JPH02298272A - Manufacture of oxide thin film and device therefor - Google Patents

Abstract

PURPOSE:To manufacture a great variety of good quality oxide thin films with high efficiency and good reproducibility by irradiating a gas on the surface of a substrate or above that with plural light beams of different wavelength while plural raw materials are fed onto the surface of the substrate. CONSTITUTION:The inside of a reaction vessel 11 is exhausted and a substrate 13 is heated by a heater 15. A gas 17a such as TiCl4 is introduced into the reaction vessel 11 from a gas introducing port 15 and a gas 17b such as O2 from a gas introducing port 16. For example, a KrF excimer laser beam 18a and an F2 excimer laser beam 18b of different wavelength are introduced into the reaction vessel 11 from a light beam introducing window 19 and the gas on the surface of the substrate 13 or directly above that is irradiated therewith. TiCl4 adsorbed on the substrate 13 is decomposed to form Ti, and O2 is decomposed to form atomic oxygen; they are brought into reaction to form a TiO2 thin film. By this method, the multi component oxide films of oxides and oxide superconductors in addition to TiO2 can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for producing an oxide thin film using photo-CVD.

2. Description of the Related Art Since around 1980, optical CVD, which deposits thin films using photochemical reactions, has been actively researched in conjunction with the demand for lower temperatures in the film formation process.

In particular, in the semiconductor field, etc., there is a need to form various oxide films at low temperatures, and photo-CVD is attracting attention. optical CV
When producing an oxide thin film by D, for example, organic metal and O
Usually, a single light source is used, which is selected according to the absorption wavelength of the source gas containing the element to be oxidized (in this example, organic gold*). Ta.

Problems to be Solved by the Invention However, when a single light source uses source gases with significantly different absorption wavelengths, the source gas containing the element to be oxidized is efficiently decomposed, but the source gas containing the element to be oxidized is The gas (in case 02 in the above example) will not be decomposed much. In order to carry out the oxidation reaction efficiently, atomic oxygen (especially
It is necessary to generate a large amount of oxidized atomic oxygen (excited state atomic oxygen), and in this case, either a large amount of the raw material gas to be oxidized is supplied, or the substrate temperature is raised to a high temperature to decompose the raw material gas to be oxidized. Operations such as promotion are required. The former is inefficient, and the latter cannot take advantage of the advantage of photoCVD, which is low process temperatures. For the above reasons, for a single light source, it is necessary to select raw material gases whose absorption wavelengths are as close as possible.
There was a problem in that the type of raw material gas was restricted.

The present invention aims to solve the problems of the prior art.

Means for Solving the Problems The present invention provides a method for forming an oxide thin film by supplying a plurality of raw material gases to the surface of a substrate and irradiating a plurality of lights having different wavelengths to the surface of the substrate or to the gas immediately above the surface of the substrate. In order to realize this manufacturing method, the method includes a vacuum chamber and at least an exhaust mechanism for evacuating the vacuum chamber, a raw material supply mechanism for introducing a plurality of raw materials into the vacuum chamber, and a raw material supply mechanism for decomposing or decomposing the raw materials. Production of an oxide thin film having a plurality of light sources for causing a reaction, a light introduction mechanism for introducing the light into the vacuum chamber, a substrate support mechanism for supporting a substrate on which an oxide thin film is to be formed, and a substrate heating mechanism for the substrate. The aim is to provide equipment.

Effect In the present invention, by using a plurality of light sources according to the absorption wavelength of the raw material gas, the types of usable raw material gases are increased, and the above-mentioned problems can be solved at once. Another advantage is that the decomposition of each source gas can be independently controlled by conditions such as light intensity and irradiation time.

Examples Examples of the present invention will be described below with reference to the drawings.

A manufacturing apparatus according to an embodiment of the present invention is shown in FIG. 1, and a manufacturing method according to an embodiment of the present invention will be explained.

In FIG. 1, 11 is a reaction tank, 12 is a vacuum pump, 1
3 is a substrate, 14 is a substrate holder, 15 is a heater, 16. ．．
18b is a gas inlet; 17. is TiC+4.17b is O
t, 1B- is a KrF-c excimer laser, 18b is an F2 excimer laser, and 19 is a light introduction window. The reaction tank 11 was evacuated to about 10” Torr by a vacuum pump 12, and a substrate (MgO (100)) 13 was placed on a substrate holder 14.
was heated to 350°C using a heater 15. Thereafter, 1117g of TLC was introduced into the reaction tank 11 through the gas inlet 15 and 0217b was introduced through the gas inlet 16, and the gas pressure inside the reaction tank 11 was set to 3X1 (1'Torr).
The partial pressure ratio within is TiC1i:CL = 1:2). TlC14 molecules and 02 molecules in the reaction tank 11 are adsorbed onto the surface of the substrate 13 for a very short time and then desorbed again. Next, a KrF excimer laser 18. Light and Fe excimer laser 18b light were introduced into the reaction tank 11 and irradiated onto the surface of the substrate 13 (KrF excimer laser 18° light repetition frequency 60 HZN intensity 40 W/cm2, F2 excimer laser 18b front repetition frequency 1008Z%)
Intensity: 80 W/cm'', irradiation time: 1 hour).

