JP2006093431A - Carrying method of photomask, exposure method and exposure treatment system, and manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a proper timing technique for carrying a reticle so as to prevent a semiconductor wafer from being put on standby even if the re-inspection of the reticle is performed in the carrying of the semiconductor wafer and the reticle to an exposure treatment step. <P>SOLUTION: A reticle allocation carrying control means 40 is controlled independently from a wafer allocation carrying control means 50, and the reticle is carried to an exposure device before a semiconductor wafer is carried to the exposure device in consideration of a time required for re-inspection of the reticle carried to the exposure device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a manufacturing technique of a semiconductor device having a photolithography process, and is particularly effective when applied to eliminate waiting for photomask reinspection of a semiconductor wafer caused by reinspection of a photomask used in the photolithography process. Technology.

  The technology described below has been studied by the present inventors in completing the present invention, and the outline thereof is as follows.

  In manufacturing a semiconductor device such as a semiconductor integrated circuit device including an LSI (Large Scale Integrated circuit) or the like, a fine pattern is formed on a semiconductor wafer by a photolithography process.

  In such a photolithography process, a resist applied on a semiconductor wafer is exposed through a photomask such as a reticle having a desired pattern, and developed after exposure to develop a resist pattern that matches the pattern of the photomask on the semiconductor wafer. Form. By using this resist pattern as an etching mask and performing necessary etching, a desired fine pattern is formed on the semiconductor wafer.

  In such a photolithography process, when performing exposure processing on the resist, first, which semiconductor wafer is to be processed by which exposure apparatus is used together with the semiconductor wafer that has been specified as the exposure apparatus. Identify the reticle. A so-called semiconductor wafer is allocated and a reticle is allocated accordingly.

  Based on the allocation command, the semiconductor wafer and the reticle are transferred to an exposure apparatus that constitutes a photolithography process, and predetermined exposure is performed on the semiconductor wafer using the transferred reticle.

  Examples of system configurations used in the photolithography process include resist coating on a semiconductor wafer, pre-baking of the resist after coating, exposure to the coated resist, development of the resist after exposure, post-baking after development, etc. An automatic exposure line configuration for performing a series of processes is known.

  Such an automatic exposure line configuration is an exposure apparatus that performs exposure using a reticle as a photomask on a resist on a semiconductor wafer, and an inline-type automated line that performs a series of processes from resist coating to post-baking.

  Further, in recent years, various apparatuses from resist coating to post-baking centering on an exposure apparatus, with an exposure apparatus that performs exposure of the applied resist as a core, a coating apparatus, a developing apparatus, a baking apparatus, and the like around the periphery. The arrangement of cluster tools is also adopted.

  In addition to this equipment configuration, a wafer stocker that temporarily stores semiconductor wafers that have been processed immediately before the photolithography process in units of lots, a reticle stocker that temporarily stores reticles used in the photolithography process, and the like are also arranged as necessary configurations. Has been.

  In order to efficiently perform the exposure processing in the exposure apparatus, the assignment and transfer of the semiconductor wafer and the reticle to the exposure apparatus are controlled by being associated with each other by a program using a computer or the like. Based on such control, the semiconductor wafer is transferred from the wafer stocker and the reticle is transferred from the reticle stocker to the exposure apparatus. In such transport, the semiconductor wafer and the reticle are transported almost simultaneously to the exposure apparatus, and the transport timing is adjusted so that no unnecessary waiting time or the like occurs at the start of the exposure process.

  For example, an exposure apparatus to be used and a reticle to be used in the exposure apparatus are allocated in accordance with a semiconductor wafer stored in a wafer stocker. In principle, semiconductor wafers are preferentially assigned according to the order of receipt to the wafer stocker, and reticles are assigned according to the semiconductor wafer assignment information to the exposure apparatus. Based on the allocation information, the semiconductor wafer and the reticle are transported without leaving much time difference, and a series of photolithography processes such as exposure are performed.

  However, in such a processing method, in principle, a processing rule is adopted such that the order in which the semiconductor wafers are received into the wafer stocker is taken into consideration in determining the start priority, and the processing of the photolithography process is performed in the order in which the semiconductor wafers are received. It has been pointed out that, although the normal process that performs the function works effectively, the express process that suddenly interrupts the process during the normal process cannot often be handled smoothly.

  In addition, even in the case of the implementation of large-mix low-volume production required in recent years, there has been a voice that the processing method having the processing order of such semiconductor wafers as a storage rule cannot achieve a sufficiently efficient production response.

Therefore, in Patent Document 1, in order to improve the above, in accordance with the processing priority given in advance, the wafer lots are transferred to the specified exposure apparatus in advance, and at the same time or earlier, the reticle of the specified exposure apparatus is used. A technique has been proposed in which the changer is transported.
JP-A-3-293712

  However, the present inventor has found that the processing technique of the photolithography process has the following problems.

  The present inventor conducted a detailed investigation on reticle conveyance as a photomask for the purpose of improving throughput of a scanner used in a photolithography process. In such a survey, it was found that there were many re-inspections by reticle inspection unexpectedly.

  In a recent system configuration used in a photolithography process of a semiconductor device, it is common to inspect a reticle with an inspection apparatus provided in an exposure apparatus. The inspection of the reticle itself can be performed in an extremely short time of about 1 minute. Therefore, even if the reticle inspection is performed in the exposure apparatus, the generation of a useless time difference regarding the start of exposure in the setting of the semiconductor wafer and the reticle transferred into the exposure apparatus has not been regarded as a problem.

  Certainly, when the result of the reticle inspection is good, the problem of the time difference based on the reticle inspection does not occur as described above. However, if the result of reticle inspection is inappropriate, re-inspection of the reticle is necessary, and re-inspection of the reticle takes time in units of several tens of minutes. A problem occurs. In particular, the higher the rate of re-inspection, the greater the total time difference and the greater the production efficiency.

  The reticle that has failed the inspection is transported from the photolithography process to another inspection area, and re-inspection is performed in the inspection area. As a result of the re-inspection, in the case of false information such as the previous inspection result being incorrect, the reticle is quickly returned to the exposure apparatus in the photolithography process after the re-inspection. However, depending on the result of the re-inspection, the reticle is returned to the exposure apparatus in the photolithography process in a state where appropriateness such as foreign matter removal is performed and whether or not use is appropriate.

  Therefore, when such re-inspection is performed, the semiconductor wafer is kept in the exposure apparatus until the re-inspection is completed and it is determined that the use is appropriate and the photomask is returned to the exposure apparatus. As described above, it has been confirmed by the inventor's field survey that the time spent for such re-examination is several tens of minutes and an average of about 30 minutes is required. Of course, there seems to be some difference depending on how the re-inspection system is configured, but the above 30 minutes were grasped as one guideline.

