JP2009021496A - Exposure apparatus and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure apparatus capable of excellently exposing a substrate while suppressing a decrease in performance of the exposure apparatus and a decrease in availability. <P>SOLUTION: The exposure apparatus exposes the substrate with exposure light in an extreme ultraviolet range. The exposure apparatus comprises a light source device which emits exposure light in pulses, a first member which forms a first space almost in a vacuum state wherein the exposure light travels, a first opening formed in at least a portion of the first member so that the exposure light passes, and an opening/closing mechanism which opens and closes the first opening in synchronism with the light emission. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exposure apparatus that exposes a substrate and a device manufacturing method.

In an exposure apparatus used in a photolithography process, an EUV exposure apparatus that uses extreme ultra-violet (EUV) light as exposure light has been devised, for example, as disclosed in Patent Document 1 below.
JP 2005-32510 A

  In the EUV exposure apparatus, a predetermined space in which exposure light travels is adjusted to a vacuum state. If an external gas enters the predetermined space, for example, the exposure light may be attenuated or the optical element (multilayer film reflector, etc.) disposed in the predetermined space may be contaminated. There is sex. In addition, when an external gas enters the predetermined space, for example, it takes time to readjust the predetermined space to a vacuum state, which may reduce the operating rate of the exposure apparatus.

  An object of the present invention is to provide an exposure apparatus capable of satisfactorily exposing a substrate while suppressing a decrease in performance and a reduction in operating rate of the exposure apparatus, and a device manufacturing method using the exposure apparatus.

  In order to solve the above-described problems, the following configurations corresponding to the respective drawings shown in the embodiments are adopted as each aspect illustrating the present invention. However, the reference numerals with parentheses attached to each element are merely examples of the element and do not limit each element.

  According to the first aspect of the present invention, an exposure apparatus that exposes a substrate (P) with exposure light (EL) in an extreme ultraviolet region, and a light source device (3) that emits the exposure light (EL) in a pulsed manner. A first member (6, 8, 22) that forms a substantially vacuum first space (6S) through which the exposure light (EL) travels, and a first member (6) so that the exposure light (EL) passes therethrough. , 8, 22) and an opening / closing mechanism (12, 60, 41) that opens and closes the first opening (11, 22, 41) in synchronization with light emission. 42), and an exposure apparatus (EX) comprising:

  According to a second aspect of the present invention, there is provided a device manufacturing method comprising: exposing a substrate (P) using the exposure apparatus (EX) of the above aspect; and developing the exposed substrate (P). Is provided.

  According to the present invention, it is possible to satisfactorily expose the substrate while suppressing a decrease in the performance of the apparatus and a decrease in the operation rate.

  Hereinafter, embodiments of the present invention will be exemplarily described with reference to the drawings, but the present invention is not limited thereto. In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as the X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as the Y-axis direction, and a direction orthogonal to the X-axis direction and the Y-axis direction (that is, the vertical direction) is defined as the Z-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively.

<First Embodiment>
A first embodiment will be described. FIG. 1 is a schematic block diagram that shows an exposure apparatus EX according to the first embodiment. In FIG. 1, an exposure apparatus EX includes a mask stage 1 that is movable while holding a mask M on which a pattern is formed, a substrate stage 2 that is movable while holding a substrate P, and a light source device that generates exposure light EL. 3, an illumination optical system IL that illuminates the mask M with the exposure light EL from the light source device 3, a projection optical system PL that projects an image of the pattern of the mask M illuminated with the exposure light EL onto the substrate P, and an exposure apparatus And a control device 4 for controlling the operation of the entire EX. The substrate P includes a substrate in which a film such as a photosensitive material (resist) is formed on the surface of a base material such as a semiconductor wafer. The mask M includes a reticle on which a device pattern projected onto the substrate P is formed.

  The exposure apparatus EX of the present embodiment is an EUV exposure apparatus that exposes the substrate P with extreme ultraviolet light. Extreme ultraviolet light is an electromagnetic wave in a soft X-ray region having a wavelength of about 5 to 50 nm, for example. In the following description, extreme ultraviolet light is appropriately referred to as EUV light. As an example, in the present embodiment, EUV light having a wavelength of 13.5 nm is used as the exposure light EL.

  In the present embodiment, the mask M is a reflective mask having a multilayer film capable of reflecting EUV light. The exposure apparatus EX illuminates the surface (reflection surface) of the mask M, on which the pattern is formed of the multilayer film, with the exposure light EL (EUV light), and the substrate P having photosensitivity with the exposure light EL reflected by the mask M. Exposure.

The exposure apparatus EX of the present embodiment includes a chamber apparatus 5 including a vacuum system that adjusts a predetermined space in which the exposure light EL travels to a vacuum state. In the present embodiment, the chamber device 5 includes a main body chamber 6, a light source chamber 7, and an intermediate chamber 8 that connects the main body chamber 6 and the light source chamber 7. The internal space 6S formed by the main body chamber 6 and the internal space 7S formed by the light source chamber 7 are connected via an internal space 8S formed by the intermediate chamber 8. In the present embodiment, a first vacuum system 9 is connected to the main body chamber 6, and a second vacuum system 10 is connected to the light source chamber 7. The control device 4 uses the first and second vacuum systems 9 and 10 to substantially vacuum a predetermined space (for example, 1 × 10 ⁻⁴ Pa) including the internal spaces 6S, 7S, and 8S in which the exposure light EL travels. To a reduced pressure atmosphere).

  In the present embodiment, at least the mask stage 1, the illumination optical system IL, and the projection optical system PL are accommodated in the internal space 6 </ b> S of the main body chamber 6. Further, at least a part of the light source device 3 is accommodated in the internal space 7 </ b> S of the light source chamber 7. The exposure light EL generated from the light source device 3 travels through the internal space 7S of the light source chamber 7, travels through the internal space 8S of the intermediate chamber 8, and then travels through the internal space 6S of the main body chamber 6.

