JP5385425B2 - Inspection device and mini-environment structure - Google Patents

Description

  The present invention relates to an inspection device and a mini-environment structure for cleaning a specific space.

  For example, in the manufacturing process of semiconductors, liquid crystals, hard disks and the like, if a large amount of dust is present in the work environment, the dust adheres to work-in-progress and causes a decrease in yield. Therefore, in order to avoid the adhesion of dust to work-in-progress as much as possible, equipment that operates in an atmospheric environment among inspection devices and manufacturing devices used in the manufacturing process is, for example, a fan filter unit (hereinafter referred to as FFU). Conventionally, a mini-environment structure has been made by placing it in a specific space (hereinafter referred to as a clean room as appropriate) maintained at a positive pressure with respect to the surroundings (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-200669

  In general, the mini-environment structure as described above is constructed in a clean room, and the outside air itself fed into the clean room through the FFU is clean to some extent. However, in the conventional mini-environment structure, the air sent from the outside is only filtered once by the FFU filter before being sent to the clean room, so the cleanliness in the clean room is equal to the cleanliness of the clean room in the outside. Depends on FFU filter performance. Therefore, when the cleanliness of the clean room is reduced due to some disturbance or the like, there may be a case where the cleanliness in the clean room cannot be sufficiently maintained due to the influence.

  The present invention has been made in view of the above, and an object of the present invention is to provide an inspection apparatus and a mini-environment structure capable of suppressing the influence of the cleanliness of the outside world and maintaining the target cleanliness of a specific space. .

In order to achieve the above object, the present invention includes a first semi-clean chamber, a first fan filter unit for introducing purified air into the first semi-clean chamber, and a first semi-clean chamber. and also highly clean clean chamber, a clean chamber cleanliness low second semi-clean chamber than clean chamber covers, the cleaned air and a second fan filter unit to be introduced into the clean room, the first A shutter for communicating the semi-clean chamber and the clean chamber, a differential pressure acquisition unit for obtaining a differential pressure between the outside and the first semi-clean chamber, and a differential pressure between the first semi-clean chamber and the clean chamber , A timer for obtaining a time during which at least one of the first and second fan filter units rotates, and a control unit, wherein the control unit synchronizes with the opening operation of the shutter. At least one of the rotational speed change predetermined time, the pressure outside the unit < Characterized in that the pressure in the pressure <cleaning chamber portion of the first semi-clean chamber.

  ADVANTAGE OF THE INVENTION According to this invention, the influence of the external cleanliness can be suppressed and the target cleanliness of a specific space can be maintained.

1 is a conceptual diagram of a mini-environment device according to an embodiment of the present invention. It is the block diagram which extracted the principal part of the control apparatus. It is a flowchart showing the rotation speed control procedure of the fan of a control apparatus. It is a conceptual diagram of the mini-environment apparatus which concerns on the 1st modification of this invention. It is a conceptual diagram of the mini-environment apparatus which concerns on the 2nd modification of this invention. It is a conceptual diagram of the mini-environment apparatus which concerns on the 3rd modification of this invention. It is a conceptual diagram of the mini-environment apparatus which concerns on the 4th modification of this invention. 1 is an external view of an optical appearance inspection apparatus to which a mini-environment apparatus of the present invention is applied. It is the horizontal sectional view seen from the top plate side of the appearance inspection apparatus of FIG. It is sectional drawing which represented typically the XX cross section in FIG. It is the functional block diagram which extracted the principal part of the control apparatus. It is the horizontal sectional view which represented typically the composition of other inspection devices to which the mini-environment device of the present invention was applied. It is sectional drawing by the XIII-XIII cross section in FIG. It is the horizontal sectional view which represented typically the structure of the semiconductor manufacturing apparatus to which the mini environment apparatus of this invention was applied. It is sectional drawing by the XV-XV cross section in FIG.

Embodiments of the present invention will be described below with reference to the drawings.
The mini-environment apparatus of the present invention is intended to clean a specific space (clean room), and is used, for example, for structuring a mini-environment of an inspection apparatus / manufacturing apparatus used in a manufacturing process of a semiconductor, liquid crystal, hard disk or the like. Is.

FIG. 1 is a conceptual diagram of a mini-environment device according to an embodiment of the present invention. The dotted arrows in the figure illustrate the air flow.
The mini-environment device 1 shown in FIG. 1 measures the pressure of each part, the housing 2, the outer FFU 3 attached to the housing 2, the clean chamber 4a disposed in the housing 2, the inner FFU 5 provided in the clean chamber 4a. And a control device 7 (see FIG. 2) for controlling the FFUs 3 and 5 based on the detection results of the pressure gauges 6a to 6c.

  The casing 2 forms the outermost part of the mini-environment structure, and is placed on the floor surface of the installation place via support means such as an adjuster or a gantry (or directly). The installation location of the housing 2 is preferably as clean as possible such as a clean room, but is not limited to this and can be installed in a normal room.

  Further, the wall surface of the housing 2 is provided with at least one intake port 2b as an air inflow port for making the internal space positive with respect to the outside world (the surrounding space of the housing 2). The place where the air inlet 2b is provided may be any wall surface of the housing 2, but the ceiling surface of the housing 2 is more preferable. The outer FFU 3 described above is attached to the intake port 2b.

  The outer FFU 3 is configured by configuring the outer dust collection filter 3a and the outer fan 3b as one unit. As the outer dust collection filter 3a, for example, a high performance air filter such as an ULPA filter (Ultra Low Penetration Air Filter) or a HEPA filter (High Efficiency Particulate Air Filter) is preferably used. The dust is removed from the outside air sent into the housing 2 from the outside. The outer fan 3b induces a flow of air for making the inside of the housing 2 have a positive pressure with respect to the outside. The outside fan 3b positively draws outside air into the housing 3 through the outside dust collecting filter 3a. Send it in. At this time, if necessary, the housing 2 may be provided with an exhaust port in a range where the exhaust amount is smaller than the intake amount.

  With the above configuration, the housing 2 is prevented from intruding dust from the outside by making the internal space positive with respect to the outside even if there is a place other than the air inlet 2b where complete confidentiality is not maintained. ing. Thus, the internal space of the housing 2 is a clean space with respect to the outside world, and is clean enough to install a device that requires a clean work environment such as an atmospheric transfer device of a semiconductor inspection device, for example. Is preserved.