Since the peak value of the absorption wavelength of TlCl4 is around 250 gm, the K to the TlC14 molecules adsorbed on the surface of the substrate 13 is
rF:c ximer laser 18. When irradiated with light (wavelength: 248 nm), it is decomposed as shown below, and metal TI is produced.

T+C+a→7' I+ 2 CIa Also, since the absorption wavelength band of 02 is from 1100n to 220nm, F2 excimer laser 18. Light (wavelength 1
57 nm) to produce atomic oxygen as shown below.

02→20 This atomic oxygen reacts with metal T1 to generate T 102 as shown below.

TI+20→TlO2 In this way, the film formation time is 1 hour, and the film thickness is 1.5μ.
A T IQ 2 thin film of m is applied to the laser 18 on the surface of the substrate 13.
a1. The light was formed in the area illuminated by 4'1.1. When the crystal +f4 structure of this film was examined using X-ray radiation (4j), it was found to be anatase-type T102 strongly oriented in the substrate direction, as shown in FIG. When film formation was carried out at a single plate temperature of 650°C and other conditions being the same, Rudal type TlO2 was also formed.

Although Mg0 (100) was used as the substrate in e here, a TlO2 thin film with good crystallinity could also be formed using a substrate made of thin film such as Sl, sapphire, or glass.

In addition, when the substrate temperature is 200°C or higher, T
A lO2 thin film was formed.

In addition, here we used an excimer laser and an F2'11-1 simmer laser as light sources, but the former uses the second harmonic of an Ar laser (wavelength 257 nm), a low-pressure mercury lamp (wavelength 25 Jnm), etc. Other light sources may be used, and the latter may be a low-pressure mercury lamp (wavelength: 185nIn), but since the F2 excimer laser is closer to the peak absorption wavelength of O2, O1! It is more effective as a light for decomposition.

In addition, here, TlC is used as a raw material for forming TlO2 thin film.
14 and 02 were used, however, the former may use an organometallic raw material containing the T1 element, and the latter may use N20, CO2, etc. In that case, a light source may be used that corresponds to the absorption wavelength of the log 1 used.

In addition, although the formation of T 102 was described here as an example of an oxide thin film, titanium oxides such as T 10 and T +30a, oxides such as PbO and ZnO, and PbTlO
It was confirmed that composite oxides such as 3 and oxide superconductors could also be formed. In the case of composite oxides, three or more types of raw materials were used, so two or more types of light sources were used depending on the absorption wavelength of each raw material. A light source was used.

Effects of the Invention Like my son, the ability to manufacture oxide thin films and the manufacturing equipment of the present invention using multiple light sources according to the absorption wavelength of the raw materials makes it possible to produce a wide variety of high-quality oxide thin films without any limitations on raw materials. It can be produced efficiently and reproducibly, and the industrial value of the present invention is extremely high.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing one embodiment of the production apparatus for the oxide thin film of the present invention [N], and FIG.
2 is an X-ray diffraction diagram of a thin film. 1t--@Reaction tank, No. 12 vacuum pump, 13 pot/fist board, 14 fist/fist board holder, 15/m-heater,
1 (3,,1(3b-...Gas inlet, 17゜"
"' T lc +4, 17b""
"Os,18.""KrF excimer laser, 18 b@kai@F2 excimer laser,
Bone 19 - Light introduction window. Name of agent: Patent attorney Shigetaka Kurino (1 person) J

Claims (4)

[Claims] (1) A method for producing an oxide thin film, which comprises supplying a plurality of source gases to the substrate surface and irradiating the substrate surface or the source gas directly above the substrate surface with a plurality of lights having different wavelengths. (2) The method for producing an oxide thin film according to claim 1, wherein at least one of the plurality of lights has a wavelength in the range of 100 nm to 220 nm. (3) The method for manufacturing an oxide thin film according to claim 2, characterized in that F_2 excimer laser light is used as the light having a wavelength in the range of 100 nm to 220 nm. (4) a vacuum chamber and at least an exhaust mechanism for evacuating the vacuum chamber, a raw material supply mechanism for a plurality of raw materials to be introduced into the vacuum chamber, a plurality of light sources for decomposing or reacting the raw materials; An apparatus for producing an oxide thin film, comprising a light introduction mechanism for introducing light into the vacuum chamber, a substrate support mechanism for supporting a substrate on which an oxide thin film is to be formed, and a substrate heating mechanism for the substrate.