JP7297531B2 - Sputter deposition apparatus and sputtering deposition method - Google Patents

Description

The present invention relates to a sputtering technique for forming a film by magnetron sputtering using a target made of a magnetic material.

2. Description of the Related Art A film forming apparatus that uses a target made of a magnetic material to form a film by magnetron sputtering conventionally has the following problems compared to a magnetron sputtering method that uses a target made of a non-magnetic material.

That is, in this type of sputtering deposition apparatus, a target made of a magnetic material such as nickel (Ni) or cobalt (Co) is consumed by repeated sputtering, and the thickness of the target becomes thin, so that the magnetic field is shielded by the magnetic material. The effect weakens and the magnetic field at the target surface changes significantly.

When the magnetic field strength on the surface of the target changes, the plasma discharge conditions change, so there is a problem that the film thickness distribution of the sputtered film changes as the consumption of the target progresses.

Japanese Patent Publication No. 2006-508242

The present invention has been made in consideration of such problems of the conventional technology, and an object of the present invention is to provide a film forming apparatus that performs magnetron sputtering using a target made of a magnetic material, and is capable of reducing the magnetic field strength on the surface of the target. To provide a technique capable of forming a film with a stable film thickness distribution from the initial stage of target consumption to the final stage by keeping the constant.

The present invention, which has been made to solve the above problems, is a sputtering deposition apparatus for depositing a film on a substrate by magnetron sputtering, comprising a deposition chamber and a magnetic material held by a backing plate in the deposition chamber. a sputtering power source that supplies a predetermined power to the target; a magnet device for magnetron discharge provided on the back side of the backing plate with respect to the substrate; a magnetic field probe for measuring magnetic field strength; a moving mechanism for changing the relative distance between the target and the magnet device; and a control unit for controlling the operation of the moving mechanism so as to change.
The present invention is the sputtering deposition apparatus, wherein the magnetic field probe is provided on a lifting pin for lifting and lowering the substrate in the deposition chamber.
The present invention is a sputtering film forming apparatus, wherein the magnetic field probe is provided in a substrate transport mechanism for carrying the substrate into the film forming chamber and carrying out the substrate from the film forming chamber.
The present invention is a sputtering deposition apparatus, wherein the magnetic field probe is provided in a shutter that controls flying of sputtered particles onto the substrate.
The present invention uses the sputtering deposition apparatus described above, controls the operation of the moving mechanism based on the measurement result of the magnetic field probe, changes the relative distance between the target and the magnet device, and It is a sputtering deposition method in which the magnetic field intensity of the target surface by the apparatus is kept constant.

In the present invention, a magnetic field probe for measuring the magnetic field strength of the target by the magnet device is provided, and the relative distance between the target made of a magnetic material and the magnet device is changed based on the measurement result of the magnetic field probe. Since the operation of the moving mechanism is controlled to change the magnetic field intensity on the surface of the target by the magnet device, by correcting the change in the magnetic field intensity due to consumption of the target and making it constant, for example, during sputtering Fluctuations in plasma discharge conditions can be suppressed.

As a result, according to the present invention, it is possible to form a film with a stable film thickness distribution from the beginning of target consumption to the final stage.

1 is a schematic configuration diagram showing the inside of an embodiment of a sputtering film forming apparatus according to the present invention; Schematic configuration diagram showing the inside of another embodiment of the present invention Schematic configuration diagram showing the inside of another embodiment of the present invention

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing the inside of an embodiment of a sputtering film forming apparatus according to the present invention, which performs film formation by deposition.

A sputter deposition apparatus 1 of the present embodiment is of the magnetron sputtering type and has a deposition chamber 2 set to ground potential.

The film formation chamber 2 is connected to an evacuation device 3 for evacuating the interior thereof, and is also connected to a sputtering gas source 4 capable of introducing a sputtering gas such as argon (Ar) gas into the film formation chamber 2 . there is

A substrate 6 is placed on a stage 5 in the deposition chamber 2, and a target 7 made of a magnetic material such as nickel (Ni) or cobalt (Co) is provided as a backing plate so as to face the substrate 6. 8 is attached.

The backing plate 8 is electrically connected to a sputtering power source 9 and configured to supply a predetermined power (voltage) to the target 7 via the backing plate 8 .