  On the other hand, the clean room 4a is a space that requires the highest degree of cleanness among the spaces in the atmospheric environment in the mini-environment device 1, and has a higher cleanliness than the internal space of the housing 2. It is. As described above, the internal space of the housing 2 is also a space having a sufficiently high degree of cleanness with respect to the outside world. However, for convenience, the semi-clean room 2a and the clean room 4a I will call it.

  The clean room 4a is installed on the floor surface of the housing 2 via, for example, a frame or some structure. Further, the wall surface 4 of the clean chamber 4a is provided with at least one intake port 4b as an air inlet for making the clean chamber 4a positive with respect to the semi-clean chamber 2a. The air inlet 4b faces the internal space of the housing 2 (semi-clean chamber 2a). The place where the air inlet 4b is provided may be any wall surface 4 of the clean chamber 4a, but more preferably the wall surface 4 on the upper side of the clean chamber 4a. The above-described inner FFU 5 is attached to the intake port 4b.

  The inner FFU 5 may have the same configuration as the outer FFU 3, and the inner dust collection filter 5a and the inner fan 5b are configured as one unit. The inner dust collection filter 5a is preferably an air filter such as a ULPA filter or a HEPA filter. The inner dust collection filter 5a covers the intake port 4b without any gap, and dust is collected from the air in the semi-clean chamber 2a fed into the clean chamber 4a from the intake port 4b. Remove. The inner fan 5b induces a flow of air for making the inside of the clean chamber 4a positive with respect to the inside of the semi-clean chamber 2a, and enters the clean chamber 4a through the inner dust collecting filter 5a. The air in 2a is sent in positively. At this time, if necessary, an exhaust port may be provided on the wall surface 4 of the clean chamber 4a in a range where the exhaust amount is smaller than the intake amount.

  With the above configuration, the clean room 4a has a positive pressure with respect to the semi-clean room 2a even if there is a place other than the air inlet 4b where complete confidentiality is not maintained, so that dust can enter from the semi-clean room 2a. Is prevented. In this way, the clean room 4a maintains a higher degree of cleanliness than the semi-clean room 2a.

  Of the pressure gauges 6a to 6c, the external pressure gauge 6a (external pressure measuring means) measures the pressure in the outside (surrounding space) of the housing 2. The mounting position is not particularly limited as long as the pressure around the housing 2 can be measured, but in the present embodiment, it is attached to the side wall surface of the housing 2. The internal pressure gauge 6b (internal pressure measuring means) measures the pressure of the semi-clean chamber 2a in the housing 2, and the mounting position is not particularly limited, but is attached to the side wall surface of the housing 2 in the present embodiment. It is. The clean chamber pressure gauge 6c (clean chamber pressure measuring means) measures the pressure in the clean chamber 4. Similarly, the mounting position is not particularly limited, but is attached to the wall surface 4 of the clean chamber 4a in this embodiment. It is.

  The pressure gauges 6a to 6c are connected to the control device 7 via differential pressure gauges 8a and 8b (see FIG. 2). The differential pressure gauge 8a measures a differential pressure ΔP1 obtained by subtracting the externally measured pressure Pa of the housing 2 by the external pressure gauge 6a from the measured pressure Pb in the semi-clean chamber 2a by the internal pressure gauge 6b. The differential pressure gauge 8b measures a differential pressure ΔP2 obtained by subtracting the measured pressure Pb in the semi-clean chamber 2a by the internal pressure gauge 6b from the measured pressure Pc in the clean room 4a by the clean room pressure gauge 6c.

FIG. 2 is a block diagram in which a main part of the control device 7 is extracted.
In FIG. 2, the control device 7 includes an input unit 7 a that appropriately converts a signal into a digital signal, inputs a storage unit 7 b that stores constants and programs necessary for control in advance, and programs and constants based on the input signals. An arithmetic unit 7c that executes various arithmetic processes, a temporary storage unit 7d that temporarily stores arithmetic results and intermediate values, a timer 7e that measures time, and an output unit that appropriately converts the calculated command signal into an analog signal and outputs it to a corresponding device 7f. This control device may be housed in the housing 2 or installed outside the housing 2.

FIG. 3 is a flowchart showing the fan speed control procedure of the control device 7.
As shown in FIG. 3, when the control device 7 inputs differential pressures ΔP1 and ΔP2 from the differential pressure gauges 8a and 8b in step 101, these control values are stored in the temporary storage unit 7d.

  In the following step 102, ΔP1 is read from the temporary storage unit 7d to determine whether ΔP1 is in an appropriate range. The upper limit value P1H (> 0) and the lower limit value P1L (> 0) of the appropriate range are stored in the storage unit 7b, and the calculation unit 7c compares the set values P1H and P1L read from the storage unit 7b with ΔP1. It is determined whether or not the semi-clean chamber 2a is maintained at a positive pressure by the set pressure with respect to the outside.

  If ΔP1 is not in the proper range and the determination in step 102 is not satisfied, the calculation unit 7c shifts the procedure to step 103 to calculate a command signal based on the current ΔP1 so as to return ΔP1 to the proper range, and serves as a fan control means. Output to control the fan speed. For example, the rotational speed of the outer fan 3b is increased when ΔP1 is smaller than the lower limit value P1L of the appropriate range, and the rotational speed of the outer fan 3b is decreased when ΔP1 is larger than the upper limit value P1H of the appropriate range. It is conceivable to decrease the rotational speed of the inner fan 5b when ΔP1 <P1L, and to increase the rotational speed of the inner fan 5b when ΔP1> P1H, or to perform combined control of the fans 3b and 5b.

  If ΔP1 is within the appropriate range and the determination at step 102 is satisfied, the procedure proceeds to step 104 to determine whether ΔP2 read from the temporary storage unit 7d is within the appropriate range. The upper limit value P2H (> 0) and the lower limit value P2L (> 0) of the appropriate range are stored in the storage unit 7b, and the calculation unit 7c compares the set values P2H and P2L read from the storage unit 7b with ΔP2. It is determined whether or not the clean chamber 4a is maintained at a positive pressure by the set pressure with respect to the semi-clean chamber 2a.

  If ΔP2 is not in the proper range and the determination in step 104 is not satisfied, the calculation unit 7c shifts the procedure to step 105 and calculates a command signal based on the current ΔP2 so as to return ΔP2 to the proper range. Output to control the fan speed. For example, the rotational speed of the inner fan 5b is increased when ΔP2 is smaller than the lower limit value P2L of the appropriate range, and the rotational speed of the inner fan 5b is decreased when ΔP2 is larger than the upper limit value P2H of the appropriate range.

