JP2711321B2 - Plasma processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a plasma processing apparatus that mounts an object to be processed on a boat and performs plasma processing in a batch manner.

(Prior Art) For example, plasma CVD processing on a semiconductor wafer
Conventionally, the process is generally performed by supporting a wafer on a susceptor disposed in a processing container.

However, this limits the number of wafers that can be processed at one time.
A method of processing about 0 wafers at a time is preferable.

A plasma CVD apparatus of the type that loads and unloads a boat of this type, which has already been put into practical use, is called a soft landing method, in which a boat loaded with wafers is loaded into a processing vessel and then the bottom surface inside the processing vessel is loaded. The plasma processing was started after the boat was mounted on the side and the carry-in / out lever was carried out.

(Problems to be Solved by the Invention) In the above-mentioned soft landing method, since the setting of the boat in the processing container cannot be performed in a non-contact manner, the problem of impurities generated at the time of setting the boat cannot be avoided. It has been pointed out that the particles adhere to the wafer and the processing yield decreases.

In order to carry out the loading and unloading of the boat in a non-contact manner, a method in which the boat is loaded by a cantilever in a cantilever shape, the processing is performed while the boat is supported by the cantilever, and the boat is unloaded after the processing is completed is considered. .

However, a boat that performs this type of plasma processing holds an electrode plate for generating plasma, and is heavier than the boat used for other processing. Furthermore, in recent years, there has been a demand for increasing the throughput by increasing the number of batches processed, and the longitudinal axis of the boat has become longer. In order to support a wafer and an electrode plate in such a long boat, the strength must be ensured accordingly. Instead, the boat weight tends to be further increased.

If such a heavy boat is supported on the free end of a cantilever cantilever, the position of the free end is displaced up and down, and the delivery of the boat to and from a boat elevator, etc. , It is difficult to position the boat elevator vertically.

Also, if an impact load is applied when a boat of considerable weight is delivered, the cantilever will be damaged unless a considerable strength is guaranteed.

Further, when this type of cantilever method is adopted, a structure in which a current is applied to the electrode plate on the boat when the boat is placed in the processing furnace cannot be adopted as in the soft landing method.

Further, even if a contact portion that comes into contact with the boat is provided in the processing furnace, the contact surface is contaminated with a reaction product, so that the number of maintenance operations increases.

Therefore, it is an object of the present invention to adopt a cantilever method capable of carrying out non-contact boat loading and unloading when performing the plasma processing in a batch manner, and to increase the number of batches to be processed while maintaining the free end of the cantilever. Section is always set to the reference position to facilitate delivery of the boat,
Another object of the present invention is to provide a plasma processing apparatus capable of reducing a load on a cantilever during non-processing.

Another object of the present invention is to provide a plasma processing apparatus capable of supplying an electric current to an electrode plate outside the processing furnace in accordance with the loading and unloading of the cantilever to and from the processing furnace in the plasma generation step. is there.

[Configuration of the Invention] (Means for Solving the Problems) A plasma processing apparatus according to the first aspect of the present invention includes:
A boat that holds an electrode plate for plasma generation and supports the object to be processed on the electrode plate, a cantilever in a cantilever shape on which the boat is placed and carried in and out of the processing furnace, and the cantilever described above. A lever support mechanism that is arranged to be able to move up and down below the free end of the cantilever when it is carried out of the processing furnace, and that supports the free end at an elevated reference position;
Is provided.

A plasma processing apparatus according to a second aspect of the present invention includes a processing furnace for performing a plasma processing on an object to be processed in a process gas atmosphere;
Holding an electrode plate for plasma generation, a boat supporting the object to be processed of the electrode plate, and a cantilever of a cantilever shape for loading and unloading the boat with the boat mounted thereon, The cantilever is formed with a cap that seals an open end of the processing furnace when the cantilever is carried into the processing furnace,
On the outer surface side of the cap, a connection terminal that is electrically connected to the electrode plate is formed, and outside the processing furnace, the connection terminal moves to a position that contacts the connection terminal and a position that does not interfere with the carry-in / out path of the cantilever. A possible power supply contact is formed, and when the cantilever is carried into the processing furnace and installed at the processing position, the power supply contact contacts the contact terminal and conducts electricity.

