material with high heat conductivity.

  The measuring apparatus M measures the liquid level 19s of the metal material 19 from above, but may measure from the side. For example, a light transmission window may be provided in a part of the peripheral wall portion 18b of the metal holding member 18, and the liquid level 19s of the metal material 19 may be measured through the light transmission window. Accordingly, the measuring device M can be provided at a position away from the lens barrel 16.

  In the first embodiment, the exposure by the exposure apparatus 10 is stopped when the liquid level height H of the metal material 19 is less than the height H1 and exceeds the height H2. Not limited to this, the exposure by the exposure apparatus 10 may be stopped when the liquid level height H is less than the height HS and exceeds the height HL.

  In the first embodiment, the exposure by the exposure apparatus 10 is stopped when the liquid level height H is less than the height H1 or exceeds the height H2. However, the present invention is not limited to this, and a warning for notifying the user of the exposure apparatus 10 that the liquid level height H is in such a range, for example, displaying a warning on the display unit or sounding a warning sound, is performed. Also good. Further, the temperature change of the lens barrel 16 is predicted, the position and inclination of the optical member are adjusted, the shot area when in such a range is stored, and the chip of the shot area is extracted later. Also good.

  In the second embodiment, the metal block 23 is provided over the entire metal holding member 18, but the metal block 23 may be provided in a part of the metal holding member 18.

  In the second embodiment, the Peltier element 24 keeps the temperature of the metal block 23 constant, but keeps the temperature of the liquid material 22, the temperature of the metal material 19, the temperature of the lens barrel 16, etc. It may be.

  In the third embodiment, the heat conducting portion 21g and the bottom wall portion 21a are formed separately, but the heat conducting portion 21g may be formed integrally with the bottom wall portion 21a. This eliminates the need for the screw 21j and prevents the metal material 19 and the liquid material 22 from being mixed. Further, the projection device 14 according to the aspect of the present invention is simplified.

  In the third embodiment, the refrigerant is circulated when the liquid level height H deviates from the range of the height H1 to the height H2, but the liquid level height H is high. The refrigerant may be circulated when it deviates from the range from HS to height HL.

  In the third embodiment, the refrigerant is circulated when the liquid surface height H of the metal material 19 deviates from the range of the height H1 or more and the height H2 or less. It may be performed all the time when 10 is used.

  In the second embodiment and the fourth embodiment, when the liquid level height H deviates from the range of the height H1 to the height H2, the Peltier elements 24 and 42 are driven and the refrigerant is circulated. However, when the liquid level height H deviates from the range of the height HS to the height HL, the Peltier elements 24 and 42 may be driven and the refrigerant may be circulated.

  In the second and fourth embodiments, the driving of the Peltier elements 24 and 42 and the circulation of the refrigerant are performed when the liquid level height H deviates from the range of the height H1 to the height H2. However, the driving of the Peltier elements 24 and 42 and the circulation of the refrigerant may be always performed when the exposure apparatus 10 is used.

  In the third embodiment and the fourth embodiment, the refrigerant pipes 31, 41, and 43 are provided over the entire metal holding member 18, but the refrigerant pipes 31, 41, and 43 are provided as part of the metal holding member 18. It may be provided in the part.

  In the first embodiment, the adjustment device of the second embodiment is adopted, that is, the metal block 19 connected to the refrigerant pipe through the Peltier element and the pipe connection portion is immersed in the metal material 19 of the first embodiment. By adopting such a configuration, the metal material 19 may be maintained in a solid-liquid coexisting phase.

  -As an adjustment apparatus of 2nd Embodiment, you may make it set it as the structure which employ | adopts the adjustment apparatus of 3rd Embodiment, ie, the refrigerant | coolant piping was immersed in the liquid material.

  As the adjusting device of the second embodiment, the adjusting device of the fourth embodiment is adopted, that is, an adjusting device having two refrigerant pipes and a Peltier element sandwiched between the refrigerant pipes may be adopted. .

  In the first embodiment, the second embodiment, the third embodiment, and the fourth embodiment, an example in which an optical device including a metal holding member, a metal material, and an adjustment device is used for the projection device 14 has been described. An aspect of the invention may be used for the lighting device 12.

