Abstract:
An exposure apparatus for exposing a substrate using a plurality of masters. The apparatus includes a stage being able to install at least one of the plurality of masters, a first housing surrounding said stage, a second housing for stocking at least one of the plurality of masters, the second housing being installed adjacent to the first housing or installed in an interior of the first housing, the second housing being allowed to communicate with the first housing, and a third housing being installed between an inside space and an outside space of the first housing, the third housing being different from said first and second housings. The first and second housings are filled by an inert gas or are adapted to be evacuated.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an exposure apparatus for exposing a substrate such as a wafer or glass plate coated with a photosensitive agent to a circuit pattern on a master such as a reticle or mask in a lithography step for manufacturing various devices such as a semiconductor element, liquid crystal element, and thin-film magnetic head and, particularly, to a master transfer system for the exposure apparatus. 
     BACKGROUND OF THE INVENTION 
     An exposure apparatus for manufacturing a semiconductor integrated circuit irradiates a wafer with an exposure beam of various wavelength bands in accordance with a circuit pattern. An exposure beam emitted by a light source illuminates a reticle via an illumination optical system. A fine circuit pattern formed on the reticle is imaged onto a wafer via a projection optical system by exposure and transfer. 
     In order to increase the integration degree of a semiconductor integrated circuit, the circuit pattern must shrink in feature size, which requires a higher resolving power of the projection optical system. Effective means for increasing the resolving power are a method of increasing the numerical aperture (also called NA) of the projection optical system and a method of decreasing the wavelength of an exposure beam. 
     As exposure beams, a g-line (wavelength: 436 [nm]), an i-line (wavelength: 365 [nm]), a KrF excimer laser (wavelength: 248 [nm]), and an ArF excimer laser (wavelength: 193 [nm]) have already been put into practice. An exposure technique by an F 2  excimer laser (wavelength: 157 [nm]) as a next-generation exposure beam has been put into practical use. 
     The wavelength band of the F 2  excimer laser is different from the conventional ones described above in that light is readily absorbed by oxygen or moisture. It is also known that light is absorbed by ammonia (NH 3 ), carbon dioxide (CO 2 ), organic gas, ozone, and the like. The atmosphere in the optical path of an F 2  laser beam must be controlled to suppress a light absorber to low density. Hence, the atmosphere in the optical path around a reticle and wafer often exchanged on the exposure apparatus is also controlled similarly to the atmosphere in optical systems such as an illumination optical system and a projection optical system. As an effective atmospheric control method, the optical path space is purged with inert gas such as helium gas (He) or nitrogen gas (N 2 ), or the optical path space is evacuated. 
     In terms of the throughput of the exposure apparatus, control of the optical path atmosphere enables exposure at high illuminance and shortens the exposure time, resulting in high throughput. To achieve higher throughput, however, the exchange time for reticles and wafers which are frequently exchanged must also be shortened. In recent years, a multiple exposure method of exposing the same shot on a wafer a plurality of number of times by using circuit patterns on a plurality of reticles has been put into practical use, improving the image quality of exposure/transfer on a wafer. Demands become stronger for shortening the time taken to transfer a substrate such as a reticle or wafer. 
     Prior art examples of a substrate transfer system for a reticle or the like in an exposure apparatus will be described. 
     Japanese Patent Laid-Open No. 7-321179 discloses a system of loading a reticle from a reticle library to a predetermined position in a temporary stocker by a multiaxial robot hand, and transferring the reticle to a reticle stage by a robot hand having vertical and rotating driving shafts. 
     Japanese Patent Laid-Open No. 2000-294496 discloses a substrate transfer system coping with an openable closed substrate vessel called an SMIF pod. In this system, a substrate in the SMIF pod is loaded into an exposure apparatus by an opening/closing elevating mechanism called an SMIF indexer. The substrate is transferred to a temporary substrate stocker by a first multiaxial robot, and transferred by a second multiaxial robot to a pre-alignment stage for aligning a substrate to a predetermined reference. The substrate is then transferred by a transfer hand to a substrate stage for holding a substrate. 
     Japanese Patent Laid-Open No. 6-260386 discloses an exposure apparatus and a reticle transfer system. This apparatus comprises a first chamber in which a reticle to be exposed is airtightly contained and the interior is purged with inert gas, a reticle exchange mechanism for exchanging the reticle with one to be exposed next, a second chamber in which the reticle to be exposed next is airtightly contained and the interior is purged with inert gas, and an opening/closing means for interrupting/allowing communication between the first and second chambers. 
