Substrate treatment system, substrate transfer method and computer storage medium

An interface station of a coating and developing treatment system has: a cleaning unit cleaning at least a rear surface of a wafer before the wafer is transferred into an exposure apparatus; an inspection unit inspecting the rear surface of the cleaned wafer whether the wafer is exposable, before it is transferred into the exposure apparatus; wafer transfer mechanisms including arms transferring the wafer between the units and a wafer transfer control part controlling operations of the wafer transfer mechanisms. When it is determined that a state of the wafer becomes an exposable state by re-cleaning in the cleaning unit as a result of the inspection, the wafer transfer control part controls the wafer transfer mechanisms to transfer the wafer again to the cleaning unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate treatment system performing treatment on a substrate, a substrate transfer method in the substrate treatment system and a non-transitory computer storage medium.

2. Description of the Related Art

For example, in a photolithography process in manufacturing processes of a semiconductor device, a series of treatments such as resist coating treatment of applying a resist solution onto a wafer to form a resist film, exposure processing of exposing the resist film to a predetermined pattern, developing treatment of developing the exposed resist film and so on are sequentially performed, whereby a predetermined resist pattern is formed on the wafer. The series of treatments are performed in a coating and developing treatment system being a substrate treatment system in which various kinds of treatment units treating the wafer and transfer units transferring the wafer are installed.

For example, a coating and developing treatment system200conventionally includes a cassette station201for transferring a cassette C in/out from/to the outside, a treatment station202in which a plurality of treatment units performing various treatments such as resist coating treatment, developing treatment, and thermal treatment are provided at the front and the back therein, and an interface station203delivering a wafer between an exposure apparatus A provided outside the coating and developing treatment system200and adjacent thereto and the treatment station202, which are integrally provided as illustrated inFIG. 20.

In recent year, miniaturization of a circuit pattern to be formed on the wafer is further advanced and the defocus margin in exposure processing becomes smaller. In association with that, it is required, as much as possible, to prevent particles from being brought into the exposure apparatus A. In particular, the particles on the rear surface of the wafer is becoming a problem. Therefore, to reduce, as much as possible, the particles brought into the exposure apparatus A, a cleaning unit210cleaning the rear surface of the wafer before it is transferred into the exposure apparatus A, an inspection unit211inspecting the cleaned wafer, a delivery unit212and wafer transfer apparatuses213provided at multiple tiers for delivering the wafer between the units210and211are provided in the interface station203in some cases (Japanese Laid-open Patent Publication No. 2008-135583).

SUMMARY OF THE INVENTION

Incidentally, in the above-described coating and developing treatment system200, the yield in the coating and developing treatment system200further improves as the number of wafers determined to be abnormal in the inspection unit211is smaller.

Review by the present inventors shows that even wafers determined to be abnormal in the inspection unit211include may wafers which will become a state of being transferable into the exposure apparatus A by re-cleaning in the cleaning unit210.

In the above-described coating and developing system200of the Patent Document JP 2008-135583, however, the wafer determined to be abnormal is collected into the cassette station201, failing to improve the yield.

The present invention has been made in consideration of the above points and its object is to improve the yield of the substrate treatment in a substrate treatment system having a function of cleaning a rear surface of a substrate before exposure.

To achieve the above object, the present invention is a substrate treatment system including a treatment station in which a plurality of treatment units each treating a substrate, and an interface station delivering the substrate between the treatment station and an exposure apparatus provided outside, the interface station including: a cleaning unit cleaning at least a rear surface of the substrate before the substrate is transferred into the exposure apparatus; an inspection unit inspecting at least the rear surface of the cleaned substrate whether the substrate is exposable, before the substrate is transferred into the exposure apparatus; a substrate transfer mechanism including an arm transferring the substrate between the cleaning unit and the inspection unit; and a substrate transfer control part controlling an operation of the substrate transfer mechanism, wherein when it is determined that a state of the substrate becomes an exposable state by re-cleaning in the cleaning unit as a result of the inspection in the inspection unit, the substrate transfer control part controls the substrate transfer mechanism to transfer the substrate again to the cleaning unit.

According to the present invention, a substrate transfer control part is provided which controls a substrate transfer mechanism, when it is determined that the substrate is in a state of being unexposable under the existing condition but becoming exposable by re-cleaning in the cleaning unit as a result of inspection in the inspection unit of the rear surface of the cleaned substrate, to transfer the substrate again to the cleaning unit. In this case, the re-cleaning of the substrate is performed as necessary, so that even the substrate which has been determined to be unexposable in the prior art can be continuously subjected to substrate treatment. Accordingly, the number of substrates for which the treatment is stopped on the way and which are collected into a cassette can be reduced as compared to the conventional coating and developing treatment system in which the treatment for all of the substrates determined to be unexposable is stopped on the way and the substrates are collected into the cassette. Consequently, the yield of the substrate treatment by the substrate treatment system can be improved.

The present invention according to another aspect is a substrate transfer method in a substrate treatment system including a treatment station in which a plurality of treatment units each treating a substrate, and an interface station delivering the substrate between the treatment station and an exposure apparatus provided outside, the interface station including: a cleaning unit cleaning at least a rear surface of the substrate before the substrate is transferred into the exposure apparatus; an inspection unit inspecting at least the rear surface of the cleaned substrate whether the substrate is exposable, before the substrate is transferred into the exposure apparatus; and a substrate transfer mechanism including an arm transferring the substrate between the cleaning unit and the inspection unit, wherein when it is determined that a state of the substrate becomes an exposable state by re-cleaning in the cleaning unit as a result of the inspection in the inspection unit, the substrate is transferred again to the cleaning unit.

According to the present invention in yet another aspect is a non-transitory computer-readable storage medium storing a program running on a computer of a control unit controlling a substrate treatment system to cause the substrate treatment system to execute a method of transferring a substrate, said substrate treatment system comprising a cleaning unit cleaning at least a rear surface of the substrate before the substrate is transferred into said exposure apparatus, an inspection unit inspecting at least the rear surface of the cleaned substrate whether the substrate is exposable, before the substrate is transferred into said exposure apparatus; and a substrate transfer mechanism including an arm transferring the substrate between said cleaning unit and said inspection unit, wherein said program control the substrate transfer mechanism when it is determined that a state of the substrate becomes an exposable state by re-cleaning in the cleaning unit as a result of the inspection in the inspection unit, the substrate is transferred again to the cleaning unit.

