JPS639586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an apparatus for performing sputter processing in a continuous plurality of steps in a vacuum on element thin films such as semiconductor wafers and communication devices.

[Background of the invention]

FIG. 1 is a front view showing an example of a known device of this type, with the upper side of the figure being above the earth. Second
The figure is a sectional view taken along the line AA in FIG. 1. For convenience of explanation, the left side of FIG. 2 will be referred to as the front, and the right side will be referred to as the rear. As shown in both figures, a gas pipe 2, a vacuum valve 3, a variable valve 4, and a vacuum pump 5 are connected to a thin cylindrical vacuum container 1. 6a is a front wall, and 6b is a rear wall.

A plurality of openings 7 are provided in the front wall 6a of the vacuum container 1 on the same radius from the center, and as shown in FIG. 3 processing station 10, 4th processing station 11,
and a fifth processing station 12.

The loading station 8 is provided with a door 13, and when the door is opened, a claw 23 appears as shown in FIG. 2, allowing the board 14 to be attached or removed.

The substrate holding claws 23 described above are installed around the substrate holding holes 22 of the circular transport plate 15 provided in contact with the front wall 6a.

An air cylinder 20 is installed on the rear wall 6b of the vacuum container 1 at a position corresponding to the loading station so as to be able to press the pressure plate 19 toward the conveyance plate 15.

Further, in the center of the rear wall 6b, there is a conveyor plate 1.
An air cylinder 21 is installed to drive 5 back and forth.

The aforementioned substrate holding holes 22 are bored in the transport plate 15 at equal intervals on the same radius as each opening 7 .

The above-mentioned conveyance plate 15 is a pressure plate 19
When the front wall 6 is not pressed by
It is rotated by a motor 24, gear 25, and chain 26 installed at a. A shaft 27 attached to the front and rear of the central axis of the conveyor plate 15 is connected to the vacuum container 1.
The walls 6 and 7 are vacuum sealed.

Also, inside the vacuum vessel 1 there is a pressure plate 19 that is moved back and forth by an air cylinder 20, and includes a door 13, an opening 7 of the loading station 8,
A vacuum preliminary chamber 28 is formed in cooperation with the substrate holding hole 22 of the transfer plate 15 and the pressure plate 19. Further, the pressure plate 19 is provided with openings 29 at positions corresponding to the second to fifth processing stations 9 to 12 in the wall 6.

Each processing station 9-22 is equipped with a unit or blind lid 16 for sputtering substrates.

The conventional continuous sputtering device constructed as described above operates as follows.

After evacuating the vacuum chamber 1 to a high vacuum using the vacuum pump 5, open the vacuum valve 3, introduce Ar gas into the vacuum chamber 1 from the gas pipe 2, and adjust the variable valve 4 appropriately to evacuate the inside of the vacuum chamber 1. Maintain an appropriate low pressure atmosphere. The transport plate 15 is pressed against the front wall 6a of the vacuum chamber 1 by the air cylinder 21,
Furthermore, the pressure plate 19 is controlled by the air cylinder 20.
is pressed against the transfer plate 15 to create a vacuum preliminary chamber 28 in the loading station 8. After the vacuum preparatory chamber 28 is brought to atmospheric pressure by a leak means (not shown), the door 13 is opened, and the sputtered substrate 14 is taken out by a transport means (not shown).
The unprocessed substrate 14 is attached to the claw 23 in the substrate holding hole 22 of the transport plate 15. Next, the door 13 is closed, and the vacuum preliminary chamber 28 is roughly evacuated by a rough evacuation means (not shown). Next, air cylinder 2
0 and 21, the pressure plate 19, the conveyance plate 15, and the front wall 6a are spaced apart from each other. Next, after the conveying plate 15 is rotated by one station by the motor 24, gear 25, and chain 26, the front wall 6a, the conveying plate 15, and the pressure plate 19 are again brought into close contact with each other by the air cylinders 20, 21. The loading station 8 repeats the above-described operations, and the second to fifth processing stations 9 to 12 perform predetermined processing on the substrate 14.

By repeating the above operations, the sputtering process is successively performed on the substrates 14 one by one.

