JP2010283015A - Optical device and method of fabricating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device which can eliminate contaminants in the atmosphere near the optical system without having adverse effect on the optical system. <P>SOLUTION: An aligner for exposing a wafer W by illumination light through a projection optical system PL includes an annular member 40 which is provided between the wafer side optical element L11 of the projection optical system PL and the wafer W to surround a part of the optical path of the illumination light ILE between the optical element L11 and the wafer W, a plurality of gas supply openings 40e provided in the annular member 40 to blow gas outward from the optical path of the illumination light ILE, and a blower which blows gas from the gas supply openings 40e and produces a negative pressure in the annular member 40 as the gas is blown. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical apparatus that irradiates an object with illumination light via an optical system, and is suitable for an exposure apparatus that exposes an object via a projection optical system, for example. Furthermore, the present invention relates to a device manufacturing method using the optical apparatus.

  For example, in an exposure apparatus used in a lithography process for manufacturing an electronic device (microdevice) such as a semiconductor device, a KrF excimer laser (wavelength 248 nm) as an exposure light, and an ArF excimer laser having a shorter wavelength than this ( Wavelength of 193 nm) is used. When such exposure light having a short wavelength is used, conventionally, dry air or low-humidity nitrogen gas is supplied to the optical path of the exposure light.

  In addition, a trace amount of organic gas may be generated from the photoresist applied to the wafer (or glass plate or the like) to be exposed. Also, in the atmosphere of the reticle to be transferred, a trace amount of organic gas may be generated from the drive system of the reticle stage that holds and moves the reticle. When such organic gas adheres to the surface of the optical element at the end of the projection optical system as a contaminant, and fogging occurs due to the interaction between the contaminant and exposure light, the transmittance of the projection optical system decreases. . Therefore, a predetermined clean gas is supplied from the gas supply device into the space from the optical member on the object plane side end of the projection optical system to the reticle and / or the space from the optical member on the image plane side of the projection optical system to the wafer. There has been proposed an exposure apparatus that supplies a substantially constant flow rate and exhausts contaminants together with the gas (see, for example, Patent Document 1).

JP 2002-373850 A

  In the conventional exposure apparatus, the gas supplied from the gas supply apparatus is blown directly onto the surface of the optical member of the projection optical system, so that turbulent flow is generated near the surface of the optical element and is caught in this turbulent flow. There is a possibility that the occurrence of fogging is promoted by the adhering contaminants to the surface of the optical member. Further, there is a possibility that temperature unevenness that affects the imaging characteristics may occur on the surface of the optical member to which the gas is blown.

  In view of such circumstances, the present invention provides an optical apparatus capable of eliminating contaminants in the atmosphere in the vicinity of the optical system without adversely affecting the optical system, and a device manufacturing method using the optical apparatus. With the goal.

  An optical device according to the present invention is an optical device that irradiates an object with illumination light via an optical system, and at least one of the object side of the optical system and the side on which the illumination light is incident, the object side of the optical system, and the illumination light Part of the optical path of the illumination light between the object side of the optical system and at least one of the light incident side and the substrate. A space forming member that surrounds the gas and a gas that blows outward in the direction toward the optical path of the illumination light, and a negative pressure that generates a negative pressure between the space forming member and the substrate as the gas is blown out. A pressure generating unit.

  A device manufacturing method according to the present invention includes forming a pattern of a photosensitive layer on a substrate using the optical apparatus of the present invention, and processing the substrate on which the pattern is formed.

  According to the present invention, since the gas is not directly blown against the optical system, the optical system is not adversely affected. Further, since the gas in the vicinity of the optical system is exhausted outside the optical path of the illumination light by the negative pressure generating unit, the contaminants in the atmosphere in the vicinity of the optical system can be excluded by the flow of the gas.

It is a perspective view which shows the exposure apparatus used in an example of embodiment. (A) is sectional drawing which shows the principal part of the mechanism which supplies purge gas between the projection optical system PL of FIG. 1, and the wafer W, (B) is a bottom view which shows the annular member 40 of FIG. 2 (A). . 1A is a cross-sectional view showing a main part of a mechanism for supplying a purge gas between the projection optical system PL and the reticle R in FIG. 1, and FIG. 3B shows a first modification of the mechanism in FIG. Sectional drawing and (C) are sectional drawings which show the 2nd modification of the mechanism of FIG. 3 (A). (A) is sectional drawing which shows the 1st modification of the mechanism of FIG. 2 (A), (B) is sectional drawing which shows the 2nd modification of the mechanism of FIG. 2 (A). 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.
FIG. 1 shows a schematic configuration of a scanning exposure type exposure apparatus 100 including a scanning stepper (scanner) according to the present embodiment. In FIG. 1, an exposure apparatus 100 includes an exposure light source (not shown) and an illumination optical system 10 that illuminates a reticle R (mask) with exposure illumination light (exposure light) IL emitted from the exposure light source. ing. Further, the exposure apparatus 100 projects a reticle stage RST that holds and moves the reticle R, and illumination light IL emitted from the reticle R onto a wafer W (substrate) coated with a photoresist (photosensitive material). An optical system PL, a wafer stage WST that positions and moves the wafer W, a main control system 2 that includes a computer that controls the overall operation of the apparatus, and other drive systems are provided. The exposure apparatus 100 is housed in a box-like chamber (not shown) as a whole, and the temperature of the exposure apparatus 100 is controlled, and the gas (for example, dry air) that has passed through the dustproof filter and the chemical filter is a downflow system. Supplied at.

