Pod and method of cleaning it

A pod for storing and carrying substrates consists of a pod body and a cover. An inlet and an outlet are formed on one of the pod body and cover. The cover is tightly fitted to the pod body to close the inside of the pod body. A washing liquid is introduced into the pod through the inlet and is discharged from the pod through the outlet, thereby easily washing the inside of the pod with the pod itself serving as a washing tank. A washing cover has an inlet, an outlet, and a heater. The washing cover is attached to the pod body when washing the inside of the pod body. Further provided is a cleaning apparatus having pipes and a pump that are connected to the washing cover. The cleaning apparatus may have a table serving as the washing cover. The table is connected to pipes and a pump.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to a pod used to store and carry substrates
 or wafers, and particularly, to the structure of a pod that is easy to
 clean, a method of cleaning a pod, an apparatus for cleaning a pod, and an
 apparatus for processing substrates.
 2. Description of the Related Art
 Generally, substrates or wafers made of, for example, silicon (Si) are
 stored and carried in wafer cassettes during manufacturing. Each wafer
 cassette carries 13 or 25 wafers. The wafer cassettes with wafers are
 transferred between processing apparatuses such as film forming and
 etching apparatuses during manufacturing. A wafer/substrate transferring
 system that employs the wafer cassettes is called a cassette-to-cassette
 system.
 FIG. 25A shows a conventional open-type wafer cassette 800. The cassette
 800 consists of a top plate 820, a bottom plate 810, and three posts that
 support the top and bottom plates 820 and 810. The posts 830 have grooves
 for supporting wafers, and the post 840 serves as a stopper for preventing
 the wafers from dropping.
 In place of such wafer cassettes, pods have been studied to store and carry
 substrates or wafers, to meet needs for highly integrated fine devices to
 be produced from the substrates or wafers.
 FIGS. 25B, 25C, and 25D show pods presently studied. Each pod consists of a
 pod body and a cover. The pod body is a box having an opening for taking
 in and out wafers, and the cover closes the opening of the pod body. The
 pod of FIG. 25B has a bottom opening that is closed by a cover 920. The
 pods of FIGS. 25C and 25D have side openings that are closed by covers 921
 and 922, respectively. The pods of FIGS. 25B and 25D store the
 conventional open-type wafer cassettes with wafers. The pod of FIG. 25C
 has grooves on the inner wall thereof, to directly hold wafers without a
 wafer cassette.
 The pods are capable of storing and carrying wafers in a closed dust-free
 space, thereby improving the yield of semiconductor products to be
 produced from the wafers.
 Recent wafers are large in diameter, size, and weight to improve
 productivity. For these large wafers, the conventional wafer cassettes
 involve a risk of dropping the wafers during carriage, and therefore, the
 pods are preferable for such large wafers.
 The pods are advantageous in keeping dust-free environment for wafers and
 securing safe carriage. The pods, however, have some problems. This will
 be explained.
 The open wafer cassettes can be washed while holding wafers. On the other
 hand, wafers stored in closed pods are unable to wash. To wash them, they
 must be taken out of the pods. This means that the pods themselves are
 rarely washed during wafer processing.
 As a result, the insides of the pods are gradually contaminated. This
 deteriorates the cleanliness of wafers stored therein, thereby lowering
 the yield of semiconductor products to be produced from the wafers.
 The pods may be washed separately from the wafers during wafer processing.
 To wash large pods that store 200-mm to 300-mm diameter wafers, a large
 washing tank is needed. FIG. 26A shows a washing tank 950 for washing a
 pod 911. The tank 950 must be larger than the pod 911, and if the pod 911
 is large, the tank 950 must be very large. FIG. 26B shows a pod washing
 apparatus having a washing tank 960 and a dryer chamber 980. This
 apparatus is very large. In a limited space in a clean room, such a large
 apparatus is hardly acceptable.
 SUMMARY OF THE INVENTION
 An object of the present invention is to provide a pod that is easy to
 clean, a method of cleaning a pod, an apparatus for cleaning a pod, and a
 semiconductor processing apparatus having a pod cleaning system.
 In order to accomplish the object, a first aspect of the present invention
 provides a pod for storing substrates, having a pod body provided with an
 opening for taking in and out the substrates, a cover removably attached
 to the opening, and a fixing unit for fixing the pod body and cover
 together to tightly close the pod body. The cover has an inlet for
 introducing fluid into the pod and an outlet for discharging the fluid
 from the pod.
 The first aspect tightly closes the pod body with the cover, introduces a
 washing fluid into the pod through the inlet, and discharges the washing
 fluid from the pod through the outlet. This aspect needs no separate
 washing tank to clean the inside of the pod because it uses the pod itself
 as a washing tank.
 A second aspect of the present invention provides a pod for storing
 substrates, having a pod body provided with an opening for taking in and
 out the substrates, a cover removably attached to the opening, and a
 fixing unit for fixing the pod body and cover together to tightly close
 the pod body. The pod body has an inlet for introducing fluid into the pod
 and an outlet for discharging the fluid from the pod.
 The second aspect tightly closes the pod body with the cover, introduces a
 washing fluid into the pod through the inlet, and discharges the washing
 fluid from the pod through the outlet. This aspect needs no separate
 washing tank to clean the inside of the pod because it uses the pod itself
 as a washing tank.
 A third aspect of the present invention provides a pod for storing
 substrates, having a pod body provided with an opening for taking in and
 out the substrates, a cover removably attached to the opening, and a
 fixing unit for fixing the pod body and cover together to tightly close
 the pod body. The cover is provided with a nozzle for jetting fluid into
 the pod and an outlet for discharging the fluid from the pod.
 The third aspect tightly closes the pod body with the cover, jets a washing
 fluid into the pod through the nozzle, and discharges the washing fluid
 from the pod through the outlet. This aspect needs no separate washing
 tank to clean the inside of the pod because it uses the pod itself as a
 washing tank. The nozzle showers a washing fluid of high pressure into the
 pod, thereby improving the physical cleaning power of the washing fluid in
 the pod.
 A fourth aspect of the present invention provides an apparatus for cleaning
 a pod for storing substrates. The apparatus has a cover and a discharge
 pump. The pod has an opening for taking in and out substrates. The cover
 is removably attached to the opening and has an outlet for discharging gas
 from the pod. The discharge pump is connected to the outlet of the cover.
