JPS6376868A - Sputtering device - Google Patents

Abstract

PURPOSE:To permit easy formation of an intermediate sputtered material having uniform quality by providing a gas reaction accelerating mechanism having a reactive gas outflow port to a position except the area where a substrate and target face each other to effect the additional reaction of the sputtering material. CONSTITUTION:A gaseous mixture composed of an inert gas and reactive gas is introduced from a gas introducing pipe 30 into a vacuum vessel 21. The substrate 23 is rotated and glow discharge is started by supplying a high-frequency power between the target 25 and a substrate supporting body 22 to convert the reactive gas to plasma. The target 25 is thereby sputtered and an Fe3O4 film containing Fe molecule is formed on the surface of the substrate 23. The substrate supporting body 22 in this state is moved to the position where said body faces a discharge electrode 32 of the gas reaction accelerating mechanism 31, and the discharge is generated by impressing a prescribed voltage to the electrode. The gaseous atmosphere of a high-pressure is maintained at this time by controlling the flow rate of the reactive gas flowing out of a reactive gas outflow port 33 and the rate of the discharge from a discharge port 35. The reactive gas is converted to the plasma and brought into contact with the Fe3O4 film on the substrate 23 to react with the unoxidized Fe, by which Fe3O4 is formed.

Description

[Detailed Description of the Invention] [Summary] The present invention is a reactive sputtering apparatus applied to the production of various magnetic recording media, semiconductor integrated circuit elements, etc. Control is performed by gas reaction accelerating mechanisms placed on the target side and the substrate side, thereby easily forming an intermediate oxide film consisting of a homogeneous intermediate reaction sputtering material, for example, a homogeneous Fe304 film with a lower oxidation degree than α-Fe203. It is designed so that it can be formed into a film.

[Industrial application field]

The present invention relates to the improvement of sputtering equipment used in the manufacture of various magnetic recording media and semiconductor integrated circuit elements, and in particular, it is possible to stably form a thin film with a desired degree of oxidation by a reactive sputtering method using a reactive gas such as oxygen. The present invention relates to a reactive sputtering device for forming the present invention.

Sputtering equipment, which forms a thin film of a reaction product made of oxide, nitride, carbide, or sulfide of a Kugett material on a substrate by reactive sputtering, is now used in the manufacture of magnetic recording media and semiconductor devices. It is widely used in the field, and various device configurations have already been proposed.

Generally, such a reactive sputtering device is used to form an α-Fe203 film, which is the basis for forming a γ-Fe203Trn film of a magnetic recording medium.
yFe203 magnetic film formation process (α-Fe203 film-F
In order to improve the efficiency and reduce the cost of the e304 film (r -Fe2 o3 magnetic film), the r
- Although it is extremely difficult to form a Fe203 magnetic film,
What is desired is a reactive sputtering apparatus that can at least easily deposit and form the Fe304 film in the preliminary stage.

[Conventional technology]

A conventional E-responsive sputtering apparatus for forming a reaction product film made of oxides, etc., has a target 3 in a vacuum chamber 1 equipped with an exhaust device 2, as shown in FIG.
A water-cooled target support 4 having a water-cooled target support 4 attached thereto, and a substrate support 5 opposing thereto supporting a substrate 6 on which a thin film is to be formed are rotatably arranged by a rotation mechanism 7.

Therefore, in order to form, for example, an oxide film on the surface of the substrate 6, the inside of the vacuum container 1 is heated by the exhaust device 2 to
After evacuating to a degree of vacuum of approximately 0 Torr, an inert gas consisting of argon (Ar) gas and oxygen (0
2) Mixed gas with reactive gas consisting of gas from 10-4 to
In a state filled with gas pressure of about 10' Torr, a predetermined high frequency power is supplied between the target 3 and the substrate support 5 from the high frequency power source 9, and the shutter 8 on the target 3 is opened to start discharge. .

Gas ions in the plasma generated by the discharge generated at this time are accelerated by the electric field and collide with the target 3, and the target material is sputtered from the surface of the target 3, and the target material that has reacted with the reactive gas is deposited on the opposing surface of the substrate 6. An oxide film is formed from the oxide of

[Problem that the invention seeks to solve]

By the way, it is well known that it is extremely difficult to form a γ-Fe203 magnetic film directly on a disk substrate using the conventional reactive sputtering apparatus as described above. First, an α-Fe203 film, which is the basis for the film, is formed by a reactive sputtering method, and then the α-Fe203 film is heat-treated in a reducing atmosphere to transform into a Fe304 film.
By further heat-treating the 4 film in an oxidizing atmosphere,
A Fe2034fl film is formed.

