JP2005235852A - Process for forming multilayer film and process for fabricating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for depositing a multilayer film exhibiting good inter-film adhesion and interface characteristics, and to provide a process for fabricating a device using that film deposition process. <P>SOLUTION: The process for forming a multilayer film including at least a first film and a second film formed thereon comprises a step for coating a substrate with a first liquid material containing solvent to form a first coating, a step for removing at least a part of the solvent existing in the first coating to form a first solvent removed film, a step for coating the first solvent removed film with a second liquid material, and a step for performing heating and/or optical treatment at least of the first solvent removed film and the second liquid material to form the first film from the first solvent removed film and the second film from the second liquid material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for forming a multilayer film applied to an integrated circuit, a thin film transistor, a photoelectric conversion device, an electric device, a photoreceptor, and the like.

  Patterning of a silicon thin film (amorphous silicon film or polysilicon film) applied to an integrated circuit or a thin film transistor is performed by forming a silicon film on the entire surface of the substrate by a vacuum process such as a CVD (Chemical Vapor Deposition) method, and then performing photolithography. The process is generally performed by removing unnecessary portions. However, this method has problems such as requiring a large-scale device, poor use efficiency of the raw material, difficulty in handling because the raw material is gas, and generation of a large amount of waste.

  In contrast to such conventional methods, in recent years, a liquid silane compound, higher order silane or a solution thereof is applied to a substrate, and a silicon film is formed by heat energy such as heating or light energy irradiation such as ultraviolet light or laser. (For example, JP 2003-115532 A: Patent Document 1, JP 2003-124486 A: Patent Document 2, JP 2003-133306 A: Patent Document 3, JP 2003-171556 A. Publication: Patent Document 4, Japanese Patent Application Laid-Open No. 2003-313299: Patent Document 5, etc.). According to this method, since the raw material is a liquid, it is easy to handle and a large-sized apparatus is not required, so that a silicon film can be formed at low cost.

  Further, by using the method of Japanese Patent Application Laid-Open No. 2001-179167, it becomes possible to form a silicon film by directly patterning a liquid silane compound, a higher order silane or a solution thereof by a technique such as inkjet, This discloses that man-hours and material waste due to photolithography can be saved (Patent Document 6).

An actual device such as an IC or a thin film transistor is manufactured by forming not only an amorphous silicon or polysilicon film but also a film such as an electrode layer or an insulating film layer on the multilayer. However, when the next electrode layer or insulating film layer is laminated after the silicon layer is completely formed from the liquid material as in the conventional method, the film is peeled off between the two layers, or good interface characteristics are obtained. However, there were problems such as poor device performance.
JP 2003-115532 A JP 2003-124486 A JP 2003-133306 A JP 2003-171556 A JP 2003-313299 A JP 2001-179167 A

  Accordingly, an object of the present invention is to provide a method for forming a multilayer film having good adhesion and interfacial characteristics between films, and a method for manufacturing a device using the method for forming a multilayer film.

  According to the present invention, there is provided a method for forming a multilayer film including at least a first film and a second film formed on the first film, wherein the first liquid material including a solvent is disposed above the substrate. A step of forming a first coating film by coating; a step of forming a first solvent removal film by removing at least a part of the solvent present in the first coating film; and the first solvent. Applying a second liquid material on the removal film, and heating and / or optically treating the first solvent removal film and the second liquid material at least from the first solvent removal film. This is solved by a multilayer film forming method (hereinafter referred to as “first invention”) in which the second film is formed from one film and the second liquid material.

  With such a configuration, the step of forming the first film from the first solvent removal film and the step of forming the second film from the second liquid material can be performed in the same step. The number of processes can be reduced as compared to forming a film of polysilicon or the like one by one. In addition, it is possible to form a multilayer film having good adhesion and interfacial characteristics between the films, and an improvement in the performance of the resulting product can be expected.

  Preferred embodiments of the first invention are as follows. The step of forming the first solvent removal film is performed by heating the first coating film. The heating of the first coating film is more preferably performed in the range of 100 to 250 ° C.

  The first coating film is preferably heated in a reduced pressure atmosphere. By heating in a reduced-pressure atmosphere, the solvent can be removed more efficiently in a shorter time, the solvent remaining as an impurity in the silicon film can be reduced, and high performance of the silicon film can be expected.

  The first coating film is preferably applied by a droplet discharge method. As a result, a liquid material can be applied directly on the pattern onto the substrate, and the silicon film can be patterned on the substrate without using photolithography by heat treatment and / or light treatment using the present invention. .

  The first film is preferably formed from a liquid silicon material. The liquid silicon material contains a silane compound and / or a higher order silane. In addition, the liquid silicon material may include a substance containing a Group 3B element of the periodic table or a substance containing a Group 5B element of the periodic table. By including such a substance in the liquid silicon material, the silicon film can be made a doped silicon film.

  Another object of the present invention is a method of forming a multilayer film including at least a first film and a second film formed on the first film, by applying a first liquid material containing a solvent over the substrate. A step of forming a first coating film; a step of forming a first solvent removal film by removing at least a part of the solvent present in the first coating film; and a second liquid material containing a solvent. Forming a second coating film by coating on the first solvent removal film, and forming a second solvent removal film by removing at least part of the solvent present in the second coating film; And, at least, the first solvent removal film and the second solvent removal film are heated and / or subjected to light treatment to form the first film and the second solvent removal film from the first solvent removal film. Forming the second film from the shape of a multilayer film Also solved by a method (hereinafter referred to as "second invention").

