Semiconductor processing apparatus

A first transfer device and a second transfer device, each for transferring a wafer, are arranged opposite each other, and a cooling processing unit group is arranged between the first transfer device and the second transfer device. A first thermal processing unit group and a second thermal processing unit group are arranged on both sides of the first transfer device, and a first solution processing unit group and a second solution processing unit are arranged on both sides of the second transfer device. The first transfer device transfers the wafer between the cooling processing unit group, and units included in the first thermal processing unit group and the second thermal processing unit group, and the second transfer device transfers the wafer between the cooling processing unit group, and units included in the first solution processing unit group and the second solution processing unit group.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a semiconductor processing apparatus and,
 more particularly, to a semiconductor processing apparatus capable of
 obtaining thermal stability.
 2. Description of the Related Art
 In a photo-resist process of semiconductor device fabrication, a resist
 solution is coated on a substrate such as a semiconductor wafer
 (hereinafter referred to as "a wafer" ) to form a resist film thereon.
 After a pattern is exposed, the wafer is supplied with a developing
 solution to be developed. A coating and developing apparatus has been
 conventionally used in performing a series of processing described above.
 In the coating and developing apparatus, a heating apparatus for heating a
 wafer, a cooling apparatus for cooling the heat-treated wafer, a resist
 coating apparatus for coating the wafer with a resist solution to form a
 resist film thereon and a solution processing apparatus of a developing
 apparatus for supplying the wafer with a developing solution to perform
 predetermined development processing are individually provided.
 The transfer of the wafer to/from these thermal processing apparatus and
 solution processing apparatus is performed by a transfer device. The
 transfer device is provided vertically with, for example, three pairs of
 tweezers which can carry the wafer into and out of each apparatus while
 holding the wafer. A pair of topmost tweezers out of the above tweezers is
 used exclusively for carrying the wafer out of the resist coating
 apparatus, and structured not to carry the wafer into and out of the
 heating apparatus having a high processing temperature. Namely, the pair
 of topmost tweezers is never warmed by the heating apparatus.
 Thus, the wafer held by the topmost tweezers is hardly influenced by heat,
 and the heat-sensitive resist film never receives a thermal bad influence.
 By the way, in a coating and developing apparatus of late years, in order
 to reduce an installation area, a heating apparatus, solution processing
 apparatus, and the like are more integratedly arranged as compared with
 the conventional apparatus. Consequently, there is a possibility that in
 the aforesaid coating and developing apparatus, heat generated by the
 heating apparatus exerts a bad influence on the solution processing
 apparatus.
 Especially in the coating and developing apparatus of late years, a
 large-sized heating apparatus, solution processing apparatus, and the like
 corresponding to a wafer with a large area are used, whereby heat
 generated by the heating apparatus is increased in amount and in
 temperature. Accordingly, there is a possibility that in the aforesaid
 coating and developing apparatus, unintentional changes occur not only in
 the solution processing apparatus but also, for example, in the thickness
 of a resist film or a processing solution film.
 Further, large-sized tweezers corresponding to the wafer with a large area
 are used in the recent coating and developing apparatus, thereby
 increasing the heat reserve capacity of the tweezers. Therefore, there is
 a possibility that in the recent coating and developing apparatus, heat is
 transmitted from the tweezers to the solution-processed wafer, for
 instance, the wafer on which a resist film has formed, thereby exerting a
 bad influence on the wafer. Also in this case, there is a possibility that
 unintentional changes occur in the thickness of a resist film or a
 processing solution film as described above.
 Since the heating apparatus, solution processing apparatus, and the like
 are integrated and arranged in the aforesaid coating and developing
 apparatus, the maintenability for the heating apparatus and the solution
 processing apparatus is low, and hence improvement is required.
 SUMMARY OF THE INVENTION
 The present invention is made in view of the aforesaid disadvantages. A
 first object of the present invention is to provide a processing apparatus
 in which even a solution processing apparatus, a heating apparatus, and
 the like are integrated and arranged or a large-sized heating apparatus is
 used, a thermal bad influence on the solution processing apparatus is
 small.
 A second object of the present invention is to provided a processing
 apparatus in which maintenance can be easily carried out even the solution
 apparatus, heating apparatus, and the like are integrated and arranged.
