JP2016161923A - Exposure device, and method for manufacturing article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exposure device capable of performing effective temperature adjustment of a projection optical system inside while suppressing enlarging of device size.SOLUTION: In an exposure device, a projection optical system includes an optical system where a pair of recessed mirror and projecting mirror are arranged oppositely so as to let light reflect in the order of a first area of a reflection plane of the recessed mirror, and a second area of a reflection plane of the projecting mirror and a reflection plane of the recessed mirror. A first through hole piercing into the front and back of the recessed mirror is formed between the first area and the second area of the recessed mirror. A temperature adjusting mechanism circulates temperature-adjusted gas through the first through hole in a direction where the recessed mirror and the projecting mirror are aligned.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exposure apparatus and an article manufacturing method.

  In an exposure apparatus that exposes a substrate via an original and a projection optical system, deformation due to absorption of exposure heat of a mirror of the projection optical system that reflects exposure light and temperature fluctuations in the surrounding space can be problematic. With respect to such a problem, Patent Document 1 discloses a projection optical system having an optical element including a concave mirror and a gas supply mechanism for supplying gas into a space surrounded by a lens barrel wall surface. In Patent Document 1, the gas supply ports are arranged in a direction along natural convection that is generated in the space when exposure light is irradiated to the concave mirror.

JP 2009-043810 A

  However, in particular, in the projection optical system in which the concave mirror and the convex mirror have the same center of curvature, the space through which the exposure light passes becomes wide, so the influence becomes larger, and not only in the vicinity of the mirror but also in the entire projection optical system. It is necessary to consider temperature control. Further, in Patent Document 1, it is necessary to provide an exhaust port around the optical element, leading to an increase in the size of the projection optical system. Further, since the temperature control fluid is supplied in a direction intersecting with the propagation direction of the exposure light in the projection optical system, the temperature distribution is biased in the direction intersecting with the exposure light, and the exposure light is easily refracted. As a result, necessary image performance may not be ensured.

  Along with the increase in the size of the liquid crystal panel, the size of the area where the exposure apparatus performs exposure in a lump is increasing year by year, and the projection optical system is also increasing in size accordingly. If a temperature control component such as the exhaust port described above is added and the projection optical system is further increased in size, the size of the exposure apparatus also increases, which may lead to a decrease in usability (problems such as limitations during installation). Therefore, it is desired that the projection optical system be limited to the minimum necessary size.

  Therefore, an object of the present invention is to provide an exposure apparatus that can effectively control the temperature inside the projection optical system while suppressing an increase in the size of the apparatus.

  According to one aspect of the present invention, there is provided an exposure apparatus that exposes a substrate, and includes a projection optical system that projects an original pattern onto the substrate, and a temperature control mechanism that controls the temperature of the inside of the projection optical system. In the projection optical system, a pair of concave mirrors and convex mirrors emit light in the order of the first region of the reflective surface of the concave mirror, the reflective surface of the convex mirror, and the second region of the reflective surface of the concave mirror. A first through hole penetrating the front and back of the concave mirror is formed between the first region and the second region of the concave mirror, An exposure apparatus is provided in which the temperature adjustment mechanism distributes the temperature-controlled gas in the direction in which the concave mirror and the convex mirror are arranged through the first through hole.

  According to the present invention, it is possible to provide an exposure apparatus that can effectively control the temperature inside the projection optical system while suppressing an increase in the size of the apparatus.

1 is a diagram showing a configuration of an exposure apparatus in a first embodiment. The figure which shows the example of the irradiation area | region of the concave mirror in embodiment. The figure which shows the example of arrangement | positioning of the air nozzle in embodiment. The figure which shows the structure of the exposure apparatus in 2nd Embodiment. The figure which shows the structure of the exposure apparatus in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. Moreover, not all combinations of features described in the following embodiments are indispensable for solving the problems of the present invention.