  Further, the exposure apparatus EX of the present embodiment includes a first opening 11 formed in a part of the main body chamber 6 so that the exposure light EL passes, and an opening / closing mechanism 12 that opens and closes the first opening 11. . When the opening / closing mechanism 12 closes the first opening 11, the internal space 6 </ b> S is almost sealed. Further, the opening / closing mechanism 12 opens the first opening 11, whereby the exposure light EL can pass through the first opening 11.

  The exposure apparatus EX of the present embodiment is a so-called scanning stepper, which is a scanning exposure apparatus that projects an image of the pattern of the mask M onto the substrate P while synchronously moving the mask M and the substrate P in a predetermined scanning direction. In the present embodiment, the scanning direction (synchronous movement direction) of the substrate P is the Y-axis direction, and the scanning direction (synchronous movement direction) of the mask M is also the Y-axis direction. The exposure apparatus EX moves the substrate P in the Y-axis direction with respect to the projection area of the projection optical system PL and synchronizes with the movement of the substrate P in the Y-axis direction with respect to the illumination area of the illumination optical system IL. Then, the mask M is illuminated with the exposure light EL while moving the mask M in the Y-axis direction, and the substrate P is exposed by irradiating the exposure light EL from the mask M onto the substrate P.

  The light source device 3 generates exposure light EL. In the present embodiment, the light source device 3 emits exposure light EL (EUV light) in a pulse shape. The light source device 3 according to the present embodiment is a so-called LPP (Laser Produced Prasma) type light source device that irradiates a target material with laser light, converts the target material into plasma, and generates EUV light. .

  The light source device 3 includes a laser device 13 for generating laser light for exciting the target material, a supply member 15 having a supply port 14 for supplying the target material to the internal space 7S of the light source chamber 7, and a laser beam from the laser device 13. A condensing optical system 16 that condenses the laser light and a condensing mirror (condenser) 17 that reflects and condenses the light including the generated EUV light are included. In the present embodiment, the target material supplied from the supply port 14 includes xenon (Xe) gas. The target material may contain tin (Sn).

  In the present embodiment, the laser device 13 is disposed outside the light source chamber 7. A transmission window 18 capable of transmitting laser light is disposed in a part of the light source chamber 7. The laser light emitted from the laser device 13 enters the condensing optical system 16 disposed in the internal space 7S of the light source chamber 7 through the transmission window 18. The laser light emitted from the laser device 13 and condensed by the condensing optical system 16 is applied to the target material supplied from the supply port 14 at the tip of the supply member 15. By irradiating the target material with laser light, the target material is turned into plasma. Thereby, light (exposure light EL) including EUV light is generated. Thus, in the present embodiment, the target material is turned into plasma in the vicinity of the supply port 14 at the tip of the supply member 15, and EUV light (exposure light EL) is generated. In the following description, a partial region (space) in the vicinity of the tip (supply port 14) of the supply member 15 where the target material is turned into plasma and EUV light is generated will be referred to as a light emitting unit 19 as appropriate. The light emitting unit 19 is disposed in the internal space 7 </ b> S of the light source chamber 7.

  In the present embodiment, the laser device 13 emits laser light in a pulse shape. FIG. 2 is a schematic diagram for explaining the light emission state of the laser device 13. As in the pulse waveform shown in FIG. 2, the laser device 13 emits laser light in a pulse shape with a predetermined period T. The laser light emission time (pulse width) T1 is sufficiently shorter than the time T2 when the laser light is not emitted.

  The EUV light (exposure light EL) is emitted in a pulse form in the light emitting unit 19 in accordance with the timing of laser light emission of the laser device 13. Thus, in the present embodiment, the light source device 3 emits the exposure light EL in a pulse shape at a timing according to the light emission timing of the laser device 13.

  In FIG. 1, the light emitted from the light emitting unit 19 is reflected by the condenser mirror 17 and collected. The condensing mirror 17 includes a multilayer film reflecting mirror including a multilayer film capable of reflecting EUV light. The multilayer film includes, for example, a Mo / Si multilayer film. The light reflected by the collecting mirror 17 is collected at an intermediate focusing point (IF) 20.

  In the present embodiment, the condensing mirror 17 forms an intermediate condensing point 20 in the internal space 8S of the intermediate chamber 8. In the internal space 8S of the intermediate chamber 8, a filter 21 and a plate member 23 having an opening 22 for allowing the exposure light EL to pass therethrough are arranged. The filter 21 transmits light in the extreme ultraviolet region and blocks transmission of light other than the extreme ultraviolet region, such as visible light and ultraviolet light. The filter 21 can be formed of, for example, zirconium (Zr), beryllium (Be), silicon (Si), or the like.

  The opening 22 is circular (pinhole), and the intermediate condensing point 20 is formed in the vicinity (inside) of the opening 22. The EUV light (exposure light EL) emitted from the light emitting unit 19 and passed through the filter 21 enters the illumination optical system IL disposed in the internal space 6S of the main body chamber 6.

  The illumination optical system IL is disposed in the internal space 6S of the main body chamber 6. The illumination optical system IL illuminates the mask M with the exposure light EL from the light source device 3. The illumination optical system IL includes a plurality of optical elements, and illuminates a predetermined illumination area on the mask M with the exposure light EL having a uniform illuminance distribution. The optical element of the illumination optical system IL includes a multilayer film reflecting mirror including a multilayer film capable of reflecting EUV light. The multilayer film of the optical element includes, for example, a Mo / Si multilayer film.

  The mask stage 1 is disposed in the internal space 6S of the main body chamber 6. The mask stage 1 is movable in six directions including the X-axis, Y-axis, Z-axis, θX, θY, and θZ directions while holding the mask M. In the present embodiment, the mask stage 1 holds the mask M so that the surface (reflection surface) of the mask M and the XY plane are substantially parallel. In the present embodiment, the mask stage 1 holds the mask M so that the reflective surface of the mask M faces the −Z direction. In the present embodiment, a laser interferometer (not shown) that can measure the position information of the mask stage 1 (mask M) and a focus / leveling detection system (not shown) that can detect the surface position information of the reflecting surface of the mask M. The control device 4 controls the position of the mask M held on the mask stage 1 based on the measurement result of the laser interferometer and the detection result of the focus / leveling detection system.

