JP3324907B2 - Magnetron sputtering equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates a thin film on a substrate having a large area by the magnetron sputtering deposition to luma grayed magnetron sputtering apparatus, and more particularly to an improved structure of a backing plate for cooling the target.

[0002]

2. Description of the Related Art In general, a film formed on a glass substrate by a magnetron sputtering method, for example, a liquid crystal display is used for screen display of a computer, a television or the like. The basic structure of a liquid crystal display is a liquid crystal sandwiched between glass substrates. Electrodes and transistors are formed on the glass substrate by using fine processing techniques such as film formation, etching, and photolithography. For film formation, a sputtering apparatus or a CVD (chemical vapor deposition) apparatus is usually used.

[0003] In the sputtering apparatus, a single-wafer sputtering apparatus, which is advantageous in terms of film characteristics, low dust generation, and operation rate, tends to be used in many cases.
In this single-wafer sputtering apparatus, the glass substrate conveyed to the processing chamber is fixed (stationary), and the surface of the glass substrate is processed in that state. Therefore, a target having a size slightly larger than the glass substrate should be used. Is required.

[0004] In order to make the film thickness distribution uniform, a magnet is also moved during discharge. The prior art for moving a magnet is disclosed in, for example, JP-A-60-11
There is a technique described in Japanese Patent No. 4568 (hereinafter referred to as a first prior art) and Japanese Patent Application No. 6-23960 (hereinafter referred to as a second prior art). In each of these first and second prior arts, the magnet can linearly reciprocate with respect to the substrate and the target, so that the use efficiency of the target can be increased and the film thickness distribution can be made uniform. It is described. In addition to the above, there have been proposed magnets in which a magnet rotates.

On the other hand, in today's liquid crystal displays, the size of glass substrates to be subjected to processes such as film formation and etching is increasing in order to achieve both a large screen and high productivity. As the size of the target increases, the size of the target also needs to be increased. The target is usually attached to a flat plate called a backing plate by a conductive adhesive. The prior art (hereinafter referred to as the third prior art)
Is configured as shown in FIG. 9 and FIG.

That is, as shown in FIG. 9, a glass substrate 2 is disposed in a vacuum vessel 1, and a target 3 attached to a backing plate 4 is disposed at a position facing the glass substrate 2. Further, a magnet unit 5 is provided on the backing plate 4, and the magnet unit 5 is
Thus, a predetermined magnetron magnetic field is formed on the target 3 by moving in parallel with the target 3 and the glass substrate 2. As shown in FIGS. 9 and 10, the magnet unit 5 is provided with a first magnet 5a formed in a long box shape, a second magnetron 5b linearly arranged inside the first magnet 5a, and these. And a yoke 5c. In addition, 8 is a DC power supply and 9 is a heater unit.

When the vacuum container 1 is in a predetermined gas atmosphere state and a predetermined microtron magnetic field is formed in the vacuum container 1, the glass substrate 2 in the container 1 is heated to a predetermined temperature. When a negative potential is applied to the target 3 by the DC power supply 8, a discharge occurs on the inner surface of the target 3 to generate plasma,
Ions in the generated plasma collide with the target 3 and scatter metal particles of the target 3, and the scattered particles are formed into a desired film thickness on the surface of the glass substrate 2 having a large screen.

During the sputtering process, the backing plate 4 has a function of cooling the target 3 and a function of suppressing deformation of the target 3 due to atmospheric pressure, since the target 3 is attached as described above. It must be made of a copper-based metal material in terms of thermal conductivity. Since the backing plate 4 needs to suppress the deformation of the target 3 due to the atmospheric pressure, the plate thickness must be increased to some extent.

[0009]

As described above, in order to increase the size of the glass substrate in order to increase the screen size of the liquid crystal display, it is necessary to increase the area of the target and the backing plate on which the target is mounted. None of the first to third prior arts shown above takes account of the problem associated with increasing the area.

That is, when the area of the backing plate 4 is increased, the stress due to the atmospheric pressure increases accordingly.
The backing plate 4 must be made thicker to reduce the amount of deformation. For this reason, the target 3 and the backing plate 4 are consumables and are frequently replaced. Therefore, when the weight becomes extremely large as in the case of the backing plate 4, there is a problem that the handling becomes difficult.