  If ΔP2 is within the appropriate range and the determination in step 104 is satisfied, the control device 7 ends the procedure of FIG. And the control apparatus 7 keeps (DELTA) P1 and (DELTA) P2 in the appropriate range always preset by repeatedly performing this series of control procedures.

  As described above, in the present embodiment, a clean chamber 4a that requires higher cleanliness is provided in the semi-clean chamber 2a that is maintained at a positive pressure with respect to the outside by the outer FFU 3, and the clean chamber 4a is provided separately. The FFU 5 is provided so that air that has already been cleaned in the semi-clean chamber 2a is sent to the clean chamber 4a, and the inside of the clean chamber 4a is further maintained at a positive pressure with respect to the semi-clean chamber 2a. That is, the air for making the clean chamber 4a positive pressure is taken in from the semi-clean chamber 2a that has been cleaned with respect to the outside, and the double dust collecting filter is used before being sent from the outside to the clean chamber 4a. Will pass.

  For example, when a ULPA filter having a particle collection rate of 99.9995% or more with respect to particles having a particle size of 0.15 μm with a rated air volume is used for the dust collection filters 3a and 5a, the fan 3b has a rated air volume. , 5b, the dust per unit volume in the semi-clean chamber 2a is 0.0005% or less with respect to the outside. The dust per unit volume in the clean chamber 4a is 0.0005% or less with respect to that in the semi-clean chamber, that is, 0.000000025% or less with respect to that in the outside. In this case, even if 99.9995% of dust is removed due to some disturbance, the cleanliness of the outside air may be lowered so that the cleanliness of the semi-clean chamber 2a is insufficient as the target work environment. However, the influence of the cleanliness of the outside world on the cleanliness of the clean chamber 4a is almost zero. As described above, according to this embodiment, it is possible to suppress the influence of the cleanliness of the outside world and maintain the target cleanliness of a specific space.

  In the present embodiment, a configuration and an example in which two fans 3b and 5b are controlled by one control device 7 have been described. However, as a configuration in which a plurality of control devices that respectively control the fans 3b and 5b are provided. Also good. For example, a first control device that controls the rotation speed of the outer fan 3b so that ΔP1 is in the proper range, and a second control device that controls the rotation speed of the inner fan 5b so that ΔP2 is in the proper range may be adopted. .

  The upper limit value P1H for setting the pressure of the clean chamber 2a is set according to the specifications of the dust collection filter 3a, etc., and energy generated by the intrusion of dust from the suction port 2b, consumption of the dust collection filter 3a, and driving of the fan 3b. This value has been examined in advance so that the increase in consumption does not become larger than necessary. The lower limit value P1L is a value sufficient to suppress the entry of dust from the outside world. For example, about 1 to 2 Pa is one standard for P1L and P1H. P1H may be higher than P1L, or may be set to the same value as P1L. The same applies to P2L and P2H as well as P1L and P1H. P2L may be the same value as P1L or a different value. The same applies to P2H and P1H.

The mini-environment device of the present invention is not limited to the configuration as shown in FIG. 1, and various design changes can be made within the scope of the technical idea. That is, within the range of the configuration in which air that has already passed through the dust collection filter and further purified is sent through the dust collection filter to the clean room that requires the highest degree of cleanness among the spaces placed in the atmospheric environment. Various modifications can be considered.
Some typical modifications are illustrated below.

(First modification)
FIG. 4 is a conceptual diagram of a mini-environment device 1A according to a first modification of the present invention. Parts in FIG. 1 that are the same as or similar to those in FIG. 1 are assigned the same reference numerals as in FIG.

  In FIG. 1, the case where the clean room 4a is completely surrounded by the semi-clean room 2a has been described as an example. However, if the inside of the clean room 4a is maintained at a positive pressure with respect to the surroundings, at least the clean room 4a The intake port 4b only needs to face the semi-clean chamber 2a. Therefore, you may arrange | position so that the clean room 4a may contact the floor surface of the housing | casing 2 like FIG. In this case, the clean chamber 4a can be a space defined by a wall surface 4 configured in a box shape separately from the housing 2, and the space (semi-clean chamber 2a) in the housing 2 is defined as the partition wall 4. It can also be a space formed by partitioning. The latter has a configuration in which the floor surface of the clean room 4a also serves as the floor surface of the semi-clean room 2a, and the lower side of the clean room 4a is separated only by the floor surface of the housing 2. Other configurations are the same as those in FIG.

  Even in such an arrangement of the clean room 4a, the clean room 4a is arranged in the semi-clean room 2a, so that the air in the semi-clean room 2a can be fed into the clean room 4a via the inner FFU 5. Therefore, by controlling the FFUs 3 and 5 based on the measured pressures from the pressure gauges 6a to 6c to make the clean chamber 4a positive with respect to the surroundings, the embodiment described with reference to FIGS. Similar effects can be obtained.

(Second modification)
FIG. 5 is a conceptual diagram of a mini-environment device 1B according to a second modification of the present invention. Parts in FIG. 1 that are the same as or similar to those in FIG. 1 are assigned the same reference numerals as in FIG.

  This example is also a configuration example in which the clean room 4a is not completely surrounded by the semi-clean room 2a. In the case of this example, in addition to the floor surface of the clean room 4 a, one or more surfaces among the side surfaces facing in the horizontal direction are separated from the outside by the wall surface of the housing 2. Other configurations are the same as those in FIG.

  Even in such an arrangement of the cleaning chamber 4a, the same effect as that of the embodiment described with reference to FIGS. 1 to 3 is obtained by setting the cleaning chamber 4a to a positive pressure with respect to the surroundings as in the first modification. be able to.

(Third Modification)
FIG. 6 is a conceptual diagram of a mini-environment device 1C according to a third modification of the present invention. Parts in FIG. 1 that are the same as or similar to those in FIG. 1 are assigned the same reference numerals as in FIG.

