JP2005251982A - Silicon film forming method, manufacturing method of device using the same, and manufacturing method using manufacturing method of the same device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silicon film forming method which can form a pattern of a fine silicon film using the photoresist having excellent heat resistance property. <P>SOLUTION: The silicon film forming method comprises the steps of forming a recess by forming a resist pattern on the base material, coating the recess with a liquid silicon material, conducting optical process and a first heat treatment of the resist pattern and the liquid silicon material coated, and conducting a second heat treatment of the liquid silicon material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a silicon film forming method, an integrated circuit using the silicon film forming method, a method for manufacturing a device such as a thin film transistor and a photoelectric conversion device, and an electro-optical device such as a display using the device manufacturing method.

  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 recent years, with the increase in the size of displays, the size of the substrate has exceeded 1 m square. Silicon film can be uniformly formed on such a huge substrate while reducing the cost. The technical problem that this is difficult has also surfaced.

  In contrast to such conventional methods, in recent years, a method has been proposed in which a liquid silicon material such as a liquid silane compound, a higher order silane compound, or a solution thereof is applied to a substrate, and a silicon film is formed by heating or UV irradiation. (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: Patent. Reference 4). 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 manufactured at low cost.

Japanese Patent Application Laid-Open No. 2001-179167 discloses that a silicon film can be formed by directly patterning a solution silicon material by a technique such as ink jetting, thereby reducing the number of man-hours and material waste due to photolithography. Is disclosed (Patent Document 5).
JP 2003-115532 A JP 2003-124486 A JP 2003-133306 A JP 2003-171556 A JP 2001-179167 A

  In the above prior art, the silicon film can be directly patterned by using the ink jet method or other droplet patterning methods. It is difficult to form a silicon pattern.

  Further, the SAM film can be miniaturized by a lyophobic / lyophilic pattern using a SAM film (self-assembled monolayer). However, the SAM film is resistant to ultraviolet (hereinafter referred to as “UV”) light. Due to the low sensitivity, patterning requires a very high intensity lamp, which is disadvantageous in terms of cost and time. Also, it is difficult to say that the pattern of the obtained SAM film is fine at the submicron level.

  In addition, since it is necessary to heat at a temperature of 300 ° C. or higher in order to cause thermal decomposition of the liquid silicon material, a photoresist having a normal heat-resistant temperature of about 180 ° C. cannot withstand high temperatures. As a result, the photoresist is deformed and the photoresist is thermally decomposed, so that there is a problem in using it for silicon film formation using the liquid silicon material.

  Therefore, an object of the present invention is to provide a method for forming a silicon film, which can perform patterning of a fine silicon film using a photoresist having excellent heat resistance.

  The inventors of the present invention have intensively studied to solve the above-mentioned problems, and as a result, when the photoresist is processed under certain conditions, the heat resistance is improved, and even at a temperature at which the liquid silicon material is thermally decomposed, It was found that a cured photoresist that does not deform or decompose is obtained. The present invention is based on this knowledge, a step of forming a resist pattern on a substrate and forming a recess, a step of applying a liquid silicon material to the recess, the resist pattern and the applied liquid silicon material In contrast, there may be a silicon film forming method (hereinafter referred to as “first invention”), which includes a step of performing a light treatment and a first heat treatment, and a step of performing a second heat treatment on the liquid silicon material. ).

  As a result, a resist pattern with excellent heat resistance can be formed, and the resist pattern does not change even at the temperature at which the liquid silicon material is thermally decomposed. It is possible to pattern the silicon film. The resist pattern obtained by the above method can be easily removed by a normal resist stripping process such as acetone cleaning or ashing.

Preferred embodiments of the present invention are as follows. It is preferable to perform photopolymerization of the liquid silicon material by the light treatment. It is preferable to remove the solvent of the liquid silicon material by the first heat treatment. The light treatment and the first heat treatment are preferably performed under conditions including a pressure of 10 ^{−9 to} 100 Torr, a wavelength of light of the light treatment of 170 to 600 nm, and a temperature of the first heat treatment of 20 to 150 ° C. . The second heat treatment is preferably performed at 300 to 450 ° C. The light source used for the light treatment is preferably selected from any one of a high pressure mercury lamp, a low pressure mercury lamp, an excimer lamp, and an excimer laser. The liquid silicon material preferably contains a silane compound and / or a higher order silane. The liquid silicon material is preferably applied by a droplet discharge method.

