JP2005045036A - Manufacturing method of crystalline film, crystalline film, semiconductor thin film, semiconductor device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily manufacture a crystalline film superior in an electrical characteristics, reliability, and stability. <P>SOLUTION: After forming an insulating film 2 on a substrate 1, a non-single-crystal film 4 is formed by introducing an impurity element 3 by providing a concentration gradient in a crystallization region by an ion implantation or an ion doping. After that, the film 4 is crystallized by irradiating an energy beam to melt and solidify the film 4. When the energy beam is irradiated, a gradient of a heat conductivity in response to a concentration gradient of the element 3 in the crystallization region of the film 4 is generated, and a gentle temperature distribution is formed to widen a molten region of the film 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a crystalline film by irradiating an energy beam to a non-single crystal film formed on a substrate to melt the non-single crystal film and then solidifying the crystal, and a crystal produced by the method. The present invention relates to a conductive film, a semiconductor thin film, a semiconductor device having a semiconductor element using the semiconductor thin film as an active layer, and a display device.

  In recent years, a thin film semiconductor element typified by a thin film transistor (TFT) has attracted attention. A thin film semiconductor element usually forms a semiconductor thin film having a thickness of several tens to several hundreds of nanometers on a substrate having an insulating surface by a CVD (Chemical Vapor Deposition) method or the like. Thin film semiconductor elements such as insulated gate field effect transistors (TFTs) and diodes are formed using the thin film as an active layer. As an application field of such a semiconductor thin film element, an active matrix type liquid crystal electro-optical device is known. In an active matrix type liquid crystal electro-optical device, one or more TFTs are provided on each of hundreds of thousands or more of pixel electrodes arranged in a matrix, and charges supplied to the pixel electrodes are connected to the pixel electrodes. Each TFT is controlled.

  As a semiconductor thin film used for the active layer of the TFT, there is an amorphous silicon film that can be easily formed. However, this amorphous silicon film has a problem that its electrical characteristics are low. Therefore, in order to improve TFT characteristics, it is preferable to use a crystalline silicon thin film rather than an amorphous silicon film. A silicon thin film having crystallinity is called polycrystalline silicon, microcrystalline silicon, or the like.

  Conventionally, a non-single-crystal semiconductor thin film such as amorphous or polycrystalline is formed on a non-single-crystal insulating film or a non-single-crystal insulating substrate formed on a substrate, and energy is applied to the formed non-single-crystal semiconductor thin film. There is known a method of crystallizing a semiconductor thin film by adding.

  The method of crystallizing a molten non-single crystal semiconductor thin film by laser beam irradiation gives high energy only to the non-single crystal semiconductor thin film without significantly increasing the temperature of the substrate on which the non-single crystal semiconductor thin film is provided. Therefore, a crystalline semiconductor thin film can be formed on an inexpensive glass substrate. In addition, when a linear (linear) laser beam is used, the entire irradiated surface can be efficiently irradiated by scanning in a direction perpendicular to the longitudinal direction of the laser beam. Is also excellent. For this reason, methods using such laser beam irradiation have become the mainstream, and are actively researched in various institutions.

  For example, the non-single-crystal semiconductor thin film is melted and solidified for each predetermined region in the substrate by scanning in a direction orthogonal to the longitudinal direction while intermittently irradiating a linear laser beam. Thus, a method for forming a crystalline semiconductor thin film has been developed. In this method, a crystalline semiconductor thin film can be efficiently formed over a wide area.

  However, normally, the crystalline semiconductor thin film manufactured by such a method is composed of a large number of crystal grains having a size of 1 μm or less. When a TFT is manufactured using such a crystalline semiconductor thin film, the crystalline semiconductor thin film is formed in the channel region. There is a high possibility that a large number of crystal grain boundaries are formed, which causes a decrease in electrical characteristics, variation in characteristics, and the like.

  One of the reasons for the reduction in crystal grains is that the cooling time of the non-single-crystal semiconductor thin film melted at the time of laser beam irradiation is short.

