TW439114B - Exposure device - Google Patents

Abstract

An exposure system is provided with an illuminating optical system for applying an illuminating light IL from a light source 1 to a reticle R which exposes a wafer W as a photosensitive substrate to an illuminating light via the reticle R, and which comprises a supply device 31, 32, 43, 46 for supplying a gas (e.g. helium gas) high in transmittance for an illuminating light in a sealed chamber (lens barrel, etc.) including at least a part (e.g. a projection optical system PL, an illuminating optical system, the light source 1) of an illuminating light path, a recovering device 33, 34 for recovering at least part of the supplied gas, and a purifying device 35, 37, 80 for removing from the recovered gas substances which change the optical characteristics in a gas-supplied atmosphere.

Description

4 3 91 14 V. Description of the Invention (!) —- :: The technical field of the invention is related to the use of semiconductor devices and liquid crystals, no. . The photoetching process of the 5 溥 film magnetic head etc. transfers the mask pattern to the exposure device used on the A plate. 1-Conventional technology 1 For example, when manufacturing a semiconductor device, the same stepper (Sk 为了 and other exposure devices) is required to increase the resolution in order to adapt to the increase in the density and fineness of the semiconductor device. Because of the resolution and lighting, The wavelength of light is approximately proportional, and the exposure wavelength is gradually shorter than the conventional one. That is, the illumination light is replaced by the g-ray (wavelength 436nm) in the visible region of the mercury lamp with the i-ray (wavelength 3 6 5nm) in the ultraviolet region Recently, KrF Excimer has been used to emit light (wavelength 248nm). However, the use of ArF Excimer laser light (wavelength 193nm), F2 Exciraer laser light (wavelength i57nm), and even Ar2 are currently under review.

Excimer laser light (wavelength 126ηπι). In addition, due to previous studies on X-ray photoetching, the use of so-called extreme ultraviolet (Eϋν or XUV) regions, which are nearly X-rays with a wavelength of i3nm or 7nm, and even X-rays with an Inm wavelength, have also been reviewed. However, in the wavelength region below the level of ArF Excimer laser light, that is, in the vacuum ultraviolet region (VUV) below about 200 nm, absorption occurs due to oxygen in the air, and ozone causes the transmittance to decrease. Therefore, for example, in an exposure apparatus using ArF Excimer laser light, most of the gas in the light path of the illumination light is replaced with nitrogen, and so-called nitrogen purge (N2 Purge) is performed. In addition, in a region having a wavelength shorter than the wavelength of the ArF Excimer laser light (about 190 nm or less), especially the wave below the F2 Exc i mer laser light

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Page 4 V. Description of Invention (2)

Long regional fleur-de-lis U milk is also absorbed. In this case, if the new recitation + r is narrow, its absorption is extremely high, and the area through which the lice pass is extremely unavailable. It is suitable for exposure on the night, but the amount of light in the long light path is reduced by less than 190 dragons. / Of its exposure. Therefore, it is necessary to replace most of the light path of the light in the wavelength region where the light is transmitted. As above, another gas is set to a vacuum. The following light ^, in the exposure device, in the use of the wavelength region of about 190nm atmosphere or absorption I want to replace most of its optical path with extremely high purity, the latter will be light: nitrogen gas or vacuum. However, 'such as ^ ^ ^ most of Saki' is set to vacuum, because it must adopt a structure that can withstand direct work, the manufacturing cost of the exposure device rises D ', Liba is I to deal with this problem, and the structure makes the lighting One of the light paths P of the light, the royal body becomes a sealed space ', and a gas having two transmittances of inert exposure light (for example, helium gas) is sealed therein, or the sealed space gas is supplied under pressure by considering leakage. In addition, for example, when the projection optical system is a reflection-refraction system, it is also used in an exposure apparatus using ArF Excimer laser light, which uses helium. However, for example, an optical element unit for arranging optical elements such as a plurality of lenses or reflectors in a lens barrel used in an illumination optical system or a projection optical system, an anti-reflective paint from the inner surface of the lens barrel, or an optical element used to fix the optical element. Contaminants such as organic materials and moisture such as adhesives and filling materials may condense and adhere to the surface of optical elements, which may reduce the illuminance of the illuminating light or cause uneven optical characteristics, which may degrade the optical characteristics. In addition, helium (He) is the most inert and safe gas, but it is expensive because it is the least amount in the earth ’s crust or the atmosphere.

Page 5 V. Description of the invention (3) Small atomic weight 'is easy to leak from the gaps of the cover or lens barrel constituting the sealed space, which consumes a large amount, and has the disadvantage of increasing the operating cost of the exposure device. SUMMARY OF THE INVENTION Therefore, 'the object of the present invention is to provide an exposure device that sufficiently supplies illumination light = at least a part of a light path with a high transmittance (inert) gas' to sufficiently prevent contamination of a prior element and the like located on the light path of the illumination light. Surface, and can save the amount of gas. * According to the present invention, an exposure device is provided, which "transmits an image of a pattern formed on the photomask onto a predetermined surface after irradiating the photomask with illumination light from a light source." At least part of the light path of the illuminating light-a gas that transmits the illuminating light; a recovery device that recovers at least a part of the gas that supplies the light path of the side illuminating light; and a purifying device that removes the influence of the recovered gas on the predetermined surface. Substance with precision of the image of the pattern. Here, the substance that affects the transfer accuracy of the image of the pattern on the predetermined surface is, for example, a substance that changes the optical characteristics. The transfer accuracy means the line width accuracy of the pattern when transferring the pattern to the surface of the photosensitive substrate as the predetermined surface, the transfer position accuracy of the pattern f, or the positional deviation accuracy between the patterns. In addition, the substance that changes the optical characteristics is not particularly limited, for example, a substance that deteriorates the optical characteristics, a substance that changes the illuminance or illumination distribution of the illumination light, and, more specifically, the second line is in a space located in the light path of the illumination light Impurities generated from gases (air, nitrogen, helium, etc.), molecules of organic substances generated from adhesives or filling materials used to fix optical elements, etc., from the inner wall of the lens barrel (painted surface to prevent reflection, etc.) Occurrence of impurities (e.g. water molecules,

V. Description of the invention (4) Molecules of hydrocarbons, or other substances that diffuse illuminating light), vaporization of purification liquid (ether, water, etc.) remaining on the surface of optical elements, etc. These pollutants or pollutants produced by the reaction between these pollutants and the illumination light cause the characteristics of the optical element to deteriorate due to agglomeration and adhesion to the surface of the optical element, which causes the illumination intensity or illumination distribution to change. According to the present invention, since a part of the gas supplied to the optical path is recovered by a recovery device, substances that change the optical characteristics of the optical path located on the optical path are removed from the optical path to prevent or prevent the optical characteristic from changing. In addition, the gas is purified by removing the recovered gas from the recovered gas using a purification device, and the gas can be reused (recycled). Therefore, the amount of gas used can be saved, and the operating cost can be greatly reduced when the gas system is expensive. The above-mentioned structure is not particularly limited, but a gas system purified by the purification device can be used to constitute a circulation system by re-supplying the light path of the illumination light through the supply device. However, it is also possible to use this supply device to constantly supply new gas, press (recover) the recovered and purified gas into a high-pressure container, or supply it to another exposure device. The gas supply object using the supply device may be a space including the entire light path of the illumination light (the entire light path from the light source through the illumination system and the projection optical system to the exposure target object), but it includes a part of the light path. The space may be, for example, a light source, all or part of an illumination system, or all or part of a projection optical system. Also 'is the space between the projection optical system and the photosensitive substrate (the so-called wafer chamber) or the space between the illumination optical system and the projection optical system (the so-called light

439114 V. Description of the invention (5) Cover room) is also available. This supply device 'The recovery device may be directly operated, but a control device is provided to control its operation more efficiently. When using the control memory, the memory device including the purifying device should operate can be operated according to the device of the memory device. Alternatively, the projection optical system detected on the photosensitive substrate can also be set to exceed the detected * transmittance * variation. In addition, the supply port and the discharge port connected to the recovery device are respectively provided in the room divided into at least a part (Chamber), an optical element, and the like that are included in the optical path of the supply device, and the control device is used. When the purification device is operated, the on-off valve can be closed when the open-exposure pre-treatment is not performed, and the on-off valve is closed during processing. Because it is in the light state, stable exposure processing can be performed. Before the purification device operates, the pollutants that irradiate the illumination light on the surface of the optical element include the gas of the pollutants to prevent the pollution, the decrease of the illuminance or the unevenness of the illuminance. In addition, the supplied and recovered gas of the purification device The action is controlled by the motion control device according to the optical characteristics. The control data of the control data of ^ s ^ t on the system 'setting the pre-time and time >] makes the purification pattern image projection detection clam device. If the set value is exceeded, the purification device will be used to supply the gas to the lighting knife (for example, using the cabin setting and the confession # 1 exit and: more connected and connected between the supply port and the opening and closing room, in > In this case (by being in the body; purifying, being exposed in the body & the body becomes stable 'In this case, a case, by making the ** use the light washing effect to make the state of the net swim 竑¥ # H Recycling and purifying the display materials and attaching them will become less. 7 people learn 7L first, for example, you can use oxygen or gas

