WO2002053267A1 - Fan filter unit and method of manufacturing the unit, exposure device, and method of manufacturing device - Google Patents

Abstract

A fan filter unit (100), comprising a unit body (180) and a filter part (140) selectively removing ammonia, sulfur oxides, nitrogen oxides, and removed chemical substances as at least one of organic substances contained in the gas passing a flow path (130) formed in the unit body (180), whereby a chemically clean gas can be fed by selectively removing chemical contaminated substances contained in the gases at an installation place, e.g., a space in a chamber can be maintained in a chemically clean state by connecting the fan filter unit (100) to the chamber of an exposure device.

Description

 Specification

TECHNICAL FIELD The present invention relates to a fan filter unit, a manufacturing method thereof, an exposure apparatus, and a device manufacturing method.

 The present invention relates to a fan filter unit and a method of manufacturing the same, an exposure apparatus, and a device manufacturing method. More specifically, the present invention is connected to a device manufacturing apparatus such as an exposure apparatus when manufacturing an electronic device such as a semiconductor element. The present invention relates to a fan filter unit and a manufacturing method thereof, an exposure apparatus connected to the fan filter unit, and a device manufacturing method using the exposure apparatus.

S.

 2. Description of the Related Art Conventionally, in a lithographic process for manufacturing semiconductor devices, liquid crystal display devices, and the like, a step-and-repeat type reduction projection exposure apparatus (so-called stepper) and a step-and-scan type scanning projection exposure apparatus (so-called An exposure apparatus such as a scanning-stepper is used.

In recent years, in these exposure apparatuses, the circuit pattern has become finer in accordance with the higher integration of semiconductor elements and the like, and the need for improved resolution has been inevitably increased. ing. At present, a 1 rF excimer laser with an oscillation wavelength of 2488 门 1 ^ and an ArF excimer laser with an oscillation wavelength of 19.3 nm having a shorter wavelength have been used as light sources. In an exposure apparatus using such a light source having a shorter wavelength, from the viewpoint of increasing the sensitivity of the resist in order to compensate for the lack of luminance of each light source, the resist applied on the substrate is used as a resist in the resist. The photosensitizer contains an acid generator, and the acid generated by exposure induces a catalytic reaction in the subsequent heat treatment (PEB) and promotes insolubilization (negative type) or solubilization (positive type) in the developer. , Highly sensitive chemically amplified resists have been used.

 By the way, it has recently been found that trace gases in the atmosphere have an adverse effect on exposure equipment. For example, when a positive-type chemically amplified resist is applied on a substrate, a slight amount of a basic gas (such as ammonia) at the PPb level in the atmosphere causes an acid catalyst generated on the surface of the positive-type chemically amplified resist. After the resist is neutralized to form a surface insoluble layer, exposed and developed, a phenomenon occurs in which the resist cross section, which should be rectangular, forms an eaves resembling a T-shape, called a T-shape. Until that time, a chemically amplified resist, which is a high-sensitivity resist, cannot be used, so that a smart coat is required and the throughput is reduced.

 In addition, with the shortening of the wavelength of the exposure light and the increase in illuminance, for example, ammonia, sulfur oxides, nitrogen oxides, or organic substances in the atmosphere receive a strong energy due to the short wavelength exposure light, causing a photochemical reaction, and Precipitates as a cloudy substance on the surface of optical components in the equipment. It has been found that this precipitation, when it reaches a certain amount, causes light scattering and light absorption, and causes phenomena such as a decrease in illuminance on the irradiated surface and a deterioration in in-plane uniformity of illuminance. Thus, it has become important to keep chemical contaminants in the atmosphere at low concentrations.

 For these reasons, current exposure equipment requires strict control of the internal environment.

 On the other hand, the lithography system is very precise, so each part can exhibit the desired performance. In the conventional lithography system, the main body of the lithography system is housed in an environmental control chamber (environmental chamber). Have been. In order to reduce the concentration of ammonia and other chemical contaminants described above, a filter device (hereafter referred to as “appropriate”) that removes chemical contaminants by chemical adsorption and physical adsorption is provided inside the environmental control chamber. Chemical Filling Device).

It is certain that semiconductor devices will be required to achieve higher integration in the future. In order to respond to this, the exposure equipment is required to be able to realize more precise exposure. For this reason, it is required to further improve the performance of each component of the exposure apparatus, and one of them is to further reduce chemical contaminants inside the environmental control chamber. Inside the environmental control chamber, a plurality of chemical filter devices for efficiently removing chemical contaminants contained in the gas inside the environmental control chamber are arranged.

 Most of the gas inside the environmental control chamber circulates, but some outside air is taken in to maintain a positive pressure inside the environmental control chamber. However, the type and concentration of the chemical pollutants contained in the outside air are not always constant depending on the location of the environmental control chamber. If high concentrations of chemical contaminants are present in the outside air, they cannot be sufficiently removed by the chemical filter device inside the environmental control chamber. If the required exposure accuracy becomes severe, this may be an obstacle to achieving the exposure accuracy. In addition, the deterioration of the chemical filling equipment located inside the environmental control chamber is accelerated, and frequent replacement of the filling medium may reduce productivity.

 The present invention has been made in view of such circumstances, and a first object of the present invention is to provide a fan filter capable of selectively removing a chemical contaminant contained in a gas at an installation site and delivering a chemically clean gas. To provide evening units.

 A second object of the present invention is to improve the exposure accuracy and the productivity by maintaining the concentration of the chemical contaminant of the gas supplied into the environment control chamber within an allowable range. To provide an exposure apparatus capable of performing the above-described operations.

 A third object of the present invention is to provide a device manufacturing method capable of manufacturing highly integrated microdevices with high productivity. Disclosure of the invention

According to a first aspect, the present invention provides a method for removing chemical contaminants contained in a gas. A fan unit having a gas flow path formed therein; a fan unit having a gas flow path formed therein; and a fan unit disposed inside the unit body for sucking the gas into the channel. A blower that sends out the gas that has passed through the flow path to the outside of the unit main body; and a blower that is disposed in the flow path portion inside the unit main body and is included in the gas that passes through the flow path. A chemical substance containing at least one specific chemical substance of ammonia, sulfur oxides and nitrogen oxides is defined as a chemical substance to be removed, and the concentration of the specific chemical substance contained in the gas after passing through is 0.01. a filter unit for adjusting the concentration in the range of ^{gZmS O. 5 ^ g / m 3} ; is a flow Ann filter unit comprising a.

〜0. 5 igZm³) の濃 度に調整される。 従って、 特定化学物質の濃度が規定範囲の上限値以下に抑え られたケミカルクリーンな気体をュニッ卜本体の外部に送出することができる。 ここで、 特定化学物質がアンモニア、 硫黄酸化物、 及び窒素酸化物の全てを含 む場合には、 これらの全ての濃度が規定範囲の上限値以下に抑えられる。 According to this, the blower gas is sucked into a flow passage formed inside the unit body, and the chemical substance to be removed contained in the gas, that is, ammonia, sulfur among the chemical pollutants is contained in the gas. oxide, and at least one concentration of a particular chemical substance of the nitrogen oxides, when the concentration exceeding the maximum value of the prescribed range (0. 5 gZm ³⁾ is selectively removed by the filter unit The concentration of the specified chemical substance is within the above specified range (0.01

Adjusted to a density of ~ 0.5 igZm ³ ). Therefore, a chemical-clean gas in which the concentration of the specific chemical substance is kept below the upper limit of the specified range can be sent out of the unit. Here, when the specified chemical substance includes all of ammonia, sulfur oxides, and nitrogen oxides, the concentration of all of them is suppressed to the upper limit of the specified range or less.

 In addition, when the specified chemical substance includes a plurality of substances such as ammonia, sulfur oxides, and nitrogen oxides, the upper limit of the specified range may be set with respect to a total concentration of the plurality of substances.

In this case, it is preferable that the filter unit adjusts the concentration of the specific chemical substance contained in the gas after passing through the gas to a concentration in a range of 0.01 zgZm ³ to 0.2 g / m ³ .

In the fan filter unit of the present invention, the chemical substance to be removed is an organic substance. When the filter further contains, the filter unit adjusts the concentration of the organic substance contained in the gas after passing through the filter in a range of 0.1 _g / m ³ to 30 Ac g Zm ³ in terms of toluene. The concentration can be adjusted.

In this case, the filter section, the concentration of the organic matter contained in said gas after passing through, be adjusted to ^{0. 1 g Zm 3 ~1 O} tg / m 3 in the range of concentration with toluene terms preferable.

 In the fan filter unit of the present invention, the fan filter unit may include a supply unit that is provided in the unit main body and supplies the gas that has passed through the filter unit to a device manufacturing apparatus.

 In this case, various devices can be connected to the fan filter unit as a device manufacturing apparatus. For example, the device manufacturing apparatus exposes a substrate through an optical system using an energy beam to form a predetermined pattern. In the case of an exposure apparatus formed on a substrate, the supply unit may be connected to a chamber accommodating at least a part of the exposure apparatus.

