JPH10286454A - Film forming device and film forming method of oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an oxide film which satisfies objective performance (such as uniformity and physical properties) on a substrate simply and in a short time, by irradiating the film forming material with electromagnetic waves when the film is formed by thermal plasma method. SOLUTION: A platinum substrate 107 is arranged in a vacuum chamber 103. After a plasma torch 102 and the vacuum chamber 103 are enoughly evacuated, argon gas is introduced into the chamber to control the inner pressure to about 1 Torr. A high frequency voltage is applied on the plasma torch 102 to produce argon plasma and while increasing the argon gas pressure, oxygen gas is introduced to control the pressure in the vacuum chamber 103 to 100 Torr and to stabilize the plasma. A source material is prepared by dispersing a zirconia powder having about 20 μm average particle size in ethylalcohol, and the source material is atomized in a ultrasonic wave tank 110 and introduced into the vacuum chamber 103 to initiate the film forming process on the substrate 107. In this process, the film is formed while being irradiated with electromagnetic waves 104 such as UV rays and excimer laser light.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for evaporating and decomposing a raw material containing a substance to be formed in a thermal plasma to form an oxide film on a substrate or a surface of a structural material, and a composition using the apparatus. It relates to a membrane method. The obtained oxide film is used as a film of a substrate or a structural material, or as an electronic device material utilizing the properties of an oxide. Further, it is peeled off from the substrate and used as a structural material as an oxide film alone.

[0002]

2. Description of the Related Art As a method for forming a film on a substrate using thermal plasma, a thermal plasma CVD method (Japanese Patent Laid-Open No. 5-32091) is known.
6), plasma spray-ICP method (Appl. Phis. Le
tt. 14 (1990) 1452), a plasma flash evaporation method (JP-A-5-31462), and a plasma spraying method (JP-A-6-7).
6986).

In each case, a raw material containing a substance to be film-formed is supplied into a plasma, which is evaporated, decomposed, or reacted in the plasma to form a film on a substrate.

[0004]

However, in the above-mentioned conventional method, the feed material does not sufficiently react in the plasma, and a film having a desired structure cannot be obtained on the substrate, or the plasma reaction region (tail frame) Since it is difficult to control the distribution of the particles, the resulting film is also non-uniform on the substrate or causes a problem.

[0005] For the purpose of improving the density of the film obtained on the substrate and, in the case of a crystalline film, improving the crystallinity, the substrate is heated at the time of film formation as necessary, or There is also a conventional technique in which a film is heated and baked. However, when the substrate is heated, stress is generated due to the difference in the coefficient of thermal expansion between the substrate and the film on the substrate, which causes the entire substrate to warp, cracks in the film, and peeling. There was a problem. Further, even in the heating and firing treatment after film formation, there are disadvantages in mass production, such as a problem of thermal distortion, an increase in cost due to an increase in the number of steps, and a delay in manufacturing time.

Accordingly, the present invention is to solve such various problems of the prior art, and an object thereof is to provide a film which satisfies the desired performance (uniformity and physical properties) simply and in a short time. An object of the present invention is to provide a plasma film forming apparatus formed on a substrate and a film forming method using the apparatus.

[0007]

The oxide film forming apparatus of the present invention introduces a raw material containing a substance to be formed into a plasma generating section, evaporates and decomposes the raw material and installs the raw material on a substrate provided downstream of the plasma. Alternatively, an oxide film formation apparatus that can be deposited on a surface of a structural material is characterized by including a structure capable of irradiating the substrate portion with an electromagnetic wave or an electromagnetic wave irradiation apparatus. Further, the oxide film forming apparatus of the present invention is characterized in that the electromagnetic wave is ultraviolet light or the electromagnetic wave irradiation device is an ultraviolet light generating device. Further, the oxide film forming apparatus of the present invention is characterized in that the electromagnetic wave is an excimer laser or the electromagnetic wave irradiation device is an excimer laser generator.

According to the method of forming an oxide film of the present invention, a raw material containing a substance to be formed is introduced into a plasma generating section, and the material is evaporated and decomposed to deposit on a substrate or a structural material surface installed downstream of the plasma. In the oxide film formation method to be performed, an electromagnetic wave is applied to the film formation material at or near the substrate portion when the film formation material is deposited on the substrate. Also,
The method for forming an oxide film according to the present invention is characterized in that the electromagnetic waves are ultraviolet rays. In the method for forming an oxide film according to the present invention, the electromagnetic wave is an excimer laser.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, irradiation with an excimer laser or the like during film formation allows the substrate to be formed on the substrate with the assistance of irradiation energy even if the reaction is insufficient or uneven in the plasma. Thus, a substance to be deposited is deposited while rearrangement or crystallization is completed, so that a favorable film can be obtained on the substrate. Since there is no excessive substrate heating, problems such as warpage, peeling, and cracks due to thermal damage to the substrate and differences in the coefficient of thermal expansion between the substrate and the film do not occur. Further, no post-processing is required.

