JPS63283737A - Vacuum reactive vessel - Google Patents

Abstract

PURPOSE:To release impurities such as H2O adhered to an inner shell surface at high speed and enhance the membrane quality by subjecting wall of a reactive vessel of sputtering to double structure, forming a space between a inner shell and a outer shell and providing with a heating means on the inner shell in said space. CONSTITUTION:In case of preparing a membrane in a vacuum reactive vessel, a reactive space 13 and an insulated space 14 are vacuumized through a vacuum aspirating device after exposing once these spaces in a reactive vessel to the atmosphere and the reactive vessel inner shell 2 is heated by a baking heater 9. In that case, as the pressure of both spaces 13 and 14 is always same, it is not necessary to make the wall of inner shell 2 thick for enduring to vacuum, and the time required to raise the temperature required for the release of impurities such as H2O adhered to the inner shell inside surface is shortened to a large extent. Also, as he produced membrane on a substrate 5 by bean generator 4 and target 6 is prepared after releasing impurities, any impurities are not migrated to the membrane surface, and a high quality membrane can be prepared in a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vacuum reaction vessel, and particularly to the prevention of contamination inside the vessel due to adhesion of impurities such as water (H snow 0) inside the vessel to the inner wall surface of the vessel. The present invention relates to a vacuum reaction vessel suitable for reducing .

[Conventional technology]

2. Description of the Related Art Generally, various devices have been developed for forming a desired substance on a substrate or the like in a container maintained under reduced pressure.

FIG. 3 is a cross-sectional view showing an example of a sputtering apparatus for forming an Aj film on an 81 substrate by a sputtering method.

In FIG. 3, an electrode 22 for generating plasma is installed in a reaction vessel 21, and turns argon gas (Ar gas) supplied into the reaction vessel 21 from a gas supply nozzle 23 into plasma. A generated by this plasma formation
The r''' ions are accelerated toward the target 24 kept at a negative potential and collide with it to knock out Aj atoms from the target 24. These AN atoms are
The AI film is diffused into the inner space and attached onto the substrate 25 to form an AI film on the substrate 25. During such a sputtering operation, the inside of the reaction vessel 21 is evacuated by a vacuum evacuation device (not shown) through an exhaust port 26 provided at the bottom of the reaction vessel 21.
The pressure of the reaction vessel 21 is maintained at 1 Torr or less, and the degree of vacuum in the reaction vessel 21 is maintained more reliably by an O-ring 27.

In the above-described sputter fabrication, if impurities such as HIO are present in the reaction vessel 21, the AI deposited on the substrate 25 will be oxidized to Ajg03, and the conductivity of the /l thin film will decrease. In order to solve this problem, as shown in FIG. 3, the inner wall of the reaction vessel 21 is heated by a baking heater 28 before forming a thin film by sputtering.
An operation is performed to remove impurities such as HgO that have adhered to the inner wall of the tube.

[Problem that the invention seeks to solve]

However, since the first reaction vessel 21 has a wall thickness (approximately 10 fi) necessary to withstand a predetermined degree of vacuum, when the inner wall surface of the reaction vessel 21 is heated from the outside, for example, the inside of the reaction vessel 21 is heated by the outside air. When exposed to water, it takes about 24 to 48 hours to complete the predetermined elimination reaction.

Furthermore, when the baking heater 28 is attached to the inner surface of the reaction container 21, impurities, dust, etc. accumulate in the gap between this heater and the inner wall surface of the container, and these impurities and dirt are deposited on the AI formed on the substrate 25. This causes problems such as adhesion to the surface and impairing the smoothness of the thin film.

The purpose of the present invention is to solve the problems of the prior art described above,
It is an object of the present invention to provide a vacuum reaction vessel capable of rapidly removing impurities attached to the inner wall surface of the vacuum reaction vessel and performing rapid film forming operations.

[Means for solving problems]

The above object is achieved by forming the reaction vessel into a double structure in which a space is formed between the inner wall of the reaction vessel and the outer wall of the reaction vessel, and by providing means for heating the inner wall of the reaction vessel within the space.

[Effect]

Both the inside of the reaction vessel inner wall and the space formed between the reaction vessel inner wall and the reaction vessel outer wall can be depressurized,
The inner wall of the reaction vessel does not need to be thick enough to withstand vacuum. Therefore, when heating from the outer peripheral side of the inner wall of the reaction vessel to remove impurities attached to the inner wall of the reaction vessel, the inner wall of the reaction vessel has a thin wall thickness. Therefore, the heating time required to remove deposits is significantly reduced.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention.

This vacuum reaction vessel includes a reaction vessel inner wall 2 having a beta heater 9 attached to its outer circumferential surface, and a reaction vessel outer wall 1G arranged on the outer circumferential side thereof to form a predetermined space with the reaction vessel inner wall 2. It mainly consists of

The inner wall 2 of the reaction vessel has a 017 ring 3 for vacuum maintenance on the bottom plate l.
It is fixed via a plasma generation electrode 4 inside it.
is installed. A substrate 5 is placed facing the plasma generation electrode 4, and a target 6 is placed on the plasma generation electrode 4. A gas supply nozzle 7 and an exhaust port 8 are provided on the bottom plate 1 in the inner wall 2 of the reaction vessel. Each is drilled.