According to a second aspect of the present invention, there is provided a method of manufacturing a fan filter unit for removing a chemical contaminant contained in a gas by a filter portion and sending the gas to the outside. A step of measuring the concentration of each of the plurality of types of chemical contaminants contained in the gas; and a plurality of types of filters for respectively removing the plurality of types of chemical contaminants from the gas based on the measurement results. Selecting at least one filter medium from the medium and configuring the filter section using the selected filter medium. According to this, a chemical contaminant to be measured is determined in advance in accordance with the atmosphere of the place where the fan filter unit is installed, so that an optimal filter unit is configured for the place where the fan filter unit is installed. For this reason, the concentration of chemical pollutants contained in the gas sent out from the fan filter unit to the outside, that is, the concentrations of chemical pollutants that need to be controlled in particular, should be within the specified range. Can be suppressed it can.

 In this case, the chemical contaminants to be measured may include at least one of ammonia, sulfur oxides, nitrogen oxides, and organic substances.

 According to a third aspect of the present invention, there is provided an exposure apparatus for exposing a substrate with an energy beam via an optical system to form a predetermined pattern on the substrate, comprising: a fan filter according to the present invention; A chamber connected to a unit for supplying a gas in which chemical contaminants are suppressed through the fan filter unit; and a component including at least a part of an optical path of the energy beam is provided in the chamber. And an exposure apparatus main body for exposing a substrate via the optical system by the energy beam.

 According to this, the concentration of at least one specific chemical substance among ammonia, sulfur oxides, and nitrogen oxides among the chemical pollutants is controlled by the fan fill unit according to the present invention so that the concentration falls within the above-mentioned specified range. Gas suppressed below the upper limit is supplied into the chamber. Therefore, the inside of the chamber can be maintained in a chemically clean state. Therefore, as a result, it is possible to suppress a decrease in exposure accuracy due to chemical contamination of the optical member constituting the optical path of the energy beam.

According to a fourth aspect of the present invention, there is provided an exposure apparatus connected to a fan filter unit, wherein the exposure apparatus forms a predetermined pattern on the substrate by exposing the substrate with an energy beam via an optical system. A main body; a chamber accommodating at least a part of the exposure apparatus main body including at least a part of an optical path of the energy beam, and supplying a gas in which chemical contaminants are suppressed through the fan filter unit; The concentration of ammonia, sulfur oxides, and nitrogen oxides contained in the gas in the chamber is maintained at a concentration in the range of 0.0 ltg / m ³ to 0.5 g / m ³ , respectively. This is a second exposure apparatus characterized in that: According to this, it is supplied from the fan filter unit into the chamber. The concentrations of ammonia, sulfur oxides, and nitrogen oxides, which are the chemical contaminants contained in the gas, are kept below the upper limit (0.5 g Zm ³ ) permitted in the chamber. Therefore, the gas in the chamber can be maintained in a chemically clean state. Therefore, as a result, it is possible to suppress a decrease in exposure accuracy due to chemical contamination of the optical member constituting the optical path of the energy beam.

In this case, ammonia contained in the gas in the chamber, sulfur oxides, and the concentration of nitrogen _{oxides, 0. 0 lt g / m} 3 ~ 0. 2 respectively is maintained at a concentration in the range of tg Zm ³ Is preferred.

 In the second exposure apparatus of the present invention, the exposure apparatus further includes a chemical substance removal filter disposed in the chamber and using at least one of ammonia, sulfur oxide, and nitrogen oxide as a substance to be removed. be able to. In such a case, the deterioration of the chemical substance removing filter is suppressed, and the time interval until the chemical substance removing filter is replaced becomes longer, and as a result, the productivity can be improved. According to a fifth aspect of the present invention, there is provided an exposure device connected to a fan filter unit, wherein the exposure device forms a predetermined pattern on the substrate by exposing the substrate via an optical system using an energy beam. An apparatus main body; a chamber in which at least a part of the exposure apparatus main body including at least a part of an optical path of the energy beam is accommodated, and a gas to which a chemical contaminant is suppressed is supplied through the fan filter unit. Wherein the concentration of the organic substance contained in the gas in the chamber is maintained at a concentration within an allowable range corresponding to the wavelength of the energy beam.

According to this, the concentration of the organic substance, which is a chemical contaminant, contained in the gas supplied from the fan filter unit into the chamber is equal to or less than an upper limit allowed according to the wavelength of the energy beam. The gas in the chamber is maintained in a chemically clean state corresponding to the wavelength of the energy beam. can do. Therefore, as a result, it is possible to suppress a decrease in exposure accuracy due to chemical contamination of the optical member constituting the optical path of the energy beam.

In this case, when the energy beam is the case of ArF excimer laser light having a wavelength of 193 nm, the concentration of the organic substance contained in the gas in the chamber is 0.1 ^ g in terms of toluene as an allowable range. / m ³ to 3, preferably in the range of 0.1 T tgZm ³ to 1 O / ^ gZm ³ .

In the third exposure apparatus of the present invention, when the energy beam is a KrF excimer laser beam having a wavelength of 248 nm, the concentration of organic substances contained in the gas in the chamber is converted into toluene as an allowable range. At g / mS l SO tg, m ³ , preferably 0.1 Atg / m ³ to 50 g / m ³ .

 The third exposure apparatus according to the present invention may further include a chemical substance removal filter disposed in the chamber and having at least an organic substance as a substance to be removed. In such a case, the deterioration of the chemical substance removing filter is suppressed, and the time interval until the chemical substance removing filter is replaced becomes longer, so that the productivity can be improved as a result.

 According to a sixth aspect of the present invention, there is provided an exposure apparatus connected to a fan filter unit, wherein the substrate is exposed to an energy beam via a re-optical system to form a predetermined pattern on the substrate. An exposure apparatus main body; a chamber in which at least a part of the exposure apparatus main body is housed, and a gas to which a chemical contaminant is suppressed through the fan filter unit is supplied; and air conditioning in the chamber is performed. A fourth exposure apparatus, comprising: an air conditioner; and a controller that controls the fan filter unit, the air conditioner, and the exposure apparatus main body in accordance with each other's operating state.

According to this, the control device controls the fan fill unit, the air conditioner, And the exposure apparatus main body are controlled in accordance with each other's operation state. That is, the control device controls the fan filter unit, the air conditioner, and the exposure device main body in conjunction with each other. For this reason, the control device can automatically stop the gas supply from the fan filter unit when the air conditioner and the exposure device main body are stopped, for example. It is possible to prevent contaminants from being mixed. Further, the control device can automatically stop the air conditioner and the exposure device main body, for example, when an abnormality occurs in the fan filter unit, whereby chemical contaminants are contained in the chamber. Mixing can be prevented.

 In this case, the control device stops the supply of gas from the fan filter unit into the chamber when the operation state of the air conditioner and the exposure apparatus main body is either power off or emergency stop. It can be done.

 Further, in the fourth exposure apparatus of the present invention, the control unit may stop power supply to the air conditioner and the exposure apparatus main body when the operation state of the fan filter unit is an emergency stop. can do.

 In the fourth exposure apparatus of the present invention, when the control apparatus further includes an alarm device for notifying an external air supply state from the fan filter unit, the control device may control whether the operation state of the fan filter unit is When the power is turned off, the external device may be notified that the supply of outside air has been stopped using the alarm device.

Further, in the lithographic process, by performing exposure using any of the first to fourth exposure apparatuses of the present invention, it is possible to suppress the occurrence of adverse effects such as a decrease in illuminance due to clouding of the optical material over a long period of time As a result, a high-throughput device can be manufactured with high productivity while maintaining a high throughput. Therefore, from a further viewpoint, the present invention can be said to be a method of manufacturing a noise by performing exposure using any of the first to fourth exposure apparatuses of the present invention. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a view schematically showing an exposure apparatus according to an embodiment to which a fan filter unit according to the present invention is connected.

 FIG. 2 is a block diagram schematically showing a control system of the exposure apparatus of FIG.

 FIG. 3 is a sectional view taken along line AA of FIG.

 FIG. 4 is a diagram schematically showing an overall configuration of the fan filter unit of FIG. FIG. 5 is a block diagram schematically showing an in-face portion of the fan-fill unit of FIG.

 FIG. 6 is a diagram showing the relationship between the rate of decrease in the transmittance of exposure light and the concentration of organic substances in air when the exposure light is ArF excimer laser light.

 FIG. 7 is a diagram showing the relationship between the rate of decrease in the transmittance of exposure light and the concentration of organic substances in air when the exposure light is KrF excimer laser light.

 FIG. 8 is a flowchart for explaining an embodiment of a manufacturing method for manufacturing a device according to the present invention.

 FIG. 9 is a flowchart showing the processing in step 304 of FIG. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 schematically shows an overall configuration of an exposure apparatus 100 as a device manufacturing apparatus according to an embodiment to which a fan filter unit 100 according to the present invention is connected.

 First, the configuration of the exposure apparatus 10 will be described.

As shown in FIG. 1, the exposure apparatus 10 includes a chamber 12 installed on a floor F in a clean room, and a machine room 14 arranged adjacent to the chamber 12. I have. An intake 50 as an outside air intake is formed at the bottom of the machine room 14 on the side opposite to the chamber 12, and the fan The unit 100 is connected to the intake 50 through a stainless steel duct 200 as a supply unit.

 The duct 200 is not limited to stainless steel, but may be made of a material that is less degassed and that is easy to clean (for example, a fluorine-based resin).

