Display device

Abstract

In order to take advantage of the characteristics of a display device including an oxide semiconductor, which has excellent operation characteristics and can be manufactured at low temperatures, a protection circuit or the like having an appropriate structure is needed.SOLUTION: A protective circuit is formed using a non-linear device 105a including a gate insulating layer 102 covering gate electrodes 101, first oxide-semiconductor layers 103 overlapping with the gate electrodes 101 over the gate insulating layer 102, and a pair of first and second wiring layers 38 and 39 whose end portions overlap with the gate electrodes over the first oxide-semiconductor layers 103 and in which a conductive layer 104a and a second oxide-semiconductor layer 170a are stacked. When a junction of oxide-semiconductor layers having different physical properties is formed over the gate insulating layer 102, stable operation can be performed as compared to a Schottky junction, junction leakage can be reduced, and characteristics of a non-linear device 170a can be improved.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a display device using an oxide semiconductor. [Background technology]

[0002] As typified by liquid crystal display devices, thin film transistors formed on flat plates such as glass substrates are , amorphous silicon, and polycrystalline silicon. Thin film transistors using silicon have low field effect mobility, but are suitable for enlarging the area of ​​glass substrates. On the other hand, thin film transistors using crystalline silicon have high field effect mobility. However, a crystallization process such as laser annealing is required, and enlarging the glass substrate is essential. However, it has the characteristic of not being adaptable.

[0003] In response to this, thin film transistors are being fabricated using oxide semiconductors, and they are being used in electronic devices and optical devices. For example, zinc oxide (ZnO) is used as an oxide semiconductor film. and fabricating thin-film transistors using In-Ga-Zn-O oxide semiconductors to display images. The technology used for the switching elements of the device is disclosed in Patent Documents 1 and 2. . [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-123861 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-96055 Summary of the Invention [Problem to be solved by the invention]

[0005] Thin film transistors that use oxide semiconductors for the channel formation region use amorphous silicon. The operating speed is faster than that of thin-film transistors that use polycrystalline silicon. The manufacturing process is simpler than that of oxide semiconductors. By doing so, it is possible to produce thin-film transistors with high field-effect mobility even at low temperatures below 300°C. It is possible to create a

[0006] To take advantage of the characteristics of display devices using oxide semiconductors, which have excellent operating characteristics and can be manufactured at low temperatures, In addition, a protection circuit or the like having an appropriate configuration is required. It is important to ensure safety.

[0007] An object of one embodiment of the present invention is to provide a structure suitable for a protection circuit.

[0008] One embodiment of the present invention is a semiconductor device for various applications in which an insulating film and a conductive film are stacked in addition to an oxide semiconductor. An object of the present invention is to improve the function of a protection circuit in a display device and stabilize the operation thereof. [Means for solving the problem]

[0009] One embodiment of the present invention is a semiconductor device in which a protection circuit is formed using a nonlinear element including an oxide semiconductor. This nonlinear element is made up of a combination of oxide semiconductors with different oxygen contents. It has been completed.

[0010] An exemplary embodiment of the present invention is a semiconductor device in which scanning lines and signal lines are provided crossing each other on a substrate having an insulating surface. The pixel section has pixel electrodes arranged in a matrix, and the outer region of the pixel section is made of an oxide semiconductor. The pixel portion is a display device having a nonlinear element formed in a first oxide semiconductor layer. The thin film transistor in the pixel portion has a scanning line forming region. a gate electrode connected to the signal line; a first wiring layer connected to the signal line and in contact with the first oxide semiconductor layer; The pixel electrode is connected to the second wiring layer, and the second wiring layer is in contact with the first oxide semiconductor layer. A nonlinear element is provided between the signal input terminal and the pixel section. a gate insulating layer covering the gate electrode and the gate electrode; a first oxide semiconductor layer overlapping the gate electrode; and a second oxide semiconductor layer overlapping the gate electrode. a pair of first wiring layers and a second oxide semiconductor layer, the first wiring layers and the second oxide semiconductor layer being stacked on top of each other at their ends; and a second wiring layer. The gate electrode of the nonlinear element is connected to a scanning line or a signal line, The first wiring layer or the second wiring layer of the nonlinear element is connected to the third wiring so that the potential of the gate electrode is applied. are connected by layers.

[0011] An exemplary embodiment of the present invention is a semiconductor device in which scanning lines and signal lines are provided crossing each other on a substrate having an insulating surface. The pixel electrode is arranged in a matrix, and the pixel electrode has a protection circuit in the outer area of ​​the pixel electrode. The pixel portion is a thin film in which a channel formation region is formed in the first oxide semiconductor layer. The thin film transistor in the pixel portion has a gate electrode connected to a scanning line. a first wiring layer connected to the signal line and in contact with the first oxide semiconductor layer; The pixel area has a second wiring layer in contact with the oxide semiconductor layer. A protection circuit that connects the wiring and a protection circuit that connects the signal line and the common wiring are provided. The protection circuit includes a gate electrode and a gate insulating layer covering the gate electrode. a first oxide semiconductor layer overlapping the gate electrode; and a second oxide semiconductor layer a pair of gate electrodes each having an end portion overlapping the gate electrode and a conductive layer and a second oxide semiconductor layer stacked thereon; The nonlinear element has a first wiring layer and a second wiring layer. The pole is connected to the first wiring layer or the second wiring layer by the third wiring layer.

[0012] Here, the oxygen concentration of the first oxide semiconductor layer is higher than the oxygen concentration of the second oxide semiconductor layer. That is, the first oxide semiconductor layer is an oxygen-excess type, and the second oxide semiconductor layer is an oxygen-excess type. The electrical conductivity of the first oxide semiconductor layer is higher than the electrical conductivity of the second oxide semiconductor layer. The first oxide semiconductor layer and the second oxide semiconductor layer have a non-single-crystal structure. The second oxide semiconductor layer has an amorphous structure and contains at least an amorphous component. may contain nanocrystals.

[0013] The ordinal numbers such as 1st and 2nd are used for convenience and do not indicate the order of processes or stacking. Furthermore, the specific names used in this specification are not intended to identify the invention. This does not indicate [Effects of the Invention]

[0014] According to one embodiment of the present invention, a protection circuit is formed using a nonlinear element using an oxide semiconductor. As a result, it is possible to obtain a display device having a structure suitable for a protection circuit. In the connection structure between the first oxide semiconductor layer and the wiring layer, the second oxide semiconductor layer has a higher electrical conductivity than the first oxide semiconductor layer. By providing a region that is in contact with the second oxide semiconductor layer, which has a high This allows for stable operation, improving the functionality of the protection circuit and stabilizing operation. This can be achieved. [Brief explanation of the drawings]

[0015] [Figure 1] 1A and 1B are diagrams illustrating the positional relationship between signal input terminals, scanning lines, signal lines, a protection circuit including a nonlinear element, and a pixel portion, which constitute a display device. [Figure 2] FIG. 10 is a diagram showing an example of a protection circuit. [Figure 3] FIG. 10 is a diagram showing an example of a protection circuit. [Figure 4] FIG. 2 is a plan view showing an example of a protection circuit. [Figure 5] FIG. 10 is a cross-sectional view showing an example of a protection circuit. [Figure 6] FIG. 2 is a plan view showing an example of a protection circuit. [Figure 7] FIG. 2 is a plan view showing an example of a protection circuit. [Figure 8] 1A to 1C are cross-sectional views illustrating a manufacturing process of a protection circuit. [Figure 9] 1A to 1C are cross-sectional views illustrating a manufacturing process of a protection circuit. [Figure 10] Cross-sectional view of electronic paper. [Figure 11] FIG. 1 is a block diagram illustrating a semiconductor device. [Figure 12] FIG. 2 illustrates a configuration of a signal line driver circuit. [Figure 13] 4 is a timing chart illustrating the operation of the signal line driver circuit. [Figure 14] 4 is a timing chart illustrating the operation of the signal line driver circuit. [Figure 15] FIG. 2 is a diagram illustrating the configuration of a shift register. [Figure 16] FIG. 15 is a diagram for explaining the connection configuration of the flip-flop shown in FIG. 14. [Figure 17] 1A and 1B are a top view and a cross-sectional view illustrating a semiconductor device of an embodiment. [Figure 18] 1 is a cross-sectional view illustrating a semiconductor device according to an embodiment; [Figure 19] 1A and 1B are diagrams illustrating pixel equivalent circuits of a semiconductor device according to an embodiment; [Figure 20] 1A to 1C illustrate a semiconductor device according to an embodiment; [Figure 21]1A and 1B are a top view and a cross-sectional view illustrating a semiconductor device of an embodiment. [Figure 22] 1A and 1B are diagrams illustrating examples of usage of electronic paper. [Figure 23] FIG. 1 is an external view showing an example of an electronic book. [Figure 24] FIG. 1 is an external view showing an example of a television device and a digital photo frame. [Figure 25] FIG. 1 is an external view showing an example of a gaming machine. [Figure 26] FIG. 1 is an external view showing an example of a mobile phone. [Figure 27] FIG. 10 is a cross-sectional view showing an example of a protection circuit. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described below with reference to the accompanying drawings. The present invention is not limited to the above, and various modifications and variations in form and detail are possible without departing from the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications may be made to the present invention. The present invention is not limited to the description of the embodiments. In the drawings, the same reference numerals are used to refer to the same parts.

[0017] (Embodiment 1) This embodiment is one aspect of a display device in which a pixel section and a protection circuit including a nonlinear element are formed in the periphery thereof. This will be explained with reference to the drawings.

[0018] Figure 1 shows the signal input terminals, scanning lines, signal lines, and protection circuits including nonlinear elements that make up a display device. 1 is a diagram illustrating the positional relationship between the scanning lines 13 and the pixel portion on a substrate 10 having an insulating surface. The signal lines 14 intersect to form pixel sections 17 .

[0019] The pixel section 17 is configured by arranging a plurality of pixels 18 in a matrix. A pixel transistor 19, a storage capacitor 20, and a pixel electrode 21 connected to the line 13 and the signal line 14 are It is composed of including.

[0020] In the pixel configuration illustrated here, one electrode of the storage capacitor 20 is connected to the pixel transistor 19 The pixel electrode 21 is connected to the capacitor line 22. While driving display elements (liquid crystal elements, light-emitting elements, contrast media (electronic ink), etc.) The other electrodes of these display elements are connected to a common terminal 23.

[0021] The protection circuit is disposed between the pixel section 17 and the scanning line input terminal 11 and the signal line input terminal 12. In this embodiment, a plurality of protection circuits are provided to protect the scanning lines 13, the signal lines 14, and the capacitance bus lines 15. 27 is applied with a surge voltage due to static electricity or the like, and the pixel transistor 19 and the like are not destroyed. Therefore, when a surge voltage is applied to the protection circuit, It is configured to release the charge to the line 29 or the common wiring 28.

[0022] In this embodiment, a protection circuit 24 is provided on the scanning line 13 side, a protection circuit 25 is provided on the signal line 14 side, and a capacitance bus line 2 7 shows an example in which a protection circuit 26 is provided. However, the configuration of the protection circuit is not limited to this. stomach.

[0023] FIG. 2 shows an example of a protection circuit. This protection circuit is a non-transitory circuit arranged in parallel with the scanning line 13. It is composed of a linear element 30 and a nonlinear element 31. The element 31 is composed of a two-terminal element such as a diode or a three-terminal element such as a transistor. For example, it is possible to form it in the same process as the pixel transistor of the pixel portion. For example, by connecting the gate terminal and drain terminal, it can have the same characteristics as a diode. This can be done.

[0024] The first terminal (gate) and the third terminal (drain) of the nonlinear element 30 are connected to the scanning line 13, The second terminal (source) is connected to the common wiring 29. The first terminal of the nonlinear element 31 The gate and drain terminals are connected to a common wiring 29, and the source terminal is connected to a The protection circuit shown in FIG. The scanning line 13 and the common wiring 29 are connected in opposite directions to each other. In other words, between the scanning line 13 and the common wiring 29, the rectification direction is from the scanning line 13 to the common wiring 29. The transistors facing the wiring 29 and the transistors whose rectification direction is from the common wiring 29 to the scanning line 13 This is a configuration in which a resistor is connected.

[0025] The protection circuit shown in FIG. 2 prevents the scanning line 13 from being charged positively or negatively with respect to the common line 29 due to static electricity or the like. For example, if the scanning line 13 is positively charged, a current flows in the direction that cancels the charge. When the positive charge is released, a current flows in the direction of dissipating the positive charge to the common wiring 29. Electrostatic breakdown or threshold voltage shift of pixel transistor 19 connected to the energized scanning line 13 In addition, the scanning line 13 is electrically charged and the insulating layer is interposed therebetween. It is possible to prevent dielectric breakdown of the insulating film between other wirings.

[0026] 2 shows a nonlinear element 30 having a first terminal (gate) connected to the scanning line 13 and a common wiring 2 9, i.e., two nonlinear elements 31 with their first terminals (gates) connected to the A pair of nonlinear elements is used, and the second terminal (source) and the third terminal (drain) of each element are connected in common. The line 29 is connected to the scanning line 13. That is, the nonlinear element 30 and the nonlinear element 31 are connected in parallel. As another configuration, a nonlinear element connected in parallel may be added to further improve the behavior of the protection circuit. For example, FIG. 3 shows a structure of a scanning line 13 and a common line 29. , the nonlinear elements 30a and 30b, and the nonlinear elements 31a and 31b The protection circuit shown in FIG. 1 has a first terminal (gate) connected to a common wiring 29. The first terminal (gate) of each of the two nonlinear elements (30b, 31b) is connected to the scanning line 13. In this example, four nonlinear elements are used, including two other nonlinear elements (30a, 31a). A set of two nonlinear elements connected so that the rectification directions are opposite to each other is connected to a common wiring 29. Two sets are connected between the scanning lines 13. In other words, between the scanning lines 13 and the common wiring 29, Two transistors whose rectification direction is from the scanning line 13 to the common wiring 29 and two transistors whose rectification direction is common The two transistors are connected from the wiring 29 toward the scanning line 13. By connecting the common wiring 29 and the scanning line 13 with four nonlinear elements, the surge current is prevented from being applied to the scanning line 13. Not only when a voltage is applied, but also when the common wiring 29 is charged by static electricity, etc. This prevents the electric charge from flowing directly into the scanning line 13. FIG. 6 shows four nonlinear elements 740a, 740b, 740c, and 740d arranged on a substrate. In this case, the reference numeral 650 denotes a scanning line, the reference numeral 651 denotes a common line, and the equivalent circuit diagram is shown. Wiring is shown.