  With this configuration, the step of forming the first film from the first solvent removal film and the step of forming the second film from the second solvent removal film can be performed in the same step, and amorphous silicon. The number of steps can be reduced as compared to forming a film of polysilicon or polysilicon one by one. In addition, it is possible to form a multilayer film having good adhesion and interfacial characteristics between the films, and an improvement in the performance of the resulting product can be expected.

  Preferred embodiments of the second invention are as follows. The first solvent removal film is heated by heating the first coating film, and the second solvent removal film is formed by heating the second coating film. The heating of the first coating film and the heating of the second coating film are preferably performed in a range of 100 to 250 ° C. The heating of the first coating film and the heating of the second coating film are preferably performed in a reduced pressure atmosphere. It is preferable that at least one of the first coating film and the second coating film is applied by a droplet discharge method. It is preferable that at least one of the first film and the second film is formed of a liquid silicon material. The liquid silicon material preferably contains a silane compound and / or a higher order silane. The liquid silicon material may include a substance containing a Group 3B element of the periodic table or a substance containing a Group 5B element of the periodic table.

  Furthermore, the above-described problem is a method for forming a multilayer film including at least a first film and a second film formed on the first film, by applying a first liquid material containing a solvent over the substrate. Forming a first coating film; forming a first solvent removal film by removing at least a portion of the solvent present in the first coating film; and on the first solvent removal film. After the step of forming the second film and the step of forming the second film, at least the first solvent removal film is heated and / or subjected to light treatment to form the first film from the solvent removal film. Is also solved by a multilayer film forming method (hereinafter referred to as “third invention”).

  With such a configuration, it is possible to form a multilayer film having good adhesion and interfacial characteristics between the films, and an improvement in the performance of the resulting product can be expected.

  Preferred embodiments of the third invention are as follows. The second film can be formed by a CVD method, a vapor deposition method, or a sputtering method. That is, a film can be formed on the surface of the first solvent removal film by a sputtering method, a vacuum deposition method, a CVD method, or the like, and then the first film can be formed by heat treatment and / or light treatment. The first film is preferably formed from a liquid silicon material. The liquid silicon material contains a silane compound and / or a higher order silane. The liquid silicon material may include a substance containing a Group 3B element of the periodic table or a substance containing a Group 5B element of the periodic table.

  The present invention also provides a device manufacturing method (hereinafter referred to as “fourth invention”) using the multilayer film forming method according to any one of the first to third inventions.

  With such a configuration, the multilayer film according to any one of the first to third inventions is compared with a device manufactured by a conventional multilayer film forming method in which the second film is formed after the silicon film is completely formed. By using this forming method, the number of steps can be simplified, and a multilayer film having good adhesion and interfacial characteristics can be formed, so that a high-quality device can be obtained. it can.

[First invention]
As described above, the first invention is a method for forming a multilayer film including at least a first film and a second film formed on the first film, wherein a first liquid material containing a solvent is disposed above the substrate. A step of forming a first coating film by coating; a step of forming a first solvent removal film by removing at least a part of the solvent present in the first coating film; and the solvent removal film. A step of applying a second liquid material thereon, and heating and / or light treatment of at least the first solvent removal film and the second liquid material from the solvent removal film to the first film and the first film. Forming the second film from two liquid materials.

  First, a process of forming a first coating film by applying a first liquid material containing a solvent over the substrate will be described.

  In the present invention, the “liquid silicon material” is a material that contains at least a substance containing silicon in a molecule and is a liquid in a state where it is itself liquid or dissolved in a solvent at room temperature, and is subjected to heat treatment and / or It is a material that forms a silicon film by light treatment.

  As the liquid silicon material, it is preferable to use a silane compound, a higher order silane, a mixture thereof or a solution thereof. Furthermore, what added the dopant to the said solution can also be used.

  Here, the “dopant” is included in the liquid silicon material, and can form n-type or p-type doped silicon by the above-described activation by microwave irradiation. Examples thereof include compounds containing elements or Group 5B elements of the periodic table, such as boron, yellow phosphorus, decaborane, and substances described in JP-A No. 2000-31066.

Examples of the silane compound include a general formula Si _n X _m (wherein n is 3 or more and m is an independent integer of 4 or more, and X is a substituent such as a hydrogen atom and / or a halogen atom). The silane compound etc. which are represented by this is mentioned.

  The liquid silicon material may be a composition containing a higher order silane obtained by photopolymerization by irradiating the silane compound with ultraviolet rays (hereinafter referred to as “UV”), or a solution of the silane compound. In addition, a composition containing a higher order silane obtained by photopolymerization by irradiation with UV can also be used.

This higher order silane is formed by irradiating UV to a solution of a photopolymerizable silane compound and photopolymerizing the silane compound, and its molecular weight is a silane used in a conventional silicon production method. Compared to a compound (for example, Si ₆ H ₁₄ has a molecular weight of 182), it is too large to be compared (having a molecular weight of up to about 1800). Higher-order silanes with such a huge molecular weight have a boiling point higher than the decomposition point, and can form a film before it evaporates. Formation can be performed. In addition, when such higher order silane is actually heated, it decomposes before reaching the boiling point, so a boiling point higher than the decomposition point cannot be determined experimentally. However, here, it means the temperature dependence of the vapor pressure and the boiling point at normal pressure as a theoretical value obtained by theoretical calculation.

