JP2020193352A - Sputtering film deposition apparatus and sputtering film deposition method - Google Patents

Abstract

To provide a technique capable of depositing a film having a thickness distribution stable from the consumption start of a target composed of a magnetic material to the final stage by constantly keeping magnetic field intensity on the surface of the target in a film deposition apparatus of performing magnetron sputtering using the target.SOLUTION: A sputtering film deposition apparatus 1 comprises: a target 7 composed of a magnetic material and held on a backing plate 8 in a film deposition chamber 2; a magnet device 10 for magnetron discharge provided on the rear surface side of the backing plate 8 with respect to a substrate 6; a magnetic field measurement probe 15 for measuring a magnetic field intensity on the surface of the target 7 by the magnet device 10; a moving mechanism 13 for changing a relative distance between the target 7 and the magnet device 10; and a control part for controlling the operation of the moving mechanism 13 so as to change the magnetic field intensity on the surface of the target 7 by the magnet device 10 on the basis of the results of the measurement by the magnetic field measurement probe 15 to keep the magnetic field intensity constant.SELECTED DRAWING: Figure 1

Description

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

A film forming apparatus that uses a target made of a magnetic material to form a film by magnetron sputtering has the following problems as compared with the magnetron sputtering method using a target made of a non-magnetic material.

That is, in this type of sputtering film forming apparatus, a target made of a magnetic material such as nickel (Ni) or cobalt (Co) is consumed by repeated sputtering, and the thickness thereof is reduced to shield the magnetic field with a magnetic material. The effect is weakened and the magnetic field on the target surface changes significantly.

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

Special Table 2006-508242

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

The present invention made to solve the above problems is a sputter film forming apparatus for forming a film on a substrate by magnetron sputtering, from a film forming chamber and a magnetic material held on a backing plate in the film forming chamber. A target, a sputter power source for supplying 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, and a magnet device on the surface of the target. The magnetic field strength of the target surface by the magnet device is determined based on the magnetic field gauger for measuring the magnetic field strength, the moving mechanism for changing the relative distance between the target and the magnet device, and the measurement result of the magnetron device. It is a sputter film forming apparatus having a control unit which controls the operation of the moving mechanism so as to change it.
The present invention is a sputtering film forming apparatus in which the magnetic field stylus is provided on an elevating pin for raising and lowering the substrate in the film forming chamber.
The present invention is a sputter film forming apparatus provided in a substrate transport mechanism for the magnetic field stylus to carry the substrate into the film forming chamber and to carry out the substrate from the film forming chamber.
The present invention is a sputter film forming apparatus in which the magnetic field stylus is provided on a shutter that controls the flight of sputter particles onto the substrate.
In the present invention, using the sputter film forming apparatus described above, the operation of the moving mechanism is controlled based on the measurement result in the magnetic field transducer to change the relative distance between the target and the magnet device, and the magnet is used. This is a sputter film forming method for making the magnetic field strength of the target surface constant by the apparatus.

In the present invention, a magnetic field gauger 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. By controlling the operation of the moving mechanism and changing the magnetic field strength of the target surface by the magnet device, the change in the magnetic field strength due to the consumption of the target is corrected and made 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 initial stage of consumption of the target to the final stage.

Schematic configuration diagram showing the inside of the embodiment of the sputtering film forming apparatus according to the present invention. Schematic block diagram showing the inside of another embodiment of the present invention. Schematic block diagram showing the inside of another embodiment of the present 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 the sputter film forming apparatus according to the present invention, in which film formation is performed by depot down.

The sputtering film forming apparatus 1 of the present embodiment is of a magnetron sputtering method, and has a film forming chamber 2 set to a ground potential.

The film forming chamber 2 is connected to a vacuum exhaust device 3 that performs vacuum exhaust inside the film forming chamber 2, and is also connected to a sputter gas source 4 capable of introducing a sputter gas such as argon (Ar) gas into the film forming chamber 2. There is.

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

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

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

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

The magnet device 10 of the present embodiment is attached to the lower surface of the support plate 11 so as to generate a magnetic field on the sputter surface side of the target 7.

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

The outer peripheral magnet does not necessarily mean that it has a seamless ring shape. That is, it may be composed of a plurality of parts as long as it has a shape that surrounds the periphery of the central magnet.

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

In the present embodiment, the magnetic field transducer 15 for measuring the magnetic field in the film forming chamber 2 by the magnet device 10 is provided, and the target 7 and the magnet device 10 are located based on the result obtained by the magnetic field transducer 15. Change the relative distance.

In this case, the magnetic field stylus 15 is provided on each of the plurality of elevating pins 16 for elevating and lowering the substrate 6. Each elevating pin 16 is fixed to the frame 18 in the vertical direction in the stage 5, and is configured to move upward and downward by the elevating mechanism 17.