  In a pulse laser, the irradiation time of a laser beam per pulse is usually as short as several tens of ns, so that a large temperature difference occurs between the non-single crystal semiconductor thin film to be crystallized and the substrate, and the molten non-single crystal The semiconductor thin film is rapidly cooled and crystallized. As a result, the crystal grain size obtained is reduced, the crystal grain boundary density is increased, and many crystal defects are generated between the crystal grains.

  Recently, when a laser beam is irradiated, a non-uniform temperature distribution is formed in a molten non-single crystal semiconductor thin film, and crystal nuclei are generated in a low temperature region in the non-single crystal semiconductor thin film. Thus, a method for crystal growth from a region where crystal nuclei are generated to a region where cooling is slow and the temperature is high has been studied. By such a method, a high-quality crystalline semiconductor thin film can be manufactured. As a method of forming a non-uniform temperature distribution in a molten non-single crystal semiconductor thin film, a method of patterning an insulating film provided on an upper layer or a lower layer of an amorphous or polycrystalline semiconductor thin film, a laser beam itself There is a method of forming an energy intensity distribution.

In Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-26331), a heat insulating layer is formed between a semiconductor thin film and a substrate, and a heat insulating layer is also formed on the semiconductor thin film, so that heating is performed at the time of laser beam irradiation. A method of increasing the crystal grain size by slowly cooling the non-single-crystal semiconductor thin film to increase the crystal growth time is disclosed.
JP 2002-26331 A

  However, as disclosed in Patent Document 1, since the heat insulating layer is formed over the entire substrate, the grain size of the crystal grains can be increased over the entire substrate. There is a problem that the crystal grains cannot be enlarged for each predetermined region to be crystallized. In the configuration described in Patent Document 1, in order to increase the crystal grain size for each region where the non-single crystal in the substrate is crystallized, the thickness of the heat insulating layer and the film type itself are changed for each region. There is a problem that it is not easy to form a temperature gradient in each region and increase the crystal grain size in each region.

  The present invention solves such problems, and an object of the present invention is to make it possible to easily manufacture a crystalline film excellent in characteristics, reliability and stability for each predetermined region of a substrate. It is an object of the present invention to provide a manufacturing method, a crystalline film and a semiconductor thin film manufactured by the method, a semiconductor device in which a semiconductor element is manufactured using the semiconductor thin film as an active layer, and a display device.

  The method for producing a crystalline film according to the present invention includes irradiating an energy beam to a non-single crystal film formed on a substrate via an insulating film, and melting and solidifying the non-single crystal film. A method of manufacturing a crystalline film in which a film is crystallized in a predetermined direction, wherein a difference in thermal conductivity is formed in the crystallization direction in the insulating film in a region where the non-single crystal film is crystallized. An impurity element is introduced into the insulating film.

  In the region to be crystallized, the impurity is introduced into the insulating film in a concentration gradient so that the thermal conductivity decreases in the crystallization direction.

  The impurity introduced into the insulating film has a concentration gradient in the region to be crystallized in the range of 10 at% to 80 at%.

  The impurity element is introduced into the insulating film by an ion implantation method or an ion doping method.

  The insulating film is at least one of a silicon oxide compound, a silicon nitride compound, a silicon nitride oxide compound, an aluminum oxide compound, an aluminum nitride compound, a fluorinated silicon oxide compound, a fluorinated silicon oxynitride compound, and a silicon oxycarbide compound. Including one.

  The impurity element introduced into the insulating film includes at least one of carbon, nitrogen, oxygen, fluorine, silicon, and aluminum.

  The thermal conductivity of the insulating film into which the impurity element is introduced has a gradient in the film plane in the range of 5 W / m · K or less.

  The non-single crystal film is a semiconductor film.

  The semiconductor thin film is made of a silicon material.

  The insulating film has a thickness of 50 nm or more.

