JP2008066577A - Method of manufacturing substrate for semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a substrate for a semiconductor device capable of forming a polysilicon film having desired quality with favorable productivity when manufacturing a substrate for the semiconductor device including a polysilicon type TFT. <P>SOLUTION: The method of manufacturing the substrate for the semiconductor device comprises a process of forming a material film 204b having conductivity on the substrate 200; a process of forming an amorphous silicon film 1 on the substrate; and a process of forming the polysilicon film on the substrate by heating and crystallizing the amorphous silicon film by subjecting a material film to high frequency induction heating. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a substrate for a semiconductor device.

As a thin film transistor (TFT) formed on a substrate for a semiconductor device such as an element substrate (TFT array substrate) of a liquid crystal device or an element substrate (TFT array substrate) of an organic EL device, an amorphous silicon type TFT has been conventionally used. Are known. An amorphous silicon type TFT is a TFT in which a semiconductor layer is formed of an amorphous silicon film. In recent years, polysilicon TFTs are often used for the purpose of higher functionality and higher definition. A polysilicon type TFT is a TFT in which a semiconductor layer is formed of a polysilicon film. Polysilicon is formed by polycrystallizing amorphous silicon. Conventionally known methods for polycrystallizing amorphous silicon include a solid phase growth method, an energy beam irradiation method, and the like. Examples of the energy beam irradiation method include an electron beam annealing method, a flash beam annealing method, a lamp annealing method, an RTA (Rapid Thermal Anneal) method, and an excimer laser annealing (ELA) method. Among these, the ELA method is widely used as a method for polycrystallizing amorphous silicon because a low temperature process is possible. Patent Document 1 below discloses an example of a technique for forming polysilicon by polycrystallizing amorphous silicon by an ELA method. The ELA method utilizes the fact that an amorphous silicon film formed on a substrate is irradiated with laser light, the amorphous silicon film is melted by the energy of the laser light, and crystallizes when the melted silicon is solidified. A polysilicon film is formed.
JP 2004-327539 A

  In the conventional ELA method, the amorphous silicon film is irradiated with laser light while relatively moving the substrate on which the amorphous silicon film is formed and the laser light in a predetermined scanning direction. In this case, the quality of the formed crystal (polysilicon) (for example, the size of crystal grains) may be nonuniform in the surface direction of the substrate. For example, the quality of the formed crystal (polysilicon) may become non-uniform due to the change over time of the light intensity (illuminance) of the laser beam to be irradiated. In addition, since the area on the substrate that can be irradiated with laser light in a single scan is limited, when the substrate is large, it is necessary to repeat relative movement between the substrate and the laser light multiple times. In that case, there is a possibility that the quality of the crystal formed for each of a plurality of movements may change, and even in that case, the quality of the formed crystal (polysilicon) may be non-uniform in the surface direction of the substrate. is there. If the quality of the crystal becomes uneven, the display quality of a display device such as a liquid crystal device or an organic EL device may be deteriorated.

  Further, as in the conventional ELA method, the amorphous silicon film is irradiated with laser light while the substrate and laser light are relatively moved in a predetermined scanning direction, and the substrate and laser light are moved relative to each other. If it is repeated several times, productivity may be reduced.

  The present invention has been made in view of the above circumstances, and a method of manufacturing a semiconductor device substrate capable of forming a polysilicon film having a desired quality with high productivity when manufacturing a substrate for a semiconductor device having a polysilicon type TFT. The purpose is to provide.

In order to solve the above problems, the present invention adopts the following configuration.
According to one embodiment of the present invention, there is provided a method for manufacturing a substrate for a semiconductor device including a thin film transistor, the step of forming a conductive material film on the substrate, and the step of forming an amorphous silicon film on the substrate. And heating the amorphous silicon film to crystallize the amorphous silicon film to form a polysilicon film on the substrate by high-frequency induction heating of the material film. .

  According to one embodiment of the present invention, an amorphous silicon film is efficiently and well polycrystalline by providing a conductive material film on a substrate and heating the amorphous silicon film by high-frequency induction heating the material film. Thus, a polysilicon film having a desired quality can be formed. For example, by forming a material film in a wide area on the substrate and collectively applying a high frequency to the material film, the amorphous silicon film is polycrystallized with high uniformity in a large area on the substrate, It can be converted into a polysilicon film. Applying a high frequency to a wide region at once is easier than, for example, collectively irradiating a wide region with laser light, and a polysilicon film having a desired quality can be formed with high productivity. In addition, by forming a material film having desired physical properties (melting point, electrical resistance value, etc.) on the substrate, the material film can be efficiently heated without melting the material film itself by high-frequency induction heating. The amorphous silicon film can be heated by the heat generated from the film to form the polysilicon film satisfactorily and efficiently.

