JP4911413B2 - Oxide thin film forming equipment - Google Patents

Description

  The present invention relates to a technique for producing an oxide thin film by an oxidation reaction utilizing light from a thin film of a silicon compound coated on a substrate having plasticity such as general-purpose plastic and low durability against heat and ultraviolet rays. .

  In the world of the electronics industry, in order to realize the manufacture of large area electronic devices that have been attracting much attention in recent years, there is an interest in technology for producing high performance electronic devices on a flexible substrate such as plastic by a low temperature printing process. .

  An organic polymer thin film exists as a thin film material that performs the same function, but an inorganic oxide film such as silicon oxide that has high durability against high electric fields and long-term performance reliability is more suitable for electronic device applications. ing.

  As a method for producing a silicon oxide thin film by printing, there are a sol-gel method using a metal alkoxide compound as a raw material and an organometallic thermal decomposition method using an organic metal compound as a raw material. In order to complete the reaction to the silicon oxide thin film by these methods, it is necessary to heat and bake at a high temperature of 400 ° C. or higher after the raw material is applied to the substrate. Since the maximum heat-resistant temperature is 200 ° C., it cannot be used for manufacturing an electronic device by such a printing method on a substrate.

  When silicon oxide is produced by performing a heat treatment of silazane compound in an oxidizing atmosphere at 200 ° C. or lower, the electrical characteristics of the obtained film are extremely low due to imperfection of the reaction product.

  There already exists a technique for producing a silicon oxide thin film by adding a catalyst such as organic amine or palladium to a silazane compound by low-temperature heating and humidification treatment (see Patent Document 1). However, since the catalyst remains, there is a disadvantage that the electrical characteristics are lowered due to the impurity effect.

  In addition, there is a report that realizes the reaction at a low temperature by bringing the catalyst into contact with the outside instead of adding the catalyst to the raw material (see Patent Document 2). However, even in this case, the catalyst component is adsorbed on the surface of the film, and the above-described impurity effect appears. In the above method, water molecules adsorbed by the humidification process deteriorate the electrical properties of the film, so it is necessary to remove the water molecules. To that end, high temperature treatment or heat treatment in a vacuum environment is necessary. Thus, it is impossible to realize a low-temperature printing process for manufacturing a device on a substrate having low heat resistance like a general-purpose plastic plastic.

  In order to overcome the above-described problems of impurities, a silicon oxide thin film is produced by low-temperature treatment at 150 ° C. or lower and irradiation with ultraviolet light from an ultraviolet lamp from a coating film of a silazane compound and siloxane compound not containing impurities such as a catalyst. Patent applications regarding technology have been made (see Patent Document 3).

However, the resistivity of the silicon oxide insulating film manufactured based on the invention described in Patent Document 3 is 10 ¹² to 10 ¹⁴ Ωcm, which is too low for an insulating film that can be used in a semiconductor element. is there. Currently, there is a demand for a resistivity of 10 ¹⁵ Ωcm, which is an insulating performance equivalent to that of a thermal oxide film on the surface of a silicon crystal, which is an insulating film element used for general purposes.

  A patent application has been filed for an apparatus and a forming method for forming a silicon oxide thin film by irradiation with ultraviolet light from a silicon compound coating film that satisfies the above-described required insulation performance (see Patent Document 4).

However, the thin film forming apparatus shown in Patent Document 4 performs ultraviolet irradiation from directly above the thin film, so that the irradiated ultraviolet light passes through the silicon oxide thin film on which the ultraviolet light has been formed and reaches the substrate. Some general-purpose plastics that cause alteration by light cannot be used for the substrate. Further, many general-purpose plastics have a large volume change even at a temperature of 200 ° C. or lower, and the thin film forming apparatus shown in Patent Document 4 for these materials has a thin film temperature holding mechanism. Is achieved by heat conduction from the substrate, resulting in a decrease in adhesive force and the generation of cracks and grain boundaries due to large differences in volume change due to heat between the thin film and the substrate, resulting in mechanical properties and electrical properties. It has the disadvantage that the characteristics are degraded.
JP-A-11-105187 Japanese Patent Laid-Open No. 7-223867 WO2006 / 019157 Japanese Patent Application No. 2006-346861

  The present invention efficiently forms a silicon oxide thin film having high insulation performance on a general-purpose plastic substrate having low durability against heat and ultraviolet light without directly irradiating the substrate with the heat or light energy. An object of the present invention is to provide an apparatus for performing the method and a method for forming the thin film. Further, by providing a substrate that moves back and forth between a thin film coating apparatus and a thin film forming apparatus, an apparatus for producing a large number of semiconductor thin film elements at high speed by a simple and low-cost printing method such as a roll-to-roll method is provided. With the goal.

