JPH08209351A - Plasma cvd device - Google Patents

Abstract

PURPOSE: To collectively form a film on a large-area substrate which is difficult to form by the conventional electron beam utilizing device. CONSTITUTION: This device consists of a plasma producing container 2 for ionizing a neutral gas to produce plasma, electrodes 6 and 7 for drawing out electron from the plasma as an electron beam, a substrate 12 into which the electron beam is made incident and a vacuum container 13. A permanent magnet 3 is provided in a plasma producing chamber so that the magnetic poles are changed alternately on the outer periphery or inner periphery of the plasma producing container 2. A film forming gas on the substrate surface is decomposed by the electron beam drawn out of the plasma producing camber, and a film is formed on the substrate surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma CVD apparatus for forming a film on the surface of a substrate.

[0002]

2. Description of the Related Art In a conventional film forming apparatus using an electron beam, the intensity and uniformity of the electron beam are not sufficient, and it is difficult to form a film uniformly on a substrate having a diameter of 6 inches or 8 inches.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to generate a uniform and high-density electron beam over a large area and irradiate the substrate with the electron beam while supplying a film-forming gas onto the substrate. Then, the object is to provide an apparatus for decomposing a gas for film formation on the surface of a large-area substrate to form a film.

[0004]

In order to obtain a uniform and high-density electron beam over a large area, plasma is confined by a multicusp magnetic field of many permanent magnets, and the electron beam is extracted from the plasma through a plurality of extraction electrode holes. The surface of the substrate to which the gas for film was supplied was irradiated.

[0005]

[Function] After plasma is confined by a multicusp magnetic field formed by a large number of permanent magnets to generate plasma of a uniform density in a large area, electrons are extracted from this plasma by a porous extraction electrode, thereby making it possible to spread the electrons over a large area. An electron beam output with the same current density can be obtained. The film forming gas is decomposed by this electron beam, and the decomposition product of the film forming gas is deposited on the heated substrate surface.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. The cathode 1 is made of a hairpin-shaped tungsten filament and emits thermoelectrons. The plasma generation container 2 forming the plasma generation chamber also serves as an anode electrode that causes arc discharge with the cathode 1. A large number of permanent magnets 3 are provided on the outer periphery of the plasma generation container 2 so that the magnetic poles alternate on the surface of the plasma generation container 2. The plasma generation container 2 has, for example, an inner diameter of 300 m.
32 columns of permanent magnets 3 magnetized in the height direction with a width of 8 mm, a height of 25 mm, and a length of 200 mm, which are made of stainless steel and have an outer diameter of 308 mm and a depth of 200 mm, are arranged on a cylinder to hold the cathode 1. On the surface, the width and height are the same and the length is 280 mm,
270 mm, 240 mm, 190 mm, and 100 mm, two types of permanent magnets, each with two magnetic poles facing the plasma generation chamber, and the polarities of adjacent magnets are 30 mm apart so that the N and S poles alternate. It is provided at intervals. Permanent magnet 3
The remanent magnetization of each used the cobalt samarium magnet of 8500 gauss. Cathode 1 and plasma generation container 2
A DC voltage is applied between the electrodes, and the hydrogen gas introduced from the gas inlet 20 is ionized by arc discharge at a low pressure to extract electrons as an electron beam, and each is an accelerating electrode having a large number of holes. 6 and the deceleration electrode 7. Further, the vacuum container 13 together with the substrate 12
And is evacuated by the vacuum pump 14. Board 12
A ring 21 in which 36 small holes each having a diameter of 100 μm were opened at equal intervals around the circumference of was circulated around, and a gas for film formation was supplied. Ring 2
For No. 1, a tube made of oxygen-free copper having an outer diameter of 6 mm was processed into a donut shape having a diameter of 300 mm and used. The substrate holder 10 is equipped with a heater so that it can be heated. The electron beam is accelerated by the electric field between the acceleration electrode 6 and the deceleration electrode 7, and decomposes the gas for film formation supplied from the ring 21. As the gas for film formation, hydrides, chlorides, and fluorides of semiconductors and metals such as silane are used.

A negative high voltage is applied to the acceleration electrode 6 from the acceleration power source 8 and the deceleration electrode 7 is grounded, or the deceleration power source 9 is applied.
A more positive voltage is applied to prevent positive ions from flowing back to the plasma generation chamber side. In this embodiment, maintenance such as cleaning of the plasma generation chamber is easy.

Although the permanent magnet 3 is provided outside the plasma generating container 2 (atmospheric pressure side) in the embodiment of FIG. 1, it is also possible to dispose the permanent magnet inside the plasma generating container 2 (vacuum side). Is. At this time, a magnetic material can also be used as the plasma generation container. By providing the permanent magnet in the plasma generating container, the strength of the plasma confining magnetic field can be increased, and there is an effect that discharge can be performed at a lower gas pressure. Further, by using a magnetic material for the plasma generating container, there is an effect that the height of the permanent magnet can be reduced to 50% in FIG.

Further, instead of the tungsten filament of the cathode 1, it is also possible to introduce plasma ionized by microwaves or high frequencies, and removing the high temperature filament has the effect of increasing the continuous operation time.

[0010]

According to the present invention, it becomes possible to collectively form a film on a large-area substrate of 6 inches or 8 inches or more, which has been difficult with the conventional electron beam utilizing apparatus.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Cathode, 2 ... Plasma generating container, 3 ... Permanent magnet,
6 ... Acceleration electrode, 7 ... Deceleration electrode, 8 ... Acceleration power supply, 9 ... Deceleration power supply, 10 ... Substrate holder, 12 ... Substrate, 13 ... Vacuum container, 14 ... Vacuum pump, 20 ... Gas inlet port, 21 ... Annular ring.

Claims (1)

[Claims] 1. An electron beam apparatus comprising a plasma generation container for ionizing a neutral gas to generate plasma, an extraction electrode for extracting electrons from the plasma as an electron beam, a substrate on which the electron beam is incident, and a vacuum container. A means for supplying a film-forming gas onto the substrate and a permanent magnet on the outer or inner circumference of the plasma generation container so that the magnetic poles are alternately changed, and an electron beam is taken out from the plasma generation container to remove the substrate. Plasma CVD equipment characterized by irradiation.