 To attain the above objects, a processing apparatus in the present
 invention is a processing apparatus for performing predetermined
 processing for a substrate, including a plurality of solution processing
 apparatus for supplying the substrate with a processing solution to
 perform processing, a plurality of heating apparatus for heating the
 substrate to a predetermined temperature, a cooling apparatus for cooling
 the substrate to a predetermined temperature, and a first transfer device
 and a second transfer device each for transferring the substrate, the
 first transfer device and the second transfer device being arranged
 opposite each other with the cooling apparatus therebetween, the
 respective heating apparatus being arranged opposite each other with the
 first transfer device therebetween, the respective solution processing
 apparatus being arranged opposite each other with the second transfer
 device therebetween, and the first transfer device being capable of
 carrying the substrate into/out of the respective heating apparatus and
 the cooling apparatus, and the second transfer device being capable of
 carrying the substrate into/out of the respective solution processing
 apparatus and the cooling apparatus.
 In the present invention, the second transfer device for transferring the
 substrate to the solution processing apparatus never transfers the hot
 substrate immediately after heating. Accordingly a holding member provided
 in the second transfer device for holding the substrate is not heated,
 thus preventing the thickness of a film on the substrate from changing by
 radiation heat generated from the holding member. Further, the respective
 transfer devices are arranged opposite each other with the cooling
 apparatus therebetween, the heating apparatus are arranged on both sides
 of the first transfer device, and the solution apparatus are arranged on
 both sides of the second transfer device. As a result, spaces are formed
 between the solution apparatus and the heating apparatus, thereby
 preventing the transmission of heat generated from the heating apparatus.
 Consequently, thermal influence exerted on solution processing apparatus
 is prevented, thus enabling predetermined solution treatment for the
 substrate. Furthermore, no other apparatus is disposed on the outsides of
 the first and the second transfer devices and spaces are formed on both
 sides of the cooling apparatus, thus facilitating the maintenance of the
 solution processing apparatus, heating apparatus, cooling apparatus, and
 the like.

DESCRIPTION OF PREFERRED EMBODIMENT
 As shown in FIG. 1, a coating and developing apparatus 1 of a first
 embodiment according to the present invention has a configuration in which
 a cassette station 2 where, for example, 25 wafers W per cassette, as a
 unit, are transferred from/to the outside of the apparatus 1 and where the
 wafer W is carried into/out of a cassette C, a process station 3 in which
 various kinds of baking units, resist coating units, and the like each for
 applying predetermined processing to the wafers W one by one are
 multi-tiered, and an interface section 5 as an intermediary section where
 the wafer W is sent and received to/from an aligner 4 adjacent to the
 process station 3 are connected to one another in parallel.
 In the cassette station 2, a plurality of cassettes C are mountable with
 respective transfer ports for the wafer W facing the process station 3
 side at the positions of positioning projections 10a on a cassette
 mounting table 10 as a mounting section in a line along an X-direction (a
 vertical direction in FIG. 1). A wafer carrier 11 movable in an
 arrangement direction of the cassettes C (the X-direction) and in an
 arrangement direction of the wafers W housed in the cassette C (a
 Z-direction: a depth direction in FIG. 1) is movable along a transfer path
 12 and selectively accessible to each of the cassettes C. The wafer
 carrier 11 is also structured to be rotatable in a .theta.-direction (in a
 rotation direction with the depth direction in FIG. 1 as a central axis)
 so that it can carry the wafer W into/out of extension and cooling units
 31 and 32 of a first thermal processing unit group 30 described later.
 A cooling processing unit group 20 is arranged in the central portion of
 the process station 3 in plane view. As shown in FIG. 2, cooling units 21,
 22, 23, and 24 each for cooling the wafer W to a predetermined temperature
 are, for instance, four-tiered from the bottom in order in the cooling
 processing unit group 20. These cooling units 21, 22, 23, and 24 basically
 have identical functions and structures. For example, the cooling unit 21
 located at the bottommost tier is provided with a cooling mounting table
 25 which can freely cool the wafer W mounted on the cooling unit 21 and
 three, for example, of raising and lowering pins 28 which are driven by a
 cylinder 27 to vertically move through through-holes 26 provided in the
 cooling mounting table 25. A circulation path (not shown) through which
 constant-temperature water and the like of which the temperature is
 controlled at, for example, 23.degree. C. circulates is provided inside
 the cooling mounting table 25. Thereby, the wafer W mounted on the cooling
 mounting table 25 is cooled. On the top of the cooling unit 24 at the
 topmost tier, mounting tables 29 and 29 on which the wafer W can be freely
 mounted are tiered.