  In the present invention, a coating film of a silicon compound containing a silazane structure or a siloxane structure is formed on a plastic substrate having plasticity, the coating film is converted into a silicon oxide thin film, and the thin film is part of an insulating layer or a sealing layer. Thus, a semiconductor thin film element is formed.

When ozone or atomic oxygen is reacted with a silazane compound having a silazane structure, SiO ₂ , ammonia and oxygen are generated based on the following reaction formulas (1) and (2).

_{2 (-SiR 2 -NR -) +} 2O 3 → 2 (-SiO 2 -) + 2RNH 2 + O 2 (1)
(—SiR ₂ —NR —) + 2O → (—SiO ₂ —) + NR ₃ (2)

This reaction does not require a particularly high temperature in order to cause the reaction, and the reaction can proceed without using a catalyst. Therefore, at a temperature close to room temperature and without using an additive or the like. SiO ₂ can be produced.

In addition, the substance supplied for the reaction is oxygen, and the exhausted substances after the reaction are ammonia and oxygen, both of which are gases, so there is almost no possibility that impurities will remain in the thin film. High-purity SiO ₂ can be produced. In addition, since no water is used for the reaction, it is possible to prevent insulation deterioration due to residual adsorbed water or the like.

In the case of the present invention, since the reactivity of active ozone or atomic oxygen is remarkably high, the reaction can proceed until the Si—N bond is almost completely eliminated, and a high-purity SiO ₂ thin film can be produced. it can.

When ozone or atomic oxygen is reacted with a silicon compound having a siloxane structure, SiO ₂ , carbon dioxide and water are generated based on the following reaction formulas (3) and (4).
_{3 (-Si (CH 3) 2} -O -) + 8O 3 → 3 (-SiO 2 -) + 6CO 2 +
9H ₂ O (3)
_{(-Si (CH 3) 2 -O} -) + 8O → (-SiO 2 -) + 2CO 2 +
3H ₂ O (4)

This reaction does not require a particularly high temperature to cause the reaction, and the reaction can proceed without using a catalyst. For this reason, SiO ₂ can be produced at a temperature near room temperature and without using an additive or the like.

In the reaction of converting the alkyl siloxane to produce SiO ₂ , carbon dioxide and water, which are gases, are generated as the effluent after the reaction. Therefore, a high-purity SiO 2 can be obtained by performing a heat treatment at 100 ° C. _Two thin films can be produced.

  According to the present invention, a silicon compound coating film containing a silazane structure or a siloxane structure is formed on an inexpensive general-purpose plastic substrate that has low resistance to heat and ultraviolet rays and has plasticity, and a silicon oxide insulating film is produced from the coating film In the step of performing, at least one conversion step to silicon oxide is performed by bringing active oxygen species such as ozone and oxygen atomic species generated by irradiation of ultraviolet light to the atmospheric gas containing oxygen chemical species into contact with the coating film. By including the steps or more, a semiconductor element can be manufactured by converting into silicon oxide.

  In addition, by including at least one direct heating process to the coating film without conducting heat to the substrate, the presently used general-purpose thin film transistor semiconductor element without impairing the physical properties of the substrate such as plasticity. It is possible to manufacture a semiconductor element having a silicon oxide thin film having the same insulation performance and high reliability.

  In addition, a silicon oxide thin film having a device for irradiating ultraviolet light and a device for heating in a chamber controlled by an atmospheric gas containing oxygen species on a substrate having a silicon compound coating film having a silazane structure or a siloxane structure An apparatus for manufacturing a semiconductor device used in the method for forming a semiconductor device is provided.

  Furthermore, in the present invention, the light energy from the ultraviolet light necessary for the conversion reaction on the thin film coated on the substrate surface is absorbed by the oxygen species in the atmospheric gas without degrading the substrate, and the conversion reaction takes place. An arrangement of an ultraviolet light lamp that efficiently generates the necessary active oxygen species, and an arrangement of a temperature holding device that does not cause thermal expansion or thermal degradation of the substrate by efficiently transferring thermal energy only to the thin film. By simultaneously satisfying, it is possible to produce a thin film having the required performance at a high speed and in a large amount.