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

Then, each magnetic field stylus 15 is electrically connected to the control unit 14 via the wiring 19, and the control unit 14 sends a command to the moving mechanism 13 based on the signal from the magnetic field stylus 15, and the moving mechanism 13 is configured to move the support plate 11 (magnet device 10) in the vertical direction based on a command from the control unit 14.

The mechanical portion provided with the wiring 19 and the control unit 14 described above is preferably configured to maintain the vacuum atmosphere in the film forming chamber 2 by using bellows or the like as necessary.

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

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

In this case, the timing at which the magnetic field strength in the film forming chamber 2 by the magnet device 10 is measured by the magnetic field transducer 15 can be arbitrarily set, for example, immediately before the start of the sputtering process.

Then, for example, when the measurement result of each magnetic field transducer 15 is different from the predetermined reference value (range), each magnet device 10 is raised or lowered by operating the moving mechanism 13 by a command from the control unit 14. The distance from the target 7 is changed, and the magnetic field measured by the magnet device 10 (particularly the magnetic field in the direction perpendicular to the target 7) is measured by the magnetic field transducer 15.

In this case, for example, the magnetic field stylus 15 is continuously turned on, and each magnet device 10 is continuously raised or lowered until the magnetic field strength obtained by the magnetic field stylus 15 becomes equivalent to, for example, the previous sputtering process.

Then, when the magnetic field strength obtained by the magnetic field transducer 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 sputtering is performed. Start the process.

In the present embodiment described above, a magnetic field transducer 15 for measuring the magnetic field strength on the surface of the target 7 by the magnet device 10 is provided, and the target 7 made of a magnetic material and a magnet are provided based on the measurement results of the magnetic field transducer 15. Since the operation of the moving mechanism 13 was controlled so as to change the relative distance to the device 10 and the magnetic field strength on the surface of the target 7 by the magnet device 10 was changed, the magnetic field strength associated with the consumption of the target 7 was changed. By correcting the change and making it constant, for example, it is possible to suppress fluctuations in the discharge conditions of the plasma during sputtering.

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

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

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

Hereinafter, the parts corresponding to the above-described embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

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

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

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

Then, the magnetic field transducer 15 is electrically connected to the control unit 14 via the wiring 19 as in the above embodiment.

In the present embodiment, the substrate transfer arm 20 is moved in the vertical direction and the horizontal direction in the film forming chamber 2, the magnetic field transducer 15 is turned on at a predetermined position, and the magnetic field strength by the magnet device 10 is measured. It is configured so that it can be done.

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

The timing at which the magnetic field strength in the film forming chamber 2 by the magnet device 10 is measured by the magnetic field transducer 15 can be arbitrarily set as in the above embodiment, for example, immediately before starting the sputtering process.

Since the present embodiment having such a configuration does not cause any inconvenience even if the vertical relationship between the stage 5 and the target 7 is reversed, it can be applied to a sputter film forming apparatus of either a depot down or a depot up type. ..

Further, according to the present embodiment, since the magnetic field analyzer 15 is provided on the substrate transport arm 20 that can move in the vertical direction and the horizontal direction, the change in the magnetic field strength on the surface of the target 7 can be accurately changed over a wide range. It can be measured, and it is also possible to measure the change in the magnetic field strength of each part of the surface of the target 7 by one magnetic field transducer 15.

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

Hereinafter, the parts corresponding to the above-described embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, in the sputter film forming apparatus 1B of the present embodiment, the magnetic field stylus 15 is arranged between the target 7 and the substrate 6, and a shutter that controls the flight of sputter particles to the substrate 6 is controlled. It is provided in 22.

The shutter 22 is, for example, a flat plate-shaped member that can rotate in a plane parallel to the surface of the target 7 about a shaft 23 extending in a direction orthogonal to the surface of the target 7, and covers the entire surface of the target 7. Those that can be covered can be preferably used.

The shutter 22 may be provided with a plurality of magnetic field transducers 15.

By providing the shutter 22 with a plurality of magnetic field transducers 15, the magnetic field strength 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 stylus 15 is provided on the shutter 22 is not particularly limited, but from the viewpoint of preventing the material of the target 7 from adhering to the magnetic field stylus 15, for example, the target of the shutter 22. It is preferable to provide it on the surface on the side that does not face 7.

Then, the magnetic field transducer 15 is electrically connected to the control unit 14 via the wiring 19 as in the above embodiment.

In the present embodiment, the timing at which the magnetic field strength in the film forming chamber 2 by the magnet device 10 is measured by the magnetic field transducer 15 can be arbitrarily set, for example, immediately before the start of the sputtering process, as in the above embodiment. ..

Since the present embodiment having such a configuration does not cause any inconvenience even if the vertical relationship between the stage 5 and the target 7 is reversed, it can be applied to a sputter film forming apparatus of either a depot down or a depot up type. ..

Further, according to the present embodiment, since the magnetic field analyzer 15 is provided on the shutter 22 that can rotate in a plane parallel to the surface of the target 7, the surface of the target 7 is not provided with a new mechanism. Changes in magnetic field strength in parallel directions can be measured.

