Patent ID: 12201995

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

<1. Overall Configuration of EFEM>

The overall configuration of an EFEM (Equipment Front End Module)100according to an embodiment of the present disclosure will be described with reference toFIGS.1to3.FIG.1is a perspective view schematically showing the appearance of the EFEM100according to the embodiment.FIG.2is a plan view schematically showing a main part of the EFEM100.FIG.3is a side view schematically showing a main part of the EFEM100.

The EFEM100is a module configured to deliver a wafer9between a processing apparatus900configured to perform various processes on the wafer9and a storage container90configured to accommodate the wafer9. As shown inFIG.1, the EFEM100is used by being connected to the processing apparatus900(typically, a load lock chamber of the processing apparatus900). As shown inFIG.3, the storage container (carrier)90is a closed type container including a main body portion91configured to accommodate wafers9in multiple stages in a horizontal posture, and a lid portion92configured to close an opening provided on one side wall of the main body portion91. The storage container90is also called a FOUP (Front Opening Unified Pod), a cassette, or the like.

As shown inFIG.1, the EFEM100includes a plurality of (three, in the example of the figure) load ports1, a main body part2, and a control part3. The load ports1are arranged on one end side of the main body part2. The processing apparatus900is connected to the other end side of the main body part2(i.e., the end portion on the side opposite to the side which the load ports1are connected). In the following, for the sake of convenience of explanation, the side of the main body part2to which the load ports1are connected will be referred to as “front”, and the side of the main body part2to which the processing apparatus900is connected will be referred to as “rear.” In addition, the horizontal direction orthogonal to the front-rear direction will be referred to as “left-right direction.”

(Load Port1)

The load port1is a module configured to connect the storage container90to the EFEM100, and includes a base plate11, a mounting part12, a door part13, and the like.

The base plate11is a flat plate-shaped member arranged in an upright posture. A support base121projecting in a horizontal posture is provided on one main surface of the base plate11, and the mounting part12is provided on the support base121. An upper surface of the mounting part12forms a mounting surface on which the storage container90is mounted. The mounting part12is provided with a mechanism (mounting part drive mechanism) configured to advance and retreat the mounting part12on the support base121. By the driving of the mechanism, the mounting part12is moved between a proximity position in close proximity to the base plate11and a spaced-apart position spaced apart from the base plate11. Further, the mounting part12is provided with a mechanism (gas replacement mechanism) configured to replace the atmosphere in the storage container90mounted on the mounting part12with a predetermined gas (nitrogen gas in the present embodiment).

Meanwhile, the base plate11has an opening111formed at a position where the opening111faces the lid portion92when the storage container90is mounted on the mounting part12. The door part13is provided to close the opening111. The door part13includes a mechanism (lid holding mechanism) configured to remove (unlatch) the lid portion92arranged opposite to the door part13from the main body portion91and connect and integrate (dock) the lid portion92to the door part13. Further, the door part13is provided with a mechanism (door part driving mechanism) configured to move the door part13. By the driving of the door part driving mechanism, the door part13is moved between a closing position where the door part13closes the opening111and an opening position where the door part13retreats to a position below the opening111to open the opening111.

The mounting part12, the door part13, and the case14in which various drive mechanisms are stored, are supported by the base plate11. The base plate11that supports the mounting part12, the door part13and the case14is attached to close an opening2111formed in the front wall of the housing21of the main body part2.

The operation of the load port1is as follows. First, the storage container90containing unprocessed wafers9is transferred by an external robot such as an OHT, an AMHS, a PGV, etc., such that the lid portion92is mounted on the upper surface of the mounting part12in such an orientation as to face the door part13. At this time, the mounting part12is arranged at the spaced-apart position. After the storage container90is mounted on the mounting part12, the mounting part drive mechanism moves the mounting part12from the spaced-apart position to the proximity position. As a result, the lid portion92of the storage container90mounted on the mounting part12is arranged to face the door part13while being close to the door part13.

In such a state, the lid holding mechanism provided in the door part13removes the lid portion92of the storage container90from the main body portion91and connects and integrates the lid portion92to the door part13. Subsequently, the door part drive mechanism moves the door part13from the closing position to the opening position, together with the lid portion92integrated with the door part13. As a result, the inside of the storage container90communicates with the inside of the main body part2through the opening111, and the unprocessed wafer9stored in the storage container90is taken out by a transfer mechanism22(described later) arranged inside the main body part2.

(Main Body Part2)

The main body part2includes a housing21which is a rectangular parallelepiped frame provided between the plurality of load ports1and the processing apparatus900. As shown inFIGS.2and3, the housing21includes a plurality of panels211, a plurality of corner columns212, a plurality of intermediate columns213, a support plate214, and the like.

The panel211is a substantially rectangular flat plate-shaped member that forms a peripheral wall surface of the housing21. In this example, six panels211are combined in a rectangular parallelepiped shape. That is, four of the six panels211are arranged in a vertical posture to form a front wall, a rear wall, a left wall and a right wall of the housing21. Further, the remaining two panels211are arranged in a horizontal posture to form a ceiling and a bottom plate of the housing21. These six panels211are precisely attached so as not to create a gap through which the internal gas may flows out. The space surrounded by the six panels211is a substantially airtight closed space. Needless to say, a sealing member or the like may be provided between the adjacent panels211to improve airtightness of an internal space.