  The thickness of the non-single crystal film is in the range of 10 nm to 200 nm.

  The energy beam is a laser beam having a wavelength of 400 nm or less.

The energy beam, the energy density of 250 mJ / cm ² or more 250~500mJ / cm ² or less of the pulse laser.

  The crystalline film of the present invention is manufactured by the above manufacturing method.

  The semiconductor thin film of the present invention is manufactured by the manufacturing method.

  In the semiconductor device of the present invention, the semiconductor thin film is an active layer.

  In the display device of the present invention, an active matrix substrate in which pixel electrodes connected to each of a plurality of thin film transistors each having the semiconductor thin film as a channel region are provided in a matrix, and a counter substrate provided with a counter electrode are predetermined. Each pixel electrode and the counter electrode are arranged so as to face each other with a gap therebetween, and a display medium is sandwiched between the substrates.

  As described above, according to the present invention, when the non-single crystal film formed on the substrate is crystallized by irradiating the energy beam, the insulating film is formed in the region where the non-single crystal film is crystallized. Since an impurity element is introduced into the insulating film so that a difference in thermal conductivity is formed in the crystallization direction, a gentle temperature gradient is generated in the crystallization region of the non-single crystal film by irradiation with the energy beam. Thus, crystal growth can be performed at a low crystallization rate, and a crystalline film with large crystal grains can be easily formed. By manufacturing a semiconductor element such as a thin film transistor by using the crystalline semiconductor thin film thus manufactured as an active region, a semiconductor device and a display device with excellent electrical characteristics and excellent reliability with little variation in characteristics Can be realized.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIGS. 1A to 1C are schematic views for explaining a manufacturing process in the method for manufacturing a crystalline silicon film according to the embodiment of the present invention.

First, as shown in FIG. 1A, an SiO ₂ film 2 that is an insulating film is formed on a glass substrate 1. The SiO ₂ film 2 formed on the glass substrate 1 is formed to 200 nm, for example, by a plasma CVD method using TEOS (tetraethoxysilane) gas and O ₃ gas. In this case, the thermal conductivity of the SiO ₂ film 2 is about 1.4 W / m · K throughout.

  The substrate on which the insulating film is formed is not limited to a glass substrate, and a substrate having an insulating surface such as a quartz substrate or a semiconductor substrate such as a silicon wafer is used.

Next, as shown in FIG. 1B, nitrogen as the impurity element 3 is introduced into the SiO ₂ film 2 by ion implantation or ion doping. Nitrogen as the impurity element 3, in the plane of the SiO ₂ film 2, in a subsequent step, the crystallization area amorphous silicon film is a non-single-crystal film is formed on the SiO ₂ film 2 is crystallized Each time a predetermined concentration gradient is formed. Specifically, in the subsequent crystallization process of the amorphous silicon film, the concentration is such that the concentration decreases in the direction in which the amorphous silicon film is crystallized in the crystallization region (crystallization direction). Nitrogen as the impurity element 3 is introduced so as to have a gradient.

In this case, nitrogen as the impurity element 3 is introduced into the SiO ₂ film 2 with a concentration difference of about 10 at% to 80 at%.

The SiO ₂ film 2 which is an insulating film has a high thermal conductivity when the impurity element 3 is introduced. Therefore, in each crystallized region, the thermal conductivity is large at the crystal growth start portion where the impurity concentration is high, and the thermal conductivity is gradually decreased due to the decreasing impurity concentration toward the crystallization direction, and the crystal growth is stopped. The thermal conductivity is the smallest in the part. The maximum thermal conductivity in each crystallization region is 5 W / m · K or less.

Next, as shown in FIG. 1 (c), on the SiO ₂ film 2 is an insulating film, an amorphous silicon film 4 which is a non-single-crystal film is formed over the entire surface of the SiO ₂ film 2. The amorphous silicon film 4 is formed to a thickness of 50 nm by, for example, a low pressure CVD method using Si ₂ H ₆ gas.