However, in recent years, attempts have been made to form Fe304 films by reactive sputtering in order to improve the efficiency of such formation processes.

However, in the conventional reactive sputtering apparatus described above, most of the reaction of the reactive gas such as 02 gas during sputtering occurs on the surface of the target 3 to be sputtered, and the reaction with the reactive gas is not sufficiently performed. When this is done, an α-Fe203 film is formed. Furthermore, when the reaction is suppressed, a Fe304 film containing unreacted Fe particles is formed.

Therefore, the oxidation reaction state on the surface of the target 3 is always maintained at Fe
It is necessary to stably control the sputtering conditions such as gas atmosphere pressure and power supply so that α-Fe is sputtered, but the control range is extremely narrow and difficult.
It was difficult to form an intermediate oxide film consisting of a homogeneous Fe304 film with a lower oxidation degree than Fe303.

In view of the above-mentioned conventional circumstances, the present invention controls the reaction of a sputtering material with a reactive gas during reactive sputtering on the substrate side as well as on the target side, thereby producing a homogeneous intermediate reactive sputtering material. The purpose of this invention is to provide a new reactive sputtering apparatus that can easily form a film.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method to avoid the facing area between the substrate and the target, which are rotatably arranged in a vacuum container, by moving the substrate close to the surface of the substrate. A gas reaction promoting mechanism consisting of a discharge electrode, a reactive gas outlet around the discharge electrode, and an outer enclosure equipped with an exhaust port for gas pressure control is arranged around the discharge electrode, and a reactive gas is generated on the rotating substrate surface. The sputtered material deposited by sputtering is further reacted with a reactive gas by a gas reaction promotion mechanism.

[For production]

Sputtering li! of the present invention! The reaction of the reactive gas to the sputtering material during reactive sputtering can be controlled at three locations: on the target side and on the substrate side. Even if some unreacted sputtered material is present in the intermediate reactive sputtered material, the unreacted sputtered material can be removed by promoting the reaction with the reactive gas in the gas reaction promotion mechanism. It becomes possible to form a homogeneous intermediate reaction sputtering material without any mixture of.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a main part of an embodiment of a sputtering apparatus according to the present invention.

In the figure, 21 is a vacuum container, and 22 is a substrate support on which a substrate 23 on which a thin film is to be formed is rotatably supported by a rotating mechanism 24. A target support 26 supporting a target 25 is disposed with a shutter 27 in between.

28 is an earth shield, 29 is an exhaust pipe connected to an exhaust device, and 30 is a mixed gas introduction pipe for supplying a mixed gas of an inert gas made of Ar and a reactive gas made of, for example, 02.

Reference numeral 31 denotes a gas reaction promotion mechanism, which has a water-cooled discharge electrode 32, a reactive gas outlet 33 for discharging reactive gas around it, and an exhaust port 35 connected to an exhaust device on its outer periphery. The outer peripheral portion 36 is arranged close to the surface of the substrate 23, avoiding the region facing the target 25.

34 is an earth shield for limiting the four reactive gases and the discharge area.

Now, the operation of the sputtering apparatus having such a structure will be explained below.
An example of forming an intermediate oxide film consisting of a 0.04 film will be described.

First, the inside of the vacuum container 21 is evacuated to a vacuum level of I X 1O-6 Torr or less, and then a mixed gas of an inert gas such as 02 and a reactive gas such as 02 is introduced through the mixed gas introduction pipe 30 at a pressure of 5 X 1O-3 Torr. Introduce the gas so that the gas pressure is at about the same level. At this time, a suitable mixing ratio of the meter gas and the 02 gas is approximately 4:l in terms of flow rate ratio.

In this state, the substrate 23 is rotated and the target 2
5 and the substrate support 22 from the high frequency power source 37, and the shutter 27 on the target 25.
Open to start glow discharge.

The reactive gas is turned into plasma by this discharge, and sputters the target 25 while reacting on the surface of the target 25. At this time, if sputtering is performed under sputtering conditions in which the emission peak of Fe does not appear in the emission spectrum of the plasma, the oxidation reaction with the reactive gas consisting of 02 becomes strong, and the surface of the substrate 23 is coated with an α-Fe203 film. will be formed.