  In the manufacturing method of the above aspect, the polysilicon film forms a semiconductor layer including a channel region of the thin film transistor, and the material film is formed so as to sandwich a first insulating film between the polysilicon film and the polysilicon film. A configuration including a light shielding film can be employed.

  According to this, heat generated in the light shielding film can be favorably given to the amorphous silicon film through the first insulating film by high-frequency induction heating of the light shielding film. In addition, the amorphous silicon film can be satisfactorily heated by using the light shielding film formed to block light without forming a new material film for heating the amorphous silicon film.

  In the manufacturing method of the above aspect, the light shielding film may employ a configuration that suppresses light from entering the channel region.

  According to this, in order to suppress the incidence of light to the channel region of the thin film transistor, the polysilicon film can be efficiently formed in the vicinity of the channel region by using the light shielding film formed in the predetermined region in the vicinity of the channel region. Then, the occurrence of a problem that the performance of the thin film transistor changes when light enters the channel region can be suppressed by the light shielding film.

  In the manufacturing method of the above aspect, the light shielding film is formed on the substrate so as to sandwich a second insulating film between the substrate, and the amorphous silicon film is disposed on the light shielding film between the light shielding film and the substrate. The first insulating film may be sandwiched between the first insulating films, and the first insulating film may have a higher thermal conductivity than the second insulating film.

  According to this, the heat generated in the light shielding film can be efficiently given to the amorphous silicon film through the first insulating film having high thermal conductivity by high-frequency induction heating of the light shielding film. In addition, the second insulating film having low thermal conductivity can suppress the heat generated in the light shielding film from being supplied to the substrate. Therefore, it is possible to suppress the substrate from being excessively heated or thermally deformed.

  In the manufacturing method of the above aspect, the light shielding film may have a higher melting point than the amorphous silicon film.

  According to this, the amorphous silicon film can be satisfactorily heated without melting the light shielding film, for example.

  In the manufacturing method of the above aspect, a configuration in which the amorphous silicon film is heated until immediately before the amorphous silicon film is melted can be adopted.

  According to this, for example, it is possible to suppress the occurrence of a problem that a part of the silicon film aggregates.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
The semiconductor device substrate according to the present embodiment will be described with reference to FIGS. FIG. 1 is a plan view showing a pixel portion PX of a semiconductor device substrate SP according to this embodiment, and FIG. 2 shows the vicinity of a thin film transistor (TFT) 30b of the semiconductor device substrate SP according to this embodiment. It is sectional drawing, Comprising: It corresponds to the sectional view on the AA line of FIG.

  1 and 2, the semiconductor device substrate SP includes a substrate 200 such as glass and a thin film transistor (TFT) 30 b formed on the substrate 200. The semiconductor device substrate SP includes a storage capacitor 70 having a pixel potential side capacitor electrode 301 and a capacitor line 300.

  As shown in FIG. 2, the semiconductor device substrate SP includes a base insulating film 202 formed on the substrate 200, a conductive light-shielding film 204b formed on the base insulating film 202, and a light-shielding film 204b. A first interlayer insulating film 206b formed to cover the light shielding film 204b, a semiconductor layer 1b including a channel region 250b formed on the first interlayer insulating film 206b, and the semiconductor layer 1b and the first interlayer insulating film 206b A gate insulating film 208b formed to cover the semiconductor layer 1b, a gate electrode 210b formed on the gate insulating film 208b, a second interlayer insulating film 212b formed on the gate electrode 210b, and a second interlayer A third interlayer insulating film 218b formed on the insulating film 212b and a transparent pixel electrode 9a formed on the third interlayer insulating film 218b are provided. The semiconductor layer 1b is formed of a polysilicon film.

  The TFT 30b includes a semiconductor layer 1b including a channel region 250b, a gate electrode 210b, a source electrode 216b, and a drain electrode. The source electrode 216b is connected to one end side of the semiconductor layer 1b through the contact hole 214b. The pixel electrode 9a is connected to the other end side of the semiconductor layer 1b through the contact hole 220b.

  The light shielding film 204b has conductivity. The light shielding film 204b is for suppressing the incidence of light on the channel region 250b of the semiconductor layer 1b and the polysilicon film, and the first interlayer insulation between the light shielding film 204b and the semiconductor layer 1b formed of the polysilicon film. It is formed so as to sandwich the film 206b. Further, the light shielding film 204b is formed so as to sandwich the base insulating film 202 with the substrate 200. The light shielding film 204b is formed larger than the channel region 250b so as to cover all of the channel region 250b in the surface direction of the substrate 200 in order to prevent light from the substrate 200 from entering the channel region 250b. Yes.

