JPH08176818A - Sputtering equipment - Google Patents

Abstract

(57) [Summary] [Structure] A first electrode 12 for mounting a target 11 and a second electrode 14 for mounting a substrate 13 in a vacuum chamber 10.
And a fourth electrode 18 having a mesh shape between the first electrode 12 and the third electrode 15 for the sputtering device having the coil-shaped third electrode 15 between them. High-frequency voltage is applied to each of 12 and the third electrode 15,
A DC voltage is applied to the second electrode 14 to perform sputtering. [Effect] High-quality conductive films, insulating films, and semiconductor films can be deposited on substrates made of various materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus capable of improving the characteristics of an insulating thin film, a conductive thin film or a semiconductor thin film used in electronic devices and optical devices.

[0002]

2. Description of the Related Art Sputtering is widely used for forming thin films used in devices such as electronic devices and optical devices. The reason for this is that various kinds of good quality thin films can be easily obtained even when the substrate temperature is low. The principle of the sputtering method is that a vacuum chamber having a first electrode for setting a target serving as a thin film source and a second electrode for setting a substrate in a vacuum chamber is provided with an inert gas such as Ar at a specific pressure. Introducing a sputtering gas containing, and applying a negative DC voltage or high-frequency voltage to the first electrode,
First, the positive ions generated by causing a plasma-like discharge
This is based on the fact that when the target on the electrode is collided with at high speed, target constituent atoms are knocked out, and a thin film containing target constituent atoms is deposited on the surface of the substrate on the second electrode. During the formation of this thin film, the high-speed positive ions collide not only with the target surface but also with the surface of the thin film on the substrate, and a good quality thin film can be obtained at a low temperature by this collision. This is significantly different from the vacuum vapor deposition method that does not involve irradiation of fast ions. As a method of further improving the characteristics of the thin film by increasing the irradiation amount of ions on the substrate surface, a bias sputtering method in which a negative DC voltage or a high frequency voltage is applied to the second electrode on which the substrate is installed has been attempted. Generates more ions than this bias sputtering method
As a method of irradiating and dramatically improving the characteristics of a thin film, there is a sputtering apparatus in which a coiled third electrode is inserted between a target and a substrate. The features and problems of the sputtering apparatus will be described with reference to FIG.

An inert gas such as Ar having a predetermined pressure is introduced into a vacuum chamber 40, and a first electrode 4 having a target 41 is installed.
When a negative DC voltage is applied to 2 through the DC power supply 46, plasma is generated and the ions generated there are accelerated,
It collides with the target surface with high energy, the target constituent atoms are knocked out, and a thin film is deposited on the substrate 43 on the second electrode 44. At this time, when a high-frequency voltage is applied to the third coil-shaped electrode 45 by the high-frequency power source 47, high-density plasma is generated, and the target constituent atoms knocked out are
When passing through this high-density plasma, it is efficiently ionized or excited and reaches the substrate surface. For this reason,
The film characteristics can be remarkably improved. Further, in order to further improve the film characteristics, a method of applying a negative DC voltage to the second electrode 44 on which the substrate is installed through a DC power supply 48 has been attempted. By this method, the ions have higher energy and reach the substrate, so that the characteristics of the film are improved. However, the above method has some problems.

As shown in FIG. 4, only a negative DC voltage can be applied to the first electrode on which the target is placed. That is, when a high-frequency voltage is applied to the first electrode, it becomes difficult to generate high-density plasma due to the interaction with the coil-shaped third electrode to which the high-frequency voltage is applied, and unstable plasma is generated. It becomes a state. If the high frequency voltage cannot be applied to the target as described above, the types of thin films that can be deposited are greatly limited, and the thin films having high conductivity are limited. For example, high-quality Si that is indispensable as a semiconductor device
It becomes difficult to form an O ₂ film. The reason for this is Si
This is because plasma cannot be generated by applying a DC voltage to a target made of an insulator such as O ₂ . For the same reason, it is difficult to apply a high frequency voltage to the second electrode on which the substrate is placed. This bias sputtering method, in which only a DC voltage can be applied to the substrate, is limited to those having high conductivity as the type of substrate, and there is a problem that it is difficult to use a substrate made of an insulating material such as glass.

[0005]

As described above, the conventional sputtering apparatus in which the third electrode is inserted between the target and the substrate is excellent in forming a thin film made of a material having high conductivity. There is a problem in forming an insulating film or a semiconductor film having excellent characteristics, and there is a problem in that the type of substrate is limited to one having high conductivity. The reason is that it was difficult to stably apply a high frequency to the electrode on which the target or the substrate is installed.

An object of the present invention is to solve the problems of the prior art and to apply a high frequency voltage to an electrode on which a target or a substrate is installed. In addition to a high quality conductive film having excellent characteristics, an insulating film is also provided. Another object of the present invention is to provide a sputtering apparatus that can easily deposit a semiconductor thin film.