  Hereinafter, the Z-axis is taken in parallel with the optical axis AX of the projection optical system PL, the X-axis and the Y-axis are taken in two orthogonal directions within a plane (substantially a horizontal plane), and the X-axis, Y-axis, and Z The description will be made assuming that the rotation (inclination) directions around the axis parallel to the axis are the θx, θy, and θz directions, respectively. 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).

An ArF excimer laser (wavelength 193 nm) is used as the exposure light source. Other exposure light sources include ultraviolet pulsed laser light sources such as KrF excimer laser (wavelength 248 nm), harmonic generation light source of YAG laser, harmonic generation device of solid state laser (semiconductor laser, etc.), or discharge lamp such as mercury lamp. Etc. can also be used.
The illumination optical system 10 includes an illuminance uniformizing optical system including an optical integrator (a fly-eye lens, a rod integrator, a diffractive optical element, etc.) as disclosed in, for example, US Patent Application Publication No. 2003/0025890. It includes an integrator sensor that monitors the intensity of the illumination light IL, a reticle blind (variable field stop), a condenser optical system, and the like. The illumination optical system 10 illuminates the illumination area 18R elongated in the X direction (non-scanning direction) on the pattern area PA with illumination light IL with a substantially uniform illuminance on the pattern surface of the reticle R. Further, the intensity distribution of the illumination light IL on the pupil plane in the illumination optical system 10 is switched by a setting mechanism (not shown) according to illumination conditions such as normal illumination, dipole or quadrupole illumination, or annular illumination.

A thin pellicle (protective film) (not shown) is stretched over the pattern surface (reticle surface) of the reticle R via a rectangular frame so as to cover the pattern area PA.
Under the illumination light IL, the circuit pattern in the illumination region 18R of the reticle R is given a predetermined projection magnification (for example, 1/4, 1/1) via the projection optical system PL of both-side telecentric (or one-side telecentric on the wafer side). And an exposure area 18W (an area conjugate to the illumination area 18R) on one shot area SA on the wafer W. The wafer W is obtained by applying a photoresist on a disk-like silicon or SOI (Silicon on Insulator) or the like having a diameter of 200 mm, 300 mm, 450 mm, or the like and a thickness of about 0.5 to 1 mm. is there. The projection optical system PL is, for example, a refractive system, but a catadioptric system or the like can also be used. The reticle surface and the surface of the wafer W (wafer surface) are arranged on the object plane and the image plane of the projection optical system PL, respectively.

  The reticle R is sucked and held on the reticle stage RST via a reticle holder (not shown). The reticle stage RST is mounted on an upper surface of the reticle base 12 parallel to the XY plane via an air bearing, and moves on the upper surface at a constant speed in the Y direction, as well as a position in the X direction, the Y direction, and a rotation angle in the θz direction. Make fine adjustments. As an example, two-dimensional positional information including the position of the reticle stage RST in at least the X and Y directions and the rotation angle in the θz direction includes an X-axis laser interferometer 14X and a Y-axis two-axis laser interferometer 14YA. , 14YB, and the measurement value is supplied to the stage drive system 4 and the main control system 2. The stage drive system 4 controls the speed and position of the reticle stage RST via a drive mechanism (not shown) based on the position information and the control information from the main control system 2.

  Wafer W is sucked and held on wafer stage WST via wafer holder 20. Wafer stage WST includes an XY stage 24 and a Z tilt stage 22 that is installed on the XY stage 24 and holds the wafer W. The XY stage 24 is placed on an upper surface parallel to the XY plane of the wafer base 26 via an air bearing, and the upper surface moves in the X direction and the Y direction, and the rotation angle in the θz direction is corrected as necessary. . The Z tilt stage 22 individually drives, for example, three Z driving units (not shown) that can be displaced in the Z direction, and the position (Z position) of the upper surface (wafer W) of the Z tilt stage 22 in the optical axis AX direction. ), And the rotation angle in the θx and θy directions.

  Further, an oblique incidence method for measuring the focus position at a plurality of points on the wafer surface is formed on the side surface of the projection optical system PL with the same configuration as disclosed in, for example, US Pat. No. 5,448,332. A multipoint autofocus sensor (not shown) is provided. The stage drive system 4 drives the Z tilt stage 22 so that the surface of the wafer W is focused on the image plane of the projection optical system PL based on the measurement result of the autofocus sensor.

