Semiconductor device

Abstract

To provide a touch panel including an oxide semiconductor film with conductivity.SOLUTION: The touch panel includes a transistor, a second insulating film, and a touch sensor. The transistor includes a gate electrode, a gate insulating film, a first oxide semiconductor film, a source electrode and a drain electrode, a first insulating film, and a second oxide semiconductor film. The second insulating film is provided on the second oxide semiconductor film so that the second oxide semiconductor film is held between the first insulating film and the second insulating film. The touch sensor includes a first electrode and a second electrode. One of the first electrode and the second electrode includes the second oxide semiconductor film.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] One embodiment of the present invention relates to a semiconductor device. Another embodiment of the present invention relates to a display device. Another embodiment of the present invention relates to an input According to another aspect of the present invention, there is provided an output device.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. One aspect of the present invention relates to a process, a machine, or a method of manufacture. , manufacture, or composition of matter. More specifically, a technical field of one embodiment of the present invention disclosed in this specification and the like is semiconductor device. , display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices, input / output devices The present invention relates to an apparatus, a driving method thereof, or a manufacturing method thereof.

[0003] In this specification and the like, a semiconductor device is a device that can function by utilizing semiconductor characteristics. Refers to devices in general. Semiconductor elements such as transistors, semiconductor circuits, computing devices, memory The device is one aspect of a semiconductor device. power devices, input / output devices, electro-optical devices, power generation devices (including thin-film solar cells, organic thin-film solar cells, etc.) Some of the equipment and electronic devices include semiconductor devices. [Background technology]

[0004] It is used in many flat panel displays, such as liquid crystal displays and light-emitting displays. The transistors used are made of amorphous silicon and single crystal silicon formed on a glass substrate. The silicon semiconductor is made of silicon semiconductor such as polycrystalline silicon or polysilicon. Transistors using silicon semiconductors are also used in integrated circuits (ICs).

[0005] In recent years, metal oxides that exhibit semiconducting properties have been used in transistors instead of silicon semiconductors. In this specification, the term "oxide" refers to a metal oxide that exhibits semiconductor properties. For example, zinc oxide or In-Ga- A transistor using a Zn-based oxide is manufactured, and the transistor is used as a pixel switch of a display device. Technologies for use in chip elements and the like have been disclosed (see Patent Documents 1 and 2). Therefore, various touch sensors have been developed (see Patent Documents 3 to 7). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2007-123861 A [Patent Document 2] JP 2007-96055 A [Patent Document 3] JP 2011-197685 A [Patent Document 4] JP 2014-44537 A [Patent Document 5] JP 2014-178847 A [Patent Document 6] U.S. Patent No. 7,920,129 [Patent Document 7] JP 2009-244958 A Summary of the Invention [Problem to be solved by the invention]

[0007] One embodiment of the present invention is to provide a touch panel including a conductive oxide semiconductor film. Another object of the present invention is to provide a touch panel having a simplified structure. Another object of the present invention is to provide a novel input device. One object of the present invention is to provide a power device. [Means for solving the problem]

[0008] One aspect of the present invention is a semiconductor device including a transistor, a second insulating film, and a touch sensor. In the semiconductor device, the transistor has a gate electrode and a gate an insulating film; a first insulating film provided in contact with the gate insulating film and at a position overlapping the gate electrode; a source electrode and a drain electrode electrically connected to the first oxide semiconductor film; a first oxide semiconductor film, a source electrode, and a drain electrode; an insulating film; a second insulating film provided over the first insulating film so as to overlap with the first oxide semiconductor film; and a second insulating film, the second oxide semiconductor film being separated from the first insulating film. The touch sensor is provided on the second oxide semiconductor film so as to be sandwiched between the insulating film of the second oxide semiconductor film and the insulating film of the second oxide semiconductor film. The sensor has a first electrode and a second electrode, and either one of the first electrode and the second electrode The second oxide semiconductor film and the third oxide semiconductor film are semiconductor devices formed at the same time.