The processing performed at each processing station includes a baking process in which the substrate 14 is heated in a vacuum to remove impurity gas adhering to the surface of the substrate 14, and a sputter etch process in which the surface of the substrate 14 is bombarded with Ar ions to remove the underlying surface layer. processing, sputtering processing to form a thin film, etc.

As a standard configuration, a second processing station 9 performs a baking process or a sputter etch process,
The third processing station 10 performs baking or sputter etch processing, and the fourth and fifth processing stations 11 and 12 perform sputter processing, but which processing station performs what kind of processing can be arbitrarily set.

The conventional continuous sputtering apparatus described above has the following drawbacks.

Although the second to fifth processing stations have the same vacuum atmosphere, sputter processing and sputter etch processing, which have different optimum operating pressures, must be performed under the same pressure. Processing speed and film quality decrease. Further, gas generated from the baking station and the sputter etch station reaches the sputter etch station and deteriorates the film quality.

Of the processing units 18, the sputtering processing unit processes a target (not shown) which is a source of film forming material.
It must be replaced periodically as the target is consumed, but at that time the entire inside of the vacuum container 1 becomes atmospheric pressure, so it takes a long time to evacuate the inside of the vacuum container 1 to a clean high vacuum again after replacing the target. As a result, the operating rate of the equipment decreases, reducing the effective production capacity.

Further, since the substrate 14 rotates in the vertical plane within the vacuum container 1, foreign matter falling from above when the substrate 14 is at the bottom adheres to the substrate 14, reducing the yield.

[Object of the Invention] The present invention has been made in view of the above circumstances, and its purpose is to provide a continuous sputtering device that improves the yield in the process of forming a thin film on a substrate and also improves the effective production capacity. There is a particular thing.

[Summary of the invention]

A feature of the present invention is that a sub-vacuum chamber is provided for each processing station on a sputtering apparatus which apparently consists of a set of vacuum systems, so that each processing can be set to an independent atmosphere.

Furthermore, by setting only the sub-vacuum chamber to atmospheric pressure while keeping the main vacuum chamber under vacuum, it is possible to shorten the evacuation time associated with target exchange, thereby achieving improvement in operating efficiency and effective production capacity.

In order to achieve the above object based on the above principle, the continuous sputtering apparatus of the present invention includes a cylindrical vacuum container, an exhaust means connected to the vacuum container, and a rotary conveyor provided concentrically within the vacuum container. a plurality of substrate holders provided at equal angular intervals on the transport means; an opening provided in a side wall of the vacuum container to face the substrate holders; and an airtight press of the substrate holder against the opening. , a driving means for separating the openings, an airtight door provided in at least one of the openings, a sub-vacuum chamber provided outside of at least one opening other than the opening provided with the door, and at least one [Embodiment of the Invention] Next, an embodiment of the present invention is shown in FIG. FIG. 4 will be explained. FIG. 3 is a vertical sectional view. Fourth
The figure is a horizontal cross-sectional view taken along the line C--C shown in FIG. 3, and the plane B--B in the figure shows a vertical cross-section in FIG. 3.

A main vacuum chamber 32 is constituted by a pentagonal vacuum container 30 and a lid 31 having a cylindrical recess in the center. In the wall surface 38 of the vacuum container 30, openings 33 having central axes on substantially the same horizontal plane are formed at equal angular intervals, forming a loading station 8 and second to fifth processing stations 9 to 12 in this order. Further, a door 13 is attached to be able to open and close the opening 33 of the loading station 8, and a sub-vacuum chamber 34 is formed outside the opening 33 of the second to fifth processing stations. The sub-vacuum chamber 34 and the main vacuum chamber 32 are connected to the opening 33
In addition, vacuum communication is possible through an exhaust port 35. The exhaust port 35 is opened and closed by a valve 37 operated by an air cylinder 36.

Between the vacuum container 30 and the lid 31, the vacuum container 3
There is a drum 39 having a plurality of planes 40 substantially parallel to the wall surface 38 of 0 . The drum 39 is rotatably supported at the center of the bottom surface of the lid 31, and is connected to the motor 2.
4, rotated by gear 25 and chain 26.