  As described above, when re-inspection of the reticle occurs, the semiconductor wafer transferred to the exposure apparatus is forced to wait unnecessarily until the reticle has been re-inspected and is set in the exposure apparatus. In order to improve the efficiency of the photolithography process, intense efforts are being made to compete for minutes and seconds, but it takes even a few tens of minutes of such improvement efforts. Even if the occurrence probability of dead time is small, it is a very big problem.

  According to the inventor's investigation regarding the scanner throughput in the photolithography process, it has been found that in some cases, the transition is about 5 to 8%. Therefore, for example, assuming that a re-inspection occurs with a probability of 7% in the current KrF light (wavelength 248 nm) exposure apparatus, the conventional processing method has a loss of 7% and a loss of production capacity of 7%. It will occur. Considering such a re-inspection rate, as a result, when the operation rate is 90%, the cycle time becomes 40% longer. It is a very serious problem.

In addition, it has been reported that in the exposure process using ArF light (wavelength 193 nm), fogging called HAZE occurs on the reticle over time. Kurt R. Kimmel, et al,. . "193nm haze contamination: a close relationship between mask and its environment", Proc SPIE Vol.5256, to ^{PP.440-448,23 rd Annual BACUS Symposium on Photomask Technology} , the report is It can be seen.

  In the photolithography process of 90 nm or the like that uses two reticles for exposure of one wafer, it is naturally expected that the probability of re-inspection will naturally increase as the number of reticles used increases. For example, Hiroshi Fukuda and Takuya Hagiwara, "Patterning of random interconnect using double exposure of strong-type PSMs", in Proc. Of SPIE Vol. 4346 An example is found in Optical Microlithography XIV, pp. 695-702 (2001).

  As described above, the more reticles used on a single semiconductor wafer, the more time is required for re-inspection associated with reticle inspection. (SOC: system on chip, also referred to as system LSI) etc., the present inventor considered that the problem of loss time associated with such re-inspection will be an important problem that cannot be avoided in the future.

  The time required for the re-inspection of the reticle is spent for the time for inspecting the reticle with a microscope and the like, and for the substantial inspection necessary for performing appropriate processing such as removing foreign substances as necessary after the inspection. In addition to the time, the reticle conveyance time between the photolithography process area where the exposure apparatus for which the reticle inspection has been completed is located and another re-inspection area is also included. In simple calculations, if the number of re-inspections of the reticle is reduced from one to two, the substantial re-inspection time and transport time should be doubled. The re-inspection time also increases corresponding to the increase in the number of reticles.

  In the exposure processing in the photolithography process so far, a processing program is set in advance based on the premise that the reticle to be used is normal. Therefore, the reticle is almost aligned with the transfer of the semiconductor wafer to the exposure apparatus. Is carried out. Therefore, when the reticle needs to be re-inspected after being transferred to the exposure apparatus, as described above, the re-inspection of the reticle is completed for the semiconductor wafer that has been transferred to the exposure apparatus almost simultaneously with the transfer of the reticle. Until the exposure apparatus waits.

  Furthermore, as a major premise, the semiconductor wafer transferred to the exposure apparatus is transferred on the premise that the reticle to be used is normal as described above, so that the resist processing can be performed quickly using the reticle. Is applied. However, when the resist used is, for example, a currently commonly used resist called a chemically amplified resist, depending on the length of elapsed time from the application of the resist to the semiconductor wafer until exposure, There arises a problem that the dimensions after development are different.

  For this reason, unless the time from the resist application to the start of exposure is not managed accurately, the dimension of the pattern after development will vary, leading to a very serious failure. In particular, in today's situation where pattern miniaturization and thinning are required, this point cannot be ignored.

  Of course, when the semiconductor wafer after resist coating is waited in the exposure apparatus to such an extent that the dimensional variation after development is expected to exceed the allowable limit, the semiconductor wafer is regenerated. However, even if the problem of variation in pattern dimensions is dealt with by such measures, it takes a very long time, for example, about 4 hours to regenerate the semiconductor wafer. The time loss in the cycle time of the semiconductor wafer of the lot is extremely large and must be serious.

  FIGS. 1A and 1B schematically show an outline of a sequence associated with the reticle conveyance so far. As shown in FIG. 1A, it is assumed that a lot of semiconductor wafers and a reticle to be used are allocated, and the arrival of the semiconductor wafer to the automatic exposure line and the arrival of the reticle to the exposure apparatus are made almost simultaneously. .

  The semiconductor wafer is coated with a resist by an automatic exposure line, and then transferred to an exposure apparatus. On the other hand, the reticle is transported to the exposure apparatus, and after passing through the reticle inspection, is set in the exposure apparatus so that exposure processing is possible. When the reticle is normal, as shown in FIG. 1A, since the reticle inspection is performed at a high speed, a normal reticle after completion of the inspection is set and applied to the semiconductor wafer that has been transferred so far. On the other hand, exposure is started promptly without causing a time difference that would be an obstacle.

  However, when the reticle needs to be re-inspected, as shown in FIG. 1B, the resist-coated semiconductor wafer is awaiting inspection until the re-inspection is completed in the exposure apparatus. As shown, it will be kept waiting until reexamination is completed. As mentioned above, when the abnormality found in the first inspection is a false alarm such as an erroneous measurement, it is possible to wait for a relatively short time until it is confirmed that the abnormality is normal by the reexamination. In the case of finding a foreign object or the like, it is necessary to check the position of the foreign object and to remove the foreign object, which takes more time than in the case of a false report or the like.

  In some cases, as shown in FIG. 1B, it may be assumed that the exposure process cannot be performed within an appropriate time after the resist application until the start of exposure. In such a case, the semiconductor wafer side regeneration process must be performed. No longer get. As illustrated in the figure, for such reproduction, for example, about four hours are spent.

  The time loss associated with such reticle inspection and re-inspection cannot be adequately addressed by the invention disclosed in Patent Document 1. The invention described in Patent Document 1 is excellent in changing the processing rules and the like so that it is easy to perform the interrupting express processing or the high-mix low-volume production, etc. Although it is the invention of the contents, there is no recognition of the problem of time loss in reticle inspection. Therefore, sufficient handling cannot be performed for reticle conveyance in an appropriate photolithography process in consideration of the time loss of reticle inspection.

  In the configuration of Patent Document 1, the processing urgency of a semiconductor wafer being stored in a wafer stocker, the number of wafers, the location of each reticle, the operating status of each exposure apparatus, and the capacity of each reticle changer can be accommodated. Based on the grasp, the processing priority order of the semiconductor wafers in the wafer stocker is determined according to a pre-programmed procedure, and the exposure apparatus that specifies the reticle at the same time or before the semiconductor wafer is transferred to the exposure apparatus specified in lot units. It is the structure conveyed to.