According to the present invention, it is possible to improve the yield of the substrate treatment in a substrate treatment system having a function of cleaning a rear surface of a substrate before exposure.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described.FIG. 1is an explanatory view illustrating the outline of an internal configuration of a coating and developing treatment system1as a substrate treatment system according to this embodiment.FIG. 2andFIG. 3are explanatory views illustrating the outline of the internal configuration of the coating and developing treatment system1from the front side and the back side, respectively.

The coating and developing treatment system1has, as illustrated inFIG. 1, a configuration in which, for example, a cassette station2to/from which a cassette C housing a plurality of wafers W therein is transferred in/out from/to the outside, a treatment station3including a plurality of treatment units performing predetermined treatments on the wafer W in the photolithography processing, and an interface station5delivering the wafers W to/from an exposure apparatus4, are integrally connected. The coating and developing treatment system1further has a control unit6performing control on various treatment units and so on.

The cassette station2is composed of, for example, a cassette transfer-in/out section10and a wafer transfer section11. The cassette transfer-in/out section10is provided, for example, at the end on a Y-direction negative direction (the left direction inFIG. 1) side in the coating and developing treatment system1. In the cassette transfer-in/out section10, a cassette mounting table12as a cassette mounting part is provided. On the cassette mounting table12, for example, four cassette mounting plates13are provided. The cassette mounting plates13are provided side by side in a line in an X-direction (an up and down direction inFIG. 1) being the horizontal direction. On the cassette mounting plates13, cassettes C can be mounted when the cassettes C are transferred in/out from/to the outside of the coating and developing treatment system1.

In the wafer transfer section11, a wafer transfer apparatus21movable on a transfer path20extending in the X-direction is provided as illustrated inFIG. 1. The wafer transfer apparatus21is movable also in the up and down direction and around the vertical axis (in a θ-direction) and can transfer the wafer W between the cassette C on each of the cassette mounting plates13and a later-described delivery unit in a third block G3in the treatment station3.

In the treatment station3adjacent to the cassette station2, a plurality of, for example, four blocks G1, G2, G3, G4are provided each of which includes various kinds of units. On the front side (an X-direction negative direction side inFIG. 1) in the treatment station3, the first block G1is provided, and on the back side (an X-direction positive direction side inFIG. 1) in the treatment station3, the second block G2is provided. Further, on the cassette station2side (a Y-direction negative direction side in the inFIG. 1) in the treatment station3, the third block G3is provided, and on the interface station5side (a Y-direction positive direction side in the inFIG. 1) in the treatment station3, the fourth block G4is provided.

For example, in the first block G1, a plurality of solution treatment units, for example, a lower anti-reflection film forming unit30forming an anti-reflection film under a resist film of the wafer W (hereinafter, referred to as a “lower anti-reflection film”), a resist coating unit31applying a resist solution onto the wafer W to form a resist film, an upper anti-reflection film forming unit32forming an anti-reflection film on top of the resist film of the wafer W (hereinafter, referred to as an “upper anti-reflection film”), and a developing treatment unit33performing developing treatment on the wafer W, are stacked at four tiers from the bottom as illustrated inFIG. 2.

Each of the units30to33in the first block G1has a plurality of cups F each of which houses the wafer W therein during treatment in the horizontal direction to be able to treat a plurality of wafers W in parallel.

For example, in the second block G2, as illustrated inFIG. 3, thermal treatment units40each performing thermal treatment on the wafer W, adhesion units41as hydrophobic treatment apparatuses each performing hydrophobic treatment on the wafer W, and edge exposure units42each exposing the outer peripheral portion of the wafer W are arranged one on top of the other in the vertical direction and side by side in the horizontal direction as illustrated inFIG. 3. The thermal treatment unit40has a thermal plate that mounts and heats the wafer W thereon and a cooling plate that mounts and cools the wafer W thereon so as to be able to perform both heat treatment and cooling treatment. Note that the numbers and the arrangement of the thermal treatment units40, adhesion units41, and edge exposure units42can be arbitrarily selected.

For example, in the third block G3, a plurality of delivery units50,51,52,53,54,55,56are provided in order from the bottom. Further, in the fourth block G4, a plurality of delivery units60,61,62are provided in order from the bottom.

A wafer transfer region D is formed in a region surrounded by the first block G1to the fourth block G4as illustrated inFIG. 1. In the wafer transfer region D, for example, a plurality of, for example, three wafer transfer apparatuses70are provided. The wafer transfer apparatuses70have the same structure.

The wafer transfer apparatus70has a transfer arm70athat is movable, for example, in the Y-direction, a forward and backward direction, the θ-direction, and the up and down direction. The transfer arm70acan move in the wafer transfer region D and transfer the wafer W to a predetermined unit in the first block G1, the second block G2, the third block G3, and the fourth block G4therearound. A plurality of wafer transfer apparatuses70are provided one above top of the other as illustrated inFIG. 3and can transfer the wafers W, for example, to predetermined units at the similar levels in the blocks G1to G4.

Further, in the wafer transfer region D, a shuttle transfer apparatus80linearly transferring the wafer W between the third block G3and the fourth block G4is provided.

The shuttle transfer apparatus80is configured to be linearly movable, for example, in the Y-direction inFIG. 3. The shuttle transfer apparatus80can move in the Y-direction while supporting the wafer W and transfer the wafer W between the delivery unit52in the third block G3and the delivery unit62in the fourth block G4.

As illustrated inFIG. 1, a wafer transfer apparatus90is provided on the X-direction positive direction side of the third block G3. The wafer transfer apparatus90has a transfer arm90athat is movable, for example, in the forward and backward direction, the θ-direction, and the up and down direction. The wafer transfer apparatus90can move up and down while supporting the wafer W to transfer the wafer W to each of the delivery units in the third block G3.

On the X-direction positive direction side of the fourth block G4, a wafer transfer apparatus85is provided. The wafer transfer apparatus85has a transfer arm85athat is movable, for example, in the forward and backward direction, the θ-direction, and the up and down direction. The wafer transfer apparatus85can move up and down while supporting the wafer W to transfer the wafer W to the interface station5.