[0027] As an example of a protection circuit using an odd number of nonlinear elements, the layout of nonlinear elements on a board is shown below. FIG. 7(A) shows an equivalent circuit diagram, and FIG. 7(B) shows an equivalent circuit diagram. In this circuit, for the nonlinear element 730c, The nonlinear element 730b and the nonlinear element 730a are connected as switching elements. By connecting nonlinear elements in series as shown above, the instantaneous Here, reference numeral 650 denotes a scanning line, and reference numeral 651 denotes a common line.

[0028] FIG. 2 shows an example of a protection circuit provided on the side of the scanning line 13, but a protection circuit of a similar configuration can also be provided on the side of the signal line 14. It can also be applied to the side.

[0029] FIG. 4A is a plan view showing an example of a protection circuit, and FIG. 4B shows its equivalent circuit diagram. FIG. 5 shows a cross-sectional view corresponding to the Q1-Q2 cutting line shown in FIG. 4(A). In the following description, an example of the configuration of the protection circuit will be described with reference to FIGS.

[0030] The nonlinear element 170a and the nonlinear element 170b are gate electrodes formed in the same layer as the scanning line 13. The electrode 101 and the gate electrode 16 are provided on the gate electrode 101 and the gate electrode 16. A gate insulating layer 102 is formed on the first oxide semiconductor layer 101. 103 is formed on the gate electrode 101 so as to face each other on the gate electrode 101 with the first oxide semiconductor layer 103 interposed therebetween. The first wiring layer 38 and the second wiring layer 39 are provided as shown in FIG. It is made of silicon or an oxide such as aluminum oxide. The nonlinear elements 170a and 170b have the same configuration in the main part.

[0031] The first oxide semiconductor layer 103 is provided under the first wiring layer 38 and the second wiring layer 39 facing each other. The first oxide film is formed so as to cover the gate electrode 101 via an insulating film. The semiconductor layer 103 overlaps the gate electrode 101 and is connected to the upper surface of the gate insulating layer 102 and the second oxide film. The first insulating layer 104 is provided so as to be in contact with the lower surfaces of the compound semiconductor layers 104a and 104b. The first wiring layer 38 is formed by connecting the second oxide semiconductor layer 104a and the conductive layer 104b from the first oxide semiconductor layer 103 side. Similarly, the second wiring layer 39 has a structure in which the first oxide semiconductor layer 105a is stacked. The second oxide semiconductor layer 104b and the conductive layer 105b are stacked from the side of the insulating film 103. do.

[0032] The oxygen concentration of the first oxide semiconductor layer 103 is higher than that of the second oxide semiconductor layers (104a and 104b). In other words, the first oxide semiconductor layer 103 has a higher oxygen concentration than the oxygen-excess type. The second oxide semiconductor layers (104a and 104b) are oxygen-deficient. By increasing the oxygen concentration in the compound semiconductor layer 103, donor type defects can be reduced. The second oxide semiconductor has the effect of improving the lifetime and mobility of the second oxide semiconductor. The oxide semiconductor layers (104a and 104b) have a lower oxygen concentration than the first oxide semiconductor layer 103. By doing so, the carrier concentration can be increased, and It can be used for this purpose.

[0033] In terms of the oxide semiconductor structure, the first oxide semiconductor layer 103 contains In, Ga, Zn, and O. The non-single-crystal oxide semiconductor layer contains at least an amorphous component. The second oxide semiconductor layers (104a and 104b) are made of a non-metallic compound containing In, Ga, Zn, and O. It is a single-crystal oxide semiconductor layer, and nanocrystals may be included in the non-single-crystal structure. The first oxide semiconductor layer 103 is then separated into the second oxide semiconductor layers (104a and 104b). b) has a lower electrical conductivity than the nonlinear element 1 of this embodiment. 70a and the second oxide semiconductor layers (104a and 104b) in the nonlinear element 170b. The source region and the drain region of a transistor function similarly. The second oxide semiconductor layer 104a which becomes the drain region and the second oxide semiconductor layer 104b which becomes the drain region are , n-type conductivity, and activation energy (ΔE) is 0.01 eV or more and 0.1 eV or less. Yes, n + It can also be called an area.

[0034] The first oxide semiconductor layer 103 and the second oxide semiconductor layer (104a and 104b) are formed by oxidizing Typical examples of semiconductors include zinc oxide (ZnO) and oxides containing In, Ga, and Zn. It is formed from a semiconductor material.

[0035] The second oxide semiconductor layers (104a and 104b) are formed by bonding the first oxide semiconductor layer 103 and the conductive layer (1 105a and 105b), which are in contact with and provided between oxide semiconductor layers having different physical properties. A gap is formed between the first oxide semiconductor layer 103 and the conductive layer. By providing the second oxide semiconductor layer (104a and 104b) having the highest electrical conductivity, In comparison with a Schottky junction in which the first oxide semiconductor layer and the conductive layer are in direct contact with each other, the nonlinear element can be made more stable. In other words, thermal stability is increased, and stable operation is possible. This makes it possible to improve the functionality of the protection circuit and stabilize its operation. In addition, the junction leakage is reduced, improving the characteristics of the nonlinear element 170a and the nonlinear element 170b. It is possible.

[0036] A protective insulating film 107 is provided on the first oxide semiconductor layer 103. is formed of an oxide such as silicon oxide or aluminum oxide. or silicon nitride, aluminum nitride, silicon oxide nitride or oxide on aluminum oxide By laminating aluminum nitride, the function as a protective film can be improved.

[0037] In any case, the protective insulating film 107 in contact with the first oxide semiconductor layer 103 is made of an oxide. As a result, oxygen is extracted from the first oxide semiconductor layer 103, and the first oxide semiconductor layer 103 is transformed into an oxygen-deficient type. In addition, the first oxide semiconductor layer 103 can be prevented from directly contacting the insulating layer made of nitride. By adopting a structure in which the nitride is not in contact with the first oxide semiconductor layer 103, hydrogen in the nitride is diffused and the hydrogen is transferred to the first oxide semiconductor layer 103. This can prevent the formation of defects caused by acid groups and the like.

[0038] The protective insulating film 107 is provided with contact holes 125 and 128 through which the gate electrodes The scanning line 13 formed in the same layer as the electrode 101 and the third terminal (drain) of the nonlinear element 170a This connection is made by the third wiring layer 1 made of the same material as the pixel electrodes of the pixel section. The third wiring layer 110 is made of indium tin oxide (ITO). Transparent conductive films such as zinc oxide (ZnO) and tin oxide (SnO2) As a result, the third wiring layer 110 has a higher resistance than wiring made of a metal material. By including wiring with such a resistance component in the protection circuit, excessive This can prevent excessive current from flowing and damaging the nonlinear element 170a.

[0039] 4 and 5A show an example of a protection circuit provided on the scanning line 13. The protection circuit can be applied to signal lines, capacitive bus lines, and the like.

[0040] As described above, according to the present embodiment, a protection circuit made of an oxide semiconductor is provided. As a result, a display device having a structure suitable for a protection circuit can be obtained. The function of the protection circuit can be improved to stabilize operation.

[0041] (Embodiment 2) In this embodiment, a nonlinear element is included in the pixel portion and its periphery as shown in FIG. 4(A) in the first embodiment. One embodiment of a manufacturing process of a display device including a protective circuit will be described with reference to FIGS. 8 and 9. 8 and 9 are cross-sectional views corresponding to the Q1-Q2 cutting line in FIG. 4(A).

[0042] In FIG. 8(A), a commercially available barium borosilicate glass substrate 100 is used as a light-transmitting substrate. Glass substrates such as glass, aluminoborosilicate glass, and aluminosilicate glass are used. For example, the ratio of barium oxide (Ba) to boric acid (B2O3) can be It is preferable to use a glass substrate containing a large amount of oxide semiconductor (O) and having a distortion point of 730°C or higher. This is because the glass substrate does not warp even when the layer is heat-treated at a high temperature of around 700°C. .

[0043] Next, a conductive layer is formed on the entire surface of the substrate 100, and then a first photolithography process is performed. A resist mask is formed, and unnecessary portions are removed by etching to form wiring and electrodes (gate At this time, at least a gate wiring including a gate electrode 101, a capacitance wiring, and a terminal are formed. Etching is performed so that the end of the gate electrode 101 is tapered.

[0044] The gate wiring including the gate electrode 101, the capacitance wiring, and the terminal of the terminal part are made of aluminum (Al). It is desirable to form it with a low-resistance conductive material such as aluminum (Al) or copper (Cu), but aluminum alone has poor heat resistance. However, since there are problems such as poor electrical conductivity and susceptibility to corrosion, it is necessary to combine it with a heat-resistant conductive material. Heat-resistant conductive materials include titanium (Ti), tantalum (Ta), and tungsten (W ), molybdenum (Mo), chromium (Cr), Nd (neodymium), Sc (scandium) or an alloy containing the above elements or a combination of the above elements. It is formed of an alloy film or a nitride containing the above-mentioned elements as a component.

[0045] Next, a gate insulating layer 102 is formed on the entire surface of the gate electrode 101. The film 2 is formed to a thickness of 50 to 250 nm by using a sputtering method or the like.

[0046] For example, a silicon oxide film is used as the gate insulating layer 102 by sputtering, and the thickness is 100 nm. Of course, the gate insulating layer 102 is not limited to such a silicon oxide film. Silicon oxide nitride film, silicon nitride film, aluminum oxide, tantalum oxide film It may be formed as a single layer or a laminated structure made of these materials using other insulating films such as those mentioned above. stomach.

[0047] Next, plasma treatment is performed on the gate insulating layer 102 before the first oxide semiconductor film is formed. Here, oxygen gas and argon gas are introduced into the deposition chamber to generate plasma and perform reverse sputtering. The gate insulating layer is irradiated with oxygen radicals or oxygen. The surface of the gate insulating layer is then modified to an oxygen-excess region. By performing oxygen radical treatment and making the surface an oxygen-excess region, reliability in subsequent processes can be improved. The gate insulating layer and the first oxide semiconductor layer are then subjected to a heat treatment (200°C to 600°C) for This is effective in creating a source of oxygen to modify the interface.

[0048] The gate insulating film layer, the first oxide semiconductor film, and the second oxide semiconductor film are formed by sputtering. By appropriately switching the gas introduced into the beam and the target to be installed, the gate insulation The insulating layer, the first oxide semiconductor film, and the second oxide semiconductor film are formed successively without being exposed to the air. Continuous film formation without exposure to the atmosphere prevents the inclusion of impurities. When forming films continuously without exposing them to the atmosphere, it is recommended to use a multi-chamber manufacturing device. It is preferable that:

[0049] In particular, the gate insulating layer 102 in contact with the first oxide semiconductor film and the first oxide semiconductor film are formed continuously. By forming the film continuously, atmospheric components such as water vapor and impurities floating in the air can be prevented. Since the layered interface is free from contamination by pure elements and dust, it is possible to fabricate nonlinear elements and thin film transistors. This reduces the variation in transistor characteristics.

[0050] In this specification, continuous film formation refers to a process from the first film formation process performed by sputtering to the second film formation process performed by sputtering. During the series of processes up to the second film formation step, the atmosphere in which the substrate is placed is the air, etc. Always keep the equipment in a vacuum or inert gas atmosphere (nitrogen or rare earth) without contact with contaminated atmosphere. By performing continuous film deposition, the surface is cleaned and Film formation can be performed while avoiding re-adhesion of moisture and the like to the processing substrate.

[0051] Next, a first oxide semiconductor film is formed without exposing the plasma-treated substrate to the air. The first oxide semiconductor film is formed without exposing the plasma-treated substrate to the atmosphere. This can prevent problems such as dust and moisture from adhering to the interface between the gate insulating layer and the semiconductor film. Here, an oxide semiconductor target containing In, Ga, and Zn with a diameter of 8 inches (composition ratio and In2O3:Ga2O3:ZnO=1:1:1) was used to form a thin film between the substrate and the target. The distance between the electrodes was 170 mm, the pressure was 0.4 Pa, the DC power was 0.5 kW, and the atmosphere was oxygen. Furthermore, if a pulsed direct current (DC) power supply is used, dust can be reduced and the film thickness distribution can be made uniform. The thickness of the first oxide semiconductor film is set to 5 nm to 200 nm. In this embodiment, the thickness of the first oxide semiconductor film is 100 nm.

[0052] The first oxide semiconductor film is formed under different film formation conditions from the second oxide semiconductor film. For example, the oxygen concentration in the second oxide semiconductor film is higher than that in the first oxide semiconductor film. For example, the second oxide semiconductor film is formed under the following conditions: The ratio of the oxygen gas flow rate to the argon gas flow rate in the first oxide semiconductor film deposition conditions is higher than that in the first oxide semiconductor film deposition conditions. The flow rate of the oxygen gas is set to a high ratio. Specifically, the film formation conditions for the second oxide semiconductor film are as follows: The conditions are as follows: under a rare gas (argon, helium, etc.) atmosphere (or oxygen gas 10% or less, The first oxide semiconductor film was formed under an oxygen atmosphere (or an oxygen atmosphere). The oxygen gas flow rate is greater than or equal to the argon gas flow rate, and the ratio is 1:1 or more. By including the first oxide semiconductor film, the conductivity of the first oxide semiconductor film can be made lower than that of the second oxide semiconductor film. In addition, by including a large amount of oxygen in the first oxide semiconductor film, Since the off-current can be reduced, a thin film transistor with a high on-off ratio can be obtained. This can be done.

