KR102889439B1 - Efem and gas replacement method in efem - Google Patents

Abstract

In an EFEM of the type that circulates an inert gas within a housing, it is possible to suppress the emission of particles within a return chamber while suppressing an increase in cost.
The EFEM (1) has a return room (41) in which nitrogen purified by an FFU (44) for removing particles flows in a predetermined direction, and a return path (43) for returning the nitrogen to the FFU (44) from the downstream side of the return room (41), and is configured so that the nitrogen circulates. The EFEM (1) is provided with a transfer robot (3) that is arranged in the return room (41) and performs a predetermined operation while holding and supporting a wafer. The transfer robot (3) has a case member (61) in which an opening is formed, an arm mechanism (70) that is arranged on the outside of the case member (61) and holds and supports a wafer, a supporter that supports the arm mechanism (70) and is inserted and penetrated into the opening, and a drive mechanism that is accommodated in the case member (61) and drives the supporter, and a connection path (82a) that connects the case member (61) and the return path (43) is installed.

Description

EFEM AND GAS REPLACEMENT METHOD IN EFEM

The present invention relates to an Equipment Front End Module (EFEM) capable of circulating an inert gas.

Patent Document 1 discloses an EFEM that performs wafer transfer between a processing device that performs a predetermined process on a semiconductor substrate (wafer) and a FOUP (Front-Opening Unified Pod) that accommodates the wafer. The EFEM comprises a housing having a transfer room in which wafer transfer is performed, a plurality of load ports arranged in a row on the outside of the housing and each on which a FOUP is loaded, and a transfer device that travels on a rail extended into the transfer room to transfer the wafer.

Previously, the influence of oxygen and moisture within the transfer chamber on semiconductor circuits manufactured on wafers was minimal. However, in recent years, with the further miniaturization of semiconductor circuits, these influences have become more pronounced. Therefore, the EFEM described in Patent Document 1 is configured so that the transfer chamber is filled with nitrogen, an inert gas. Specifically, the EFEM comprises a circulation path including a transfer chamber that circulates nitrogen within the housing, a gas supply means for supplying nitrogen to the circulation path, and a gas discharge means for discharging nitrogen from the circulation path. Nitrogen is appropriately supplied and discharged according to fluctuations in the oxygen concentration, etc. within the circulation path. This makes it possible to maintain a nitrogen atmosphere within the transfer chamber while suppressing an increase in the amount of nitrogen supplied, compared to a configuration that constantly supplies and discharges nitrogen.

However, in order to maintain an appropriate atmosphere within the transfer room while suppressing an increase in the nitrogen supply, it is necessary to install sensor devices that monitor oxygen concentration, humidity, etc. However, simply installing sensor devices within the transfer room may cause interference with the moving transfer device. Therefore, the inventor of the present application is considering the application of a fixed-position transfer device (transfer robot) as described in Patent Document 2, instead of a transfer device that moves on a rail. Specifically, the transfer robot comprises a hollow body fixed within the transfer room, a support arranged to protrude upward from the body, a driving mechanism for driving the support up and down, and a multi-joint arm installed on the support and driven horizontally to hold, support, and transfer wafers. This transfer robot can access FOUPs loaded in multiple load ports by driving the multi-joint arm horizontally. In other words, since there are no rails within the transfer room and the body does not move, it is possible to secure that much space for installing sensor devices within the transfer room.

Japanese Patent Publication No. 2015-146349 Japanese Patent Publication No. 2012-169691

In the transport robot described in Patent Document 2, the wafer is transported in both the vertical and horizontal directions by moving the support column supporting the multi-joint arm up and down. When such a transport robot is applied to the EFEM described in Patent Document 1, the following problems arise. Specifically, if the gas (inert gas) within the body is discharged to the external space outside the EFEM housing in order to remove particles that may be generated within the body during the operation of the drive mechanism, the nitrogen supplied into the transport chamber through the empty gap between the body and the support column is drawn into the body and then discharged to the external space. This creates a need to replenish the nitrogen, which may increase the cost of nitrogen supply. However, if the structure is configured so that nitrogen is not discharged from the body to the outside, then when the support column is driven downward (the internal volume of the body is reduced), the gas (inert gas) within the body is extruded to the periphery along with the movement of the support column. Because of this, there is a risk that gas (inert gas) containing particles may be released into the return chamber through the gap.

The purpose of the present invention is to suppress the emission of particles into a return chamber while suppressing an increase in cost in an EFEM of a type that circulates an inert gas within a housing.

The EFEM of the first invention comprises a return room in which an inert gas purified by a fan filter unit for removing particles flows in a predetermined direction, a case member disposed in the return room and accommodating a driving mechanism, and a return path for returning the inert gas to the fan filter unit from the downstream side of the return room in the predetermined direction, and is configured such that the inert gas circulates, and a connection path connecting the case member and the return path is provided, and a first fan for sending the gas in the return path to the downstream side in the predetermined direction is provided in the return path, and the connection path is characterized in that it is connected to the return path at a location downstream of the return room and upstream of the first fan in the predetermined direction.

When the support member is driven by the driving mechanism of the automatic device, particles may be generated in the internal space of the case member. If an inert gas containing these particles leaks from the gap between the opening of the case member and the support member, there is a risk that the interior of the transfer chamber may be contaminated with the particles. In the present invention, since a connection path connecting the case member and the return path is provided, even if particles are generated in the internal space of the case member, these particles are discharged to the return path through the connection path, thereby suppressing the leakage of particles into the transfer chamber. Furthermore, particles discharged to the return path are removed by a fan filter unit arranged downstream of the return path. Therefore, it is possible to suppress the transfer chamber from being contaminated by particles generated in the internal space of the case member. Furthermore, in this configuration, since the inert gas within the case member is not discharged as is to the outside, there is no need to replenish the amount of inert gas discharged within the case member, thereby suppressing an increase in the supply of inert gas and thus suppressing an increase in cost. Accordingly, in an EFEM of the type that circulates inert gas within the housing, it is possible to suppress the emission of particles within the return chamber while suppressing an increase in cost.