  Two-dimensional position information including at least the position in the X direction, the Y direction, and the rotation angle in the θz direction of wafer stage WST (Z tilt stage 22) is, for example, two-axis laser interferometers 36XP and 36XF of the X axis. The measurement values are measured by a wafer side interferometer including two Y-axis laser interferometers 36YA and 36YB, and the measured values are supplied to the stage drive system 4 and the main control system 2. The position information is also supplied to the alignment control system 6. The stage drive system 4 determines the two-dimensional position of the XY stage 24 of the wafer stage WST via a drive mechanism (not shown) based on the position information and the control information from the main control system 2. Control.

  Further, on the side surface of the projection optical system PL, an off-axis type wafer alignment system 38 for measuring the position of the alignment mark on the wafer W is supported by a frame (not shown). The detection result of the wafer alignment system 38 is supplied to the alignment control system 6. Further, a reference member 28 is fixed in the vicinity of the wafer holder 20 on the Z tilt stage 22, and a slit pattern and a reference mark are formed on the reference member 28. The aerial image measurement system 34 that receives the light beam that has passed through the slit pattern is housed on the bottom surface of the reference member 28 in the Z tilt stage 22, and the detection signal of the aerial image measurement system 34 is supplied to the alignment control system 6. . The position of the image of the alignment mark (not shown) of the reticle R can be measured by the aerial image measurement system 34, and the alignment of the reticle R can be performed based on the measurement result. Further, by detecting the reference mark on the reference member 28 by the wafer alignment system 38, the positional relationship (baseline) between the center of the pattern image of the reticle R (exposure center) and the detection center of the wafer alignment system 38 is measured. it can. After processing the positions of a predetermined plurality of alignment marks on the wafer W measured by the wafer alignment system 38 to obtain the array coordinates of each shot area on the wafer W, the array coordinates and the baseline are used. Each shot area on the wafer W and the pattern image of the reticle R can be overlaid and exposed with high accuracy.

  At the time of exposure, while exposing an image of the pattern in the illumination area 18R of the reticle R by the projection optical system PL onto one shot area on the wafer W, the reticle R and the wafer W are projected in the Y direction with the projection magnification as the speed ratio. By moving in synchronization, the pattern image of the reticle R is scanned and exposed in the shot area. After that, the wafer stage WST is driven to move the wafer W stepwise in the X and Y directions, and the scanning exposure operation is repeated, so that the reticle is applied to each shot area on the wafer W by the step-and-scan method. An R pattern image is exposed.

  During this exposure, a small amount of organic gas generated from the photoresist on the wafer W or a small amount of organic gas generated from the driving system for driving the reticle stage RST is applied to the surface of the optical element at the end of the projection optical system PL. If it adheres as a contaminant and the contaminant reacts with the illumination light IL to form fog, the transmittance of the projection optical system PL decreases, and the utilization efficiency of the illumination light IL decreases. Therefore, the exposure apparatus 100 includes a local gas supply mechanism for preventing such contaminants from adhering to the surface of the optical element. This gas supply mechanism is an annular on the reticle side arranged so as to surround the optical path of the illumination light IL between the optical element L21 (see FIG. 3A) on the reticle R side of the projection optical system PL and the reticle R. Between the member 19 and the optical element L11 on the wafer W side of the projection optical system PL (see FIG. 2A) and the wafer W, an annular member 40 on the wafer side disposed so as to surround the optical path of the illumination light IL. And an air blower 5 that supplies the purge light, which is a gas whose temperature is controlled and highly dust-removed, to the inside of the annular members 19 and 40, and that supplies a purge gas at a substantially constant flow rate. . As an example, the purge gas of the present embodiment is the same type as a gas (for example, dry air) supplied by a downflow method in a chamber (not shown) in which the exposure apparatus 100 is accommodated. Note that an inert gas such as nitrogen gas or a rare gas can be used as the gas and purge gas supplied into the chamber.

  When the air supply control information is input from the main control system 2, the blower 5 supplies the purge gas to the annular members 19 and 40 through the flexible pipes 7A and 7B and the joints 8A and 8B at a substantially constant flow rate. Supply with. For example, the blower 5 passes the gas collected after flowing through a chamber (not shown) containing the exposure apparatus 100 through a dust filter (HEPA filter, ULPA filter, etc.) and a chemical filter, and then targets this gas to the target. A gas whose temperature is controlled within the temperature range is supplied (fanned) to the pipes 7A and 7B at a predetermined flow rate as a purge gas. Note that, for example, when the wafer W or the reticle R is exchanged, the purge gas supply operation from the blower 5 is stopped during a period in which the wafer W or the reticle R does not exist near the end of the projection optical system PL. Also good.

  2A is a cross-sectional view showing the annular member 40 disposed at the end of the projection optical system PL in FIG. 1 on the wafer W side, and FIG. 2B shows the annular member 40 in FIG. It is a bottom view. In FIG. 2A, the projection optical system PL includes a parallel plate-like optical element L11 disposed facing the wafer W, and a lens L12 disposed thereon, and the lens L12 is a partial lens barrel. The partial barrel 41 is supported by a frame (not shown). Further, the annular member 40 is fixed to the bottom surface of the partial barrel 41 by bolts 42 at three locations. The annular member 40 does not shield the outermost illumination light ILE incident on the exposure area 18W on the wafer W. A rectangular opening 40a long in the X direction through which illumination light for exposing W passes is formed. In the present embodiment, the optical element L11 is supported on the upper surface 40b side of the annular member 40 so as to cover the opening 40a.