(Operation) According to the first aspect of the present invention, when the cantilever on which the boat is mounted is present outside the processing furnace, the support portion provided on the lever support mechanism is raised toward the free end of the cantilever. The cantilever free end can be supported at the raised reference position.

Therefore, when the boat is delivered, the cantilever can be maintained at the predetermined reference position, and the delivery of the boat mounted thereon can always be performed at a fixed position.

Furthermore, by supporting the free end of the cantilever,
The load on the cantilever can be reduced.

According to the second aspect of the present invention, the opening end of the processing furnace is sealed by the cap, and the plasma processing is performed on the object mounted on the boat. In performing this plasma processing, a contact terminal formed on the outer surface of the cap and a power supply contact formed outside the processing body are energized by contact when the cantilever is carried in,
Plasma processing can be realized.

In addition, since power is supplied to each electrode plate for plasma generation mounted on the boat by a power supply connection provided outside the processing furnace, the contact surface of the power supply connection is contaminated with a reaction product. In addition, the frequency of maintenance can be greatly reduced, and the maintenance work can be realized outside the processing furnace, so that the work load can be greatly reduced.

(Example) Hereinafter, an example in which the present invention is applied to a plasma CVD apparatus will be specifically described with reference to the drawings.

First, an outline of the plasma CVD apparatus will be described with reference to FIG.

In FIG. 1, the horizontal processing furnace 10 is stacked, for example, in three stages, and provided with a boat loading / unloading device 12 having a cantilever (not shown) for loading the boat 30 into each horizontal processing furnace 10. I have. The boat loading / unloading device 12
The boat liner 14 can move the boat 30 linearly between a wafer transfer position A and an elevator transfer position B.

At a position facing the elevator transfer position B,
A boat elevator 16 is provided, and the boat 30 can be supported and transported by two boat receiving bars 18a, 18a attached to an elevator arm 18 that can move up and down and move horizontally.

At a position facing the wafer transfer position A, a wafer transfer robot 20 having an articulated arm is provided. The wafer transfer robot 20 includes a first movable unit 22b that rotates about a first rotation shaft 22a, and a first movable unit 2b.
2b that rotates with respect to the second rotation shaft 24a supported by 2b
And a third movable portion 24b supported by the second movable portion 24b.
And a third movable portion 24b that rotates with respect to the rotation shaft 26a. And, in the third movable portion 26b,
A robot arm (not shown) for holding a wafer by suction, whose details will be described later, is provided.

Then, the wafer transfer position A on the boat liner 14 is moved by the rotation operation of the wafer transfer robot 20.
The robot arm can be moved between the boat 10 set to the above and the plurality of carriers 28, and wafer transfer is possible.

Next, the boat 30 will be described with reference to FIGS.
This will be described with reference to FIG.

In this boat 30, two handle portions 32, 32 are connected by two connecting rods 34, 34, and two power supply rods 36, 36 are disposed between the handle portions 32, 32. I have. The electrode plate 40 for supporting the wafer and generating the plasma is electrically connected to one of the power supply rods 36 for the odd-numbered electrode plate and electrically connected to the other power supply rod 36 for the other one. Are supported so that a positive connection can be made. Insulating spacers 38 made of, for example, quartz glass are interposed between the electrode plates 40 at the three locations, respectively, to keep the distance between the electrodes equal and to maintain the verticality.

The two electrode plates 40 at both ends in the longitudinal direction of the boat support wafers on only one side, and the other electrode plates 40 can support wafers on both sides. For this, its electrode support surface
Two taper pins 44 are fixed to each of the pins 42, and can support the lower end of the wafer and hold it in close contact with the wafer support surface 42. The wafer support surface on the left side of the electrode plate 40 shown in FIG.
42a, and the right side is a wafer supporting surface 42b. Relief portions 46a, 46b for preventing interference with the robot arm are formed at the upper ends of the wafer support surfaces 42a, 42b, respectively.Since the electrode plate 40 is thin, the relief portions 46a, 46b The electrode plates 40 are formed at positions shifted from the center line P in different directions.

