WO2005077525A1 - Crystalline thin film and method for producing same - Google Patents

Abstract

Disclosed is a uniform crystalline thin film which can be formed on a resin substrate. The crystalline thin film can be obtained by crystallizing an amorphous thin film and/or a thin film with low crystallinity for a short time while maintaining the temperature of the thin film low. Also disclosed is a method for producing such a crystalline thin film. The crystalline thin film is characterized in that it is obtained by placing an amorphous thin film and/or a thin film with low crystallinity in a high-frequency application apparatus, and having the thin film crystallized by generating a plasma under such conditions that a high-frequency electric field concentrates on the thin film while satisfying at least one of the following conditions: (1) the crystallization is performed while keeping the temperature at 150˚C or less; and (2) the crystallization time is not more than 15 minutes. It is preferable to control the pressure of a gas for generating a plasma in such a manner that a high-frequency electric field concentrates on the amorphous thin film and/or thin film with low crystallinity.

Description

 Specification

 Crystal thin film and manufacturing method thereof

 Technical field

 The present invention relates to a crystalline thin film and a method for producing the same, and in particular, to an amorphous thin film and Z or a thin film having low crystallinity obtained by crystallizing a thin film in a short time while keeping the temperature of the thin film low. The present invention relates to a crystalline thin film and a method for manufacturing the same.

 Background art

 In general, using a crystalline thin film rather than using an amorphous thin film is more suitable for most industrial thin film applications. This is because the amorphous state is in a metastable state, and the atomic arrangement is unstable in the amorphous state. Due to this instability, mechanical properties such as inferior abrasion resistance are lower than those of crystals. This is because there are problems such as low mechanical strength, large diffusion of gaseous and liquid phase substances into the inside, high reactivity and susceptibility to corrosion, and low mobility of the charge carrier for imparting conductivity.

Conventionally, to form a crystalline thin film while heating, it is necessary to heat the substrate during film formation, it takes time to raise the temperature of the substrate, and the heating causes Since it is necessary to make the heating area sufficiently larger than the size of the substrate in order to make the temperature of each area uniform, there is a problem that the crystal thin film manufacturing apparatus is undesirably enlarged. On the other hand, a crystalline thin film has been manufactured by a method of performing a crystallization treatment after forming an amorphous thin film. The main means of crystallizing an amorphous thin film once formed is to heat the amorphous thin film in a furnace. Even when heating in the furnace is not used, laser irradiation or electron beam irradiation can be performed. Then, the only method was to heat the amorphous thin film into a crystalline thin film by any means. The crystallization process by such a heat treatment has the following problems. That is, the heat treatment causes undesired thermal diffusion of a different substance from an adjacent material. Further, a material having low heat resistance cannot be used as a substrate of the thin film. Due to the difference in the coefficient of thermal expansion, cracks occur in the thin film having lower mechanical strength than the substrate when the temperature is increased or decreased. [0004] In addition, even if crystallization of an amorphous thin film can be stably performed by optimizing the heat treatment conditions in a furnace, the amorphous thin film can be formed on a plastic substrate having poor heat resistance. The formed amorphous film cannot be crystallized by heating in a furnace, and a method of heating a substrate to form a crystalline thin film cannot be performed.

 [0005] For this reason, in recent years, there has been a growing need for application to lightweight 'flexible electronic devices' displays, and for the production of crystalline thin films on plastic substrates, amorphous silicon thin films Has been started to form a crystalline silicon thin film by forming a crystalline silicon thin film by applying laser scanning irradiation after forming a film on a plastic substrate. Extremely delicate control of irradiation intensity and the like is required, which makes it difficult to increase product yield, and there is a growing demand for alternative crystallization technologies.

As described above, there is a high demand for a technique for crystallizing an amorphous thin film at a low temperature and at a high speed.

 In order to solve this, for example, a method has been proposed in which an amorphous thin film is crystallized by exposing it to plasma in a high-frequency electric field (for example, see Patent Document 1). Although it is possible to crystallize a crystalline thin film by exposing it to low-temperature plasma, it is difficult to achieve crystallization with good reproducibility because the conditions to be controlled are not clear. Met.

 That is, despite the fact that there are many factors to be controlled such as the frequency of the applied high frequency, the input power, the location of the amorphous thin film, the pressure of the gas to be plasma, etc. Adjust the elements to make them the best! / Therefore, it was far from satisfactory as a manufacturing technology for stable production. For this reason, for example, in order to obtain a crystalline film having characteristics that can be used practically, it was necessary to repeat the formation of an amorphous thin film and exposure to plasma a plurality of times. As is clear from the present invention, since the control region in which crystallization can be realized is small as described below, in most cases, the optimum control conditions cannot be found and obtained.

