KR20140027524A - Sputtering device - Google Patents

Abstract

By slowing down the etching rate of a portion that is likely to be eroded, a sputtering device having a good use efficiency of the target is provided. The rectangular magnetic circuit unit 11 provided in the magnetron cathode 31 is configured such that the swing distances of the linear unit 111 made of the rectangular long side magnet and the end unit 112 having the short side magnet are different. It is. The swinging distance of the end unit 112 in the X direction parallel to the target mounting surface is longer than that of the linear unit 111.

Description

[0001] SPUTTERING DEVICE [0002]

The present invention relates to a sputter apparatus having a magnetron cathode, and more particularly, to a sputter apparatus having a magnetron cathode in which a magnetic circuit unit swings.

There are various kinds of cathodes of the sputter apparatus. Among these, the magnetron cathode which has a magnet in the back side of a flat target is used a lot. Magnetron cathodes can be classified into two aspects: shape and operation of the magnetic circuit unit. Here, the shape of the magnetron cathode is determined by the shape of the target installed on the magnetron cathode, and can be largely divided into approximately circular and approximately rectangular.

Circular magnetron cathodes are often used for circularly formed films such as semiconductors and magnetic disks. On the other hand, rectangular magnetron cathodes are often used for the thing in which film-forms, such as a display and a solar cell, are rectangular. In view of the operation of the magnetic circuit unit, the magnetic circuit unit is largely distinguished from being fixed and oscillating. The reason for rocking the magnetic circuit unit is to improve the utilization efficiency of the target, to prolong its life, and to reduce the oscillation from the target by eliminating the non-eroded region.

The magnetron cathode is rectangular in shape and the magnetron cathode in which the magnetic circuit unit fluctuates has a problem that the etching speed of the end part in the long side direction of the magnetron cathode is high, resulting in poor target utilization efficiency and short lifespan. This consists of As one of them, there is a method of arranging a magnetic shunt having a high permeability in the magnet unit, lowering the leakage magnetic flux density at the long side direction end of the magnetron cathode, and slowing down the etching speed (see Patent Document 1, for example).

Japanese Patent Laid-Open No. 2010-111915

However, there is a limit to the method of slowing down the etching speed by disposing a magnetic shunt on the magnet unit. This is because magnetron discharge is established by restraining electrons by magnetic force. Lowering the leakage magnetic flux density at the long side end of the magnetron cathode is equivalent to weakening the restraint force of the electrons here. If the leakage magnetic flux density is made too low, the electrons cannot be constrained and an endless plasma ring cannot be formed. In other words, the lower limit of the etching rate at the lower limit of the leakage magnetic flux density at which the magnetron discharge can be formed is a limit of the improvement of the utilization efficiency and the life of the target by this method.

This invention is made | formed in view of the said subject, and slows down the etching speed of the part which is easy to be eroded, and provides the sputter | spatter device with favorable target utilization efficiency.

The sputtering apparatus of this invention is a vacuum container, the board | substrate holder arrange | positioned in the inside of a vacuum container, and which can hold | maintain a film-forming process, the target installation surface which can install a target opposite a substrate holder, and the 1st parallel to the target installation surface. A magnetron cathode having a magnetic circuit unit capable of oscillating in a direction, the magnetic circuit unit comprising: a first unit having magnet pairs arranged in a direction parallel to the first direction, and a magnet pair disposed in a direction crossing the first direction; It has a 2nd unit which has a 2nd unit, It is characterized by the oscillation distance longer than a 1st unit.

According to the present invention, more uniform erosion can be realized in the entire target. Therefore, the utilization efficiency of a target is good and a sputter apparatus with a long target life can be provided.

