JP2010182834A - Method and apparatus of exposure, and method of manufacturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately perform local temperature control with a simple mechanism without preparing a blower fan. <P>SOLUTION: An exposure system for exposing a wafer to an illuminating light through a reticle includes: a flow control valve 48F through which compressed air is supplied; a heat exchanger 45 for cooling the compressed air to a temperature lower than a predetermined temperature by performing heat exchange between the compressed air taken in through the flow control valve 48F and cooling water Co; a heater 50A for heating the cooled air; and an air supply duct 44A for supplying the heated air A5 to a temperature control object region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure technique using a temperature control technique, and is suitable for controlling the temperature of members constituting an exposure apparatus used when manufacturing various devices such as semiconductor devices and liquid crystal displays. The present invention also relates to a device manufacturing technique using such an exposure technique.

  For example, in an exposure apparatus used in a lithography process which is one of manufacturing processes of semiconductor devices (electronic devices, micro devices), the illumination characteristics of the illumination optical system and the imaging characteristics of the projection optical system are maintained in a predetermined state. In addition, the positional relationship among the reticle (or photomask, etc.), the projection optical system, and the wafer (or glass plate, etc.) coated with the photoresist is maintained in a predetermined relationship with high exposure accuracy (positioning accuracy, overlay accuracy, etc.). In order to perform exposure, it is necessary to maintain the temperature of a portion that affects the illumination characteristics, imaging characteristics, positional relationship, and the like within the target temperature range. Therefore, conventionally, the illumination optical system, reticle stage, projection optical system, and wafer stage of the exposure apparatus are installed in a box-shaped chamber, and the chamber is controlled to a predetermined temperature and passes through a dustproof filter. Clean air is supplied in a down flow manner.

  Recently, a part of the mechanism installed in the chamber that requires particularly high temperature control accuracy, such as the optical path of the measurement beam of a laser interferometer that measures the position of the stage, has been controlled to a higher degree of temperature. Local temperature control is also performed in which air is supplied by a downflow method and / or a sideflow method (see, for example, Patent Document 1).

International Publication No. 2006/028188 Pamphlet

In a conventional exposure apparatus, the air for performing local temperature control in the chamber is the same as the air supplied by the down flow method for the entire chamber, and after flowing in the chamber and / or air taken from outside air. The recovered air is generated through, for example, an air conditioning unit including a cooling mechanism using a refrigerant and a dustproof filter.
However, since the air taken in from the outside air and the air collected after flowing in the chamber are almost atmospheric pressure, it is necessary to provide a blower fan to supply (blow) it to the local temperature control target area. There is a problem that the temperature control mechanism becomes complicated.

  In view of the above, the present invention provides an exposure technique that can perform local temperature control with high accuracy with a simple mechanism without providing a blower fan, and a device manufacturing technique that uses this exposure technique. Objective.

  An exposure method according to the present invention is an exposure method in which a pattern is illuminated with exposure light, and an object is exposed through the pattern with the exposure light, and heat is exchanged between the compressed gas and the refrigerant, The compressed gas is cooled to a temperature lower than a predetermined temperature, the gas cooled to a temperature lower than the predetermined temperature is heated, and the heated gas is supplied to the temperature control target region.

  In addition, an exposure apparatus according to the present invention illuminates a pattern with exposure light, and in the exposure apparatus that exposes an object with the exposure light through the pattern, a gas intake unit to which a compressed gas is supplied, and the gas intake A heat exchanger that exchanges heat between the compressed gas taken in through the unit and the refrigerant, and cools the compressed gas to a temperature lower than a predetermined temperature, and more than the predetermined temperature. A heater that heats the gas cooled to a low temperature and a blower passage that supplies the gas heated by the heater to the temperature control target region are provided.

  The device manufacturing method of the present invention includes forming a pattern of a photosensitive layer on a substrate using the exposure method or apparatus of the present invention and processing the substrate on which the pattern is formed.

  According to the present invention, after the compressed gas is taken in and cooled by heat exchange and adiabatic expansion, the gas is heated to the target temperature and supplied to the temperature control target region. Therefore, temperature control can be performed with high accuracy, and the gas is blown to the temperature control target region side by the initial pressure, so that it is not necessary to provide a separate blower fan. In addition, since a compressed gas supply source is provided in a normal factory, it is not necessary to provide a dedicated supply source.

  Furthermore, it is not necessary to provide a waste heat mechanism in the heating mechanism that heats the gas to the target temperature, and the heating mechanism can be downsized. It is also possible to control the temperature.

It is the figure which notched the part which shows the structure of the exposure apparatus of an example of embodiment. It is a block diagram which shows the control system of the exposure apparatus of FIG. It is the figure which notched a part which shows the structure of the 2nd local air conditioner 43 in FIG. (A) is sectional drawing which shows the structure of 50 A of heating apparatuses in FIG. 3, (B) is sectional drawing which shows the structure of the temperature measurement part 54A in FIG. It is a flowchart which shows an example of the air-conditioning operation | movement of the 2nd local air conditioner 43. It is the figure which notched a part which shows the modification of a 2nd local air conditioner. It is a flowchart which shows an example of the manufacturing process of an electronic device.

Hereinafter, an exemplary embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the present invention is applied when performing temperature control of a scanning exposure type exposure apparatus composed of a scanning stepper (scanner).
FIG. 1 shows a configuration of an exposure apparatus 10 of the present embodiment. In FIG. 1, an exposure apparatus 10 is installed on a floor FL in a clean room of a semiconductor device manufacturing factory, for example. The exposure apparatus 10 moves by adsorbing and holding the reticle R, the light source unit 4 that generates illumination light (exposure light) EL for exposure, the illumination optical system ILS that illuminates the reticle R (mask) with the illumination light EL, and the reticle R. A reticle stage RST and a projection optical system PL that projects an image of the pattern of the reticle R onto a wafer W (substrate) are provided. Further, the exposure apparatus 10 includes a control system (see FIG. 2) including a wafer stage WST that moves by sucking and holding the wafer W, and a main controller 20 that includes a computer that comprehensively controls the operation of the exposure apparatus 10. Other drive mechanisms, support mechanisms, sensors, and the like, and a box-shaped chamber 2 that houses the illumination optical system ILS, reticle stage RST, projection optical system PL, wafer stage WST, and the like are provided. The main controller 20 is disposed outside the chamber 2.