  In addition, if a liquid silicon material containing such higher order silane is used, the boiling point of this higher order silane is higher than the decomposition point, so that it is rapidly heated at a high temperature before evaporating as in the prior art. There is no need. That is, it is possible to perform a process in which the heating rate is moderated or heating is performed at a relatively low temperature while reducing the pressure. This can not only control the bonding speed of silicon when forming a silicon film, but also a temperature higher than the boiling point of the solvent in the process of forming a solvent removal film, which will be described later, but not so high as to form a silicon film. This means that the solvent that causes the deterioration of the characteristics of the silicon film can be reduced more efficiently than the conventional method from the coating film of the liquid silicon material.

  As described above, the higher order silane formed by photopolymerization preferably has a boiling point higher than its decomposition point. Higher order silanes having a boiling point higher than the decomposition point are selected from the following preferable silane compounds as silane compounds as precursors, or UV having a preferable wavelength described below as irradiation UV, irradiation time, irradiation method, It can be easily obtained by selecting irradiation energy, a solvent to be used, and a purification method after UV irradiation.

  Further, the molecular weight distribution of this higher order silane can be controlled by the UV irradiation time, irradiation amount, and irradiation method. Furthermore, this higher order silane can be taken out of the higher order silane compound having an arbitrary molecular weight by separating and purifying using GPC which is a general polymer purification method after UV irradiation of the silane compound. . Further, purification can be performed by utilizing the difference in solubility between higher order silane compounds having different molecular weights. Further, purification by fractional distillation can be performed by utilizing the difference in boiling points between higher-order silane compounds having different molecular weights under normal pressure or reduced pressure. In this way, by controlling the molecular weight of the higher order silane in the liquid material, it is possible to obtain a high-quality silicon layer in which the characteristic variation is further suppressed.

  Higher order silanes have higher boiling points and lower solubility in solvents as the molecular weight increases. For this reason, depending on the UV irradiation conditions, higher-order silane after photopolymerization may not be completely dissolved in the solvent and may be precipitated. In that case, insoluble components are removed by filtration using a microfilter, etc. Secondary silanes can be purified.

  The UV irradiation time is preferably from 0.1 seconds to 120 minutes, particularly preferably from 1 to 30 minutes, in order to obtain a high-order silane having a desired molecular weight distribution.

  Moreover, about the said liquid material containing the silane compound which is a precursor of such higher order silane, the viscosity and surface tension are adjusted with the said adjustment method regarding the molecular weight distribution of the higher order silane to form, and a solvent. Can be easily controlled. This is because when a silicon layer is formed from a liquid material, the greatest merit is that a patterning method using an ink jet method can be adopted. The fact that the tension can be easily controlled by the solvent serves as a very advantageous point.

The silane compound to be a precursor of the high-order silane is not particularly limited as long as having a photopolymerizable that can be polymerized by irradiation with UV, for example, in the above-mentioned general formula Si _n X _m (wherein, n represents 3 And m represents an independent integer of 4 or more, and X represents a substituent such as a hydrogen atom and / or a halogen atom).

As such a silane compound, a cyclic silane compound represented by the general formula Si _n X _2n (wherein n represents an integer of 3 or more and X represents a hydrogen atom and / or a halogen atom), In addition to a silane compound having two or more cyclic structures represented by the general formula Si _n X _2n-2 (wherein n represents an integer of 4 or more and X represents a hydrogen atom and / or a halogen atom), All of the silane compounds to which the polymerization process by microwave irradiation according to the present invention can be applied, such as silicon hydride having at least one cyclic structure in the molecule and a halogen substitution product thereof.

Specifically, examples having one cyclic structure include cyclotrisilane, cyclotetrasilane, cyclopentasilane, cyclohexasilane, cycloheptasilane, and the like, and those having two cyclic structures include 1 1, 1'-bicyclobutasilane, 1, 1'-bicyclopentasilane, 1, 1'-bicyclohexasilane, 1, 1'-bicycloheptasilane, 1, 1'-cyclobutasilylcyclopentasilane, 1, 1 '-Cyclobutasilylcyclohexasilane, 1,1'-cyclobutasilylcycloheptasilane, 1,1'-cyclopentasilylcyclohexasilane, 1,1'-cyclopentasilylcycloheptasilane, 1,1'- Cyclohexasilylcycloheptasilane, spiro [2.2] pentasilane, spiro [3.3] heptatasilane, spiro [4.4] nona Examples include silane, spiro [4.5] decasilane, spiro [4.6] undecasilane, spiro [5.5] undecasilane, spiro [5.6] undecasilane, spiro [6.6] tridecasilane, and the like. Examples thereof include silicon compounds in which the hydrogen atoms of the skeleton are partially substituted with SiH ₃ groups or halogen atoms. These may be used in combination of two or more.

Among these compounds, a silane compound having a cyclic structure in at least one position in the molecule is preferably used as a raw material from the viewpoint that it has extremely high reactivity with light and photopolymerization can be performed efficiently. Among these, Si _n X _2n such as cyclotetrasilane, cyclopentasilane, cyclohexasilane, cycloheptasilane (wherein n represents an integer of 3 or more, X is a hydrogen atom and / or a fluorine atom, a chlorine atom, A silane compound represented by a halogen atom such as a bromine atom or an iodine atom is particularly preferable because it has an advantage of being easily synthesized and purified in addition to the above reasons.