Next, as shown in FIG. 2, the amorphous silicon film 4 is scanned with a linear laser beam 5 as an energy beam in a scanning direction (direction indicated by an arrow A) perpendicular to the longitudinal direction. By irradiation, the amorphous silicon film 4 is melted and solidified to be crystallized. For example, the laser beam 5 is set to have a length in the longitudinal direction so as to cover the entire area of the amorphous silicon film 4 in the longitudinal direction of the laser beam, and the width dimension along the scanning direction A is 2 μm. . The laser beam 5 is, for example, an excimer laser beam of 400 mJ / cm ² , and is irradiated so as to be repeatedly turned on and off every time it is moved in the scanning direction A by 1 μm.

When the amorphous silicon film 4 is irradiated with the laser beam 5, energy is given only to the amorphous silicon film 4, and the amorphous silicon film 4 enters a molten state. In this case, in the SiO ₂ film 2 in contact with the lower side of the amorphous silicon film 4, a gradient is formed in the concentration of N (nitrogen) that is an impurity for each crystallization region, so that the thermal conductivity coefficient is increased. Due to the nonuniformity, the amorphous silicon film 4 is thermally diffused nonuniformly in each crystallized region. As a result, a non-uniform temperature distribution is formed in the amorphous silicon film 4 in the molten state.

Within each crystallized region, thermal diffusion from the molten amorphous silicon film 4 to the glass substrate 1 is large where the N concentration introduced into the SiO ₂ film 2 is high, and conversely, where the N concentration is low, This thermal diffusion is reduced. As a result, a temperature gradient is generated in the film surface of the molten amorphous silicon film 4. By making the concentration gradient of N gentle, the temperature gradient in each crystallization region can also be made gentle.

  As described above, in this embodiment, since the temperature gradient is gentle in the crystallization region, the melting region can be expanded and the crystal growth region can be expanded. As a result, large crystal grains are formed. be able to.

  In this manner, the crystalline silicon film in which the amorphous silicon is crystallized in each crystallized region in the amorphous silicon film 4 so that a crystal having a large grain size is formed in each crystallized region. Can be formed.

  The crystalline silicon film thus formed is used as an active layer of a semiconductor element such as a thin film transistor, and the semiconductor element is used in a semiconductor device such as a driver of a liquid crystal display device, a semiconductor memory, or a semiconductor logic circuit. .

  Further, since the crystal growth distance in each crystallized region is increased by widening the melting region of the amorphous silicon film 4 which is a semiconductor thin film in this way, the scanning pitch of the intermittently irradiated laser beam is increased. The number of shots of the laser beam can be reduced.

  Furthermore, by irradiating a line-shaped laser beam intermittently and scanning in a direction perpendicular to the longitudinal direction, crystals having a large grain size are formed in a large number of crystallization regions in a large-area substrate, respectively. It is possible. Further, since the melting region of the amorphous silicon film 4 can be widened and the crystal growth distance can be increased in this way, crystallization can be performed even by irradiation with one shot of the laser beam, and the desired amount on the substrate can be obtained. It is also possible to form crystal grains having a large grain size only at the position.

  In this way, when one-shot laser beam is irradiated, the concentration is high in the central portion of the amorphous silicon film in the crystallization direction in the crystallization region, and the concentration decreases sequentially as it goes to both sides of the crystallization direction. Nitrogen as the impurity element 3 is introduced so as to have such a concentration gradient. As a result, the temperature distribution of the amorphous silicon film 4 in the crystallization region becomes as shown in FIG. 3A, and the temperature difference between the central portion and both side portions in the crystallization direction in the crystallization region is small. The temperature gradient in the conversion region becomes gentle.

FIG. 3B shows an amorphous structure when the amorphous silicon film 4 provided on the SiO ₂ film is irradiated with a laser beam without introducing impurities into the SiO ₂ film 2 which is an insulating film. The temperature distribution in the crystallization region of the silicon film is shown. In this case, the temperature difference between the center portion and both side portions in the crystallization direction of the crystallization region is large, and the temperature gradient is steep.

