JP2012136320A - Conveying device and vacuum treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying device capable of preventing demagnetization by cooling a helical magnet.SOLUTION: A magnetic screw driving mechanism 9 of the conveying device T for rotates a helical magnet shaft 11 having the helical magnet 11a helically magnetized on its surface and pivotally supported in a housing by a driving shaft 13 coupled with a motor. The helical magnet shaft 11 is housed in a case 23 and arranged in a state that it is isolated from an atmosphere in a chamber. By introducing a refrigerant into the case 23, the helical magnet 11a can be effectively cooled.

Description

  The present invention relates to a transfer apparatus and a vacuum processing apparatus, and more particularly, to a transfer apparatus including an oil seal structure and a vacuum processing apparatus including such a transfer apparatus.

  In a semiconductor manufacturing process such as a film forming process, it is necessary to prevent dust from adhering to a film formation surface. Therefore, reduction of dust existing in a vacuum vessel is required. It is known that dust is generated in the vacuum container for various reasons, and for example, it is caused by film peeling of the film forming material adhering to the substrate holder and wear due to contact between the substrate and another member. In particular, in a vacuum processing apparatus provided with a substrate transport mechanism, a member that constitutes the transport device has a structure in contact with each other, and therefore there is a transport mechanism that can further reduce the generation of dust due to wear and corrosion. It is desired.

  In order to reduce the generation of dust, it is desirable to use a non-contact transmission type transport mechanism. Various systems have been proposed as a non-contact transmission type transport mechanism. Among them, a method using magnetic coupling (hereinafter referred to as “magnetic transfer device”) is known as a method having a relatively simple structure. As for the magnetic transfer device, there has been proposed a linear transfer mechanism in which a magnetic screw having a magnetized portion formed in a spiral shape and a magnetic pole of a permanent magnet on the carrier side are combined (for example, see Patent Documents 1 to 5).

  A technique disclosed in Patent Document 2 will be described as an example of the prior art. The technique disclosed in Patent Document 2 is a magnetic transfer device used in an in-line vacuum processing apparatus in which a plurality of processing chambers are connected in series. The load lock chamber, the processing chamber, and the unload lock chamber have gate valves. And a magnetic transfer device is disposed through each of the chambers. The substrate held on the carrier by the magnetic transfer device can be transferred between the chambers.

  A magnetic screw drive mechanism is used as the magnetic transport mechanism. A carrier-side magnet (permanent magnet) is provided at the lower end of each carrier, and a magnetic screw is disposed on the chamber side below the carrier-side magnet. Since the helical magnetic pole formed on the magnetic screw is magnetically coupled to the carrier-side magnet, the carrier can be conveyed in the horizontal direction according to the rotation of the magnetic screw. Since each chamber is partitioned by a gate valve, a magnetic screw drive mechanism is provided for each chamber.

  During normal operation, a structure is adopted in which the magnetic screw drive mechanism is housed in a case and isolated from the film formation region in the vacuum vessel. However, at the time of maintenance, there is a case where a region where the magnetic screw driving mechanism provided with a magnetic screw or the like is provided and a film forming region are connected, so that dust in the magnetic screw driving mechanism needs to be reduced as much as possible.

  The magnetic screw drive mechanism used in Patent Document 2 will be described. The magnetic screw drive mechanism is a mechanism for transmitting a rotational force from a motor (not shown) to the magnetic screw side, and includes a power transmission unit having a pair of bevel gears as a main component. The magnetic screw drive mechanism and the carrier are not in contact with each other, and instead of providing a guide, it becomes a straight guide. By driving the carrier in a non-contact manner by using a magnetic screw drive mechanism, the guide that contacts the carrier while it is moving can be limited to bearings for self-weight reception and guide bearings, greatly reducing the generation of dust. Can do.