As a solvent used for the liquid silicon material used in the present invention, a silane compound is dissolved, a higher order silane formed by photopolymerization of the silane compound is dissolved, and the silane compound or the higher order silane Those that do not react are preferred. As this solvent, those having a vapor pressure of 1 × 10 ⁻³ to 2 × 10 ² Torr at room temperature are usually used. If the vapor pressure is higher than 2 × 10 ² Torr, the solvent will evaporate first when the coating film is formed by coating, and it becomes difficult to form a good coating film. On the other hand, in the case where the vapor pressure is lower than 1 × 10 ⁻³ Torr, drying is slow when the coating film is similarly formed by coating, and the solvent tends to remain in the coating film. This is because it is difficult to obtain a high-quality solvent-removing film in the forming step, and it is difficult to obtain a high-quality silicon film even after heating and / or light treatment described later.

  As the solvent, it is preferable to use a solvent having a boiling point at normal pressure of room temperature or higher and lower than 250 ° C. to 300 ° C. which is the decomposition point of the silane compound or higher silane. By using a solvent lower than the decomposition point of the silane compound or higher order silane, it is possible to selectively remove only the solvent without decomposing the silane compound or higher order silane by heating after coating. This is because it is possible to prevent the solvent from remaining and to obtain a higher quality film.

  The solvent used for the liquid silicon material is, for example, a solvent in a solution of a silane compound when it contains a silane compound, and in a solution of a silane compound as a precursor before UV irradiation in the case of a solution containing a higher order silane. Which is a solvent in the higher silane solution after UV irradiation. Specific examples thereof include hydrocarbon solvents such as n-hexane, n-heptane, n-octane, n-decane, dicyclopentane, benzene, toluene, xylene, durene, indene, tetrahydronaphthalene, decahydronaphthalene and squalane. In addition, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran, tetrahydropyran, 1,2-dimethoxyethane, bis (2- Methoxyethyl) ether, ether solvents such as p-dioxane, propylene carbonate, γ-butyrolactone, N- Chill-2-pyrrolidone, dimethylformamide, acetonitrile, polar solvent such as dimethyl sulfoxide.

  The solute concentration in the solvent is usually about 1 to 80% by weight, preferably about 5 to 30% by weight, and can be adjusted according to the desired silicon film thickness. If it exceeds 80% by weight, higher-order silane tends to precipitate, and it becomes difficult to obtain a uniform coating film.

  Further, the viscosity of the liquid silicon material can usually be adjusted in the range of 1 to 100 mPa · s, but the viscosity can be appropriately selected according to the coating apparatus and the target coating film thickness. When the viscosity is less than 1 mPa · s, coating becomes difficult, and when it exceeds 100 mPa · s, it is difficult to obtain a uniform coating film.

  Note that a small amount of a surface tension adjusting material such as a fluorine-based material, a silicone-based material, or a nonionic-based material can be added to the liquid silicon material as necessary as long as the target function is not impaired. This nonionic surface tension modifier improves the wettability of the solution to the application object, improves the leveling of the applied film, and helps prevent the occurrence of coating film crushing and itching. It is.

  The coating film is generally applied at a temperature of room temperature or higher. If the temperature is lower than room temperature, the solubility of the higher order silane compound may decrease and partly precipitate. Since the silane compound and the higher order silane compound used in the present invention are modified by reacting with water and oxygen, it is preferable that the series of steps is in a state where water and oxygen are not present. Therefore, the atmosphere during the series of steps is preferably performed in an inert gas such as nitrogen, helium, or argon. Furthermore, what mixed reducing gas, such as hydrogen, as needed is preferable. Further, it is desirable to use a solvent or additive from which water or oxygen has been removed.

  The coating film can be formed by any method generally used for applying a liquid material, such as spin coating, spray coating, dip coating, roll coating, droplet discharge method, dispensing method, etc. is there. Among these, by using a droplet discharge method and a dispensing method, a liquid material can be directly applied onto a pattern on a substrate, and a silicon film can be patterned on a substrate without using photolithography. It is preferable.

  In the present invention, the droplet discharge method is a method of forming a desired pattern including an object to be discharged by discharging droplets to a desired region, and is sometimes called an ink jet method. However, in this case, the liquid droplets to be ejected are not so-called ink used for printed matter, but a liquid containing a material substance constituting the device, and this material substance functions as, for example, a conductive substance or an insulating substance constituting the device. It contains a possible substance. Furthermore, the droplet discharge is not limited to spraying at the time of discharge, but also includes a case where each droplet of liquid is discharged so as to be continuous.

  In addition, the spinner rotation speed in the case of using the spin coating method is determined by the thickness of the film to be formed and the composition of the coating solution, but is generally 100 to 5000 rpm, preferably 300 to 3000 rpm.

  Next, a process of forming the first solvent removal film by removing at least a part of the solvent present in the first coating film will be described. Here, “removing at least a part of the solvent” means reducing the residual ratio of the solvent in the coating film by evaporating at least a part of the solvent in the coating film. Therefore, the “solvent removal film” is a film in which at least a part of the solvent in the coating film evaporates and the residual ratio of the solvent in the coating film is reduced, and the liquid silicon material is in an amorphous or polycrystalline state. It is a film in a state before becoming.