  The structure in which at least the air inlet 4b of the clean room 4a faces the semi-clean room 2a is not limited to the structure in which the clean room 4a is disposed in the semi-clean room 2a, and the space in the housing 2 is not limited to the structure in this example. The structure which divides into the clean room 4a and the semi-clean room 2a by the partition 9 is also considered. The partition wall 9 is provided with an air inlet 4b and an inner FFU 5 that covers the air inlet 4b so that air in the adjacent semi-clean chamber 2a is sent into the clean chamber 4a. Of course, the outer FFU 3 that cleans the air from the outside and sends it to the semi-clean chamber 2a is provided on the wall surface of the housing 2 that is divided on the semi-clean chamber 2a side.

  Even in such a configuration, since clean air in the semi-clean chamber 2a is sent to the intake port 4b of the clean chamber 4a, as described above, by setting the clean chamber 4a to a positive pressure with respect to the surroundings, FIG. The same effect as the embodiment described in FIG. 3 can be obtained.

  In addition, in this example, although the internal space of one housing | casing 2 was divided into 2 by the partition 9, it can also be divided into three or more spaces. Moreover, it is also conceivable that a plurality of casings are connected and air is sent from an adjacent casing configured as a semi-clean chamber to a casing configured as a clean chamber via an FFU.

(Fourth modification)
FIG. 7 is a conceptual diagram of a mini-environment device 1D according to a fourth modification of the present invention. Parts in FIG. 1 that are the same as or similar to those in FIG. 1 are assigned the same reference numerals as in FIG.

  In each of the examples described above, the configuration in which at least the surface of the clean chamber 4a provided with the intake port is covered with one semi-clean chamber 2a is illustrated, but a plurality (two in this example but three or more may be used) as shown in FIG. ) Of semi-clean chambers 2aa and 2ab. In this case, it is not always necessary to define the vertical relationship of pressure between adjacent semi-cleaning chambers 2aa and 2ab. If the secrecy between the semi-cleaning chambers 2aa and 2ab is perfect and air flow does not occur between the two, What is necessary is just to set by the relationship with the clean room 4a, and what is necessary is just to control to a comparable pressure, when an air flow arises. In particular, when the cleanliness required as a work environment between the semi-clean chambers 2aa and 2ab is superior or inferior, the semi-clean chamber with the higher required cleanliness has a positive pressure with respect to the lower clean chamber. You can do that.

  Even in such a configuration, there is no difference in sending the air in the semi-clean chamber 2a to the clean chamber 4a via the inner FFU 5, and the same procedure as in FIG. 3 is performed based on the measured pressures from the pressure gauges 6a to 6d. By controlling the FFUs 3 and 5 and setting the clean chamber 4a to a positive pressure with respect to the surroundings, the same effects as those of the embodiment described with reference to FIGS.

  In the case of this example, outside air is taken into the semi-clean chambers 2aa and 2ab via the outer FFU 3, but, for example, the FFU 3 and the intake air of the semi-clean chamber 2ab are added to the partition 10 between the semi-clean chambers 2aa and 2ab. The port 2b may be moved so that air is sent from the adjacent semi-clean chamber 2aa to the semi-clean chamber 2ab via the FFU. If it does in that way, semi-clean room 2ab will become a positive pressure with respect to semi-clean room 2aa, and will become an environment with higher cleanliness than semi-clean room 2aa. The clean room 4a becomes an environment with higher cleanliness than the semi-clean room 2ab.

  In each of the above examples, the FFU is provided at each intake port. However, any one or all of them may be replaced with a configuration in which the air duct is connected to a dust collection filter provided at the intake port. it can. In this case, the fan of the air duct and the dust collection filter do not need to be unitized. That is, it is not always necessary to provide the FFU at the intake port. In each example, the air flow indicated by a dotted arrow is an example, and various design changes can be made according to the purpose and the configuration of the apparatus to be mini-environmented.

  In addition, the measurement result of the differential pressure gauge that takes the differential pressure of the measurement result of each pressure gauge is input to the control device 7. However, the measurement result of each pressure gauge is directly input to the control device 7, and the control device 7 For example, the configuration may be such that the differential pressure is calculated by the calculation unit 7c.

  Various methods such as a turbulent flow (conventional) method, a horizontal laminar flow (cross flow) method, and a vertical laminar flow (down flow) method can be applied to clean the semi-clean room and the clean room. In addition, a configuration has been adopted in which the differential pressure in the adjacent space is adjusted by the number of rotations of the fan. A configuration in which the differential pressure is adjusted by adjusting the exhaust flow rate is also conceivable.

  Next, some typical embodiments of various devices having a mini-environment structure by applying the mini-environment device of the present invention will be illustrated.

FIG. 8 is an external view of an optical appearance inspection apparatus to which the mini-environment apparatus of the present invention is applied.
The appearance inspection apparatus of the present embodiment is used for appearance inspection of, for example, a wafer, a liquid crystal, a hard disk, etc., and its mini-environment structure is the example of FIG. 7 in each example shown in FIGS. Close to. An intake port and FFUs 102 and 103 covering the air inlets are installed on the top plates of the two adjacent casings 100 and 101, respectively.

9 is a horizontal sectional view as seen from the top plate side of the appearance inspection apparatus in FIG. 8, and FIG. 10 is a sectional view schematically showing the XX section in FIG.
As shown in FIGS. 9 and 10, a housing 120 that defines a clean room is disposed inside the housing 101. An intake port and an FFU 121 that covers the intake port are provided on the side surface of the housing 120. That is, the internal space of the casings 100 and 101 into which the external air is sent through the FFUs 102 and 103 corresponds to the “semi-clean chamber” described above, and the casing 120 into which the air in the casing 101 is sent through the FFU 121. The internal space corresponds to the “clean room” described above.

  The casing 120 is arranged close to the wall surface separating the casings 100 and 101, and communicates with the space in the casing 100 when the shutter 122 is opened. The housing 100 also includes a gate 123 for taking the wafer 104 into and out of the outside.

  The appearance inspection apparatus includes an optical inspection apparatus 105 that inspects the appearance of a sample (in this example, a wafer) 104, a load port 107 on which a wafer pod 106 that houses a wafer 104 that is subjected to appearance inspection by the optical inspection apparatus 105 is placed, A transfer device 108 that transfers the wafer 104 between the load port 107 and the optical inspection device 105, a pre-alignment unit 109 that adjusts the circumferential direction of the wafer 104, and each mounted device are controlled and data processed. The controller 110 is provided.