V. Description of the invention (6) Inert gas such as gas. In particular, because helium is safe, and when using illuminating light in a wavelength range of about 150 nm or less, the transmittance is high and the thermal conductivity is about 6 times that of nitrogen, which is excellent for cooling the optical element. Further, for example, in the case where the helium-diffused air is recovered by the recovery device, the purification device and the oxygen absorbing material process the oxygen in the mixed gas, and nitrogen and helium can be separated by cooling, and the remaining helium can be extracted. Or by removing the generated liquid after cooling the mixed gas to the temperature of the liquid air, only the helium gas which is still a gas can be easily extracted. It is desirable that a plurality of exposure devices share a purification device. ‘This reduces the equipment cost of the purification device. Brief Description of the Drawings Fig. 1 is a schematic configuration diagram showing a part of a projection exposure apparatus and a helium cycle apparatus according to Embodiment 1 of the present invention. Fig. 2 is a schematic structural view showing a part of a plurality of projection exposure apparatuses and a helium cycle apparatus according to Embodiment 2 of the present invention. Fig. 3 is a schematic structural view showing a part of a main portion of a projection exposure apparatus according to a third embodiment of the present invention. Fig. 4 is a flowchart showing a purification process of a control device of a projection exposure apparatus according to a third embodiment of the present invention. Fig. 5 is a flowchart showing another purification process of the control device of the projection exposure apparatus according to the third embodiment of the present invention. Embodiments of the Invention Next, the present invention will be described in more detail with reference to the accompanying drawings. First Embodiment A first embodiment of the present invention will be described with reference to FIG. 1. This embodiment 1

Page 9 4 3 91 1 4 V. Description of the invention (7) " ----- It is applied to a projection exposure device which is used to supply most of the light path for the illumination light supply gas. FIG. 1 shows a schematic structure of a projection exposure / position and a helium cycle device of this embodiment. ^ ^ In Figure 1, the projection exposure t is set in the dust room on the floor F1 on a certain floor of the semiconductor manufacturing plant, and the supply building is set in the so-called Uti 1 ity Space on the floor F2 below. The above-mentioned projection exposure device is a helium circulation device that recovers and purifies helium. In this way, by installing a device that easily generates dust and is a source of vibration generation on a different floor from the floor on which the projection exposure device is installed, the cleanliness of the clean room in which the projection exposure device is installed can be extremely high, and The effect of vibration on the projection exposure is small. Further, the F2 laser light source 3 is arranged on the floor F2, so that the footprint (Footprint) of the floor F1 of the apparatus body can be reduced, and the vibration to the apparatus body can be reduced. However, because the helium gas is light and easily rises, the helium cycle device of this embodiment may be placed on the floor where the projection exposure device is installed. The supply device of the helium circulation device may be disposed on the floor F2, and the recovery device may be disposed on the floor F1 or above. Firstly, in a clean room on the floor F1, a box-shaped housing 1 is provided via the vibration isolation tables 2A and 2B, and a dagger laser light source 3 (a vibration wavelength of 1 5 7 nm) as an illumination source is provided in the housing 1, including A beam matching unit (BMU) 4 such as a movable mirror and the exposure main body for matching the light path of the illumination light in position and the light-shielding tube 5 passing through the interior. In addition, a box-shaped environmental chamber 7 with good airtightness is provided beside the casing 1. A platform 24 is provided on the floor F1 in the environmental chamber 7 via vibration isolation tables 25A and 25B for damping vibration from the floor. An exposure body portion 26 is provided on 24. Again

Page 10

V. Description of the invention (8) A secondary chamber 6 with good airtightness is provided from the tube 5 protruding from the housing 1 to the inside of the environmental chamber 7, and most of the illumination optical system is stored in the secondary chamber 6. At the time of exposure, the ultraviolet pulse light IL having a wavelength of 15 7 nm emitted from the F2 laser light source 3 inside the housing 1 passes through the inside of the BMU 4 and the tube 5 into the sub-chamber 6. In the sub-chamber 6, the ultraviolet pulse light il enters the fly-eye lens 11 through a beam shaping optical system composed of a variable light attenuator 8 serving as an optical attenuator, and lens systems 9A and 9B. The aperture system of the lighting system is arranged on the exit surface of the fly-eye lens 11 to perform various changes in lighting conditions. 2 ^ The ultraviolet pulse light of the predetermined aperture of the aperture system 12 after passing through the fly-eye lens 11 * The IL enters the fixed field of view diaphragm (fixed shielding) 15A having a slit-shaped opening in the mask shielding mechanism 16 through the reflecting mirror 13 and the condenser lens 糸 14. A movable mask 15B is provided in the mask masking mechanism 16 and the fixed mask 15A to make the width of the scanning direction of the illumination field variable. The masking mechanism 16 forms a slit-shaped ultraviolet pulse light I l through The imaging lens system 17, the reflecting mirror 18, and the main condenser lens 糸 19 illuminate the slit-shaped illumination area on the circuit pattern area of the photomask R with the same intensity distribution. In this embodiment, "the space from the exit surface of the light-shielding tube 5 to the main condenser lens 糸 · 19 is also sealed" and communicates with the space in the sub-chamber 6. Further, the helium circulation device from the downstairs supplies the temperature-controlled helium gas (He) having a predetermined purity or higher in the space in the sub-chamber 6 through the branch pipe 31a and the branch pipe 31b of the pipe 31 at two positions. An on-off valve V11 and an on-off valve V1 1 are provided in the piping 31, and the counter-rotation can be switched. The control system 45 is used to control the supply and

page 1

V. Description of the invention (9) Stop ° The on-off valve v 1 3 is also installed on the branch pipe 3 1 a of piping 3 丨, and the on-off valve ¥ 14 and the lighting system are set between the branch pipe 31b and the projection optical system. (Sub-chamber 6) An on-off valve ¥ 15 is installed. In addition, a temperature-controlled helium gas having a predetermined purity or higher in the outer casing 1 such as the F2 laser light source 3, the BMU4, and the like is supplied through the branch 31c of the piping 31 and the on-off valve V12. Therefore, at least one helium gas is required in the second subchamber 6 (lighting optical system) and the projection optical system PL by using the control system 45 to independently open and close the on-off valves V12 to n5. In addition, due to the small molecular weight of helium, which is liable to leak ', part of the helium naturally leaked from the sub chamber β rises and stays in the space 7a near the environment chamber 7. In the image of the ultraviolet pulse wave passing through the projected light gap-like shot area, the system's PL-based refractive material is limited. The projection light is k under the projection light and in the plane of the projection optical straight and the Y axis is taken. Under the illustrated light IL, the circuit pattern system PL in the illuminated area of the mask R is transferred to the slit of the photoresist layer on the wafer w. The exposure area is located on one of a plurality of shots on the wafer. Since the projection light of this embodiment and the glass-wood science system PL that can transmit short-wavelength ultraviolet light can also adopt the reflective refraction system or the reflection system, the transmission rate of the ultraviolet pulse light condition of the system PL is learned. Take the 2 axis parallel to the optical axis Ax of the PL of the c system, take the X axis parallel to the paper surface looking at the z axis, and perpendicular to the paper surface of the figure. At this time, the 'mask R is adsorbed and held on the mask table 2. On the photomask table 20, the photomask base 21 can be moved at a constant speed in the X direction (scanning direction 3 directions) and placed so as to be able to move slightly in the X direction, Y direction, and rotation direction. The second element position and rotation angle of the photomask 20 (photomask R) are determined by the laser interferometer.