  Further, the exposure apparatus 10 includes an overall air conditioning system for performing air conditioning of the entire interior of the chamber 2. In this overall air conditioning system, clean air (for example, dry air) that has passed through a dust-proof filter (HEPA filter, ULPA filter, etc.) is temperature-controlled in the chamber 2 through a number of openings 2a at the top of the chamber 2 in a downflow manner. The main air conditioner 8 to supply and the main air-conditioning control system 35 (refer FIG. 2) which control this operation | movement are provided. As an example, the air that flows in the chamber 2 flows into a pipe (not shown) under the floor through a number of openings (not shown) provided in the floor FL on the bottom surface of the chamber 2, and the air in the pipe is a main air conditioner. 8 is returned to the gas recovery unit and reused.

  Hereinafter, in FIG. 1, the Z-axis is taken in parallel to the optical axis AX of the projection optical system PL, and the X-axis is perpendicular to the paper surface of FIG. 1 within a plane perpendicular to the Z-axis (substantially a horizontal plane). A description will be given taking the Y axis parallel to the paper surface. In the present embodiment, the scanning direction of reticle R and wafer W during scanning exposure is a direction parallel to the Y axis (Y direction). The rotation directions around the X, Y, and Z axes are also referred to as θx, θy, and θz directions.

  First, the light source unit 4 installed on the floor FL outside the chamber 2 includes a laser light source (exposure light source) that generates ArF excimer laser light (wavelength 193 nm) as the illumination light EL, and the illumination light EL as an illumination optical system. A beam transmission optical system that leads to the ILS and a beam shaping optical system that shapes the cross-sectional shape of the illumination light EL into a predetermined shape are provided. An emission end of the illumination light EL of the light source unit 4 is disposed in the chamber 2 through an opening at the upper side surface of the chamber 2 in the + Y direction. As an exposure light source, an ultraviolet pulse laser light source such as a KrF excimer laser light source (wavelength 248 nm), a harmonic generation light source of a YAG laser, a harmonic generation device of a solid laser (semiconductor laser, etc.), or a mercury lamp (i-line etc.) ) Etc. can also be used.

  The illumination optical system ILS disposed in the upper part of the chamber 2 is an optical integrator as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-313250 (corresponding US Patent Application Publication No. 2003/0025890). (Fly-eye lens, rod integrator (internal reflection type integrator), diffractive optical element, etc.) etc., illuminance uniformizing optical system, reticle blind, first condenser lens (all not shown), optical path bending mirror ME, A plurality of optical members such as a second condenser lens CL are provided. These optical members are supported in the illumination system barrel 6. The illumination optical system ILS illuminates a slit-shaped illumination area elongated in the X direction on the reticle R defined by the reticle blind with illumination light EL with a substantially uniform illuminance.

Of the pattern area formed on the reticle R, an image of the pattern in the illumination area is resisted via the projection optical system PL with the telecentric projection on both sides and the reduction magnification (for example, 1/4, 1/5, etc.). An image is projected onto the wafer W coated with the photosensitive material. As an example, the field diameter of the projection optical system PL is about 27 to 30 mm.
A lower frame 12 is installed on the floor FL in the chamber 2 of FIG. 1 via a plurality of pedestals 11, and a flat base member 13 is fixed to the center of the lower frame 12. For example, a flat wafer base WB is supported via three (or four) anti-vibration tables 14, and the wafer stage WST is placed in the X direction via an air bearing on the upper surface parallel to the XY plane of the wafer base WB. It is mounted so as to be movable in the Y direction and rotatable in the θz direction. Further, an optical system frame 16 is supported on the upper end of the lower frame 12 via, for example, three (or four) anti-vibration tables 15 disposed so as to surround the wafer base WB. The projection optical system PL is disposed in the central opening of the optical system frame 16, and the upper frame 17 is fixed on the optical system frame 16 so as to surround the projection optical system PL. The vibration isolators 14 and 15 are active vibration isolators that combine an air damper and an electromagnetic damper such as a voice coil motor, for example.

  Further, a Y-axis laser interferometer 21WY is fixed to an end portion in the + Y direction on the bottom surface of the optical system frame 16, and an X-axis laser interferometer (not shown) is fixed to an end portion in the + X direction on the bottom surface. . Wafer interferometer 21W (refer to FIG. 2) made up of these interferometers irradiates a reflecting surface (or moving mirror) on the side surface of wafer stage WST with a plurality of measurement beams, for example, on the side surface of projection optical system PL. The reference position (not shown) is used as a reference to measure the position of wafer stage WST in the X and Y directions at a plurality of locations, and the measurement values are supplied to wafer stage drive system 22W via main controller 20 in FIG. . Based on these measurement values, rotation angles of wafer stage WST in the θx, θy, and θz directions are also obtained.

  Further, on the bottom surface of the optical system frame 16 in FIG. 1, an off-axis image processing type alignment system AL that measures the position of the alignment mark on the wafer W and a plurality of measurement points on the wafer W in the Z direction. An autofocus sensor (hereinafter referred to as an AF sensor) 25 (see FIG. 2) including an irradiation system 25a and a light receiving system 25b for optically measuring (focus position) by an oblique incidence method is fixed. The position information of the test mark is obtained by processing the image signal of the alignment system AL by the signal processing system 27 in FIG. 2, and this position information is supplied to the main controller 20, and the main controller is based on this position information. 20 performs alignment of the wafer W. Further, information on the focus position of the measurement point on the wafer W obtained by processing the detection signal of the AF sensor 25 by the signal processing system 26 is supplied to the wafer stage drive system 22W via the main controller 20.