  The exposure object of the scanning exposure apparatus 10 includes a wafer W for forming a microdevice such as a semiconductor chip such as the silicon substrate, an optical exposure apparatus, an EUV exposure apparatus, an X-ray exposure apparatus, and an electronic device. It may be a substrate for forming a reticle or mask used in a line exposure apparatus or the like. The exposure target of the scanning exposure apparatus may be a substrate for forming a liquid crystal display, a plasma display, or the like, or a substrate for forming an imaging device such as a CCD.

  When a light source that emits EUV is adopted as the light source device 11, gaseous tin (Sn), liquid or solid tin, and xenon ( Xe) or the like can be used.

The light source device 11 includes, for example, g-line (436 nm), i-line (365 nm), ArF excimer laser (193 nm), KrF excimer laser (248 nm), F ₂ laser (157 nm), Kr ₂ laser (146 nm), A light source that emits an Ar ₂ laser (126 nm) or the like can be used. In addition, as the light source device 11, a fiber amplifier in which a single wavelength laser beam in an infrared region or a visible region oscillated by a solid-state laser light source such as a DFB semiconductor laser or a fiber laser is doped with erbium or both erbium and ytterbium, etc. It is also possible to use a light source that emits a harmonic wave that has been amplified by the above and wavelength-converted into ultraviolet light using a nonlinear optical crystal.

  In addition, as the light source mounted on the light source device 11, a discharge-type plasma light source can be adopted.

  The scanning exposure apparatus 10 can be embodied as a step-and-repeat apparatus.

  Next, an embodiment in which a device manufacturing method using the exposure apparatus 10 of the above embodiment is embodied as a micro device manufacturing method will be described with reference to FIGS. 9 and 10. FIG. 9 is a flowchart showing an example of a manufacturing method of these micro devices such as a semiconductor chip such as an IC or LSI, a display panel, a CCD, a thin film magnetic head, a micromachine, or the like.

  First, in the design process, functional design and performance design of a micro device are performed, and then a target pattern for realizing the designed function and performance is designed (step S101). Subsequently, in the mask manufacturing process, a mask, for example, a reticle R, or pattern data for driving a variable molding mask, for example, a pattern formed by the variable molding mask is generated based on the target pattern based on the designed target pattern. (Step S102). On the other hand, in the substrate manufacturing process, a substrate that is a base material of a micro device such as a silicon substrate, a glass substrate, or a ceramic substrate is prepared (step S103).

  Next, in the substrate processing step as a processing step, a film formation technique for forming various films on the substrate, a lithography technique using the pattern data and the exposure apparatus 10 described above, and a part of the film formed on the substrate An actual pattern such as a circuit pattern is formed on the substrate by an etching technique or the like for etching (step S104). Subsequently, in the device assembly process, the device is assembled using the substrate after the substrate processing (step S105). In this device assembly process, various mounting processes such as dicing, bonding, and packaging are performed as necessary. Next, in the inspection process, various inspections such as an operation confirmation test and a durability test of the microdevice assembled in the device assembly process are performed (step S106). And a micro device is manufactured through these processes.

  FIG. 10 is an example showing a part of the substrate processing step described above, and is a flowchart showing various processes for forming a thin film transistor on a silicon substrate.

  First, in the oxidation step, the surface of the heated silicon substrate is thermally oxidized in an oxygen atmosphere, whereby a gate insulating film is formed (step S111). In the CVD process, a gate electrode film such as a polysilicon film is formed on the gate oxide film by a CVD method (step S112). In the resist film forming step, a photosensitive material is applied on the gate electrode film, thereby forming a resist film on the entire surface of the substrate (step S113). In the exposure process, an exposure pattern is formed on the resist film by the exposure apparatus 10 based on the mask pattern formed by the reticle R and the variable shaping mask (step S114). In the development process, the resist film exposed in the exposure process is developed, thereby forming a resist pattern that covers a portion where the gate is formed (step S115). In the etching process, etching using the resist pattern as a mask is performed, whereby the gate insulating film and the gate electrode film are patterned (step S116). In the ion implantation step, ions are implanted into a region of the silicon substrate that is not covered with the resist mask (step S117). In the resist removal process, the resist pattern used for the etching is removed, for example, in an oxygen radical atmosphere (step S118).