  If it is assumed that a transfer instruction is simultaneously given to a wafer and reticle in a conjugate relationship in accordance with the processing procedure in the embodiment of Patent Document 1, the wafer processing process is more than that for the reticle and takes 5 to 10 minutes. Since it takes a certain amount of time, the reticle inevitably arrives at the exposure apparatus earlier. However, if an abnormality is detected in the reticle inspection, for example, if there is a foreign object in the reticle or if there is a measurement error, re-inspection or removal of the foreign object is necessary. Time is required, the wafer arrives first, and a state of waiting for inspection as shown in FIG. 1B occurs.

  In the configuration of the invention described in Patent Document 1, no consideration is given to reticle inspection and re-inspection performed after being conveyed to the exposure apparatus as described above, and the invention described in Patent Document 1 is applied. However, the semiconductor wafer standby time associated with the re-inspection of the reticle as described above cannot be sufficiently dealt with.

  Further, in the configuration described in Patent Document 1, the order of priority is determined in advance by a program so that both the reticle and the semiconductor wafer arrive at the exposure apparatus almost simultaneously, or the reticle arrives first. However, as shown in FIG. 2, it is unclear how much time is required for the re-inspection of the reticle and cannot be predicted.

  As shown in FIG. 2, with respect to reticle inspection, the transfer time from the completion of reticle assignment to the exposure apparatus is a predictable time, and the inspection time after being transferred to the exposure apparatus is also reticle inspection. It can be handled as a constant determined by the specifications of the device. However, in the re-inspection, the time required for the re-inspection is completely different between the case where the inspection result is false information and the case where an optimization process such as actual removal of foreign matters is required.

  As described above, as shown in FIG. 2, the re-examination time is a variable that is difficult to grasp, and should be grasped as time uncertainty. In consideration of such time uncertainty, it is practically impossible to program the reticle and the semiconductor wafer in advance so that the reticle can be transported before that. It is impossible to set up a pre-program without taking into account any time uncertainty. From this point of view as well, it is apparent that the configuration of the invention disclosed in Patent Document 1 cannot solve the problem recognized by the inventor.

  The present inventor is required to reduce the waiting time of the semiconductor wafer due to the re-inspection of the reticle while the miniaturization of the pattern is increasingly required and the configuration in which the number of the reticles used per semiconductor wafer is increased is being studied. The technical solution to be considered was an urgent issue.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an appropriate timing technique for reticle conveyance so that the semiconductor wafer is not put on standby even when a re-inspection of the reticle occurs during conveyance of the semiconductor wafer and reticle to the exposure processing step. There is.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  That is, in order to prevent waiting for the inspection due to the re-inspection of the reticle from occurring on the semiconductor wafer after the resist application, the exposure processing step is performed earlier than the time before the arrival of the semiconductor wafer by a time that takes into account the time necessary for re-inspecting the reticle in advance Carry the reticle.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  In the present invention, the reticle is transferred to the exposure processing step earlier than before the arrival of the semiconductor wafer, in consideration of the time required for the re-inspection of the reticle in advance, even when the re-inspection of the reticle is necessary. Unlike before, it is possible to prevent the semiconductor wafer from waiting for inspection due to reticle re-inspection.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof may be omitted.

(Embodiment 1)
In this embodiment mode, a photomask transport method, an exposure method, an exposure processing system, and a semiconductor device manufacturing method according to the present invention will be described together.

  FIG. 3 is an explanatory view schematically showing a main configuration of the exposure processing system according to the present invention. FIG. 4 is an explanatory diagram schematically showing the main configuration of the scanner used in the exposure apparatus. FIG. 5 is an explanatory view schematically showing a flow in the photomask transport method according to the present invention.

  The photomask transport method according to the present invention is a technique relating to the transport timing of a semiconductor wafer and a photomask to an exposure processing step in a photolithography process of a semiconductor device.

  As described above, since the setting of the transport timing so far has been performed on the assumption that the photomask transported to the exposure processing step is normal, the photomask is transported to the exposure processing step after being transported to the exposure processing step. When an abnormality is found in the inspection and it is necessary to re-inspect the photomask, the semiconductor wafer after application of the resist that has already been transported to receive the exposure process is wasted.

  The present invention eliminates the waste of waiting time of a semiconductor wafer after resist coating related to re-inspection after transport of the photomask such as a reticle to the exposure processing step, and improves the efficiency of the cycle time of the exposure processing and the photolithography process. Furthermore, it is intended to improve quality such as variation in pattern dimensions after development based on the standby time.

  In the following description, a reticle applied as a photomask to a reduced projection exposure apparatus such as a scanner will be described as an example. However, the application of the present invention is naturally applicable to the case of using a mask other than the reticle used in the 1X projection type exposure apparatus.

  3, the exposure processing system A according to the present invention includes an exposure apparatus 10a as an exposure processing means 10, and a resist coating apparatus 20a as a resist coating means for applying a resist to a semiconductor wafer. A resist coating and developing apparatus 20 provided with a developing device 20b as a developing means for performing development after exposure is configured as a cluster tool so that resist coating-exposure-development can be integrated. Such an exposure processing system A is arranged in a photolithography process area (not shown).

  By adopting a cluster tool configuration in this way, the time required for transport between the resist coating means, exposure means, and development means is shortened, and the dimensional accuracy due to the semiconductor wafer holding time after resist coating. Is to avoid the deterioration of the as much as possible. However, the application of the present invention can naturally be applied to configurations other than such cluster tools. For example, an in-line line configuration is naturally applicable.

  As shown in FIG. 3, the exposure apparatus 10a is transported to a scanner main body 11 as a reduction projection exposure apparatus that performs exposure processing, a reticle buffer 12 that temporarily stores the reticle transported to the exposure apparatus 10a, and the exposure apparatus 10a. And a reticle inspection device 13 for automatically inspecting the reticle.

As shown in FIG. 4, the scanner body 11 is configured, for example, as a scanning reduction projection exposure apparatus having a reduction ratio of 4: 1. As the exposure conditions, for example, KrF excimer laser light having an exposure wavelength of about 248 nm is used as the exposure light Lp, the numerical aperture NA = 0.65 of the optical lens, the illumination shape is circular, and the coherency (σ: sigma) value. = 0.7. However, as the exposure light Lp, for example, g-line, i-line, ArF excimer laser light (wavelength 193 nm) or F ₂ (fluorine) gas laser light (wavelength 157 nm) may be used.

  The light emitted from the exposure light source E1 illuminates the mask RET via the fly-eye lens E2, the aperture E3, the condenser lenses E4 and E5, and the mirror E6. Of the optical conditions, the coherency was adjusted by changing the size of the opening of the aperture E3. A pellicle PE is provided on the photomask RET to prevent pattern transfer failure due to adhesion of foreign matter.

  The mask pattern drawn on the photomask RET is projected onto a semiconductor wafer (object to be processed) W that is a processing substrate via a projection lens E7. The photomask RET is placed on the stage Est controlled by the mask position control means E8 and the mirror E9, and its center and the optical axis of the projection lens E7 are accurately aligned.