An object of the present invention, in view of the problems of the prior art, even without the backing plate thicker, the luma grayed <br/> magnetron sputtering apparatus can be sufficiently maintain the strength of the backing plate To provide.

[0012]

According to the present invention, there is provided a vacuum vessel in which a substrate to be formed is disposed, a target disposed in a position facing the substrate, a backing plate on which the target is mounted, and the backing plate. are movable parallel to the substrate and the target above, and the data
A magnet portion for forming a magnetron magnetic field on the surface of Getto, and a drive mechanism for moving the magnet portion.
Further, the magnet portion is transferred to the backing plate.
Providing at least one reinforcing means along the direction of movement, and
The magnet section is provided along both sides of the reinforcing means along the reinforcing means.
In such a manner as to be movable .

[0013]

According to the present invention, as described above, in addition to having the vacuum vessel, the target, the backing plate, the magnet section, and the driving mechanism, the reinforcing means for increasing the rigidity of the backing plate itself is provided. The rigidity of the backing plate can be increased, and the thickness of the backing plate itself can be reduced. Therefore, even if the backing plate is made thinner and lighter, its rigidity can be maintained. As a result, even if the target and the backing plate have a size corresponding to a large screen, it can be easily dealt with. There is an effect that the processing can be surely realized.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention, FIG. 2 is an external perspective view of the whole, and FIG. 3 is a perspective view showing a magnet.

When the vacuum vessel 21 is in a predetermined gas atmosphere state and a predetermined magnetron magnetic field is formed in the vacuum vessel 21, the apparatus 2
When the glass substrate 10 in 1 reaches a predetermined temperature and a negative potential is applied to the target 16 by the DC power supply 27, a discharge occurs on the inner surface of the target 16 to generate plasma, and the generated plasma contains The ions collide with the target 16 to scatter the metal particles of the target 16, and the scattered particles are formed into a desired film thickness on the surface of the glass substrate 10.

This device is roughly divided into FIG. 1 and FIG.
As shown in FIG. 2 , a vacuum vessel 21, a target 16 for scattering metal particles to be sputtered, magnets 11 formed separately, and a drive mechanism 30 for moving the magnets 11, 11 are provided. are doing.

The vacuum vessel 21 has a box shape with an open top, and the glass substrate 10 set on the heater 24 is disposed inside the vacuum vessel 21. The heater unit 24 is supported by a heater moving shaft 25, and the glass substrate 10 is positioned at a desired position by moving the shaft 25 up and down. An earth shield 22 is mounted in the vacuum vessel 21, and a deposition-preventing plate 23 made of the insulating material is mounted. The deposition-preventing plate 23 includes
The tip on the inner diameter side is extended to the outer periphery of the substrate 10 to prevent particles scattered from the target 16 from adhering to unnecessary parts of the glass substrate 10 during the sputtering process.

The target 16 is made of a film-forming metal material that scatters sputtered particles.
And the outer surface thereof is attached to the backing plate 15.

The backing plate 15 has a target 16 attached to the inner surface thereof by a conductive adhesive, and the outer peripheral portion thereof is attached to the opening end of the vacuum vessel 21 via an insulating seal 26. The material of the backing plate 15 is formed of, for example, a copper material in consideration of the supporting strength of the target 16 and the cooling efficiency. Therefore, the backing plate 15 must suppress deformation of the target 16 due to the atmospheric pressure, and must have rigidity for that purpose.

Therefore, in the embodiment, FIGS.
As shown in (1), a reinforcing rib 15a protrudes from the center of the outer surface of the backing plate 15. This reinforcing rib 1
5a has a uniform thickness at the center of the outer surface of the backing plate 15 and is formed with an appropriate height so as to be arranged between the divided magnet parts 11. Therefore, the backing plate 15 has a T shape. A DC power supply 27 for applying a negative potential to the target 16 and for applying a positive potential to the vacuum vessel 21 and the earth shield 22 is provided.