 Highly conditioned air circulates in the chamber 12 and is always kept at a positive pressure against the outside in order to maintain the cleanliness of the chamber 12. For this reason, air leaks to the outside from the front of the chamber 12 or the unillustrated face of the interface, etc., and outside air (air in the clean room where the chamber # 2 is installed) is taken in to compensate for this leak. An intake 50 is provided. The exposure apparatus 10 includes a control rack (not shown) that controls the entire exposure apparatus, and a control apparatus 70 (not shown in FIG. 1; see FIG. 2) is installed in the control rack. I have. Further, the control rack is provided with a power switch 95 of the exposure apparatus and an emergency stop button 96 (not shown in FIG. 1; see FIG. 2), and is operated by an operator. When the operator operates the power switch 95 and the emergency stop button 96, the controller 70 is notified. Further, the control rack is provided with an outside air supply stop lamp 97 (not shown in FIG. 1; see FIG. 2) so as to notify an operator of the outside air supply status from the fan filter unit 100. ing. The outside air supply stop lamp 97 is turned on and off according to an instruction from the control device 70.

 Further, as shown in FIG. 2, the controller 70 has four signal lines (operating Z-stop input signal OPI, emergency stop input signal) for interlocking with the fan filter unit 100. It is electrically connected to the fan filter unit 100 via an EM error output signal ERO (emergency stop output signal EMO).

In addition, the environmental conditions (cleanliness, temperature, pressure, etc.) in the chambers 12 are almost the same. In the interior space, there is one large room 16 on the machine room 14 side and two upper and lower tiers arranged on the opposite side of the machine room 14 of this large room 16 Small rooms 18 and 20 are provided. The large room 16 is an exposure room in which the exposure apparatus main body 22 is housed. Hereinafter, this large room 16 is referred to as an exposure room 16.

 The exposure apparatus main body 22 housed in the exposure chamber 16 includes an illumination optical system 28 including mirrors M 1 and M 2, a projection optical system PL disposed below the illumination optical system 28, A reticle stage RST arranged between the optical system PL and the illumination optical system 28 and holding a reticle R as a mask, and a wafer stage WS arranged below the projection optical system PL and holding a wafer W as a substrate It has a main column 30, etc., which holds Τ, and the projection optical system PL, and on which the wafer stage WS 搭載 is mounted. The illumination optical system 28 and the projection optical system PL form a part of the optical system of the exposure apparatus main body 22.

 The illumination optical system 28 includes, in addition to the mirrors Ml and M2, a optical integrator, a field stop (both not shown), and the like, and these optical members are provided in an illumination system housing (not shown). It is housed in the positional relationship of. The illumination optical system 28 is connected to a KrF excimer laser (output wavelength: 248 nm) or an ArF excimer laser (output wavelength) as a light source (not shown) via a drawing optical system (relay optical system) (not shown). It is connected to an excimer laser with a wavelength of 193 nm. The routing optical system includes at least a part of an optical system for adjusting the optical axis between the light source and the illumination optical system 28, which is called a beam matching unit. Although not shown, the illumination system housing in which the illumination optical system 28 is accommodated, and the housing (barrel) in which the routing optical system is accommodated, each have an inert gas (for example, nitrogen or helium). ), And the cleanliness is maintained extremely well.

The one small room 18 has a plurality of reticles as masks inside. A reticle library 80 for storing the vesicles and a reticle loader 82 composed of a horizontal articulated type robot are sequentially arranged from the side opposite to the exposure chamber 16. The reticle R is carried into and out of the reticle stage RST constituting the exposure apparatus main body 22 by the reticle opening 82. In the present embodiment, a reticle loader system is configured by the reticle library 80 and the reticle loader 82, and is housed in the small room 18. Therefore, in the following, the small room 18 is referred to as a reticle loader room 18.

 The reticle loader system is not limited to the above configuration. For example, a bottom-open type closed cassette (container) capable of accommodating a plurality of reticles may be used instead of the reticle library 80, Alternatively, a mechanism for sliding the transfer arm may be used as a reticle loader. Further, the reticle storage unit (reticle library 80) and the reticle loader 82 may be arranged in different rooms, or the above-mentioned closed cassette is placed on the upper part of the reticle loader room 18 and the airtightness thereof is set. The reticle may be carried into the reticle loader room 18 with the bottle open while maintaining the performance. That is, only the reticle loader may be arranged in the small room 18.

 The other small room 20 has a wafer carrier 84 for storing wafers as a plurality of substrates, and a horizontal articulated robot 86 for transferring wafers into and out of the wafer carrier 84. And a wafer transfer device 88 for transferring a wafer between the robot 86 and a wafer stage WST constituting the exposure device main body 22. In the present embodiment, a wafer loader system is constituted by the wafer carrier 84, the robot 86, and the wafer transfer device 88, and is housed in the small room 20. Therefore, hereinafter, the small room 20 is referred to as a wafer loader room 20.

Note that the wafer loader system is not limited to the above-described configuration. For example, the wafer loader system may be configured only with articulated robots, or the wafer loader chamber 20 may be used. Only the wafer loader may be arranged in the inside.

 The exposure chamber 16, the reticle loader chamber 18, and the wafer loader chamber 20 are provided with an air supply pipe 24 made of a material with low degassing such as stainless steel or Teflon (registered trademark) and an elastic bellows-like. It is connected to the machine room 14 via the connection 26.

 At least a part of the illumination optical system 28 may be arranged outside the exposure chamber 16, and in addition or alone, the light source, the leading optical system, and the rest except the illumination optical system 28 may be provided. (For example, the wafer stage WS) may be placed in a separate housing from the exposure chamber. In this case, the another housing may be arranged inside the exposure chamber or outside the exposure chamber. In short, it is sufficient that at least a part of the main body of the exposure apparatus is disposed in the exposure chamber 16. The members to be disposed in the exposure chamber 16 and the configuration thereof are arbitrary.

 The main body column 30 is supported above a base plate BP provided on the bottom surface of the chamber 12 via a plurality of vibration isolators 32. The main body column 30 has a main column 34 supported by a vibration isolator 32 and a support column 36 erected above the main column 34. The projection optical system PL is held by a main frame constituting a ceiling surface of the main column 34 via a holding member (not shown) called a first invar with its optical axis direction as the vertical direction in FIG. Here, as the projection optical system PL, a reduction optical system with a projection magnification of 1 Z4 or 1/5 is used. The support column 36 supports at least a part of a lighting system housing (not shown) from below.

The wafer stage WST is driven two-dimensionally by a driving device such as a plane motor or a linear motor (not shown) on a stage base constituting a bottom plate of the main column 34. The wafer W is fixed on the upper surface of the wafer stage WST via a wafer holder 38 by vacuum suction or the like. Wafer stage WST position in XY plane and rotation amount (jowing amount, pitching amount, and rolling At least one of the above-mentioned amounts is measured with a laser interferometer IF through a moving mirror (not shown) provided on the wafer stage WST with a resolution of, for example, about 0.5 to 1 nm.

 The reticle stage R ST is mounted on a reticle stage base (not shown) constituting a ceiling of a support member, not shown, provided on the upper surface of the main column 34 and called a second driver. The reticle stage RST is configured to be finely drivable in a horizontal plane when the exposure apparatus main body 22 performs static exposure, and is configured in addition to the above in a case where the exposure apparatus main body 22 performs scanning exposure. It is configured to be able to be driven within a predetermined stroke range in the scanning direction.

 According to the exposure apparatus main body 22 configured in this manner, the pulse ultraviolet light emitted from the excimer laser (not shown) is required to have the size and illuminance required by the illumination optical system 28 including various lenses and mirrors. The reticle R on which a predetermined pattern is formed is formed into a uniform pattern, and the pattern formed on the reticle R is illuminated by the respective shots on the wafer W held on the wafer stage WST via the projection optical system PL. The image is reduced and transferred to the print area.

 In the present embodiment, for example, the surface of which a positive-type chemically amplified resist is applied as a photosensitive agent is used as the wedge W.

 At one end of the air supply pipe 24 in the chamber 12 (the end on the machine room 14 side), a chemical contaminant contained in the air supplied into the chamber 12 from the machine room〗 4 is removed. Chemical Filler CF 1a is located.

The other end of the air supply pipe 24 is branched into two, and one branch 24 a is connected to the reticle loader chamber 18. A filter box AF 1 comprising an ULPA filter (ultra low penetration air-filter) for removing particles in the air flowing into the reticle loader chamber 18 and a filter plenum is provided. Also, a return section 40 is provided on the opposite side of the reticle loader chamber 18 from the filter box AF 1. One end of a return duct 42 is connected to a portion outside the return section 40, and the other end of the return duct 42 is connected to a part of the bottom surface of the machine room 14.

 The branch path 24a is further provided with a branch path 24c. The branch path 24c is connected to the wafer loader chamber 20. A filter box AF2 including a ULPA filter as a filter for removing particles in the air flowing into the wafer loader chamber 20 and a filter plenum is provided. Further, a return section 44 is provided on the side of the wafer loader chamber 20 opposite to the filter box AF 2, and a return duct 42 is provided on the opposite side of the return section 44 to the loader chamber 20. There is an exhaust port that communicates with

 Further, the other branch path 24 b is provided with an exposure chamber 16 arranged on the side of the reticle loader chamber 18 of the ejection port 90 formed at the boundary between the reticle loader chamber 18 and the exposure chamber 16. It is connected to a filter box AF3 consisting of a ULPA filter and a filter plenum for removing particles in the air flowing into the inside. Then, a uniform air current is sent from the ejection port 90 into the upper space of the exposure chamber 16 by side flow. At the boundary between the reticle loader chamber 18 where the ejection port 90 is formed and the exposure chamber 16, as shown in FIG. Except for this, a plurality of filter boxes AF 3 are arranged around it.