In the interface station5, three blocks G5, G6, G7each including various units are provided. For example, on the front side (an X-direction negative direction side inFIG. 1) in the interface station5, the fifth block G5is provided. The sixth block G6is provided on the back side (the X-direction positive direction side inFIG. 1) in the interface station5. Further, the seventh block G7is provided in a region between the fifth block G5and the sixth block G6.

For example, in the fifth block G5, cleaning units100each cleaning the rear surface of the wafer W before the wafer W is transferred into the exposure apparatus4are provided, for example, at four tiers stacked in the up and down direction as illustrated inFIG. 4.

In the sixth block G6, inspection units101each inspecting whether the rear surface of the wafer W cleaned in the cleaning unit100is in a state of allowing exposure in the exposure apparatus4before the wafer W is transferred into the exposure apparatus4, and dehydration units102each removing moisture adhering to the wafer W after it is cleaned in the cleaning unit100, are provided stacked at two tiers each in this order from the bottom to the top. Note thatFIG. 4is an explanatory view illustrating the outline of the internal configuration of the interface station5when the interface station5is seen from the cassette station2side.

In the seventh block G7, delivery units110each delivering the wafer W to/from the treatment station3via the wafer transfer apparatus85, buffer units111as buffer housing parts each temporarily housing the wafer W inspected in the inspection unit101, and temperature regulation units112as temperature regulation mechanisms each regulating the temperature of the inspected wafer W to a predetermined temperature before it is transferred into the exposure apparatus4, are provided at multiple tiers in the up and down direction. More specifically, in an upper part of the seventh block G7, the delivery units110and the buffer units111are arranged alternately stacked at three tiers each in this order from the top. In a lower part of the seventh block G7, the delivery units110and the temperature regulation units112are arranged alternately stacked at two tiers each in this order from the top. The temperature regulation unit112has a temperature regulation plate including a temperature regulation member such as a Peliter element and thus can temperature-regulate the wafer W mounted on the temperature regulation plate to a predetermined temperature, for example, room temperature.

In a region between the fifth block G5and the seventh block G7and adjacent to the fifth block G5, a wafer transfer mechanism120as a substrate transfer mechanism is provided. The wafer transfer mechanism120has a first transfer arm121and a second transfer arm122as a plurality of transfer arms. Each of the transfer arms121,122is configured to be movable, for example, in the forward and backward direction, the θ-direction, and the up and down direction. Each of the transfer arms121,122can thus move up and down while supporting the wafer W to transfer the wafer W between the units in the blocks G5, G7.

In a region between the sixth block G6and the seventh block G7and adjacent to the sixth block G6, a wafer transfer mechanism130is provided. The wafer transfer mechanism130is provided with a third transfer arm123and a fourth transfer arm124. Each of the transfer arms123,124is configured to be movable, for example, in the forward and backward direction, the θ-direction, and the up and down direction. Each of the transfer arms123,124can thus move up and down while supporting the wafer W to transfer the wafer W between the units in the block G6, between the sixth block G6and the seventh block G7, and between the sixth block G6and the exposure apparatus4. Note that as the wafer transfer mechanism120, the plurality of independently moving transfer arms121,122are illustrated inFIG. 4, but one transfer arm provided with a plurality of, for example, two sets of tweezers holding the wafer W may be used in place of the plurality of transfer arms. This also applies to the wafer transfer mechanism130.

The transfer by the wafer transfer mechanisms120,130is controlled by a wafer transfer control part125as a substrate transfer control part of the control unit6illustrated inFIG. 1. The wafer transfer control part125controls the wafer transfer mechanism120so that the first transfer arm121transfers the wafer W between the cleaning unit100and the delivery unit110and the second transfer arm122transfers the cleaned wafer W to the delivery unit110. The wafer transfer control part125further controls the wafer transfer mechanism130so that the third transfer arm123performs transfer of the wafer W cleaned in the cleaning unit100from the delivery unit110to the dehydration unit102, transfer from the dehydration unit102to the inspection unit101, transfer from the inspection unit101to the buffer unit111, and transfer from the buffer unit111to the temperature regulation unit112.

The wafer transfer control part125also controls the wafer transfer mechanism130so that the fourth transfer arm124transfers the wafer W between the temperature regulation unit112and the delivery unit110and the exposure apparatus4. Note that the wafer transfer control part125also controls the operations of the other wafer transfer apparatuses in the coating and developing treatment system1.

Next, the configuration of the cleaning unit100will be described.FIG. 5is a plan view illustrating the outline of the configuration of the cleaning unit100, andFIG. 6is a longitudinal sectional view illustrating the outline of the configuration of the cleaning unit100.

The cleaning unit100has two suction pads140,140horizontally suction-holding the wafer W transferred via the first transfer arm121, a spin chuck141horizontally suction-holding the wafer W received from the suction pads140, a brush142cleaning the rear surface of the wafer W, and a casing143having an upper surface open.

As illustrated inFIG. 5, the two suction pads140,140are provided substantially parallel to each other with the spin chuck141intervening therebetween in a plan view to be able to hold the edge portion of the rear surface of the wafer W. Each of the suction pads140,140is supported at its both ends by a frame body144movable in the horizontal direction and the up and down direction by a drive mechanism (not illustrated).

On an upper surface of the frame body144, an upper cup145is provided. In an upper surface of the upper cup145, an opening145awith a diameter larger than the diameter of the wafer W is formed so that the wafer W is delivered between the first transfer arm121and the suction pads140through the opening145a.

As illustrated inFIG. 6, the spin chuck141is connected to a drive mechanism151via a shaft150so that the spin chuck141is configured to freely rotate and rise and lower by means of the drive mechanism151.

Around the spin chuck141, raising and lowering pins152are provided which freely rise and lower by means of a raising and lowering mechanism (not illustrated).

The brush142is configured, for example, by bundling many plastic fibers in a column shape, and is supported by a support body153. The support body153is connected to a drive mechanism154. The drive mechanism154is connected to the casing143and can horizontally move in the X-direction inFIG. 5and along the casing143. Accordingly, by moving the drive mechanism154in the X-direction, the brush142can be moved in the X-direction inFIG. 5via the support body153. The brush142is configured to freely rotate by means of a drive mechanism (not illustrated) built in the support body153so that particles adhering to the rear surface of the wafer W can be removed by rotating the brush142with its upper surface pressed against the rear surface of the wafer W and sliding the brush142on the rear surface of the wafer W.