Page 12 Fifth, the description of the invention ⑽) Control of the drive control unit not shown in the figure. In addition, the wafer W is fixed on the wafer table 23 by the suction retainer M, and the wafer is held on it. The wafer table 23 is automatic; 隹: The table 23 is placed on the platform 24 (position in the direction of the Z direction) and the inclination angle ~ ", 曰 .〆 Controls the focal position of the wafer W on the imaging surface of the PL, and enters the surface Aligning the steps of the projection optical system direction and the ， direction, the ^ -direction constant speed scanning and «and the rotation angle are made by the two-dimensional position of the laser dry round table (wafer 趵 23). During scanning exposure, The illumination area of the drive control unit that controls the IL not shown in the figure is + X ^^^ For the ultraviolet pulse light step by the mask table 20, the wafer is scanned at a speed of ^ by the wafermaker at a speed of ^) and the exposure area is at a speed of + x direction (or -X square drawing. (point is the projection magnification from the mask R to the wafer W) = = number of chambers 6J: sample = the inner ring device of the lens barrel in the projection optical system The space for gastroscopic pain) The whole is also from the temperature control i above the helium cycle downstairs = the branch pipe 31b and the on / off valve ¥ 14 supply the predetermined purity but also rise and stay in ί =. Since the lens tube of the projection optical system leaks out Oxygen, in addition, from the floor ;: space 7a near the ceiling of room 7 Circulation devices (38 ~ 40, 82 ~ 88, 95, etc.) are supplied for ν. The courtesy oxygen content is suppressed to be extremely low and the temperature is controlled by nitrogen (the exhaust gas of n V = the gas of the chamber ring, for example, through the bottom surface of the environmental chamber 7 to The piping 95 and its on-off valve V19 connected to the nitrogen circulation device on the one side are returned. In this embodiment, from the F2 laser light source 3 to the main condenser lens, the 13th page of the invention 43 91 1 4 88117652_1〇 ^ / Month / f The optical path of the ultraviolet pulse light IL up to 甬 糸 19 and the optical path of the ultraviolet pulse light IL in the projection optical system PL are provided for helium with a high transmittance even for light below about 19.0 n in. In addition, for the self-condensing lens 糸 19 to the incident surface of the projection optical system PL, and from the projection surface of the projection optical system PL to the surface of the wafer $, the light transmittance is not good for light below about 190 nm. However, since the light path passing through the nitrogen gas is extremely short, the absorption amount of nitrogen gas is extremely small. Therefore, the ultraviolet pulse light IL emitted from the F2 laser light source 3 reaches the wafer with high transmittance (utilization efficiency) as a whole. The surface of W; can shorten the exposure time 'The output in the exposure process is increased.' Also, because the heat transfer coefficient of helium is about 6 times higher than that of nitrogen, the optical elements in the illumination optical system and the optical elements in the projection optical system pL are stored due to the irradiation of UV ^ pulse light IL The heat energy of the helium gas is transmitted to the outer cover of the chamber 6 and the lens barrel of the projection optical system PL through the helium gas. The heat energy of the outer cover of the sub-chamber 6 and the lens barrel of = = uses the temperature-controlled air in the ballastless room. Or the temperature-controlled nitrogen in the clothes from 7 to downstairs and other ancient = manufacturing KI light: system and projection optics track: the temperature of the optical element: suppression = very low 'imaging performance degradation is suppressed due to helium The change in refractive index for air-dust changes is smaller than the J limit. This is because the content of —k A + 1 is extremely small. For example, the refractive index change in the PL of the Jiuzi system is maintained at this point. Very small amount, stable imaging performance. Next, the helium cycle of this embodiment will be described in detail. Straight inside A, because the helium leaked from the auxiliary chamber 6 and the nitrogen in the soil area to 7 gas ratio nitrogen 轫, bucket; · * α Only the helium leaked by the helium leaked from the Beijing / Jiu Xue System PL tc disorder I, rising and stayed In the ring 7 | θ, ^ p ^ 7 Brother < The space system in the space near the ceiling ^ In addition to helium, the gas system is mixed with an atmosphere or

4 3 9 3 1 4 V. Description of the invention (12) A mixed gas of air entering from the outside of the environmental chamber 7. In this embodiment, from the outside of the environmental chamber 7 and the space 33, the piping 33 passes through the opening provided on the floor F1, and communicates with the arrangement / location downstairs. In addition, the casing 1 is connected to each installation 92 by a pipe 92 and a pipe 33 to provide an opening and closing chamber V16. Furthermore, the illumination optical system (the auxiliary chamber and the system PL are also connected by piping 93, 94 and piping 33. On and off, the on-off valves V17 and m are automatically installed. Therefore, by using the control; each is independent Opening and closing the opening and closing room v18, can be from the shell Bu-two systems (sub-chamber 6) and the projection optical system pL required less stone and one door _ etc .. Line plate η: Recycling two sets of inhalation outline Or fan), the mixed gas sucked by the pipe 33 and the fruit 32a flows to the helium circulation device downstairs. And the mixed gas that has reached the dust collection and drainage device 35, in order to avoid the k-surface heat insulation compression The cooling path is blocked to remove a small amount of dust and moisture. "The mixed gas that has passed through the dust collection and drainage device 35 reaches the freezing device 37 through the pipe 36. Here, the use of heat insulation compression cooling to cool to liquid nitrogen temperature is a technology. Therefore, because of Nitrogen and air solitary components are liquefied, and the liquefied components including air and gaseous helium can be easily separated. The main components of the liquefaction in the refrigerating unit 37 are collected in a high-pressure container 40 through a pipe 38 and a suction pump disposed in the middle thereof. Air gas such as radon gas vaporized in the high-pressure container 40: for example, it can be re-sharpened (recycled). Meanwhile, the helium gas still in the refrigerator 37 flows through the pipe 41 and the suction pump (or wind) 42 arranged in the middle to the inlet of the mixing temperature control device 43.

'q A No. 88117 阽 2_ Year, month, day, and year 1 (1) Explained in addition (13) In addition,' Using the dust collection and drainage device 35 'Refrigerator 37 and other components constitute air, nitrogen, and other impurities that separate and remove impurities from helium Purification device for pollutants, but it is better to install and separate and remove the pollutants that remain in the front section (pipe 36) or the rear section (pipe 4i) of the freezing device 37, which can not be separated and removed by those devices, and regenerate high purity. Helium is also suitable for single or combined devices such as chemical filters for separating and removing polluting substances contained in helium, other filtering devices, and separating devices that use different chemical properties of helium and polluting materials. In this embodiment, a removing device 80 for removing impurities contained in the mixed gas is provided between the dust collecting and draining device 35 and the refrigerating device 37. The removal device 80 is an activated carbon filter (for example,？ ー v ー — ー v ー v ー v ー v ー v ー 文 ー ー), or a zeolite filter, or a combination of these. It removes the environmental chamber 7, the illumination optical system, and the projection optical system PL. Internal silicon such as siloxane (substances with Si — 0 chain as axis) or silazane (substances with Si —N chain as axis) have organic components! ί Here, the silicon-based adhesives, sealants, and coatings used in projection exposure devices, which contain Si—0, which is one of the series of siloxanes, become cyclic “ring siloxanes”, which are released due to aging. gas. Toroidal siloxanes are easily attached to the surface of photosensitive substrates or optical elements (lenses, etc.). They are also oxidized when they are exposed to ultraviolet light and become silicon dioxide-based frosting substances on the surface of optical elements. In addition, there is tiMDS (Hexamethyl disilazane) which is used as a pre-processing chamber agent in the photoresist coating process on the silamine. HMDS reacts with water and changes (hydrolyzes) to silanol. Silicone alcohol easily adheres to light

2a30-2829-PFl-3tc Page 16 V. Description of the invention (u) — ------ The surface of the learning element, etc. When the ultraviolet light is irradiated, the oxygen is formed on the surface of the prior learning element. Frost substance. In addition, in the case of silicon, ammonia is generated during the above-mentioned hydrolysis, and when the helium and siloxane coexist, the optical element is reduced, and the surface is more easily blurred. ^ / However, after cleaning and separating organic matter (hydrocarbons) attached to the surface of the illumination optical system or the projection system, etc., it is mixed with helium to remove it by using a removing device 80 in this embodiment. This hydrocarbon compound D, in addition, the above-mentioned silicon-based organic substances also generate plasticizers (phthalates, etc.), fire retardants (phosphoric acid, Gaseous substances), etc. However, in this embodiment, some plasticizers, flame retardants, etc. are also removed by the removing device 80. In addition, ammonia ions or sulfate ions floating in the dust chamber enter the environmental chamber 7 and these high-pressure vessels 46 that remove / self-enclose high-purity helium gas at high pressure 46 are removed by a removing device 80. The piping 47 f opens and closes the valve 48. High-purity helium gas is supplied to the second inlet of the mixing temperature control device 43. In addition, the liquefied helium can also be stored in the high-pressure container 46. A helium ion · degree sf 4 for measuring the concentration (or purity) of helium is also provided near the inflow port for mixing temperature adjustment 43 in the piping 4 through which the helium purified by the freezing device 37 is passed. 4 'Supply control system 4 5 This measurement data. The control system 45 opens and closes the on-off valve 48 when the recovered helium concentration measured with the helium concentration "10-4 4 does not reach a predetermined allowable value", and supplies high-purity helium in the mixing temperature control device 43 from the high-pressure container 46. And when the helium concentration measured by the helium concentration meter 4 4 exceeds its allowable value, the control system 4 5 closes the on-off valve 4 8. Further, the 'on-off valve 48 is closed while the exposure operation is not performed. Alternatively, an oxygen concentration meter can be used instead of helium

Page 17 V. Description of the invention C15) '---- Concentration meter 44. Also 'For the impurities not shown on the drawing, set the dust collection and drainage device 35 and the freezing device 37 to the purification device near the inlet (= oxygen concentration sensor or random concentration sensor), and the supply control system 45 $ = Measurement result of concentration sensor. The factory piping of the flow path switching valve (not shown) is connected between the pump 34 and the purification device. The control system 45 switches the flow path switching valve according to the measurement result of the parallel concentration sensor. ..., Qiao Bei