[0053] The first oxide semiconductor film was formed in the same chamber as the previous reverse sputtering. Alternatively, if it is possible to form a film without exposing it to the atmosphere, reverse sputtering should be performed first. The film may be formed in a chamber different from the chamber where the film is formed.

[0054] Next, a second oxide semiconductor film is formed on the first oxide semiconductor film by sputtering. Indium oxide (In2O3), gallium oxide (Ga2O3), and zinc oxide (ZnO) A target with a composition ratio of 1:1:1 (=In2O3:Ga2O3:ZnO) was used. The distance between the substrate and the target was 170 mm, the pressure in the deposition chamber was 0.4 Pa, and the direct current (DC ) The power supply was 0.5 kW, the deposition temperature was room temperature, and argon gas was introduced at a flow rate of 40 sccm. As a result, a second oxide semiconductor film containing In, Ga, Zn, and oxygen is formed. A semiconductor film is formed with the composition ratio of 1:1:1 (= In2O3:Ga2O3:Z Although a target with a thickness of 100 nm was intentionally used, the size of the particles was 1 nm to 100 nm immediately after deposition. An oxide semiconductor film containing 10 nm crystal grains is often formed. Ratio, deposition pressure (0.1 Pa to 2.0 Pa), power (250 W to 3000 W: 8 inch diameter) By appropriately adjusting the temperature (room temperature to 100°C) and reactive sputtering film formation conditions, the crystal grains The presence or absence of crystals, the density of the crystal flow, and the diameter size can be adjusted in the range of 1 nm to 10 nm. The thickness of the second oxide semiconductor film is set to 5 nm to 20 nm. When the crystal grains are contained in the film, the size of the crystal grains contained in the film does not exceed the film thickness. The thickness of the second oxide semiconductor film is set to 5 nm.

[0055] Next, a second photolithography step is performed to form a resist mask, and a first oxide semiconductor is formed. The conductive film and the second oxide semiconductor film are etched. Here, ITO07N (Kanto Chemical Co., Ltd.) The unnecessary portions are removed by wet etching using a material (made of a material such as SiO 2 ) to form the first oxide semiconductor layer 10. 3 and the second oxide semiconductor layer 111. Note that the etching here is performed by wet etching. The process is not limited to etching, and dry etching may also be used. B).

[0056] Next, a conductive film made of a metal material is formed on the second oxide semiconductor layer 111 and the gate insulating layer 102. The conductive film 132 is formed by sputtering or vacuum deposition. , Ta, Ti, Mo, W, or an alloy containing the above elements as components, or Examples of the film include an alloy film made up of the above elements.

[0057] In addition, when heat treatment is performed at 200 to 600°C, the conductive film must have heat resistance to withstand this heat treatment. It is preferable to use aluminum alone because it has poor heat resistance and is prone to corrosion. Therefore, it is formed by combining it with a heat-resistant conductive material. Heat-resistant conductive material combined with Al Materials include titanium (Ti), tantalum (Ta), tungsten (W), molybdenum (M o), chromium (Cr), Nd (neodymium), Sc (scandium), or or an alloy containing the above elements as components, or an alloy film of a combination of the above elements, or It is formed from nitrides containing the elements.

[0058] Here, the conductive film 132 is a Ti film and an aluminum film containing Nd is laminated on the Ti film. A three-layer structure is formed by laminating an (Al-Nd) film and then forming a Ti film on top of that. The conductive film 132 may have a two-layer structure, in which a titanium film is laminated on an aluminum film. The conductive film 132 may have a single layer structure of an aluminum film containing silicon or a single layer structure of a titanium film. A cross-sectional view at this stage is shown in Figure 8(C).

[0059] Next, a third photolithography step is performed to form a resist mask 131 and etch the resist mask. Unnecessary portions of the conductive film 132 are removed by etching to form the conductive layers 105a and 105b. (See FIG. 9(A)). The etching method used here may be wet etching or dry etching. Here, a mixture of SiCl4, Cl2 and BCl3 is used as the reaction gas. Using dry etching, a Ti film, an aluminum containing Nd (Al-Nd) film, and a Ti film were The conductive film in which these are sequentially stacked is etched to form conductive layers 105a and 105b.

[0060] Next, a second resist mask is formed using the same resist mask as that used in the etching step of the conductive film 132. The oxide semiconductor film is etched. Here, a wafer using ITO07N (manufactured by Kanto Chemical Co., Ltd.) is used. By hot etching, unnecessary portions are removed to form the second oxide semiconductor layers 104a and 104b. The etching here is not limited to wet etching, but may be dry etching. Depending on the etching conditions, etching of the second oxide semiconductor layer 111 may be performed. In the etching step, the exposed region of the first oxide semiconductor layer 103 is also partially etched. As a result, the channel of the first oxide semiconductor layer 103 between the second oxide semiconductor layers 104a and 104b The formation region is an area with a thin film thickness as shown in FIG. 9(A).

[0061] Furthermore, the first oxide semiconductor layer 103 may be subjected to oxygen plasma treatment. By performing this, damage caused by etching of the first oxide semiconductor layer 103 can be repaired. A typical oxygen plasma treatment is a laser generated by glow discharge plasma of oxygen gas. The purpose of this project is to treat the surface of an oxide semiconductor with a silicon dioxide gas. The gas may be not only oxygen but also a mixed gas of oxygen gas and a rare gas.

[0062] Next, it is preferable to carry out a heat treatment at 200°C to 600°C, typically 300°C to 500°C. Here, the material is placed in a furnace and heat treated at 350°C for 1 hour in a nitrogen atmosphere. This heat treatment causes atomic-level rearrangement of semiconductor films containing In, Ga, and Zn. The heat treatment (including photo-annealing) here releases the distortion that inhibits carrier movement. The timing of the heat treatment is important. The process is not particularly limited as long as it is performed, and may be performed after the formation of the protective film, for example. A nonlinear element 170a having the conductor layer 103 as a channel forming region can be fabricated. A cross-sectional view is shown in FIG.

[0063] The resist mask is then removed, and a protective insulating layer covering the semiconductor layer containing In, Ga, and Zn is left. The protective insulating film 107 is made of silicon nitride obtained by sputtering or the like. film, silicon oxide film, silicon oxynitride film, aluminum oxide film, tantalum oxide film, etc. It can be used.

[0064] Next, a fourth photolithography step is performed to form a resist mask, and a protective insulating film 1 By etching the layer 07, a contact hole 125 is formed that reaches the conductive layer 105b. In order to reduce the number of masks, the gate insulating layer 102 is further formed using the same resist mask. The contact hole 128 that reaches the gate electrode by etching is also formed using the same resist mask. A cross-sectional view at this stage is shown in Figure 9(B).

[0065] Next, the resist mask is removed, and then a transparent conductive film is formed. are indium oxide (In2O3) and indium oxide tin oxide alloy (In2O3-SnO 2, abbreviated as ITO) is formed using a sputtering method or a vacuum deposition method. Etching of such materials is done with a hydrochloric acid solution. However, etching of ITO in particular Residues tend to be generated, so indium oxide zinc oxide alloy is used to improve etching processability. Gold (In2O3-ZnO) may also be used.

[0066] Next, a fifth photolithography step is performed to form a resist mask and then to perform etching. Unnecessary portions of the transparent conductive film are then removed to form pixel electrodes (not shown).

[0067] In this fifth photolithography step, the gate in the capacitor portion (not shown) is The gate insulating layer 102 and the protective insulating film 107 are used as dielectrics to form a storage capacitor between the capacitor wiring and the pixel electrode. A quantity is formed.

[0068] In this fifth photolithography step, the terminal portion is covered with a resist mask. The transparent conductive film formed on the terminal part is left. The transparent conductive film is the electrode or are wirings, connection terminal electrodes that function as input terminals of source wirings, etc.

[0069] In this embodiment, the third wiring layer 110 made of a transparent conductive film is connected to the nonlinear element 17. The conductive layer 105b, which will be the drain electrode of the gate electrode 0a, and the scanning line 108 are connected through the contact hole 125 and the gate electrode 106. and 128 to form a protection circuit.

[0070] Next, the resist mask is removed. The cross-sectional view at this stage is shown in Figure 9(C).

[0071] In this way, five photolithography processes were performed using five photomasks to produce multiple (In this embodiment, two nonlinear elements 170a and 170b are used.) The protection circuit can be completed by forming a first oxide semiconductor layer and wiring of the nonlinear element. a second oxide semiconductor layer having higher electrical conductivity than the first oxide semiconductor layer in a connection structure with the first oxide semiconductor layer; By providing an area that connects to the layer, it is possible to achieve more stable operation than when only metal wiring is used. This makes it possible to improve the functionality of the protection circuit and stabilize its operation. According to this embodiment, a plurality of TFTs can be fabricated in the same manner as the formation of the nonlinear element. Therefore, we fabricated a pixel part with a bottom gate type n-channel TFT and a protection circuit. That is, according to the process shown in this embodiment, the thin film Active matrix with protection diodes that reduce the risk of failure of the protection circuit due to peeling A substrate for a display device of a glass type can be produced.

[0072] (Embodiment 3) This embodiment is an embodiment of a display device in which a pixel section and a protection circuit including a nonlinear element are formed in the periphery thereof. An embodiment different from the second embodiment will be described with reference to FIG.

[0073] Figure 27 shows a circuit diagram of a thin film transistor and a protection circuit including a nonlinear element arranged on the same substrate in the pixel area. 1 is a diagram showing a cross-sectional structure of a display device formed. Conductive layers (105a, 105b) that serve as source and drain electrodes are provided in contact with the layer 103. It is being used.

[0074] In the nonlinear element 270a, the first oxide semiconductor layer 10 modified by the plasma treatment It is preferable that the conductive layer 105a and the conductive layer 105b are in contact with the insulating film 3. Before the conductive film is formed, the first oxide semiconductor layer 103 is subjected to plasma treatment.

[0075] An example of the plasma treatment is reverse sputtering. The treatment can be performed using argon gas, hydrogen gas, or a mixture of argon and hydrogen gas. The above gases may contain oxygen gas. Alternatively, other rare gases may be used instead of argon gas. It may be used.

[0076] The conductive film is etched to form conductive layers (105a, 105b) which will become source and drain electrodes. In this embodiment, the titanium film is formed by ammonia hydrogen peroxide (hydrogen peroxide: ammonia The source and drain electrodes are then formed by wet etching using a mixture of SiO2 and water (SiO2:SiO2=5:2:2). In this etching process, conductive layers (105a, 105b) are formed. A part of the exposed region of the first oxide semiconductor layer containing a and Zn is etched. The region sandwiched between the conductive layer 105a and the conductive layer 105b, i.e., the first oxide semiconductor layer 10 The channel forming region 3 is a thin region as shown in FIG.

[0077] The source electrode and the drain electrode are formed in contact with the first oxide semiconductor layer 103 modified by the plasma treatment. By forming conductive layers (105a, 105b) that serve as gate electrodes, the first oxide semiconductor The contact between the layer 103 and the conductive layers (105a, 105b) which will become the source and drain electrodes. Furthermore, the contact resistance of the first oxide semiconductor layer 103 can be reduced by the plasma treatment. The bonding strength of the conductive layers (105a, 105b) that become the source and drain electrodes is increased. Defects caused by peeling of the thin film are less likely to occur.

[0078] By the above steps, a display device having a highly reliable protection circuit as a nonlinear element semiconductor device is obtained. can be produced.

[0079] (Fourth embodiment) In this embodiment, a display device to which one embodiment of the present invention is applied includes a protection circuit and a pixel portion. This shows an example of electronic paper having TFTs on the same substrate.

[0080] FIG. 10 shows an active matrix type electronic display device as an example of a display device to which one embodiment of the present invention is applied. The thin film transistor 581 used in the semiconductor device is It can be fabricated in the same way as the nonlinear element shown in 2, and the semiconductor is an oxide semiconductor containing In, Ga, and Zn. It is a thin film transistor with high electrical characteristics, which is used for the body layer, source region, and drain region. .

[0081] The electronic paper in Figure 10 is an example of a display device that uses the twisting ball display method. The spherical display method is an electrode layer that uses spherical particles painted in black and white as display elements. and a potential difference is applied between the first electrode layer and the second electrode layer. This is a method of displaying by controlling the orientation of spherical particles by generating a magnetic field.

[0082] The thin film transistor 581 is a thin film transistor with a bottom gate structure, and the source electrode layer The drain electrode layer is electrically connected to the first electrode layer 587 through an opening formed in the insulating layer. Between the first electrode layer 587 and the second electrode layer 588, there are black areas 590a and A spherical particle with a white region 590b and a liquid-filled cavity 594 around it. 589 is provided, and the periphery of the spherical particle 589 is filled with a filler 595 such as resin. (See Figure 10.)

[0083] Also, instead of the twist ball, an electrophoretic element can be used. and a diameter of 10 μm to 20 μm that contains positively charged white particles and negatively charged black particles. Microcapsules of about 0 μm in size are used. When an electric field is applied by the first and second electrode layers, the microcapsules turn white. White particles and black particles move in opposite directions, allowing the display to be white or black. The display element that applies this principle is an electrophoretic display element, which is generally called electronic paper. Electrophoretic display elements have a higher reflectivity than liquid crystal display elements, so auxiliary lights are not required. It also consumes little power and the display can be seen even in dimly lit places. Even if power is not supplied to the display unit, the image that has been displayed can be retained. Therefore, for example, a semiconductor device with a display function (simply a display) can be connected to a radio wave source that serves as a power supply source. Even if the display device (also called a display device or a semiconductor device equipped with a display device) is placed far away, the display This allows the captured image to be stored.

