JP2005243771A - Aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform preheating of an optical element without shortening the lifetime of a light source for exposure. <P>SOLUTION: The pattern image of a mask 111 is projected to a photosensitive substrate 112 through a plurality of optical elements by exposure light 108 from a light source 101. At least two of the plurality of optical elements are irradiated with preheating light from a second light source L. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection exposure apparatus, for example, a projection exposure apparatus suitable for use in an X-ray projection exposure apparatus that transfers a pattern on a mask onto a photosensitive substrate by using a mirror projection method using X-rays.

  2. Description of the Related Art Conventionally, an exposure apparatus used for manufacturing a semiconductor element projects and transfers a circuit pattern formed on a mask (reticle) onto a photosensitive substrate such as a wafer via a projection optical system. A resist is applied on the photosensitive substrate, and the resist is exposed by projection exposure through a projection optical system to obtain a resist pattern corresponding to the mask pattern.

Here, the resolving power W of the exposure apparatus depends on the wavelength λ of the exposure light and the numerical aperture NA of the projection optical system, and is expressed by the following equation.
W = k × λ / NA (k: constant)
Therefore, in order to improve the resolving power of the exposure apparatus, it is necessary to shorten the wavelength λ of the exposure light or increase the numerical aperture NA of the projection optical system to a predetermined value or more.
In general, since it is difficult to increase the numerical aperture NA of the projection optical system to a predetermined value or more from the viewpoint of optical design, it is necessary to shorten the wavelength of exposure light in the future. For example, when a KrF excimer laser having a wavelength of 248 nm is used as exposure light, a resolution of 0.25 μm can be obtained, and when an ArF excimer laser having a wavelength of 193 nm is used, a resolution of 0.18 μm can be obtained.

  Further, when X-rays having a shorter wavelength are used as the exposure light, for example, a resolution of 0.1 μm or less at a wavelength of 13 nm can be obtained. This technique is also recently called EUV (Extreme Ultraviolet, Soft X-ray) lithography, and is expected as a lithography technique having a resolution of 45 nm or less that cannot be realized by conventional optical lithography.

In an EUV exposure apparatus that performs this type of EUV lithography, all optical elements are reflective systems, and a multilayer film that reflects EUV light is applied to the surface thereof. Mo / Si or the like is used for the EUV light multilayer film, but its reflectance is approximately 70%, and the remaining 30% is absorbed by the multilayer film and converted to heat. For this reason, each mirror generates heat upon irradiation with EUV light, and there is a concern that the mirror may be thermally deformed (thermal expansion) to deteriorate the characteristics of the optical system. For this reason, measures for suppressing thermal deformation of the mirror and measures for efficiently cooling the mirror have been studied, and various devices that do not deteriorate the characteristics of the optical system even if heat is generated in the mirror have been studied. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 5-190409

However, the above-described prior art is mainly for the characteristics in the thermal steady state, and the behavior is more complicated in the unsteady state where the EUV light starts to be irradiated until the steady state is reached. It is considered that the characteristics of the optical system fluctuate greatly during
Therefore, if the exposure operation is performed during that period (unsteady state), there is a possibility that a good image cannot be obtained due to the characteristic deterioration due to the thermal unsteady state of the optical system.

  Therefore, it is conceivable to perform a so-called warm-up operation in which the optical system is preheated by irradiating EUV light in order to keep it in a thermally stable state before exposure, but the exposure light source was operated in the warm-up operation. In this case, there is a possibility that the lifetime of the expensive light source is shortened and the illumination optical system is contaminated.

Further, it is necessary to introduce EUV light into the optical system in a state where the wafer is not mounted on the stage so that the wafer is not exposed to the warm-up EUV light. In order to start the exposure, it is necessary to once stop the operation of the light source, and then start the operation of the light source again after mounting the wafer on the stage.
In this case, there is a time to stop the irradiation of the EUV light while the wafer is mounted on the stage, so that the optical system cools down during this time, and at the start of exposure, it is said to be in a thermally unsteady state again. Problems arise.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide an exposure apparatus capable of preheating the optical element without reducing the life of the exposure light source. Another object of the present invention is to provide an exposure apparatus that enables exposure processing in a state in which an optical element is thermally stable.
In addition, the steady state described in this specification is a state in which the characteristic variation of the optical system (optical element) is within a range (specification range) that does not deteriorate the exposure performance.