  Wafer stage drive system 22W has a position and speed in the X and Y directions of wafer stage WST via a drive mechanism including linear motor 24 and the like based on the measurement value of wafer interferometer 21W and control information from main controller 20. And the rotation angle in the θz direction is controlled. Further, the wafer stage drive system 22W aligns the surface of the wafer W with the image plane of the projection optical system PL via the Z drive unit in the wafer stage WST based on the focus position information measured via the AF sensor 25. The position of the wafer W in the Z direction and the rotation angles in the θx direction and the θy direction are controlled so as to be focused.

Wafer stage WST is also provided with an aerial image measurement system (not shown) for measuring the position of the image of alignment mark of reticle R by projection optical system PL. Based on the measurement value of the aerial image measurement system, main controller 20 performs alignment of reticle R.
On the other hand, the illumination system barrel 6 of the illumination optical system ILS is fixed to the upper part of the upper frame 17 in the + Y direction. Further, a reticle stage RST is placed on the upper surface of the upper frame 17 parallel to the XY plane so as to be movable at a constant speed in the Y direction via an air bearing. The reticle stage RST can also move in the X direction and rotate in the θz direction on the upper surface of the upper frame 17.

  A Y-axis laser interferometer 21RY is fixed to the + Y direction end of the upper surface of the upper frame 17, and an X-axis laser interferometer (not shown) is fixed to the + X direction end of the upper surface. The reticle interferometer 21R shown in FIG. 2 is constituted by these interferometers. The Y-axis laser interferometer 21RY irradiates a measuring beam to a movable mirror 21MY composed of retro-reflectors arranged at two positions on the + Y direction end of the reticle stage RST, and the X-axis laser interferometer A rod-shaped moving mirror (not shown) fixed to the end of the stage RST in the + X direction is irradiated with a measurement beam having a plurality of axes. The laser interferometer 21RY, for example, measures the position of the reticle stage RST in the X direction and the Y direction at a plurality of locations on the basis of a reference mirror (not shown) on the side surface of the projection optical system PL, and the measured values are shown in FIG. It is supplied to the reticle stage drive system 22R via the control device 20. Based on these measured values, the rotation angles of the reticle stage RST in the θz, θx, and θy directions are also obtained. The reticle stage drive system 22R is configured to detect the speed and position of the reticle stage RST in the Y direction and the X direction through a drive mechanism including a linear motor 23 based on the measurement value of the reticle interferometer 21R and control information from the main controller 20. The position in the direction and the rotation angle in the θz direction are controlled. Instead of the movable mirror 21MY or the like, a reflective surface on the side surface of the reticle stage RST may be used.

  In the present embodiment, the wafer stage drive system 22W and the reticle stage drive system 22R serve as heat sources. Therefore, the wafer stage drive system 22W and the reticle stage drive system 22R are collected in a box-like control box 30 supported by the optical system frame 16 in the vicinity of the anti-vibration table 15 in the -Y direction in FIG. Are arranged. In addition, you may arrange | position the control box 30 in other positions, such as the vicinity of the vibration isolator 15 of + Y direction, for example.

  When the exposure apparatus 10 of the present embodiment is a liquid immersion type, for example, a ring-shaped nozzle head (not shown) is disposed on the lower surface of the optical member at the lower end of the projection optical system PL, and the liquid supply shown in FIG. A predetermined liquid (pure water or the like) is supplied from the apparatus 28 to a local liquid immersion area between the optical member and the wafer W through a pipe (not shown) and its nozzle head. The liquid in the immersion area is recovered by the liquid recovery device 29 in FIG. 2 via a pipe (not shown). Examples of the liquid immersion mechanism including the nozzle head, the liquid supply device 28, and the liquid recovery device 29 include, for example, International Publication No. 2004/053955, European Patent Application No. 1420298, or International Publication No. 2005/122218. The immersion mechanism disclosed in pamphlets and the like can be used. When the exposure apparatus 10 is a dry type, it is not necessary to include the liquid immersion mechanism.

  Further, a reticle loader system (not shown) and a wafer loader system (not shown) are arranged in the side surface direction of the chamber 2 in FIG. The reticle loader system and the wafer loader system are installed in a sub-chamber (not shown) that is air-conditioned separately from the chamber 2, and the reticle loader system and the wafer loader system pass through the opening (not shown) on the side surface of the chamber 2. Then, the wafer W is exchanged.

  When the exposure apparatus 10 shown in FIG. 1 performs exposure, the reticle R and the wafer W are first aligned. After that, irradiation of the illumination light EL to the reticle R is started, and an image of a part of the pattern of the reticle R is projected onto one shot area on the wafer W while the reticle stage RST and The pattern image of the reticle R is transferred to the shot area by a scanning exposure operation that moves (synchronously scans) the wafer stage WST and the wafer stage WST in synchronism with the Y direction using the projection magnification β of the projection optical system PL as a speed ratio. Thereafter, the irradiation of the illumination light EL is stopped, and the step-and-scan method is performed by repeating the operation of moving the wafer W stepwise in the X and Y directions via the wafer stage WST and the above-described scanning exposure operation. Thus, the pattern image of the reticle R is transferred to all shot areas on the wafer W.

  Next, the exposure apparatus 10 of the present embodiment maintains the illumination characteristics (coherence factor (σ value), illuminance uniformity, etc.) of the illumination optical system ILS and the imaging characteristics (resolution, etc.) of the projection optical system in a predetermined state. In addition, temperature control is performed inside the chamber 2 in order to perform exposure with high exposure accuracy (positioning accuracy, overlay accuracy, etc.) while maintaining the positional relationship among the reticle R, the projection optical system PL, and the wafer W in a predetermined relationship. An overall air conditioning system including a main air conditioner 8 that supplies the clean air in a downflow manner is provided. Further, the exposure apparatus 10 is provided with a local air conditioning system for controlling the temperature of a portion where high temperature control accuracy is required.