  The projection optical system PL is disposed in the internal space 6S of the main body chamber 6. Projection optical system PL includes a plurality of optical elements, and projects an image of the pattern of mask M onto substrate P at a predetermined projection magnification. The optical element of the projection optical system PL includes a multilayer reflector having a multilayer film capable of reflecting EUV light. The multilayer film of the optical element includes, for example, a Mo / Si multilayer film.

  The substrate stage 2 is disposed outside the internal space 6S of the main body chamber 6. The substrate stage 2 is movable in six directions including the X axis, Y axis, Z axis, θX, θY, and θZ directions while holding the substrate P. The substrate stage 2 is movable in the external space 24 outside the internal space 6S. In the present embodiment, the substrate stage 2 holds the substrate P so that the surface (exposure surface) of the substrate P and the XY plane are substantially parallel. In the present embodiment, the substrate stage 2 holds the substrate P so that the surface of the substrate P faces the + Z direction. In this embodiment, a laser interferometer (not shown) that can measure the position information of the substrate stage 2 (substrate P), and a focus / leveling detection system (not shown) that can detect the surface position information of the surface of the substrate P. The control device 4 controls the position of the substrate P held on the substrate stage 2 based on the measurement result of the laser interferometer and the detection result of the focus / leveling detection system.

  The first opening 11 is formed at a position where the exposure light EL emitted from the projection optical system PL accommodated in the internal space 6S can enter. The exposure light EL that has passed through the first opening 11 is emitted to the external space 24 outside the internal space 6S. The substrate stage 2 is movable outside the internal space 6S to a position facing the first opening 11 while holding the substrate P. By arranging the substrate P held by the substrate stage 2 at a position facing the first opening 11, the exposure light EL emitted from the projection optical system PL and passing through the first opening 11 is applied to the substrate P. Irradiated.

  In the present embodiment, the outside of the main body chamber 6 (chamber device 5) is an atmospheric space. Therefore, the substrate stage 2 is disposed in the atmospheric space.

  Next, the opening / closing mechanism 12 will be described. FIG. 3 is a view showing the vicinity of the opening / closing mechanism 12. In FIG. 3, the exposure apparatus EX includes a first opening 11 and an opening / closing mechanism 12 that opens and closes the first opening 11. The opening / closing mechanism 12 opens and closes the first opening 11 in synchronization with the pulsed light emission of the light source device 3. The opening / closing mechanism 12 opens the first opening 11 when the light source device 3 emits the exposure light EL, and closes the first opening 11 when the light source device 3 does not emit the exposure light EL.

  The opening / closing mechanism 12 is movable with respect to the first opening 11 in the vicinity of the first opening 11, and includes a plate member 25 larger than the first opening 11 and a driving device 26 that moves the plate member 25. In the present embodiment, the plate member 25 is disposed outside the internal space 6 </ b> S with respect to the main body chamber 6. Specifically, the plate member 25 is disposed between the main body chamber 6 and the substrate stage 2 (substrate P). The driving device 26 is also disposed outside the internal space 6 </ b> S with respect to the main body chamber 6.

  In the present embodiment, the plate member 25 has a second opening 27 through which the exposure light EL can pass. The second opening 27 is disposed at a position closer to the substrate P than the first opening 11. The second opening 27 defines an irradiation area (exposure area, projection area) of the exposure light EL on the substrate P.

  FIG. 4 is a plan view schematically showing the main body chamber 6 and the plate member 25. As shown in FIG. 4, the first opening 11 has an arc shape in the XY plane. The second opening 27 is also arc-shaped in the XY plane. In the present embodiment, the second opening 27 has substantially the same size and shape as the first opening 11. The second opening 27 may be smaller than the first opening 11.

  The upper and lower surfaces of the plate member 25 are flat and substantially parallel to the XY plane. The lower surface of the main body chamber 6 facing the upper surface of the plate member 25 is also flat and substantially parallel to the XY plane. The driving device 26 includes, for example, a piezo element, and can move the plate member 25 in the XY directions in a state where the upper surface of the plate member 25 and the lower surface of the main body chamber 6 are brought close to each other.

  As shown in FIG. 3, the first opening 11 is opened by moving the plate member 25 in the Y-axis direction so that the first opening 11 and the second opening 27 coincide with each other. Thereby, the exposure light EL from the projection optical system PL can be emitted to the external space 24 through the first opening 11 and the second opening 27.

  On the other hand, as shown in FIG. 5, the plate member 25 is moved in the Y-axis direction so that the first opening 11 and the second opening 27 are displaced, whereby the first opening 11 is covered with the plate member 25, and the first opening 11 is covered with the first opening 11. The opening 11 is closed. In the present embodiment, the gap (gap) G1 between the upper surface of the plate member 25 and the lower surface of the main body chamber 6 is sufficiently small. As a result, the internal space 6S is sealed, and the gas (air) in the external space 24 (atmospheric space) is suppressed from entering the internal space 6S. For example, a seal member containing a magnetic fluid or the like can be provided between the upper surface of the plate member 25 and the lower surface of the main body chamber 6.

  The plate member 25 has a sufficient strength so as not to be deformed or damaged by the pressure difference between the internal space 6S and the external space 24, and the internal space 6S can be sealed well.

  Next, an example of the operation of the exposure apparatus EX having the above-described configuration will be described.

  The internal space of the chamber device 5 including the internal spaces 6S, 7S, and 8S is adjusted to a vacuum state by the first and second vacuum systems 9, 10 and the like. When the exposure process for the substrate P is not executed, the opening / closing mechanism 12 closes the first opening 11 as shown in FIG. Thereby, the vacuum state of the internal space of the chamber apparatus 5 including the internal space 6S of the main body chamber 6 is maintained.