In order to achieve the above object, the present invention adopts the following configuration corresponding to FIGS. 1 to 3 showing the embodiment.
The exposure apparatus of the present invention exposes a pattern image of a mask (111) onto a photosensitive substrate (112) via a plurality of optical elements (CM1 to CM6) by exposure light (108) from a light source (101). The apparatus (100) has a second light source (L) that irradiates a plurality of optical elements (CM1 to CM6) with preheating light.

  Therefore, in the exposure apparatus of the present invention, before the exposure, light for preheating (preheating light) is irradiated from the second light source (L), and the plurality of optical elements (CM1 to CM6) are preheated, so that the optical The elements (CM1 to CM6) can be thermally brought into a steady state (stable state). At this time, in the present invention, since the operation of the light source (101) for exposure light can be stopped, it is possible to prevent the life of the light source (101) from being shortened. Further, since light is used for preheating, it is possible to heat a plurality of optical elements with one light source. In an actual exposure apparatus, the space for arranging the heating means in the apparatus is limited. In the present invention, since the optical elements can be warmed by the number of light sources for preheating smaller than the number of optical elements, the degree of freedom in designing the apparatus is increased.

The second light source (L) preferably emits light having a non-photosensitive wavelength region with respect to the photosensitive substrate (112).
In the preliminary heating, the preliminary heating light applied to the optical elements (CM1 to CM6) is emitted from the optical elements (CM1 to CM6) toward the photosensitive substrate (112). 112) is not exposed to light, so that the preheating light can be continuously irradiated even when the substrate (112) is mounted on the stage. Therefore, the optical elements (CM1 to CM6) are cooled down and thermally unsteady again. It is possible to avoid falling into a state.

The optical path range of the preheating light is preferably substantially the same as a part of the optical path range of the exposure light (108).
The optical path range means an effective luminous flux size and its optical path. That is, by making the effective beam size and a part of the optical path of the beam common to the preheating light and the exposure light, for example, the temperature distribution of the optical elements (CM1 to CM6) is irradiated with the exposure light. Thus, the optical element can be brought into a steady state in substantially the same state, and the exposure process can be started in a more thermally stable state.

Moreover, it is preferable to set the output of the second light source (L) based on the energy amount of the exposure light after the exposure light is reflected by the mask (111).
As a result, the optical elements (CM1 to CM6) can be preheated with an energy amount substantially the same as the amount of energy irradiated to the optical elements (CM1 to CM6) during exposure, and the exposure process is performed in a more thermally stable state. It becomes possible to start.

A configuration having a third light source (LL) that irradiates a part of the plurality of optical elements (CM5, CM6) with preheating light is also preferable.
Therefore, in the present invention, even if the amount of irradiation energy decreases while the preheating light irradiated from the second light source (L) reflects some of the plurality of optical elements (CM1 to CM4), the third The preheated light emitted from the light source (LL) can compensate for the reduced irradiation energy amount.
Even when the third light source (LL) is used, the configuration in which light having a non-photosensitive wavelength is emitted to the photosensitive substrate (112) and the optical path thereof are substantially the same as part of the optical path of the exposure light. A configuration is preferred.
The preheating light from the second light source (L) is an optical element between the optical element (CM1) that first enters the light from the mask (111) and the mask (111) among the plurality of optical elements. A configuration introduced into (CM1 to CM6) can be adopted.
Since it is relatively easy to secure a space for allowing the light beam to enter between the mask (111) and the projection optical system, it is preferable to introduce preheating light from here.
In addition, a configuration in which the preheating light is also applied to the mask (111) and the mask (111) is preheated simultaneously with the optical elements (CM1 to CM6) is also preferable.
According to this means, since the mask is also preheated, it is possible to perform exposure using the mask (111) that has changed from a thermal transient state to a steady state.
In order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings showing one embodiment, but it goes without saying that the present invention is not limited to the embodiment.

  In the present invention, contamination of the illumination optical system can be suppressed, and the lifetime of an expensive light source can be extended, which is beneficial in terms of cost. In the present invention, since the exposure process can be performed after the optical element is in a steady state, a stable and good pattern image can be transferred onto the substrate.

