JPH11350123A - Thin film production apparatus and production of liquid crystal display substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency in use of a target. SOLUTION: This thin film production apparatus forms a thin film on the opposite surface of an insulating substrate 106 arranged to face the target by sputtering the target surface by the plasma 109 generated on the target surface of a target assembly constituted by fixing the target 107 to a backing plate 108. In such a case, the target assembly 113 is divided to a plurality and the plasma generation positions on the surfaces of the divided targets are successively moved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film manufacturing apparatus and a thin film manufacturing method, and more particularly to a technique effective when applied to a sputtering apparatus for forming a thin film on a liquid crystal display substrate.

[0002]

2. Description of the Related Art In a DC magnetron sputtering type thin film manufacturing apparatus used for manufacturing a liquid crystal display panel (liquid crystal display substrate), it is necessary to form a thin film on a glass substrate surface having a size of 1 mm square. For this purpose, a target is arranged on one side of a film forming chamber (vacuum chamber, chamber), a glass substrate is arranged on the other side, and a magnet is placed outside the film forming chamber on the side where the target is arranged. And swing this magnet parallel to the target (reciprocating movement)
By doing so, the position where the plasma is generated by the magnetron discharge is caused to fluctuate sequentially on the target surface to generate a uniform thin film on the glass substrate.

A target is bonded (bonded, bonded) to a flat plate surface called a backing plate with an indium alloy.
Fixed), and was fixed to a back plate constituting a part of the wall of the film forming chamber with bolts or the like. The backing plate is, for example, a flat plate made of copper having high thermal conductivity, and a water passage is provided therein. By circulating water in the water passage, a target that becomes high in temperature during sputtering is cooled.

[0004]

SUMMARY OF THE INVENTION As a result of studying the above prior art, the present inventor has found the following problems. In a conventional DC magnetron sputtering type thin film manufacturing apparatus, since the permanent magnet is reciprocated in parallel with the target, there is a difference in the time during which the permanent magnet stays between the opposite ends of the target at the reversal position and other intermediate parts. As a result, there was a difference in the erosion speed of the target. Generally, the erosion progresses rapidly at both ends of the target, which is the inversion portion of the permanent magnet, and slows at other portions. For this reason, the life of the entire target has been determined by the erosion depth at both ends. For example, in a conventional thin film manufacturing apparatus, even when only about 15 to 20% of the total target weight is used, the erosion depth at both ends is set to a predetermined depth (a depth at which uniform sputtering can be performed). It would have to be replaced.

As a method of solving this problem, there is a method of extending the life of the entire target by forming a target having a thickness only at both ends where the erosion proceeds at a higher speed than the thickness of the other portions. .

However, when only the thickness of both ends of the target is increased, there is a problem that the shape of the target and the backing plate joining surface becomes complicated and the processing cost increases. In addition, since the thickness of the backing plate needs to be increased due to the problem of strength, the weight of the target unit (target assembly) increases, the labor and time required for replacement thereof increase, and the production efficiency decreases. There was a problem that would.

Further, in recent years, the size of a glass substrate as a substrate has been increased due to an increase in size of a liquid crystal display device and a reduction in manufacturing cost, and accordingly, it has been necessary to further increase the target area. Therefore, there is a strong demand for a longer target life while reducing the increase in the weight of the target unit even slightly.

An object of the present invention is to provide a technique capable of improving the use efficiency of a target. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. (1) Sputtering the target surface by plasma generated on the target surface of a target assembly in which the target is fixed to a backing plate;
In a thin-film manufacturing apparatus for forming a thin film on a facing surface of an insulating substrate arranged to face the target, the target assembly is divided into a plurality of parts, and a plasma generation position on a surface of the divided target is sequentially moved.

(2) In the thin film manufacturing apparatus described in (1), the target assembly is divided into three or more parts.

(3) In the thin-film manufacturing apparatus described in (1) or (2) above, the interval between the targets during the sputtering is 0.5 mm or less.

(4) In the thin film manufacturing apparatus according to any one of (1) to (3), the target assembly and the insulating substrate are arranged in a vacuum.

(5) The position of the plasma generated on the target surface of the target assembly in which the target is fixed to the backing plate is swung, the target is sputtered, and the target is sputtered on the insulating substrate opposed to the target. In the method for manufacturing a liquid crystal display substrate on which particles are deposited, the target assembly is divided into a plurality of parts, and a plasma generation position on a surface of the divided target is sequentially moved.

