JP6134173B2 - Magnetic annealing equipment - Google Patents

Description

  The present invention relates to a magnetic annealing apparatus.

  In recent years, MRAM (Magnetic Random Access Memory), which is one of nonvolatile memories, has attracted attention as a next-generation semiconductor memory device. An MRAM is manufactured by, for example, subjecting a magnetic film formed on an object to be processed, which is a semiconductor wafer (hereinafter referred to as a wafer), to heat treatment (magnetic annealing) in a strong magnetic field to develop its magnetic characteristics.

  For example, Patent Document 1 discloses a magnetic annealing apparatus having a relatively small installation area using a solenoid type magnet as magnetic field generating means for magnetic annealing.

JP 2004-263206 A

  However, the magnetic annealing apparatus of Patent Document 1 or the like is a small-scale apparatus for HDD (hard disk drive) or MRAM research and development. In view of the expected market size of MRAM in the future, development of a magnetic annealing apparatus capable of (semi-) continuously processing a large number of wafers, for example, 100 wafers, is demanded.

  In order to improve the number of wafers processed per unit time, not only a large number of wafers can be processed at once, but also the wafers for the next batch can be taken into the magnetic annealing apparatus in a short time. A device configuration is required.

  In view of the above problems, an object of the present invention is to provide a magnetic annealing apparatus capable of continuously performing a magnetic annealing process on a large number of wafers.

In a magnetic annealing apparatus having a control unit, a storage container transfer area for transferring a storage container storing a group of objects to be processed and a process object transfer area for transferring the object to be processed are formed through an open / close door. And
In the storage container transport area,
A first mounting table for mounting a storage container carried into the magnetic annealing apparatus;
A plurality of second mounting tables on which the storage container is mounted in order to transfer the target object in an airtight manner from the storage container transfer region to the target object transfer region via the open / close door;
A storage unit for storing a plurality of the storage containers;
A storage container transport mechanism for carrying in and out the storage container between the first mounting table, the second mounting table and the storage unit;
Is placed,
In the workpiece conveyance area,
An aligner for aligning a plurality of the objects to be processed;
A workpiece holder that can hold a plurality of groups of the workpieces;
A target object transport mechanism for transporting the target object between the storage container mounted on the second mounting table, the aligner and the target object holder;
Heating means for heating the object to be processed;
A magnetic field generating means having a horizontal superconducting magnet for applying a magnetic field to the object to be processed;
A transfer mechanism for transferring the target object held by the target object holder into the magnetic field generating means;
Is placed,
The length of the uniform magnetic field region of the horizontal superconducting magnet is greater than twice the diameter of the object to be processed,
The object holder holds a plurality of laminated bodies in which a plurality of the objects to be processed are stacked in a direction perpendicular to the direction of the magnetic field, arranged in parallel in a direction parallel to the direction of the magnetic field,
Magnetic annealing equipment.

  ADVANTAGE OF THE INVENTION According to this invention, the magnetic annealing apparatus which can process many wafers continuously can be provided.

2 is a schematic perspective view of an example of a carrier for a wafer W. FIG. It is a schematic top view of an example of a magnetic annealing apparatus. It is a schematic longitudinal cross-sectional view of the carrier conveyance area | region vicinity of a magnetic annealing apparatus. It is a schematic plan view of the vicinity of the wafer transfer region of the magnetic annealing apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Career)
In FIG. 1, the schematic perspective view of an example of the carrier C of the wafer W is shown. In the present embodiment, a case where a sealed FOUP (Front Opening Unified Pod) is used as the carrier C that accommodates the wafer W will be described, but the present invention is not limited in this respect.

  As shown in FIG. 1, the carrier C of the wafer W has one end portion formed as an opening and the other end portion formed in a substantially semi-elliptical shape, for example.

  On the inner wall surface of the carrier C, a support portion on which the wafers W can be arranged in multiple stages is formed. For example, by placing and supporting the peripheral portion of a wafer W having a diameter of 300 mm on this support portion, the wafers W can be accommodated in multiple stages at a substantially equal pitch. Generally, 25 wafers W can be stored in one carrier C.

  A grip 10 that can be gripped when the carrier C is gripped is provided on the ceiling of the carrier C.

  An opening / closing lid 12 corresponding to the opening is detachably attached to the opening of the carrier C, and the inside of the carrier C is substantially airtight by the opening / closing lid 12. Generally, the atmosphere inside the carrier is clean air.