 Arranged in series on one side (the upper side in FIG. 1) of the cooling
 processing unit group 20 are the first thermal processing unit group 30
 and a second thermal processing unit group 50, each composed of various
 thermal processing units for heat-treating the mounted wafer W at a
 predetermined temperature.
 As shown in FIG. 3, in the first thermal processing unit group 30, the
 extension and cooling units 31 and 32 as delivery sections for making the
 wafer W standby and cooling the wafer W on standby to a predetermined
 temperature, an adhesion unit 33 for enhancing the fixedness of a resist
 and the wafer W, an alignment unit 34 for aligning the wafer W, an
 extension unit 35 for making the wafer W standby, prebaking units 36, 37,
 and 38 for heat-treating the resist-coated wafer W, postbaking units 39,
 40, and 41 for heat-treating the developed wafer W, and the like are, for
 example, ten-tiered from the bottom in order.
 The extension and cooling unit 31 has a wafer transfer port 42 provided on
 the cassette station 2 side and a wafer transfer port 43 provided on the
 interface section 5 side, through both of which the wafer W can freely
 pass, while the extension and cooling unit 32 has a wafer transfer port 44
 provided on the cassette station 2 side and a wafer transfer port 45
 provided on the interface section 5 side.
 The prebaking units 36, 37, and 38 are provided protruding from the first
 thermal processing unit group 30 toward a first solution processing unit
 70 described later (See FIG. 1). These prebaking units 36, 37, and 38
 basically have identical functions and structures. As shown in FIG. 4, the
 prebaking unit 36, for example, includes a hot plate 36a on which the
 wafer W can be mounted and a cooling device 36b. The hot plate 36a allows
 the wafer W to be lifted, for instance, by three raising and lowering pins
 36e formed to be vertically movable through through-holes 36c provided in
 the hot plate 36a by a drive device 36d. The cooling device 36b can
 support the wafer W lifted off the hot plate 36a in such a way to scoop it
 off and carry the wafer W into/out of the hot plate 36a by moving along a
 rail 36f extending to the hot plate 36a. In the above prebaking unit 36,
 the cooling device 36d is placed closer to the first solution processing
 unit group 70 side than the hot plate 36a. Thereby, the hot plate 36a
 exerts no thermal influence on the first solution processing unit group 70
 and the processing temperature in the first solution processing unit group
 70 can be stabilized.
 Returning to FIG. 3, in the second thermal processing unit group 50,
 extension and cooling units 51 and 52, prebaking units 53, 54, and 55,
 post-exposure baking units 56 and 57 for heat-treating the exposed wafer
 W, postbaking units 58, 59, and 60, and the like are, for example,
 ten-tiered from the bottom in order.
 The extension and cooling unit 51 has a wafer transfer port 61 provided on
 the cassette station 2 side and a wafer transfer port 62 provided on the
 interface section 5 side, while the extension and cooling unit 52 has a
 wafer transfer port 63 provided on the cassette station 2 side and a wafer
 transfer port 64 provided on the interface section 5 side.
 In the above first thermal processing unit group 30 and second thermal
 processing unit group 50, units having a high processing temperature are
 arranged at the upper portion, and units having a low processing
 temperature are arranged at the lower portion, thus minimizing mutual
 thermal interference between thermal processing units and improving
 thermal stability in each thermal processing unit.
 Incidentally, as shown in FIG. 1, the transfer port 64 opens obliquely
 along a direction intersecting at a predetermined angle to the arrangement
 direction of the first thermal processing unit group 30, the second
 thermal processing unit group 50, and a first transfer device 90 (a
 lateral direction in FIG. 1), thus permitting a wafer carrier 110
 described later to make access diagonally to the transfer port 64.