In this embodiment, an SiO ₂ film (silicon oxide film) is used as the insulating film. For example, a silicon oxide compound, a silicon nitride compound, a silicon nitride oxide compound, an aluminum oxide compound, an aluminum nitride compound, and a silicon fluoride oxide compound are used. The same effect can be obtained by using a silicon fluorinated silicon oxynitride compound and a silicon oxycarbide compound.

  In this embodiment, nitrogen is used as the impurity element. However, any impurity element having higher thermal conductivity than the insulating film, such as carbon, nitrogen, oxygen, fluorine, silicon, and aluminum, is used. be able to. These impurity elements can also be used as a mixture.

  In this embodiment, a silicon (Si) film that is a semiconductor film is used as the non-single crystal film, but a SiGe film, a GaAs film, a GaP film, an InP film, or the like may be used.

  The thermal conductivity of the insulating film into which the impurity element is introduced is preferably provided with a gradient in the range of 5 W / m · K or less. When the thermal conductivity of the insulating film is greater than 5 W / m · K, the heat applied to the non-single crystal film is immediately diffused into the substrate, so the melting time of the non-single crystal film is shortened and the crystal grains are large This is because a crystalline film cannot be obtained. If the thermal conductivity of the insulating film is 5 W / m · K or less, the melting time of the non-single-crystal film can be increased, and a crystalline film with large crystal grains can be obtained.

  The thickness of the insulating film is preferably 50 nm or more. This is because if the insulating film is thinner than 50 nm, a sufficiently gentle temperature gradient cannot be formed when an energy beam such as a laser beam is irradiated thereafter. When the thickness of the insulating film is 50 nm or more, the crystallization speed is reduced by gradually reducing the temperature gradient of the crystallization region in the non-single crystal film when irradiated with an energy beam such as a laser beam due to the concentration gradient of the impurity element. And a crystalline film with large crystal grains can be obtained.

  The thickness of the non-single crystal film is preferably in the range of 10 nm to 200 nm. This is because if the thickness of the non-single crystal film is thinner than 10 nm, the energy beam is not sufficiently absorbed, and it is difficult to melt the non-single crystal film. Further, if the non-single crystal film is thicker than 200 nm, an energy beam of excessive energy is required to melt the non-single crystal film, and the non-single crystal film cannot be stably melted. This is because it becomes difficult to form a gentle temperature gradient in the crystallization region. When the thickness of the non-single crystal film is in the range of 10 nm to 200 nm, the non-single crystal film can be stably melted and a gentle temperature gradient can be formed in the crystallization region.

  Furthermore, in the present embodiment, pulsed excimer laser light is used as the energy beam, but other energy beams such as other pulsed laser light, pulsed light, and pulsed charged particles may be used.

This is because if the energy density of the energy beam is smaller than 250 mJ / cm ² , the energy is small and the non-single crystal film cannot be sufficiently melted. On the other hand, when the energy density is higher than 500 mJ / cm ² , the energy is so high that a part of the non-single crystal film may be scattered. If the energy density of the energy beam is 250 mJ / cm ² or more 250~500mJ / cm ² or less of a pulse laser, it is possible to sufficiently melt the non-single-crystal film, and does not occur scattering of non-single-crystal film.

  FIG. 4 is a cross-sectional view showing a manufacturing process of an active matrix substrate of a liquid crystal display device provided with a thin film transistor which is a semiconductor element using a crystalline silicon film manufactured by the above-described manufacturing method as an active layer, and FIG. FIG. 6 is a cross-sectional view of the active matrix substrate, and FIG. 6 is a cross-sectional view of a counter substrate that is bonded to the active matrix substrate via a liquid crystal layer to form a liquid crystal display device.

  An active matrix substrate 31 shown in FIG. 5 is provided with a large number of pixel electrodes 15 (see FIG. 5) in a matrix, and each pixel electrode 15 is driven by a thin film transistor 33.