  Furthermore, in the present invention, since the temperature to be held required for the conversion reaction is 0 ° C. or more and 200 ° C. or less, this is efficiently realized, and a temperature holding device suitable for eliminating thermal diffusion to the substrate A thin film forming apparatus provided with

  Furthermore, the present invention provides a thin film forming apparatus provided with an optimal arrangement of ultraviolet light irradiation device and temperature holding device in order to cause the aforementioned ultraviolet light and thermal energy to continuously act on the coated thin film.

  Furthermore, in this invention, a board | substrate is carried in continuously and the substrate surface cleaning process, the coating process of the thin film to the substrate surface, and a part or all components except raw materials, such as a solvent, are removed from a coating film. In order to carry out part or all of the steps, the conversion reaction step by contact of the active oxygen species generated by ultraviolet light irradiation with the thin film and the heat treatment, and the substrate with the thin film after the conversion reaction is quickly carried out By having a mechanism for continuously moving the substrate between the divided process chambers and the substrate, it is possible to efficiently manufacture thin film elements on the substrate that is continuously transported.

  Further, in the present invention, as means for forming a gas atmosphere controlled during the conversion reaction step described above, a gas inlet for introducing a gas whose composition, flow rate, pressure, temperature and other conditions are controlled, and a reaction It has a gas outlet for quickly discharging the later gas component from the conversion reaction process chamber.

  Furthermore, in the present invention, a laminated thin film is formed by alternately performing the above-described thin film coating step and conversion reaction step on the same substrate, thereby making it possible to manufacture a thin film element.

  The thin film transistor obtained by the manufacturing apparatus based on the present invention and the manufacturing method using the same can be produced by a printing method on a film base material made of a general-purpose plastic having a heat resistant temperature of about 100 ° C., which is difficult in the conventional vacuum process. In addition, since continuous film formation at low temperature and normal pressure is possible, high-speed mass production is realized by simple and low-cost means of a large area and flexible device. Unlike semiconductor elements formed from conventional organic coatings, the elements are composed of metal oxides with higher insulation performance, withstand voltage, and reliability, thereby miniaturizing the elements, extending their lifetime, and improving stability. Bring. In addition, the thin film produced by the multilayer structure according to the present invention enables the production of a high-quality thin film element regardless of the properties of the substrate and the electrode surface.

  Below, the preferable form for implementing this invention is shown.

The insulating layer constituting the semiconductor element manufactured according to the present invention is composed of a silicon oxide thin film manufactured by a coating process. The silicon oxide thin film is obtained by a conversion reaction from a coating film of a silicon compound containing a silazane structure or a siloxane structure. The silazane structure (the following [Chemical formula 1]) or the siloxane structure (the following [Chemical formula 2]) referred to here is a chemical structure represented by the following chemical formula.

R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the formula are each independently a hydrogen atom, alkyl group, alkenyl group, alkoxy group, hydroxyalkyl group, carboxylalkyl group, alkylcarbonyl group, alkoxycarbonyl group. Represents a substituent selected from the group consisting of an alkylcarbonyloxy group, an aromatic hydrocarbon group, and an aromatic heterocyclic group.

  The molecular chain of the compound may be any of linear, cyclic, and network by crosslinking. Although the molecular weight and molecular weight distribution of the above compound are not particularly defined, those having a molecular weight of 100 to 100,000 are generally used.

  The thin film element forming apparatus according to the invention of the present application is configured to apply active oxygen species such as ozone and oxygen radicals generated by irradiating the atmosphere gas introduced into the apparatus with ultraviolet rays to the substrate coated with the silicon compound. By contacting the coating film and maintaining the thin film at a specific temperature of 200 ° C. or lower, the silicon compound thin film is converted into a silicon oxide thin film and at the same time the physical and electrical performance is improved by the thermal annealing effect. A thin film whose properties are controlled according to the application to be used can be easily produced.

  In the present invention, a silicon oxide thin film having high insulation performance can be obtained simply by maintaining the coating film of the silicon compound at a temperature of 200 ° C. or lower. Therefore, 400 is performed by the conventional sol-gel method and thermal decomposition method. The heating temperature may be markedly lower than the heat treatment at from 1000C to 1000C or higher.

  Compared to these methods, it is possible to manufacture large-area thin films at a short time, with low energy costs, and without requiring large facilities such as heat diffusion prevention. It can be much cheaper. Conventionally, the only way to form a silicon oxide thin film on a general-purpose plastic substrate with low heat resistance is to use a vacuum process such as vapor deposition or sputtering. Whereas an exhaust device was necessary, the present invention made it possible to produce a high-performance silicon oxide thin film element on a plastic substrate by a simple device.