The EFEM of the second invention is characterized in that, in the first invention, it further comprises a second fan that sends an inert gas within the case member to the return path through the connection path.

In the present invention, since the inert gas inside the case member can be reliably sent to the return path by the airflow generated by the second fan, the inert gas inside the case member can be suppressed from leaking from the gap between the opening and the support, and the emission of particles into the return room can be more reliably suppressed.

The EFEM of the third invention further comprises, in the second invention, a fan driving device that rotates the second fan, and a control unit that controls the fan driving device, wherein the control unit is characterized in that, when the driving device is in operation, the rotation speed of the second fan is increased compared to when the driving device is not in operation.

Within the case member, there is a risk of particles being generated when the driving mechanism operates to drive the support member. In the present invention, when the driving mechanism operates, the rotation speed of the second fan is increased to increase the wind speed, thereby reliably sending the inert gas within the case member to the return path. Furthermore, when the driving mechanism is not operating, the rotation speed of the second fan is decreased, thereby reducing the power consumption required to drive the second fan.

The EFEM of the fourth invention is characterized in that it comprises an automatic device that is arranged in the transfer room and performs a predetermined operation while holding and supporting a substrate in the first invention, and the automatic device comprises a case member having an opening formed therein, a holding and supporting portion that is arranged on the outside of the case member and holds and supports the substrate, a support portion that supports the holding and supporting portion and is inserted and penetrated into the opening, and a driving mechanism that is accommodated in the case member and drives the support portion.

The EFEM of the fifth invention is characterized in that, in any one of the first to third inventions, a transport robot for transporting the substrate is installed as the automatic device, the case member is fixed in the transport room, an arm mechanism for transporting the substrate in a horizontal direction by holding and supporting the substrate is installed as the holding and supporting member, and a supporter for supporting the arm mechanism is installed as the support member, and the supporter is driven up and down by the driving mechanism.

In the present invention, the case member of the transport robot is fixed within the transport chamber. That is, since the case member itself does not move within the transport chamber, space for installing various devices within the transport chamber can be secured accordingly. On the other hand, in a configuration where the support member supporting the arm mechanism is moved up and down, there is a risk that inert gas containing particles generated within the case member will be extruded upwards along with the movement of the support member, and may escape through the gap between the case member and the support member and be released into the transport chamber. In the present invention, even in such a configuration, since the case member is connected to the return path by a connection path, particles are discharged to the return path through the connection path. Therefore, the inert gas containing particles can be effectively prevented from entering the transport chamber.

The EFEM of the sixth invention is characterized in that, in the fifth invention, the arm mechanism has a hollow arm member, and the arm member is formed with an inlet for introducing the inert gas supplied from an inert gas supply source for purge into the internal space of the arm member, and an outlet for discharging the inert gas from the internal space of the arm member.

The arm member of a transport robot typically has a hollow structure to house the driving mechanism. While the internal space of the arm member should be completely sealed against the transport room, in a configuration where this is not the case, for example, when the transport room is released to the atmosphere during maintenance, the internal space of the arm member may also be released to the atmosphere, potentially allowing oxygen or moisture to enter the internal space. In this case, if it takes time to replace the inert gas within the arm member when restarting after maintenance, there is a risk of reduced production efficiency. In the present invention, since the arm member is provided with inlets and outlets, the time required for gas replacement within the internal space of the arm member can be shortened compared to a case where these are not formed, thereby suppressing a reduction in production efficiency.

The gas replacement method in the EFEM of the seventh invention is applied in the EFEM of any one of the first to fourth inventions, and is characterized by supplying the inert gas from the inert gas supply source to the inside of the case member, sending the gas from the inside of the case member to the return path, thereby replacing the gas inside the case member, and after the gas atmosphere inside the return chamber becomes lower than a predetermined oxygen concentration, stopping the supply of the inert gas from the supply source, and thereafter introducing the gas inside the return chamber into the inside of the case member and sending it to the return path.

In the present invention, for example, when the EFEM is started, the gas inside the case member can be quickly replaced by actively supplying an inert gas from a supply source. Furthermore, by sending the gas from inside the case member to the return path, it is possible to suppress the emission of particles inside the case member into the transfer chamber when the EFEM is started, etc. In addition, in the present invention, instead of normally supplying the inert gas from the supply source to the case member, the gas is introduced from the transfer chamber into the case member and sent to the return path, thereby suppressing an increase in costs. Furthermore, since the backflow of gas from the case member into the transfer chamber can be suppressed, the emission of particles inside the case member into the transfer chamber can be suppressed.

Figure 1 is a schematic plan view of the EFEM and its surroundings according to the present embodiment.
Figure 2 is a diagram showing the electrical configuration of EFEM.
Figure 3 is a front view of the housing.
Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3.
Figure 5 is a VV cross-sectional view of Figure 3.
Figure 6 is a drawing showing the structure of a transport robot.
Figure 7 is a schematic diagram showing the supply and discharge paths of nitrogen to the circulation path.
Figure 8 is a drawing showing a nitrogen outlet in a transport robot.
Fig. 9 is a drawing showing a return robot according to a modified example.
Figure 10 is a drawing showing an aligner according to another modified example.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 8. For convenience of explanation, the directions shown in FIG. 1 are referred to as front-back, left-right, and forward-backward directions. That is, the direction in which the EFEM (Equipment Front End Module) (1) and the substrate processing device (6) are arranged is referred to as the front-back direction. The EFEM (1) side is referred to as the front, and the substrate processing device (6) side is referred to as the rear. The direction in which a plurality of load ports (4) are arranged, orthogonal to the front-back direction, is referred to as the left-right direction. In addition, the direction orthogonal to both the front-back direction and the left-right direction is referred to as the up-down direction.