 Patent Document 1: International Publication No. 03Z031673 pamphlet

 Disclosure of the invention

Problems the invention is trying to solve [0007] The present invention provides an amorphous thin film and a thin film of Z or low crystallinity which are obtained by crystallizing the thin film at a low temperature for a short time while keeping the temperature of the thin film uniform and on a resin substrate. It is a technical object of the present invention to provide a crystal thin film that can be formed at a low temperature, and a method of manufacturing a crystal thin film capable of manufacturing such a crystal thin film with good reproducibility.

 Means for solving the problem

[0008] To achieve the above object, the present inventors have made it possible to crystallize an amorphous thin film and Z or a thin film having low crystallinity in a short time while keeping the temperature at 150 ° C or less. In order to obtain a thin film, we examined the elements to be controlled to find out that it was possible to achieve the above object by generating plasma under conditions where the high-frequency electric field was concentrated on the thin film. Thus, the present invention has been completed.

 That is, in the crystalline thin film of the present invention, an amorphous thin film and a thin film having low Z or crystallinity are arranged in a high-frequency application device, and plasma is generated under the condition that a high-frequency electric field is concentrated on the thin film. Under the conditions that satisfy at least one of the following two conditions: (1) conditions for crystallization while maintaining the temperature at 150 ° C or lower, and (2) conditions for crystallization within 15 minutes required for crystallization. It is characterized by being obtained by converting

 The present inventors have studied factors to be controlled in order to concentrate a high-frequency electric field on the thin film. As a condition for generating the plasma under the condition that the high-frequency electric field is concentrated on the thin film, the pressure of the gas generating the plasma It was found that crystallization can be achieved with good reproducibility by controlling the crystallization.

 [0010] In the method for producing a crystalline thin film of the present invention, an amorphous thin film and a thin film having low Z or crystallinity are arranged in a high-frequency application device so that a high-frequency electric field is concentrated on the thin film. After optimizing the pressure of the gas in the equipment, plasma is generated and (1) crystallization conditions while maintaining the temperature at 150 ° C or lower, (2) crystallization time within 15 minutes The crystallization is performed under a condition that satisfies at least one of the following two conditions.

Here, means for concentrating the high-frequency electric field on the thin film include the shape of the high-frequency application device, the installation position of the amorphous thin film and the Z or low-crystalline thin film in the high-frequency application device, , And one or more selected from the type of gas that becomes plasma According to the above conditions, it is preferable to take a means for optimizing the pressure of the gas to be plasma.

 The high-frequency application device that can be used in the method of the present invention is not particularly limited, and for example, a capacitively-coupled high-frequency application device can be used. Examples of the capacitively-coupled high-frequency application device include a device in which opposed electrodes are provided, and more specifically, a device in which a pair of opposed electrodes are provided.In this specification, as shown below, As an example, a capacitively-coupled high-frequency application device in which a pair of electrodes each composed of a divided half cylinder having a cylindrical chamber is used.

 [0012] As described in the section of the problem to be solved by the invention, there are many control elements to be controlled to enable crystallization of an amorphous thin film. The high-frequency electric field, which is an energy source for performing the operation, is a main element for simultaneously generating plasma, and the plasma is uniform in the region where the high-frequency electric field is applied in the amorphous thin film region, while the plasma is uniform. It is equivalent to a three-dimensional electric circuit element for achieving a significantly higher strength compared to other spaces.

[0013] That is, when high-frequency power is supplied to the electrode, a force that generates a high-frequency electric field in the processing chamber has a spatial distribution depending on the electrode arrangement. The high-frequency electric field generates plasma, but the plasma density changes depending on the high-frequency electric field strength. On the other hand, the spatial intensity distribution of the high-frequency electric field changes depending on the plasma density distribution. As described above, it is not easy to control the concentration of the high-frequency electric field in the thin film in order to cause crystallization of the amorphous thin film.

[0014] Among the various control parameters for plasma generation described above, the inventors first set the electrode arrangement for applying a high-frequency electric field, the position of the thin film to be crystallized, and the method for generating plasma. By setting the type of gas to be introduced and then optimizing the pressure of the gas, the amorphous thin film can be (2) crystallized while (1) the substrate temperature is kept below 150 ° C. It has been found that crystallization can be performed at a low temperature and in a short time so as to satisfy one or both of the required times of 15 minutes or less, or both. Furthermore, once the optimum gas pressure is determined in the high-frequency application device, the gas pressure is set to that value, and by applying the same device and conditions, the stability is improved in reproducibility. Crystallize I confirmed that I can do it.

 The invention's effect

 [0015] The crystalline thin film of the present invention is obtained by crystallizing an amorphous thin film and a thin film of Z or low crystallinity in a short time while keeping the temperature of the thin film low, and is homogeneous and has a low melting point. If the resin substrate can be formed on a non-heat-resistant substrate, the effect is achieved.

 Further, according to the method for producing a crystalline thin film of the present invention, a crystalline thin film having the above characteristics can be produced in a short time and with good reproducibility while keeping the temperature of the thin film low.