  In particular, it has become possible to form a high-performance electronic element such as a thin film transistor on a sheet substrate made of general-purpose plastic that is lightweight, inexpensive, plastic, and highly moldable. Low-cost general-purpose plastic sheet substrates that are currently distributed in large quantities in the market are currently only those with a heat-resistant temperature of around 100 ° C. Therefore, a thin-film plastic sheet having necessary electrical characteristics without thermal diffusion to the substrate The device can be formed by the present invention, and is expected to be applied to lightweight and inexpensive flexible electronic devices that will appear in the future.

  In the present invention, the silicon oxide thin film to be produced is obtained by applying the above compound on a substrate to produce the original thin film and converting it, but the substrate used at that time is Anything may be used without any particular limitation.

  Commonly used materials are polycarbonate, polyetherimide, polyimide, polyethylene terephthalate (PET), polyethylene naphthalate, polypropylene, polyphenylene sulfide, polyether ether ketone, polyether ketone, polyether sulfone, polysulfone, polyphenylene sulfide, Although it is a flexible plastic substrate such as polyarylate and polyaramid, a glass, metal, or ceramic substrate may be used. Alternatively, a crystal substrate such as silicon, gallium nitride, gallium arsenide, and gallium phosphide can be used. At this time, in order to stabilize the device, extend the life, and improve the workability of the sealing thin film formed thereon, the device is composed of a mixture or lamination of a plurality of materials or subjected to a surface treatment. It is also possible.

In the thin film forming apparatus according to the present invention, the surface of the substrate on which the silicon oxide thin film is formed is cleaned, degassed, and impurities are improved in order to improve the physical and electrical performance of the thin film and the adhesion of the coating film. Although there is a means for performing removal or the like, the method is not particularly limited. Commonly used cleaning and impurity removal methods include immersion cleaning with flowing clean water, organic chemicals, acidic chemicals, alkaline chemicals, and mixtures thereof, flowing liquid cleaning, ultrasonic cleaning, and vapor generated from the above chemicals. Contact cleaning, contact cleaning of ozone and active gas species (molecules, ions, radicals, plasma, etc.), methods of removing impurities by impinging inert chemical species such as argon and xenon on the substrate surface, lasers and various energy beams And a method for removing impurities by irradiation. Moreover, methods generally used as a degassing method include heat treatment, laser and various energy ray irradiation, or discharge treatment. It is desirable to perform cleaning and degassing without using a chemical solution in a reduced pressure atmosphere. The degree of vacuum is preferably in the range of 10 ⁻¹⁰ Torr to 10 ⁻³ Torr.

  Before applying the silicon compound to the substrate, in order to control surface properties such as wettability such as the surface of the substrate or the electrode surface produced on the substrate, a surface modification layer is formed by applying or adsorbing a surface active substance or the like. Forming a multilayer structure by coating a silicon compound thereon, improving the adhesion, denseness, surface smoothness, etc. of the thin film element, and producing a thin film element having excellent mechanical and electrical performance Obtainable.

  The silicon oxide thin film produced by the thin film forming apparatus of the present invention is obtained by preparing the original thin film by the process of applying the above-described silicon compound on the substrate, and obtaining the thin film by a conversion reaction. There is no limitation in particular as a formation method of the coating film at the time. Commonly used methods include spin coating, dip coating, cast coating, spray coating, ink jet, transfer, and letterpress printing, stencil printing, offset printing, and gravure printing, which are developed from these methods. A general printing method such as micro contact printing or a soft lithography printing method such as micro molding may be used.

  A thin film made of a silicon compound containing a silazane structure or a siloxane structure used in the present invention is formed by a coating method. The solvent used in this step is an aromatic hydrocarbon, an aliphatic hydrocarbon, an alicyclic carbonization, or the like. Hydrogen, halogenated hydrocarbons, halogenated aromatic hydrocarbons, ethers, amines and the like can be used. In general, benzene, toluene, xylene, ethylbenzene, cyclohexane, methylcyclohexane, pentane, hexane, heptane, octane, nonane, decane, ethyl ether, dipropyl ether, dibutyl ether, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran are preferably used. , Chloroform, methyl chloride, pyridine and the like. The solvent is preferably purified by removing impurities such as moisture and a small amount of inorganic components.

  A thin film made of a silicon compound containing a silazane structure or a siloxane structure used in the present invention is formed by a coating method, and the solvent used in this step is a single component or a mixed solvent containing two or more kinds of the above-mentioned solvents. Used as.

  The thickness of the silicon compound thin film containing a silazane structure or siloxane structure used in the present invention is 1 nm or more and 10 μm or less, preferably 5 nm or more and 1 μm or less.