  After the mask M is held on the mask stage 1 and the substrate P is held on the substrate stage 2, the control device 4 starts an exposure process for the substrate P. In order to illuminate the mask M with the exposure light EL, the control device 4 starts the light emission operation of the light source device 3.

  As described above, in the present embodiment, the light source device 3 emits the exposure light EL in a pulse shape. The control device 4 uses the opening / closing mechanism 12 to open and close the first opening 11 in synchronization with the emission of the exposure light EL from the light source device 3. The control device 4 controls the opening / closing mechanism 12 so as to open the first opening 11 when the light source device 3 emits the exposure light EL. Further, the control device 4 controls the opening / closing mechanism 12 so as to close the first opening 11 when the light source device 3 is not emitting the exposure light EL. In the present embodiment, the plate member 25 of the opening / closing mechanism 12 moves so as to reciprocate in the Y-axis direction in synchronization with the light emission of the light source device 3.

  The exposure light EL emitted from the light source device 3 by the light emission operation of the light source device 3 enters the illumination optical system IL disposed in the internal space 6S of the main body chamber 6. The exposure light EL that has entered the illumination optical system IL travels through the illumination optical system IL, and then enters the mask M held in the mask stage 1 disposed in the internal space 6S of the main body chamber 6. The mask M held on the mask stage 1 is emitted from the light source device 3 and illuminated with exposure light EL (EUV light) through the illumination optical system IL. The exposure light EL that is irradiated onto the reflective surface of the mask M and reflected by the reflective surface enters the projection optical system PL disposed in the internal space 6S of the main body chamber 6. The exposure light EL that has entered the projection optical system PL travels through the projection optical system PL and is then supplied to the first opening 11.

  The first opening 11 is formed at a position where the exposure light EL that has traveled through the internal space 6S of the main body chamber 6 can enter. When the light source device 3 emits light, the first opening 11 is open. In the external space 24, the substrate P held by the substrate stage 2 is disposed at a position facing the first opening 11. Therefore, the exposure light EL that is emitted from the light source device 3 and passes through the illumination optical system IL, the mask M, and the projection optical system PL passes through the first opening 11 and the second opening 27 and the surface (exposure surface) of the substrate P. ).

  On the other hand, when the light source device 3 is not emitting light, the first opening 11 is closed. Thereby, the gas (air) in the external space 24 (atmospheric space) is prevented from entering the internal space 6S, and the vacuum state and environment of the internal space 6S are maintained.

  The control device 4 performs the opening / closing operation of the first opening 11 in synchronization with the light emission of the light source device 3, and moves the substrate P in the Y axis direction in synchronization with the movement of the mask M in the Y axis direction. The mask M is illuminated with the exposure light EL. Thereby, the substrate P is exposed with the exposure light EL, and an image of the pattern of the mask M is projected onto the substrate P.

  As described above, according to the present embodiment, the first opening 11 is opened only when the exposure light EL for irradiating the substrate P is emitted, and when the exposure light EL is not emitted, the first opening 11 is performed. Since the opening 11 is closed, the gas (air) in the external space 24 can be prevented from entering the internal space 6S. Therefore, it is possible to suppress the exposure light EL traveling in the internal space 6S from being attenuated or to prevent the gas in the external space 24 from affecting the multilayer mirror in the internal space 6S, so that the substrate P can be exposed satisfactorily. it can.

  Moreover, in this embodiment, since the board | substrate P is arrange | positioned on the outer side of the internal space 6S, it can suppress that the board | substrate P influences the internal space 6S. For example, contaminants (organic substances) due to the photosensitive material (resist) or the like may be generated from the substrate P. If the contaminant enters the internal space 6S, for example, it may affect the multilayer mirror in the internal space 6S, which may degrade the performance of the exposure apparatus EX. According to the present embodiment, since the substrate P is disposed outside the internal space 6S, it is possible to suppress a decrease in the performance of the exposure apparatus EX due to contaminants caused by the substrate P.

  In the present embodiment, since the substrate stage 2 is disposed outside the internal space 6S, it is possible to suppress the substrate stage 2 from affecting the internal space 6S. For example, contaminants such as degassing may be generated from various members (for example, cables) provided on the substrate stage 2. If the contaminant enters the internal space 6S, for example, it may affect the multilayer mirror in the internal space 6S, which may degrade the performance of the exposure apparatus EX. According to the present embodiment, since the substrate stage 2 is disposed outside the internal space 6S, it is possible to suppress a decrease in the performance of the exposure apparatus EX due to contaminants caused by the substrate stage 2.

  Further, by arranging the substrate stage 2 in the external space 24, adjustment processing, maintenance processing and the like of the substrate stage 2 can be executed smoothly. When the substrate stage 2 is disposed in the internal space 6S, there is a high possibility that the vacuum state of the internal space 6S must be once released in order to perform maintenance processing or the like of the substrate stage 2. In that case, after the completion of the maintenance process or the like, a process for readjusting the internal space 6S to a vacuum state is required. Such processing takes time, and as a result, the operation rate of the exposure apparatus EX may be reduced. In the present embodiment, since the substrate stage 2 is disposed in the external space 24, adjustment processing, maintenance processing, and the like of the substrate stage 2 can be smoothly executed while maintaining the vacuum state of the internal space 6S. Therefore, it is possible to suppress a decrease in the operating rate of the exposure apparatus EX.

  In the present embodiment, the exposure light EL (EUV light) travels in the air between the first opening 11 and the surface of the substrate P, but the distance traveled in the air is suppressed. As a result, the attenuation of the exposure light EL can be suppressed.

FIG. 6 shows a simulation result in which a relationship between pressure (air density), transmittance, and travel distance (optical path length) in a predetermined space when EUV light having a wavelength of 13.5 nm travels in the predetermined space. FIG. The relationship between pressure and transmittance was derived for optical path lengths of 10 μm, 100 μm, 1 mm, 1 cm, 10 cm, 1 m, and 10 m, respectively. As shown in FIG. 6, even when the pressure is high (the air density is high), if the optical path length is sufficiently short, a decrease in transmittance can be sufficiently suppressed. For example, when the pressure is 1 × 10 ⁵ [Pa], the transmittance of about 50% can be maintained by setting the optical path length to about 100 μm.

