JP2020002441A - Facing target sputtering film deposition apparatus - Google Patents

Abstract

To provide a technique for preventing a non-erosion region from occurring on a target surface to suppress the occurrence of particles caused by the peeling of film in the non-erosion region in a facing target sputtering film deposition apparatus.SOLUTION: A facing target sputtering film deposition apparatus comprises: backing plates 6A and 6B arranged to sandwich an electrical discharge space 21; targets 5A and 5B oppositely arranged to sandwich the electrical discharge space 21; magnet devices 9A and 9B arranged so as to face different magnetic poles to each other at positions corresponding to edge portions of the targets 5A and 5B on the rear surface sides of the backing plates 6A and 6B; and a high frequency power supply 22 for supplying high frequency electric power to each of the backing plates 6A and 6B. Anode electrodes 7A and 7B having a coupling capacity controlled between the surfaces of the targets 5A and 5B are provided so as to adjacently surround the peripheries of the targets 5A and 5B.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an apparatus for forming a film by sputtering, and more particularly to a sputter film forming apparatus for forming a film by discharging using a high frequency power supply with a pair of sputtering targets (hereinafter, appropriately referred to as “targets”) facing each other. About technology.

In recent years, various devices (semiconductors, electronics, displays, solar cells, and the like) have been improved in performance and miniaturization.
In order to manufacture such a device, a high-quality thin film forming technique that generates few particles in a vacuum is important.

As such a thin film forming technique, a magnetron type sputtering apparatus and a facing target type sputtering apparatus are conventionally known.
However, the magnetron sputtering apparatus has a problem in that particles having high kinetic energy collide with the substrate surface during film formation and cause deterioration in film quality.

  On the other hand, the facing target type sputtering device has a structure in which a pair of targets face each other and the substrate is set on the side of the target, so that particles having high kinetic energy during the film formation are prevented from colliding with the substrate surface. Thus, a high-quality thin film can be formed.

  However, the facing target type sputtering apparatus has a structure in which the target faces each other. Therefore, when a non-erosion region exists on the target surface, a film is deposited on the non-erosion region. There is a problem that the film is peeled off from the substrate and particles are generated.

In a conventional facing target type sputtering apparatus, the center portion of the target is sputtered by a magnetic field structure formed by a permanent magnet installed on the back side of the facing target, but the target edge is not sputtered at all near the edge of the target. A non-erosion region is formed in the portion.
Therefore, in order to suppress the generation of particles, it is important to discharge so that a non-erosion region is not generated on the target surface.

On the other hand, conventionally, a technique has been proposed in which a deposition plate is provided on the surface of a non-erosion region of a target to suppress generation of particles (for example, see Patent Document 1).
However, since this conventional deposition-preventing plate is easily heated by the influence of plasma and is structurally difficult to cool, the deposition-preventing plate repeatedly undergoes thermal expansion and contraction due to thermal cycles during film formation and non-film formation. As a result, there is a problem that particles are generated when used for a long time.

International Publication No. WO 2015/162778 JP-A-10-008246

  The present invention has been made in consideration of such problems of the related art, and an object of the present invention is to prevent the generation of a non-erosion region on a target surface in a facing target type sputtering film forming apparatus. An object of the present invention is to provide a technique for suppressing generation of particles due to peeling of a film in an erosion region.

The present invention made in order to achieve the above object is a facing target type sputtering film forming apparatus for performing sputtering film formation with a pair of sputtering targets facing each other in a grounded vacuum chamber. A cathode electrode, first and second sputtering targets electrically connected to the first and second cathode electrodes, respectively, and opposed to each other with a discharge space interposed therebetween; A first and a second magnet device arranged at positions corresponding to the edges of the first and second sputtering targets on the back side so that different magnetic poles face each other across the discharge space; A high-frequency power supply for supplying high-frequency power between power supply terminals of the first and second cathode electrodes and a ground terminal of the vacuum chamber, respectively; A first and a second anode electrodes, each of which has a coupling capacity between the first and second sputtering targets and a target surface thereof, respectively, so as to surround the ring target in close proximity to each other. It is.
In the present invention, it is also effective that the first and second anode electrodes are provided with irregularities on the target surface side of the first and second sputtering targets.
In the present invention, it is also effective that the angles of the surfaces of the first and second anode electrodes with respect to the target surfaces of the first and second sputtering targets are respectively −45 ° or more and 90 ° or less. It is.
In the present invention, it is also effective that an insulator having a predetermined thickness is provided between the first and second sputtering targets and the first and second anode electrodes, respectively.
In the present invention, it is also effective that the first and second cathode electrodes are configured to supply high-frequency power of 13.56 MHz to 100 MHz, respectively.
In the present invention, it is also effective that the high-frequency power is supplied to the central portions of the first and second cathode electrodes, respectively.
In the present invention, it is also effective that DC power is further supplied to each of the first and second cathode electrodes.
According to the present invention, it is also advantageous that, when high-frequency power is supplied to the first and second cathode electrodes, impedance adjusting means for adjusting the impedance of each portion of the first and second cathode electrodes are provided. It is a target.