  In the present invention, the silicon compound thin film coating step can be performed twice or more in order to produce a thin film having a sufficient film thickness as desired. In that case, it is also possible to perform the above-mentioned washing and degassing steps before and after the coating step. Moreover, when performing the above-mentioned application | coating process 2 times or more, it is also possible to laminate | stack and coat the thin film of a different compound.

  The silicon compound thin film used in the present invention may be provided with a step of heating the thin film after coating to remove part or all of the solvent. The heating device used here is not particularly limited, but generally a resistance heating device, an infrared heating device, or the like is used. At this time, the temperature atmosphere to be heated varies depending on the solvent to be used, but generally the heating temperature is preferably 20 ° C. or higher and 150 ° C. or lower.

  A method of irradiating the coating film with a laser or various energy rays for the purpose of removing the solvent is also possible. The atmosphere in which the silicon compound thin film is placed when heating is preferably performed in an atmospheric pressure atmosphere. Further, the time required for removing the heated solvent at this time is not particularly limited. Generally, it is 1 second or more and 180 minutes or less, but preferably 30 seconds to 60 minutes.

  Next, the substrate having the silicon compound thin film is carried into the conversion reaction process chamber. There is no particular limitation on the means for carrying in at this time. It is also possible to move the inside of the reaction section at a certain speed in order to continuously produce a thin film element. However, since some of the silicon compounds used in the present invention may be altered by oxygen, moisture, or temperature in the atmosphere, it is desirable that the atmosphere for transporting the substrate with the silicon compound thin film is controllable. .

  In the present invention, it is desirable that the reaction chamber for converting the silicon compound coating film into silicon oxide can control the gas atmosphere and temperature to appropriate conditions.

  As the whole or part of the atmospheric gas during the process of converting the silicon compound thin film used in the present invention into a silicon oxide thin film, ultraviolet light is applied to the atmospheric gas having all or part of the gas species containing oxygen. It is desirable to use ozone, active oxygen molecules, and active oxygen atoms obtained by irradiation. The oxygen-containing gas species used here are oxygen, ozone, carbon dioxide, carbon monoxide, sulfur dioxide, sulfur suboxide, water vapor, oxygen nitride, nitrogen dioxide, nitrous oxide, oxynitride, active oxygen molecules, Atoms and radicals.

  Nitrogen, argon, ammonia, and hydrogen that do not contain oxygen atoms may be used as part of the atmospheric gas during the process of converting the silicon compound thin film used in the present invention into a silicon oxide thin film. Of these, nitrogen and argon are inert gases that do not contribute to the conversion reaction to silicon oxide, and by adding this, the concentration of the reaction gas in the atmospheric gas and the intensity of ultraviolet light irradiation from the ultraviolet lamp can be adjusted. This makes it possible to control the film forming property and reaction rate of the silicon oxide thin film. Ammonia and hydrogen act as a catalyst for the conversion reaction, and thereby effects such as acceleration of the reaction and improvement of the film quality can be obtained.

  When irradiating ultraviolet light to an atmospheric gas containing oxygen species to convert the silicon compound thin film used in the present invention into a silicon oxide thin film, the wavelength of the irradiated ultraviolet light is not particularly limited. Generally used is 100 nm to 450 nm. Light having such a wavelength can be obtained by an excimer laser or the like in addition to a deuterium lamp, a xenon lamp, a metal halide lamp, an excimer lamp, a mercury lamp, or the like.

  In order to convert the silicon compound thin film used in the present invention into a silicon oxide thin film, the irradiation energy per unit time and unit area of the ultraviolet light is high when irradiating the atmosphere gas containing oxygen chemical species with ultraviolet light. As the total amount of active oxygen species involved in the conversion reaction increases and the conversion efficiency to silicon oxide improves, the same effect can be obtained by irradiating ultraviolet light with low energy for a long time. Therefore, the minimum necessary unit time of irradiation with ultraviolet light and irradiation energy per unit area are not particularly specified. Irradiation with ultraviolet light is not necessarily performed continuously, and there is no particular problem even with intermittent light irradiation or light irradiation with a pulsed light source.

  In the present invention, a silicon compound containing a silazane structure or a siloxane structure is used as a raw material, and it is applied on a substrate to form an elementary thin film, which is converted into a silicon oxide thin film. The process temperature for converting the silicon compound thin film to the silicon oxide thin film is generally 0 ° C. or higher and 200 ° C. or lower. However, the higher the temperature, the better the silicon oxide thin film having better electrical properties. Further, the time required for the conversion reaction at this time is not particularly limited. Generally, it is 1 minute or more and 720 minutes or less, but 5 minutes to 120 minutes is preferable.