     Of these prior art systems, Japanese Patent Laid-Open Nos. 7-321179 and 2000-294496 aim to shorten the substrate transfer time. Japanese Patent Laid-Open No. 6-260386 aims to enable reticle exchange without disturbing the inert gas atmosphere in the reticle stage space. 
     However, the prior art systems suffer from the following problems. 
     Japanese Patent Laid-Open Nos. 7-321179 and 2000-294496 do not disclose any atmosphere control means regarding the space around a reticle. These systems are not practical reticle transfer systems in an exposure apparatus using an F 2  excimer laser as described above. If the atmosphere in the whole reticle transfer system disclosed is simply controlled to reduce a light absorber, the exposure apparatus becomes bulky, complicated in structure, and very high in cost. 
     Japanese Patent Laid-Open No. 6-260386 discloses a system of purging the space around a reticle with inert gas, as described above. However, the second chamber is a so-called load-lock chamber. In the layout of directly connecting the load-lock chamber to the first chamber, a reticle to be exposed next is supplied only after the completion of gas purge in the load-lock chamber for every reticle exchange. This system is effective only when the reticle exchange frequency is very low and the time required to complete gas purge of the load-lock chamber is shorter than the reticle exchange interval. If the reticle exchange frequency is very high, the throughput greatly decreases. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to overcome the conventional drawbacks, and has as its object to provide a high-throughput exposure apparatus for realizing both low light absorption loss in the optical path of an exposure beam around a master and a short master exchange time. 
     According to the present invention, the foregoing object is attained by providing an exposure apparatus for transferring a pattern on a master onto a substrate via an optical system comprising: 
     a first housing for surrounding an exposure position of the master; 
     a second housing for stocking the master; and 
     a third housing for transferring the master between an inside and an outside of said first housing, 
     wherein an interior of each housing is controlled to a predetermined atmosphere. 
     Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing an exposure apparatus according to the first embodiment of the present invention; 
     FIG. 2 is a perspective view showing the second embodiment of the present invention; 
     FIG. 3 is a perspective view showing the third embodiment of the present invention; 
     FIG. 4 is a view showing a semiconductor device production system including the exposure apparatus according to an embodiment of the present invention when viewed from a given angle; 
     FIG. 5 is a view showing the semiconductor device production system including the exposure apparatus according to the embodiment of the present invention when viewed from another angle; 
     FIG. 6 is a view showing an example of a user interface in the semiconductor device production system including the exposure apparatus according to the embodiment of the present invention; 
     FIG. 7 is a flow chart for explaining a device manufacturing apparatus process performed by the exposure apparatus according to the embodiment of the present invention; and 
     FIG. 8 is a flow chart for explaining a wafer process performed by the exposure apparatus according to the embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     &lt;First Embodiment&gt; 
     FIG. 1 is a perspective view showing an exposure apparatus according to the first embodiment of the present invention. FIG. 1 particularly shows the interior of a chamber which covers the overall exposure apparatus, keeps the interior of the exposure apparatus at a predetermined temperature, and keeps dust to a low level. 
     In FIG. 1, reference numeral  1  denotes a reticle bearing a circuit pattern. This circuit pattern is illuminated via an illumination optical system (not shown) with a beam emitted by an F 2  excimer laser having an oscillation wavelength around 157 [nm]. The pattern is projected on a wafer  3  at a predetermined magnification via a projection optical system  2 . The wafer  3  is set on a wafer stage  4  having driving shafts in at least the X and Y directions of the coordinate system shown in FIG.  1 . The reticle  1  is set on a reticle stage (not shown), and driven in at least the Y direction. The exposure apparatus shown in FIG. 1 is a step and scan type exposure apparatus, which performs scanning exposure in the Y direction while making the reticle  1  and wafer  3  be in synchronism with each other, and sequentially moves the target shot to a next one, step by step. 