Further, at the tip end of the support body153, a cleaning solution nozzle153asupplying a cleaning solution for washing away the particles removed by the brush, and a purge nozzle153bsupplying gas such as nitrogen for drying the cleaning solution adhering to the rear surface of the wafer W after cleaning, are provided.

At the bottom of the casing143, a drain pipe160draining the cleaning solution and an exhaust pipe161forming downward airflow in the cleaning unit100and exhausting the airflow are provided.

Next, the cleaning of the wafer W in the cleaning unit100will be described. For the cleaning of the wafer W, the wafer W is transferred by the first transfer arm121to above the upper cup145as illustrated inFIG. 7. Then, the raising and pins152are raised and the wafer W is delivered to the raising and lowering pins152. In this event, the suction pads140are waiting with the upper surfaces thereof located at a position higher than the upper surface of the brush142, and the spin chuck141is retracted to a position lower than the upper surface of the brush142. Thereafter, the raising and lowering pins152are lowered, whereby the wafer W is delivered to and held on the suction pads140as illustrated inFIG. 8.

Subsequently, the frame body144is horizontally moved so that, for example, the brush142is located in a region corresponding to the center part of the rear surface of the wafer W with the wafer W suction-held by the suction pads140as illustrated inFIG. 9. Then, the suction pads140are lowered and the rear surface of the wafer W is pressed against the upper surface of the brush142.

Then, the cleaning solution is supplied from the cleaning solution nozzle153aand the brush142is rotated to clean the center part of the rear surface of the wafer W. In this event, the support body153reciprocates in the X-direction inFIG. 5and the frame body144reciprocates in the Y-direction, whereby the center part of the rear surface of the wafer W is evenly cleaned.

After the cleaning of the center part of the rear surface of the wafer W is finished, the frame body144is horizontally moved so that the center of the wafer W is aligned with the center of the spin chuck141in a plan view as illustrated inFIG. 10. Then, the spin chuck141is raised, whereby the wafer W is delivered from the suction pads140to the spin chuck141.

Thereafter, as illustrated inFIG. 11, the wafer W is rotated with the brush142pressed against the rear surface of the wafer W and the brush142is slid in the X-direction via the support body153, whereby the edge portion of the rear surface of the wafer W is cleaned. This removes the particles on the entire rear surface of the wafer W.

After the cleaning of the rear surface of the wafer W is completed, the rotation of the brush142and the supply of the cleaning solution are stopped and the spin chuck141is rotated at a high speed, whereby the cleaning solution adhering to the rear surface of the wafer W is spin-dried. In this event, the purge by the purge nozzle153bis performed in parallel.

After the drying is finished, the wafer W is delivered to the second transfer arm122in the order reverse to that when it is transferred to the cleaning unit100.

Next, the configuration of the inspection unit101will be described.FIG. 12is a longitudinal sectional view illustrating the outline of the configuration of the inspection unit101.

The inspection unit101has a casing170in which a holding arm171holding the wafer W with at least the rear surface of the wafer W open directed downward, a light source172applying parallel light rays in line shape to the rear surface of the wafer W held by the holding arm171, and a camera173picking up an image of the light applied to the rear surface of the wafer W are provided. The holding arm171is configured to be movable in the horizontal direction by means of a drive mechanism (not illustrated).

A locking part171aprojecting downward is formed at the tip end of the holding arm171, and a movable holding part171bmovable in the direction of the diameter of the wafer W by means of a not-illustrated drive mechanism is provided on the lower surface of the holding arm171. The holding arm171can hold, by the locking part171aand the movable holding part171b, the wafer W delivered from the third transfer arm123entering the casing170through an opening170aof the casing170and hold the wafer W with the rear surface directed downward.

The light source172is disposed below the holding arm171to apply the light rays at a predetermined angle of θ with respect to the rear surface of the wafer W. The camera173is disposed below the holding arm171in a state of being tilted at the predetermined angle of θ, similarly to the light source172, with respect to the rear surface of the wafer W to pick up an image of the light rays applied to the rear surface of the wafer W.

The light source172and the camera173are adjustable in application angle and imaging angle by means of a not-illustrated tuning mechanism. This enables observation of the particles, which cannot be observed by light rays applied at a certain angle, by applying the light rays at a different angle.

In the inspection unit101, the holding arm171moves in the horizontal direction while holding the wafer W and the camera173continuously picks up an image of the light rays applied to the rear surface of the wafer W to thereby pick up an image of the entire rear surface of the wafer W. The image picked up by the camera173is inputted into the control unit6, and the control unit6determines whether the state of the rear surface of the wafer W allows exposure in the exposure apparatus4. Note that the control unit6determines whether to perform exposure on the wafer W in the exposure apparatus4based on the number and an adhesion range of particles adhering to the rear surface of the wafer W, or the height and size of the particles.

Next, the configuration of the dehydration unit102will be described.FIG. 13is a plan view illustrating the outline of the configuration of the dehydration unit102, andFIG. 14is a longitudinal sectional view illustrating the outline of the configuration of the dehydration unit102.

The dehydration unit102has a treatment container180in which dehydration treatment is performed on the wafer W, holding members181holding the outer peripheral portion of the rear surface of the wafer W, and a raising and lowering mechanism183raising and lowering the holding members181in the up and down direction via a shaft182.

A plurality of, four in this embodiment, holding members181are each concentrically formed in an almost arc shape in a plan view as illustrated, for example, inFIG. 13. The holding member181has a cross-sectional shape in an almost U-shape as illustrated inFIG. 14. An upper end part181aon the outer peripheral side of the holding member181is formed to be higher than an upper end part181bon the inner peripheral side. Thus, a part of the holding member181on the outer peripheral side functions as a guide preventing the wafer W from falling off when the wafer W is held by the upper end part181bon the inner peripheral side.