Other features and advantages of the present invention will be apparent from the following description with reference to the accompanying drawings. In addition, in the accompanying drawings, the same or similar components are denoted by the same reference numerals.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and together with the description, are used to explain the principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the sputter apparatus provided with the magnetron cathode which concerns on 1st Embodiment of this invention.
2A is a plan view of the magnetic circuit unit of the magnetron cathode according to the first embodiment of the present invention.
2B is an enlarged view of the magnetic circuit unit of the magnetron cathode according to the first embodiment of the present invention.
3 is a plan view showing a rocking state of the rocking device and the magnetic circuit unit according to the first embodiment of the present invention.
4 is a plan view showing a rocking state of the rocking device and the magnetic circuit unit according to the first embodiment of the present invention.
5 is a plan view showing a rocking state of the rocking device and the magnetic circuit unit according to the first embodiment of the present invention.
Fig. 6 is a plan view showing the positional relationship between the plasma ring and the target generated by the magnetron cathode according to the first embodiment of the present invention.
7 is a plan view showing the positional relationship between the plasma ring and the target generated by the magnetron cathode according to the first embodiment of the present invention.
8 is a plan view showing the positional relationship between the plasma ring and the target generated by the magnetron cathode according to the first embodiment of the present invention.
It is sectional drawing which shows the rocking | swing state of the rocking | fluctuation apparatus which concerns on 2nd Embodiment of this invention, and a magnetic circuit unit.
It is sectional drawing which shows the rocking | fluctuation state of the rocking | fluctuation apparatus which concerns on 2nd Embodiment of this invention, and a magnetic circuit unit.
It is sectional drawing which shows the rocking | fluctuation state of the rocking | fluctuation apparatus which concerns on 2nd Embodiment of this invention, and a magnetic circuit unit.
It is a top view which shows the shape of the erosion at the center of the fluctuation range of the X direction of the magnetic circuit unit which concerns on 2nd Embodiment of this invention.
It is a top view which shows the shape of erosion when it exists in the left edge part of the fluctuation range of the X direction of the magnetic circuit unit which concerns on 2nd Embodiment of this invention.
It is a top view which shows the shape of erosion when it exists in the right edge part of the fluctuation range of the X direction of the magnetic circuit unit which concerns on 2nd Embodiment of this invention.
It is a figure which shows the result of simulating the shape of the erosion formed in a target by sputtering while rocking the magnetic circuit unit which concerns on 2nd Embodiment of this invention.
It is a top view which shows the shape of the erosion at the center of the fluctuation range of the X direction of the magnetic circuit unit which concerns on a comparative example.
It is a top view which shows the shape of erosion when it exists in the left edge part of the movable range of the X direction of the magnetic circuit unit which concerns on a comparative example.
It is a top view which shows the shape of the erosion at the right edge part of the movable range of the X direction of the magnetic circuit unit which concerns on a comparative example.
It is a figure which shows the result of simulating the shape of the erosion formed in a target by sputtering while rocking the magnetic circuit unit which concerns on a comparative example.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail with reference to drawings. This invention is not limited to this, A various change is possible in the range which does not deviate from the meaning of this invention.

(1st embodiment)

FIG. 1: is a schematic diagram which shows schematic structure of the sputter apparatus provided with the magnetron cathode 1 which concerns on this invention. As shown in FIG. 1, the sputter apparatus has the chamber 2, the magnetron cathode 1, and the board | substrate holder 10 as main components. In addition, the sputtering apparatus is provided with the power supply 12 for applying the electric power required for sputter film-forming process to the target backplate 4. In the chamber 2 (vacuum container), a target back plate 4 to which the target 3 is joined is provided via an insulator 5. The insulator 5 is a member that electrically insulates the chamber 2 from the target back plate 4. The processing chamber 6 capable of vacuum evacuation is formed by the chamber 2, the target back plate 4, and the insulator 5.

The target back plate 4 has a target mounting surface to which the target 3 is joined by bonding. The target mounting surface is formed as a smooth surface facing the substrate holder 10. The target 3 is a film-forming material and is bonded to the target mounting surface of the target back plate 4 as described above. The magnetic circuit unit 11 is disposed on the back side of the target back plate 4 (that is, the second surface side of the first surface on the target 3 side of the target back plate 4 and the second surface on the opposite side). have. Further, a swinging device for reciprocating the magnetic circuit unit 11 in the X direction (first direction) at least parallel to the target mounting surface is provided on the back side of the target back plate 4. The rocking apparatus will be described later based on FIG. 3.