(EFEM and surrounding schematic configuration)

First, the schematic configuration of the EFEM (1) and its surroundings will be described using FIGS. 1 and 2. FIG. 1 is a schematic plan view of the EFEM (1) and its surroundings according to the present embodiment. FIG. 2 is a drawing showing the electrical configuration of the EFEM (1). As shown in FIG. 1, the EFEM (1) has a housing (2), a transfer robot (3), a plurality of load ports (4), and a control device (5). At the rear of the EFEM (1), a substrate processing device (6) for performing a predetermined process on a wafer (W) (substrate of the present invention) is arranged. The EFEM (1) transfers the wafer (W) between the FOUP (Front-Opening Unified Pod) (100) loaded on the load port (4) and the substrate processing device (6) by means of a transfer robot (3) arranged inside the housing (2). FOUP (100) is a container capable of accommodating a plurality of wafers (W) arranged in a vertical direction, and has a cover (101) installed at the rear end (the end on the housing (2) side in the front-to-back direction). FOUP (100) is transported by, for example, an OHT (overhead transport vehicle) (not shown) that runs while suspended from a rail (not shown) installed above a load port (4). FOUP (100) is transported between the OHT and the load port (4).

The housing (2) is for connecting a plurality of load ports (4) and a substrate processing device (6). Inside the housing (2), a transfer room (41) is formed, which is substantially sealed with respect to the external space and in which a wafer (W) is transferred. When the EFEM (1) is in operation, the transfer room (41) is filled with nitrogen (an inert gas of the present invention). The housing (2) is configured so that nitrogen circulates in the internal space including the transfer room (41) (details will be described later). In addition, a door (2a) is installed at the rear end of the housing (2), and the transfer room (41) is connected to the substrate processing device (6) via the door (2a).

A transport robot (3) is placed in a transport room (41) and transports wafers (W). The transport robot (3) has a fixed base (60) (see Fig. 3), an arm mechanism (70) (see Fig. 3) placed above the base (60) and configured to hold and transport a wafer (W), and a robot control unit (11) (see Fig. 2). The transport robot (3) mainly performs an operation of taking out a wafer (W) in a FOUP (100) and transferring it to a substrate processing device (6), or an operation of receiving a wafer (W) processed by the substrate processing device (6) and returning it to the FOUP (100).

The load port (4) is for loading the FOUP (100) (see Fig. 5). The plurality of load ports (4) are arranged in a left-right direction so that their respective rear ends follow the bulkhead on the front side of the housing (2). The load port (4) is configured so that the atmosphere inside the FOUP (100) can be replaced with an inert gas such as nitrogen. A door (4a) is installed at the rear end of the load port (4). The door (4a) is opened and closed by a door opening and closing mechanism (not shown). The door (4a) is configured so as to be able to release the lock of the cover (101) of the FOUP (100) and also to be able to hold and support the cover (101). When the door (4a) holds and supports the unlocked cover (101), the door moving mechanism opens the door (4a), thereby opening the cover (101). By this, the wafer (W) within the FOUP (100) can be taken out by the return robot (3).

As illustrated in Fig. 2, the control device (5) is electrically connected to the robot control unit (11) of the transport robot (3), the control unit (not illustrated) of the load port (4), and the control unit (not illustrated) of the substrate processing device (6), and communicates with these control units. In addition, the control device (5) is electrically connected to an oxygen concentration meter (55), a pressure meter (56), a hygrometer (57), etc., installed in the housing (2), and receives the measurement results of these measuring devices to obtain information about the atmosphere within the housing (2). In addition, the control device (5) is electrically connected to a supply valve (112) and a discharge valve (113) (described later), and appropriately controls the atmosphere within the housing (2) by adjusting the opening degrees of these valves.

As illustrated in Fig. 1, the substrate processing device (6) has, for example, a load lock room (6a) and a processing room (6b). The load lock room (6a) is a space for temporarily holding a wafer (W), which is connected to a transfer room (41) via a door (2a) of a housing (2). The processing room (6b) is connected to the load lock room (6a) via a door (6c). In the processing room (6b), a predetermined processing is performed on the wafer (W) by a processing mechanism (not illustrated).

(Housing and its internal composition)

Next, the housing (2) and its internal configuration will be described using FIGS. 3 to 5. FIG. 3 is a front view of the housing (2). FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. FIG. 5 is a cross-sectional view taken along line V-V of FIG. 3. In addition, in FIG. 3, the illustration of the bulkhead is omitted. In addition, in FIG. 5, the illustration of the transport robot (3), etc. is omitted.

The housing (2) has an overall rectangular parallelepiped shape. As illustrated in FIGS. 3 to 5, the housing (2) has pillars (21 to 26) and partition walls (31 to 36). The partition walls (31 to 36) are installed on the pillars (21 to 26) extending in the vertical direction, and the internal space of the housing (2) is substantially sealed from the external space.

More specifically, as illustrated in Fig. 4, in the front end of the housing (2), pillars (21 to 24) are arranged in a standing arrangement from the left to the right. Pillars (22, 23) arranged between pillars (21) and (24) are shorter than pillars (21) and (24). Pillars (25, 26) are arranged in a standing arrangement on both left and right sides of the rear end of the housing (2).