[0009] In the above, the second oxide semiconductor film and the third oxide semiconductor film have a thickness of 30 nm or less. It is preferable that the thickness is 70 nm or more.

[0010] The first oxide semiconductor film, the second oxide semiconductor film, and the third oxide semiconductor film are In-M-Zn oxide (M is Al, Ti, Ga, Y, Zr, La, Ce, Nd, Sn or The above semiconductor device, in which Hf is a metal, is also one embodiment of the present invention.

[0011] The semiconductor device may further include a first insulating film containing oxygen and a second insulating film containing hydrogen. is one aspect of the present invention.

[0012] In addition, a capacitor including a second insulating film between a pair of electrodes is provided, and the capacitor is one of a pair of electrodes of a capacitor is formed using the above-mentioned semiconductor film including a third oxide semiconductor film. A conductor device is also an aspect of the present invention.

[0013] The semiconductor device according to the present invention may further include a semiconductor device including a third oxide semiconductor film. is one aspect of the present invention.

[0014] A touch panel including the semiconductor device described above, a conductive film, and a liquid crystal element. The conductive film functions as a pixel electrode, and the third oxide semiconductor film functions as a common electrode. In the present invention, a touch panel having the above-mentioned function and in which the other of the pair of electrodes of the capacitor element includes a conductive film is also an embodiment of the present invention. It seems that.

[0015] Further, there is provided a touch panel having the above-described semiconductor device and a light-emitting element, The element includes a lower electrode, an upper electrode, and an EL layer sandwiched between the lower electrode and the upper electrode. A touch panel that can be used in this manner is also one aspect of the present invention.

[0016] The above touch panel, wherein the first electrode and the second electrode include a third oxide semiconductor film. This is also an aspect of the present invention.

[0017] In addition, the other of the first electrode and the second electrode is the above-mentioned touch panel including the upper electrode. This is also an aspect of the present invention.

[0018] Further, a semiconductor device having the above-described semiconductor device, a switch, a speaker, a display unit, or a housing is provided. An electronic device having such a configuration is also an aspect of the present invention.

[0019] In addition, a touch panel as described above, a switch, a speaker, a display unit or a housing may be provided. An electronic device that performs the above-mentioned operation is also one aspect of the present invention. Effect of the Invention

[0020] According to one aspect of the present invention, a touch panel including a conductive oxide semiconductor film is provided. It is also possible to provide a touch panel with a simplified configuration. Alternatively, a novel input device can be provided. Alternatively, a novel input / output device can be provided. This can be done. [Brief description of the drawings]