Hereinafter, an embodiment of an exposure apparatus of the present invention will be described with reference to FIGS.
(First embodiment)
FIG. 1 schematically shows an exposure apparatus according to an embodiment of the present invention.
An EUV exposure apparatus (exposure apparatus) 100 shown in this figure includes an EUV light generation apparatus (laser plasma light source, light source) 101. The EUV light generation apparatus 101 includes a spherical vacuum vessel 102, and the inside of the vacuum vessel 102 is exhausted (vacuum suction) by a vacuum pump (not shown).
A multilayer parabolic mirror 104 is installed on the upper side of the vacuum vessel 102 in the drawing with the reflecting surface 104a facing downward (+ Z direction) in the drawing.

  A lens 106 is arranged on the right side (+ Y direction) of the vacuum vessel 102 in the drawing, and a laser light source (not shown) is arranged on the right side of the lens. This laser light source emits pulsed laser light 105 in the −Y direction. The pulsed laser beam 105 is condensed at the focal position of the multilayer parabolic mirror 104 by the lens 106. Xenon (Xe) gas ejected from the nozzle tip is supplied to the focal position, and plasma 107 is generated when the condensed pulse laser beam 105 is irradiated to the ejected xenon gas (target material 103). . The plasma 107 emits EUV light (exposure light) 108 in a wavelength band near 13 nm.

  An EUV light filter 109 that cuts (shields) visible light is provided below the vacuum container 102. The EUV light 108 is reflected in the + Z direction by the multilayer parabolic mirror 104, passes through the EUV light filter 109, and is guided to the exposure chamber 110. At this time, the spectrum of the visible light band of the EUV light 108 is cut.

  In this embodiment, xenon gas is used as a target material, but a xenon cluster, a droplet, or the like may be used. Further, although a laser plasma light source is used as the EUV light generation apparatus 101, a discharge plasma light source can also be adopted. The discharge plasma light source is a device that turns a target material into plasma by pulse high voltage discharge and emits EUV light from the plasma.

  An exposure chamber 110 is installed below the EUV light generation apparatus 101 in the drawing. An illumination optical system 113 is disposed inside the exposure chamber 110. The illumination optical system 113 includes a condenser mirror, a fly-eye optical mirror, and the like (shown in a simplified manner in the drawing), and the EUV light 108 incident from the EUV light generation apparatus 101 is circular. It is shaped into an arc and irradiated toward the left (-Y direction) in the figure.

  A reflecting mirror 115 is disposed on the left side of the illumination optical system 113. The reflecting mirror 115 is a circular concave mirror, and is held vertically (parallel to the Z axis) by a holding member (not shown) so that the reflecting surface 115a faces rightward in the drawing (+ Y direction). An optical path bending reflecting mirror 116 is arranged on the right side of the reflecting mirror 115 in the drawing. Above the optical path bending reflecting mirror 116, the reflective mask 111 is disposed horizontally (parallel to the XY plane) so that the reflecting surface 111a faces downward (+ Z direction). The EUV light emitted from the illumination optical system 113 is reflected and collected by the reflecting mirror 115 and then reaches the reflecting surface 111 a of the reflective mask 111 via the optical path bending reflecting mirror 116.

The reflecting mirrors 115 and 116 are formed of a substrate made of low thermal expansion glass having a reflective surface processed with high accuracy and low thermal deformation. Similar to the reflective surface 104a of the multilayer parabolic mirror 104 of the EUV light generation apparatus 101, Mo / Si in which molybdenum (Mo) and silicon (Si) are alternately stacked on the reflective surface 115a of the reflective mirror 115. A multilayer film is formed.
When EUV light having a wavelength of 10 to 15 nm is used, a substance such as molybdenum (Mo), ruthenium (Ru), rhodium (Rh), silicon (Si), beryllium (Be), carbon tetraboride ( It may be a multilayer film combined with a substance such as B ₄ C).

  A reflective film made of a multilayer film is also formed on the reflective surface 111 a of the reflective mask 111. A mask pattern corresponding to the pattern to be transferred to the wafer (photosensitive substrate) 112 is formed on the reflective film of the reflective mask 111. The reflective mask 111 is attached to a mask stage 117 shown in the upper part of the drawing. The mask stage 117 is movable at least in the Y direction, and the EUV light reflected by the optical path bending reflecting mirror 116 is sequentially scanned on the reflective mask 111.

