JPH04268073A - Plasma generator by pressure gradient type plasma gun - Google Patents

Abstract

PURPOSE:To provide the plasma generator by pressure gradient type plasma guns which can uniformly form films even if the plural plasma guns are provided. CONSTITUTION:This plasma generator is constituted of the plural pressure gradient type plasma guns (4) juxtaposed on the same plane and the long torus- shaped plasma converging coil (5) enclosing the entire part of the plasma (6) generated from these pressure gradient type plasma guns (4) and is so constituted as to apply the magnetic field of nearly the same intensity by this plasma converging coil (5) to the above-mentioned respective plasmas.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma generator using a pressure gradient type plasma gun.

0002

[Prior Art] Conventionally, a plasma generation device using a pressure gradient type plasma gun can prevent damage to the cathode due to ion backflow from the anode region, and can stably heat the cathode from the point of ignition of the discharge. Because the gas efficiency of the carrier gas for producing is good, it is used in plasma generation devices such as ion plating, sputtering, and plasma CVD.

[0003] In the plasma generating device, as disclosed in, for example, Japanese Patent Application Laid-open No. 103362/1982,
An annular plasma focusing coil is placed near the tip of the pressure gradient plasma gun, and the magnetic field of this coil restricts the outward spread of the generated plasma.

By the way, since the strength of the magnetic field appearing around a steady current is given by the Biot-Savart law,
As shown in FIG. 6, the magnetic field distribution by the plasma converging coil is maximum at the center, and the direction of the magnetic field is opposite between the inside and outside of the plasma converging coil.

[0005] Therefore, for example, Japanese Patent Application Laid-Open No. 63-473
As disclosed in Japanese Patent Application No. 62, in an apparatus in which a plurality of pressure gradient type plasma guns are arranged in a processing chamber and a substrate is formed by the plasma generated from each pressure gradient type plasma gun,
Each pressure gradient type plasma gun is provided with an annular plasma convergence coil, and the plasma generated from each pressure gradient type plasma gun is regulated by each plasma convergence coil.

[0006]

[Problems to be Solved by the Invention] However, in the plasma generator having the above configuration, it is not possible to generate completely equal magnetic fields even if the currents flowing through each plasma convergence coil are made to match, and it is difficult to generate a completely equal magnetic field. There is a problem in that the magnetic field between the coils becomes discontinuous and the plasma distribution becomes non-uniform, that is, the ionization and excitation of the deposit becomes non-uniform, making it impossible to form a film of uniform quality on the substrate.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma generation device using pressure gradient type plasma guns that can uniformize the plasma generated by a plurality of pressure gradient type plasma guns.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a plasma generation device including a plurality of pressure gradient type plasma guns arranged in parallel on the same plane, and generating plasma from the pressure gradient type plasma guns. It consists of an elongated annular plasma convergence coil that surrounds the entire plasma.

[0008]

Therefore, according to the present invention, a substantially uniform magnetic field is generated in the plasma convergence coil over a wide range, and the plasma generated from each pressure gradient type plasma gun is subjected to this uniform magnetic field.

[0009]

Embodiment Next, an embodiment of a plasma generating apparatus using a pressure gradient type plasma gun according to the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 shows a case where the present invention is applied to an ion plating apparatus. Reference numeral 1 denotes a substrate made of a strip, 2 a rectangular evaporation raw material hearth containing a deposit, and 3 a plasma generator according to the present invention, which is installed in a processing chamber (not shown).

The plasma generating device 3 includes three pressure gradient type plasma guns 4 and one plasma convergence coil 5. The pressure gradient type plasma guns 4 are conventionally known and are arranged in parallel on the same plane at predetermined intervals. On the other hand, as shown in FIG. 2, the plasma converging coil 5 has an elongated annular shape having parallel straight parts 5a, 5a facing each other, and the three pressure gradient type plasma guns 4 have the parallel straight parts 5a.
, 5a. A magnetic field based on the Biot-Savart law is formed in the plasma focusing coil 5.