  The solvent removal film can be formed by heating the coating film. Here, “heating” is different from heating for the purpose of making the coating film amorphous or polycrystalline, and for the purpose of removing at least a part of the solvent from the coating film as described above. To do.

  The heating temperature of the coating film varies depending on the type of solvent used, the boiling point (vapor pressure) or the decomposition point, but is preferably in the range of 20 to 300 ° C, and preferably in the range of 100 to 250 ° C. . The optimum temperature can be used depending on the boiling point of the solvent to be used, but if it exceeds 300 ° C., the liquid silicon material will be thermally decomposed.

  The heating time is appropriately determined in relation to the heating temperature, but when the heating temperature is in the range of 100 to 250 ° C., it is preferably performed for 1 second to 60 minutes.

  The heating for removing the solvent can be performed using, for example, a conventionally known hot plate, furnace (furnace), UV irradiation, laser irradiation, microwave irradiation, or the like.

Moreover, it is preferable to perform a heating in a pressure-reduced atmosphere from a viewpoint of removing a solvent efficiently, and specifically, it is preferable to carry out at 10 < ^-8 > -100Torr, for example. By heating in a reduced pressure atmosphere, the solvent can be removed more efficiently in a shorter time, so that the solvent remaining as an impurity in the silicon film can be reduced, and high performance of the silicon film can be expected.

  Further, when heating for removing the solvent is performed, a mixture of an inert gas such as nitrogen, helium and argon, or a reducing gas such as hydrogen is preferable.

  Next, the process of applying the second liquid material on the first solvent removal film will be described. As the second liquid material, a liquid material having a composition different from that of the first liquid material described above may be used, or a liquid material having the same composition may be used. Moreover, the application method can also be performed by the same method as the case of applying the first liquid material.

  Next, at least the first solvent removal film and the second liquid material are heated and / or subjected to light treatment to thereby remove the first film from the solvent removal film and the second film from the second liquid material. The process to form is demonstrated.

  In this process, in order to form the first film from the solvent removal film and to form the second film from the second liquid material, first the first film is formed and then the second film is formed. Unlike the method for forming a film, the present invention is characterized in that before the first film is formed by performing heating and / or light treatment, the next liquid material is applied at the stage of forming the film from which the solvent has been removed. to differ greatly.

  Here, when a liquid material (second liquid material) for forming the second layer is applied on the solvent removal film (first solvent removal film) formed as the first layer, the liquid material is applied to the liquid material. A solvent can be included. The solvent used for the liquid material is selected so that the solvent removal film formed as the first layer does not dissolve, thereby preventing the dissolution of the first solvent removal film when the second liquid material is applied. It is preferable from the viewpoint that it is possible.

  It is also possible to include a step of forming a film above the substrate by CVD, vapor deposition, sputtering, or the like. That is, before the solvent removal film is heated and / or subjected to light treatment, a film of indium tin oxide, aluminum, titanium, titanium nitride, or the like is formed by a vacuum film formation method such as a sputtering method. A silicon film can also be formed by heat treatment and / or light treatment.

  Finally, the second liquid material for forming the first solvent-removing film formed as described above and the second layer provided on the solvent-removing film is heated and / or subjected to light treatment, whereby 2 A multilayer film of more than one layer is formed in the same process. The silicon film obtained by heating and / or light treatment is amorphous or polycrystalline, but in the case of heat treatment, it is generally amorphous when the temperature reached is about 550 ° C. or lower, and polycrystalline when the temperature is higher than that. A silicon film is obtained. When it is desired to obtain an amorphous silicon film, it is preferably performed at 300 ° C. to 550 ° C., more preferably at 350 ° C. to 500 ° C. When the ultimate temperature is less than 300 ° C., the thermal decomposition of the higher order silane compound does not proceed sufficiently, and a silicon film having a sufficient thickness may not be formed.

  In the present invention, an atmosphere in which heat treatment is performed is preferably one in which an inert gas such as nitrogen, helium or argon or a reducing gas such as hydrogen is mixed. When it is desired to obtain a polycrystalline silicon film, the amorphous silicon film obtained above can be converted into a polycrystalline silicon film by irradiating a laser.

  On the other hand, the light source used for light treatment includes low pressure or high pressure mercury lamp, deuterium lamp or discharge light of rare gas such as argon, krypton, xenon, YAG laser, argon laser, carbon dioxide gas Examples thereof include excimer lasers such as laser, XeF, XeCl, XeBr, KrF, KrCl, ArF, and ArCl. These light sources generally have an output of 10 to 5000 W, but 100 to 1000 W is usually sufficient. The wavelength of these light sources is not particularly limited as long as the higher order silane compound absorbs even a little, but it is usually 170 nm to 600 nm. In addition, the use of laser light is particularly preferable from the viewpoint of conversion efficiency into a polycrystalline silicon film. The temperature during these light treatments is usually from room temperature to 1500 ° C., and can be appropriately selected according to the semiconductor characteristics of the resulting silicon film.