  The opening / closing lid 12 is provided with, for example, two locking mechanisms 14, and the opening / closing lid 12 can be detached from the opening by locking or unlocking the locking mechanism 14.

  A plurality of positioning recesses (not shown) are provided on the bottom surface of the bottom of the carrier C, and the carrier can be positioned when it is placed on a mounting table to be described later. Further, a lock piece (not shown) is provided on the lower surface of the bottom portion of the carrier, so that the carrier can be locked when placed on the mounting table.

(Magnetic annealing equipment)
Next, the magnetic annealing apparatus of this embodiment will be described. FIG. 2 shows a schematic plan view of an example of a magnetic annealing apparatus.

  As shown in FIG. 1, the magnetic annealing apparatus 100 is configured to be housed in a housing 102. The casing 102 constitutes an exterior body of a magnetic annealing apparatus, and a carrier transfer area S1 and a wafer transfer area S2 are formed in the casing 102.

  The carrier transfer area S1 is an area where the carrier C containing the wafer W, which is the object to be processed, is carried into and out of the magnetic annealing apparatus. The wafer transfer area S2 is a transfer area for transferring the wafer W in the carrier C and loading it into a magnetic annealing furnace described later.

  The carrier transfer area S1 and the wafer transfer area S2 are partitioned by a partition wall 104.

  The carrier transfer area S1 is an area under an air atmosphere, and is an area where the wafer W stored in the carrier C is transferred. An area between the processing apparatuses corresponds to the carrier transport area S1, and in this embodiment, a space in the clean room outside the magnetic annealing apparatus 100 corresponds to the carrier transport area S1.

On the other hand, the atmosphere in the wafer transfer region S2 is not particularly limited, and may be an air atmosphere or an inert gas atmosphere, for example, a nitrogen (N ₂ ) gas atmosphere. Depending on the configuration of the object to be processed, an inert gas atmosphere may be used when processing in a lower oxygen atmosphere is required, for example, when it is desired to prevent the formation of an oxide film or the like. Further, the wafer transfer region S2 is generally higher in cleanliness than the carrier transfer region S1 and is maintained at a low oxygen concentration.

  In the following description, the arrangement direction of the carrier transfer region S1 and the wafer transfer region S2 is the front-rear direction of the magnetic annealing apparatus. The carrier transfer area S1 side is the front (X direction in FIG. 2), and the wafer transfer area S2 side is the rear (Y direction in FIG. 2).

[Carrier transport area S1]
The carrier transport area S1 will be described in more detail. FIG. 3 shows a schematic longitudinal sectional view of the vicinity of the carrier transport region of the magnetic annealing apparatus.

  The carrier transport area S1 includes a first transport area 106 and a second transport area 108 located on the rear side of the first transport area 106.

  As shown in FIG. 2, two first mounting tables 110 a and 110 b on which the carrier C is mounted are provided in the left-right direction of the first transport region 106. On the mounting surface of each of the first mounting tables 110a and 110b, pins 112 for positioning the carrier C corresponding to the positioning recesses of the carrier C are provided, for example, at three locations.

  In the second transfer area 108, two second second arrays arranged in the front-rear direction and in the vertical direction with respect to any one of the left and right first mounting tables (the mounting table 110a in the present embodiment). Mounting tables 114a and 114b are provided. Each second mounting table 114 is configured to be movable back and forth.

  Similarly to the first mounting table 110, pins 112 for positioning the carrier C are provided on the mounting surface of the second mounting table 114, for example, at three locations. In addition, a hook (not shown) for fixing the carrier C is provided on the mounting surface.

  As shown in FIG. 3, first carrier storage units 116 a and 116 b that store the carrier C are provided on the upper side of the second transport region 108 and / or the first transport region 106. The carrier storage units 116a and 116b are composed of two or more shelves, and two shelves C can be placed on the left and right of each shelf.

  In addition, as shown in FIG. 2, a second carrier storage unit 116 c configured by a plurality of shelves is provided in the left-right direction of the second mounting table 114.

  By providing the first carrier storage units 116a and 116b and the second carrier storage unit 116c, a sufficient number of carriers C (that is, wafers W) can be held in the carrier transfer region S1. . Therefore, even when, for example, 100 wafers W are transferred to the wafer transfer region S2 by the wafer transfer method described later, the number of carriers C is insufficient by storing the carriers C in the carrier storage unit 116 in advance. There is nothing.