  That is, by sufficiently shortening the distance (optical path length) between the first opening 11 and the surface of the substrate P, the substrate P can be exposed with the exposure light EL having an allowable light amount. Further, by adjusting the time for opening the first opening 11, the exhaust amount per unit time by the first and second vacuum systems 9, 10, the amount of gas (air) in the external space 24 entering the internal space 6S is adjusted. It can be suppressed to an acceptable level.

  As an example, in the present embodiment, the distance between the first opening 11 (the lower end of the first opening 11) and the surface of the substrate P is adjusted to about 100 μm. When the first opening 11 is closed by the opening / closing mechanism 12, the vicinity of the surface of the substrate P is atmospheric pressure, but when the first opening 11 is opened, the surface of the substrate P is caused by the inflow of air into the internal space 6S. In the vicinity of, the pressure is reduced from the atmospheric pressure. Thereby, attenuation of EUV light is suppressed.

  In addition, when the first opening 11 is opened, air flows into the internal space 6S. The influence of the inflowing air on the pressure (degree of vacuum) of the internal space 6S can be estimated as follows. The following explanation is based on the description of “Hogenkoshi Genichi, Vacuum Technology Second Edition, University of Tokyo Press, 1983”.

で与えられる。これを体積で表現すると、

となる。
Ｔ＝２９３Ｋ（２０℃）、Ｍ＝２９（空気）とすると、

となる。 Gas molecules incident on the first opening 11 are:

Given in. Expressing this in volume,

It becomes.
When T = 293K (20 ° C.) and M = 29 (air),

It becomes.

If the width of the first opening 11 is 2 mm and the length is 26 mm, the area is about 0.5 cm ² . Therefore, the amount of air per unit time passing through the first opening 11 and flowing into the internal space 6S is about 5.8 [l / s].

Further, when the period T of the pulse waveform of the light source device 3 (laser device 13) is 0.2 ms and the pulse width (light emission time) T1 is 10 ns, the duty ratio (the ratio of the light emission time T1 to the period T) is 5 × 10 ⁻⁵ Accordingly, the amount of air passing through the first opening 11 and flowing into the internal space 6S in one opening operation is about 2.9 × 10 ⁻⁴ [l / s]. That is, air of one atmospheric pressure (about 1 × 10 ⁵ [Pa]) flows into the internal space 6S by about 2.9 × 10 ⁻⁴ [l / s] by one opening operation. When this is expressed in consideration of pressure, it is about 29 [Pal / s]. Thus, when the light emission time T1 is small, the time during which the first opening 11 is open is also shortened, and the amount of air flowing into the internal space 6S can be sufficiently suppressed.

When the exhaust amount per unit time from the internal space 6S by the first and second vacuum systems 9 and 10 is 50000 [l / s], the pressure of the internal space 6S due to the air flowing in through the first opening 11 is reduced. The amount of increase is 6 × 10 ⁻⁴ [Pa]. For example, when the allowable value of the pressure in the internal space 6S is 1 × 10 ⁻² [Pa], the pressure in the internal space 6S can be sufficiently suppressed below the allowable level.

  In the present embodiment, the case where the light source device is an LPP type light source device has been described as an example. However, discharge is generated in a predetermined gas, the predetermined gas is turned into plasma, and EUV light is generated. It may be a discharge generated plasma light source device, that is, a so-called DPP (Discharge Produced Prasma) type light source device.

Second Embodiment
Next, a second embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 7 is a view showing the vicinity of the opening / closing mechanism 12B according to the second embodiment. As shown in FIG. 7, in this embodiment, the plate member 25 of the opening / closing mechanism 12B is disposed inside the internal space 6S. The driving device 26 is also arranged inside the internal space 6S. The first opening 11 formed in the main body chamber 6 is disposed at a position closer to the substrate P than the second opening 27 of the plate member 25. In the present embodiment, the first opening 11 defines an irradiation area (exposure area, projection area) of the exposure light EL on the substrate P.

  Also in the present embodiment, it is possible to satisfactorily expose the substrate P by suppressing the gas (air) of the external space 24 from entering the internal space 6S. Further, according to the present embodiment, the driving device 26 and the like can be separated from the substrate P.

<Third Embodiment>
Next, a third embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 8 is a view showing the vicinity of the opening / closing mechanism 12B according to the third embodiment. Similar to the second embodiment described above, the plate member 25 and the driving device 26 of the opening / closing mechanism 12B are disposed inside the internal space 6S.

  In the present embodiment, an intermediate member 30 that forms a buffer space 30 </ b> S connected to the first opening 11 is provided between the main body chamber 6 and the substrate stage 2 (substrate P). The intermediate member 30 has a third opening 31 that coincides with the first opening 11 and a fourth opening 32 that can face the surface of the substrate P. The exposure light EL that has passed through the second opening 27 and the first opening 1 enters the buffer space 30S through the third opening 31, and enters the surface of the substrate P through the fourth opening 32.

  In the present embodiment, a pressure adjusting device 33 that adjusts the pressure in the buffer space 30S is provided. The pressure adjusting device 33 adjusts the pressure in the buffer space 30S so as to be at least lower than the atmospheric pressure. In the present embodiment, the buffer space 30S is adjusted to a pressure lower than the atmospheric pressure and higher than the pressure of the internal space 6S.

  Also in the present embodiment, it is possible to satisfactorily expose the substrate P by suppressing the gas (air) of the external space 24 from entering the internal space 6S. Further, according to the present embodiment, since a space is formed between the lower surface of the main body chamber 6 and the surface of the substrate P (next to the intermediate member 30), a predetermined position such as an FIA alignment device is formed in the space. Equipment can be arranged.