  The optical inspection apparatus 105 includes an illumination optical system 111, a detection optical system 112, and an inspection stage 113. When the wafer 104 is placed on the inspection stage 113 by the transfer device 108, the inspection stage 113 is moved to the inspection position, and the illumination optical system 111 irradiates the wafer 104 with illumination light, and reflected light or scattered light from the wafer 104 is obtained. Is detected by the detection optical system 112.

  The transfer device 108 includes a handling arm 115 that picks up the wafer 104 and moves it in the horizontal plane and in the vertical direction, and a moving device 116 that slides and moves the handling arm 115 in one axis direction.

  The controller 110 processes an inspection data from the detection optical system 112 and generates image data, a storage unit 131 that stores various data, a control device 132 that controls each device, and an input for operation / input. A device 133, a display device 134 for displaying various settings, inspection images, and the like, an output device 135, an external storage device 136, and the like are provided.

  For example, when the wafer 104 is transferred from the wafer pod 106 to the optical inspection device 105 and the appearance of the wafer 104 is inspected, the moving device 116 is driven to move the handling arm 115 to the wafer pod 106 and the gate 123 is opened to open the wafer pod. The wafer 104 in 106 is picked up by the handling arm 115. If necessary, the handling arm 115 is moved toward the pre-alignment unit 109, the wafer 104 is mounted on the mounting unit 119 of the pre-alignment unit 109, and the circumferential position of the wafer 104 is aligned. The wafer 104 after alignment is picked up again by the handling arm 115 and moved to the position of the shutter 122. When the handling arm 115 is moved to the position of the shutter 122, the shutter 122 is opened and the wafer 104 is mounted on the inspection stage 113 of the optical inspection apparatus 105 by the handling arm 115. Put. Then, by moving the inspection stage 113, the wafer 104 is transported to an inspection position by the inspection optical system 112 and an appearance inspection of the wafer 104 is performed.

  When returning the inspected wafer 104 to the wafer pod 106, the procedure is the reverse of the above procedure (the pre-alignment procedure is omitted).

  In this case, after the wafer 104 is taken out from the wafer pod 106, the time that is handled by the optical inspection device 105 is longer than the time that is handled by the transfer device 108 among the time that is in the appearance inspection device. In that sense, it can be said that there is a higher risk of dust adhering to the wafer 104 during inspection than during conveyance.

  Therefore, in this embodiment, among the devices constituting the appearance inspection apparatus, the transport device 108, the pre-alignment unit 109, and the like are disposed in the housing 100, and the optical inspection device 105 is disposed in the housing 120. Etc. are arranged. In addition, the controller 110 and the like are arranged in the housing 101. And like the example previously shown in FIG. 7, the pressure gauges 6a to 6d of the respective spaces and the outside are provided at predetermined positions. The fans of the FFUs 102, 103, and 121 are controlled by the control device 132 based on the measurement results of the plurality of pressure measuring means including the pressure gauges 6 a to 6 d.

FIG. 11 is a functional block diagram in which the main part of the control device 132 is extracted.
In this embodiment, since the number of spaces is larger than the example shown in FIG. 1, the number of pressure gauges is also increased. For this reason, the differential pressure gauge that measures the differential pressure between adjacent spaces is increased accordingly, but is otherwise substantially the same as the control device shown in FIG. In addition, in this example, the opening signals Sg and Ss of the gate 123 and the shutter 122 are input to the input unit 132a. The configuration itself of the control device 132 is substantially the same as that of the control device 7 of FIG. 2, and the description of the components 7a to 7f of the control device 7 is omitted by replacing the reference symbols 132a to 132f.

The control procedure of the fans of the FFUs 102, 103, and 121 by the control device 132 can be the same as that shown in FIG. In the case of this example, the measurement result (external pressure) Pa of the pressure gauge 6a (external pressure measuring means), the measurement result of the pressure gauge 6b (first internal pressure measuring means) (semi-clean chamber (inside the casing 100)) Pressure) Pb, pressure gauge 6c (clean chamber pressure measuring means) measurement result (clean chamber (inside the casing 120) pressure) Pc, pressure gauge 6d (second internal pressure measuring means) measurement result (semi-clean chamber) The relationship between the pressure (in the housing 101) and Pd is as follows.
Pa <Pb <Pc
Pa <Pd <Pc
Moreover, it is sufficient to set the appropriate range of the differential pressure between adjacent spaces as described above.

  As described above, in this embodiment, the space in the casing 120 to which the wafer 104 is exposed for a relatively long time for appearance inspection is referred to as a “clean room”, and the inside of the casing 101 in which the air fed into the clean room exists. The space in the housing 100 where the wafer 104 is exposed for a long time after the clean chamber for the transfer operation and the like is referred to as a “quasi-clean chamber”.

  In this embodiment, when the gate 123 and the shutter 122 are opened, the confidentiality of the housing 100 and the housing 120 is lowered, and the differential pressure with respect to the adjacent spaces in the housings 100 and 120 is temporarily increased. It becomes easy to decrease. Even in such a case, the control of each fan according to the control procedure described above is continued by the fan control means, so that the differential pressure between adjacent spaces thereafter becomes stable.

  However, when it is necessary to maintain the differential pressure more strictly, the timing of opening the gate 123 and the shutter 122 is based on the processing procedure by the program stored in advance and the operation signal from the input device 133 by the operator. If signals Sg and Ss for instructing the opening of the gate 123 and the shutter 122 are input to the control device 132 via the input unit 132a, a specific value may be set before and after the gate 123 and the shutter 122 are actually opened. In order to cope with the decrease in the differential pressure, it is possible to adopt a configuration in which the rotational speed of the fan is increased or decreased for a certain time while measuring the time by the timer 132e.

12 is a horizontal sectional view schematically showing the configuration of another inspection apparatus to which the mini-environment apparatus of the present invention is applied, and FIG. 13 is a sectional view taken along the XIII-XIII section in FIG.
The inspection apparatus of the present embodiment exemplifies a CD-SEM or a review SEM using an electron microscope, and is used for, for example, observation of a semiconductor device. This example can be similarly applied to an FIB apparatus, FIB-SEM, TEM, and STEM.