  In the second transport region 108, a carrier transport mechanism 118 that transports the carrier C to and from the first and second mounting tables, the first and second mounting tables, and the carrier storage unit is provided. The carrier transport mechanism 118 includes a guide part 118a that can be moved up and down, a moving part 118b that moves up and down while being guided by the guide part 118a, and a horizontal part that supports the bottom of the moving part 118b and supports the bottom part thereof. And a transport arm 118c for transporting to the head.

  The partition 104 is provided with a transfer port 120 for the wafer W that allows the carrier transfer region S1 and the wafer transfer region S2 to communicate with each other. The transfer port 120 is provided with an opening / closing door 122 that closes the transfer port 120 from the wafer transfer region S2 side. A drive mechanism (not shown) is connected to the open / close door 122, and the open / close door 122 is configured to be movable in the front-rear direction and the up-down direction by the drive mechanism, and the conveyance port 120 is opened and closed.

  The transfer of the wafer W from the carrier transfer area S1 to the wafer transfer area S2 will be described. First, the carrier C is transferred from the first mounting table 110, the first carrier storage units 116a and 116b, or the second carrier storage unit 116c to the second mounting table 114 by the transfer arm 118c. The The carrier C is placed so that the positioning recess and the pin 112 are engaged. When the carrier C is placed on the second placement table 114, the second placement table 114 is moved to the partition wall 104 side, and the carrier C comes into contact with the partition wall 104. The contact state of the carrier C is held by a fixing mechanism (not shown).

  Thereafter, in a state where the opening / closing door 122 formed on the partition wall 104 and the opening / closing lid 12 of the carrier C are sealed, the opening / closing lid 12 is opened by an opening / closing mechanism (not shown). When the atmosphere of the wafer transfer region S2 is an inert gas atmosphere, first, with the opening / closing lid 12 of the carrier C being sealed, inert gas replacement is performed by an inert gas replacement means (not shown), and the opening / closing door 122 is opened. And the atmosphere between the opening / closing lid 12 is removed and the inert gas is filled. Next, inert gas replacement is performed in the carrier C by an inert gas replacement means.

  Then, the opening / closing door 122 formed on the partition wall 104 of the carrier C is opened, and the wafer W in the carrier C is loaded and unloaded by a wafer transfer mechanism 124 described later.

  When the carrier C is replaced and the wafer W is unloaded, the reverse operation described above is performed.

[Wafer transfer area S2]
FIG. 4 shows a schematic plan view of the vicinity of the wafer transfer region S2 of the magnetic annealing apparatus 100. FIG. As shown in FIG. 4, in the wafer transfer area S2, a wafer transfer mechanism 124, an aligner 126, a wafer boat 128, and a magnetic field generating means 130 are mainly installed.

  The wafer transfer mechanism 124 is in charge of transferring the wafer W in the wafer transfer region S <b> 2 and is provided between the wafer boat 128 and the transfer port 120 of the partition wall 104. The wafer transfer mechanism 124 is configured by moving along a guide mechanism 124a extending vertically, and by providing, for example, five movable arms 124c on a moving body 124b that rotates about a vertical axis. The wafer is transferred between the carrier C on the second mounting table 114 and the aligner 126.

  The aligner device 126, for example, grips the edge of the wafer W and performs angle alignment such as centering and notching.

  As the magnetic field generating means 130, a magnetic annealing furnace configured by a horizontal solenoid type magnet (superconducting magnet) that performs a magnetic annealing process on the wafer W and has a furnace opening on the right end is used. The solenoid-type magnet is arranged so that its center line axis direction is substantially horizontal, and is connected to a power supply device (not shown). The direction of the magnetic field generated by the horizontal solenoid magnet is the aforementioned front-rear direction.

  Further, the magnetic field generating means 130 is provided with a heating means 132 along the inner periphery thereof, so that the wafer W can be heated to a predetermined temperature. In other words, the wafer W is heated by the magnetic field generating means 130 under a uniform magnetic field.

