JPH05306455A - Film forming device - Google Patents

Abstract

PURPOSE:To form good-quality oxide film of a vapor deposited material on the surface to be subjected to vapor deposition of a substrate by irradiating the oxygen supplied into a vacuum chamber with UV rays by an oxygen supplying means, thereby enhancing the reactivity of the oxygen. CONSTITUTION:A vacuum state of about 10<-5> to 10<-7>Torr is maintained in a film forming chamber 10 and a holder 3 fixed with a substrate 7 is arranged in the prescribed position of a dome 8. The oxygen is then supplied from the oxygen supplying device 4 into the film forming chamber 10 to maintain the prescribed oxygen partial pressure. A mercury lamp 5 is then lighted to irradiate the oxygen molecules in the film forming chamber 10, by which the oxygen is partly converted to ozone and the other parts are excited to form the oxygen molecules having the high reactivity. A crucible 2a is heated in this state to heat and evaporate the oxide 6 to be deposited by evaporation, by which the powerful oxidizing effect of the excited oxygen molecules is imparted and the oxide film is formed on the surface of the substrate 7. As a result, good- quality oxide film is formed on the surface of the substrate 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus, and more particularly to a film forming apparatus for forming an oxide film on a substrate or the like by vapor deposition.

[0002]

2. Description of the Related Art For example, in the case of forming an optical thin film, film formation by a vapor deposition method is widely performed. When forming an oxide film on a substrate by a vapor deposition method, after depressurizing the inside of a vacuum chamber in which the substrate and the evaporation source are opposed to each other, oxygen is supplied into the chamber to form an oxidizing atmosphere. At this time, in order to increase the oxidizing power in the chamber, for example, a method of increasing the oxygen partial pressure in the chamber, or applying a high voltage to the chamber under high oxygen partial pressure, oxygen and clusters ) Is used to accelerate the oxidation.

[0003]

In the conventional film forming apparatus described above, the former method has insufficient oxidizing power,
Further, the supply of oxygen leads to a reduction in the degree of vacuum, so the vapor deposition power is relatively weak. Further, in the latter method, when the substance to be vapor-deposited is, for example, a non-conductive substrate, the clusters are repelled from the substrate by the charge-up of the substrate. Therefore,
A method of neutralizing oxygen ions between the evaporation source and the substrate and irradiating the vapor deposition surface of the substrate is also used. However, the device becomes complicated.

An object of the present invention is to provide a film forming apparatus capable of forming a good quality oxide film on a surface to be vapor-deposited even in a dilute oxygen atmosphere.

[0005]

A film forming apparatus according to the present invention comprises a vacuum chamber, an evaporation source arranged in the vacuum chamber, a substrate arranged on the side facing the evaporation source, and oxygen in the vacuum chamber. And oxygen irradiation means for irradiating the oxygen supplied by the oxygen supply means with ultraviolet rays.

[0006]

In the film forming apparatus according to the present invention, the substrate is placed in the vacuum chamber in which the evaporation source is placed. Then, after decompressing the inside of the vacuum chamber, oxygen is supplied from the oxygen supply means. Next, the supplied oxygen is irradiated with ultraviolet rays from the ultraviolet ray irradiation means. At this time, the oxygen in the vacuum chamber is in a state in which the reactivity is partly increased, and a strong oxidizing atmosphere can be formed without increasing the partial pressure. Oxidation in the vacuum chamber is accelerated in this oxidizing atmosphere, and a good quality oxide film can be formed on the substrate.

[0007]

EXAMPLE FIG. 1 shows a film forming apparatus according to an example of the present invention. This film forming apparatus includes a chamber 1 and an evaporation source 2
Substrate holder 3, oxygen supply device 4 and mercury lamp 5
It is mainly composed of and. In the figure, an evaporation source 2 is arranged at the bottom of a chamber 1.

A crucible 2a for accommodating the vapor-deposited oxide 6 is formed on the evaporation source 2. Inside the evaporation source 2, a heating controller (not shown) for controlling the heating of the vapor deposition oxide 6 is arranged. As the heating controller, a resistance heating method using a heater or the like, a high frequency heating method using a high frequency coil or the like, a method using an electron beam, or the like is used. A substrate holder 3 for fixing a substrate 7 on which a thin film is to be formed is arranged above the crucible 2a.