In addition, when the control system 4 5 according to the measurement result of the impurity concentration sensor shows that the recovered gas contains impurities that are above the predetermined value, the flow path of the collected gas is switched from the purification device to the factory piping. The exhausted gas is discharged through the factory piping. On the other hand, when the concentration of the impurities contained in the recovered gas becomes lower than a predetermined value, the control system 45 replaces the recovered gas from the piping ^ with a purification device to purify the gas. The situation where the recovered gas has a large amount of impurities is that after the exposure operation is stopped / fixed for a certain period of time, the light constituting the illumination optical system and the projection optical system ^ is immediately exposed to the light. Because immediately after exposure to light, impurities of organic matter stored on the surface of the optical element within a certain period of time should be decomposed by washing with light. Therefore, when the gas recovered from the space contains miscellaneous shellfish exceeding the range of the purifying device reconciliation and purifying valley, not only the life of the purifying device is shortened but also the purifying efficiency of the purifying device may be deteriorated. Therefore, if the impurity concentration of the gas supplied to the purification device is not monitored as described above, the gas corresponding to the impurity concentration of the supplied purification device and the allowable range of purification can be discharged through the factory piping if the allowable range is exceeded. Can improve the life and purification efficiency of purification equipment.

V. Description of the invention (16) In addition, the 'hybrid temperature control device 43 mixes the purified helium with the helium from the high-pressure vessel 46 to a predetermined temperature within a predetermined pressure range, and the supply pipe 31 is subject to temperature control and pressure control. Of helium. The helium circulation device of this embodiment is constituted from the dust collection and drainage device 35 to the hybrid temperature control device 43. Also, "Pair Officer 3 1 passes through the opening on the floor F above and arrives in the clean room above" and is in the middle of the piping 31 and on the floor? A pump (or fan) 32 for air supply is provided on the bottom surface side of 1. On the other hand, after the helium gas supply pipe 31 is controlled by the hybrid temperature control device 43 within a predetermined air pressure range, a predetermined concentration or more, and controlled to a predetermined temperature, the branch pipe 31a of the pipe 31 passes through the pump 31 while the air is supplied by the pump 32. 31b and 31c are supplied into the housing 1 of the projection exposure apparatus on the floor F1, the sub-chamber 6, and the projection optical system pl. Here, in the present embodiment, the control valve 45 is used to close the on-off valve VII of the piping 31, and the on-off valves V16 to V18 of the piping 92 to 94 are opened. The pump 34 is sucked into the casing 1, the sub-chamber 6, and the projection optics. Gases in the system PL (helium, etc.). At this time, in order to prevent the mixed gas in the upper space 7a of the environmental chamber 7 from flowing into the pipe 33, it is desirable to close an on-off valve (not shown in the figure) provided near the inlet of the pipe 33 in advance. Then, the opening and closing valves VI 6 to VI 8 are closed, and the opening and closing valves V11 ′ are supplied to the housing 1, the sub-chamber 6 and the projection optical system PL helium, respectively, and the opening and closing valves are sequentially closed as the helium concentration in the inside reaches a predetermined value. After V12 ~ V15 go down, the on-off valve V11 is closed after all the on-off valves V12-V15 are closed. Although not shown, a helium concentration meter or an oxygen concentration meter is provided inside the casing 1, the sub-chamber 6, and the projection optical system PL, and the control system 45 controls the opening and closing of the on-off valves V1 2 to V15 according to the output of the concentration meter. Also, in one of the housing 1, the sub-chamber 6, and the projection optical system PL, for example, in the projection optical system

Page 19 V. Description of the invention (17) ------ ^ 'When the helium concentration of PL becomes lower than the predetermined value, open the on-off valve V1 1' to supply gas. At this time, “the overall control of the projection exposure device” (not shown in the figure) is recognized as the action of the device body. For example, during the processing of the crystal system, the main control system sends an instruction to the control system 45 so that the second exposure process is completed. I have been waiting to start supplying helium. % ^ Therefore, in this embodiment, it is supplied as if it flows in most of the light path of the projection exposure device (Ultraviolet Pulse Light IL);: Nine minutes from the upper part of the loop through the pipe 33 from the downstairs V: Putting most of your mouth closed can reduce the use of expensive helium gas *. Therefore, after increasing the transmittance for the Huizhao Ming and cooling efficiency of the optical components, it is possible to reduce the operating cost of the light device. In addition, in the above-mentioned embodiment, a cold-steaming and temperature-adjusting device 43 in Fig. 1 is also provided to store the recovered strips, and this C is, for example, the above-mentioned gas high-pressure container. 4〇) It is also possible. Here is $ 7 丨 month / fan. In order to store a large amount of Weige, I hope that the compressor will compress the helium to about 1001200 atmospheres and store it in the high-pressure container. Therefore, the volume is reduced by 1/1 00 to 1/200. In addition, helium can be liquefied using a liquefaction machine using a turbine or the like and stored. Liquefaction can reduce the volume of helium to about 1 1/700. Therefore, "When reusing highly compressed or liquefied helium, for example, when returning to a state of about one atmosphere of pressure, the temperature decreases due to expansion, and heating temperature management using a heater or the like is required." Value buffer space. An on-off valve may also be provided before (upstream side) of the mixing temperature control device 43 so as to adjust the amount of helium taken in from a tall house container (not shown) storing the recovered helium, or control the flow path ( Opening and closing of piping 41)

Page 20

5. Description of the invention C18) is also available. The helium concentration supplied to the pipe 31 is adjusted by combining the on-off valve and the pipe 47 together. The opening / closing valve 48 can be more easily provided in the above-mentioned embodiment, such as supplying helium gas to the light of the illumination light, but also to cover most of the light path = the flow-through cover · table 20 or wafer table 23 Cooling rate # 'and also improve the overall helium in the light 7 "In this case, the field' makes the supply of environmental room gas' operating costs go up very little D, and in Yue Yue @ 收 ^ most of the helium adjustment The embodiment of helium and high purity purified by the temperature device 43 will reduce the concentration of helium mixed and purified. In the case of mixing two alone, the combination of helium and helium will increase rapidly to Content: It is not possible to supply and invest, and the purified helium can be stored in another high-calorie container ^. After the purity is increased, the high-purity helium in the high-pressure container 46 of the projection exposure device can also be supplied. In addition, in the above-mentioned projection exposure apparatus, 'the opening, closing valves V11 to V 1 8 are used to fill (enclose) helium into the housing 1, the sub-chamber 6, and the projection optical system PL. However, in this embodiment, since a helium circulation device is included, for example, When the on-off valves VI 6 to Y18 are closed, the flow of helium can be adjusted according to the amount of helium leaked from the housing 1, the sub-chamber 6, and the projection learning system PL. The supply can also be made, or the on-off valve can be opened. VI Bu V1 8 always with a set flow

"Supply gas" is OK. In this case, the shell worker, sub-chamber 6, and projection optics, in this case, as long as the helium gas 2 f 'in each space of the measuring space or the detector or the oxygen concentration system PL is configured to reach the allowable value, it is felt that Detector to monitor the helium / brother in each space in advance, that is, to suck in each space. If the habit of reducing the helium wave in each space >

V. Description of the invention (19) The light-absorbing substance (oxygen or organic impurities, etc.) receiving the exposure light may be above a predetermined value. Instead of supplying the purified helium, as long as high-purity helium is supplied from the high-pressure container 46, can. When high-purity helium gas is supplied from the high-pressure container 46 and the helium concentration in the space has not reached the predetermined value, an alarm may be issued to notify the operator of the message or expose the helium gas in the space due to the possibility of a large leakage. The device may stop automatically. In addition, the pipes 92 to 94 (and the on-off valves VI 6 to VI 8) that connect the housing 1, the sub-chamber 6, the projection system 5 PL, and the piping 33 may not be provided. In this case, the on-off valves V11 to V1 5 may be further omitted. In this case, since helium gas leaks from the housing 1, the sub-chamber 6, and the projection optical system PL, in order to supplement it, that is, to maintain the helium concentration above the allowable value, the helium gas may be supplied continuously or at any time (periodically). In addition, in this embodiment, the F2 laser light source 3 and the BMU4 are stored in the housing 1, but the BMU4 and the like are stored in a separate housing from the F2 laser light source 3, and the F2 laser light source 3 and the helium are also supplied to the housing can. At this time, a glass plate which is mechanically connected to the F2 laser light source 3 and the casing and serves as a partition between the F2 laser light source and the housing may be provided. The exposure device described above is installed in a clean room. However, it is desirable that the air pressure of the housing 1, the sub-room 6, and the environmental room 7 be higher than the air pressure in the clean room. By doing so, impurities in the clean room can be prevented from flowing into each space. The air pressure in the sub-chamber 6 and the projection optical system PL housed in the clean room is set higher than the air pressure in the environmental chamber 7. Since a driving mechanism such as a mask table or a wafer table is arranged in the environment room, it is possible to prevent impurities generated from these driving mechanisms from flowing into the sub-chamber 6 and the projection optical system PL. Next, the nitrogen cycle device of this embodiment will be described in detail. In this implementation