  When a similar magnetic annealing process is performed on a plurality of wafers W, for example, 100 wafers W using a solenoid type magnet, it is necessary to arrange the wafers W in the uniform magnetic field region in order to perform a uniform process on all the wafers W. There is. The uniform magnetic field region of the solenoid type magnet is about 20% of its axial length. Therefore, for example, when 100 wafers of φ300 mm are processed by a magnetic annealing apparatus, horizontal solenoid type magnets are designed as an inner diameter (bore diameter) of 570 mm, an outer diameter of φ1900 mm, a length of 2500 mm, The length of the magnetic field region can be about 680 mm).

  Further, the weight of the horizontal solenoid magnet of the above design is about 25 tons. Therefore, a bottom of the solenoid type magnet is provided with a holding base (not shown) for holding the solenoid type magnet and a holding plate (not shown) at the bottom of the holding base.

  A wafer boat 128 that holds a plurality of carriers C, for example, a large number of wafers W in the four carriers C, is placed on the left side of the cap 136 via the heat insulating portion 134 on the front side of the magnetic field generating means 130. Yes. The cap 136 is supported behind the transfer mechanism 138, and the wafer boat 128 is carried into or out of the magnetic field generation unit 130 by the transfer mechanism 138.

  For example, an arrangement configuration example of wafers W on a wafer boat when 100 wafers W are simultaneously processed by the magnetic annealing apparatus 100 will be described. When the magnetic annealing process is performed on the wafer W by the in-plane magnetization method, two stacked bodies in which 50 wafers W are stacked in the direction perpendicular to the direction of the magnetic field (front-rear direction in the present embodiment) are provided in the front-rear direction. Arrange them in parallel and place them on the wafer boat. On the other hand, when the magnetic annealing process is performed on the wafer W by the perpendicular magnetization method, one stacked body in which 100 wafers W are stacked in a shelf shape in the direction horizontal to the direction of the magnetic field is arranged on the wafer boat.

[Loading / unloading of wafer W in wafer transfer area S2]
A series of flows when carrying the wafer W from the carrier C mounted on the two second mounting tables 114a and 114b to the magnetic annealing apparatus will be briefly described. Here, a case where, for example, 100 wafers W are carried into the magnetic annealing apparatus 100 will be described.

  The wafer W carried into the wafer transfer region S2 is first transferred to the aligner 126 by the wafer transfer mechanism 124, and angle adjustment such as centering and notch is performed. Next, the wafer W is transferred from the aligner device 126 to the wafer boat 128 by the wafer transfer mechanism 124. After the transfer of the wafer W to the wafer boat 128 is completed, the wafer transfer mechanism 124 returns to the carrier C, and the next wafer W is transferred.

  The number of wafers W held in one carrier C is generally 25, and the number of wafers W transferred by the wafer transfer mechanism 124 is generally 5. Therefore, the transfer of the wafer W from the carrier C to the wafer boat 128 via the aligner 126 is performed five times for one carrier C. After the transfer of the wafer W from the carrier C mounted on one second mounting table (for example, the second mounting table 114a) is finished, the other second mounting table ( For example, the wafer W is transferred from the carrier C mounted on the second mounting table 114b). At that time, the empty carrier C placed on the second mounting table 114a is transferred while the wafer W is transferred from the carrier C placed on the other second mounting table 114b. The carrier C is replaced with another carrier C stored in the carrier storage unit 116.

  These operations are repeated, and after a predetermined number of wafers, for example, 100 wafers W are transferred to the wafer boat 128 by the wafer transfer mechanism, the wafer boat 128 is moved into the magnetic field generating means 130 by the transfer mechanism 138. And a predetermined magnetic annealing process is performed. In order to unload the wafer W after the processing yield, first, the wafer boat 128 is unloaded from the magnetic field generation unit 130, and, contrary to the above-described loading, using the wafer transfer mechanism 124, the wafer W is transferred to the second mounting table 114a or 114b. It is executed by transferring from the opening / closing window to the carrier C. Thereafter, the opening / closing lid is attached to the carrier C by an opening / closing mechanism (not shown), the carrier C is unloaded by the carrier transport mechanism 118, and the process proceeds to the next step.

