KR100529915B1 - Magnetron sputtering device and its method for the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus and a method of operating the same, which enable efficient use of a target made of a material deposited on a substrate used for sputtering to form a wiring film and an optical film during a manufacturing process of a flat panel display device. Comprising a substrate to be a target and a coating material deposited on the surface of the substrate, as the cathode is applied is ionized by a target for emitting the coating material to the substrate and the secondary electrons emitted from the target of the coating material In a magnetron sputtering apparatus comprising a spaced portion made of an inert gas to induce release, the magnetic field is formed on the target surface to improve the ionization rate of the inert gas and at the same time the erosion portion of the target due to the ionized inert gas Of the magnet to be distributed It is configured to include a magnetic field generating unit having a variable sex, by varying the magnetic field formed on the target surface to disperse local erosion of the target, improve the target use efficiency, can increase the overall operation rate of the coating process have.

Description

 Magnetron sputtering device and its method for the same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus, and more particularly, to a magnetron sputtering apparatus for efficiently using a target made of a material deposited on a substrate used during sputtering to form a wiring film and an optical film during a manufacturing process of a flat panel display device. It is about.

In general, sputtering is a technique for coating a thin film on a substrate. In a vacuum atmosphere, a high voltage is applied to a target made of a metal or a metal compound to generate a plasma discharge around the target, thereby generating cations in the plasma discharge region. When the collision with the surface of the target by an electrical force, the target atoms are released accordingly, so that the released atoms are coated on the substrate.

As shown in FIG. 1, the sputtering apparatus connects a target 2 made of a material to be coated in a vacuum state with a negative electrode and connects the substrate 1 to be coated with a positive electrode or ground. After applying the electric field V, free electrons 3a emitted from the target 2 are released from the target 2 by the applied electric field V to ionize the argon gas Ar atoms 3b. Let's go.

Accordingly, the ionized argon ions (Ar ⁺ ) 3c collide with the target 2 by the applied electric field V, and the collision causes the target atoms 3d from the target 2. When released, the released target atoms 3d are coated on the substrate 1.

Such a sputtering device is used when a uniform coating of several tens to thousands of micrometers is used, such as thin film transistor (TFT), liquid crystal display (ITO), Al-nd, Mo, Cr thin film coating and organic It is commonly used for ITO of EL (Electro Luminiscence), metal film of FED (Filed Emission Display), and Ti, TiN coating of semiconductor.

However, such a sputtering apparatus requires a high voltage and a lot of inert gas, and the inert gas (generally using argon gas) has a low ionization rate, making it difficult to achieve efficient coating, especially a high voltage of several thousand volts. Due to this causes an unstable electric shock phenomenon such as arcing (Acing) there is a problem that the substrate being coated is damaged and the coating efficiency is impaired.

In order to solve this problem, the magnetron method of installing a magnet behind the target 2, as shown in Figure 2, by installing a magnet 4 behind the target 2 to the target The free electrons 3a emitted by (2) are subjected to the force of the electric field (5) by the electric field and the magnet and Lorentz (Lorentz) by the magnetic field (6), and drafting along the upper surface of the target (2). (Drafting) movement, which can improve the probability of collision between free electrons (3a) and argon gas atoms to improve the ionization rate, which enables coating at low voltage and high vacuum.

At this time, the equation for the Lorentz force received by the free electrons 3a is the same as Equation 1.

F = q (v × B)

Here, q denotes the amount of charge of the free electrons 3a, v and B denote the electric and magnetic field vectors, respectively, and F denotes the force received by the free electrons 3a.

In this case, as shown in Equation 1, when the vectors of the electric and magnetic fields are horizontal, F becomes 0, and when F is vertical, F becomes maximum. Accordingly, the free electrons 3a receive the greatest force in a portion where the vector component of the magnetic field is parallel to the surface of the target 2, so that the ionization phenomenon of the argon gas atom occurs the most, and thus the magnetic field According to the vector component of the difference occurs in the erosion of the target (2) surface.

Accordingly, when the portion due to local erosion in the target 2 having a thickness of 6 mm to 10 mm reaches the thickness of the target 2, the target 2 can no longer be used. (2) should be replaced, and the ratio of the weight of the target before the sputtering process to the weight of the target replaced after the use is generally called the target use efficiency, and the general target use efficiency is about 20%.

A first embodiment of the magnetron sputtering method according to the related art for solving the local erosion of the target as described above will be described with reference to FIG. 3.