[0007]

The above object is to provide a new electrode between the coil-shaped electrode for generating high-density plasma and the target and / or between the coil-shaped electrode and the electrode on which the substrate is placed. It can be solved by adding.

[0008]

With the above structure, a coil-shaped electrode and a target can be installed by providing a new electrode, such as a mesh-shaped electrode, which transmits sputtered particles but is effective for shielding a high frequency electric field. Since the interaction of high frequency output with the electrode to be mounted or the electrode on which the substrate is installed is greatly reduced, not only the coiled electrode but also the electrode on which the target is installed or the electrode on which the substrate is installed Also, it becomes possible to apply a high frequency voltage, and as a result, it becomes possible to form not only a high-quality conductive film having excellent characteristics but also an insulating film and a semiconductor film.

[0009]

FIG. 1 shows a first embodiment of the present invention, in which, for example, a mesh electrode is provided as an electrode newly provided between a coil electrode and an electrode on which a target is placed. It is a sputtering device that has. The operation and features will be described below.

The first electrode 1 in which an inert gas such as Ar having a predetermined pressure is introduced into the vacuum chamber 10 and the target 11 is installed
When a high frequency voltage is applied to 2 through a high frequency power supply 17, plasma is generated and the ions generated there are accelerated,
Substrate 13 placed on the second electrode 14 by bombarding the target surface with high energy and knocking out target constituent atoms
A thin film is deposited on. At this time, the mesh-shaped fourth electrode 1
Since 8 is inserted, a high-frequency voltage can be applied to the coil-shaped third electrode 15 by the high-frequency power source 16, a higher-density plasma can be generated, and the target constituent atoms knocked out from the target surface are After passing through the hole portion of the mesh-shaped electrode, when it passes through this high-density plasma, it is efficiently ionized or excited and reaches the substrate surface. Therefore, the film characteristics can be remarkably improved.
As described above, in this embodiment, since the interaction between the coil-shaped electrode and the target setting electrode is reduced by the mesh-shaped electrode, the high-frequency voltage can be simultaneously applied to the coil-shaped electrode and the target setting electrode. . By doing so, high-density plasma can be stably generated by the coiled electrode, and since a high frequency voltage can be applied to the target electrode, it is possible to use a target having a low conductivity such as an insulator, not to mention the conductive film. That is, it is possible to form a high-quality insulating film or semiconductor film. Further, 19 is a direct current power source, and when a conductive film is formed, by applying a negative direct current voltage to the second electrode on which the substrate is set by the direct current power source 19, the irradiation amount of ions on the surface of the substrate is adjusted. The characteristics of the thin film can be further improved by increasing the number.

FIG. 2 shows a second embodiment of the present invention, which is a sputtering apparatus in which, for example, a mesh-shaped electrode is newly provided between the coil-shaped electrode and the electrode on which the substrate is placed. is there. When an inert gas such as Ar having a predetermined pressure is introduced into the vacuum chamber 20 and a negative DC voltage is applied to the first electrode 22 having the target 21 through the DC power supply 27, plasma is generated and is generated there. The ions are accelerated and collide with the target surface with high energy, the target constituent atoms are ejected, and the substrate 23 on the second electrode 24 is ejected.
A thin film is deposited on. At this time, the coiled third electrode 25
When a high-frequency voltage is applied to the high-frequency power source 26, a high-density plasma is generated, and the knocked-out target constituent atoms are efficiently ionized or excited to reach the substrate surface when passing through the high-density plasma. The film characteristics can be improved. In this embodiment, since the mesh-shaped fourth electrode 28 is provided between the coil-shaped third electrode and the second electrode on which the substrate is installed, the high frequency is applied to the second electrode 24 on which the substrate is installed. A high frequency voltage can be stably applied through the power supply 29. By doing so, a high-frequency voltage can be simultaneously applied to the coil-shaped electrode and the electrode on which the substrate is installed, the target constituent atoms knocked out from the target surface can be efficiently ionized, and further, the energy and irradiation amount of the ions can be changed. It can be controlled well by the high-frequency voltage applied to the substrate-installed electrode. Therefore, the quality of the thin film can be further improved. Further, since a high-frequency voltage can be applied to the substrate-installed electrode, it is effective not only for the conductive film but also for the formation of an insulating film or a semiconductor film. It is also effective when using a substrate made of an insulating material.