The panel211constituting the front wall of the housing21is provided with a plurality of openings2111. The load port1(specifically, the base plate11) is attached to airtightly close each opening2111(seeFIG.1). On the other hand, for example, a load lock chamber of the processing apparatus900is connected to the panel211constituting the rear wall of the housing21. The panel211constituting the rear wall is formed with an opening configured to communicate the housing21and the load lock chamber. The opening is configured to be hermetically closed by a gate valve2112or the like.

The corner columns212are rod-shaped members configured to support the panels211and are respectively provided at the four corners of the housing21. That is, the corner columns212are provided at the left front corner, the right front corner, the left rear corner, and the right rear corner of the housing21, respectively. Each corner column212has a tubular shape and has a hollow portion2121formed therein.

In order to avoid interference with the transfer device22and the like, which will be described later, a front-rear width of each corner column212is preferably set to 100 mm or less. Meanwhile, as will be described later, the hollow portion2121of the corner column212constitutes a return path T3. In order to reduce a flow path resistance of the hollow portion2121, it is preferable to increase a left-right width of each corner column212as much as possible. However, as the left-right width increases, footprint of the apparatus increases. In consideration of balance thereof, the left-right width of each corner column212is set to, for example, about 200 mm.

The intermediate columns213are rod-shaped members configured to support the panel211constituting the front wall and are provided between the adjacent openings2111of the panel211. In this example, three openings2111are provided to correspond to the three load ports1. The intermediate columns213are respectively provided between the right opening2111and the middle opening2111, and between the middle opening2111and the left opening2111. Like the corner columns212, each intermediate column213has a tubular shape and has a hollow portion2131formed therein.

In order to avoid interference with the transfer device22and the like, it is preferable that the front-rear width of each intermediate column213is also set to 100 mm or less. Meanwhile, as will be described later, the hollow portion2131of the intermediate column213constitutes an individual return path T4. In order to reduce the flow path resistance of the hollow portion2131, it is preferable that the left-right width of each intermediate column213should be as large as possible. However, as the left-right width increases, a distance between adjacent load ports1becomes wider. In consideration of the balance thereof, the left-right width of each intermediate column213is set to, for example, about 80 mm.

The support plate214is a substantially rectangular flat plate-shaped member configured to vertically divide the space surrounded by the six panels211and is provided in a horizontal posture in the vicinity of the panels211constituting the ceiling. Among the spaces surrounded by the six panels211, a space above the support plate214is hereinafter referred to as “unit installation chamber T1.” A fan filter unit41or the like is arranged in the unit installation chamber T1. Further, among the spaces surrounded by the six panels211, the space below the support plate214is hereinafter referred to as “transfer chamber T2.” The transfer chamber T2forms a space (transfer space) in which the wafer9is transferred between the storage container90mounted on the load port1and the processing apparatus900.

A transfer device22, an aligner23, and the like are arranged in the transfer chamber T2. The transfer device22is arranged substantially at the center of the transfer chamber T2. On the other hand, the aligner23is arranged on the right side of the transfer device22. In this example, the panel211constituting the right wall of the housing21has a U-shaped cross section including a portion rising in the left-right direction from the front end side and the rear end side, whereby a space that overhangs to the right of the right corner column212is formed inside the transfer chamber T2. The aligner23is arranged in the overhanging space.

The transfer device22will be described with reference toFIG.4.FIG.4is a side view schematically showing a main part of the EFEM100, in which the transfer device22and the side surface including the individual return path T4(described later) connected to the transfer device22are shown.

The transfer device22is a device configured to transfer the wafer9between the FOUP90mounted on the load port1and the processing apparatus900and is configured to include a hand221, an arm222, an elevating column223, a drive mechanism224, a case225, and the like.

The hand221is a member that grips the wafer9by an appropriate method such as a mechanical clamp method, a vacuum chuck method, an electrostatic chuck method, or the like, and is connected to the tip of the arm222. The number of hands221connected to the tip of the arm222may be one or two or more. The arm222has, for example, an articulated structure, and is driven by a drive mechanism224to freely rotate in a horizontal plane. The elevating column223is a rod-shaped member connected to the arm222and is moved up and down by being driven by the drive mechanism224. The drive mechanism224is a mechanism configured to drive the arm222, the elevating column223, and the like, and includes a motor, a ball screw mechanism, and the like.

The case225is fixed in the transfer chamber T2. The drive mechanism224is accommodated inside the case225. An opening2251is provided on the upper surface of the case225. The elevating column223is inserted through the opening2251. The elevating column223is connected to the drive mechanism224at the lower end arranged inside the case225and is connected to the arm222at the upper end protruding upward from the case225. An inner diameter of the opening2251is slightly larger than an outer diameter of the elevating column223so as not to hinder the raising and lowering of the elevating column223. A slight gap is formed between the opening2251and elevating column223.

A through-hole2252is provided in the side wall of the case225. The through-hole2252and the closing duct216, which will be described later, are connected to each other via a connecting pipe226. The case225is provided with a fan227configured to send the gas in the case225to the connecting pipe226via the through-hole2252. By driving the fan227, the gas in the case225is discharged to the connecting pipe226together with the particles generated therein.

The transfer device22executes a predetermined transfer operation under the control of the control part3. That is, by performing operations such as the raising and lowering of the elevating column223, the rotating of the arm222, the gripping and releasing of the wafer9on the hand221, and the like in combination, the transfer device22takes out the unprocessed wafer9from the FOUP90mounted on the load port1and loads the unprocessed wafer9into the processing apparatus900. Further, the transfer device22unloads the processed wafer9from the processing apparatus900and stores the processed wafer9in the FOUP90mounted on the load port1.