The substrate holder 3 is arranged on the lower surface of the dome 8 having a curved surface so as to be movable between both ends of the dome by a driving device (not shown). Substrate holder 3 and evaporation source 2
A film forming chamber 10 surrounded by the chamber 1 is formed between and. An oxygen supply device 4 for supplying oxygen into the film forming chamber 10 is arranged outside the film forming chamber 10. The oxygen supply device 4 has a pressure adjusting mechanism (not shown) and a control mechanism for controlling the supply of oxygen based on a command from the outside,
Oxygen can be supplied into the film forming chamber 10 through the pipe 4a. A mercury lamp 5 for irradiating the film formation chamber 10 with ultraviolet rays is arranged beside the evaporation source 2.

The mercury lamp 5 is arranged at the bottom of the chamber 1, and a window 11 is arranged above it. Window 11
Is made up of a glass body, which is transparent to the ultraviolet rays emitted from the mercury lamp 5, as a light-transmitting surface, and is surrounded by a cover 12. The mercury lamp 5 is hermetically sealed from the film forming chamber 10 by the window 11 and the cover 12.

Next, the operation will be described. When vapor deposition is performed, an exhaust device (not shown) is operated to evacuate the inside of the film forming chamber to make the inside of the film forming chamber 10 a vacuum state of about 10 ⁻⁵ to 10 ⁻⁷ Torr. Next, the substrate holder 3 to which the substrate 7 is fixed by a drive system (not shown) is placed at a predetermined position in the dome 8. Next, the oxygen supply device 4 is operated to supply oxygen into the film forming chamber 10 through the pipe 4a. When the oxygen partial pressure in the film forming chamber 10 reaches a predetermined range, the oxygen supply device 4 is operated to maintain that state. In this state, the mercury lamp 5 is turned on. Ultraviolet rays from the mercury lamp 5 pass through the glass body of the window 11 to irradiate oxygen molecules in the film forming chamber 10 (arrows in the figure). At this time, a part of the oxygen molecule is changed to ozone and the other part is also excited to become a highly reactive oxygen molecule. Therefore, an oxygen atmosphere having a strong oxidizing power is created in the film forming chamber 10.

Next, by operating a heating controller (not shown),
The crucible 2a is heated. Then, the vapor-deposited oxide 6 such as Ti ₂ O ₃ stored in the crucible 2a is heated and vaporized, and the titanium oxide molecules are scattered from the vaporization source 2 in the form of clusters. Start moving toward the area (two-dot chain line in the figure). Since the excited oxygen molecules are filled in the film forming chamber 10, the cluster is subjected to a strong oxidizing action when moving in this space, and the surface of the substrate 7 undergoes T oxidation.
An oxide film made of iO ₂ is formed.

As described above, since the ultraviolet irradiation is performed in the film forming chamber 10 under the oxygen atmosphere, the substrate 7 can be formed even if the film forming chamber 10 has a lower oxygen partial pressure than the conventional method.
It is possible to obtain sufficient oxidizing power to form an oxide film on top. Therefore, a higher quality oxide film can be formed on the deposition surface. [Other Examples] (a) In the above examples, the mercury lamp 5 was used as the ultraviolet irradiation means, but a laser, a fluorescent lamp, or the like can also be used as the ultraviolet irradiation means. (B) In the above embodiment, the glass body is used for the light transmitting surface of the window 11, but a transparent resin or the like having a property of transmitting ultraviolet rays may be used. In this case, in order to prevent vaporized vapor-deposited oxide from vapor-depositing on the transparent surface, it is possible to properly use materials having different surface characteristics.

A lens may be used on the transparent surface. In this case, the irradiation light can be condensed or diffused.
Furthermore, a filter may be used to select and remove a specific wavelength.

[0015]

In the film forming apparatus according to the present invention, the oxygen in the vacuum chamber supplied by the oxygen supplying means is irradiated with ultraviolet rays to enhance the reactivity of oxygen in the vacuum chamber. A good quality oxide film can be formed on the surface of the substrate to be vapor-deposited.

[Brief description of drawings]

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

[Explanation of symbols]

 1 Chamber 2 Evaporation Source 3 Substrate Holder 4 Oxygen Supply Device 5 Mercury Lamp 6 Evaporated Oxide 7 Substrate

Claims (1)

[Claims] 1. A vacuum chamber, an evaporation source arranged in the vacuum chamber, a substrate arranged on the side opposite to the evaporation source, and an oxygen supply means for supplying oxygen into the vacuum chamber. An ultraviolet irradiation unit for irradiating the oxygen supplied by the oxygen supplying unit with ultraviolet rays, and a film forming apparatus.