<Fourth embodiment>
Next, a fourth embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 9 shows an exposure apparatus EX according to the ninth embodiment. In the first to third embodiments described above, the case where the substrate stage 2 is arranged in the external space 24 has been described as an example. However, a characteristic part of the present embodiment is that the mask stage 1 is in the external space 24. It is at the point where it is placed. In the present embodiment, the substrate stage 2 is also disposed in the external space 24.

  As shown in FIG. 9, the exposure apparatus EX according to the present embodiment opens and closes the fifth opening 41 in synchronization with the fifth opening 41 formed at a predetermined position of the main body chamber 6 and the light emission of the light source device 3. And an opening / closing mechanism 42. The opening / closing mechanism 42 has the same configuration as the opening / closing mechanism 12 described in the above embodiment. The opening / closing mechanism 42 includes a plate member 43 that is movable with respect to the fifth opening 41 in the vicinity of the fifth opening 41 and that is larger than the fifth opening 41, and a drive device 44 that moves the plate member 43. Yes. A sixth opening 45 is formed in the plate member 43.

  The fifth opening 41 is formed at a position where the exposure light EL emitted from the illumination optical system IL accommodated in the internal space 6S can enter. The exposure light EL that has passed through the fifth opening 41 is emitted to the external space 24 outside the internal space 6S. The mask stage 1 is movable to a position facing the fifth opening 41 while holding the mask M outside the internal space 6S. By disposing the mask M held on the mask stage 1 at a position facing the fifth opening 41, the exposure light EL emitted from the illumination optical system IL and passing through the fifth opening 41 is applied to the mask M. Irradiated.

  When the exposure light EL is emitted from the light emitting device 3, the opening / closing mechanism 42 opens the fifth opening 41. Accordingly, the exposure light EL emitted from the illumination optical system IL passes through the fifth opening 41 and the sixth opening 45 and is irradiated onto the mask M. In the present embodiment, the exposure light EL that is incident on the reflective surface of the mask M and reflected by the reflective surface passes through the sixth opening 45 and the fifth opening 41 and enters the internal space 6S. The exposure light EL that has entered the internal space 6S enters the projection optical system PL. The exposure light EL that is incident on the projection optical system PL and travels through the projection optical system PL is irradiated onto the substrate P through the first opening 11 and the second opening 27.

  According to the present embodiment, since the mask stage 1 is disposed in the external space 24, for example, maintenance processing of the mask stage 1 can be performed smoothly while maintaining the vacuum state of the internal space 6S, and the exposure apparatus EX Decrease in operating rate can be suppressed.

<Fifth Embodiment>
Next, a fifth embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 10 is a view showing an exposure apparatus EX according to the fifth embodiment. As shown in FIG. 10, in this embodiment, the exposure apparatus EX includes a first chamber 51 connected to the exit surface of the illumination optical system IL and a second chamber 53 connected to the entrance surface of the projection optical system PL. And a third chamber 55 connected to the exit surface of the projection optical system PL. Each of the internal space of the first chamber 51, the internal space of the second chamber 53, and the internal space of the third chamber 55 is adjusted to a vacuum state by a vacuum system (not shown).

  In the present embodiment, a plurality of optical elements (multilayer film reflecting mirrors) of the illumination optical system IL are sealed and accommodated in an internal space of a lens barrel (chamber) that is adjusted to a vacuum state. A plurality of optical elements (multilayer film reflecting mirrors) of the projection optical system PL are sealed and accommodated in an internal space of a barrel (chamber) that is adjusted to a vacuum state.

  Each of the first chamber 51, the second chamber 53, and the third chamber 55 is a pipe-shaped member. The exposure light EL emitted from the emission surface of the illumination optical system IL passes through the first chamber 51 and is emitted from the opening 52 of the first chamber 51. The exposure light EL emitted from the opening 52 is applied to the reflecting surface of the mask M held on the mask stage 1. The exposure light EL that is irradiated onto the reflective surface of the mask M and reflected by the reflective surface of the mask M enters the second chamber 53 through the opening 54 of the second chamber 53. The exposure light EL that has passed through the second chamber 53 enters the incident surface of the projection optical system PL and is emitted from the emission surface of the projection optical system PL. The exposure light EL emitted from the emission surface of the projection optical system PL passes through the third chamber 55 and is emitted from the opening 56 of the third chamber 55. The exposure light EL emitted from the opening 56 is irradiated on the surface of the substrate P held by the substrate stage 2.

  The exposure apparatus EX of the present embodiment includes an opening / closing mechanism 42 </ b> C that opens and closes the openings 52 and 54 of the first and second chambers 51 and 53 in synchronization with the light emission of the light emitting device 3. The opening / closing mechanism 42C includes a plate member 43C that can move with respect to the openings 52 and 54, and a drive device (not shown) that can move the plate member 43C. The plate member 43C has an opening 45C. By moving the plate member 43C so that the openings 52, 54 of the first and second chambers 51, 53 coincide with the opening 45C of the plate member 43C, the reflecting surface of the mask M can be irradiated with the exposure light EL, The exposure light EL reflected by the reflective surface of the mask M can be incident on the projection optical system PL.

  Further, the exposure apparatus EX of the present embodiment includes an opening / closing mechanism 12 </ b> C that opens and closes the opening 56 of the third chamber 55 in synchronization with the light emission of the light emitting device 3. The opening / closing mechanism 12C includes a plate member 25C that can move with respect to the opening 55, and a drive device (not shown) that can move the plate member 25C. The plate member 25C has an opening 27C. By moving the plate member 25C so that the opening 56 of the third chamber 55 and the opening 27C of the plate member 25C coincide, the surface of the substrate P can be irradiated with the exposure light EL.

  Also in this embodiment, the substrate P can be exposed satisfactorily, the maintenance process of the mask stage 1 and the substrate stage 2 can be executed smoothly, and the reduction in the operating rate of the exposure apparatus EX can be suppressed.

<Sixth Embodiment>
Next, a sixth embodiment will be described. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is simplified or omitted.