  In the method for forming a multilayer film of the present invention, the “substrate” is not particularly limited, but other than ordinary quartz, borosilicate glass, soda glass, transparent electrodes such as ITO, gold, silver, copper, nickel, titanium, In addition to a metal substrate such as aluminum or tungsten, and a glass or plastic substrate having these metals on the surface, a silicon film or a metal film formed on the surface of these substrates is also included. In addition, a film in which a silicon film and / or a metal film are stacked, a silicon film, a metal film, or a film in which a silicon film and / or a metal film are stacked are also included.

[Second invention]
A second invention is a method for forming a multilayer film including at least a first film and a second film formed on the first film, wherein the first liquid material containing a solvent is applied to the upper side of the substrate. Forming a first coating film; forming a first solvent removal film by removing at least part of the solvent present in the first coating film; and a second liquid material containing the solvent as a substrate. Forming a second coating film by coating upward, forming a second solvent removal film by removing at least part of the solvent present in the second coating film, and at least the above Forming the second film from the first film and the second solvent removal film from the solvent removal film by performing heating and / or light treatment on the first solvent removal film and the second solvent removal film. Features.

  The present invention uses a second liquid material that includes a solvent. As the solvent and liquid material used in the present invention, the same solvent and liquid material as in the first invention can be used. And a 2nd coating film is formed by apply | coating the 2nd liquid material containing a solvent on a 1st solvent removal film | membrane.

  Here, when a second liquid material containing a solvent is applied on the solvent removal film (first solvent removal film) formed as the first layer, the solvent used for the liquid material is the first layer. It is preferable to select a solvent that does not dissolve the formed solvent removal film from the viewpoint that the dissolution of the first solvent removal film can be prevented when the second liquid material is applied.

  Then, in the same manner as in the first invention, the first solvent removal film and the second solvent removal film are formed, and the first solvent removal film and the second solvent removal film are heated and / or subjected to light treatment. The first film is formed from the first solvent removal film, and the second film is formed from the second solvent removal film. Thus, the step of forming the first film from the first solvent removal film and the step of forming the second film from the second solvent removal film can be performed in the same step.

  The method for forming a multilayer film of the second invention is the same as that of the first invention, except for the differences from the first invention. Therefore, regarding the present invention, the matters described for the first invention described above are appropriately applied to matters that are not particularly detailed.

[Third invention]
A third invention is a method of forming a multilayer film including at least a first film and a second film formed on the first film, wherein a first liquid material containing a solvent is applied to the substrate above the substrate. A step of forming one coating film, a step of forming a first solvent removal film by removing at least a part of the solvent present in the first coating film, and the second coating on the solvent removal film. After the step of forming a film and the step of forming the second film, at least the first solvent removal film is heated and / or subjected to light treatment to form the first film from the solvent removal film. It is characterized by that.

  That is, in the step of forming the second film on the first solvent removal film, the second film is formed on the first solvent removal film by using a vacuum process such as sputtering, vapor deposition, and CVD. Thereafter, at least the first solvent removal film is heated and / or light-treated to form a multilayer film.

  The method for forming a multilayer film of the third invention is the same as that of the first invention, except for the differences from the first invention. Therefore, regarding the present invention, the matters described for the first invention described above are appropriately applied to matters that are not particularly detailed.

[Fourth Invention]
The present invention also provides a device manufacturing method using the multilayer film forming method described above. If a device is manufactured by the above-described method for forming a multilayer film, a multilayer film having good adhesion and interfacial characteristics can be formed, so that a high-quality device can be obtained. The multilayer film obtained by the method for forming a multilayer film of the present invention can be applied to applications such as an integrated circuit, a thin film transistor, a photoelectric conversion device, an electric device, and a photoreceptor. Here, examples of the photoelectric conversion device include a solar battery, and examples of the electric device include a mobile phone and a display.

  FIG. 1 shows a film forming process of a multilayer film of a thin film transistor substrate used for a liquid crystal display. First, a solution (solution A) in which 10 g of cyclopentasilane was dissolved in 100 ml of toluene was prepared, and the solution A was stirred and irradiated with a 300 W high-pressure mercury lamp for 10 minutes to obtain a higher order silane solution.

This higher order silane solution was applied onto the glass substrate 12 in a nitrogen atmosphere using an inkjet method. Then, the coating film is heated at 120 ° C. for 30 minutes while reducing the pressure to 10 ⁻² Torr, and the toluene (S1), which is the solvent of the higher order silane solution, is removed from the coating film, thereby the first solvent removal film. 14 was obtained (see FIG. 1 (a)).

  Next, a 30 wt% solution (solution B) of polysilazane using xylene as a solvent was prepared, and this solution B was applied onto the first solvent removal film 14 using an inkjet method to form a coating film. . And the formed solvent film was heated at 150 degreeC for 1 hour, and the 2nd solvent removal film | membrane 16 from which xylene (S2) which is a solvent of the solution B was removed was obtained (refer FIG.1 (b)).

  Next, the first solvent removal film 14 and the second solvent removal film 16 are baked at 400 ° C. for 1 hour, thereby forming a two-layer structure film of the amorphous silicon film 15 and the gate insulating film 17 in the same process. (See FIG. 1 (c)).

Next, a solution (solution C) in which 1 g of decaborane was dissolved in the above solution A was prepared. As shown in FIG. 1D, the solution C was applied to the exposed portion of the amorphous silicon film 15 using an ink jet method to form a coating film. Then, by heating the formed coating film at 120 ° C. for 30 minutes while reducing the pressure to 10 ⁻² Torr, the third solvent removal films 18 and 20 from which the solvent toluene (S3) was removed from the coating film were obtained. It was.