     Reference numerals  5  and  6  denote pods, which are openable closed vessels for storing a plurality of reticles  1  and are called SMIF pods; and  7  and  8 , SMIF indexers having driving mechanisms (not shown) for opening the SMIF pods  5  and  6  so as to allow extracting the reticles  1  from the SMIF pods  5  and  6 . The reticles  1  ready to be unloaded by the SMIF indexers  7  and  8  are extracted by a multiaxial transfer robot  9 , and transferred to a load-lock chamber  11  along a guide  10 . One side of the load-lock chamber  11  is equipped with an opening/closing unit  12 . The reticle  1  transferred by the multiaxial transfer robot  9  is loaded into the load-lock chamber  11  via the opening/closing unit  12 , which is open. After that, the opening/closing unit  12  is closed, and a nitrogen gas purge control  13  purges the interior of the load-lock chamber  11  with nitrogen gas. 
     Although the first embodiment exemplifies the use of nitrogen gas, the present invention may use helium gas or adopt evacuation without using any inert gas. A desirable atmosphere will be described in detail below. 
     After the interior of the load-lock chamber  11  is purged to a predetermined state with nitrogen gas, an opening/closing unit  14  on the other side of the load-lock chamber  11  is opened, and the reticle  1  in the load-lock chamber  11  is extracted by a multiaxial transfer robot  15 . Whether nitrogen gas purge in the load-lock chamber  11  reaches a predetermined state is judged by a control unit (not shown) on the basis of the detection result of a gas detector  16 . If nitrogen gas purge is judged to reach the predetermined state, the opening/closing unit  14  is opened. The multiaxial transfer robot  15  receives the reticle  1  in the load-lock chamber  11  and transfers it to a temporary reticle stock unit  17 . 
     The temporary reticle stock  17  has a shelf-like structure (shelf-like stock unit) so as to stock a plurality of reticles  1 , and a shelf elevating mechanism (not shown) movable in the Z direction so as to adjust the reticle transfer height of the multiaxial transfer robot  15  to the height of a shelf to which the reticle  1  is to be stocked. The temporary reticle stock unit  17  further comprises a detection unit (not shown) for detecting the presence/absence of the reticle  1  on each shelf, and a reading unit (not shown) for a barcode formed at a predetermined position of the reticle  1 . All information about the relationship between stocked reticles  1  and their shelves is stored in the control unit (not shown). 
     The above-described operation is repeated parallel to an exposure operation of a circuit pattern on the reticle  1  at an exposure position. The temporary reticle stock unit  17  stocks a plurality of reticles  1  up to a stockable number of reticles. 
     Of a plurality of reticles  1  stocked in the temporary reticle stock unit  17 , one to be exposed next is extracted by the multiaxial transfer robot  15 , and set on an alignment stage  18 . The reticle  1  is aligned in the X direction, the Y direction, or a direction around the Z-axis on the alignment stage  18  so as to decrease the shift amount from an alignment reference (not shown) to a desired amount or less. Then, the reticle  1  waits for exposure. 
     After a reticle  1  transferred to an exposure position on the reticle stage (not shown) is exposed, the reticle stage moves to the transfer position of a rotary hand  19 , and the exposed reticle  1  is transferred to the rotary hand  19 . The rotary hand  19  receives the reticle  1  which has been set on the alignment stage  18  and waits for exposure. At this time, the rotary hand  19  holds both the exposed reticle  1  and the reticle  1  which waits for exposure. In this state, the rotary hand  19  rotates to transfer the exposed reticle  1  to the alignment stage  18  and the reticle  1  which waits for exposure to the reticle stage (not shown). 
     The reticle  1  which waits for exposure is transferred to an exposure position, and exposed. The exposed reticle  1  is transferred to the multiaxial transfer robot  15 . If the reticle  1  is to be exposed again, it is transferred to the temporary reticle stock unit  17  and temporarily stocked. If the reticle  1  is not to be exposed again, the opening/closing unit  14  of the load-lock chamber  11  is opened, and the reticle  1  is transferred to the load-lock chamber  11 . Then, the opening/closing unit  14  is closed, and the other opening/closing unit  12  is opened. The reticle  1  transferred to the load-lock chamber  11  is extracted by the multiaxial transfer robot  9 , stored at any position in the SMIF indexer  7  or  8 , and finally stored in either of the SMIF pods  5  and  6 . 