Next, a cantilever 50 arranged in the boat loading / unloading device 12 for loading / unloading the boat 30 into / from each horizontal processing furnace 10 will be described with reference to FIG. As shown in FIGS. 1A and 1B, the cantilever 50 has a cap 52 for sealing the open end of the horizontal processing furnace 10. The cantilever on the right side of this cap
A driving device (not shown) that drives the 50 toward and away from the horizontal processing furnace 10 is provided. On the surface of the cap 52, two base end pipes 54, 54, two boat support pipes 58 ', 58' fixed to the end thereof, and free end side pipes 58, 58 fixed to the end thereof. And is formed in a cantilever shape. The base end pipes 54, 54 are formed to have a length such that the boat 30 mounted on the cantilever 50 can be arranged in the soaking zone of the horizontal processing furnace 10. The boat support pipes 58 ', 58' support the boat 30 and contact portions for supplying power to the power supply rod 36.
Has 60. The cantilever 50 in this embodiment is
Two boats 30, 30 can be mounted. The boat 3
Numeral 0 has a contact portion 36a electrically connected to the power supply rod 36 at the four corners, and the contact portion 36a is formed in a cone shape as shown in FIG. On the other hand, the contact portion 60 that is in electrical contact with the conical contact portion 36a has a mortar-shaped groove 60a as shown in FIG. The area is secured. A connector bridge 56 is disposed on each of the two boat support pipes 58 ′, 58 ′, and is electrically connected to the contact section 60. Then, the connector passing on the side of the boat support pipe 58 'is electrically connected to the connect rod 62 through the base end pipe 54, and further electrically connected to the connection terminal 64 provided on the other surface side of the cap 52. It is connected to the. In the present embodiment, the cantilever 50 is carried into the horizontal processing furnace 10, and after the cap 52 seals the opening end of the horizontal processing furnace 10, the RF power source is connected to the outside of the processing furnace 10 via the connection terminal 64. Can be supplied.

Next, a lever support mechanism 70 for supporting the free end side pipe 58 of the cantilever 50 will be described with reference to FIG.

The lever support mechanism 70 is arranged to face the position where the free end side pipe 58 is arranged when the cantilever 50 is unloaded from the horizontal processing furnace 10. The lever support mechanism 70 has an elevating part 72 that can move up and down at a position facing the two free end side pipes 58, 58.
Two support grooves 74, 74 cut out in a letter shape are formed.
The elevating unit 72 is fixed to one end of an arm 76, and the other end of the arm 76 is connected to a guide shaft via a linear bearing 78.
It is supported up and down by 80. A rodless cylinder 82 is arranged to move the arm 76 up and down. The rodless cylinder 82 can move the movable portion 86 up and down by increasing the air pressure to one of the two upper and lower air introduction portions 84a and 84b, and the movable portion 86 It can be moved up and down integrally with.

 Next, the operation will be described.

Transfer of wafers from the carrier 28 to the boat 10 is performed by setting the boat 10 at the wafer transfer position A on the boat liner 14 and driving the wafer transfer robot 20. After the wafer transfer is completed, the boat 30 is moved from the wafer transfer position A shown in FIG.
After that, the two handles 32, 32 of the boat 30 are moved by the boat elevator 16 by the drive of the boat elevator 16.
Supported by 8a, 18a. Further, the boat 30 is transferred to the cantilever 50 installed on the boat carrying-in / out device 12 by the upward movement and the horizontal movement of the boat elevator 16.