  The photomask RET is placed on the stage Est in a state where the first main surface is directed to the main surface (device surface) of the semiconductor wafer W and the second main surface is directed to the condenser lens E5. Therefore, the exposure light Lp is irradiated from the second main surface side of the photomask RET, passes through the photomask RET, and is irradiated to the projection lens E7 from the first main surface side of the photomask RET.

  The semiconductor wafer W is vacuum-sucked on the sample stage E11 with its main surface facing the projection lens E7 side. On the main surface of the semiconductor wafer W, a resist sensitive to exposure light is applied. The sample stage E11 is placed on the Z stage E12 that can move in the optical axis direction of the projection lens E7, that is, the direction (Z direction) perpendicular to the substrate placement surface of the sample stage E11, and further the substrate of the sample stage E11. It is mounted on an XY stage E12 that can move in a direction parallel to the mounting surface.

  The Z stage E12 and the XY stage E13 are driven by respective driving means E15 and E16 in accordance with a control command from the main control system E14, and are configured to be movable to desired exposure positions. The position is accurately monitored by the laser length measuring machine E18 as the position of the mirror E17 fixed to the Z stage E13. In addition, the surface position of the semiconductor wafer W is measured by a focus position detection unit included in a normal exposure apparatus. By driving the Z stage E12 according to the measurement result, the surface of the semiconductor wafer W can always coincide with the image formation surface of the projection lens E7.

  The photomask RET and the semiconductor wafer W are driven synchronously according to the reduction ratio, and the mask pattern is reduced and transferred onto the semiconductor wafer W while the exposure region scans over the photomask RET. At this time, the surface position of the semiconductor wafer W is also dynamically driven and controlled with respect to the scanning of the semiconductor wafer W by the above-described means.

  When the circuit pattern on the photomask RET is superimposed and exposed on the circuit pattern formed on the semiconductor wafer W, the position of the mark pattern formed on the semiconductor wafer W is detected using an alignment detection optical system, From the detection result, the semiconductor wafer W is positioned and superimposed and transferred. The main control system E14 is electrically connected to the network device, and can remotely monitor the state of the scanner body 11.

  As shown in FIG. 3, an automatic reticle conveying means 30 is communicated to the exposure apparatus 10a having the scanner body 11 having the above-described structure. The automatic conveyance means 30 includes a track 30a laid on the ceiling and an automatic conveyance device 30b that travels along the track 30a. The reticle is transferred from the reticle stocker 32 to the exposure apparatus 10a in a state of being stored in a reticle transfer container 31 such as a reticle pod 31a mounted on the automatic transfer device 30b. The conveyance of the reticle to the exposure apparatus 10a is appropriately performed according to an instruction from a reticle allocation conveyance control unit (not shown) using a computer or the like as a photomask allocation conveyance control unit (not shown).

  On the other hand, as shown in FIG. 3, the resist coating and developing apparatus 20 is provided with a port 21, through which the semiconductor wafer is transferred to and from the resist coating and developing apparatus 20. For example, an RGV (rail guided vechicle) in which a required semiconductor wafer from a wafer stocker 23 travels on a track 33 laid on the floor in units of lots in a state of being accommodated in a wafer transfer container 22 such as a hoop as shown in FIG. ) It is conveyed to the resist coating and developing apparatus 20 by the automatic conveying apparatus 34 such as 34a. The transfer of the semiconductor wafer is appropriately performed according to an instruction from a wafer allocation transfer control unit using a computer or the like.

  The semiconductor wafer transferred to the resist coating / developing apparatus 20 is taken out from the wafer transfer container 22 for each sheet, sent to the resist coating apparatus 20a, and applied with a required resist. After applying the resist, it is sent to the scanner main body 11 of the exposure apparatus 10a, and required exposure processing is performed via the reticle. The semiconductor wafer subjected to the exposure processing is sent to a developing device 20b provided in the resist coating and developing device 20 and subjected to required development. The semiconductor wafer that has been subjected to a series of photolithography steps in this manner is transferred from the port 21 to the next step while being stored in the wafer transfer container 22 or the like.

  In the exposure processing system A having such a main configuration, the wafer allocation transfer control means and the reticle allocation transfer control means are configured to be controlled independently by software. In the configuration so far, the semiconductor wafer and the reticle are controlled in software so that their allocation and transfer are related to each other in software so that the semiconductor wafer and the reticle can be set without time difference in the exposure process. However, it was not possible to process only the transfer, irrespective of the semiconductor wafer.

  However, the exposure processing system A of the present invention is configured so that the reticle allocation and transfer and the semiconductor wafer allocation and transfer can be processed independently of each other. By using the exposure processing system A having such a configuration, even if the reticle conveyed to the exposure apparatus 10a needs to be reinspected, the resist-coated semiconductor wafer is awaited for reinspection in the exposure apparatus 10a for a long time. It is no longer necessary to wait in this state.

  In order to prevent such a waiting state for reinspection from appearing, it is only necessary to carry out the photomask transport method according to the present invention by controlling reticle transport as follows. By using such a photomask transport method, it is possible to execute the exposure method and the semiconductor device manufacturing method according to the present invention that reduce the cycle time of the photolithography process. Details will be described below.

  In the method for manufacturing a semiconductor device according to the present invention, the semiconductor wafer that has completed the process immediately before the photolithography process is temporarily stored in the wafer stocker 23 before proceeding to the photolithography process. The reticle used in the photolithography process is temporarily stored in the reticle stocker 32. That is, the semiconductor wafer entering the next photolithography process and the reticle used in the photolithography process are temporarily stored in the wafer stocker 23 and the reticle stocker 32, respectively, and are prepared for the necessary allocation and transport. .

  In this state, as shown in the flowchart of the photomask transport method according to the present invention in FIG. 5, in step S <b> 101, the storage is performed based on the storage status of the semiconductor wafer temporarily stored in the wafer stocker 23. A search for a start exposure apparatus that can appropriately perform exposure processing of a semiconductor wafer is performed. Thereafter, as shown in step S102, a list of exposure apparatuses that can be started by searching is listed. After such listing, as shown in step S103, the exposure processing start order is determined in consideration of the production status of the semiconductor wafers stored in the wafer stocker 23.

  In step S104, the reticle to be used is specified from the recipe of the semiconductor wafer to be firstly started, and whether or not the reticle is stored in the reticle stocker 32 is checked in accordance with the start order determined in step S103. If the reticle to be started first is not stored in the reticle stocker 32 (indicated as “No” in the figure), the exposure processing of the first semiconductor wafer with the starting order is canceled as shown in step S105. To do. At the same time, the storage status of the reticle with respect to the next-order semiconductor wafer is checked back to step S104.