  FIG. 11 is a view showing an exposure apparatus EX according to the sixth embodiment. A characteristic part of the present embodiment is that an opening / closing mechanism 60 that opens and closes the opening 22 formed at a position where the exposure light EL from the light source device 3 can enter in synchronization with the light emission of the light source device 3 is provided. It is in.

  In FIG. 11, the exposure apparatus EX includes an opening / closing mechanism 60 that opens and closes the opening 22 disposed in the vicinity of the intermediate focusing point 20. The opening / closing mechanism 60 is movable with respect to the opening 22 in the vicinity of the opening 22, includes a plate member 61 larger than the opening 22, and a driving device (not shown) that moves the plate member 61. The opening 22 is opened and closed in synchronization with light emission. The opening / closing mechanism 60 opens the opening 22 when the light emitting device 3 emits the exposure light EL, and closes the opening 22 when the light emitting device 3 does not emit the exposure light EL.

  The plate member 61 has an opening 62 through which the exposure light EL can pass. By moving the plate member 61 so that the opening 62 of the opening / closing mechanism 60 and the opening 22 of the intermediate focusing point 20 coincide with each other, the exposure light EL from the light source device 3 can pass through the openings 62 and 22. is there.

  In the light source device 3, for example, the supply member 15 may be sputtered by the target material (xenon gas) converted into plasma, and a contaminant (foreign matter) may be generated. When the contaminant enters the internal space 6S of the main body chamber 6, there is a possibility of affecting the illumination optical system IL, the optical element (multilayer film reflector) of the projection optical system PL, and the like.

  Further, when plasma is generated in the internal space 7S of the light source chamber 7, contaminants such as particles (debris) may be scattered from the target material. When the contaminant enters the internal space 6S of the main body chamber 6, there is a possibility of affecting the optical elements (multilayer film reflecting mirrors) of the illumination optical system IL and the projection optical system PL. In particular, when tin (Sn) or the like is used as the target material, there is a high possibility that contaminants (debris) are generated.

  According to this embodiment, the opening / closing mechanism 60 can prevent contaminants generated in the light source device 3 from entering the main body chamber 6. Therefore, contamination of the internal space 6S of the main body chamber 6 can be suppressed, and the state of the optical elements (multilayer film reflecting mirrors) of the illumination optical system IL and the projection optical system PL can be favorably maintained.

  Further, in the light source device 3, when a cleaning gas such as a halogen gas is supplied to the internal space 7 </ b> S of the light source chamber 7 in order to remove contaminants (including the above-described foreign matters and debris), the cleaning gas However, if it enters the internal space 6S of the main body chamber 6, there is a possibility of affecting the optical elements (multilayer film reflecting mirrors) of the illumination optical system IL and the projection optical system PL. Further, the degree of vacuum in the internal space 6S of the main body chamber 6 may be reduced by the cleaning gas. According to the present embodiment, the opening / closing mechanism 60 can be used to prevent the cleaning gas from entering the internal space 6 </ b> S of the main body chamber 6. When there is a possibility that the cleaning gas may affect the condenser mirror 17 of the light source device 3, a single-layer cylindrical mirror, so-called a voltaic mirror, may be used instead of the condenser mirror 17.

  Further, for example, a small amount of oxygen gas is supplied to the internal space 6S of the main body chamber 6 while irradiating the exposure light EL in order to clean the optical elements (multilayer film reflectors) of the illumination optical system IL and the projection optical system IL. In this case, when the oxygen gas flows into the light source device, the performance of the light source device may be degraded. For example, when a DPP (Discharge Produced Prasma) type light source device is used as the light source device, the discharge electrode or the like may be corroded (rusted) by oxygen gas. By providing an opening / closing mechanism between the light source chamber of the light source device and the main body chamber in which the illumination optical system IL and the projection optical system PL are disposed, the above-described oxygen gas can be prevented from flowing into the light source device. . Therefore, it is possible to suppress a decrease in performance of the light source device.

  In each of the above-described embodiments, the opening / closing mechanism opens and closes the first opening and the like by moving the plate member in a direction parallel to the surface of the plate member. For example, the opening is formed. The first opening and the like may be opened and closed by rotating the disc. Further, the opening / closing mechanism may have a hinge part (rotating part).

  In each embodiment described above, the case where the plate member of the opening / closing mechanism has an opening has been described as an example, but the opening may not be provided.

  In each of the above-described embodiments, the case where the external space 24 is an atmospheric space at atmospheric pressure has been described as an example. However, the pressure may be lower than atmospheric pressure or higher. Further, the external space 24 may be a space filled with a gas other than air, for example, nitrogen gas.

  As the substrate P in each of the above embodiments, not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus. (Synthetic quartz, silicon wafer) or the like is applied.

  As the exposure apparatus EX, in addition to the step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask M by moving the mask M and the substrate P synchronously, the mask M and the substrate P Can be applied to a step-and-repeat type projection exposure apparatus (stepper) in which the pattern of the mask M is collectively exposed while the substrate P is stationary and the substrate P is sequentially moved stepwise.

  Furthermore, in the step-and-repeat exposure, after the reduced image of the first pattern is transferred onto the substrate P using the projection optical system while the first pattern and the substrate P are substantially stationary, the second pattern With the projection optical system, the reduced image of the second pattern may be partially overlapped with the first pattern and collectively exposed on the substrate P (stitch type batch exposure apparatus). ). Further, the stitch type exposure apparatus can be applied to a step-and-stitch type exposure apparatus in which at least two patterns are partially transferred on the substrate P, and the substrate P is sequentially moved.

  Further, as disclosed in, for example, US Pat. No. 6,611,316, two mask patterns are synthesized on a substrate through a projection optical system, and one scanning exposure is performed on one substrate. The present invention can also be applied to an exposure apparatus that performs double exposure of shot areas almost simultaneously.

  Further, the present invention relates to US Pat. No. 6,341,007, US Pat. No. 6,400,441, US Pat. No. 6,549,269, US Pat. No. 6,590,634, US Pat. No. 6,208,407. The present invention is also applicable to a twin stage type exposure apparatus having a plurality of substrate stages as disclosed in US Pat. No. 6,262,796.