 As shown in FIG. 1, a return section 46 is provided at the bottom of the exposure chamber 16 on the side of the machine chamber〗 4, and a bottom wall of the chamber 12 below the return section 46 is provided on the bottom wall. An exhaust port communicating with one end of the return duct 48 is formed, and the other end of the return duct 48 is connected to a part of the bottom surface of the machine room 14.

A chemical filter CF2b for removing a chemical contaminant contained in the outside air taken in is arranged opposite to the intake 50 portion. Outside air supplied from the fan filter unit 100 passes through the chemical filter CF 2 b Then, it is sent into the machine room 14. However, the chemical filter CF 2 b is not always necessary when a fan filter unit is connected as in the present embodiment.

 A cooler (dry coil) 52 is provided in the machine room 14 at a position slightly below the center in the height direction. At the outlet of the cooler 52, a first temperature sensor 54 for detecting the temperature of the cooler surface is arranged. The detection value of the first temperature sensor 54 is supplied to a control device 70 (not shown in FIG. 1; see FIG. 2).

 Above the cooler 52 in the air passage in the machine room〗 4, a first heater 56 is arranged at a predetermined distance from the cooler 52. A first blower 58 is arranged at the outlet of the machine room 14 above the first heat sink 56.

 Below the first heater 56 in the air passage in the machine room 14, there is provided a branch 60 into which about 15 of the air that has passed through the cooler 52 from above to below flows into the branch. The end of the machine room # 4 on the side of No. 0 is constituted by an elastic bellows-like member 60a. The portion of the fork 60 that is on the opposite side of the bellows-like member 60 a from the machine room 14 is disposed in the exposure room 16. In the branch 60, a second heater 62 and a second blower 64 are sequentially arranged. On the opposite side of the machine room 14 of the second blower 64, an air outlet for air near the wafer stage WST is provided. Is formed. An air conditioner that air-conditions the inside of the chamber 12 by the cooler 52, the first heater 56, the second heater 62, the first blower 58, the second blower 64, and their control systems. Is configured.

A filter box AF4 composed of a chemical filter CF1b, a ULPA filter, and a filter plenum is arranged near the wafer stage WST at the outlet of the air sent from the second blower 64. Opposite to the discharge port provided with the chemical filter CF 1 b and the filter box AF 4, a portion of the exposure chamber 16 near the wafer loader chamber 20 is provided at one end of the retarder 66. An open end is arranged, and the other end of the return duct 66 is connected to a part of the bottom of the machine room 14.

 An opening is formed in a part of the bottom surface of the machine room 14 to which the three return ducts 42, 48, and 66 are connected, and a chemical fill CF2a is provided to face the opening. ing. The chemical filter CF2a can be easily taken in and out through an opening / closing door (not shown) provided in the machine room 14.

 Further, a drain pan 68 is disposed below the cooler 52 in the machine room 14.

 A second temperature sensor 72 that detects the temperature of the air inside the air supply line 24 is disposed in a portion of the chamber 12 near the machine room〗 4 at the branch of the air supply line 24. . The detected value of the second temperature sensor 72 is supplied to a control device 70 (not shown in FIG. 1; see FIG. 2).

 Further, a third temperature sensor 74 that detects the temperature of the air sent from the second blower 64 is disposed upstream of the chemical filter C F 1b. The detection value of the third temperature sensor 74 is supplied to a control device 70 (not shown in FIG. 1, but see FIG. 2).

 Next, the configuration of the fan filter unit 100 according to the present embodiment will be described.

 As shown in FIG. 4, the fan filter unit 100 has a unit main body 180 in which an air flow path 130 is formed, and a bottom-to-top inside the unit main body 180. Blower 120, filter section 140, HEPA filter (high efficiency particulate air.-filter 150, etc. 1) arranged in this order.

At a part of the side wall of the unit body 180 (near the lower end of the right side wall in FIG. 4), an outside air intake 110 for taking in outside air (air in a clean room) is formed. Numeral 0 communicates with one end of the above-described flow path 130 formed inside the unit main body 180. The other end of unit body 180 (Fig. 4 An outlet 170 communicating with the other end of the flow path 130 is formed at the upper end of the flow path 130. The outlet 170 has a structure in which one end portion 210 of the duct 200 can be connected in a state where airtightness is maintained. The other end portion 220 of the duct 200 is a connection portion with the machine room 14 of the exposure apparatus 10.

 The blower 120 is arranged at one end inside the flow path〗 30 so as to suck air through the outside air intake 110 and send it out toward the other end of the flow path 130. ing.

 The filter section 140 is disposed downstream of the blower 120 in the flow path 130, and includes ammonia and sulfur as chemicals to be removed contained in air sent from the blower 120. At least one of oxides, nitrogen oxides, and organic substances is selectively removed. Here, the filter section 140 will be further described. The filter section 140 selectively removes any one of ammonia, sulfur oxides, nitrogen oxides, and organic substances contained in the gas. It is composed of two types of chemical filters 14 1 and 14 2.

 Each of the chemical filters 141 and 142 has a filter medium and a holding frame (not shown) for holding the filter medium. The holding frame for the filter medium is a frame-shaped member having a rectangular cross section perpendicular to the gas passage direction, and has openings formed on both sides in the gas passage direction (vertical direction on the paper in FIG. 4). In addition, the holding frame holds the outer peripheral portion of the filter medium without gaps, and all the gas entering the inner space of the holding frame passes through the filter medium. Further, the outer peripheral portion of the holding frame is in close contact with the wall of the flow path 130 without any gap. Here, in order to further closely contact the holding frame and the wall of the flow path 130 without any gap, a fluorine-based rubber material may be filled between the holding frame and the wall of the flow path 130. good.

In addition, the holding frame is not always necessary for the capability of the filter, but greatly contributes to improvement of workability such as replacement of the filter medium and maintenance. In addition, since the filter section 140 may include a plurality of chemical filters, at least a portion for removing ammonia, sulfur, and the like in the unit body 180 where the filter section 140 is disposed is provided. Space is secured for the simultaneous placement of four types of chemical filters for oxide removal, nitrogen oxide removal, and organic matter removal. In addition, the structure is such that these chemical filters can be exchanged easily in a short time.

 Furthermore, the width of the chemical filter in the air passage direction of the filter medium and the filling rate of the filter both depend on the type and concentration of the chemical contaminant as the chemical substance to be removed, and the supply flow rate of the fan filter unit. It is determined by taking into account such factors.

 Generally, carbon fiber having a honeycomb-like structure is used as the filling medium for chemical filling. In this embodiment, the type and concentration of the chemical pollutant as the chemical substance to be removed are used. Therefore, various structures and materials are used.

 That is, an impregnated type in which one of a cation component and an anion component is adhered to a porous member such as activated carbon or ceramic, an ion-exchange type composed of a fiber having an ion-exchange group, a resin sheet, or the like; and granular activated carbon or powdered activated carbon. Alternatively, a substance adsorption type made of a porous member such as ceramic can be used.

 The HEPA filter 150 is disposed downstream of the filter section 140 in the flow path 130, and is configured to remove particles contained in air that has passed through the filter section 140. .

 In the present embodiment, the HEPA filter 150 is disposed downstream of the filter unit 140, but the present invention is not limited to this, and the HEPA filter 150 is disposed upstream of the filter unit 140. 50 may be arranged.

Further, the fan filter unit 100 has an interface section 160 with the control device 70. The fan filter unit 100 is connected to a three-phase 200 V (50/60 HZ) power supply, which supplies power to the fan filter unit 100. Switch 1667 (not shown in Fig. 4; see Fig. 5) and emergency stop button 166 (not shown in Fig. 4) for forcibly stopping fan fill unit 100 when an error occurs. , And FIG. 5). The power switch 166 and the emergency stop button 166 can be operated by an operator.

Then, when the operator operates the power switch 167 and the emergency stop button 166, the interface section 160 is notified.

 Further, as shown in FIG. 5, the interface section 160 is provided with a run / stop input signal 0 PI and an emergency stop input signal EMI as input signals from the controller 70 via respective signal lines. Is to be entered. The interface section 160 outputs an emergency stop output signal EMO and an error output signal ERO as output signals to the control device 70 through respective signal lines. Each signal is input or output via relays 16 1, 16 2, 16 3, and 16 4, respectively.

 The power supply to the blower 120 via the relay {6} corresponds to the start / stop input signal 0PI. That is, when the operation / stop input signal 0 PI becomes “high j level”, the power supply to the blower 20 is cut off. Conversely, when the operation stop input signal OPI becomes “low” level, the blower 120 The power supply is restarted. However, it is valid only when the main power supply 165 is on and the emergency stop button 166 is not pressed.

