JPH0535218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compound thin film deposition apparatus, and particularly to an apparatus for forming a high quality compound thin film by vacuum deposition.

[Conventional technology]

Conventionally, there have been devices of this type as shown in FIGS. 3 and 4. Figure 3 is a conceptual diagram schematically showing a conventional compound thin film deposition apparatus disclosed in Japanese Patent Publication No. 54-9592, and Figure 4 is a partially cutaway view of the interior of the conventional compound thin film deposition apparatus. FIG.

In the figure, 1 is a vacuum evacuation device that maintains the vacuum chamber 2 at a predetermined degree of vacuum, 3 is a gas cylinder filled with room temperature gas such as oxygen, and 4 is a leak valve for introducing room temperature gas into the vacuum chamber 2. , 5 is a closed crucible having a spout 6, and a substance 8 to be deposited on a substrate 7, such as aluminum, is loaded therein. 9 is a filament for heating the crucible, 10 is a filament for ionization, heated to about 2000℃,
The electrons 11 emitted from this are accelerated by the grid 12 and impact the material vapor cluster 13,
A part of it is ionized. 14 is an acceleration electrode that accelerates the ionized cluster ions 15 and makes them collide with the substrate 7 together with the non-ionized neutral clusters 13; 16 and 17 are heat shield plates. 18 is an ionization means for ionizing the cluster, which includes an ionization filament 10 and a grid 1;
Consists of 2.

Next, the operation will be explained. After the inside of the vacuum chamber 2 is evacuated by the vacuum exhaust device 1 until the inside of the vacuum chamber 10 reaches a vacuum level of 10 ^-6 Torr, the leak valve 4 is evacuated.
is opened and room temperature gas (oxygen in this case) is introduced into the vacuum chamber 2. Next, the vapor pressure inside the crucible 5 is
Temperature at which it becomes Torr (about 1400℃ if substance 8 is Al)
When the crucible 5 is heated by bombarding the crucible 5 with electrons emitted from the crucible heating filament 9, the substance 8 is vaporized and injected from the spout 6 into the vacuum. This injected material vapor condenses as it passes through the ejection port 6, forming a mass of molecules called a cluster 13. In this cluster 13, the molecules in the cluster are then partially ionized by electrons 11 emitted from the ionizing filament 10. As a result, ion clusters 1 of the massive population together with unionized neutral molecules
It becomes 5. The cluster ions 15 are then accelerated by the electric field of the accelerating electrode 14 and collide with the substrate 7 . On the other hand, room-temperature gas exists near the substrate 7, and the reaction between the substance vapor and the room-temperature gas (4Al+
3O ₂ →2Al ₂ O ₃ ), a compound (here Al ₂ O ₃ ) as a reaction product is deposited on the substrate 9.

[Problem that the invention seeks to solve]

Since the conventional compound thin film deposition apparatus is constructed as described above, most of the room temperature gas introduced into the vacuum chamber is exhausted, so that very little room temperature gas participates in thin film formation. Therefore, it is necessary to increase the pressure of the introduced gas, but when a reactive gas such as oxygen is used as the room temperature gas, there is a problem that the filament, which is heated to a high temperature, is rapidly consumed.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a compound thin film deposition apparatus that can stably form a high quality compound thin film.

[Means for solving problems]

The compound thin film deposition apparatus according to the present invention is provided with a gas injection nozzle that jets room-temperature gas toward a substance to be deposited, and also evacuates the inside of a heat shield surrounding a filament that heats a steam generation source at a differential pressure.
A vacuum evacuation device is provided to maintain the interior at a high vacuum.

[Effect]

The gas injection nozzle of this invention has high reactivity because the ejected room temperature gas collides frequently with high temperature and high number density steam immediately after evaporation. The area around the filament is maintained at a high vacuum of about 10 ^-7 to ^{10 -6} Torr regardless of the gas flow rate, that is, the degree of vacuum in the vacuum chamber.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram schematically showing a compound thin film forming apparatus according to an embodiment of the present invention. In the figure, reference numeral 19 denotes an injection nozzle provided near the opening 5a of the crucible 5, which injects reactive gas toward the substrate 7. 20 Crucible 5 and heat shield plate 16
A partition wall separating the material 11 and the reactive gas from spreading is suppressed. 21 is a vacuum evacuation device such as a turbo pump that differentially pumps the inside of the crucible heat shield plate 16 to maintain a high degree of vacuum.