 The fourth aspect tightly attaches the cover to the pod and evacuates
 impurity gases from the pod through the outlet, thereby cleaning the
 inside of the pod.
 A fifth aspect of the present invention provides an apparatus for cleaning
 a pod for storing substrates. The pod has an opening formed on one face
 thereof to take in and out substrates. The apparatus has a cover to be
 removably attached to the opening of the pod, an inlet formed on the cover
 to guide gas into the pod, an outlet formed on the cover to discharge gas
 from the pod, a gas supply source connected to the inlet of the cover, a
 gas adjuster arranged between the inlet of the cover and the gas supply
 source to adjust the flow rate of gas, a vacuum pump connected to the
 outlet of the cover, a pressure sensor for measuring a pressure in the
 pod, and a controller electrically connected to the gas adjuster, vacuum
 pump, and pressure sensor.
 The fifth aspect sets a washed pod in the apparatus, evacuates remnants
 from the pod, and fills the pod with an inert gas.
 A sixth aspect of the present invention provides an apparatus for
 processing substrates. The apparatus has a pod reception chamber, a pod
 processing chamber, a substrate processing chamber, and a transfer unit
 for transferring the pod and substrates between these chambers. The pod
 has an opening on one face thereof to take in and out substrates and a
 cover to be removably attached to the opening. The pod reception chamber
 has a unit for receiving a pod with substrates from the outside and a unit
 for taking the substrates out of the pod. The pod processing chamber has a
 unit for cleaning the inside of the pod. The substrate processing chamber
 has a unit for processing the substrates.
 The sixth aspect cleans the inside of the pod in the pod processing chamber
 while processing the substrates in the substrate processing chamber.
 The cover of the pod of the sixth aspect may have an inlet for guiding
 fluid into a pod and an outlet for discharging fluid from the pod. The
 unit for cleaning the inside of a pod may have a unit for fixing the
 opening of the pod and the cover together to tightly close the pod, a unit
 for introducing a washing liquid into the pod through the inlet of the
 cover, and a unit for discharging the washing liquid from the pod through
 the outlet of the cover. The cover may have a second outlet for
 discharging gas and a heater.
 The unit for cleaning the inside of a pod may have a table for tightly
 closing the pod set on the table, an inlet formed on the table to
 introduce fluid into the pod, an outlet formed on the table to discharge
 fluid from the pod, a unit for introducing a washing liquid into the pod
 through the inlet, and a unit for discharging the washing liquid from the
 pod through the outlet. The table may have a second outlet for discharging
 gas and a heater.

DETAILED DESCRIPTION OF THE EMBODIMENTS
 Various embodiments of the present invention will be described with
 reference to the accompanying drawings.
 [Embodiment 1]
 FIGS. 1A to 4B show pods according to the embodiment 1 of the present
 invention. The pods of the embodiment 1 are characterized by a structure
 that is easy to wash and by a cover that is provided with an inlet and
 outlet for fluid.
 (Embodiment 1-1)
 FIGS. 1A and 1B are sectional and perspective views showing a pod according
 to an embodiment 1-1 of the present invention. The pod consists of a pod
 body 10 and a cover 40. The pod body 10 has an opening formed on a side
 face thereof to take in and out wafers or substrates. The cover 40 is
 removably attached to the opening.
 The inner wall of the pod body 10 has grooves at regular intervals to
 horizontally support wafers. Namely, the pod can directly store wafers
 without a wafer cassette. The grooves may be formed partially on the inner
 wall of the pod body 10, to support the wafers at two or three positions.
 The plan shape of the pod body 10 may be curved in alignment with the shape
 of wafers stored therein.
 Along the opening of the pod body 10, there is a fitting part 60 having a
 hooking end to hold the cover 40. The periphery of the cover 40
 corresponding to the periphery of the opening of the pod body 10 is
 provided with a seal frame 50 so that the pod body 10 and cover 40 are
 tightly attached together. When the cover 40 is fitted to the pod body 10,
 the hooking end of the fitting part 60 warps toward the outside of the
 cover 40 and pushes the cover 40 inwardly from the outside, thereby
 tightly fixing the cover 40 to the pod body 10.
 The pod of the embodiment 1-1 is characterized by an inlet 70 and an outlet
 80 formed on the cover 40. The inlet and outlet are used to wash the
 inside of the pod.
 The cover 40 is fitted to the pod body 10 to tightly close the inside of
 the pod body 10. The inlet 70 and outlet 80 are connected to pipes, and an
 acid or alkaline washing liquid is introduced into the pod through the
 pipe and inlet 70. At this time, the outlet 80 is closed to fill the pod
 with the washing liquid. Since the pod body 10 and cover 40 are tightly
 fitted together, the washing liquid never leaks outside.
 The pod filled with the washing liquid is kept as it is for a set time to
 etch off contaminants adhering to the inner wall of the pod. Thereafter,
 the outlet 80 is opened to discharge the washing liquid from the pod.
 Rinsing pure water is supplied into the pod through the inlet 70. While
 the pure water is being poured into the pod, the liquid in the pod is
 gradually discharged from the outlet 80. Instead of the acid or alkaline
 washing liquid, a surfactant may be used. After rinsing the pod with the
 pure water, alcohol may be used to again wash the pod.
 The locations of the inlet 70 and outlet 80 are not particularly limited.
 It is preferable that the inlet 70 is positioned close to the top of the
 pod and the outlet 80 close to the bottom of the pod to make the washing
 process easier.
 The embodiment 1 is capable of washing pods without a separate washing tank
 or a bulky washing apparatus because it uses each pod itself as a washing
 tank. As a result, the embodiment 1 is inexpensive and saves the space of
 a clean room.
 When washing a pod, wafers 30 may be left in the pod as shown in FIG. 1A so
 that not only the pod but also the wafers are cleaned.
 The material of the pod is not particularly limited. It may be made of
 polycarbonate, metal, ceramics, resin, etc. A proper washing liquid must
 be selected so that it does not hurt the pod.
 In FIG. 1A, the pod body 10 and cover 40 are fitted together with the
 fitting part 60 formed on the pod body 10. Any other fitting arrangement
 is employable to fix the pod body 10 and cover 40 together.