  Further, in the annular member 40, one ventilation hole 40c to which the purge gas G is supplied from the blower 5 of FIG. 1 via the pipe 7B and the joint 8B is formed, and communicates with the ventilation hole 40c in the annular member 40. Thus, the buffer space 43 for temporarily accumulating the purge gas G is formed. A large number of supply ports 40f for supplying the purge gas G to the space in the annular member 40 are formed on the inner surface of the opening 40a of the annular member 40 so as to surround the optical path of the illumination light ILE, for example, at regular intervals. ing. Further, a cylindrical side face-like lower end face 40g facing the wafer W and a tapered face (inclined face) 40h are formed on the bottom surface of the annular member 40 such that the distance from the lower end 40g toward the outer side increases. The taper surface 40h is formed with a large number of blowing ports 40e for blowing the purge gas G outwardly with respect to the opening 40a (light path of illumination light). In the annular member 40, a large number of vent holes 40d for connecting the buffer space 43 and the large number of air blowing ports 40e are formed, and the supply ports 40f are connected to the respective vent holes 40d. In this case, the purge gas G in the buffer space 43 tends to flow toward the blower port 40e through the vent hole 40d, and the flow rate of the purge gas blown from the blower port 40e is larger than the flow rate of the purge gas supplied from the supply port 40f. Thus, in order to make the purge gas G larger than the flow rate supplied from the supply port 40f than the flow rate supplied from the blower port 40e, for example, the opening diameter of the blower port 40e is larger than the opening diameter of the supply port 40f. Or a porous body may be provided as described later.

  As shown in FIG. 2B, the buffer space 43 in the annular member 40 is formed in a ring shape so as to surround the opening 40a, and the large number of air blowing ports 40e are formed at substantially equal intervals so as to surround the opening 40a. The air blowing ports 40e are connected to the buffer space 43 through one air hole 40d. Similarly, a large number of supply ports 40f in FIG. 2A are arranged at substantially equal intervals so as to surround the opening 40a. In order to easily form the buffer space 43 and the large number of vent holes 40d in the annular member 40, as an example, the annular member 40 is connected to a plurality of members including a member in the + Z direction and a member in the −Z direction. It may be formed. The annular member 40 is made of metal, for example.

  2A and 2B, when the wafer W is exposed, the purge gas G having a predetermined flow rate and a predetermined pressure is supplied from the blower 5 of FIG. 1 to the vent hole 40c of the annular member 40 through the pipe 7B and the joint 8B. Is supplied. The supplied purge gas G is temporarily accumulated in the buffer space 43 in the annular member 40, and then is directed to the outside of the opening 40a (light path of the illumination light IL) from the blower port 40e through the vent hole 40d. As shown in FIG. As a result, the air pressure inside the annular member 40 becomes lower than the air pressure outside, and the gas inside the annular member 40 passes through the gap between the annular member 40 and the wafer W as shown by the arrow A2 due to the negative pressure effect. Exhausted to the outside. Further, as shown by an arrow A3, the purge gas G is supplied from the supply port 40f on the inner surface of the annular member 40 through the vent hole 40d as shown by an arrow A3 so as to supplement the gas exhausted from the inside of the annular member 40. .

  As a result, the gas in the space surrounded by the annular member 40 between the optical element L11 and the wafer W is continuously exhausted to the outside of the annular member 40 and cleaned inside the annular member 40 so as to compensate for it. A purge gas G is supplied. Accordingly, since the organic gas generated from the photoresist on the wafer W is exhausted together with the purge gas G, it is possible to prevent contaminants from adhering to the surface of the optical element L11. Further, the gas inside the annular member 40 is exhausted by the negative pressure effect of the purge gas G blown outward from the blower port 40e on the bottom surface of the annular member 40, and the purge gas G is directly blown onto the surface of the optical element L11. Absent. As a result, the temperature distribution of the optical element L11 is not formed, and slight deformation or the like of the optical element L11 does not occur, so that the imaging characteristics of the projection optical system PL are maintained high. Since purge gas is supplied from the supply port 40f on the inner surface of the annular member 40 to a region away from the surface of the optical element L11 so as to diffuse relatively slowly, the adverse effect of the purge gas supplied from the supply port 40f is adversely affected. Can be considered almost nonexistent.