On the other hand, since the reinforcing ribs 15a of the backing plate 15 are disposed between the magnet portions 11 and 11 as described above, the magnet portions 11 are divided into two along the longitudinal direction with the reinforcing ribs 15a interposed therebetween. Is formed. These two sets of magnet parts 11, 11 generate a racetrack-shaped plasma of a size along the length of the target 16 on the target 16 by mutual magnetic force, whereby a desired magnetron is formed on the target 16. A magnetic field can be formed. For this reason, as shown in FIGS. 1 to 3, each magnet section 11 includes a first magnet 12 made of a permanent magnet, a second magnet 13 disposed therebetween, and a yoke 14 assembled with these. And
Therefore, the gap d between the divided end of one first magnet 12 and the divided end of the other first magnet is slightly larger than the divided reinforcing rib 15a.

As shown in FIG. 2, the drive mechanism 30 includes a motor section 31, a connecting section 34 for connecting the motor section 31 and the divided magnet sections 11 and 11, and a
And a guide member (not shown) for guiding the movement of the first and the eleventh.

More specifically, the motor unit 31 is installed on a side surface of one end of the backing plate 15, and its output shaft 32 is formed of, for example, a screw shaft provided with a spiral screw portion on the outer periphery, and The tip of the output shaft 32 is rotatably held around a shaft by a shaft holder 33 installed on the side surface of the other end of the backing plate 15. The connecting portion 34 has a U-shape so as to straddle the reinforcing rib 15a of the backing plate 15, and a central portion thereof is engaged with the output shaft 32 and is inserted through the output shaft 32. One end of each of the magnets 11, 11 is connected. The guide member includes a holder 35 attached to the other end of each magnet 11, and a holder 35.
, And rod holders 37 that hold both ends of each of the guide rods 36 and are installed on the side surfaces of both ends of the backing plate 15.

When the output shaft 32 is rotated around the axis by the motor 31, the connecting portion 34 is moved by the rotation, and the magnets 11, 11 are moved together with the connecting portion 34 in the direction of the arrow as shown in FIG. Move, and at this time, each magnet part 1
The magnets 11, 11 are guided by the holder 35 inserted through the guide rod 36, so that the two magnets 11, 11 can simultaneously move linearly on the backing plate 15, that is, each magnet 11, 11 is moved. Both are moved along the reinforcing ribs 15a.

The apparatus of the embodiment has a backing plate 15
As described above, each of the magnets 11, 11 moving upward is formed in two parts along the direction orthogonal to the moving direction, and each magnet 11, one part formed on the backing plate 15 is divided into two parts.
1, the reinforcing ribs 15a protruding therefrom can increase the rigidity of the backing plate 15 by the reinforcing ribs 15a.
Since the thickness of the backing plate 5 itself can be reduced, the rigidity can be maintained even if the backing plate 15 is reduced in thickness and weight.

According to an experiment, when a backing plate having a size of 970 mm × 970 mm was used, the weight was 290 kg in the third prior art, but the backing plate 15 of the above-described embodiment was used in the same size. It was confirmed that the weight was 210 kg. Although such a difference in weight slightly differs depending on the size (thickness, height) of the reinforcing rib 15a, it is possible to surely reduce the weight significantly.

Although the magnets 11 are formed separately, they are moved together by the drive mechanism 30, so that the plasma formed on the target 16 can be generated in a race track shape in substantially the same manner as in the prior art. Thus, a desired magnetron resonance magnetic field can be formed. As a result, even if the target 16 and the backing plate 15 are formed in a size corresponding to a large screen, it can be easily dealt with, and a sputtering process for a large screen can be realized.

In the experiment, the glass substrate 10 was 6
A target having a size of 00 mm × 700 mm and an aluminum target 16 each having a sputtering gas pressure of 0.3 P
a, When a sputtering process was performed at a sputtering power of 22 kW, an aluminum thin film having a film thickness of 250 nm could be formed in a sputtering time of 1 minute, and the film thickness distribution was about ± 5% within the plane of the glass substrate 10. A uniform product within the range was obtained.