  However, even with such a magnetic screw drive mechanism, wear of the bevel gear of the power transmission unit cannot be avoided, and wear of the bevel gear may cause instability of carrier movement and phase shift of the magnetic poles. For this reason, the lubricant is applied to the sliding portion of the bevel gear of the power transmission unit to reduce wear, and the lubricant is sealed by sealing the lubricant in the power transmission unit using an oil seal. It was supposed to be a containment structure.

US Pat. No. 5,377,816 JP-A-10-159934 JP 2001-206548 A JP 2008-297092 A Japanese Patent Laid-Open No. 08-274142

  On the other hand, a chamber in which a heater is installed in a chamber in which a magnetic screw driving mechanism is installed is known. In such a chamber, the temperature of the magnetic screw driving mechanism is likely to rise, and the helical magnet portion of the magnetic screw may be demagnetized due to the temperature rise, and the magnetic coupling force with the magnet installed on the carrier may be weakened. The carrier-side magnet and the magnetic screw reduce the magnetic force attracted, so that there is a high possibility that the carrier movement will become unstable and the phase of the magnetic pole will shift.

  In addition, the oil seal installed in the magnetic screw drive mechanism generates sliding heat due to friction between the oil seal (lip portion) and the shaft in sliding contact. As the temperature of the use environment rises, the life of the oil seal is hindered, so that it is desirable to cool it like the spiral magnet.

  The magnetic screw driving mechanism is in a vacuum heat insulating state because the surroundings are in a vacuum state. Therefore, most of the sliding heat between the heater installed in the chamber and the oil seal is dissipated by heat conduction with the chamber partition connected to the magnetic screw drive mechanism. However, since the magnetic screw drive mechanism is in contact with the chamber via an O-ring for separating the vacuum atmosphere from the atmospheric pressure atmosphere, the contact surface between the metals having high thermal conductivity is small, so that efficient cooling cannot be performed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a transport apparatus and a vacuum processing apparatus that can cool a helical magnet and an oil seal of a magnetic screw.

  A transport apparatus according to the present invention includes a carrier that can move in a chamber while holding a substrate, a permanent magnet provided in the carrier, a spiral magnet that is provided in the chamber and forms a magnetic coupling with the permanent magnet, And a drive unit that rotates a helical magnet, wherein the drive unit includes a helical magnet shaft having a helical magnet, a drive shaft that transmits rotational force to the helical magnet shaft, and a helical magnet. A housing that rotatably supports the shaft and the drive shaft, a tubular case in which the spiral magnet shaft is disposed on the inner side and the inner space is separated from the atmosphere in the chamber, and an outer peripheral surface of the spiral magnet and the case And a cooling unit that introduces a refrigerant into a gap with the inner peripheral surface of the. In addition, a vacuum processing apparatus according to the present invention is characterized in that the carrier holding the substrate is transferred to a chamber in which a predetermined vacuum processing is performed by the above-described transfer apparatus.

  By using the present invention, it is possible to cool the spiral magnet provided in the transfer device or the vacuum processing device. Furthermore, oil seal cooling can be performed. Since the spiral magnet and the oil seal can be efficiently cooled, demagnetization of the spiral magnet can be suppressed, and deterioration of the oil seal can be suppressed. Therefore, the usage period of the spiral magnet and the oil seal of the transfer device or the vacuum processing device can be extended.

It is a schematic sectional drawing of the in-line type vacuum processing apparatus which concerns on one Embodiment of this invention. It is a schematic diagram of the conveyance mechanism which concerns on one Embodiment of this invention. It is AA sectional drawing of the conveyance mechanism which concerns on one Embodiment of this invention. It is sectional drawing of the magnetic screw drive mechanism which provided the cooling inlet which concerns on one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that the members, arrangements, and the like described below are examples embodying the present invention and do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

  1 to 4 are diagrams of an inline-type vacuum processing apparatus according to an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view of the inline-type vacuum processing apparatus. FIG. 2 is a cross-sectional view taken along the line AA, and FIG. 4 is a cross-sectional view taken along the line BB in FIG. In addition, in this embodiment, the conveying apparatus provided in the in-line type vacuum processing apparatus is demonstrated as an example of a vacuum processing apparatus provided with a conveying apparatus. In addition, in order to prevent complication of the drawing, it is omitted except for a part.