Page 22 43 9114 V. Description of the invention (20) For example, the nitrogen gas in the environmental chamber 7 is supplied through the pipe 88, and the nitrogen gas recovered from the environmental chamber 7 through the pipes 95 and 33 is used to circulate the nitrogen in the environmental chamber 7. In addition, when the nitrogen content in the environmental chamber 7 reaches a predetermined value, the nitrogen supply is stopped, and the on-off valve ¥ 23 (or ¥ 24, V25) and v19 are used to close the piping 88 (or its branch pipes 88a, 88b) and piping 95, When the nitrogen concentration in the environmental chamber 7 is lower than a predetermined value, the on-off valve V23 (or V24, V25) is opened, so that nitrogen can be supplied. The nitrogen gas that has been separated from the freezing device 37 and helium gas is recovered by the pump threshing device 40 through a pump 39 through a pump 39. In addition, the nitrogen moonlight pump 83 in the high-moving container $ 〇 is sent to the temperature adjustment device 86 after passing through the pipe 81 ^ Set the opening and closing selection V21 'in the pipe 8 and set the measurement to the temperature adjustment device 86 (or oxygen concentration) 2. For the measurement value of $ densitometer 82; control 糸 45 when the nitrogen concentration measured by the densitometer 82 does not reach the predetermined value, hit Geng, the nitrogen high-pressure container 84 and the piping 85 of the temperature control device 86, the on-off valve V22 ', Self-pressurizing vessel 84 supplies high-purity nitrogen gas from temperature control device 86. When the nitrogen concentration measured by the thick shoulder meter 82 is extremely low, you can also close the on-off valve V2i and send nitrogen to temperature control device 86. *, in The tachometer 8 Γ ”= Γ Λ is selected to open and close the valve V21 when the allowable value (less than the predetermined value above) is set. In addition, the 'temperature control device 86 mixes the recovered nitrogen from the high-pressure container 84 to a predetermined value. F pressure m tube 88 is controlled by temperature and force. "A pump for air supply (or wind) is installed on the bottom side of floor F1 in the middle of piping ^. Use this pump 87 to branch pipe of piping 88 ―, 8 讣Supply, gas 0 one

Page 23 439114 V. Description of the invention (21) In this embodiment, an outlet of a branch pipe 88a is provided between the projection optical system PL and the wafer W, so that nitrogen gas flows between the projection optical system PL and the wafer W. Further, the branch tube 88b is branched into two branches, one of which is disposed between the condenser lens 19 and the mask R, and the other is disposed between the mask R and the projection optical system PL. Therefore, in this embodiment, high-purity nitrogen can be preferentially supplied between the illumination optical system (condensing lens 糸) 19 and the projection optical system PL, and between the projection optical system PL and the wafer w, and in the environmental chamber. 7 Compared with the case where nitrogen is filled and the concentration is maintained above a predetermined value, the amount of nitrogen supplied can be reduced. In addition, a plurality of discharge ports arranged between the condenser lens 糸 19 and the mask R and a plurality of discharge ports arranged between the projection optical system PL and the wafer W may be used. Also in this embodiment, the nitrogen gas supplied between the condenser lens 9 and the mask r and between the projection optical system PL and the wafer W is recovered from the environmental chamber 7 through the pipes 95 and 33. However, the condenser lens 糸 丨At least one recovery pipe for gas recovery may be provided between 9 and the mask R, between the projection optical system PL and the wafer W, and the pipes 9 5 and 3 3. In this embodiment, the environment chamber 7 is set to a nitrogen atmosphere, but for example, air is removed from the environment chamber 7 and impurities are supplied between the illumination optical system and the projection optical system pL and the projection optical system pL and Nitrogen is used between the wafers, and the two spaces may be set to a nitrogen environment. In this case, helium may be supplied instead of nitrogen. In this case, it is not necessary to provide a nitrogen circulation device such as connecting the piping 3 3 and the branch pipes 8 8 a '8 8 b and supplying helium to the two spaces respectively. In addition, as the air supplied to the environmental chamber 7, chemically clean dry air (for example, humidity

Page 24 43 911 4 V. Description of the invention (22) 5% or less) is also acceptable. In addition, this structure is particularly effective for a projection exposure apparatus using an ArF Excimer laser as an exposure light source. In this case, it is possible to supply nitrogen to the housing 1, the sub-chamber 6, and the projection optical system pL, or to supply nitrogen to the housing 1, the sub-chamber 6, and PL helium to the projection optical system. The compressor may compress the recovered nitrogen gas to about 100 to 200 atmospheres, or store it after liquefying it using a liquefaction machine using a turbine or the like. In addition, the V24 and V25 series of latches provided on the branch tubes 8 8 a and 8 8 b respectively make it possible to supply and supply only between the illumination optical system and the projection optical system pL, and between the projection optical system PL and the wafer. In the case of one of the two, if the two spaces are supplied with nitrogen at the same time, the on-off valves V24 and V25 may not be provided. In this embodiment, the nitrogen gas is caused to flow between the illumination optical system and the projection optical system PL, and between the projection optical system P1 and the wafer. However, it is not the same as that of the cutter blades 88a, 88b, but only the pipe 88. Connected to the environmental chamber γ 'When the helium concentration in the environmental chamber 7 becomes a predetermined value or more, the on-off valve V23 may be closed. In addition, regardless of the presence or absence of the branch pipes 88a and 88b, nitrogen gas may be supplied at a predetermined flow rate under the opening / closing valves V 2 3 and V 19 to circulate the nitrogen gas in the environmental chamber 7. In this case, in particular, the on-off valves V23 and V19 may not be provided. In this embodiment ', nitrogen gas (helium gas) or the like supplied to the environmental chamber 7 is used, but only the chemically clean and temperature-controlled air in the environmental chamber 7 may be supplied depending on the wavelength region of the exposure illumination light. For example, if the exposure wavelength is about 1 90 nm or more, the environment in the environmental chamber 7 may be an air environment. In this embodiment, most of the illumination optical system is stored in the auxiliary room.

Hi P.25 Fifth, the description of the invention (23) 6, a part of the auxiliary room 6 is provided in the environmental room 7, but for example, the auxiliary room 6 may be entirely provided in the environmental room 7. In this case, the recovery rate of the helium gas leaked from the auxiliary chamber 6 can be improved. In order to recover helium leaked from a part of the sub-chamber 6 provided outside the environmental chamber 7, the sub-chamber 6 outside the environmental chamber 7 is covered with a casing, and the pipes 33 and the upper part of the casing may be connected. In this embodiment, a single gas (nitrogen, helium, etc.) is used to supply the housing 1, the sub-chamber 6, and the projection optical system PL, respectively. However, for example, a gas in which nitrogen and helium are mixed at a predetermined ratio may be supplied. In this case, the piping 31 of the helium cycle device may be connected to a nitrogen cycle device downstream of the on-off valve VI1. The mixed gas is not limited to a combination of nitrogen and helium, and may be a combination of neon and hydrogen. The above-mentioned mixed gas may be used in the gas system supplied to the environmental chamber 7. Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG. 2. The second embodiment uses a helium cycle device to purify helium gas from a plurality of projection exposure devices. In Fig. 2, parts corresponding to those in Fig. 1 are assigned the same reference numerals, and detailed explanations are omitted. In addition, pipings 9 2 to 9 4 respectively connecting the housing 1, the sub-chamber 6 and the projection optical system PL and the piping 33 are shown in FIG. 1, and the piping 95 connecting the environmental chamber 7 and the piping 33 is omitted. The matters described in the second embodiment that are not described in the second embodiment are also applicable in the second embodiment. Fig. 2 is a sectional view showing a plurality of projection exposure apparatuses and a helium cycle apparatus according to this embodiment. In FIG. 2, a plurality of environmental chambers 7A, 7B, and 7C are provided on the floor F1, and an exposure main body part corresponding to the exposure main body part 26 of FIG. 1 is provided in each of the environmental chambers 7A, 7B, and 7C, and is close to the figure Illumination light not shown

Page 26 V. Description of the invention (24) Source configuration. Moreover, helium gas of a predetermined purity or higher in the environmental chambers 7 A, 7 B, and 7 C is supplied from a helium supply device (not shown) on the lower floor. The mixed gas of helium, air, and nitrogen supplied to the environmental chambers 7A, 7B, and 7C and rising to the space near the ceiling inside is led to the common pipe 49 through pipes 33A, 33B, and 33C, respectively. The common pipe 49 communicates with the helium circulation device on the floor F2 below after passing through the opening of the floor F1. The bottom side of the floor F1 of the common piping 49 is provided with a suction mill 3 4 ^ A helium circulation device downstairs, a mixed gas of helium, nitrogen, and air recovered through the common piping 49 and the suction pump 34 The refrigerating device 37 is reached through the dust collecting and draining device 35, and the nitrogen gas liquefied in the refrigerating device 37 is sealed in the high-pressure container 40. In addition, the helium gas that has not been liquefied in the refrigerating device 37 is more purified by using a chemical filter in the figure, and the piping 4 丨 and the suction week pump 42 are sealed in a high pressure container 5 for storing helium after being compressed with a pressure of w . This helium gas is supplied through a pipe 51 of a high-pressure vessel through a regeneration plant or a helium supply device as shown in FIG. 1 to improve purity. As shown in the above-mentioned embodiment (shown in the description of FIG. N, the helium return device, 34 ~ 42, 49, 5G, 8G in FIG. 2) also has a nitrogen recovery device (Xiao, connected to a plurality of projection exposure devices and The eye diagram of a nitrogen supply device = the piping 81 corresponds to the piping 88 in the order of symbols), and the profit supply device supplies a plurality of high-pressure vessels of the projection exposure device to store nitrogen. Therefore, a plurality of projection exposure devices can be used in common; Therefore, in this embodiment, since a plurality of exposures can be processed, a helium cycle device and a nitrogen cycle device can be used to reduce purification W.

