JP2006086434A - Multilevel wiring substrate, semiconductor apparatus, semiconductor substrate, method of manufacturing semiconductor apparatus, electro-optical device and electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology which can suppress the amount of liquid material for forming an insulating film to the minimum limit. <P>SOLUTION: After a plurality of semiconductor films 310A, 310B are formed on a substrate 110, the liquid material for forming a gate insulating film is locally arranged on a region superposed with the respective semiconductor films 310A, 310B by using a liquid droplet discharging method. The arranged liquid material is dried, for example, at a temperature of about 100 to 200°C, and further sintered at the temperature of 350 to 400°C for about 60 min. Thereby, the gate insulating films 320A, 320B formed locally on a region superposed with the respective semiconductor films 310A, 310B are obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multilayer wiring board, a semiconductor device, a semiconductor substrate, a semiconductor device manufacturing method, an electro-optical device, and an electronic device.

  An insulating film such as a gate insulating film or an interlayer insulating film constituting a thin film transistor (TFT) is generally formed on the entire surface of the substrate by a CVD method, a sputtering method, or a coating method (for example, a patent) Reference 1).

International Publication No. WO00 / 59040 Pamphlet

  However, in the above method, since the insulating film is formed even in a region that does not need to be originally formed, the material for forming the insulating film is wasted, and there is a problem that the manufacturing cost is increased.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a technique for forming an insulating film that can suppress the amount of the material for forming the insulating film as much as possible.

  In order to achieve the above object, a method of manufacturing a semiconductor device according to the present invention includes a step of forming a semiconductor film including a portion to be a channel region on a substrate, a step of forming a gate insulating film on the semiconductor film, Forming a gate electrode on the gate insulating film, and in the step of forming the gate insulating film, the gate insulating film is locally formed in a region overlapping at least the channel region of the semiconductor film located in the lower layer It is characterized by doing.

  According to such a configuration, the gate insulating film constituting the semiconductor device is locally formed in a region overlapping at least the channel region of the semiconductor film located in the lower layer. As described above, by locally forming the gate insulating film only in a necessary portion, the amount of the liquid material for forming the gate insulating film can be minimized.

  Here, in the above method, the gate insulating film is preferably formed by a coating method using a liquid material, and a droplet discharge method is preferably used as the coating method.

  The multilayer wiring board according to the present invention is a multilayer wiring board having a plurality of wiring layers and an insulating film formed between the wiring layers, and each insulating film is formed on an upper layer of the insulating film. The wiring layer located and the wiring layer located in the lower layer are locally formed in the area | region which overlaps.

  The semiconductor device according to the present invention includes a semiconductor film having a channel region formed on a substrate, a gate insulating film formed on the semiconductor film, and a gate electrode formed on the gate insulating film. The gate insulating film is locally formed in a region overlapping at least a channel region of the semiconductor film located in a lower layer.

  The semiconductor device may be applied to an electro-optical device or an electronic device. Here, the electro-optical device is, for example, a device including a liquid crystal element, an electrophoretic element having a dispersion medium in which electrophoretic particles are dispersed, an EL element, and the like, and an apparatus in which the semiconductor device is applied to a drive circuit or the like Say. The electronic device refers to a general device having a certain function provided with the semiconductor device according to the present invention, and includes, for example, an electro-optical device and a memory. The configuration is not particularly limited, but for example, an IC card, a mobile phone, a video camera, a personal computer, a head-mounted display, a rear-type or front-type projector, a fax machine with a display function, a digital camera finder, a portable TV, A DSP device, PDA, electronic notebook, electronic bulletin board, advertising display, etc. are included.

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

A. First Embodiment FIG. 1A is a diagram for explaining the relationship among a semiconductor film 310, a gate insulating film 320, and a gate electrode 210 of a TFT according to a first embodiment, and FIG. 4 is a diagram for explaining a relationship among a semiconductor film 31, a gate insulating film 32, and a gate electrode 21 of a general TFT. FIG.