  Next, as shown in FIG. 1E, the gold fine particle ink for forming the source electrode is formed on the exposed portion of one third solvent removal film 20 and the drain electrode is formed by the ink jet method. The ITO ink was applied to the exposed portion of the other third solvent removal film 18.

  The multilayer film substrate thus fabricated is baked at 450 ° C. for 20 minutes to form the drain electrode 22 and the source electrode 24, and the n-type doped polysilicon from the third solvent removal films 18 and 20. Films 19 and 21 were formed (see FIG. 1 (f)).

  Aluminum fine particle ink was applied on the surface of the gate insulating film 17 by an ink jet method, and baked at 200 ° C. for 1 hour, thereby forming the gate electrode wiring 28 (see FIG. 1F). A liquid crystal display was manufactured using the thin film transistor substrate 1 thus manufactured.

  FIG. 2 shows a film forming process of a multilayer film of a substrate used for a solar cell. First, an aluminum film 32 having a thickness of 5000 mm was formed on the glass substrate 30 by a sputtering method (see FIG. 2A).

  A solution in which 1 g of phosphorus chloride was dissolved in the solution A used in Example 1 was prepared, and this solution was spin-coated on the surface of the aluminum film 32 at 800 rpm to form a coating film. The formed coating film was heated at 120 ° C. for 30 minutes to remove toluene (S1) as a solvent from the coating film, thereby forming a first solvent removal film 34 (see FIG. 2B).

  Next, the surface of the first solvent removal film 34 is spin-coated with the solution A at 1000 rpm to form a coating film, and the formed coating film is heated at 120 ° C. for 30 minutes, whereby toluene (S2), which is a solvent. A second solvent removal film 36 from which was removed was formed (see FIG. 2C).

  Furthermore, a solution in which 1 g of decaborane was dissolved in solution A was prepared, and this solution was spin-coated on the surface of the second solvent removal film 36 at 800 rpm to form a coating film. The formed coating film was heated at 120 ° C. for 30 minutes to form a third solvent removal film 38 from which toluene (S3) as a solvent was removed (see FIG. 2D).

  The multilayer film thus obtained was baked at 500 ° C. for 2 hours to obtain a thickness of 1000 mm (N-type silicon film 35) / 1500 mm (I-type silicon film 37) / 1000 mm (P-type silicon film 39). A solar cell structure consisting of layers was fabricated simultaneously.

  Thereafter, the ITO electrode 40 is formed by sputtering, and the ITO electrode 40 and the silicon layer (N-type silicon film 35, I-type silicon film 37, and P-type silicon film 39) are patterned by photoetching. A solar cell substrate 2 shown in 2 (e) was produced.

  When this solar cell substrate 2 was used to produce a solar cell, and the conversion efficiency was determined by measuring the photovoltaic power of the solar cell, it was 11%, and good interface characteristics were recognized. Also, no film peeling was observed. Therefore, by using the present invention, it was confirmed that since the electrical characteristics of the interface are good, the performance as a device can be improved and the film can be formed with excellent adhesion between films. In addition, since a plurality of films could be fired at the same time, the effect of shortening the time required for heat treatment was also confirmed.

  In the same manner as in Example 2, a film made of an aluminum film 32, a first solvent removal film 34, a second solvent removal film 26, and a third solvent removal film 38 was formed on the glass substrate 30 (FIG. 2 (a) to (d)).

  Next, an ITO electrode 40 is formed on the surface of the third solvent removal film 38 by sputtering, and then baked at 500 ° C. for 2 hours, thereby obtaining a thickness of 1000 mm (N-type silicon film 35) / 1500 mm (I Type solar film 37) / 1000 の (P-type silicon film 39) was formed simultaneously.

  Thereafter, the ITO electrode 40 and the silicon layer (N-type silicon film 35, I-type silicon film 37, and P-type silicon film 39) were patterned by photoetching to produce a solar cell substrate.

  A solar cell was fabricated using this solar cell substrate, and the conversion efficiency was determined by measuring the photovoltaic power of this solar cell. The conversion efficiency was 13%. By applying the present invention, the P-type silicon film 39 and ITO It was confirmed that the electrode 40 formed a good interface.

[Comparative Example 1]
Using a conventional method, a solar cell substrate was produced as follows. That is, after applying the liquid silicon material to the object to be applied, heating for the main baking was performed. This process was repeated twice to form a multilayer film composed of the N-type silicon film 35, the I-type silicon film 37, and the P-type silicon film 39. Otherwise, a solar cell substrate was prepared in the same manner as in Example 2.

  When the photovoltaic power of this solar cell was measured to determine the conversion efficiency, it was only 4%. Moreover, the part which the film | membrane peeled in the place was recognized.

[Test Example 1]
A solution obtained by adding 1% of phosphorus chloride to the solution A used in Example 1 was spin-coated on a glass substrate. This substrate was heated at 200 ° C. for 30 minutes to remove the solvent, thereby forming a solvent removal film. Next, a metal ink in which silver fine particles were dispersed in tetradecane was linearly applied to the solvent removal film by an ink jet method. The substrate was baked in the atmosphere at 500 ° C. for 1 hour, thereby forming a linear silver wiring having a width of 50 μm on the N-type silicon film having a thickness of 1000 mm (test substrate A).