The power supply to the entire fan filter unit 100 via the relay 162, that is, the main power supply 165 corresponds to the emergency stop input signal EMI. The emergency stop input signal EMI is maintained at the “high” level during normal operation to prevent malfunction and ensure operation. And the emergency stop input signal EMI The main power supply 165 is cut off when it goes to the "low" level. Also, in order to prevent malfunctions due to disturbances such as noise, it is valid only when the emergency stop input signal EMI is maintained at the "mouth" level for a certain period of time or more. And a mechanism to judge it is added.

 Further, the contact state of the emergency stop button # 6 is output as the emergency stop output signal EMO via the relay 163. The emergency stop output signal を Μ は is at “High” level during normal operation to prevent malfunction and ensure operation. When the emergency stop button〗 66 is pressed overnight, the relay 16 3 is activated and the emergency stop output signal Ε Μ に な る goes to the “low” level. In order to prevent erroneous operation due to disturbances such as noise, a mechanism has been added that activates the relay 166 only when the emergency stop button 166 is pressed for a certain period of time or longer. In addition, countermeasures against chattering of contacts have been taken. Also, in consideration of the importance of emergency stop, a mechanism has been added to maintain the “low” level of the emergency stop output signal ま で ま で ま で until the main power supply 165 is turned off and on again.

 Further, the error output signal E RO is linked with the on / off state of the power switch 167 via the relay 164. When the power switch 167 is on, the error output signal ERO is at the “high” level, and when the power switch 167 is turned off by the operator, the error output signal ERO is at the “low” level. I have.

 In the present embodiment, the interface section 160 is provided with a relay, but the present invention is not limited to this. That is, the interface section 160 may be a single terminal block only, and the control device 70 may include a switching member such as a relay. In addition, a sequencer (programmable controller) may be provided in the control device 70 or the interface section 160 to perform the above-described sequence control.

In addition, the input / output signals to the interface unit 160 are the above four types (operation / It is not limited to the stop input signal OPI, the emergency stop input signal EMI, the emergency stop output signal EMO, and the error output signal ERO). For example, it is also possible to output filter arrangement information, filter contamination information, and blower 120 abnormality information. In the present embodiment, each input / output signal is transmitted in a parallel system, but can be transmitted in a serial system such as RS232C. Next, the concentration of a chemical contaminant allowed in the chamber 12 will be described.

 In the exposure apparatus 10, when chemical contaminants contained in the air circulating inside the chamber # 2 precipitate on the surfaces of the optical members constituting the illumination optical system 28 and the projection optical system PL, the exposure light is transmitted. Rate decreases and the illuminance decreases, causing unevenness. That is, the exposure accuracy is greatly reduced.

When the exposure light passes through optical systems such as the illumination optical system 28 and the projection optical system PL, the transmittance of the exposure light per optical element is 99.5%, for example, to stably maintain a predetermined illuminance. The above needs to be secured. In the present embodiment, in the optical system through which the exposure light emitted from the light source passes before reaching the wafer W, the number of optical elements exposed to the air and easily affected by chemical contaminants is as follows. It is assumed that there are two optical elements (the optical element immediately below the reticle stage RST in the projection optical system PL and the optical element immediately above the wafer W). In this case, it is required that (0.995) ² = 0.990, that is, the rate of decrease in the transmittance of exposure light in the entire optical system due to chemical contaminants is 1.0% or less.

Therefore, when the exposure light is ArF excimer laser light, the difference between the concentration of organic matter contained in the air after passing through the chemical filter CF1a and the transmittance of the exposure light passing through the above optical system and the transmittance of the exposure light are described. The relationship was determined by experiment. As a result, as shown in FIG. Chemical Torr E emissions reduced concentration of organic matter contained in the air after passing through the filter CF 1 a is at the 30 tgZm ^3, transmission of the exposure light which has passed through the optical system The rate of decrease was 1.0%. Based on the experimental results, the chemical filter C Concentration of the organic material allowed the F 1 a to the air after passing through was defined as being ³ O ^ g / m 3 or less in toluene conversion.

However, in order to increase maintenance intervals and improve productivity, it is desirable that the transmittance of exposure light per optical element should be 99.9% or more. Therefore, when two optical elements are affected by a chemical contaminant as in this embodiment, (0.999) ² = 0.998, that is, the entire optical system due to the chemical contaminant It was determined that the rate of decrease in the transmittance of exposure light at 0.2% was preferably 0.2% or less. As shown in FIG. 6, according to an experiment, when the toluene concentration in terms of organic matter contained a chemical filter CF 1 a in the air after passing through the 1 0 At gZm ^3, transmission of the exposure light which has passed through the optical system The rate of decrease was 0.2%. Based on the results of this experiment, it was determined that the concentration of organic matter contained in air after passing through the chemical filter CF1a was desirably 10 μg / m ³ or less in terms of toluene.

Although the organic substance is not contained at all it is an ideal, defined because the detection limit of the analytical device currently used is 0. 1 gZm ^3, the lower limit value 0. 1 ^ gZm ^3. In other words, the lower limit is a value that varies depending on the detection limit of the analyzer.

That is, when the exposure light is A r F excimer laser light, chemical concentration of organic matter contained in the air after passing through the filter CF 1 a ^{is, 0. 1 g / m 3 ~30} A g / m with toluene terms ³ , preferably 0.1 gZm ³ to 10 ig / m ³ .

When the exposure light was KrF excimer laser light, in the experiment, as shown in Fig. 7, the toluene equivalent concentration of organic matter contained in air after passing through the chemical filter CF1a was 150 g. At / m ^3, the rate of decrease in the transmittance of the exposure light passing through the optical system was 1.0%. Based on the experimental results, the concentration of organic substances allowed in the air after passing through the chemical filter CF 1a was 1 '5 or less.

However, in order to increase the maintenance interval and improve the productivity, for the same reason as with the ArF excimer laser beam, the transmittance of exposure light in the entire optical system is reduced due to chemical contaminants. Is preferably 0.2% or less. As shown in FIG. 7, in the experiment, when toluene conversion concentration of organic matter contained a chemical filter CF 1 a in the air after passing the 5 O xgZm ^3, the transmittance has passed through the optical system exposure light The rate of decline was 0.2%. Based on the results of this experiment, it was determined that the concentration of organic substances contained in the air after passing through the chemical filter CF1a was desirably 50 μg / m ³ or less in terms of toluene. The lower limit was set to 0.1 Atg / m ³ for the same reason as in the case of ArF excimer laser light.

That is, when the exposure light is KrF excimer laser light, the concentration of organic matter contained in the air after passing through the chemical filter CF1a is 0.1 tg / mSl 50 ju gm, preferably 0, in terms of toluene. .1 AtgZm ^{3 to} 5 Og / m ³ must be maintained.

 Further, when the exposure light was ArF excimer laser light, the same experiment as that for the case of organic matter was performed for ammonia, sulfur oxides, and nitrogen oxides. Based on these experimental results, for the same reason as in the case of organic matter, the concentration range allowed in the air after passing through the chemical filter CF1a was defined.

That is, the concentration of ammonia as a chemical contaminant allowed in the air after passing through the chemical filter CF 1a is 0.01 g / m ^{3 to} 0.5 A 6 g / m ³ , preferably 0.1 tg. / m ^{3 to} 0.2 At gZm ³ must be maintained.

The concentration of sulfur oxides as chemical contaminants allowed in the air after passing through the chemical filter CF 1 a ^{is, 0. 01 ^ g / m 3} ~0. 5 tg / m 3, good Mashiku Must be maintained at 0. O l gZmS O. 2 gZm ³ is there.

Furthermore, the concentration of nitrogen oxides as the chemical contaminants that are allowed chemical filter CF 1 a in the air after passing, 0.01 ^ _§ Bruno ³ ~0. 5 ^{gZm 3,} preferably 0.01 igZm ³ 〜0.2 ^ gZm ³ must be maintained.

 For ammonia, sulfur oxides, and nitrogen oxides, the experimental results when the exposure light was KrF excimer laser light were almost the same as those when the exposure light was ArF excimer laser light. . Therefore, the above specified ranges for ammonia, sulfur oxides, and nitrogen oxides are the same when the exposure light is KrF excimer laser light.

 Hereinafter, the case where the exposure light is ArF excimer laser light will be described for convenience. In the present embodiment, an optical system or the like through which exposure light emitted from a light source passes has two optical elements that are affected by a chemical contaminant, but is not limited to this. Not something. Therefore, the above specified ranges may be different depending on the configuration of the optical system.

 Next, a description will be given of a procedure for manufacturing the chemical filter unit 140, which forms a part of the manufacturing process of the fan filter unit.

First, the concentrations of ammonia, sulfur oxides, nitrogen oxides, and organic substances as the chemicals to be removed contained in the air in the clean room where the fan filter unit is installed are measured by the analyzer (quantitative analysis). Is done. Then, for each chemical contaminant, this measurement result is compared with the above specified value, and a chemical substance exceeding the upper limit of the specified value is specified as a chemical substance to be removed. For example, if over the ammonia concentration in the air of clean rooms to 0. 5 At gZm ^3, ammonia is the removal target chemicals, also organic matter concentration in the air of the clean room 3 O ^ if beyond g / m ^3, organic substances are subject to removal of chemicals. Next, a filtration medium for selectively removing the chemical substance to be removed is selected. For example, if the chemical substance to be removed is ammonia, a filter medium that efficiently removes ammonia in the air is selected.If the chemical substance to be removed is organic, organic substances in the air are efficiently removed. The filter media to be removed is selected. If there are multiple chemicals to be removed, the most suitable filter medium is selected for each chemical to be removed. For example, if the chemicals to be removed are sulfur oxides and nitrogen oxides, a filter medium that efficiently removes sulfur oxides in the air and a filter medium that efficiently removes nitrogen oxides in the air The two filter media are selected.