The type of power supplied to the target 7 is not particularly limited, and may be direct current or alternating current (including high frequency power and pulse power).

A plurality of magnet devices 10 are provided on the opposite side (rear side) of the backing plate 8 to the target 7 in the deposition chamber 2 .

The magnet devices 10 of this embodiment are attached to the lower surface of the support plate 11 so as to generate a magnetic field on the sputtering surface side of the target 7 .

Each magnet device 10 has a central magnet and an outer peripheral magnet provided in a ring shape continuously around the central magnet, respectively installed on the yoke.

It should be noted that the peripheral magnet does not necessarily mean one seamless annular shape. That is, as long as the shape surrounds the center magnet, it may be composed of a plurality of parts.

The support plate 11 to which the magnet devices 10 are attached is connected to a moving mechanism 13. By operating the moving mechanism 13 to move the support plate 11 in the vertical direction, the magnet devices 10 and the target 7 are moved relative to each other. It is configured to vary the distance (for example, the distance between each magnet device 10 and the surface of the target 7 before digging).

In the present embodiment, a magnetic field probe 15 for measuring the magnetic field in the film forming chamber 2 by the magnet device 10 is provided, and based on the results obtained by the magnetic field probe 15, the magnetic field between the target 7 and the magnet device 10 is determined. Vary the relative distance.

In this case, the magnetic field measuring element 15 is provided on each of a plurality of elevating pins 16 for elevating the substrate 6 . Each elevating pin 16 is vertically fixed to a frame 18 within the stage 5 and configured to be moved upward and downward by an elevating mechanism 17 .

The magnetic field measuring element 15 detects the strength of the magnetic field formed by the magnet device 10 and converts it into an electric signal, and for example, a magnetic sensor such as a Hall element can be used.

Each magnetic field measuring element 15 is electrically connected to the control unit 14 via a wiring 19, and the control unit 14 sends a command to the moving mechanism 13 based on the signal from the magnetic field measuring element 15, and the moving mechanism 13 is configured to vertically move the support plate 11 (magnet device 10 ) based on a command from the control unit 14 .

In addition, it is preferable that the mechanical portion in which the wiring 19 and the control section 14 are provided is configured so as to maintain the vacuum atmosphere in the film forming chamber 2 by using bellows or the like as necessary.

In this embodiment, the operation of the moving mechanism 13 is controlled as follows.

First, the magnetic field probe 15 measures the magnetic field in the film forming chamber 2 generated by the magnet device 10 at a predetermined timing.

In this case, the timing of measuring the magnetic field strength in the film formation chamber 2 by the magnet device 10 with the magnetic field probe 15 can be set arbitrarily, for example, immediately before the sputtering process is started.

Then, for example, when the measurement result of each magnetic field probe 15 differs from a predetermined reference value (range), by operating the moving mechanism 13 according to a command from the control unit 14, each magnet device 10 is raised or lowered. to change the distance from the target 7, and the magnetic field measuring element 15 measures the magnetic field produced by the magnet device 10 (in particular, the magnetic field perpendicular to the target 7).

In this case, for example, the magnetic field probes 15 are continuously turned on, and each magnet device 10 continues to rise or fall until the magnetic field strength obtained by the magnetic field probes 15 is, for example, equal to that of the previous sputtering process.

Then, when the magnetic field strength obtained by the magnetic field measuring element 15 reaches a value equivalent to that of the previous sputtering process, the operation of the moving mechanism 13 is stopped, the substrate 6 is carried into the film forming chamber 2, and the sputtering is performed. start the process.

In the present embodiment described above, the magnetic field probe 15 for measuring the magnetic field strength on the surface of the target 7 by the magnet device 10 is provided, and based on the measurement result of the magnetic field probe 15, the target 7 made of a magnetic material and the magnet are detected. Since the operation of the moving mechanism 13 is controlled so as to change the relative distance to the device 10, and the magnetic field strength of the surface of the target 7 generated by the magnet device 10 is changed, the magnetic field strength is reduced as the target 7 is consumed. By correcting the change and, for example, making it constant, fluctuations in the plasma discharge conditions during sputtering can be suppressed.

As a result, according to the present embodiment, it is possible to form a film with a stable film thickness distribution from the initial consumption stage of the target 7 to the final stage.