 Examples of fitting arrangements are shown in FIGS. 1C to 2C. In FIG. 1C, a
 cover 40 has fixings 61 to tightly fit the cover 40 to a pod body 10. In
 FIG. 1D, bolts and nuts 62 fix a pod body 10 and cover 40 together.
 In FIG. 2A, a cover 40 incorporates a rotatable cross hook 90. Grooves 110
 are formed on the cover 40. A rotary tool 100 is inserted into the grooves
 110 and is turned to turn the cross hook 90. Before fitting the cover 40
 to a pod body 10, the cross hook 90 is retracted in the cover 40. After
 the cover 40 is attached to the pod body 10, the rotary tool 100 is
 inserted into the grooves 110 and is turned clockwise, so that the tips of
 the cross hook 90 may catch holes 120 formed at the periphery of the
 opening of the pod body 10. This tightly fixes the pod body 10 and cover
 40 together.
 The covers 40 of FIGS. 2A to 2C have each an inlet 70 and an outlet 80 to
 clean the insides of pods as explained above.
 (Embodiment 1-2)
 FIGS. 3A to 4B are sectional and perspective views showing pods according
 to an embodiment 1-2 of the present invention.
 The pod of FIG. 3A has no grooves on the inner wall thereof to support
 wafers. Namely, wafers are stored in an open-type wafer cassette 130,
 which is stored in the pod. Except the wafer supporting grooves, the pod
 of FIG. 3A is the same as the pod of FIG. 1A. Namely, the pod of FIG. 3A
 is characterized by a cover 40 having an inlet 70 and an outlet 80.
 After the cover 40 is fitted to a pod body 10, a washing liquid is
 introduced into the pod through the inlet 70 and is discharged from the
 pod through the outlet 80, thereby cleaning the inside of the pod.
 The pod of FIG. 3B has a pod body 10 and a cover 40 that are fixed together
 with bolts and nuts 62. The cover 40 has an inlet 70 and an outlet 80. A
 wafer cassette 130 with wafers is stored in the pod, the cover 40 is
 fitted to the pod body 10, the bolts 62 are fastened to close the pod, a
 washing liquid is introduced into the pod through the inlet 70, and the
 same is discharged from the pod through the outlet 80, thereby
 simultaneously cleaning the inside of the pod, the wafers, and the wafer
 cassette.
 The pod of FIG. 3C has an opening at the bottom of a pod body 12. A cover
 40 has an inlet 70 and an outlet 80. The cover 40 is fitted to the pod
 body 12 to close the pod, a washing liquid or rinsing liquid is introduced
 into the pod through the inlet 70, and the same is discharged from the pod
 through the outlet 80, thereby cleaning the inside of the pod. At this
 time, a wafer cassette 130 with wafers may be kept in the pod so that the
 wafers and cassette are cleaned together with the inside of the pods.
 The pod of FIGS. 4A and 4B is cylindrical, and a cover 40 is attached to
 the bottom of a pod body 12 by threads 160 and 165 formed thereon.
 In FIG. 4A, the cover 40 has an inlet 70, an outlet 80, and holes 140 for
 turning the cover 40. The threads of the pod body 12 and cover 40 are
 fastened together, a rotary tool 150 is inserted into the holes 140, and
 the same is turned clockwise to tightly fix the cover 40 to the pod body
 12.
 In this way, the pods of the embodiments 1-1 and 1-2 employ the covers 40
 each having the inlet 70 and outlet 80 to easily wash and clean the
 insides of the pods.
 The inlet 70 and outlet 80 are not limited to one each. There may be plural
 inlets and outlets formed on a pod cover. Fluid used to wash a pod through
 the inlet 70 and outlet 80 is not limited to liquid. It may be a washing
 gas. The fittings to fix a cover to a pod body are not limited to those
 explained above.
 When storing and carrying substrates or wafers in the pods, the inlet and
 outlet of each cover 40 are closed with proper plugs to seal the insides
 of the pods.
 [Embodiment 2]
 FIGS. 5A to 5D show pods according to the embodiment 2 of the present
 invention. These pods are characterized by a pod body having an inlet and
 an outlet.
 (Embodiment 2-1)
 The pod of FIG. 5A consists of a pod body 10 and a cover 41. The pod body
 10 has an opening formed on a side face thereof to take in and out wafers.
 The cover 41 is attached to the opening of the pod body 10. The pod body
 10 has an inlet 71 and an outlet 81.
 The pod body 10 and cover 41 are fixed together to tightly close the pod.
 In FIG. 5A, the cover 41 is fitted to the pod body 10. In FIG. 5B, the pod
 body 10 and cover 41 are fixed together with bolts and nuts.
 After the pod body 10 and cover 41 are fixed together, the outlet 81 is
 closed, a washing liquid such as an acid or alkaline liquid is introduced
 into the pod through the inlet 71, the liquid is kept for a predetermined
 time to etch off contaminants on the inner wall of the pod, the washing
 liquid is discharged from the pod through the outlet 81, pure water is
 supplied into the pod through the inlet 71, and the same is discharged
 from the pod through the outlet 81, thereby rinsing and cleaning the
 inside of the pod.
 This embodiment needs no separate washing tank to clean the inside of the
 pod because it uses the pod itself as a washing tank. As a result, this
 embodiment is economical and saves the space of a clean room. The pods of
 this embodiment may periodically be cleaned to properly maintain a clean
 atmosphere for wafers in the pods.
 The pods of this embodiment may be cleaned with wafers being stored
 therein. In this case, not only the pods themselves but also the wafers
 are cleaned.
 In FIGS. 5A and 5B, the pods have grooves 20 for directly supporting
 wafers. In FIGS. 5C and 5D, the pods have no such grooves, to store a
 wafer cassette that contains wafers.
 (Embodiment 2-2)
 FIG. 5E shows a pod according to an embodiment 2-2 of the present
 invention. The pod is cylindrical and has an opening at the bottom thereof
 to take in and out wafers. The pod consists of a pod body 10 and a cover
 41. The pod body 10 has an inlet 72 and an outlet 82 to easily wash the
 inside of the pod.
 It is preferable that the inlet 71 (72) is formed as high as possible on
 the pod body 10, and the outlet 81 (82) as low as possible. The pods of
 FIGS. 5A to 5D with an opening being formed on a side face thereof have
 each the inlet 71 on the top of the pod body 10 and the outlet 81 on the
 bottom of the pod body 10.
