JP3834111B2 - Magnetron sputtering method, magnetron sputtering apparatus and magnet unit used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetron sputtering method for forming a thin film on a substrate in a vacuum, a magnetron sputtering apparatus, and a magnet unit used in the magnetron sputtering apparatus.
[0002]
[Prior art]
FIG. 6 is a diagram of a conventional magnetron sputtering apparatus having a magnet unit outside the sputtering chamber. In FIG. 6, 50 is a sputtering chamber, 51 is a target disposed in the sputtering chamber 50, 52 is a backing plate for holding the target 51, 53 is an earth shield disposed around the target 51, and 54 is on the target side and sputtering. An insulating material that insulates the chamber 50, a water cooling mechanism 55 that cools the backing plate 52, a magnet unit 56, a high frequency power source that supplies high frequency power to the target 51, a belt 58, and a magnet unit 56 that rotates the magnet unit 56. It is a motor, and the rotating shaft of the motor 59 and the rotating shaft of the magnet unit 56 are connected by the belt 58. 60 is a pump for evacuating the sputtering chamber 50, 61 is a source of a reactive gas for sputtering such as argon, 62 is a substrate disposed in the sputtering chamber 50 facing the target 51, and 63 is a substrate 62. It is the board | substrate holder to hold | maintain.
[0003]
Such a magnetron sputtering apparatus has an advantage that the sputtering rate is 10 to 30 times higher than that of a sputtering apparatus that does not use the action of a magnetic field. However, this advantage is accompanied by the disadvantage that the surface of the target material is eroded inhomogeneously according to the magnetic field distribution on the surface of the sputtered material. As a result, the film thickness distribution is also inhomogeneous in the same way that the surface of the target material is eroded inhomogeneously. Depending on the depth of the eroded portion, only about 30% of the target material is sputtered, resulting in a lifetime.
[0004]
Conventionally, as shown in FIGS. 7A and 7B, most of the magnets of the magnet unit mounted on the sputtering apparatus are circularly or linearly arranged according to the target shape. The magnets or magnet groups 22 and 22 ′ manufactured in arbitrary shapes on the surface of each are held at arbitrary positions by an adhesive. At this time, the yoke 21 is made of a magnetic material so as to shield the influence of the magnetic field on the back surface and at the same time increase the magnetic field strength on the surface.
[0005]
[Problems to be solved by the invention]
In recent years, for the purpose of improving the accuracy of film thickness variation, improving the utilization efficiency of the target material, and increasing the rate, the movement for controlling the magnetic field distribution has increased, and the shape for arranging the magnets or magnet groups has become complicated. However, even when the magnet arrangement is determined and the magnet unit is created, the desired magnetic field distribution is often not obtained. At this time, the magnet is bonded by an adhesive force like a conventional magnet unit. If held, it is difficult to correct.
An object of the present invention is to use a magnetron sputtering method, a magnetron sputtering apparatus, and a magnetron sputtering apparatus having a magnet unit suitable for obtaining a complicated magnetic field distribution because the method of attaching and detaching a magnet is easy and the magnet arrangement is easily corrected. A magnet unit is provided.
[0006]
[Means and effects for solving the problems]
In order to achieve the above object, the present invention is configured as follows.
According to the magnet unit according to the first aspect of the present invention,
A magnet unit disposed on the back side of a target disposed in a magnetron sputtering apparatus,
A plurality of magnets all of the same shape ,
A yoke composed of a magnetic material;
A magnet holder that will be placed on a surface of the yoke has a plurality of pores having a respective pieces equivalent shape or size of the plurality of magnets, each of the magnet individually in each hole inserting a magnet holder for detachably holding the respective magnets to the yoke by the magnetic force of the magnet by, and holes of the magnet holder is characterized by more than the magnet.
[0007]
According to a second aspect of the present invention, in the first aspect, the magnet holder is non-magnetic and is made of a material selected from duralumin, aluminum, copper, synthetic resin, and ceramic. You can also.
According to the third aspect of the present invention, in the first or second aspect, the individual pieces and the holes of the magnet may be configured to have the same shape.
According to the fourth aspect of the present invention, in any one of the first to third aspects, the holes of the porous magnet holder may be arranged at regular intervals in at least one direction. it can.
According to the fifth aspect of the present invention, in any one of the first to third aspects, the holes of the porous magnet holder may be arranged in a staggered manner.
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the magnet includes an N-pole magnet and an S-pole magnet, and at least 1 is provided between the N-pole magnet and the S-pole magnet. It can also be configured to be disposed in the hole of the magnet holder with one hole interposed therebetween.
According to the magnetron sputtering apparatus according to the seventh aspect of the present invention, the magnetron sputtering apparatus according to any one of the first to sixth aspects can also be configured.