Here, the free end side pipe 58 of the cantilever 50 to which the boat 30 is delivered as described above is maintained at a predetermined reference height by the lever support mechanism 70. Especially,
In the case of this embodiment, two boats are placed on the cantilever 50.
Although it is designed to carry 30, 30 even after loading one boat 30, the cantilever 50 regardless of its weight
Since the reference height of the free end side pipes 58, 58 can be maintained,
The delivery of the boat 30 can always be performed at the same elevator elevating position. If the height of the free end side of the cantilever 50 does not change, the horizontal position of the groove 60a in the contact portion 60 for receiving the contact portion 36a of the boat 30 does not change. Part 3
The insertion operation of 6a can be easily realized. Further, by supporting the free end side of the cantilever 50 with the lever support mechanism 70, when the boat 30 is transferred to the cantilever 50 by the boat elevator 16, even if an impact load is applied, this cantilever is used. In addition to being received only by the cantilever 50, the burden can also be borne by the lever support mechanism 70 that supports the free end side of the cantilever 50, so that the boat 30 of an equivalent weight holds the electrode plate 40 in addition to a large number of wafers. Even if an impact load occurs, the lever support mechanism 70
This can reliably prevent the cantilever 50 from being damaged.

After the two boats 30, 30 are set on the cantilever 50, a large amount of air is introduced into the air introduction portion 84a of the lever support mechanism 70, the movable portion 86 is lowered, and the movable portion 86 is moved up and down through the arm 76. The part 72 is lowered. In this way, as shown by the chain line in FIG. 1, the elevating unit 72 is set outside the movement path of the cantilever 50. After that, the cantilever 50 is carried into the horizontal processing furnace 10 by a driving device (not shown). By closing the opening end of the processing furnace 10 with the cap 52, setting the processing temperature to a predetermined value, introducing a process gas, and generating plasma, the plasma CVD process is performed on the wafer mounted on the boat 30. become.

After the processing is completed, the cantilever 50 is retracted and set outside the horizontal processing furnace 10. After the unloading of the cantilever 50 is completed, the lever support mechanism 70 is driven again, and the two free end-side pipes 58, 58 of the cantilever 50 are supported by the elevating unit 72. In this manner, when the boat 30 is transferred to the elevator arm 18, the free end of the cantilever 50 can be maintained at a predetermined reference height.
The same effect as that at the time of loading can be obtained.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, the shape of a portion for supporting the free end of the cantilever 50 in the lever support mechanism 70 or the elevation portion 72
Can be replaced by other various members capable of realizing these functions. Further, the present invention is not necessarily applied to a plasma CVD apparatus, but can be similarly applied to another plasma processing apparatus employing a cantilever method, for example, a plasma etching apparatus.

Next, the boat is placed outside each horizontal processing furnace 10 and the boat
The power supply connection portion 90 for supplying power to each electrode plate 40 of the 30 will be described with reference to FIGS. 5 and 6. FIG.

As shown in FIG. 5, the power supply connection portion 90 is composed of a connection terminal 64 on the cantilever 50 side and a member provided in a scavenger 98 as a heat exhaust chamber outside the horizontal processing furnace 10. In this scavenger 98, contact arms 92, 92 (only one of them is shown in FIG. 1) rotatable toward the two connection terminals 64, 64 are arranged. The contact arm 92 has a base end fixed to a rotary actuator 94, and the rotation of the rotary actuator 94 causes the contact arm 92 to connect to the connection terminal 64.
It is rotatable between a position where the contact is turned on and a position where the contact is turned off, which is not in contact with the contact. A cable 92a is connected to the contact arm 92, and the other end of the cable 92a is connected to an RF power source (not shown).
The rotary actuator 94 is fixed to a mounting plate 96,
The contact arm 92 has connection terminals on the mounting plate 96.
It has a mechanical switch 96a that is in a position that is not in contact with the contact arm 64 and that comes into contact with the contact arm 92 when it is set outside the path of movement of the cantilever 50. And
Only when the contact arm 92 is detected by the mechanical switch 96a, the loading / unloading operation of the cantilever 50 is enabled. On the other hand, the rotary drive of the rotary actuator 94, that is, the operation of turning the contact arm 92 into contact with the connection terminal 64, is performed after the cantilever 50 is loaded into the horizontal processing furnace 10 and it is detected that the loading operation of the boat 30 is completed. It is supposed to be.