  The present invention also includes a step of forming a resist pattern on a substrate and forming a recess, a step of performing a light treatment and a first heat treatment on the resist pattern, and a step of applying a liquid silicon material to the recess. And a step of performing a second heat treatment on the liquid silicon material. The present invention provides a method for forming a silicon film (hereinafter sometimes referred to as a “second invention”).

  The present invention also provides a device manufacturing method (hereinafter sometimes referred to as “third invention”) using the above-described silicon film forming method. Furthermore, the present invention provides a method for manufacturing an electro-optical device (hereinafter sometimes referred to as “fourth invention”) using the device manufacturing method. By using the silicon film formation method described above, it is possible to pattern a fine silicon film down to the submicron level using a low-cost liquid silicon material. Can be manufactured.

  According to the present invention, the resist pattern is maintained without deforming or decomposing the photoresist even at a temperature (for example, 300 to 450 ° C.) at which the liquid silicon material is thermally decomposed. Can be patterned.

  Hereinafter, a silicon film forming method and the like according to the present invention will be described in detail based on preferred embodiments thereof.

[First invention]
As described above, the present invention includes a step of forming a resist pattern on a substrate and forming a recess, a step of applying a liquid silicon material to the recess, and the resist pattern and the applied liquid silicon material. And a step of performing a light treatment and a first heat treatment, and a step of performing a second heat treatment on the liquid silicon material.

  First, a process of forming a resist pattern on a substrate and forming a recess will be described. As the photoresist, a general photosensitive resin containing a photosensitive agent, a resin, and a solvent can be used, and any type of a novolak type for a visible light or UV light source or a chemical amplification type for an excimer laser light source is used. be able to. Moreover, either a negative type in which a portion irradiated with light remains or a positive type in which a portion irradiated with light is removed may be used.

  In the present invention, the “substrate” is not particularly limited, but other than ordinary quartz, borosilicate glass, soda glass, transparent electrodes such as ITO, metal substrates such as gold, silver, copper, nickel, titanium, aluminum, tungsten, etc. In addition to glass and plastic substrates having these metals on the surface, silicon films and metal films formed on the surfaces of these substrates are also included.

  The resist pattern can be formed by a commonly used photolithography technique. That is, a photoresist is applied to an object to be coated, and a mask pattern is transferred to the photoresist by irradiating with UV or excimer laser light through a photomask, and development is performed to form a desired resist pattern having a recess. be able to.

  Next, a process of applying a liquid silicon material to the recess will be described. The liquid silicon material can be applied by using a spin coating method, a roll coating method, a curtain coating method, a dip coating method, a spray method, a droplet discharge method, or the like. The application is generally performed at a temperature above room temperature. 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.

  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 performing light treatment and first heat treatment on the resist pattern and the applied liquid silicon material will be described. The light treatment and the first heat treatment are preferably performed at a predetermined pressure, wavelength, and temperature.

The pressure condition is preferably performed under reduced pressure conditions of 10 ^{−9 to} 100 Torr in order to remove moisture. Since the removal of moisture is promoted by increasing the degree of vacuum and as a result, the heat resistance of the photoresist is improved, a higher degree of vacuum is more preferable. For example, when the photoresist is cured under a pressure condition of 0.1 to 2 Torr, it can withstand a temperature of about 400 ° C. Note that if the removal of moisture from the photoresist is incomplete, the photoresist will be decomposed before being polymerized by light treatment.

  The light treatment is preferably performed with a light source having a wavelength of 170 to 600 nm, and the higher the short wavelength component, the more efficiently the polymerization can be performed. Therefore, it is more preferable to select a wavelength of 170 to 436 nm.