Next, ion plating by the plasma generator 3 having the above-mentioned configuration will be explained. When the inside of the processing chamber housing the substrate 1 is kept under vacuum and a voltage is applied to the discharge cathode of each pressure gradient type plasma gun 4, cylindrical plasma is generated. This cylindrical plasma is
The sheet plasma 6 is expanded and contracted by an elongated permanent magnet (not shown) to have a desired width, thickness, and density. The sheet plasma 6 is prevented from spreading outward by the magnetic field of the plasma converging coil 5, and converges on the evaporation source hearth 2 to evaporate the deposit in the evaporation source hearth 2. At this time, the magnetic field generated in the plasma convergence coil 5 has the same strength in the space between the parallel straight parts 5a and 5b of the plasma convergence coil 5, as is clear from the Biot-Savart law mentioned above. be done. On the other hand, each pressure gradient type plasma gun 4 has a plasma convergence coil 5.
Since the sheet plasma 6 is located between the parallel straight portions 5a and 5b of the pressure gradient type plasma guns 4, the sheet plasma 6 from each pressure gradient type plasma gun 4 receives a magnetic field of the same strength and becomes uniformly distributed. The vapor of the deposit (metal, carbon, etc.) in the evaporation raw material hearth 2 is ionized or excited by the sheet plasma 6, and a strip-shaped substrate 1 is formed. In this way, each plasma generated from each pressure gradient type plasma gun 4 becomes a sheet plasma with a uniform distribution by being subjected to a magnetic field of approximately the same strength by the plasma converging coil 5, so that the vapor of the evaporated material The ionization or excitation of is uniform, and a uniform thin film can be formed on the substrate 1.

In the above embodiment, an apparatus for ion plating on a substrate 1 made of a strip using sheet plasma was described.As shown in FIG. Plasma may also be used. In addition, as shown in FIG. 4, a sputtering apparatus that performs sputtering by arranging a plate-shaped substrate 1a and a target 9 with a sheet plasma 6 in between, or as shown in FIG. It can be used in a plasma CVD device that decomposes and excites a reactive gas. 4 and 5, 8 is an anode, and 6 is an anode-side plasma convergence coil having the same shape as the plasma convergence coil 5.

By the way, the plasma convergence coil 5 is
Although it may be an elliptical ring shape, it is better to use an elliptical ring shape with parallel straight portions 5a as in the above embodiment, since it is possible to obtain a magnetic field of the same strength over a wide range, and the plasma distribution is more uniform. ing.

[0014]

Effects of the Invention As is clear from the above description, in the plasma generation device using a pressure gradient type plasma gun according to the present invention, the magnetic field generated by one long annular plasma converging coil can be used to generate a magnetic field from each pressure gradient type plasma gun. Since the generated plasma is regulated all at once, the plasma becomes uniform and seamless plasma is formed.
Evaporation, ionization, or excitation of the deposit can be performed uniformly, and a film can be uniformly formed on the substrate.

[0015] Furthermore, since only one plasma convergence coil is required, the power supply device can be simplified compared to the conventional one, and the mounting pitch of each pressure gradient type plasma gun can be reduced, which improves plasma uniformity. .

[Brief explanation of the drawing]

FIG. 1 is an ion plating apparatus to which a plasma generator is applied.

FIG. 2 is a front view of the plasma generator.

FIG. 3 is an ion plating apparatus equipped with a plurality of evaporation source hearths to which a plasma generator is applied.

FIG. 4 is a sputtering apparatus to which a plasma generator is applied.

[Figure 5] Plasma CV using a plasma generator
This is the D device.

FIG. 6 is a graph showing the magnetic field strength of a conventional annular plasma focusing coil.

[Explanation of symbols]

4... Pressure gradient type plasma gun, 5... Plasma convergence coil, 5a... Parallel straight section, 6... Plasma.

Claims (1)

[Claims] 1. A plasma generator comprising a plurality of pressure gradient type plasma guns arranged in parallel on the same plane, and an oblong annular plasma convergence coil that surrounds the entire plasma generated from the pressure gradient type plasma guns. A plasma generator using a pressure gradient type plasma gun.