The inside of the chamber 2 is provided with the substrate holder 10 which can hold | maintain the board | substrate 9 so that the target 3 may be opposed. An exhaust device such as an exhaust pump is connected to the exhaust port 7 of the chamber 2 via a conductance valve (not shown). The chamber 2 is connected with a gas introduction system 8 having a flow rate controller MFC or the like as a means for introducing a process gas. Process gas is supplied from the gas introduction system 8 at a predetermined flow rate. As the process gas, for example, a rare gas such as argon (Ar), a single substance containing nitrogen (N 2), or a mixed gas can be used.

In this embodiment, although the magnetic circuit unit 11 is arrange | positioned at the back side of the target backplate 4 which functions as a vacuum partition, the partition board is provided in the position between the target backplate 4 and the magnetic circuit unit 11. It may be provided and the structure which makes a partition plate a vacuum partition wall may be sufficient. The magnetic circuit unit 11 includes plate A (A1, A2), the center magnets B (B1, B2), and the outer peripheral magnets C (C1, C2), for example. The magnetron cathode 1 includes, for example, a magnetic circuit unit 11, a swinging device and a target back plate 4.

2A is a schematic plan view of the magnetic circuit unit 11 according to the present embodiment, and FIG. 2B is an enlarged view of an end portion (part E of FIG. 2A) of the magnetic circuit unit 11. On the plates A (A1, A2), the center magnets B (B1, B2) composed of permanent magnets and the outer magnets C (C1, C2) are arranged to be spaced apart from each other. A rectangular outer circumferential magnet C is arranged to surround the axial center magnet B. As shown in FIG. The center magnet B and the outer magnet C are magnetized in a direction substantially perpendicular to the ground, and the magnetization directions of the center magnet B and the outer magnet C are opposite to each other. As a result, an endless magnetic tunnel is formed between the center magnet B and the outer magnet C. FIG. The magnetic tunnel is formed on the substrate side of the target mounting surface. More specifically, the magnetic tunnel is formed on the surface side of the target disposed on the target mounting surface, so that stable magnetron discharge is possible.

When a pair of magnets in which a magnetic tunnel is formed is called a magnet pair, the center magnet B1 and the outer magnet C1 form a magnet pair in the X direction (first direction), and the short side portions of the center magnet B2 and the outer magnet C2 are The magnet pair is formed in the Y direction. Since the outer magnet C1 is arranged on both sides in the X direction of the center magnet B1, the center magnet B1 forms a magnet pair with the outer magnet C1 on both sides in the X direction. Here, the short side part of the outer magnet C2 is the short side part of the rectangular outer magnet C, and is especially the part of the outer magnet C2 located in the longitudinal direction of the center magnet B. As shown in FIG.

In addition, the shape of the center magnet B and the outer magnet C is not limited to an axial shape and a rectangle. For example, the peripheral magnet C may make the shape of the end unit 112 into polygons, such as a curved shape and a triangle. In addition, a plurality of small magnets may be combined to form the center magnet B or the outer magnet C. In this case, the magnet pair of the center magnet B2 and the outer circumferential magnet C2 has a part formed in the direction shift | deviated from the Y direction.

In addition, the magnetic circuit unit 11 is divided into the linear unit 111 and the end unit 112 at the place D shown in FIG. 2. The linear part unit 111 (first unit) is formed by a portion occupying most of the long side portion of the outer magnet C (the outer magnet C1) and a portion occupying most of the long side portion of the center magnet B (the center magnet B1). It is arrange | positioned on A1 and is comprised. The end unit 112 (2nd unit) is comprised by the short side part (outer peripheral magnet C2) of the outer peripheral magnet C, and the short side part (center magnet B2) of the center magnet B arrange | positioned on the board | substrate A2.

The short side part is arrange | positioned at the both sides of the long side direction of the linear part unit 111 (namely, one end side and the other end side of the linear part unit 111). The swinging direction of the magnetic circuit unit 11 includes the X direction in FIG. 2. Here, the X direction is a direction orthogonal to the long side portion of the rectangular outer circumferential magnet C. In addition, the magnetron cathode 1 is configured so that the swing distance of the linear unit 111 of the magnetic circuit unit 11 and the swing distance of the end unit 112 can be set independently of each other.