The aligner23will be described with reference toFIG.5.FIG.5is a side view schematically showing a main part of the EFEM100, in which the aligner23and the side surface including the individual return path T4(described later) connected to the aligner23are shown.

The wafer9stored in the storage container90may undergo a slight position shift while the storage container90is conveyed by an external robot and mounted on the mounting part12of the load port1. The aligner23is a device that detects the position shift and performs position correction (alignment) to correct the position shift. The aligner23includes a table231, a rotary column232, a drive mechanism233, a detection part234, a case235, and the like.

The table231is a member on which the wafer9to be aligned is placed. The rotary column232is a rod-shaped member connected to the center position of the lower surface of the table231and is rotated about the central axis under the driving of the drive mechanism233. The drive mechanism233is a mechanism configured to drive the rotary column232and the like, and includes a motor, a pulley, and the like. The detection part234detects how much the wafer9is shifted from the desired position, based on a peripheral edge position and the like of the wafer9placed on the rotating table231.

The case235is supported by a support base (not shown) provided in the transfer chamber T2. The drive mechanism233is accommodated inside the case235. An opening2351is provided on the upper surface of the case235. The rotary column232is inserted through the opening2351. The rotary column232is connected to the drive mechanism233at the lower end arranged inside the case235and is connected to the table231at the upper end protruding upward from the case235. An inner diameter of the opening2351is slightly larger than an outer diameter of the rotary column232so as not to hinder the rotation of the rotary column232. A slight gap is formed between the opening2351and the rotary column232.

A through-hole2352is provided in the side wall of the case235. The through-hole2352and the closing duct216, which will be described later, are connected to each other via a connecting pipe236. The case235is provided with a fan237configured to send the gas in the case235to the connecting pipe236via the through-hole2352. By driving the fan237, the gas in the case235is discharged to the connecting pipe236together with the particles generated therein.

The aligner23executes a predetermined alignment operation under the control of the control part3. That is, when the transfer device22places the wafer9taken out from the storage container90on the table231of the aligner23, the aligner23detects the peripheral edge position of the wafer9placed on the table231using the detection part234while rotating the table231and specifies how much the wafer9is shifted from the desired position. The specified position shift amount is notified to the control part3. The control part3corrects the receiving position of the hand221when the transfer device22unloads the wafer9placed on the table231, based on the position shift amount. As a result, a positional relationship between the wafer9and the hand221becomes a desired one. That is, the wafer9is unloaded from the aligner23in a state in which the wafer9is appropriately aligned by being subjected to position shift correction. The wafer9is loaded into the processing apparatus900.

(Control Part3)

Referring again toFIG.1, the control part3controls operations of the respective parts included in the EFEM100. Specifically, the control part3performs various controls related to the operation of the load port1, various controls related to the operation of the transfer device22, various controls related to the operation of the aligner23, various controls related to nitrogen circulation (described later) in the housing21, and the like.

Hardware configuration of the control part3is the same as that of a general computer. That is, the control part3includes a CPU that performs various arithmetic processes, a ROM as a read-only memory that stores required programs, a RAM as a read/write memory that stores various kinds of information, a magnetic disk that stores control software, data, etc., various interfaces, and so on. When the CPU of the control part3executes the program stored in the memory, a predetermined operation is performed in the EFEM100.

<2. Circulation Path>

When the EFEM100is in an operating state, an internal space of the housing21is filled with a predetermined gas (nitrogen gas in the present embodiment) and is configured such that the predetermined gas circulates in the internal space. A circulation path through which the gas circulates will be described with reference toFIGS.6and7in addition toFIGS.2to5.FIG.6is a rear view of the panel211constituting the front wall of the housing21.FIG.7is a view showing a state in which the fan filter unit41, the chemical filter42and the cover portion202are removed fromFIG.6.

As shown inFIGS.3to5, the circulation path includes a unit installation chamber T1in which a fan filter unit41or the like is arranged, a transfer chamber T2forming a transfer space, a return path T3(seeFIG.3) configured to return the nitrogen gas flowing from one side to the other side of the transfer chamber T2, and individual return paths T4(seeFIGS.4and5) configured to return the gas flowing inside the transfer device22and the aligner23arranged in the transfer chamber T2.

(Unit Installation Chamber T1& Transfer chamber T2)

As described above, the unit installation chamber T1is a space above the support plate214in the space surrounded by the six panels211. Further, the transfer chamber T2is a space below the support plate214in the space surrounded by the six panels211. That is, the unit installation chamber T1and the transfer chamber T2are separated by the support plate214. The support plate214is provided with an opening2141(seeFIG.7). The unit installation chamber T1and the transfer chamber T2communicate with each other through the opening2141.

A fan filter unit41and a chemical filter42are provided in the unit installation chamber T1.

The fan filter unit (FFU)41is a unit configured to form a laminar flow flowing downward in the transfer chamber T2and is accommodated in the unit installation chamber T1by being supported by the support plate214. As shown inFIG.3and the like, the fan filter unit41includes a fan411and a filter412. The fan411sucks a gas from above and sends the gas downward. The filter412is configured by, for example, a ULPA filter. The filter412captures and removes particles contained in the gas sent by the fan411.

When the fan411of the fan filter unit41is operated, the nitrogen gas in the unit installation chamber T1is sent to the transfer chamber T2through the opening2141provided in the support plate214while being cleaned by the filter412. As a result, a laminar flow (downflow) flowing downward in the transfer chamber T2is formed.