<First Embodiment>
FIG. 1 is a view showing the arrangement of an exposure apparatus according to the first embodiment. The exposure apparatus 100 includes a light source device 102 that generates exposure light, an original stage 103 that holds an original (not shown), a projection optical system 101, and a substrate stage 104 that holds an unshown substrate. The exposure light generated from the light source device 102 is formed into a predetermined light flux and then illuminates the pattern of the original on the original stage 103. The illuminated pattern on the original is transferred onto the substrate held on the substrate stage 104 by the projection optical system 101. A photosensitive agent is applied on the substrate, and an original pattern can be formed on the substrate by performing development after exposure.

  The projection optical system 101 is accommodated in the lens barrel 105. The projection optical system 101 includes a pair of concave mirror 4 and convex mirror 5. An axis passing through the rotational symmetry axis of the concave mirror 4 (an axis passing through the center of curvature) and the rotational symmetry axis of the convex mirror 5 are defined as the optical axis of the projection optical system. The pair of concave mirror 4 and convex mirror 5 reflects light in the order of the first region 4 a of the reflective surface of the concave mirror 4, the reflective surface 5 a of the convex mirror 5, and the second region 4 b of the reflective surface of the concave mirror 4. Thus, the projection optical system is configured. The projection optical system 101 further includes a first reflecting surface 6a that deflects exposure light to the first region 4a of the concave mirror 4, and a second reflecting surface that deflects light reflected by the second region 4b of the concave mirror 4 to the substrate side. And a trapezoidal mirror 6 which is a deflection mirror having 6b. The air gap inside the projection optical system 101 is filled with the atmosphere. The exposure light passes through the projection optical system 101 along the optical path 7 indicated by a broken line.

  At the time of exposure, the irradiation areas on the respective mirror surfaces generate heat when a part of the energy of the exposure light is absorbed by the reflection surface when the exposure light is reflected. This heat heats the atmosphere on the mirror surface and causes a bias in the temperature distribution. In particular, when there is a temperature gradient in a direction perpendicular to the exposure light, the difference in refractive index caused by the density difference refracts the exposure light and deforms the pattern image formed on the substrate. This is so-called distortion.

  Therefore, the exposure apparatus of this embodiment includes a temperature adjustment mechanism 3 that adjusts the temperature of the inside of the projection optical system 101. Between the first region 4 a and the second region 4 b in the concave mirror 4, a first through hole 8 that penetrates the front and back of the concave mirror 4 is formed. The temperature adjustment mechanism 3 distributes the temperature-controlled gas in the direction in which the concave mirror 4 and the convex mirror 5 are arranged through the first through hole 8. In the present embodiment, the lens barrel 105 is formed with a first opening 10 that communicates with the outside of the lens barrel 105 at a position facing the first through hole 8, and the first opening 10 with the convex mirror 5 interposed therebetween. A second opening 9 communicating with the outside of the lens barrel 105 is formed on the opposite side. For example, as shown in FIG. 2, the first through-hole 8 is a hole provided in the central portion of the concave mirror 4 so as to avoid the exposure light irradiation surface 21 in the concave mirror 4. The temperature adjustment mechanism 3 supplies and collects gas to the projection optical system 101 via the first opening 10 and the second opening 9. In the present embodiment, the temperature adjustment mechanism 3 includes a blower 3a that blows temperature-controlled gas, and a flow path 3b that communicates the second opening 9 and the blower 3a outside the lens barrel 105. . In the present embodiment, the flow path 3b is used as a path for returning the gas discharged from the lens barrel 105 to the blower 3a.

  The blower 3a blows the temperature-controlled gas in the direction indicated by the arrow F. The blown gas passes through the space 2 and is blown into the projection optical system 101 through the first through hole 8 formed in the concave mirror 4. As a result, the atmosphere inside the projection optical system 101 heated by the heat generated during exposure is expelled from the second opening 9. Thus, the temperature adjustment mechanism 3 adjusts the temperature of the inside of the projection optical system 101 by causing the gas to flow in the direction (optical axis direction) in which the concave mirror 4 and the convex mirror 5 are arranged. In the present embodiment, the atmosphere inside the projection optical system 101 heated by the heat generated during exposure is collected from the second opening 9 through the flow path 3b to the blower 3a. In the exposure apparatus, the direction in which the original and the substrate are mounted is generally a horizontal direction. Based on this premise, the above-mentioned “direction in which the concave mirror 4 and the convex mirror 5 are arranged” may be a horizontal direction.