  In other words, air conditioning air (clean air, for example, clean air passing through a dust filter (HEPA filter, ULAP filter, etc.) and a chemical filter, which is controlled to a substantially predetermined temperature range, for example, in the upper part of the chamber 2 (may be under the floor or the like). Compressed air (for example, compressed air), which is air that has been compressed by being controlled through an air-conditioning air supply pipe 40 to which dry air (for example, dry air) is supplied and is controlled to a substantially predetermined temperature range and is also passed through a dustproof filter and a chemical filter. And a compressed air supply pipe 42 to which dry air is supplied. The compressed air supply pipe 42 is a facility generally provided in a semiconductor device manufacturing factory or the like. In addition, you may use the air for air conditioning branched from the inside of the main air conditioning apparatus 8, or the air taken in from the compressed air supply pipe 42, and decompressed, without using the air-conditioning air supply pipe 40.

  Moreover, the 1st local air conditioner 41 which controls the temperature of the air taken in from the air-conditioning air supply pipe | tube 40 with higher precision is provided, and the clean air highly temperature-controlled by the 1st local air conditioner 41 is 1st. The air is guided to a blower 19R on the bottom surface of the illumination system barrel 6 of the illumination optical system ILS in the chamber 2 and a blower 19W on the bottom surface of the optical system frame 16 through the duct 18R and the second duct 18W, respectively. The temperature control operation of the first local air conditioner 41 is controlled by the interference optical path air conditioning control system 36 of FIG. The blowers 19R and 19W are arranged on the optical paths of measurement beams such as the laser interferometer 21RY for the reticle stage RST and the laser interferometer 21WY for the wafer stage WST, respectively.

  The blower 19R blows out the temperature-controlled air AR guided from the duct 18R with a uniform wind speed distribution by the downflow method onto the optical path of the measurement beam irradiated to the reticle stage RST from the laser interferometer 21RY or the like. Similarly, the blower 19W blows out the temperature-controlled air AW guided from the duct 18W in a downflow manner on the optical path of the measurement beam with a uniform wind speed distribution. It is also possible to blow out the air AR, AW by the side flow method. As a result, the positions of reticle stage RST and wafer stage WST can be measured with high accuracy by reticle interferometer 21RY and the like and wafer interferometer 21WY and the like.

  Further, a second local air conditioner 43 that generates two clean airs A5 and A6 whose temperature is controlled with high accuracy from the compressed air taken in from the compressed air supply pipe 42 is provided. The second local air conditioner 43 includes air supply ducts 44A and 44B for supplying air A5 and A6, respectively. In this case, the air A6 is supplied from the second local air conditioner 43 to the inside of the illumination system barrel 6 of the illumination optical system ILS via the air supply duct 44B. It is recovered by the gas recovery unit of the main air conditioner 8 through the illustrated exhaust duct.

Further, a cylindrical member 61 having a gradually decreasing aperture diameter is attached below the second condenser lens CL of the illumination system barrel 6, and the hood portion 62 is fixed so as to gradually spread on the reticle stage RST so as to surround the reticle R. Has been. The cylindrical member 61 is disposed so as to surround the optical path of the illumination light EL.
Air A5 that is temperature-controlled with high accuracy is supplied into the cylindrical member 61 from the second local air conditioner 43 through the air supply duct 44A. The air A5 flows from the inside of the cylindrical member 61 to the hood portion 62 on the upper surface of the reticle R by a downflow method. Thereafter, the air A5 flows out from the gap around the hood portion 62 to the outside, flows to the floor FL side, and is then recovered by the gas recovery portion of the main air conditioner 8.

  The set temperatures (target temperatures) of the airs A5 and A6 are the same as the set temperature (for example, a predetermined target temperature within 20 to 25 ° C.) of air supplied from the main air conditioner 8 in the down flow into the chamber 2. Is set to However, the allowable range of the temperature of the air A5 and A6 is set narrower than the allowable range (control accuracy) of the temperature of the air supplied from the main air conditioner 8 in the down flow. As a result, the temperature of the optical path of the illumination light EL is maintained within a set range with high accuracy, and minute foreign matter on the upper surface of the reticle R is removed together with the air A5. The operation of the second local air conditioner 43 is controlled by the local air conditioning control system 37 in FIG.

  Hereinafter, the configuration of the second local air conditioner 43 will be described in detail with reference to FIGS. 3 and 4. FIG. 3 is a partially cutaway view showing the configuration of the second local air conditioner 43. In FIG. 3, the second local air conditioner 43 is connected to the compressed air supply pipe 42 via a pipe 47 </ b> A to lower the temperature of the compressed air A <b> 1 supplied from the compressed air supply pipe 42 and to reduce its atmospheric pressure to some extent. A heat exchanger 45 that is exhausted at a lower temperature (however, set to be higher than the atmospheric pressure (some positive pressure) in the chamber 2 in FIG. 1), and connected to the heat exchanger 45 via a pipe 47B. A distributor 49 for exhausting the air A2 exhausted from the heat exchanger 45 into a plurality (four in this case) of branch pipes 49a, 49b, 49c, 49d is provided.

  A pressure smoothing regulator 48R and a flow control valve 48F are installed in the middle of the pipe 47, and the local air conditioning control system 37 controls the flow rate of the flow control valve 48F. The heat exchanger 45 includes a metal cooling pipe 45b wound in a spiral shape and having a good thermal conductivity, and an airtight container 45a that houses the cooling pipe 45b. The other end (exhaust port) of the cooling pipe 45b is connected to the pipe 47B. Further, a cooling water temperature adjuster 46 is provided, and the cooling water temperature adjuster 46 supplies the temperature-controlled cooling water Co into the container 45a of the heat exchanger 45 as shown by an arrow B1 via the pipe 46a. The cooling water Co that has flowed through 45a is recovered through the pipe 46b as indicated by an arrow B2.