  For example, when the semiconductor device substrate SP of the present embodiment is used in a liquid crystal device, in the liquid crystal device, when the TFT 30b is irradiated with light such as external irradiation light from the backlight, or return light such as back surface reflection light, There is a possibility that a light leakage current is generated by the excitation by the light, and the characteristics of the TFT 30b are changed, or that the TFT 30b malfunctions. In the present embodiment, since the light shielding film 204b is formed in the pixel portion PX, it is possible to suppress the light from entering the channel region 250b of the pixel switching TFT 30b, and to suppress the occurrence of the above-described problems.

  Next, a method for manufacturing the semiconductor device substrate SP according to the present embodiment will be described with reference to FIG. FIG. 3 is a schematic view for explaining the method for manufacturing the semiconductor device substrate SP according to this embodiment.

  First, as shown in FIG. 3, in step (1), a substrate 200 made of glass or the like is prepared.

  Next, in step (2), a base insulating film 202 is formed on the substrate 200. The base insulating film 202 is formed of a silicate glass film such as NSG (non-silicate glass), PSG (phosphorus silicate glass), BSG (boron silicate glass), or BPSG (boron phosphorus silicate glass), a silicon nitride film, a silicon oxide film, or the like. Is possible.

In the present embodiment, the base insulating film 202 disposed between the substrate 200 and the light shielding film 204 is formed of a material having low thermal conductivity, for example, silicon dioxide (SiO ₂ ).

  The base insulating film 202 is about 450 using, for example, TEOS (tetraethylorthosilicate) gas, TEB (tetraethylboatate) gas, TMOP (tetramethyloxyphosphorate) gas, or the like. It can be formed by a low pressure CVD method in a relatively low temperature environment of ˜550 ° C. (preferably about 500 ° C.).

  The base insulating film 202 has a function of suppressing reaction of impurities from, for example, an etching gas (or an etchant) and glass when etching a light shielding film 204 described later (see step (3)).

  Next, a light shielding film 204 is formed over the base insulating film 202. The light shielding film 204 is formed on the substrate 200 so that the base insulating film 202 is sandwiched between the light shielding film 204 and the substrate 200.

  The light shielding film 204 is formed of a conductive material having a high melting point and a high electric resistance value. The light shielding film 204 is made of a metal such as Ti (titanium), Cr (chromium), W (tungsten), Ta (tantalum), Mo (molybdenum), Al (aluminum), Ag (silver), or an alloy thereof, or graphite. Etc. can be formed.

  In the present embodiment, the light shielding film 204 is formed of Mo (molybdenum) having a high melting point and a high electric resistance and good light shielding properties.

  The light shielding film 204 can be formed by sputtering using the above-described metal as a target material. The light-shielding film 204 is formed with a film thickness of, for example, about 100 to 500 nm, preferably 200 nm.

  Next, in step (3), a light shielding film 204b having a predetermined pattern as shown in FIGS. 1 and 2 is formed by a photolithography technique including an exposure process, a development process, and an etching process.

  Next, in step (4), the first interlayer insulating film 206b made of a silicate glass film, a silicon nitride film, a silicon oxide film, or the like is formed by the same method as the method for forming the base insulating film 202 in the above step (2). Is formed. The film thickness of the first interlayer insulating film 206b is, for example, about 100 to 2000 nm.

  Next, the amorphous silicon film 1 is formed on the substrate 200 on which the base insulating film 202, the light shielding film 204b, and the first interlayer insulating film 206b are formed. The amorphous silicon film 1 (later polysilicon film) is formed on the light shielding film 204b so as to sandwich the first interlayer insulating film 206b with the light shielding film 204b.

  In the present embodiment, the first interlayer insulating film 206b disposed between the light shielding film 204b and the amorphous silicon film 1 is higher than the base insulating film 202 disposed between the light shielding film 204b and the substrate 200. Has thermal conductivity. In the present embodiment, the first interlayer insulating film 206b is formed of, for example, silicon nitride (SiN).

  The amorphous silicon film 1 can be formed by a low pressure CVD method in a relatively low temperature environment of about 200 to 550 ° C. (preferably about 300 ° C.) using, for example, a monosilane gas or a disilane gas having a flow rate of about 400 to 600 cc / min. is there.

  After the amorphous silicon film 1 is formed, a process for crystallizing the amorphous silicon film 1 to form a polysilicon film is performed.

