JPH0542507B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a continuous sputtering apparatus capable of bias sputtering, which performs sputter film formation while sputter etching a substrate.

[Background of the invention]

For example, to deposit a wiring film on a semiconductor substrate by sputtering, vacuum evacuation, substrate heating to remove gas adsorbed on the substrate, sputter etch cleaning to remove natural oxide on the underlying surface, sputtering film deposition, and atmospheric pressure are required. All or part of the restoration process is necessary. In the sputtering film forming process, in the case of a fine pattern with a pattern width of about 1 μm or less, a bias sputtering method in which the sputtering film is formed while etching the substrate is effective in order to improve step coverage.

Conventional bias sputtering equipment, for example,
Discussed in "Multi-layer wiring technology using bias sputtering" by Semiconductor World, Vol. 3, No. 10 (October 1984). In this conventional example, after a large number of substrates are arranged on the substrate electrodes of a sputtering apparatus consisting of one processing chamber, the above steps are sequentially performed, and the process has the following drawbacks.

(1) Processing time is long because the above steps are performed sequentially.

(2) After the sputtering film formation chamber is brought into the atmosphere each time a substrate is taken in and out, it is evacuated. For this reason, the total pressure or gas partial pressure reached within a given time varies,
Vary the vacuum atmosphere during sputtering film formation.

(3) Since substrate heating, sputter etch cleaning, and sputter film deposition are performed in the same room, substrate heating,
Contaminant gas generated during sputtering etching cleaning remains in the processing chamber and is incorporated into the film during sputtering film formation, deteriorating film quality.

(4) When processing multiple substrates at once, the distance between the sputter electrode and the substrate is usually increased to maintain a uniform film thickness distribution within the substrate. For this reason, the film formation rate is low, and the amount of gas taken into the film increases, degrading the film quality.

[Purpose of the invention]

An object of the present invention is to provide a continuous sputtering apparatus that enables high-quality bias sputtering film formation in vacuum at high speed.

[Summary of the invention]

In order to improve quality, the present invention (1) provides an intake/take-out chamber and maintains the processing chamber at high vacuum at all times; (2) independently controls the vacuum atmosphere of multiple processing stations within the processing chamber; Bias sputtering is possible by eliminating cross-contamination between processing stations, and (3) incorporating an etching electrode into the substrate holder that moves while holding the substrate within the processing chamber, allowing sputtering film formation and sputtering to be performed simultaneously. This is what I did.

In order to further increase the speed, (1) multiple processes are performed simultaneously at each processing station, (2) the substrate is statically opposed to the sputtering electrode, and high-speed film formation is performed.
(3) By transporting the substrate between processing stations within the processing chamber while it is placed on the substrate holder, transport time can be shortened.

[Embodiments of the invention]

An embodiment of the present invention will be described based on the drawings.

(1) Configuration FIG. 1 is a vertical sectional view of a sputtering device showing one embodiment of the present invention. Figure 2 shows D- shown in Figure 1.
It is a horizontal sectional view taken along the D plane, and the E-E plane of the figure shows the vertical sectional view of FIG. 1.

A main vacuum 32 is constituted by a pentagonal vacuum container 30 (FIG. 2) and a lid 31 (FIG. 1) having a cylindrical recess in the center. Wall surface 38 of vacuum container 30 (second
Figure) shows an opening 3 with its central axis on almost the same horizontal plane.
3 (FIG. 2) are spaced at equal angular intervals, forming a loading station 78 and first to fourth stations 79 to 82 in order. Also, a loading chamber 51 is located on the atmospheric side of the loading station 78.
and an intake/extraction chamber 52 are attached, and the first to
A sub-vacuum chamber 34 is formed outside the opening 33 of the fourth processing station. As shown in FIG. 1, the sub-vacuum chamber 34 and the main vacuum chamber 32 can communicate in vacuum through an exhaust port 35 in addition to the opening 33. The exhaust port 35 is a valve 37 driven by an air cylinder 36.
It is opened and closed by

As shown in FIG. 2, between the vacuum container 30 and the lid 31 is a drum 39 having a plurality of flat surfaces 40 substantially parallel to the wall surface 38 of the vacuum container 30. The drum 39 is rotatably supported at the center of the bottom surface of the lid 31 and is rotated by the motor 24, gear 25, and chain 26.