The chemical filter42is a filter configured to remove an active gas, molecular pollutants, and the like, and is arranged on the upstream side of the fan filter unit41in the unit installation chamber T1. Therefore, the nitrogen gas flowing into the unit installation chamber T1will flow into the fan filter unit41after the active gas, the molecular contaminants, and the like are removed when passing through the chemical filter42.

(Return Path T3)

The return path T3is provided in each of the hollow portions2121of the two corner columns arranged on the front side (i.e., the corner columns arranged at the left front corner and the right front corner, respectively, which will be hereinafter also referred to as “front corner columns”)212.

As shown inFIG.3, an opening2122communicating with the hollow portion2121is formed at a position near the lower end on the rear surface of each front corner column212, and an opening duct215is provided to close the opening2122. As shown inFIGS.3,6and the like, the opening duct215extends downward along the front corner column212and reaches an open end2151. The open end2151is opened downward at a position below the opening2122to bring the inside of the opening duct215into communication with the transfer chamber T2. That is, the return path T3formed by the hollow portion2121of each front corner column212communicates with the transfer chamber T2via the opening2122and the opening duct215.

Further, as shown inFIGS.3,7and the like, each front corner column212is connected to a beam member217at the upper end portion thereof. A hollow portion is formed inside the beam member217. The hollow portion2121of each front corner column212communicates with the hollow portion of the beam member217. The hollow portion of the beam member217communicates with the unit installation chamber T1via an opening2142(seeFIG.7) provided in the support plate214. That is, the return path T3formed by the hollow portion2121of each front corner column212communicates with the unit installation chamber T1via the hollow portion of the beam member217and the opening2142of the support plate214.

A first fan43is arranged in the return path T3. As shown inFIG.3, the first fan43is arranged inside the opening duct215and is configured to suck a gas from the lower side and send the gas upward to form an air flow flowing upward through the return path T3. That is, when the first fan43is operated, the nitrogen gas in the transfer chamber T2(i.e., the nitrogen gas flowing downward through the transfer chamber T2and reaching the vicinity of the bottom of the transfer chamber T2) is sucked through the opening duct215and sent upward in the return path T3. The nitrogen gas flowing upward through the return path T3flows into the unit installation chamber T1. That is, the nitrogen gas flowing downward in the transfer chamber T2is returned to the unit installation chamber T1through the return path T3. The nitrogen gas returned to the unit installation chamber T1is cleaned by the filters42and412, and then sent back to the transfer chamber T2.

(Individual Return Path T4)

The individual return path T4is provided in each of the hollow portions2131of the two intermediate columns213.

As shown inFIGS.4and5, an opening2132communicating with the hollow portion2313is formed at a position near the lower end on the rear surface of each intermediate column213. A closing duct216is formed to close the opening2132. As shown inFIGS.4,5,6and the like, the closing duct216extends downward along the intermediate column213to reach the closed end2161which is closed with respect to the transfer chamber T2.

As shown inFIGS.2and4, a connecting pipe226extending from the case225of the transfer device22is connected to the closing duct216provided in the intermediate column213arranged on the left side. Further, as shown inFIGS.2and5, a connecting pipe236extending from the case235of the aligner23is connected to the closing duct216provided in the intermediate column213arranged on the right side. That is, the individual return path T4formed by the hollow portion2131of each intermediate column213communicates with the cases225and235of the transfer device22and the aligner23arranged in the transfer chamber T2via the opening2132, the closing duct216, and the connecting pipes226and236.

Further, as shown inFIGS.4,5,7, and the like, each intermediate column213is connected to a beam member217at the upper end portion thereof. A hollow portion is formed inside the beam member217. The hollow portion2131of each intermediate column213communicates with the hollow portion of the beam member217. Further, as described above, the hollow portion of the beam member217communicates with the unit installation chamber T1via an opening2142(seeFIG.7) provided in the support plate214. That is, the individual return path T4formed by the hollow portion2131of each intermediate column213communicates with the unit installation chamber T1via the hollow portion of the beam member217and the opening2142of the support plate214.

A second fan44is arranged in the individual return path T4. As shown inFIGS.4and5, the second fan44is arranged inside the closing duct216. The second fan44sucks a gas from below and sends the gas upward to form an air flow flowing upward through the individual return path T4. That is, when the second fan44is operated, the nitrogen gas sent from the cases225and235of the transfer device22and the aligner23arranged in the transfer chamber T2is sucked into the closing duct216via the connecting pipes226and236and is sent upward through the individual return path T4. The nitrogen gas flowing upward through the individual return path T4flows into the unit installation chamber T1. That is, the nitrogen gas flowing inside each of the transfer device22and the aligner23is returned to the unit installation chamber T1through the individual return path T4. The nitrogen gas returned to the unit installation chamber T1is cleaned by the filters42and412, and then sent back to the transfer chamber T2.

As described above, a circulation path including the unit installation chamber T1, the transfer chamber T2, the return path T3, and the individual return path T4is formed inside the housing21of the EFEM100. In this circulation path, there are provided a gas supply part45configured to supply the nitrogen gas and a gas discharge part46configured to discharge the nitrogen gas from the circulation path.

As shown inFIG.3, the gas supply part45includes a supply pipe451and a supply valve452provided at the supply pipe451. One end of the supply pipe451is connected to the side wall of the unit installation chamber T1, and the other end thereof is connected to the nitrogen gas supply source. The supply valve452is configured to include, for example, a mass flow controller whose opening degree can be freely adjusted. In response to an instruction from the control part3, the control valve542changes an amount of nitrogen gas flowing through the supply pipe451(i.e., a supply amount of nitrogen gas s).