Further, according to the present embodiment, since the magnetic field measuring element 15 is provided on the elevating pin 16 that moves upward and downward, the magnetic field in the direction perpendicular to the surface of the target 7 can be detected without providing a new mechanism. Changes in intensity can be measured.

FIG. 2 is a schematic configuration diagram showing the inside of another embodiment of the present invention.

Hereinafter, portions corresponding to those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 2, in the sputtering film forming apparatus 1A of the present embodiment, the magnetic field probe 15 carries the substrate 6 into the film forming chamber 2 and carries out the substrate 6 from the film forming chamber 2. is provided in the substrate transfer arm (substrate transfer mechanism) 20 of the .

The substrate transfer arm 20 is driven by a transfer robot (not shown) provided in a transfer chamber 2A connected to the film formation chamber 2 via a gate valve 21, for example, and can move vertically and horizontally. is configured as

In this embodiment, one or more magnetic field probes 15 can be provided on the substrate transfer arm 20 . The position where the magnetic field probe 15 of the substrate transport arm 20 is provided is not particularly limited, and it may be provided at a position where the magnetic field strength of the magnet device 10 can be measured more accurately.

The magnetic field measuring element 15 is electrically connected to the controller 14 via the wiring 19 as in the above-described embodiment.

In this embodiment, the substrate transfer arm 20 is moved vertically and horizontally in the film forming chamber 2, and the magnetic field strength by the magnet device 10 can be measured by turning on the magnetic field probe 15 at a predetermined position. configured to allow

In this case, the magnetic field strength can be measured while the substrate 6 is being held by the substrate transfer arm 20 .

The timing of measuring the magnetic field strength in the film formation chamber 2 by the magnet device 10 with the magnetic field probe 15 can be arbitrarily set, for example, immediately before the sputtering process is started, as in the above embodiment.

In this embodiment having such a configuration, even if the vertical relationship between the stage 5 and the target 7 is reversed, no problem occurs. .

According to the present embodiment, since the magnetic field probe 15 is provided on the substrate transfer arm 20 that can move vertically and horizontally, changes in the magnetic field strength on the surface of the target 7 can be detected accurately over a wide range. It is also possible to measure changes in the magnetic field intensity of each portion of the surface of the target 7 with a single magnetic field probe 15 .

FIG. 3 is a schematic configuration diagram showing the inside of another embodiment of the present invention.

Hereinafter, portions corresponding to those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, in the sputtering film deposition apparatus 1B of the present embodiment, the magnetic field probe 15 is arranged between the target 7 and the substrate 6. A shutter for controlling the flight of sputtered particles to the substrate 6 is provided. 22.

The shutter 22 is, for example, a plate-like member that can rotate in a plane parallel to the surface of the target 7 around an axis 23 that extends in a direction perpendicular to the surface of the target 7. A material that can be covered can be preferably used.

A plurality of magnetic field probes 15 can be provided on the shutter 22 .

By providing a plurality of magnetic field probes 15 on the shutter 22, the magnetic field intensity of each portion of the surface of the target 7 can be measured.

In the case of the present invention, the position where the magnetic field probe 15 is provided on the shutter 22 is not particularly limited. It is preferable to provide it on the side that does not face 7 .

The magnetic field measuring element 15 is electrically connected to the controller 14 via the wiring 19 as in the above-described embodiment.

In this embodiment, the timing of measuring the magnetic field strength in the film formation chamber 2 by the magnet device 10 with the magnetic field probe 15 can be arbitrarily set, for example, immediately before the sputtering process is started, as in the above embodiment. .

In this embodiment having such a configuration, even if the vertical relationship between the stage 5 and the target 7 is reversed, no problem occurs. .

Further, according to the present embodiment, since the magnetic field measuring element 15 is provided on the shutter 22 that can rotate in a plane parallel to the surface of the target 7, the target 7 surface can be detected without providing a new mechanism. Changes in magnetic field strength in parallel directions can be measured.

It should be noted that the present invention is not limited to the above-described embodiments, and can be modified in various ways.