Next, the operation will be explained. After evacuating the inside of the vacuum chamber 2 to a degree of vacuum of 10 ^-6 Torr using the vacuum evacuation device 1, the turbo pump 21 is operated, and the inside of the heat shield plate 16 surrounding the filament 9 is
Furthermore, differential pumping is performed to a high degree of vacuum, about 10 _-7 to ^{10 -6} Torr. After that, the reactive gas in the gas cylinder 3 is ejected from the gas injection nozzle 19 into the crucible 5,
The flow rate adjustment valve 4 is adjusted to adjust the gas concentration in the vacuum chamber 2 to a predetermined gas pressure of about 10 ^-4 to ^{10 -1} Torr.
On the other hand, when the crucible 5 is heated by the heating filament 9 and the steam 22 of the vapor deposition material 8 stored in the crucible 5 is injected, this steam and the reactive gas are generated at a high temperature and a high concentration inside the crucible 5. (10 ^-3 ~
Because they collide at a number density of about 10Torr),
A highly reactive and high quality compound will be formed.

FIG. 2 shows another embodiment of this invention.
A gas injection nozzle 19 is provided inside the crucible 5, and the ejection port 6 of the crucible 5 is made smaller as in the conventional case.

With this configuration, a compound is formed within the crucible 5. The formed compound is partially ionized by the electrons 11 emitted from the ionizing filament 10 to become compound ions. Furthermore, they are accelerated by the electric field of the accelerating electrode 14 and collide with non-ionized compound molecules on the substrate 7 to be vapor deposited.

In the embodiment shown in FIG. 2, an electron beam irradiation method is used as the ionization means 18, but other types of ionization means may be used as long as they can obtain ions (for example, a high frequency discharge type ion source).

In the embodiment shown in FIG. 2, the ionization means 18 and the acceleration electrode 14 are provided in the vacuum chamber 2, but
These may be removed and the compound ejected from the crucible 5 may be used for vapor deposition as is, as shown in FIG.

Furthermore, in the embodiment shown in FIG. 2, the reactive gas injected from the injection nozzle 19 and the vapor of the substance 11 react in the crucible 5, but the injection nozzle 19 is arranged near the injection port 6. The same effect can be obtained even if the reactive gas and the vapor of the substance 11 are caused to react outside the crucible 5.

In addition, in the above example, the case where this apparatus was used as a compound thin film forming apparatus was shown, but Ar gas or He gas was used as the supply gas, and this was ionized to form Ar ions or He ions. By controlling the acceleration and irradiating the substrate, it is possible to perform physical cleaning in which the deposition surface is spattered, and then the gas introduction is stopped and the crucible 5
By heating and performing conventional vapor deposition, a very high-performance thin film can be formed because the substrate is activated by high cleaning.

〔Effect of the invention〕

As described above, according to the present invention, the area around the filament is always maintained at a high degree of vacuum, so that it can be operated stably and with a long life.
Furthermore, since the reactive gas and the vapor come into contact in a state activated at a high temperature and in a state with a high number density, a high-quality thin film can be efficiently formed.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of this invention, Fig. 2 is a block diagram showing another embodiment of this invention, and Fig. 3 is a block diagram showing another embodiment of this invention.
This figure is a block diagram showing a conventional compound thin film forming apparatus, and FIG. 4 is a perspective view showing the main parts of FIG. 3. In the figure, 2 is a vacuum chamber, 5 is a crucible, 6 is a spout, 7 is a substrate, 8 is a substance, 9 is a filament,
16 is a heat shield plate, and 19 is a spray nozzle.
In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A vacuum chamber maintained at a predetermined degree of vacuum, a crucible disposed within the vacuum chamber and provided with an opening above, and a substance in the crucible heated through the crucible. A filament that generates vapor of the substance, a heat shield that seals the filament, a vacuum exhaust device that evacuates the inside of the heat shield, and is located near the opening of the crucible and is capable of ejecting a predetermined gas toward the substrate. Compound thin film deposition equipment equipped with a spray nozzle. 2. A vacuum chamber maintained at a predetermined degree of vacuum, a crucible placed in the vacuum chamber and provided with a spout above, and heating the substance in the crucible through the crucible to generate vapor of the substance. A compound thin film deposition apparatus comprising: a filament for heating, a heat shield sealing the filament; a vacuum evacuation device for evacuating the inside of the heat shield; and an injection nozzle capable of ejecting a predetermined gas into the crucible. 3. The compound thin film deposition apparatus according to claim 2, wherein the injection direction of the injection nozzle is configured to be an extension of the center of the substrate and the injection port of the crucible.