  The mini-environment structure of this inspection apparatus is close to the example of FIG. 7 among the examples shown in FIGS. An intake port and FFUs 202 and 203 covering the air inlets are installed on the top plates of the two adjacent casings 200 and 201 that respectively form the atmospheric transfer unit and the main body of the examination room. A housing 220 that defines a load lock chamber is disposed inside the housing 201. The top plate of the housing 220 is provided with an air inlet and an FFU 221 that covers it. That is, the internal space of the casings 200 and 201 into which the outside air is sent through the FFUs 202 and 203 corresponds to the “semi-clean chamber”, and the inside of the casing 220 into which the air in the casing 201 is sent through the FFU 221. The space corresponds to a “clean room”.

  The casing 220 is disposed between the wall surface separating the casings 200 and 201 and the sample chamber 205a of the SEM 205, and when the gates 222a and 222b are opened, the internal space of the casing 200 and the space of the sample chamber 205a. And communicate with each other. In addition, the housing 200 includes a gate 223 for taking in and out the wafer 204 with the outside world.

  The inspection apparatus includes an SEM 205 for observing a sample (in this example, a wafer) 204, a load port 207 for placing a wafer pod 206 containing the wafer 204 observed by the SEM 205, and a wafer 204 between the load port 207 and the SEM 205. And a controller (not shown) for controlling each mounted device and processing data.

  The SEM 205 includes a sample chamber 205a, an electron source 211, a secondary electron detector 212, a sample stage 213, a vacuum pump 214 for evacuating the sample chamber 205a, and the like. The wafer 204 is placed on the sample stage 213 through the transfer robot 208, the load lock chamber 225, and a vacuum mounting means (not shown) in this order. Next, the wafer 204 is irradiated with an electron beam extracted from the electron source 211, and secondary electrons from the wafer 204 are detected by the secondary electron detector 212. At this time, the scanning signal of the electron beam and the detection signal of the secondary electron are synchronized, and an SEM image of the wafer 204 is obtained by an image generation unit or the like in the controller.

  The transfer robot 208 includes a transfer arm 215 that picks up the wafer 204 and moves it in the horizontal plane and in the vertical direction. The configuration of the controller is almost the same as in the first embodiment.

  The housing 225a as the load lock chamber 225 includes a shutter 217 that separates the atmospheric chamber on the FFU 221 side and a space in which the sample stage 216 is accommodated, the driving mechanism 218 of the shutter 217, and the sample stage 216 when the shutter 217 is closed. A vacuum pump 219 that evacuates the space on the side, a housing 220 that defines a clean chamber, and an exhaust port 226 are provided. Clean air from the FFU 221 is supplied to the clean chamber in the housing 220 and is then discharged from the exhaust port 226, and the differential pressure between the clean chamber in the housing 220 and the space in the housing 201 is maintained.

  For example, when the wafer 204 is transferred from the wafer pod 206 to the SEM 205 and the wafer 204 is observed by SEM, the gate 223 is opened, the wafer 204 in the wafer pod 206 is picked up by the transfer arm 215, the gate 222 a is opened, and the sample stage 216 is opened by the transfer arm 215. Place on top. After that, the gate 222 a on the atmosphere transfer unit side is closed, and the load pump chamber 225 is evacuated by the vacuum pump 216. At this time, the shutter 217 and the gate 222b are closed. When the load lock chamber 225 is in a vacuum state, the gate 222b on the SEM 205 side is opened, the wafer 204 is moved into the vacuum sample chamber 205a by the vacuum mounting means, and the wafer 204 on the sample stage 213 is irradiated with an electron beam. To obtain an SEM image.

When returning the inspected wafer 204 to the wafer pod 206, the gate 222b is opened, and the wafer 204 is moved onto the sample stage 216 by the vacuum mounting means. Next, the gate 222b is closed, and gas such as N ₂ or air whose dew point is controlled is supplied from a gas supply means (not shown) provided with a line filter (not shown), and a leak ( Air release). When the pressure in the load lock chamber 225 is detected by a pressure measuring means including a pressure sensor (not shown) and the pressure becomes approximately the same as or slightly lower than the pressure Pc in the housing 220, the drive mechanism 218 is driven. Thus, the shutter 217 is opened and clean air is supplied from the FFU 221 so that the periphery of the sample stage 216 is an atmospheric environment. The dust in the load lock chamber 225 that has been rolled up at the time of the leak is quickly settled by the supplied clean air, and the adhesion of dust to the surface of the wafer 204 is suppressed. Thereafter, the gate 222a is opened, the wafer 204 on the sample stage 216 is moved to the wafer pod 206 by the transfer robot 208, and the gate 223 is closed.

  As described above, in this embodiment, since the examination room is in a vacuum environment, the load lock chamber is defined by the housing 220 as a specific clean area among the work areas that can be in the atmospheric environment. The space in the housing 201 that holds the air sent to the load lock chamber 225 and the space in the housing 200 in which the transfer robot 208 is disposed are referred to as “semi-clean chamber”. Further, similarly to the example shown in FIG. 7, a plurality of pressure measuring means including pressure gauges 6a to 6d for measuring the pressures in the respective spaces and the outside are provided at predetermined positions.

The fans of the FFUs 202, 203, and 221 are controlled by a control device (not shown) based on the measurement results of the pressure gauges 6a to 6d. The control procedure of each fan of the FFUs 202, 203, and 221 by the control device can be the same as the above example. In the case of this example, the measurement result (external pressure) Pa of the pressure gauge 6a (external pressure measurement means), the measurement result of the pressure gauge 6b (first internal pressure measurement means) (semi-clean chamber (inside the casing 200)) Pressure) Pb, measurement result of pressure gauge 6c (clean chamber pressure measuring means) (pressure in clean chamber (inside housing 220)) Pc, measurement result of pressure gauge 6d (second internal pressure measurement means) (semi-clean chamber) The relationship between the pressure (in the casing 201) Pd is as follows.
Pa <Pb <Pc
Pa <Pd <Pc
Moreover, it is sufficient to set the appropriate range of the differential pressure between adjacent spaces as described above.

  In addition, as described in the first embodiment, the control for suppressing the change in the differential pressure when the shutter and gate open signals are input to the control device so that they are opened may be performed together. .

FIG. 14 is a horizontal sectional view schematically showing the configuration of a semiconductor manufacturing apparatus to which the mini-environment apparatus of the present invention is applied, and FIG. 15 is a sectional view taken along the XV-XV section in FIG.
A typical example of the semiconductor manufacturing apparatus according to this embodiment is a dry etching apparatus, a plasma CVD apparatus, or a thermal CVD apparatus. In this example, the mini-environment structure and the fan control are almost the same as those in the second embodiment.