 In FIG. 1, on the other side (the lower side in FIG. 1) of the cooling
 processing unit group 20, the first solution processing unit group 70 and
 a second solution processing unit group 80 each for performing solution
 treatment for the wafer W are arranged.
 As shown in FIG. 5, in the first solution processing unit group 70, a
 resist coating unit 71 for supplying the wafer W in a cup CP with a resist
 solution to form a resist film thereon and developing units 72 and 73 for
 supplying the wafer W in a cup CP with a developing solution to develop
 the same are, for example, three-tiered from the bottom in order.
 Meanwhile, in the second solution processing unit group 80, as is the case
 with the first solution processing unit group 70, a resist coating unit 81
 and developing units 82 and 83 are, for example, three-tiered from the
 bottom in order.
 The first transfer device 90 for transferring the wafer W is disposed
 between the first thermal processing unit group 30 and the second thermal
 processing unit group and a second transfer device 100 is disposed between
 the first solution processing unit group 70 and the second solution
 processing unit group 80.
 The first transfer device 90 and the second transfer device 100 basically
 have identical functions and structures.
 As shown in FIG. 6, for instance, the first transfer device 90 is provided
 with a wafer transfer device 91 which is ascendable and descendable in the
 vertical direction (the Z-direction). The wafer transfer device 91 is
 supported by a rotating shaft 93 rotated by the rotational driving force
 of a motor 92, thereby being rotatable in the .theta.-direction. Two pairs
 of tweezers 95 and 96 for holding the wafer W are vertically provided on a
 transfer base 94 of the wafer transfer device 91. These tweezers 95 and 96
 basically have identical structures and movable independently from each
 other in a longitudinal direction by a motor (not shown) provided within
 the transfer base 94.
 As shown in FIG. 1, the first transfer device 90 is structured to transfer
 the wafer W between the cooling processing unit group 20, and respective
 units included in the first thermal processing unit group 30 and the
 second thermal processing unit group 50. The transfer of the wafer W
 from/to various units included in the respective unit groups 20, 30, and
 50 can be performed independently with each of the tweezers 95 and 96.
 Meanwhile, the second transfer device 100 is structured to transfer the
 wafer W between the cooling processing unit group 20, and respective units
 included in the first solution processing unit group 70 and the second
 solution processing unit group 80. The transfer of the wafer W from/to
 various units included in the respective unit groups 20, 70, and 80 can be
 performed independently with each of tweezers 105 and 106.
 Provided in the interface section 5 is the wafer carrier 110 for
 transferring the wafer W, which is accessible to the second thermal
 processing unit group 50. The wafer carrier 110 is structured to be
 movable in the X-direction along a rail 111 and the Z-direction (the depth
 direction in FIG. 1), and rotatable in the .theta.-direction, and can
 freely transfer the wafer W between the aligner 4 and the extension and
 cooling units 51 and 52 included in the second thermal processing unit
 group 50.
 The transfer of the wafer W from/to the extension and cooling unit 51 by
 means of the wafer carrier 110 is carried out through the wafer transfer
 port 62, and the transfer of the wafer W from/to the extension and cooling
 unit 52 is carried out through the wafer transfer port 64 (See FIG. 3).
 The wafer carrier 110 is accessible obliquely to the wafer transfer port
 62 as described above, thus making it possible to shorten the length of
 the rail 111. As a result, spaces are produced on both ends of the rail
 111, and a peripheral aligner 5b and a buffer cassette 5a for temporarily
 keeping the wafer W can be arranged in the spaces.
 As shown in FIG. 7, in the coating and developing apparatus 1, an exhaust
 port 201 is provided below the first transfer device 90, and an exhaust
 port 202 is provided below the second transfer device 100. An exhauster
 203 exhausts the inside of the apparatus 1 of gas via the exhaust ports
 201 and 202. The exhaust of the first transfer device 90 side and the
 exhaust of the second transfer device 100 side are performed separately as
 described above, which allows the first thermal processing unit group 30
 and the second thermal processing unit group 50 not to exert thermal
 influence on the first solution processing unit group 70, thereby
 stabilizing the processing temperature in the first solution processing
 unit group 70.