  A solution obtained by adding 1% of phosphorus chloride to the solution A used in Example 1 was spin-coated on a glass substrate. This was fired at 500 ° C. for 10 minutes to form an N-type silicon film having a thickness of 1000 mm. Next, a metal ink similar to the above is applied to the N-type silicon film by the ink jet method to form a silver wiring, and further baked at 500 ° C. for 1 hour, thereby forming a width on the N-type silicon film having a thickness of 1000 mm. A 50-μm linear silver wiring was formed (test substrate B).

  About manufactured test board | substrate A and B, the adhesive evaluation by the tape peeling test of silver wiring was performed by measuring the peeling number per 100 places. The result is shown below with the result of measuring the contact resistance.

以上のように、本発明を用いた試験基板Ａにおいては、従来法で製造した試験基板Ｂと比べて、シリコン膜と金属配線の密着性が非常に良好であり、また金属配線とＮ型シリコン膜の間の接触抵抗が少ないことが判明した。

As described above, in the test substrate A using the present invention, the adhesion between the silicon film and the metal wiring is very good as compared with the test substrate B manufactured by the conventional method, and the metal wiring and the N-type silicon are used. It was found that the contact resistance between the membranes was low.

It is a figure which shows the film-forming process of the multilayer film of the thin-film transistor substrate used for a liquid crystal display. It is a figure which shows the film-forming process of the multilayer film of the board | substrate used for a solar cell.

Explanation of symbols

1: thin film transistor substrate, 2: solar cell substrate, 12: glass substrate, 14: first solvent removal film, 15: amorphous silicon film, 16: second solvent removal film, 17: gate insulating film, 18 and 20: Third solvent removal film, 19 and 21: polysilicon film, 22: drain electrode, 24: source electrode, 28: gate electrode wiring, 30: glass substrate, 32: aluminum film, 34: first solvent removal film, 36: second solvent removal film, 38: third solvent removal film, 40: ITO electrode

Claims (18)

A method for forming a multilayer film including at least a first film and a second film formed on the first film,
Forming a first coating film by applying a first liquid material containing a solvent over the substrate;
Forming a first solvent removal film by removing at least a part of the solvent present in the first coating film;
Applying a second liquid material on the first solvent removal film;
At least the first film from the first solvent removal film and the second film from the second liquid material by performing heating and / or light treatment on the first solvent removal film and the second liquid material. A method for forming a multilayer film.   The method for forming a multilayer film according to claim 1, wherein the step of forming the first solvent removal film is performed by heating the first coating film.   The method for forming a multilayer film according to claim 2, wherein the heating of the first coating film is performed in a range of 100 to 250 ° C. 4.   The method for forming a multilayer film according to claim 2 or 3, wherein the heating of the first coating film is performed in a reduced pressure atmosphere.   The method for forming a multilayer film according to claim 1, wherein the first coating film is applied by a droplet discharge method.   The method for forming a multilayer film according to claim 1, wherein the first film is formed from a liquid silicon material. A method for forming a multilayer film including at least a first film and a second film formed on the first film,
Forming a first coating film by applying a first liquid material containing a solvent over the substrate;
Forming a first solvent removal film by removing at least a part of the solvent present in the first coating film;
Forming a second coating film by coating a second liquid material containing a solvent on the first solvent removal film;
Forming a second solvent removal film by removing at least a part of the solvent present in the second coating film;
At least the first solvent removal film and the second solvent removal film are heated and / or subjected to a light treatment to heat the first solvent removal film and the second solvent removal film to the second film. A method for forming a multilayer film.   The multilayer according to claim 7, wherein the formation of the first solvent removal film is performed by heating the first coating film, and the formation of the second solvent removal film is performed by heating the second coating film. Method for forming a film.   The method of forming a multilayer film according to claim 8, wherein the heating of the first coating film and the heating of the second coating film are performed in a range of 100 to 250 ° C.   The method for forming a multilayer film according to claim 8 or 9, wherein the heating of the first coating film and the heating of the second coating film are performed in a reduced pressure atmosphere.   The method for forming a multilayer film according to claim 7, wherein at least one of the first coating film and the second coating film is applied by a droplet discharge method.   The method for forming a multilayer film according to claim 7, wherein at least one of the first film and the second film is formed of a liquid silicon material. A method for forming a multilayer film including at least a first film and a second film formed on the first film,
Forming a first coating film by applying a first liquid material containing a solvent over the substrate;
Forming a first solvent removal film by removing at least a part of the solvent present in the first coating film;
Forming the second film on the first solvent removal film;
A method for forming a multilayer film, wherein, after the step of forming the second film, at least the first solvent removal film is heated and / or light-treated to form the first film from the solvent removal film.   The multilayer film forming method according to claim 13, wherein the second film is formed by a CVD method, an evaporation method, or a sputtering method.   The method for forming a multilayer film according to claim 13, wherein the first film is formed from a liquid silicon material.   The method for forming a multilayer film according to claim 6, wherein the liquid silicon material includes a silane compound and / or a higher order silane.   17. The multilayer film according to claim 6, wherein the liquid silicon material includes a substance containing a Group 3B element of the periodic table or a substance containing a Group 5B element of the periodic table. Method. The manufacturing method of the device which uses the formation method of the multilayer film of any one of Claims 1-17.

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