  According to the present invention, in the facing target type sputtering film forming apparatus, the first and second sputtering targets are located on the back side of the first and second cathode electrodes at positions corresponding to the edges of the first and second sputtering targets, respectively. Are disposed so as to sandwich the discharge space, and the coupling capacities between the target surfaces of the first and second sputtering targets are respectively set so as to surround the first and second sputtering targets in close proximity to each other. Since the adjusted anode electrode is provided, when high-frequency power (for example, 13.56 MHz or more and 100 MHz or less) is supplied to the first and second sputtering targets, between the central portions of the pair of sputtering targets, In addition, each between the edge of the pair of sputtering targets and the pair of anode electrodes It is possible to cause the discharge.

  As a result, according to the present invention, discharge is generated over the entire surface of each sputtering target and sputtering is performed, so that generation of non-erosion regions on the target surface of each sputtering target is prevented, and particles due to film peeling of non-erosion regions are prevented. Generation can be suppressed.

  Further, according to the present invention, the entire surface of each sputtering target can be an erosion region, so that the use efficiency of the sputtering target can be improved.

  Furthermore, conventionally, for example, in a reactive sputtering using oxygen or nitrogen gas using a metal target, an oxide film, a nitride film or A method of forming an oxynitride film is known (metal mode sputtering). At this time, if a non-erosion portion exists on the target surface of the target, an oxide film, a nitride film, or an oxynitride film is deposited on the surface. When this film is insulating, an insulating film charged with Ar ions at the time of discharge is formed.

  In this case, when a predetermined amount of charge accumulates, dielectric breakdown occurs in the insulating film, and an ionic current flows from the insulating film to the metal target or to the erosion portion in a metal state, thereby causing abnormal discharge.

  However, according to the present invention, since the entire discharge is generated in each sputtering target and the sputtering is performed, the abnormal discharge described above can be prevented.

  In the present invention, when the first and second anode electrodes are provided with irregularities on portions of the first and second sputtering targets on the target surface side, the first and second sputtering targets have a first surface with respect to the target surface. And when the angle of the surface of the second anode electrode is -45 ° or more and 90 ° or less, respectively, or between the first and second sputtering targets and the first and second anode electrodes. In the case where an insulator having a predetermined thickness is provided, the coupling capacity between the first and second anode electrodes and the target surfaces of the first and second sputtering targets can be easily adjusted. Can be.

  In the present invention, when high-frequency power is supplied to the first and second cathode electrodes, and when impedance adjusting means for adjusting the impedance of each portion of the first and second cathode electrodes is provided, In combination with the operation of the anode electrode whose coupling capacity between the first and second sputtering targets and the target surface is adjusted, it is possible to uniformly discharge the respective portions of the first and second sputtering targets. Thereby, it is possible to uniformly discharge between each of the edge portions of the first and second sputtering targets and the anode electrode.

FIG. 1 is a schematic diagram showing an internal configuration of a facing target type sputtering film forming apparatus according to the present invention. (A) to (c): explanatory diagrams schematically showing means for adjusting the coupling capacitance between the surfaces of the first and second anode electrodes and the target surfaces of the first and second targets, respectively. FIGS. 3A and 3B are diagrams for explaining the principle of the present invention. FIG. 3A is an explanatory diagram schematically showing a distribution of a magnetic field (magnetic flux) generated by the magnetic circuit according to the present embodiment. FIG. 3B is an explanatory view schematically showing the distribution of plasma generated in the present embodiment. (A) (b): Schematic configuration diagram showing an example of impedance adjustment means when the target and the backing plate are square in shape. (A) (b): Schematic configuration diagram showing an example of the impedance adjusting means when the target and the backing plate have a rectangular shape.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing the internal configuration of a facing target type sputtering film forming apparatus according to the present invention.