  The light source used for the light treatment includes a low pressure mercury lamp, a low pressure mercury lamp, an excimer lamp, an excimer laser such as XeF, XeCl, XeBr, KrF, KrCl, ArF, ArCl, a deuterium lamp, argon, krypton, etc. In addition, a rare gas discharge light such as xenon, a YAG laser, an argon laser, a carbon dioxide gas laser, and the like can be mentioned, and a high-pressure mercury lamp, a low-pressure mercury lamp, an excimer lamp, and an excimer laser are preferable.

These light sources generally have an output of 10 to 5000 W, but 100 to 1000 W is usually sufficient. The energy density is preferably set from the viewpoint of efficiently cured resist in a short time 10~4000mW / cm ^2, and more preferably set to 100~1000mW / cm ^2.

  The first heat treatment is performed at 20 to 150 ° C. When the temperature is too low, the polymerization reaction hardly occurs. When the temperature is too high, the shape of the resist pattern may be broken before the photoresist is cured.

  The time for performing the curing treatment is appropriately set according to the pressure, the wavelength of the light treatment, and the heating temperature described above.

  Ordinary photoresist begins to soften at a temperature of 200 ° C. or less, and the pattern collapses. On the other hand, the resist pattern cured by the above method exhibits excellent heat resistance without causing shape change or decomposition up to a temperature of about 450 ° C. Therefore, the resist pattern does not change even at a temperature (for example, 300 to 450 ° C.) at which the liquid silicon material is thermally decomposed. Note that even if it is necessary to peel and remove the resist in the subsequent steps, it can be easily removed by a normal resist stripping process such as acetone cleaning or ashing.

  Further, by curing the photoresist coated with a liquid silicon material containing a solvent as described above, a curing process for improving heat resistance performed on the photoresist, a photopolymerization process of the coated liquid silicon material, and Solvent removal can also be performed almost simultaneously. Therefore, the number of processes can be reduced.

  Note that “removing the solvent” means reducing the residual ratio of the solvent in the coating film by evaporating and / or decomposing the solvent in the coating film of the liquid silicon material. Therefore, the film after the solvent is removed is a film in which the solvent in the coating film is evaporated and / or decomposed and the residual ratio of the solvent in the coating film is lowered, before it becomes amorphous or polycrystalline. The film in the state of

  Next, a process of performing a second heat treatment on the liquid silicon material will be described. The second heat treatment can be performed at 300 to 450 ° C. using the liquid silicon material from which the solvent has been removed. As described above, since the photoresist is cured and has improved heat resistance, the resist pattern formed is maintained as it is even when the liquid silicon material from which the solvent has been removed is exposed to a temperature at which it is thermally decomposed. Can do. In addition, since the steps of curing the photoresist and photopolymerizing / removing the solvent of the liquid silicon material and the step of thermally decomposing the liquid silicon material can be performed continuously, the process is simplified, A silicon film can be formed in a shorter time.

  In the present invention, the “liquid silicon material” refers to a material that contains at least a substance containing silicon in the molecule and is liquid at room temperature. As the liquid silicon material, it is preferable to use a silane compound, a higher order silane or a solution thereof. Furthermore, what added the dopant to the silane compound, higher order silane, or its 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.

  Moreover, as this liquid silicon material, it is a composition containing a higher order silane formed by photopolymerization by irradiating UV to the silane compound, or by irradiating the solution of the silane compound with UV. A composition containing a higher order silane obtained by photopolymerization 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 not only controls the bonding speed of silicon when forming a silicon film, but also maintains the temperature of the liquid silicon material at a temperature that is not high enough to form a silicon film but higher than the boiling point of the solvent. This means that the solvent that causes the deterioration of the characteristics of the silicon film from the coating film can be reduced more efficiently than the conventional method.

  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′-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. This is because when the vapor pressure is higher than 2 × 10 ² Torr, the solvent evaporates first when forming a coating film by coating, and it becomes difficult to form a good coating film. On the other hand, when 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, thereby obtaining a high-quality silicon film. It is because it becomes difficult to be taken.

