JPH042773A - High speed film forming sputtering apparatus - Google Patents

Abstract

PURPOSE:To carry out high speed film formation with a compact apparatus when a base plate is disposed in the sideward space of a pair of polygonal targets by arranging the plural pairs of targets side by side and providing specified magnets. CONSTITUTION:A cooling roll 18 is disposed sidewards in the plasma space parts 13-15 of the polygonal target provided with permanent magnets on the rear surfaces in a vacuum vessel 1, and the base plate 16 is transferred along the cooling roll. In the figure, three pairs of polygonal targets 2,2a-4,4a are confronted with each space part 13-15 between, and the permanent magnets 8-11 are disposed between adjacent targets. The pole of magnet is directed to the target, and the magnetic lines B of force perpendicular to the surface of target to be sputtered as shown with arrow are formed. The inside of the vessel 1 is evacuated, sputtering gas is introduced, voltage is impressed making the target as cathode to form the magnetic lines B of force, and the plasma is formed which is made of atoms, etc., flying out of the sputtered target. These atoms, etc., are deposited on the base plate 16, and the film 17 is formed in high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a sputtering apparatus for forming a functional thin film on the surface of a plastic film, paper, steel plate, etc.

(Prior Art) FIGS. 3 to 5 are conceptual diagrams of a facing target type sputtering apparatus described in Japanese Patent Application Laid-Open No. 60-46369, and FIG. 3 is a perspective view showing the arrangement of targets and substrates. FIG. 4 is a cross-sectional view of the entire facing target sputtering apparatus, and FIG. 5 is a plan view taken along the arrow ^-A in FIG. 4.

In FIG. 3, on the sides of the space of a pair of rectangular targets 21.21a held by a holder 22.22a,
Cooling rolls 20 are arranged in parallel, and a continuous tape-shaped substrate 19 wound around the cooling roll 2o is transferred while a film is formed on the substrate 19 by a plasma flow from the space.

In FIG. 4, the target 22.22a held by a holder 22.22a is a rectangular target made of a ferromagnetic material in the shape of a rectangular plate facing each other with a space 23 in between. A shield ring 24.24a is provided outside the periphery of the sputtering surface 25°25a with a slight distance therebetween, and the shield ring 242
4a is the target holder 22.22a and the insulator 2
It is insulated and grounded by 6°26a. The shield chip 27.27a shown in FIG.
Shield ring 24.24a provided around the periphery of ゜21a
They are arranged at appropriate intervals at six locations approximately in the center of the screen, and are opposed to each other so as to protrude upward. The rolled chip 27.27a is grounded via a shield ring 24.24a. In addition, there is a permanent magnet 2 on the back of 21.21a.
828a are disposed and are arranged opposite to each other so as to generate a magnetic field perpendicular to the sputtering surface 25.25a of the square targetera 21.21a. The vacuum chamber 29 surrounds the rectangular targets 2], 21a, and the space 23.

To explain the procedure for film formation using the apparatus shown in FIG. 4, first, the inside of the vacuum chamber 29 is evacuated, a sputtering gas such as argon is introduced, and then a voltage is applied so that the rectangular target 21° 21a serves as a cathode. , grounded shield ring 2
4.24a, generate a glow discharge between the permanent magnet 2
8.28a in a direction perpendicular to the rectangular target 2424a, a plasma state is formed in the space 23 in which metal atoms of the rectangular target 21.21a, secondary electrons, argon gas ions, etc. are scattered. A seal knob 27.2 protruding into the space 23
7a absorbs secondary electrons in the plasma space and controls the ionization of argon gas to make the plasma density uniform. The metal atoms in the plasma space thus homogenized repeatedly collide and lose energy while being diffused and adhere to the substrate 19 on the side of the space 23 to form a film.

(Problem to be Solved by the Invention) The above-mentioned facing target type sputtering device has a higher thin film formation speed than a bipolar sputtering device, a magnetic sputtering device, a tarring device, etc., but it is a vacuum evaporation device that is widely used in industry. The thin film formation rate is less than one-tenth that of the previous method.

This is because there are restrictions on the plasma density in the plasma space for maintaining stable glow discharge. In the example shown in FIG. 4 above, the plasma density is improved by applying a magnetic field perpendicular to the sputtering surface.
Since the structure uses a pair of rectangular targets, the thin film formation speed on the substrate is insufficient. It is also conceivable to install a plurality of the above sputtering apparatuses, but there is a problem that the entire apparatus becomes large and expensive.

Therefore, the present invention aims to solve the above-mentioned problems and provide a compact and inexpensive high-speed film forming sputtering apparatus.