  As shown in FIG. 1, a facing target type sputtering film forming apparatus 1 of the present embodiment has, for example, a box-shaped vacuum film forming chamber 2 in which a substrate 15 which is a film formation target is arranged.

The vacuum film forming chamber 2 is provided, for example, on one side thereof with an exhaust unit 2a connected to a vacuum exhaust device (not shown) and a gas introducing unit 2b for introducing a process gas containing an argon gas. .
The vacuum film forming chamber 2 is grounded via a ground terminal 2d provided on the outer wall.

  For example, a portion of the vacuum film forming chamber 2 opposite to the side on which the exhaust unit 2a and the gas introducing unit 2b are provided is attached to the opening 2c side of the vacuum film forming chamber 2 so that high frequency radiates to an external space. A high-frequency shield cover 3 is provided to suppress the occurrence of noise.

  Inside the high-frequency shield cover 3, a pair of first and second sputtering units 4A and 4B having the same basic configuration are communicated with the vacuum film forming chamber 2 and have a vacuum atmosphere equivalent to that of the vacuum film forming chamber 2. Is provided with the discharge space 21 provided so as to be maintained.

  The first sputter unit 4A and the second sputter unit 4B of the present embodiment include a plurality of members including the first and second targets 5A and 5B assembled to the housings 20A and 20B constituting the target unit, respectively. And the first and second targets 5A and 5B are arranged so that the sputtering surfaces thereof face each other and are parallel to each other.

  In the present invention, a vacuum chamber is formed by the above-described vacuum film forming chamber 2 and the housings 20A and 20B of the first and second sputtering units 4A and 4B.

  Here, the first and second targets 5A and 5B are made of the same material (eg, oxide), and are each formed in a disk shape in this example. Then, the first and second targets 5A and 5B are placed on the first and second backing plates 6A and 6B as cathode electrodes so that the respective sputtering surfaces are perpendicular to the film formation surface of the substrate 15. Each is attached.

  Around the first and second targets 5A and 5B, first and second anode electrodes 7A and 7B made of a conductive metal material (for example, an alloy mainly containing aluminum) are provided with the first and second anodes. Are provided so as to surround the targets 5A and 5B and the first and second backing plates 6A and 6B. The first and second anode electrodes 7A and 7B of this example are each formed in a circular ring shape.

  These first and second anode electrodes 7A and 7B are electrically insulated from the first and second targets 5A and 5B and the first and second backing plates 6A and 6B by an insulator 70, respectively. It is electrically connected to the outer wall of the vacuum film forming chamber 2.

  Further, the first and second anode electrodes 7A and 7B are also provided by surrounding the first and second backing plates 6A and 6B by the flange members 8A and 8B made of an insulating material. The backing plates 6A, 6B are electrically insulated from each other.

  In this case, the first and second anode electrodes 7A and 7B are arranged such that their inner peripheral portions are close to the outer peripheral portions of the first and second targets 5A and 5B via the insulator 70. I have.

  The first and second anode electrodes 7A and 7B are configured so that the coupling capacitance between the first and second targets 5A and 5B and the target surface is adjusted as described later. Have been.

  In the first and second sputtering units 4A and 4B, the first and second backing plates 6A and 6B are provided on the opposite sides of the sputtering surfaces of the first and second targets 5A and 5B, that is, on the back side. For example, first and second magnet devices 9A and 9B made of permanent magnets are attached and fixed to yoke plates 10A and 10B, respectively.

  These first and second magnet devices 9A and 9B are formed in a shape (for example, a circular ring shape) along the edges of the first and second targets 5A and 5B, and have different polarities across the discharge space 21. Are arranged to face each other.

  With such a configuration, the discharge space 21 between the first and second targets 5A and 5B has a shape along the edges of the first and second targets 5A and 5B. A magnetic field is generated.

  On the other hand, a high-frequency power supply 22 is provided outside the high-frequency shield cover 3, and the high-frequency power generated by the high-frequency power supply 22 is supplied to the first and second sputtering units 4A and 4B via the matching box 23. The first and second backing plates 6A, 6B are configured to be supplied respectively.