  An in-line vacuum processing apparatus S (hereinafter referred to as a vacuum processing apparatus S) shown in FIG. 1 is a film forming apparatus for performing a film forming process on a hard disk substrate in a vacuum, and includes a load lock chamber LC, The processing chambers PC (PC1, PC2, PC3) and the unload chamber UL are connected through a gate valve GV. By opening each gate valve GV, the internal spaces of these chambers (PC1, PC2, PC3) can be connected. Each chamber (LC, PC, UL) is provided with a transfer device T as a magnetic transfer device capable of transferring the substrate 4 between adjacent chambers.

  The transfer device T includes a carrier 5 that holds the substrate 4 and is movable, and a magnetic screw drive mechanism 9 and a guide guide as drive units provided on each chamber (LC, PC, UL) side. It is said. The magnetic screw drive mechanism 9 includes a spiral magnet shaft 11, a drive shaft 13 that transmits a rotational force to the spiral magnet shaft, a motor (not shown) as a power source that supplies power to the drive shaft 13, and a cooling that will be described later. And an in-case cooling device as a device.

  The guide guide is a roller attached to the chamber side through a bearing, and a guide for receiving the weight of the carrier 5 (self-weight receiving bearing 15) and a guide bearing for guiding the side surface of the carrier 5 along the transport direction ( (Not shown). Particles can be reduced by limiting the part that the carrier 5 contacts while moving to the guide guide. At the lower end of each carrier 5, a carrier-side magnet portion 5 a that is a permanent magnet configured so that opposite magnetic poles appear alternately at a predetermined interval is provided. A helical magnet shaft 11 is disposed on the magnetic screw drive mechanism 9 located below the carrier-side magnet portion 5a.

  Here, the magnetic screw drive mechanism 9 will be described with reference to FIG. As described above, the magnetic screw drive mechanism 9 includes the helical magnet shaft 11, the drive shaft 13, and the motor (not shown), and the rotational force of the motor is transmitted via the drive shaft 13 to the helical magnet shaft. 11 is a mechanism to transmit to 11. Further, the helical magnet shaft 11 and the drive shaft 13 are arranged so that the axial directions thereof are orthogonal to each other, and a power transmission portion for transmitting a rotational force by a pair of bevel gears 21 and 22 is configured at these connecting portions. ing. The in-case cooling device as a cooling unit is a device for cooling predetermined components of the magnetic screw drive mechanism 9 and will be described later.

  A connecting portion between the helical magnet shaft 11 and the drive shaft 13 is rotatably supported by a substantially box-shaped housing 17, and the bevel gears 21 and 22 are disposed inside the housing 17. The drive shaft 13 is disposed through the vacuum seal surface (reference numeral PC in FIG. 3) of the processing chamber PC, and rotates from the motor connected on the atmosphere side (outside). It is introduced inside (inside the housing 17).

  The spiral magnet shaft 11 is formed with a spiral magnet 11a magnetized in a spiral shape on the surface thereof. On the other hand, the interval between the magnetic poles of the carrier side magnet portion 5a provided on the carrier 5 side is a spiral magnet. It is formed at the same pitch as the spiral magnet 11 a of the shaft 11. Therefore, the carrier-side magnet portion 5a and the spiral magnet 11a of the spiral magnet shaft 11 can form a magnetic coupling (magnetic coupling) while maintaining a predetermined distance.