 Brief Description of Drawings

 [FIG. 1] In a capacitively-coupled high-frequency application device, the pressure of oxygen, which is a gas for generating plasma, is controlled to 4000 Pa, and an amorphous film is formed by a sol-gel method on a silicon wafer placed in the center of the chamber. 5 is a graph showing a temperature change of the titania thin film when a high frequency electric field having a frequency of 13.56 MHz is applied to the thin film.

 FIG. 2 is an X-ray diffraction profile of an amorphous titanium thin film formed by a sol-gel method before and after application of a high-frequency electric field when an oxygen pressure is 4000 Pa.

 [Figure 3] X-ray diffraction of amorphous titania thin film formed by sol-gel method before applying high frequency electric field when oxygen pressure was changed to 1200Pa, 1700Pa, 2200Pa, 3300Pa, 4300Pa, 5400Pa (6 cases) It is Profai Nore.

 FIG. 4 is an X-ray diffraction profile of a low-crystalline, tin-doped indium oxide thin film formed by a sputtering method before and after the application of a high-frequency electric field when the oxygen pressure is 4000 Pa.

 [Fig.5] Crystalline low-V, tin-doped indium oxide formed by sputtering after applying a high-frequency electric field when the oxygen pressure was changed to 1200 Pa, 1700 Pa, 2200 Pa, 4300 Pa, 3300 Pa, and 5400 Pa 3 is an X-ray diffraction profile of a thin film.

 [Figure 6] Crystals formed by the sputter method using argon gas containing 3% by volume of oxygen after application of a high-frequency electric field when the pressure of argon gas was changed to 4 ways of 12000 Pa, 10000 Pa, 7900 Pa, and 3300 Pa 5 is an X-ray diffraction profile near the indium oxide (2, 2, 2) diffraction line of a tin-doped indium oxide thin film having low property.

[Figure 7] Change the pressure of argon gas to 4 kinds of 10000Pa, 7900Pa, 3300Pa, 1300Pa Indium oxide of a tin-doped indium oxide thin film with low crystallinity formed by a sputtering method using an argon gas containing 1% by volume of oxygen after application of a high-frequency electric field

It is an X-ray diffraction profile near a (2, 2, 2) diffraction line.

 [Fig. 8] Crystals formed by the sputter method using argon gas containing 5% by volume of oxygen after applying a high-frequency electric field when the pressure of argon gas was changed to four types of 12000Pa, 10000Pa, 7900Pa, and 6600Pa. 5 is an X-ray diffraction profile near the indium oxide (2, 2, 2) diffraction line of a tin-doped indium oxide thin film having low property.

 BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

 In the crystalline thin film of the present invention, an amorphous thin film and a thin film having a low Z or crystallinity (hereinafter, appropriately referred to as an amorphous thin film) are arranged in a high-frequency application device, and a high-frequency electric field is concentrated on the thin film. It is obtained by generating and crystallizing plasma under the conditions.

 Typical examples of the crystalline thin film of the present invention include a metal oxide, a metal nitride, a metal oxynitride, a metal carbide, and a thin film containing at least one selected from the group consisting of semiconductors. Can be

Further, in the method for producing a crystalline thin film of the present invention, the amorphous thin film is arranged in a high-frequency application device, and the pressure of the gas in the device is adjusted so that the high-frequency electric field is concentrated on the thin film. After optimization, a plasma is generated and (1) conditions for crystallization while maintaining the temperature at 150 ° C or lower, and (2) conditions for crystallization within 15 minutes required for crystallization. The crystallization is performed under a condition that satisfies at least one of the conditions.

 Of course, both conditions may be satisfied.

In the present invention, a plasma is generated under the condition that a high-frequency electric field is concentrated on an amorphous thin film, which is a raw material that is different from a generally used uniform high-frequency plasma, so that a substrate supporting the thin film can be formed. Eliminates the need to heat the temperature with a heater, etc., and avoids extreme temperature rise due to the application of high frequency.It enables the production of crystalline thin films in a relatively short time while maintaining the temperature at 150 ° C or less. .

The inventors set the electrode arrangement for applying a high-frequency electric field, the position of the thin film to be crystallized, and the type of gas introduced to generate plasma, among various control parameters. After that, by optimizing the gas pressure, the amorphous thin film can be filled in a short time of 15 minutes or less, or while the substrate temperature is kept at 150 ° C or less, or both. It has been found that crystallization can be carried out at a substrate temperature of 150 ° C. or less for minutes or less.

[0020] Specifically, various conditions in the apparatus, such as the shape of the high-frequency application apparatus to be used, the installation position of the amorphous thin film in the high-frequency application apparatus, the frequency of the applied high-frequency wave, and the type of plasma gas, are set. After setting, the gas pressure in the device is optimized, and the gas pressure is once specified in this way, and thereafter, the gas pressure is set to the specified condition only, and the reproducibility is stable. It was confirmed that a uniform crystal thin film could be obtained.