Furthermore, even if the magnet portion 11 is divided into two parts, they can be moved synchronously by the driving mechanism 30, so that a track race-like plasma can be reliably generated on the target 16. There is no possibility that the uniformity of the film is impaired. In addition, since the drive mechanism 30 includes the motor section 31, the connection section 34, and the guide member, a simple connection structure in which the two magnet sections 11 are connected to each other can be achieved.

FIG. 4 shows a second embodiment of the present invention. This embodiment is different from the first embodiment in that the magnet part 11 is formed into three parts and the backing plate 15 has reinforcing ribs 15a, 15b projecting between the three part magnet parts 11. Is protruding.

That is, the magnet portion 11 is formed into three parts along the longitudinal direction, and these are both connected to the drive mechanism 30. In this case, the connecting portion 34 of the driving mechanism 30
Is formed in a Y-shape, and the central portion 34a engages with and passes through the output shaft 32 of the motor portion 31, as in the first embodiment. Further, both end portions 34b and 34c of the connecting portion 34 are configured to penetrate the two guide rods 36.

Therefore, both ends 34b, 3 of the connecting portion 34
4c is attached to the upper central part of two sets of magnets 11 arranged on both sides of the three divided magnets 11, and two guide rods 36 are inserted therethrough. Guide rod 36
Is attached to the backing plate 15 in the same manner as in the first embodiment.

Therefore, the connecting portion 30 is connected to the motor portion 31
When the output shaft 32 rotates around the axis, the connecting portion 34
As a result, the magnet unit 11 located at the center moves along the output shaft 32, and two sets of magnet units 11,
Since 11 is guided by the guide bar 36, the three sets of magnet units 11 move simultaneously.

On the other hand, on the outer surface of the backing plate 15, a first reinforcing rib 15a projecting between the magnet 11 at one end and the magnet 11 arranged at the center, And a second reinforcing rib 15b protruding toward the magnet 11 disposed in the second direction.

According to this embodiment, as described above, even if the backing plate 15 becomes larger due to the larger area of the target 16, the number of divided magnets 11 and the number of reinforcing ribs 15a and 15b are increased as described above. Since the rigidity of the backing plate 15 can be maintained by the amount of the reinforcing ribs, the weight of the backing plate 15 can be reduced by increasing the thickness.

In this embodiment, even if the magnet unit 11 is divided into three parts, the driving mechanism is substantially the same as that of the first embodiment, and all the magnet units 11 are connected together by only one driving unit. Since the driving can be performed, there is no danger that the configuration becomes complicated with the increase in the number of divisions of the magnet unit 11 or the number of driving units becomes plural, and the configuration can be simplified.

In the first and second embodiments described above, an example is shown in which the reinforcing ribs 15a (or 15a and 15b) are formed integrally with the backing plate 15. The backing plate body 15 may be formed separately and attached by welding or the like, and in any case, the size and the shape may be such that the rigidity of the backing plate body 15 can be increased to the extent that the thickness of the plate itself does not increase.
Also, an example is shown in which the reinforcing rib protrudes only between the divided portions of the magnet portion 11 in the backing plate 15,
If it is formed at both ends of the backing plate 15, it is possible to further reinforce it, and it is possible to further increase the rigidity.

FIGS. 5 to 8 show other embodiments of the present invention. In the above-described embodiments, the magnet unit 1
1 is divided into a plurality of parts in the longitudinal direction and has a gap d. In this manner, when the division is formed so as to have the gap d, as shown in FIG.
Although the plasma 91 generated above is generated in the shape of a race track, the plasma 91 has a narrow portion 91a corresponding to the gap d while the width thereof is slightly small, so that the intensity of the magnetron magnetic field on the surface of the target 16 is reduced. The size is slightly smaller than when the magnet is not divided.

The size of the gap d and the target 16
The relationship with the parallel magnetic field strength on the surface of the surface will be described with reference to FIG. In FIG. 8, the horizontal axis indicates the gap d between the magnet parts, and the vertical axis indicates the parallel magnetic field intensity on the target surface. The solid line A indicates that the parallel magnetic field intensity decreases with the size of the gap d. .