  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 10 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 this 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 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 target, improves the leveling of the applied film, and helps prevent the occurrence of coating crushing and the occurrence of distorted skin. It is.

[Second invention]
As described above, the present invention includes a step of forming a resist pattern on a substrate and forming a recess, a step of performing a light treatment and a first heat treatment on the resist pattern, and a liquid silicon material in the recess. And a step of applying a second heat treatment to the liquid silicon material. Therefore, the present invention is different from the first invention in that a resist pattern is formed and a photoresist is cured (light treatment and first heat treatment), and then a liquid silicon material is applied and a second heat treatment is performed.

The silicon film forming method of the second invention is the same as that of the first invention, except for the parts different 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 and fourth inventions]
The present invention also provides a device manufacturing method using the above silicon film forming method. Furthermore, the present invention provides a method for manufacturing an electro-optical device using the device manufacturing method. Since the silicon film can be patterned to the submicron level by using the above silicon film forming method, a high-quality device can be obtained. The silicon film obtained by the method for forming a silicon film of the present invention can be applied to electro-optical devices such as integrated circuits, thin film transistors, photoelectric conversion devices, and photoreceptors.

  FIG. 1 shows an example of a transistor manufacturing process using a silicon film forming method according to an embodiment of the present invention.

  The surface of the glass substrate 10 was subjected to HMDS (Hexamine Disilazane) treatment (see FIG. 1A), and a photoresist 12 was spin-coated on the glass substrate 10 at 2000 rpm (see FIG. 1B).

  Next, after performing heat treatment at 50 ° C. for 10 minutes to remove the solvent of the photoresist 12, pattern exposure and development were performed using a photomask to pattern the photoresist 12 (see FIG. 1C).

A solution in which cyclohexasilane is dissolved in toluene is prepared, and this solution is irradiated with UV light from a high-pressure mercury lamp of 50 mW / cm ² for 10 minutes, and 1 ml of the liquid is dissolved in 10 ml of decane (solution A). Was prepared as a liquid silicon material. This solution A was applied to the recesses formed by patterning by an ink jet method to form a coating film 14 of the solution A (see FIG. 1D). The application of the solution A can be performed not only by the ink jet method but also by any of the spin coating method, the dip coating method, and the mist deposition method.

The glass substrate 10 was placed in a vacuum chamber (not shown) and irradiated with excimer lamp light having an energy density of 10 mW / cm ² and a wavelength of 308 nm under a reduced pressure of 1 Torr and simultaneously heated at 130 ° C. for 2 hours. As a result, toluene (T), which is the solvent in the coating film 14 of the solution A, was removed, and at the same time, a curing process for forming the photoresist 13 with heat resistance was simultaneously performed (see FIG. 1E). ).

  Subsequently, the glass substrate 10 was heated at 400 ° C. for 1 hour, and the coating film 14 of the solution A from which toluene was removed was thermally decomposed to form an amorphous silicon film 15 (see FIG. 1F).

  Next, by peeling off the photoresist 13, the finely patterned amorphous silicon film 15 could be formed on the glass substrate 10 by a simple process (see FIG. 1G).

The patterned silicon film (amorphous silicon film 15) can be directly applied to the manufacture of a conventional thin film transistor. A polysilicon film 16 is formed by recrystallization by a generally used laser irradiation, and then the gate. The insulating film 18 is formed, the gate electrode 20 is formed, ions are implanted into the polysilicon film 16 (n ⁺ ), the interlayer insulating film 22 is formed, the contact hole 24 is formed, and the source electrode 26 and the drain electrode 28 are formed sequentially. Thus, a polysilicon thin film transistor 1 was produced.

When the characteristics of the transistor 1 thus manufactured were evaluated, the mobility was 80 cm ² / Vs. Therefore, it has been found that by applying the present invention, the transistor 1 having no inferior performance can be manufactured by a simpler and cheaper process than the conventional method.

  As described above, the process can be simplified by performing the curing process of the photoresist and the solvent removal of the liquid silicon material (solution A) substantially at the same time.