 [0021] By controlling the pressure of the gas for generating plasma in the high-frequency application device in which the amorphous thin film is disposed to the pressure optimized in the present invention, the high-frequency electric field is converted to the amorphous thin film. You will concentrate. This means that the temperature of the unprocessed thin film is maintained at a low temperature of 150 ° C or less until it is crystallized, or that it is crystallized in a relatively short time of 15 minutes or less. It can be confirmed that at least one is satisfied. Furthermore, when optimized by controlling the gas pressure, it is possible to achieve crystallization while maintaining the temperature at about 60-80 ° C depending on the conditions. Therefore, a low-melting resin film is used as the substrate. Even in the case where it is used, if it is possible to produce a crystalline thin film, it has the following advantages.

 [0022] Specific examples of the optimal pressure of gas include, for example, a capacitively coupled high-frequency application device in which two electrodes each consisting of a divided semi-cylindrical chamber and a cylindrical chamber having an approximate diameter of 20 cm are installed. When oxygen is used as a gas for generating plasma when the frequency of the applied high frequency is 13.56 MHz, the amorphous thin film is crystallized by changing the pressure of oxygen from 2800 Pa to 4800 Pa. It is possible to do.

By applying the above conditions, for example, an amorphous titer thin film formed on a silicon wafer by a sol-gel method can be made an anatase-type titania crystal, and can be formed on soda lime glass by a sputtering method. The formed amorphous titanium thin film was able to be an anatase type titanium crystal. In addition, amorphous tin doped by sputtering was formed on a substrate in which a silica thin film was formed as an Al-Li-bar on soda-lime glass. It was possible to crystallize the imide oxide thin film.

 As described above, by optimizing the gas pressure, crystallization can be stably performed with good reproducibility irrespective of the method and material for forming an amorphous thin film and regardless of the type of substrate. What we can do is now possible.

 [0025] Further, in the above-described capacitively coupled high-frequency application device, when the gas generating plasma is also replaced by argon, oxygen pressure is set to 3300 Pa or more to crystallize the amorphous thin film. It is possible. Although the upper limit of the preferable pressure is not clear, the extrapolation of the experimental results is considered to be 15000 Pa, although the limiting force of the experimental apparatus used in the present invention is not clear. In other words, when the gas generating plasma is argon, the amorphous thin film can be crystallized by setting the pressure of argon to 35,000 Pa to 15000 Pa.

 Thus, the pressure range of the gas suitable for crystallization can be specified by the type of gas generating the plasma, and the crystallization can be stably performed with good reproducibility.

 [0026] It was also confirmed that in any of the above cases, crystallization was achieved by applying a high-frequency electric field for about 5 minutes. In addition, in order to confirm the temperature change of the thin film when the manufacturing method of the present invention is applied, the application of the high-frequency electric field is continued for up to one hour, and the temperature of the thin film during the process is measured using a radiation thermometer. Was measured. FIG. 1 is a graph showing a temperature change of a thin film during a high-frequency electric field application process. As is clear from Fig. 1, the temperature of the thin film increased only to about 70 ° C by the crystallization treatment for 5 minutes, and even after 1 hour, the temperature of the thin film did not exceed 120 ° C.

 [0027] The crystalline thin film of the present invention is usually formed on a substrate, but the substrate used in the present invention is not particularly limited, for example, a conductor such as a metal or a silicon wafer, various inorganic compounds, and the like. A general-purpose substrate such as various organic compounds (various polymers) can be used without limitation.

For example, various substrates (for example, soda lime glass and quartz glass), quartz, and the like can be given as the substrate made of an inorganic compound. In the case of using an inorganic compound containing an alkali component such as soda lime glass, a transparent conductive oxide thin film or a thin film containing titanium oxide used as a photocatalyst as a main component or a crystallization process is used. In addition, in order to prevent alkali components from being mixed into the thin film from the substrate, it is also preferable to laminate silica as an alkali barrier layer on the substrate.

 [0028] Examples of the base of various organic compounds include, but are not limited to, polyethylene terephthalate, polyethylene, polystyrene, polycarbonate, polypropylene, and polyimide. When using these plastics, it is also preferable to laminate an acrylic hard coat on the substrate in order to improve the hardness of the plastic substrate and improve the scratch resistance of the thin film. Further, it is also preferable to laminate silica / silicon nitride on the substrate in order to improve the adhesion to the laminate.

 [0029] In particular, since the heat resistance is low, and it is extremely difficult to obtain a crystalline thin film by a conventional technique for a substrate, the true value of the present invention is exhibited.

 That is, as described above, the crystalline thin film of the present invention has a temperature of 150 ° C.