 The pod of FIG. 5E having the bottom opening has the inlet 72 on the top of
 the pod body 10 and the outlet 82 on the side wall of the pod body 10
 adjacent to a fitting for fixing the cover 41 to the pod body 10.
 The fittings of the embodiment 1 or any other fittings for fixing a cover
 to a pod body are applicable to the embodiment 2.
 [Embodiment 3]
 FIGS. 6A to 6C show pods according to the embodiment 3 of the present
 invention. The embodiment 3 is characterized in that each cover has an
 inlet and an outlet and the inlet has a structure for jetting fluid.
 (Embodiment 3-1)
 FIG. 6A shows a pod according to an embodiment 3-1. The pod consists of a
 pod body 10 and a cover 42 that is tightly fitted to the pod body 10 to
 close the pod. The fittings of the embodiments 1 and 2 or any other
 fittings for fixing a cover to a pod body are applicable to the embodiment
 3.
 The cover 42 has an injection inlet 75 and an outlet 85. The injection
 inlet 75 has thin holes arranged parabolically to jet liquid into the pod.
 The cover 42 is removably fitted to the pod body 10 to tightly close the
 pod. A washing liquid is supplied into the pod through the injection inlet
 75 and is discharged from the pod through the outlet 85, thereby washing
 the inside of the pod without a special washing apparatus. The washing
 liquid of high pressure is showered into the pod through the injection
 inlet 75, to strongly wash the inside of the pod.
 (Embodiment 3-2)
 FIG. 6B shows a pod according to an embodiment 3-2 of the present
 invention. The pod consists of a pod body 10 and a cover 42. The cover 42
 has an inlet 75 and an outlet 85. The inlet 75 is provided with a nozzle
 160.
 FIG. 6C is an enlarged view showing the nozzle 160 and the periphery
 thereof. The tip of the nozzle 160 is thinned to jet liquid of high
 pressure into the pod, thereby enhancing a washing effect.
 The nozzle 160 may be fixed to the cover 42 in various ways. In FIG. 6C,
 the nozzle 160 is screwed into the cover 42 so that it may easily be
 replaced.
 It is possible to use a conventional cover for the pod body 10 when storing
 and carrying the pod, and only when washing the pod, attach one of the
 covers 42 of the embodiments 3-1 and 3-2 to the pod body 10.
 Wafers can be left in the pods when the pods are washed so that not only
 the inner walls of the pods but also the wafers are washed.
 In FIGS. 6A and 6B, the pod bodies 10 have grooves for directly supporting
 wafers. These grooves are not always necessary for the pod bodies. The pod
 bodies and covers of the embodiment 3 are fixed together in various ways
 like the embodiments 1 and 2.
 [Embodiment 4]
 FIGS. 7A and 7B show pods according to the embodiment 4 of the present
 invention. This embodiment is characterized by a cover having a
 projection.
 (Embodiment 4-1)
 FIG. 7A is a sectional view showing a pod according to an embodiment 4-1.
 The pod consists of a pod body 10 and a cover 43.
 The cover 43 has a projection protruding into the pod body 10. The size of
 the projection is not particularly limited. For example, the diameter of
 the projection is 1/2 to 2/3 of the inner diameter of the pod body 10. The
 cover 43 has an inlet 73 and an outlet 83.
 The cover 43 is tightly fitted to the pod body 10. A washing liquid is
 introduced into the pod through the inlet 73 and is discharged from the
 pod through the outlet 83, thereby washing the inside of the pod by using
 the pod itself as a washing tank. At this time, the projection of the
 cover 43 reduces the inner volume of the pod, so that a small quantity of
 washing liquid can fill the inside of the pod. Namely, a small quantity of
 washing liquid will sufficiently wash the inside of the pod in a short
 time.
 The pod body 10 has an opening for taking in and out wafers. The pod body
 10 may have grooves for directly supporting wafers as shown in FIG. 7A.
 (Embodiment 4-2)
 FIG. 7B is a sectional view showing a pod according to an embodiment 4-2.
 The pod consists of a pod body 10 and a cover 43.
 The cover 43 has a projection protruding into the pod body 10. An inlet 74
 of the cover 43 is branched into thin holes in the cover 43. The thin
 holes are equally distributed on the surface of the projection to jet
 liquid equally onto the inner wall of the pod, thereby realizing a high
 washing effect over the inner wall of the pod.
 It is possible to use conventional covers for the pods of the embodiment 4
 when storing and transferring the pods, and only when washing the pods,
 use the covers 42 of the embodiment 4.
 [Embodiment 5]
 FIGS. 8A to 8C show pods according to the embodiment 5. This embodiment is
 characterized by an agitating fin.
 (Embodiment 5-1)
 FIG. 8A is a sectional view showing a pod according to an embodiment 5-1.
 The pod consists of a pod body 10 and a cover 44.
 The cover 44 has an inlet 75 and an outlet 85. In addition, the cover 44
 has an agitating fin 180 and a motor 200 for driving the fin 180. The
 cover 44 is tightly attached to the pod body 10, a washing liquid is
 introduced into the pod through the inlet 75 to fill the pod with the
 washing liquid, and the motor 200 is started to rotate the fin 180. The
 fin 180 agitates the washing liquid and generates swirls in the pod,
 thereby improving the washing power of the washing liquid.
 FIG. 8C is a partial section showing the details of the motor 200 and fin
 180 of the cover 44. The motor 200 has a magnet at a rotary end 210
 thereof, and the fin 180 also has a magnet at a base 220 thereof. When the
 rotary end 210 turns, the fin 180 also turns due to magnetic repulsion.
 (Embodiment 5-2)
 FIG. 8B is a sectional view showing a pod according to an embodiment 5-2 of
 the present invention. The pod consists of a pod body 10 and a cover 44.
 The cover 44 has an inlet 75, an outlet 85, a rotary brush 190, and a motor
 200 for driving the brush 190.
 The cover 44 is tightly attached to the pod body 10 to close the pod, a
 washing liquid is supplied into the pod through the inlet 75 to fill the
 pod with the washing liquid, and the motor 200 is started to rotate the
 brush 190. The brush 190 generates swirls in the washing liquid and
 applies physical washing force on the inner wall of the pod.