  FIG. 2 shows an example of a manufacturing process of a transistor using a silicon film forming method according to another embodiment of the present invention.

  As shown in FIGS. 2A to 2C, the process is the same as in Example 1 until the photoresist is applied to the glass substrate 10 that has been subjected to the HMDS process, and the photoresist 12 is patterned by exposure and development. The description is omitted here.

Next, the glass substrate 10 is placed in a vacuum chamber (not shown) and irradiated with excimer lamp light having an energy density of 10 mW / cm ² and a wavelength of 308 nm under a reduced pressure of 1 Torr and simultaneously heated at 130 ° C. for 2 hours, A photoresist 13 to which was applied was obtained (see FIG. 2D).

  Next, a solution (solution B) in which 1 ml of hexasilane is dissolved in 10 ml of xylene is prepared as a liquid silicon material, and the solution B is applied to the recesses formed by patterning the photoresist 13 by the ink jet method. A film 17 was formed (see FIG. 2E).

  Next, the substrate 10 was heated at 400 ° C. for 1 hour to remove xylene (X) and thermally decompose the coating film 17 of the solution B to form an amorphous silicon film 19 (see FIG. 2F). .

Subsequently, various films were formed in the same manner as in Example 1 to manufacture the thin film transistor 2 (see FIG. 2H). When the characteristics of the thin film transistor 2 were evaluated, the mobility was 90 cm ² / Vs.

  As described above, when the photoresist is easily dissolved in the solvent (in this case, xylene) of the liquid silicon material (solution B), the photoresist is dissolved by first performing the curing process of the photoresist as in this embodiment. Can be prevented.

It is a figure which shows an example of the manufacturing process of the transistor using the formation method of the silicon film which concerns on embodiment of this invention. It is a figure which shows an example of the manufacturing process of the transistor using the formation method of the silicon film which concerns on other embodiment of this invention.

Explanation of symbols

1: Polysilicon thin film transistor, 10: Glass substrate, 12: Photoresist, 13 Photoresist with heat resistance, 14: Coating film of solution A, 15, 19: Amorphous silicon film, 16: Polysilicon film, 17: Coating film of solution B, 18: gate insulating film, 20: gate electrode, 22: interlayer insulating film, 24: contact hole, 26: source electrode, 28: drain electrode

Claims (11)

Forming a resist pattern on the substrate and forming a recess;
Applying a liquid silicon material to the recess;
Performing a light treatment and a first heat treatment on the resist pattern and the applied liquid silicon material;
Performing a second heat treatment on the liquid silicon material;
A method for forming a silicon film. Forming a resist pattern on the substrate and forming a recess;
Performing a light treatment and a first heat treatment on the resist pattern;
Applying a liquid silicon material to the recess;
Performing a second heat treatment on the liquid silicon material;
A method of forming a silicon film including:   The method for forming a silicon film according to claim 1, wherein the liquid silicon material is photopolymerized by the light treatment.   4. The method for forming a silicon film according to claim 1, wherein the solvent of the liquid silicon material is removed by the first heat treatment. The light treatment and the first heat treatment are performed under conditions including a pressure of 10 ^{-9 to} 100 Torr, a wavelength of light of the light treatment of 170 to 600 nm, and a temperature of the first heat treatment of 20 to 150 ° C. 5. The method for forming a silicon film according to any one of 1 to 4.   The method for forming a silicon film according to claim 1, wherein the second heat treatment is performed at 300 to 450 ° C. 6.   The method of forming a silicon film according to claim 1, wherein a light source used for the light treatment is selected from any one of a high pressure mercury lamp, a low pressure mercury lamp, an excimer lamp, and an excimer laser.   The method for forming a silicon film according to claim 1, wherein the liquid silicon material contains a silane compound and / or a higher order silane.   The method of forming a silicon film according to claim 1, wherein the liquid silicon material is applied by a droplet discharge method.   A device manufacturing method using the method for forming a silicon film according to claim 1. An electro-optical device manufacturing method using the device manufacturing method according to claim 10.

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