  Since the helical magnet 11a of the helical magnet shaft 11 is helical, the position where it is magnetically coupled to the carrier-side magnet portion 5a can be gradually changed in the axial direction as the helical magnet shaft 11 rotates. Accordingly, the carrier-side magnet portion 5 a, that is, the carrier 5 can be conveyed in the axial direction of the spiral magnet shaft 11 in synchronization with the rotation of the spiral magnet shaft 11. The spiral magnet 11a of the spiral magnet shaft 11 is divided into two on the left and right sides of the housing 17, and a bevel gear 21 is provided in a portion between the divided spiral magnets 11a. Further, the outer peripheral side of the spiral magnet 11a is covered by the cylindrical case 23 and is isolated from the vacuum side. An end portion of the case 23 is hermetically connected to the housing 17.

  The power transmission unit includes, as main components, a helical magnet shaft 11 and a drive shaft 13 to which bevel gears 21 and 22 are fixed, and a housing 17 that supports them at predetermined positions. The helical magnet shaft 11 and the drive shaft 13 are arranged orthogonally and are rotatably supported by the housing 17 via bearings 24. A collar 19 is attached to each of the helical magnet shaft 11 and the drive shaft 13.

  The collar 19 is a cylindrical stainless steel member, and is attached in a state where the spiral magnet shaft 11 or the drive shaft 13 is inserted inside. Oil seals 20 that are in sliding contact with the outer peripheral sides of the respective collars 19 are attached to the housing 17. On the other hand, an O-ring 26 for closing a gap between the inner surface side of the collar 19 and the spiral magnet shaft or the drive shaft is attached to the inside of each collar 19. The lubricant Gr injected into the housing 17 in which the bevel gears 21 and 22 are arranged is sealed in the housing 17 by the oil seal 20 and the O-ring 26. Since the collar 19 is disposed outside the housing 17 with respect to the bearing 24 that supports the shafts (11, 13), the lubricant Gr can also be supplied to the bearing 24.

  The number of O-rings arranged in the gap between the helical magnet shaft 11 and the drive shaft 13 may be one, but preferably two. On the other hand, the outer peripheral surface of the collar 19 comes into sliding contact with the oil seal 20, and the sliding contact portion of the collar 19 generates heat by sliding. Since each collar 19 rotates integrally with the helical magnet shaft 11 or the drive shaft 13, even if it is simply referred to as the helical magnet shaft 11 or the drive shaft 13 in the present specification, the collar 19 includes the collar 19. Is attached.

Note that a structure in which the oil seal 20 is in direct sliding contact with the drive shaft 13 (or the helical magnet shaft 11) without using the collar 19 may be adopted. However, even in such a structure, the oil seal 19 and the drive shaft 13 ( Alternatively, heat is generated at the sliding contact portion with the helical magnet shaft 11). Therefore, it goes without saying that the present invention can be applied even when the collar 19 is not used. Since the portion that is in sliding contact with the oil seal 20 is more easily etched than other places due to the influence of friction, heat, etc., when the collar 19 is used, the drive shaft 13 (or the helical magnet shaft 11) is continuously used. In addition, the maintenance cost can be reduced by replacing only the collar 19.

  The cylindrical case 23 is connected to the housing 17 via a seal material (O-ring) 23a to keep the internal space airtight. Therefore, the spiral magnet 11a in the case 23 is isolated from the vacuum atmosphere in the processing chamber PC. The inside of the case 23 is an atmospheric pressure atmosphere. The case 23 is fixed to the housing 17 fixed to the processing chamber PC side. On the other hand, since the spiral magnet 11a rotates together with the spiral magnet shaft 11, the inner surface (inner peripheral surface) of the case 23 and the spiral magnet 11a. The outer peripheral surface has a predetermined gap 25.

  The housing 17 is made of stainless steel (SUS304), and as described above, supports the drive shaft 13 and the helical magnet shaft 11 via the bearing 24, and lubricates the bevel gears 21 and 22. This is a member that supports an oil seal 20 for sealing the inside. The housing 17 is formed with a communication path 18 that communicates with the gap 25 on one end side. As will be described later, the other end side of the communication path 18 is connected to the discharge port 32.