  In this embodiment, the amorphous silicon film 1 on the substrate 200 is heated by high-frequency induction heating of the light shielding film 204b, and the amorphous silicon film 1 is crystallized to form a polysilicon film.

  FIG. 4 is a schematic diagram showing a state where the light shielding film 204b is heated by high frequency induction. In this embodiment, the amorphous silicon film 1 on the substrate 200 is heated by high-frequency induction heating of the light shielding film 204b, and the amorphous silicon film 1 is crystallized to form a polysilicon film.

  In FIG. 4, the light shielding film 204b is formed so as to sandwich the first interlayer insulating film 206b with the amorphous silicon film 1 (later polysilicon film). In other words, the first interlayer insulating film 206b is disposed so as to be sandwiched between the light shielding film 204b and the amorphous silicon film 1 (later polysilicon film). When the light shielding film 204b is subjected to high-frequency dielectric heating, heat is generated in the light shielding film 204b. The heat generated in the light shielding film 204b is supplied to the amorphous silicon film 1 through the first interlayer insulating film 206b. Thereby, the amorphous silicon film 1 is heated.

  In the present embodiment, the light-shielding film 204b is made of metal and has conductivity, and high efficiency (heating efficiency) is obtained by high frequency (high frequency energy) applied from a coil connected to a high frequency oscillator (high frequency power supply). ). That is, the high frequency induction heating method in this embodiment is a direct heating method on the premise that the object to be heated (here, the light shielding film 204b) is a conductor, and the non-heated object (light shielding film 204b) is efficiently used. It can be heated well.

  In the present embodiment, an alternating magnetic field having a frequency of, for example, 0.5 kHz to 100 MHz is applied to the light shielding film 204b from the coil arranged in the vicinity of the substrate 200 so as to penetrate the light shielding film 204b. An induced current is generated in the light shielding film 204b by the applied magnetic field, and the light shielding film 204b generates heat due to resistance loss.

  In the present embodiment, the light shielding film 204b is made of a material having a high electric resistance value such as Mo (molybdenum), and can efficiently generate heat (Joule heat). The heat generated in the light shielding film 204b is supplied to the amorphous silicon film 1 through the first interlayer insulating film 206b, and the amorphous silicon film 1 is heated by the heat from the light shielding film 204b.

As described above, in the present embodiment, the first interlayer insulating film 206b disposed between the light shielding film 204b and the amorphous silicon film 1 is formed of, for example, SiN, and the light shielding film 204b and the substrate 200 are separated from each other. The base insulating film 202 disposed therebetween is made of, for example, SiO ₂ , and the first interlayer insulating film 206 _b has a higher thermal conductivity than the base insulating film 202. Therefore, the heat generated in the light shielding film 204b is efficiently supplied to the amorphous silicon film 1 via the first interlayer insulating film 206b having high thermal conductivity. In addition, the base insulating film 202 having low thermal conductivity can suppress the heat generated in the light shielding film 204b from being supplied to the substrate 200. Therefore, it is possible to suppress the substrate 200 from being excessively heated or thermally deformed.

  The light shielding film 204b is desirably formed of a material having a high melting point. In the present embodiment, the light shielding film 204b is formed of a material having a melting point higher than that of the amorphous silicon film 1 at least. Yes. When the melting point of the light shielding film 204b is lower than the melting point of the amorphous silicon film 1, there is a possibility that the light shielding film 204b itself is melted when the amorphous silicon film 1 is heated. In the present embodiment, since the conductive light-shielding film 204b is formed of a material having a melting point higher than that of at least the amorphous silicon film 1, such as Mo (molybdenum), the occurrence of the above-described problems can be suppressed.

  In the present embodiment, the amorphous silicon film 1 is heated until just before the amorphous silicon film 1 is melted. For example, when the temperature at which the amorphous silicon film 1 melts is about 1300 ° C., the amorphous silicon film 1 is heated to about 1000 ° C. by the heat from the light shielding film 204b. Then, after the amorphous silicon film 1 is heated to about 1000 ° C. and then gradually cooled, the amorphous silicon film 1 is polycrystallized to form a polysilicon film. Since crystallization of silicon occurs at about 600 ° C., even if the amorphous silicon film 1 is not completely melted (even if it is not heated to 1300 ° C. or higher), it is heated to a temperature just before melting (for example, 1000 ° C.). By gradually cooling from the temperature, the amorphous silicon film 1 can be crystallized to form a polysilicon film.