 The pod bodies 10 of the embodiment 5 have grooves on the inner walls
 thereof to directly support wafers. Any other pod bodies such as those of
 the embodiments 1 and 2 are applicable to the embodiment 5.
 [Embodiment 6]
 FIGS. 9A to 10B show pods according to the embodiment 6 of the present
 invention. This embodiment is characterized by a cover having an outlet.
 Unlike the embodiments 1 to 5 that wash the inside of a pod, the embodiment
 6 cleans and dries the inside of a pod.
 (Embodiment 6-1)
 FIG. 9A is a sectional view showing a pod according to an embodiment 6-1 of
 the present invention. The pod consists of a pod body 10 and a cover 45.
 The left part of FIG. 9A shows the cover 45 being attached to the pod body
 10, and the right part thereof shows a vacuum pump 230 being operated.
 The pod body 10 has an opening on a side face thereof to take in and out
 wafers. The cover 45 is attached to the opening. The cover 45 has an
 outlet 240, which is connected to the vacuum pump 230.
 The cover 45 can be fitted to the pod body 10 according to any fitting
 technique. In FIG. 9A, the cover 45 has a fixing frame 61 to fix the cover
 45 to the pod body 10.
 Conventional pods used for semiconductor processing are rarely washed, and
 therefore, the inner walls thereof accumulate contaminants 250 after a
 long time of use as shown in the left part of FIG. 9A. The contaminants
 are water, oxygen, etc., to contaminate wafers stored in the pods.
 After a certain period of use of the pod, the cover 45 having the outlet
 240 is attached to the pod body 10 to close the same, and the outlet 240
 is connected to the vacuum pump 230 through a pipe. The pump 230 evacuates
 the pod so that the contaminants are discharged from the pod as shown in
 the right part of FIG. 9A.
 Although the pod of FIG. 9A stores no wafers, wafers may be left in the pod
 when the cover 45 is attached to the pod body 10 to evacuate the pod.
 A conventional cover having no outlet 240 can be attached to the pod body
 10 when storing and transferring the pod, and only when the pod is
 cleaned, the conventional cover is replaced with the cover 45 having the
 outlet 240.
 (Embodiment 6-2)
 FIG. 9B is a sectional view showing a pod according to an embodiment 6-2.
 The pod consists of a pod body 10 and a cover 45.
 The cover 45 has an outlet 240 to be connected to a vacuum pump 230, as
 well as a heater 260 for heating the inside of the pod.
 In the left part of FIG. 9B, the cover 45 is tightly fitted to the pod body
 10, and the heater 260 is turned on to heat the inside of the pod. Then,
 the vacuum pump 230 is started to easily volatilize contaminants adhering
 to the inner wall of the pod. In particular, water in the pod is easily
 volatilized by the heater 260 and is discharged from the pod. This
 embodiment effectively cleans the inside of the pod.
 The temperature attained by the heater 260 is higher the better. The
 temperature, however, must be determined according to the heat resistance
 of the material of the pod. The pod may be made of metal. For example, the
 pod body 10 and cover 45 may be made of stainless steel and the seal
 thereof of copper. In this case, the temperature may be increased to
 several hundreds of degrees.
 (Embodiment 6-3)
 FIGS. 10A and 10B are sectional views showing pods each consisting of a pod
 body 10 and a cover 45. The left part of each figure shows the cover 45
 being fitted to the pod body 10, and the right part thereof shows a vacuum
 pump 230 being operated.
 Each pod has an opening at the bottom thereof, and the cover 45 is screwed
 into the pod body 10.
 Irrespective of whether the opening of the pod body 10 is on the bottom or
 side face thereof, the cover 45 having an outlet 240 is fitted to the pod
 body 10, and the vacuum pump 230 is connected to the outlet 240. The
 vacuum pump 230 is driven to evacuate the pod, to thereby discharge
 contaminants adhering to the inner wall of the pod to the outside of the
 pod.
 In FIG. 10B, the cover 45 has a heater 260 in addition to the outlet 240.
 The heater 260 heats the inside of the pod to volatilize contaminants in
 the pod, to more effectively discharge the contaminants out of the pod.
 [Embodiment 7]
 The embodiment 7 of the present invention will be explained with reference
 to FIG. 11A.
 The embodiment 7 relates to a post-process to be carried out after a pod is
 washed according to any one of the embodiments 1 to 5 or any other
 techniques. The post-process is carried out with the use of the cover 45
 of the embodiment 6.
 In FIG. 11A, a pod is washed according to a conventional washing process. A
 washing tank 270 is filled with a washing liquid 280. A pod body 10 of the
 pod is dipped in the washing liquid 280 so that contaminants on the inner
 wall of the pod body 10 are etched off. Thereafter, the pod body 10 is
 washed with pure water. After that, remnants on the inner wall of the pod
 body 10 must be removed and the pod body 10 must be dried.
 In FIG. 11B, the cover 45 having the outlet 240 connected to the vacuum
 pump 230 is tightly fitted to the pod body 10, to evacuate the pod body
 10. This technique needs no large dryer, to effectively remove remnants
 from the pod body 10.
 In FIG. 11C, the cover 45 having the heater 260 is used to dry the pod body
 10. The heater 260 quickly dries the inside of the pod body 10 and removes
 remnants 250 from the pod body 10.
 The inside of a pod can be washed not only by dipping the pod in a tank
 filled with a washing liquid but also by any one of the embodiments 1 to 5
 that employ the covers having an inlet and an outlet. If any one of the
 embodiments 1 to 5 is employed, a series of washing processes can be
 completed only by changing the cover of a given pod.
 Fixing a cover to a pod body can be achieved according to any technique as
 mentioned above.
 [Embodiment 8]
 The embodiment 8 of the present invention will be explained with reference
 to FIGS. 12A to 14B. This embodiment employs a cleaning apparatus to carry
 out a post-process on a washed pod.
 (Embodiment 8-1)
 FIG. 12A is a sectional view showing a cleaning apparatus employing a pod
 body 10 and a cover 46 according to an embodiment 8-1 of the present
 invention.
 The cover 46 has an inlet 75 and an outlet 85. The inlet 75 is connected to
 a pipe, which is connected to a gas supply source (not shown). In the
 middle of the pipe, a valve 320 for adjusting a gas supply rate is
 arranged.