  Here, the in-case cooling device (cooling unit) will be described. The in-case cooling device is a device that cools the spiral magnet 11 a and the oil seal 20 by circulating a refrigerant in the magnetic screw driving mechanism 9, and a pump (not shown) for supplying the refrigerant into the magnetic screw driving mechanism 9. A power supply (not shown) for supplying power to the pump, and a refrigerant flow path formed in the magnetic screw drive mechanism 9. A pump and a power source constituting the in-case cooling device are installed outside the processing chamber PC (atmosphere), and known ones can be used as appropriate.

  The distribution path is such that the inlet 31 for introducing the refrigerant into the case 23, the inner surface of the case 23 and the outer peripheral surface of the spiral magnet 11a are a predetermined gap 25, the communication path 18 in the housing 17, and the exhaust for discharging the refrigerant from the housing 17. And an outlet 32. Further, a tubular member composed of a known bellows tube or the like may be attached between the inlet 31 and the pump. Similarly, a configuration in which a tubular member can be attached to the discharge port 32 may also be used.

  In the present embodiment, air is used as the refrigerant. Also, as shown in FIG. 3, since a part of the housing 17 that supports the drive shaft 13 is disposed through the wall of the processing chamber PC, the discharge port 32 communicates with the atmospheric atmosphere outside the processing chamber PC. ing. That is, the refrigerant supplied from the pump is introduced into the gap 25 from the introduction port 31, passes through the communication path 18, and is discharged from the discharge port 32 to the atmosphere.

  In the gap 25, the refrigerant directly contacts the surface of the spiral magnet 11a, so that the spiral magnet 11a can be effectively cooled. Further, the oil seal 20 can be cooled via the housing 17 by the refrigerant passing through the communication path 18. That is, since the oil seal 20 is fixed to the stainless steel housing 17, when the housing 17 is cooled, the oil seal 20 can be cooled by the housing 17 cooled by the refrigerant.

  Although the communication path 18 in the present embodiment is formed in the housing 17, the housing 17 is made of a material having high heat conduction. Therefore, if the refrigerant is circulated along the outer peripheral surface of the housing 17, the housing 17 is provided. In addition, the oil seal 20 can be cooled. That is, the same effect as that of the present embodiment can be exhibited even in a configuration in which a member that forms a communication path is disposed between the housing 17 and the outer peripheral surface, and the refrigerant flows through the communication path. In this case, since the member which forms the communication path with the housing 17 is held in contact with the housing 17, the configuration is the same as that of the housing 17 of the present embodiment.

  In this embodiment, compressed air is used as the refrigerant. However, as long as the medium can cool the helical magnet 11a and the oil seal 20 by heating from the surroundings and heat generated by sliding, a liquid or gas such as compressed air or water is used. It can be used as a refrigerant regardless of the type. The compressed air used in the present embodiment is collected from the atmosphere by a pump, and the temperature of the air at the time of collection is equal to the ambient temperature.

  Moreover, when circulating a refrigerant | coolant, it is necessary to comprise a distribution path so that the refrigerant | coolant discharged | emitted from the discharge port 32 may be returned to a pump. In this case, for example, a temperature adjusting device (refrigeration device) for cooling the refrigerant is preferably attached at a position between the discharge port 32 and the introduction port 31. Of course, it is of course possible that the refrigerant is first introduced into the communication path 18 of the housing 17 and discharged from the case 23 side.

  Since it is desirable to keep the oil seal 20 at 40 ° C. or lower and the helical magnet 11a at 40 ° C. or lower, the temperature adjusting device can keep the temperature of the oil seal 20 and the helical magnet 11a below these predetermined temperatures. It cools to the extent. Of course, the output of the temperature adjusting device may be adjusted with reference to the temperature measurement values of the housing 17 and the helical magnet 11a. Since the cooling capacity of the in-case cooling device can be adjusted by changing the temperature, flow rate, and type (heat capacity) of the refrigerant, the output of the temperature adjusting device and the pump may be adjusted at the same time. In addition, said predetermined temperature is an example and it cannot be overemphasized that the cooling target temperature of the oil seal 20 and the helical magnet 11a can be set suitably.