  As shown in FIG. 2, the magnetic annealing apparatus 100 is provided with a control unit 140 made up of a computer, for example. The control unit 140 includes a program, a memory, a data processing unit including a CPU, and the like. The program sends a control signal from the control unit to each unit of the magnetic annealing apparatus to instruct each process step to proceed (each step ) Is incorporated. By the control signal, carrier C, wafer W, opening / closing door opening / closing, lid opening / closing, and other processes are performed. This program is stored in a storage medium such as a computer storage medium such as a flexible disk, a compact disk, a hard disk, an MO (magneto-optical disk), and a memory card and installed in the control unit.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

DESCRIPTION OF SYMBOLS 10 Handle 12 Opening / closing lid 14 Lock mechanism 100 Magnetic annealing apparatus 102 Case 104 Bulkhead 106 1st conveyance area 108 2nd conveyance area 110 1st mounting base 112 Pin 114 2nd mounting base 116 Carrier storage part 118 Carrier conveyance Mechanism 120 Transfer port 122 Opening / closing door 124 Wafer transfer mechanism 126 Aligner device 128 Wafer boat 130 Magnetic field generation means 132 Heating means 134 Heat insulation part 136 Cap 138 Transfer mechanism 140 Control part S1 Carrier transfer area S2 Wafer transfer area C Carrier W Wafer

Claims (6)

In a magnetic annealing apparatus having a control unit, a storage container transfer area for transferring a storage container storing a group of objects to be processed and a process object transfer area for transferring the object to be processed are formed through an open / close door. And
In the storage container transport area,
A first mounting table for mounting a storage container carried into the magnetic annealing apparatus;
A plurality of second mounting tables on which the storage container is mounted in order to transfer the target object in an airtight manner from the storage container transfer region to the target object transfer region via the open / close door;
A storage unit for storing a plurality of the storage containers;
A storage container transport mechanism for carrying in and out the storage container between the first mounting table, the second mounting table and the storage unit;
Is placed,
In the workpiece conveyance area,
An aligner for aligning a plurality of the objects to be processed;
A workpiece holder that can hold a plurality of groups of the workpieces;
A target object transport mechanism for transporting the target object between the storage container mounted on the second mounting table, the aligner and the target object holder;
Heating means for heating the object to be processed;
A magnetic field generating means having a horizontal superconducting magnet for applying a magnetic field to the object to be processed;
A transfer mechanism for transferring the target object held by the target object holder into the magnetic field generating means;
Is placed,
The length of the uniform magnetic field region of the horizontal superconducting magnet is greater than twice the diameter of the object to be processed,
The object holder holds a plurality of laminated bodies in which a plurality of the objects to be processed are stacked in a direction perpendicular to the direction of the magnetic field, arranged in parallel in a direction parallel to the direction of the magnetic field,
Magnetic annealing equipment. The control unit is configured to store the processing object in the storage container placed on one mounting table of the plurality of second mounting tables while transporting the processing object to the processing object holder. Control to transport the storage container stored in the section to another mounting table of the plurality of second mounting tables,
The magnetic annealing apparatus according to claim 1. The control unit is configured to transfer the processing object holder to the magnetic field generation unit after a predetermined number of the objects to be processed are held by the processing object holder. To control the
The magnetic annealing apparatus according to claim 1 or 2. The controller is
(I) The object to be processed so as to convey the object to be processed in the storage container placed on one of the plurality of second placement tables to the object holder through the aligner. Control the body transport mechanism,
(Ii) During the transfer in (i), the storage container mounted on the other mounting table of the plurality of second mounting tables is unloaded from the other mounting table, and is stored in the storage unit. Controlling the storage container transport mechanism to transport the stored storage container to the other mounting table;
(Iii) The storage container mounted on the other mounting table after all the processed objects in the storage container mounted on the one mounting table are transferred to the processing object holder Controlling the target object transport mechanism so as to transport the target object within to the target object holder via the aligner,
(Iv) During the transfer in (iii), the storage container placed on the one placement table is unloaded from the one placement table, and the storage container stored in the storage unit is Controlling the storage container transport mechanism to transport to the one mounting table;
(V) repeating (i) to (iv), and after the predetermined number of groups of the objects to be processed are held by the object holder, the object holder is moved to the magnetic field generating means. Controlling the transfer mechanism to transfer in,
The magnetic annealing apparatus according to claim 1. The plurality of second mounting tables are two mounting tables,
The two mounting tables are arranged in series in the vertical direction.
The magnetic annealing apparatus as described in any one of Claims 1 thru | or 4. The object to be processed is a wafer, and the storage container is a FOUP.
The FOUP can store 25 wafers,
The object holder can hold 100 wafers.
The magnetic annealing apparatus according to any one of claims 1 to 5.

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