Further, each flat surface 40 of the drum 39 has a
A substrate holder 42 is attached to the substrate holder 42 by a set of leaf springs 41 that can move back and forth while remaining substantially parallel to the plane 40, and a pusher 43 allows the substrate holder 42 to be brought into close contact with the wall surface 38 of the vacuum container 30. Lid 31
Air cylinder 44 (first
When the conical cam 45 is lowered by the movement shown in FIG.
6 simultaneously press the substrate holder 42 against the wall surface 38 at all stations. 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 retreats to the outer circumferential surface of the recess in the lid 31, and the substrate holder 42 is moved away from the wall by the leaf spring 41 and attached to the drum. 3
Approaching 9.

In FIG. 2, a first processing station 79,
For the second processing station 80 and the fourth processing station 82, the pusher 43 and the guide 4
6. Illustrations of the board holder 42 and leaf spring 47 are omitted.

As shown in FIG. 1, at least one sub-vacuum chamber 34 is provided with a processing unit 18, a gas pipe 72, a vacuum valve 73, and a variable valve 74.

Further, the main vacuum chamber 32 is connected to a vacuum pump 75 through a pipe 48 and is evacuated to a high vacuum.

Further, as shown in FIG. 2, a loading chamber 51 is installed on the atmosphere side of the loading station 78, and an intake/extraction chamber 52 is installed on the atmosphere side. There are two sets of conveyance means 5 in the intake/unloading chamber 52.
3 and 54, and a set of transport means 55 is installed in the loading chamber 51.

Gate valves 5 are installed on both sides of the intake/extraction chamber 52.
6,57 are installed.

Gate valves 5 are installed on both sides of the intake/extraction chamber 52.
6,57 are installed. gate valve 56,
When 57 is open, the substrate 5 is carried into the loading/unloading chamber 52 by an atmospheric conveyance means (not shown),
It can be transported to the atmosphere side again through the loading chamber 51 by the transport means 53, 55, and 54.

In addition, as shown in FIG. 1, the intake/extraction chamber 52 is connected to an auxiliary vacuum pump 60 via a vacuum pipe 58 and a vacuum valve 59, and to a leak gas source (not shown) via a leak pipe 61 and a leak valve 62. )It is connected to the.

Loading chamber 51 is connected to vacuum pump 91 via piping 63.

When the substrate is at the loading position 64 (FIG. 2) in the loading chamber 51, the substrate is lifted by the elevator 65 shown in FIG. 1 and chucked by the arm 66 (FIG. 1). (not shown). Arm 66 (shown by center line)
The substrate 5 is rotated around the shaft 67 and transferred to the wafer holder 42 .

Note that the elevator 65 is, for example, an air cylinder 68.
Accordingly, the shaft 67 of the arm 66 is driven by a motor (not shown).

A detailed cross-sectional view of the third processing station 81 is shown in the third
As shown in the figure.

The substrate holder 42 includes an etching electrode 101 and an insulating plate 102, and holds the substrate 5 on the surface of the insulating plate 102 by a holding mechanism (not shown). An etching electrode 101 is exposed on the side surface of the substrate holder 42, forming a power supply port 103. Note that an insulator 110 is inserted between the etching electrode 101 and the substrate holder 42, so that the etching electrode 101 is insulated from the wafer holder 42, which is at ground potential.