  The gate insulating film 32 of the general TFT shown in FIG. 1B is formed on the entire surface of the substrate 11 so as to cover the semiconductor film 31, whereas the TFT according to the first embodiment shown in FIG. The gate insulating film 320 is different in that the gate insulating film 320 is locally formed in a region overlapping the channel region 226 of the semiconductor film 310 (that is, the source region 224 and the drain region 225 of the semiconductor film 310 are exposed). As described above, by locally forming the gate insulating film 320 in a necessary region, it is possible to minimize the amount of use of a material for forming the gate insulating film (details will be described later). Hereinafter, a manufacturing process of a TFT (semiconductor device) having such a gate insulating film 320 will be described with reference to FIG.

  First, a silicon oxide film having a thickness of about 200 to 500 nm is formed on the substrate 110 such as the glass substrate shown in FIG. 2A by a plasma CVD method using TEOS (tetraethoxylane) or oxygen gas as a raw material as necessary. A base insulating film (not shown) is formed. In addition to the silicon oxide film, a silicon nitride film or a silicon oxynitride film may be provided as the base insulating film. By providing such an insulating film, contamination from the glass substrate can be prevented.

  Next, the temperature of the substrate 110 is set to about 350 ° C., and a semiconductor film 310 made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the substrate 110 (or the base insulating film) using a plasma CVD method or the like. Form. The semiconductor film is not limited to an amorphous silicon film, and may be a semiconductor film including an amorphous structure such as a microcrystalline semiconductor film or a polycrystalline semiconductor film. Alternatively, a compound semiconductor film including an amorphous structure such as an amorphous silicon germanium film may be used.

Subsequently, a crystallization process such as a laser annealing method or a rapid heating method (for example, a lamp annealing method or a flash annealing method) is performed on the semiconductor film 310 to crystallize the semiconductor film 310 into a polysilicon film. In the laser annealing method, for example, a line beam having a beam length of about 400 mm is used with an excimer laser, and the output intensity is set to 400 mJ / cm ² , for example. Note that the second harmonic or the third harmonic of the YAG laser may be used. For the line beam, it is preferable to scan the line beam so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps for each region.

  Next, as shown in FIG. 2B, unnecessary portions of the semiconductor film (silicon film) 310 are removed by patterning using a photolithography method or the like, and an island-shaped semiconductor film corresponding to the size of each TFT is obtained. 310A and 310B are formed. Since the shape and size of the film pattern of this semiconductor film are determined according to the size of the TFT to be formed, a plurality of film patterns having different sizes on the same substrate (in FIG. 2B, the semiconductor films 310A and 310B). ) Will be formed.

  When a plurality of semiconductor films 310A and 310B are formed over the substrate 110, a gate is locally formed in a region overlapping with a region where a channel region is formed in each of the semiconductor films 310A and 310B by using a droplet discharge method (inkjet method). A liquid material for forming an insulating film is disposed. As the liquid material, for example, a material obtained by dissolving perhydropolysilazane in an organic solvent (for example, a 20% xylene solution) can be used, but other SOG materials having a siloxane bond, high-k, low-k materials, etc. are used. May be. Note that when it is difficult to locally dispose the liquid material in a region overlapping with each channel region, the liquid material may be locally disposed in a region overlapping with each of the semiconductor films 310A and 310B including each channel region. good.

Then, the liquid material arranged in this way is dried at a temperature of, for example, about 100 ° C. to 200 ° C., and further baked at a temperature of 350 ° C. to 400 ° C. for about 60 minutes, as shown in FIG. Gate insulating films 320A and 320B are locally formed in regions of the semiconductor films 310A and 310B that overlap with regions where the channel regions 226 are formed. As apparent from FIG. 2C, the film thickness d1 of the gate insulating film 320A formed over the semiconductor film 310A is greater than the film thickness d2 (<d1) of the gate insulating film 320B formed over the semiconductor film 310B. Also set to be thicker. Thus, by changing the film thickness of the gate insulating film 320, it is possible to form a TFT having desired characteristics (such as a gate breakdown voltage and a threshold voltage _Vth ).

Specifically, when it is desired to increase the gate breakdown voltage or the threshold voltage V _th , the film thickness of the gate insulating film 320 is set thick, while when it is desired to decrease the threshold voltage V _th , the film thickness of the gate insulating film 320 is set. Set thinly. Note that the film thickness of the gate insulating film 320, the size of the formation region of the gate insulating film 320, and the like include the surface state of the substrate 110 before the droplet containing the liquid material is dropped, the component and viscosity of the liquid material, Control may be performed by changing the surface energy and drying conditions (temperature, atmosphere, temperature gradient depending on the position of the substrate 110, convection inside the droplet, etc.). For example, the liquid material can be applied a plurality of times in a region where the gate insulating film is to be thickened. Further, a coating film may be formed a plurality of times twice or more in a region where the gate insulating film is desired to be thickened. Of course, the thickness of each gate insulating film 320 and the size of the formation region may all be controlled to be equal.