  In the case of the present embodiment, high-frequency power is supplied to the first and second power supply terminals 6a and 6b at the central portions of the first and second backing plates 6A and 6B, respectively.

  In the case of the present invention, the frequency of the high frequency power supplied to the first and second backing plates 6A and 6B is not particularly limited, but the edges of the first and second targets 5A and 5B are surely sputtered. In view of this, the frequency is preferably 13.56 MHz or more, and more preferably 27 MHz or more and 100 MHz or less.

  When the frequency of the high-frequency power is smaller than 13.56 MHz, the density of the high-frequency plasma generated at the edges of the first and second targets 5A and 5B is small as in the case of using the DC power supply. The rate at which the film is deposited is higher.

  On the other hand, when the frequency of the high-frequency power is higher than 100 MHz, when the density of the high-frequency plasma generated at the edges of the first and second targets 5A and 5B increases, the first and second backing plates 6A and 6B The high frequency power supplied to the first and second anode electrodes 7A and 7B easily flows through the high frequency plasma. As a result, high-frequency power does not reach the central portion of the target, the plasma density decreases, and the deposition rate of the film becomes higher than the sputtering rate.

  That is, in the present invention, the sputtering rate at the center / edge of the first and second targets 5A and 5B is adjusted by the frequency of the supplied high-frequency power.

  Further, in the present invention, although not particularly limited, the first and second backing plates 6A and 6B may be configured so that DC power is further superimposed on high-frequency power and supplied.

That is, as the frequency of the high-frequency power supplied to the first and second backing plates 6A, 6B increases, the density of the high-frequency plasma generated at the edges of the first and second targets 5A, 5B increases. As a result, the DC voltage components (V _DC ) applied to the first and second targets 5A and 5B become small, and thus a problem may occur that the sputtering rate is reduced.

  Therefore, even when the frequency of the supplied high-frequency power is increased by supplying DC power to the first and second backing plates 6A and 6B while further superimposing DC power on the high-frequency power, the sputtering rate is increased. Can be prevented from decreasing.

  FIGS. 2A to 2C show surfaces of the first and second anode electrodes 7A and 7B (surfaces on the discharge space side) and target surfaces of the first and second targets 5A and 5B (discharge space side). FIG. 4 is an explanatory view schematically showing a means for adjusting the coupling capacitance between the first and second surfaces.

  Hereinafter, in FIGS. 2A to 2C, the first and second targets 5A and 5B are referred to as a target 5, the first and second backing plates 6A and 6B are referred to as a backing plate 6, and the first and second backings 6A and 6B are referred to as a backing plate 6. And, the second anode electrodes 7A and 7B will be comprehensively described as anode electrodes 7a to 7c.

  First, in the example shown in FIG. 2A, a plurality of holes 71 extending in a direction perpendicular to the surface 7S of the anode electrode 7a are formed as irregularities on the anode electrode 7a, for example, on the surface 7S of the anode electrode 7a. Things.

The opening shape of these holes 71 can be circular, square, polygonal, or the like.
In consideration of the fact that the plasma contacts the wall inside the hole 71 reliably, it is preferable that the opening diameter of the hole 71 is set to 5 mm or more in the case of a circular shape, for example.

  In this example, by forming a plurality of holes 71 extending in a direction orthogonal to the surface 7S of the anode electrode 7a, the area of the surface 7S of the anode electrode 7a is smaller than that in a case where the hole 71 is not formed. It is configured to be large.

  In the present example having such a configuration, the coupling capacity between the surface 7S of the anode electrode 7a and the target surface 5S of the target 5 electrically connected to the backing plate 6 serving as the cathode electrode causes the hole 71 to be formed. As compared with the case where the target is not formed, the impedance becomes larger, whereby the impedance between the surface 7S of the anode electrode 7a and the target surface 5S of the target 5 becomes relatively small.

  As a result, according to the present example, high-frequency power easily flows from the target surface 5S of the target 5 to the surface 7S of the anode electrode 7a, and the density of high-frequency plasma generated at the edge of the target 5 can be improved.

  In this example, by adjusting the opening area and depth of the hole 71 provided in the anode electrode 7a and the number of the holes 71, the area of the surface 7S of the anode electrode 7a is adjusted and the edge of the target 5 is formed. The density of the generated high frequency plasma can be adjusted to an optimum value.