As shown in FIG. 3, negative and positive electrodes are applied to the upper and lower sides of the shield 40 which maintains a vacuum state and forms a space in which argon gas is introduced. The substrate 10 to be coated is connected to the anode 41 to which the positive electrode is connected, and the negative electrode is connected to the target 20 made of a material to be coated.

The magnet 30 installed on one surface of the target is configured such that the north pole and the south pole alternately face the surface of the target 20, and the magnetic field by the magnet 30 is horizontal to the surface of the target 20. Since it is possible to improve the target use efficiency to 25% to 30%.

In addition, referring to FIG. 4, a moving magnetron sputtering method, which is a second embodiment of the magnetron sputtering method according to the related art, maintains a vacuum state and forms a space such that argon gas is introduced as shown in FIG. 4. A negative electrode and a positive electrode are respectively applied to the upper and lower sides of the shield 40 ', and the substrate 10' to be coated is connected to the anode 41 'to which the positive electrode is connected. The negative electrode is connected to a target 20 'made of a material to be coated and a magnet 30' positioned above the target 20 '.

In particular, the magnet 30 'is reciprocated in the horizontal direction with the target 20' surface. This causes the magnet 30 'to reciprocate horizontally with the target 20' surface, so that local erosion of the target 20 'occurs over the entire surface of the target 20', The target use efficiency accordingly has a value of 30% to 35%, and is mainly used when a large area substrate is to be coated.

However, as shown in FIG. 5, which shows a target in which local erosion has occurred, this magnetron sputtering method has some local targets at the ends of the targets, despite moving the magnets as a means for improving target use efficiency. Erosion occurs.

Referring to FIG. 5B, which is an enlarged view of a portion A shown in FIG. 5A, the depth C of the portion eroded from the target by sputtering on the average is 1.9 mm, whereas Depth B has an average of 5.4 mm.

This improves the target collision energy of the ionized Ar gas as the local high voltage is formed due to the electron's closed-circuit phenomena caused by electrons traveling along the magnet closed-circuit passing through the part formed by the round at the end of the magnet. This is caused by sputtering.

Particularly, in the case of a magnet which does not reciprocate both ends of the target, a lot of sputtering occurs when electrons come out from the rounded part of the magnet end, but when the magnet moves, a lot of sputtering occurs when the electron passes the round part. do.

Therefore, in theory, when the magnet is reciprocated, a target use efficiency of about 45% can be obtained, but in reality, a target use efficiency of about 33 to 35% is possible due to a local target erosion phenomenon. This often means that targets must be replaced, which results in lower process utilization and higher coating costs.

As shown in FIG. 6 illustrating the structure of the magnet, this phenomenon occurs only at the upper right end and the lower left end of the target 20 'when the magnet having the NSN structure 31 is used. In the case of using a magnet having a (32), it appears only at the upper left end and the lower right end of the target 20 '.

In particular, because the vacuum is released to replace the target, and the vacuum is required for the coating using the sputtering method, about 12 hours are required to form the vacuum again after the vacuum is released, thus producing a loss of production. .

The present invention has been made to solve the above-described problems of the prior art, by configuring the magnetron sputtering device to periodically change the polarity of the magnet to minimize the influence of the polarity of the magnet causing a local target erosion phenomenon, the target It is an object of the present invention to provide a magnetron sputtering apparatus and an operation method thereof for improving the use efficiency of the same.

In addition, the sputtering method of the present invention is a first step of putting the substrate to be coated, a second step of coating the substrate while the magnet located in the rear of the target facing the substrate is horizontally moved from one side to the other side of the target, And a fourth step of removing the substrate on which the coating film is formed, and returning to the first step after vertically rotating the magnet such that the polarity oriented with the target in the second step is opposite to the target. It is done.

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Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. 7 and 8 are views showing a first embodiment of the magnetron sputtering apparatus according to the present invention, Figure 9 is a view showing a second embodiment of the magnetron sputtering apparatus according to the present invention.

As shown in Figs. 7 and 8, first, a target 100 made of a material to be coated is deposited. A magnetic field generating unit for forming a magnetic field on the surface of the target 100 is positioned to face one surface of the target 100, and reciprocally moves both ends of the target such that the magnetic field generating unit is parallel to one surface of the target 100. At the same time it is composed of a transfer unit for varying the distribution of the magnetic field formed by the magnetic field generating unit.

The magnetic field generating part is a yoke 112 which is positioned to face the target 100 and is rotatable, and a plurality of permanent magnets fixed to one surface of the yoke to face the target and alternately arranged with the north pole and the south pole. The first magnet 110 and the plurality of permanent magnets are fixed to the other surface of the yoke to be aligned with the target and the N pole and the S pole are disposed so as to be opposite to the plurality of permanent magnets forming the first magnet 110. It is configured to include a second magnet 111 made.