  Next, FIG. 3A is a cross-sectional view showing the annular member 19 disposed at the end of the projection optical system PL in FIG. 1 on the reticle R side. In FIG. 3A, a pellicle (not shown) is stretched through a rectangular frame so as to cover the pattern surface of the reticle R. The projection optical system PL includes a parallel plate-like optical element L21 disposed facing the reticle R, and a lens L22 disposed below the optical element L21. The lens L22 is held by the partial barrel 51, The partial barrel 51 is supported by a frame (not shown). A ring-shaped holding member 52 is fixed to the upper surface of the partial barrel 51 via, for example, three bolts 53 </ b> A, and the optical element L <b> 21 is held by the holding member 52. Further, the annular member 19 is fixed on the holding member 52 through, for example, three bolts 53B, and the annular member 19 is not shielded from the outermost illumination light ILE emitted from the illumination region 18R of the reticle R. A rectangular opening that is long in the X direction through which illumination light passes is formed. In this case, an opening 12a through which illumination light passes is formed below the illumination area 18R of the reticle base 12, and the tip of the annular member 19 is housed in the concave portion of the reticle base 12 following the opening 12a.

  Further, in the annular member 19, one vent hole 19c to which purge gas G is supplied from the blower 5 of FIG. 1 via the pipe 7A and the joint 8A, and a ring-shaped buffer space 54 communicating with the vent hole 19c, Is formed. Further, a large number of air outlets 19b are formed on the inner surface of the annular member 19 so as to surround the optical path of the illumination light ILE, and a large number of air holes connecting the buffer space 54 and the large number of air outlets 19b in the annular member 19 19d is formed. In this case, each of the vent holes 19d is bent upward at the partition wall 19a on the inner surface of the annular member 19, and then communicated with the outlet 19b. As an example, the annular member 19 may be formed by connecting a plurality of members including a member in the + Z direction and a member in the −Z direction. The annular member 19 is also made of metal, for example.

  3A, at the time of wafer exposure, a purge gas G having a predetermined flow rate is supplied from the blower 5 of FIG. 1 to the vent hole 19c of the annular member 19 through the pipe 7A and the joint 8A at a predetermined pressure. The supplied purge gas G is temporarily accumulated in the buffer space 54 in the annular member 19, and then blown to the partition wall 19a through the vent hole 19d as shown by the arrow B1, and the air passage is bent. From the blowout port 19b, the air is blown into the annular member 19 at a substantially constant flow rate. As a result, the gas inside the annular member 19 is exhausted to the outside of the annular member 19 through the gap between the annular member 19 and the concave portion of the reticle base 12 as indicated by an arrow B2. Accordingly, the organic gas generated from the pellicle (not shown) of the reticle R is exhausted together with the purge gas G, so that contaminants are prevented from adhering to the surface of the optical element L21. Furthermore, since the purge gas G in the annular member 19 is blown and diffused to the partition wall 19a and then supplied to the upper side of the optical element L21 from the blowout port 19b, the purge gas G may be directly blown onto the surface of the optical element L21. Absent. As a result, the temperature distribution of the optical element L21 is not formed, and slight deformation or the like of the optical element L21 does not occur, so that the imaging characteristics of the projection optical system PL are maintained high.

Effects and the like of this embodiment are as follows.
(1) The exposure apparatus 100 of the present embodiment is an exposure apparatus that irradiates the wafer W with illumination light via the projection optical system PL. As shown in FIG. An annular member 40 (space forming member) provided between the element L11 and the wafer W (substrate) and surrounding a part of the optical path of the illumination light ILE between the optical element L11 of the projection optical system PL and the wafer W; A mechanism that blows out the purge gas G that transmits the illumination light in the direction toward the outside with respect to the optical path of the illumination light ILE and generates a negative pressure in the space between the annular member 40 and the wafer W as the purge gas G is blown out. And.

Further, the mechanism for generating the negative pressure includes a blower port 40e formed in the annular member 40 so as to blow a gas in a direction outward from the optical path of the illumination light ILE, and a blower that supplies the purge gas G to the blower port 40e. And 5.
According to the present embodiment, the purge gas G is not sprayed directly onto the optical element L11, and therefore does not adversely affect the projection optical system PL (optical element L11). Furthermore, contaminants in the atmosphere in the vicinity of the optical element L11 can be efficiently eliminated by the negative pressure generated when the purge gas G is blown out.

A mechanism for positively sucking and exhausting the purge gas G blown from the air blowing port 40e and the gas exhausted from the inside of the annular member 40 may be provided around the annular member 40.
(2) Further, the annular member 40 has a supply port 40f for supplying the purge gas G toward the inside thereof, and is exhausted from the inside of the annular member 40 by a negative pressure effect when the purge gas G is blown from the blower port 40e. A blower 5 for supplying the purge gas G to the supply port 40f is provided so as to replenish the gas.

Accordingly, the optical element L11 or the wafer W is prevented from being deformed by the negative pressure. Note that the purge gas G may be supplied to the supply port 40f from a supply device different from the blower device 5.
In FIG. 2A, the supply port 40f of the annular member 40 may be formed simply as a vent hole that communicates the inside and the outside of the annular member 40.