  When the amorphous silicon film 1 is completely melted (heated to 1300 ° C. or higher) and then cooled, a phenomenon of aggregation occurs when a part of the amorphous silicon film 1 is solidified, for example, a step shown in FIG. There is a high possibility that a phenomenon in which the portion is cut off due to aggregation or the like (so-called step breakage phenomenon) occurs. In addition, when an agglomerated portion is generated, there is a possibility that the agglomerated portion is not sufficiently removed and remains as a foreign substance (residue) even if an etching process is performed later.

  In the present embodiment, the amorphous silicon film 1 is not completely melted, and the amorphous silicon film 1 is heated until immediately before the amorphous silicon film 1 is melted. Occurrence of problems such as occurrence can be suppressed.

  In the present embodiment, for example, the material characteristics (type) and film thickness of the light shielding film 204b used and the material of the first interlayer insulating film 206b are used so that the amorphous silicon film 1 can be set (heated) to a desired temperature. The high frequency conditions to be applied are optimized according to the characteristics and film thickness, the material characteristics and film thickness of the amorphous silicon film 1, and the like. The high frequency condition includes, for example, a high frequency, high frequency energy, and the like. Further, the optimization of the high-frequency conditions can be performed in advance using at least one of a preliminary experiment and a simulation in accordance with the material characteristics and film thickness of each film described above. Therefore, the amorphous silicon film 1 can be set to a desired temperature (can be heated).

  Further, for example, by reducing the frequency of the applied high frequency, the entire light shielding film 204b can be heated, so that the sensible heat can be increased. Further, by increasing the frequency of the applied high frequency, only the surface layer of the light shielding film 204b is heated, so that the sensible heat can be reduced. Therefore, it is possible to adjust the crystallinity of the amorphous silicon film 1 by adjusting the high-frequency condition and adjusting the heating state of the light shielding film 204b.

  As described above, the amorphous silicon film 1 is crystallized to form a polysilicon film. In this embodiment, the region to be crystallized (region where amorphous silicon is converted into polysilicon) is only in the vicinity of the light shielding film 204b, and a polysilicon film can be selectively formed.

  Here, after crystallization of the silicon film, a dopant (impurity) such as phosphorus (P) or boron (B) may be introduced by an ion implantation method or an ion doping method. Preferably, the dopant is activated in a relatively low temperature environment of about 300 ° C. by using an ion doping method.

  Next, in step (5), as shown in FIGS. 1 and 2, a predetermined region including the source region, the channel region, and the drain region of the TFT 30b is obtained by a photolithography technique including an exposure process, a development process, and an etching process. A semiconductor layer 1b having a pattern is formed.

  Next, the gate insulating film 208b is formed by a low pressure CVD method or the like in a relatively low temperature environment of about 450 to 550 ° C. (preferably about 500 ° C.). The gate insulating film 208b can be formed using a silicate glass film, a silicon nitride film, a silicon oxide film, or the like.

  Next, the gate electrode 210b is formed over the gate insulating film 208b. The gate electrode 210b is formed in a predetermined pattern by a photolithography technique after depositing a conductive polysilicon film by the above-described low pressure CVD method or the like. Note that, as in the present embodiment, in a manufacturing process in a relatively low temperature environment, for example, the gate electrode 210 made of a low-resistance metal such as Cr, Ta, or Al can be formed by sputtering or the like.

  Note that in step (5), the source region, the channel region, and the drain region in the semiconductor layer 1b can be formed by implanting impurities into the semiconductor layer 1b using the gate electrode 210b as a mask. When the implanted dopant (impurity) is an ion of a group V element such as boron (B), the finally formed TFT is a P-channel type. When the implanted dopant (impurity) is an ion of a group III element such as phosphorus (P), the finally formed TFT is an N-channel type.

  Next, in step (6), for example, after the second interlayer insulating film 212b made of a silicon oxide film or the like is formed, the second interlayer insulating film 212b is dry-etched to reach the source region of the semiconductor layer 1b. A contact hole 220b that communicates with the contact hole 214b and the drain region of the semiconductor layer 1b is formed. Then, a source electrode 216b and a drain electrode made of, for example, aluminum are formed on the second interlayer insulating film 212b and the insides of the contact hole 214b and the contact hole 220b. After the formation of the source electrode 216b, the third interlayer insulating film 218b and the pixel electrode 9a are formed.

  The TFT 30b is formed on the substrate 200 by the above steps (1) to (6).

  As described above, in order to prevent light from entering the channel region 250b of the TFT 30b, the amorphous silicon film 1 is heated by high-frequency induction heating the light shielding film 204b formed in the vicinity of the channel region 250b. By doing so, the amorphous silicon film 1 can be polycrystallized efficiently and satisfactorily to form a polysilicon film. In the present embodiment, the light shielding film 204b is formed in a wide area on the substrate 200. By applying a high frequency to the light shielding film 204b at once, the amorphous silicon film 1 is formed in a wide area on the substrate 200. It can be converted into a polysilicon film at once with high uniformity. Applying a high frequency to a wide region at once is easier than, for example, irradiating laser light to a wide region at once, and a polysilicon film having a desired quality even if the substrate 200 is large. Can be formed with high productivity.