 The outlet 85 is connected to a pipe in which a vacuum pump 230 is arranged
 to evacuate the pod.
 The cover 46 is provided with a pressure sensor 310 to monitor a pressure
 in the pod. The pressure sensor 310, valve 320, and pump 230 are
 electrically connected to a controller 300, which controls a gas supply
 rate and gas discharge rate according to the pressure in the pod.
 The post-process to be carried out on a washed pod will be explained. The
 pod is washed according to a conventional technique or any one of the
 embodiments 1 to 5. The cover 46 is tightly attached to the pod body 10.
 The valve 320 is closed, and the pump 230 is started to evacuate the pod
 and remove remnants from the pod. When the pressure sensor 310 indicates a
 pressure level below a set level, for example, 100 Pa, the pump 230 is
 stopped, or a valve (not shown) is used to stop the discharging of the
 pod.
 The valve 320 is opened to gradually introduce a high purity inert gas of,
 for example, nitrogen (N.sub.2) or argon (Ar). When the pressure sensor
 310 indicates an atmospheric pressure, the valve 320 is closed, or the
 cover 46 is removed from the pod body 10, to complete the post-process. At
 this time, remnant gases in the pod have been replaced with the high
 purity inert gas.
 Although the arrangement of FIG. 12A shows no tool for fixing the cover 46
 to the pod body 10, they will naturally be joined together when the pod is
 evacuated, or any fitting of the preceding embodiments will be employed.
 The embodiment of FIG. 12B provides the cover 46 of FIG. 12A with a heater
 340. The cover 46 is attached to the pod 10, and the heater 340 is turned
 on before evacuating the pod with the pump 230 or during the evacuation of
 the pod. Heating the inside of the washed pod easily gasifies remnants in
 the pod. Thereafter, the pod is filled with an inert gas as mentioned
 above, to thereby effectively remove the remnants from the pod.
 FIG. 13 shows the details of the cover 46 of FIG. 12A and piping connected
 thereto. An automatic pressure controller (APC) 231 may be connected to
 the pipe that is connected to the outlet of the cover 46. The APC 231 is
 in front of the pump 230. The APC 231 is electrically connected to the
 controller 300, to automatically adjust a discharge rate in response to
 the output of the pressure sensor 310.
 A valve 321, a pressure gauge 322, a filter 323, a mass flow controller
 (MFC) 324, etc., may be connected to the pipe that extends between the
 inlet of the cover 46 and the inert gas supply source 325. The MFC 324 is
 electrically connected to the controller 300, to automatically adjust a
 gas supply rate in response to the output of the pressure sensor 310.
 In FIGS. 11A to 12B, each pod body 10 has grooves on the inner wall
 thereof, to directly support wafers, and jointing between the pod body 10
 and the cover 46 is by fitting them together. These structures do not
 limit the present invention. For example, pod bodies having no grooves for
 supporting wafers may be used as shown in FIGS. 14A and 14B. Jointing
 between the pod bodies 10 and the covers 46 may be of a screw type as
 shown in FIGS. 14A and 14B, or of any other type.
 [Embodiment 9]
 The embodiment 9 of the present invention will be explained with reference
 to FIGS. 15 to 24. This embodiment relates to semiconductor processing
 apparatuses having a pod cleaning function.
 (Embodiment 9-1)
 FIG. 15A shows a semiconductor processing apparatus according to an
 embodiment 9-1 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. The wafer
 processing chamber 420 involves wafer processing units for forming or
 etching thin films on wafers.
 The apparatus handles, as an example, a cylindrical pod having an opening
 at the bottom thereof to take in and out wafers. Wafers are stored in a
 conventional open-type wafer cassette 130, which is stored in the pod. The
 pod consists of a pod body 10 and a cover 47. The cover 47 may be of the
 embodiment 1 having an inlet 70 and an outlet 80.
 Generally, wafers are transferred in pods between semiconductor processing
 apparatuses. The pod reception chamber 400 of the semiconductor processing
 apparatus receives a given pod. Although the pod of FIG. 15A is carried by
 a person, it may be carried by machine such as a transportation robot.
 In FIG. 15A, the pod with wafers is set in the pod reception chamber 400.
 The wafers set in the wafer cassette 130 are taken out of the pod and
 transferred to the wafer processing chamber 420. The vacant pod is left in
 the pod processing chamber 410.
 FIGS. 16A to 16C show the wafer transferring process. In FIG. 16A, the pod
 is in the pod reception chamber 400. In FIG. 16B, the cover 47 is removed
 from the bottom of the pod. The pod body 10 is left there. The cover 47
 and the wafer cassette 130 thereon are put on a vertically movable table,
 which carries them downwardly. The pod processing chamber 410 has an arm
 430. The arm 430 carries the wafer cassette 130 with the wafers therein
 from the pod reception chamber 400 to the wafer processing chamber 420
 through the pod processing chamber 410. The wafers in the chamber 420 are
 processed in various ways.
 In FIG. 16C, the cover 47 is returned to a predetermined position in the
 pod reception chamber 400 where the pod body 10 is left and is attached to
 the opening of the pod body 10. The pod body 10 with the cover 47 is moved
 to the pod processing chamber 410 and is set at a predetermined position
 by the arm 430.
 The inlet and outlet of the cover 47 are connected to pipes arranged in the
 pod processing chamber 410. The pipes have valves 350 and 360. The valve
 360 is opened to introduce a washing liquid into the pod and is closed to
 fill the pod with the washing liquid, thereby washing the inside of the
 pod.
 In this way, the semiconductor processing apparatus of this embodiment has
 the pod processing chamber 410 separately from the wafer processing
 chamber 420, to clean a pod while processing wafers in the chamber 420.
 The pod processing chamber 410 is provided with the pipes to be connected
 to the inlet 70 and outlet 80 of the cover 47, so that the pod itself
 serves as a washing tank to wash the inside thereof. This helps reduce the
 size of the pod processing chamber 410. Since the pod processing chamber
 410 is adjacent to the wafer processing chamber 420, there is no need of
 transferring the pod to a cleaning apparatus at a distant location,
 thereby improving the efficiency of the pod cleaning process.