  DESCRIPTION OF SYMBOLS 10 ... Exposure apparatus, 11 ... Light source device, 11a ... Connection part, 12 ... Illumination device, 12a ... Case, 13 ... Reticle stage, 14 ... Projection apparatus, 15 ... Wafer stage, 16 ... Lens barrel, 17 ... Mirror, 18 , 21 ... Metal holding member, 18a, 21a ... Bottom wall part, 18b, 21b ... Peripheral wall part, 18c, 21c ... Connection part, 18d, 21d, 21j ... Screw, 18e, 18f, 21e, 21f ... O-ring, 19 ... Metal material, 19s ... Liquid level, 21g ... Heat conduction part, 21h ... Partition part, 21i ... Flange part, 22 ... Liquid material, 23 ... Metal block, 24, 42 ... Peltier element, 25 ... Pipe connection part, 26, 31 ... refrigerant pipe, 41 ... first refrigerant pipe, 41a ... first pipe connection part, 43 ... second refrigerant pipe, 43a ... second pipe connection part, C ... exposure chamber, EL ... exposure light, M ... measuring apparatus, R ... Retic , Ra ... pattern formation surface, RM ... reflecting mirror, S ... holding space, S1 ... first holding space, S2 ... second holding space, W ... wafer, Wa ... exposed surface.

Claims (15)

An optical device comprising an optical member held inside a lens barrel,
A metal material having a phase transition between a liquid phase and a solid phase, wherein the liquid phase and the solid phase coexist;
A first holding portion that is provided on an outer peripheral portion of the lens barrel and holds the metal material;
An optical device comprising: The metal material is
The optical apparatus according to claim 1, wherein a ratio between the liquid phase and the solid phase is changed by changing a temperature. The metal material is
The optical apparatus according to claim 2, wherein when the temperature of the lens barrel rises, the ratio of the liquid phase to the solid phase is increased by receiving heat from the lens barrel. The metal material is
The optical apparatus according to claim 2, wherein when the temperature of the lens barrel decreases, heat is applied to the lens barrel to reduce the ratio of the liquid phase to the solid phase. The metal material is
The single metal or metal alloy selected to be a solid-liquid coexisting phase in which the liquid phase and the solid phase coexist at the reference temperature set in the lens barrel. The optical device according to any one of claims 1 to 4. The single metal is
6. The optical device according to claim 5, wherein the optical device is gallium (Ga) or cesium (Cs). The metal alloy is
6. The material according to claim 5, comprising at least one of gallium (Ga), indium (In), tin (Sn), zinc (Zn), aluminum (Al), sodium (Na), and mercury (Hg). Optical device.   8. The apparatus according to claim 5, further comprising an adjusting device that adjusts a ratio between a liquid phase and a solid phase of the lens barrel or the metal material so as to be the reference temperature. The optical device described. The adjusting device is
A second holding unit that is provided outside the first holding unit with respect to the lens barrel and holds a liquid material that exchanges heat with the metal material via the first holding unit;
A temperature adjustment device that adjusts the temperature of the liquid material by contacting at least a portion of the liquid material and exchanging heat with the liquid material;
The optical apparatus according to claim 8, comprising: The liquid material is
The optical device according to claim 9, wherein the optical device absorbs vibration propagated from the temperature control device. The liquid material is
The optical device according to claim 9, wherein the optical device is a liquid metal containing at least one of gallium (Ga) and indium (In).   The optical device according to claim 1, further comprising a detection device that detects a ratio between a solid phase and a liquid phase of the metal material. It further comprises a detection device for detecting the ratio of the solid phase and the liquid phase of the metal material,
The adjusting device is
The optical device according to any one of claims 8 to 11, wherein a ratio between a liquid phase and a solid phase of the metal material is adjusted based on a detection result of the detection device. An illumination device that illuminates the mask using light from a light source;
In an exposure apparatus comprising: a projection device that projects an image of a pattern formed on the mask onto an object;
An exposure apparatus, wherein at least one of the illumination device and the projection device comprises the optical device according to any one of claims 1 to 13. A device manufacturing method for manufacturing a device, comprising:
An exposure step of exposing an object using the exposure apparatus according to claim 14;
A development step of developing the object exposed in the exposure step;
A processing step of processing the surface of the object;
A device manufacturing method including:

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