For delivery of the wafer W between each holding member181and the third transfer arm123, the third transfer arm123enters through a shutter180aof the treatment container180, for example, as illustrated inFIG. 13, and the third transfer arm123is moved so that the center part of the wafer W held by the third transfer arm123is aligned with the center of the arcs formed by the plurality of holding members181. Then, in this state, the raising and lowering mechanism183raised the holding members181. Thereby, the wafer W is delivered from the third transfer arm123to the holding members181. Thereafter, the third transfer arm123is retracted to the outside of the treatment container180. Note that the delivery of the wafer W between the third transfer arm123and the holding members181may be performed, for example, by raising and lowering the third transfer arm123.

At the bottom of the treatment container180, an exhaust pipe185connected to an exhaust mechanism184and a purge pipe186purging the inside of the treatment container180by feeding, for example, a nitrogen gas into the treatment container180are provided. To the purge pipe186, a gas supply source187supplying the nitrogen gas is connected.

For performing the dehydration treatment on the wafer W in the dehydration unit102, the wafer W is first transferred by the third transfer arm123into the treatment container180, and the wafer W is then delivered to the holding members181. Thereafter, the third transfer arm123is retracted to the outside of the treatment container180, and the shutter180ais closed. Subsequently, the exhaust mechanism184reduces the pressure inside the treatment container180. This vaporizes the moisture adhering to the wafer W and thereby performs the dehydration treatment on the wafer W.

After the dehydration treatment on the wafer W is finished, purge and increase in pressure inside the treatment container180are performed through the purge pipe186. Thereafter, the shutter180ais opened, and the wafer W is transferred by the third transfer arm123to the inspection unit101.

The control unit6is composed of a computer including, for example, a CPU and a memory. In the control unit6, a treatment recipe in which contents of the wafer treatment in the various treatment units in the coating and developing treatment system1and the transfer route of each wafer W are stored as a program, for example, in the memory. By executing the program, the control unit6controls the various treatment units in the coating and developing treatment system1, and the operations of the wafer transfer mechanism120and the wafer transfer apparatuses by the above-described wafer transfer control part125, to thereby control the various treatments and transfer of the wafers W in the coating and developing treatment system1. Note that the program may be the one that is stored, for example, in a computer-readable storage medium H such as a computer-readable hard disk (HD), flexible disk (FD), compact disk (CD), magneto-optical disk (MO), or memory card, and installed from the storage medium H into the control unit6.

In the coating and developing treatment system1configured as described above, for example, the following wafer treatment is performed.FIG. 15is a flowchart illustrating an example of main steps of the wafer treatment.

For the treatment on the wafer W, the cassette C housing a plurality of wafers W therein is first mounted on a predetermined cassette mounting plate13in the transfer-in/out section10. Then, the wafers W in the cassette C are successively taken out by the wafer transfer apparatus21and transferred, for example, to the delivery unit53in the third block G3in the treatment station3.

Next, the wafer W is transferred by the wafer transfer apparatus70to the thermal treatment unit40in the second block G2and temperature-regulated (Step S1inFIG. 15). The wafer W is then transferred by the wafer transfer apparatus70, for example, to the lower anti-reflection film forming unit30in the first block G1, where a lower anti-reflection film is formed on the wafer W (Step S2inFIG. 15). The wafer W is then transferred to the thermal treatment unit40in the second block G2and subjected to heat treatment. The wafer W is then returned to the delivery unit53in the third block G3.

The wafer W is then transferred by the wafer transfer apparatus90to the delivery unit54in the third block G3. The wafer W is then transferred by the wafer transfer apparatus70to the adhesion unit41in the second block G2and subjected to adhesion treatment (Step S3inFIG. 15). The wafer W is then returned by the wafer transfer apparatus70to the resist coating unit31, where a resist film is formed on the wafer W (Step S4inFIG. 15).

The wafer W is then transferred by the wafer transfer apparatus70to the thermal treatment unit40and subjected to pre-baking treatment (Step S5inFIG. 15). Then, the wafer W is transferred by the wafer transfer apparatus70to the delivery unit55in the third block G3.

Subsequently, the wafer W is transferred by the wafer transfer apparatus70to the upper anti-reflection film forming unit32, where an upper anti-reflection film is formed on the wafer W (Step S6inFIG. 15). The wafer W is then transferred by the wafer transfer apparatus70to the thermal treatment unit40and heated and temperature-regulated. The wafer W is then transferred to the edge exposure unit42and subjected to edge exposure processing (Step S7inFIG. 15).

The wafer W is then transferred by the wafer transfer apparatus70to the delivery unit56in the third block G3.

The wafer W is then transferred by the wafer transfer apparatus90to the delivery unit52and transferred by the shuttle transfer apparatus80to the delivery unit62in the fourth block G4.

The wafer W is then transferred by the wafer transfer apparatus85to the delivery unit110in the seventh block G7. The wafer W is then transferred by the first transfer arm121to the cleaning unit100, in which the rear surface of the wafer W is cleaned (Step S8inFIG. 15).

The wafer W whose rear surface has been cleaned is transferred by the second transfer arm122to the delivery unit110in the seventh block G7. The wafer W is then transferred by the third transfer arm123to the dehydration unit102and subjected to dehydration treatment (Step S9inFIG. 15).

The wafer W which has been subjected to the dehydration treatment is transferred by the third transfer arm123to the inspection unit101, in which the rear surface of the wafer W is inspected (Step S10inFIG. 15). The wafer W is then transferred by the third transfer arm123to the buffer unit111and temporarily housed in the buffer unit111until the inspection result of the wafer W in the inspection unit101is available.

After the inspection result in the inspection unit101is available, the wafer transfer control part125controls the wafer transfer mechanism120based on a predetermined rule to transfer the wafer W. More specifically, as a result of the inspection in the inspection unit101, when it is determined that the wafer W is in a state of being exposable in the exposure apparatus4, the wafer W is transferred by the third transfer arm123to the temperature regulation unit112and then transferred by the fourth transfer arm124to the exposure apparatus4. As a result of the inspection, when it is determined that the wafer W is in a state of being unexposable in the exposure apparatus4, the subsequent treatments on the wafer W are stopped and the wafer W is transferred by the third transfer arm123to the delivery unit110. Thereafter, the wafer W for which the subsequent treatments are stopped is transferred by the wafer transfer apparatus85to the treatment station3, and then collected into a cassette C on a predetermined cassette mounting plate13(Step S11inFIG. 15). Note that the route for collecting the wafer W determined to be unexposable may be a route using, for example, the shuttle transfer apparatus80or a route for collecting the wafer W via the tier of the developing treatment unit33in the first block G1. The reason why the tier of the developing treatment unit33is used is that the transfer direction of the exposed wafer W at the tier of the developing treatment unit33is the direction from the exposure apparatus4to the cassette station2side as with the transfer direction of the wafer W determined to be unexposable, and therefore the wafer W determined to be unexposable can be transferred without interfering with the transfer of normal wafers W.