 (Embodiment 9-2)
 FIG. 15B shows a semiconductor processing apparatus according to an
 embodiment 9-2 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 47. The pod body 10
 has a bottom opening, and the cover 47 has an inlet 70, a first outlet 80,
 and a second outlet 370.
 Wafers are held in a wafer cassette 130, which is stored in the pod. After
 the cassette 130 with the wafers is transferred from the pod to the wafer
 processing chamber 420, the pod body 10 and cover 47 are moved to a
 predetermined position in the pod processing chamber 410. The inlet 70 and
 outlet 80 of the cover 47 are connected to pipes having valves 350 and
 360. The outlet 370 is connected to a pipe that is connected to a vacuum
 pump 230.
 The pod is filled with a washing liquid to clean the inside thereof.
 Thereafter, the pod is evacuated by the pump 230 through the outlet 370,
 to remove remnants from the pod.
 Mechanisms for transferring the pod and wafers of the apparatus of FIG. 15B
 are the same as those of FIG. 16A to 16C.
 (Embodiment 9-3)
 FIG. 17A shows a semiconductor processing apparatus according to an
 embodiment 9-3 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 47. The pod body 10
 has an open bottom, and the cover 47 has an inlet 70 and an outlet 80. The
 embodiment 9-3 is characterized by a heater 450 arranged in the pod
 processing apparatus 410, to surround the pod.
 The heater 450 heats the pod and a washing liquid in the pod, to improve
 the washing power of the washing liquid. The heater 450 may heat pure
 water to rinse the pod. Heated waterdrops in the pod speedily dry to
 shorten a drying time. The heater 450 may be used to dry remnants in a
 washed pod.
 (Embodiment 9-4)
 FIG. 17B shows a semiconductor processing apparatus according to an
 embodiment 9-4 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 47. The pod body 10
 has an open bottom, and the cover 47 has an inlet 70 and an outlet 80. The
 embodiment 9-4 is characterized by a valve 350 and a heater 460 both
 arranged in the middle of a pipe connected to the inlet 70.
 The heater 460 surrounds a part of the pipe to heat a washing liquid
 passing through the pipe, thereby improving the washing power of the
 washing liquid. The heater 460 may heat a rinsing liquid such as pure
 water to rinse the inside of the pod. Waterdrops in the pod dry speedily
 to shorten a drying time.
 (Embodiment 9-5)
 FIG. 18A shows a semiconductor processing apparatus according to an
 embodiment 9-5 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the opening of the pod body 10 is
 directly set on a table. To tightly close the opening of the pod body 10,
 the table has a fitting part.
 In FIG. 18A, the fitting part has the same shape as the opening of the pod
 body 10. The table has an inlet 470 and an outlet 480.
 The inlet 470 and outlet 480 are connected to pipes to introduce fluid into
 the pod and discharge the same from the pod. The pipes have valves 350 and
 360 to adjust the supply and discharge rates of the fluid. The embodiment
 9-5 washes the inside of the pod in the same manner as the embodiment 9-1.
 In this way, the table arranged in the pod processing chamber 410 has the
 fitting part for closing the pod body 10 on the table, the inlet 470 for
 introducing a washing liquid into the pod, and the outlet 480 for
 discharging the washing liquid from the pod. This arrangement efficiently
 uses the time for processing wafers, to wash the inside of the pod. Since
 the pod processing chamber 410 is adjacent to the wafer processing chamber
 420, no labor is needed to transfer the pod between them, thereby
 improving workability.
 The embodiment 9-5transfers the pod and wafers as shown in FIGS. 19A and
 19B.
 In FIG. 19A, the pod processing chamber 410 has an arm 430 for carrying a
 pod or a wafer cassette.
 In FIG. 19B, a pod with wafers is at a predetermined position in the pod
 reception chamber 400. A cover and a wafer cassette 130 on the cover are
 removed from a pod body 10 and are put on a table that is vertically
 movable. The table is moved downwardly for a predetermined distance. The
 arm 430 carries the wafer cassette 130 with the wafers from the pod
 reception chamber 400 to the wafer processing chamber 420 through the pod
 processing chamber 410.
 The pod body 10 is transferred from the pod reception chamber 400 to the
 pod processing chamber 410 by, for example, a belt conveyor arranged in
 the pod reception chamber 400. Th arm 430 sets the pod body 10 to a
 predetermined position on the table in the pod processing chamber 410.
 (Embodiment 9-6)
 FIG. 18B shows a semiconductor processing apparatus according to an
 embodiment 9-6 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 The pod body 10 is directly set on a table in the pod processing chamber
 410. The table is shaped to tightly close the bottom opening of the pod
 body 10.
 The table has an inlet 470, a first outlet 480, and a second outlet 490.
 The outlet 490 is connected to a vacuum pump 230 to evacuate the pod.
 The inlet 470 and outlet 480 are used to wash the inside of the pod, and
 the outlet 490 and pump 230 are used to evacuate the washed inside of the
 pod, thereby removing remnants from the pod in a short time.
 The mechanisms for transferring the pod and wafers are the same as those of
 FIGS. 19A and 19B.
 (Embodiment 9-7)
 FIG. 20A shows a semiconductor processing apparatus according to an
 embodiment 9-7 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table. The table has a fitting part for tightly closing the pod body 10.
 The table has an inlet 470 and an outlet 480.
 The pod processing chamber 410 has a heater 450 to surround the pod body
 10. The inlet 470 and outlet 480 are used to wash the inside of the pod
 body 10. At this time, the heater 450 is turned on to heat a washing
 liquid and improve the washing power thereof. After the washing of the pod
 body 10, the heater 450 may be turned on to heat the pod body 10 and dry
 remnants in the pod body 10 in a short time.
 (Embodiment 9-8)
 FIG. 20B shows a semiconductor processing apparatus according to an
 embodiment 9-8 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table. The table has a fitting part for tightly closing the pod body 10,
 an inlet 470, an outlet 480, and a heater 451 to be entirely received in
 the pod body 10.
 The inlet 470 and outlet 480 are used to wash the inside of the pod body
 10. At this time, the heater 451 is turned on to heat a washing liquid and
 improve the washing power thereof. The heater 451 may be turned on after
 the washing of the pod body 10, to dry remnants in the pod body in a short
 time.