  A projection optical system 114 and a wafer (a substrate coated with a photosensitive resin) 112 are disposed in order from the top below the reflective mask 111 in the drawing. The wafer 112 is fixed on a wafer stage 118 that can move in the XYZ directions so that the exposure surface 112a faces upward (−Z direction) in the drawing. The EUV light reflected by the reflective mask 111 is reduced to a predetermined reduction magnification (for example, ¼) by the projection optical system 114 and imaged on the wafer 112. A resist that is sensitive to EUV light is applied on the wafer 112, and the resist is exposed according to the pattern image of the mask 111, whereby the pattern on the mask 111 is transferred onto the wafer 112.

FIG. 2 is a diagram showing a projection optical system 114 composed of six reflecting mirrors.
The projection optical system 114 shown in this figure includes six reflecting mirrors (optical elements) CM1 to CM6, and projects the EUV light reflected by the reflective mask 111 onto the wafer 112. The four reflecting mirrors CM1 to CM4 on the upstream side (side close to the reflective mask 111) constitute a first reflective imaging optical system G1 that forms an intermediate image of the mask pattern on the mask 111, and the downstream side (wafer) The two reflecting mirrors CM5 and CM6 on the side close to 112 constitute a second reflective imaging optical system G2 that projects the intermediate image of the mask pattern on the wafer 112 in a reduced scale.

The EUV light reflected by the mask 111 is reflected by the reflecting surface R1 of the first concave reflecting mirror CM1, and is reflected by the reflecting surface R2 of the second concave reflecting mirror CM2. The EUV light reflected by the reflecting surface R2 passes through the aperture stop AS and is sequentially reflected by the reflecting surface R3 of the third convex reflecting mirror CM3 and the reflecting surface R4 of the fourth concave reflecting mirror CM4, and then the mask pattern. An intermediate image is formed. Then, EUV light from the intermediate image of the mask pattern formed through the first reflective imaging optical system G1 is sequentially reflected on the reflective surface R5 of the fifth convex reflector CM5 and the reflective surface R6 of the sixth concave reflector CM6. After the reflection, a reduced image of the mask pattern is formed on the wafer 112.
That is, in the present embodiment, the EUV light is configured to form a pattern image on the wafer 112 via a plurality of optical elements (hereinafter simply referred to as optical elements) such as the reflecting mirrors CM1 to CM6.

  In the present embodiment, a lamp (second light source) L for irradiating the exposure chamber 110 with light having a non-photosensitive wavelength region for the resist on the wafer 112 as preheating light, and a lamp A reflecting mirror 2 that reflects the light irradiated from L, that is, the preheating light, is provided. The lamp L may be any lamp having a non-photosensitive wavelength range with respect to the resist, such as visible light, ultraviolet light, and infrared light. Ideally, the reflectance by the Mo / Si multilayer film in the reflecting mirrors CM1 to CM6 is EUV. What has a wavelength range which is equivalent to the reflectance of light is preferable.

Further, the spread of the light emitted from the lamp L and the arrangement of the reflecting mirror 2 are such that the preheating light reflected by the reflecting mirror 2 has an optical path range substantially the same as the optical path range of EUV light at the time of exposure by the projection optical system 114 at least. It is set to progress. Further, the lamp L is set to have such an intensity that the amount of incident light on each of the reflecting mirrors CM1 to CM6 is equal to the amount of incident light (incident energy amount) in the case of EUV light. More specifically, the light amount (energy amount) of the EUV light after the EUV light is reflected by the mask 111 is measured in advance, and the output of the lamp L is set so as to be equal to the measured light amount. When the reflective mask 111 needs to be preheated, the light of the lamp L is incident on the mask 111 and the preheated light reflected from the mask 111 is guided to the projection optical system 114. Is also possible. In this case, the amount of EUV light incident on the mask 111 is measured, and the output of the lamp L is set so that heating of the optical element by the measured amount of light is equivalent to heating by the lamp L.
Further, the reflecting mirror 2 is movable between a preheating position (position shown in FIG. 1) where the driving device 3 reflects the preheating light on the optical path of the EUV light and a retreat position retracted from the optical path of the EUV light. It has become.