  Further, for example, in the ELA method, various devices for performing the ELA method, such as a laser irradiation device and an optical system, are complicated and expensive, and the running cost such as maintenance is high. In the present embodiment, the cost for maintenance and the like can be kept low due to the device configuration.

  Further, in the present embodiment, the light shielding film 204b has at least a melting point and a higher electric resistance value than the amorphous silicon film 1, so that the light shielding film 204b is not melted by high frequency induction heating. The light shielding film 204b can be efficiently heated. Then, the amorphous silicon film 1 can be satisfactorily heated by the heat generated from the light shielding film 204b.

  In this embodiment, the light shielding formed in a predetermined region on the substrate 200 to block the incidence of light on the channel region 250b without forming a new material film for heating the amorphous silicon film 1. Since the film 204b is used, the region where the amorphous silicon film 1 is desired to be a polysilicon film can be efficiently heated.

  In the present embodiment, the first interlayer insulating film 206 b disposed between the light shielding film 204 b and the amorphous silicon film 1 is more than the base insulating film 202 disposed between the light shielding film 204 b and the substrate 200. Has high thermal conductivity. Therefore, the heat generated in the light shielding film 204b is efficiently supplied to the amorphous silicon film 1 through the first interlayer insulating film 206b having high thermal conductivity. In addition, the base insulating film 202 having low thermal conductivity can suppress the heat generated in the light shielding film 204b from being supplied to the substrate 200. Therefore, it is possible to suppress the substrate 200 from being excessively heated or thermally deformed.

  In the present embodiment, since the amorphous silicon film 1 is heated until immediately before the amorphous silicon film 1 is melted, as described above, a phenomenon of aggregation occurs when a part of the amorphous silicon film 1 is solidified. Further, it is possible to suppress the occurrence of a step break phenomenon due to aggregation or the like. Therefore, it is possible to suppress the occurrence of problems such as deterioration of the performance of the semiconductor device substrate SP due to the step breakage phenomenon and the generation of foreign matters (residues) due to the aggregated portion after the etching process. In addition, since the occurrence of the step break phenomenon can be suppressed, the necessity for adjusting the shape of the light shielding film 204b is reduced.

  In the present embodiment, the light shielding film 204b is induction-heated by high frequency, and the light from the backlight of the liquid crystal device or the like is suppressed from entering the channel region 250b or the like by using the light shielding film 204b. The semiconductor substrate SP of the present embodiment is not limited to the element substrate of the liquid crystal device, and can be applied to an element substrate of an organic EL device, for example. For example, when a light-shielding film for suppressing light from entering the TFT channel region of the element substrate provided in the organic EL device is provided, the light-shielding film can be subjected to high-frequency induction heating.

  In this embodiment, the light shielding film 204b is heated by high frequency induction, and the amorphous silicon film 1 can be heated without forming a new material film for heating the amorphous silicon film 1, but the light shielding film 204b When a material film having conductivity other than the above is formed, the amorphous silicon film 1 may be heated using the material film. Further, a new material film for heating the amorphous silicon film 1 may be formed.

<Second Embodiment>
Next, an example of an electro-optical device including the substrate for a semiconductor device according to the present embodiment will be described with reference to FIGS. In the present embodiment, the above-described semiconductor device substrate is provided as a TFT array substrate. The TFT array substrate and the counter substrate are arranged to face each other, and an electro-optical material such as a liquid crystal is sandwiched therebetween. 1 is an embodiment according to an electro-optical device.

  First, the overall configuration of the electro-optical device of the present invention will be described with reference to FIGS. FIG. 5 is a plan view of the electro-optical device when the TFT array substrate is viewed from the side of the counter substrate together with each component formed thereon, and FIG. 6 is a cross-sectional view taken along line HH ′ of FIG. It is. Here, a TFT active matrix driving type liquid crystal device with a built-in driving circuit, which is an example of an electro-optical device, is taken as an example.

  5 and 6, in the electro-optical device according to the present invention, the TFT array substrate 10 and the counter substrate 20 are arranged to face each other. A liquid crystal layer 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and the TFT array substrate 10 and the counter substrate 20 are provided with a sealing material 52 provided in a seal region positioned around the image display region 10a. Are bonded to each other.