  In the mini-environment structure of this manufacturing apparatus, a “quasi-clean chamber” is defined by a casing 300 into which air is sent from the outside by the FFU 302. A case 305 adjacent to the case 300 is a “semi-clean room” into which air is sent from the outside by the FFU 306. The casing 305 is provided with a “clean room” defined by the casing 301. Air is fed into the casing 301 as a clean room from the semi-clean room in the casing 300 by the FFU 303.

  The “semi-clean chamber” defined by the casing 305 includes a plurality of processing chambers 310 and a vacuum having a vacuum transfer robot 311 that transfers the wafer 304 between the processing chambers 310 and the load lock chamber (housing 301). A transfer chamber 312 and a load lock chamber (housing 301) are provided.

  In the “semi-clean chamber” defined by the casing 300, an atmospheric transfer robot 315 and an atmospheric transfer robot 315 that transfer the wafer 30 between the wafer pod 314 on the load port 313 adjacent to the casing 300 and the load lock chamber. A Y-axis unit 316 for moving the wafer in one axis direction, and an alignment unit 317 for aligning the circumferential position of the wafer 304 and the like.

  The housing 300 is provided with a gate 320 that separates the wafer pod 314 on the load port 313, and the space in the wafer pod 314 communicates with the space in the housing 300 by opening the gate 320. . Further, gates 321 and 322 are provided on the atmosphere transfer robot 315 side and the vacuum transfer robot 311 side in the housing 339 of the load lock chamber 350, respectively. The lock chambers 350 are separated from each other. A housing 301 for defining a clean chamber having an exhaust port 338 is disposed on the upper portion of the housing 339 of the load lock chamber 350, and the internal space is divided into two atmosphere chambers, an atmospheric chamber on the FFU 303 side and a vacuum chamber on the sample stage 323 side. A shutter 324 and a driving mechanism 325 for separating the space are provided. Clean air from the FFU 303 is supplied to the clean chamber in the housing 301 and is then discharged from the exhaust port 226, so that the differential pressure between the clean chamber in the housing 301 and the space in the housing 305 is maintained.

  The processing chamber 310 has a known configuration as this type, and includes an upper electrode (or gas supply head) 330, a lower electrode (or a susceptor provided with a heating means) 331, a matching box 332, and the like. In addition, vacuum pumps 335, 336, and 337 for evacuating these spaces are connected to the load lock chamber 350, the vacuum transfer chamber 312, and the processing chamber 310. Between the load lock chamber 350 and the vacuum pump 335, when the main exhaust pipe for maintaining the vacuum state in the load lock chamber 350 and the load lock chamber 350 are in the atmospheric state, the clean air of the FFU 303 is downward. An air conditioning exhaust pipe for forming an air flow is provided. The air conditioning exhaust pipe is provided with control means such as an air valve 352 and flow rate adjusting means such as a needle valve 355 so that the atmosphere in the load lock chamber 350 can be exhausted at a predetermined flow rate.

  For example, when the wafer 304 is transferred from the wafer pod 314 to the processing chamber 310 and a film forming process or an etching process is performed on the wafer 304, the bolt plate is opened and the wafer 304 in the wafer pod 314 is picked up by the atmospheric transfer robot 315, and the alignment unit. After the alignment at 317, the gate 321 is opened and the wafer 304 is placed on the sample stage 323 in the load lock chamber 350. Thereafter, the gate 321 on the atmospheric transfer robot 315 side is closed, and the vacuum pump 335 is evacuated through the main exhaust pipe to make the space around the sample stage 323 in the load lock chamber 350 into a vacuum state. At this time, the shutter 324 and the gate 322 are closed, and the inside of the vacuum transfer chamber 312 and the processing chamber 310 is in a vacuum state. When the periphery of the sample stage 323 is in a vacuum state, the shutter 322 on the vacuum transfer chamber 312 side is opened, the wafer 304 is placed on the lower electrode 331 in the processing chamber 310 via the vacuum transfer robot 311, and a predetermined amount is placed on the wafer 304. Apply the process.

When returning the processed wafer 304 to the wafer pod 314, the shutter 322 is opened, and the wafer 304 is moved onto the sample stage 323 in the load lock chamber 350 via the vacuum transfer robot 311 in a vacuum environment. Next, the gate 322 and the valve 351 are closed, and gas such as N ₂ or air whose dew point is controlled is supplied from the gas supply means 354 provided with the line filter 356, and the load lock chamber 350 is leaked (open to the atmosphere). To do. Gas supply means when the pressure in the load lock chamber 350 is detected by a pressure measuring means comprising a pressure sensor (not shown), and when the pressure is substantially the same as or slightly lower than the pressure Pc in the housing 301 The gas supply from 354 is stopped, the shutter 324 is opened, clean air from the FFU 303 is supplied, and the periphery of the sample stage 323 is set as an atmospheric environment. At substantially the same time as or before or after the shutter 324 is opened, the air valve 352 of the air-conditioning exhaust pipe is opened to form an airflow below the clean air. The dust in the load lock chamber 350 rolled up at the time of the leak is promptly replaced by the clean air, and the adhesion of dust to the surface of the wafer 204 is suppressed. Thereafter, the gate 321 is opened, the wafer 304 on the sample stage 323 is moved to the wafer pod 314 by the atmospheric transfer robot 315, and the gate 320 is closed.

  As described above, in this embodiment, since the processing chamber 310 is in a vacuum environment, the load lock chamber 350 is defined by the casing 301 as a specific cleaning region among the working regions that can be in the atmospheric environment. The space in the housing 305 that holds the air sent to the load lock chamber 350 and the space in the housing 300 in which the transfer robot 315 is disposed are referred to as “semi-clean rooms”. The pressure in the outside of the housing 300, the semi-clean chamber in the housing 300, the clean chamber in the housing 301, and the semi-clean chamber in the housing 305 are each measured by a plurality of pressure measuring means including pressure gauges 6a to 6d. Based on the measurement result, the fan control means controls the rotational speed of each of the FFUs 302, 303, and 306, and maintains the differential pressure between the outside, the semi-clean room, and the clean room.