In the example shown in FIG. 2B, the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S of the target 5 is changed.
In this case, when the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S of the target 5 is larger than 0 ° (θ ₁ ), the distance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 becomes smaller. Since the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S of the target 5 is smaller than when the angle is 0 °, the coupling capacitance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 is relatively large. As a result, the impedance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 becomes relatively small.

  As a result, high-frequency power easily flows from the target surface 5S of the target 5 to the surface 7S of the anode electrode 7b, and the density of the high-frequency plasma generated at the edge of the target 5 increases.

On the other hand, when the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S of the target 5 is smaller than 0 ° (θ ₂ ), the distance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 is equal to the target. 5 is larger than when the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S is 0 °, the coupling capacitance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 is relatively small. As a result, the impedance between the surface 7S of the anode electrode 7b and the target surface 5S of the target 5 becomes relatively large.

  As a result, it becomes difficult for high-frequency power to flow from the target surface 5S of the target 5 to the surface 7S of the anode electrode 7b, and the density of high-frequency plasma generated at the edge of the target 5 decreases.

  In the case of the present invention, although not particularly limited, if the angle of the surface 7S of the anode electrode 7b with respect to the target surface 5S of the target 5 is not less than −45 ° and not more than 90 °, the edge of the target 5 can be formed. The density of the high-frequency plasma generated at this time can be adjusted to an optimum value.

In the example shown in FIG. 2C, the thickness of the insulator 70 provided between the target 5 and the anode electrode 7c is changed.
In this case, when the thickness of the insulator 70 provided between the target 5 and the anode electrode 7c is reduced (D ₁ > D ₂ ), the distance between the surface 7S of the anode electrode 7c and the target surface 5S of the target 5 is reduced. Since the distance is reduced, the coupling capacity between the surface 7S of the anode electrode 7c and the target surface 5S of the target 5 electrically connected to the backing plate 6 serving as the cathode electrode becomes relatively large. The impedance between the surface 7S of the electrode 7c and the target surface 5S of the target 5 becomes relatively small.

  As a result, high-frequency power easily flows from the target surface 5S of the target 5 to the surface 7S of the anode electrode 7c, and the density of the high-frequency plasma generated at the edge of the target 5 can be improved.

  Thus, in this example, by adjusting the thickness of the insulator 70 provided between the target 5 and the anode electrode 7c, the distance between the surface 7S of the anode electrode 7c and the target surface 5S of the target 5 is adjusted. By adjusting the distance, the density of the high-frequency plasma generated at the edge of the target 5 can be adjusted to an optimum value.

  In the case of the present invention, the thickness of the insulator provided between the target 5 and the anode electrode 7 is not less than 3 mm and not more than 50 mm. The density of the plasma can be adjusted to an optimum value.

  The means for adjusting the coupling capacitance between the surface 7S of the anode electrode 7 and the target surface 5S of the target 5 described with reference to FIGS. 2A to 2C may be configured in combination. it can.

  3A and 3B are diagrams for explaining the principle of the present invention, and FIG. 3A is a diagram schematically illustrating a distribution of a magnetic field (magnetic flux) generated by the magnetic circuit according to the present embodiment. FIG. 3B is an explanatory diagram schematically showing the distribution of the plasma generated in the present embodiment.

  As shown in FIG. 3A, in the present embodiment, the N pole of the first magnet unit 9A of the first sputtering unit 4A and the S pole of the second magnet unit 9B of the second sputtering unit 4B. Are arranged to face each other.

  As a result, in the present embodiment, an opposing magnetic field 30 having magnetic lines of force in the direction from the first magnet device 9A to the second magnet device 9B is generated. The opposing magnetic field 30 is formed so as to penetrate the edges of the first target 5A and the second target 5B, respectively.

  As described above, since the first and second magnet devices 9A and 9B are formed in a circular ring shape, the generated counter magnetic field 30 is formed in a cylindrical shape in the discharge space 21.

In the first sputtering unit 4A, a first magnetron magnetic field 31 is generated inside the ring of the first magnet device 9A in the direction from the N pole to the S pole.
On the other hand, in the second sputtering unit 4B, a second magnetron magnetic field 32 is generated inside the ring of the second magnet device 9B in the direction from the N pole to the S pole.