(Means for Solving the Problems) The present invention provides a high-speed film-forming sputtering apparatus in which the sputtering surfaces of a pair of rectangular targets serving as cathodes are opposed to each other, and a substrate is placed on the side of a plasma space between the sputtering surfaces. , a high-speed film-forming sputtering apparatus characterized in that a plurality of the above-mentioned pairs of rectangular targets are installed side by side, and magnets are arranged on the back surfaces of adjacent pairs of rectangular targets so as to apply a magnetic field substantially perpendicular to the target surfaces. .

(Function) The principle of electric discharge of opposing targets according to the present invention is that by arranging both poles of permanent magnets on the back surfaces of a pair of targets, lines of magnetic force are formed to perpendicularly penetrate the sputtering surfaces of multiple targets. Ru. Then, a DC or RF high voltage is applied using the target as a cathode to generate a discharge between the targets, ionizing the gas between the targets and generating plasma. According to Faraday's law, electrons around the magnetic field lines perpendicular to the target start a spiral motion and collide with other atoms, promoting ionization.
The plasma density is increased, the ionization region becomes wider, and the thin film formation rate can be increased. In addition, while conventional facing target sputtering equipment places a permanent magnet for each target, in the present invention, one permanent magnet provided on the back side of the target acts on two adjacent targets. The number of permanent magnets used can be significantly reduced, multiple pairs of targets can be easily incorporated into a vacuum chamber with limited volume, and films can be formed simultaneously using multiple pairs of targets. , the thin film formation rate can be dramatically increased.

(Example) FIG. 1 is a conceptual diagram showing a cross-section of a high-speed film-forming sputtering apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of FIG. 1.

A cooling roll 18 is placed in the vacuum chamber 1 on the side of the plasma space +3.14.15 of a rectangular target equipped with a permanent magnet on the back, and the substrate 1 is transferred along the cooling roll.
A formation M17 is formed on 6. In the figure, three sets of rectangular targets 2.2a, 3.3a, 4, 4a are held from the back with holders 5, 5a, 6, 6a, 7, 7a (see Figure 2), and a space 13, 14, 15. Permanent magnets 8, 9, .
By directing the magnet pole toward the target as shown in the figure, lines of magnetic force B perpendicular to the sputtering surface of the target are formed as shown by the arrows.

Note that the permanent magnets may be provided at the front and rear ends of the target y) facing the substrate 16, or may be provided on the entire back surface of the target throat. In the apparatus shown in the drawings, in order to form a plasma space toward the substrate 16 on the cooling roll 18, both ends of the square target holder and the permanent magnet are held by arc-shaped mounts 12.12a. For substrates to be transferred on a flat surface, rectangular targets may be arranged substantially parallel.

Next, the film-forming step and tumbling operation using this apparatus will be explained. First, a predetermined target is attached to the holder. After evacuating the inside of the vacuum chamber 1, a gas such as argon is introduced, and a voltage is applied using the rectangular target y) as a cathode to form magnetic lines of force B perpendicular to the sputtering surface. A plasma containing ejected atoms, secondary electrons, argon gas ions, etc. is formed. Atoms of the target material in the plasma space repeatedly collide with electrons γ, etc. spirally moving around the magnetic field lines B, and thus diffuse while losing energy, expanding the ionization region β, and moving at high speed to the substrate 16 on the side of the space. A film 17 is formed by adhering to the surface. In the device shown, the square target 7)
Atoms of square target 3.3a adhere to the film formed by atoms of 2,2a, and then atoms of square target 4,4a adhere, increasing the thickness of the film. I'm going to go. When three pairs of rectangular target materials are the same, it is possible to obtain a deposition rate three times as high as when using one pair. Also,
When using different rectangular target materials, a film with a different composition ratio than the target can be obtained.

Note that the number of sets of opposing square targets to be used is not limited to the above three sets, but is selected depending on the purpose.

(Effects of the Invention) By employing the above configuration, the present invention allows a plurality of pairs of opposing targets to be easily incorporated into a vacuum chamber with a limited volume, and a substrate that is transferred on a relatively small cooling roll. The plasma space can also be made to face the plasma space, making it possible to configure the apparatus compactly as a whole. In addition, since the plasma density can also be increased,
High-speed film formation capability can be easily ensured.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram showing a cross section of a high-speed film-forming sputtering apparatus that is an embodiment of the present invention, FIG. 2 is a perspective view of FIG. 1, and FIG. FIG. 4 is a cross-sectional view of the entire conventional facing target type sputtering apparatus, and FIG.
FIG. Figure 2 Figure 3

Claims (1)

[Claims] In a high-speed film-forming sputtering apparatus in which the sputtering surfaces of a pair of rectangular targets serving as cathodes are opposed to each other and a substrate is placed on the side of the plasma space between the sputtering surfaces, a plurality of pairs of the above-mentioned rectangular targets are installed side by side and adjacent A high-speed film-forming sputtering apparatus characterized in that a magnet is arranged on the back side of a set of rectangular targets so as to apply a magnetic field substantially perpendicular to the target surface.