  The sealing material 52 is made of, for example, an ultraviolet curable resin, a thermosetting resin, or the like for bonding the two substrates, and is applied on the TFT array substrate 10 in the manufacturing process and then cured by ultraviolet irradiation, heating, or the like. It is. Further, in the sealing material 52, a gap material such as glass fiber or glass beads for dispersing the distance (inter-substrate gap) between the TFT array substrate 10 and the counter substrate 20 to a predetermined value is dispersed. That is, the electro-optical device according to the present embodiment is suitable for a small and enlarged display for a projector light valve.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. However, part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side. In the present embodiment, there is a peripheral area that defines the periphery of the image display area 10a. In other words, particularly in the present embodiment, when viewed from the center of the TFT array substrate 10, the distance from the frame light shielding film 53 is defined as the peripheral region.

  Among the peripheral regions, the data line driving as an example of the peripheral circuit in the first and second embodiments of the semiconductor device of the present invention described above is particularly provided in a region located outside the seal region where the sealing material 52 is disposed. A circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10. Further, in the region along the two sides adjacent to this one side and covered with the frame light shielding film 53, scanning as another example of the peripheral circuit in the first embodiment and the second embodiment of the semiconductor device of the present invention is performed. A line driving circuit 104 is provided. Further, in order to connect the two scanning line driving circuits 104 provided on both sides of the image display area 10a in this way, the TFT array substrate 10 is covered with the frame light shielding film 53 along the remaining side. A plurality of wirings 105 are provided.

  In addition, vertical conduction members 106 that function as vertical conduction terminals between the two substrates are disposed at the four corners of the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region facing these corners. Thus, electrical conduction can be established between the TFT array substrate 10 and the counter substrate 20.

  In FIG. 6, on the TFT array substrate 10, an alignment film is formed on the pixel electrode 9a after the pixel switching TFT, the scanning line, the data line and the like are formed. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an alignment film are formed on the uppermost layer portion. Further, the liquid crystal layer 50 is made of, for example, a liquid crystal in which one or several types of nematic liquid crystals are mixed, and takes a predetermined alignment state between the pair of alignment films.

  Next, the configuration in the image display region 10a of the electro-optical device according to the present embodiment will be described with reference to FIG. FIG. 7 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix that forms the image display region 10a of the electro-optical device.

  In FIG. 7, each of a plurality of pixels formed in a matrix has a pixel electrode 9a and a TFT 30 for controlling the switching of the pixel electrode 9a, and a data line 6a to which an image signal is supplied. The TFT 30 is electrically connected to the source. The image signals S1, S2,..., Sn written to the data lines 6a may be supplied line-sequentially in this order, or may be supplied for each group to a plurality of adjacent data lines 6a. Good.

  Further, the scanning line 3a is electrically connected to the gate of the TFT 30, and the scanning signals G1, G2,..., Gm are applied to the scanning line 3a in a pulse-sequential manner in this order at a predetermined timing. It is configured. The pixel electrode 9a is electrically connected to the drain of the TFT 30, and the image signal S1, S2,..., Sn supplied from the data line 6a is obtained by closing the switch of the TFT 30 as a switching element for a certain period. Write at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written in the liquid crystal as an example of the electro-optical material via the pixel electrode 9a is between the counter electrode 21 (see FIG. 6) formed on the counter substrate 20. Is held for a certain period. The liquid crystal modulates light and enables gradation display by changing the orientation and order of the molecular assembly depending on the applied voltage level. In the normally white mode, the transmittance for incident light is reduced according to the voltage applied in units of each pixel, and in the normally black mode, the light is incident according to the voltage applied in units of each pixel. The light transmittance is increased, and light having a contrast corresponding to the image signal is emitted from the electro-optical device as a whole. In order to prevent the image signal held here from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode. The storage capacitor 70 is provided side by side with the scanning line 3a, and includes a capacitor line 300 as a fixed potential side capacitor electrode fixed at a constant potential.

  In the electro-optical device described above with reference to FIGS. 5 to 7, since the substrate for a semiconductor device described in the first embodiment is used as the TFT array substrate 10, the data line driving circuit 101 and The polysilicon type TFT constituting the scanning line driving circuit 104 is excellent in transistor characteristics. In addition, the pixel switching TFT 30 is also light-shielded by the conductive light-shielding film, and in addition to or instead of this, the crystallinity of the polysilicon film is improved, so that the off-current characteristics are remarkably improved. It has been. Therefore, the electro-optical device according to this embodiment can display a high-quality image.