The control procedure of each fan of the FFU 302, 303, 306 by the control device (not shown) can be the same as the above-mentioned example including the control of maintaining the differential pressure when the gate / shutter is opened. In the case of this example, the measurement result (external pressure) Pa of the pressure gauge 6a (external pressure measurement means), the measurement result of the pressure gauge 6b (first internal pressure measurement means) (pressure in the semi-clean chamber (housing 300)) ) Pb, measurement result of pressure gauge 6c (clean chamber pressure measuring means) (pressure of clean chamber (housing 301)) Pc, measurement result of pressure gauge 6d (second internal pressure measuring means) (quasi-clean chamber (housing) The magnitude relationship of the pressure) Pd of the body 305) is as follows.
Pa <Pb <Pc
Pa <Pd <Pc
As described above, some examples of applying the mini-environment device of the present invention to various devices have been illustrated using FIGS. 8 to 15 as examples, but the application examples are not limited thereto. For example, a coater / developer device that applies or develops a photosensitive agent on the wafer surface, a liquid crystal / hard disk inspection device, a heat treatment device that diffuses impurities, a low-pressure CDV device, and other precision devices that require a clean working environment. The present invention can be applied to an inspection apparatus and a manufacturing apparatus.

DESCRIPTION OF SYMBOLS 1 Mini environment apparatus 1A-D Mini environment apparatus 2 Case 2a Semi-clean room 2b Inlet 3 Outer FFU
3a Outside dust collecting filter 3b Outside fan 4 Housing 4a Clean room 4b Intake port 5 FFU
5a Inner dust collection filter 5b Inner fan 6a-d Pressure gauge 7 Controller 9 Partition 10 Partition 100 Housing 101 Housing 102 FFU
103 FFU
120 housing 121 FFU
122 Shutter 123 Gate 105 Optical Inspection Device 108 Transfer Robot 132 Control Device 200 Case 201 Case 202 FFU
203 FFU
205 SEM
208 Atmospheric transfer robot 220 Case 216 Sample stage 221 FFU
222a Gate 222b Gate 300 Case 301 Case 302 FFU
303 FFU
305 Housing 306 FFU
310 Processing chamber 315 Atmospheric transfer robot 321 Gate 322 Gate 323 Sample stage Pa to d Measurement pressure

Claims (10)

In inspection equipment,
A first semi-clean chamber having a pre-aligner therein;
A first fan filter unit for introducing purified air into the first semi-clean chamber;
A clean room having higher cleanliness than the first semi-clean room;
A second semi-clean chamber that covers the clean chamber and is less clean than the clean chamber ;
A second fan filter unit for introducing purified air into the clean chamber;
An inspection unit disposed in the clean room;
A shutter for communicating the first semi-clean chamber and the clean chamber;
A first differential pressure between the pressure outside the inspection apparatus and the pressure in the first semi-clean chamber, and a second differential pressure between the pressure in the first semi-clean chamber and the pressure in the clean chamber are obtained. A differential pressure acquisition unit;
A timer for obtaining a time for rotation of at least one of the first fan filter unit and the second fan filter unit;
Have a control unit,
The control unit changes the rotation speed of at least one of the first fan filter unit and the second fan filter unit for a predetermined time in synchronization with the opening operation of the shutter (external to the inspection apparatus). Pressure) <(pressure inside the first semi-cleaning chamber) <(pressure inside the cleaning chamber) . The inspection apparatus according to claim 1,
The control unit determines whether the first differential pressure and the second differential pressure are within a predetermined range. If the first differential pressure pressure is outside the predetermined range, the first fan filter unit , And the rotation speed of at least one of the second fan filter units is changed so that (pressure outside the inspection apparatus) <(pressure inside the first semi-cleaning chamber) <(inside the cleaning chamber) Pressure). The inspection apparatus according to claim 2,
The first fan filter unit has a filter;
The upper limit value of the predetermined range is determined in consideration of the specifications of the filter. The inspection apparatus according to claim 2,
The upper limit value of the predetermined range is determined in consideration of an energy consumption amount of the first fan filter unit. The inspection apparatus according to claim 1 ,
A third fan filter unit for introducing purified air into the second semi-clean chamber;
Wherein the control unit, the second fan filter units, and to change at least one of the rotational speed of the third fan filter units, the (external pressure of the testing device) <(the second semi-clean chamber (Internal pressure) <(Internal pressure of the clean chamber). In the mini-environment structure,
A first semi-clean room;
A first fan filter unit for introducing purified air into the first semi-clean chamber;
A clean room having higher cleanliness than the first semi-clean room;
A second semi-clean chamber that covers the clean chamber and is less clean than the clean chamber ;
A second fan filter unit for introducing purified air into the clean chamber;
A shutter for communicating the first semi-clean chamber and the clean chamber;
The first differential pressure between the pressure outside the mini-environment structure and the pressure in the first semi-clean chamber, and the second differential pressure between the pressure in the first semi-clean chamber and the pressure in the clean chamber A differential pressure acquisition unit for obtaining
A timer for obtaining a time for rotation of at least one of the first fan filter unit and the second fan filter unit;
Have a control unit,
The control unit changes the rotational speed of at least one of the first fan filter unit and the second fan filter unit for a predetermined time in synchronization with the opening operation of the shutter (the mini-environment structure). (Minimum pressure) <(pressure inside the first semi-cleaning chamber) <(pressure inside the cleaning chamber) . The mini-environment structure according to claim 6 ,
The control unit determines whether the first differential pressure and the second differential pressure are within a predetermined range. If the first differential pressure pressure is outside the predetermined range, the first fan filter unit , And the rotation speed of at least one of the second fan filter units is changed so that (pressure outside the mini-environment structure) <(pressure inside the first semi-clean chamber) <(pressure inside the clean chamber) Mini-environment structure characterized by internal pressure). The mini-environment structure according to claim 7 ,
The first fan filter unit has a filter;
The mini-environment structure according to claim 1, wherein an upper limit value of the predetermined range is determined in consideration of a specification of the filter. The mini-environment structure according to claim 7 ,
The mini-environment structure according to claim 1, wherein the upper limit value of the predetermined range is determined in consideration of an energy consumption amount of the first fan filter unit. The inspection apparatus according to claim 1 ,
A third fan filter unit for introducing purified air into the second semi-clean chamber;
Wherein the control unit, the second fan filter units, and to change at least one of the rotational speed of the third fan filter unit, (the pressure outside of the mini-environment structure) <(the second semi-clean the pressure inside the chamber) <(the inspection device, characterized in that the said internal pressure of the clean chamber).

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