KR910010168B1 - Amorphous thin film manufacturing device - Google Patents

Abstract

No content.

Description

Amorphous thin film forming apparatus

1 is a cross-sectional view of an apparatus showing one embodiment according to the present invention.

2 is a side cross-sectional view of a conventional apparatus.

* Explanation of symbols for the main parts of the drawings

1: reaction vessel 2 ₁ ~ 2 _n : electrode

4: low frequency power source 5: coil

6: AC power supply 7: Reaction gas introduction pipe

8: exhaust hole 9: vacuum pump

10: substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing amorphous thin films used in various electronic devices such as solar cells, fuel cells, thin film semiconductors, electrophotographic photosensitive members, and optical sensors.

FIG. 2 shows a conventional apparatus for manufacturing a semiconductor thin film, which is a known technique described in, for example, Japanese Patent Laid-Open No. 57-04771.

In the same figure, electrodes 02 and 03 for forming a discharge space in the hermetically sealed reaction vessel 01 are provided in the vertical direction, and the electrodes 02 and 03 are electrically connected to the high frequency power supply 04. Is connected. A coil 05 for generating a magnetic field parallel to the electric field direction in the discharge space is arranged horizontally on the outer circumference of the reaction vessel 01, and is electrically connected to the AC power supply 06. The exhaust hole 07 communicates with a vacuum pump (not shown), and the reaction gas inlet tube 08 communicates with a cylinder of monosilane (SiH ₄ ) and hydrogen gas (H ₂ ), respectively. In addition, (09) is a heater for heating the board | substrate 10. As shown in FIG.

By the way, the substrate 10 is placed on the electrode 02, the pressure inside the reaction vessel 01 is reduced to about 1 mmHg, and then the mixed gas of monosilane and hydrogen gas is discharged from the reaction gas introduction pipe 08. While supplying into the reaction vessel 01, a high frequency voltage of 13.5 MΩ is applied between the electrodes 02 and 03.

On the other hand, a commercial AC voltage of 50 or 60 mA is applied to the coil 05 to generate a magnetic field of about 100 gauss between the electrodes 02 and 03. In addition, the board | substrate 10 is heated to about 300 degreeC by the heater 09.

Gases such as monosilane introduced into the reaction vessel 01 from the reaction gas introduction pipe 08 are decomposed in the discharge space between the electrodes 02 and 03 and subjected to the fluctuating magnetic field generated by the coil 05. While agitated, it is attached to the surface of the substrate 10 to form an amorphous thin film.

In the above-described conventional apparatus, since the variable magnetic field generated in the coil 05 is applied in parallel with the direction of the electric field generated between the two electrodes 02 and 03, the discharge space between the electrodes 02 and 03 is applied. Ions such as silicon present in the agitation are stirred to form a relatively uniform amorphous thin film on the substrate 10.

But,

The place where the substrate 10 is placed is on the electrode 02 and is located in the discharge space between the electrodes 02 and 03. Because of this, ions with high energy basically collide directly with the substrate.

That is, a coulomb force (F ₁ = q E) acts on the ions of the charge q by the electric field E between the electrodes 02 and 03, and the ion particles collide directly with the substrate 10. It damages the amorphous thin film being formed.

(2) Since the direction of the variable magnetic field (B) generated by the coil (05) is parallel to the electric field (E) generated in the discharge space, the ions and electrons in the discharge space are rotated by the lamor motion. However, the stirring action by the swinging movement is too large, requiring very large electric power.

(3) Since the substrate is arranged between the electrodes, the shape of the substrate is limited to the parallel plate shape.

In the apparatus of the present invention, a reaction vessel, means for introducing the reaction gas into the reaction vessel by depressurizing the reaction vessel, a plurality of discharge electrodes disposed radially in the reaction vessel, and the discharge electrode are adjacent to each other. A coil having a power supply for supplying a glow discharge voltage between the ones, an axial center containing a plurality of discharge electrodes, and generating a magnetic field in a direction orthogonal to an electric field generated between the discharge electrodes; An amorphous power supply was formed on the surface of a substrate having an alternating current power supply for supplying a current for generating magnetic fields to the coil, and facing the end face of the discharge electrode.

In this invention, the electrode which generate | occur | produces a glow discharge plasma was arrange | positioned radially in the reaction container. In addition, a magnetic field was generated in a direction orthogonal to the electric field for discharge generated between these adjacent ones.

The charged particles drift in the direction orthogonal to the electric field in the form of giving the initial velocity to the klong force imparted from the discharge electric field and the loorent force imparted by the magnetic field. Fly while drawing the Lamor Armored Orbit by cyclotron motion.

On the other hand, the electrically neutral radical particles try to go straight from the orbit of the charged particle group, but collide with the charged particles (especially ions) to correct the course. In addition, since this magnetic field is fluctuating, radical particles scatter uniformly. Therefore, a uniform amorphous thin film is formed on the surface of the substrate toward the end face of the discharge electrode.