  In a state where such a magnetic field is formed, a process gas is introduced into the vacuum film forming chamber 2 under vacuum, and the high-frequency power generated by the high-frequency power supply 22 is supplied to the first and second via the matching box 23. When supplied to the first and second power supply terminals 6a, 6b at the center of the first and second backing plates 6A, 6B of the sputter units 4A, 4B, these high-frequency powers are respectively supplied to the first by the skin effect. And flows through the edges of the second backing plates 6A, 6B and the edges of the first and second targets 5A, 5B toward the central portion of the sputtering surface of the first and second targets 5A, 5B.

  As a result, a discharge is generated in the discharge space 21 between the first target 5A and the second target 5B, and as shown in FIG. 3B, at the center of the first and second targets 5A and 5B. An opposing plasma 35 is generated.

  The opposed plasma 35 is confined inside the opposed magnetic field 30 by the cylindrical opposed magnetic field 30 generated in the discharge space 21 between the first magnet device 9A and the second magnet device 9B. .

  In this case, the electrons in the opposing plasma 35 fly in the discharge space 21 so as to reciprocate between the first and second targets 5A and 5B. In the vicinity of the first and second targets 5A and 5B, the electrons in the opposing plasma 35 fly so as to orbit along the respective lines of magnetic force due to the first and second magnetron magnetic fields 31 and 32 described above. .

  Then, the argon ions in the opposed plasma 35 collide with the central portions of the first and second targets 5A and 5B, whereby sputtering is performed at the central portions of the first and second targets 5A and 5B.

  On the other hand, as described above, the high-frequency power supplied to the first and second power supply terminals 6a and 6b at the central portions of the first and second backing plates 6A and 6B respectively correspond to the first and second power supply terminals. When flowing toward the center of the sputtering surface of the first and second targets 5A, 5B via the edges of the backing plates 6A, 6B and the edges of the first and second targets 5A, 5B, Discharge also occurs between the first and second targets 5A and 5B and the first and second anode electrodes 7A and 7B disposed close to each other, and as shown in FIG. Plasmas 36 and 37 are generated, respectively.

  In this case, for example, using the means shown in FIGS. 2A to 2C described above, the surface of the first and second anode electrodes 7A and 7B and the surface of the first and second targets 5A and 5B are By adjusting the coupling capacitance between them to appropriate values, the plasma density of the plasmas 36 and 37 can be generated in an optimum state.

  Then, the argon ions in the plasmas 36 and 37 collide with the edges of the first and second targets 5A and 5B, whereby sputtering is performed on the edges of the first and second targets 5A and 5B.

  As described above, in the present embodiment, when high-frequency power (for example, 13.56 MHz or more and 100 MHz or less) is supplied to the first and second targets 5A and 5B, the first and second targets 5A and 5B Between the central portions of the first and second anodes 7A and 7B, and between the edges of the first and second targets 5A and 5B and the first and second anode electrodes 7A and 7B, respectively. The sputtering is performed on the entire surface of each of the targets 5A and 5B.

  Then, the sputtered particles sputtered from the first and second targets 5A and 5B through such a sputtering process reach the surface of the substrate 15 in the vacuum film forming chamber 2 so that the first and second targets are formed on the surface of the substrate 15. A film of the material of the second targets 5A and 5B is formed.

  According to the above-described embodiment, the generation of non-erosion regions on the surfaces of the first and second targets 5A and 5B can be prevented, and the generation of particles due to the peeling of the non-erosion regions can be suppressed.

  Incidentally, when the first and second targets 5A and 5B and the corresponding first and second backing plates 6A and 6B are circular in shape as in the above embodiment, the backing as the cathode electrode is used. When supplying high-frequency power to the first and second power supply terminals 6a and 6b at the central portions of the plates 6A and 6B, the first and second targets 5A and 5B have the edge portions and the first and second targets from the central portion. Are equal over the entire circumference of the first and second targets 5A, 5B, so that the first and second targets 5A, 5B and the first and second anode electrodes 7A, 7B Is uniformly discharged over the entire circumference.

However, when the target and the corresponding backing plate have a rectangular shape such as a square shape or a rectangular shape, the distance between the center and the edge of the target and the anode electrode is changed from the center of the target to the edge. Depends on the rotation angle of the line segment extending in the direction, and as a result, the impedance also depends on the rotation angle of the line segment. Therefore, when high-frequency power is supplied to the center of the backing plate, each of the first and second targets is It is not possible to discharge uniformly between the first and second anode electrodes and the first and second anode electrodes.
Specifically, as the distance between the power supply terminal of the high-frequency power and the discharge unit increases, the impedance increases and the density of the generated plasma decreases.