In the active matrix substrate 31, the SiO ₂ film 2 as an insulating film is formed on the glass substrate 1. Further, when the crystalline silicon film is formed by the method described above, the crystalline silicon film is shaped into a predetermined shape. By patterning, the active layer 8 of the thin film transistor 33 provided corresponding to each pixel electrode 15 is formed.

  The active layer 8 made of a crystalline silicon film is provided with a channel region 8a at the center, and a source region 8b and a drain region 8c are formed on both sides of the channel region 8a. A gate electrode 10 is provided on the channel region 8 a via a gate insulating film 9, and an insulating film 11 is provided so as to cover the gate insulating film 9 and the gate electrode 10. The gate insulating film 9 and the insulating film 11 are provided with contact holes so as to reach the source region 8b and the drain region 8c, and the source electrode 12b and the drain electrode 12c are connected to the source region 8b and the drain region 8c through the contact holes. Is connected. An insulating film 13 is provided so as to cover the insulating film 11 and the source electrode 12b and the drain electrode 12c. A through hole 13a is formed in the insulating layer 13 so that a part of the source electrode 12b and the drain electrode 12c is exposed.

  FIG. 4 is a cross-sectional view of this state, in which a thin film transistor 33 using a crystalline silicon film as the active layer 8 is formed. Such a thin film transistor 33 is not limited to a configuration used as a driver of a liquid crystal display device, but is also used as a semiconductor device such as a semiconductor memory or a semiconductor logic circuit. When used as a semiconductor device such as a semiconductor memory or a semiconductor logic circuit, a resistor, a capacitor, and the like are provided on a substrate.

  As shown in FIG. 5, the active matrix substrate 31 of the liquid crystal display device in which the thin film transistors 13 shown in FIG. 4 are formed in a matrix on the glass substrate 1 has a drain electrode 12c on the insulating layer 13 through a through hole 13a. Are connected to each other, and a protective film 16 is provided so as to cover the insulating layer 13 and the pixel electrode 15. An alignment film 17 is provided so as to cover the protective film 16.

  The active matrix substrate 31 having such a structure is bonded to the counter substrate 32 shown in FIG. 6 via a liquid crystal layer, whereby a liquid crystal display device is obtained. The counter substrate 32 shown in FIG. 6 is provided with a color filter 19, a counter electrode 20, a protective film 22, and an alignment film 21 on a glass substrate 18 that is an insulating substrate. Then, the alignment film 21 is disposed opposite to the alignment film 17 of the active matrix substrate 31 with a predetermined interval, and a liquid crystal layer is formed within the interval to obtain a liquid crystal display device.

The active matrix substrate 31 shown in FIG. 5 is manufactured as follows. First, when a crystalline silicon film is formed on the SiO ₂ film 2 of the glass substrate 1 by the above-described method, the crystalline silicon film is formed on each pixel by RIE using CF ₄ gas and O ₂ gas. The active layer 8 of each thin film transistor 33 is formed by patterning in a matrix corresponding to the electrode 15.

Thereafter, similarly to the manufacturing process of the conventional thin film transistor, formed by a plasma CVD method using the TEOS gas and the _{O 3} gas, as a gate insulating film 9 made of SiO _2, covering the active layer 8 and the SiO ₂ film 2 To do.

Next, after forming a WSi ₂ / polycrystalline Si film by sputtering, patterning is performed by RIE using CF ₄ gas and O ₂ gas, whereby the gate electrode 10 is formed on the channel region 8 a of the active layer 8. Respectively.

Next, using the gate electrode 10 as a mask, P (phosphorus) and B (boron) are implanted into the source region 8b and the drain region 8c by ion doping. Thereafter, an insulating film 11 made of SiO ₂ is formed so as to cover each gate electrode 10 and the gate insulating film 9 by plasma CVD using TEOS gas and O ₃ gas. In such a state, the contact hole is formed so that the source region 8b and the drain region 8c of each active layer 8 are exposed by etching the insulating film 11 by RIE using CF ₄ gas and CHF ₃ gas. Form each one.