Substrates that can be manufactured under temperature conditions of about 0 ° C and that have been difficult to use because of the low heating of substrates, such as low melting point thermoplastic resin substrates And heat-resistant resin substrates, specifically, ionomers, acetal resins, low-density polyethylene resins, and the above-mentioned organic compound substrates having a low melting point can be used. By forming a uniform and good crystalline thin film on a resin substrate, it can be applied to a wide range of application fields such as semiconductor devices, displays and optical films.

 [0030] Further, not only a resin substrate but also paper, cloth, non-woven fabric, etc. may be used to form an amorphous thin film thereon, or the surface of fibers constituting paper, cloth, non-woven fabric, etc. may be made amorphous. Even in the case of coating with an amorphous thin film, these amorphous thin films can be crystallized well without affecting the base material. Therefore, not only the above-mentioned substrates but also a fiber material, which has conventionally been difficult to form a crystalline thin film, a plurality of bundled or bonded fiber aggregates, a paper made of the fiber material, a cloth (woven cloth, knitted cloth) In addition, it has become possible to form a crystalline thin film on the surface of a nonwoven fabric or the like as a substrate (substrate).

[0031] In the present invention, the amorphous thin film and the thin film having low Z or crystallinity prepared for obtaining a crystallized thin film may have any composition, as well as a method of producing the amorphous thin film. For example, a metal alkoxide solution is applied to obtain a thin film. Thin film and Z or low crystallinity formed by various manufacturing methods such as so-called dry film forming method, such as a sputtering method, a sputtering method, a plasma CVD method, a photo CVD method, and a laser ablation method. The deviation of the thin film can be suitably applied to the present invention.

 In the present invention, the term “amorphous thin film and Z or thin film having low crystallinity” strictly means that the positional correlation between two atoms is up to a middle distance of about 1.5 nm like glass. This refers to a thin film with an amorphous structure that has only an amorphous structure, or a thin film that shows a slight crystal diffraction peak by X-ray diffraction but does not have sufficient crystal diffraction peak intensity to be a single crystal or polycrystalline thin film. In addition to the `` amorphous thin film and Z or thin film having low crystallinity '' defined in the narrow sense described above, `` a crystalline thin film having a certain crystal diffraction peak by X-ray diffraction, This means that a thin film having a crystal diffraction peak intensity sufficient to form a single-crystal or polycrystalline thin film may be included.

 As the amorphous thin film, in addition to “amorphous thin film completely forming a continuous layer”, “strictly speaking, it cannot be said that an amorphous substance forms a thin film. Also, in the case of a “thin film in which fine particles are arranged in a layer with slight voids on the surface of the substrate”, the crystallization effect of the present invention can be similarly exhibited. It shall be included in the crystalline thin film.

 [0034] The method of applying a high-frequency electric field includes a so-called capacitive coupling type method in which an amorphous thin film is placed between two electrodes, and a so-called induction method in which an amorphous thin film is placed inside a coil electrode. There are a method called a coupling type and a method of introducing a high frequency into a space where an amorphous thin film is placed by a waveguide. In the present invention, a method of applying a shifted high-frequency electric field may be employed. Industrially, the application of a high-frequency electric field by the capacitive coupling method is more preferably used because the size can be more easily increased.

As described above, in the present invention, a method of optimizing the pressure of a gas for generating plasma in order to generate plasma under a condition where a high-frequency electric field is concentrated on the amorphous thin film is used. However, this optimization is based on various conditions selected from the shape of the high-frequency application device, the installation position of the amorphous thin film in the high-frequency application device, the frequency of the applied high frequency, and the type of gas to be plasma. First, an amorphous thin film formed on a substrate by the above-described method is placed in a high-frequency application device, and the frequency of the applied high-frequency wave is changed. After deciding the wave number and the type of plasma gas, the pressure of the gas generating the plasma may be experimentally optimized. Once this optimization is performed, a uniform crystalline thin film can be produced with good reproducibility regardless of the type of the amorphous thin film and the type of the substrate as long as the same apparatus and the same gas are used.

 [0036] As the pressure of the gas, a high pressure condition exceeding lOOOPa is preferably used. For example, the apparatus used in the examples described later may be, for example, a radio frequency of 13.56 MHz, which is approved for industrial use under the Radio Law. In an example in which an electric field was applied and oxygen was used as the gas, crystallization was achieved in 15 minutes or less while maintaining the temperature at 100 ° C or less when the oxygen pressure was set at 2800 Pa to 4800 Pa.

 In an example where the gas that generates plasma is argon, the pressure of argon is set to 3300 Pa, and when extrapolated from the experimental results to 15000 Pa, the temperature is maintained at 100 ° C or less and within 15 minutes. Crystallization was achieved.

 From this, it can be seen that the optimal pressure is in a very limited range, rather than simply setting the gas pressure to low or high pressure. For this reason, it is considered that such knowledge has not been obtained in the past. In this way, by finding the optimal pressure under the predetermined conditions, the crystallization of the amorphous thin film can be achieved under the low temperature condition regardless of the type of the amorphous thin film and the type of the substrate. That is useful.