  Further, temperature sensors 58A and 58B are installed in a pipe 47A near the air supply port of the heat exchanger 45 and a pipe 47B near the exhaust port of the heat exchanger 45, respectively, and the temperature of the air measured by the temperature sensors 58A and 58B. Is supplied to the local air conditioning control system 37. The local air conditioning control system 37 controls the temperature of the cooling water Co supplied from the cooling water temperature adjuster 46 into the container 45a based on the temperature. In this case, the temperature of the air A2 exhausted from the heat exchanger 45 is set to a set temperature TTi (i = i) of a plurality of local regions in the chamber 2 to which the temperature-controlled air is supplied from the second local air conditioner 43. Is set to a set temperature Tset that is lower than the minimum value Tmin of 1, 2,. However, in this embodiment, the set temperature TTi and the minimum value Tmin are the same temperature.

Further, the temperature of the air near the exhaust port of the cooling pipe 45b becomes lower than the temperature of the cooling water Co due to the adiabatic expansion of the air. Accordingly, the temperature of the cooling water Co supplied from the cooling water temperature adjuster 46 into the container 45a is usually higher than the set temperature Tset.
Further, the second local air conditioner 43 is connected to the branch pipes 49a to 49d, and each of the heating apparatuses 50A, 50B, which exhausts the air supplied from the corresponding branch pipe by independently raising the temperature to the set temperature TTi. 50C, 50D, temperature measuring units 54A, 54B, 54C, 54D connected to the heating devices 50A-50D via pipes 53A-53D, and air supply ducts 44A, 44B connected to the temperature measuring units 54A-54D, 44C, 44D. The temperature measuring units 54A to 54D have temperature sensors 55A to 55D that measure the temperature of the air passing through the inside.

  Air A5 and A6 that have passed through the air supply ducts 44A and 44B are supplied into the cylindrical member 61 and the illumination system barrel 6 in the chamber 2 of FIG. Further, the air A7 and A8 that have passed through the air supply ducts 44C and 44D are supplied to the space between the bottom surface of the reticle R and the projection optical system PL in FIG. When the exposure apparatus 10 in FIG. 1 is a dry exposure type that is not an immersion type, for example, air that has passed through one of the air supply ducts 44C and 44D is supplied between the projection optical system PL and the wafer W. Also good.

  FIG. 4A shows a configuration of the heating device 50A of FIG. In FIG. 4A, the heating device 50A includes a heater 51 composed of an elongated cylindrical heating element 51a and a support portion 51b that supports the heating element 51a, and a heat insulating duct member 52 that covers the heating element 51a. The duct member 52 includes a cylindrical member 52a that covers from the end of the support portion 51b to the tip of the heating element 51a, and a cylindrical member 52b that is provided at the tip of the cylindrical member 52a and connected to the branch pipe 49a in FIG. And an L-shaped exhaust pipe 52c provided so as to cover an opening 52e formed so as to be in contact with the bottom surface of the cylindrical member 52a. The exhaust pipe 52c is connected to the pipe 53A of FIG. 3, and the current (heat generation amount) flowing through the heater 51 (heat generating body 51a) is controlled by the local air conditioning control system 37 of FIG.

  In the heating device 50A shown in FIG. 4A, the air supplied from the branch pipe 49a shown in FIG. 3 is heated in the cylindrical member 52a through the cylindrical member 52a and the opening 52d as shown by the flow path A31. It flows into the space covering 51a. As shown by the flow path A32, the air that flows around the heating element 51a flows to the pipe 53A of FIG. 3 via the flow path A33 passing through the opening 52e and the flow path A34 going outward from the inside of the exhaust pipe 52c. . In this case, in the flow path A32 around the heating element 51a, a side flow in the radial direction from the heating element 51a is generated by convection, so the air flowing along the longitudinal direction around the heating element 51a is uniformly and efficiently To be heated. Therefore, without increasing the surface area of the heating element 51a so much, as a result, the amount of chemical contaminants generated can be reduced as much as possible, and the air flowing inside the heating device 50A can be efficiently heated. The other heating devices 50B to 50D in FIG. 3 are configured similarly to the heating device 50A.

  On the other hand, FIG. 4B shows a configuration of the temperature measurement unit 54A of FIG. In FIG. 4B, the temperature measurement unit 54A includes a temperature sensor 55A composed of an elongated columnar temperature measurement unit 55Aa and a support unit 55Ab that supports the temperature measurement unit 55Aa, and a portion from the lower end to the tip of the temperature measurement unit 55Aa. The duct member 56 is covered, and a heat-insulating box-shaped protection member 57 covering the duct member 56 is formed. As an example, the temperature sensor 55A is a platinum resistance thermometer method, and the temperature measuring portion 55Aa is repeatedly wound with a thin wire of a platinum resistor around its tip, so that the portion including the tip becomes elongated as a whole. It is hardened with resin. A thermistor or the like can be used as the temperature sensor 55A. The duct member 56 covers the cylindrical portion 56a connected to the piping 53A of FIG. 3, the cylindrical portion 56c connected to the air supply duct 44A of FIG. 3, and the cylindrical portion from the lower end to the tip of the temperature measuring portion 55Aa. It is comprised from the cylindrical part 56b which connects 56a, 56c. The cylindrical portions 56b and 56c are connected in a substantially L shape.