V. Description of the Invention (25) Embodiment 3 The embodiment of the invention will be described with reference to FIG. 3. This embodiment 3 specifically discloses a structure in which lens units (projection lens units) constituting a part or all of the projection optical systems PL in the first and second embodiments (projection lens units) are purged with helium and actively cycled. The matters described in the third embodiment which are not described in the third embodiment are also applicable in the third embodiment. In FIG. 3 ′, three lenses 6 3, 6 4, and 6 5 are arranged at predetermined intervals in the lens barrel 62 of the projection lens unit 6 丨 and fixed by the pressing ring 6 6. 6 7 is a lens separation ring used to hold the lens 6 4_ and the lens 65 at predetermined intervals. Actually, the 'projection lens unit 61 includes a plurality of lenses, but FIG. 3 shows three of them for simplicity of explanation. The lens chambers R1, R2 are divided between the lenses µ, 64 and between the lenses 64, 65 by using these lenses and the inner wall of the lens barrel 62. The lens chamber R1 is provided with a gas supply port G1 to which a quick coupler is installed and a gas discharge port G2 to which a quick coupler Q2 is installed. The lens chamber R2 is provided with a gas supply port G3 to which the quick coupler Q3 is installed and a gas discharge port G4 to which the quick coupler Q4 is installed. One end of the piping L1 is connected to the output side of the pump controlled by the control device 71 or the supply device 72 constituted by a control valve, etc., and the other end of the piping L1 is branched into an upper branch. One of the piping L2 is connected to the gas supply port G1. The other pipe L3 is connected to the gas supply port. The piping [2 and piping L3 are respectively inserted with an on-off valve (control valve) Vi, which is controlled by the control device 71. One end of the pipe L4 is connected to the input side of the purification device 73, and the other end of the pipe L4 is branched into two branches. One of the pipes L5 is connected to the gas discharge port G2, and the other pipe L6 is connected to the gas discharge port G4. Insert pipe 15 and pipe L6 separately from

Page 28-~ SS__BJJ652_Year Month Date 傣 正 ___ V. Description of the invention (26) On / off valve (control valve) controlled by control device 71 ¥ 2 '^ 4. The output side of the purification device 73 is connected to the input side of the supply device 72 via a pipe L7. The other input side of the supply device 72 is connected to a high-pressure container 74 to which high-purity helium gas has been injected via a pipe [8]. / Yinhua device ί 3 is a device that separates and removes the polluted substances (solid particles, liquid particles, and gas) contained in the helium gas that is input as purified gas, and regenerates helium gas with a purity of south. The monomers or combinations of chemical filters, other filtering devices, and separation devices that use the differences in chemical properties of helium and polluting substances, as shown in the following examples, constitute the pollutants to be separated and removed. For example, the gases or impurities contained in the lens chambers R1 and R2 of the projection lens unit 6i originally, molecules of organic substances generated from adhesives or filling materials used to fix optical elements such as lenses to the lens barrel, Impurities (such as water molecules, hydrocarbon molecules, or other substances that diffuse illumination light) generated on the inner wall of the lens barrel (painting surface for anti-reflection), and cleaning liquid remaining on optical elements, etc. (Ether, water, etc.) vaporized, and these substances produced by reaction with illumination light, etc., and these surfaces condensed and attached to the lens due to illumination light The above-mentioned silicon-based organic substances, plasticizers, and fire retardants that float and float due to the light-washing effect caused by radiation are used as purification devices suitable for separating, removing, and other substances. ^ In addition > As the chemical filter used in the purification device 73, an ion exchange resin such as an ion exchange fiber, which is a filter for removing ions, can be used. The surface area and the reaction speed are large, and the forming process is easy. It is more suitable to change the fiber. Ion exchange fibers such as polypropylene fibers

43911 4 V. Description of Invention (27) ---- Manufactured by radiation graft polymerization. In addition, adsorption materials such as activated carbon, silica gel, and zeolite can be used for removing moisture. · The gas-first control device 71 controls the supply device 72, the purification device 73, and the micro-computer and other devices composed of two systems to perform the purification process according to the appropriate timing. It has previously memorized the mechanism including the purification process. Control data storage device 75. After making the control data as the most effective in experience and experiments, the memory is set to 75 memories ^ In addition, 5 Ji Yi device 7 5 memory exposure device operation time, Zhao Mingguang for the illumination optical system or projection optical system The exposure history such as the irradiation time or the time when the illumination light is not emitted may also be used. For example, the same situation is made after the lens unit has been assembled. As shown above, contaminated substances caused by adhesives, fillers, coatings, or purifying agents are condensed and attached to the surface of the shovel = light transmission. The overall or partial reduction of the rate tends to be higher, and the control data is made like "dagger processing." Furthermore, because this phenomenon tends to gradually decrease as the operation progresses, the number of purification times decreases with the operation time. If a certain amount of operating time has elapsed, ^ make control data as if the purification process is relatively loose and regular. According to the control data created in this way, the control device 71 performs the processing shown in the flow chart of _ 4 ^. First, the self-memory device 75 reads the control ST 1), and judges whether it is time to perform the purification process (ST2) according to the information on the time when the purification process is performed, and when it is time to perform the purification process, it is preliminary. Irradiate the illumination light, and use the light f effect of the external light to float the pollutants attached to the surface of the lens (ST3). Consider the operation time of the past exposure device, that is, the illumination light For optical systems

1 4 L.tM ·... 88117652 Invention ^ 28) The exposure time such as the irradiation time or the time when the illumination light is not irradiated is determined after the exposure time. In addition, when the illumination light is preliminarily irradiated, a gas such as ozone that promotes the light-washing effect may be supplied. In the state up to the seventh point, 'the opening and closing valves V1 to V4 of the projection lens unit 61 are closed.' Here, the opening and closing valves VI to V4 (ST4) are opened, and the supply device 72 and the purification device 73 are operated, and the helium gas is circulated. The purification starts (ST 5). ^ That is, "the supply of pipes LI, L2, L3 from the high-pressure vessel 74 by the supply device 72 or one of the helium gas purified by the purification device or a mixture thereof" will each lens room of the projection lens unit 61 The inside of R1 and R2 is replaced with clean helium. Gases including the floating pollutants that have been present in the lens chambers R1 and R2 of the projection lens unit 61 until now are recovered through the pipes L5 and L6 'L4 and sent to the purification device 73. Separation by the purification device 73: After removing the pollutants contained in the nitrogen gas, the purified gas is randomly transported to the supply rack 72 'or lower through the pipe 1 ^, and helium gas circulation is performed. Then, according to the information on the time for purification treatment (the time since the opening of the mouth) set in the control and control data, it is judged that the purification has started (ST 6), and the supply will be stopped when the predetermined time has passed. The device 72, the paint bucket key is less red, CT7, Βθ ^ Fan 'stop-annualization device 73 operation (ST7), close VH4 (ST8) when enlightened, and end the purification process. 1 Opening and closing valve The above-mentioned control system 71 is used to perform purification processing. The control system 71 previously memorizes and holds the control data stored in advance. The system is shown in Figure 5. It is also possible to measure the light transmittance after measuring the light transmittance. Once it is controlled like a purification process. An illuminance sensor for detecting the illuminance of the illuminating light is set at the stage where the condition of the wafer wood as the object of exposure is maintained (wafer of detection ^ ^ Ψ \ 7 R,

Five instructions for clear instructions ^ (29) 88117652 January, 2011 Corrected the illuminance of the monitored light, and after detecting the light transmittance (S T1), 'compare the amount of change in the detected light transmittance with the memory device 7 5 It is assumed that the predetermined value of memory retention (ST2) is used when the detected light transmittance fluctuates more than the predetermined value. 'Preparative irradiation of illuminating light, washing with ultraviolet light, causing attachment to lenses, etc. Contaminants float on the surface (ST3). The time when the illumination light is preliminarily damaged by the difference between the change in the transmittance of the detected light and the predetermined value memorized and held by the memory device. That is, when the amount of variation is large, the irradiation time becomes long; when the amount of variation is small, the irradiation time can be short. In the state so far, the opening and closing valves VI to V4 of the projection lens unit 61 are closed, and here, the opening and closing valves VI to V4CST4 are opened, so that the supply device 72 and the purification unit 73 are operated, and the circulation and purification of helium begin ( ST5).

