Exposure apparatus and air-conditioning apparatus for use with exposure apparatus

Abstract

Air-conditioning is effected in a chamber of an exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure. The chamber houses at least a part of the exposure apparatus. An impurity-removing filter is provided for removing gaseous impurities from a stream of ambient air being introduced into the chamber and/or from a gas stream recirculating in the chamber. A pair of impurity-concentration-measuring devices are disposed upstream and downstream, respectively, of the filter. End-of-life of the filter is determined based on measurements from the impurity-concentration-measuring devices. Introducing the ambient air into the chamber is stopped when the impurity-concentration-measuring device disposed upstream of the filter has indicated a gaseous impurity concentration above a predetermined level. The integrity of the airtightness of the chamber around a negative pressure area in the chamber is sensed. When a failure in airtightness is detected, the failure is indicated and/or the recirculation of a gas stream in the chamber is stopped to prevent the ambient air containing impurities from leaking into the chamber under the influence of the negative pressure. In the exposure apparatus, among others the photosensitized substrate and the illumination optical system are quite sensitive to impurities, so that dehumidified gas is supplied to the areas around them. An air-conditioning apparatus for effecting air-conditioning to the chamber is separated from the chamber, and an impurity-removing filter element is disposed in a gas supply duct in the air-conditioning apparatus.

What is claimed is:  
     
         1 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    an ambient air introducing unit for introducing ambient air into said chamber;    an impurity-removing filter for removing gaseous impurities from one of gas streams including a stream of ambient air being introduced into said chamber and a gas stream recirculating in said chamber;    a pair of impurity-concentration-measuring devices disposed upstream and downstream, respectively, of said impurity-removing filter; and    a filter end-of-life determination device for determining end-of-life of said impurity-removing filter based on measurements from said impurity-concentration-measuring device disposed upstream of said impurity-removing filter and measurements from said impurity-concentration-measuring device disposed downstream of said impurity-removing filter.    
     
     
         2 . An exposure apparatus according to  claim 1 , wherein: 
 said impurity-removing filter is arranged for removing gaseous impurities from said stream of ambient air being introduced into said chamber, and wherein said exposure apparatus further comprises a control device for stopping operation of said ambient air introducing unit when said impurity-concentration-measuring device disposed upstream of said impurity-removing filter has indicated a gaseous impurity concentration above a predetermined level.    
     
     
         3 . An exposure apparatus according to  claim 1 , wherein: 
 each of said impurity-concentration-measuring devices measures concentration of at least one of impurities including ammonium ion (NH 4   + ) and sulfate ion (SO 4   2− ).    
     
     
         4 . An exposure apparatus according to  claim 1 , wherein: 
 each of said impurity-concentration-measuring devices measures concentration of organosilicon compounds.    
     
     
         5 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    an ambient air introducing unit for introducing ambient air into said chamber;    an impurity-removing filter for removing gaseous impurities from a stream of ambient air being introduced into said chamber;    an impurity-concentration-measuring device disposed upstream of said ambient air introducing unit; and    a control device for stopping operation of said ambient air introducing unit when said impurity-concentration-measuring device has indicated a gaseous impurity concentration above a predetermined level.    
     
     
         6 . An exposure apparatus according to  claim 5 , wherein: 
 said impurity-concentration-measuring device measures concentration of at least one of impurities including ammonium ion (NH 4   + ) and sulfate ion (SO 4   2− ).    
     
     
         7 . An exposure apparatus according to  claim 5 , wherein: 
 said impurity-concentration-measuring device measures concentration of organosilicon compounds.    
     
     
         8 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus, said chamber having an air inlet for introducing ambient air into said chamber;    a gas-recirculating device disposed in said chamber for producing a gas stream recirculating in said chamber while generating a negative pressure area near said air inlet; and    an airtightness-integrity-sensing device for sensing integrity of airtightness of said chamber around said negative pressure area.    
     
     
         9 . An exposure apparatus according to  claim 8 , further comprising: 
 a control device for taking, when a failure of integrity of airtightness of said chamber is detected by means of said airtightness-integrity-sensing device, at least one of actions including providing an alarm of a failure of integrity of airtightness and stopping operation of said gas-recirculating device.    
     
     
         10 . An exposure apparatus according to  claim 8 , wherein: 
 said airtightness-integrity-sensing device comprises a differential pressure gauge.    
     
     
         11 . An exposure apparatus according to  claim 8 , wherein: 
 said airtightness-integrity-sensing device comprises an anemometer disposed in said air inlet of said chamber.    
     
     
         12 . An exposure apparatus according to  claim 8 , further comprising: 
 a first gaseous-impurity-removing device disposed in said air inlet of said chamber; and    a second gaseous-impurity-removing device disposed in a flow path of said gas stream recirculating in said chamber.    
     