In this case, the yoke 112 fixes the permanent magnet and rotates to change the position of the permanent magnet, as well as a first magnet 110 fixed to one side of the yoke and a second fixed side of the yoke. It performs a function of blocking the mutual influence between the magnets (111). Therefore, in order to perform this function, the yoke preferably has a thickness of 12 mm or more.

The transfer unit rotates the yoke 180 degrees so that the positions of the first magnet 110 and the second magnet 111 connected to both sides of the yoke are reversed, and the plurality of permanent magnets are fixed. The yoke 112 may be configured as a horizontal transfer unit for reciprocating both ends of the target.

The vertical transfer unit reverses the positions of the motor shaft (not shown) connected to the yoke 112 and the first magnet 110 and the second magnet 111 connected to the motor shaft and connected to both sides of the yoke. It comprises a motor 130 for rotating the yoke 112 by 180 degrees to vary the distribution of the magnetic field generated by the permanent magnet.

The horizontal conveying part is connected to the yoke 112 and a ball screw 121 positioned perpendicular to the ball screw of the vertical conveying part, and the yoke 112 to which the first and second magnets 110 and 111 are fixed is Couple the motor 120 to rotate the ball screw 121 to reciprocate both ends of the target 100 and the motor and the ball screw 121 to transfer the rotational force of the motor to the ball screw Ring 122.

Here, according to the second embodiment of the present invention, as shown in FIG. 9, the magnetic field generating unit positioned to face one surface of the target 200 may include an external power source (not shown) for varying the direction of the electric field, and A plurality of electromagnets 210 whose magnetic poles (N pole or S pole) are varied by an external power source, and a yoke 211 for fixing the plurality of electromagnets.

In this case, the transfer unit is a ball screw 221 connected to the yoke 211, and the motor 220 to rotate the ball screw 221 so that the yoke 211 reciprocates both ends of the target 200. And a coupling 222 connecting the motor and the ball screw 221 to transfer the rotational force of the motor to the ball screw.

Referring to the accompanying drawings, the operation of the present invention configured as described above is as follows. 10 is a flow chart showing the operation of the magnetron sputtering apparatus according to the present invention, Figure 11 is a diagram showing the target erosion distribution of the magnetron sputtering apparatus according to the present invention.

First, a substrate to be coated is introduced for the sputtering process. (S1)

When the substrate is input, about 5 kw of power is applied for 40 seconds after the input (S2).

When power is applied, the motor connected to the yoke operates to start the sputtering process. When the motor operates, a plurality of permanent magnets fixed to one surface of the yoke to reciprocate from one side of the target to the other side of the target to face the target. The reciprocating motion is about 4 to 10 times depending on the thickness of the coating film. (S3)

While the sputtering process is in progress, it is detected whether the thickness of the set coating film is formed. (S4)

In this case, when the set thickness of the coating film is formed, the applied power is turned off and the substrate on which the coating is completed is removed. (S5)

There is a waiting time of about 140 seconds until the next substrate comes after the substrate is removed, which is the time required for the next substrate to reciprocate in a vacuum / standby state, where the vertical conveying portion is perpendicular to the direction of motion of the permanent magnet. By rotating the yoke 180 degrees by a motor connected to the yoke.

When the yoke is rotated 180 degrees, a plurality of permanent magnets fixed to the yoke are oriented to the target so as to face the target in an initial process, and a plurality of permanent magnets positioned to orient the target are opposed to the target. After the waiting time, the next substrate is input and the above process is repeated. (S6)

When the sputtering process is performed by varying the magnetic field of the permanent magnet or the electromagnet by the method as described above, as shown in FIG. 9, the local target erosion phenomenon is the upper left and the lower right or the lower left and the diagonal. It can be seen that the use efficiency of the target is improved because the erosion phenomenon appears in all of the top, bottom, left and right ends of the target rather than occurring in the upper right end.

In the case of the second embodiment using an electromagnet, since the process waiting time for varying the magnetic poles (N pole or S pole) is not required, the present invention can be applied to a coating process in which the process must proceed continuously.

In addition, the above embodiment has been described the configuration and operation of the present invention based on the moving magnetron sputtering method, which is equally applicable to the magnetron sputtering method in which the permanent magnet or the electromagnet is not moved because the horizontal transfer part is removed. .

As described above, the magnetron sputtering apparatus and its operation method according to the present invention have been described with reference to the illustrated drawings. However, the present invention is not limited by the embodiments and drawings disclosed herein, and the application is within the scope of the technical idea. Can be.