As illustrated in Fig. 3, a bulkhead (31) is arranged at the bottom of the housing (2), and a bulkhead (32) is arranged at the ceiling. As illustrated in Fig. 4, a bulkhead (33) is arranged at the front end, a bulkhead (34) is arranged at the rear end, a bulkhead (35) is arranged at the left end, and a bulkhead (36) is arranged at the right end. At the right end of the housing (2), a loading section (53) (see Fig. 3) on which an aligner (54) described later is loaded is installed. The aligner (54) and the loading section (53) are also accommodated inside the housing (2) (see Fig. 4).

As illustrated in FIGS. 3 and 5, a support plate (37) extending horizontally is arranged on the upper portion (above the pillars (22, 23)) within the housing (2). As a result, the interior of the housing (2) is divided into the aforementioned return room (41) formed on the lower side and the FFU installation room (42) formed on the upper side. An FFU (fan filter unit) (44) described later is arranged within the FFU installation room (42). An opening (37a) is formed in the central portion in the front-rear direction of the support plate (37) to connect the return room (41) and the FFU installation room (42). In addition, the bulkheads (33 to 36) of the housing (2) are divided into a lower wall for the return room (41) and an upper wall for the FFU installation room (42) (for example, see the bulkheads (33a, 33b) of the front end and the bulkheads (34a, 34b) of the rear end in Fig. 5).

Next, the internal configuration of the housing (2) will be described. Specifically, the configuration for circulating nitrogen within the housing (2), its surrounding configuration, and the devices placed within the return room (41) will be described.

The configuration for circulating nitrogen within the housing (2) and its surrounding configuration will be described using FIGS. 3 to 5. As shown in FIG. 5, a circulation path (40) for circulating nitrogen is formed inside the housing (2). The circulation path (40) is composed of a return room (41), an FFU installation room (42), and a return path (43). In summary, in the circulation path (40), clean nitrogen is sent downward from the FFU installation room (42), reaches the lower end of the return room (41), then rises through the return path (43) and returns to the FFU installation room (42) (see arrows in FIG. 5). This will be described in detail below.

In the FFU installation room (42), an FFU (44) disposed on a support plate (37) and a chemical filter (45) disposed on the FFU (44) are installed. The FFU (44) has a fan (44a) and a filter (44b). The FFU (44) discharges nitrogen in the FFU installation room (42) downward by the fan (44a), while removing particles (not shown) contained in the nitrogen by the filter (44b). The chemical filter (45) is for removing, for example, an active gas or the like that is brought into the circulation path (40) from the substrate processing device (6). The nitrogen purified by the FFU (44) and the chemical filter (45) is discharged from the FFU installation room (42) to the return room (41) through an opening (37a) formed in the support plate (37). Nitrogen sent to the return room (41) forms a laminar flow and flows downward.

The return path (43) is formed on pillars (21 to 24) (pillars (23) in FIG. 5) and a support plate (37) arranged at the front end of the housing (2). That is, the pillars (21 to 24) are hollow, and nitrogen-permeable spaces (21a to 24a) are formed therein, respectively (see FIG. 4). That is, the spaces (21a to 24a) each constitute a return path (43). The return path (43) is connected to the FFU installation room (42) by an opening (37b) formed at the front end of the support plate (37) (see FIG. 5).

The return path (43) will be described in more detail with reference to Fig. 5. In addition, although Fig. 5 illustrates a pillar (23), the same applies to other pillars (21, 22, 24). An introduction duct (27) is installed at the lower end of the pillar (23) to facilitate the introduction of nitrogen in the return chamber (41) into the return path (43) (space (23a)). An opening (27a) is formed in the introduction duct (27), so that nitrogen reaching the lower end of the return chamber (41) can be introduced into the return path (43). An expanded portion (27b) is formed at the upper end of the introduction duct (27), which becomes wider toward the rear as it goes downward. A fan (46) is arranged below the expanded portion (27b). The fan (46) is driven by a motor (not shown) and sucks nitrogen that has reached the lower end of the return chamber (41) into the return path (43) (space (23a) in FIG. 5) and discharges it upward, returning the nitrogen to the FFU installation room (42). The nitrogen that has returned to the FFU installation room (42) is purified by the FFU (44) or the chemical filter (45) and discharged again to the return chamber (41). In this manner, nitrogen can be circulated within the circulation path (40).

In addition, as illustrated in Fig. 3, a supply pipe (47) for supplying nitrogen into the circulation path (40) is connected to the side of the FFU installation room (42). The supply pipe (47) is connected to a nitrogen supply source (111). A supply valve (112) capable of changing the amount of nitrogen supplied per unit time is installed in the middle of the supply pipe (47). In addition, as illustrated in Fig. 5, a discharge pipe (48) for discharging gas in the circulation path (40) is connected to the front end of the return room (41). The discharge pipe (48) is connected to an external space. A discharge valve (113) capable of changing the amount of gas discharged per unit time in the circulation path (40) is installed in the middle of the discharge pipe (48). The supply valve (112) and the discharge valve (113) are electrically connected to a control device (5) (see Fig. 2). By this, it is possible to appropriately supply and discharge nitrogen into the circulation path (40). For example, when the oxygen concentration in the circulation path (40) increases, the oxygen concentration can be lowered by temporarily supplying a large amount of nitrogen into the circulation path (40) from the supply source (111) through the supply pipe (47) and discharging oxygen together with nitrogen through the discharge pipe (48).

Next, the devices and the like placed in the transfer room (41) will be described using FIGS. 3 and 4. As shown in FIGS. 3 and 4, the above-described transfer robot (3), the control unit housing box (51), the measuring instrument housing box (52), and the aligner (54) are placed in the transfer room (41). The structure of the transfer robot (3) will be described later. The control unit housing box (51) is installed, for example, on the left side of the base (60) (see FIG. 3) of the transfer robot (3) and is positioned so as not to interfere with the arm mechanism (70) (see FIG. 3). The robot control unit (11) described above is housed in the control unit housing box (51). The measuring instrument housing box (52) is installed, for example, on the right side of the base (60) and is positioned so as not to interfere with the arm mechanism (70). The measuring instrument receiving box (52) is configured to accommodate measuring instruments (see Fig. 2) such as the oxygen concentration meter (55), pressure meter (56), and hygrometer (57) described above.