  4B, the air supplied from the pipe 53A in FIG. 3 flows into the cylindrical portion 56a of the duct member 56 along the flow path A41, and the cylindrical portion 56b along the flow path A42. After flowing around the temperature measuring section 55Aa, the air is exhausted to the air supply duct 44A of FIG. 3 along the flow path A43 through the cylindrical section 56c. In this case, since the support portion 55Ab of the temperature sensor 55A is in contact with air outside the chamber (outside air), the temperature of the support portion 55Ab may fluctuate. Further, the temperature of the support portion 55Ab (outside air) may affect the temperature measuring portion 55Aa by conduction. However, in the present embodiment, the platinum resistor is located at the tip of the temperature measuring section 55Aa, is separated from the support section 55Ab, and the air that flows in along the flow path A41 flows along the flow path A42. Since it does not stay in the base portion of the temperature section 55Aa, heat is efficiently dissipated, and the influence of outside air on the temperature measurement section 55Aa is reduced. Furthermore, although the platinum resistor in the temperature measuring section 55Aa has a slight self-heating, the air along the flow path A42 flows at a sufficiently high speed around the temperature measuring section 55Aa. Influence is suppressed. Therefore, the temperature of the air can be measured with high accuracy without substantially affecting the air to be measured. The other temperature measurement units 54B to 54D in FIG. 3 are configured similarly to the temperature measurement unit 54A.

  In FIG. 3, the temperature measuring units 54A to 54D measure the temperatures of the air A5 to A8 flowing from the pipes 53A to 53D to the air supply ducts 44A to 44D through the internal temperature sensors 55A to 55D, respectively, at a predetermined sampling rate. The measurement result is supplied to the local air conditioning control system 37. The local air-conditioning control system 37 is configured so that the temperature of the air A5 to A8 measured by the temperature sensors 55A to 55D becomes the set temperature TTi (i = 1 to 4), respectively. Control the amount of heat generated).

In the present embodiment, the air pressure supplied from the compressed air supply pipe 42 to the distributor 49 via the heat exchanger 45 is maintained higher than the air pressure in the chamber 2. Therefore, the air supplied to the distributor 49 is exhausted into the chamber 2 in a state where the temperature is controlled through the flow paths from the branch pipes 49a to 49d to the air supply ducts 44A to 44D.
Next, an example of the air conditioning operation of the second local air conditioner 43 of FIG. 3 will be described with reference to the flowchart of FIG. This operation is executed in parallel with the exposure operation of the exposure apparatus 10 and is controlled by the local air conditioning control system 37 under the overall control of the main controller 20. At this time, the pressure of the air output from the regulator 48R is set to about 3 to 5 times the atmospheric pressure, for example. When a control command for starting air conditioning is sent from the main controller 20 to the local air conditioning control system 37, first, in step 101 of FIG. 5, the local air conditioning control system 37 opens the flow rate control valve 48F, and the compressed air supply pipe 42 The intake of the compressed air A1 into the heat exchanger 45 is started via the pipe 47A. The flow rate of the flow rate control valve 48F is such that the taken compressed air A1 is finally exhausted into the chamber 2 through the air supply ducts 44A to 44D at a pressure slightly higher than the pressure in the chamber 2. Is set.

  In the next step 102, supply and recovery of the cooling water Co from the cooling water temperature adjuster 46 into the heat exchanger 45 is started, and the temperature of the cooling water Co is changed to the above-described temperature of the air exhausted from the heat exchanger 45. The initial value is set slightly higher than the set temperature Tset (temperature lower than the set temperature TTi of the air A5 to A8). In the next step 103, the temperature T12 of the air A2 on the exhaust port side of the cooling pipe 45b of the heat exchanger 45 is measured via the temperature sensor 58B. In the next step 104, the local air conditioning control system 37 determines whether or not the measured temperature T12 is within an allowable range with respect to the set temperature Tset. When the temperature T12 is within the allowable range, the process returns to step 103 and the measurement of the temperature T12 of the air A2 is repeated.

  On the other hand, when the temperature T12 is outside the allowable range in step 103, the process proceeds to step 105, and when the temperature T12 is lower than the allowable range, the local air conditioning control system 37 heats through the cooling water temperature adjuster 46. The temperature of the cooling water Co supplied to the exchanger 45 is increased by a predetermined step amount ΔTC. When the temperature T12 is higher than the allowable range, the temperature of the cooling water Co supplied to the heat exchanger 45 is lowered by ΔTC. The measured value of the temperature of the temperature sensor 58A on the air inlet side of the heat exchanger 45 may be used, for example, when calculating the step amount ΔTC. Thereafter, the operation returns to step 103, and the operations of steps 103 to 105 are repeated thereafter. Thus, the temperature of the air A2 exhausted from the heat exchanger 45 is maintained within an allowable range with respect to the set temperature Tset.

  In parallel with the operations of Steps 101 to 105, the operations of Steps 111 to 114 are performed on the heating devices 50A to 50D side. That is, in step 111, the local air conditioning control system 37 sets the current of the heater 51 of the heating devices 50A to 50D to the median value of the variable range. In the next step 112, the temperature T2i (i = 1 to 4) of the air on the exhaust port side of the heating devices 50A to 50D is measured by the temperature sensors 55A to 55D in the temperature measuring units 54A to 54D. In the next step 113, the local air conditioning control system 37 determines whether the measured temperature T2i is within a predetermined allowable range with respect to the set temperatures TTi of the air A5 to A8 blown from the air supply ducts 44A to 44D, respectively. To do. The predetermined allowable range is set to about a fraction of the allowable range ΔTi actually required in the chamber 2 for the air A5 to A8. The allowable range ΔTi may be different depending on a region where air is supplied from the air supply ducts 44A to 44D.

  When the temperature T2i is within the allowable range, the operation returns to step 112, and the measurement of the temperature T2i by the temperature sensors 55A to 55D is repeated. When the temperature T2i exceeds the allowable range, the operation proceeds to step 114. When the temperature T2i is lower than the allowable range, the local air conditioning control system 37 determines the current of the heater 51 in the heating devices 50A to 50D. (Heat generation amount) is increased by a predetermined step amount ΔIi (i = 1 to 4). When the temperature T2i is higher than the allowable range, the current of the heater 51 in the heating devices 50A to 50D is decreased by ΔIi. Thereafter, the operation returns to step 112, and the operations of steps 112 to 114 are repeated. Accordingly, the temperatures of the air A5 to A8 supplied (blowed) from the heating devices 50A to 50D via the air supply ducts 44A to 44D are within the allowable range ΔTi that is actually required for the set temperature TTi. Maintained.

