JP2006216759A - Optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device which is capable of reducing a deterioration in its optical characteristics due to impurities present inside it. <P>SOLUTION: The optical device is equipped with an optical element which forms a part of a partition that demarcates a space. The optical device is equipped with an additional matter feeding means 135 which feeds into the space an additional matter that combines with impurities that are attachable to the optical element, an exhaust means 136 which exhausts the atmosphere from the space, a gas feed means 134 which feeds gas into the space, a detecting means 137 which detects impurities, and a control means 138 which controls the amount of the loaded additional matter resting on the concentration of the impurities. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention generally relates to cleaning of a space including an optical element of an optical device, and more particularly to an optical device using light in a short wavelength range from an ultraviolet region to a vacuum ultraviolet region as a light source. The present invention is suitable for an exposure apparatus used for exposing an object to be processed such as a single crystal substrate for a semiconductor wafer and a glass substrate for a liquid crystal display (LCD).

  Due to the recent demand for smaller and thinner electronic devices, there is an increasing demand for miniaturization of semiconductor elements mounted on electronic devices. As a lithography (baking) method for manufacturing a semiconductor element, a circuit pattern drawn on a mask or a reticle (in this application, these terms are used interchangeably) is projected onto a wafer or the like by a projection optical system, and a circuit is formed. Conventionally, a projection exposure apparatus for transferring a pattern has been used.

The minimum dimension (resolution) that can be transferred by the projection exposure apparatus is proportional to the wavelength of light used for exposure and inversely proportional to the numerical aperture (NA) of the projection optical system. Therefore, the shorter the wavelength, the better the resolution. For this reason, KrF excimer laser (wavelength: about 248 nm) and ArF excimer laser (wavelength: about 193 nm) with shorter wavelengths are used as ultra-high pressure mercury lamps in recent years, and F ₂ laser (wavelength: about 157 nm) has been put into practical use. Progressing.

  On the other hand, the projection exposure apparatus is also required to improve the throughput (the number of sheets processed per unit time). In order to improve the throughput, it is necessary to increase the illuminance of the exposure light, that is, the amount of exposure light per unit time irradiated to the target object in order to shorten the exposure time for each target object.

  However, light absorption by substances (oxygen, water vapor, carbon dioxide, organic matter, halides, etc.) contained in the optical path atmosphere of the optical element and exposure light is used in exposure light with a shorter wavelength, that is, in the wavelength band belonging to the vacuum ultraviolet region. Therefore, the throughput of the apparatus is reduced along with a decrease in the amount of exposure light on the object to be processed.

In general, as the wavelength of light becomes shorter, the photon energy gradually increases. For example, 114.1 kcal / mol with a KrF excimer laser, 147.2 kcal / mol with an ArF excimer laser, and 180.1 kcal / mol with an F ₂ laser. Become. Increasing photon energy causes the decomposition and generation of substances by photochemical reactions. The product generated by the photochemical reaction accumulates on the optical element, and when such a substance adheres to the optical element, the amount of exposure light is further reduced and the imaging performance is deteriorated.

  Such deterioration of optical characteristics (that is, throughput and imaging performance) becomes a greater problem as the exposure light wavelength becomes shorter. This is because the photochemical reaction is activated by increasing the photon energy of the exposure light, and a very small amount of a substance that has not caused the photochemical reaction until now becomes an impurity. In addition, even in the wavelength band belonging to the visible to normal ultraviolet region, even a substance that adheres to the optical element and has little effect on the optical characteristics has a larger absorption for light in the wavelength band belonging to the vacuum ultraviolet region. Or having a specific refractive index, it adversely affects the optical characteristics.

  For example, when a phthalate such as dibutyl phthalate (DBP) or dioctyl phthalate (DOP) is present in the apparatus atmosphere as a desorption gas from a member to be used, it adheres and accumulates on the optical element due to its strong adsorptivity. . Further, it is known to absorb light with a short wavelength. Although these are relatively hardly volatile organic compounds, they are likely to become impurities because they are generally widely used as plasticizers.

  Therefore, Patent Document 1 proposes an exposure apparatus that prevents and suppresses deterioration of optical characteristics due to a photochemical reaction by circulating a space containing an optical element with a clean inert gas.