The aligner (54) is used to detect how much the holding and supporting position of the wafer (W) held and supported by the arm mechanism (70) (see Fig. 3) of the transport robot (3) is deviated from the target holding and supporting position. For example, there is a concern that the wafer (W) may move slightly inside the FOUP (100) (see Fig. 1) being transported by the above-described OHT (not shown). Therefore, the transport robot (3) first loads the unprocessed wafer (W) taken out from the FOUP (100) onto the aligner (54). The aligner (54) measures how much the wafer (W) is held and supported by the transport robot (3) at a position deviated from the target holding and supporting position, and transmits the measurement result to the robot control unit (11). The robot control unit (11) corrects the holding position by the arm mechanism (70) based on the above measurement results, controls the arm mechanism (70) to hold and support the wafer (W) at the target holding position, and returns it to the load lock chamber (6a) of the substrate processing device (6). As a result, the wafer (W) can be processed normally by the substrate processing device (6).

(Structure of a transport robot)

Next, the structure of the transport robot (3) (automatic device of the present invention) will be described using Fig. 6. Fig. 6 (a) is a cross-sectional view showing the internal structure of the transport robot (3). Fig. 6 (b) is a plan view of the robot hand (74) described later. As described above, the transport robot (3) has a base portion (60) and an arm mechanism (70) (holding support portion of the present invention).

As shown in (a) of Fig. 6, a case member (61), a support member (62), and a driving mechanism (63) are installed in the base portion (60). The support member (62) protrudes upward from within the case member (61) and supports the arm mechanism (70). The support member (62) is driven up and down by the driving mechanism (63).

The case member (61) is a tubular member extending vertically. The case member (61) is fixed within the return chamber (41). An opening (61a) is formed on the upper surface of the case member (61) for inserting a support (62) therethrough. The support (62) is a columnar member that protrudes upward from the inside of the case member (61) through the opening (61a). A gap is formed between the support (62) and the opening (61a). An arm mechanism (70) is installed at the upper end of the support (62).

The driving mechanism (63) has, as an example, a motor (64), a belt (65), a ball screw shaft (66), and a slider (67). The power of the motor (64) is transmitted to the ball screw shaft (66) through the belt (65), and the ball screw shaft (66) extending in the vertical direction rotates. When the ball screw shaft (66) rotates, the slider (67) screw-coupled to the ball screw shaft (66) moves up and down, thereby moving the support (62) up and down.

The motor (64) is a general AC motor having a rotation shaft (64a). The motor (64) is controlled by the robot control unit (11) (see Fig. 2). A pulley (not shown) is installed at the tip of the rotation shaft (64a), and a belt (65) is wound around it. A ball screw shaft (66) extends in the vertical direction. A pulley (not shown) is installed at the lower end of the ball screw shaft (66), and a belt (65) is wound around it. A male screw (not shown) is formed on the ball screw shaft (66). A slider (67) is a member that supports the support (62). A female screw (not shown) that is screw-connected with the male screw of the ball screw shaft (66) is formed on the slider (67). The slider (67) is configured to be able to move up and down along a guide (not shown) that extends in the vertical direction in accordance with the rotation of the ball screw shaft (66). By means of the driving mechanism (63) having the above configuration, the support (62) is driven up and down. As a result, it is possible to hold and support the wafer (W) accommodated at each position in the up-and-down direction within the FOUP (100) by means of the arm mechanism (70).

As illustrated in (a) of Fig. 6, the arm mechanism (70) has, as an example, three arm members (71 to 73) and two robot hands (74). The arm mechanism (70) is supported from below by a support (62), and the arm members (71 to 73) rotate to horizontally move the robot hand (74) that holds and supports the wafer (W). Furthermore, only one robot hand (74) may be installed.

The arm members (71 to 73) are hollow members extending in a predetermined direction. That is, internal spaces (71a, 72a, 73a) are formed in the arm members (71, 72, 73), respectively. Furthermore, the internal spaces (71a, 72a, 73a) are connected to each other through a gap. The arm members (71, 72, 73) are arranged from below in this order. One end of the arm member (71) is rotatably connected to a support (62), and one end of the arm member (72) is rotatably connected to the other end. One end of the arm member (73) is rotatably connected to the other end of the arm member (72). A robot hand (74) is rotatably connected to the other end of the arm member (73). The arm members (71 to 73) and the robot hand (74) are each driven to rotate in the horizontal direction by a motor not shown.

As shown in (b) of Fig. 6, the robot hand (74) has a loading member (75), projections (76a to 76d), and a movable part (77) (a switching part of the present invention). A wafer (W) is loaded on the loading member (75) extending in the extension direction of the robot hand (74) (see (b) of Fig. 6). The wafer (W) is gripped by projections (76a, 76b) arranged on the front end side of the loading member (75), projections (76c, 76d) arranged on the base end side of the loading member (75), and a pressing part (78) installed on the front end of the movable part (77). In this way, the wafer (W) is held and supported by the robot hand (74). The movable part (77) is moved in the extension direction of the robot hand (74) by a cylinder (79) built into the robot hand (74). The rod (not shown) of the cylinder (79) is configured to be extendable in the extension direction by supplying nitrogen from a different supply source (114) than the above-described supply source (111) (see FIG. 3). When nitrogen is supplied to the cylinder (79) and the pressing portion (78) is positioned at the front end (see the solid line in FIG. 6 (b)), the wafer (W) is pressed and held by the pressing portion (78) (holding and supporting state). When nitrogen is not supplied to the cylinder (79) and the pressing portion (78) is positioned at the base end (see the two-dot chain line in FIG. 6 (b)), the holding and supporting state is released (released state).