In the exposure apparatus having the above configuration, the wafer 112 is mounted on the wafer stage 118 before the operation is started, and during the movement to the exposure start position, the irradiation of the EUV light is stopped and the reflecting mirror 2 is moved to the preheating position. The lamp L is operated. Thereby, preheating light is introduced into the projection optical system 114, and the reflecting mirrors (optical elements) CM1 to CM6 are preheated.
At this time, even when the wafer 112 is positioned directly under the projection optical system 114, the wafer 112 (resist thereof) is not exposed to light, and thus the above-described optical element is continuously preheated. Can be warmed up.

Then, the irradiation time of the preheating light necessary for these optical elements to be in a thermal steady state (stable state) is obtained in advance by experiments, simulations, etc., and the warm-up operation is performed until the required irradiation time is reached. carry out. When the preparation of the wafer 112 is completed, the wafer 112 moves to the exposure start position, and the warm-up operation is performed for a predetermined time and the optical element is in a steady state, the operation of the lamp L is stopped and the driving device 3 By moving the reflecting mirror 2 to the retracted position, the irradiation of EUV light is started. Thereby, the pattern image formed on the mask 111 can be projected onto the wafer 112.
At this time, the switching between the preheating light and the EUV light can be performed in a very short time, so that the disturbance in the steady state of the optical elements CM1 to CM6 can be suppressed to a negligible level.

  When the exposure process on the wafer 112 is completed, after the EUV light irradiation is stopped, the reflecting mirror 2 is moved to the preheating position, and the operation of the lamp L is resumed. Then, the exposed wafer is unloaded, and the wafer to be subjected to the next exposure process is mounted on the wafer stage 118 to prepare for the exposure process. During this time, since the preheating light is continuously applied to the optical element, the thermal steady state of the optical element is maintained. Then, when the wafer for the next processing is ready, the irradiation of the preheating light is stopped, the reflecting mirror 2 is moved to the retracted position, and then the EUV light is irradiated to project the pattern image on the wafer.

  In addition, when a minor trouble occurs in the EUV exposure apparatus 100 or the exposure process and the laser light source or the EUV light generation apparatus 101 is temporarily stopped, the optical element gradually cools even in a short time. Also in this case, the optical steady state of the optical elements CM1 to CM6 can be maintained by preheating the optical elements CM1 to CM6 with preheating light in the same manner as in the wafer exchange described above.

  As described above, in this embodiment, since the plurality of optical elements CM1 to CM6 can be preheated by one lamp L, it is more efficient than the case of preheating each optical element, and EUV light is generated. There is no need to operate the apparatus 101 in warm-up operation. The EUV light generation apparatus 101 consumes a target material (such as a Xe gas target or a tin target) that emits EUV light, and the EUV light source has a low conversion efficiency and a very high input power, so that the laser that converts the target material into plasma is used. Consume energy. Furthermore, the EUV light generation apparatus 101 contaminates the illumination optical system with a substance called debris depending on the type of target, and damages the multilayer film by plasma or high-speed ions in a reflector close to plasma. Although the light source (apparatus) is heavily consumed, since the operation is stopped in the warm-up operation as in this embodiment, it is possible to extend the life of the expensive EUV light generation apparatus 101, which is beneficial in terms of cost. Become.

In the present embodiment, since preheating light having a wavelength region that is non-photosensitive to the resist of the wafer 112 is used, even when the wafer 112 is positioned directly below the projection optical system 114. Without stopping the warm-up operation, the exposure process for the wafer 112 can be performed after the optical element is brought into a steady state. Therefore, unlike the prior art, the optical element is not started in an unsteady state particularly in the initial stage of the exposure process, and a stable and good pattern image can be transferred onto the wafer 112.
In addition, in this embodiment, the optical path range of the EUV light and the optical path range of the preheating light are made substantially the same, and the amount of incident light on the optical elements CM1 to CM6 is also reflected by the mask 111 that requires reproduction accuracy. Since it is equivalent to the case of EUV light based on the amount of energy, it becomes possible to pre-heat in almost the same state as during exposure, and a steady state for the optical elements CM1 to CM6 can be created easily and quickly.

(Second Embodiment)
Next, a second embodiment of the exposure apparatus of the present invention will be described with reference to FIG.
The second embodiment is different from the first embodiment in that a preheating lamp LL is additionally arranged.
Details will be described below.