  Thereafter, as shown in FIG. 2D, gate electrodes 210A and 210B are formed on the gate insulating films 320A and 320B, and impurity ions are introduced into the semiconductor films 320A and 320B using the gate electrodes 210A and 210B as a mask. Introduce. As a result, source / drain regions 224 and 225 having a high impurity concentration are formed in a self-aligned manner, and a channel region 226 is formed in a portion that is covered with the gate electrodes 210A and 210B and no impurity is introduced. .

FIG. 3 is a diagram illustrating the relationship among the semiconductor film 310, the gate insulating film 320, and the gate electrode 210.
In the present embodiment, only the channel region 226 of the semiconductor film 310 is covered (in other words, the electrode extraction portion 224-1 in the source region and the electrode extraction portion 225-1 in the drain region are not covered with the gate insulating film 320. The gate insulating film 320 is formed (see FIG. 3A). For example, as shown in FIG. 3B, the gate insulating film 320 may be formed so as to cover the entire semiconductor film 310. However, when the gate insulating film 320 is formed so as to cover the entire semiconductor film 310, contact holes are formed at positions corresponding to the electrode extraction portion 224-1 in the source region and the electrode extraction portion 225-1 in the drain region. Since it is necessary, it is desirable to form the gate insulating film 320 so as to cover only the channel region 226 of the semiconductor film 310 as described above.

  Thereafter, an interlayer insulating film (not shown) is formed so as to cover the gate electrode 210. The interlayer insulating film can be formed over the entire surface of the substrate 110, but may be locally formed in a region overlapping with the gate electrode 210 located in the lower layer, like the gate insulating film 320. Note that this interlayer insulating film may be locally formed in a region overlapping with the gate electrode 210 by using a liquid material by a droplet discharge method, similarly to the gate insulating film 320. Specifically, the interlayer insulating film may be formed of a single layer or stacked insulating film containing silicon such as a silicon oxynitride film or a silicon oxide film.

  Subsequently, after forming a conductive film such as an aluminum film, a chromium film, or a tantalum film directly (or via an interlayer insulating film or the like) on each electrode lead-out portion 224-1, 225-1, a source electrode to be formed A source electrode and a drain electrode are formed simultaneously by forming a mask (not shown) at the position of the drain electrode and patterning. As a result of such a process, a plurality of TFTs having a gate insulating film whose film thickness and the like are optimized are formed on the substrate 110.

  As described above, according to the present embodiment, since the gate insulating film of each TFT is locally formed in a region overlapping with the semiconductor film located in the lower layer, the amount of liquid material used for forming the gate insulating film is reduced. It can be minimized.

  Further, when the gate insulating film is locally formed in a region of the semiconductor film that overlaps only with the channel region (see FIG. 3B), contact holes are formed to form electrode extraction portions in the source / drain regions. It is not necessary to expose, and the manufacturing process can be simplified.

Further, since the gate insulating film of each TFT is formed using a liquid material, it is possible to form gate insulating films having different film thicknesses or the like in accordance with required characteristics of each TFT.
In the above example, a plurality of gate insulating films having the same film quality are formed using the same type of liquid material. However, the liquid material is appropriately selected according to the characteristics of each TFT, and the film quality is determined using different liquid materials. A plurality of different gate insulating films may be formed.

B. Second Embodiment In the first embodiment described above, the insulating film constituting the TFT has been described as an example. In the second embodiment described below, an insulating film formed on a multilayer wiring board will be described as an example.