When applying the transport robot (3) having the above configuration to the EFEM (1), the following problems arise. First, when the support (62) in the base (60) is driven up and down by the driving mechanism (63), particles are generated inside the case member (61). There is a concern that the generated particles may leak into the transport room (41) through the gap between the opening (61a) and the support (62). In particular, when the support (62) is driven downward by the driving mechanism (63) as indicated by the arrow in Fig. 6 (a), there is a concern that the nitrogen inside the case member (61) is extruded upward, so that the nitrogen including particles may be scattered into the transport room (41) through the gap.

In addition, when the movable part (77) of the robot hand (74) is driven by the cylinder (79), there is a concern that particles may be generated within the return room (41). If exhaust is provided to remove these particles, nitrogen will be discharged from within the return room (41), and thus, it will be necessary to supplement nitrogen from the supply source (111), which may increase costs.

In addition, in a configuration where the internal space (71a to 73a) of the arm member (71 to 73) is not completely sealed with respect to the return room (41), for example, when the return room (41) is released to the atmosphere during maintenance, the internal space (71a to 73a) is also released to the atmosphere, and there is a risk that oxygen, moisture, etc. may enter. In this case, if it takes time to replace the internal space (71a to 73a) with nitrogen when restarting after maintenance, there is a risk that production efficiency may decrease. Therefore, in order to solve these problems, the EFEM (1) has the following configuration.

(Nitrogen discharge path in transport robots, etc.)

The nitrogen discharge path in the transport robot (3) will be described using Figs. 7 and 8. Fig. 7 is a schematic diagram showing the nitrogen supply path and discharge path to the circulation path (40). Fig. 8 is a diagram showing the nitrogen discharge port in the transport robot (3).

First, a configuration for discharging nitrogen containing particles from within the case member (61) of the transport robot (3) will be described. As illustrated in FIGS. 7 and 8, an outlet (61b) for discharging nitrogen to a circulation path (40) is formed on the side of the case member (61). In addition, a discharge unit (81) for discharging nitrogen from within the case member (61) to the circulation path (40) is installed within the housing (2). The discharge unit (81) has a connection path (82a) formed by a connection pipe (82), a fan (83) (a fan of the present invention), and a motor (84) (a fan driving device of the present invention). The connection path (82a) connects the case member (61) and the return path (43). The connection path (82a) extends from the discharge port (61b) of the case member (61) and is connected to the upstream end of the return path (43) in the nitrogen flow direction (more specifically, upstream of the fan (46). In other words, the case member (61) and the return path (43) are directly connected without passing through the return chamber (41). The fan (83) is arranged near the discharge port (61b) and is driven to rotate at a constant rotation speed by a motor (84).

By the above configuration, nitrogen inside the case member (61) is discharged to the return path (42) through the discharge port (61b) (see arrows (201, 202) in Fig. 8). This prevents the return room (41) from being contaminated by particles generated inside the case member (61). In addition, since the nitrogen inside the case member (61) is not discharged directly to the outside of the housing (2), there is no need to immediately replenish the amount of nitrogen discharged from the case member (61), thereby suppressing an increase in the amount of nitrogen supplied. In addition, since the nitrogen inside the case member (61) is reliably sent to the return path by the airflow generated by the fan (83), leakage of nitrogen inside the case member (61) from the gap between the opening (61a) (see Fig. 6 (a)) and the support (62) (see Fig. 6 (a)) is suppressed.

Next, a configuration for removing particles generated when the movable part (77) of the robot hand (74) is driven by the cylinder (79) will be described. As illustrated in Fig. 7, the EFEM (1) has a suction part (86) that suctions and removes particles generated by the operation of the cylinder (79). The suction part (86) has an ejector (87) that suctions and removes particles by nitrogen supplied from a different supply source (115) (an inert gas supply source for particle removal of the present invention) than the supply sources (111, 114) described above (see Fig. 6 (b)). The ejector (87) has a nozzle (87a), a diffuser (87b), and a suction port (87c). The ejector (87) generates a negative pressure in the suction port (87c) by the flow of nitrogen ejected from the nozzle (87a) toward the diffuser (87b). The nozzle (87a) is connected to a supply path (88a) through which nitrogen supplied from a supply source (115) flows. The diffuser (87b) is connected to a discharge path (88b) for sending nitrogen to the circulation path (40). The downstream end of the discharge path (88b) is connected to the middle part of the connection path (82a) and joins the discharge section (81). The suction port (87c) is connected to a suction path (88c) extending from the vicinity of the cylinder (79).

In the suction unit (86) having the above configuration, nitrogen is supplied from the supply source (115) to the ejector (87), so that particles generated by the operation of the cylinder (79) are sucked in through the suction path (88c). In addition, the supplied nitrogen, together with the sucked particles, flows into the connection path (82a) through the discharge path (88b) and is then sent out to the return path (43). In other words, the nitrogen is not discharged as is into the external space of the housing (2), but is first introduced into the circulation path (40).

Next, a configuration for nitrogen replacement in the internal space (71a to 73a) (see Fig. 8) of the arm members (71 to 73) of the transport robot (3) will be described. As shown in Figs. 7 and 8, the transport robot (3) is provided with a replacement path (91) passing through the interior of the arm members (71 to 73). The replacement path (91) has a supply path (91a) and an internal passage (91b) (see Fig. 8). The supply path (91a) extends from a supply source (116) (an inert gas supply source for purge of the present invention) different from the supply sources (111, 114, 115) described above, and nitrogen supplied from the supply source (116) flows. The supply path (91a) is formed by, for example, a flexible tube or the like, and passes through the interior of the case member (61) and the interior of the female members (71 to 73). The tip of the supply path (91a) is arranged within the interior space (73a) of the uppermost female member (73). That is, nitrogen is first supplied into the interior space (73a) of the female member (73) through the supply path (91a). The internal passage (91b) is a passage for nitrogen that includes the interior spaces (71a to 73a) and is arranged downstream of the supply path (91a) in the nitrogen flow direction.