3 to 5 are plan views illustrating rocking states of the rocking device and the magnetic circuit unit, and are schematic views of the magnetron cathode 1 seen from above the sputtering device. 3-5, the structure and operation | movement of a rocking | swing device are demonstrated. In addition, in order to show the position of the magnetic circuit unit 11 easily, the target 3 was shown with the broken line in FIGS.

3 shows a case where the magnetic circuit unit 11 is in the center of the movable range in the X direction. Nuts 113a and 113b are provided in each of the straight portion unit 111 and the end units 112 disposed on both sides thereof, and the straight portion unit 111 and the end unit 112 are nuts 113a and 113b, respectively. Is connected to the screw shafts 114a and 114b. Each of the screw shafts 114a and 114b is connected to the motors 115a and 115b, respectively. The screw shafts 114a and 114b are rotated (forward rotation and reverse rotation) by the motors 115a and 115b. That is, the ball screw mechanism is comprised by the nuts 113a and 113b and the screw shaft 114a and 114b. The linear unit 111 and the end unit 112 swing in the X direction with the rotation of the screw shafts 114a and 114b. In addition, since the linear unit 111 and the end unit 112 are driven by different motors 115a and 115b, the linear unit unit ( It is possible to swing 111 and the end unit 112 at different swing distances.

4 and 5 show a case where the linear unit 111 and the end unit 112 of the magnetic circuit unit 11 are at the left end and the right end of the movable range in the X direction, respectively. As described above, since it is possible to swing the linear unit 111 and the end unit 112 at different swing distances, the swing distance of the end unit 112 is longer than the swing distance of the straight unit unit 111. can do. In addition, according to the above-described configuration, the swing distance between the linear unit 111 and the end unit 112 can be performed only by changing the control of the motor, which is convenient.

In the above embodiment, a mechanism using a ball screw is employed as the swinging device for the X direction. However, since the effects of the present invention do not depend on the specific configuration of the rocking device, other structures can be employed as the rocking device. As another configuration of the swinging device, the swinging power is one, and a device for changing their gear ratio through the gears in the power transmission path from the power to the linear unit 111 or the end unit 112 is considered. As another configuration of the swinging device, the swinging power is one, and the crank disc of the linear part unit 111 and the end unit 112 is provided with a crank provided in each of the linear part unit 111 and the end unit 112. It is contemplated that the device may be different. As another configuration of the swinging device, a configuration using a rack and pinion or an eccentric cam can be considered.

6 to 8 respectively show the plasma ring 14 when the magnetic circuit unit 11 is in the center of the movement range of the magnetron cathode 1 in the X direction, the swing end on the left side of the movement range, and the swing end on the right side of the movement range. It is a top view which illustrates the position and shape of. As is apparent from FIG. 10 and FIG. 11, the moving distance of the plasma ring in the portion corresponding to the end portion disposed on both sides of the linear portion of the magnetron cathode 1 is compared with the moving distance of the plasma ring in the portion corresponding to the linear portion. long. This is because the moving distance (moving range) of the end unit 112 is larger than the moving distance (moving range) of the linear unit 111. Here, a large moving distance (moving range) means a fast moving speed, which contributes to the flattening (uniformation) of the distribution of the etching speed in the moving range. The movement of the magnetic circuit unit 11 makes it possible to slow down the etching speed of the target at the end portion of the magnetron cathode 1 in the long side direction, or to flatten (even) the distribution of the etching speed. The service life can be extended by improving utilization efficiency.

As described above, the magnetic circuit unit 11 is constituted by a plurality of units, and the movement range (swing range) of the plurality of units is individually determined to flatten (even) the distribution of the etching speed of the target, thereby making the target more efficient to use. Can improve.

(Second Embodiment)

9 to 11 are cross-sectional views illustrating a rocking state of the magnetic circuit unit provided in the magnetron cathode 31 according to the second embodiment. 9-11, the structure and operation | movement of the magnetron cathode 31 are demonstrated. Fig. 9 shows a case where the magnetic circuit units 11 (111, 112) are in the center of the movement range in the Y direction. In addition, in each following embodiment, the same code | symbol is attached | subjected to the member, arrangement | positioning, etc. similar to 1st Embodiment, and the detailed description is abbreviate | omitted.