FIG. 3 is a configuration diagram showing the projection optical system 114 in the second embodiment.
As shown in this figure, in the projection optical system 114, the lamp LL is disposed in the vicinity of the fourth concave reflecting mirror CM4, and the reflecting mirror 4 is disposed in the vicinity of the sixth concave reflecting mirror. The lamp LL emits preheating light having a wavelength region that is non-photosensitive to the wafer 112 as in the case of the lamp L. The reflecting mirror 4 reflects the preheating light emitted from the lamp LL.

The spread of the light emitted from the lamp LL and the arrangement of the reflecting mirror 4 are arranged such that the preheating light reflected by the reflecting mirror 4 is reflected by the fourth concave reflecting mirror CM4 and is exposed to the fifth convex reflecting mirror CM5 during the exposure. The optical path range is set so as to travel in substantially the same optical path range. Further, the lamp LL is set to have such intensity that the preheating light irradiated by the lamp L emits a light amount corresponding to the light amount that is reduced by being absorbed by the reflecting mirrors CM1 to CM4. The amount of preheating light absorbed by the reflecting mirrors CM1 to CM4 is obtained in advance by experiments, simulations, and the like.
Further, the preheating of the reflecting mirrors CM1 to CM4 by the lamp L and the preheating of the reflecting mirrors CM5 and CM6 by the lamp LL may be made independent so that the light from the lamp L does not reach the reflecting mirrors CM5 and CM6. .

In the EUV exposure apparatus 100 having the above-described configuration, for example, when infrared rays having a large absorption by the reflecting mirrors CM1 to CM6 are used as the preheating light, the latter half of the optical path of the preheating light emitted from the lamp L (here, In the reflecting mirrors CM5 and CM6), there is a possibility that the decrease in the amount of light becomes large and the optical element cannot be heated sufficiently. In this embodiment, the reflecting mirrors CM5 and CM6 are irradiated with the preheating light emitted from the lamp LL. Thus, it is possible to supplement the amount of preheating light from the lamp L that has been reduced by reflection at the reflecting mirrors CM1 to CM4, and it is possible to perform preheating in substantially the same state as during exposure.
In the present embodiment, since the preheating light emitted from the lamp LL also has a non-photosensitive wavelength region in the resist of the wafer 112, the wafer 112 is located immediately below the projection optical system 114. Even so, the warm-up operation can be continued and an improvement in production efficiency can be expected.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  For example, in the above embodiment, the lamps L and LL emit preheating light having a wavelength region that is non-photosensitive to the resist of the wafer 112. For example, the lamps L and LL are emitted from the projection optical system 114 to the wafer 112. A light source that emits EUV light may be used as the second light source and the third light source as long as a shutter that blocks the preheating light that travels is provided.

  Further, the arrangement of the lamps L is not limited to the arrangement shown in the above embodiment, and any position can be used as long as the preheating light can be introduced into the projection optical system 114. For example, a lamp L and a reflector having the same configuration as that of the reflector 2 are arranged in the vicinity of the EUV light source, and the existing illumination optical system is switched by switching the EUV light source and the lamp L by driving the reflector. The preheating light may be guided to the inside of the projection optical system 114 via the 113. Further, a lamp L and a reflecting mirror are arranged in the vicinity of the illumination optical system 113, and a configuration in which the EUV light source and the lamp L are switched by driving the reflecting mirror, or the lamp L and the reflecting mirror in the vicinity of the mask 111 are arranged. And driving the reflecting mirror to switch between the EUV light source and the lamp L, or arranging the lamp L in the vicinity of the mask 111 (for example, the −Z side of the mask 111), and the mask stage 117 A configuration may be adopted in which the preliminary heating light is directly guided into the projection optical system 114 while the mask 111 is temporarily retracted by driving.

  When adjusting the illuminance in the above embodiment and performing the warm-up operation of the optical element, the illuminance is large at the initial stage so that the warm-up operation is completed within the processing time other than the exposure process (for example, wafer exchange). It is preferable to irradiate the optical element with, and then irradiate the optical element with an illuminance equivalent to that during the exposure process for settling.

  The substrate of each of the above embodiments is 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 100, in addition to a step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes the pattern of the mask 111 by moving the mask 111 and the substrate 112 synchronously, the mask 111 and the substrate 112 It can also be applied to a step-and-repeat projection exposure apparatus (stepper) in which the pattern of the mask 111 is collectively exposed while the substrate is stationary and the substrate 112 is sequentially moved stepwise. The present invention can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on the substrate 112.