An example of an internal passage (91b) will be described with reference to Fig. 8. Inlets (71b to 73b) for introducing nitrogen and outlets (71c to 73c) for discharging gas are formed in the female members (71 to 73), respectively. More specifically, they are as follows. That is, the tip of the supply passage (91a) is installed near the inlet (73b) formed in the lower portion of the female member (73). The internal space (73a) of the female member (73) is connected to the supply passage (91a). The internal space (72a) of the female member (72) is connected to the internal space (73a) through the outlet (73c) and the inlet (72b). The internal space (71a) of the female member (71) is connected to the internal space (72a) through the outlet (72c) and the inlet (71b). The internal space (71a) and the interior of the case member (61) are connected through the outlet (71c). Accordingly, nitrogen supplied from the supply source (116) to the internal space (73a) through the supply path (91a) passes through the internal spaces (73a, 72a, 71a) in that order, flows into the interior of the case member (61), and is sent to the return path (42) through the outlet (61b).

Next, a method for replacing the gas inside the transport robot (3) will be described. First, for example, when the EFEM (1) is started, nitrogen is supplied from the supply source (116) (see FIG. 7, the supply source of the present invention) to the internal space (73a) of the arm member (73) through the supply path (91a), and nitrogen is supplied to the inside of the case member (61) through the internal spaces (72a, 71a) (see FIG. 8). In addition, the gas inside the case member (61) is sent to the return path (43) through the discharge port (61b). As a result, the gas inside the case member (61) is quickly replaced with nitrogen. Then, after the oxygen concentration inside the transport room (41) becomes lower than a predetermined value (e.g., lower than 100 ppm), the supply of nitrogen from the supply source (116) is stopped. Normally, by rotating the fan (83), gas is introduced from the return chamber (41) into the case member (61) through an opening (61a) or the like. Then, the gas within the case member (61) is discharged to the return path (43). As a result, the emission of particles into the return chamber (41) is suppressed.

As described above, a connection path (82a) connecting the case member (61) of the transport robot (3) and the return path (43) is installed. Therefore, even if particles are generated in the internal space of the case member (61), the particles are discharged to the return path (43) through the connection path (82a), thereby preventing the particles from leaking into the transport room (41). In addition, the particles discharged to the return path (43) are removed by the FFU (44) arranged on the downstream side of the return path (43). Therefore, contamination of the transport room (41) by particles generated in the internal space of the case member (61) can be prevented. In addition, in this configuration, since the nitrogen inside the case member (61) is not discharged to the outside as it is, there is no need to supplement the amount of nitrogen discharged from inside the case member (61), thereby preventing an increase in the supply amount of nitrogen, thereby preventing an increase in costs. Accordingly, in the EFEM (1) of the type that circulates nitrogen within the housing (2), it is possible to suppress the emission of particles into the return chamber (41) while suppressing an increase in cost. In addition, for example, by actively supplying an inert gas from the supply source (116) when the EFEM (1) is started, the gas within the case member (61) can be quickly replaced. In addition, by stopping the supply of nitrogen from the supply source (116) after the oxygen concentration within the return chamber (41) falls below a predetermined value, it is possible to suppress an increase in cost.

In addition, since the nitrogen inside the case member (61) can be reliably sent to the return path (43) by the airflow generated by the fan (83), the nitrogen inside the case member (61) can be prevented from leaking from the gap between the opening (61a) and the support (62), and thus the emission of particles into the return room (41) can be more reliably prevented.

In addition, since particles generated near the cylinder (79) are sucked in by the ejector (87), and nitrogen supplied from the supply source (115) is discharged together with the particles to the return path (43), the nitrogen circulates as is. In addition, the particles are removed by the FFU (44). Therefore, compared to a configuration that performs vacuum exhaust, an increase in cost due to nitrogen supplementation can be suppressed.

In addition, since inlets (71b to 73b) and outlets (71c to 73c) are formed in the female members (71 to 73), respectively, the time required for gas replacement in the internal space (71a to 73a) of the female members (71 to 73) can be shortened compared to the case where these are not formed, thereby suppressing a decrease in production efficiency.

Next, a description will be given of a modified example that has been modified from the above embodiment. However, for those having a configuration similar to that of the above embodiment, the same reference numerals are assigned and the description thereof is omitted as appropriate.

(1) In the above embodiment, the fan (83) is driven to rotate at a constant rotation speed by the motor (84), but this is not limited thereto. When the drive mechanism (63) drives the support (62) up and down inside the case member (61), there is a concern that particles may easily be generated. Therefore, as illustrated in Fig. 9, the transport robot (3a) may have a fan control unit (12) (control unit of the present invention) that controls the motor (84). In addition, the fan control unit (12) may increase the rotation speed of the fan (83) when the drive mechanism (63) is operating compared to when the drive mechanism (63) is not operating. Accordingly, by increasing the rotation speed of the fan (83) and increasing the wind speed when the drive mechanism (63) is operating, the nitrogen inside the case member (61) can be reliably sent to the return path (43). In addition, when the driving mechanism (63) is not operating, the power consumption of the motor (84) can be reduced by slowing down the rotation speed of the fan (83). In addition, the control device (5) (see Fig. 1, etc.) or the robot control unit (11) (see Fig. 2, etc.) may be configured to control the rotation speed of the fan (83).