Further, Patent Document 2 proposes an exposure apparatus provided with a filter for increasing the purity of the introduced gas. In such an exposure apparatus, by installing a filter at the gas inlet, impurities contained in the gas of the supply source and impurities generated from the member desorption gas component when passing through the air supply unit can be removed. It is also necessary to cope with impurities caused by desorbed gas from members in the exposure apparatus. This is dealt with by selecting and using a member that has a small amount of desorbed gas or that is less affected by the deterioration of the optical characteristics due to the desorbed gas.
Japanese Patent Laid-Open No. 02-210813 Japanese Patent Laid-Open No. 06-077114

However, as will be more shorter wavelength into F ₂ wavelength from KrF wavelength, the more substance adversely affect the optical properties. In addition, depending on the substance, even a minute amount of an order such as ppb or ppt may cause a serious problem in deterioration of optical characteristics. In other words, in an optical device having a light source with a shorter wavelength, the conditions required for desorbed gas from members in the device are more severe.

  On the other hand, various types of members and the like must be used in the optical device in order to achieve the device performance. Therefore, in practice, it is difficult to completely eliminate the desorbed gas from all the members to be used, and a trace amount of impurities is included.

  Therefore, an object of the present invention is to provide an optical device capable of reducing deterioration of optical characteristics due to impurities present in the device.

  In order to achieve the above object, an optical device according to one aspect of the present invention is an optical device in which an optical element forms part of a partition wall that defines a space, and bonds with impurities that can adhere to the optical element. An additive substance supply means for supplying an additive substance to be formed into the space; and an exhaust means for exhausting the atmosphere in the space. It further has gas supply means for supplying a predetermined gas into the space. It has a detection means for detecting the concentration of the impurity, and a control means for controlling the addition amount of the additive substance based on the concentration of the impurity detected by the detection means. It has a detection means for detecting the concentration of the additive substance, and a control means for controlling the addition amount of the additive substance based on the concentration of the additive substance detected by the detection means. The additive material has a strong chemical structure for forming a bond with the impurity on the surface. The additive substance is an oxide having an anion on the surface. The additive material is an organic compound having a strongly polar functional group for forming a bond with the impurity on the surface. The functional group includes any one of a carboxyl group, a carbonyl group, an aldehyde group, an alcoholic hydroxyl group, a phenolic hydroxyl group, and an ester group. The additive substance is an organic compound having lipophilicity. The additive material has a pore structure, an intercalation compound structure, or a helical structure. The optical device is an exposure device. The optical device is a spectrophotometer.

  A device manufacturing method according to another aspect of the present invention includes a step of exposing a target object using the above-described optical apparatus, and a step of performing a predetermined process on the exposed target object. To do.

  Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the optical apparatus which can reduce deterioration of the optical characteristic resulting from the impurity which exists in an apparatus can be provided.

  The present inventor returned to the basics to provide an optical device capable of reducing deterioration of optical characteristics due to impurities existing in the device, and as a result of earnestly examining the impurities, as a result of adhesion and deposition to the optical element. The details of easiness vary depending on the surface state of the optical element, etc., but in general, it has been discovered that a substance having a higher polarity has a higher adsorptivity and tends to adhere and deposit on the optical element. In addition, light in a wavelength band belonging to the vacuum ultraviolet region has a large light energy, and a product due to a photochemical reaction may adhere to and deposit on the optical element. It has been found that such a photochemical reaction is suppressed in the presence of a negative catalyst that increases the activation energy required for the reaction.

  Hereinafter, an optical device according to one aspect of the present invention will be described with reference to the accompanying drawings.

  In addition, in each figure, about the same member, the same reference number is attached | subjected and the overlapping description is abbreviate | omitted. Here, FIG. 1 is a schematic block diagram showing an exemplary embodiment of an optical device 100 as one aspect of the present invention.

  The optical apparatus 100 is a projection exposure apparatus that exposes a circuit pattern formed on the mask 120 to the plate 140 by, for example, a step-and-repeat method or a step-and-scan method. Such an exposure apparatus is suitable for a lithography process of submicron or quarter micron or less, and in the present embodiment, a step-and-scan type exposure apparatus (also referred to as a “scanner”) will be described as an example. Here, the “step-and-scan method” means that the wafer is continuously scanned (scanned) with respect to the reticle to expose the mask pattern onto the wafer, and the wafer is stepped after the exposure of one shot is completed. This is an exposure method for moving to the next exposure region. The “step-and-repeat method” is an exposure method in which the wafer is stepped and moved to the next exposure region for every batch exposure of wafer shots.