     Reference numeral  20  denotes a closed vessel for interrupting ventilation to the atmosphere. The interior of the closed vessel  20  is purged with nitrogen gas by a nitrogen gas purge control unit  21 . In the first embodiment, the closed vessel  20  houses the reticle  1 , reticle stage (not shown), multiaxial transfer robot  15 , alignment stage  18 , rotary hand  19 , and temporary reticle stock unit  17 . In loading/unloading a reticle into/from the closed vessel  20 , the load-lock chamber  11  enables loading/unloading without substantially influencing the atmosphere in the closed vessel  20 . The opening/closing unit  14  of the load-lock chamber  11  allows/interrupts communication between the closed vessel  20  and the load-lock chamber  11 . 
     Although the interiors of the closed vessel  20  and load-lock chamber  11  are purged with nitrogen gas in the first embodiment, they may be purged with, e.g., helium gas, or a mixture of nitrogen gas and helium gas. Instead of the above-described purge with inert gas, the interiors of the closed vessel  20  and load-lock chamber  11  may be evacuated. 
     The closed vessel  20  has openings  22  and  23  for transmitting an exposure beam. Optical elements  24  and  25  for ensuring airtightness are arranged near the openings  22  and  23 . The optical element  24  may serve as, e.g., an optical element of the illumination optical system (not shown) that is nearest to the reticle  1 . Similarly, the optical element  25  may serve as, e.g., an optical element of the projection optical system  2  that is nearest to the reticle  1 . 
     Nitrogen gas purge in the closed vessel  20  by the nitrogen gas purge control unit  21  will be explained in detail below. 
     Nitrogen gas from the nitrogen gas purge control unit  21  is supplied from the vicinity of the temporary reticle stock unit  17  via a pipe system  21   a . Nitrogen gas with a relatively high purity is first supplied to the stocked reticle  1 , thereby preventing deposition of an impurity or the like on the surface of the reticle  1  stocked in the temporary reticle stock unit  17 . The nitrogen gas supplied to the closed vessel  20  is discharged from a pipe system  21   b  laid out on the reticle stage side. The discharged nitrogen gas may be directly discharged from the exposure apparatus, or the nitrogen gas purge control unit  21  may incorporate a circulation path extending to the pipe system  21   a  via a cleaning means (not shown) such as a filter for removing the impurity. 
     A gas detector  26  is adopted to detect a nitrogen gas purge state in the closed vessel  20 . If the detection result exhibits an impurity concentration higher than a predetermined state, the gas supply amount from the pipe system  21   a  is increased. If the impurity density decreases to a predetermined state or less, the gas supply amount from the pipe system  21   a  is decreased. In this way, the gas flow rate is desirably controlled. This gas flow rate control can reduce the nitrogen gas consumption amount in the arrangement of discharging nitrogen gas from the exposure apparatus. 
     The control unit (not shown) controls the operations of the reticle stage (not shown) for holding the reticle  1 , the wafer stage  4 , the driving mechanisms (not shown) of the SMIF indexers  7  and  8 , the multiaxial transfer robots  9  and  15 , the opening/closing units  12  and  14 , the alignment stage  18 , the rotary hand  19 , and the shelf elevating mechanism (not shown) of the temporary reticle stock unit  17 . 
     As described above, according to the first embodiment, a master (reticle  1 ) is set in the first housing (closed vessel  20 ) controlled to a predetermined atmosphere at an exposure position. The master (reticle  1 ) can be placed in an environment in which a substance such as oxygen or moisture which absorbs an exposure beam is suppressed to a low level. The third housing (load-lock chamber  11 ) enables transferring the master (reticle  1 ) without influencing the environment in the first housing (closed vessel  20 ) in loading/unloading the master (reticle  1 ) into/from the first housing (closed vessel  20 ). 
     The second housing (temporary reticle stock unit  17 ) can stock a plurality of masters (reticles  1 ) loaded to the exposure apparatus. This can shorten the transfer path from the stock position of the master (reticle  1 ) to an exposure position. The atmosphere in the second housing (temporary reticle stock unit  17 ) is so controlled as not to disturb the atmosphere in the first housing (closed vessel  20 ) in exchanging the master (reticle  1 ) at the exposure position. This can shorten the time taken to exchange the master (reticle  1 ) and start exposure. As a result, high throughput can be realized without greatly increasing the apparatus cost. 
     &lt;Second Embodiment&gt; 
     The second embodiment of the present invention will be described with reference to FIG.  2 . 