Further, in the apparatus of the present embodiment, when the cantilever 50 is carried out of the horizontal processing furnace 10, an automatic door 100 is provided to prevent heat release from the opening end 10a of the processing furnace 10. The cantilever 50 is located at a position where the automatic door 100 is not in contact with the open end 10a of the horizontal processing furnace 10.
Can be moved in a direction orthogonal to the carry-in / out route.

Next, the rotary actuator 94 and the automatic door
The 100 drive systems will be described with reference to FIG.

When pressure is applied to the A port of the F-side rotary actuator 94 and the B port of the B-side rotary actuator 94 shown in FIG. 6, each of the contact arms 92 is turned on.
In this direction. On the other hand, when pressure is applied from the B port of the F-side rotary actuator 94 and the A port of the B-side rotary actuator 94, each of the contact arms 92 is driven in the direction of contact OFF. A first solenoid valve 102 is provided to switch air introduction to each port. In the state shown in FIG. 6, air is introduced in a direction in which the two contact arms 92 are turned on.

The air drive system is also used to open and close the automatic door 100. That is, the automatic door 100 is connected to the movable part 10 of the rodless cylinder 106 shown in FIG.
8, the auto door 100 is opened by introducing air to the open side of the rodless cylinder 106,
By introducing air to the closed side, the automatic door 10
0 is set at a position facing the open end 10a of the horizontal processing furnace 10. A second solenoid valve 104 is provided to switch the air introduction. In the state shown in FIG. 6,
Air is introduced on the closed side and therefore the auto door 100
Is set at a position to close its open end 10a.

Here, two boats 30, 30 are placed on the cantilever 50.
And the contact portion 36a connected to the power supply rod 36 of each boat 30 is connected to the contact portion 6 on the cantilever 50 side.
It is fitted into the groove 60a at 0 and its electrical connection is established.

Next, the cantilever 50 is driven to drive the two boats 30, 30.
Is loaded into the horizontal processing furnace 10. At this time, the contact arms 92, 92 arranged near the open end 10a of the processing furnace 10 are set to the contact OFF position by driving the rotary actuators 94, 94, and the automatic door 100 is set to the open position. Therefore, there is no trouble in carrying in the cantilever 50.

When the loading of the cantilever 50 is completed, the cantilever 50
Opening end of the horizontal processing furnace 10 by the cap 52 provided at
10a will be sealed. When the completion of the loading operation of the cantilever 50 is detected by a sensor (not shown) or the like, the first solenoid valve 102 shown in FIG. 6 is switched as shown in FIG. Pressurized from the B port and the A port of the F side rotary actuator 94, the two contact arms 92
Are driven in the direction of contact ON. As a result, the two contact arms 92, 92 come into contact with the connection terminals 64, 64 projecting outside the cap 52.

Thereafter, the inside of the horizontal processing furnace 10 is set to a predetermined process temperature, a process gas is introduced, and an RF power source (not shown) is turned on, and the cable 92a, the contact arm 92, the connection terminal 64, the connect rod 62, the connector handover 56, Contact part 6
0, electricity is supplied to the power supply rods 36, 36 through the contact portions 36a, and R is applied to the electrode plate 40 in electrical connection with the power supply rods 36, 36.
F power can be supplied. As a result, plasma by the process gas is generated between the two electrodes 40, 40, and the plasma for the wafer mounted on the boat 30 is generated.
CVD processing can be performed.

After the processing is completed, the driving of the above-described various processes is stopped, and the port of the first solenoid valve 102 is switched and controlled, so that the B port and the B port of the F-side rotary actuator 94 are controlled.
The two contact arms 92, 92 are connected to the connection terminals 64, by applying pressure from the A port of the side rotary actuator 94.
Set to the contact OFF position that is not in contact with 64. Then, it is detected by the mechanical switches 96a, 96a that the two contact arms 92, 92 are respectively located at the contact OFF position.
Can be carried out. When it is detected that the cantilever 50 has been completely unloaded from the horizontal processing furnace 10, the port of the second solenoid valve 104 is switched, air is introduced into the closed side of the rodless cylinder 106, and the auto door 100 is opened. The horizontal processing furnace 10 is linearly moved to a position facing the opening end 10a. As a result, the heat inside the horizontal processing furnace 10 is suppressed from being released to the outside of the processing furnace 10 due to the convection, and the rise in the next process can be accelerated. Here, in this embodiment, since the automatic door 100 is simply moved linearly, the opening end 10a cannot be completely sealed.However, heat release can be prevented so that the start of the next process can be accelerated. In particular, auto doors
Since the 100 is simply moved linearly, the drive mechanism can be reduced in size and weight.