FIG. 4 is a diagram showing a manufacturing process of the multilayer wiring board.
First, in order to control the conductive ink discharged on the substrate 51 with high accuracy, the surface of the substrate 51 is subjected to ink repellent treatment (liquid repellent treatment). Specifically, after cleaning the substrate 51 made of polyimide with IPA, the substrate is cleaned (ultraviolet irradiation cleaning) by irradiating ultraviolet rays having a wavelength of 254 nm with an intensity of 10 mW / cm 2 for 10 minutes. In order to perform the liquid-repellent treatment on the substrate 51, 0.1 g of hexadecafluoro 1, 1, 2, 2, tetrahydrodecyltriethoxysilane and the substrate 51 are placed in a sealed container having a volume of 10 liters at 120 degrees Celsius for 2 hours. Hold. Thereby, a liquid repellent monomolecular film is formed on the substrate 51. Thereafter, the monomolecular film is locally irradiated with ultraviolet rays or the like to remove the liquid repellent film in the region where the wiring is to be formed. When the liquid repellent film is formed on the entire surface of the substrate, the wiring layer 57 cannot be formed. Therefore, the liquid repellent film formed on the entire surface is locally irradiated with UV light to remove the liquid repellent film in the region where the wiring is to be formed. Thus, the liquid repellent film is formed only in the region excluding the region where the wiring layer 57 is to be formed.

  Next, conductive ink for wiring formation is continuously ejected onto the substrate 51 that has been subjected to the liquid repellent treatment by a droplet ejection method. As the conductive ink, for example, a gold fine particle dispersion (manufactured by Vacuum Metallurgical Co., Ltd., trade name “Perfect Gold”) in which gold fine particles having a diameter of about 10 nm are dispersed in toluene is diluted with toluene, and the viscosity is 3 [mPa · s] is used. Next, a first layer (lower layer) wiring pattern (wiring layer) 57 made of a conductive film is formed by performing heat treatment or the like (see FIG. 4A).

Next, when forming the interlayer insulating film, the substrate 51 on which the first wiring pattern 57 is formed as a pretreatment is irradiated with ultraviolet rays having a wavelength of 256 nm at an intensity of 10 [mW / cm 2] for 5 minutes. This ultraviolet ray is applied only to the region where the interlayer insulating film is formed. As a result, the surface of the substrate 51 and the first wiring pattern 57 become ink-philic.
Then, a liquid material for forming an interlayer insulating film is disposed at a predetermined position of the first-layer wiring pattern 57 by using a droplet discharge method. Specifically, as shown in FIG. 5, the liquid material for forming the interlayer insulating film 58 is applied to a region where the first-layer wiring pattern 57 and the second-layer wiring pattern 56 formed later overlap. Place locally. As a liquid material for forming the interlayer insulating film, for example, a commercially available polyimide varnish (manufactured by DuPont, product name “Pile ML”) is diluted with a solvent (N-methyl-2-pyrrolidone), and the viscosity is What was adjusted so that it might become 20 [mPa * s] can be used.

  Next, the substrate 51 is heat-treated at 400 degrees Celsius for 30 minutes to remove the solvent and cure the polyimide. By repeatedly performing such a process several times, an interlayer insulating film 58 having a desired film thickness is locally formed on the substrate 51 (see FIG. 4B).

  A second wiring pattern 56 is formed on the interlayer insulating film 58 thus formed (see FIG. 4C). In addition, about each process at the time of forming the wiring pattern 56 of the 2nd layer, since it can be demonstrated similarly to each process of the 1st layer, it omits.

  As described above, according to the present embodiment, each interlayer insulating film is locally formed in a region where the wiring pattern located in the lower layer (first layer) and the wiring pattern located in the upper layer (second layer) overlap. Is done. Therefore, as in the first embodiment described above, the amount of liquid material used for forming the interlayer insulating film can be minimized. In the above example, the case where two layers of wiring patterns are formed has been described, but it is needless to say that the above-described series of steps may be repeated as many times as necessary to form three or more layers.

C. Third Embodiment In the first and second embodiments described above, each insulating film is formed using a droplet discharge method, but other methods using a liquid material (for example, a spinless method or a dip coating method). May be formed.