The control part3monitors oxygen concentration, water concentration, etc. of the nitrogen gas circulating through the circulation path and controls the opening degree of the supply valve452, etc. so that the above-mentioned concentrations are maintained at predetermined values or less. Specifically, for example, in a case where the oxygen concentration exceeds a predetermined value, the control part3controls the supply valve452to increase the flow rate of the nitrogen gas supplied to the circulation path and decrease the oxygen concentration.

As shown inFIG.3, the gas discharge part46includes a discharge pipe461and a discharge valve462provided at the discharge pipe461. One end of the discharge pipe461is connected to the vicinity of the lower end of the side wall of the transfer chamber T2, and the other end thereof is connected to an exhaust line. The discharge valve462is configured to include, for example, a mass flow controller whose opening degree can be freely regulated. In response to an instruction from the control part3, the discharge valve462changes an amount of nitrogen gas flowing through the discharge pipe461(i.e., a discharge amount of nitrogen gas).

The control part3monitors a pressure in at least one predetermined position in the circulation path and controls the opening degree of the discharge valve462, and the like such that the pressure at each position is maintained within a predetermined appropriate range. Specifically, for example, when the pressure value becomes larger than the appropriate range, the opening degree of the discharge valve462is increased, and when the pressure value becomes smaller than the appropriate range, the opening degree of the discharge valve462is reduced. In a state in which the control part3is performing appropriate control, the pressure in the transfer chamber T2becomes slightly higher than the pressure in the external space of the housing21. That is, the appropriate range of the pressure value of the transfer chamber T2is set to a value slightly higher than the pressure value in the external space of the housing21. As a result, while suppressing the leakage of the nitrogen gas from the transfer chamber T2to the external space of the housing21, it is possible to prevent the outside air from entering the transfer chamber T2from the external space of the housing21.

<3. Capture Part5>

As described above, a circulation path including the unit installation chamber T1, the transfer chamber T2, the return path T3and the individual return path T4is formed in the internal space of the housing21of the EFEM100. The nitrogen gas is sent from the unit installation chamber T1to flow downward through the transfer chamber T2and is returned back to the unit installation chamber T1through the return path T3such that circulation of the nitrogen gas is formed. In addition, the nitrogen gas flows inside the transfer device22and the aligner23arranged in the transfer chamber T2. The nitrogen gas is returned back to the unit installation chamber T1through the individual return path T4.

In this circulation path, flow path cross-sectional areas of the return path T3and the individual return path T4are smaller than a flow path cross-sectional area of the opening2141that brings the unit installation chamber T1and the transfer chamber T2into communication with each other. Flow path resistances of the return path T3and the individual return path T4are larger than a flow path resistance of the opening2141. Therefore, the flow rate of the nitrogen gas sent through the opening2141tends to be larger than the flow rate of the nitrogen gas returned from the return path T3and the individual return path T4, and the pressure in the unit installation chamber T1tends to decrease. In a case where the pressure in the unit installation chamber T1becomes lower than the pressure in the external space of the housing21, the outside air may enter the unit installation chamber T1from the external space. However, in this EFEM100, the nitrogen gas is positively sent to the return path T3or the individual return path T4by the first fan43and the second fan44, thereby suppressing a pressure drop in the unit installation chamber T1and preventing the intrusion of the outside air.

Meanwhile, when the first fan43sends the nitrogen gas to the return path T3, the pressure in the return path T3is increased, and a differential pressure is generated on both sides of the partition wall separating the return path T3and the transfer chamber T2(i.e., on the inside and outside of the front corner column212) such that a pressure on the side of the return path T3becomes higher than that on the side of the transfer chamber T2. Similarly, when the second fan44sends the nitrogen gas to the return path T3, the pressure in the individual return path T4is increased, and a differential pressure is generated on both sides of the partition wall separating the individual return path T4and the transfer chamber T2(i.e., on the inside and outside of the intermediate column213) such that a pressure on the side of the individual return path T4becomes higher than that on the side of the transfer chamber T2.

When the differential pressure is generated on both sides of the partition wall separating the return path T3and the transfer chamber T2such that the pressure on the side of the return path T3becomes higher than that on the side of the transfer chamber T2, there is a possibility that a slight gas leak may occur from the return path T3to the transfer chamber T2through a minute gap formed in the partition wall. In this regard, the gas flowing through the return path T3may contain particles. That is, the downflow formed in the transfer chamber T2also plays a role of pushing the particles floating in the transfer chamber T2downward, and the nitrogen gas returned through the return path T3may contain particles floating in the transfer chamber T2. In a case where the gas containing such particles leaks into the transfer chamber T2, cleanliness of the transfer chamber T2may decrease.

Similarly, when the differential pressure is generated on both sides of the partition wall separating the individual return path T4and the transfer chamber T2such that the pressure on the side of the individual return path T4becomes higher than that on the side of the transfer chamber T2, there is a possibility that a slight gas leak may occur from the individual return path T4to the transfer chamber T2through a minute gap formed in the partition wall. In this regard, the gas flowing through the individual return path T4may also contain particles. That is, when the transfer device22or the aligner23is driven, the particles generated by the drive mechanisms224and233and the like and floating in the cases225and235are sent together with the nitrogen gas in the cases225and235via the connecting pipes226and236by the fans227and237and are allowed to flow into the individual return path T4connected to the connecting pipes226and236. Therefore, the gas flowing through the individual return path T4may contain particles generated by the drive mechanisms224and233and the like of the transfer device22and the aligner23. In a case where the gas containing such particles leaks into the transfer chamber T2, the cleanliness of the transfer chamber T2may decrease.