[0084] By the above steps, the first oxide semiconductor layer and the wiring layer of the nonlinear element are connected to each other. A region that is in contact with a second oxide semiconductor layer having higher electrical conductivity than the first oxide semiconductor layer is provided. This allows for more stable operation than when using only metal wiring. This improves the function of the protection circuit and stabilizes operation. High reliability with a protection circuit made of nonlinear elements that are less susceptible to defects caused by film peeling It is possible to produce electronic paper with high performance.

[0085] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0086] (Embodiment 5) In this embodiment, in a display device which is an example of a semiconductor device of one embodiment of the present invention, At least a protection circuit, a part of a driving circuit, and a thin film transistor to be arranged in a pixel portion are arranged on the board. An example of the fabrication will be described below with reference to FIGS.

[0087] The thin film transistor disposed in the pixel portion on the same substrate as the protection circuit is the same as that shown in Embodiment Mode 2 or 3. The thin film transistor is formed in the same manner as the nonlinear element. Therefore, among the driver circuits, one that can be configured with n-channel TFTs is The pixel portion and the thin film transistor are formed on the same substrate.

[0088] A block diagram of an active matrix liquid crystal display device, which is an example of a semiconductor device of one embodiment of the present invention, is shown. An example of the circuit diagram is shown in FIG. 11A. The display device shown in FIG. 11A is a display device on a substrate 5300. A pixel portion 5301 having a plurality of pixels each having a display element, and a scanning line driver circuit 5302 for selecting each pixel. 302 and a signal line driver circuit 5303 for controlling the input of a video signal to a selected pixel. Has.

[0089] The pixel portion 5301 is a signal line driver circuit 5303. The signal line driver circuit 5303 is arranged to extend in the column direction. The signal line driver circuit 5303 is connected to the signal line driver circuit 5303 by lines S1 to Sm (not shown). A plurality of scanning lines G1 to Gn (not shown) are arranged extending from 5302 in the row direction. The scanning line driver circuit 5302 is connected to the signal lines S1 to Sm and the scanning lines G1 to Gn. The image sensor has a plurality of pixels (not shown) arranged in a matrix. signal line Sj (one of the signal lines S1 to Sm), scanning line Gi (one of the scanning lines G1 to Gn), (either one) is connected.

[0090] In addition, a thin film transistor can be formed in the same manner as the nonlinear element shown in the second or third embodiment. The signal line driver circuit is an n-channel TFT. This will be explained with reference to FIG.

[0091] The signal line driver circuit shown in FIG. 12 includes a driver IC 5601 and a group of switches 5602_1 to 5602_56. 02_M, a first wiring 5611, a second wiring 5612, a third wiring 5613 and a wiring 56 Each of the switch groups 5602_1 to 5602_M includes: A first thin film transistor 5603a, a second thin film transistor 5603b, and a third thin film transistor It has a transistor 5603c.

[0092] The driver IC 5601 is connected to a first wiring 5611, a second wiring 5612, and a third wiring 5613. and are connected to the wirings 5621_1 to 5621_M. 5602_M are connected to the first wiring 5611, the second wiring 5612, and the third wiring 561 3 and wiring 5621_1 to 5621_5 corresponding to the switch groups 5602_1 to 5602_M, respectively. Each of the wirings 5621_1 to 5621_M is connected to the first A thin film transistor 5603a, a second thin film transistor 5603b, and a third thin film transistor For example, the wiring 5621 in the Jth column is connected to three signal lines via a resistor 5603c. _J (one of the wirings 5621_1 to 5621_M) is connected to the switch group 5602 The first thin film transistor 5603a, the second thin film transistor 5603b, and and the third thin film transistor 5603c, the signal line Sj-1, the signal line Sj, the signal line S j+1 is connected to the

[0093] The first wiring 5611, the second wiring 5612, and the third wiring 5613 are each connected to a signal line. The number is entered.

[0094] It is desirable that the driver IC 5601 be formed on a single crystal substrate. The switch groups 5602_1 to 5602_M are formed on the same substrate as the pixel section. Therefore, the driver IC 5601 and the switch group 5602_1 to 5602_ It is recommended to connect to M via an FPC or similar.

[0095] Next, the operation of the signal line driver circuit shown in FIG. 12 will be described with reference to the timing chart of FIG. The timing chart in FIG. 13 is explained with reference to the timing chart when the i-th scanning line Gi is selected. Furthermore, the timing chart shows the selection period of the i-th scanning line Gi. is divided into a first sub-selection period T1, a second sub-selection period T2, and a third sub-selection period T3. Furthermore, when a scanning line of another row is selected, the signal line driver circuit of FIG. In this case, the same operation as in FIG. 13 is performed.

[0096] In the timing chart of FIG. 13, the wiring 5621_J in the Jth column is connected to the first thin-film transistor. a second thin film transistor 5603a, a second thin film transistor 5603b, and a third thin film transistor 560 When connected to signal line Sj-1, signal line Sj, and signal line Sj+1 via 3c It shows.

[0097] The timing chart of FIG. 13 shows the timing when the i-th scanning line Gi is selected, The on / off timing 5703a of the first thin film transistor 5603a, The on / off timing 5703b of the third thin film transistor 56 The on / off timing of 03c is input to 5703c and the J-th row wiring 5621_J. Signal 5721_J is shown.

[0098] The wirings 5621_1 to 5621_M are connected to the first sub-selection period T1 and the second sub-selection period T2. In the first sub-selection period T2 and the third sub-selection period T3, different video signals are input. For example, the video signal input to the wiring 5621_J in the first sub-selection period T1 is The signal is input to the signal line Sj-1 and input to the wiring 5621_J in the second sub-selection period T2. The video signal to be output is input to the signal line Sj, and the signal is output to the wiring 5621 during the third sub-selection period T3. The video signal input to the first sub-selection period is input to the signal line Sj+1. During the period T1, the second sub-selection period T2, and the third sub-selection period T3, the wiring 5621_ The video signals input to J are Data_j-1, Data_j, and Data_j+ Let's say it's 1.

[0099] As shown in FIG. 13, in the first sub-selection period T1, the first thin film transistor 5603 a is turned on, and the second thin film transistor 5603b and the third thin film transistor 5603c At this time, Data_j-1 input to the wiring 5621_J is turned off. The signal is input to the signal line Sj-1 via the transistor 5603a. Second sub-selection period T2 In this case, the second thin film transistor 5603b is turned on, and the first thin film transistor 5603a The third thin film transistor 5603c is turned off. The output Data_j is input to the signal line Sj via the second thin film transistor 5603b. In the third sub-selection period T3, the third thin film transistor 5603c is turned on, and the first The first thin film transistor 5603a and the second thin film transistor 5603b are turned off. At this time, Data_j+1 input to the wiring 5621_J is input to the third thin film transistor 56 It is input to the signal line Sj+1 via 03c.

[0100] From the above, the signal line driver circuit in FIG. 12 can achieve the following by dividing one gate selection period into three. During one gate selection period, a video signal is input from one wiring 5621 to three signal lines. Therefore, the signal line driver circuit of FIG. The number of connections between the substrate on which the display is mounted and the substrate on which the pixel section is formed is reduced to about one-third of the number of signal lines. By reducing the number of connections to about one-third, the signal line driver circuit of FIG. This can improve productivity and yield.

[0101] As shown in Figure 12, one gate selection period is divided into multiple sub-selection periods, and multiple sub-selection periods are During each selection period, a video signal is input from one line to each of multiple signal lines. As long as this can be achieved, there are no limitations on the arrangement, number, driving method, etc. of the thin film transistors.

[0102] For example, three or more signal lines are connected to one wiring in each of three or more sub-selection periods. When a video signal is input to each, a thin film transistor and a thin film transistor are controlled. However, it is necessary to divide one gate selection period into four or more sub-selection periods. Therefore, one gate selection period is divided into two or Preferably, it is divided into three sub-selection periods.

[0103] As another example, as shown in the timing chart of FIG. 14, one selection period is precharged. The first sub-selection period Tp, the first sub-selection period T1, the second sub-selection period T2, and the third selection period T3 are Furthermore, in the timing chart of FIG. 14, the i-th scanning line Gi is selected. the timing at which the first thin film transistor 5603a is turned on and off; a, the on / off timing 5803b of the second thin film transistor 5603b, The on / off timing 5803c of the membrane transistor 5603c and the J-th column wiring 562 14, the signal 5821_J input to the precharge During the period Tp, the first thin film transistor 5603a and the second thin film transistor 5603 At this time, the input to the wiring 5621_J is turned on. The input precharge voltage Vp is applied to the first thin film transistor 5603a, the second thin film transistor 5603b, and the and the signal line Sj- 1, signal line Sj, and signal line Sj+1. The thin film transistor 5603a is turned on, and the second thin film transistor 5603b and the third thin film transistor At this time, the membrane transistor 5603c is turned off. a_j-1 is input to the signal line Sj-1 via the first thin film transistor 5603a. In the second sub-selection period T2, the second thin film transistor 5603b is turned on, and the first thin film transistor The third thin film transistor 5603a and the third thin film transistor 5603c are turned off. Data_j input to the wiring 5621_J is input to the second thin film transistor 5603b. During the third sub-selection period T3, the third thin film transistor 5603c is turned on, and the first thin film transistor 5603a and the second thin film transistor 5 At this time, Data_j+1 input to the wiring 5621_J is The signal is input to the signal line Sj+1 via the third thin film transistor 5603c.

[0104] From the above, the signal line driver circuit of FIG. 12 to which the timing chart of FIG. 14 is applied By providing a precharge selection period before the block selection period, the signal lines can be precharged. This allows for high-speed writing of video signals to the pixels. 13 are denoted by the same reference numerals, and the same parts or similar functions are shown. A detailed description of the portion having the symbol will be omitted.

[0105] The configuration of the scanning line driving circuit will be described. The scanning line driving circuit includes a shift register, a buffer, and a In some cases, a level shifter may be included. In the circuit, a clock signal (CLK) and a start pulse signal (SP) are input to the shift register. ) is input, the selection signal is generated. The generated selection signal is The signal is buffered and amplified in the scanning line and then supplied to the corresponding scanning line. The gate electrodes of the transistors are connected. Since they must all be turned on at the same time, the buffer must be able to pass a large current. It is used.

[0106] One form of a shift register used as part of a scanning line driving circuit is shown in FIGS. 15 and 16. I will explain.

[0107] The circuit configuration of the shift register is shown in Figure 15. The shift register shown in Figure 15 has multiple free The flip-flops are composed of flip-flops (flip-flops 5701_1 to 5701_n). The first clock signal, the second clock signal, the start pulse signal, and the reset signal are input. It works like this.

[0108] The connection relationship of the shift register in Fig. 15 will be explained. The shift register in Fig. 15 has i-stage Flip-flop 5701_i (flip-flop 5701_1~5701_n) In either case, the first wiring 5501 shown in FIG. 16 is connected to the seventh wiring 5717_i-1. 16 is connected to the seventh wiring 5717_i+1. 16 is connected to the seventh wiring 5717_i, and The sixth wiring 5506 is connected to the fifth wiring 5715 .

[0109] In addition, the fourth wiring 5504 shown in FIG. 16 is the second wiring in the odd-numbered flip-flops. 5712, and in the even-numbered flip-flops, it is connected to the third wiring 5713. The fifth wiring 5505 shown in FIG.

[0110] However, the first wiring 5501 shown in FIG. 16 of the first-stage flip-flop 5701_1 is 16 of the n-th flip-flop 5701_n. The second wiring 5502 is connected to the sixth wiring 5716 .

[0111] The first wiring 5711, the second wiring 5712, the third wiring 5713, and the sixth wiring 57 16 can be called the first signal line, the second signal line, the third signal line, and the fourth signal line, respectively. Furthermore, the fourth wiring 5714 and the fifth wiring 5715 are respectively connected to the first power supply line and the This may also be called the power line 2.

[0112] Next, the details of the flip-flop shown in FIG. 15 are shown in FIG. 16. The flip-flop includes a first thin film transistor 5571, a second thin film transistor 5572, A third thin film transistor 5573, a fourth thin film transistor 5574, a fifth thin film transistor a sixth thin film transistor 5575, a sixth thin film transistor 5576, a seventh thin film transistor 5577, and and an eighth thin film transistor 5578. A second thin film transistor 5572, a third thin film transistor 5573, a fourth thin film transistor a fifth thin film transistor 5574, a fifth thin film transistor 5575, a sixth thin film transistor 5576, The seventh thin film transistor 5577 and the eighth thin film transistor 5578 are n-channel A transistor in which the gate-source voltage (Vgs) exceeds the threshold voltage (Vth) When this occurs, the device is in a conductive state.

[0113] Next, the connection configuration of the flip-flop shown in FIG. 16 will be described below.

[0114] A first electrode (either a source electrode or a drain electrode) of the first thin film transistor 5571 is connected to a fourth wiring 5504, and a second electrode (source) of the first thin film transistor 5571 is connected to a The other of the source electrode and the drain electrode is connected to a third wiring 5503 .

[0115] A first electrode of the second thin film transistor 5572 is connected to the sixth wiring 5506, and A second electrode of the thin film transistor 5572 is connected to a third wiring 5503 .

[0116] A first electrode of the third thin film transistor 5573 is connected to a fifth wiring 5505. The second electrode of the thin film transistor 5573 is the gate electrode of the second thin film transistor 5572. , and the gate electrode of the third thin film transistor 5573 is connected to the fifth wiring 5505. will be done.