 As described above, in the present invention, it is possible to form a crystalline thin film with good reproducibility by optimizing the gas, and the method of the present invention provides an amorphous thin film formed on a low-melting-point substrate and Z or a crystalline thin film. Since the present invention is applicable to a thin film having a low thickness, the crystalline thin film of the present invention and the method for producing the same can be applied to a wide range of technical fields.

 Example

 Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the examples.

 (Example 1)

 (Formation of amorphous thin film)

Titanium alkoxide (NDH-510C) manufactured by Nippon Soda Co., Ltd. is formed on a silicon wafer by a spin coating method, and dried at 120 ° C in the air. Your thin film was created.

 [0038] (crystallization)

 In a capacitively coupled high-frequency application device in which two divided semicylindrical electrodes of a cylindrical chamber with an approximate diameter of 20 cm were installed, the amorphous titanium thin film obtained above was placed roughly in the center of the chamber. With the pressure of oxygen set to 4000 Pa, a high frequency electric field of 13.56 MHz was applied at a power of 300 W for 10 minutes. When the temperature of the titanium thin film was measured with a radiation thermometer, the temperature was 27 ° C., the same as room temperature, before application of the high-frequency electric field, and was 60 ° C. immediately after application of the high-frequency electric field.

FIG. 2 shows an X-ray diffraction profile before and after the application of a high-frequency electric field to the above-mentioned titer thin film. FIG. 2 shows that the titania thin film was amorphous before the application of the high-frequency electric field and was crystalline after the application of the high-frequency electric field.

 In Example 1, crystallization can be achieved at a low temperature of 60 ° C. and in a short time of 10 minutes by optimizing the pressure of the gas. It is estimated that plasma is generated.

[Examples 2 and 3]

 A high-frequency electric field was applied in the same manner as in Example 1 except that the amorphous titanium thin film used in Example 1 was used, and the oxygen pressure was changed to two kinds, 4300 Pa and 3300 Pa. As a result of measuring the X-ray diffraction profile in the same manner as in Example 1, it was found that in each case, after the application of the high-frequency electric field, the titanium thin film was crystallized. When the temperature of the titanium thin film was measured with a radiation thermometer, the temperature was 25 ° C, the same as room temperature, before application of the high-frequency electric field, and was 55 ° C to 60 ° C immediately after the application of the high-frequency electric field.

 In Examples 2 and 3, as in Example 1, crystallization could be achieved at a low temperature of 55-60 ° C and in a short time by optimizing the gas pressure.

[Comparative Examples 1 to 4]

A high-frequency electric field was applied in the same manner as in Example 1 except that the amorphous titanium thin film used in Example 1 was used, and the oxygen pressure was changed to 1200 Pa, 1700 Pa, 2200 Pa, and 5400 Pa. . As a result of measuring the X-ray diffraction profile, it was found that the titanium thin film was crystallized even after the application of a high-frequency electric field in any case. Comparison with Example 2 Figure 3 shows the X-ray diffraction profile near the (1, 0, 1) diffraction line of the titania thin film after application of the high-frequency electric field obtained in Example 1. FIG. 3 shows that crystallization can be performed in a short time by controlling the oxygen pressure!

 In Comparative Examples 1 to 4 in which the gas pressure was not optimized, crystallization could not be achieved under low-temperature conditions.Therefore, plasma was generated under the condition that the high-frequency electric field was concentrated on the amorphous thin film. It is estimated that

Example 4

The 15nm silica on a substrate was formed as an alkali barrier layer on soda lime glass, using an indium oxide containing tin 10 at _^0/0 as a target to indium, the DC sputtering method, a thickness of 150nm tin-doped oxide An indium thin film was formed.

 A high-frequency electric field was applied in the same manner as in Example 1 (gas pressure: 4000 Pa). Figure 4 shows the X-ray diffraction profiles before and after the application of the high-frequency electric field. From FIG. 4, it can be seen that the tin-doped indium oxide thin film has a low crystallinity before the application of the high-frequency electric field, and becomes a crystalline thin film after the application of the high-frequency electric field.

 The temperature of the tin-doped indium oxide thin film was measured with a radiation thermometer. The temperature was 27 ° C before application of the high-frequency electric field, and was 60 ° C immediately after the application of the high-frequency electric field. This indicates that crystallization can be achieved at a low temperature of 60 ° C. in a short time by optimizing the gas pressure, as in Example 1, even when the types of the substrate and the amorphous thin film are changed.