     FIG. 2 shows a modification of the nitrogen gas supply to the closed vessel  20  in FIG.  1 . The same reference numerals as in FIG. 1 denote the same parts, and a description thereof will be omitted. 
     Nitrogen gas from a nitrogen gas purge control unit  21  is supplied into a closed vessel  20  via pipe systems  21   a  and  21   c . Similar to the first embodiment, the pipe system  21   a  supplies nitrogen gas to the vicinity of a temporary reticle stock unit  17 . The pipe system  21   c  supplies nitrogen gas to the vicinity of a reticle stage (not shown), i.e., exposure position. A pipe system  21   b  discharges gas in the closed vessel  20 . Similar to the first embodiment, gas may be directly discharged from the exposure apparatus, or the nitrogen gas purge control unit  21  may incorporate a circulation path extending to the pipe systems  21   a  and  21   c  via a cleaning means (not shown) such as a filter for removing the impurity. 
     By supplying/discharging nitrogen gas by the pipe systems  21   a ,  21   b , and  21   c , nitrogen gas with a relatively high purity can be supplied to a stocked reticle  1  and the optical path of an exposure beam near the reticle stage. Deposition of an impurity on the surface of the reticle  1  which is being stocked or exposed can be prevented. Compared to the first embodiment, the light absorption preventing effect for the optical path of an exposure beam near the reticle stage can be enhanced. 
     The second embodiment employs gas detectors  27  and  28  to detect nitrogen gas concentrations at three portions in the closed vessel  20  together with the gas detector  26  in the first embodiment. The gas detectors, however, are not limited to three portions as in the second embodiment. The layout positions and the number of gas detectors are desirably determined as needed. 
     &lt;Third Embodiment&gt; 
     The third embodiment of the present invention will be described with reference to FIG.  3 . FIG. 3 is a perspective view showing an exposure apparatus according to the third embodiment of the present invention. The same reference numerals as in FIGS. 1 and 2 denote the same parts, and a description thereof will be omitted. 
     Reference numeral  31  denotes a closed vessel, which is different from the closed vessel  20  of FIG. 1 in that the closed vessel  31  does not house a temporary reticle stock unit  17 . The temporary reticle stock unit  17  is housed in another closed vessel  32  (including a control means for a shelf elevating mechanism and the like). The closed vessel  32  comprises an opening/closing unit  33  for allowing/interrupting communication between the closed vessels  31  and  32 . The third embodiment further adopts a gas detector  34  and nitrogen gas purge control unit  35  to control the atmosphere in the closed vessel  32 . The reticle transfer path and the operation procedures of respective elements in the third embodiment are the same as those in the first embodiment, and a description thereof will be omitted. The third embodiment is different from the first embodiment in that the opening/closing unit  33  is opened/closed in loading/unloading a reticle  1  into/from the temporary reticle stock unit  17 . 
     The first to third embodiments (see FIGS. 1,  2 , and  3 ) have been described. The exposure apparatus according to the present invention can be applied to not only the above-mentioned step &amp; scan type exposure apparatus but also a step &amp; repeat type exposure apparatus (also called a stepper). 
     Each of the above embodiments has exemplified a reticle transfer system coping with an SMIF pod. The present invention is not limited to this, and can also be applied to a reticle transfer system coping with a storage means of a reticle library form for storing a plurality of cassettes called reticle cassettes, which store reticles one by one. The present invention can also be applied to a reticle transfer system coping with another mini-environment scheme called a FOUP (Front Opening Unified Pod). 
     Each of the above embodiments has described an exposure apparatus using a light-transmitting reticle. The present invention can also be applied to an exposure apparatus using a reflecting reticle which uses a light source with a wavelength around 13.5 [nm] (EUV: Extreme UltraViolet) or the like. In this case, the closed vessels  20 ,  31 , and  32  and the load-lock chamber  11  are desirably evacuated instead of purge with nitrogen gas or helium gas. 
     &lt;Embodiment of Semiconductor Production System&gt; 
     A production system for producing a semiconductor device (e.g., a semiconductor chip such as an IC or LSI, liquid crystal panel, CCD, or thin-film magnetic head, micromachine, or the like) using the above-described exposure apparatus will be exemplified. A trouble remedy or periodic maintenance of a manufacturing apparatus installed in a semiconductor manufacturing factory, or maintenance service such as software distribution is performed by using a computer network outside the manufacturing factory. 