  On the other hand, if it is confirmed in step S104 that the reticle used for the first-ranked semiconductor wafer is stored in the reticle stocker 32 (shown as Yes in the figure), the list is first listed in step S106. An exposure apparatus suitable for the exposure process of the semiconductor wafer is identified from the group of exposure apparatuses that can be started, and an instruction is given to assign and transport a reticle whose storage status has already been confirmed in step S104 to the exposure apparatus.

  The reticle allocation conveyance instruction is issued from a computer server 40a as the reticle allocation conveyance control means 40 as shown in FIG. Based on the instruction from the computer server 40a, the reticle to be used is accommodated in the reticle transport container 31 such as the reticle pod 31a from the reticle stocker 32 and transported to the exposure apparatus 10a in the photolithography process area as shown in FIG. Is done.

  In step S107, the reticle conveyed to the exposure apparatus 10a is inspected by the reticle inspection apparatus 13 provided in the exposure apparatus 10a as shown in FIG. If it is determined that the reticle inspection is appropriate, the inspected reticle is temporarily stored in the reticle buffer 12 in the exposure apparatus 10a and waited as shown in step S109.

  If any abnormality is found in the reticle inspection and determined to be unsuitable, the unsuitable reticle is sent to re-inspection, and processing such as cleaning is performed in the re-inspection as shown in step S108. In the re-inspection, for example, optimization processing such as foreign matter removal processing is performed as necessary, and the cleaning is restored to a usable state. In this way, after the unsuitable state is recovered until it is determined to be usable after re-inspection, the re-inspected reticle passes through steps S106 and S107, and the reticle in step S109. Once stored in the buffer 12.

  The re-inspection of the reticle is performed by transferring an unsuitable reticle from the exposure apparatus 10a in the photolithography process area to a re-inspection area set separately from the photolithography process area. In the re-inspection area, re-inspection is performed by examining the reticle surface with a microscope or the like. If necessary, so-called foreign matter removal processing such as cleaning is performed, and the appropriate processing is performed to make it suitable for use.

  As described above, in the re-inspection of the reticle, the area of the re-inspection process is performed in an area different from the photolithography process area and in an area having a different contamination class. In consideration of the round trip between the two photolithography process areas and the re-inspection area, the re-inspection time in the re-inspection area, and the optimization processing time such as foreign matter removal processing, the average re-inspection time takes about 30 minutes. It was estimated based on the experiment of the person.

  According to the inventor's experiment, as shown in FIG. 6 (a), when the distribution state of the reinspection time of the reticle is confirmed, the reinspection time spends various times depending on the abnormal state of the reticle. However, when the reinspection time is up to 50 minutes, it can be seen that the proportion of reinspection cases included by 50 minutes of the reinspection time occupies about 80%. Furthermore, if a part of the re-inspection method or the like is used to shorten the time that can easily cope with the work procedure, etc., as shown in FIG. 6B, about 97% (2σ) to 99% of the entire re-inspection case. It was confirmed that about 97% to 99% of the re-inspection occurred within this time range, the re-inspection could be completed within this time.

  Therefore, as described above, when the reticle is transported to the exposure apparatus prior to the semiconductor wafer, it is longer than the average reinspection time, and if it is suppressed within 50 minutes, 97% of the reinspection occurs. It was found that the waiting of the semiconductor wafer accompanying the occurrence of the re-inspection of the reticle can be solved with probability.

  The lower limit of the average reinspection time may be set longer than the physical time required for reticle reinspection, as can be seen from the above description. Furthermore, the present inventor has considered whether there is an appropriate upper limit when the reticle is transported prior to the semiconductor wafer.

  The upper limit of the timing of reticle pre-allocation is considered to depend on the capacity (Nb) of the reticle buffer and the process time (RPT) of the lot. That is, the maximum possible time is Nb × RPT or less. For example, when Nb = 6 and RPT = 12 minutes, it becomes 72 minutes. No more is meaningful.

  In addition, due to lot reassignment of the exposure apparatus, interruption of lots with high priority overlaps, and as a result, the reticle transported initially may turn to another apparatus, so it is desirable to transport it more than necessary. Absent. According to the result data, if it is set to 50 minutes, 99.7% of the whole can be covered, and this is one guideline. Even in consideration of prior allocation of the highest priority lot, it can be said that the upper limit of 50 minutes is a reasonable value if the accuracy of determining the arrival time is about 1 hour.

  The present inventor, from the above viewpoint, for practical purposes, for example, after the arrival of the semiconductor wafer, calculates the time to complete the reticle transfer before the arrival of the semiconductor wafer to the exposure apparatus in the exposure processing step. Thus, it was considered that it was sufficient if it was 30 minutes or more and 50 minutes or less. In addition, as described above, the starting point of such time may be considered as the starting point after the arrival of the semiconductor wafer, that is, the arrival point, but from the starting point of the exposure starting from the starting point of the exposure of the semiconductor wafer. It may be defined as 30 minutes or more and 50 minutes or less before. The point is that the re-inspection of the reticle is completed within a time range of 30 minutes or more and within 50 minutes, and the above-mentioned time is used so that the exposure of the semiconductor wafer after resist coating can be started quickly with the reticle after the re-inspection is completed. The starting point of the range may be selected, and it is not necessary to limit to the starting point.

  In this way, the reticle is transported to the exposure apparatus ahead of the re-inspection time, and is stored in the reticle buffer in a state where the re-inspection is completed. On the other hand, the semiconductor wafer is in lot units as described above. The wafer is stored in the wafer stocker 23 and is in an allocation standby state as shown in step S200 of FIG.

  As described above, the allocation transfer of the semiconductor wafer is controlled independently of the allocation transfer of the reticle. That is, it is controlled by the computer server 50a as the wafer allocation transfer control means 50 shown in FIG. 5, and a required semiconductor wafer is allocated from the wafer stocker 23 to the exposure apparatus 10a to be used, and the exposure apparatus 10a and the cluster tool are formed. It is conveyed to the resist coating and developing apparatus 20 having the above structure.

  When allocating and transferring the semiconductor wafer, as shown in FIG. 5, in step S201, it is confirmed in advance whether the reticle used by the semiconductor wafer is in the reticle buffer 12 in the exposure apparatus 10a. When the desired reticle is not stored in the reticle buffer 12 (indicated as “No” in the figure), the allocation standby in the wafer stocker 23 for allocation transfer of the semiconductor wafer is canceled as shown in step S202. To do. The semiconductor wafer of the next order is made to wait for the allocation transfer.

  As described above, at the start of the semiconductor wafer process, it is confirmed that the reticle foreign matter inspection of the reticle to be used is completed. If the foreign matter inspection is not completed, the operation is canceled. It is also possible to lower the rank of the construction queue by one without making it happen. This is preferable to the case of canceling because the cycle time of the semiconductor wafer of the lot can be shortened.