Therefore, in this EFEM100, a capture part5configured to capture particles is provided in each of the return path T3and the individual return path T4. The capture part5will be described with reference toFIG.8in addition toFIGS.6and7.FIG.8is a view showing a front corner column212and a charging part51provided therein.

The capture part5electrically captures the particles contained in the gas and includes a charging part51, a voltage applying part52configured to apply a voltage to the charging part51, and a conducting wire53that connects the charging part51and the voltage applying part52.

The charging part51is a thin-walled member, and one main surface thereof constitutes a charging surface511. When the voltage applying part52applies a predetermined voltage to the charging part51through the conducting wire53, the charging surface511of the charging part51is charged. When the charging surface511is charged, the particles around the charging surface511are attracted by an electrostatic force and captured by the charging surface511as the particles adhere to (adsorb) to the charging surface511.

As described above, each of the front corner columns212and the intermediate columns213has a cylindrical shape with a rectangular cross section, and the hollow portions2121and2131formed therein constitute the return path T3and the individual return path T4. The charging part51is provided on the inner wall surface of each of the front corner columns212and the intermediate columns213.

Now, the configurations of the respective columns (target columns)212and213to which the charging part51is attached will be specifically described. Each of the target columns212and213includes a main body portion201having a U-shaped cross section with an opening on the rear side thereof, and a cover portion202attached to the main body portion201to airtightly close the opening2011on the rear side of the main body portion201. The cover portion202airtightly closes the opening2011to form the airtight hollow portions2121and231. When the cover portion202is removed from the main body portion201, the opening2011on the rear side of the main body portion201is exposed such that the inner wall surfaces (i.e., the front inner wall surface201aand the left and right inner wall surfaces201b) of the main body portion201are accessible.

The charging part51is provided on the inner wall surface which is accessible through the opening2011when the cover portion202is removed. Specifically, the charging part51is attached to the front inner wall surface201asuch that the charging surface511faces rearward. The charging part51may be attached to the inner wall surface201ain any manner. For example, a plurality of stud bolts203may be erected on the inner wall surface201a, the respective stud bolts203may be inserted through the respective through-holes provided in the charging part51, and nuts204may be fastened to the stud bolts203from above such that the charging part51is attached to the inner wall surface201a.

The conducting wire53extending from the charging part51is drawn out through the opening duct215(or the closing duct216) together with the wiring extending from the first fan43(or the second fan44) accommodated therein and is connected to the voltage applying part52.

The charging part51is preferably shaped and sized to cover substantially the entire inner wall surface201ato which the charging part51is attached. That is, it is preferable that a left-right width of the charging part51is substantially the same as a left-right width of the inner wall surface201a, and a vertical dimension of the charging part51is substantially the same as a vertical dimension of the inner wall surface201a. Alternatively, a plurality of charging parts51smaller than the inner wall surface201amay be arranged to cover substantially the entire inner wall surface201a.

When the voltage applying part52applies a predetermined voltage to the charging part51provided on the inner wall surface201aof the target columns212and213, the charging surface511is charged. Then, the particles around the charging surface511, i.e., the particles contained in the nitrogen gas flowing through the return path T3and the individual return path T4configured by the hollow portions2121and2131of the target columns212and213are attracted by an electrostatic force and are adsorbed and captured on the charging surface511. As a result, the particles contained in the nitrogen gas flowing through the return path T3and the individual return path T4are removed. Therefore, even in a case where the gas leaks from the return path T3or the individual return path T4toward the transfer chamber T2having a lower pressure than the pressure in the return path T3or the individual return path T4, the number of particles in the transfer chamber T2is unlikely to increase. That is, the cleanliness of the transfer chamber T2is unlikely to decrease.

The captured particles are accumulated on the charging surface511. Therefore, it is preferable that at an appropriate timing such as the timing of maintenance of the EFEM100, or the like, an operation is performed to stop the application of the voltage to the charging part51and to wipe off and collect the particles adhering to the charging surface511(wet cleaning). In this example, the charging part51is provided at a position which is accessible through the opening2011exposed by removing the cover portion202. Therefore, the operator can collect the particles adhering to the charging surface511by removing the cover portion202and wiping the charging surface511appearing inside the opening2011with a cloth or the like.

<4. Effect>

The EFEM100according to the above-described embodiment is provided with a circulation path including the transfer chamber T2configured to form the transfer space in which the wafer9is transferred and the return path T3configured to return the gas flowing from one side to the other side of the transfer chamber T2. The return path T3and the transfer chamber T2are provided to interpose a partition wall therebetween and are configured to generate a differential pressure on both sides of the partition wall such that a pressure on the side of the return path T3becomes higher than that on the side of the transfer chamber T2in a state in which the gas circulates through the circulation path. The EFEM100includes the capture part5provided in the return path T3and configured to electrically capture particles contained in the gas flowing therethrough.

According to this configuration, the particles contained in the gas flowing through the return path T3are electrically captured. Therefore, even in a case where the gas leaks from the return path T3toward the transfer chamber T2having a lower pressure than the pressure in the return path T3, the number of particles in the transfer chamber T2is unlikely to increase. Accordingly, it is possible to sufficiently suppress the adhesion of particles to the wafer9in the transfer chamber T2.