The present invention is not limited to the above-described embodiment, and various modifications can be made.

For example, in the above embodiment, the case where the magnetic field transducer 15 is provided on the elevating pin 16, the substrate transport arm 20, or the shutter 22 has been described as an example, but the present invention is not limited to this, and the inside of the film forming chamber 2 is not limited to this. It can also be provided as a stand-alone mechanism.

However, if the magnetic field stylus 15 is provided on the elevating pin 16, the substrate transport arm 20, or the shutter 22 as in the above embodiment, the existing configuration can be diverted without providing a new mechanism. , The configuration can be simplified and the cost can be reduced.

Further, in the above embodiment, the magnetic field stylus 15 is electrically connected to the control unit 14 by the wiring 19, but the magnetic field stylus 15 can be electrically connected to the control unit 14 by radio.

Further, 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 of the modified examples, it is conceivable to provide a plurality of raising positions of the elevating pin 16.

For example, one of the ascending positions is a normal position and the other is a measuring position.

Here, the normal position refers to the position where the substrate 6 is carried in and out, which is the original function of the elevating pin 16, and the measurement position is the position where the magnetic field strength is measured and is in the range from the normal position to the surface of the target 7. Therefore, it shall indicate a position provided above the normal position.

According to this modified example, the magnetic field stylus 15 can be brought closer to the surface of the target 7, and as a result, the signal value of the magnetic field strength measured by the magnetic field stylus 15 becomes large, so that the S / N ratio is improved. Can be made to.

For example, if the measurement position is set to a position where the elevating pin 16 contacts the surface of the target 7 or is in the vicinity of the contact, the signal value of the measured magnetic field strength can be maximized.

In the configuration in which the elevating pins 16 are provided with two elevating positions in this way, even in the embodiment in which the magnetic field stylus 15 is provided on the substrate transport arm 20 or the shutter 22, an elevating mechanism known to both drive introduction portions or This can be realized by adding a tilt mechanism, and the measurement position can be set to an arbitrary position according to the position detection method of the detection means attached to each mechanism.

Then, in any of the above configurations, the S / N ratio can be improved.

Further, in the above-described modified example, the magnetic field strength is measured by the magnetic field stylus 15 at a measurement position closer to the surface of the target 7 than the normal position. In addition, the magnetic field strength is measured by the magnetic field stylus 15 also at the normal position. It can also be measured.

In measuring the magnetic field strength at two or more multiple positions in this way, the control unit 14 determines the signal value of the magnetic field strength at the plane at the normal position, that is, at two or more multiple planes, in addition to the plane at the measurement position. It means that you can get it.

The signal values of the magnetic field strengths at each of these multiple planes were plotted in a two-dimensional or three-dimensional space prepared in the arithmetic unit inside the control unit 14, and plotted against a magnetic circuit model prepared in advance. By applying the signal value of the magnetic field strength, it is also possible to obtain an estimated value of the magnetic field strength on the surface of the target 7.

As a method for obtaining this estimated value, a known numerical calculation method may be used, and the simplest example is a method in which the signal values of the magnetic field strengths at two points are obtained and inversely proportional to the square of the distance (2). A known calculation method according to the number of measurement points and the required accuracy, such as the next approximation method), may be used.

1 ... Sputter film forming apparatus 2 ... Film forming chamber 5 ... Stage 6 ... Substrate 7 ... Target 8 ... Backing plate 9 ... Sputter power supply 10 ... Magnet device 15 ... Magnetic field stylus 16 ... Elevating pin 17 ... Elevating mechanism 20 ... Board transfer arm (board transfer mechanism)
22 ... Shutter

Claims (5)

A sputter film forming apparatus that forms a film on a substrate by magnetron sputtering.
The film formation room and
A target made of a magnetic material held on a backing plate in the film forming chamber,
A sputtering power supply that supplies a predetermined power to the target, and
A magnet device for magnetron discharge provided on the back side of the backing plate with respect to the substrate,
A magnetic field transducer that measures the magnetic field strength of the target surface by the magnet device,
A moving mechanism that changes the relative distance between the target and the magnet device,
A sputter film forming apparatus having a control unit that controls the operation of the moving mechanism so as to change the magnetic field strength of the target surface by the magnet device based on the measurement result of the magnetic field transducer. The sputtering film forming apparatus according to claim 1, wherein the magnetic field stylus is provided on an elevating pin for raising and lowering the substrate in the film forming chamber. The invention according to any one of claims 1 or 2, wherein the magnetic field stylus 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. Spatter film forming equipment. The sputter film forming apparatus according to any one of claims 1 to 3, wherein the magnetic field transducer is provided on a shutter that controls the flight of sputter particles onto the substrate. Using the sputtering film forming apparatus according to any one of claims 1 to 4,
Based on the measurement result of the magnetic field transducer, 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 strength of the target surface by the magnet device becomes constant. Spatter film formation method.

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