JPH1025572A - Magnetron sputtering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently form thin coating excellent in uniformity at a high speed even on a large substrate. SOLUTION: This system is provided with a substrate holding member 3 which is arranged in a vacuum vessel 1 and on which a substrate 2 to be used to form coating film is mounted, a target 4, arranged at a position opposite to the substrate holding member, plural magnetic field generating means 9, 9' arranged at the rear face of the target and a magnet controlling means for reciprocating the magnetic field generating means parallel to the target and furthermore controlling the movement of the magnetic field generating means. Then, the magnetic controlling means controls the movement of the plural magnetic field generating means independently.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron sputtering apparatus, for example, a TFT (Thin-Film Tran-sistor).
The present invention relates to a magnetron sputtering apparatus suitable for forming a uniform thin film on the surface of a substrate having a particularly large area, such as a liquid crystal display using the same.

[0002]

2. Description of the Related Art Conventionally, when a thin film is formed on the surface of a substrate, a magnetron sputtering apparatus having a high film forming rate has been often used. The basic configuration of the magnetron sputtering apparatus is described in, for example, "Sputtering Phenomenon" (Todai Publishing Co., Ltd.), p. That is, a target which is a thin film base material is placed in a vacuum vessel, and a tunnel-like magnetic field is formed on the target surface. When a voltage is applied to the target, high-density plasma can be generated in the tunnel of the magnetic field, and a ring-shaped or race-track-shaped high-density plasma is formed on the target surface. Then, ions in the plasma collide with the target due to the electric field. Substances constituting the target are scattered at the atomic level due to collision of ions with the target, and the scattered particles adhere to the substrate, thereby forming a thin film.
This magnetron sputtering method has a feature that high-density plasma can be locally generated in a ring or a racetrack shape, thereby enabling high-speed film formation and suppressing a rise in substrate temperature. It also has disadvantages that it is difficult to form a film uniformly on the substrate and that the target is locally consumed. In order to form a uniform film on a large-area substrate, a method of moving a substrate or a magnet is used.

On the other hand, with the spread of portable personal computers and the like in recent years, demand for liquid crystal displays is increasing. The screen size of a liquid crystal display is required to be large in view of visibility, and in view of cost, there is a demand to manufacture a large number of products from a single piece of glass. In order to satisfy these two requirements, it is necessary to increase the size of the substrate on which the film forming process is performed. When a substrate on which a film is formed becomes large, it is necessary to perform sputtering for a long time. However, when sputtering is performed for a long time, problems such as (1) uneven film thickness due to generation of particles and (2) reduction in production efficiency occur. In order to solve these problems, for example, as disclosed in Japanese Patent Application Laid-Open No. HEI 5-117851, a plurality of sets of magnets (magnet units) are made adjacent to each other, and the plurality of sets of adjacent magnets are placed on a target. A method of reciprocating in parallel is considered. According to this method, the range of film formation that can be performed at one time is widened.
Compared with the case of a set of magnets, the film formation time can be shortened, and as a result, the above-described problem associated with the longer film formation time can be solved.

[0004]

However, when a plurality of magnets are arranged adjacent to each other as in the above-mentioned known example, plasma generated from a tunnel-shaped magnetic field formed by each magnet is generated between the magnets. The interference causes the plasma density distribution, that is, the film thickness distribution, to be difficult to predict. As a result, there arises a problem that it is difficult to uniformly distribute the film thickness.

An object of the present invention is to provide a magnetron sputtering apparatus capable of forming a film with a uniform thickness distribution and efficient film formation even if the substrate size is increased.

[0006]

In order to achieve the above object, the present invention provides a method of reciprocating a plurality of magnetic field generating means arranged on a back surface of a target arranged at a position facing a substrate in parallel with the target. In a magnetron sputtering apparatus adapted to move, the movements of the plurality of magnetic field generating means are controlled independently of each other.

According to the above arrangement, since the movements of the plurality of magnetic field generating means are controlled independently of each other, the uniformity of thin film formation is eliminated even on a relatively large substrate, and a uniform thin film can be formed at high speed. Will be able to

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a magnetron sputtering apparatus according to one embodiment of the present invention. In the figure, a vacuum vessel 1 is formed with an opening at an upper part, and a substrate 2 on which a film is to be formed and a substrate holding member having a heater function for heating the substrate 2 and for holding the substrate 2 in the vacuum vessel 1. 3 are arranged. A target 4 is disposed at a position facing the substrate 2 with the back surface supported by the backing plate 5.
This backing plate 5 covers the upper opening of the vacuum vessel 1 and maintains the inside of the vacuum vessel 1 in a vacuum state. Around the end of the target 4, an earth shield 6 is
It is arranged so as to surround the end of the target 4 while maintaining the gap with the end of the target 4, so that plasma does not flow into the gap. A first protection plate 7 is horizontally installed above the end of the substrate 2 so as to cover the end, and furthermore, an earth shield 6, and an L-shaped second protection plate 7 surrounds the first protection plate 7. The sputter particles scattered by the sputtering phenomenon adhere to the surface of the substrate holding member 3 and the inner wall of the vacuum vessel 1 with the first and second anti-plates 7 and 8. Is preventing.