(2) In the embodiments up to the above, the case member (61) of the transport robot (3) and the return path (43) are connected by a connection path (82a) (i.e., the transport robot (3) corresponds to the automatic device of the present invention), but this is not limited thereto. For example, the present invention may be applied to the aligner (54) described above. In this case, the aligner (54) also corresponds to the automatic device of the present invention. Hereinafter, a specific description will be made using Fig. 10. Fig. 10 (a) is a partial cross-sectional view showing the structure of the aligner (54). Fig. 10 (b) is a plan view of the aligner (54) and its surroundings.

The configuration of the aligner (54) will be briefly described. As illustrated in Fig. 10 (a), the aligner (54) has a case member (92), a holding support member (93), a support member (94), a motor (95) (driving mechanism of the present invention), and a camera (96). An opening (92a) is formed in the case member (92). A holding support member (93) for holding and supporting a wafer (W) is arranged on the outside of the case member (92). The support member (94) supports the holding support member (93) from below. The motor (95) drives the holding member (94) to rotate. The camera (96) photographs the outer edge of the wafer (W) that is rotating while being held and supported by the holding support member (93). By this, the aligner (54) measures how much the wafer (W) is held and supported by the return robot (3) at a position that is deviated from the target holding and support position, and transmits the measurement result to the robot control unit (11).

Since the support member (94) is driven to rotate by the motor (95), particles may be generated within the case member (92). Therefore, as illustrated in (a) of Fig. 10, a nitrogen exhaust port (97) is formed in the case member (92). The exhaust port (97) is connected to a connection path (98a) formed by a connection pipe (98). As illustrated in (b) of Fig. 10, the connection path (98a) connects the case member (92) and the return path (43). In addition, a fan (99) may be arranged in the connection path (98a).

(3) In the embodiments up to the above, the space (21a to 24a) formed inside the pillars (21 to 24) is the return path (43), but this is not limited to this. That is, the return path (43) may be formed by another member.

(4) In the embodiments up to the above, nitrogen is used as the inert gas, but this is not limited to this. For example, argon or the like may be used as the inert gas.

1: EFEM
3: Return robot (automatic device)
12: Fan control unit (control unit)
43: Return route
44: FFU (Fan Filter Unit)
54: Aligner (automatic device)
61: Absence of case
61a: Opening
62: Support
63: Drive mechanism
70: Arm mechanism (holding support)
71, 72, 73: Absence of cancer
71a, 72a, 73a: Interior space
71b, 72b, 73b: Inlet
71c, 72c, 73c: Outlet
74: Robot Hand
77: Movable part (transition part)
82a: Access route
83: Fan
87: Ejector
92: Absence of case
93: Holding support
94: Support
95: Motor (driving mechanism)
98a: Access route
W: wafer (substrate)

Claims (8)

An EFM having a return room in which an inert gas purified by a fan filter unit for removing particles flows in a predetermined direction, and a return path for returning the inert gas from the downstream side of the return room in the predetermined direction to the fan filter unit, and configured so that the inert gas circulates.
An automatic device is provided that is placed in the above return room and performs a predetermined operation while holding and supporting a substrate.
The above automatic device,
A case member with an opening formed therein,
A holding support portion arranged on the outside of the case member and supporting the substrate,
Supporting the above-mentioned holding support, and a support inserted and penetrated into the above-mentioned opening,
It is accommodated in the above case member and has a driving mechanism that drives the support member,
A connection path connecting the above case member and the above return path is installed,
In the above return path, a first fan is installed to send gas within the return path to the downstream side in the predetermined direction,
The above connection path is characterized in that it is connected to the return path on the downstream side of the return room and on the upstream side of the first fan in the above-mentioned direction. In the first paragraph,
An EFM characterized in that it further comprises a second fan that sends an inert gas within the case member to the return path through the connection path. In the second paragraph,
A fan driving device that rotates and drives the second fan,
Further comprising a control unit for controlling the above fan driving device,
The above control unit,
An EFM characterized in that when the driving mechanism is operating, the rotation speed of the second fan is increased compared to when the driving mechanism is not operating. In the first paragraph,
As the above automatic device, a return robot for returning the substrate is installed,
The above case member is fixed within the return room,
As the above holding support, a female mechanism is installed to hold and support the substrate and return it in a horizontal direction,
As the above support, a pillar supporting the above-mentioned arm mechanism is installed,
The above-mentioned support is characterized in that it is driven up and down by the driving mechanism. In paragraph 4,
The above-mentioned female device has a hollow female member,
An EFM characterized in that the female member is provided with an inlet for introducing the inert gas supplied from an inert gas supply source for purge into the internal space of the female member, and an outlet for discharging the gas from the internal space of the female member. In the first paragraph,
As the above automatic device, an aligner is installed to detect whether the holding and supporting position of the substrate held and supported by the return robot that returns the substrate is deviated from the target holding and supporting position,
The above case member is fixed within the return room,
As the above support, a support member is installed to support the above holding support member,
The above-mentioned support is characterized in that it is rotationally driven by the above-mentioned driving mechanism. In paragraph 6,
The above aligner further includes a photographing member that photographs the outer edge of the substrate while it is rotated while being held and supported by the holding support member. A gas substitution method in an EFM, which is applied to an EFM described in any one of claims 1 to 7,
By supplying the inert gas from the source of the inert gas to the inside of the case member and sending the gas from the inside of the case member to the return path, the gas inside the case member is replaced,
A gas replacement method in an EFM, characterized in that after the gas atmosphere within the return chamber becomes lower than a predetermined oxygen concentration, the supply of the inert gas from the supply source is stopped, and the gas within the return chamber is introduced into the interior of the case member and sent to the return path.