The magnetron cathode 31 of the present embodiment is provided with a rocking device (second rocking device) in the Y direction (see FIG. 9) parallel to the target mounting surface, in addition to the rocking device (first rocking device) in the X direction described above. It differs from 1st Embodiment in the point which it does. The rocking device in the Y direction is configured to rock the whole rocking device in the X direction supporting the magnetic circuit unit 11 in the Y direction, and the support plate 117 for supporting the rocking device in the X direction and the support plate 117 are Y The ball screw mechanism which oscillates in a direction is provided as a main component. Although the Y direction is orthogonal to the X direction in this embodiment, it is not limited to the structure which a Y direction and an X direction orthogonally cross.

The support plate 117 is a member for supporting the rocking device in the X direction, and the magnetic circuit units 11 (111, 112) are provided in the rocking device in the X direction. The ball screw mechanism has the nut 118 and the screw shaft 119 as main components. The nut 118 is provided in the support plate 117, and the screw shaft 119 and the motor 120 connected to the screw shaft 119 are provided in the chamber 2 side. By the power of the motor 120, the screw shaft 119 rotates (forward rotation and reverse rotation). The support plate 117, which is connected to the screw shaft 119 via the nut 118, swings in the Y direction with the rotational motion of the screw shaft 119.

According to the film-forming apparatus using the magnetron cathode 31 of this embodiment, it becomes possible to slow down the etching speed of the edge part of the magnetron cathode 31 in the long side direction, and can improve the utilization efficiency of a target, and can lengthen life. Since the magnetron cathode 31 of the present embodiment swings in the Y direction as a whole of the magnetic circuit unit 11, the etching speed of the end portion of the cathode in the longer side direction can be slower than that of the magnetron cathode 1 of the first embodiment. have.

In the magnetron cathode 31 of the present embodiment described above, the entire magnetic circuit unit 11 swings in the Y direction at the same distance, and the swing distance between the linear unit 111 and the end unit 112 is different in the X direction. to be. However, the whole magnetic circuit unit 11 may swing at the same swing distance in the X direction, and the swing distances of the linear unit 111 and the end unit 112 may be different from each other in the Y direction. In this case, the two end units 112 are arranged so as to be spaced apart from the straight unit unit 111 in the Y direction, and the end unit 112 is larger in the Y direction than the straight unit unit 111 at the swing end in the Y direction. It is thought that it is set as the structure which fluctuates. In this case, the swinging device in the X direction is connected to the support plate.

(Example)

The example which set the oscillation distance of the end unit 112 longer than the oscillation distance of the linear part unit 111 using the magnetron cathode 31 of 2nd Embodiment mentioned above is demonstrated. 12, 13, and 14 show the shape of the erosion 15 of the target when the magnetic circuit unit 11 is in the center of the movable range in the X direction, the swing end on the left side of the movable range, and the swing end on the right side of the movable range, respectively. The top view shown is shown. The shape of erosion was simulated from the position of the plasma ring 14. At this time, the erosion was to follow the Gaussian distribution in the cross-sectional direction across the ring of the plasma ring 14.

12 to 14 illustrate the erosion 15 corresponding to the shape of the plasma ring 14 of FIGS. 6 to 8. That is, when the magnetic circuit unit 11 is located at the left and right swing end portions, the end portion 112 is formed in the shape of erosion 15 under the condition that the end unit 112 is located outside the X direction than the linear unit 111.

FIG. 15 shows a result of simulating the shape of the erosion 16 formed on the target 4 by sputtering while swinging the magnetic circuit unit 11. In the simulation of FIG. 15, the swing distance in the X direction of the magnetic circuit unit 11 was ± 55 mm for the linear unit 111 and ± 70 mm for the end unit 112. The swing distance in the Y direction of the magnetic circuit unit 11 is ± 25 mm. In addition, the dimension of a cathode is 300 mm x 920 mm. In this simulation result, the utilization efficiency of the target 4 was 50.0%. In FIG. 15, 16a, 16b, and 16c are attached | subjected according to the depth of erosion 16. As shown in FIG. Reference sign 16c indicates the deepest erosion point. In addition, a target utilization rate is the ratio of the usage-amount of the target 3 whole when the part with the deepest erosion reached the target backplate 4.