 (Embodiment 9-9)
 FIG. 21A shows a semiconductor processing apparatus according to an
 embodiment 9-9 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table. The table has a fitting part for tightly closing the opening of the
 pod body 10. The table has an inlet 470 and an outlet 480, which are
 connected to pipes. A part of the pipe that is connected to the inlet 470
 is covered with a heater 460.
 The inlet 470 and outlet 480 are used to wash the inside of the pod body
 10. At this time, the heater 460 heats a washing liquid to improve the
 washing power thereof and shorten a drying time of the washing liquid in
 the pod body 10.
 (Embodiment 9-10)
 FIG. 21B shows a semiconductor processing apparatus according to an
 embodiment 9-10 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table. The table has an inlet 470, an outlet 480, and a fitting part for
 tightly closing the opening of the pod body 10. An end of the inlet 470 is
 provided with a nozzle 500.
 The nozzle 500 jets liquid into the pod body 10, to realize high washing
 power. The tip of the nozzle 500 may be narrowed as shown in FIG. 6C.
 (Embodiment 9-11)
 FIG. 22A shows a semiconductor processing apparatus according to an
 embodiment 9-11 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table. The table has a projection 510 entering into the pod body 10. The
 table has an inlet 471 and an outlet 481 at the periphery of the
 projection 510.
 The projection 510 reduces the inner volume of the pod body 10, so that the
 inside of the pod body 10 can efficiently be washed with a small quantity
 of washing liquid.
 (Embodiment 9-12)
 FIG. 22B shows a semiconductor processing apparatus according to an
 embodiment 9-12 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table, which is provided with an agitating fin 530.
 The fin 530 agitates a washing liquid filled in the pod body 10, to improve
 the washing power thereof.
 (Embodiment 9-13)
 FIG. 23 shows a semiconductor processing apparatus according to an
 embodiment 9-13 of the present invention and a series of processes carried
 out thereby. The apparatus has a pod reception chamber 400, a pod
 processing chamber 410, and a wafer processing chamber 420. A pod handled
 by the apparatus consists of a pod body 10 and a cover 48. The pod body 10
 has an open bottom, and the cover 48 is a conventional one having no inlet
 or outlet.
 In the pod processing chamber 410, the pod body 10 is directly set on a
 table, which is provided with a rotary brush 540.
 When the inside of the pod is washed, the brush 540 is used to improve
 washing power.
 (Embodiment 9-14)
 FIG. 24A shows a semiconductor processing apparatus according to an
 embodiment 9-14 of the present invention and a series of processes carried
 out thereby. This embodiment is based on the embodiment 9-1 of FIG. 15A.
 Namely, the apparatus has a pod reception chamber 400, a pod processing
 chamber 410, and a wafer processing chamber 420. A pod handled by the
 apparatus consists of a pod body 10 and a cover 47 having an inlet 70 and
 an outlet 80. In the pod processing chamber 410, the pod body 10 and the
 cover 47 are tightly fitted together to close the pod.
 The inlet 70 and outlet 80 are connected to pipes through which a washing
 liquid is introduced into the pod and discharged therefrom, thereby
 washing the inside of the pod. At this time, wafers are left in the pod.
 The pod and wafers are simultaneously washed in the pod processing chamber
 410, and then, the wafers are taken out of the pod and are transferred to
 the wafer processing chamber 420. Namely, the chamber 420 can process the
 wafers that have been washed and clean.
 The other embodiments mentioned above may also simultaneously wash a pod
 and wafers stored therein if a space left in the pod is sufficient to hold
 the wafers. Simultaneously washing a pod and wafers and transferring the
 washed wafers to the wafer processing chamber 420 improves the yield of
 semiconductor products to be produced from the wafers.
 The wafer processing chamber 420 forms thin films such as silicon oxide
 films and silicon films on the wafers and patterns the thin films by, for
 example, photolithography. In this case, the cleanliness of the surface of
 each wafer greatly influences the characteristics and yield of the thin
 films to be formed and processed. Accordingly, washing wafers just before
 processing them is effective to form quality thin films thereon.
 If the wafer processing chamber 420 etches a film on the wafers, the pod
 and wafers may simultaneously be washed as mentioned above after the
 completion of the etching process.
 (Embodiment 9-15)
 FIG. 24B shows a semiconductor processing apparatus according to an
 embodiment 9-15 of the present invention and a series of processes carried
 out thereby. This embodiment is based on the embodiment 9-5 of FIG. 18A.
 Namely, the apparatus has a pod reception chamber 400, a pod processing
 chamber 410, and a wafer processing chamber 420. A pod handled by the
 apparatus consists of a pod body 10 and a cover 48. The pod body 10 has an
 open bottom, and the cover 48 is a conventional one having no inlet or
 outlet. The pod processing chamber 410 has a table on which the pod body
 10 is directly set. At this time, the pod body 10 is holding wafers, and
 the pod body 10 and wafers are simultaneously washed.
 In the pod processing chamber 410, the pod body 10 is tightly fixed to the
 table. A washing liquid is introduced into and discharged from the pod
 body 10 through an inlet 471 and an outlet 481 formed on the table,
 thereby washing the inside of the pod body 10. At this time, the wafers in
 the pod body 10 are also washed.
 The washed wafers are taken out of the pod body 10 and are transferred to
 the wafer processing chamber 420. Processing the clean wafers improves the
 yield of semiconductor products to be produced from the wafers. The
 embodiment is particularly effective when forming thin films such as
 silicon oxide films and silicon films on the wafers because the
 cleanliness of the surface of each wafer greatly influences the yield of
 the thin films.
 Although the embodiments 9-1 to 9-15 handle pods having a bottom opening,
 they can also handle pods having a side opening by changing the mechanisms
 for transferring a pod. The structure for attaching a pod body to the
 table in the pod processing chamber 410 may have any design.
 The wafer processing chamber 420 may contain various semiconductor
 processing units including plasma CVD apparatuses, spattering apparatuses,
 and thermal CVD apparatuses for forming insulation films, semiconductor
 films, and conductive films, as well as ion injection apparatuses, thermal
 diffusion apparatuses, and dry etching apparatuses.
 Various modifications will become possible for those skilled in the art
 after receiving the teachings of the present disclosure without departing
 from the scope thereof.
 Wafers and substrates stored in the pods may be silicon wafers, sapphire
 substrates, GaAs substrates, glass substrates, etc.