JPH0192374A - Thin film-manufacturing equipment - Google Patents

Abstract

PURPOSE:To prevent deterioration in mu-wave introduction efficiency due to film adhesion by forming a microwave guide into a coaxial line structure and short-circuiting the internal conductor and the external conductor of the coaxial line so as to generate a magnetic field in a vacuum vessel. CONSTITUTION:A base 4 containing a heater 3 is provided inside a plasma chamber 2 in a vacuum vessel 1, and an image-formed substrate 5 is placed on the base 4. Subsequently, the inside of the plasma chamber 2 is evacuated and the substrate 5 is heated by means of the heater 3, and then, a gaseous material is introduced via a gas inlet 6 and microwaves are introduced via a waveguide 7 and the gaseous material is formed into plasmic state and allowed to deposit on the substrate 5, by which a thin film is formed. At this time, the waveguide 7 is formed into a coaxial line 13 structure and short-circuit is applied between the internal conductor 16 and the external conductor 17 of the above coaxial line 13 by means of a coil 14 so as to generate a magnetic field in the vacuum vessel 1. By this method, microwaves are introduced by means of a magnetic field formed by a microwave current flowing through the short-circuit part in a direction orthogonal to the magnetic field and the introduced gaseous material is formed into a plasmic state, by which microwave introduction efficiency can be excellently maintained.

Description

[Detailed Description of the Invention] [Summary] Regarding a thin film manufacturing apparatus using the plasma CVD method, a coil is used in the part where microwaves (hereinafter referred to as μ waves) are introduced into the plasma chamber, so that the μ waves can be introduced even if the film is attached. In order to avoid affecting efficiency, the material gas introduced into the vacuum container that holds the substrate to be imaged is turned into plasma by microwaves introduced into the vacuum container via a waveguide. , a thin film manufacturing apparatus for forming a thin film by depositing it on the substrate, wherein the waveguide has a coaxial line structure, and between an inner conductor and an outer conductor of the coaxial line,
A short circuit is formed through the vacuum container so as to generate a magnetic field within the vacuum container.

[Industrial Application Field] - The present invention relates to a thin film manufacturing apparatus using plasma CVD method. - In the microwave CVD method, which uses microwaves as an excitation source to decompose a source gas and deposit a thin film on a substrate, a quartz tube or a quartz window is generally used in the part where microwaves are introduced into a vacuum.

However, the raw material gas introduced into a vacuum is excited by the introduction of microwaves, and the generated plasma adheres to the quartz tube and quartz window other than the substrate, causing absorption and reflection of microwaves. Therefore, there is a need for a device that does not reduce the efficiency of introduction into the vacuum.

[Prior Art] FIGS. 2(a) and 2(b) show a conventional microwave CVD apparatus.

In FIG. 2(a), in a plasma chamber 2 within a vacuum container 1, there is a table 4 having a built-in heater 3, and a substrate 5 is placed on the table 4. The plasma chamber 2 is evacuated by a pump, and the heater 3
The substrate 5 is heated.

A silane-based gas is flowed from a gas port 6 into a quartz tube 9 in a cylindrical cavity 8 in contact with a waveguide 7, and a μ wave is discharged to turn the gas into plasma, thereby depositing amorphous silicon on a substrate 5. At this time, the movable shunt 10 is moved to match the μ waves and adjust so that the μ waves are efficiently sent into the quartz tube 9.

FIG. 2(b) shows a device in which the way of inputting μ waves is slightly different. The difference from FIG. 2(a) is that in order to introduce μ waves directly into the plasma chamber 2 from the waveguide 7, the vacuum vessel 1 is
Electromagnet 1 is connected to the
2 are provided. The rest is the same as in Figure 2 (a), ■
3 is a vacuum container, 3 is a heater, 4 is a stand, 5 is a substrate, and 6 is a gas inlet. Silane-based gas is introduced into the vacuum container 1, and amorphous silicon is deposited on the substrate 5 in the same manner as described above.

[Problem that the invention seeks to solve]

In a conventional μ-wave CVD apparatus, a quartz tube 9 and a quartz window 11 are used in the part where μ-waves are introduced into the vacuum vessel 1, as shown in FIGS. 2(a) and 2(b). Ta. This part must pass μ-waves well without loss, have high heat resistance, and be able to maintain a vacuum, so quartz is used as the most excellent material. However, as the thin film is deposited on the substrate 5, the film also adheres to the quartz part, so the μ-waves are absorbed or reflected in this part, and the efficiency of introducing the μ-waves decreases. It was not introduced at all. For this reason, the film forming time per cycle is limited, making it unsuitable for depositing relatively thick films, and requiring frequent cleaning or replacement of the quartz portion.

Therefore, an object of the present invention is to prevent the introduction efficiency of μ-waves from being affected even if a film is attached to the portion where μ-waves are introduced into the plasma chamber.

[Means for solving problems]

The problem is that, as shown in FIGS. 1(a) and 1(b), the material gas introduced into the vacuum container 1 holding the substrate 5 to be imaged is transferred through the waveguide 7 to the vacuum container 1. This is a thin film manufacturing apparatus that forms a plasma by microwaves introduced into the substrate and deposits it on the substrate 5 to form a thin film, wherein the waveguide 7 has a coaxial line 13 structure and is short-circuited through the coaxial line. This problem is solved by the thin film manufacturing apparatus of the invention.