As a result of the inspection, when it is determined that the wafer W is in a state of being unexposable under the existing condition but becoming exposable in the exposure apparatus4by re-cleaning in the cleaning unit100, the wafer W is delivered by the third transfer arm123to the delivery unit110and transferred by the first transfer arm121again to the cleaning unit100. The wafer W re-cleaned in the cleaning unit100is then transferred again to the inspection unit101. Thereafter, when the wafer W is determined to be exposable in the inspection unit101, the wafer W is transferred by the third transfer arm123to the temperature regulation unit112, and then transferred by the wafer transfer mechanism130to the exposure apparatus4and subjected to exposure processing (Step S12inFIG. 15).

The wafer W which has been subjected to the exposure processing is transferred by the fourth transfer arm124to the delivery unit110in the seventh block G7. The wafer W is then transferred by the wafer transfer apparatus85to the delivery unit40in the fourth block G4. The wafer W is then transferred by the wafer transfer apparatus70to the thermal treatment unit40and subjected to post-exposure baking treatment (Step S13inFIG. 15). The wafer W is then transferred by the wafer transfer apparatus70to the developing treatment unit33and subjected to developing treatment (Step S14inFIG. 15). After the development, the wafer W is transferred by the wafer transfer apparatus70to the thermal treatment unit40and subjected to post-baking treatment (Step S15inFIG. 15).

The wafer W is then transferred by the wafer transfer apparatus70to the delivery unit50in the third block G3, and then transferred by the wafer transfer apparatus21in the cassette station2to the cassette C on a predetermined cassette mounting plate13. Thus, a series of photolithography processes end.

According to this embodiment, as a result of the inspection of the cleaned wafer W in the inspection unit101, when it is determined that the wafer W is in a state of being unexposable under the existing condition but becoming exposable by re-cleaning in the cleaning unit100, the wafer transfer control part125controls the wafer transfer mechanism120to transfer the wafer W again to the cleaning unit100. In this case, the number of wafers W for which the subsequent treatments are stopped and which are collected into the cassette C can be reduced as compared to the conventional coating and developing treatment system200in which the subsequent treatments for all of the wafers W determined to be unexposable are stopped and the wafers W are collected into the cassette C. Consequently, the yield of the treatment on the wafer W by the coating and developing treatment system1can be increased.

Further, since the buffer unit111for temporarily housing the wafer W inspected in the inspection unit101is provided, the inspected wafer \V can be kept waiting in the buffer unit111until the inspection result in the inspection unit101is available. If the wafer W is transferred without inspection result being available, a need to change the transfer destination of the wafer W during transfer may arise depending on the inspection result available afterward to greatly influence the transfer of the wafer W. However, such influence is never caused by keeping the inspected wafer W in the buffer unit111until the inspection result is available, because the wafer W can be transferred after decision of the transfer destination.

Note that the time period for keeping in the buffer unit111the wafer W inspected in the inspection unit101does not need to be terminated at the time when the inspection result of the wafer W is available, but the wafer W may be kept waiting for a longer time. For example, in the case where a plurality of inspected wafers W are housed in the buffer unit111, when the inspection result of a wafer W whose inspection result is available first is the above-described “re-cleaning,” the inspection result of another wafer W housed in the buffer unit111may be available during the process of the former wafer W being re-cleaned in the cleaning unit100. In this case, if the next wafer W whose inspection result has been available is transferred to the exposure apparatus4side, the latter wafer W will be transferred to the exposure apparatus4passing the former wafer W to be re-cleaned. In this case, the latter wafer W will be transferred to the exposure apparatus4in an order different from the transfer schedule for the latter wafer W set in the treatment recipe, for example, for each lot, thus possibly causing a transfer error because the exposure apparatus4cannot recognize the latter wafer W.

Accordingly, when an arbitrary wafer W is determination to require “re-cleaning” as described above, it is preferable to keep the next wafer W in the buffer unit111until the arbitrary wafer W is inspected again in the inspection unit101after the re-cleaning and the inspection result of the re-cleaning is available after the arbitrary wafer W is housed in the buffer unit111. By adjusting the time for keeping the wafer W waiting in the buffer unit111as described above, the wafer W can be transferred in a predetermined order even in the case of “re-cleaning.” Note that the buffer unit111may be configured to be able to house a plurality of wafers W, for example, at multiple tiers. In this case, for example, when a wafer W in the buffer until111is determined to be unexposable, the wafer W is housed in the buffer unit111until the timing when the wafer W does not influence any longer the schedule of the wafer transfer by the wafer transfer mechanism120, thereby making it possible to collect the wafer W without influencing the transfer schedule. It is also adoptable to keep, for example, a plurality of wafers W determined to be exposable waiting in the buffer unit111. In this case, the exposable wafers W kept waiting are transferred to the exposure apparatus4during the time when the wafer W determined to require “re-cleaning” is re-cleaned, thereby ensuring the wafer W to be transferred to the exposure apparatus4at all times to prevent the exposure apparatus4from being kept waiting.

In the above embodiment, since the cleaned wafer W is transferred by each transfer arm122,123,124to each unit, it is possible to suppress contamination of each transfer arm122,123,124transferring the cleaned wafer W with particles adhering to the rear surface of the wafer W. As a result, it is possible to keep each transfer arm122,123,124clean and to reduce the possibility that the rear surface of the wafer W is contaminated with particles adhering to each transfer arm122,123,124when the cleaned wafer W is transferred.