FIG. 6 is a diagram for explaining a method of forming an insulating film using a spinless method.
The nozzle head 500 ejects a liquid material for forming an insulating film, and is fixedly supported by a holding member (not shown). The protrusions 510 of the nozzle head 500 are arranged so as to be parallel to the surface of the substrate 610 while maintaining a gap G. The protrusion 510 is provided with a discharge port (not shown) set to a length slightly smaller than the length (width) of the substrate 610 in the Y direction, and in the X direction according to an instruction from a controller (not shown). A liquid material for forming an insulating film is discharged onto the surface of the substrate 610 to be conveyed. By using the nozzle head 500 having such a configuration, an insulating film may be locally formed at a predetermined position of the substrate 610. Although FIG. 6 illustrates the case where the discharge port of the nozzle head 500 faces downward, the substrate is located at a position facing the discharge port with the discharge port facing upward according to the physical properties and flow characteristics of the liquid material. The substrate may be disposed with the surface facing downward, and the liquid material may be discharged onto the surface of the substrate 610 while relatively moving the substrate 610 and the discharge port 510 in this state.

  Although the method for forming an insulating film using the spinless method has been described above, the insulating film may be formed by a dip coating method. When the insulating film is formed by using the dip coating method, as a pretreatment, a region where the insulating film is to be formed is made lyophilic and a region where the insulating film is not to be formed is made liquid repellent. The substrate subjected to such pretreatment is immersed in a liquid material for forming an insulating film, and this is pulled up and dried to form an insulating film on the substrate. As described above, an insulating film may be locally formed in a predetermined region on the substrate by using a dip coating method.

D. Fourth Embodiment FIG. 7 is a connection diagram of an organic EL device 100 that is a type of electro-optical device according to a fourth embodiment.
A pixel circuit formed in each pixel region includes a light emitting layer OELD capable of emitting light by an electroluminescence effect, a storage capacitor for storing a current for driving the light emitting layer OELD, and the TFTs 111 to 114 having the gate insulating film 320 described above. Is done. On the other hand, each of the drive circuits 101 and 102 formed in the drive circuit region includes a plurality of TFTs (not shown) having the gate insulating film 320 described above. From the drive circuit 101, the scanning line Vsel and the light emission control line Vgp are supplied to the corresponding pixel circuits, and from the drive circuit 102, the data line Idata and the power supply line Vdd are supplied to the corresponding pixel circuits. By controlling the scanning line Vsel and the data line Idata, light emission by the corresponding light emitting units OELD can be controlled. The drive circuit is an example of a circuit in the case where an electroluminescent element is used as a light emitting element, and other circuit configurations are possible.

E. Fifth Embodiment FIG. 8 is a diagram illustrating an electronic device according to a fifth embodiment.
FIG. 8A shows a mobile phone manufactured by the manufacturing method of the present invention. The mobile phone 430 includes an electro-optical device (display panel) 100, an antenna unit 431, an audio output unit 432, an audio input unit 433, and An operation unit 434 is provided. The present invention is applied to, for example, the manufacture of a substrate on which a pixel circuit and a driving circuit in the display panel 100 are arranged. FIG. 8B shows a video camera manufactured by the manufacturing method of the present invention. The video camera 440 includes an electro-optical device (display panel) 100, an image receiving unit 441, an operation unit 442, and an audio input unit 443. ing. The present invention is applied to, for example, the manufacture of a substrate on which a pixel circuit and a driving circuit in the display panel 100 are arranged.

  FIG. 8C shows an example of a portable personal computer on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The computer 450 includes an electro-optical device (display panel) 100, a camera unit 451, and the like. An operation unit 452 is provided. The present invention is applied to, for example, the manufacture of a substrate on which a pixel circuit and a driving circuit in the display panel 100 are arranged.

  FIG. 8D shows an example of a head mounted display on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The head mounted display 460 includes an electro-optical device (display panel) 100 and a band portion 461. And an optical system storage section 462. The present invention is applied, for example, to the manufacture of a substrate on which a pixel circuit and a driving circuit in the display panel 100 are arranged. FIG. 8E shows an example of a rear projector on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The projector 470 includes an electro-optical device (light modulator) 100, a light source 472, and a synthesis. An optical system 473 and mirrors 474 and 475 are provided in the housing 471. The present invention is applied to, for example, manufacturing a substrate on which a pixel circuit and a drive circuit in the optical modulator 100 are arranged. FIG. 8F shows an example of a front projector on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The projector 480 includes an electro-optical device (image display source) 100 and an optical system 481. An image can be displayed on the screen 483 in the body 482. The present invention is applied to, for example, manufacturing a substrate on which a pixel circuit and a drive circuit in the image display source 100 are arranged.