[Example 5-7, Comparative Example 5-7]

 A tin-doped indium oxide thin film prepared in the same manner as in Example 4 was prepared by setting the oxygen pressure to 12 OOPa (Comparative Example 5), 1700 Pa (Comparative Example 6), 2200 Pa (Comparative Example 7), 3300 Pa (Example 5), 4300 Pa ( A high-frequency electric field was applied in the same manner as in Example 4, except that the method was changed to 6 in Example 6) and 5400 Pa (Example 7). As a result, it was clear that crystallization was performed in Examples 5 to 7, and that the thin film was not crystallized in Comparative Examples 5 to 7.

FIG. 5 shows an X-ray diffraction profile near the indium oxide (2, 2, 2) diffraction line of the tin-doped indium oxide thin film after application of the high-frequency electric field in Example 5-7 and Comparative Example 5-7. FIG. 5 indicates that crystallization can be performed in a short time by controlling the oxygen pressure. Incidentally, the tin-doped indium oxide thin film was compared with the titanium used in Example 1. Because of its characteristics of easy crystallization and crystallization, a certain degree of crystallization has been achieved even under the condition of 5400 Pa, in which the titanium is not crystallized by the treatment for 10 minutes. However, in comparison with Examples 5 and 6, the degree of crystallization is low, and from the viewpoint of good crystallization in a short time, particularly excellent crystallization is achieved in the optimal pressure range obtained in the case of titaure. You can see that

 When the temperature of these tin-doped indium oxide thin films was measured with a radiation thermometer, the temperature was 25 ° C to 28 ° C, the same as room temperature, before application of the high-frequency electric field, and 55 ° C to 65 ° C immediately after application of the high-frequency electric field. there were.

 [0044] Further, from the results of Figs. 3 and 4, crystallization can be achieved by controlling the oxygen pressure regardless of the composition of the thin film, whether it is an amorphous thin film or a thin film having low crystallinity. It can be done at low temperature and in a short time!

 [Examples 8, 9 and Comparative Examples 8-10]

 An amorphous titanium thin film having a thickness of 270 nm was formed in the same manner as in Example 1 on a substrate in which 40 nm silica was formed as a gas barrier layer on a polyethylene terephthalate film by a DC scanner method. Except that the oxygen pressure was changed in six ways: 1200 Pa (Comparative Example 8), 2200 Pa (Comparative Example 9), 3300 Pa (Example 8), 4300 Pa (Example 9), and 5400 Pa (Comparative Example 10). In the same manner as in 1, a high-frequency electric field was applied. As a result of measuring the X-ray diffraction profile, almost the same results as in FIG. 3 were obtained. This indicates that the present invention is suitable for crystallization of an amorphous thin film formed on a substrate having poor heat resistance.

 [Examples 10-12, Comparative Examples 11-13]

 A high-frequency electric field was applied in the same manner as in "Examples 5-7 and Comparative Examples 5-7" except that a substrate formed by depositing 40 nm silica as a gas barrier layer on a polyethylene terephthalate film by a DC notch method was used. did. As a result, almost the same results as in FIG. 5 were obtained. The degree of crystallization achieved also showed the same tendency as in Examples 5-7. This indicates that the present invention is suitable for crystallization of an amorphous thin film formed on a substrate having poor heat resistance.

 [Example 13-16]

The 20nm silica on a substrate was formed as an alkali barrier layer on soda lime glass, using an indium oxide containing tin 10 at _^0/0 as a target to indium, spa Using an argon gas containing oxygen of 3% by volume _^0/0 as Ttagasu, by a DC sputtering method to deposit a tin-doped indium film having a thickness of LOOnm. A high-frequency electric field was applied in the same manner as in Example 1, except that the plasma gas was argon, the gas pressure was 12000 Pa (Example 13), and the output from the power supply was 300 W. In addition, a high-frequency electric field was applied in the same manner except that the pressure was set to 100 OOPa (Example 14), 7900 Pa (Example 15), and 3300 Pa (Example 16).

 FIG. 6 shows an X-ray diffraction profile near the indium oxide (2, 2, 2) diffraction line of the tin-doped indium thin film. Figure 6 shows that the tin-doped indium thin film has crystallized to some extent even before the plasma treatment, but its crystallinity is low. I understand.

[Examples 17-19, Comparative Example 14]

Except that the sputtering gas using an argon gas containing oxygen of 1 volume _^0/0 was deposited tin-doped indium thin film in the same manner as in Example 13. A high-frequency electric field was applied in the same manner as in Example 13 except that the plasma gas pressure was 100000Pa (Example 17), 7900Pa (Example 18), 3300Pa (Example 19), and 1300Pa (Comparative Example 14).

 FIG. 7 shows an X-ray diffraction profile near the indium oxide (2, 2, 2) diffraction line of the tin-doped indium thin film. From FIG. 6, no X-ray diffraction peak was observed before the plasma treatment, indicating that the tin-doped indium thin film was amorphous. When the plasma gas pressure was 1300 Pa, crystallization did not progress even after plasma treatment, but when the plasma gas pressure was 7900 Pa and 100 000 Pa, crystallization progressed in a short time. When the gas pressure is 3300 Pa, the crystallization is progressing, but it is difficult to say that crystallization is sufficient.