Next, an Al film is formed on the insulating film 11 and in each contact hole by sputtering, and patterned by RIE using BCl ₃ gas and Cl ₂ gas, whereby the source electrode 12b and the drain electrode 12c are formed. Form. Then, the insulating protective film 13 made of SiN is covered with the insulating film 11 and the source electrode 12b and the drain electrode 12c by plasma CVD using SiH ₄ gas, NH ₃ gas, and N ₂ gas. Form. Thereafter, etching is performed by an RIE method using CF ₄ gas and CHF ₃ gas to open a part of the protective film 13 so that a part of the electrode and the wiring 12 is exposed. Thereby, the thin film transistor 33 shown in FIG. 4 is formed.

Thereafter, an insulating layer 13 made of SiO ₂ is formed by a plasma CVD method using TEOS gas and O ₃ gas, and etched by an RIE method using CF ₄ gas and CHF ₃ gas. Through-holes 13a are formed.

Next, an ITO film is formed in the insulating layer 13 and the through hole 13a by sputtering, and is patterned using HCl and FeCl ₃ , thereby connecting the pixel electrode connected to the drain electrode 12c through the through hole 13a. 15 is formed. Thereafter, an insulating protective film 16 made of SiN is formed so as to cover the insulating layer 13 and each pixel electrode 15 by plasma CVD using SiH ₄ gas, NH ₃ gas, and N ₂ gas. Then, an alignment film 17 made of polyimide is formed on the protective film 16 by an offset printing method, and a rubbing process is performed. Thereby, the active matrix substrate 31 shown in FIG. 5 is formed.

  The counter substrate 32 shown in FIG. 6 transfers a film in which a photosensitive resin thin film of each color of red, green, and blue is provided on an insulating substrate 18 such as a glass substrate by thermocompression bonding, and the transferred film is photolithography. The color filter 19 is formed by patterning according to the process and further forming the black matrix portion in the same manner in the space between the colored portions of red, green and blue. Thereafter, a counter electrode 20 made of an ITO film is formed on the color filter 19 by a sputtering method, and an alignment film 21 made of polyimide is formed on the formed counter electrode 20 by an offset printing method. Do. Thereby, the counter substrate 32 shown in FIG. 6 is formed.

  In this way, the active matrix substrate 31 on which the thin film transistor 33, the pixel electrode 15 and the like are formed, and the counter substrate 32 on which the color filter 19, the counter electrode 20 and the like are formed are arranged to face each other at a predetermined interval. The peripheral edges facing each other are bonded together with a seal resin. In this case, true spherical fine silica is uniformly dispersed so that a constant space is formed between the active matrix substrate 31 and the counter substrate 32. In this state, after injecting liquid crystal between the active matrix substrate 31 and the counter substrate 32 to form a liquid crystal layer, polarizing plates are respectively applied to the glass substrate 1 of the active matrix substrate 31 and the glass substrate 18 of the counter substrate 32. A liquid crystal display device is manufactured by pasting and mounting a driver IC or the like around the active matrix substrate 31.

  In the liquid crystal display device manufactured in this way, each thin film transistor 33 is good because the active region 8 of the thin film transistor 33 connected to each pixel electrode 15 is composed of a crystalline semiconductor thin film having a large crystal grain. In addition, the characteristics of the thin film transistors 33 are reduced. As a result, good display characteristics can be realized over the entire display area.