[0008]
According to the magnetron sputtering method of the eighth aspect of the present invention, the magnet holder arranged on the surface of the yoke made of a magnetic material has a size equal to or greater than the shape of each piece of a plurality of magnets having the same shape. have a plurality of pores having a, and the hole of the magnet holder in the magnetron sputtering method using a sputtering apparatus which is configured larger than the magnet,
Each of the magnet was inserted separately in the upper Symbol in each hole, by the magnetic force of the respective magnet detachably retains the respective magnets to the yoke, then, characterized in that to perform the magnetron sputtering.
[0009]
According to a ninth aspect of the present invention, in the eighth aspect, when the arrangement of the magnets is changed, the magnet is taken out from the hole of the magnet holder, the magnet is inserted into another hole, and the magnetic force of each magnet is changed. Thus, the magnet can be replaced by holding the magnet detachably on the yoke and holding the magnet in the hole.
[0010]
According to the magnetron sputtering method, magnetron sputtering apparatus, and magnet unit of the present invention, each magnet has a shape equivalent to or larger than the magnet , and has more holes than the magnet. by the configuration in which each magnet and each hole size and shape to unify each holds in each hole of the holder, attachment and detachment of the magnets is facilitated, any position on the magnet arrangement correction is facilitated The magnet can be freely held in the hole . Therefore, when the desired magnetic field distribution cannot be obtained, or when it is desired to change the magnet arrangement for other reasons, it is easy to remove the magnet once arranged and re-arrange it to another location. A magnet unit suitable for distribution can be provided .
The of et, in the above-mentioned aspect of the present invention, parallel shape or zigzag shape the position of the magnet holder of holes, if the entire surface uniformly subjected at regular intervals like a concentric shape, greater flexibility of the magnet arrangement management if It becomes easy. In particular, if the zigzag shape is used, the magnets can be arranged most densely, so that the strength of the magnetic field can be improved and the above effects can be exhibited.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a plan view and a side view of a magnet unit of the magnetron sputtering apparatus according to the above embodiment for carrying out the magnetron sputtering method according to the embodiment of the present invention.
1 and 2, 11 is a yoke, 12 is a non-magnetic porous magnet holder supported by the yoke 11, 13 is a number of through holes provided in the magnet holder 12, and 14 and 14 'are through holes of the magnet holder 12. These are N-pole and S-pole magnets arranged in the hole 13.
Here, the yoke 11 is made of a magnetic material in order to shield the influence of the magnetic field on the back surface of the magnet unit and at the same time increase the magnetic field strength on the surface, and the magnet holder 12 is preferably a non-magnetic material. The material of the magnet holder 12 is appropriately selected from duralumin, aluminum, copper, synthetic resin, and ceramic in the case of a nonmagnetic material. The material of the magnet holder 12 can be a magnetic material.
[0012]
As an example of the present embodiment, iron is used for the yoke 11, duralumin is used for the magnet holder 12, and the magnets 14, 14 'are composed of neodymium magnets (including Nd, Fe, and B) made of neodymium. A cylindrical shape having a diameter of 8 mm and a height of 8 mm is used. The shapes of the through holes 13 of the magnet holder 12 were all the same, and the diameter was 8 mm and the height was 8 mm according to the shapes of the magnets 14 and 14 '. Further, the arrangement was made by staggering a pitch of 9 mm on the entire surface. Here, the yoke 11 and the magnet holder 12 are joined, and the magnets 14 and 14 'are arranged in the holes 13 of the magnet holder 12 as shown in FIGS. The through hole 13 in which the magnets 14 and 14 'are not arranged remains a hole.
At this time, as shown in FIG. 3, the yoke-side back surface of each magnet 14, 14 ′ disposed in each through-hole 13 is held by the magnetic force F _{1 on} the surface of the yoke 11 exposed at the base of each through-hole 13. However, even if the magnet unit is turned upside down, the magnets 14 and 14 are in surface contact with the inner wall of the through hole 13 by the repulsive force F ₂ with the magnets 14 and 14 ′ of the same polarity arranged in the adjacent holes 13. 'Will never fall. When the magnets 14 and 14 ′ are held with a sufficiently large holding force with respect to the yoke 11, the magnets 14 and 14 ′ need not be in surface contact with the inner wall of the through hole 13.