     
         13 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiations;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus, said chamber having an air inlet for introducing ambient air into said chamber;    a gas-recirculating device disposed in said chamber for producing a gas stream recirculating in said chamber while generating a negative pressure area near said air inlet;    an airtightness-integrity-sensing device for sensing integrity of airtightness of said chamber around said negative pressure area; and    a control device for taking, when a failure of integrity of airtightness of said chamber is detected by means of said airtightness-integrity-sensing device, at least one of actions including providing an alarm of a failure of integrity of airtightness and stopping operation of said gas-recirculating device.    
     
     
         14 . An exposure apparatus according to  claim 13 , wherein: 
 said airtightness-integrity-sensing device comprises a differential pressure gauge.    
     
     
         15 . An exposure apparatus according to  claim 13 , wherein: 
 said airtightness-integrity-sensing device comprises an anemometer disposed in said air inlet of said chamber.    
     
     
         16 . An exposure apparatus according to  claim 13 , further comprising: 
 a first gaseous-impurity-removing device disposed in said air inlet of said chamber; and    a second gaseous-impurity-removing device disposed in a flow path of said gas stream recirculating in said chamber.    
     
     
         17 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiations;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus, said chamber having an air inlet for introducing ambient air into said chamber;    a gas-recirculating device disposed in said chamber for producing a gas stream recirculating in said chamber while generating a negative pressure area near said air inlet;    a differential pressure gauge for sensing integrity of airtightness of said chamber around said negative pressure area;    a control device for taking, when a failure of integrity of airtightness of said chamber is detected by means of said differential pressure gauge, at least one of actions including providing an alarm of a failure of integrity of airtightness and stopping operation of said gas-recirculating device;    a first gaseous-impurity-removing device disposed in said air inlet of said chamber; and    a second gaseous-impurity-removing device disposed in a flow path of said gas stream recirculating in said chamber.    
     
     
         18 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiations;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus, said chamber having an air inlet for introducing ambient air into said chamber;    a gas-recirculating device disposed in said chamber for producing a gas stream recirculating in said chamber while generating a negative pressure area near said air inlet;    an anemometer disposed in said air inlet of said chamber for sensing integrity of airtightness of said chamber around said negative pressure area;    a control device for taking, when a failure of integrity of airtightness of said chamber has been detected by means of said anemometer, at least one of actions including providing an alarm of a failure of integrity of airtightness and stopping operation of said gas-recirculating device;    a first gaseous-impurity-removing device disposed in said air inlet of said chamber; and    a second gaseous-impurity-removing device disposed in a flow path of said gas stream recirculating in said chamber.    
     
     
         19 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiations;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    a gas supply device for supplying dehumidified gas to a desired area around said exposure apparatus.    
     
     
         20 . An exposure apparatus according to  claim 19 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         21 . An exposure apparatus according to  claim 19 , further comprising: 
 a gaseous-impurity-removing filter and a dehumidifier, wherein said dehumidified gas is generated by causing a gas stream to pass through said gaseous-impurity-removing filter and then through said dehumidifier.    
     
     
         22 . An exposure apparatus according to  claim 19 , wherein: 
 said desired area around said exposure apparatus includes an area of said illumination optical system.    
     
     
         23 . An exposure apparatus according to  claim 19 , wherein: 
 said desired area around said exposure apparatus includes an area on and around said photosensitized substrate.    
     
     
         24 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    a gas supply device for supplying dehumidified gas to an area of said illumination optical system;    wherein said dehumidified gas is generated by causing a gas stream to pass through a gaseous-impurity-removing filter and then through a dehumidifier.    
     
     
         25 . An exposure apparatus according to  claim 24 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         26 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiations;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    a gas supply device for supplying dehumidified gas to an area on and around said photosensitized substrate;    wherein said dehumidified gas is generated by causing a gas stream to pass-through a gaseous-impurity-removing filter and then through a dehumidifier.    
     
     
         27 . An exposure apparatus according to  claim 26 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         28 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    a gas supply device for supplying dehumidified gas to an area on and around said photosensitized substrate; and    an antistatic device provided for parts which come into contact with said photosensitized substrate in a local atmosphere in said area to which said dehumidified gas is supplied.    
     
     
         29 . An exposure apparatus according to  claim 28 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         30 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    a gas supply device for supplying dehumidified gas to an area on and around said photosensitized substrate; and    a humidity-measuring device for measuring humidity of a local atmosphere in said area on and around said photosensitized substrate; and    a control device for controlling said gas supply device based on humidity data from said humidity-measuring device.    
     
     
         31 . An exposure apparatus according to  claim 30 , further comprising: 
 a gaseous-impurity-removing filter and a dehumidifier, wherein said dehumidified gas is generated by causing a gas stream to pass through said gaseous-impurity-removing filter and then through said dehumidifier.    
     
     
         32 . An exposure apparatus according to  claim 30 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         33 . An exposure apparatus according to  claim 30 , wherein: 
 an antistatic device is provided for parts which come into contact with said photosensitized substrate in a local atmosphere in said area to which said dehumidified gas is supplied.    
     
     
         34 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    a gas supply device for supplying dehumidified gas to an area on and around said photosensitized substrate;    a sensing device for sensing the existence of said photosensitized substrate; and    a control device for controlling said gas supply device based on sensing data from said sensing device in order to adjust the supply of said dehumidified gas depending on presence/absence of said photosensitized substrate.    
     