(A)-(c) is sectional drawing for demonstrating an example of embodiment of the manufacturing method of the crystalline thin film of this invention, respectively. It is the schematic for demonstrating the manufacturing method of the crystalline thin film. (A) is the graph which shows the temperature distribution of the crystallization area | region of the amorphous silicon film irradiated with the laser beam in the manufacturing method of the crystalline thin film of this invention, (b) is the manufacturing method of the conventional crystalline thin film 2 is a graph showing the temperature distribution of the crystallization region of the amorphous silicon film irradiated with the laser beam. It is sectional drawing of the thin-film transistor which is a semiconductor device manufactured by the manufacturing method of the crystalline thin film. It is sectional drawing of the active matrix transistor of the liquid crystal display device using the thin-film transistor. It is sectional drawing of the opposing board | substrate of the liquid crystal display device.

Explanation of symbols

1 glass substrate 2 SiO ₂ film 11, 14 insulating film 3 impurity element 4 amorphous silicon film 5 laser beam 8 active layer 9 gate insulating film 10 gate electrode 12b source electrode 12c drain electrode 13 insulating layer 15 pixel electrode 17 and 21 oriented Membrane 19 Color filter 20 Counter electrode

Claims (17)

A crystalline film that crystallizes the non-single crystal film in a predetermined direction by irradiating an energy beam to the non-single crystal film formed on the substrate via an insulating film, and melting and solidifying the non-single crystal film A manufacturing method of
In a region where the non-single crystal film is crystallized, an impurity element is introduced into the insulating film so that a difference in thermal conductivity is formed in the crystallization direction in the insulating film. Production method.   2. The crystalline film according to claim 1, wherein the impurity is introduced into the insulating film in a concentration gradient so that thermal conductivity decreases in the crystallization direction in the region to be crystallized. Method.   The method for manufacturing a crystalline film according to claim 2, wherein the impurity introduced into the insulating film is provided with a concentration gradient in a range of 10 at% to 80 at% in the region to be crystallized.   The method for producing a crystalline film according to claim 1, wherein the impurity element is introduced into the insulating film by an ion implantation method or an ion doping method.   The insulating film is at least one of a silicon oxide compound, a silicon nitride compound, a silicon nitride oxide compound, an aluminum oxide compound, an aluminum nitride compound, a fluorinated silicon oxide compound, a fluorinated silicon oxynitride compound, and a silicon oxycarbide compound. The manufacturing method of the crystalline film in any one of Claims 1-4 containing one.   The method for producing a crystalline film according to claim 1, wherein the impurity element introduced into the insulating film includes at least one of carbon, nitrogen, oxygen, fluorine, silicon, and aluminum.   The crystalline film according to any one of claims 1 to 6, wherein the insulating film into which the impurity element has been introduced has a gradient in the film plane within a range of 5 W / m · K or less. Method.   The method for manufacturing a crystalline film according to claim 1, wherein the non-single crystal film is a semiconductor film.   The method for producing a crystalline film according to claim 8, wherein the semiconductor thin film is made of a silicon material.   The method for manufacturing a crystalline film according to claim 1, wherein the insulating film has a thickness of 50 nm or more.   The method for producing a crystalline film according to claim 1, wherein the film thickness of the non-single crystal film is in a range of 10 nm to 200 nm.   The method for producing a crystalline film according to claim 1, wherein the energy beam is a laser beam having a wavelength of 400 nm or less. Wherein the energy beam is a manufacturing method of a crystalline film of the energy density according to any one of claims 1 to 12 is 250 mJ / cm ² or more 250~500mJ / cm ² or less of the pulse laser.   A crystalline film manufactured by the method for manufacturing a crystalline film according to claim 1.   The semiconductor thin film manufactured by the manufacturing method of the crystalline film in any one of Claims 7-13.   A semiconductor device comprising a semiconductor element having the semiconductor thin film according to claim 15 as an active layer.   An active matrix substrate in which pixel electrodes connected to each of a plurality of thin film transistors each having the semiconductor thin film according to claim 15 as a channel region are provided in a matrix and a counter substrate provided with a counter electrode are spaced apart from each other by a predetermined distance. A display device in which each pixel electrode and the counter electrode are arranged to face each other with a display medium opened, and a display medium is sandwiched between the substrates.

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