[0117] A first electrode of the fourth thin film transistor 5574 is connected to a sixth wiring 5506, and The second electrode of the thin film transistor 5574 is the gate electrode of the second thin film transistor 5572. , and the gate electrode of the fourth thin film transistor 5574 is connected to the first thin film transistor 5 It is connected to the gate electrode of 571.

[0118] A first electrode of the fifth thin film transistor 5575 is connected to a fifth wiring 5505. The second electrode of the thin film transistor 5575 is the gate electrode of the first thin film transistor 5571. , and the gate electrode of the fifth thin film transistor 5575 is connected to the first wiring 5501. will be done.

[0119] A first electrode of the sixth thin film transistor 5576 is connected to the sixth wiring 5506. The second electrode of the thin film transistor 5576 is the gate electrode of the first thin film transistor 5571. , and the gate electrode of the sixth thin film transistor 5576 is connected to the second thin film transistor 5 It is connected to the gate electrode of 572.

[0120] A first electrode of the seventh thin film transistor 5577 is connected to the sixth wiring 5506. The second electrode of the thin film transistor 5577 is the gate electrode of the first thin film transistor 5571. , and the gate electrode of the seventh thin film transistor 5577 is connected to the second wiring 5502. A first electrode of the eighth thin film transistor 5578 is connected to the sixth wiring 5506. The second electrode of the eighth thin film transistor 5578 is connected to the gate of the second thin film transistor 5572. The gate electrode of the eighth thin film transistor 5578 is connected to the first wiring 550. Connected to 1.

[0121] The gate electrode of the first thin film transistor 5571 and the gate electrode of the fourth thin film transistor 5574 the gate electrode of the fifth thin film transistor 5575, the second electrode of the sixth thin film transistor The connection point of the second electrode of the seventh thin film transistor 5576 and the second electrode of the seventh thin film transistor 5577 is Further, the gate electrode of the second thin film transistor 5572, the gate electrode of the third thin film transistor 5573, and the gate electrode of the third thin film transistor 5574 are connected to the gate electrode of the second thin film transistor 5575. a second electrode of the fourth thin film transistor 5573; a second electrode of the fourth thin film transistor 5574; The gate electrode of the sixth thin film transistor 5576 and the gate electrode of the eighth thin film transistor 5578 The connection point of the two electrodes is designated as node 5544.

[0122] The first wiring 5501, the second wiring 5502, the third wiring 5503 and the fourth wiring 5504 are 504 can be called the first signal line, the second signal line, the third signal line, and the fourth signal line, respectively. Furthermore, the fifth wiring 5505 is a first power supply line, and the sixth wiring 5506 is a second power supply line. It can also be called.

[0123] In addition, the signal line driver circuit and the scanning line driver circuit may be used together with the nonlinear element shown in the second or third embodiment. It is also possible to fabricate the device using only n-channel TFTs, which can be formed in the same way as above. An n-channel TF that can be formed in the same manner as the nonlinear element shown in the second or third embodiment. Since T has a high transistor mobility, it is possible to increase the driving frequency of the driving circuit. In addition, the n-channel nonlinear element shown in the second or third embodiment can be formed in the same manner. The panel-type TFT is a silicon-based thin-film transistor (SFT) that uses an oxygen-deficient oxide semiconductor layer containing indium, gallium, and zinc. The source or drain region reduces the parasitic capacitance, resulting in a better frequency response (called the f characteristic). For example, it can be formed in the same manner as the nonlinear element shown in the second or third embodiment. The scanning line driver circuit using n-channel TFTs can be operated at high speed. It is also possible to increase the frame frequency or insert a black screen. This can be done.

[0124] Furthermore, the channel width of the transistor of the scanning line driving circuit can be increased, and multiple scanning lines can be formed. By arranging the drive circuit, it is possible to achieve an even higher frame frequency. When multiple scanning line driving circuits are arranged, the scanning line driving circuits for driving the even-numbered scanning lines are The circuit for driving the odd-numbered scanning lines is placed on one side, and the scanning line driving circuit for driving the odd-numbered scanning lines is placed on the other side. By placing the frame frequency at a higher level, it is possible to increase the frame frequency.

[0125] Furthermore, an active matrix light-emitting display device, which is an example of a semiconductor device to which one embodiment of the present invention is applied, When manufacturing a display device, a plurality of thin film transistors are arranged in at least one pixel. It is preferable that a plurality of scanning line driving circuits are arranged. An example of a block diagram is shown in FIG.

[0126] The light-emitting display device shown in FIG. 11B has a plurality of pixels each having a display element over a substrate 5400. A pixel portion 5401 for selecting each pixel, a first scanning line driver circuit 5402 for selecting each pixel, and a second scanning line driver circuit 5403 for selecting each pixel. A driver circuit 5404 and a signal line driver circuit 5405 for controlling the input of a video signal to a selected pixel 403 and

[0127] When a video signal input to a pixel of the light-emitting display device shown in FIG. 11(B) is in a digital format, When a pixel is turned on, it emits light or does not emit light by switching the transistor on or off. Therefore, gray scale display can be performed using area gray scale or time gray scale. The stacked gray scale method divides one pixel into multiple sub-pixels, and each sub-pixel is independently driven based on a video signal. The time gray scale method is a driving method that displays gray scales by moving the pixel. This is a driving method that displays gradation by controlling the period during which the light is turned on.

[0128] Light-emitting elements have a higher response speed than liquid crystal elements, making them more suitable for time gray scale modulation than liquid crystal elements. Specifically, when displaying using the time gray scale method, one frame period is divided into multiple subframes. Then, in accordance with the video signal, the light emitting element of the pixel is By dividing the period into multiple subframes, The total length of the period during which pixels actually emit light during one frame is controlled by the video signal. It is possible to control the brightness and display gradation.

[0129] In the light-emitting display device shown in FIG. 11B, one pixel has a switching TFT and a When two TFTs are arranged, the first TFT is the gate wiring of the switching TFT. The signal input to the scanning line is generated by the first scanning line driver circuit 5402, and the signal is input to the current control TFT. A signal input to the second scanning line, which is a gate wiring, is generated by a second scanning line driver circuit 5404. The example shows a signal input to the first scanning line and a signal input to the second scanning line. The signals for the scanning lines may be generated by a single scanning line driving circuit. The operation of the switching element is controlled by the number of transistors that the switching element has. In this case, a plurality of first scanning lines may be provided for each pixel. All signals input to the plurality of first scanning lines may be generated by one scanning line driving circuit. , may be generated by a plurality of scanning line driving circuits.

[0130] In addition, in the light-emitting display device, the driver circuit may be configured with an n-channel TFT. A part of the driver circuit can be formed on the same substrate as the thin film transistor of the pixel portion. In addition, the signal line driver circuit and the scanning line driver circuit may be used together with the nonlinear element shown in Embodiment 2 or 3. It is also possible to fabricate only n-channel TFTs, which can be formed in the same manner as above.

[0131] The above-mentioned driving circuit is not limited to liquid crystal display devices and light-emitting display devices, but may also be used in It may also be used in electronic paper, which uses electrically connected elements to drive electronic ink. Electronic paper is also called an electrophoretic display (electrophoretic display), and has the same properties as paper. The advantages are readability, low power consumption compared to other display devices, and the possibility of making them thin and light. It has points.

[0132] Electrophoretic displays can be of various forms, but the first particle has a positive charge. A microcapsule containing a negatively charged particle and a second particle is immersed in a solvent or solute. By applying an electric field to the microcapsules, The particles in the capsule are moved in opposite directions to each other, and only the color of the particles that have gathered on one side is displayed. The first particles or the second particles contain a dye, and in the absence of an electric field, The first particle and the second particle have different colors (colorless). (including

[0133] Thus, electrophoretic displays allow materials with high dielectric constants to migrate to areas of high electric field. This is a display that utilizes the so-called dielectrophoretic effect. Electrophoretic displays do not require polarizing plates or opposing substrates, which are necessary for display devices, and are half the thickness and weight. Decrease.

[0134] The microcapsules dispersed in a solvent are called electronic ink. The electronic ink can be printed on surfaces such as glass, plastic, fabric, and paper. Color display is also possible by using color filters or particles containing pigments.

[0135] Furthermore, the microphone is appropriately placed on the active matrix substrate so as to be sandwiched between two electrodes. By arranging multiple microcapsules, an active matrix display device is completed. By applying an electric field to the cell, display can be performed. Active matrix elements obtained by thin film transistors can be fabricated in a similar manner as linear elements. A trix substrate can be used.

[0136] The first particles and the second particles in the microcapsules may be made of a conductive material, an insulating material, Semiconductor materials, magnetic materials, liquid crystal materials, ferroelectric materials, electroluminescent materials, A material selected from magnetochromic materials, magnetophoretic materials, or a composite material thereof Just use it.

[0137] By the above steps, the first oxide semiconductor layer and the wiring layer of the nonlinear element are connected to each other. a region in contact with a second oxide semiconductor layer having higher electrical conductivity than the first oxide semiconductor layer, or By providing a modified area through plasma treatment, the wiring is more stable than when using only metal wiring. This will improve the functionality of the protection circuit and stabilize operation. In addition, the operation is stabilized and defects caused by peeling of the thin film are less likely to occur. A highly reliable display device incorporating a protection circuit made of a nonlinear element can be manufactured.

[0138] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0139] (Embodiment 6) A thin film transistor is fabricated together with the nonlinear element according to one embodiment of the present invention, and the thin film transistor is printed. A semiconductor device (also called a display device) having a display function is manufactured by using the semiconductor device in the element part and further in the driver circuit. In addition, the nonlinear element according to one embodiment of the present invention and the thin film transistor can be used in a driving circuit. It is used in part or the whole of the substrate, and is integrated with the pixel section to form a system-on-panel. It is possible.

[0140] The display device includes a display element. The display element includes a liquid crystal element (also called a liquid crystal display element), a light-emitting element, A light-emitting element (also called a light-emitting display element) can be used. This category includes elements whose brightness is controlled by the light emitted from the light source, specifically inorganic EL (Electroluminescent) Also, electronic inks and other electronic devices are also included. A display medium whose contrast changes due to mechanical action can also be applied.

[0141] The display device also includes a panel in which a display element is sealed, and a controller for the panel. Furthermore, one aspect of the present invention is a module in which an IC or the like including the above-mentioned is mounted. In the process of manufacturing a display device, the element substrate corresponds to one form before the display element is completed. The element substrate includes a means for supplying a current to each of the plurality of pixels. Specifically, the substrate may be in a state where only pixel electrodes of the display element are formed, or After forming the conductive film that will become the electrode, but before etching to form the pixel electrode It's fine, and all forms apply.

[0142] In this specification, the term "display device" refers to an image display device, a display device, or an optical device. It also refers to connectors, such as FPC (Flexible Printed Circuit) integrated circuit) or TAB (Tape Automated Bon ding) tape or TCP (Tape Carrier Package) Modules with printed wiring boards attached to the end of TAB tape or TCP or the display element is mounted on an IC (integrated circuit) by the COG (Chip On Glass) method. The display device also includes all modules in which the display device (circuit) is directly mounted.

[0143] In this embodiment, the appearance of a liquid crystal display panel, which is one mode of a display device according to one embodiment of the present invention, is The cross section will be explained using FIG. 17. FIG. 17 shows a nonlinear element and a similar method. Thin film transistors 4010 and 4011 and liquid crystal elements 4013 with high electrical properties can be fabricated. 4005 is used to seal the second substrate 4006. FIG. 17(B) corresponds to a cross-sectional view taken along line MN in FIGS. 17(A1) and 17(A2).

[0144] A pixel portion 4002 and a scanning line driver circuit 4004 are provided on a first substrate 4001. In this way, a sealing material 4005 is provided. A second substrate 4006 is provided on the path 4004. The line driver circuit 4004 is made up of a first substrate 4001, a sealing material 4005, and a second substrate 4006. The first substrate 4001 is sealed together with the liquid crystal layer 4008. In a region different from the region surrounded by the material 4005, a single crystal is formed on a separately prepared substrate. A signal line driver circuit 4003 formed of a semiconductor film or a polycrystalline semiconductor film is mounted.

[0145] The method of connecting the separately formed drive circuit is not particularly limited, and may be a COG method, Wire bonding or TAB method can be used. is an example of mounting a signal line driver circuit 4003 by the COG method, and FIG. 17(A2) is This is an example in which a signal line driver circuit 4003 is mounted by the TAB method.

[0146] A pixel portion 4002 and a scanning line driver circuit 4004 are provided on a first substrate 4001. 17B, ​​the thin film transistor included in the pixel portion 4002 is A transistor 4010 and a thin film transistor 4011 included in the scanning line driver circuit 4004 Insulating layers 4020 and 4022 are formed on the thin film transistors 4010 and 4011. 1 is provided.

[0147] The thin film transistors 4010 and 4011 are made of an oxide semiconductor containing In, Ga, and Zn. The conductive layer and the source and drain regions are used in thin film transistors with high electrical characteristics. In this case, a thin film transistor can be formed in the same manner as the nonlinear element shown in the second or third embodiment. In this embodiment, thin film transistors 4010 and 40 11 is an n-channel thin film transistor.

[0148] The pixel electrode layer 4030 of the liquid crystal element 4013 is connected to the thin film transistor 4010. The counter electrode layer 4031 of the liquid crystal element 4013 is electrically connected to the second substrate 40. 06. The pixel electrode layer 4030, the counter electrode layer 4031, and the liquid crystal layer 4008 are The overlapping portion corresponds to the liquid crystal element 4013. The electrode layer 4031 is provided with insulating layers 4032 and 4033 which function as alignment films. A liquid crystal layer 4008 is sandwiched between insulating layers 4032 and 4033 .

[0149] The first substrate 4001 and the second substrate 4006 may be made of glass or metal (typically, stainless steel). Stainless steel, ceramics, and plastics can be used. , FRP (Fiberglass-Reinforced Plastics) board, PV F (polyvinyl fluoride) film, polyester film or acrylic resin film Aluminum foil can also be used with PVF film or polyester film. A sheet sandwiched between films can also be used.