  The present invention can also be applied to a twin stage type exposure apparatus disclosed in Japanese Patent Application Laid-Open No. 10-163099, Japanese Patent Application Laid-Open No. 10-214783, and Japanese Translation of PCT International Publication No. 2000-505958.

  The type of the exposure apparatus 100 is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on the substrate 112. An exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD) ) Or an exposure apparatus for manufacturing reticles or masks.

  When a linear motor (see USP 5,623,853 or USP 5,528,118) is used for the substrate stage 118 and the mask stage 117, either an air levitation type using an air bearing or a magnetic levitation type using a Lorentz force or reactance force is used. Also good. Each stage 117, 118 may be a type that moves along a guide, or may be a guideless type that does not provide a guide.

  As a driving mechanism for each stage 117, 118, a planar motor that drives each stage 117, 118 by electromagnetic force with a magnet unit having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil facing each other is provided. It may be used. In this case, either the magnet unit or the armature unit may be connected to the stages 117 and 118, and the other of the magnet unit and the armature unit may be provided on the moving surface side of the stages 117 and 118.

As described in JP-A-8-166475 (USP 5,528,118), the reaction force generated by the movement of the substrate stage 118 is not transmitted to the projection optical system 114, and is mechanically floored using a frame member. You may escape to (earth).
As described in JP-A-8-330224 (USP 5,874,820), the reaction force generated by the movement of the mask stage 117 is not transmitted to the projection optical system 114, but mechanically using a frame member. You may escape to (earth). Further, as described in JP-A-8-63231 (USP 6,255,796), the reaction force may be processed using a momentum conservation law.

  The exposure apparatus 100 according to the embodiment of the present application is manufactured by assembling various subsystems including the constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Is done. 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. 4, a microdevice such as a semiconductor device includes a step 201 for performing a function / performance design of the microdevice, a step 202 for manufacturing a mask (reticle) based on the design step, and a substrate which is a base material of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus 100 of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a figure which shows typically the exposure apparatus which concerns on one Embodiment of this invention. It is a figure which shows the projection optical system comprised with six reflective mirrors. It is a figure which shows the projection optical system which concerns on 2nd Embodiment. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

CM1 to CM6 reflectors (optical elements)
CM1 First concave reflector (optical element)
CM2 Second concave reflector (optical element)
CM3 Third convex reflector (optical element)
CM4 Fourth concave reflector (optical element)
CM5 Fifth convex mirror (optical element)
CM6 6th concave reflecting mirror (optical element)
L lamp (second light source)
LL lamp (third light source)
2 Reflector 100 EUV exposure equipment (exposure equipment)
101 EUV light generator (laser plasma light source, light source)
108 EUV light (exposure light)
111 mask 112 wafer (photosensitive substrate)
114 Projection optical system

Claims (9)

An exposure apparatus that projects a pattern image of a mask onto a photosensitive substrate through a plurality of optical elements with exposure light from a light source,
An exposure apparatus comprising: a second light source that irradiates at least two or more of the plurality of optical elements with preheating light. The exposure apparatus according to claim 1, wherein
The exposure apparatus, wherein the second light source emits light having a non-photosensitive wavelength range with respect to the photosensitive substrate. The exposure apparatus according to claim 1 or 2,
An exposure apparatus characterized in that an optical path range of the preheating light is substantially the same as a part of the optical path range of the exposure light. In the exposure apparatus according to any one of claims 1 to 3,
An exposure apparatus, wherein an output of the second light source is set based on an energy amount of the exposure light after the exposure light is reflected by the mask. In the exposure apparatus according to any one of claims 1 to 4,
An exposure apparatus comprising: a third light source that irradiates a part of the plurality of optical elements with preheating light. The exposure apparatus according to claim 5, wherein
The exposure apparatus, wherein the third light source emits light having a non-photosensitive wavelength with respect to the photosensitive substrate. In the exposure apparatus according to any one of claims 1 to 6,
An exposure apparatus, wherein the exposure light is an X-ray.   The preheating light from the second light source is introduced into the optical element from between the mask and the optical element that first enters light from the mask among the plurality of optical elements. An exposure apparatus according to any one of claims 1 to 7. 9. The exposure apparatus according to claim 1, wherein the preheating light is also applied to the mask, and the mask is also preheated simultaneously with the optical element.

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