  (3) Further, as shown in FIG. 3A, the exposure apparatus 100 is disposed so as to surround a part of the optical path of the illumination light ILE outside the optical element L21 at the end of the projection optical system PL on the reticle side. The annular member 19 is formed with a vent hole 19c for supplying gas to the optical path side of the illumination light ILE, the side wall portion 19a is blown with the gas supplied to the inside of the annular member 19 through the vent hole 19c, and the vent hole 19c. And a blower 5 for supplying a purge gas G that transmits the illumination light ILE. That is, the purge gas G is supplied between the projection optical system PL and the reticle R.

In this case, since the side wall portion 19a is in the middle of the air passage for the purge gas G, the purge gas G is blown after the pressure is reduced with respect to the optical element L21. Accordingly, contaminants in the atmosphere in the vicinity of the optical element L21 can be eliminated by the flow of the purge gas G without adversely affecting the optical element L21.
In addition, you may provide the side wall part (pressure adjustment mechanism) similar to the side wall part 19a in the supply port 40f of the annular member 40 of FIG. 2 (A). As a result, the blow pressure of the purge gas G with respect to the optical element L11 is reduced, so that the adverse effect on the optical element L11 is further reduced.

In FIG. 3A, a mechanism may be provided in which the purge gas G is blown out of the annular member 19 so that the space between the annular member 19 and the reticle R is negative.
(4) The annular member 40 includes a lower end surface 40g facing the wafer W, and a tapered surface 40h that increases the distance from the wafer W as it moves away from the lower end surface 40g, and the air blowing port 40e is provided on the tapered surface 40h. It has been. Therefore, the purge gas G can be blown out of the optical path of the illumination light with a simple configuration.

In FIG. 2A, the purge gas G is blown out parallel to the surface of the wafer W, but the purge gas G may be blown out gradually from the wafer W through the blower port 40e.
Next, a modification of the embodiment of the present invention will be described with reference to FIGS. 3B, 3C, 4A, and 4B. 3B and 3C, portions corresponding to those in FIG. 3A are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in FIGS. 4A and 4B, portions corresponding to those in FIG. 2A are denoted by the same reference numerals, and detailed description thereof is omitted.

  First, instead of the annular member 40 of FIG. 2A, the annular member 40A of FIG. 4A may be used. In FIG. 4A, the optical element L 11 is held by a ring-shaped holding member 44, and the holding member 44 is fixed to the bottom surface of the partial barrel 41 by a bolt 42. Further, an annular member 40A disposed so as to surround the optical path of the illumination light ILE incident on the exposure area 18W on the wafer W is fixed to the bottom surface of the partial barrel 41 via the connecting member 45. A ventilation portion 40Af through which gas passes is secured between the bottom surface of the holding member 44 and the top surface of the annular member 40A, and a part of the connecting member 45 is similar to the blower device 5 in FIG. 1 via a joint 8C and a pipe 7C. The blower is connected.

  Further, a flat surface 40Ag that faces the wafer W and a tapered surface 40Ah that is further away from the wafer W are formed on the bottom surface of the annular member 40A, and the tapered surface 40Ah faces the outside of the optical path of the illumination light ILE. A large number of air outlets 40Ae for blowing out gas are formed, and an air hole 40Ac and a ring-shaped buffer part 43A are formed inside the annular member 40A. The buffer part 43A and the air holes 40Ae are respectively formed by air holes 40Ad. It is connected. A blower similar to the blower 5 of FIG. 1 is connected to the vent 40Ac via a joint 8B and a pipe 7B.

  4A, when the wafer W is exposed, a purge gas G having a predetermined flow rate is supplied from a blower (not shown) to the vent hole 40Ac of the annular member 40A through the pipe 7B and the joint 8B. The supplied purge gas G is blown out at a substantially constant flow rate as indicated by an arrow A1 from the blower opening 40Ae toward the outside of the optical path of the illumination light ILE via the buffer portion 43A in the annular member 40A and each vent hole 40Ad. The As a result, due to the negative pressure effect, the gas inside the annular member 40A is exhausted to the outside of the annular member 40A as indicated by the arrow A2. Further, as shown by an arrow A3, the purge gas G is supplied from a blower (not shown) through the pipe 7C, the joint 8C, and the ventilation portion 40Af so as to supplement the gas exhausted from the inside of the annular member 40A.

As a result, the organic gas generated from the photoresist on the wafer W is exhausted together with the purge gas G, so that contaminants are prevented from adhering to the surface of the optical element L11. Furthermore, since the purge gas G is not directly blown onto the surface of the optical element L11, the imaging characteristics of the projection optical system PL are maintained high.
Next, instead of the annular member 40 of FIG. 2A, the annular member 40B of FIG. 4B may be used. 4B, the annular member 40B fixed to the bottom surface of the partial barrel 41 is formed with an opening 40Ba so as to surround the optical path of the illumination light ILE, and the optical element L11 is held so as to cover the opening 40Ba. ing. In addition, a large number of gas supply ports 40Bf are formed on the inner surface of the annular member 40B, and a cylindrical porous body 46 for reducing the gas wind speed is fixed to each of the supply ports 40Bf. Furthermore, the vent hole 40Bc, the buffer space 43 communicating with the vent hole 40Bc, and the numerous vent holes 40Bd connecting the buffer space 43 and the numerous supply ports 40Bf (porous body 46) are formed inside the annular member 40B. ing.