     
         35 . An exposure apparatus according to  claim 34 , further comprising: 
 a gaseous-impurity-removing filter and a dehumidifier, wherein said dehumidified gas is generated by causing a gas stream to pass through said gaseous-impurity-removing filter and then through said dehumidifier.    
     
     
         36 . An exposure apparatus according to  claim 34 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         37 . An exposure apparatus according to  claim 34 , wherein: 
 an antistatic device is provided for parts which come into contact with said photosensitized substrate in a local atmosphere in said area to which said dehumidified gas is supplied.    
     
     
         38 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into said mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus;    a gas supply device for supplying dehumidified gas to an area on and around said photosensitized substrate;    a humidity-measuring device for measuring humidity of a local atmosphere in said area on and around said photosensitized substrate;    a sensing device for sensing the existence of said photosensitized substrate; and    a control device for controlling said gas supply device based on humidity data from said humidity-measuring device and sensing data from said sensing device in order to adjust supply of said dehumidified gas depending on presence/absence of said photosensitized substrate.    
     
     
         39 . An exposure apparatus according to  claim 38 , further comprising: 
 a gaseous-impurity-removing filter and a dehumidifier, wherein said dehumidified gas is generated by causing a gas stream to pass through said gaseous-impurity-removing filter and then through said dehumidifier.    
     
     
         40 . An exposure apparatus according to  claim 38 , wherein: 
 said dehumidified gas comprises dehumidified ambient air.    
     
     
         41 . An exposure apparatus according to  claim 38 , wherein: 
 an antistatic device is provided for parts which come into contact with said photosensitized substrate in a local atmosphere in said area to which said dehumidified gas is supplied.    
     
     
         42 . An air-conditioning apparatus for removing impurities from gas, adapted for effecting air-conditioning to a semiconductor device factory and/or an exposure apparatus, comprising: 
 a body housing;    a gas supply duct housed in said body housing; and    an impurity-removing filter element disposed inside said gas supply duct.    
     
     
         43 . An air-conditioning apparatus according to  claim 42 , wherein: 
 said impurity-removing filter element comprises a hollow cylindrical body.    
     
     
         44 . An air-conditioning apparatus according to  claim 42 , wherein: 
 said impurity-removing filter element comprises a bellows wall.    
     
     
         45 . An air-conditioning apparatus according to  claim 42 , wherein: 
 said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.    
     
     
         46 . An air-conditioning apparatus for removing impurities from gas, adapted for effecting air-conditioning to a semiconductor device factory and/or an exposure apparatus, comprising: 
 a body housing;    a gas supply duct housed in said body housing; and    an impurity-removing filter element comprising a hollow cylindrical body and disposed inside said gas supply duct;    wherein said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.    
     
     
         47 . An air-conditioning apparatus for removing impurities from gas, adapted for effecting air-conditioning to a semiconductor device factory and/or an exposure apparatus, comprising: 
 a body housing;    a gas supply duct housed in said body housing; and    an impurity-removing filter element comprising a bellows wall and disposed inside said gas supply duct;    wherein said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.    
     
     
         48 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into a mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    an air-conditioning apparatus for effecting conditioning of gas in said chamber, said air-conditioning apparatus being disposed outside said chamber and comprising a body housing, a gas supply duct housed in said body housing and an impurity-removing filter element disposed inside said gas supply duct.    
     
     
         49 . An exposure apparatus according to  claim 48 , wherein: 
 said impurity-removing filter element comprises a hollow cylindrical body.    
     
     
         50 . An exposure apparatus according to  claim 48 , wherein: 
 said impurity-removing filter element comprises a bellows wall.    
     
     
         51 . An exposure apparatus according to  claim 48 , wherein: 
 said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.    
     
     
         52 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into a mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    an air-conditioning apparatus for effecting conditioning of gas in said chamber, said air-conditioning apparatus being disposed outside said chamber and comprising a body housing, a gas supply duct housed in said body housing and an impurity-removing filter element disposed inside said gas supply duct, said impurity-removing filter element comprises a hollow cylindrical body;    wherein said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.    
     
     
         53 . An exposure apparatus for transferring a pattern formed on a mask onto a photosensitized substrate by exposure, comprising: 
 a light source for emitting a light beam having a wavelength falling in a range from ultraviolet to deep ultraviolet radiation;    an illumination optical system for directing said light beam from said light source into a mask;    an exposure unit for making exposure of a photosensitized substrate in order to transfer said pattern formed on said mask onto said photosensitized substrate;    a chamber for housing at least a part of said exposure apparatus; and    an air-conditioning apparatus for effecting conditioning of gas in said chamber, said air-conditioning apparatus being disposed outside said chamber and comprising a body housing, a gas supply duct housed in said body housing and an impurity-removing filter element disposed inside said gas supply duct, said impurity-removing filter element comprises a bellows wall;    wherein said impurity-removing filter element is so supported by a support member as to be kept out of contact with an inner wall of said gas supply duct.