The second processing station 80, the third processing station 81 and, if necessary, the fourth processing station 82, at the corresponding position on the wall surface 38 facing the power supply port 103, are surrounded by an insulator 111 and an earth shield 105. There is a power supply member 106.
The power supply member 106 is generally 13.56M while being insulated from the wall surface 38 and the earth shield 105.
It is connected to a high frequency power source 107 of Hz.

At the positions facing the substrate 5 of the third processing station 81 and the fourth processing station 82, there is a sputter processing unit 1 connected to a sputter power source 112.
8 is installed.

(2) Operation Next, the operation of the continuous sputtering device configured as above will be described.

The conical cam 4 is operated by the air cylinder 44 (Fig. 1).
5 and lower the substrate holder 42 at each station.
is pressed against the wall surface 38 of the vacuum container 30. With the valve 37 opened by the air cylinder 36, the vacuum pump 75 is operated, and the vacuum valve 73 and the variable valve 74 are coordinated to introduce Ar gas from the gas pipe 72 into at least one sub-vacuum chamber 34. Vacuum chamber 34 and main vacuum chamber 3
2 are each maintained in a predetermined low pressure atmosphere. Sub-vacuum chamber 34
The internal pressure is adjusted by changing the opening degree of the variable valve 74 and the diameter of the exhaust port 35.

In addition, in the intake/extraction chamber 52, with the gate valves 56, 57 and vacuum valve 59 on both sides closed, the leak valve 62 is opened, leak gas is introduced from the leak pipe 62, and the inside of the intake/extraction chamber 52 is brought to atmospheric pressure. Keep it.

In the loading chamber 51, the elevator 65 is kept in a descending state and the vacuum pump 91 is evacuated to, for example, 10 ^-7 Torr level.

The operation cycle starts from the above state.

After opening the gate valve 56 of the intake/removal chamber 52, the atmosphere side conveying means (not shown) and the conveying means 53
(Fig. 2)
After carrying it into the building, the gate valve 56 is closed.

Next, the auxiliary vacuum pump 60 (Fig. 1) is activated, the vacuum valve 59 is opened, and the intake/extraction chamber 52 is evacuated to, for example, 0.1 Torr.
Open 7. After the substrate 5 is transported to the loading position 64 by the cooperation of the transport means 53 and 55 (FIG. 2), the substrate 5 is mounted on the substrate holder 42 by the cooperation of the elevator 65 and the arm 66 (FIG. 1).

Next, when the conical cam 45 is raised by the air cylinder 44, the pusher 43 is moved toward the center by the compression spring 47, and the substrate holder 42 is moved by the leaf spring 41, respectively. Next, the motor 24, gear 25,
After the drum 39 is rotated one station by the chain 26, the substrate holder 42 is rotated again by the air cylinder 44, the conical cam 45, and the pusher 43.
is pressed against the wall surface 38 of the vacuum container 30. At the loading station 78 (FIG. 2), the processed substrate 5 mounted on the substrate holder 42 is loaded by the arm 66 and the elevator 65 (FIG. 1).
Transfer onto the conveying means 55 (FIG. 2). After opening the gate valve 57, the substrate 5 is transported to the unloading position 70 in the loading/unloading chamber 52 by the cooperation of the transporting means 55 and 54, and the unprocessed substrate 5 is transported from the loading position 69 to the loading position 64. After that, the gate valve 57 is closed.

As described above, after the intake/unloading chamber is brought to atmospheric pressure and the gate valve 56 is opened, the unprocessed substrate 5 to be processed next is carried in, and the processed substrate 5 at the carry-out position 70 is carried out simultaneously.

In parallel with the loading/unloading process at the loading station 78, predetermined processes are performed on the substrates 5 at the first to fourth stations.

The first to fourth processing stations perform substrate heating treatment to remove contaminant gas adsorbed on the substrate surface, sputter etch treatment to remove the oxide layer on the substrate surface before sputtering, or form a thin film while sputter etching the substrate. The sputtering process is carried out in any combination, but typically the first station performs the substrate heat treatment, the second station performs the sputter etch process, and the third and fourth stations perform the sputter process. In that case, the processing units 18 at each station are such that the first station is a substrate heating unit, the second station is a sputter etching unit, and the third and fourth stations are sputter processing units.