  If it is confirmed in step S201 that the reticle used in the semiconductor wafer is stored in the reticle buffer 12 in the exposure apparatus 10a (shown as OK in the figure), the allocation of the semiconductor wafer is performed in step S203. Then, the transfer is instructed from the computer server 50a as the wafer allocation transfer control means 50. In accordance with such an instruction, the semiconductor wafer is transferred from the wafer stocker 23 to the resist coating and developing apparatus 20 in lot units.

  The transferred semiconductor wafer starts a series of processes as shown in step S204. That is, a resist is applied to a predetermined layer thickness by a method such as a spin coating method, and the semiconductor wafer after the resist coating is transported and set to the scanner body 11 of the exposure apparatus 10a. The reticle that has been in the inspected state in the reticle buffer 12 in advance is set by the time the semiconductor wafer arrives at the scanner main body 11, and exposure processing is quickly performed in accordance with the setting of the semiconductor wafer after resist coating. Applied. The semiconductor wafer subjected to the exposure process is subjected to the development process as described above, and is further transported to the next process in units of lots after the development is completed.

  Thus, by independently controlling the reticle assignment / conveyance control means 40 and the wafer assignment / conveyance control means 50 in the exposure processing system according to the present invention, the reticle is exposed ahead of the semiconductor wafer by the time required for reinspection. Unlike the conventional method in which the semiconductor wafer and the reticle are transferred to the exposure apparatus almost simultaneously, the semiconductor wafer is waiting for inspection even if re-inspection occurs on the reticle. There is no waiting.

  As described above, the present inventor, when the reticle arrives in advance by the time required for the re-inspection of the reticle, as described above, the time required for the re-inspection is extremely indefinite. Taking into account how the fixed time is handled, the idea was to adopt the concept of average re-examination time. The average re-inspection time is defined as the time during which most of the re-inspection cases, for example, 97% or more can be subjected to the optimization process until it can be determined that the unsuitable state is appropriate within the re-inspection time. It was decided to.

  When calculating the average re-inspection time, as described above, the reticle that needs to be re-inspected is transported from the exposure apparatus to the re-inspection area, and the time required to return to the exposure apparatus after the re-inspection is calculated. Must. Therefore, the re-inspection time was calculated after setting the conditions of the conveying means.

  When calculating the re-inspection time, the re-inspection time is calculated on the assumption that the conventional conveying means is followed. FIG. 7A shows the configuration of the transport route required for the previous re-inspection assumed when calculating the average re-inspection time.

  As shown in FIG. 7A, the photolithography process area 100 and the reinspection area 200 in the conventional photolithography process are set separately. In the photolithography process area 100, a reticle stocker 110 is provided so that a plurality of reticles used in the exposure apparatus 10a in the photolithography process can be temporarily stored. A reticle stocker 210 is also provided in the reinspection area 200.

  The reticle stocker 110 can deliver a reticle to / from a reticle inspection apparatus 13 provided on the exposure apparatus 10a side by an overhead track traveling type transport vehicle 120 such as an overhead transport. The reticle stocker 110 can deliver a reticle by a reticle stocker 210 in the reinspection area 200 and an overhead track traveling type transport vehicle 130 such as an overhead shuttle. Transfer between the reticle inspection device 13 and the reticle stocker 110 and between the reticle stockers 110 and 210 is performed in a state of being accommodated in the reticle transport container 31 configured in the reticle pod 31a or the like.

  If an abnormality is detected by the reticle inspection apparatus 13 provided in the exposure apparatus 10a in the photolithography process area 100, the reticle is stored in the reticle transport container 31 such as the reticle pod 31a, and the ceiling track. It is transported to the reticle stocker 110 by the traveling transport vehicle 120 and set aside.

  The re-inspection reticle placed on the reticle stocker 110 is transported to the reticle stocker 210 in the re-inspection area 200 by the overhead traveling type transport vehicle 130 and placed there. The reticle placed in the reticle stocker 210 is transported to the re-examination room 230 configured as a clean room having a predetermined cleanness by a clean ventilation 220 or the like on the ceiling side.

  In the re-examination room 230, as shown in FIG. 7A, the re-inspection of the reticle carried to the re-inspection room 230 is performed by a person for scrutiny. For example, the foreign matter on the reticle surface is confirmed with a microscope or the like, and foreign matter removal processing is performed as necessary. Reticles that have been judged to be usable after the foreign substance removal process have been carried into reticle stocker 110 along the reverse route from the photolithography process area 100 to the re-inspection chamber 230. Inspected again by the reticle inspection apparatus 13.

  When the reinspection reticle travels back and forth between the photolithography process area 100 and the reinspection area 200 through the conveyance path shown in FIG. 7A, it is estimated that the average is about 10 minutes in one way, and about 20 in the reciprocation. Minutes. Furthermore, the time required for re-inspection in the re-inspection room 230 is about 10 minutes on average including the foreign substance removal processing. Therefore, when assuming that the re-inspection reticle passes through the conveyance path as shown in FIG. 7A, the present inventor takes about 30 minutes, and this about 30 minutes is adopted as the average inspection time. did.

  FIG. 7B shows the state of transport of the re-inspection reticle described above for easy understanding. For example, reticle foreign matter inspection is performed in the exposure apparatus in S1, transported by the ceiling orbit traveling transport in S2, and placed in the reticle stocker in the photolithography process area (abbreviated as photo area in the drawing) in S3, and then the ceiling in S4 It is transported by orbital traveling and placed on the reticle stocker in the re-inspection area. In step S5, the foreign substance on the reticle is confirmed and removed, and the re-inspection is completed. If a reticle abnormality is found by reticle inspection in the exposure apparatus, it is transported along the route of S1, S2, S3, S4, S5, and S6, and the reinspection is completed and it is determined that the possibility of use is appropriate. In this case, conversely, it is reversely conveyed in the order of S6 → S5 → S4 → S3 → S2 → S1.

  More specifically, this effect is as follows. That is, for example, assume that 7% of the reticles used require re-inspection. Note that the 7% reticle re-inspection rate is assumed in consideration of the numerical value actually grasped by the present inventor in order to improve the cycle time of the scanner in the photolithography process. It can be grasped as a very practical numerical value, unlike an assumed numerical value with no proof.

  Under such condition setting, the queuing theory was applied to calculate how much cycle time could be improved. The result is as follows.

  First, let λ be the average arrival number of semiconductor wafers in lot units, μ be the average start capacity, S be the number of start points, ρ = λ / μ occupancy (Tool Utilization), and RPT be the lot process time. Then, when the arrival probability follows the Poisson distribution and the start payout probability follows the exponential function distribution, the cycle time (CT) follows the following equations (1) and (2).