 Then, the filter medium selected in this way is fixed by the holding frame and arranged in the chemical fill portion.

In the present embodiment, the case where the number of chemical substances to be removed is two is described as an example. However, it is obvious from the above description that the present invention is not limited to this. Here, it is assumed that the chemical substances to be removed are ammonia and organic substances. In this case, the filter section 140 of FIG. 4 is composed of a chemical filter 141 provided with a filter medium for efficiently removing ammonia in air and a filter medium for efficiently removing organic substances in air. And a chemical filter provided. Next, ammonia, sulfur oxide, and the like as chemicals to be removed in the air sent out from the outlet 170 of the fan filter unit having the filter section 140 constructed as described above, The concentrations of nitrogen oxides and organic substances are measured (quantitative analysis). Then, it is confirmed whether or not each chemical substance is within the specified range. If there is a chemical substance outside the above specified range, a filter medium for efficiently removing the chemical substance is added to the chemical filter section 140. That is, a plurality of the same filter media are provided. On the other hand, if the concentrations of ammonia, sulfur oxides, nitrogen oxides, and organic substances in the air sent from the outlet 170 of the fan filter unit 100 are all within the above specified range, the filter section 14 0 is determined to be the optimal configuration. That is, the fan filter unit 100 includes the filter section 140 that is optimal for the air in the clean room in the present embodiment.

 Next, the air conditioning in the exposure device to which the fan filter unit manufactured as described above is connected will be described.

 In the fan fill unit 100, when the power switch 167 is turned on by the operator, the blower 120 operates, and the air in the clean room is forcibly taken in from the outside air intake 110. At this time, the emergency stop output signal EMO output from the interface section 160 is at the “high” level indicating that the power supply switch 167 is on, indicating that the emergency stop output signal EMO is normal. This is a “high” level indicating that

 Ammonia is removed from the air sent from the blower 120 while passing through the chemical filter 141. Organic matter is removed from the air that has passed through the chemical filter 14 1 while passing through the chemical filter 14 2. As a result, the concentrations of ammonia, sulfur oxides, nitrogen oxides, and organic substances contained in the air that has passed through the filter section 140 all fall within the above-specified ranges.

 Further, particles included in the air that has passed through the chemical filter 142 are removed by the HEPA filter 150.

 The air that has passed through the HEPA filter 150 is supplied to the intake port 50 through a stainless steel duct 200 connected to the output port 170.

 In other words, ammonia and organic substances are selectively removed from the air in the clean room, and chemical-clean air whose concentrations of ammonia, sulfur oxides, nitrogen oxides, and organic substances are within the above specified ranges, respectively, are supplied to the fan. The light is supplied from the filter unit 100 to the exposure apparatus 10.

In the present embodiment, the chemical filter 14 1 is provided with a filter medium for removing ammonia, and the chemical filter 14 2 is provided with a filter medium for removing organic substances. However, the chemical filter 14 1 may be provided with a filter medium for removing organic substances, and the chemical filter 14 2 may be provided with a filter medium for removing ammonia.

 On the other hand, in the exposure device 10, when the power switch 95 is turned on by the operator, the first and second blowers 58, 64 are operated by the control device 70, whereby the filter box AF is operated. Air is fed into the reticle loader chamber 18, the wafer loader chamber 20, the exposure chamber 16 and the vicinity of the wafer stage WST in the exposure chamber 16 via the AF chambers 1, AF 2, AF 3, and AF 4, respectively. Air conditioning of each part is performed. In this case, air conditioning is performed in the reticle loader chamber 18 and the wafer loader chamber 20 by downflow. In the exposure chamber 16, air conditioning of each part of the exposure apparatus main body 22 during the above-described exposure operation is performed by a side flow. The air returned to the return duct 42 via the return sections 40 and 44, respectively, and the return section

The air returned to the return duct 48 via the return duct 46 and the air returned to the return duct 66 via the return ducts on the machine room 14 side (in the present embodiment, the machine room 14 Through the chemical filter CF 2a provided in the section).

 In the fan filter unit 100, the air in the clean room, in which the concentrations of ammonia, sulfur oxides, nitrogen oxides, and organic substances were suppressed within the specified ranges, was taken from the intake 50 through the duct 200. Supplied. Then, this air passes through the chemical filter CF2b, and is cooled to a predetermined temperature by the cooler 52 together with the air that has passed through the chemical filter CF2a. In this case, in the present embodiment, the control device 70 controls the cooling operation of the cooler 52 while monitoring the output of the first temperature sensor 54. At this time, the humidity of the air passing through the cooler portion is controlled. A temperature that is so depressed that condensation does not occur on the cooler surface at pressure, eg

It is cooled to a temperature slightly higher than 5 ° C or around 15 ° C. As described above, since condensation does not occur on the surface of the cooler 52, the drain piping system is not used in this embodiment. Not provided. However, the failure of the first temperature sensor 54 or the occurrence of some malfunction of the cooler 52 may make it difficult to control the surface temperature of the cooler 52 as described above. Therefore, in this embodiment, the drain pan 68 is provided in consideration of such an emergency.

 About 80% of the air that has passed through the cooler 52 and cooled to a predetermined temperature is sent to the second heater 56, and the remaining about 20% is consumed by the second heater in the branch passage 60.

It is sent to 2 and is heated to each target temperature. In this case, the control device

At 70, the first heater 56 is feedback-controlled based on the detection value of the second temperature sensor 72, and the second heater 62 is feedback-controlled based on the detection value of the third temperature sensor 74. . In this case, the target temperature of the air blown into the inside of the exposure chamber 16 and the like via the air supply pipe 24 and the target temperature of the air blown to the vicinity of the wafer stage WST through the branch 60 are: Each can be set individually.

 Then, the air heated to the respective target temperatures by the first and second heaters 56 and 62 is supplied to the chemical filters CF 1 a and CF 1 b by the first and second blowers 58 and 64, respectively. Sent in. The air that has passed through the chemical fill CF 1 a passes through the air supply line 24 in the chamber 12 and the filter boxes AF 1, AF 2, and AF 3, respectively, so that the reticle loader chamber # 8 and the wafer loader chamber 20. , Are sent into the exposure chamber 16 respectively. The air that has passed through the chemical filter CF1b passes through the filter box AF4 and is sent to the vicinity of the wafer stage WST (and the laser interferometer IF).

Particles in the air are almost certainly removed by passing through the ULPA filters in the filter boxes AF1, AF2, AF3, AF4, respectively, so the reticle loader chamber 18, wafer loader chamber 20, exposure Only high-purity air is supplied to the interior of the chamber 16 and to the vicinity of the J-stage WST, in the sense that it does not contain fine particles such as particles and chemical contaminants. Then, the reticle loader system, the wafer loader system, and the exposure apparatus main body 22 are air-conditioned. Then, this air conditioning is completed, and chemically contaminated air containing chemical contaminants resulting from degassing from the exposure apparatus main body 22 and the like is returned to the return ducts 42, 48, and 66. The air conditioning of each section is repeatedly performed as described above.

In this embodiment, the concentration of ammonia contained in the air before passing through the chemical filter CF Ί a chamber ί 2 1. O gZm ³ or less, the concentration of sulfur oxides 0. 5 / gZm ³ or less, It was possible to maintain the concentration of nitrogen oxides at 0.5 AtgZm ³ or less and the concentration of organic substances at 30 _g / m ³ or less in toluene.

 Furthermore, the concentration of ammonia contained in the air near the wafer W is 0.

Zm ³ or less and the concentration of organic substances could be maintained at 3 O g / m ³ or less in terms of toluene.

Also, the concentration of ammonia contained in the air in the wafer loader chamber could be kept at 0.5 g / m ³ or less.

 As the specified range set for the fan filter unit 100, the total concentration of ammonia, sulfur oxides, nitrogen oxides, and organic substances in the air sent from the outlet of the fan filter unit 100 is set. May be.

 Next, an interlocking operation between the control device 70 and the interface unit 160 of the fan filter unit in the present embodiment will be described.

 When the exposure device main body 22 and the air conditioner are operating normally, the control device 70 maintains the operation / stop input signal OPI at the “mouth” level and the emergency stop input signal EMI at the “high J level”. .

When the operator turns off the power switch 95 to stop the exposure apparatus main body 22 and the air conditioner, the controller 70 changes the operation Z stop input signal OPI to the high J level. On the other hand, the interface unit 160 of the fan filter unit confirms that the run / stop input signal OP I has changed to the “high” level. If it does, it activates relay 161, and shuts off the power supply to blower 120. As a result, the gas supply from the fan filter unit 100 is stopped. This is because the outside air is supplied from the fan filter unit 100 in a state where the air conditioner in the chamber 12 is not operating, the pressure in the machine room 14 increases, and the chemical filter CF 2a, CF 2b, and air conditioning equipment.