FIG. 3 shows a third embodiment of the present invention.
In this example, for example, a mesh electrode is provided not only between the coil electrode and the target setting electrode but also between the coil electrode and the substrate setting electrode. An inert gas such as Ar having a predetermined pressure is introduced into the vacuum chamber 30, and the target 3
When a high-frequency voltage is applied to the first electrode 32 having No. 1 through the high-frequency power source 391, plasma is generated, the ions generated there are accelerated, collide with the target surface with high energy, and the target constituent atoms are knocked out. , A thin film is deposited on the substrate 33 placed on the second electrode 34. At this time, since the mesh-shaped fourth electrode 36 is inserted, a high-frequency voltage can be applied to the coil-shaped third electrode 35 by the high-frequency power source 38, high-density plasma can be generated, and the high-frequency plasma can be ejected. The target constituent atoms thus generated are efficiently ionized or excited and reach the substrate surface when passing through the high density plasma. In this embodiment, since the mesh-shaped fifth electrode 37 is also provided between the coil-shaped third electrode 35 and the second electrode 34 on which the substrate is placed,
A high frequency voltage can be stably applied to the second electrode 34 on which the substrate is installed through the high frequency power source 392. Furthermore, in the present embodiment, since the mesh-shaped fourth electrode 36 is provided, a high-frequency voltage can be simultaneously applied to the coil-shaped third electrode 35 and the second electrode 34 on which the substrate is installed, and from the target surface The energy and irradiation amount of the target constituent atoms atomized and ionized can be well controlled by the high-frequency voltage applied to the substrate-installed electrode, and a high-quality thin film can be formed. In this embodiment, the coil-shaped third electrode 35, the target-installed first electrode 32, and the substrate-installed second electrode 34 are used.
A high frequency voltage can be applied to all of. Therefore, it is effective not only for the conductive film but also for the formation of an insulating film and a semiconductor film. Further, in addition to a substrate having a high conductivity, a substrate made of an insulator such as glass can be used. There are advantages.

As described above, the present invention has an advantage that a high quality thin film can be formed at a low temperature by providing a new electrode. In addition, a fourth electrode (reference numeral 18,
28, 36, 37) and coil electrodes (reference numerals 15, 2)
5, 35) If the surface is covered with a dielectric film containing the same material as the target (for example, alumina when the target is aluminum, silicon oxide film when the target is silicon), the surfaces of these electrodes are sputtered by high-speed particles. It is possible to prevent the surface of the sample substrate from being contaminated with the electrode constituent material. Further, since a high frequency voltage can be applied to the substrate and the electrode on which the target is placed, it is not only effective for the insulating film and the semiconductor film in addition to the conductive film, but also has a feature that various substrates can be used.

In the embodiments of the present invention, the case where the mesh-shaped electrode is used has been described as an example. However, the newly provided electrode is not limited to the mesh-shaped electrode, and a blind-shaped electrode may be used. Also, a plurality of blind-shaped ones may be stacked. Further, the size and shape of the hole of the electrode newly provided in the sputtering apparatus of the present invention has an advantage that it can be changed according to the purpose of use. Further, the potential state of the newly provided electrode can be ground potential or floating state, or a positive or negative DC potential can be easily applied, so that the formation of the film and the control of the film characteristics can be performed more accurately. You can do it. In each of the above embodiments, the coiled electrode (1
5, 25, 35) is a one-turn circular shape, but is not limited to this, and may be, for example, an elliptical or rectangular shape, and the number of turns is not limited to one. .

[0015]

As described above, the present invention provides an extremely effective sputtering apparatus capable of depositing high quality conductive films, insulating films and semiconductor films on various substrates, and manufacturing semiconductor devices and optical devices. Of course, it is effective for
It also plays an extremely important role in application to other devices.

The sputtering apparatus of the present invention has a frequency of 1 which is widely used for industrial purposes at present.
Since it can use 3.56 MHz, it has a wide range of applications.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional sputtering apparatus in which a coil-shaped electrode is inserted between a target and a substrate.

[Explanation of symbols]

10, 20, 30, 40 ... Vacuum tank 11, 21, 31, 41 ... Target 12, 22, 32, 42 ... First electrode 13, 23, 33, 43 ... Substrate 14, 24, 34, 44 ... Second 15, 25, 35, 45 ... Coiled third electrode 18, 28, 36 ... Fourth electrode 37 ... Fifth electrode 16, 17, 26, 29, 38, 47, 391, 392
… High frequency power supply 19, 27, 46, 48… DC power supply

Claims (5)

[Claims] 1. A first electrode for setting a target, a second electrode for setting a substrate, and a coiled third electrode arranged between the first electrode and the second electrode. The sputtering apparatus has an electrode group including at least one electrode between the first electrode and the second electrode. 2. The electrode group includes the first electrode and the third electrode.
Having at least one electrode placed between the electrodes of
The sputtering apparatus according to claim 1, wherein a high frequency voltage is applied to the first electrode. 3. The electrode group includes the second electrode and the third electrode.
Having at least one electrode placed between the electrodes of
The sputtering apparatus according to claim 1, wherein a high frequency voltage is applied to the second electrode. 4. The electrode group includes the first electrode and the third electrode.
At least one electrode disposed between the electrodes, and at least one electrode disposed between the second electrode and the third electrode, the first and second electrodes
The sputtering apparatus according to claim 1, wherein a high frequency voltage is applied to the electrode. 5. The sputtering apparatus according to claim 1, wherein the surface of the third electrode is covered with a dielectric.