The magnetron sputtering apparatus and its operating method according to the present invention configured as described above comprises a first and a second magnet made of a plurality of permanent magnets alternately arranged with the N pole and the S pole or an external power source is applied. The magnetic field is variable according to a direction, and after a predetermined time, the positions of the first and second magnets are reversed or the magnetic poles of the electromagnets are changed, thereby dispersing a local erosion phenomenon of the target. It is possible to improve the use efficiency, thereby increasing the operation rate of the coating process and the effect of reducing the production cost.

1 shows a typical sputtering apparatus,

2 is a diagram illustrating a general magnetron sputtering scheme;

3 is a view showing a first embodiment of a conventional magnetron sputtering scheme;

4 is a view showing a second embodiment of the conventional magnetron sputtering method;

5 is a diagram illustrating a local target erosion by the conventional magnetron sputtering method,

6 is a diagram showing the configuration of a magnet in a conventional magnetron sputtering method;

7 is a first plan view showing a first embodiment of a magnetron sputtering apparatus according to the present invention;

8 is a second plan view showing a first embodiment of a magnetron sputtering apparatus according to the present invention;

9 is a plan view showing a second embodiment of a magnetron sputtering apparatus according to the present invention;

10 is a flow chart showing the flow of operation of the magnetron sputtering apparatus according to the present invention,

11 is a diagram showing a target erosion distribution by the magnetron sputtering apparatus according to the present invention.

<Explanation of symbols on main parts of the drawings>

1, 10, 10 ': substrate 2, 20, 20', 100, 200: target

110: first magnet 111: second magnet

120: first motor 130: second motor

210: electromagnet 220: motor

Claims (11)

A spaced portion comprising a substrate to be coated, a target for emitting a coating material to the substrate, an inert gas for inducing release of the coating material by free electrons emitted from the target, and a magnetic field on the target surface. In the magnetron sputtering apparatus comprising a magnetic field generating unit for forming a, And a vertical transfer unit for vertically reversing the positions of the first magnet and the second magnet forming the magnetic field, and a horizontal transfer unit for causing the magnetic field generating unit to horizontally reciprocate both ends of the target. Magnetron sputtering device characterized by the above-mentioned. The method of claim 1, The magnetic field generating unit and the yoke is located opposite to the target and rotatable; A first magnet having a plurality of permanent magnets fixed to one surface of the yoke to face the target and alternately arranged with the north pole and the south pole; And a second magnet made of a plurality of permanent magnets, the N pole and the S pole of which are fixed to the other surface of the yoke so as to be oriented with the target and opposed to the plurality of permanent magnets constituting the first magnet. Magnetron sputtering device. The method of claim 1, The magnetic field generating unit and the yoke is located opposite the target; The magnetron sputtering device, characterized in that it comprises a plurality of electromagnets fixed to one surface of the yoke facing the target, the magnetic pole is variable in accordance with the direction in which external power is applied. The method of claim 3, wherein The magnetic field generating unit further comprises a power supply for varying the direction of the current applied to the plurality of electromagnet magnetron sputtering device. The method of claim 2, The vertical transfer unit is a magnetron sputtering device, characterized in that for rotating the yoke to reverse the position of the first magnet and the second magnet connected vertically to both ends of the yoke. The method of claim 5, The vertical transfer unit and the motor shaft connected to the yoke vertically; And a motor which is connected to the motor shaft and rotates the positions of the first magnet and the second magnet by 180 degrees so that the magnetic field formed on the target surface has the opposite polarity. delete The method of claim 2, A ball screw connected to the yoke to allow the magnetic field generator to reciprocate horizontally while rotating both ends of the target; A magnetron sputtering apparatus, comprising a drive motor connected to one side of the ball screw to rotate the ball screw. A first step of putting a substrate to be coated; A second step of coating the substrate while the magnet located behind the target facing the substrate moves horizontally from one side to the other side of the target; Removing the substrate on which the coating film is formed; And a fourth step of returning the magnet to the first step after vertically rotating the magnet so that the polarity of the target is opposite to the target in the second step. The method of claim 9, The fourth step is to rotate the position of the first magnet connected to one side of the yoke opposite to the target surface and the second magnet connected to the other side of the yoke so that the magnetic field formed on the target surface is reversed by 180 degrees. Method of operation of a magnetron sputtering device. The method of claim 9, The fourth step is a method of operating a magnetron sputtering device, characterized in that for changing the pole of the external power applied to the plurality of electromagnets fixed to the yoke so that the magnetic field formed on the target surface is reversed.