Hereinafter, the present invention will be described by the apparatus of one embodiment shown in FIG.

(1) is a reaction vessel, in which electrodes 2 ₁ to 2 _n for generating a glow discharge plasma are arranged radially. Reference numeral 4 denotes a low frequency power supply, and may be a direct current or a high frequency power supply, and is alternately connected to the electrodes 2 ₁ to 2 _n using, for example, a commercial frequency of 60 Hz. The coil 5 surrounds the reaction vessel 1 and is connected to an AC power source 6. Reference numeral (7) is a reaction gas introduction pipe, which communicates with a bomb (not shown) to supply a mixed gas of monosilane and argon to the reaction vessel (1). The exhaust hole 8 communicates with the vacuum pump 9 and exhausts the gas in the reaction vessel 1.

By the way, in the interior of the cylinder for forming the electrode _{(2 1) ~ (2 n} ) , as shown the substrate 10 is a cylindrical shape, that is, the distance is substantially toward the end surface of the electrode _{(2 1) ~ (2 n} ) Equally deter by appropriate means. After driving the vacuum pump 9 to evacuate the reaction vessel 1, the mixed gas of monosilane and argon is supplied from the reaction gas introduction pipe 7. Filling the mixed gas into the reaction vessel (1) to maintain a pressure of 0.05 to 0.5 Torr, so that a glow discharge plasma is generated between the low-frequency power source (4) between the adjacent of the electrode (2 ₁ ) to (2 _n ) Apply voltage.

On the other hand, for example, an alternating voltage of 100 kV is applied to the coil 5, and the direction orthogonal to the electric field E generated between the electrodes 2 ₁ to 2 _n (here, in the plane of FIG. Magnetic field B in a direction perpendicular to the direction of the magnetic field B. The magnetic flux density may be about 10 gauss.

The monosilane gas in the gas supplied from the reaction gas introducing pipe 7 is decomposed into radical Si by a glow discharge plasma generated between the electrodes 2 ₁ to 2 _n , and adheres to the surface of the substrate 10. To form a thin film.

At this time, charged particles such as argon ions have a clock force (F ₁ = qE) and a Lorentz force [F ₂ = q (V × B)] caused by an electric field (E) between the electrodes 2 ₁ to 2 _n . Causes a so-called E × B drift movement. In addition, V is the speed of charged particles. That is, the charged particles fly in the direction orthogonal to the electrodes 2 ₁ to 2 _n in the form of the initial velocity given by E × B drift, and fly toward the substrate 10. However, the outer surface of the discharge space where the influence of the electric field generated between the electrodes 2 ₁ to 2 _n is small, the reamer track is drawn by the cyclotron motion caused by the magnetic field B generated by the coil 5. Fly away.

Therefore, charged particles such as argon ions do not directly collide with the substrate 10.

On the other hand, the electrically neutral radical Si reaches the substrate 10 from the trajectory of the charged particle group without being affected by the magnetic field B, and forms an amorphous thin film on the surface thereof. At this time, since the radical Si collides with the charged particles flying through the lamor orbit, an amorphous thin film is formed on the surface of the substrate 10 arranged toward the end faces of the electrodes 2 ₁ to 2 _n .

In addition, since the magnetic field B is varied and the distance to the electrode end surface is substantially the same, the amorphous thin film can be uniformly formed on the surface of the substrate 10.

In addition, the length of the electrodes 2 ₁ to 2 _n does not cause any problem even if the length of the reaction vessel 1 is allowed to be as long as possible, so that even a long cylindrical substrate 10 has a uniform amorphous surface. It becomes possible to form a thin film.

Further, although not shown, it may be disposed a substrate 10 having a cylindrical shape so as to pose the electrode _{(2 1) ~ (2 n} ). In this way, it is also possible to form an amorphous thin film on the inner surface of the substrate.

In addition, in the above embodiment, the coil 5 is disposed outside the reaction vessel 1, but this may be arranged in the reaction vessel 1, and the curved surface constituting the cross section of the electrode is not limited to a cylindrical shape, or a portion thereof. It may be cotton.

Industrial Applicability According to the present invention, in the production of various devices such as solar cells, fuel cells, electrophotographic photosensitive members, an amorphous thin film can be uniformly formed on the surface of a substrate having a cylinder or a curved surface, which is very valuable industrially.

Claims (1)

A reaction vessel (1), a means (7) for introducing a reaction gas into the reaction vessel by depressurizing the inside of the reaction vessel, a discharge electrode (2 ₁ to 2 _n ) disposed in plural radially in the reaction vessel; And a power source 4 for supplying a glow discharge voltage between adjacent ones of the discharge electrodes and a plurality of discharge electrodes in a direction orthogonal to an electric field generated between the discharge electrodes. Amorphous on the surface of the substrate 10 having a coil 5 having an axial center for generating a magnetic field and an AC power supply 6 for supplying a current for generating a magnetic field to the coil, and arranged toward the end face of the discharge electrode. An amorphous film forming apparatus, characterized in that to form a thin film.