Therefore, the present invention can solve the above-mentioned problem by employing the following means.
FIGS. 4A and 4B are schematic configuration diagrams showing an example of the impedance adjusting means when the target and the backing plate have a square shape. Hereinafter, in order to facilitate understanding of the present invention, one of the pair of sputtering units, such as the above-described first and second sputtering units 4A and 4B, will be described as an example.

  In the example shown in FIG. 4A, a square backing plate 41 is provided on the back side of the square target 40, and a square ring-shaped anode electrode 42 surrounds the periphery of the target 40 and the backing plate 41. Is provided.

In this example, a “+” shaped high-frequency power diffusion member 43 is provided on the back surface of the backing plate 41.
The high-frequency power diffusion member 43 is made of a metal material having a low conductivity like the backing plate 41 such as copper (Cu), and is electrically connected to the backing plate 41 (target 40).

  Here, the high-frequency power diffusion member 43 is provided with four linear diffusion portions 43a having the same length with respect to the center portion 41a of the target 40 and the backing plate 41 at a rotation angle of 90 degrees, respectively. Are provided so as to extend toward the four corners of the backing plate 41.

  In this case, the high-frequency power diffusion member 43 is configured such that the end of each diffusion portion 43a and the four corners of the backing plate 41 are electrically connected to each other. It is preferable to provide a predetermined space therebetween.

  Then, it is configured to supply high-frequency power to the power supply terminal 60a of the high-frequency power diffusion member 43 provided at a position corresponding to the center portion 41a of the target 40 and the backing plate 41.

In this example, the four linear portions of the high-frequency power diffusion member 43 are formed with the same width.
In the present example having such a configuration, when high-frequency power is supplied to the power supply terminal 60a of the high-frequency power diffusion member 43, the high-frequency power is supplied along the four diffusion portions 43a of the high-frequency power diffusion member 43. Become.

  As a result, according to the present example, higher high-frequency power can be supplied to each corner where the distance between the target 40 and the backing plate 41 with respect to the central portion 41a is the largest. Discharge can be performed, whereby uniform discharge can be performed between each part of the edge of the target 40 and the anode electrode 42.

  Then, by adopting the same configuration for the other sputter portion, the above-described operation allows each portion between the first and second targets and each portion of the edge of the first and second targets. And the first and second anode electrodes can be uniformly discharged.

  FIGS. 5A and 5B are schematic configuration diagrams showing examples of impedance adjustment means when the target and the backing plate have a rectangular shape. Hereinafter, in order to facilitate understanding, one of the pair of sputtering units will be described as an example.

  In the example illustrated in FIG. 5A, a rectangular backing plate 51 is provided on the back side of the rectangular target 50, and a rectangular ring-shaped anode electrode 52 surrounds the periphery of the target 50 and the backing plate 51. Is provided.

In this example, a high-frequency power diffusion member 53 having diffusion portions with different widths is provided on the back surface of the backing plate 51.
As shown in FIG. 5B, the high-frequency power diffusion member 53 of the present example has a linear first diffusion portion 53 a parallel to the long side of the backing plate 51 at the center of the rectangular backing plate 51. Is provided.

  Further, at both ends of the first diffusion portion 53a, second diffusion portions 53b which are continuous with the first diffusion portion 53a and extend linearly toward the four corners of the backing plate 51 are provided.

  Further, a plurality of third diffusion portions 53c extending linearly toward the opposing long sides of the backing plate 51 are provided at the central portion of the backing plate 51.

  Further, between the second diffusion portions 53b of the backing plate 51, fourth diffusion portions 53d extending linearly toward the short sides of the backing plate 51 are provided.

  Here, the high-frequency power diffusion member 53 includes an end of the second diffusion part 53b, four corners of the backing plate 51, an end of the third diffusion part 53c, a long side of the backing plate 51, 4 is electrically connected to the short side of the backing plate 51, and a predetermined space is provided between the other part of the high-frequency power diffusion member 53 and the backing plate 51. Is preferred.

In the case of this example, the respective dimensions are set such that the width of the first diffusion portion 53a is larger than the widths of the third and fourth diffusion portions 53c and 53d.
The respective dimensions are set such that the length of the second diffusion portion 53b is longer than the lengths of the third and fourth diffusion portions 53c and 53d.