According to the above-mentioned means (1) to (5),
For example, when a thin film is formed by sputtering on the surface of an insulating substrate opposed to the target assembly, a magnet arranged on the backing plate side of the target assembly is swung to swing plasma generated on the surface of the target. By dividing the vicinity of the turning point of the magnet where the erosion progresses most in the thin film manufacturing apparatus of the magnetron sputtering system and the vicinity of the center part which is the passing point part, it becomes possible to exchange each individually, that is, the part where the erosion progresses fast Because only the target assembly can be replaced, the efficiency of use of the target can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings together with embodiments (examples) of the invention. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

<< Overall Configuration of Apparatus >> FIG. 1 is a view for explaining a schematic configuration of a thin film manufacturing apparatus according to an embodiment of the present invention, and is a view particularly showing a schematic configuration of a sputtering film forming chamber. The thin film manufacturing apparatus of the present embodiment is a DC magnetron sputtering type thin film manufacturing apparatus.

In FIG. 1, 101 is a magnet, 102 is a vacuum vessel (chamber), 103 is an electrode, 104 is a mask jig, 105 is a susceptor, 106 is an insulating substrate, 107 is a target, 108 is a backing plate, and 109 is plasma. , 110 is a DC power supply, 111 is a vacuum exhaust port, 112
Indicates a gas supply port. Here, X, Y, and Z indicate the X axis, the Y axis, and the Z axis, respectively. A mechanism for attaching the target assembly including the target 107 and the backing plate 108 to the vacuum vessel 102 will be described later.

As shown in FIG. 5, the magnet 101 is formed so as to surround an N pole extending in the Y-axis direction with an S pole.
In particular, the length of the N pole in the Y-axis direction is shorter than the length of the target assembly 113 in the Y-axis direction. This is because the erosion region of the target 107 is configured to be smaller than the target size so that other members in the vacuum chamber 102 (the film forming chamber) are not sputtered. The magnet 101 is arranged such that the longitudinal direction is the Y-axis direction and the vacuum vessel 1 is parallel to the XY plane.
02, and swings in the X-axis direction indicated by the arrow. Since the swing mechanism is the same as that of the conventional thin film manufacturing apparatus, a detailed description thereof will be omitted.

With the oscillation of the magnet 101, the position of the plasma 109 generated by the magnetron discharge is determined by the target 10
7, the surface of the target 107 is sputtered, and a thin film is formed on the surface of the insulating substrate 106, that is, the surface facing the target. The generation of the plasma 109 at this time is caused by the electric field between the target assembly 113 to which one side of the DC power supply 110 is connected and the electrode 103 to which the other side of the DC power supply 110 is connected.

The target assembly 113 is fixed to a back plate (not shown) provided on a side surface inside the vacuum vessel 102 where the magnet 101 is arranged. A susceptor 105 whose temperature can be controlled is provided at a position facing the target assembly 113, and an insulating substrate 106 is held on the surface side of the susceptor 105, that is, on the side facing the target assembly. This insulating substrate 10
A mask jig 104 that covers the outer peripheral portion of the insulating substrate 106 and prevents the film from sticking to the inner wall of the film formation chamber, that is, the inner wall of the vacuum vessel 102, is disposed on the front surface side of 6.

On the side where the susceptor 105 is provided, a vacuum exhaust port 111 is provided.
A well-known vacuum exhaust system (not shown) is connected,
The evacuation system evacuates the gas in the vacuum vessel 102 and regulates the pressure to a predetermined pressure. A gas supply port 112 is also provided on the side where the susceptor 105 is provided, and supplies, for example, a well-known argon gas (Ar alone or Ar + O ₂ or the like).

Therefore, in the present embodiment, during the generation of the plasma 109, the argon ions collide with the target 107, which is a cathode, and the particles sputtered therefrom cause the insulating substrate 106 to face the target 107.
And deposited on the surface of the film. At this time, the magnet 101
Is generated, the generated plasma 109 is confined in the vicinity of the target 107, and its electrons are
Since the drift motion is performed while drawing a cycloid curve, the probability of ionization collision between electrons and gas molecules is increased, and the deposition rate of the thin film can be increased. At this time, since the plasma 109 is confined in the vicinity of the target 107, the influence of the plasma 109 on the insulating substrate 106 can be reduced.

<< Schematic Configuration of Target Assembly >> FIG.
FIG. 3 is a front view for explaining a schematic configuration of a target assembly, and FIG. 3 is a sectional view of an AA part.