 Subsequently, when the operator turns on the power switch 167 of the exposure apparatus to operate the exposure apparatus main body 22 and the air conditioner, the controller 70 sets the operation Z stop input signal OPI to the “low” level. Change. On the other hand, when the interface section 160 of the fan filter unit recognizes that the operation stop input signal OPI has changed to the "low" level, the interface section 160 disables the relay 161, and switches to the blower 120. Supply power. Thus, the supply of gas from the fan filter unit 100 is restarted.

 Further, when the operator presses the emergency stop button 96 of the control rack, the control device 70 changes the emergency stop input signal EMI to the “mouth__ | level. On the other hand, the interface 1 of the fan filter unit 1 When the 60 recognizes that the emergency stop input signal EMI has changed to the "low" level, it disables the relay 162 and turns off the main power supply 1665 of the fan filter unit. In an emergency, it is desirable to stop all power supply so that unexpected abnormalities do not occur. If you want to operate the fan filter unit 00 again, check that there is no abnormality, and then manually turn on the main power supply 165.

When the operator presses the emergency stop button 166 of the fan filter unit, the interface unit 160 changes the emergency stop output signal EMO to the “mouth” level. On the other hand, when the control device 70 recognizes that the emergency stop output signal EMO has changed to the “mouth—J level”, it forcibly turns off the power supply 98 of the exposure device. Things can be expected in the entire exposure system This is because there is a possibility that abnormalities may occur. To operate the exposure apparatus 10 again, confirm that there is no abnormality, and then manually turn on the power supply 98.

 In the present embodiment, the configuration has been described in which the emergency stop output signal EMO is changed to the "mouth" level when the emergency stop button 166 is pressed, but the present invention is not limited to this configuration. For example, a sensor is installed at the outlet of the fan filter unit 100 to measure the concentration of chemical pollutants contained in the air that has passed through the filter. If it is determined that the allowable value is exceeded, for example, the interface unit 160 may change the emergency stop output signal EMO to the “low” level. By adopting such a configuration, it is possible to check the life of the filter or the abnormality of the filter, and to check that the concentration of the chemical contaminant in the chamber accommodating the exposure apparatus (or the exposure apparatus main body) increases. It can be effectively prevented.

When the operator turns off the power switch 167 to stop the fan filter unit 100, the interface unit 160 changes the error output signal ERO to the "mouth" level. On the other hand, when the control device 70 recognizes that the error output signal ERO has changed to the “low” level, the control device 70 turns on the outside air supply stop lamp 97 of the control rack. In the exposure apparatus 10, various preparation processes such as stabilization of the atmosphere and collection of various data are performed before the actual exposure processing operation is performed. That is, once the power supply 98 of the exposure apparatus is turned off, preparation time is required even if the power supply 98 is turned on again. On the other hand, with the fan filter unit 100, even when the power supply 98 of the exposure apparatus is on, the power supply switch 167 of the fan filter unit may be turned off to replace the filter or check for an abnormality. is there. If the power supply 98 of the exposure apparatus is automatically turned off in conjunction with the fan filter unit 100 in this case, a preparation time is required when the power supply 98 is turned on again. In other words, productivity decreases. To prevent this, if the power switch 1 6 7 of the fan filter unit becomes old for any reason other than an emergency stop, The power supply 98 of the exposure apparatus is not turned off, and only the outside air supply stop lamp 97 is lit to notify the operator in the evening. If the controller 70 is not notified that the supply of outside air from the fan filter unit 100 is stopped, the exposure device 10 may continue to operate without supplying outside air. In this case, the inside of the chamber 12 cannot be maintained at a positive pressure, and as a result, the environment in the chamber 12 cannot be maintained and controlled to a high degree. This, of course, has a negative impact on device quality and productivity.

 As described above in detail, according to the present embodiment, the concentration of chemical contaminants (ammonia, sulfur oxides, nitrogen oxides, and organic substances) contained in the air circulating in the exposure chamber 16 Is maintained within a specified range. As a result, it is possible to effectively suppress the occurrence of adverse effects such as a decrease in illuminance due to clouding of the optical members such as the illumination optical system and the projection optical system in the chamber over a long period of time.

 Further, the space near the wafer stage WST can maintain a chemically clean atmosphere in which the concentration of chemical contaminants (ammonia and organic substances) is maintained within a specified range.

 In addition, the wafer loader chamber 20 and the reticle loader chamber 18 maintain a chemical-clean atmosphere in which the concentrations of chemical contaminants (ammonia, sulfur oxides, nitrogen oxides, and organic substances) are maintained within specified ranges. be able to.

 Moreover, the service life of the chemical filters CF 2 a, CF 2 b, CF 1 a, and CF 1 b is extended, and replacement over a long period of time is not required. As a result, it is possible to improve productivity. it can.

 The fan filter unit according to the present embodiment is suitably applied not only to an exposure apparatus but also to other device manufacturing apparatuses, for example, an ion etching apparatus, a dry etching apparatus, a CVD apparatus, an asshing apparatus, an ion implantation apparatus, and the like. can do.

In the above embodiment, when manufacturing the fan filter unit, Although the description has been given of the case where the object to be removed is nitrogen, sulfur oxides, nitrogen oxides, and organic substances, the method for producing a fan-fill unit of the present invention is not limited thereto. That is, the method of manufacturing a fan filter unit of the present invention includes: a step of measuring the concentration of each of a plurality of types of chemical contaminants contained in the gas in the installation space; and Selecting at least one filter medium from a plurality of types of filter media that respectively remove types of chemical contaminants, and configuring the filter portion using the selected filter media. Just go there. In other words, the method of manufacturing a fan filter unit according to the present invention reduces the concentration of a chemical contaminant in the gas in the space where the fan filter unit is to be installed, in particular, the concentration of which needs to be suppressed. Based on the results of actual measurement, based on the measurement results, a filter medium for removing chemical contaminants whose concentration exceeds the specified value is selected or selectively combined to construct an optimal filter section. Is what it does. Therefore, if the fan filter unit manufactured as a result is used, the chemical contaminants whose concentration is measured in the gas sent out from the fan filter unit to the outside, that is, the chemical contaminants whose concentration needs to be suppressed in particular, are required. The concentration of pollutants can be kept within the specified range.

 The arrangement of the chemical filters C F1a and C F1b described in the above embodiment, and the configuration of the ventilation path and the like may be arbitrary. For example, a chemical filter C F1a may be provided in place of the filter box A F3 or together with the filter box A F3 in order to maintain the impurity concentration in the exposure apparatus 16 within the above specified range.

 In the above embodiment, the case where the reticle loader chamber, the wafer loader chamber, and the exposure chamber are provided in the chamber has been described. However, the present invention is not limited to this. Only the exposure chamber is provided in the chamber, and They may be provided together or separately in another environmental control chamber.

In the above embodiment, the case where a machine room is provided separately from the chamber is described. However, the present invention is not limited to this, and one chamber may be partitioned by a partition to form a chamber in which the exposure apparatus main body is housed and a machine room. This is because outside air can be supplied through the duct if an intake for connecting to the fan fill unit is formed.

 Although the machine room is arranged adjacent to the chamber in Fig. 1, the machine room may be arranged below the clean room floor (utility space). In this case, the light source may be arranged under the floor. This is because if an intake for connecting to the fan filter unit is formed, outside air can be supplied through the duct.

In the above embodiment has been described about the case of using the A r F excimer one The as a light source, not limited to this, K r F excimer laser as the light source, F ₂ Les - The, using the A r ₂ laser Alternatively, a metal vapor laser or a YAG laser may be used, and these harmonics may be used as illumination light for exposure. Alternatively, a single-wavelength laser beam in the infrared or visible range emitted from a DFB semiconductor laser or a fiber laser is doped with, for example, erbium (Er) (or both erbium and ytterbium (Yb)). Harmonics amplified by a fiber amplifier and wavelength-converted to ultraviolet light using a nonlinear optical crystal may be used as illumination light for exposure.

 In addition, the present invention is not limited to an exposure apparatus of a step-and-repeat method, a step-and-scan method, or a step-and-stitch method, for example, a mirror projection aligner and a proximity method exposure apparatus. , And a photo repeater. That is, the present invention can be applied regardless of the configuration of the exposure apparatus main body.

 《Device manufacturing method》

 Next, an embodiment of a device manufacturing method using an exposure apparatus to which the above-described fan filter unit is connected in a lithographic process will be described.

Figure 8 shows devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, Flow charts of manufacturing examples of thin-film magnetic heads, micromachines, etc.) are shown. As shown in FIG. 7, first, in step 301 (design step), a function and performance design of a device (for example, a circuit design of a semiconductor device) is performed, and a pattern design for realizing the function is performed. . Subsequently, in step 302 (mask manufacturing step), a mask on which the designed circuit pattern is formed is manufactured. On the other hand, in step 303 (wafer manufacturing step), a wafer is manufactured using a material such as silicon.

 Next, in step 304 (wafer processing step), using the mask and wafer prepared in steps 301 to 303, an actual circuit is formed on the wafer by lithography technology or the like as described later. Etc. are formed. Next, in step 304 (device assembling step), device assembly is performed using the wafer processed in step 304. This step 305 includes processes such as a dicing process, a bonding process, and a packaging process (chip encapsulation) as necessary.

 Finally, in step 300 (inspection step), the device manufactured in step 305 is inspected for an operation check test, a durability test, and the like. After these steps, the device is completed and shipped.