Further, each flat surface 40 of the drum 39 has a
A substrate holder 42 is attached by a set of leaf springs 41 and is movable back and forth while remaining substantially parallel to a plane 40, and a pusher 43 allows the substrate holder 42 to come into close contact with the wall surface 38 of the vacuum container 30. Lid 31
When the conical cam 45 is lowered by the air cylinder 44 located at the center of the recess, the pusher 43 receives a force outward from the center, and all stations simultaneously push the substrate holder 42 against the wall surface 38 while being guided by the guide 46. wear. When the conical cam 45 rises, the pusher 43 receives a force toward the center due to the compression spring 47, and the tip of the pusher 43 moves toward the lid 31.
The substrate holder 42 is moved away from the wall 38 by the leaf spring 41 and approaches the drum 39 .

In FIG. 4, in the second processing station 9 and the third processing station 10, the pusher 4 is
3. The guide 46, board holder 42, and leaf spring 47 are omitted.

As shown in FIG. 3, at least one sub-vacuum chamber 34 is provided with a processing unit 18, a gas pipe 2, a vacuum valve 3, and a variable valve 4. These components are the same or similar to those in the conventional device shown in FIG.

Further, the main vacuum chamber 32 is connected to the vacuum pump 5 through a pipe 48 and is evacuated to a high vacuum.

Also, at loading station 8, door 1
3. The opening 33 and the substrate holder 42 cooperate to form a vacuum preliminary chamber 28.

Next, the operation of the continuous sputtering device constructed as above will be described.

The door 13 of the loading station 8 is closed, and the conical cam 45 is lowered by the air cylinder 44 to press the substrate holder 42 against the wall surface 38 of the vacuum container 30 at each station. With the valve 37 opened by the air cylinder 36, the vacuum pump 5 is operated, and the vacuum valve 3 and the variable valve 4 are coordinated to introduce Ar gas from the gas pipe 2 into at least one sub-vacuum chamber 34. The vacuum chamber 34 and the main vacuum chamber 32 are each maintained at a predetermined low pressure atmosphere. The pressure within the sub-vacuum chamber 34 is adjusted by changing the opening degree of the variable valve 4 and the diameter of the exhaust port 35.

The operation cycle starts from the above state.

Vacuum preliminary chamber 28 of loading station 8
A leak gas is introduced into the chamber by a leak means (not shown) and brought to atmospheric pressure. Next, the door 13 is opened (opening/closing mechanism not shown), and the processed substrate 1 is chucked into the substrate holder 42 (chuck mechanism not shown).
4 is taken out by a conveying means (not shown),
The unprocessed substrate 14 is mounted on the substrate holder 42. After closing the door 13, the vacuum preliminary chamber 28 is evacuated to a predetermined pressure by rough evacuation means (not shown).

Next, when the conical cam 45 is raised by the air cylinder 44, the pusher 43 and the substrate holder 42 are moved toward the center by the compression spring 47 and the leaf spring 41, respectively. Next, motor 24, gear 2
5. After the drum 39 is rotated by one station by the chain 26, the substrate holder 42 is again pressed against the wall surface 38 of the vacuum container 30 by the air cylinder 44, the conical cam 45, and the pusher 43. At the loading station 8, the above-described operations are repeated, and at the second to fifth stations, predetermined treatments are applied to the substrate 14, respectively.

In the second to fifth processing stations, a wafer bake process to remove contaminant gas adsorbed on the wafer surface, a sputter etch process to remove an oxide layer on the wafer surface before sputtering, or a sputter process to form a thin film can be optionally performed. Processing is performed in combination, but typically the second station performs the wafer bake process, the third station performs the sputter etch process, and the fourth and fifth stations perform the sputter process. In that case, the processing units 18 at each station are a wafer baking unit at the second station, a sputter etching unit at the third station, and a sputter processing unit at the fourth and fifth stations.

The pressures in each chamber in this example are as follows.

Main vacuum chamber: 1 mm, sub-vacuum chamber of second processing station: 1 mm, sub-vacuum chamber of third processing station: 8 mm, sub-vacuum chamber of fourth and fifth processing stations: 2 mm.

By repeating the above operation, a large number of substrates 1
4 are successively subjected to sputtering treatment.