 The coating and developing apparatus 1 according to the first embodiment in
 the present invention is configured as above. First, in the cassette
 station 2, the wafer carrier 11 makes access to the cassette C to take out
 one unprocessed wafer W, and then transfers the wafer W to the alignment
 unit 34 of the first thermal processing unit group 30.
 Thereafter, the aligned wafer W is carried into the adhesion unit 33 in the
 first thermal processing unit group 30 while held by the tweezers 96 of
 the first transfer device 90. While being held by the tweezers 95 of the
 first transfer device 90, the wafer W which has undergone hydrophobic
 treatment is then transferred to the cooling processing unit group 20 and
 carried into, for example, the cooling unit 21.
 The wafer W which has been cooled to a predetermined temperature on the
 cooling mounting table 25 of the cooling unit 21 is taken out this time
 with the tweezers 106 of the second transfer device 100 and transferred
 to, for example, the resist coating unit 71 included in the first solution
 processing unit group 70. The wafer W which has been coated with a resist
 solution in the resist coating unit 71 is mounted on the mounting table 29
 provided in the cooling processing unit group 20 while held by the
 tweezers 105 of the second transfer device 100.
 Subsequently, after being held by the tweezers 96 of the first transfer
 device 90, the wafer W is transferred from the mounting table 29 to, for
 example, the prebaking unit 53 included in the second thermal processing
 unit group 50. The wafer W which has undergone predetermined heat
 treatment in the prebaking unit 53 is carried into the extension and
 cooling unit 51 through the wafer transfer port 61 while held by the
 tweezers 95 of the first transfer device 90. Thereafter, the wafer W is
 taken out by the wafer carrier 110 which has entered the extension and
 cooling unit 51 through the wafer transfer port 62, and transferred to the
 aligner 4. In the aligner 4, predetermined exposure treatment is performed
 for the wafer W.
 The exposed wafer W is carried into the extension and cooling unit 52 of
 the second thermal processing group 50 through the wafer transfer port 64
 while held by the wafer carrier 110. Subsequently, the wafer W is carried
 into the post-exposure baking unit 57 of the same second thermal
 processing unit group 50 from the extension and cooling unit 52 while held
 by the tweezers 96 of the first transfer device 90, and undergoes
 predetermined heat treatment.
 The wafer W thus heat-treated is transferred to the cooling processing unit
 group 20 and carried into the cooling unit 23 while held by the tweezers
 95 of the first transfer device 90. The wafer W which has been cooled to a
 predetermined temperature in the cooling unit 23 is taken out of the
 cooling unit 23 with the tweezers 106 of the second transfer device 100
 and carried into the developing unit 82 included in the second solution
 processing unit group 80.
 The wafer W which has undergone development treatment in the developing
 unit 82 is taken out of the developing unit 82 with the tweezers 105 of
 the second transfer device 100, and then transferred as it is to the
 cooling processing unit group 20 and mounted once on the mounting table
 29. Thereafter, the wafer W is held by the tweezers 95 of the first
 transfer device 90, transferred from the cooling processing unit group 20
 to the first thermal processing unit group 30, and brought into the
 postbaking unit 41 included in the first thermal processing unit group 30,
 where heat treatment after development treatment is performed for the
 wafer W.
 Subsequently, the wafer W is carried into the extension and cooling unit 32
 through the wafer transfer port 45 while held by the tweezers 96 of the
 first transfer device 90, and cooled to a predetermined temperature in the
 extension and cooling unit 32. The wafer W is then taken out of the
 extension and cooling unit 32 through the wafer transfer port 44 by means
 of the wafer carrier 11, and transferred onto the cassette mounting table
 10. Subsequently, the wafer W is housed in the cassette C for housing the
 processed wafer W mounted on the cassette mounting table 10. Thus, a
 series of coating and developing processes are completed.
 In the coating and developing apparatus 1 according to the first embodiment
 of the present invention, the first transfer device 90 and the second
 transfer device 100 are arranged separately. The first transfer device 90
 transfers the wafer W between the cooling processing unit group 20, and
 the thermal processing unit groups 30 and 50. The second transfer device
 100 transfers the wafer W between the cooling processing unit group 20,
 and the solution processing unit groups 70 and 80. Accordingly, the
 tweezers 105 and 106 of the second transfer unit 100 never hold the wafer
 W of high temperature immediately after heat treatment. As a result, the
 tweezers 105 and 106 accumulate no heat, thereby preventing the thickness
 of a resist film on the wafer W from changing by radiation heat from the
 tweezers 105 and 106.