[0013]
When removing the magnets 14 and 14 ', as shown in FIG. 4, the previously installed magnets 14 and 14' are not bonded by an adhesive or the like as in the prior art. If the other hand-held magnets 20 are combined with the desired magnets 14 and 14 'and pulled out while being attracted with each other's magnetic force, only the desired magnets 14 and 14' can be taken out easily. For example, when it is desired to take out the S-pole magnet 14 ′ from the through-hole 13, the S-pole magnet 14 ′ to be taken out is attracted against the repulsive force acting from the S-pole magnet 14 ′ adjacent to the S-pole magnet 14 ′. An N-pole magnet having a magnetic force large enough to be taken close to the S-pole magnet 14 ′ to be taken out, the S-pole magnet holder 14 ′ and the N-pole magnet 14 are attracted by a magnetic force, and the adjacent S-pole magnet 14 The S-pole magnet 14 'desired to be taken out can be taken out by overcoming the repulsive force against "and the holding force between the S-pole magnet 14' desired to be taken out and the yoke 11. At this time, for example, a magnet take-out unit that faces the magnet unit that holds the magnets 14 and 14 ′ is arranged, and this take-out unit is made to face the magnets 14 and 14 ′ of the magnet unit of the present embodiment, respectively. The magnet 20 is held in the magnet unit, and a plurality of magnets 20 having poles opposite to the poles of the plurality of magnets 14 or 14 'to be taken out from the magnet unit of the present embodiment are brought close to the magnet 14 or 14', as shown in FIG. A plurality of magnets 14 or 14 'may be taken out simultaneously as shown in FIG.
Conversely, when installing or re-installing the magnet 14 or 14 ′, the magnet 14 or 14 ′ is aligned with the through-hole 13 at the position where the magnet 14 or 14 ′ is desired to be installed, and the desired magnet 14 or 14 is securely inserted into the through-hole 13. 14 'can be held.
[0014]
In the magnet unit obtained by the above-described embodiment, all the horizontal components of the magnetic field exceeded 300 G (Gauss) when the vertical component of the magnetic field at the target material surface position 30 mm away from the surface was 0.
In the example of the present embodiment, iron is used as the material of the yoke 11, duralumin is used in the magnet holder 12-, and neodymium is used in the magnets 14 and 14 '. However, the present invention is not limited to this. Further, the shapes of the magnets 14, 14 'and the through holes 13 are not limited to this.
[0015]
Further, the arrangement of the magnets 14 and 14 'is not limited to that shown in FIG. The magnet unit of FIG. 1 is adapted to a circular substrate. As an example, the N-pole magnet 14 is arranged in a substantially ε shape, and the S-pole magnet 14 ′ is arranged in a substantially C-shape. A magnetic field is generated during sputtering between the pole magnet 14 'and electrons circulate in a closed loop portion corresponding to the gap shape between the N pole magnet 14 and the S pole magnet 14'. Regardless of the N pole magnet 14 or the S pole magnet 14 ', by arranging the pole magnets arranged on the outer periphery of the magnet unit in a substantially closed loop shape, the circulating electrons can be prevented from scattering and the sputtering efficiency is improved. This is preferable. In addition, the N-pole magnet 14 is arranged not only in an annular shape on the outer peripheral portion of the circular magnet unit, but also arranged so as to enter the radial direction toward the center side, so that the N-pole magnet 14 and the S-pole are also provided in the center portion of the magnet unit. A magnetic field is formed with the magnet 14 'to form a path for electrons to circulate so that sputtering is efficiently performed not only on the outer peripheral side of the target but also on the central side. Since this magnet unit is rotated as described in the conventional apparatus, symmetry is not a problem in the magnet arrangement.
In addition, for example, the S pole magnet 14 'has a generally C shape in which all the S pole magnets 14' are arranged in the inner portion in order to increase the magnetic field strength, but there is no need to increase the magnetic field strength to that extent. May be arranged in a generally C-shaped frame shape without arranging the magnet 14 'in the inner portion. Thus, in the present embodiment, for example, it is possible to finely adjust the magnetic field intensity by putting one magnet into and out of one through hole.
[0016]
FIG. 1 shows an arrangement example of a magnet unit applied to a circular target. FIG. 5 shows a magnet unit 32 according to another embodiment of the present invention applied to a rectangular target. In FIG. 5, the rectangular magnet unit 32 reciprocates along the longitudinal direction with respect to the rectangular target 37 instead of rotating with respect to the target. The magnets 34 and 34 ′ in the magnet unit 32 are arranged such that an N-pole magnet 34 is arranged on the outside, and the S-pole magnet 34 ′ is arranged on the inside of the N-pole magnet 34 in a shape substantially similar to the arrangement shape of the N-pole magnet 34. It is arranged. And the arrangement direction of both magnets 34 and 34 'does not have the part which becomes parallel with the moving direction of the magnet unit 32, and it is trying to improve sputtering efficiency.