The operation and effects have been briefly described above.
Hereinafter, the present invention will be described in more detail based on examples.

(Embodiment 1) An outline of a film forming apparatus of the present invention is shown in FIG. After the platinum substrate is set in the vacuum chamber 103, the inside of the plasma torch unit 102 and the chamber 103 is sufficiently evacuated, and argon gas is introduced thereinto for 1 ton.
rr. A high frequency was applied to the torch to generate argon plasma, and oxygen gas was simultaneously introduced while increasing the argon gas pressure, so that the flow ratio of argon to oxygen was 10: 1.
, The pressure in the chamber 103 was set to 100 torr to stabilize the plasma.

On the other hand, a zirconia powder having an average particle size of about 20 μm is dispersed in ethyl alcohol to obtain a raw material, which is mist-formed by applying an ultrasonic wave (110), introduced into a plasma chamber, and a film is formed on a substrate. did. At this time, a film was formed for 10 minutes while irradiating an excimer laser (KrF, wavelength: 248 nm) 104 at an irradiation density of 20 mJ / cm 2 (Sample 1). On the other hand, for comparison, a film formed under the same conditions without excimer laser irradiation was also prepared (Comparative Example 1).

The film on the substrate obtained as described above is
Both Sample 1 and Comparative Example 1 had a thickness of about 0.2 μm. In order to examine the structure, X-ray diffraction measurement of the two was carried out. As a result, the sample 1 was a cubic zirconia crystal film, but in Comparative Example 1, no diffraction peak was observed, indicating that the film was an amorphous film. found. When the film was peeled from the substrate, the amorphous film of Comparative Example 1 collapsed into a powder state and could not be obtained as a film, but the crystalline film of Sample 1 had a thickness of 0.2% at the time of film formation.
The film could be peeled cleanly while maintaining the thickness of μm, and as a result of analysis, it was found that the zirconia film had high density and high rigidity.

As described above, by irradiating a laser at the time of plasma film formation, a crystallized film can be obtained in situ without heating the substrate at a high temperature, and the effect has been shown. XeCl, ArF, A
Other excimer lasers such as r2, Kr2, and Xe2, and ultraviolet light sources such as a mercury lamp were also tested, and it was found that the same irradiation effect as in this embodiment could be obtained if the conditions were selected.

(Embodiment 2) In FIG. 1, after a silicon substrate with platinum is placed in a vacuum chamber 103, the inside of the plasma torch section 102 and the chamber 103 is sufficiently evacuated, and argon gas is introduced to reduce the pressure to 1 torr. did. A high frequency is applied to the torch to generate argon plasma, and oxygen gas is simultaneously introduced while increasing the argon gas pressure, and the pressure in the chamber 103 is reduced while maintaining the flow ratio of argon to oxygen at 10: 1. 100t
The plasma was stabilized at orr.

On the other hand, a sol solution containing a predetermined concentration of lead acetate and titanium tetraisopropoxide is prepared as a raw material, which is mist-formed by applying an ultrasonic wave (110), introduced into a plasma chamber, and formed into a film on a substrate. Started. At this time, an excimer laser (KrF, wavelength 248 n
m) A film was formed for 20 minutes while irradiating 104 at an irradiation density of 20 mJ / cm 2 (Sample 1). On the other hand, for comparison, a film formed under the same conditions without excimer laser irradiation was also prepared (Comparative Example 1).

The film on the substrate obtained as described above is
Sample 1 and Comparative Example 1 had a thickness of about 1.0 μm. In order to examine the structure, X-ray diffraction measurement was performed on both of them. In Sample 1, tetragonal perovskite-type lead titanate (PbT
iO3) was found to be deposited on the substrate. On the other hand, in Comparative Example 1, no clear diffraction peak was observed, and it was found that the film was an amorphous film.

In both Sample 1 and Comparative Example 1, aluminum was deposited on the obtained film, and the current-voltage characteristics between the film and platinum on the substrate were measured. As a result, Sample 1 showed ferroelectricity. In contrast, Comparative Example 1 did not show ferroelectricity.

As described above, by irradiating a laser at the time of plasma film formation, a crystallized film can be obtained in situ without heating the substrate at a high temperature, and the effect has been demonstrated. XeCl, ArF, A
Other excimer lasers such as r2, Kr2, and Xe2, and ultraviolet light sources such as a mercury lamp were also tested, and it was found that the same irradiation effect as in this embodiment could be obtained if the conditions were selected.