[0150] 4035 is a columnar spacer obtained by selectively etching the insulating film. To control the distance (cell gap) between the pixel electrode layer 4030 and the counter electrode layer 4031 A spherical spacer may also be used.

[0151] Alternatively, a liquid crystal that exhibits a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases. When the temperature of cholesteric liquid crystal is increased, the phase immediately transitions from the cholesteric phase to the isotropic phase. The blue phase appears only in a narrow temperature range, so the temperature range needs to be improved. In order to achieve this, a liquid crystal composition containing 5% by weight or more of a chiral agent is used for the liquid crystal layer 4008. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent has a response speed of 10 μs to It is optically isotropic, requiring no alignment treatment, and has little viewing angle dependency. stomach.

[0152] Note that this embodiment mode is an example of a transmissive liquid crystal display device, but one embodiment of the present invention is a reflective liquid crystal display device. The present invention can be applied to both a liquid crystal display device and a semi-transmissive liquid crystal display device.

[0153] In the liquid crystal display device of this embodiment, a polarizing plate is provided on the outer side (viewing side) of the substrate, and a polarizing plate is provided on the inner side. An example is shown in which a colored layer and an electrode layer used for a display element are provided in this order, but the polarizing plate is provided on the inner side of the substrate. The laminated structure of the polarizing plate and the colored layer is not limited to that of the present embodiment. The coloring layer may be appropriately selected depending on the material and manufacturing process conditions of the coloring layer. A light-shielding film that functions as a light-shielding film may be provided.

[0154] In this embodiment, in order to reduce the surface unevenness of the thin film transistor, In order to improve the reliability of the resistor, the nonlinear element shown in the second or third embodiment and the nonlinear element At the same time, a thin film transistor that can be formed by the same method is also formed. The insulating layer (insulating layer 4020, insulating layer 4021) covers the insulating layer. It is designed to prevent the intrusion of polluting impurities such as organic matter, metals, and water vapor floating in the air. The protective film is preferably a silicon oxide film, a silicon nitride film, an oxide film, or the like, which is formed by sputtering. Silicon oxynitride film, silicon oxynitride film, aluminum oxide film, aluminum nitride film, aluminum oxynitride film The insulating film may be formed of a single layer or a multilayer of an aluminum film or an aluminum nitride oxide film. In the embodiment, the protective film is formed by sputtering, but it may be formed by various methods without any particular limitation. Just do that.

[0155] Here, an insulating layer 4020 having a stacked structure is formed as a protective film. As the first layer of the silicon dioxide film, a silicon dioxide film is formed by sputtering. By using the above, it is possible to prevent hillocks in the aluminum film used as the source electrode layer and the drain electrode layer. It is effective in stopping.

[0156] In addition, an insulating layer is formed as the second layer of the protective film. Then, a silicon nitride film is formed by sputtering. When a silicon nitride film is used as a protective film, Mobile ions such as thorium penetrate into the semiconductor region and change the electrical properties of the TFT. can be suppressed.

[0157] After forming the protective film, the IGZO semiconductor layer is annealed (300°C to 400°C). It is also possible.

[0158] An insulating layer 4021 is formed as a planarization insulating film. Heat-resistant organic compounds such as amide, acrylic, benzocyclobutene, polyamide, and epoxy. In addition to the above organic materials, low-k materials can also be used. , siloxane resin, PSG (phosphorus glass), BPSG (borophosphorus glass), etc. Siloxane resins can have fluorine, alkyl groups, or alkyl groups in addition to hydrogen as a substituent. The insulating material formed from these materials may have at least one of the following groups: The insulating layer 4021 may be formed by laminating a plurality of insulating films.

[0159] Siloxane-based resin is a Si-OS compound formed using siloxane-based materials as starting materials. Siloxane resins contain hydrogen as a substituent, as well as fluorine and alkyl groups. The alkyl group may have at least one of a methyl group, a methyl group, an alkyl ...

[0160] The method for forming the insulating layer 4021 is not particularly limited, and may be a sputtering method, an SOG method, or the like, depending on the material. , spin coating, dip coating, spray coating, droplet ejection method (inkjet method, screen printing, offset printing, etc.), doctor knife, roll coater, curtain coater, knife When the insulating layer 4021 is formed using a material liquid, The IGZO semiconductor layer can be annealed (at 300°C to 400°C) at the same time during the coating process. The baking process of the insulating layer 4021 and the annealing process of the IGZO semiconductor layer are combined to efficiently A semiconductor device can be manufactured.

[0161] The pixel electrode layer 4030 and the counter electrode layer 4031 are made of indium oxide containing tungsten oxide. , indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, Indium tin oxide containing titanium oxide, indium tin oxide (hereinafter referred to as ITO), Translucent materials such as indium zinc oxide and indium tin oxide doped with silicon oxide A conductive material can be used.

[0162] The pixel electrode layer 4030 and the counter electrode layer 4031 are made of a conductive polymer (conductive polymer The conductive composition can be used to form the conductive film. The pixel electrode has a sheet resistance of 10,000 Ω / □ or less and a light transmittance of 550 nm. It is preferable that the resistance of the conductive polymer contained in the conductive composition is 70% or more. It is preferable that the electrical conductivity is 0.1 Ω·cm or less.

[0163] As the conductive polymer, a so-called π-electron conjugated conductive polymer can be used. For example, polyaniline or its derivatives, polypyrrole or its derivatives, polythiophene or or a derivative thereof, or a copolymer of two or more of these.

[0164] A signal line driver circuit 4003 and a scanning line driver circuit 4004 or a pixel section 4 Various signals and potentials applied to 002 are supplied from FPC4018.

[0165] In this embodiment, the connection terminal electrode 4015 is connected to the pixel electrode layer 40 of the liquid crystal element 4013. The terminal electrode 4016 is formed from the same conductive film as the thin film transistors 4010 and 40 The source electrode layer and the drain electrode layer 11 are formed of the same conductive film.

[0166] The connection terminal electrode 4015 is connected to the terminal of the FPC 4018 via the anisotropic conductive film 4019. are electrically connected.

[0167] In FIG. 17, a signal line driver circuit 4003 is formed separately and mounted on a first substrate 4001. However, this embodiment is not limited to this configuration. Alternatively, a part of the signal line driver circuit or a part of the scanning line driver circuit may be formed separately and mounted. Alternatively, the circuit board may be formed separately and mounted.

[0168] FIG. 18 shows a semiconductor device using a TFT substrate 2600 manufactured according to one embodiment of the present invention. 1 shows an example of a liquid crystal display module.

[0169] FIG. 18 shows an example of a liquid crystal display module, in which a TFT substrate 2600 and an opposing substrate 2601 are connected. The substrate is fixed by a bonding material 2602, and a pixel portion 2603 including a TFT and the like and a liquid crystal layer are disposed between the substrate and the bonding material 2602. A display element 2604 and a colored layer 2605 are provided to form a display area. is required for color display, and in the case of the RGB method, it corresponds to each color of red, green, and blue. A colored layer is provided corresponding to each pixel. On the outside, a polarizing plate 2606, a polarizing plate 2607, and a diffusion plate 2613 are arranged. It is composed of a cathode ray tube 2610 and a reflector 2611, and a circuit board 2612 is a flexible wiring board. The wiring board 2609 is connected to the wiring circuit section 2608 of the TFT substrate 2600, and the controller It also incorporates external circuits such as a polarizing plate and a power supply circuit. The layers may be laminated with a retardation film interposed therebetween.

[0170] The LCD module is available in TN (Twisted Nematic) mode, IPS (In-Plane Switching) mode, n-Plane-Switching mode, FFS (Fringe Field Switching) Switching mode, MVA (Multi-domain Vertical A alignment) mode, PVA(Patterned Vertical Alignment) mode, PVA(Patterned Vertical Alignment) mode nment), ASM(Axially Symmetric aligned Mic ro-cell) mode, OCB(Optical Compensated Bire) fringence mode, FLC (Ferroelectric Liquid Crystal Crystal mode, AFLC (AntiFerroelectric Liquid Crystal) can be used.

[0171] By the above steps, the first oxide semiconductor layer and the wiring layer of the nonlinear element are connected to each other. a region in contact with a second oxide semiconductor layer having higher electrical conductivity than the first oxide semiconductor layer, or By providing a modified area through plasma treatment, the wiring is more stable than when using only metal wiring. This will improve the functionality of the protection circuit and stabilize operation. In addition, the operation is stabilized and defects caused by peeling of the thin film are less likely to occur. It is now possible to fabricate highly reliable liquid crystal display panels equipped with a protection circuit made up of nonlinear elements. Cut.

[0172] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0173] (Embodiment 7) A thin film transistor is fabricated together with the nonlinear element according to one embodiment of the present invention, and the thin film transistor is printed. A semiconductor device (also called a display device) having a display function is manufactured by using the semiconductor device in the element part and further in the driver circuit. It can be manufactured.

[0174] In this embodiment, an example of a light-emitting display device will be described as a display device of one embodiment of the present invention. As the display element of the device, a light-emitting element using electroluminescence is used here. For example, a light-emitting element that utilizes electroluminescence uses an organic compound as the light-emitting material. Generally, the former is an organic EL element and the latter is an inorganic compound. These are called organic EL elements.

[0175] In an organic EL element, electrons and holes are released from a pair of electrodes by applying a voltage to the light-emitting element. are injected into the layers containing the light-emitting organic compounds, causing a current to flow. The recombination of the electrons and holes creates an excited state in the light-emitting organic compound. The excited state is then converted to the ground state, at which point light is emitted. Such a light-emitting element is called a current-excited light-emitting element.

[0176] Inorganic EL elements are divided into dispersion-type inorganic EL elements and thin-film-type inorganic EL elements depending on the element structure. Dispersion-type inorganic EL elements have a light-emitting layer in which particles of a light-emitting material are dispersed in a binder. The emission mechanism is a donor-acceptor interaction that utilizes the donor and acceptor levels. Thin-film inorganic EL devices sandwich the light-emitting layer between dielectric layers. Furthermore, this structure is sandwiched between electrodes, and the light emission mechanism utilizes the inner-shell electron transition of metal ions. In this example, the light-emitting element is an organic EL element. do.

[0177] FIG. 19 shows an example of a semiconductor device to which digital time gray scale driving is applied. FIG. 1 shows an example of a possible pixel configuration.

[0178] The configuration and operation of a pixel to which digital time gray scale driving can be applied will be described. The nonlinear element shown in the second embodiment is also formed by the same method as the IGZO semiconductor layer. An example in which two n-channel transistors are used in the panel formation region in one pixel is shown.

[0179] The pixel 6400 includes a switching transistor 6401, a driving transistor 6402, It has a light emitting element 6404 and a capacitor element 6403. 01 has a gate connected to a scanning line 6406 and a first electrode (one of the source and drain electrodes) The first electrode (the other of the source electrode and the drain electrode) is connected to a signal line 6405, and the second electrode (the other of the source electrode and the drain electrode) is connected to a drive The driving transistor 6402 is connected to the gate of the driving transistor 6402. The gate is connected to a power supply line 6407 via a capacitor element 6403, and the first electrode is connected to a power supply line 640 7, and the second electrode is connected to the first electrode (pixel electrode) of the light emitting element 6404. The second electrode of the light emitting element 6404 corresponds to the common electrode 6408 .

[0180] A low power supply potential is set to the second electrode (common electrode 6408) of the light emitting element 6404. The low power supply potential is a low power supply potential with respect to the high power supply potential set to the power supply line 6407. Potential < High power supply potential. For example, GND, 0V, etc. are set as low power supply potential. The potential difference between the high power supply potential and the low power supply potential is applied to the light emitting element 6404. Then, in order to make the light emitting element 6404 emit light by passing a current through the light emitting element 6404, a high power supply potential and the low power supply potential is set to be equal to or greater than the forward threshold voltage of the light emitting element 6404. Each potential is set.

[0181] The capacitor element 6403 is omitted by substituting the gate capacitance of the driving transistor 6402. The gate capacitance of the driving transistor 6402 is determined by the channel formation A capacitance may be formed between the region and the gate electrode.

[0182] In the case of a voltage input voltage driving method, the gate of the driving transistor 6402 is connected to The driving transistor 6402 is either fully on or off. A video signal is input, that is, the driving transistor 6402 is operated in a linear region. The driving transistor 6402 is operated in a linear region, so that the voltage of the driving transistor 6402 is higher than the voltage of the power supply line 6407. A high voltage is applied to the gate of the driving transistor 6402. The signal line 6405 is connected to A voltage equal to or greater than (power supply line voltage+Vth of the driving transistor 6402) is applied.

[0183] Furthermore, when analog grayscale driving is performed instead of digital time grayscale driving, the input of the signal is different. By doing so, the same pixel configuration as in FIG. 19 can be used.

[0184] When analog gradation driving is performed, a light emitting element 6404 is connected to the gate of a driving transistor 6402. A voltage equal to or greater than the forward voltage of the light emitting element 64 and the Vth of the driving transistor 6402 is applied. The forward voltage in 04 refers to the voltage required to achieve the desired brightness, and It should be noted that the driving transistor 6402 is designed to operate in the saturation region. By inputting an optical signal, a current can be passed through the light emitting element 6404. In order to operate the transistor 6402 in the saturation region, the potential of the power supply line 6407 is The potential of the light emitting element is made higher than the gate potential of the capacitor 6402. A current corresponding to a video signal is passed through 6404, enabling analog gradation driving.

[0185] Note that the pixel configuration shown in Fig. 19 is not limited to this. For example, A switch, a resistor, a capacitor, a transistor, a logic circuit, or the like may be added.