     FIG. 4 shows the overall system cut out at a given angle. In FIG. 4, reference numeral  101  denotes a business office of a vendor (apparatus supply manufacturer), which provides a semiconductor device manufacturing apparatus. Assumed examples of the manufacturing apparatus are semiconductor manufacturing apparatus for performing various processes used in a semiconductor manufacturing factory, such as pre-process apparatuses (e.g., a lithography apparatus including an exposure apparatus, a resist processing apparatus, and an etching apparatus, an annealing apparatus, a film formation apparatus, a planarization apparatus, and the like) and post-process apparatuses (e.g., an assembly apparatus, an inspection apparatus, and the like). The business office  101  comprises a host management system  108  for providing a maintenance database for the manufacturing apparatus, a plurality of operation terminal computers  110 , and a LAN (Local Area Network)  109 , which connects the host management system  108  and computers  110  to construct an intranet. The host management system  108  has a gateway for connecting the LAN  109  to the Internet  105  as an external network of the business office, and a security function for limiting external accesses. 
     Reference numerals  102  to  104  denote manufacturing factories of the semiconductor manufacturer (semiconductor device manufacturer) as users of manufacturing apparatuses. The manufacturing factories  102  to  104  may belong to different manufacturers or the same manufacturer (pre-process factory, post-process factory, and the like). Each of the factories  102  to  104  is equipped with a plurality of manufacturing apparatuses  106 , a LAN (Local Area Network)  111  which connects these apparatuses  106  to construct an intranet, and a host management system  107  serving as a monitoring apparatus for monitoring the operation status of each manufacturing apparatus  106 . The host management system  107  in each of the factories  102  to  104  has a gateway for connecting the LAN  111  in the factory to the Internet  105  as an external network of the factory. Each factory can access the host management system  108  of the vendor  101  from the LAN  111  via the Internet  105 . The security function of the host management system  108  authorizes access of only a limited user. 
     More specifically, the factory notifies the vendor via the Internet  105  of status information (e.g., the symptom of a manufacturing apparatus in trouble) representing the operation status of each manufacturing apparatus  106 . The factory can receive, from the vendor, response information (e.g., information designating a remedy against the trouble, or remedy software or data) corresponding to the notification, or maintenance information such as the latest software or help information. Data communication between the factories  102  to  104  and the vendor  101  and data communication via the LAN  111  in each factory adopt a communication protocol (TCP/IP) generally used in the Internet. Instead of using the Internet as an external network of the factory, a dedicated-line network (e.g., an ISDN) having high security which inhibits access of a third party can be adopted. It is also possible that the user constructs a database in addition to one provided by the vendor and sets the database on an external network and that the host management system authorizes access to the database from a plurality of user factories. 
     FIG. 5 is a view showing the concept of the overall system of this embodiment that is cut out at a different angle from FIG.  4 . In the above example, a plurality of user factories having manufacturing apparatuses and the management system of the manufacturing apparatus vendor are connected via an external network, and production management of each factory or information of at least one manufacturing apparatus is communicated via the external network. In the example of FIG. 5, a factory having manufacturing apparatuses of a plurality of vendors, and the management systems of the vendors for these manufacturing apparatuses are connected via the external network of the factory, and maintenance information of each manufacturing apparatus is communicated. In FIG. 5, reference numeral  201  denotes a manufacturing factory of a manufacturing apparatus user (semiconductor device manufacturer) where manufacturing apparatuses for performing various processes, e.g., an exposure apparatus  202 , a resist processing apparatus  203 , and a film formation apparatus  204  are installed in the manufacturing line of the factory. 
     FIG. 5 shows only one manufacturing factory  201 , but a plurality of factories are networked in practice. The respective apparatuses in the factory are connected to a LAN  206  to construct an intranet, and a host management system  205  manages the operation of the manufacturing line. The business offices of vendors (apparatus supply manufacturers) such as an exposure apparatus manufacturer  210 , a resist processing apparatus manufacturer  220 , and a film formation apparatus manufacturer  230  comprise host management systems  211 ,  221 , and  231  for executing remote maintenance for the supplied apparatuses. Each host management system has a maintenance database and a gateway for an external network, as describe above. The host management system  205  for managing the apparatuses in the manufacturing factory of the user, and the management systems  211 ,  221 , and  23  of the vendors for the respective apparatuses are connected via the Internet or dedicated-line network serving as an external network  200 . If trouble occurs in any one of a series of manufacturing apparatuses along the manufacturing line in this system, the operation of the manufacturing line stops. This trouble can be quickly solved by remote maintenance from the vendor of the apparatus in trouble via the Internet  200 . This can minimize the stoppage of the manufacturing line. 