According to FIG. 8, the gap d between the magnet portions 11
Is 0 mm, that is, when the magnet part is not divided, the parallel magnetic field strength is about 40 mT. On the other hand, the magnet part is divided into two as in the first embodiment, and the gap d is 10
mm, the parallel magnetic field strength is about 35 mT, which is slightly smaller. However, this is a sufficient magnetic field strength for discharge in magnetron sputtering.

However, even if the magnetic field intensity is sufficient, the width of the portion 91a corresponding to the gap d of the plasma 91 is slightly different as shown in FIG. Moving to 92, the uniformity of the scattered particles from the target 16 is inferior, and it is difficult to achieve a more uniform film thickness distribution.

Therefore, in the present embodiment, even if the magnet portion 11 has a gap d due to the division, the intensity of the parallel magnetic field at a portion corresponding to the gap d is prevented from decreasing. .

That is, in the embodiment shown in FIG. 5, the first magnet 1
2, magnetic flux reinforcing projections 12a and 13a are provided at the divided end portions of the second magnet 13, respectively. The magnetic flux reinforcing projections 12a and 13a are
2, a permanent magnet made of the same material as the second magnet 13 is protruded from the divided end of the first magnet 12 and the second magnet 13, so that the area of the divided end of each magnet is increased. I have to.

Thus, the first and second magnets 12,
The magnetic flux reinforcing projections 12a and 13a having the same magnetic flux density as these are protrudingly provided at the divided end of 13 to increase the area of the divided end, so that the decrease in the parallel magnetic field strength at the gap d is suppressed accordingly. be able to.

According to the experiment, as in the case of the first embodiment, 6
A glass substrate 10 of 00 mm × 700 mm and a target 16 made of aluminum were used, respectively, and the sputtering gas pressure was 0.1 mm.
When a sputtering process was performed at 3 Pa and a sputtering power of 22 kW, an aluminum thin film having a thickness of 250 nm could be formed with a sputtering time of 1 minute. The film thickness distribution could be kept within ± 4% within the plane of the glass substrate 10. Accordingly, although this film thickness distribution varies depending on the ratio of the protrusions of the magnetic flux reinforcing projections 12a and 13a, as compared with the first embodiment, a more uniform film thickness can be obtained. But high quality can be maintained.

The embodiment shown in FIG. 6 is different from the embodiment shown in FIG. 5 in that the divided ends 12b and 13b of the first magnet 12 and the second magnet 13 are formed of a material having a large residual magnetic flux density. Things.

That is, in this embodiment, the divided end portion 12b of the first magnet 12 has a residual magnetic flux density larger than that of the material of the first magnet 12, and the divided end portion 13b of the second magnet 13 is also used. A material having a residual magnetic flux density larger than that of the material of the second magnet 13 is used to suppress a decrease in the parallel magnetic field strength at the gap d at each of the divided ends 12b and 13b.
In this case, the material constituting the first and second magnets 12, 13 may be changed for the divided ends 12b, 13b, but it is not necessary to change them.

In the experiment, the first and second magnets 12, 1
3 itself has a residual magnetic flux density Br of 0.9T.
-Co, the residual magnetic flux density Br is 1.
Divided ends 12b, 13b made of 1T Sm-Co
Was performed in the same manner as in the first example, and it was confirmed that the film thickness distribution of the glass substrate 10 of 600 mm × 700 mm was within ± 4%.

Therefore, according to the embodiment shown in FIGS. 5 and 6, even if the magnet portion 11 is formed in a divided manner, the decrease in the parallel magnetic field strength due to the divided end portions of the first and second magnets is suppressed. Since a uniform film thickness can be obtained, high quality can be maintained even when the area is increased.

[0050]

As described above, claims 1 to 5 of the present invention.
According to No. 3, the rigidity of the backing plate can be increased by the reinforcing means of the backing plate, and the thickness of the backing plate itself can be reduced. Therefore, even if the backing plate is reduced in thickness and weight, its rigidity can be improved. As a result, even if the target and the backing plate are large enough for a large screen,
There is an effect that it can be easily dealt with and the sputter processing for a large screen can be surely realized.