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

Main vacuum chamber: 2 mTorr, sub-vacuum chamber of first processing station: 2 mTorr, sub-vacuum chamber of second processing station: 6 mTorr, sub-vacuum chamber of third and fourth processing stations: 3 mTorr.

As shown in FIG.
0, the substrate holder 42 is pressed against the wall of the vacuum chamber 30, so that the power supply member 106 and the etching electrode 101 come into contact at the power supply port 103, and high frequency power is applied from the high frequency power source 107 to the etching electrode 10.
1. Then, the substrate 5 and the insulating plate 10
A high negative self-bias voltage is generated on the surface of the substrate 2, plasma is generated between the wall of the sub-vacuum chamber 34 and the insulating plate 102, and Ar ions are incident on the substrate 5.
An etching process is performed on the substrate 5.

At the third processing station 81 and the fourth processing station, bias sputtering is performed by supplying power from a sputtering power supply 112 to a sputtering processing unit 18 facing the substrate 5.

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 addition, in this embodiment, loading station 7
8 is provided with a loading chamber 51 and an intake/unloading chamber 52, but the loading chamber 51 is omitted, the loading/unloading chamber 52 is directly attached to the main vacuum chamber 32, and the loading/unloading chamber 52 is directly attached to the main vacuum chamber 32. A similar effect can be obtained by providing an arm 66 for loading the elevator 65 in the take-out chamber 52.

〔Effect of the invention〕

As mentioned above, by maintaining the processing chamber at high vacuum at all times, providing a sub-vacuum chamber for each processing station, and controlling the pressure of each sub-vacuum chamber independently, mutual gas contamination between processing stations is eliminated. It is possible to reduce the incorporation of contaminant gas into the spatter film.

Further, by incorporating an etching electrode into the substrate holder and using a bias sputter to perform sputter film formation and sputter etching at the same time, step coverage can be improved.

In addition, multiple processes can be performed simultaneously at each processing station, and high-speed film formation can be achieved by statically facing the substrate to the sputtering electrode.Furthermore, the substrate can be transported between processing stations while remaining on the substrate holder. The time can be shortened and high-speed processing can be performed due to the above effects.

Furthermore, according to the present invention, when performing maintenance on each sub-vacuum chamber, it is only necessary to evacuate only the corresponding sub-vacuum chamber to the atmosphere while the main vacuum chamber is evacuated to a high vacuum.
Vacuum start-up time after maintenance can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a front view of a continuous sputtering device showing an embodiment of the present invention, FIG. 2 is a DD cross-sectional view of FIG. 1,
FIG. 3 is a partially detailed view of the EE cross section in FIG. 2. 5... Substrate, 30... Vacuum container, 31... Lid, 32...
Main vacuum chamber, 33...opening, 34...sub-vacuum chamber, 35...
Exhaust port, 36...Air cylinder, 37...Valve, 4
0... Plane, 41... Leaf spring, 42... Board holder, 4
3... Pusher, 44... Air cylinder, 65... Elevator, 66... Arm, 67... Shaft, 68... Air cylinder.

Claims (1)

[Claims] 1. In a continuous sputtering device that performs multiple sputtering processes on a substrate, a main vacuum chamber and a plurality of openings provided in a part of the main vacuum chamber, a processing chamber connected to the openings, and a substrate can be opened in the main vacuum chamber while holding the substrate. move and
a substrate holder in close contact with the end of the opening, an etching electrode built into the substrate holder, a power feeding mechanism that supplies etching power to the etching electrodes of some of the substrate holders that are in close contact with the end of the opening; A continuous sputtering apparatus having a sputtering film forming means attached to the processing chamber, facing the substrate held by a part of the substrate holder that is in close contact with the end of the opening.