     Each manufacturing apparatus in the semiconductor manufacturing factory comprises a display, a network interface, and a computer for executing network access software and apparatus operating software which are stored in a storage device. The storage device is a built-in memory, hard disk, or network file server. The network access software includes a dedicated or general-purpose web browser, and provides a user interface having a window as shown in FIG. 6 on the display. While referring to this window, the operator who manages manufacturing apparatuses in each factory inputs, in input items on the windows, pieces of information such as the type of manufacturing apparatus  401 , serial number  402 , subject of trouble  403 , occurrence date  404 , degree of urgency  405 , symptom  406 , remedy  407 , and progress  408 . The pieces of input information are transmitted to the maintenance database via the Internet, and appropriate maintenance information is sent back from the maintenance database and displayed on the display. 
     The user interface provided by the web browser realizes hyperlink functions  410 ,  411 , and  412 , as shown in FIG.  6 . This allows the operator to access detailed information of each item, receive the latest-version software to be used for a manufacturing apparatus from a software library provided by a vendor, and receive an operation guide (help information) as a reference for the operator in the factory. The maintenance information provided by the maintenance database also includes information about the features of the present invention described above. The software library also provides the latest-version software for implementing the features of the present invention. 
     A semiconductor device manufacturing process using the above-described production system will be explained. FIG. 7 shows the flow of the whole manufacturing process of the semiconductor device. In step  1  (circuit design), a semiconductor device circuit is designed. In step  2  (master formation), a master having a designed circuit pattern is formed. In step  3 , (wafer manufacture), a wafer is manufactured using a material such as silicon. In step  4  (wafer process) called a pre-process, an actual circuit is formed on the wafer by lithography using the prepared master and wafer. Step  5  (assembly) called a post-process is the step of forming a semiconductor chip by using the wafer manufactured in step  4 , and includes an assembly process (dicing and bonding) and a packaging process (chip encapsulation). In step  6  (inspection), inspections such as the operation confirmation test and durability test of the semiconductor device manufactured in step  5  are conducted. After these steps, the semiconductor device is completed and shipped (step  7 ). The pre-process and post-process are performed in separate dedicated factories, and maintenance is done in each of the factories by the above-described remote maintenance system. Information for production management and apparatus maintenance is communicated between the pre-process factory and the post-process factory via the Internet or dedicated-line network. 
     FIG. 8 shows the detailed flow of the wafer process. In step  11  (oxidation), the wafer surface is oxidized. In step  12  (CVD), an insulating film is formed on the wafer surface. In step  13  (electrode formation), an electrode is formed on the wafer by vapor deposition. In step  14  (ion implantation), ions are implanted in the wafer. In step  15  (resist processing), a photosensitive agent is applied to the wafer. In step  16  (exposure), the above-mentioned exposure apparatus exposes the wafer to the circuit pattern of a master. In step  17  (developing), the exposed wafer is developed. In step  18  (etching), the resist is etched except for the developed resist image. In step  19  (resist removal), an unnecessary resist after etching is removed. These steps are repeated to form multiple circuit patterns on the wafer. A manufacturing apparatus used in each step undergoes maintenance by the remote maintenance system, which prevents trouble in advance. Even if trouble occurs, the manufacturing apparatus can be quickly recovered. The productivity of the semiconductor device can be increased in comparison with the prior art. 
     As has been described above, the present invention can greatly decrease the light absorption loss of an exposure beam. The use of a master stock means enables stocking a plurality of masters in an exposure apparatus in advance. Since the transfer distance from the stock means to an exposure position is short, masters can be exchanged within a short time. A load-lock chamber is disposed, and a master is transferred to the stock means via the load-lock chamber. The master can be transferred without adversely influencing the environment of the optical path of an exposure beam near the exposure position of the master. Accordingly, a low-cost, high-throughput exposure apparatus can be provided. 
     As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.