  In part or all of the process of converting the silicon compound thin film used in the present invention into a silicon oxide thin film, in a reaction atmosphere containing ozone, water vapor, active oxygen molecules, active oxygen atoms, etc. that are more reactive than ordinary oxygen gas It is desirable to perform heat treatment at 0 ° C. or higher and 200 ° C. or lower. At this time, the heat treatment may be performed on the thin film of the coating raw material at the same time as the contact with the active oxygen species generated by the ultraviolet light irradiation or after the energy beam irradiation for a certain time.

  In the production process of converting the silicon compound thin film used in the present invention into a silicon oxide thin film, a temperature holding treatment of 0 ° C. or higher and 200 ° C. or lower is performed in a reaction atmosphere gas containing ozone, water vapor, active oxygen molecules, active oxygen atoms, and the like. There are no particular restrictions on the method used, but generally a resistance heating method, an infrared lamp heating method, a flash lamp heating method, a laser heating method, an electromagnetic wave heating method, or the like is used. Moreover, about the heating apparatus used for this heat processing, if the temperature of the thin film surface or the inside of a film | membrane is controllable, it will not specifically limit about the form, performance, and arrangement | positioning.

  The conversion reaction at the time of converting the silicon compound thin film used in the present invention into a silicon oxide thin film is performed once or more to obtain a silicon oxide thin film having finally required performance. The shape of the film at this time is not particularly limited.

  The conceptual diagram of the thin film forming apparatus of this invention is shown in FIG.1 and FIG.2. This thin film forming apparatus is used, for example, for forming a silicon oxide thin film used as a sealing layer and a gate insulating layer of a thin film transistor element in the process of manufacturing a display device on a flexible plastic substrate. FIG. 1 shows a pretreatment unit that performs surface treatment for improving the surface of a substrate to clean, deaerate, or improve wettability while the substrate is transported inside the manufacturing apparatus using the substrate transport device. A mechanism for sequentially moving a coating section for forming a thin film by applying the coating, a drying section for drying and removing a part or all of the solvent in the coating film, and a reaction section for performing a conversion reaction to silicon oxide The concept of arrangement is shown.

  The pretreatment unit includes a substrate pretreatment apparatus 50 having the above-described substrate cleaning means and substrate surface modification means. The coating section is provided with a coating film forming apparatus 40 having means for applying a liquid containing the above-described silicon compound as a part or all of the components onto the substrate. The drying unit is provided with a drying device 60 for removing all or part of the solvent in the coating film by heating or heating under reduced pressure. FIG. 2 shows a cross-sectional view of only the reaction part as seen from the direction of movement of the substrate. The reaction section is provided with a gas introduction pipe 70 and a gas discharge pipe 80 for introducing an atmospheric gas whose components, composition, temperature, flow rate and the like are controlled.

  Furthermore, the ultraviolet light 20 having means for irradiating ultraviolet light before reaching the coating film on the substrate with respect to the atmospheric gas, and heating for maintaining the coating thin film on the substrate at a certain temperature, and in some cases by light irradiation When the temperature of the equipment rises to a temperature higher than the heat resistant temperature, a temperature holding device 30 having means for cooling the substrate is provided. Further, although not shown in the figure, there are provided means for measuring the substrate temperature, means for evacuating the reaction part, means for controlling the composition, flow rate, pressure and the like of the gas introduced into the reaction part.

  In the above-described thin film element manufacturing apparatus, it is not always necessary to include a drying unit for drying and removing the solvent from the coating film. In that case, the solvent may be removed by irradiation with ultraviolet light in the reaction part or heating with a temperature holding device.

  In the above-described thin film element manufacturing apparatus, the pretreatment section, the coating section, the drying section, and the reaction section do not necessarily exist in the same apparatus, and may be independent apparatuses depending on the specifications of the substrate and the thin film element. Absent.

  The material and shape of the jig 10 for transporting the substrate are not particularly limited. In general, those made of soft rubber, metal, or glass are used, and not only the sheet-like shape shown in FIG. 1 but also a lattice or rod-like shape may be used.

  Since the speed at which the substrate is transported may need to be different in each process, means for independently controlling the transport speed in each process is required. A multi-stage roll mechanism or a dancer roll mechanism is used depending on the situation as a means for absorbing the speed difference between the respective steps that occurs at that time.