  4B, when the wafer W is exposed, a purge gas G having a predetermined flow rate is supplied from a blower (not shown) to the vent hole 40Bc of the annular member 40B through the pipe 7B and the joint 8B. The supplied purge gas G is blown out from the supply port 40Bf toward the optical path of the illumination light ILE as indicated by an arrow A4 through the buffer space 43 in the annular member 40B, the vent holes 40Bd, and the porous body 46. . As a result, due to the deceleration effect of the porous body 46, the purge gas G supplied to the inside of the annular member 40B gently flows into the gap between the annular member 40B and the wafer W as indicated by the arrow A5, and then the arrow A6. As shown, the air is exhausted to the outside of the annular member 40B.

As a result, the organic gas generated from the photoresist on the wafer W is exhausted together with the purge gas G. Further, the purge gas G is supplied so as to be diffused on the surface of the optical element L11, and there is no adverse effect on the optical element L11, so that the imaging characteristics of the projection optical system PL are maintained high.
Instead of the porous body 46, another member that adjusts the pressure by decelerating or diffusing gas such as a mesh member may be used.

Further, for example, a porous body or a mesh member similar to the porous body 46 may be installed at the supply port 40f of the annular member 40 in FIG.
Next, instead of the annular member 19 on the reticle R side in FIG. 3A, the annular member 19A in FIG. 3B may be used. In FIG. 3B, a ring-shaped protection plate 55 is fixed to the upper surface of the holding member 52 that holds the optical element L21. A cylindrical annular member 19 </ b> A is fixed on the divided lens barrel 51 so as to surround the side surfaces and upper portions of the holding member 52 and the protection plate 55. An airtight O-ring 56 is mounted between the annular member 19 </ b> A and the holding member 52, and a ventilation portion 19 </ b> Ab that allows gas to pass between the distal end portion of the annular member 19 </ b> A and the protection plate 55 is formed. Further, a vent hole 19Ac that communicates the joint 8A and the vent portion 19Ab is formed in the annular member 19A.

  3B, at the time of wafer exposure, a purge gas G having a predetermined flow rate is supplied from a blower similar to the blower 5 of FIG. 1 to the vent hole 19Ac of the annular member 19A via the pipe 7A and the joint 8A. Is done. The supplied purge gas G is sprayed from the vent hole 19Ac in the annular member 19A to the protective plate 55 as indicated by an arrow B3, and then supplied from the vent portion 19Ab to the optical path of the illumination light ILE inside the annular member 19A. . Further, the gas inside the annular member 19A is exhausted to the outside of the annular member 19A through a gap between the annular member 19A and the concave portion of the reticle base 12 as indicated by an arrow B2. Accordingly, the organic gas generated from the pellicle (not shown) of the reticle R is exhausted together with the purge gas G. Furthermore, since the purge gas G in the annular member 19A is blown onto the protective plate 55 and diffused, the purge gas G is supplied above the optical element L21. Therefore, the purge gas G is not directly blown onto the surface of the optical element L21. As a result, the imaging characteristics of the projection optical system PL are maintained high.

As in the example of FIG. 3B, a mechanism for spraying the purge gas G onto the protective plate 55 may be provided at a portion where the purge gas G is supplied from the supply port 40f of the annular member 40 of FIG.
Next, instead of the annular member 19 on the reticle R side in FIG. 3 (A), the annular member 19B in FIG. 3 (C) may be used. In FIG. 3C, a communication hole 19Bc and a buffer space 54 are formed in the annular member 19B, and the buffer space 54 is a region where the illumination light of the optical element L21 does not pass through the vent hole 19Bd (a region outside the effective region). ) Communicated with the opening opposite to. Further, a ventilation portion 19Bb through which gas passes is provided between the tip of the annular member 19B and the optical element L21.

  In the modification of FIG. 3C, at the time of wafer exposure, a purge gas G having a predetermined flow rate is supplied from a blower (not shown) to the vent hole 19Bc of the annular member 19B through the pipe 7A and the joint 8A. The supplied purge gas G is blown from the buffer space 54 and the vent hole 19Bd in the annular member 19B to the area outside the effective area of the optical element L21 as shown by an arrow B3, and then from the vent 19Bb to the inside of the annular member 19B. Is supplied to the optical path of the illumination light ILE. Accordingly, the organic gas generated from the pellicle (not shown) of the reticle R is exhausted together with the purge gas G. Further, since the purge gas G in the annular member 19B is blown out of the effective area of the optical element L21 and diffused, the purge gas G is supplied to the upper side of the optical element L21, so that the imaging characteristics of the projection optical system PL are maintained high.