  Further, as disclosed in, for example, Japanese Patent Laid-Open No. 11-135400 (corresponding to International Publication No. 1999/23692), US Pat. No. 6,897,963, etc., a substrate stage for holding the substrate and a reference mark are provided. The present invention can also be applied to an exposure apparatus that includes a formed reference member and / or a measurement stage on which various photoelectric sensors are mounted. The present invention can also be applied to an exposure apparatus that includes a plurality of substrate stages and measurement stages. By moving the measurement stage to a position facing the first opening 11 outside the internal space 6S, the exposure light EL measurement process by the measurement stage can be executed. In addition, measurement stage adjustment processing, maintenance processing, and the like can be executed smoothly.

  The type of exposure apparatus EX is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern onto a substrate P, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD). In addition, the present invention can be widely applied to an exposure apparatus for manufacturing a micromachine, MEMS, DNA chip, reticle, mask, or the like.

  As described above, the exposure apparatus EX according to the embodiment of the present application maintains various mechanical subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Manufactured by assembling. In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 12, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for producing a mask (reticle) based on the design step, and a substrate which is a base material of the device. Manufacturing step 203, substrate processing step 204 including exposing the substrate with an image of a mask pattern and developing the exposed substrate according to the above-described embodiment, device assembly step (dicing process, bonding process, package) (Including processing processes such as processes) 205, inspection step 206, and the like.

  It should be noted that the disclosure of all published publications and US patents related to the exposure apparatus and the like cited in each of the above embodiments and modifications is incorporated herein by reference.

  In addition, although embodiment of this invention was described as mentioned above, this invention can use combining all the above-mentioned components suitably, and may not use a one part component.

It is a schematic block diagram which shows an example of the exposure apparatus which concerns on 1st Embodiment. It is a schematic diagram which shows the light emission state of a laser apparatus. It is a sectional side view which shows the vicinity of the opening / closing mechanism which concerns on 1st Embodiment. It is a top view which shows typically the opening-closing mechanism which concerns on 1st Embodiment. It is a figure for demonstrating operation | movement of the opening-closing mechanism which concerns on 1st Embodiment. It is a figure which shows the simulation result which derived | led-out the relationship between a pressure, the transmittance | permeability, and an optical path. It is a sectional side view which shows the vicinity of the opening / closing mechanism which concerns on 2nd Embodiment. It is a sectional side view which shows the vicinity of the opening / closing mechanism which concerns on 3rd Embodiment. It is a schematic block diagram which shows an example of the exposure apparatus which concerns on 4th Embodiment. It is a schematic block diagram which shows an example of the exposure apparatus which concerns on 5th Embodiment. It is a schematic block diagram which shows an example of the exposure apparatus which concerns on 6th Embodiment. It is a flowchart figure which shows an example of the manufacturing process of a microdevice.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mask stage, 2 ... Substrate stage, 3 ... Light source device, 6 ... Main body chamber, 6S ... Internal space, 7 ... Light source chamber, 7S ... Internal space, 8 ... Intermediate chamber, 8S ... Internal space, 11 ... 1st opening , 12 ... Opening / closing mechanism, 19 ... Light emitting part, 22 ... Opening, 24 ... External space, 25 ... Plate member, 27 ... Second opening, 30 ... Intermediate member, 30S ... Buffer space, 33 ... Pressure adjusting device, EL ... Exposure Light, EX ... exposure device, IL ... illumination optical system, M ... mask, P ... substrate, PL ... projection optical system

Claims (18)

An exposure apparatus for exposing a substrate with exposure light in an extreme ultraviolet region,
A light source device for emitting the exposure light in a pulsed manner;
A first member forming a substantially vacuum first space in which the exposure light travels;
An exposure apparatus comprising: a first opening formed in at least a part of the first member so that the exposure light passes; and an opening / closing mechanism that opens and closes the first opening in synchronization with the light emission.   The exposure apparatus according to claim 1, wherein at least one of an illumination optical system and a projection optical system is disposed in the first space.   The exposure apparatus according to claim 1, wherein the first opening is formed at a position where the exposure light after traveling through the first space can enter. A movable member movable outside the first space;
The exposure apparatus according to claim 3, wherein the movable member is movable to a position facing the first opening.   The exposure apparatus according to claim 4, wherein the movable member is movable while holding an object irradiated with the exposure light.   The exposure apparatus according to claim 5, wherein the object includes the substrate.   The exposure apparatus according to claim 5, wherein the object includes a mask on which a pattern is formed.   The exposure apparatus according to claim 4, wherein the outside of the first space includes an atmospheric space.   The exposure apparatus according to any one of claims 4 to 8, further comprising a second member that forms a second space connected to the first opening between the first member and the movable member.   The exposure apparatus according to claim 9, further comprising a pressure adjusting device that adjusts the pressure of the second space so as to be at least lower than atmospheric pressure.   The exposure apparatus according to claim 1, wherein the first opening is formed at a position where the exposure light from the light source device can enter. A third member forming a third space connected to the first opening;
The exposure apparatus according to claim 11, wherein at least a part of the light source device is disposed in the third space. The light source device has a light emitting unit in which a target material is turned into plasma,
The exposure apparatus according to claim 12, wherein the light emitting unit is disposed in the third space.   The exposure apparatus according to claim 1, wherein the opening / closing mechanism includes a predetermined member that is movable with respect to the first opening in the vicinity of the first opening and is larger than the first opening.   The exposure apparatus according to claim 14, wherein the predetermined member is disposed outside the first space.   The exposure apparatus according to claim 14, wherein the predetermined member is disposed inside the first space.   The exposure apparatus according to claim 14, wherein the predetermined member has a second opening through which the exposure light can pass. Exposing the substrate using the exposure apparatus according to any one of claims 1 to 17,
Developing the exposed substrate; and a device manufacturing method.

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