[Function] That is, the inner conductor 16 and outer conductor 17 of the coaxial line 13 are connected to the vacuum chamber so that the part that guides μ waves to the plasma chamber 2 in the vacuum chamber 1 generates a magnetic field within the vacuum chamber. Since it is short-circuited through the inside of y, the magnetic field caused by the μ-wave current flowing through the short-circuited portion introduces μ-waves in a direction perpendicular to the magnetic field, and the introduced material gas becomes a plasma state.

In this way, in the present invention, the μ-waves are introduced by the action of the magnetic field, so even if there is film adhesion to the short-circuited portion, the μ-wave current will flow through the short-circuited portion without being absorbed or reflected.
There is no equivalence issue.

〔Example〕

FIGS. 1(a) and 1(b) are diagrams illustrating an embodiment of the present invention. Note that the same reference numerals indicate the same objects throughout the figures.

FIG. 1(a) shows a μ-wave CVD apparatus according to the present invention, and FIG. 1(b) shows details of the coil portion of FIG. 1(a). In FIG. 1(b), the part where μ waves are introduced into the plasma chamber 2 in the vacuum vessel 1 is configured such that the end of the coaxial line 13 is short-circuited with a coil 14 so that a magnetic field is generated within the vacuum vessel 7. There is. Due to the magnetic field caused by the μ wave current flowing through the coil 14, μ waves are generated in the plasma chamber 2 due to the electric field generated in the direction orthogonal to the magnetic field.
will be introduced in

The μ waves sent through the waveguide 7 are converted into a coaxial line mode and propagate through the coaxial line 13. The coil part is coaxial line 1
The inner conductor 16 and outer conductor 17 of No. 3 are short-circuited by a coil 14. Further, the space between the internal conductor 16 and the external conductor 17 is vacuum-sealed with an insulator 15. This insulator 15 is made of Teflon, which is a good dielectric material against μ waves.
Quartz, monument stone (porcelain), etc. are suitable, but quartz and monument stone are particularly good because of their excellent heat resistance.

・Title Also, as the material for the outer conductor 17, stainless steel is preferable since metal* is used.

In FIG. 1(a), there is a stand 4 containing a heater 3 in a plasma chamber 2 in a vacuum vessel 1, and a quartz glass substrate 5 is placed on it. The plasma chamber 2 is evacuated by a pump to a vacuum degree of 10 to 10 Torr), and the substrate 5 is heated by the heater 3. A silane-based gas, such as monosilane SiH4, was flowed from the gas port 6, and μ waves were introduced from the waveguide 7 to turn the gas into plasma and deposit amorphous silicon on the substrate 5. At this time, move the movable short circuit 10 to
One wave is matched and adjusted so that the μ-wave is efficiently sent to the plasma chamber 2.

When the film is formed using the conventional apparatus shown in Figure 2(b), the film thickness is 1~
Matching could no longer be achieved at 2 .mu.m, and no microwaves were introduced at 5 .mu.m, but in the apparatus of the present invention shown in FIG. 1(a), stable plasma was obtained even when a 10 .mu.m thick film was formed.

Note that in the method according to the present invention, the film also adheres to the insulator 15, but the inner conductor 16 and the outer conductor 17 are attached to the coil 14.
Since the magnetic field is short-circuited and the μ-waves are introduced by the magnetic field, there is less influence compared to conventional methods. Further, it is even better if the entire coil 14 is covered with an insulator, since no film is formed between the inner conductor 16 and the outer conductor 17.

In this embodiment, the coil 14 has one winding, but it may have a large number of windings, or may have a shape other than circular.In short, it must have a shape that can generate a magnetic field inside the vacuum chamber 2. It's good to have.

〔Effect of the invention〕

As explained above, according to the present invention, by using a coil in the part where μ waves are introduced into the plasma chamber, the μ wave introduction efficiency does not change depending on the film forming time, stable plasma can be obtained for a long time, and a thick film can be obtained. Even films can be formed continuously.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are diagrams for explaining an embodiment of the present invention, and FIGS. 2(a') and (b) are diagrams for explaining a conventional microwave CVD apparatus. In the figure, 1 is a vacuum vessel, 2 is a plasma chamber, 3 is a heater, 4 is a stand, 5 is a substrate, 6 is a gas inlet, 7 is a waveguide, 10 is a movable short circuit, 13 is a coaxial line, and 14 is a coil , 15 is an insulator, 16 is an internal conductor, (α

Claims (2)

[Claims] (1) Vacuum container (1) holding the substrate (5) to be imaged
) is made into a plasma by microwaves introduced into the vacuum container (1) through the waveguide (7), and is deposited on the substrate (5) to form a thin film. A manufacturing device comprising: connecting the waveguide (7) to a coaxial line (13);
) structure, and the inner conductor (16) and outer conductor (17) of the coaxial line (13) are short-circuited through the vacuum vessel (1) so as to generate a magnetic field within the vacuum vessel (1). A thin film manufacturing device characterized by: (2) The thin film manufacturing apparatus according to claim 1, wherein the coaxial line (13) is short-circuited between the inner conductor (16) and the outer conductor (17) by a coil.