Further, when the particles contained in the gas flowing through the return path T3are to be captured by, for example, a gas permeation type filter (physical particle filter), it is inevitable that the flow path resistance of the return path T3will increase significantly, and it is inevitable that the size of the fan (first fan)43configured to send the gas to the return path T3will increase. Since the capture part5provided in the return path T3electrically captures the particles, the particles can be captured without significantly increasing the flow path resistance of the return path T3. Accordingly, it is possible to avoid increasing the size of the first fan43.

Further, in the above configuration, since the capture part5is provided in the return path T3, the particles contained in the gas flowing through the circulation path are dispersed and captured by the filter412of the fan filter unit41and the capture part5. Therefore, the number of particles accumulated in the filter412is smaller than that in the case where the capture part5is not provided. As a result, life of the fan filter unit41is extended, and replacement cycle thereof is lengthened.

Further, in the EFEM100according to the above-described embodiment, the capture part5is configured to capture the particles contained in the gas by causing the particles to adhere to a charging surface511by an electrostatic force.

According to this configuration, the particles contained in the gas flowing through the return path T3can be sufficiently captured with a simple configuration, and the maintenance is easy to perform. For example, when capturing the particles with a filter, periodic filter replacement is required. However, in the case where the particles are to be captured by causing the particles to adhere to the charging surface511, the particles can be collected by a relatively simple operation such as releasing the charging of the charging surface511and wiping the charging surface511.

Further, the EFEM100according to the above-described embodiment includes the housing21including the plurality of panels211and the columns212and213configured to support the plurality of panels211, wherein the columns212and213include a front corner column212with the hollow portion2121in which the return path T3is provided, and the capture part5is provided on the inner wall surface201aof the front corner column212.

According to this configuration, the return path T3is provided in the hollow portion2121of the front corner column212. Therefore, the footprint of the apparatus can be suppressed to a small size. On the other hand, since the return path T3is limited to the narrow space of the hollow portion2121of the front corner column212, it is inevitable that the flow path resistance of the return path T3becomes relatively large. Since the capture part5provided in the return path T3electrically captures the particles, as described above, an increase in the width of the flow path resistance due to the provision of the capture part5is sufficiently small. Accordingly, it is possible to avoid increasing the size of the first fan43.

Further, in the EFEM100according to the above-described embodiment, the front corner column212includes an opening2011through which the capture part5is accessible and a cover portion202by which the opening2011is closable and openable.

According to this configuration, by keeping the opening2011in an open state, the capture part5can be accessed through the opening2011. Accordingly, the maintenance of the capture part5can be performed easily.

Further, in the EFEM100according to the above-described embodiment, the circulation path includes the individual return path T4configured to return the gas flowing inside predetermined devices22and23arranged in the transfer chamber T2, the individual return path T4and the transfer chamber T2are provided with a partition wall interposed therebetween such that when the gas circulates through the circulation path, a differential pressure is generated on both sides of the partition wall with the pressure on the side of the individual return path T4kept higher than that on the side of the transfer chamber T2, and the capture part5is provided in each of the return path T3and the individual return path T4.

According to this configuration, the gas flowing inside the devices22and23arranged in the transfer chamber T2is returned through the individual return paths T4. Therefore, it is possible to sufficiently suppress occurrence of the situation in which the particles generated inside the devices22and23are discharged to the transfer chamber T2and adhere to the wafer9in the transfer chamber T2. Further, the particles contained in the gas flowing through the individual return path T4are electrically captured. Therefore, even in the case where the gas leaks from the individual return path T4toward the transfer chamber T2having a lower pressure than the pressure in the individual return path T4, the number of particles in the transfer chamber T2is unlikely to increase.

<5. Other Embodiment>

In the above-described embodiment, the connecting pipes226and236configured to guide the gas flowing inside the transfer device22and the aligner23are connected to the intermediate column213. Alternatively, as in the EFEM100ashown inFIG.9, the connecting pipes226and236may be connected to an intermediate portion of the return path T3at a position upstream of the capture part5(specifically, for example, a position between the open end2151of the opening duct215provided in the front corner column212and the first fan43).

According to this configuration, the gas flowing inside the transfer device22and the aligner23is introduced into the return path T3from the position upstream of the capture part5in the middle of the return path T3and is returned through the return path T3. Therefore, it is possible to sufficiently suppress occurrence of the situation in which the particles generated inside the transfer device22and the aligner23are discharged to the transfer chamber T2and adhere to the wafer9in the transfer chamber T2. Further, since the gas flowing inside the transfer device22and the aligner23is introduced into the return path T3at a position upstream of the capture part5, the particles contained in the mixed gas including the gas flowing through the transfer chamber T2and the gas flowing through the transfer device22and the aligner23are captured by the capture part5. Accordingly, the particles contained in both gases can be efficiently captured.

In the example ofFIG.9, both the connecting pipe226extending from the case225of the transfer device22and the connecting pipe236extending from the case235of the aligner23are connected to the same front corner column212. Alternatively, the connecting pipe226on the side of the transfer device22may be connected to, for example, the left front corner column212, and the connecting pipe236on the side of the aligner23may be connected to, for example, the right front corner column212.

In the above-described embodiment, the return path T3is configured by the hollow portion2121of each front corner column212. However, the configuration of the return path T3is not limited thereto. Further, although the individual return path T4is configured by the hollow portion2131of each intermediate column213, the configuration of the individual return path T4is not limited thereto.

For example, the hollow portion2121of the corner column212arranged on the rear side or the hollow portion2131of the intermediate column213may constitute the return path T3. Alternatively, the hollow portion2121of the corner column212may constitute the individual return path T4.