  As illustrated in FIG. 1, the optical device 100 includes an illumination device 110 that illuminates a mask 120 on which a circuit pattern is formed, and a projection optical system 130 that projects diffracted light generated from the illuminated mask pattern onto a plate 140. .

  The illumination device 110 illuminates the mask 120 on which a transfer circuit pattern is formed, and includes a light source unit 112 and an illumination optical system 114.

The light source unit 112 uses, for example, a laser as a light source. As the laser, an ArF excimer laser with a wavelength of about 193 nm, a KrF excimer laser with a wavelength of about 248 nm, an F ₂ laser with a wavelength of about 153 nm, etc. can be used, but the type of laser is not limited. For example, a YAG laser is used. The number of lasers is not limited. For example, if two solid-state lasers that operate independently are used, there is no coherence between the solid-state lasers, and speckle due to the coherence is considerably reduced. Further, the optical system may be swung linearly or rotationally to reduce speckle. When a laser is used for the light source unit 112, a light beam shaping optical system that shapes the parallel light beam from the laser light source into a desired beam shape and an incoherent optical system that makes the coherent laser light beam incoherent are used. Is preferred.

  The illumination optical system 114 is an optical system that illuminates the mask 120, and includes a lens, a mirror, an optical integrator, a stop, and the like. For example, a condenser lens, a fly-eye lens, an aperture stop, a condenser lens, a slit, and an imaging optical system are arranged in this order. The illumination optical system 114 can be used regardless of on-axis light or off-axis light. The optical integrator has a role of uniformly illuminating the mask 120 with a predetermined numerical aperture, and includes an integrator configured by stacking a fly-eye lens and two sets of cylindrical lens array (or lenticular lens) plates. In some cases, an optical rod or a diffraction element may be substituted.

  The mask 120 is made of, for example, quartz, on which a circuit pattern (or image) to be transferred is formed, and is supported and driven by a mask stage (not shown). The diffracted light emitted from the mask 120 passes through the projection optical system 130 and is projected onto the plate 140. The mask 120 and the plate 140 are arranged in an optically conjugate relationship. Since the optical apparatus 100 is a step-and-scan type exposure apparatus, the mask pattern is reduced and projected onto the plate 140 by scanning the mask 120 and the plate 140.

  The projection optical system 130 forms an image of the light flux from the mask 120 (ie, the object plane) on the plate 140 (ie, the image plane). The projection optical system 130 includes an optical system composed only of a plurality of lens elements, an optical system (catadioptric optical system) having a plurality of lens elements and at least one concave mirror, a plurality of lens elements, and at least one kinoform. An optical system having a diffractive optical element such as an all-mirror optical system can be used. When correction of chromatic aberration is required, a plurality of lens elements made of glass materials having different dispersion values (Abbe values) can be used, or the diffractive optical element can be configured to generate dispersion in the opposite direction to the lens element. To do.

  FIG. 2 is a schematic sectional view showing an exemplary form of the projection optical system 130. As shown in FIG. 2, the projection optical system 130 includes a plurality of optical elements 132 supported by a support part 131, a gas supply unit 134, an additive substance supply unit 135, an exhaust unit 136, a detection unit 137, And control means 138. The optical element 132 forms a part of a partition wall that defines the space 133 and is embodied as a lens in this embodiment.

  The gas supply unit 134 supplies a predetermined gas into the space 133 to replace (purge) the atmosphere in the space 133. The predetermined gas is a gas with little light absorption, such as an inert gas.

  The additive substance supply means 135 supplies the additive substance AM that forms a bond with the impurity CN that can adhere to the optical element 132 into the space 133. The additive substance supply means 135 adds the additive substance AM having a higher adsorptivity than the optical element 132 to the impurity CN attached and deposited on the optical element 132, so that the adhesion characteristic of the impurity CN to the optical element 132 is improved. Can be reduced. Here, the impurities include products and intermediate products generated and attached and deposited by a photochemical reaction, and the additive material supply unit 135 adds the additive material AM to suppress and prevent the photochemical reaction due to the impurities. can do.

  Further, by arranging the additive substance supply means 135 in the vicinity of the optical element 132, the effect of suppressing the adhesion and deposition of the impurity CN on the optical element 132 can be improved. This is intended to obtain a sufficient effect even with a minute amount of desorbed gas from a member in the space 133, for example, the support portion 131. When the additive supply means 135 cannot be disposed in the vicinity of the optical element 132, it is desirable to attach a blower plate or the like to spray the additive substance AM on the optical element 132.