On the other hand, magnets 9 and 9 'are provided on the back side of the target 4. As shown in FIG. 3, the magnets 9 and 9 'each have an S-pole peripheral magnet and an N-pole central magnet, or vice versa. Used. In this embodiment, the magnets 9 and 9 'having different polarities are used.

As shown in FIG. 1, the magnets 9, 9 '
They are respectively attached to the magnet driving devices 10 and 10 ', and can move in parallel with the target 4 and along the Y-axis direction shown in FIG. As shown in FIG. 4, the magnet driving device 10 includes a motor 11, a driving shaft 12 that is rotationally driven by the motor 11,
The rotational motion of the drive shaft 12 is converted into a linear motion,
And a bracket 13 for allowing the magnet 9 to move on the drive shaft 12. The motor 11 has
A rotary encoder 14 that converts the rotation angle of the motor 11 into a resistance and detects the rotation position of the motor 11, that is, the position of the magnet 9, is provided. The rotary encoder 14 controls the rotation direction and the number of rotations of the motor 11. The controller 15 is connected.

The controller 15 has input means 151 for reading a signal from the rotary encoder 14, number-of-times setting means 152 for setting the number of reciprocating movements of the magnet 9, and storage means 153 having a map for controlling the movement of the magnet 9. The value read by the input means 151 is compared with the map in the storage means 153 to calculate the movement speed of the magnet 9, and the comparison calculation means 154 for counting the number of reciprocating movements of the magnet 9, and the values obtained by the comparison calculation means 154. Output means 15 for transferring a control signal to the motor 11 based on the value
5 is comprised.

In this embodiment, the magnet control device is constituted by combining the magnet drive device 10, the rotary encoder 14, and the controller 15. The magnet drive device 10 'and the magnet control device for controlling the movement of the magnet 9' shown in FIG. 1 have almost the same configuration and operation as the magnet drive device 10 and the magnet control device for controlling the movement of the magnet 9. The description is omitted (the controller 15 in the magnet control devices 16 and 16 'is common).

Next, the operation of this embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing a control procedure according to the present embodiment. In the figure, first, in s101, the power of the magnetron sputtering apparatus is turned on, and the apparatus is started. Then, the controller 15 sends a command to the motor 11 to dispose the magnet 9 at a preset position (stored in the storage means 153) set in advance. The motor 11 rotates based on a command from the controller 15, and the rotation is converted into linear motion by the bracket 13, so that the magnet 9 is arranged at the initial setting position. At this time, the magnet 9 'is also arranged at the same initial setting position as the magnet 9 at a period difference of 1/2. When the control is the same, the description of the magnet 9 will be referred to as the description of the magnet 9 '.

In s102, the number of reciprocating movements of the magnets 9, 9 'is set, and the start switch for the sputtering operation is turned on. Then, the magnets 9 and 9 'start reciprocating movements in the range A and the range A' along the Y-axis direction in FIG. 2, respectively, and the sputtering operation is started. Here, the movement of the magnets 9 and 9 'will be described first.

The speed of the movement of the magnet 9 is controlled near the end of the substrate 2. This is because the size of the target 4 is finite,
The solid angle varies depending on the position on the substrate 2, and as a result, in the vicinity of the end of the substrate 2 where the film formation density tends to be low, FIG.
As shown in FIG. 7, the speed is reduced to make the film thickness distribution uniform. The storage means 153 stores 19 shown in FIG. 7 as the speed pattern of the magnet 9 and 20 shown in the figure as the speed pattern of the magnet 9 ', and the comparison operation means 154 stores the speed pattern 19,
The movement command according to 20 is transferred to the motors 11 and 11 'via the output means 155. The magnet 9 and the magnet 9 'reciprocate in the range A and the range A', respectively, while maintaining the period difference 1/2 from the movement start point by the rotation of the motors 11 and 11 '. This magnet 9, 9 '
A voltage is applied to the target 4 at the same time as the movement of the target starts, and a sputtering operation is started.

In s103, the number of reciprocating movements of the magnet 9 is counted, and in s104, the value of s103, which is the number of reciprocating movements of the magnet 9, is compared with the value of the initially set number of reciprocating movements 152. If N in s104, that is, if the actual number of reciprocating motions of the magnet 9 does not match the set number, the process returns to s103,
This routine is repeated until it becomes Y in s104.

If Y in s104, that is, if the number of reciprocating motions of the magnet 9 reaches the set number, s1
Proceeding to step 05, the movement of the magnets 9, 9 'and the sputtering operation are stopped, and further proceeding to s106, the magnets 9, 9' are arranged at the initial setting positions.

At s107, the continuation of the operation is inquired. If the operation is to be continued, the process returns to s102, and the subsequent steps are repeated. When the operation is to be ended, this control ends. The magnetron sputtering apparatus according to the present embodiment can use the previously set number of reciprocating motions without any special instructions when performing continuous operations.