A mechanism for spraying the purge gas G outside the effective area of the optical element L21 as in the example of FIG. 3C is provided at a portion where the purge gas G is supplied from the supply port 40f of the annular member 40 of FIG. Also good.
2 and 4, the configuration in which the annular member 40 is disposed between the projection optical system PL and the wafer W has been described. However, the annular member 40 is disposed between the illumination optical system 10 and the reticle R. May be.
In this case, it is only necessary to replace the projection optical system PL with the illumination optical system 10 and the wafer W with the reticle R in FIGS.
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 reticle (mask) based on this design step, Step 223 for manufacturing a substrate (wafer) as a base material of the device and applying a resist, Reticle pattern by the exposure apparatus 100 of the above-described embodiment Substrate exposure process on substrate (photosensitive substrate), development process on exposed substrate, substrate processing step 224 including heating (curing) and etching process on developed substrate, device assembly step (dicing process, bonding process, packaging process) 225) as well as inspection step 2 It is produced through a 6 or the like.

  In other words, the device manufacturing method includes exposing the substrate (wafer) using the exposure apparatus of the above-described embodiment, and processing the exposed substrate (step 224). At this time, according to the exposure apparatus of the above-described embodiment, the transmittance of the projection optical system PL is maintained high, and the imaging characteristics of the projection optical system PL are maintained high. Devices can be manufactured.

  The present invention can be applied not only when the exposure is performed with the above-described scanning exposure type exposure apparatus but also when the exposure is performed with a batch exposure type exposure apparatus such as a stepper. Furthermore, the present invention is also applicable to, for example, projection optics when exposure is performed with an immersion type exposure apparatus disclosed in, for example, US Patent Application Publication No. 2007/242247 or European Patent Application Publication No. 1420298. It can be similarly applied to supply purge gas around the optical member on the reticle side of the system.

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

  In addition, this invention is not limited to the above-mentioned embodiment, A various structure can be taken in the range which does not deviate from the summary of this invention.

  R ... reticle, RST ... reticle stage, PL ... projection optical system, L11, L21 ... optical element, W ... wafer, WST ... wafer stage, 2 ... main control system, 5 ... air blower, 10 ... illumination optical system, 19 ... Reticle side annular member, 40... Wafer side annular member

Claims (15)

In an optical device that irradiates an object with illumination light via an optical system,
Provided between at least one of the object side of the optical system and the side on which the illumination light is incident and a substrate disposed on at least one of the object side of the optical system and the side of the illumination light; A space forming member surrounding a part of the optical path of the illumination light between at least one of the object side of the optical system and the side on which the illumination light is incident and the substrate;
A negative pressure generating section that blows out gas in a direction toward the outside with respect to the optical path of the illumination light, and generates a negative pressure between the space forming member and the substrate along with the blowing of the gas;
An optical device comprising:   The optical apparatus according to claim 1, wherein the negative pressure generating unit has a blow-out port that blows out the gas. The space forming member includes a gas supply port that supplies gas toward the inside of the space forming member;
A gas replenishing unit that supplies a gas that transmits the illumination light to the gas supply port of the space forming member so as to replenish the gas exhausted from the inside of the space forming member when the gas is blown out from the blowing port. The optical apparatus according to claim 2, further comprising:   The optical device according to claim 1, further comprising a vent hole that communicates an inner space and an outer space of the space forming member.   The optical apparatus according to claim 3, further comprising a pressure adjustment mechanism that is provided at the gas supply port and adjusts the pressure of the gas supplied to the inside of the space forming member.   The optical device according to claim 5, wherein the pressure adjusting mechanism includes a porous member disposed in a part of the gas supply port of the space forming member. The optical system includes an optical member and a holding member that holds the optical member,
The optical apparatus according to claim 5, wherein the pressure adjustment mechanism includes a mechanism that blows the gas supplied from the gas supply port of the space forming member to the holding member.   The optical apparatus according to claim 5, wherein the pressure adjusting mechanism includes a side wall portion to which a gas supplied to the inside of the space forming member through the gas supply port of the space forming member is blown. The space forming member includes a facing surface that faces the substrate, and a tapered surface that increases a distance from the substrate as the distance from the facing surface increases.
The optical apparatus according to claim 2, wherein the gas outlet is provided on the tapered surface.   The optical device according to claim 9, wherein the facing surface of the space forming member is a surface closest to the inside of the space forming member. The space forming member has a facing portion facing the substrate,
The optical apparatus according to claim 2, wherein the gas outlet is provided on an opposite side to the inner side of the space forming member with respect to the facing portion.   The optical device according to any one of claims 9 to 11, wherein the gas blowing port blows out the gas in a direction parallel to the substrate or in a direction away from the substrate. The optical system is a projection optical system that forms an image of a pattern formed on a mask on an object,
The optical device according to any one of claims 1 to 12, wherein the space forming member is disposed between the projection optical system and the object. The optical system is a projection optical system that forms an image of a pattern formed on a mask on the object,
The optical device according to claim 1, wherein the space forming member is disposed between the projection optical system and the mask. Forming a pattern of a photosensitive layer on a substrate using the optical device according to any one of claims 1 to 14,
Processing the substrate on which the pattern is formed.

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