(Embodiment 3) In FIG. 1, after a silicon substrate with platinum is placed in a vacuum chamber 103, the inside of the plasma torch unit 102 and the chamber 103 is sufficiently evacuated, and argon gas is introduced to reduce the pressure to 1 torr. did. A high frequency is applied to the torch to generate argon plasma, and oxygen gas is simultaneously introduced while increasing the argon gas pressure, and the pressure in the chamber 103 is reduced while maintaining the flow ratio of argon to oxygen at 10: 1. 100t
The plasma was stabilized at orr.

On the other hand, a sol solution containing barium and titanium alkoxides in a predetermined concentration was prepared as a raw material, and this was converted into a mist by applying an ultrasonic wave (110) and introduced into a plasma chamber to start film formation on a substrate. . At this time, a film was formed for 10 minutes while irradiating an excimer laser (KrF, wavelength: 248 nm) 104 at an irradiation density of 20 mJ / cm 2 (Sample 1). On the other hand, for comparison, a film formed under the same conditions without excimer laser irradiation was also prepared (Comparative Example 1).

The film on the substrate obtained as described above is
Both Sample 1 and Comparative Example 1 had a thickness of about 0.8 μm. In order to examine the structure, X-ray diffraction measurement was performed on both of them. As a result, it was found that tetragonal perovskite-type barium titanate (BaTiO3) was formed on the substrate in Sample 1. On the other hand, in Comparative Example 1, no clear diffraction peak was observed, and it was found that the film was an amorphous film.

In both Sample 1 and Comparative Example 1, aluminum was vapor-deposited on the obtained film, and an electromotive force was measured between the film and platinum on the substrate. In Comparative Example 1, no piezoelectricity was exhibited.

As described above, by irradiating a laser at the time of plasma film formation, a crystallized film can be obtained in situ without heating the substrate at a high temperature. XeCl, ArF, A
Other excimer lasers such as r2, Kr2, and Xe2, and ultraviolet light sources such as a mercury lamp were also tested, and it was found that the same irradiation effect as in this embodiment could be obtained if the conditions were selected.

[0025]

As described above, by irradiating an excimer laser or the like during film formation, even if the reaction of the raw material introduced into the plasma is insufficient or non-uniform, the irradiation energy assists the irradiation. Since a substance to be deposited is deposited on the substrate while rearrangement or crystallization is completed, a favorable film can be obtained on the substrate. Since there is no excessive substrate heating, problems such as warpage, peeling, and cracks due to thermal damage to the substrate and differences in the coefficient of thermal expansion between the substrate and the film do not occur. Further, no post-processing is required. In general, compared to the conventional method, the film forming method using the film forming apparatus of the present invention is a stable film forming method characterized by rapid and high yield. Therefore, the effect is greatly exhibited especially in mass production.

[Brief description of the drawings]

FIG. 1 is a schematic view of an oxide film forming apparatus of the present invention.

[Explanation of symbols]

 In FIG. 1, reference numeral 101 denotes a raw material supply port. In FIG. 1, reference numeral 102 denotes a plasma torch portion. In FIG. 1, reference numeral 103 denotes a vacuum chamber. In FIG. In FIG. 1, 106... Plasma tail frame portion 107 in FIG. 1, substrate in FIG. 1 108, substrate holder in FIG. 1 109, exhaust port in FIG. 1, 110 in FIG. ... Supply materials

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C23C 18/02 C23C 18/02 C30B 1/02 C30B 1/02 29/32 29/32 A

Claims (6)

[Claims] 1. An oxide film capable of introducing a raw material containing a substance to be deposited into a plasma generating section, evaporating and decomposing the raw material, and depositing the oxide on a substrate or a surface of a structural material provided downstream of the plasma. An oxide film formation apparatus, comprising: a structure capable of irradiating the substrate portion with an electromagnetic wave; or an electromagnetic wave irradiation device. 2. The oxide film forming apparatus according to claim 1, wherein the electromagnetic wave is ultraviolet light or the electromagnetic wave irradiating device is an ultraviolet light generating device. 3. The oxide film forming apparatus according to claim 1, wherein the electromagnetic wave is an excimer laser or the electromagnetic wave irradiation device is an excimer laser generating device. 4. An oxide film forming method comprising: introducing a material containing a substance to be deposited into a plasma generating section; evaporating and decomposing the raw material; and depositing the material on a substrate or a surface of a structural material provided downstream of the plasma. A method for forming an oxide film, comprising: irradiating an electromagnetic wave to a film-forming substance at or near a substrate portion when the film-forming substance is deposited on the substrate. 5. The method according to claim 4, wherein the electromagnetic waves are ultraviolet rays. 6. The method according to claim 4, wherein the electromagnetic wave is an excimer laser.