For example, in the above-described embodiment, the case where the magnetic field probe 15 is provided on the elevating pin 16, the substrate transfer arm 20, or the shutter 22 has been described as an example, but the present invention is not limited to this. can also be provided as a separate mechanism in the

However, if the magnetic field probe 15 is provided on the elevating pin 16, the substrate transfer arm 20, or the shutter 22 as in the above embodiment, the existing configuration can be diverted without providing a new mechanism. , simplification of the configuration and cost reduction can be achieved.

Furthermore, in the above embodiment, the magnetic field probe 15 is electrically connected to the control unit 14 by the wiring 19, but the magnetic field probe 15 can be electrically connected to the control unit 14 wirelessly.

Moreover, the configuration of the embodiment shown in FIGS. 1 to 3 is an example, and various modifications can be made within the scope of the present invention.

As one example of this modification, it is conceivable to provide a plurality of lifting positions for the lifting pins 16 .

For example, one of the elevated positions is the normal position and the other is the measurement position.

Here, the normal position refers to the position where the substrate 6 is loaded and unloaded, which is the original function of the lift pins 16, and the measurement position is the position where the magnetic field strength is measured, and is within the range from the normal position to the surface of the target 7. and refers to a position provided above the normal position.

According to this modification, the magnetic field probe 15 can be brought closer to the surface of the target 7. As a result, the signal value of the magnetic field intensity measured by the magnetic field probe 15 is increased, thereby improving the S/N ratio. can be made

For example, the signal value of the measured magnetic field strength can be maximized by setting the measurement position to a position near or in contact with the surface of the target 7 with the elevating pin 16 .

The configuration in which two elevation pins 16 are provided in this manner is an embodiment in which the magnetic field probe 15 is provided on the substrate transfer arm 20 or the shutter 22. This can be achieved by adding a tilt mechanism, and the measurement position can be set to any position according to the position detection method of the detection means attached to each mechanism.

In any of the configurations described above, the S/N ratio can be improved.

In the modified example described above, the magnetic field strength is measured by the magnetic field probe 15 at the measurement position closer to the surface of the target 7 than the normal position. can also be measured.

By measuring the magnetic field intensity at two or more multiple positions in this way, the signal values of the magnetic field intensity at two or more multiple planes, that is, the plane at the normal position in addition to the plane at the measurement position, are detected by the controller 14. means it can be obtained.

The signal value of the magnetic field strength at each point on these multiple planes is plotted in a two-dimensional or three-dimensional space prepared in the calculator inside the control unit 14, and plotted against a magnetic circuit model prepared in advance. Application of the signal value of the magnetic field strength also makes it possible to obtain an estimate of the magnetic field strength at the target 7 surface.

The method of obtaining this estimated value may use a known numerical calculation method. The simplest example is a method of obtaining the signal values of the magnetic field strength at two points and using the fact that the distance is inversely proportional to the square of the distance (2 Next approximation method) may be used according to the number of measurement points and the desired accuracy.

Reference Signs List 1 Sputtering film forming apparatus 2 Film forming chamber 5 Stage 6 Substrate 7 Target 8 Backing plate 9 Sputtering power source 10 Magnet device 15 Magnetic field probe 16 Lifting pin 17 Elevating mechanism 20: Substrate transfer arm (substrate transfer mechanism)
22 ... Shutter

Claims (2)

A sputtering deposition apparatus for depositing a film on a substrate by magnetron sputtering,
a deposition chamber;
a target made of a magnetic material held by a backing plate in the deposition chamber;
a sputtering power supply that supplies predetermined power to the target;
a magnet device for magnetron discharge provided on the back side of the backing plate with respect to the substrate;
a magnetic field probe for measuring the magnetic field intensity of the target surface by the magnet device;
a moving mechanism that changes the relative distance between the target and the magnet device;
a control unit that controls the operation of the movement mechanism so as to change the magnetic field intensity of the target surface by the magnet device based on the measurement result of the magnetic field probe ;
A sputtering deposition apparatus , wherein the magnetic field probe is provided in a shutter that controls flying of sputtered particles to the substrate . Using the sputtering film deposition apparatus according to claim 1 ,
Based on the measurement result of the magnetic field measuring element, the operation of the moving mechanism is controlled to change the relative distance between the target and the magnet device so that the magnetic field intensity of the target surface by the magnet device is constant. A sputtering method for forming a film.

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