  Examples of the additive substance AM having high adsorptivity include zeolite, activated carbon, and silica gel, which are widely used for filter materials. All of these have a micropore structure and thus have a wide area and high adsorptivity. Silica gel has high surface adsorptivity because of the presence of hydroxyl groups with high polarity on the surface. Further, when an organic substance is used as the additive substance AM, the adsorptivity is related to the functional group of the substance. The high adsorptivity of activated carbon is partly due to functional groups present on the surface.

  FIG. 3 is a schematic plan view showing an example in which the additive substance AM and the impurity CN form a bond. As an example of the bond between additive substance AM and impurity CN, FIG. 4 shows a chemical formula when additive substance AM is a silicon oxide compound and impurity CN is palmitic acid. 3 and 4, the silicon oxide compound as the additive substance AM has a hydroxyl group on the surface, and the hydroxyl group forms a bond with the carboxyl group of palmitic acid as the impurity CN. With these bonds formed, before being attached and deposited on the optical element 132, it is emitted out of the space 132 by the exhaust means 136 that replaces the atmosphere in the space 132. Therefore, there is no adverse effect on the deterioration of the optical characteristics of the optical device 100.

  Here, some of the additive substance AM including the silicon oxide compound will be described. The silicon oxide compound has a pore structure, a large surface area, and has many hydroxyl groups on the surface. For this reason, it is possible to form bonds and adsorb moisture, ammonia ions, or organic substances.

  When oxides such as aluminum, sodium, titanium, vanadium, or mixed oxides thereof are used as the additive material AM, they have a strong polarity on the surface, and the structure is a fine structure or an intercalation compound structure, so that a large area is required. It has the characteristic of having.

  In addition, for impurities CN having a highly polar surface portion, an organic compound having a highly polar functional group such as a carboxyl group, a carbonyl group, an aldehyde group, an alcoholic hydroxyl group, a phenolic hydroxyl group, or an ester group on the surface May be the additive substance AM.

  In the case where the impurity CN is a surface nonpolar organic compound, it is effective to use an organic compound having many nonpolar groups on the surface and having lipophilicity as the additive substance AM. These organic compounds only have to satisfy either one of the conditions that the absorption at the light source wavelength is small or the effect is small enough not to affect the light source wavelength.

  In addition, the light in the wavelength band belonging to the vacuum ultraviolet region may have various photochemical reactions depending on the wavelength and illuminance of the light, and the products generated by changing the photochemical reaction may adhere to and deposit on the optical element 132. . Similarly, for this type of impurity, the additive substance AM forms a bond with the impurity CN, thereby increasing the energy required for the photochemical reaction and suppressing the occurrence of the photochemical reaction.

  The additive substance AM is a substance that can achieve a sufficient effect with an addition amount that does not adhere to the optical element 132 or does not cause deterioration of optical characteristics even if it adheres. In addition, the additive substance AM is present in the space 133 replaced with a predetermined gas by being supplied into the space 133, but it does not cause deterioration of optical characteristics.

  The additive substance AM is preferably useful for all the impurities CN remaining in the space 133 and adhering to and depositing on the optical element 132, but a combination of several kinds may be used.

  Further, if the additive substance AM is in a small amount, a sufficient effect cannot be obtained. Conversely, if the additive substance AM is excessively present, the additive substance AM may adversely affect the optical characteristics. The concentration of additive substance AM to be optimized must be optimized. Therefore, the detection unit 137 is provided to detect the concentration of the impurity CN existing in the space 133, and based on the concentration of the impurity CN detected by the detection unit 137, control is performed so that the concentration of the additive substance AM is always optimal. The addition amount of the additive substance AM supplied from the additive substance supply means 135 is controlled by the means 138. Further, the detecting means 137 detects the concentration of the additive substance AM existing in the space 133, and based on the concentration of the additive substance AM, the addition amount of the additive substance AM supplied from the additive substance supply means 135 by the control means 138 is determined. It is also possible to control.

  The detection means 137 can perform continuous measurement by atmospheric pressure mass spectrometry, flame ionization detection, non-dispersive infrared absorption, or the like. There is also a method of periodically performing GC / MS measurement. The control unit 138 can arbitrarily set the concentration of the additive substance AM in the space 133 by controlling the gas flow rate, contact area, and temperature of the additive substance AM supplied by the additive substance supply unit 135.