  The present invention is not limited to the above example and can be applied to the manufacture of all electronic devices. For example, the present invention can also be applied to a fax machine with a display function, a finder for a digital camera, a portable TV, a DSP device, a PDA, an electronic notebook, an electric bulletin board, a display for advertisement announcement, an IC card, and the like. The present invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the gist of the present invention. For example, in each of the embodiments described above, the gate insulating film and the interlayer insulating film are exemplified as the insulating film, but the present invention can be applied to any other solid film. In the above-described embodiment, a TFT (thin film transistor) is illustrated as an example of a circuit element. However, it is needless to say that the present invention may be applied to other circuit elements.

It is a figure which shows the relationship between the semiconductor film which concerns on 1st Embodiment, a gate insulating film, and a gate electrode. It is a figure which shows the manufacturing process of TFT concerning the embodiment. It is a figure which shows the relationship between the semiconductor film which concerns on the embodiment, a gate insulating film, and a gate electrode. It is a figure which shows the manufacturing process of the multilayer wiring board which concerns on 2nd Embodiment. It is a figure which shows the relationship between each wiring pattern and interlayer insulation film concerning the embodiment. It is a figure which shows the formation method of the insulating film using the spinless method which concerns on 3rd Embodiment. It is the figure which illustrated the structure of the electro-optical apparatus which concerns on 4th Embodiment. It is the figure which illustrated each electronic device concerning a 5th embodiment.

Explanation of symbols

110, 51, 610 ... substrate, 310 ... semiconductor film, 320 ... gate insulating film, 210 ... gate electrode, 224 ... source region, 225 ... drain region, 226 ... Channel region, 224-1, 225-1 ... electrode extraction part, 56, 57 ... wiring pattern, 58 ... interlayer insulating film.

Claims (12)

  A multilayer wiring board having a plurality of wiring layers and an insulating film formed between the wiring layers, wherein each insulating film includes a wiring layer located in an upper layer and a wiring layer located in a lower layer of the insulating film A multilayer wiring board characterized in that the multilayer wiring board is locally formed in an overlapping region. A semiconductor film having a channel region formed on a substrate;
A gate insulating film formed on the semiconductor film;
A semiconductor device comprising a gate electrode formed on the gate insulating film,
The semiconductor device is characterized in that the gate insulating film is locally formed in a region overlapping at least a channel region of the semiconductor film. The semiconductor device according to claim 2,
A source region and a drain region sandwiching the channel region are formed in the semiconductor film,
The semiconductor device is characterized in that the gate insulating film is not formed in any of the electrode extraction portion in the source region and the electrode extraction portion in the drain region. 4. A semiconductor substrate comprising a plurality of the semiconductor devices according to claim 2, wherein the gate insulating film has two or more kinds of film thicknesses.   4. A semiconductor substrate comprising a plurality of semiconductor devices according to claim 2, wherein two or more types of film qualities of the gate insulating film are present. A semiconductor film having a channel region formed on a substrate;
A gate insulating film formed on the semiconductor film;
A gate electrode formed on the gate insulating film;
A semiconductor device comprising an interlayer insulating film covering the gate electrode formed on the gate insulating film,
The semiconductor device, wherein the interlayer insulating film is locally formed in a region overlapping with the gate electrode.   An electro-optical device comprising the semiconductor device according to claim 2. An electronic device comprising the semiconductor device according to claim 2. Forming a semiconductor film including a portion to be a channel region on a substrate;
Forming a gate insulating film on the semiconductor film;
Forming a gate electrode on the gate insulating film,
In the step of forming the gate insulating film, the gate insulating film is locally formed in a region overlapping with at least the channel region of the semiconductor film.   The method for manufacturing a semiconductor device according to claim 9, wherein the gate insulating film is formed by a coating method using a liquid material.   The method of manufacturing a semiconductor device according to claim 10, wherein the coating method is a droplet discharge method. Forming a semiconductor film including a portion to be a channel region on a substrate;
Forming a gate insulating film on the semiconductor film;
Forming a gate electrode on the gate insulating film;
Forming an interlayer insulating film covering the gate electrode on the gate insulating film,
In the step of forming the interlayer insulating film, the interlayer insulating film is locally formed in a region overlapping with the gate electrode.

Images