That is, using the supply device 72 to supply the pipes LI, L2, and L3 from the high-pressure container 74, the new helium gas, or the helium gas purified by the R & D purifying device, one of the following: the mixture thereof will be the lens chambers R1 of the projection lens unit 61. Replace the internal $ of R2 with clean helium. Through the pipes L5, L6, and L4, the floating two including the lens chambers R1 and R2 existing in the lens chamber 61 of the projection lens unit 61 are recovered, and the material gas 5 is sent to the purification device 73. By using the purification device 0, the helium gas is separated and removed, and then 77 helium gas is sent to the supply device 72 through the distribution 7, and the helium gas cycle is performed as follows. Next, the illuminance sensor 76 on the wafer table is used to detect the light transmittance (ST6). 'The detected light transmittance is compared with the predetermined value C and stored in the memory device which is preset and retained. In ST2, the value used is the same or smaller than the predetermined value) (ST7) 'When the variation of the detected light transmittance does not exceed the predetermined value (small case), stop supplying the device 7 2 and Purification

V. Description of the invention (30) Operation of the device 73 (ST8) ′ Close the on-off valves VI to V4 (ST9) ′ Jiedong purification treatment. In the processing shown in FIG. 5 'in ST1 and ST2 or ST6 and ST7, after the illuminance is detected by the illuminance sensor provided on the wafer table,' the variation of the light transmittance is calculated, and the value of the transmittance is calculated. The change f is compared with the preset value. However, a non-sensor for detecting the illuminance distribution of the illumination light is provided on the wafer table. The difference between the maximum and minimum values of the detected illuminance distribution can be compared with the preset value. Set the comparison value to perform the purification process or end the purification process. In addition, the position of the illuminance sensor is not limited to the wafer table. Beamsplitters are provided on the upstream side and the downstream side of the projection lens unit 61, respectively, and the visibility of the spectroscopy is monitored. The monitored illuminance, illuminance distribution, and illuminance are compared. One of the fluctuation amount, the light transmittance, and the light transmittance fluctuation amount and a predetermined value corresponding to the set value may be subjected to a purification process or the purification process may be terminated according to the result. One of the control processing shown in Fig. 4 or the control processing shown in Fig. 5 or a combination thereof may be selected. In addition to these control processes, in addition to the exposure process of exposing and transferring the pattern of the photomask onto the wafer, for example, the exposure process is performed immediately before the operation of the exposure process i. It can be performed before the exposure processing, or immediately after the exposure processing for one wafer is completed, and immediately before the exposure processing for the next wafer. When the gas circulation is performed during the exposure process, pressure or temperature changes in the lens chambers R1 and R2 of the projection lens unit may adversely affect the accuracy of the exposure. As shown above, by opening and closing VI ~ V4 only during the purification process and closing the opening and closing valves VI ~ V4 during the exposure process, the gas in the lens chambers in and R2 of the projection unit 61 can be prevented from flowing and stabilized. ^

Page 33 V. Description of Invention (31) State. In the example shown in FIG. 3, 'an on-off valve is provided in each of the pipes L2, L3, L5, and L6 in terms of structure', so that the flow of helium can be controlled for each of the lens chambers R1 and R2, but the flow of the lens chambers R1 and R2 The range in which the gas flow rate is not extremely reduced, delete the on-off valves VI to V4 ', and set the on-off valves in the pipes L1 and L4 respectively, so that the gas flow in the lens chambers R1 and R2 can be controlled in total. As shown in FIG. 3, the gas supply ports G1, G3, and the gas discharge ports G2, G4 are not provided for all the lens chambers R1 and R2, and only the most effective lens chamber can be provided with a piping by design. '— The projection lens unit 61 shown in FIG. 3 is a lens unit used in a projection optical system.' However, the lens unit to be purified is not limited to a lens unit of this structure. The above-mentioned gas purification system is applied to a projection optical system. An exposure device can be constituted by using a lens unit having a different structure or by using the same lens unit in an illumination optical system. In addition, it is not limited to a lens unit, but an optical element unit using a lens and a mirror, and an optical element unit using only a mirror can be similarly applied. In the above-mentioned embodiment, 'helium gas is used for a gas with high transmittance and good thermal conductivity for illumination light, but a gas other than helium gas (such as high-purity nitrogen, neon, or helium and nitrogen gas) is used for such a gas. In the case of mixed gas, etc.), the present invention can be applied. It should be noted that the examples 1 to 3 described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments also includes all design changes or equivalents that belong to the technical scope of the present invention.

43 9114 V. Description of the invention (32) For example, in the above embodiments, the exposure device that emits F2Excimer laser light (wavelength 157nm) is used in the light source, but it can also be applied to KrF Excimer laser light (wavelength 157nm) ), ArF Excimer laser light (wavelength 193_), Ar2 Excimer laser light (wavelength 126rm), and the light and wavelength of 13nm or 7nm wavelength which is almost close to X-ray, which emits the so-called extreme ultraviolet (EUV or χϋν) region X-ray and other light source exposure device. In each of the above-mentioned embodiments, the step-and-scan type reduction technique β-type scanning exposure device _ (scanning stepper) is described, but for example, the mask pattern is Reduction type projection scanning exposure device (stepper) for stepwise and repeating the entire batch exposure of illumination light for exposure and stepwise and repeating of a divided area (irradiated area) of the mask pattern to be transferred The invention can also be applied to an exposure device such as a projection method or a proximity method. Optical elements that are not limited to all in the projection optical system are refractive elements (lenses), optical systems consisting of only reflective elements (reflectors, etc.) may be used, or refractive elements and reflective elements (concave mirrors, reflective elements) Mirror, etc.) is also possible. The projection optical system is not limited to a magnification optical system such as a reduction optical system 'or a magnification optical system. On the illumination light for exposure, a fiber amplifier with erbium-doped erbium (or bait and yttrium) is used to amplify the single-wavelength laser in the infrared region or visible light region excited by DFB semiconductor laser or fiber laser. Non-linear optical crystals can also be used to convert wavelengths to high harmonics of ultraviolet light. For example, if a single wave is set: When the excitation wavelength of the laser is within the range of 丨 .5 卜 丨 .5 9 μm, the output will be

Page 35 43 9114. V. Description of the invention (33) The generation wavelength is 8 times higher harmonics in the range of 1 8 9 to 1 99 nm or the generation wavelength is 1 10 times higher harmonics in the range of 1 5 1 to 1 59 nm. wave. Especially when the excitation wavelength is in the range of 1.544 ~ 1.553, we get! In the range of 93 to 194 nm, 8 times the south chirp wave, that is, ultraviolet light having a wavelength substantially the same as that of the ArF Excimer laser chirp; when the excitation wavelength is in the range of 1. 5 7 to 1. 5 8 " m, 10 times higher harmonics in the range of 157 ~ 158nm, that is, ultraviolet light with a wavelength approximately the same as F2 Exciiner laser light. The excitation wavelength is] · 〇3 ~ 丨 .1 2 # ^ in the range of 寸 inch 'output generation wavelength is 7 times higher within the range of 147 ~ I60nm high wave; especially the excitation wavelength is .0 994. 1〇6 When it is within the range, 7 times higher harmonics with wavelengths ranging from 157 to 158 nm are obtained, that is, ultraviolet light with a wavelength that is approximately the same as h Exc 1 mer laser light. In addition, yttrium-doped fiber lasers are used on single-wavelength lasers. The present invention is not only applied to a projection exposure device used in the manufacture of semiconductor elements, liquid crystal displays, thin-film magnetic heads, and photographic elements (CCD, etc.), but also can be applied to transferring circuit patterns to silicon wafers and the like in order to manufacture photomasks. Projection exposure device. Here, a transmission type photomask is generally used in an exposure device using Duv (far ultraviolet) light or vuv (vacuum ultraviolet) light. On the photomask substrate, quartz glass is broken, quartz glass doped with fluorine, and fluorite are used. , Magnesium fluoride or crystal. In the EUV exposure apparatus, a reflective mask is used, and a silicon wafer is used on the mask substrate. By mounting the illumination optical system and projection optical system composed of multiple lenses into the exposure device body first and then performing optical adjustment, a mask table or wafer table composed of a plurality of mechanical parts is installed behind the exposure device body. Connect wiring or piping, and connect housing i, illumination optical system (subchamber 6), and projection