  A silicon compound was dissolved in a solvent to prepare a solution, which was used as a raw material for producing a coated thin film. A mirror-polished silicon wafer having a diameter of 2 cm and a thickness of 0.5 mm was used as a substrate for producing a silicon oxide thin film. As a pretreatment of the substrate, the substrate was passed through ultrapure water for 1 minute to remove deposits on the surface, and then water was removed with an air gun. The pretreated substrate was introduced into the coating part and mounted on a spin coater. Then, the raw material liquid was developed on the substrate using a syringe. Then, the board | substrate was rotated and the coating film with the uniform film thickness of the silicon compound was obtained. After completion of the rotation, the solvent was removed by heating the substrate, and then immediately introduced into the reaction part.

  In order to control the gas atmosphere in the reaction section, a mixed gas of nitrogen and oxygen through a desiccant was introduced from the gas inlet. The introduced mixed gas was irradiated with ultraviolet light using an ultraviolet lamp. At that time, a lamp was arranged so that ultraviolet rays were not directly irradiated onto the substrate. The substrate and the gas outlet were arranged so that the mixed gas irradiated with the ultraviolet light flowed toward the gas outlet while contacting the coating film on the substrate. At the same time, the coating film on the substrate was heated using an infrared lamp heating device.

  The thin film temperature on the upper surface of the substrate measured with a thermocouple thermometer was 170 ° C. The reaction time was 20 minutes. After completion of the reaction, the substrate was taken out to obtain a thin film element. The thickness of the silicon oxide thin film thus produced was about 18 nm.

FIG. 3 shows an FT-IR pattern spectrum of the thin film thus produced. In this spectrum, the absorption peak that appeared in the raw material thin film disappeared, and the absorption of 1100 cm ⁻¹ derived from the bond of silicon and oxygen appears strongly. Therefore, the raw silicon compound thin film was converted into a silicon oxide thin film. You can see that

FIG. 4 shows a correlation curve between the leakage current density and the electric field strength of this silicon oxide thin film. The thin film had a withstand voltage of about 28 MV / cm ² and a resistivity of 10 ¹⁵ Ωcm.

  A silicon compound was dissolved in a solvent to prepare a solution, which was used as a raw material for producing a coated thin film. A colorless transparent polyethylene terephthalate (PET) film having a 1.5 cm square and a thickness of 0.5 mm was used as a substrate for producing a silicon oxide thin film. As a pretreatment of the substrate, the substrate was passed through ultrapure water for 1 minute to remove deposits on the surface, and then water was removed with an air gun. The pretreated substrate was introduced into the coating part and mounted on a spin coater. Then, the raw material liquid was developed on the substrate using a syringe. Then, the board | substrate was rotated and the coating film with the uniform film thickness of the silicon compound was obtained. After completion of the rotation, the solvent was removed by heating the substrate at a temperature lower than the heat-resistant temperature, and then immediately introduced into the reaction part.

  In order to control the gas atmosphere in the reaction section, a mixed gas of nitrogen and oxygen through a desiccant was introduced from the gas inlet. The introduced mixed gas was irradiated with ultraviolet light using an ultraviolet lamp. At that time, a lamp was arranged so that ultraviolet rays were not directly irradiated onto the substrate. The substrate and the gas outlet were arranged so that the mixed gas irradiated with the ultraviolet light flowed toward the gas outlet while contacting the coating film on the substrate. At the same time, the coated surface was heated using an infrared lamp heating device.

  The thin film temperature on the upper surface of the substrate measured using a thermocouple thermometer was 130 ° C. The reaction time was 60 minutes. After completion of the reaction, the substrate was taken out to obtain a thin film element. It can be seen that the film with a thin film maintains a colorless and transparent state, and a high-quality silicon oxide thin film is formed.

  [Reference Example] A silicon compound was dissolved in a solvent to prepare a solution, which was used as a raw material for producing a coated thin film. A colorless transparent polyethylene terephthalate (PET) film having a 1.5 cm square and a thickness of 0.5 mm was used as a substrate for producing a silicon oxide thin film. As a pretreatment of the substrate, the substrate was passed through ultrapure water for 1 minute to remove deposits on the surface, and then water was removed with an air gun. The pretreated substrate was introduced into the coating part and mounted on a spin coater. Then, the raw material liquid was developed on the substrate using a syringe. Then, the board | substrate was rotated and the coating film with the uniform film thickness of the silicon compound was obtained. After completion of the rotation, the solvent was removed by heating the substrate at a temperature lower than the heat-resistant temperature, and then immediately introduced into the reaction part.