 Spaces are formed between the thermal processing unit groups 30 and 50, and
 the solution processing unit groups 70 and 80, whereby it can be prevented
 by the spaces that heat generated in the heating units included in the
 thermal processing unit groups 30 and 50 is transmitted to the solution
 processing unit groups 70 and 80. Consequently, in the solution processing
 unit groups 70 and 80, predetermined heat treatment can be suitably
 performed for the wafer W. No other device is arranged on the outsides of
 the first transfer device 90 and the second transfer device 100, and the
 above spaces are formed on both sides of the cooling processing unit group
 20, thus facilitating the maintenance of each unit or device included in
 the process station 3.
 The wafer W is smoothly transferred from/to the cassette station 2 to/from
 the first thermal processing unit group 30 through the wafer transfer port
 42 provided in the extension and cooling unit 31 of the first thermal
 processing unit group 30 and the wafer transfer port 44 of the extension
 and cooling unit 32 thereof. The wafer W is smoothly transferred from/to
 the first thermal processing unit group 30 to/from the first transfer
 device 90 through the wafer transfer port 43 provided in the extension and
 cooling unit 31 and the wafer transfer port 45 of the extension and
 cooling unit 32.
 Further, the wafer W is smoothly delivered from/to the first transfer
 device 90 to/from the second thermal processing unit group 50 through the
 wafer transfer port 61 provided in the extension and cooling unit 51 of
 the second thermal processing unit group 50 and the wafer transfer port 63
 provided in the extension and cooling unit 52 thereof. The wafer W is
 smoothly delivered from/to the second thermal processing unit group 50
 to/from the interface section 5 through the wafer transfer port 62
 provided in the extension and cooling unit 51 and the wafer transfer port
 64 provided in the extension and cooling unit 52. Therefore, the wafer W
 is smoothly transferable between the cassette station 2 and the interface
 section 5.
 Incidentally, it is possible in the present invention to propose a coating
 and developing apparatus 120 according to a second embodiment which is
 described later in addition to the coating and developing apparatus 1
 according to the first embodiment in which the cassette station 2, the
 process station 3, and the interface section 5 are arranged in parallel.
 As shown in FIG. 8, in the coating and developing apparatus 120, the
 cassette station 2 and the process station 3 are arranged in parallel, and
 the interface section 121 is placed on the outer side of the first
 transfer device 90 relative to the process station 3. The extension and
 cooling units 51 and 52 included in the second thermal processing unit
 group 50 are provided with the wafer transfer ports 61 and 63,
 respectively, only where the first transfer device 90 is disposed.
 Provided in the interface section 121 are wafer mounting tables 122, 123,
 and 124 on which, for example, the wafer W can be freely mounted. The
 first transfer device 90 is accessible to the mounting tables 122, 123,
 and 124.
 According to the coating and developing unit 120, a space is produced
 between the second thermal processing unit group 50 and the second
 solution processing unit group 80, whereby the maintenance of various
 units, including the cooling processing unit group 20, can be easily made
 by the above space.
 Further, the wafer W can be directly transferred between the second thermal
 processing unit group 50 and the interface section 121 by the first
 transfer device 90. As a result, the wafer carrier 110 described in the
 first embodiment of the present invention becomes unnecessary in the
 interface section 121, thus enabling further simplification of the
 structure of the interface section 5.
 Furthermore, by the arrangement of the coating and developing unit 120
 described above, it becomes unnecessary to provide the wafer transfer
 ports 62 and 64 respectively in the extension and cooling units 51 and 52
 of the second thermal processing unit group 50, thereby enabling also the
 simplification of the structures of the extension and cooling units 51 and
 52.
 Incidentally, although the aforesaid embodiments are described giving
 examples in which the wafer W is used as a substrate, a substrate used in
 the present invention is not limited to the wafer W, but may be an LCD
 substrate, and the like.