[0186] Next, the configuration of the light emitting element will be described with reference to FIG. 20. Here, the driving TFT is The cross-sectional structure of a pixel will be explained using the example of the type shown in Figures 20(A), (B), and (C). The TFTs 7001, 7011, and 7021, which are driving TFTs used in semiconductor devices, are actually A thin film transistor that can be formed in the same manner as the nonlinear element shown in embodiment 2, The semiconductor layer and the source and drain regions are formed of an oxide semiconductor containing n, Ga, and Zn. The thin film transistor used has excellent electrical properties.

[0187] The light emitting element only needs to have at least one of the anode and cathode transparent in order to extract light. Then, a thin film transistor and a light emitting element are formed on the substrate, and light is taken from the surface opposite to the substrate. Top emission, bottom emission, and top emission. There is a light-emitting element having a dual emission structure in which light is extracted from the side surface. It can be applied to any light emitting element with any emission structure.

[0188] A light emitting element with a top emission structure will be described with reference to FIG.

[0189] In FIG. 20(A), a TFT 7001 which is a driving TFT is an n-type, and a light emitting element 7002 emits light. FIG. 20(A) shows a cross-sectional view of a pixel when incident light exits the anode 7005 side. A cathode 7003 of the light emitting element 7002 and a TFT 7001 which is a driving TFT are electrically connected. A light-emitting layer 7004 and an anode 7005 are stacked in this order on a cathode 7003. 7003 uses various materials as long as they have a small work function and are conductive films that reflect light. For example, Ca, Al, CaF, MgAg, AlLi, etc. are preferable. The light-emitting layer 7004 may be composed of a single layer or a plurality of layers stacked together. When it is composed of multiple layers, the electron injection layer is formed on the cathode 7003. The electron transport layer, the light emitting layer, the hole transport layer, and the hole injection layer are laminated in this order. It is not necessary to provide all of the anodes. The anode 7005 is made of a conductive material that transmits light. For example, indium oxide containing tungsten oxide, indium oxide containing tungsten oxide Indium zinc oxide, indium oxide with titanium oxide, indium tin oxide with titanium oxide oxide, indium tin oxide (hereinafter referred to as ITO), indium zinc oxide, oxidized silicon dioxide, A light-transmitting conductive film such as indium tin oxide to which indium is added may also be used.

[0190] The region where the light-emitting layer 7004 is sandwiched between the cathode 7003 and the anode 7005 is the light-emitting element 7002. In the case of the pixel shown in FIG. 20(A), the light emitted from the light emitting element 7002 is The light is emitted toward the anode 7005 as shown by the mark.

[0191] Next, a light emitting element with a bottom emission structure will be described with reference to FIG. When 011 is n-type and light emitted from the light emitting element 7012 is emitted to the cathode 7013 side, 20(B) shows a cross-sectional view of the pixel. A cathode 7013 of a light-emitting element 7012 is formed on a light-transmitting conductive film 7017. On the cathode 7013, a light-emitting layer 7014 and an anode 7015 are laminated in this order. When the 015 has a light-transmitting property, a shielding layer for reflecting or blocking light is applied to cover the anode. The cathode 7013 may have a film 7016 formed thereon, as in the case of FIG. Various conductive materials with small electrical conductivity can be used. The thickness is set to a level that allows light to pass through (preferably, about 5 nm to 30 nm). For example, a 20 nm film An aluminum film having a thickness of 700 nm can be used as the cathode 7013. 014 is composed of a single layer, as in FIG. 20(A), but multiple layers are laminated. The anode 7015 does not need to transmit light, but as shown in FIG. As with 20(A), it can be formed using a light-transmitting conductive material. The shielding film 7016 may be made of, for example, a metal that reflects light, but is not limited to a metal film. For example, a resin containing a black pigment may be used.

[0192] The region where the light-emitting layer 7014 is sandwiched between the cathode 7013 and the anode 7015 is the light-emitting element 7012. In the case of the pixel shown in FIG. 20B, light emitted from the light-emitting element 7012 corresponds to The light is emitted toward the cathode 7013 as shown by the arrow.

[0193] Next, a light emitting element with a dual emission structure will be described with reference to FIG. Then, on the conductive film 7027 having light-transmitting properties and electrically connected to the driving TFT 7021, A cathode 7023 of the light-emitting element 7022 is formed as a film. A light-emitting layer 7024 is formed on the cathode 7023. The cathode 7023 is laminated in the same manner as in FIG. Various conductive materials with small electrical conductivity can be used. For example, Al having a thickness of 20 nm is used as the cathode 7023. The light-emitting layer 7024 can be formed of a single layer, as in FIG. The anode 70 may be formed by laminating a plurality of layers. 25 is formed using a light-transmitting conductive material, similar to FIG. 20(A). It is possible.

[0194] The overlapping portion of the cathode 7023, the light-emitting layer 7024, and the anode 7025 is the light-emitting element 70. In the case of the pixel shown in FIG. 20C, the light emitted from the light emitting element 7022 is emitted to both the anode 7025 side and the cathode 7023 side as shown by the arrows.

[0195] Although organic EL elements have been described as light-emitting elements here, inorganic EL elements can also be used as light-emitting elements. It is also possible to provide an L element.

[0196] In this embodiment, a thin film transistor (driving TFT) that controls driving of a light emitting element is Although an example in which the light emitting element is electrically connected has been shown, it is possible to prevent a current from flowing between the driving TFT and the light emitting element. A control TFT may be connected.

[0197] Note that the semiconductor device shown in this embodiment mode is not limited to the configuration shown in FIG. Various modifications based on the technical concept of the present invention are possible.

[0198] Next, a light-emitting display panel (also referred to as a light-emitting panel) which corresponds to one mode of a semiconductor device of one embodiment of the present invention will be described. The appearance and cross section of the device (referred to as "device") will be explained with reference to FIG. 21. FIG. 21(A) shows one example of the device of the present invention. The oxide semiconductor containing In, Ga, and Zn formed in the same manner as the nonlinear element of the embodiment Thin film transistor with high electrical characteristics using a silicon dioxide as the semiconductor layer and the source and drain regions 10 is a top view of a panel in which a capacitor and a light-emitting element are sealed between the capacitor and the second substrate by a sealant. 21(B) corresponds to a cross-sectional view taken along line HI in FIG. 21(A).

[0199] A pixel portion 4502, a signal line driver circuit 4503a, and a signal line driver circuit 4504 are provided on a first substrate 4501. 3b and the scanning line driver circuits 4504a and 4504b. In addition, a pixel portion 4502, signal line driver circuits 4503a and 4503b, and A second substrate 4506 is provided on the scanning line driver circuits 4504a and 4504b. The pixel portion 4502, the signal line driver circuits 4503a and 4503b, and the scanning line driver circuit 45 4504a and 4504b are a first substrate 4501, a sealing material 4505, and a second substrate 4506. The seal is sealed together with the filler 4507 by the sealant. Highly airtight protective film with little outgassing (lamination film, UV curable resin film) It is preferable to package (enclose) the product in a protective film (such as a film) or a cover material.

[0200] In addition, a pixel portion 4502, a signal line driver circuit 4503a, 4503b and the scanning line driver circuits 4504a and 4504b have a plurality of thin film transistors. In FIG. 21B, a thin film transistor 4510 included in a pixel portion 4502 and A thin film transistor 4509 included in a signal line driver circuit 4503a is illustrated.

[0201] The thin film transistors 4509 and 4510 are made of an oxide semiconductor containing In, Ga, and Zn. The conductive layer and the source and drain regions are used in thin film transistors with high electrical characteristics. In this case, a thin film transistor that can be formed in the same manner as the nonlinear element shown in the second embodiment is also provided. In this embodiment mode, the thin film transistors 4509 and 4510 are It is an n-channel thin film transistor.

[0202] Further, 4511 corresponds to a light-emitting element, and a first electrode which is a pixel electrode of the light-emitting element 4511 is The electrode layer 4517 is electrically connected to the source electrode layer or the drain electrode layer of the thin film transistor 4510. The light-emitting element 4511 is configured with a first electrode layer 4517, an electroluminescent The second electrode layer 4512 and the second electrode layer 4513 are stacked in a stacked structure. The light emitting element 4511 is not fixed according to the direction of the light extracted from the light emitting element 4511. The configuration can be changed as appropriate.

[0203] The partition wall 4520 is formed using an organic resin film, an inorganic insulating film, or organic polysiloxane. In particular, a photosensitive material is used to form an opening on the first electrode layer 4517, and the sidewall of the opening It is preferable to form the inclined surface so that the inclined surface has a continuous curvature.

[0204] The electroluminescent layer 4512 may be composed of a single layer or a plurality of layers stacked. It doesn't matter whether it's done or not.

[0205] The second electrode layer is formed to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4511. A protective film may be formed on the partition wall 4513 and the partition wall 4520. The protective film may be a silicon nitride film, A silicon nitride oxide film, a DLC film, or the like can be formed.

[0206] In addition, signal line driver circuits 4503a and 4503b, scanning line driver circuits 4504a and 4504b Various signals and potentials applied to the pixel portion 4502 are transmitted through the FPC 4518a, 4518b, and It is supplied by b.

[0207] In this embodiment, the connection terminal electrode 4515 is connected to the first electrode layer 4 The terminal electrode 4516 is formed from the same conductive film as the thin film transistors 4509 and 517. The source electrode layer and the drain electrode layer 510 are formed from the same conductive film.

[0208] The connection terminal electrode 4515 is connected to the terminal of the FPC 4518a via the anisotropic conductive film 4519. are electrically connected to each other.

[0209] The second substrate 4506 located in the direction of light extraction from the light emitting element 4511 must be light-transmitting. In this case, glass plates, plastic plates, polyester films or A light-transmitting material such as an acrylic film is used.

[0210] In addition to inert gases such as nitrogen and argon, filler 4507 can also be used as UV-curable resin. It can be made of oil or thermosetting resin, and PVC (polyvinyl chloride), acrylic, Polyimide, epoxy resin, silicone resin, PVB (polyvinyl butyral) or EV A (ethylene vinyl acetate) can be used. In this embodiment, filler 4507 Nitrogen was used as the gas.

[0211] If necessary, a polarizing plate or a circular polarizing plate (including an elliptical polarizing plate) may be provided on the light-emitting surface of the light-emitting element. Optical films such as retardation plates (λ / 4 plates, λ / 2 plates) and color filters may be provided as appropriate. In addition, an anti-reflection film may be provided on the polarizing plate or the circular polarizing plate. Anti-glare treatment can be applied to diffuse reflected light and reduce glare.

[0212] The signal line driver circuits 4503a and 4503b and the scanning line driver circuits 4504a and 4504b are A driving circuit formed of a single crystal semiconductor film or a polycrystalline semiconductor film on a separately prepared substrate is Alternatively, only the signal line driver circuit, or a part of the signal line driver circuit, or the scanning line driver circuit may be mounted. Only the path or only a part of the path may be separately formed and mounted. In this embodiment, the structure shown in FIG. Not limited.

[0213] By the above steps, the first oxide semiconductor layer and the wiring layer of the nonlinear element are connected to each other. a region in contact with a second oxide semiconductor layer having higher electrical conductivity than the first oxide semiconductor layer, or By providing a modified area through plasma treatment, the wiring is more stable than when using only metal wiring. This will improve the functionality of the protection circuit and stabilize operation. In addition, the operation is stabilized and defects caused by peeling of the thin film are less likely to occur. Fabrication of a highly reliable light-emitting display device (display panel) equipped with a protection circuit consisting of a nonlinear element It is possible.

[0214] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0215] (Embodiment 8) The display device of one embodiment of the present invention can be used as electronic paper. It can be used in any electronic device that displays information. For example, electronic paper can be used for electronic books, posters, and on trains and other vehicles. It can be used for in-car advertising, display on various cards such as credit cards, etc. An example of a slave device is shown in FIG. 22 and FIG.

[0216] FIG. 22(A) shows a poster 2631 made of electronic paper. In the case of printed matter, the advertisements are exchanged manually. By using electronic paper, the display of advertisements can be changed in a short time. It is possible to obtain a stable image without any distortion. It may also be possible to use the following.

[0217] FIG. 22(B) shows an advertisement 2632 inside a vehicle such as a train. In the case of paper printouts, the advertisements are exchanged manually. By using electronic paper, it is possible to change the display of advertisements in a short time without requiring much manpower. In addition, the poster can be displayed with a stable image without any distortion. It may be configured to be able to send and receive information.

[0218] 23 shows an example of an electronic book 2700. For example, the electronic book 2700 includes: It consists of two housings, housing 2701 and housing 2703. The body 2703 is integrated with a shaft 2711, and the opening and closing movement is performed around the shaft 2711. This configuration allows the device to operate like a paper book. This becomes:

[0219] A display unit 2705 is incorporated in the housing 2701, and a display unit 2707 is incorporated in the housing 2703. The display unit 2705 and the display unit 2707 are configured to display a continuous screen. Alternatively, a different screen may be displayed. For example, a sentence is displayed on the right display unit (display unit 2705 in FIG. 23) and An image can be displayed on the display unit 2707 in FIG.

[0220] 23 shows an example in which the housing 2701 is provided with an operation unit. 701 includes a power supply 2721, operation keys 2723, a speaker 2725, etc. The operation keys 2723 can be used to turn pages. It may also be configured to include a touch panel, a pointing device, etc. On the side, there are external connection terminals (earphone terminal, USB terminal, or AC adapter and USB A configuration including a terminal that can be connected to various cables, a recording medium insertion section, etc. Furthermore, the electronic book 2700 may be configured to have the function of an electronic dictionary. That's fine.

[0221] The electronic book 2700 may also be configured to be able to send and receive information wirelessly. The desired book data can be purchased and downloaded from the e-book server. is also possible.