ここで、上記式でS=2とすると、サイクルタイムをロットのプロセス時間RPTで規格化したＣＴ／ＰＲＴで示されるX-factorと、占有率（Tool Utilization）には、図８（ａ）に示すような関係が見られる。図８（ａ）からは、横軸にとった占有率（Tool Utilization ）が９０％のときには、ロット単位でのプロセス時間で規格化したサイクルタイムは、４０％の改善効果があることが分かる。

If S = 2 in the above equation, the X-factor indicated by CT / PRT with the cycle time normalized by the process time RPT of the lot and the occupation rate (Tool Utilization) are shown in FIG. The relationship shown is seen. FIG. 8A shows that when the occupation ratio (Tool Utilization) on the horizontal axis is 90%, the cycle time normalized by the process time in lot units has an improvement effect of 40%.

  As described above, with regard to reticle re-inspection for which special attention has not been paid so far, by using the above-described exposure processing system according to the present invention, the reticle transport method according to the present invention is temporarily applied. Deterioration of dimensional accuracy due to reticle wait time of resist-coated wafer based on re-inspection of reticle inspection that has been assumed to occur as much as 7%, 4 hours stagnation time spent on wafer regeneration based on the deterioration, 7% The 7% reduction in production capacity due to the regeneration rate can be improved at once, and as described above, the cycle time can be improved by 40%.

  FIG. 8B shows the effect of improving the substantial cycle time as a graph. As can be seen from FIG. 8B, when the reticle and the semiconductor wafer are transported almost simultaneously without considering the reinspection at all, a reinspection occurs at a rate of 7%. Assuming that a wasteful waiting time of the semiconductor wafer occurs, the cycle time is shown as 4.5.

  However, by applying the present invention, on the premise that re-inspection occurs at a predetermined rate from the beginning, the reticle is preceded by the time required for re-inspection before the semiconductor wafer and the exposure apparatus, etc. By arriving at the exposure area, the reticle is inspected and re-inspected within that time, so that no unnecessary waiting time is generated in the semiconductor wafer, and as a result, the cycle time can be reduced to 2.6. did it. In fact, the cycle time can be improved by about 40%.

  By the way, if the effect of improving the cycle time is converted into a monetary amount, it is estimated that the lead time of 13 hours is reduced in all photolithography processes, and the investment reduction effect of 1 billion yen is achieved in the φ300 wafer production line of 12,000 wafers / month. .

  As for the application of the present invention described above, a small number of various types of SOCs (system on chip) having a high reticle replacement frequency among semiconductor devices, in particular, a wafer having a reticle replacement frequency higher than the wafer lot replacement frequency after 90 nm. In the product, the effect becomes more obvious.

  Incidentally, for comparison with the present invention, the conventional reticle transport method is shown as a flow in FIG. As shown in FIG. 9, in step S <b> 300, a semiconductor wafer is allocated and waited in the wafer stocker 23. Thereafter, as shown in step S310, the wafer / reticle assignment / conveyance control means 60 configured in the computer server 60a or the like assigns both the semiconductor wafer and the reticle in association with each other.

  Further, in step S320, the reticle is assigned to the exposure apparatus, and conveyance is instructed. As shown in step S330, the reticle transferred to the exposure apparatus is subjected to a foreign object inspection of the reticle. If an abnormality is detected in the foreign object inspection, cleaning is performed by re-inspecting the reticle as shown in step S340. Is done. While the transfer of the semiconductor wafer is instructed in succession in step S340 and the re-inspection of the reticle is being performed, the semiconductor wafer is kept waiting in the inspection apparatus by the exposure apparatus.

  The reticle whose use possibility is determined to be appropriate by the re-inspection in step S340 is returned to the exposure apparatus, and thereafter, as shown in step S350, the exposure process for the semiconductor wafer is started and the process is started. However, in such a conventional method, the semiconductor wafer stays in the exposure apparatus for the cycle in which re-inspection is performed through step S330 → step S340 and returned to the exposure apparatus, and in the worst case, a resist is applied. In some cases, it is necessary to regenerate the semiconductor wafer.

(Embodiment 2)
In the above-described embodiment, the reticle is transported to the exposure apparatus ahead of time by the average re-inspection time of the reticle, but the reticle inspection is performed at a high speed in the exposure apparatus. For example, the case where the exposure apparatus is taken out of the exposure apparatus and transported to a re-inspection area outside the photolithography process area where the exposure apparatus is disposed, for example, is performed in a re-inspection room provided in the re-inspection area .

  In such a case, the average reinspection time includes the reciprocal conveyance time of the reticle between the photolithography process area and the reinspection area, and the ratio of the time to the average reinspection time is ignored as described above. I can't do it. Of the above-mentioned average re-inspection time of about 30 minutes calculated when adopting the conventional re-inspection method, about 20 minutes is the time used for transportation between such areas.

  Therefore, the present inventor, in the average re-inspection time, it is difficult to shorten the time required for the re-inspection such as scrutinizing the reticle surface with a microscope or removing foreign matter on the reticle surface. I thought it would be possible to shorten the time. The ratio of the conveyance time to the average re-inspection time is 2/3 and cannot be ignored.

  As shown in FIG. 10, the present inventor has devised a configuration in which a reticle re-inspection apparatus 14 is provided in the exposure apparatus 10a in parallel with the reticle inspection apparatus 13. Such a reticle re-inspection apparatus 14 may be configured to have a review function for automatically re-examining the reticle surface again in detail when, for example, an abnormality is detected by the reticle inspection apparatus 13.

  The re-inspection includes a false alarm that a foreign object has been detected in the reticle inspection. However, even in the case of such a false alarm, it has been necessary to carry out re-inspection between different areas so far. About 20 minutes could not be shrunk. However, if the review function is provided, the false inspection at the time of reticle inspection can be quickly performed in the exposure apparatus 10a, and the reinspection time can be greatly shortened because the conveyance time between areas can be omitted.

  Further, it is more preferable to add a configuration having a foreign matter removing function in addition to the review function. If such a foreign matter removal function is provided, re-inspection can be completed within the exposure apparatus 10a, including confirmation of false information, and the average re-inspection time of about 30 minutes is about 10 minutes by simple calculation. Will be shortened.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  In the above embodiment, the description of the present invention has been made by taking a reticle as an example. However, the present invention can be applied to a mask for 1 × exposure in addition to a reticle as a photomask for reduced projection exposure. I do not care.

  In the above description, the scanner of the scanning reduction projection exposure apparatus has been described as an example of the exposure processing means using the reticle. However, it may be applied to other types of reduction projection exposure apparatuses.

  The present invention can be effectively used in a photolithography process using a photomask such as a reticle in the field of manufacturing semiconductor devices.