 FIG. 9 shows a detailed flow example of step 304 in the case of a semiconductor device. In FIG. 9, in step 311 (oxidation step), the surface of the wafer is oxidized. In step 312 (CVD step), an insulating film is formed on the wafer surface. In step 3 13 (electrode formation step), electrodes are formed on the wafer by vapor deposition. In step 3-4 (ion implantation step), ions are implanted into the wafer. Each of the above steps 311 to 3114 constitutes a pre-processing step of each stage of wafer processing, and is selected and executed according to a necessary process in each stage.

At each stage of the wafer process, when the above pre-treatment process is completed, The post-processing step is performed as described above. In this post-processing step, first, in steps 3-5 (registration forming step), a photosensitive agent is applied to the wafer. Subsequently, in step 316 (exposure step), the circuit pattern of the mask is transferred to the wafer by the exposure apparatus described above. Next, in Step 317 (development step), the exposed wafer is developed, and in Step 318 (etching step), the exposed members other than the portion where the resist remains are removed by etching. . Then, in step 319 (resist removing step), unnecessary resists after etching are removed.

 By repeating these pre-processing and post-processing steps, multiple circuit patterns are formed on the wafer.

 If the device manufacturing method of the present embodiment described above is used, the exposure step (step 316) uses the exposure apparatus 10 to which the fan filter unit 100 of the above embodiment is connected. As a result, it is possible to effectively suppress a decrease in exposure accuracy due to a chemical contaminant or the like, and thereby a highly integrated device can be manufactured with high productivity. Industrial applicability

 As described above, the fan filter unit of the present invention is suitable for efficiently removing specific chemical substances contained in the installed atmosphere and producing a chemically clean gas. Further, the method for manufacturing a fan filter unit of the present invention is suitable for manufacturing a fan filter unit that efficiently removes a specific chemical substance contained in an installed atmosphere. Further, the exposure apparatus of the present invention is suitable for forming a pattern on a substrate. Further, the device manufacturing method of the present invention is suitable for producing a highly integrated microdevice.

Claims

The scope of the claims 1. A fan-fill unit that removes chemical contaminants contained in gas and sends it out.  A unit body with a gas descendant path formed therein; A blower arranged inside the unit main body, for sucking the gas into the flow path and sending out the gas passing through the flow path to the outside of the unit main body; The chemical to be removed is a chemical that is disposed in the flow path portion and contains at least one specific chemical substance of ammonia, sulfur oxide, and nitrogen oxide contained in the gas that passes through the flow path. A filter unit for adjusting the concentration of the specific chemical substance contained in the gas after passing through the gas to a concentration in the range of 0.0 lg / m ^{3 to} 0.5 gZm ³ . Cut. 2. In the fan filter unit according to claim 1, The filter unit, said specified chemical concentrations of substances _{0. 01 / α β / / Γη} 3 ~ 0 contained in said gas after passing through. 2 ^ FEATURE: to adjust the concentration in the range of GZm ³ Fanfill evening. 3. In the fan filter unit according to claim 1,  The chemical substance to be removed further includes an organic substance, The filter unit is characterized in that the concentration of the organic substance contained in the gas after passing the gas is adjusted to a concentration in the range of 0.1 Atg / m ³ to 30 At g / m ³ in toluene. Fanfill evening. 4. The fan filter unit according to claim 3, wherein the filter unit is configured to determine the concentration of the organic substance contained in the gas after passing through the filter unit from 0.1 g / m ³ to 10 At in terms of toluene. fan filter Interview Knitting Bok, characterized by adjusting the concentration in the range of g / m ^3. 5. The fan filter unit according to claim 1,  A fan filter unit, comprising: a supply unit provided on the unit main body, for supplying the gas having passed through the filter unit to a device manufacturing apparatus. 6. The fan filter unit according to claim 5,  The device manufacturing apparatus is an exposure apparatus that forms a predetermined pattern on the substrate by exposing the substrate through an optical system using an energy beam.  The supply unit is connected to a chamber accommodating at least a part of the exposure apparatus. 7. A method for producing a fan filter unit that removes a chemical contaminant contained in a gas by a filter unit and sends the gas to the outside,  Measuring each of the concentrations of a plurality of chemical contaminants contained in the gas in the installation space;  Based on the measurement result, at least one filter medium is selected from a plurality of types of filter media that respectively remove the plurality of types of chemical contaminants from the gas, and the selected filter medium is used. Forming the filter unit by using the above method. 8. The method for producing a fan fill unit according to claim 7, A method for producing a fan filter unit, wherein the chemical contaminants to be measured include at least one of ammonia, sulfur oxides, nitrogen oxides, and organic substances. 9. An exposure apparatus for exposing a substrate with an energy beam through an optical system to form a predetermined pattern on the substrate,  2. A chamber connected to the fan filter unit according to claim 1, to which a gas in which chemical contaminants are suppressed is supplied via the fan filter unit; and a configuration including at least a part of an optical path of the energy beam. An exposure device main body, a part of which is housed in the chamber, and which exposes the substrate to the energy beam via a through-beam optical system. 10. An exposure apparatus connected to the fan filter unit,  An exposure apparatus main body for exposing a substrate to an energy beam through an optical system to form a predetermined pattern on the substrate;  A chamber accommodating at least a part of the exposure apparatus main body including at least a part of an optical path of the energy beam, and supplying a gas in which chemical contaminants are suppressed through the fan filter unit; With Ammonia contained in the gas in the chamber, sulfur oxides, and the concentration of nitrogen oxides, characterized by being respectively maintained in a concentration ranging from ^{0. 0 1 ^ gZm 3 ~0.} 5 igZm 3 Exposure apparatus. 1 1-The exposure apparatus according to claim 0, Ammonia contained in the gas in the chamber, sulfur oxides, and the concentration of nitrogen oxides, characterized by being respectively maintained in a concentration ranging from ^{0. 0 1 8 3 ~ 0.} 2 At gZm 3 Exposure apparatus. 1 2. The exposure apparatus according to claim 10, wherein  An exposure apparatus, further comprising a chemical substance removal filter disposed in the chamber and using at least one of ammonia, sulfur oxides, and nitrogen oxides as a substance to be removed. 1 3. An exposure device connected to the fan filter unit,  An exposure apparatus main body for exposing the substrate with an energy beam through a re-optical system to form a predetermined pattern on the substrate;  A chamber in which at least a part of the main body of the exposure apparatus including at least a part of an optical path of the energy beam is accommodated, and a gas in which a chemical contaminant is suppressed through the fan filter unit is supplied; With;  An exposure apparatus, wherein the concentration of an organic substance contained in the gas in the chamber is maintained at a concentration within an allowable range corresponding to the wavelength of the energy beam. . 1 4. The exposure apparatus according to claim 13, The energy beam wavelength 1 93 nm of A r F excimer laser beam at § Li, the concentration of organic matter contained in the gas in the chamber is in the range of ^{0. 1 g / m 3 ~30 gZm} 3 in toluene terms Characterized by being maintained at a concentration 1 5. The exposure apparatus according to claim 4, The concentration of organic substances contained in the gas in the chamber is maintained at a concentration in the range of 0.1 Atg / m ³ to 10 At g / m ³ in terms of toluene. 1 6. The exposure apparatus according to claim 13, The energy beam is a K r F excimer one laser light of wavelength 248 nm, the concentration of organic matter contained in the gas in the chamber, the ^{0. 1 tg / m 3 ~1 50} tg / m 3 in toluene terms Characterized by being maintained in a range of concentrations 1 7. The exposure apparatus according to claim 6, wherein An exposure apparatus, wherein the concentration of an organic substance contained in the gas in the chamber is maintained at 0.1 g / m ³ to 50 g / m ³ in toluene. 1 8. The exposure apparatus according to claim 13,  An exposure apparatus, further comprising a chemical substance removing filter disposed in the chamber and configured to remove at least an organic substance as a substance to be removed. 1 9. An exposure unit connected to the fan filter unit,  An exposure apparatus main body for exposing the substrate with an energy beam through an optical system to form a predetermined pattern on the substrate;  A chamber in which at least a part of the exposure apparatus main body is accommodated, and a gas in which a chemical contaminant is suppressed is supplied through the fan filter unit;  An air conditioner for performing air conditioning in the chamber;  A control device for controlling the fan filter unit, the air conditioner, and the exposure device main body in accordance with each other's operating state. 20. The exposure apparatus according to claim 19, The control device may be configured to control the air conditioner and the exposure apparatus main body to be in a state where the power supply is off or the emergency stop is performed. An exposure apparatus for stopping supply of gas into the chamber. 21. The exposure apparatus according to claim 19,  An exposure apparatus, wherein the controller stops power supply to the air conditioner and the exposure apparatus main body when the operation state of the fan filter unit is an emergency stop. 22. In the exposure apparatus according to claim 19,  An alarm device for notifying the outside air supply status from the fan filter unit,  The exposure apparatus, wherein when the operating state of the fan-fill unit is power off, the control device notifies the outside that the supply of outside air has been stopped using the alarm device. 2 3. A device manufacturing method including a lithographic process,  A device manufacturing method, comprising: performing exposure using the exposure apparatus according to any one of claims 9 to 22 in the lithographic process.