  Further, when both the discharge port 32 and the introduction port 31 are provided in the case 23, only the spiral magnet 11a can be effectively cooled. When the housing 17 is cooled by another mechanism using a Peltier element or the like, only the spiral magnet 11a needs to be cooled.

  When the inside of the processing chamber PC is in a vacuum atmosphere, the periphery of the case 24 is in a heat insulating state due to the vacuum. Therefore, the configuration of the present invention that can directly cool the spiral magnet 11a inside the case 24 with a refrigerant is efficiently spiraled. The magnet 11a can be cooled.

  The oil seal 20 is made of an elastomer material and is a member that is fixed to the housing 17 in order to seal the lubricant Gr. Therefore, the structure of the present invention that indirectly cools the oil seal 20 by cooling the housing 17 having a large contact surface with the oil seal 20 and having good heat conduction is extremely useful as a cooling means for the oil seal 20. It is valid.

  That is, by adopting the structure of the present invention, the helical magnet 11a and the oil seal 20 can be efficiently cooled, so that demagnetization of the helical magnet 11a can be prevented, and the oil seal 20 is deteriorated. Can be suppressed. Therefore, the usage period of the spiral magnet 11a and the oil seal 20 of the transfer device T or the vacuum processing device S can be extended. Therefore, the maintenance interval of the vacuum processing apparatus S can be extended and the maintenance cost can be reduced.

S In-line type vacuum processing device LC Load lock chamber UL Unload lock chamber PC, PC1, PC2, PC3 Processing chamber GV Gate valve T Transport device Gr Lubricant a Sliding part 4 Substrate 5 Carrier 5a Carrier side magnet portion 5a (permanent magnet )
9 Magnetic screw drive mechanism (drive unit)
DESCRIPTION OF SYMBOLS 11 Spiral magnet shaft 11a Spiral magnet 13 Drive shaft 15 Self-weight receiving bearing 17 Housing 18 Communication passage 19 Collar 20 Oil seal 21, 22 Bevel gear 23 Case 25 Clearance 24 Bearing 23a, 26 O-ring 31 Inlet port 32 Outlet port 101 Magnetic screw drive mechanism 102 Bevel gear mechanism 103 Power transmission part 105 Oil seal

Claims (4)

A carrier capable of moving in the chamber while holding the substrate, a permanent magnet provided in the carrier, a helical magnet provided in the chamber and forming a magnetic coupling with the permanent magnet, and rotating the helical magnet A transport device comprising a drive unit,
The drive unit is
A helical magnet shaft having the helical magnet;
A drive shaft for transmitting rotational force to the helical magnet shaft;
A housing that rotatably supports the helical magnet shaft and the drive shaft;
A tubular case in which the helical magnet shaft is disposed on the inner side and the inner space is separated from the atmosphere in the chamber;
And a cooling unit that introduces a refrigerant into a gap between the outer peripheral surface of the spiral magnet and the inner peripheral surface of the case. The drive unit is
An oil seal attached to the housing so as to be in sliding contact with the surface of the drive shaft or the helical magnet shaft, and sealing a lubricant in the housing;
The transport apparatus according to claim 1, further comprising a communication path formed in the housing and in airtight communication with the gap at one end. The gap is held in an air atmosphere, and the other end of the communication path is connected to the air atmosphere outside the chamber,
The transport apparatus according to claim 2, wherein the refrigerant introduced into the gap is discharged to the outside of the chamber after flowing through the communication path from one end to the other end. 4. The vacuum processing apparatus according to claim 1, wherein the carrier holding the substrate is transported to a chamber in which predetermined vacuum processing is performed by the transport apparatus according to claim 1.