(Comparative Example)

In this comparative example, the magnetic circuit unit (one magnetic circuit unit) which is not divided into the end unit 111 and the linear part unit 112 is demonstrated. 16, 17 and 18 respectively, the shape of the erosion 18 when the one magnetic circuit unit is in the center of the movement range in the X direction of the magnetron cathode, the swing end on the left side of the movement range, and the swing end on the right side of the movement range. The top view which shows is shown. The shape of erosion was simulated from the position of the plasma ring 15. At this time, the erosion 18 was assumed to follow a Gaussian distribution in the cross-sectional direction across the ring of the plasma ring 15.

FIG. 19 shows a result of simulating the shape of the erosion 19 formed on the target 4 by sputtering while swinging an integral magnetic circuit unit. In the simulation of FIG. 19, the swing distance in the X direction of the integrated magnetic circuit unit was ± 55 mm, and the swing distance in the Y direction was ± 25 mm. In addition, the dimension of a cathode is 300 mm x 920 mm. 19a, 19b, and 19c are attached | subjected according to the difference of the depth of erosion 19 in FIG. Numeral 19c indicates the deepest erosion.

The utilization efficiency of the target 4 in this simulation was calculated to be 39.9%. In addition, the utilization efficiency of the target 4 in measured erosion was 39.3%. The actual measurement of the utilization efficiency of the target 4 was performed by obtaining the volume of the measured erosion. Erosion was measured using a three-dimensional meter with a laser displacement sensor. When the simulation result of FIG. 19 is compared with the simulation result of the Example shown in FIG. 15, it turns out that an Example has a small difference in the erosion depth of the vicinity of an edge part and a linear part compared with the comparative example, and the use efficiency of a target is high.

The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to clarify the scope of the present invention, the following claims are attached.

This application claims priority based on Japanese Patent Application No. 2011-145708 for which it submitted on June 30, 2011, and uses all of the description here.

X, Y swing direction
1, 31 magnetron cathode
2 chamber
3 target
4 target back plate
5 Insulator
6 treatment room
7 air vent
8 gas introduction system
9 substrate
10 board holder
11 magnetic circuit unit
12 Power
14 Plasma Ring
15, 16, 18, 19 erosion
A, A1, A2 Edition
B, B1, B2 Center Magnets
C, C1, C2 outer magnet
111 Straight Unit
112 end units
113a, 113b, 118 Nut
114a, 114b, 119 screw shaft
115a, 115b, 120 motor
117 support plate

Claims (5)

A vacuum container,
A substrate holder disposed in the vacuum container and capable of holding a substrate to be formed into a film;
A magnetron cathode having a target mounting surface capable of mounting a target opposite the substrate holder and a magnetic circuit unit capable of swinging in a first direction parallel to the target mounting surface,
The magnetic circuit unit has a first unit having magnet pairs arranged in a direction parallel to the first direction, and a second unit having magnet pairs arranged in a direction crossing the first direction,
And the second unit has a longer swing distance than the first unit. The magnetic circuit unit of claim 1, wherein the magnetic circuit unit includes two rectangular outer circumferential magnets and a center magnet disposed between the two outer circumferential magnets.
The first direction is a direction orthogonal to the long side direction of the rectangles of the two outer magnets and parallel to the target mounting surface;
And the second unit constitutes the rectangular short side portion of the outer magnet. The sputtering apparatus according to claim 1 or 2, wherein the swing distance in the first direction of the second unit is longer than the swing distance in the first direction of the first unit. The sputtering apparatus according to any one of claims 1 to 3, wherein the magnetic circuit unit is swingable in a second direction orthogonal to the first direction. A vacuum container,
A substrate holder for holding a substrate in the vacuum container;
A magnetron cathode having a target mounting surface on which a target can be installed and a magnetic circuit unit that can be swinged against the substrate holder;
The magnetic circuit unit comprises a first unit having a magnet pair and a second unit having a magnet pair,
And a swing range of the first unit and a swing range of the second unit are different from each other.

Images