  The mechanism for suppressing the concentration of the additive substance AM, that is, the detection means 137 and the control means 138 has a wide concentration range in which the additive substance AM sufficiently exhibits the effect of suppressing the adhesion and deposition of the impurity CN on the optical element 132. If the increase in density does not adversely affect the optical characteristics of the apparatus, there is no problem even if it is not installed. In this embodiment, the additive substance supply unit 135 is provided in the space 133 including all the optical elements 132. However, the additive substance supply unit 135 may be provided only in a portion that causes a large deterioration in optical characteristics.

  Returning to FIG. 1 again, the plate 140 is a wafer in this embodiment, but widely includes a liquid crystal substrate and other objects to be processed (objects to be exposed). The plate 140 is coated with a photoresist. The photoresist coating process includes a pretreatment, an adhesion improver coating process, a photoresist coating process, and a prebaking process. Pretreatment includes washing, drying and the like. The adhesion improver coating process is a surface modification process for improving the adhesion between the photoresist and the base (that is, a hydrophobic process by application of a surfactant), and an organic film such as HMDS (Hexmethyl-disilazane) is used. Coat or steam. Pre-baking is a baking (baking) step, but is softer than that after development, and removes the solvent.

  The plate stage 150 supports the plate 140. Since any configuration known in the art can be applied to the plate stage 150, a detailed description of the structure and operation is omitted here. For example, the plate stage 150 can move the plate 140 in the XY directions using a linear motor. For example, the mask 120 and the plate 140 are synchronously scanned, and the positions of the mask stage and the plate stage 150 (not shown) are monitored by, for example, a laser interferometer, and both are driven at a constant speed ratio. The plate stage 150 is provided on a stage surface plate supported on a floor or the like via a damper, for example, and the mask stage and the projection optical system 130 are, for example, a damper on a base frame placed on the floor or the like. It is provided on a lens barrel surface plate (not shown) supported via the like.

  In the exposure, the light beam emitted from the light source unit 112 irradiates the mask 120 with, for example, Kohler illumination by the illumination optical system 114. The light that passes through the mask 120 and reflects the mask pattern is imaged on the plate 140 by the projection optical system 130.

  In the projection optical system 140 used by the optical apparatus 100, since the impurity CN is removed by the additive material AM, the device (semiconductor element, LCD element, imaging element (CCD, etc.), thin film magnetic field with high resolution and high throughput can be obtained economically. Head, etc.).

  The optical apparatus 100 has been described above as an exposure apparatus, but this form is exemplary, and for example, the optical apparatus 100 can be realized as a spectrophotometer. That is, in all spaces including optical elements such as lenses and mirrors of spectrophotometers, the supply of additive substances that similarly supplies additive substances that have the effect of suppressing and preventing impurities from adhering to and depositing on the optical elements. Attach means. The amount of light used for a spectrophotometer is generally much smaller than that of an exposure apparatus. Therefore, there is almost no adverse effect on the apparatus due to the substance produced by the photochemical reaction being deposited on the surface of the optical element. By the additive substance, the adhesion and deposition of impurities on the optical element can be suppressed and prevented, and the measurement accuracy of the spectrophotometer can be maintained.

  Next, an embodiment of a device manufacturing method using the above-described optical apparatus 100 will be described with reference to FIGS. FIG. 5 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, etc.). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), a device circuit is designed. In step 2 (mask production), a mask on which the designed circuit pattern is formed is produced. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the mask and the wafer. Step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer created in step 4, and includes processes such as an assembly process (dicing and bonding), a packaging process (chip encapsulation), and the like. . In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 6 is a detailed flowchart of the wafer process in Step 4. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. Step 16 (exposure) uses the optical apparatus 100 to expose a circuit pattern on the mask onto the wafer. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer. According to the device manufacturing method of the present embodiment, it is possible to manufacture a higher quality device than before. Thus, the device manufacturing method used by the optical apparatus 100 and the resultant device also constitute one aspect of the present invention.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