[0222] In the connection structure between the first oxide semiconductor layer and the wiring layer of the nonlinear element, a region bonded to the second oxide semiconductor layer, which has higher electrical conductivity than the first oxide semiconductor layer, or a region bonded to the second oxide semiconductor layer by plasma treatment By providing a modified region, it is possible to achieve more stable operation than with metal wiring alone. This makes it possible to improve the functionality of the protection circuit and stabilize its operation. The device is made up of nonlinear elements that are stable in operation and are less susceptible to defects caused by peeling of thin films. It is possible to create highly reliable electronic paper equipped with a protection circuit.

[0223] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0224] (Embodiment 9) A semiconductor device according to one embodiment of the present invention can be applied to various electronic devices (including gaming machines). The electronic device can be, for example, a television device (television or television (also called a TV receiver), monitors for computers, cameras such as digital cameras, digital video cameras, digital photo frames, mobile phones (also known as mobile phones or mobile phone devices) (hereinafter referred to as "games"), portable game machines, personal digital assistants, sound reproduction devices, large game machines such as pachinko machines Examples include:

[0225] FIG. 24(A) shows an example of a television device 9600. The display unit 9603 is incorporated in the housing 9601. In this case, the housing 9601 is supported by a stand 9605. This shows a configuration in which the above is supported.

[0226] The television device 9600 can be operated using an operation switch on the housing 9601 or a separate remote control. This can be done by the remote control operation device 9610. The channel and volume can be controlled by the 9609, and the information displayed on the display 9603 is In addition, the remote control operation device 9610 can operate the video. A display portion 9607 for displaying information output from 9610 may be provided.

[0227] The television device 9600 is configured to include a receiver, a modem, and the like. It can receive more general television broadcasts and also provides wired or wireless reception via a modem. By connecting to a communication network, it can be one-way (sender to receiver) or two-way. It is also possible to communicate information (between a sender and a receiver, or between receivers).

[0228] FIG. 24B shows an example of a digital photo frame 9700. The photo frame 9700 has a display unit 9703 built into a housing 9701. The unit 9703 is capable of displaying various images, for example, images taken with a digital camera. By displaying the image data, it can function like a normal photo frame.

[0229] The Digital Photo Frame 9700 has an operation panel, external connection terminals (USB terminal, US A terminal that can be connected to various cables such as B cable, etc., and a recording medium insertion section. These components may be incorporated on the same surface as the display unit, but they may be incorporated on the side or back. It is preferable to have a recording medium for a digital photo frame as it improves the design. A memory that stores image data taken with a digital camera is inserted into the body insertion section. The image data can be captured and the captured image data can be displayed on the display portion 9703 .

[0230] The digital photo frame 9700 may also be configured to be capable of transmitting and receiving information wirelessly. It is also possible to configure the device so that desired image data can be wirelessly acquired and displayed.

[0231] FIG. 25(A) shows a portable gaming machine, which is composed of two cabinets, a cabinet 9881 and a cabinet 9891. The housing 9881 is connected to a connector 9893 so as to be openable and closable. A display unit 9883 is incorporated in the housing 9891. The portable gaming machine shown in 25(A) also includes a speaker unit 9884, a recording medium insertion unit 988 6, LED lamp 9890, input means (operation key 9885, connection terminal 9887, sensor 9 888 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, Chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration (including functions for measuring movement, smell or infrared rays), microphone 9889) Of course, the configuration of the portable gaming machine is not limited to the above, and It is sufficient if the semiconductor device according to one aspect is included, and other auxiliary equipment is appropriately provided. The portable gaming machine shown in FIG. 25(A) can be configured as It has the function of reading out programs or data and displaying them on the display, as well as wireless communication with other portable gaming machines. The portable gaming machine shown in Figure 25(A) has the function of communicating with the user and sharing information. The functions are not limited to these, and various other functions may be provided.

[0232] FIG. 25(B) shows an example of a slot machine 9900, which is a large gaming machine. The machine 9900 has a display unit 9903 built into a housing 9901. Machine 9900 also has other operating means such as a start lever and stop switch, coin It is equipped with an insertion slot, a speaker, etc. Of course, the configuration of the slot machine 9900 is The present invention is not limited to the above, and may be implemented in any configuration as long as it includes at least a semiconductor device according to one embodiment of the present invention. In addition, other auxiliary equipment may be provided as appropriate.

[0233] FIG. 26 shows an example of a mobile phone 1000. The mobile phone 1000 has a housing 100 1, in addition to the display unit 1002, operation buttons 1003, an external connection port 1004, It is equipped with a speaker 1005, a microphone 1006, etc.

[0234] The mobile phone 1000 shown in FIG. 26 allows users to input information by touching the display unit 1002 with a finger or the like. In addition, operations such as making a call or sending an email can be performed by the display unit 100. This can be done by touching 2 with a finger or something.

[0235] The screen of the display unit 1002 has three main modes. The first is a display mode that mainly displays images. The first mode is a display mode, and the second mode is an input mode that mainly inputs information such as characters. This is a display + input mode that combines two modes: display mode and input mode.

[0236] For example, when making a call or creating an email, the display unit 1002 is used to input characters. This is the main character input mode, and you can input characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display unit 1002. I wish.

[0237] In addition, the mobile phone 1000 may include a sensor for detecting tilt, such as a gyro or an acceleration sensor. By providing a detection device having the above configuration, the orientation of the mobile phone 1000 (portrait or landscape) can be determined and the display The screen display of the display unit 1002 can be automatically switched.

[0238] The screen mode can be switched by touching the display unit 1002 or by operating the housing 1001. This is done by operating the button 1003. Also, depending on the type of image displayed on the display unit 1002, For example, if the image signal to be displayed on the display unit is a video signal, If it is data, the display mode is switched to, and if it is text data, the input mode is switched to.

[0239] In the input mode, the optical sensor of the display unit 1002 detects a signal and displays it. If there is no input by touch operation of the part 1002 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0240] The display unit 1002 can also function as an image sensor. By touching the palm or fingers to the sensor 02, the palm print, fingerprint, etc. can be captured and identity authentication can be performed. In addition, the display unit may be equipped with a backlight that emits near-infrared light or a sensor that emits near-infrared light. By using a scanning light source, it is also possible to capture images of finger veins, palm veins, etc.

[0241] In the connection structure between the first oxide semiconductor layer and the wiring layer of the nonlinear element, a region bonded to the second oxide semiconductor layer, which has higher electrical conductivity than the first oxide semiconductor layer, or a region bonded to the second oxide semiconductor layer by plasma treatment By providing a modified region, it is possible to achieve more stable operation than with metal wiring alone. This makes it possible to improve the functionality of the protection circuit and stabilize its operation. The device is made up of nonlinear elements that are stable in operation and are less susceptible to defects caused by peeling of thin films. A highly reliable electronic device incorporating a protection circuit can be manufactured.

[0242] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is. [Explanation of symbols]

[0243] 10 Substrate 11 Scanning line input terminal 12 Signal line input terminal 13 scan lines 14 Signal line 16 gate electrode 17 Pixel section 18 pixels 19 pixel transistor 20 Holding capacity section 21 pixel electrode 22 Capacitance line 23 Common terminal 24 Protection circuit 25 Protection circuit 26 Protection circuit 27 capacity bus lines 28 Common wiring 29 Common wiring 30 Nonlinear elements 30a Nonlinear element 30b Nonlinear element 31 Nonlinear elements 31a Nonlinear element 31b Nonlinear element 38 wiring layer 39 Wiring layer 100 boards 101 gate electrode 102 Gate insulating layer 103 Oxide semiconductor layer 104a Oxide semiconductor layer 104b Oxide semiconductor layer 105a Conductive layer 105b conductive layer 107 Protective insulating film 108 scan lines 110 wiring layer 111 Oxide semiconductor layer 125 Contact Hole 128 Contact Holes 131 Resist mask 132 Conductive film 170a Nonlinear element 170b Nonlinear element 270a Nonlinear element 581 Thin-film transistor 585 Insulation Layer 587 Electrode layer 588 Electrode layer 589 Spherical particles 590a black area 590b White area 594 Cavity 595 Filling material 730a Nonlinear element 730b Nonlinear element 730c Nonlinear Element 740a Nonlinear element 740b Nonlinear element 740c Nonlinear Element 740d Nonlinear Element 1000 mobile phones 1001 Case 1002 Display section 1003 Operation button 1004 External connection port 1005 Speaker 1006 Mike 2600 TFT substrate 2601 Opposing substrate 2602 Sealing material 2603 Pixel section 2604 Display element 2605 Colored layer 2606 Polarizing plate 2607 Polarizing plate 2608 Wiring circuit section 2609 Flexible wiring board 2610 cold cathode tube 2611 Reflector 2612 Circuit Board 2613 Diffuser 2631 Poster 2632 In-car advertising 2700 e-books 2701 Housing 2703 Housing 2705 ​​Display section 2707 Display section 2711 Shaft 2721 Power supply 2723 Operation Key 2725 Speaker 4001 board 4002 Pixel section 4003 Signal line driver circuit 4004 Scanning line driver circuit 4005 Sealing material 4006 board 4008 Liquid crystal layer 4010 Thin Film Transistor 4011 Thin-film transistor 4013 Liquid crystal element 4015 Connection terminal electrode 4016 Terminal electrode 4018 FPC 4019 Anisotropic conductive film 4020 Insulation layer 4021 Insulation layer 4030 Pixel electrode layer 4031 Counter electrode layer 4032 Insulation layer 4501 Circuit Board 4502 Pixel section 4503a Signal line driver circuit 4504a Scanning line driver circuit 4505 Sealing material 4506 board 4507 Filling material 4509 Thin-film transistor 4510 Thin-film transistor 4511 Light-emitting element 4512 Electroluminescent layer 4513 Electrode layer 4515 Connection terminal electrode 4516 Terminal electrode 4517 Electrode layer 4518a FPC 4519 Anisotropic conductive film 4520 Bulkhead 5300 board 5301 Pixel unit 5302 Scanning line driver circuit 5303 Signal line driver circuit 5400 board 5401 Pixel unit 5402 Scanning line driver circuit 5403 Signal line driver circuit 5404 Scanning line driver circuit 5501 Wiring 5502 Wiring 5503 Wiring 5504 Wiring 5505 Wiring 5506 Wiring 5543 nodes 5544 nodes 5571 Thin-film transistor 5572 Thin-film transistor 5573 Thin-film transistor 5574 Thin-film transistor 5575 Thin-film transistor 5576 Thin-film transistor 5577 Thin-film transistor 5578 Thin-film transistor 5601 Driver IC 5602 switches 5603a Thin Film Transistor 5603b Thin Film Transistor 5603c Thin Film Transistor 5611 Wiring 5612 Wiring 5613 Wiring 5621 Wiring 5701 Flip-Flop 5703a Timing 5703b Timing 5703c Timing 5711 Wiring 5712 Wiring 5713 Wiring 5714 Wiring 5715 Wiring 5716 Wiring 5717 Wiring 5721 Signal 5803a Timing 5803b Timing 5803c Timing 5821 Signal 6400 pixels 6401 Switching transistor 6402 Drive transistor 6403 Capacitor element 6404 Light-emitting element 6405 signal line 6406 scan lines 6407 Power line 6408 Common electrode 7001 TFT 7002 Light-emitting element 7003 Cathode 7004 Light-emitting layer 7005 Anode 7011 Driving TFT 7012 Light-emitting element 7013 Cathode 7014 Light-emitting layer 7015 Anode 7016 Shielding membrane 7017 Conductive film 7021 Driving TFT 7022 Light-emitting element 7023 Cathode 7024 Light-emitting layer 7025 Anode 7027 Conductive film 9600 Television Equipment 9601 Housing 9603 Display section 9605 Stand 9607 Display section 9609 Operation Key 9610 Remote Control Machine 9700 Digital Photo Frame 9701 Housing 9703 Display section 9881 Case 9882 Display section 9883 Display section 9884 Speaker section 9885 Input means (operation keys) 9886 Recording medium insertion section 9887 Connection terminal 9888 Sensor 9889 Microphone 9890 LED Lamp 9891 Case 9893 Connection section 9900 slot machine 9901 Housing 9903 Display section

Claims

1. a pixel portion and a circuit electrically connected to the pixel portion, the circuit is a display device having a first transistor, a second transistor, a third transistor, and a fourth transistor, the circuit includes a first oxide semiconductor layer including a channel formation region of the first transistor; a second oxide semiconductor layer including a channel formation region of the second transistor; a third oxide semiconductor layer including a channel formation region of the third transistor; a fourth oxide semiconductor layer including a channel formation region of the fourth transistor; an insulating film having a region in contact with an upper surface of the first oxide semiconductor layer, a region in contact with an upper surface of the second oxide semiconductor layer, a region in contact with an upper surface of the third oxide semiconductor layer, and a region in contact with an upper surface of the fourth oxide semiconductor layer; a first conductive layer having a function as a gate electrode of the first transistor and a function as a gate electrode of the third transistor; a second conductive layer serving as a gate electrode of the second transistor; a third conductive layer having a function as one of a source electrode or a drain electrode of the first transistor, a function as one of a source electrode or a drain electrode of the second transistor, a function as one of a source electrode or a drain electrode of the third transistor, and a function as one of a source electrode or a drain electrode of the fourth transistor; a fourth conductive layer that functions as the other of the source electrode and the drain electrode of the first transistor and the other of the source electrode and the drain electrode of the second transistor; the first conductive layer has a region that intersects with the third conductive layer in a plan view; In a plan view, the first conductive layer does not have a region intersecting with the second conductive layer and does not have a region intersecting with the fourth conductive layer; The insulating film has a region in contact with an upper surface of the third conductive layer and a region in contact with an upper surface of the fourth conductive layer.

2. In claim 1, the first oxide semiconductor layer, the second oxide semiconductor layer, the third oxide semiconductor layer, and the fourth oxide semiconductor layer each contain In, Ga, and Zn.

Images