Note that the case where, for example, it is determined that the wafer W is in a state of being unexposable in the exposure apparatus4as a result of the inspection by the inspection unit101shows that the second transfer arm122and the third transfer arm123have transferred the wafer W with particles adhering to the rear surface. Then, the particles adhering to the wafer W may adhere to each transfer arm122,123and contaminate the rear surface of the wafer W to be transferred next. Accordingly, when it is determined that the wafer W is in a state of being unexposable in the exposure apparatus4as a result of the inspection in the inspection unit101or becoming exposable by re-cleaning, the second transfer arm122and the third transfer arm123may be cleaned after the transfer of that wafer W. The cleaning of the second transfer arm122may be performed, for example, in the cleaning unit100. In this case, the brush142in the cleaning unit100may be configured to be freely vertically reversed so that the upper surface of the second transfer arm122which has entered the cleaning unit100is cleaned with the reversed brush142. Further, separately from the cleaning unit100, another cleaning unit as an arm cleaning mechanism cleaning the second transfer arm122may be provided in the fifth block G5or the seventh bock G7. Note that when cleaning the third transfer arm123, another cleaning unit may be provided in the sixth block G6or the seventh block G7. Further, a cleaning mechanism for the transfer arms122,123may be provided in the buffer unit111.

Though the cleaning unit100is arranged, for example, on the front side and the inspection unit101and the dehydration unit102are arranged on the back side in the coating and developing treatment system1in the above embodiment, for example, the cleaning unit100and the dehydration unit102may be arranged on the front side in the interface station5, namely, provided at multiple tiers in the fifth block G5, and only the inspection unit101may be provided in the sixth block G6. This can minimize the number of times of the cleaned wafer W coming into contact with the transfer arm. In other words, in the case where the cleaning unit100and the dehydration unit102are provided separately on the front side and the back side, for transferring the wafer W from the cleaning unit100to the dehydration unit102, it is necessary to transfer the wafer W first from the cleaning unit100to the delivery unit110and then transfer the wafer W from the delivery unit110to the dehydration unit102. In this case, the rear surface of the cleaned wafer W comes into contact with the transfer arms122,123of the wafer transfer mechanisms120,130at least one time each. In contrast, the arrangement of the cleaning unit100and the dehydration unit102in the up and down direction eliminates the necessity of passage through the delivery unit110and therefore reduces the number of contact times between the wafer W and the second transfer arm122of the wafer transfer mechanism120to one. As a result, the possibility that the rear surface of the wafer W is contaminated with the particles adhering to the wafer transfer mechanism120can be reduced as compared to the prior art.

Further, the cleaning unit100and the inspection unit101may be arranged on the front side in the interface station5, namely, provided at multiple tiers in the fifth block G5, and only the dehydration unit102may be provided in the sixth block G6. The arrangement of only the dehydration unit102on the back side ensures, on the back side, the installation location for large-sized and heavy devices such as the exhaust mechanism184and the treatment container180which are provided in association with the dehydration unit102.

Note that though the dehydration unit102is provided in the interface station5in the above embodiment, the dehydration unit102does not always need to be provided in the present invention, and whether to install the dehydration unit102can be arbitrarily selected.

Further, provision of the plurality of transfer arms121,122,123,124in the wafer transfer mechanisms120,130makes it possible to even the number of steps of transfer by the transfer arms121,122,123,124so as to facilitate the management of the transfer time of the wafer W.

Though the temperature regulation is performed on the wafer W by the temperature regulation unit112before the wafer W is transferred to the exposure apparatus4in the above embodiment, a temperature regulation mechanism regulating, for example, the temperature of the atmosphere in the inspection unit101to a predetermined temperature may be provided in the inspection unit101to perform temperature regulation on the wafer W during the time when the wafer W is being inspected in the inspection unit101. This can reduce the treatment time in the temperature regulation unit112and the transfer time to the temperature regulation unit112, thereby improving the throughput of the coating and developing treatment system1.

Though the cleaning unit100and the inspection unit101are separately provided in the above embodiment, the cleaning unit100and the inspection unit101may be provided in the same casing. In a concrete example in this case, a cleaning and inspection unit310is used in which a wafer cleaning part300cleaning the rear surface of the wafer W, a wafer inspection part301inspecting the cleaned wafer W before the wafer W is transferred into the exposure apparatus4, and a transfer means302transferring the wafer W between the wafer cleaning part300and the wafer inspection part301are housed in one casing303as illustrates inFIG. 16,FIG. 17. Note that the devices given the same numerals as those of the devices constituting the already-described cleaning unit100and inspection unit101in the drawings have the same configurations and therefore the description thereof will be omitted. Further, the arrangement of the cleaning and inspection unit310in the interface station5is arbitrarily set in consideration of the transfer order and the throughput of the wafer W and is thus not particularly limited.

As illustrated inFIG. 16, the wafer cleaning part300and the wafer inspection part301are arranged in this order from the bottom to the top in the casing303. In a region between the wafer cleaning part300and the wafer inspection part301, namely, above the wafer cleaning part300and below the wafer inspection part301, a waiting and mounting table320is arranged which temporarily keeps the wafer W inspected in the wafer inspection part301waiting thereon.

The transfer means302includes a transfer arm302ain an almost U-shape having a tip branched off into two parts as illustrated inFIG. 17. At the end of the transfer arm302a, an arm drive mechanism302bmoving the transfer arm302ain the forward and backward direction is provided. The arm drive mechanism302bis supported by a base302c.

In the base302c, a drive mechanism (not illustrated) is built which freely moves the base302cin the θ-direction and the up and down direction along a raising and lowering rail302dprovided to extend in the vertical direction. Thus, the transfer arm302ais configured to be movable in the forward and backward direction, the θ-direction, and the up and down direction and can move up and down while holding the wafer W to transfer the wafer W between the wafer cleaning part300and the wafer inspection part301.

The waiting and mounting table320has raising and lowering pins (not illustrated) built therein and can deliver the wafer W through use of the raising and lowering pins to/from the transfer arm302aand each transfer arm in the interface station5.

In the cleaning and inspection unit310, the cleaning of the rear surface of the wafer W and the spin-drying of the cleaning solution are performed first at the wafer cleaning part300. After the spin-drying is finished, the wafer W is delivered to the transfer arm302a. Then, the transfer arm302ais raised while holding the wafer W up to the wafer inspection part301and moved to below the holding arm171. Then, the wafer W is sandwiched between the locking part171aand the movable holding part171bof the holding arm171and thereby delivered to the holding arm171, and subjected to inspection at the wafer inspection part301.