The outer wall 10 of the reaction vessel is fixed to the bottom plate 1 via an O-ring 11 for maintaining vacuum, and a connecting pipe 12 is connected to a heat insulating space 14 formed between the outer wall 10 of the reaction vessel and the inner wall 2 of the reaction vessel. is provided, and this connecting pipe 12 communicates with the exhaust lower.

Next, the operation of the vacuum reaction vessel configured as described above will be explained.

In this vacuum reaction vessel, when forming a film after once exposing the space inside the reaction vessel inner wall 2 (reaction space 13) to the outside air, the inside of the reaction space 13 and the heat insulating space 14 are
A vacuum state is created via a vacuum evacuation device (not shown), and in this state, the inner wall 2 of the reaction vessel is heated by the beta heater 9. In this case, the inner side of the reaction vessel inner wall 2 (reaction space 13) and the outer side of the reaction vessel inner wall 2 (insulation space 14)
Since both are maintained in a vacuum state at the same time, the thickness of the inner wall 2 of the reaction vessel can be made significantly thinner, approximately 1 m, compared to the case of conventional reaction vessels.

Therefore, when heating the inner wall 2 of the reaction vessel with the beta heater 9, if the capacity of the beta heater 9 is the same as that of the conventional reaction vessel, the inner surface of the inner wall 2 of the reaction vessel is For example, if the wall thickness of the conventional reaction vessel 21 shown in FIG.
When the internal volume of 1 and the volume of reaction space 13 shown in FIG. 1 are the same, the heating time according to this embodiment can be shortened to about 1/10 of the conventional one.

In addition, since the area where the beta heater 9 is installed is an insulated space that can be maintained in a vacuum state, the beta heater 9
The amount of heat loss can be significantly reduced compared to conventional equipment in which the heat loss is exposed to the outside air.

After heating the inner wall 2 of the reaction vessel in a short time to remove impurities attached to the inner surface of the inner wall 2 of the reaction vessel, Ar gas is supplied from the gas supply nozzle 7 into the reaction space 13, and is turned into plasma. The generated Ar' ions collide with the AI target 6 kept at a negative potential, knock out AJ atoms, and these Al atoms adhere to the substrate 5. in this case,
Since the impurities in the reaction space 13 have already been removed by heating by the beta heater 9, the AJ adhering to the substrate 5
This prevents impurities from entering the membrane surface.

FIG. 2 is a sectional view showing another embodiment of the present invention. This vacuum reaction vessel has an inner wall 15 of the reaction vessel to which no beta heater is attached, and lamp heaters 17 at predetermined intervals on the inner peripheral surface. The attached reaction vessel outer wall 16 is disposed with a heat insulating space 18 interposed therebetween. In FIG. 2, the other components are substantially the same as those shown in FIG. 1, so they are designated by the same reference numerals, and a detailed explanation of the structure will be omitted.

In the vacuum reaction vessel shown in FIG. 2, the outer circumferential surface of the inner wall 15 of the reaction vessel is heated by the lamp heater 17 to raise the temperature of the inner circumferential surface of the inner wall 15 of the reaction vessel. impurities can be removed.

In this embodiment, since no heating heater is attached to the inner wall 15 of the reaction vessel, the thickness of the inner wall 15 of the reaction vessel can be made thinner, and therefore the time required to raise the temperature of the inner wall 15 of the reaction vessel can be shortened. be able to.

In the above-mentioned embodiments, a sputtering apparatus was particularly explained as an example, but the present invention is designed to prevent impurities from adhering to the inner wall surface of a reaction vessel that is kept under reduced pressure, so that impurities can be removed by heating. It can be applied to any reaction vessel. Such a reaction vessel includes, for example, a plasma CV
Examples include a D device, a vacuum evaporation device, a molecular beam epitaxial device, a low pressure CVD device, a device using an ion blating method, a device using an ion etching method, and the like.

〔Effect of the invention〕

As described above, according to the present invention, when removing impurities attached to the inner wall surface of the reaction container by heating, the time required to raise the temperature of the inner wall of the reaction container can be shortened. Further, when heating the inner wall of the reaction vessel, the heating region can be maintained in a vacuum, so heat loss can be reduced. Therefore, a high vacuum can be achieved in a short time, and a desired film maintained at high purity can be formed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment of the invention, and FIG. 3 is a sectional view showing a conventional vacuum reaction vessel. l...Bottom plate, 2...Inner wall of reaction vessel, 4
..... Electrode for plasma generation, 5 ..... Substrate, 6 .... Target, 7 .... Gas supply nozzle, 8 .... Exhaust port, 9... Beta heater, lO... Reaction vessel outer wall, 13...
...Reaction space section, 14... Heat insulation space section, 15
...Inner wall of the reaction vessel, 16...Outer wall of the reaction container, 17...Lamp heater. Agent: Patent Attorney Masaru Nishimoto - Figure 1 Figure 2

Claims (1)

[Claims] In a vacuum reaction vessel having a reaction vessel capable of maintaining a vacuum inside, at least a wall portion of the reaction vessel has a double structure with a space between an inner wall of the reaction vessel and an outer wall of the reaction vessel, and the space is reduced in pressure. 1. A vacuum reaction vessel, characterized in that the space is configured to be capable of heating and heating means for heating the inner wall of the reaction vessel is provided in the space.