As shown in FIG. 2, in the thin film manufacturing apparatus according to the present embodiment, the target assembly 113 is divided into three in the Y-axis direction, that is, in the direction perpendicular to the magnet swing direction. 113a, 1
13b and 113c are independently fixed to a back plate 203 provided on the wall surface of the vacuum vessel 102. Therefore, in the present embodiment, as is clear from the diagram showing the relationship between the target position and the erosion depth in FIG.
By exchanging only the target assemblies 113a and 113c in which the erosion depth of the target 107 is deep, that is, the erosion progress speed is high and the life is short, the frequency of exchanging the target assembly 113b in the central portion where the erosion progress speed is low is reduced. be able to. However, the bonding between the target 107 and the backing plate 108 is made of indium or indium alloy as in the case of the conventional target assembly.

As is apparent from FIG. 2, the target assemblies of the present embodiment have respective backing plates 108 for attachment to the back plate so that each target assembly can be replaced independently from the back plate. A screw hole 202 is provided in the periphery. As shown in FIG. 3, the back plate is provided with recesses 301a, 301b, and 301c (hereinafter, referred to as "vacuum chambers") corresponding to the respective target assemblies 113a, 113b, and 113c.

When the inside of the vacuum vessel 102 is evacuated, vacuum chambers 301a, 301 provided on the back plate are provided.
Exhaust holes 201 are provided in the periphery of each backing plate 108 as holes for removing air of b and 301c. At this time, the first vacuum chamber is evacuated by the first vacuum chamber.
The second exhaust hole 201b exhausts the second vacuum chamber, and the third exhaust hole 201c exhausts the third vacuum chamber.

At this time, the mounting position of the target 107 on the adjacent backing plate 108 is determined by taking into consideration the difference between the backing plate temperature and the target temperature during film formation and the difference between the respective coefficients of thermal expansion. The targets 107 are bonded so that the distance between adjacent targets 107 is 0.5 mm or less. At this time, when a thin film of aluminum or copper is formed on the insulating substrate 106, the thermal expansion coefficients of the target 107 and the backing plate 108 do not greatly differ from each other. In general, the backing plate 108 is formed of copper or the like, and the coefficient of thermal expansion is largely different. Therefore, in the present embodiment, when the material of the target 107 and the material of the backing plate 108 are different and the coefficients of thermal expansion are different, the end of the backing plate 108 and the target 10
7 is not aligned with the backing plate 1
08 is formed shorter (or longer) than the target 107 in the X-axis direction to provide a step. Thereby, in general, the target 1 during film formation at a high temperature is formed.
07 can be prevented from being deformed or cracked. The step at this time is an interval at which the interval between the targets 107 adjacent to the film is 0.5 mm or less, and the interval is determined to be an optimum value through experiments or the like. This can prevent the backing plate 108 and the like from being sputtered as impurities from the gap between the adjacent targets 107 during the film formation.

In the present embodiment, each target 1
Although the divisions are made such that the sizes of 07a, 107b, and 107c are equal, it is needless to say that the present invention is not limited to this, and they may be divided into different sizes. Further, each backing plate 108a, 108
It goes without saying that only the target 107 may be further divided on b and 108c.

As shown in FIG. 3, the vacuum chamber 301 on the back of the backing plate 108 is also divided according to the size of each backing plate 108,
It goes without saying that the strength of the back plate 203 can be improved.

In the present embodiment, the number of divisions of the target assembly is set to 3, but is not limited to this.
As shown in FIG. 4, the number of divisions is not limited to three, but may be more than three as long as the portions having greatly different erosion speeds can be separated. In this case, it is possible to reduce the weight of each target assembly 113 and increase its strength (including the strength against deformation).

Further, in the conventional thin film manufacturing apparatus for a liquid crystal display substrate, the vacuum vessel 1 is formed by increasing the size of the liquid crystal display device and increasing the number of the liquid crystal display substrates for cost reduction.
The size of the vacuum container 102 tends to be large in order to maintain its strength. On the other hand, in order to maintain stable discharge of the plasma 109, the magnetic field intensity on the surface of the target 107 needs to be maintained at a predetermined value or more. As a measure for this, there are a first method using a magnet 101 stronger than before, and a second method for reducing the thickness of the target 107 and the backing plate 108. However, with the current technology, it is difficult to create a strong magnet having a uniform magnetic field strength distribution, so that the second method or a method combining the first and second methods is generally used. Has been adopted. However, when the second method is adopted, there is a problem that the strength of the backing plate 108 decreases as the thickness decreases, and in the conventional thin film manufacturing apparatus, the target assembly becomes larger and thinner. And the exchange work requires more time. Also in this regard, by applying the present invention, that is, each target assembly 113
By reducing the sizes of the target assemblies 113a, 113b, 113c,
Since the strength of c can be improved (sufficient strength can be ensured), the degree of freedom at the time of replacement can be increased, and the efficiency of the replacement work can be improved. As a result, the production efficiency of the liquid crystal glass substrate can be improved.