[Examples 20 to 22, Comparative Example 15]

Except that the sputtering gas used was argon gas containing oxygen of 5 vol _^0/0 was deposited tin-doped indium thin film in the same manner as in Example 13. A high-frequency electric field was applied in the same manner as in Example 13 except that the plasma gas pressure was 12000 Pa (Example 20), 100 000 Pa (Example 21), 7900 Pa (Example 22), and 6600 Pa (Comparative Example 15).

Figure 8 shows the vicinity of the indium oxide (2, 2, 2) diffraction line of the tin-doped indium thin film described above. 3 is an X-ray diffraction profile of the sample. Fig. 8 shows that the tin-doped indium thin film has crystallized to some extent before the plasma treatment, but its crystallinity is low. If the plasma gas pressure is 6600 Pa, crystallization does not proceed even if plasma treatment is performed. If the plasma gas pressure is 7900 Pa, 10000 Pa, and 12000 Pa, crystallization proceeds in a short time. I understand.

 From these results, it is not possible to achieve crystallization in a short time unless the argon gas pressure is at least 3300 Pa or more.Although it depends on the properties of the tin-doped indium thin film, the best results are obtained at around 7900 Pa. It can be said that crystallization can be achieved.

 The plasma gas pressure at which crystallization can be favorably achieved in the treatment with argon plasma in Examples 13 to 22 is different from the Bra gas pressure at which crystallization can be favorably achieved in the treatment with oxygen plasma in Examples 11 to 12. From these comparisons, it was shown that the suitable pressure range differs depending on the type of gas used for generating the plasma.

Claims

The scope of the claims  [1] An amorphous thin film and a thin film of Z or low crystallinity are placed in a high-frequency application device, and plasma is generated under the condition that a high-frequency electric field is concentrated on the thin film. A crystalline thin film obtained by crystallization under at least one of the following two conditions: crystallization conditions while maintaining the following conditions, and (2) crystallization time within 15 minutes.  [2] The crystal thin film according to claim 1, wherein the crystal thin film is a thin film containing as a main component at least one selected from metal oxides, metal nitrides, metal oxynitrides, metal carbides, and semiconductors. Crystal thin film.  [3] After arranging an amorphous thin film and a thin film of Z or low crystallinity in a high-frequency applying device and optimizing the gas pressure in the device so that the high-frequency electric field is concentrated on the thin film, And at least one of the following two conditions: (1) conditions for crystallization while maintaining the temperature at 150 ° C or lower, and (2) conditions for crystallization within 15 minutes required for crystallization. A method for producing a crystalline thin film, characterized by crystallizing under conditions.  [4] The shape of the high-frequency application device, the installation position of the amorphous thin film and the Z or low-crystalline thin film in the high-frequency application device, the frequency of the applied high frequency, and the type and force of the plasma gas are selected. 4. The method for producing a crystalline thin film according to claim 3, wherein the pressure of a gas serving as plasma is optimized according to the above conditions.  [5] The method for producing a crystal thin film according to claim 3, wherein a capacitively-coupled high-frequency applying device is used as the high-frequency applying device.  6. The method for producing a crystalline thin film according to claim 3, wherein a capacitively coupled high-frequency applying device provided with opposed electrodes is used as the high-frequency applying device.  7. The method for producing a crystalline thin film according to claim 3, wherein a capacitively coupled high-frequency applying device provided with a pair of electrodes facing each other is used as the high-frequency applying device.  [8] The method for producing a crystalline thin film according to claim 3, wherein a capacitively-coupled high-frequency application device provided with two divided semi-cylindrical electrodes in a cylindrical chamber is used as the high-frequency application device. . [9] Place the amorphous thin film formed on the substrate in the high frequency After deciding the frequency and the type of plasma gas, we experimentally optimize the pressure of the gas that generates the plasma,  Then, the plasma is generated by setting the pressure of the gas for generating the plasma in the high-frequency application device within the range of the optimum value experimentally obtained.  (1) Conditions for crystallizing the amorphous thin film placed in the high-frequency application device while maintaining the temperature at 150 ° C or less, (2) Conditions for crystallization within 15 minutes, A method for producing a crystalline thin film, characterized in that crystallization is performed under a condition that satisfies at least one of the two conditions.  [10] Plasma is generated by using oxygen as the plasma gas and setting the pressure of oxygen in the high-frequency application device to 2800Pa-4800Pa when the applied high-frequency frequency is 13.56MHz. 10. The method for producing a crystalline thin film according to claim 9.  [11] Using argon gas as the plasma gas and generating plasma by setting the pressure of oxygen in the high-frequency application device to 3300Pa-15000Pa when the applied high-frequency frequency is 13.56 MHz. 10. The method for producing a crystalline thin film according to claim 9, wherein: