JP3671983B2 - Vacuum processing equipment - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a vacuum processing apparatus.
[0002]
[Prior art]
Among vacuum processing apparatuses for manufacturing semiconductors, there are various apparatuses such as etching, film forming process, ashing, and sputtering, and there are single wafer type and batch type apparatuses. This type of semiconductor manufacturing apparatus has been devised and improved in order to cope with high integration and high throughput of semiconductors. For example, for a single wafer type vacuum processing apparatus, a plurality of vacuum processing chambers are shared by a common transfer chamber. There is also known an apparatus that is connected to each other and transported from a common input / output port to each vacuum processing chamber.
[0003]
FIG. 6 is a view showing such an apparatus. A plurality of vacuum processing chambers 13 and cassette chambers 14 are arranged in a transfer chamber 12 having a transfer arm 11 that can be moved forward and backward and rotated with respect to the rotation center of the transfer arm 11. A vacuum processing apparatus is configured by connecting in a radial pattern. A wafer cassette 10 containing, for example, 25 semiconductor wafers (hereinafter referred to as wafers) is loaded into the cassette chamber 14, and the wafer cassette 10 is decompressed by the transfer arm 11. The wafers inside are sequentially transferred into the vacuum processing chambers 13 and, for example, the wafers are processed in parallel in the respective vacuum processing chambers 13.
[0004]
In such an apparatus, compared with the case where the vacuum processing chamber and the load lock chamber are connected one-to-one, the transfer arm is shared by a plurality of vacuum processing chambers. If different processes are performed in the vacuum processing chamber and continuous processing is performed on one wafer, there is an advantage that throughput can be improved.
[0005]
[Problems to be solved by the invention]
The present invention has been made under such circumstances, and an object of the present invention is to eliminate the need for a magnetic fluid seal or the like at the bearing of the rotary shaft of the transfer means in the transfer chamber in the vacuum processing apparatus. It is an object of the present invention to provide a technique capable of suppressing the scattering of particles during driving.
[0006]
[Means for Solving the Problems]
The invention according to claim 1, provided in the transfer chamber of the airtight structure which is a vacuum atmosphere, an articulated arm which is pivoted in a horizontal direction as the rotation shaft provided in the bottom of the transfer chamber by the rotation shaft through a bearing portion of the pivot shaft while accommodating a drive unit for rotating the arm - with bets, and conveying means for conveying the object to be processed with the vacuum processing chamber, a of the conveying means A case portion configured such that an internal space communicates with the transfer chamber and is airtightly partitioned from the atmosphere side;
Evacuation means for evacuating the transfer chamber;
A first exhaust pipe connecting the transfer chamber and the vacuum exhaust means;
A second exhaust pipe connecting the case portion and the vacuum exhaust means;
An inert gas supply unit that is provided near the upper part of the rotation shaft of the transfer means and supplies an inert gas into the transfer chamber;
A suction path that allows the bearing portion of the joint portion of the transport means to communicate with the internal space of the case portion through the arm and the rotation shaft ,
At least during the transfer operation of the transfer means, an inert gas is supplied from the inert gas supply unit into the transfer chamber, and the inert gas is evacuated through the second exhaust pipe. A vacuum processing apparatus.
[0007]
In the present invention, the valve that opens and closes the second exhaust pipe is opened when the transfer chamber is roughly drawn, and the valve is closed after the transfer chamber is depressurized to a predetermined pressure. The air may be exhausted through the exhaust pipe.
Further, for example, a labyrinth seal is formed between the bearing portion of the rotation shaft of the transfer means and the transfer chamber. Moreover, the said inert gas supply part is a sintered compact provided, for example in the front-end | tip part of the inert gas supply pipe | tube. A plurality of projections made of, for example, resin are formed on the target object holding portion of the conveying means.
[0008]
[Action]
According to the present invention , since the drive unit of the conveying means is housed in the case part that is airtightly separated from the atmosphere side, a magnetic fluid seal is not required in the bearing part of the rotating shaft. And since an inert gas can be supplied in a conveyance chamber, since the airflow which goes to the inside from the outside of a case part is formed, scattering of a particle can be prevented more reliably.
[0009]
【Example】
FIG. 1 and FIG. 2 are a partially broken perspective view and a plan view showing the overall configuration of the embodiment of the present invention, respectively. In the figure, reference numeral 2 denotes a transfer chamber, and the transfer chamber 2 is composed of a chamber having an airtight structure formed in a rectangular parallelepiped shape. In the transfer chamber 2, two wafer loading / unloading ports 31, 31 are formed on the side wall along one long side, and two cassette chambers 3 A having an airtight structure in which the wafer cassette C is placed, 3B is airtightly connected to the transfer chamber 2 through the carry-in / out entrances 31 and 31, respectively.
[0010]
The wafer cassette (hereinafter simply referred to as a cassette) C is a container for storing 25 wafers, and the cassette chambers 3A and 3B correspond to a container mounting portion in this embodiment. In the upper part of the cassette chambers 3A and 3B, a lid 32 that can be opened and closed freely is formed so that the cassette C can be taken in and out, and the cassette C is raised and lowered intermittently as shown in FIG. An elevating mechanism 33 is provided, and an exhaust pipe 34 is connected to the bottom. The exhaust pipe 34 is connected to a vacuum pump 34a such as a dry pump via a valve V1.
[0011]
Further, in the transfer chamber 2, two wafer transfer ports 41 and 41 are formed on the side wall along the other long side, and two vacuum processing chambers such as, for example, Vacuum processing chambers 4 </ b> A and 4 </ b> B for performing plasma etching using a magnet are hermetically connected to the transfer chamber 2. In this example, the vacuum processing chamber 4 </ b> C is also airtightly connected to the short side of the transfer chamber 2 via the carry-in / out port 41. Note that gate valves G (common reference numerals) are provided at the respective loading / unloading ports 31 of the cassette chambers 3A and 3B and the loading / unloading ports of the vacuum chambers 4A to 4C.
[0012]
As shown in FIG. 3, the vacuum processing chamber 4A (4B, 4C) is provided with a lower electrode 42 and an upper electrode 43 that also serve as a susceptor, and a processing gas supply pipe 44 and an exhaust pipe 45 are connected thereto. Above the upper electrode 43, a magnet housing case 46 is provided separately from the vacuum processing chamber, in which a magnet 47 that forms a magnetic field in the vacuum processing chamber 4A (4B, 4C). A magnet 48 for preventing magnetic field leakage is disposed so as to be rotated by a motor 49.
[0013]
In the transfer chamber 2, transfer means 5 for transferring the wafer W between the cassette chambers 3 </ b> A, 3 </ b> B and the vacuum processing chambers 4 </ b> A to 4 </ b> C is provided. The transport means 5 comprises an articulated transport arm having three arms 51, 52 and 53 that are independently rotated in the horizontal direction. The lower arm 51 is transported as shown in FIG. It is attached to a rotating shaft 61 extending from a drive unit 6 provided at the lower part of the chamber. A hole for attaching the arm 51 is formed in the bottom surface portion of the transfer chamber 2, and a flange portion 62 is detachably provided on the bottom surface portion so as to cover the hole.
[0014]
A cylindrical portion 63 extending downward is formed at the center of the flange portion 62, and a bearing portion 64 is interposed between the inner wall of the cylindrical portion 63 and the rotating shaft 61. A cylindrical case portion 65 having an airtight structure is attached to the lower side of the flange portion 62, and a space in the case portion 65 is partitioned airtightly from the atmosphere side.
[0015]
The drive unit 6 includes three drive motors corresponding to the three arms 51 to 53, and upper and middle arms 52 and 53 are independently provided in the rotation shaft 61. And a rotation shaft (not shown) for driving. Between the upper and middle arms 52 and 53, there are provided a rotation shaft 53a and a bearing portion 53b for rotating the upper arm 53, and between the middle and lower arms 51 and 52, the upper arm 53 and 53 are provided. A rotation shaft 52a and a bearing portion 52b for rotating the middle-stage arm 52, which incorporates a rotation shaft (not shown) for the arm 53, are provided. Inside the middle and lower arms 51 and 52, a transmission mechanism such as a belt and a pulley is incorporated so that the upper and middle arms 52 and 53 are independently driven by the drive of the drive unit 6. A suction path (indicated by a dotted line) 54 for sucking particles generated in the bearing parts 52 b and 53 b of the joint part is formed. The suction path 54 passes through the rotation shaft 61 and is an internal space of the case part 65. Is open.
[0016]
An exhaust pipe 36 is connected to the case portion 65, and the exhaust pipe 36 is connected to the vacuum pump 35 such as a turbo molecular pump via a valve V2. Therefore, when the valve V2 is opened, the internal space of the case portion 65 is evacuated, whereby particles generated in the bearing portions 64, 52b, and 53b are discharged into the exhaust pipe 36 through the internal space of the case portion 65. It will be. Further, a labyrinth (maze) seal is formed between the bearing portion 64 and the inside of the transfer chamber 2. That is, the rotation shaft 64 and the cylindrical portion 63 are configured to have a shape with a gap between them.
[0017]
The wafer holding portion of the upper arm 53 is provided with projections 55 made of a material that hardly generates particles due to friction, such as fluororesin, at three positions where the wafer can be stably held, for example. With this configuration, the wafer can be prevented from being displaced when the wafer is held on the arm 53, and the wafer itself is not damaged.
[0018]
An exhaust pipe 21 is connected to the transfer chamber 2, and the exhaust pipe 21 is connected to the vacuum pump 35 via a valve V3. In the transfer chamber 2, a vertically movable buffer stage 22 for temporarily placing a wafer and an alignment for aligning the orientation and center position of an orientation flat (hereinafter referred to as “orientation flat”) of the wafer. A mechanism 7 is arranged (see FIGS. 1 and 2). The alignment mechanism 7 includes a rotary stage 71 that can move in the X, Y, Z, and θ directions, a light emitting / receiving unit 72 that optically detects the peripheral portion of the wafer, and the like.
[0019]
In addition, an inert gas supply pipe 23 for supplying an inert gas such as nitrogen gas is provided in the transfer chamber 2 as shown in FIGS. 1 and 2 to an upper position near the rotation center of the lower arm 51. An inert gas supply section 24 made of, for example, a sintered metal is formed at the tip of the inert gas supply pipe 23. The base end side of the inert gas supply pipe 23 is connected to, for example, a nitrogen gas supply source 25.
[0020]
Next, the operation of the above embodiment will be described. First, the gate valve G is closed, and the inside of the transfer chamber 2 and the vacuum processing chambers 4A to 4C is evacuated. At the initial stage of evacuation in the transfer chamber 2 (during rough evacuation), the valve V2 is opened, and the inside of the case portion 65 is evacuated by the vacuum pump 35 through the exhaust pipe 36, and is discharged from the inert gas supply pipe 23. An inert gas such as nitrogen gas is supplied into the transfer chamber 2 through the active gas supply unit 24. As a result, the gas in the transfer chamber 2 is added to the path from the exhaust pipe 21, the path of the bearing part 64 of the rotating shaft 61 → the case part 65 → the path of the exhaust pipe 36, and the bearing parts 52 b and 53 b of the joint part of the transfer means 5. → Exhaust through the suction path 54 → case portion 65 → exhaust pipe 36. Then, after the pressure in the transfer chamber 2 is reduced to some extent, the valve V2 is closed, and thereafter, the pressure is reduced through the exhaust pipe 21 to, for example, a vacuum degree of 50 to 900 mTorr.
[0021]
On the other hand, the lid 32 of the cassette chambers 3A and 3B is opened, and the cassette C as a container containing 25 wafers W to be processed is placed in a posture in which the wafer W is horizontal, for example, one cassette chamber 3A (loading cassette chamber 3A). ) Is placed on the lifting mechanism 33 in the inside by an operator, for example, and an empty cassette C is placed in the other cassette chamber 3B (unloading cassette chamber 3B), the lid 32 is closed, and the cassette chambers 3A and 3B are closed. Is evacuated to the same degree of vacuum as in the transfer chamber 2, and then the gate valves G of the cassette chambers 3A and 3B are opened. Next, the arm 51 of the transfer means 5 enters the cassette C in the cassette chamber 3 </ b> A via the transfer port 31 and receives the wafer W. In this case, the elevating mechanism 33 is intermittently lowered to carry out the wafer W from the cassette C one by one, and the wafer W is held by the three protrusions 54 of the holding portion at the tip of the arm 53.
[0022]
The arm 53 places the wafer W received from the cassette C on the rotary stage 71 of the alignment mechanism 7, detects the peripheral edge of the wafer W by, for example, the light emitting / receiving unit 72, and moves the rotary stage 71 based on the result. The orientation of the orientation flat and the center of the wafer W are aligned. Subsequently, the wafer W is loaded into the vacuum processing chamber 4 </ b> A through the loading / unloading port 41 by the transfer unit 5. In the vacuum processing chamber 4A, a wafer is placed on the susceptor 42 through an elevating operation of an unillustrated elevating pin combined with the susceptor 42, and the high frequency power between the susceptor 42 and the upper electrode 43 and the magnetic field of the magnet 47 are changed. Etching is performed by plasma obtained by energy.
[0023]
The wafers W in the cassette C are distributed to, for example, the vacuum processing chambers 3A to 3C by the transfer process as described above, and vacuum processing, for example, plasma etching is performed in parallel. The processed wafer W is transferred, for example, into the cassette C of the other cassette chamber 3B by the transfer means 5, but the wafer W to be processed next is processed in the vacuum processing chambers 3A to 3C. Is aligned and waiting on the buffer stage 22.
[0024]
While the conveying means 5 is being driven, the valve V2 is opened to evacuate the inside of the case portion 65, and the suction is sucked from the bearing portions 64, 52b, 53b as described above, and from the inert gas supply portion 24, for example, nitrogen Gas is supplied into the transfer chamber 2. Since the inert gas supply unit 24 is in the vicinity of the upper part of the rotating shaft 61 of the conveying means 5, the nitrogen gas mainly flows into the case unit 65 from the bearing units 64, 52b, and 53b through the above-described path.
[0025]
According to the above-described embodiment, since the transfer means 5 including the articulated transfer arm provided with the three arms 51 to 53 that are each independently movable in the horizontal direction is provided in the transfer chamber 2. The degree of freedom that the horizontal posture of the means 5 can take is great, and the wafer transfer path by the arms 51 to 53 can be freely selected as long as it is within the stroke range of the arm. Therefore, since the degree of freedom in the positional relationship between the direction of the carry-in / out entrance 41 of each of the vacuum processing chambers 4A to 4C and the carry-in / out entrance 31 of the cassette chambers 3A and 3B and the carrying means 5 is large, the carrying chamber 2 is formed in a rectangular parallelepiped shape. Then, along the one side, the inlet / outlet ports 41, 41 of the vacuum processing chambers 4A, 4B can be arranged, and the inlet / outlet ports 31, 31 of the cassette chambers 3A, 3B can be arranged. In other words, the degree of freedom of the layout of the transfer chamber 2 and the layout of the vacuum processing chambers 4A to 4C and the cassette chambers 3A and 3B is large. As described above around the rectangular transfer chamber 2 By arranging the vacuum processing chambers 4A to 4C and the cassette chambers 3A and 3B, the arrangement space of the apparatus is narrower than the case where the vacuum processing chambers and the cassette chambers are arranged radially with respect to the rotation center of the transfer means. This is very effective in installing an apparatus combining a plurality of vacuum processing chambers in an expensive clean room. Furthermore, since the degree of freedom in layout of each room is large, the transport distance can be shortened, so that the throughput can be improved.
[0026]
In addition, since the drive motor that forms the drive unit 6 of the transport unit 5 is housed in the case unit 65 that is airtightly separated from the atmosphere side, a magnetic fluid seal or the like is not required as the bearing unit 64 of the rotating shaft 61. Then, the bearings 64, 52b and 53b of the conveying means 5 are scavenged, and an inert gas is supplied from the upper vicinity of the conveying means 2 to form an air flow from the outside to the inside of each of the bearing parts 64, 52b and 53b and a labyrinth. Since the seal is formed, it is possible to prevent the particles generated from the bearing portion from being driven into the transfer chamber 2 as the transfer means 5 is driven, and it is extremely effective as a manufacturing apparatus for a semiconductor device to be finely patterned. is there. The gas used as the inert gas is not limited to nitrogen gas but may be argon gas or helium gas.
[0027]
Further, if the buffer stage 22 is provided in the transfer chamber 2, the transfer efficiency can be improved, for example, the next wafer can be aligned and kept waiting, and the throughput is improved. In this case, if the buffer stage 22 is raised or lowered so that the wafer being transferred and the wafer on the buffer stage 22 do not interfere with each other in the height direction, the transfer path for transferring the wafer from the vacuum processing chamber to the cassette C will be described. A buffer stage 22 can be provided nearby. Two alignment mechanisms 7 may be prepared and used as buffer stages.
[0028]
Furthermore, in the present invention, the vacuum processing chambers 4A to 4D are not limited to the layout according to the above-described embodiment, but two vacuum processing chambers 4A to 4D are provided on the opposite long sides of the transfer chamber 2 having a rectangular planar shape as shown in FIG. It is also possible to adopt a layout in which the cassette chambers 3A and 3B are arranged one by one on the short sides facing each other.
[0029]
In the above-described embodiment, the cassette chambers 3A and 3B correspond to the preliminary vacuum chamber of the first aspect of the invention. However, the preliminary vacuum chamber is not limited to the cassette chamber, and only one wafer is placed. It may be a load lock chamber for carrying out or another transfer chamber provided with transfer means. The vacuum processing chamber is not limited to a processing chamber that performs etching using a magnet, but may be a vacuum processing chamber that performs plasma CVD, thermal CVD, ashing, sputtering, or the like, or a separate vacuum in each vacuum processing chamber. Processing may be performed. The object to be processed is not limited to a wafer but may be an LCD substrate.
[0030]
【The invention's effect】
According to the present invention, a magnetic fluid seal is not required, and scattering of particles into the transfer chamber can be prevented.
[Brief description of the drawings]
FIG. 1 is a partially broken perspective view showing an overall configuration of an embodiment of the present invention.
FIG. 2 is a plan view showing an overall configuration of an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing an overall configuration of an embodiment of the present invention.
FIG. 4 is a longitudinal sectional side view showing a conveying unit and a driving unit thereof.
FIG. 5 is a plan view showing another embodiment of the present invention.
FIG. 6 is a plan view showing a conventional vacuum processing apparatus.
[Explanation of symbols]
2 Transfer chamber 24 Inert gas supply unit 3A, 3B Cassette chamber 31, 41 Unloading / inlet port 35 Vacuum pumps 4A-4C Vacuum processing chamber 5 Transfer means 51-53 Arms 52a, 53a, 63 Rotary shafts 52b, 53b, 64 Bearing unit 6 Drive unit 65 Case unit

Claims (5)

It provided in the transfer chamber of the airtight structure which is a vacuum atmosphere, and an articulated arm which is pivoted in a horizontal direction as the rotation shaft provided in the bottom of the transfer chamber by the rotation shaft, vacuum processing chamber and conveying means for conveying the object to be processed with the,
A of the transport means - as the inner space through the bearing portion of the pivot shaft while accommodating a drive unit for rotating the arm is in communication with the transfer chamber and the atmosphere side is constructed is partitioned into airtight The case part,
Evacuation means for evacuating the transfer chamber;
A first exhaust pipe connecting the transfer chamber and the vacuum exhaust means;
A second exhaust pipe connecting the case portion and the vacuum exhaust means;
An inert gas supply unit that is provided near the upper part of the rotation shaft of the transfer means and supplies an inert gas into the transfer chamber;
A suction path that allows the bearing portion of the joint portion of the transport means to communicate with the internal space of the case portion through the arm and the rotation shaft ,
At least during the transfer operation of the transfer means, an inert gas is supplied from the inert gas supply unit into the transfer chamber, and the inert gas is evacuated through the second exhaust pipe. Vacuum processing equipment. A valve that opens and closes the second exhaust pipe is opened when roughing the transfer chamber, and after the pressure in the transfer chamber is reduced to a predetermined pressure, the valve is closed. the vacuum processing apparatus according to claim 1, characterized in that it is exhausted through. The vacuum processing apparatus according to claim 1, wherein a labyrinth seal is formed between a bearing portion of the rotation shaft of the transport unit and the transport chamber. The vacuum processing apparatus according to claim 1, wherein the inert gas supply unit is a sintered body provided at a distal end portion of an inert gas supply pipe. The vacuum processing apparatus according to any one of claims 1 to 4, wherein a plurality of protrusions made of resin are formed on the target object holding portion of the conveying means.

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