  As shown in FIG. 3, in the present embodiment, a plurality of air nozzles 15 are provided on the outer peripheral portion of the concave mirror 4, and the gas from the blower 3 a is supplied toward the trapezoidal mirror 6 by these air nozzles 15. Is done. The air nozzle 15 guides gas to the outer peripheral portion of the concave mirror 4 using the Coanda effect. Due to the Coanda effect (air attraction) of the air nozzle 15, the gas whose temperature is adjusted by the blower 3 a is drawn into the air nozzle 15 through the outer periphery of the concave mirror 4 in addition to the first through-hole 8, and the exposure light irradiation surface 21 is blown into the projection optical system 101 from a position where 21 is avoided.

  In this way, by using the air nozzle 15 in combination, the temperature-controlled air can be made to flow uniformly throughout the projection optical system. Thereby, it is possible to prevent the temperature distribution from being biased inside the projection optical system 101 and the temperature of the atmosphere inside the projection optical system 101 from rising.

  The air nozzle 15 may be configured by a box having a slit-like outlet in a cylindrical box, or may be configured by arranging several nozzles having a single hole in a circle. Further, as long as the position and number do not obstruct the optical path 7, any number may be installed at any location in the projection optical system 101.

  There may be a temperature gradient from the concave mirror 4 toward the trapezoidal mirror 6 due to the residual heat that cannot be recovered when the temperature-controlled air is supplied. However, since such a temperature gradient is substantially parallel to the optical path 7, the refraction amount of the exposure light is reduced as compared with a temperature gradient orthogonal to the optical path 7. Therefore, the amount of distortion generated is small.

  In the projection optical system 101, what fills the gap is not limited to the atmosphere, but may be other fluid. There is no particular limitation as long as it is a fluid substance that is chemically inert, such as nitrogen or pure water, and does not absorb exposure light. Further, the optical element that provides the flow path outside the irradiation region is not limited to the concave mirror 4, and may be another optical element that constitutes the projection optical system.

Second Embodiment
Next, an exposure apparatus according to the second embodiment will be described with reference to FIG. The same components as those in FIG. 1 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, as shown in FIG. 4, a second through hole 6 c that penetrates the front and back of the trapezoidal mirror 6 is formed between the first reflecting surface 6 a and the second reflecting surface 6 b of the trapezoidal mirror 6. Yes. The second opening 9 of the lens barrel 105 is formed at a position facing the second through hole 6 c, and the flow path 3 b from the blower 3 a is connected to the second opening 9.

  The blower 3a blows the temperature-controlled gas in the direction opposite to that of the first embodiment (indicated by the arrow F '). The blown gas is blown into the projection optical system 101 through the flow path 3b, the second opening 9, and the second through hole 6c. Thereby, the atmosphere inside the projection optical system 101 heated by the heat generated at the time of exposure is expelled from the first through-hole 8 and recovered to the blower 3a. As described above, the temperature adjustment mechanism 3 adjusts the temperature of the inside of the projection optical system 101 by circulating the gas in the direction opposite to that of the first embodiment.

  Further, the temperature-controlled gas may be supplied from the air nozzles 11 and 12 toward the concave mirror 4. Thus, the temperature-controlled gas can be made to flow uniformly throughout the projection optical system.

  The air nozzles 11 and 12 may be a box having a slit-like outlet, or may be one in which an outlet is provided directly on the wall surface of the projection optical system. Further, the portion that was the blowout port by the nozzle may be an exhaust port, and a separately supplied port may be provided to supply the temperature-controlled gas into the projection optical system. Further, as long as the position and number do not obstruct the optical path 7, any number may be installed at any location in the projection optical system 101.