After the inspection is finished, the wafer W is delivered again to the transfer means302and then delivered to the waiting and mounting table320. In parallel with that, the control unit6determines which of three kinds of states the state of the wafer W belongs to: a state of being exposable in the exposure apparatus4; a state of being unexposable in the exposure apparatus4; and a state of being unexposable in the exposure apparatus4under the existing condition but becoming exposable in the exposure apparatus4by re-cleaning in the wafer cleaning part300.

As a result of the inspection at the wafer inspection part301, when it is determined that the wafer W is in a state of being exposable in the exposure apparatus4, the wafer W on the waiting and mounting table320is transferred out of the cleaning and inspection unit310and transferred to the dehydration unit102. Further, also when it is determined that the wafer W is in a state of being unexposable, the wafer W is transferred out of the cleaning and inspection unit310and the subsequent treatments on the wafer W are stopped.

When the inspection result of the wafer W is “re-cleaning,” the wafer W on the waiting and mounting table320is transferred by the transfer means302again to the wafer cleaning part300. The wafer W transferred again to the wafer cleaning part300is subjected again to the above-described cleaning and inspection, and the re-cleaned and re-inspected wafer W is transferred out of the cleaning and inspection unit310and transferred to the dehydration unit102. The subsequent steps S12to S15are the same as those in the above-described embodiment and therefore the description thereof will be omitted.

According to this embodiment, the wafer cleaning part300cleaning the rear surface of the wafer W and the wafer inspection part301inspecting the cleaned wafer W are housed in the same casing303, and the transfer of the wafer W between the wafer cleaning part300and the wafer inspection part301can be performed by the transfer means302provided inside the casing303. Therefore, for transferring the wafer W between the wafer cleaning part300and the wafer inspection part301, it becomes unnecessary to use the wafer transfer apparatus provided, for example, outside the casing303, namely, in the interface station5as in the prior art. As a result, the wafer transfer distance in the coating and developing treatment system1can be reduced and the load on the wafer transfer apparatus in the interface station5can be reduced.

Further, since the transfer of the wafer W accompanying the re-cleaning at the wafer cleaning part300is performed by the transfer means302, the load on the wafer transfer apparatus outside the casing303is never increased in the re-cleaning. Note that the wafer inspection part301is arranged above the wafer cleaning part300in the above embodiment, but the wafer cleaning part300may be arranged above the wafer inspection part301the other way round.

Further, the transfer arms are selectively used for the wafer determined to be unexposable in the exposure apparatus4and the wafer W determined to be exposable among the wafers W which have been subjected to the cleaning and inspection. In this case, it is possible to prevent a clean transfer arm from being contaminated with particles adhering to the wafer W determined to be unexposable. Consequently, the transfer arms and the units used in the downstream steps can be kept clean.

Note that when it is determined that the wafer W is in a state of being unexposable or requiring re-cleaning as a result of the inspection at the wafer inspection part301, the transfer means302may be cleaned at the wafer cleaning part300after transferring the wafer W.

Further, the dehydration unit102may be provided inside the cleaning and inspection unit310. In this case, for example, the dehydration unit102is arranged inside the casing303in place of the waiting and mounting table320. It is preferable to transfer, after the inspection at the wafer inspection part301, the wafer W to the dehydration unit102and to perform dehydration treatment on the wafer W. This makes it possible to perform the dehydration treatment in parallel while waiting for the inspection result of the wafer W, thus improving the throughput of the wafer W.

Further, the temperature regulation performed in the temperature regulation unit112in the above embodiment may be performed, for example, inside the cleaning and inspection unit310. In this case, a cooling mechanism400cooling, for example, the air inside the casing303is provided at a ceiling part of the casing303of the cleaning and inspection unit310as illustrated, for example, inFIG. 18, and the cooling mechanism400regulates the temperature of the atmosphere inside the casing303to a predetermined and thereby performs temperature regulation of the wafer W. For the cooling mechanism400, a radiator through which coolant at a predetermined temperature flows can be used. This enables temperature regulation of the wafer W during the time when the wafer W is kept waiting on the waiting and mounting table320after the inspection of the wafer W is finished. Consequently, the time required for the temperature regulation of the wafer W can be reduced and the transfer to the temperature regulation unit112becomes unnecessary, thus improving the throughput in the coating and developing treatment system1. Further, the temperature regulation unit112itself becomes unnecessary, leading to downsizing of the interface station5.

Note that though the wafer cleaning part300and the wafer inspection part301are arranged in the up and down direction in the casing303of the cleaning and inspection unit310in the above embodiment, the arrangement of the wafer cleaning part300and the wafer inspection part301is not limited to that in this embodiment. For example, as illustrated inFIG. 19, the wafer cleaning part300and the wafer inspection part301may be arranged in the horizontal direction. In this case, the transfer of the wafer W between the wafer cleaning part300and the wafer inspection part301may be performed by moving the frame body144, for example, with the wafer W held on the suction pads140of the wafer cleaning part300. Then, the rear surface of the wafer W held on the suction pads140is inspected by the light source172and the camera173.

Further, the wafer W may be held on the suction pads140, for example, until the inspection result of the rear surface of the wafer W is available. This eliminates the need to transfer the wafer W to the waiting and mounting table320and therefore eliminates the necessity of not only the waiting and mounting table320but also the transfer means302. In the re-cleaning, the wafer W held on the suction pads140is moved to the wafer cleaning part300, and after the cleaning, the wafer W held on the suction pads140is moved again to the wafer inspection part301. Further, when the wafer W is determined to be exposable or unexposable, the wafer W is delivered to the raising and lowering pins152of the wafer cleaning part300and transferred out of the cleaning and inspection unit310by the wafer transfer mechanism120. In this case, the suction pads140supported on the frame body144serve as the transfer means of this embodiment.

Preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the embodiments. It should be understood that various changes and modifications are readily apparent to those skilled in the art within the scope of the technical spirit as set forth in claims, and those should also be covered by the technical scope of the present invention. The present invention is not limited to the embodiments but may take various forms. The present invention is also applicable to the case where the substrate is a substrate other than the wafer, such as an FPD (Flat Panel Display), a mask reticle for a photomask or the like.