  On the TFT array substrate 10 shown in FIGS. 5 and 6, in addition to the data line driving circuit 101 and the scanning line driving circuit 104, the image signal on the image signal line is sampled and supplied to the data line. Sampling circuit, precharge circuit for supplying a precharge signal of a predetermined voltage level to a plurality of data lines in advance of an image signal, for inspecting the quality, defects, etc. of the electro-optical device during production or at the time of shipment An inspection circuit or the like may be formed. As for the TFTs constituting any of the circuits, the transistor characteristics can be remarkably improved by constructing the TFTs using the polysilicon film having excellent crystallinity as in the above-described embodiment.

  The electro-optical device configured as described above can be used as a display unit of various electronic apparatuses, and an example thereof will be specifically described with reference to FIGS.

  FIG. 8 is a block diagram illustrating a circuit configuration of an electronic apparatus using the electro-optical device according to the present invention as a display device.

  In FIG. 8, the electronic device includes a display information output source 77, a display information processing circuit 71, a power supply circuit 72, a timing generator 73, and a liquid crystal display device 74. The liquid crystal display device 74 includes a liquid crystal display panel 75 and a drive circuit 76. As the liquid crystal device 74, the above-described electro-optical device can be used.

  The display information output source 77 includes a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a storage unit such as various disks, a tuning circuit that tunes and outputs a digital image signal, and the like. Display information such as an image signal in a predetermined format is supplied to the display information processing circuit 71 based on the generated various clock signals.

  The display information processing circuit 71 includes various known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information, The image signal is supplied to the drive circuit 76 together with the clock signal CLK. The power supply circuit 72 supplies a predetermined voltage to each component.

  FIG. 9 shows a mobile personal computer which is an embodiment of an electronic apparatus according to the present invention. The personal computer 80 shown here has a main body 82 provided with a keyboard 81 and a liquid crystal display unit 83. The liquid crystal display unit 83 includes the electro-optical device 100 described above.

  FIG. 10 shows a mobile phone which is another electronic device. A cellular phone 90 shown here includes a plurality of operation buttons 91 and a display unit including the electro-optical device 100 described above.

  The present invention is not limited to the above-described embodiments, and various modifications can be made as appropriate without departing from the spirit or concept of the invention which can be read from the claims and the entire specification. A semiconductor device manufactured by a manufacturing method and a manufacturing method of a semiconductor device, and an electro-optical device and an electronic apparatus including the semiconductor device are also included in the technical scope of the present invention.

It is a top view which shows a part of board | substrate for semiconductor devices which concerns on this embodiment. It is the sectional view on the AA line of FIG. It is a schematic diagram for demonstrating the manufacturing method of the board | substrate for semiconductor devices which concerns on this embodiment. It is a schematic diagram for demonstrating the manufacturing method of the board | substrate for semiconductor devices which concerns on this embodiment. It is a top view which shows the whole structure of the liquid crystal device which concerns on this embodiment. It is HH 'sectional drawing of FIG. 4 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels constituting an image display area of the liquid crystal device according to the present embodiment. It is a block diagram which shows the circuit structure of the electronic device using the liquid crystal device which concerns on this embodiment as a display apparatus. It is a perspective view which shows an example of the electronic device which concerns on this embodiment. It is a perspective view which shows an example of the electronic device which concerns on this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1b ... Semiconductor layer, 9a ... Pixel electrode, 30b ... TFT, 200 ... Substrate, 202b ... Base insulating film, 204b ... Light shielding film, 206b ... First interlayer insulating film, SP ... Semiconductor device substrate

Claims (6)

A method for manufacturing a substrate for a semiconductor device comprising a thin film transistor,
Forming a conductive material film on the substrate;
Forming an amorphous silicon film on the substrate;
Heating the amorphous silicon film by high-frequency induction heating the material film to crystallize the amorphous silicon film to form a polysilicon film on the substrate. The polysilicon film forms a semiconductor layer including a channel region of the thin film transistor,
The manufacturing method according to claim 1, wherein the material film includes a light shielding film formed so as to sandwich the first insulating film between the material film and the polysilicon film.   The manufacturing method according to claim 2, wherein the light shielding film suppresses light from entering the channel region. The light shielding film is formed on the substrate so as to sandwich a second insulating film between the substrate and the substrate,
The amorphous silicon film is formed on the light shielding film so as to sandwich the first insulating film between the amorphous silicon film and the light shielding film,
The manufacturing method according to claim 2, wherein the first insulating film has a higher thermal conductivity than the second insulating film.   The manufacturing method according to claim 2, wherein the light shielding film has a melting point higher than that of the amorphous silicon film.   The manufacturing method according to claim 1, wherein the amorphous silicon film is heated until immediately before the amorphous silicon film is melted.

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