<Third Embodiment>
Next, an exposure apparatus according to the third embodiment will be described with reference to FIG. The same components as those in FIG. 1 according to the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the present embodiment, the flow path 3 c from the blower opening of the blower 3 a is inserted through the first through hole 8. The temperature-controlled gas is blown into the projection optical system 101 from the flow path 3c. The exhaust gas after the heat recovery is discharged from the second opening 9 behind the trapezoidal mirror 6 and returns to the blower 3a through the flow path 3b. In the present embodiment, a temperature sensor 13 that is a detection unit that detects the temperature inside the projection optical system 101 is provided. The blower 3 a adjusts either or both of the temperature and flow rate of the gas flowing through the projection optical system 101 according to the temperature inside the projection optical system 101 detected by the temperature sensor 13. Thereby, the temperature control mechanism 3 can effectively control the temperature inside the projection optical system.

  The temperature sensor 13 may be installed anywhere in the projection optical system 101 as long as it does not obstruct the optical path 7, and the number is not limited. In the case of using a plurality of sensors, the temperature at a plurality of points can be individually measured, and it is possible to cope with local high and low temperatures. A value obtained by averaging the temperatures at a plurality of points may be used for temperature control.

<Embodiment of Method for Manufacturing Article>
The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing an article such as a microdevice such as a semiconductor device or an element having a fine structure. In the method for manufacturing an article according to the present embodiment, a latent image pattern is formed on the photosensitive agent applied to the substrate using the above-described exposure apparatus (a step of exposing the substrate), and the latent image pattern is formed in this step. Developing the substrate. Further, the manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, and the like). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

DESCRIPTION OF SYMBOLS 100: Exposure apparatus, 101: Projection optical system, 102: Light source apparatus, 103: Original stage, 104: Substrate stage, 3: Temperature control mechanism, 4: Concave mirror, 5: Convex mirror, 6: Trapezoid mirror

Claims (8)

An exposure apparatus for exposing a substrate,
A projection optical system for projecting an original pattern onto the substrate;
A temperature control mechanism for controlling the temperature inside the projection optical system;
Have
In the projection optical system, a pair of concave mirror and convex mirror emit light in the order of the first region of the reflective surface of the concave mirror, the reflective surface of the convex mirror, and the second region of the reflective surface of the concave mirror. Including an optical system disposed opposite to reflect;
Between the first region and the second region of the concave mirror, a first through-hole penetrating the front and back of the concave mirror is formed,
The exposure apparatus according to claim 1, wherein the temperature adjustment mechanism distributes the temperature-controlled gas in a direction in which the concave mirror and the convex mirror are arranged through the first through hole. A lens barrel that accommodates the projection optical system, wherein the first aperture is formed at a position facing the first through hole, and communicates with the outside of the lens barrel, and the first aperture with the convex mirror interposed therebetween. And a lens barrel having a second opening that communicates with the outside of the lens barrel,
2. The exposure apparatus according to claim 1, wherein the temperature adjustment mechanism supplies and collects gas to and from the projection optical system via the first opening and the second opening. The projection optical system includes a first reflecting surface for deflecting light from a light source to the first region of the concave mirror, and a second reflecting surface for deflecting light reflected by the second region of the concave mirror to the substrate. A deflection mirror having
A second through-hole penetrating the front and back of the deflection mirror is formed between the first reflection surface and the second reflection surface of the deflection mirror,
The exposure apparatus according to claim 2, wherein the second opening is formed at a position facing the second through hole.   The temperature control mechanism supplies gas into the projection optical system through the first opening, and collects the gas discharged from the second opening. The exposure apparatus described.   The temperature control mechanism supplies gas into the projection optical system through the second opening, and collects the gas discharged from the first opening. The exposure apparatus described.   The temperature control mechanism includes an air nozzle for guiding gas to the outer peripheral portion of the concave mirror using the Coanda effect inside the projection optical system. 2. The exposure apparatus according to item 1. A detector that detects a temperature inside the projection optical system;
The temperature control mechanism adjusts at least one of a temperature and a flow rate of a gas flowing through the projection optical system according to a temperature detected by the detection unit. The exposure apparatus according to any one of the above. A step of exposing the substrate using the exposure apparatus according to claim 1;
Developing the substrate exposed in the step;
A method for producing an article comprising:

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