  In order to control the gas atmosphere in the reaction section, a mixed gas of nitrogen and oxygen through a desiccant was introduced from the gas inlet. From the back of the stage on which the substrate was set, an infrared lamp heating device was used to heat the stage together with the substrate that was in close contact. The stage temperature was maintained at 180 ° C. using a thermocouple thermometer provided on the stage, and at the same time, ultraviolet light was irradiated from above the substrate using an ultraviolet lamp.

  At this time, the thin film temperature on the upper surface of the substrate measured using a thermocouple thermometer was 154 ° C. The reaction time was 60 minutes. After completion of the reaction, the substrate was taken out to obtain a thin film element. It can be seen that the film with a thin film was damaged by ultraviolet rays and could not hold a colorless and transparent silicon oxide thin film, and a good thin film could not be formed.

  FIG. 5 is another conceptual diagram of the reaction unit in the thin film forming apparatus. The reaction section is provided with a gas introduction pipe 70 for introducing an atmospheric gas whose composition, composition, temperature, flow rate, etc. are controlled obliquely from above the coating film and a gas discharge pipe 80 for discharging the atmospheric gas. It has been. Further, an ultraviolet lamp 20 having means for irradiating ultraviolet light before reaching the coating film on the substrate with respect to the atmospheric gas, and heating for maintaining the coating thin film on the substrate at a certain temperature, and light irradiation in some cases When the temperature of the equipment rises to a temperature higher than the heat resistance temperature, a temperature holding device 30 having a means for cooling the substrate is provided. Further, although not shown in the figure, there are provided means for measuring the substrate temperature, means for evacuating the reaction part, means for controlling the composition, flow rate, pressure and the like of the gas introduced into the reaction part.

  FIG. 6 is another conceptual diagram of the reaction unit in the thin film forming apparatus. The reaction section is provided with a gas introduction pipe 70 for introducing an atmospheric gas whose composition, composition, temperature, flow rate, etc. are controlled from directly above the coating film, and a gas discharge pipe 80 for discharging the atmospheric gas. It has been. Further, the coating thin film is held at a certain temperature from below the ultraviolet light lamp 20 having means for irradiating ultraviolet light before reaching the coating film on the substrate with respect to the atmospheric gas, and the substrate to be coated or the stage supporting the substrate. A temperature holding device 30 having means for cooling the substrate is provided in the case where the temperature of the equipment rises to a temperature higher than the heat-resistant temperature due to heating for heating or, in some cases, light irradiation. Further, although not shown in the figure, there are provided means for measuring the substrate temperature, means for evacuating the reaction part, means for controlling the composition, flow rate, pressure and the like of the gas introduced into the reaction part.

Conceptual diagram of a thin film forming apparatus according to the present invention Sectional drawing of reaction part of thin film forming apparatus according to the present invention Infrared absorption spectrum of the insulating film produced in Example 1 of the present invention Leakage current density / electric field strength characteristic diagram of silicon oxide thin film produced in Example 1 of the present invention Conceptual diagram of other thin film forming equipment Conceptual diagram of other thin film forming equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate conveyance jig 20 Ultraviolet light lamp 30 Temperature holding device 40 Coating film forming apparatus 50 Substrate pretreatment apparatus 60 Coating film drying apparatus 70 Reactive gas introduction pipe 80 Generated gas discharge pipe 90 Substrate to be coated

Claims (5)

An oxide thin film forming apparatus for forming a coating film and converting the coating film into an oxide thin film ,
A coating means for coating a thin film on the substrate surface, a gas atmosphere control means for adjusting the atmospheric gas during the reaction, a temperature holding device for holding the temperature of the substrate and the thin film on the substrate, and a coating surface above Equipped with an ultraviolet light source,
Light source is arranged so light emitted from the light source is irradiated to the atmospheric gas without being directly irradiated to the coating設面,
The light source, the gas inlet, and the gas outlet are arranged so that the light is irradiated to the gas before the atmospheric gas reaches the coating surface on the substrate . Thin film forming equipment.   2. The thin film forming apparatus according to claim 1, wherein the thin film is a film made of a silicon compound containing a silazane structure or a siloxane structure.   2. The thin film forming apparatus according to claim 1, wherein the temperature holding device is disposed immediately above the coating surface.   2. The thin film forming apparatus according to claim 1, wherein the temperature maintaining device and the light source are arranged in parallel on a straight line perpendicular to the substrate transport direction above the thin film coating surface. 3. apparatus. 2. The thin film forming apparatus according to claim 1, further comprising a carry-in part and a carry-out part for continuously carrying the substrate below the temperature holding device.