When the air conditioning operation is stopped, the local air conditioning control system 37 closes the flow rate control valve 48F, stops the supply of the cooling water Co from the cooling water temperature adjuster 46 to the heat exchanger 45, and then the heating devices 50A to 50D. The heater current is reset to zero.
Effects and the like of this embodiment are as follows.
(1) The exposure apparatus 10 of the present embodiment illuminates the pattern of the reticle R with the illumination light EL, and exposes the wafer W through the pattern with the illumination light EL. A second local air conditioner 43 controlled by a local air conditioning control system 37 for controlling the temperature of the area is provided. The second local air conditioner 43 exchanges heat between the piping 47A with the flow rate control valve 48F to which the compressed air A1 is supplied and the compressed air A1 taken in via the piping 47A and the cooling water Co. Then, the heat exchanger 45 that cools the compressed air A1 to the air A2 having a temperature lower than the final set temperature, the heating device 50A that heats the air A2 cooled to the lower temperature, and the heat thus heated And an air supply duct 44A for supplying air A5 to a region in the cylindrical member 61 on the reticle R.

Further, the exposure method by the exposure apparatus 10 includes steps 103 to 105 for cooling the compressed air A1 to the air A2 by exchanging heat between the compressed air A1 and the cooling water Co, and a step 112 for heating the air A2. ˜114 and a step 101 for supplying heated air A5 into the cylindrical member 61.
According to this embodiment, after taking compressed air A1 and cooling the compressed air A1 by heat exchange and adiabatic expansion, the cooled air A2 is heated to a set temperature (target temperature) and supplied to the target region. ing. Therefore, temperature control can be performed with high accuracy. Further, since the air A2 is naturally blown toward the target area by the pressure of the compressed air A1, there is no need to provide a separate blower fan.

Furthermore, since the compressed air supply pipe 42 and a compressed air source (such as a compressor) therefor are generally provided in a semiconductor device manufacturing factory or the like, the manufacturing cost of the second local air conditioner 43 can be kept low.
(2) Further, since there is no need to provide a waste heat mechanism in the heating device 50A, and the heating device 50A can be reduced in size, for example, heating devices 50A to 50D are provided in a plurality of target areas, respectively, and temperature control is performed individually with high accuracy. can do. In this case, since the temperature of the air A2 exhausted from the heat exchanger 45 is set lower than the minimum value Tset of the set temperatures of the plurality of target regions, the heating device 50A to 50D is used only at the subsequent stage, and the final temperature is set. Therefore, the temperature of the air A5 to A8 supplied can be controlled to the set temperature.

(3) The temperature of the air A5 to A8 supplied to the target area is measured by the temperature sensors 55A to 55D in the temperature measuring units 54A to 54D, and the heating amount in the heating devices 50A to 50D is calculated based on the measurement result. I have control. Therefore, the temperature of the air A5 to A8 can be controlled with high accuracy.
(4) In the present embodiment, since the air exhausted from the heat exchanger 45 is blown along the longitudinal direction around the heating element 51a of the heater 51 of the heating devices 50A to 50D, a small amount of heat is generated. The heater 51 can be used to efficiently and efficiently reduce the amount of chemical pollutants generated (maintaining a high chemical cleanness) and heat the air to a desired temperature.
Instead of the heater 51, for example, a heater having a mesh-like heating element can be used. In this case, air may be supplied almost vertically to the entire surface of the mesh-like heating element.

(5) In the present embodiment, the temperature measuring unit 55Aa of the temperature sensor 55A has a rod shape, and the air to be measured is blown to the tip side along the longitudinal direction thereof. An increase in the temperature of the air to be measured due to the influence of heat generation is suppressed.
Note that instead of the temperature sensors 55A to 55D, it is also possible for the temperature measuring unit to use, for example, a flat or disk-shaped temperature sensor.

  The following modifications can be made to the above embodiment. First, in the above embodiment, in the second local air conditioner 43, the air A2 cooled by the heat exchanger 45 is branched into the branch pipes 49a to 49d by the distributor 49, and then heated by the heating devices 50A to 50D, respectively. ing. However, as shown in the second local air conditioner 43A of the modification of FIG. 6, heating may be performed before branching by the distributor 49.

  That is, in FIG. 6 in which parts corresponding to those in FIG. 3 are assigned the same reference numerals, the pipe 47B connected to the heat exchanger 45 of the second local air conditioner 43A is connected to the pipe 47C via the heating device 50A. The pipe 47C is connected to the distributor 49, the branch pipe 49a of the distributor 49 is connected to the air supply duct 44A via the temperature measuring unit 54A, and the other branch pipes 49b to 49c are connected to the air supply ducts 44B to 44D. It is connected. Other configurations are the same as those of the embodiment of FIG.

  In the second local air conditioner 43A of FIG. 6, the air A2 cooled by the heat exchanger 45 is heated to a predetermined temperature by the heating device 50A. The temperature of the air A5 is measured by the temperature sensor 55A of the temperature measurement unit 54A, and the local air conditioning control system 37 sets the heating amount in the heating device 50A so that the measured temperature is within the allowable range with respect to the set temperature. Control. In this case, since the set temperatures of the other airs A6 to A8 are the same as the set temperature of the air A5, the temperature of the air A5 is controlled within the allowable range with respect to the set temperature by the heating device 50A. The temperatures A6 to A8 are also controlled within an allowable range.

In the above embodiment, the temperature is controlled using the compressed air taken in from the compressed air supply pipe 42. For example, compressed air generated using a compressor, a regulator, a dustproof filter, and a chemical filter is used. It may be used for temperature control or cooling.
In the above embodiment, air (for example, dry air) is used as the air conditioning gas. Instead, nitrogen gas or rare gas (helium, neon, etc.), or a mixed gas of these gases is used. May be used.