As described above, according to the above configuration, power supply to each of the electrode plates 40 for plasma generation mounted on the boat 30 is realized by the power supply connection unit 90 provided outside the horizontal processing furnace 10. Therefore, the contact surface of the power supply connection portion 90 is not contaminated by the reaction product, and the frequency of maintenance can be greatly reduced.In addition, the maintenance work can be realized outside the horizontal processing furnace 10, so that Work load can be greatly reduced.

According to the first aspect of the present invention, when the cantilever is carried out of the processing furnace, the free end of the cantilever can be held at the predetermined reference position by the lever support mechanism. In addition, when transferring a boat of equivalent weight holding an electrode plate for plasma generation, the free end of the cantilever does not move up and down, so that the operation can be carried out reliably. Can be reduced by the lever support mechanism, so that the cantilever can be prevented from being damaged even when an impact load is applied.

According to the second aspect of the present invention, when performing the plasma processing, the contact terminal and the power supply contact portion are brought into contact with each other when the cantilever is carried in, so that electricity is supplied, and the plasma processing can be realized.

In addition, since power is supplied to each electrode plate for plasma generation mounted on the boat by a power supply connection provided outside the processing furnace, the contact surface of the power supply connection is contaminated with a reaction product. The frequency of maintenance can be greatly reduced, and the maintenance work can be realized outside the processing furnace, so that the work load can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a lever support mechanism at a free end of a cantilever in a plasma CVD apparatus to which the present invention is applied. FIGS. 2A and 2B are a front view and a plan view of a plasma processing boat, respectively. FIG. 3 is a schematic plan view for explaining the overall configuration of the apparatus of the embodiment, and FIGS. 4 (A), (B) and (C) are front views of cantilevers mounted with two boats, respectively. FIG. 3 is a plan view, a schematic cross-sectional view of a connector portion of a boat and a cantilever. 5 (A) and 5 (B) are a front view and a side view, respectively, of a power supply connection part in a plasma CVD apparatus, and FIG. 6 is for explaining a drive system of a rotary actuator and an automatic door in the power supply connection part. Schematic illustration of, 10 ... Process furnace, 16 ... Boat elevator, 30 ... Boat, 40 ... Electrode plate 50 ... Cantilever, 58 ... Free end, 70 ... Lever support mechanism, 74 ... Support Groove, 82 …… Rodless cylinder.

Claims (2)

(57) [Claims] 1. A processing furnace for performing plasma processing on an object to be processed in a process gas atmosphere, a boat holding an electrode plate for plasma generation, and supporting the object to be processed on the electrode plate; A cantilever shaped to be carried into and out of the processing furnace; and a cantilever disposed below the free end of the cantilever when the cantilever is carried out of the processing furnace. A plasma processing apparatus, comprising: a lever support mechanism that supports the unit. 2. A processing furnace for performing plasma processing on an object to be processed in a process gas atmosphere, a boat holding an electrode plate for generating plasma, and supporting the object to be processed on the electrode plate; And a cantilever in a cantilever shape to be carried into and out of the processing furnace, wherein the cantilever is formed with a cap that seals an open end of the processing furnace when the cantilever is carried into the processing furnace. A connection terminal that is electrically connected to the electrode plate is formed on the outer surface side of the cap, and can be moved outside the processing furnace to a position that contacts the connection terminal and a position that does not interfere with the carry-in / out path of the cantilever. A plasma processing apparatus, wherein when the cantilever is carried into a processing furnace and installed at a processing position, the power supply contact section contacts the contact terminal to conduct electricity.