According to the fourth aspect of the present invention, it is preferable that the reinforcing means
A magnetic flux reinforcing projection is protruded from an end of each magnet portion disposed on the reinforcing means side according to claim 5, and is arranged via the reinforcing means.
Since the end portion of each magnet portion on the reinforcing means side is formed of a material having a high magnetic flux density, the film thickness distribution can be made more uniform, and a high quality film can be obtained. There is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the overall configuration showing a first embodiment of the present invention.

FIG. 2 is an external perspective view of the whole.

FIG. 3 is a perspective view showing a magnet of a divided magnet unit.

FIG. 4 is a sectional view of the overall configuration showing a second embodiment of the present invention.

FIG. 5 is a perspective view of a magnet of a magnet unit according to another embodiment of the present invention.

FIG. 6 is a perspective view of a magnet of a magnet section showing still another embodiment of the present invention.

FIG. 7 is an explanatory view showing plasma generated on a target.

FIG. 8 is an explanatory diagram showing the relationship between the size of the gap between the magnet units and the magnitude of the parallel magnetic field intensity on the target surface.

FIG. 9 is an explanatory diagram of an overall configuration showing a configuration example of a third conventional technique.

FIG. 10 is a perspective view showing a magnet of a magnet unit according to a third conventional technique.

[Explanation of symbols]

10: glass substrate, 11: divided magnet part, 12
... First magnet, 12a Flux reinforcing projection, 12b Divided end of first magnet, 13 Second magnet, 13
a: magnetic flux reinforcing protrusion, 13b: divided end of the second magnet, 21: vacuum vessel, 15: backing plate, 15
a, 15b: reinforcing ribs, 16: target, 30: drive mechanism.

Continuation of the front page (56) References JP-A-2-305611 (JP, A) JP-A-4-314857 (JP, A) JP-A-6-172988 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (5)

(57) [Claims] 1. A vacuum vessel in which a substrate on which a film is to be formed is disposed, a target disposed in a position facing the substrate, a backing plate on which the target is mounted, and the substrate and target on the backing plate A magnetron sputtering apparatus that is movable in parallel with respect to and has a magnet unit that forms a magnetron magnetic field on the surface of the target, and a drive mechanism that moves the magnet unit. A magnetron sputtering apparatus, wherein at least one reinforcing means is provided along a moving direction of the magnet part, and the magnet part is arranged on both sides of the reinforcing means so as to be movable along the reinforcing means. 2. A vacuum container in which a substrate to be formed is placed.
Vessels,SaidTarget placed at a position facing the substrate
When,TheA backing plate with a target attached,
On the backing plateSaidSubstrate and targetAgainst
handCan be moved in parallelAnd on the surface of the target
A magnetron magnetic fieldA magnet section,The magnetIshibe moved
Drive mechanism to moveMagnetron sputtering device
And Movement of the magnet section on the outer surface of the backing plate
Along the direction of the backing plate
At least one reinforcing rib is integrally protruded, and
A stone part is transferred along both sides of the reinforcing ribs.
Arranged to be movable Characterized byRumaGuntro
Sputtering equipment. 3. A driving mechanism comprising : a connecting portion for connecting the magnet portion; an output shaft engaging with the connecting portion and moving the connecting portion along a moving direction of the magnet portion with rotation;
3. The magnetron sputtering apparatus according to claim 1, further comprising: a motor unit for rotating the output shaft; and a guide unit for guiding the magnet unit in a moving direction of the magnet unit. 4. Before SL each magnet unit includes a respective first magnet and a second magnet, said reinforcing means respective magnet unit
With the first and second magnets facing each other on both sides
Place and in the first and second magnets
Said reinforcing means side, according to claim 1, 2 or 3, characterized in that projecting from the magnetic flux reinforcing projections made of a material having the same magnetic flux density and each of said first and second magnet
Ma grayed magnetron sputtering device. 5. Before SL each magnet unit includes a respective first magnet and a second magnet, said reinforcing means respective magnet unit
With the first and second magnets facing each other on both sides
Place and in the first and second magnets
Said reinforcing means side, Ma grayed magnetron sputtering apparatus according to claim 1, 2 or 3, characterized in that formed of a material having a respectively larger magnetic flux density of said first and second magnet.