Therefore, in order to form a Fe304 film with an intermediate oxidation degree lower than the oxidation degree of the α-Fe203 film, it is necessary to adjust the gas atmosphere pressure and high frequency to such an extent that the Fe emission peak appears in the plasma emission spectrum. F is applied to the surface of the substrate 23 by sputtering under controlled conditions such as electric power.
A Fe304 film mixed with e molecules is deposited.

Next, when the Fe304 film in this state is moved to a position facing the discharge electrode 32 of the gas reaction promotion mechanism 31 by rotation of the substrate support 22, the discharge electrode 32 is applied with a predetermined voltage from the discharge power supply 38. A discharge occurs between 32 and 32.

At this time, between the discharge electrode 32 and the substrate 23, an amount of reactive gas consisting of 02 flowing out from the reactive gas outlet 33,
The amount of exhaust gas exhausted from the exhaust port 35 on the outer periphery is appropriately controlled, and the gas pressure is as high as 500 mTorr, for example.
The reactive gas, that is, the 02 gas, is turned into plasma, and the activated 02 gas contacts the Fe004 film on the substrate 23 in which unoxidized Fe molecules are mixed. Then, it undergoes an oxidation reaction with the unoxidized Fe molecules to form Fe304.

In this case, by heating the substrate 23 to about 200° C., the above-mentioned oxidation reaction is promoted more smoothly.

In this way, by alternately repeating the process of sputtering the Fe304 film containing Fe molecules and the process of oxidizing the unoxidized Fe molecules mixed in the Fe304 film into Fe304, unoxidized Fe It has now become possible to easily form a homogeneous intermediate oxide film made of Fe304 without any mixture of molecules.

The reason why the gas atmosphere pressure of the reactive gas consisting of 02 is kept relatively high between the discharge electrode 32 and the substrate 23 is as follows.
■When the gas atmosphere pressure is high (the probability of collision between 02 molecules in the 02 gas increases, and the energy possessed by the 02 molecules decreases).■Fe containing unoxidized Fe molecules of the substrate 23
By lowering the energy of the 02 molecules colliding with the 304 film, it becomes easier to obtain a Fe304 film with an intermediate oxidation degree, and when the energy of the 02 molecules is lower, the discharge electrode 32
This is based on the fact that the substance is no longer sputtered.

In addition, if a planar magnetron system is used in which a permanent magnet or an electromagnet is placed in the target support directly under the target in this example, the reaction of the reactive gas consisting of 02 on the target surface will not occur during reactive sputtering. Since Fe molecules with a low oxidation degree and Fe molecules that undergo no oxidation reaction are sputtered uniformly, it is extremely effective for forming a Fe304 film with an intermediate oxidation degree, and it is possible to sputter homogeneous Fe304 at a higher speed. can be formed into

〔Effect of the invention〕

As is clear from the above description, according to the sputtering apparatus according to the present invention, the reaction of the reactive gas to the sputtering material during reactive sputtering can be controlled at three locations: on the target side and on the substrate side. Therefore, it has the excellent advantage of making it possible to easily form intermediate reactants such as Fe304 films with intermediate oxidation degrees, which were previously considered difficult, and forming r -Fe203 magnetic films for magnetic recording media. It is extremely advantageous when applied to the formation of the Fe304 film that is the basis for the process, and produces remarkable effects.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an embodiment of a sputtering apparatus according to the present invention, and FIG. 2 is a sectional view of a main part of a conventional sputtering apparatus. In FIG. 1, a second-generation vacuum vessel, 22 a base 1 anti-support, 23 a substrate, and 24
25 is a rotation mechanism, 25 is a target, 26 is a target support, 31 is a gas reaction promotion mechanism, 32 is a discharge electrode, 33 is a reactive gas outlet, 34 is an earth shield, 35 is an exhaust port, and 36 is an outer enclosure. Each is shown below. Figure 1 guχA [4> So9! TtEI Month'1 Shirai (Dozevut d)
Force'/] Figure 2

Claims (1)

[Claims] A target (25) and a substrate (23) are placed in a vacuum container (21).
) are arranged facing each other, and an electric discharge is generated in the container (21) in which a mixed gas atmosphere of an inert gas and a reactive gas is created.
In an apparatus configuration in which a sputtering material is deposited on the surface of the rotating substrate (23) by sputtering, the surface of the substrate (23) is coated with a sputtering material in an area that avoids the area where the rotating substrate (23) and the target (25) face each other. A gas reaction promoting mechanism ( 31)
A sputtering apparatus characterized in that the sputtering material deposited on the surface of the substrate (23) is further reacted with a reactive gas by a gas reaction promotion mechanism (31).