Also, the target, which is a consumable item, is replaced as follows.

Air cylinder 44, conical cam 45, pusher 4
The sub-vacuum chamber 34 and the main vacuum chamber 32 are vacuum-sealed by pressing the substrate holders 4 against the wall surface 38 in cooperation with the sub-vacuum chambers 3 and 3, and closing the valve 37 of the station using the air cylinder 36 of the station where targets are exchanged. Next, after the sub-vacuum chamber 34 is brought to atmospheric pressure by a leak means (not shown) in the sub-vacuum chamber 34, the sputter electrode of the processing unit 18 attached to the station is removed and the target is replaced. After assembling the sputter electrode again, the corresponding sub-vacuum chamber 34 is roughly evacuated by a rough evacuation means (not shown). Next, the substrate holder is moved back, and the inside of the sub-vacuum chamber 34 is evacuated to a high vacuum.

As described above, according to the present invention, when a target is to be exchanged, only the sub-vacuum chamber of the station where the target is to be exchanged may be exposed to the atmosphere while the main vacuum chamber 32 is evacuated to a high vacuum.

In the above embodiment, a total of five stations, one loading station and four processing stations, were provided, but when implementing the present invention,
The number of stations to be installed can be set arbitrarily.

In this embodiment, as is clear from the structural functions described above, in a sputtering apparatus which apparently consists of a set of vacuum systems, the pressure in each sub-vacuum chamber is controlled by providing a sub-vacuum chamber for each processing station. They can be controlled independently, and by setting the optimal pressure for each treatment, it is possible to improve the processing speed and film quality. Further, impurity gases generated from the baking station and sputter etching station exit into the main vacuum chamber through the exhaust ports of each station and reach the vacuum pump. In this case, the probability that the impurity gas once released into the main vacuum chamber will enter the sub-vacuum chamber from the exhaust port of another station is so small that it can be ignored in practical terms. As a result, the possibility that impurity gases generated from the baking station and the sputter etching station will enter the sputtering station and adversely affect the sputtering process can be practically ignored.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to improve the yield in the process of forming a thin film on a substrate, and also to improve the effective production capacity.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a conventional continuous sputtering device, FIG. 2 is a sectional view taken along line A-A in FIG. 1, FIG. 3 is a vertical sectional view of one embodiment of the continuous sputtering device of the present invention, and FIG. 3 is a horizontal sectional view taken along the line CC in FIG. 3. FIG. 1... Vacuum container, 2... Gas piping, 3... Vacuum valve, 4... Variable valve, 5... Vacuum pump,
8... Loading station, 9... Second processing station, 10... Third processing station, 11... Fourth processing station, 12... Fifth processing station, 13... Door, 14... Blind lid, 17...Aperture, 18...Processing unit, 19
...Pressure plate, 20 ...Air cylinder, 21
...Air cylinder, 22...Substrate holding hole, 23...
...Claw, 24...Motor, 25...Gear, 26...
Chain, 27...Shaft, 28...Vacuum preliminary chamber, 3
0...Vacuum container, 31...Lid, 32...Main vacuum chamber, 33...Opening, 34...Sub-vacuum chamber, 35...
Exhaust port, 36... Air cylinder, 37... Valve, 38... Wall surface, 39... Drum, 40... Plane, 41... Leaf spring, 42... Board holder, 43
...Putsha, 44...Air cylinder, 45...
Conical cam, 46...guide, 47...compression spring,
48...Piping.

Claims (1)

[Claims] 1. A cylindrical vacuum container, an exhaust means connected to the vacuum container, a rotary transport means provided concentrically within the vacuum container, and a plurality of substrate holders provided at equal angular intervals on the transport means, an opening provided in a side wall of the vacuum container so as to face the substrate holder; a drive means for airtightly pressing and separating the substrate holder from the opening; and at least one of the openings. an airtight door, an auxiliary vacuum chamber provided outside at least one opening other than the opening provided with the door, an evacuation means connected to the at least one auxiliary vacuum chamber, and a gas introduction connected to the at least one auxiliary vacuum chamber. A continuous sputtering device characterized by comprising a means and a means.