(A) is explanatory drawing which shows the condition of the exposure process start when there is no re-inspection of a reticle, (b) It is explanatory drawing which shows the delay condition of the exposure start when there exists re-inspection. It is explanatory drawing which shows clearly that the time of a reexamination is indefinite. It is explanatory drawing which shows typically an example of the principal part structure of one Embodiment of the exposure processing system which concerns on this invention. It is explanatory drawing which shows the main components of a scanner typically. It is a flowchart which shows an example of the flow structure of one Embodiment of the conveyance method of the photomask which concerns on this invention. It is explanatory drawing which shows the distribution condition of the re-inspection time of a reticle. (A) It is explanatory drawing which shows typically the conveyance path | route of the reinspection reticle based on the calculation premise of average reinspection time, (b) is a conveyance flow figure of a reinspection reticle. (A) It is explanatory drawing which showed the relationship between the occupation rate at the time of 90% operation rate, and cycle time, (b) is the conventional method of the cycle time at the time of 90% operation rate and the case of application of the present invention. It is explanatory drawing which shows a comparison. It is a flowchart which shows the flow in the conventional conveying method of a reticle. It is explanatory drawing which shows typically the modification of the principal part structure of one Embodiment of the exposure processing system which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exposure processing means 10a Exposure apparatus 11 Scanner main body 12 Reticle buffer 13 Reticle inspection apparatus 14 Reticle inspection apparatus 20 Resist coating and developing apparatus 20a Resist coating apparatus 20b Developing apparatus 21 Port 22 Wafer transfer container 23 Wafer stocker 30 Reticle transfer means 30a Track 30b Automatic transfer device 31 Reticle transfer container 31a Reticle pod 32 Reticle stocker 34 Automatic transfer device 34a RGV
40 reticle allocation transfer control means 40a computer server 50 wafer assignment transfer control means 50a computer server 60 wafer / reticle assignment transfer control means 60a computer server 100 photolithography process area 110 reticle stocker 120 overhead track traveling type transport vehicle 130 ceiling track traveling type transport Car 200 Re-inspection area 210 Reticle stocker 220 Clean ventilation 230 Re-inspection room A Exposure processing system E1 Exposure light source E2 Fly eye lens E3 Aperture E4 Condenser lens E5 Condenser lens E6 Mirror E7 Projection lens E8 Mask position control means E9 Mirror E11 Sample stage E12 Z stage E13 XY stage E14 Main control system E15 Driving means E16 Driving means 17 mirror E18 laser length measuring machine Est stage Lp exposure light PE pellicle RET mask W semiconductor wafer

Claims (13)

A method of transporting the photomask to an exposure processing step of performing exposure processing on a resist of a semiconductor wafer using a photomask,
In the exposure processing step, the transported photomask is inspected, reinspected as necessary based on the result of the inspection, and using a photomask that is determined to be usable after the reinspection. The exposure process is performed,
The photomask transport to the exposure processing step is preceded by a time required for re-inspection of the photomask, and is terminated before the semiconductor wafer arrives at the exposure processing step. Transport method. The photomask transport method according to claim 1,
Transport of the photomask to the exposure process step is completed before the start of the exposure process and at least before an average reinspection time required for reinspection of the photomask. . The photomask transport method according to claim 1,
The transport of the photomask to the exposure processing step has been transported to the exposure processing step and the average exposure processing time required for the exposure processing of the semiconductor wafer in the exposure processing step before the start of the exposure processing. A photomask transport method comprising: ending the photomask within a time indicated by a product of the number of photomasks that can be waited for which the exposure processing step temporarily waits. In the conveyance method of the photomask of any one of Claims 1-3,
The photomask that is determined to be usable after the re-inspection includes a photomask that has been made unusable in the re-inspection and usable by the optimization process. A photomask conveying method as a feature. The photomask transport method according to claim 4,
The photomask that has been made usable by the optimization process is a photomask that is in an inappropriate state due to adhesion of foreign matter, and can be used after the foreign matter has been removed by the foreign matter removal process as the optimization process. A photomask transport method, wherein the photomask is in a state. In the photomask conveying method according to any one of claims 1 to 5,
The exposure processing step is performed by an exposure apparatus that performs exposure to the resist using the photomask,
The photomask transport method, wherein the exposure apparatus is formed into a cluster tool by a coating apparatus that coats the resist onto the semiconductor wafer and a developing apparatus that develops the resist after exposure. . A method of transporting a semiconductor wafer stored in a wafer stocker and a reticle stored in a reticle stocker to an exposure area, and performing an exposure process on a resist on the semiconductor wafer using the reticle,
In the exposure area, the reticle that has been transported is inspected, re-inspected as necessary based on the result of the inspection, and the exposure that has been determined to be usable through the re-inspection. Processing takes place,
An exposure method comprising carrying the reticle to the exposure area prior to carrying the semiconductor wafer for a time required for re-inspection of the reticle. An exposure processing system that performs exposure processing on a resist of a semiconductor wafer using a photomask,
Exposure processing means for performing the exposure processing;
Inspection means for inspecting the photomask conveyed to the exposure processing means;
Wafer allocation transfer control means for controlling the allocation and transfer of the semiconductor wafer to the exposure processing means;
A photomask allocation transfer control unit that is controlled independently of the wafer allocation transfer control unit and controls the allocation and transfer of the photomask to the exposure processing unit;
An exposure processing system, wherein the photomask allocation transport control means terminates the transport of the photomask to the exposure processing means before the semiconductor wafer arrives at the exposure processing means. The exposure processing system according to claim 8, wherein
An average reinspection time required for reinspecting the photomask at least before the start of exposure processing of the semiconductor wafer in the exposure processing means
Calculated by multiplying the average exposure processing time required for the exposure processing of the semiconductor wafer by the exposure processing means by the number of standby photomasks that allow the exposure processing means to temporarily wait for the photomask transported to the exposure processing means. Within the photomask proper transport time range specified by
The exposure processing system, wherein the photomask is transported to the exposure processing means by using the photomask allocation transport control means. The exposure processing system according to claim 9, wherein
An exposure processing system, wherein the photomask transported to the exposure processing means within the appropriate time range for the photomask is re-inspected and it is determined that the photomask can be used. The exposure processing system according to claim 9, wherein
If the suitability for use after re-inspection after inspection of the photomask that has been transported to the exposure means within the appropriate time range for the photomask cannot be determined to be appropriate, the exposure processing is performed by the semiconductor wafer allocation transport means. An exposure processing system for stopping conveyance of the semiconductor wafer to the means. A method of manufacturing a semiconductor device having a photolithography process for forming a desired pattern using a photomask on a semiconductor wafer,
In the photolithography process, after the possibility of using the photomask transported to the exposure processing step constituting the photolithography process is determined to be appropriate in the re-inspection in the exposure processing step, the semiconductor wafer is A method for manufacturing a semiconductor device, wherein the exposure process is carried out by carrying to an exposure process step. In the manufacturing method of the semiconductor device according to claim 12,
The photomask whose use possibility is determined to be appropriate in the re-inspection is the re-inspection, and the photomask in an unsuitable state due to the attachment of foreign matter is the foreign matter removal process as the optimization process. A method for manufacturing a semiconductor device, characterized in that the photomask is made usable by removing foreign substances.

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