Further, in the heat exchanger 45, other refrigerants such as a fluorine-based inert liquid (for example, Fluorinert (registered trademark or trade name)) may be used instead of the cooling water Co.
When an electronic device (or micro device) such as a semiconductor device is manufactured using the exposure apparatus of the above embodiment, the electronic device performs function / performance design of the electronic device as shown in FIG. Step 222 for manufacturing a mask (reticle) based on this design step, Step 223 for manufacturing a substrate (wafer) that is a base material of the device and applying a resist, and a reticle pattern by the exposure apparatus of the above-described embodiment. Exposure process to substrate (sensitive substrate), development process of exposed substrate, substrate processing step 224 including heating (curing) and etching process of developed substrate, device assembly step (dicing process, bonding process, packaging process, etc.) 225) and the inspection step 226, etc. It is produced through.

  Therefore, in this device manufacturing method, the pattern of the photosensitive layer is formed on the substrate using the exposure apparatus or the exposure method of the above embodiment, and the substrate on which the pattern is formed is processed (step 224). Is included. According to the exposure apparatus or the exposure method, the temperature of the exposure apparatus can be controlled at low cost by using compressed air at a low maintenance frequency. Therefore, an electronic device can be manufactured with high accuracy and low cost.

The present invention can be applied not only to a scanning exposure type projection exposure apparatus but also to exposure using a batch exposure type (stepper type) projection exposure apparatus. The present invention can also be applied when exposure is performed using a proximity type or contact type exposure apparatus that does not use a projection optical system.
Further, as disclosed in, for example, International Publication No. 2001/035168, an exposure apparatus (lithography system) that projects an image of a line and space pattern on a wafer by forming interference fringes on the wafer. The present invention can also be applied when using.

  In addition, the present invention is not limited to application to a semiconductor device manufacturing process. For example, a manufacturing process of a display device such as a liquid crystal display element or a plasma display formed on a square glass plate, or an imaging element (CCD, etc.), micromachines, MEMS (Microelectromechanical Systems), thin film magnetic heads, and various devices such as DNA chips can be widely applied. Furthermore, the present invention can also be applied to a manufacturing process when manufacturing a mask (photomask, reticle, etc.) on which mask patterns of various devices are formed using a photolithography process.

  As described above, the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be taken without departing from the gist of the present invention.

  R ... reticle, PL ... projection optical system, W ... wafer, 2 ... chamber, 8 ... main air conditioner, 10 ... exposure apparatus, 37 ... local air conditioning control system, 42 ... compressed air supply pipe, 43 ... second local air conditioner 44A to 44D ... Air supply duct, 45 ... Heat exchanger, 46 ... Cooling water temperature controller, 50A to 50D ... Heating device, 54A to 54D ... Temperature measuring unit, 55A to 55D, 58A, 58B ... Temperature sensor, 61 ... Cylindrical member, 62 ... Hood part

Claims (15)

In an exposure method of illuminating a pattern with exposure light and exposing an object through the pattern with the exposure light,
Heat exchange is performed between the compressed gas and the refrigerant, and the compressed gas is cooled to a temperature lower than a predetermined temperature,
Heating the gas cooled to a temperature lower than the predetermined temperature;
An exposure method comprising supplying the heated gas to a temperature control target region. The temperature control target area is plural,
2. The exposure method according to claim 1, wherein the predetermined temperature is a temperature lower than a lowest value among set target temperatures of the plurality of temperature control target regions. Measure the temperature information of the gas supplied to the temperature control target region,
3. The exposure method according to claim 1, wherein the gas cooled to a temperature lower than the predetermined temperature is heated based on the measurement result.   4. The exposure method according to claim 1, wherein when the gas is heated, the gas is blown around a heating element and is exhausted from a support portion side of the heating element. 5.   5. The exposure method according to claim 4, wherein the heating element has a rod shape, and the gas is blown along a longitudinal direction of the heating element when the gas is sent around the heating element.   The exposure method according to claim 3, wherein when measuring the temperature information of the gas, the gas is blown around the temperature measuring body and exhausted from the front end side of the temperature measuring body.   The exposure method according to claim 6, wherein the temperature measuring body is rod-shaped, and when the gas is blown around the temperature measuring body, the air is blown along the longitudinal direction of the temperature measuring body. The pattern is formed on a mask;
The exposure method according to claim 1, wherein the temperature control target region is in contact with at least a part of the mask. Forming a pattern of a photosensitive layer on a substrate using the exposure method according to claim 1;
Processing the substrate on which the pattern is formed. In an exposure apparatus that illuminates a pattern with exposure light and exposes an object through the pattern with the exposure light,
A gas intake section to which compressed gas is supplied; and
A heat exchanger that cools the compressed gas to a temperature lower than a predetermined temperature by performing heat exchange between the compressed gas and the refrigerant taken in via the gas intake unit;
A heater for heating the gas cooled to a temperature lower than the predetermined temperature;
An air supply path for supplying the gas heated by the heater to the temperature control target area;
An exposure apparatus comprising: The temperature control target area is plural,
The exposure apparatus according to claim 10, wherein the predetermined temperature is a temperature lower than a minimum value among set target temperatures of the plurality of temperature control target regions. A temperature sensor for measuring temperature information of the gas supplied to the temperature control target region;
The exposure apparatus according to claim 10, wherein the heater heats the gas based on temperature information measured by the temperature sensor.   The said heater has a 1st ventilation path which ventilates the said gas around the said heat generating body and the said heat generating body, and exhausts the said gas from the support part side of the said heat generating body. 13. The exposure apparatus according to any one of 1 to 12.   The temperature sensor includes a temperature measuring body, and a second air passage that blows the gas around the temperature measuring body and exhausts the gas from a tip end side of the temperature measuring body. Item 13. The exposure apparatus according to Item 12. Forming a pattern of a photosensitive layer on a substrate using the exposure apparatus according to claim 10;
Processing the substrate on which the pattern is formed.

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