  This is because the impedance of the linear conductive member increases as the width decreases, and the distance in the direction from the first diffusion portion 53a toward the long side and the short side of the backing plate 51 and the four corners In consideration of the difference in the distance from the heading direction, uniform discharge is performed on the target surface.

  According to the present example having such a configuration, a larger high-frequency power can be supplied to each corner of the backing plate 51 shown in FIG. The discharge can be uniformly performed in each part of the target 50, and thus, the discharge can be uniformly performed between each part of the edge of the target 50 and the anode electrode.

  Then, by adopting the same configuration for the other sputter portion, the above-described operation allows each portion between the first and second targets and each portion of the edge of the first and second targets. And the first and second anode electrodes can be uniformly discharged.

  Note that the present invention is not limited to the above embodiment, and various changes can be made. For example, in the above embodiment, the high-frequency power is supplied to one power supply terminal for the backing plate, but the present invention is not limited to this, and two or more power supplies may be supplied to the backing plate. High-frequency power can also be supplied to the supply terminal.

  In this case, the position for supplying the high-frequency power is not limited to the central portion of the backing plate. High-frequency power can be supplied to both ends in the longitudinal direction.

  Further, the impedance adjusting means shown in FIGS. 4A and 5B and FIGS. 5A and 5B are added to the surface 7S of the anode electrodes 7a to 7c shown in FIGS. Means for adjusting the coupling capacity with the surface 5S may be combined.

1 ... opposed target type sputtering film forming apparatus 2 ... vacuum film forming chamber 2d ... ground terminal 3 ... high frequency shield cover part 4A ... first sputtering part 4B ... second sputtering part 5A ... first sputtering target 5B ... Second sputtering target 6A. First backing plate (first cathode electrode).
6B: second backing plate (second cathode electrode)
6a first power supply terminal 6b second power supply terminal 7A first anode electrode 7B second anode electrode 9A first magnet device 9B second magnet device 15 substrate 21 discharge space

Claims (8)

A facing target type sputtering film forming apparatus that performs sputtering film formation by facing a pair of sputtering targets in a grounded vacuum chamber,
First and second cathode electrodes;
First and second sputtering targets electrically connected to the first and second cathode electrodes, respectively, and opposed to each other with a discharge space interposed therebetween;
The first and second cathode electrodes are arranged at positions corresponding to the edges of the first and second sputtering targets on the back side, respectively, such that different magnetic poles are arranged so as to face each other with the discharge space interposed therebetween. And a second magnet device;
A high-frequency power supply for supplying high-frequency power between a power supply terminal of the first and second cathode electrodes and a ground terminal of the vacuum chamber,
First and second anodes each having a controlled coupling capacity between the first and second sputtering targets and a target surface of the first and second sputtering targets so as to closely surround the first and second sputtering targets, respectively. A facing target type sputtering film forming apparatus provided with electrodes.   2. The facing target type sputtering film forming apparatus according to claim 1, wherein the first and second anode electrodes are provided with projections and depressions on target surface side portions of the first and second sputtering targets. 3.   3. The device according to claim 1, wherein an angle of a surface of the first and second anode electrodes with respect to a target surface of the first and second sputtering targets is in a range of not less than -45 degrees and not more than 90 degrees. 2. The facing target type sputtering film forming apparatus according to claim 1.   4. The opposing target according to claim 1, wherein an insulator having a predetermined thickness is provided between the first and second sputtering targets and the first and second anode electrodes, respectively. 5. Type sputter film forming equipment.   The facing target type sputtering film forming apparatus according to any one of claims 1 to 4, wherein a high-frequency power of 13.56 MHz to 100 MHz is supplied to the first and second cathode electrodes, respectively. .   The facing target type sputtering film forming apparatus according to any one of claims 1 to 5, wherein the high frequency power is supplied to central portions of the first and second cathode electrodes, respectively.   The facing target type sputtering film forming apparatus according to any one of claims 1 to 6, wherein a direct current power is further supplied to each of the first and second cathode electrodes.   8. An apparatus according to claim 1, further comprising an impedance adjusting unit that adjusts the impedance of each part of the first and second cathode electrodes when high-frequency power is supplied to the first and second cathode electrodes. 2. The facing target type sputtering film forming apparatus according to claim 1.

Images