When the thickness of the thin film formed on the substrate is required to be uniform, the magnet passes through the center of the rectangular magnet unit 32 in the longitudinal direction and is symmetrical with respect to the center line in the direction perpendicular to the longitudinal direction. 34, 34 'are preferably arranged. Further, the hole 13 in which the magnets 14 and 14 ′ of the magnet holder 13 are disposed is not limited to the through hole in which the surface of the yoke 111 is exposed to the magnets 14 and 14 ′ side, and the magnetic force of the magnets 14 and 14 ′ is transmitted. If a holding force that can hold the magnet sufficiently with the yoke 11 is applied, there is a bottom portion, and the magnets 14 and 14 ′ may face the yoke 11 through the bottom portion.
[0017]
According to the above configuration of the present embodiment, each magnet 14, 14 ', 34, 34' has a porous magnet holder 12, which has each through-hole 13, 33 having a shape equivalent to or larger than this. In each of the thirty-two through holes 13 and 33, the magnetic holes are detachably held. Therefore, when the desired magnetic field distribution cannot be obtained or it is desired to change the magnet arrangement for other reasons, it is easy to remove the magnets 14, 14 ′, 34, 34 ′ once arranged and rearrange them in another place. Can be done. Further, if the sizes and shapes of the through holes 13 and 33 of the magnets 14, 14 ', 34 and 34' and the magnet holders 12 and 32 are unified, the through holes 13 and 33 at any position are free. Can hold magnets 14, 14 ′, 34, 34 ′ having arbitrary poles. Furthermore, if the positions of the through holes 13 and 33 of the magnet holders 12 and 32 are uniformly provided at regular intervals in at least one direction such as a parallel shape, a staggered shape, a concentric circular shape, etc., The degree of freedom increases and management becomes easier. In particular, the staggered arrangement allows the magnets 14, 14 ', 34, 34' to be arranged most densely, so that the magnetic field strength can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view of a magnet unit of a sputtering apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional side view of the magnet unit of FIG.
3 is an explanatory diagram showing a state in which a magnet is held in a hole of a magnet holder of the magnet unit of FIG.
FIG. 4 is an explanatory diagram when a magnet held in a hole of the magnet holder is taken out.
FIG. 5 is a plan view of a magnet unit of a sputtering apparatus according to another embodiment of the present invention.
FIG. 6 is a schematic view of a conventional sputtering apparatus.
7A and 7B are diagrams showing examples of arrangement of magnet units in the conventional sputtering apparatus.
[Explanation of symbols]
11 Yoke 12, 32 Magnet holder 13, 33 Holes 14, 14 ', 34, 34' provided in the magnet holder Magnet 21 Yoke 22 Magnet 37 Substrate

Claims (9)

A magnet unit disposed on the back side of a target disposed in a magnetron sputtering apparatus,
A plurality of magnets all of the same shape ,
A yoke composed of a magnetic material;
A magnet holder is disposed on a surface of the yoke has a plurality of pores having a respective pieces equivalent shape or size of the plurality of magnets, each of the magnet individually in each hole inserting a magnet holder for detachably holding the respective magnets to the yoke by the magnetic force of the magnet by, and holes of the magnet holder magnet unit, characterized in that more than the magnet.   The magnet unit according to claim 1, wherein the magnet holder is non-magnetic and is made of a material selected from duralumin, aluminum, copper, synthetic resin, and ceramic.   The magnet unit according to claim 1 or 2, wherein each piece and each hole of the magnet have the same shape.   The magnet unit according to any one of claims 1 to 3, wherein the holes of the magnet holder are arranged at regular intervals in at least one direction.   The magnet unit according to claim 1, wherein the holes of the magnet holder are arranged in a staggered manner.   The magnet includes an N-pole magnet and an S-pole magnet, and is arranged in the hole of the magnet holder with at least one hole interposed between the N-pole magnet and the S-pole magnet. The magnet unit according to any one of 5.   A magnetron sputtering apparatus comprising the magnet unit according to claim 1. Magnet holder disposed on the surface of the yoke consists of magnetic material, have a plurality of pores having a plurality of respective pieces equivalent to the shape or the size of the magnet in all the same shape, and the magnet holder The hole is a magnetron sputtering method that uses a sputtering device configured more than the magnet ,
Each of the magnet was inserted separately in the upper Symbol in each hole, by the magnetic force of the respective magnet detachably retains the respective magnets to the yoke, then, characterized in that to perform the magnetron sputtering magnetron Sputtering method.   When changing the arrangement of the magnet, the magnet is taken out from the hole of the magnet holder, the magnet is inserted into another hole, and the magnet is detachably held in the yoke by the magnetic force of each magnet. The magnetron sputtering method according to claim 8, wherein replacement is performed.

Images