Page 36 4 4

The optical system PL and the environmental chamber 7 are connected to a helium cycle device or a nitrogen cycle device, respectively, and comprehensively adjusted (electrical adjustment, operation confirmation, etc.) to manufacture the exposure device of the above embodiment. It is desirable to manufacture such an exposure device in a clean room that manages temperature and clean sound. In addition, the inner wall of each pipe or chamber described in this embodiment is mechanically polished, electrolytically polished, polished and chemically polished, etc., to reduce the surface roughness. Please vacuum-degas the surface (for baking) and other treatments. It is sufficient to reduce the amount of degassing from the surface of the component material. In addition, it is desirable to supply materials to each space by using a material that reduces impurity gas (deaeration) (for example, various polymers such as stainless steel, tetrafluoroethylene, tefrailuoroethylene-ternuoro (alkylvinylether), or tetrafluoroethylene). The piping of helium or nitrogen. The semiconductor device is subjected to the function * performance design step of the device, the step of making a mask according to the design step, the step of making a wafer from a silicon material, and the light using the exposure device of the above embodiment. The pattern exposure of the mask is transferred to the wafer, the steps of component assembly (including the cutting process, the soldering process, the packaging process), and the inspection step are manufactured. When manufacturing semiconductor elements, especially the pattern exposure of the photomask is transferred to The wafer step is performed when a gas transmitting the illumination light is supplied to at least a part of the light path of the illumination light, and at least a part of the gas is recovered, and then the substance affecting the transfer accuracy of the pattern image is removed from the recovered gas. Similarly, after recovering at least a part of the gas supplied to the space, The shadow optical system transfers a patterned image to the photosensitive substrate. In addition, the operations described in Examples 1, 2, and 3 are performed, or the

P.37 439114 V. Description of the invention (35) The steps of performing exposure transfer after operation. In addition, the unaltered references include the entire disclosure of the specification, patent application scope, drawings, and abstracts, which were filed on October 13, 1998, and issued in their country's franchise, No. 10-2 9 0 3 2 6 This manual.

Page 38

Claims (1)

4 3 9 η 4 VI. Patent application scope 1. An exposure device that irradiates a photomask with illumination light from a light source and transfers an image of a pattern formed on the photomask to a predetermined surface, which is characterized by: A device for supplying at least a part of the light path of the illuminating light to transmit the gas of the illuminating light; a recovery device for recovering at least a part of the gas to the light path of the illuminating light; and a purification device for removing the influence of the recovered gas on the predetermined gas The image of the pattern on the surface is transfer-accurate. 2. For the exposure device according to item 1 of the patent application scope, wherein the purification device is connected to the supply device, and the supply device is used to supply the light path of the illumination light to the gas purified by the purification device. 3. The exposure device according to item 1 of the patent application scope, wherein at least a part of the gas of the lighting system is supplied by the supply device. 4. For the exposure device according to item 3 of the patent application, wherein the purification device removes the substance from the gas. 5. The exposure device according to item 1 of the patent application scope, further comprising a projection optical system for projecting an image of the pattern of the mask on the photosensitive substrate; using the supply device to supply at least a part of the gas of the projection optical system. 6. The exposure device as claimed in claim 5 wherein the purification device is used to remove the substance from the gas. 7. The exposure device according to item 1 of the patent application scope, wherein the light source and the gas are supplied by the supply device. Page 39 6. Scope of patent application 8 · If the exposure device of the scope of patent application No. 1 is used, the purification device removes from the gas substances that change the illuminance or illuminance distribution on the surface illuminated by the illumination light. 9. The exposure device according to item 1 of the scope of patent application, wherein the substance changes the optical characteristics of an optical element of at least a part of the plurality of optical elements arranged between the light source and the predetermined surface; A control device that variably controls the operation of the purification device. 10. The exposure device as claimed in item 9 of the scope of patent application, which further includes pre-memory control data including the time and time when the purification device should operate: a memory device; the control device according to the control data order memorized by the memory device The purification device operates. Π. The exposure device according to item 9 of the patent application scope, further comprising: a projection optical system that projects an image of the pattern of the photomask on the photosensitive substrate; and a detection device that detects the transmittance of the projection optical system The control device causes the purification device to operate when the variation of the transmittance detected by the detection device exceeds a predetermined value. 1 2. The exposure device according to item 9 of the scope of patent application, wherein a supply unit connected to the supply device is provided in a room divided into and including at least a part of an optical element in an optical path of the illumination light to which the supply device supplies the gas. Port and a discharge port connected to the recovery device; each of the supply port and the discharge port is set to be controllable by the control device Page 40 6. The on-off valve in the scope of patent application; The control device closes the on-off valve when the purification device is not activated. 1 3. The exposure device according to item 12 of the scope of patent application, which causes the control device to irradiate the illumination light before causing the purification device to move, causing the pollutants attached to the surface of the optical element to float. 14. The exposure apparatus according to item 12 of the patent application scope, which further includes a gas supply source for supplying a new gas. 1 5. The exposure device according to item 1 in the scope of patent application, wherein the purification device operates according to the exposure history. 1 6. The exposure device according to item 1 in the scope of patent application, wherein at least a part of the light path of the illumination light includes the light. The space of the hood or the given face. 17. The exposure device according to item 16 of the scope of patent application, wherein the supply device has a first supply mechanism that transmits a first gas that transmits the illumination light in a first space that supplies the illumination light, and supplies the illumination light. A second supply mechanism that transmits a second gas of the illumination light in a second space different from the first space in the light path; the purification device removes the substance from the recovered gas, and separates the first gas from the second gas gas. 1 8. The exposure device according to item 17 of the scope of patent application, wherein: the first space includes a space of at least one optical element among a plurality of optical elements disposed between the light source and the predetermined surface; the second The space is the space including the mask or the predetermined surface. 1 9. An exposure device that irradiates the photomask with illumination light from a light source and transfers the image of the pattern formed on the photomask to the sensor via a projection optical system. Page 41 D it # No. 88117652 Correction Yong, .. " f and · I —r, Yun 烦, please ask iS · * ί t '% yt Li ^ t $'] I month;!? Hua Then the positive κ * > of 1 year _, the extension of the application for the Yan-W light base is characterized by including: a supply device for supplying a space between the projection optical system and the photosensitive substrate to transmit the gas that transmits the illumination light; and a recovery device At least a part of the gas supplied to the space is recovered. 20. If the exposure device according to item 19 of the patent application scope, the gas recovered by the recovery device includes a gas of a different type and a gas that transmits the illumination light and a gas that transmits another kind of the illumination light. 2 1. The exposure device according to item 20 of the patent application scope, wherein one of the nitrogen gas or helium which transmits the gas system of the illumination light, and the other of the nitrogen gas or helium which transmits the gas system of the other illumination light. 2 2. An exposure method in which a mask is irradiated with illuminating light from a light source, and an image of a pattern formed on the reticle is transferred to a predetermined surface, which is characterized in that at least a part of an optical path for supplying the illuminating light is transmitted The gas recovery arch of the illumination light gives at least a part of the gas to the light path of the illumination light; and removes from the recovered gas a substance that affects the accuracy of transferring the image of the pattern on the predetermined surface. 2 3. The exposure method according to item 22 of the scope of patent application, wherein the gas from which the substance has been removed is supplied to at least a part of the light path of the illumination light. 2 4. The exposure method according to item 23 of the patent application scope, wherein the recovered gas system includes a gas in the space of the photomask or the predetermined surface. 2035-2329- ^ 1 -p: c Page 42 43 911 4 6. Application for Patent Scope 2 5. An exposure method in which a photomask is irradiated with illumination light from a light source through a projection optical system and formed on the photomask The image of the pattern is transferred to a photosensitive substrate, which is characterized in that: a gas for transmitting the illumination light between the projection optical system and the photosensitive substrate is provided; and at least a part of the gas supplied to the space is recovered. 2 6. A manufacturing method in which a photomask is irradiated with illumination light from a light source, and an image of the ΪΓ case formed on the photomask is transferred to a photosensitive substrate, which is characterized by: The supply pipe is connected to a gas chamber that divides at least a part of the light path of the illumination light; a recovery pipe that recovers at least a part of the gas that is supplied to the gas chamber is connected to the gas chamber; and the recovery pipe and the removal effect on the predetermined surface The purification device of the substance of the pattern image transfer accuracy is connected. 2 7. —A manufacturing method in which a semiconductor element is manufactured by transferring an image of a pattern formed on the mask to a predetermined surface after irradiating the mask with illumination light from a light source, wherein at least a part of a light path of the illumination light is supplied Transmits the illumination light: gas, and recovers at least a part of the gas in the gas chamber supplying the light path of the illumination light, and removes from the recovered gas a substance that affects the transfer accuracy of the image of the pattern on the predetermined surface Next, the image of the pattern is transferred to a predetermined surface. Page 43 VI. The scope of patent application. IHII Page 45