<< Method of Manufacturing Thin Film >> An ITO film (Ind) is formed on a glass substrate constituting a liquid crystal display device as the insulating substrate 106.
The case where sputter-deposited ium tin oxide is formed will be described. However, in this case, the target 107 of the thin film manufacturing apparatus shown in FIG.
The backing plate 108 is made of copper.

First, a vacuum exhaust system (not shown) connected to the exhaust hole 111 is operated to
07 is evacuated to a predetermined pressure. Next, an argon gas (Ar + O ₂ ) is introduced into the deposition chamber from the air inlet to regulate the pressure, and then a DC voltage is applied between the target assembly and the electrode 103 by the DC power supply 110. Then, the plasma 109 generated near the surface of the target 107 moves together with the reciprocating magnet 101. The number of movements of the magnet 101 at this time (the number of swings)
Is several to several tens of times.

The plasma 1 moving by this swinging motion
09 moves on the surface of the target 107 and sputtered particles sputtered from the surface of the target 107 exposed to the plasma 109 are deposited on the insulating substrate (glass substrate) 106 opposed to the insulating substrate 106.
Then, an ITO sputtered thin film is formed.

At this time, in this embodiment, only the first and third target assemblies 113a and 113c in which the erosion depth of the surface of the ITO target is the deepest, that is, the life of the target is short, can be replaced. The second target 107b having a longer life than the first targets 107a and 107c can be continuously used up to the life. In this case, since the first and third target assemblies can be replaced separately, the weight can be reduced, and the replacement efficiency can be improved. Therefore, it is possible to reduce the downtime of the thin film manufacturing apparatus, and improve the production efficiency.

In this embodiment, the description has been given of the case of the sputter-down system in which the target and the substrate are held in a horizontal state and the sputtered particles fly in the vertical direction to form a film, but the present invention is not limited to this. However, it is needless to say that the present invention can be applied to a side sputtering method in which a sputtered particle is made to fly in a horizontal direction to form a film.

In this embodiment, the target 107 of each target assembly is divided so that the length in the X-axis direction is equal. However, the present invention is not limited to this.
For example, an optimal length can be obtained by determining according to the erosion depth shown in FIG.

As described above, the invention made by the present inventor is:
Although specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the present invention, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .

[0039]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. Since the target can be exchanged according to the erosion depth, the use efficiency of the target can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a schematic configuration of a thin film manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a front view for explaining a schematic configuration of a target assembly.

FIG. 3 is a sectional view of an AA part shown in FIG. 2;

FIG. 4 is a diagram illustrating an example of a relationship between a target position and an erosion depth.

FIG. 5 is a diagram for explaining a schematic configuration of a magnet.

[Explanation of symbols]

101: magnet, 102: vacuum container (chamber), 103
… Electrode, 104… mask jig, 105… susceptor, 10
6: insulating substrate, 107: target, 108: backing plate, 109: plasma, 110: DC power supply, 1
11 vacuum exhaust port, 112 gas supply port, 113 target assembly, 201a first exhaust hole, 201b
... second exhaust holes 201b, 201c ... third exhaust holes 20
1c, 202: screw hole, 203: back plate, 301
a: first vacuum chamber, 301b: second vacuum chamber, 301c
... the third vacuum chamber.

Claims (5)

[Claims] 1. A target assembly comprising a target assembly fixed to a backing plate, wherein the target surface is sputtered by plasma generated on the target surface, and a thin film is formed on an opposing surface of an insulating substrate disposed opposite to the target. 2. The thin film manufacturing apparatus according to claim 1, wherein the target assembly is divided into a plurality of parts, and a plasma generation position on a surface of the divided target is sequentially moved. 2. The thin film manufacturing apparatus according to claim 1, wherein the target assembly is divided into three or more parts. 3. The thin film manufacturing apparatus according to claim 1, wherein an interval between the targets during the sputtering is 0.5 mm or less. 4. The thin film manufacturing apparatus according to claim 1, wherein the target assembly and the insulating substrate are arranged in a vacuum. 5. The position of plasma generated on a target surface of a target assembly having a target fixed to a backing plate is swung, the target is sputtered, and the plasma is sputtered on an insulating substrate opposed to the target. A method of manufacturing a liquid crystal display substrate on which particles are deposited, wherein the target assembly is divided into a plurality of parts, and a plasma generation position on a surface of the divided target is sequentially moved.