Using the magnetron sputtering apparatus of the present embodiment, a Cr film was formed by applying a sputtering power of 25 kW to a substrate having a size of 550 mm × 650 mm. Film thickness distribution ± 4.2
% Met. On the other hand, in the case of a conventional apparatus using only one set of magnets, the probability of abnormal discharge increases in a region where the sputter power is 20 kW or more, so that the power cannot be further increased. Sputter power is 20kW
It took 50 seconds to form a 182 nm Cr film. That is, in the magnetron sputtering apparatus of the present embodiment, the Cr film formation time was reduced from 50 seconds to 36 seconds, and the productivity was improved by about 40%.

As described above, the magnetron sputtering apparatus of the present embodiment uses two magnets, the magnet 9 and the magnet 9 ', so that the film forming process time is shorter than that of a single magnet. Since the movements of the two sets of magnets are controlled separately and at different periods, mutual interference between the magnets can be prevented. For this reason, even if the substrate size is large, a thin film can be efficiently formed with a uniform thickness.

Further, since the speed is controlled near the end of the target 4, a thin film having a uniform film thickness can be formed also at the end of the substrate.

Since the magnets 9 and 9 'have different polarities, the interaction between the magnets, that is, the interference of plasma is reduced, and a thin film having a uniform thickness can be formed between the magnets.

In the present embodiment, the period difference between the magnet 9 and the magnet 9 'is set to 1/2, but it is not necessarily 1
It is not necessary to be, and it is also possible to apply between 〜 and ／ from the relation of mutual interference between the magnets.

In this embodiment, the speed control is performed in the vicinity of the end of the target. Of course, no special speed control may be performed, and the magnets 9 and 9 'having different polarities are used. And the same polarity may be used.

Further, although two sets of magnets are used in this embodiment, the present invention can be applied to more than two sets of magnets.

[0027]

According to the present invention, there is provided a magnetron sputtering apparatus wherein a plurality of magnetic field generating means disposed on a back surface of a target disposed at a position facing a substrate are reciprocated in parallel with the target. Since the movements of a plurality of magnetic field generating means are controlled independently of each other,
Even for a relatively large substrate, the uniformity of the thin film formation is eliminated, and a uniform thin film can be formed quickly and efficiently.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a magnetron sputtering apparatus according to the present invention.

FIG. 2 is a plan view showing one embodiment of a magnetron sputtering apparatus according to the present invention.

FIG. 3 is an external perspective view for explaining a configuration of a magnet employed in the present invention.

FIG. 4 is a perspective view illustrating a magnet driving device employed in the present invention.

FIG. 5 is a flowchart showing a control procedure of a magnet in the present invention.

FIG. 6 is a characteristic diagram showing a relationship between a position of a magnet and a moving speed according to the present invention.

FIG. 7 is a characteristic diagram showing displacement of each magnet with respect to time and a difference between periods of two sets of magnets in the present invention.

DESCRIPTION OF SYMBOLS 1 ... vacuum container, 2 ... substrate, 3 ... substrate holding member, 4 ... target, 5 ... backing plate, 9, 9 '... magnet (magnetic field generating means), 11 ... motor, 12 ... drive shaft ( Rotational drive transmission member), 13: bracket (movement direction conversion member), 14: rotary encoder (magnet motion detection means), 15: controller.

Claims (6)

[Claims] Claims: 1. A vacuum vessel, and disposed in the vacuum vessel,
A substrate holding member on which a substrate to which a film is to be attached is attached,
A target disposed at a position facing the substrate holding member, a plurality of magnetic field generating means disposed on the back surface of the target, and reciprocating the magnetic field generating means in parallel with the target; A magnetron sputtering apparatus provided with magnet control means for controlling the movement of the magnetic field, wherein the magnet control means controls the movements of the plurality of magnetic field generation means independently of each other. 2. A magnetron sputtering apparatus according to claim 1, wherein said magnet control means controls a moving speed of said magnetic field generating means at a target end portion to be lower than a moving speed at a target central portion. A magnetron sputtering apparatus, characterized in that: 3. The magnetron sputtering apparatus according to claim 1, wherein at least one of the plurality of magnetic field generating means has a moving cycle difference of 1/4.
A magnetron sputtering apparatus characterized in that the period is between ３ and 周期. 4. The magnetron sputtering apparatus according to claim 1, wherein said plurality of magnetic field generating means have different polarities from adjacent magnetic field generating means. 5. The magnetron sputtering apparatus according to claim 1, wherein the back surface of the target is supported by a backing plate, and the backing plate forms a part of the vacuum vessel. . 6. A vacuum vessel, and disposed in the vacuum vessel,
A substrate holding member on which a substrate to which a film is to be attached is attached,
A target disposed at a position facing the substrate holding member, a plurality of magnetic field generating means disposed on the back surface of the target, and reciprocating the magnetic field generating means in parallel with the target; A magnetron sputtering device provided with magnet control means for controlling the movement of the motor, the magnet control means comprising: a motor, a rotational drive transmitting member rotationally driven by the motor, and converting the rotational movement of the rotational drive transmission member into linear motion. And two or more magnet drive devices each including a movement direction conversion member that causes the magnet to move along the rotation drive transmission member; and a magnet movement detection unit that detects a position and a movement direction of the magnet. And a controller for controlling the motion of the magnet drive device. Data device.