The present application further discloses the following matters.
[Embodiment 1] An optical device in which an optical element forms a part of a partition wall defining a space,
An additive substance supply means for supplying a substance that forms a bond with impurities that can adhere to the optical element into the space;
An optical device comprising exhaust means for exhausting the atmosphere in the space.
[Embodiment 2] The optical apparatus according to Embodiment 1, further comprising gas supply means for supplying a predetermined gas into the space.
[Embodiment 3] Detection means for detecting the concentration of the impurities;
2. The optical apparatus according to claim 1, further comprising a control unit that controls an addition amount of the additive substance based on the concentration of the impurity detected by the detection unit.
[Embodiment 4] Detection means for detecting the concentration of the additive substance;
2. The optical apparatus according to claim 1, further comprising a control unit configured to control an addition amount of the additive substance based on the concentration of the additive substance detected by the detection unit.
[Embodiment 5] The optical apparatus according to Embodiment 1, wherein the additive substance has a strong chemical structure for forming a bond with the impurity on the surface.
[Embodiment 6] The optical apparatus according to Embodiment 1, wherein the additive substance is an oxide having an anion on the surface.
[Embodiment 7] The optical apparatus according to Embodiment 1, wherein the additive substance is an organic compound having a highly polar functional group for forming a bond with the impurity on the surface.
[Embodiment 8] The optical device according to Embodiment 7, wherein the functional group includes any one of a carboxyl group, a carbonyl group, an aldehyde group, an alcoholic hydroxyl group, a phenolic hydroxyl group, and an ester group. .
[Embodiment 9] The optical apparatus according to Embodiment 1, wherein the additive substance is an organic compound having lipophilicity.
[Embodiment 10] The optical apparatus according to Embodiment 1, wherein the additive substance has a pore structure, an intercalation compound structure, or a helical structure.
[Embodiment 11] The optical apparatus according to any one of Embodiments 1 to 10, wherein the optical apparatus is an exposure apparatus.
[Embodiment 12] The optical device according to any one of Embodiments 1 to 10, wherein the optical device is a spectrophotometer.
[Embodiment 13] A step of exposing an object to be processed using the optical device according to Embodiment 11;
And performing a predetermined process on the exposed object to be processed.

1 is a schematic block diagram illustrating an exemplary embodiment of an optical device according to one aspect of the present invention. It is a schematic sectional drawing which shows an exemplary form of the projection optical system shown in FIG. It is a schematic plan view which shows an example in which an additive substance and an impurity form a bond. As an example of the bond between the additive substance and the impurity, a chemical formula in the case where the additive substance is a silicon oxide compound and the impurity is palmitic acid. It is a flowchart for demonstrating manufacture of devices (semiconductor chips, such as IC and LSI, LCD, CCD, etc.). 6 is a detailed flowchart of the wafer process in Step 4 shown in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Optical apparatus 110 Illuminating device 112 Light source part 114 Illumination optical system 120 Mask 130 Projection optical system 131 Support part 132 Optical element 133 Space 134 Gas supply means 135 Additive substance supply means 136 Exhaust means 137 Detection means 138 Control means 140 Plate 150 Plate stage AM additive substance CN impurity

Claims (13)

An optical device in which an optical element forms a part of a partition wall that defines a space,
An additive substance supply means for supplying an additive substance that forms a bond with impurities that can adhere to the optical element into the space;
An optical device comprising exhaust means for exhausting the atmosphere in the space.   The optical apparatus according to claim 1, further comprising gas supply means for supplying a predetermined gas into the space. Detection means for detecting the concentration of the impurities;
The optical apparatus according to claim 1, further comprising a control unit that controls an addition amount of the additive substance based on a concentration of the impurity detected by the detection unit. Detection means for detecting the concentration of the additive substance;
The optical apparatus according to claim 1, further comprising a control unit that controls an addition amount of the additive substance based on the concentration of the additive substance detected by the detection unit.   The optical device according to claim 1, wherein the additive substance has a strong chemical structure for forming a bond with the impurity on a surface.   The optical device according to claim 1, wherein the additive substance is an oxide having an anion on the surface.   2. The optical apparatus according to claim 1, wherein the additive substance is an organic compound having a functional group having a strong polarity for forming a bond with the impurity on the surface.   The optical device according to claim 7, wherein the functional group includes any one of a carboxyl group, a carbonyl group, an aldehyde group, an alcoholic hydroxyl group, a phenolic hydroxyl group, and an ester group.   The optical device according to claim 1, wherein the additive substance is an organic compound having lipophilicity.   The optical device according to claim 1, wherein the additive substance has a pore structure, an intercalation compound structure, or a helical structure.   The optical apparatus according to claim 1, wherein the optical apparatus is an exposure apparatus.   The optical device according to claim 1, wherein the optical device is a spectrophotometer. Exposing the object to be processed using the optical device according to claim 11;
And performing a predetermined process on the exposed object to be processed.

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