Further, for example, in the vicinity of the panel211constituting the peripheral wall (front wall, rear wall, left wall, or right wall) of the housing21, a partition panel extending parallel to the panel211may be provided while having a gap between the panel211and the partition panel. The return path T3or (and) the individual return path T4may be configured by the space between the panel211and the partition panel.

In the above-described embodiment, in the state in which the gas circulates through the circulation path, the differential pressures are generated on both sides of the partition wall separating the return path T3(or the individual return path T4) and the transfer chamber T2such that the pressure on the side of the return path T3(or the individual return path T4) is higher than that on the side of the transfer chamber T2. The pressure difference is preferably 10 Pa or more and 100 Pa or less, more preferably 30 Pa or more and 50 Pa or less. That is, the present disclosure functions particularly effectively when such a pressure difference is generated between the return path T3(or the individual return path T4) and the transfer chamber T2.

In the above-described embodiment, the individual return path T4is not an essential configuration and may be omitted. For example, the connecting pipes226and236extending from the cases225and235of the transfer device22or (and) the aligner23may be connected to the exhaust line such that the gas in the cases225and235is exhausted without being circulated. When the individual return path T4is not provided, the hollow portion2131of the intermediate column213may constitute the return path T3.

In the above-described embodiment, the capture part5is configured to capture the particles contained in the gas by allowing the particles to adhere to the charging surface511by an electrostatic force. However, the configuration of the capture part5is not limited thereto. That is, the capture part5may have any configuration as long as it can electrically capture the particles contained in the gas. For example, the particles may be electrically collected by arranging an electrode in the middle of the gas flow path and forming an electromagnetic field with the electrode. Alternatively, the particles contained in the gas may be electrically captured by generating plasma.

In the above-described embodiment, any configuration may be used to charge the charging part51of the capture part5. For example, by bringing a terminal serving as a charge supply source into contact with the charging part, electric charges may be supplied to and accumulated in the charging part. Alternatively, the charging part may be charged by a corona discharge method.

In the above embodiment, the first fan43and the second fan44are not essential configurations, and one or both of them may be omitted.

In the above-described embodiment, the supply pipe451of the gas supply part45is connected to the unit installation chamber T1and the nitrogen gas is supplied to the unit installation chamber T1. However, a supply position of the nitrogen gas is limited thereto. The nitrogen gas may be supplied from an arbitrary position in the circulation path. For example, the supply pipe451of the gas supply part45may be connected to the return path T3to supply the nitrogen gas to the return path T3. When the nitrogen gas is supplied to the return path T3, the pressure in the return path T3is increased by the supply of the nitrogen gas. Therefore, even in a case where the first fan43is not provided, there is a possibility that, in the state in which the nitrogen gas circulates through the circulation path, the differential pressure is generated on both sides of the partition wall separating the return path T3and the transfer chamber T2(i.e., the inside and outside of the front corner column212) such that the pressure on the side of the return path T3becomes higher than that on the side of the transfer chamber T2. Furthermore, there is a possibility that the gas leaks from the return path T3to the transfer chamber T2. However, by providing the capture part5in the return path T3as described above, even in a case where such a gas leak occurs, the number of particles in the transfer chamber T2is unlikely to increase. That is, the cleanliness of the transfer chamber T2is unlikely to decrease.

In the above-described embodiment, the discharge pipe461of the gas discharge part46is connected to the transfer chamber T2, and the nitrogen gas is discharged from the transfer chamber T2. However, a discharge position of nitrogen gas is not limited thereto. The nitrogen gas may be discharged from any position in the circulation path.

In the above-described embodiment, when the hand221grips the wafer9by a so-called mechanical clamp method in which the clamp member is driven by the drive mechanism to hold and release the wafer9, it may be possible to adopt a configuration in which the particles generated when the clamp member is driven are sucked and introduced into the connecting pipe226.

In the above-described embodiment, the filter configured to capture particles may be provided in the vicinity of the fan227provided in the case225of the transfer device22. Similarly, a filter configured to capture particles may be provided in the vicinity of the fan237provided in the case235of the aligner23.

In the above-described embodiment, the gas circulating through the circulation path is the nitrogen gas. However, the circulating gas is not limited to the nitrogen gas and may be other gases (e.g., various inert gases such as an argon gas and the like, a dry air, etc.).

In the above-described embodiment, an object to be transferred is not limited to the wafer9but may be a glass substrate or the like.

In the above-described embodiment, there is exemplified the case where the present disclosure is applied to the EFEM100. However, a target to which the present disclosure is applied is not limited to the EFEM100. For example, the present disclosure may be applied to various devices that internally form a transfer space configured to transfer an object which requires a clean environment. Specifically, for example, the present disclosure may be applied to a sorter apparatus configured to replace or rearrange an object stored in a storage container (e.g., the wafer9stored in the storage container90). Further, for example, the present disclosure may be applied to a substrate processing apparatus including a plurality of processing units that form a substrate transfer space therebetween. In addition, the present disclosure may be applied to an apparatus (e.g., a stocker apparatus) in which a storage space configured to store an object requiring a clean environment is formed, an apparatus (e.g., various substrate processing apparatuses) in which a processing space configured to process an object requiring a clean environment is formed, and so forth.

Other configurations may also be variously modified without departing from the spirit of the present disclosure.

According to the present disclosure in some embodiments, it is possible to reduce particle contamination of a substrate in a gas circulation type EFEM.

While certain embodiments have been described, these embodiments have been presented by way of example only and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.