[0021] [Figure 1] 1A and 1B are a block diagram and a timing chart of a touch sensor according to an embodiment. [Diagram 2] 1A to 1C are diagrams illustrating a pixel including a touch sensor according to an embodiment. [Diagram 3] 1A to 1C are diagrams illustrating a pixel including a touch sensor according to an embodiment. [Figure 4] 1A to 1C are diagrams illustrating a pixel including a touch sensor according to an embodiment. [Diagram 5] 5A to 5C are diagrams illustrating operations of a touch sensor and a pixel according to an embodiment. [Figure 6] 1 is a schematic cross-sectional view showing a touch panel system according to an embodiment. [Figure 7] FIG. 1 is a perspective view showing an example of a touch panel according to an embodiment. [Figure 8]FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 9] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 10] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 11] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 12] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 13] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 14] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 15] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 16] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 17] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 18] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 19] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 20] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 21] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Figure 22] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 23] FIG. 1 is a cross-sectional view showing an example of a touch panel according to an embodiment. [Figure 24] FIG. 2 is a top view showing a configuration of a touch sensor electrode according to the embodiment. [Diagram 25] 1A to 1C are cross-sectional views illustrating a method for manufacturing a transistor or the like according to an embodiment. [Figure 26] 1A to 1C are cross-sectional views illustrating a method for manufacturing a transistor or the like according to an embodiment. [Figure 27]1A to 1C are cross-sectional views illustrating a method for manufacturing a transistor or the like according to an embodiment. [Figure 28] 1A to 1C are cross-sectional views illustrating a method for manufacturing a transistor or the like according to an embodiment. [Figure 29] 1 is a cross-sectional view showing a configuration of a transistor and the like according to an embodiment; [Diagram 30] Cs-corrected high-resolution TEM image of a cross section of CAAC-OS, and a schematic cross-sectional diagram of CAAC-OS. [Diagram 31] Cs-corrected high-resolution TEM image of the CAAC-OS in the plane. [Diagram 32] 13A to 13C show structural analyses of a CAAC-OS and a single-crystal oxide semiconductor by XRD. [Diagram 33] Electron diffraction pattern of CAAC-OS. [Diagram 34] FIG. 1 shows the change in the crystal part of an In-Ga-Zn oxide due to electron irradiation. [Diagram 35] 1A to 1C are diagrams illustrating a method for forming a CAAC-OS film. [Diagram 36] A diagram explaining the InMZnO4 crystal. [Figure 37] 1A to 1C are diagrams illustrating a method for forming a CAAC-OS film. [Figure 38] 1A and 1B are a top view and a cross-sectional view illustrating an example of a transistor. [Figure 39] FIG. 1 is a cross-sectional view illustrating an example of a transistor. [Diagram 40] FIG. 2 is a diagram for explaining a band structure. [Diagram 41] FIG. 1 is a cross-sectional view illustrating an example of a transistor. [Diagram 42] 1A to 1C illustrate examples of the structure of a light-emitting element. [Diagram 43] 1A to 1C are diagrams illustrating a display module according to an embodiment. [Diagram 44] 1A to 1C are diagrams illustrating electronic devices according to an embodiment. [Diagram 45] 1A to 1C are diagrams illustrating electronic devices according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiment, and various changes and modifications may be made in the form and details without departing from the spirit and scope of the present invention. It will be easily understood by those skilled in the art that the present invention can be realized by the following embodiments. The present disclosure should not be construed as being limited to the contents of the preceding paragraph.

[0023] In the configuration of the invention described below, the same parts or parts having similar functions are The same reference numerals are used in common between different drawings, and the repeated explanations are omitted. When referring to a function, the hatch pattern may be the same and no particular symbol may be used.

[0024] In each figure described in this specification, the size, layer thickness, or area of ​​each component is indicated by the following formula: The figures may be exaggerated for clarity and are not necessarily limited to scale. stomach.

[0025] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. The numbers are added for the purpose of convenience and are not intended to be limiting.

[0026] The words "film" and "layer" can be used interchangeably. For example, the term "conductive layer" may be changed to the term "conductive film." In some cases, the term "insulating layer" may be changed to the term "insulating film." .

[0027] In addition, even when the term "semiconductor" is used in this specification, for example, If the electrical conductivity is low enough, the material may have the properties of an insulator. The boundary between "insulators" and "insulators" is unclear, and it may not be possible to strictly distinguish them. In some cases, the term "semiconductor" in the above can be replaced with "insulator." The term "insulator" in the specification etc. may be replaced with "semiconductor".

[0028] In addition, even when the term "semiconductor" is used in this specification, for example, If the electrical conductivity is high enough, it may have the properties of a "conductor". The boundary between the term "conductor" and the term "electrical conductor" is unclear, and it may not be possible to strictly distinguish between them. In some cases, the term "semiconductor" in the above can be replaced with "conductor." The term "conductor" in the specification etc. may be replaced with "semiconductor" in some cases.

[0029] The functions of the "source" and "drain" of a transistor are different for transistors of different polarities. When using a current source, or when the direction of the current changes during circuit operation, For this reason, in this specification, the terms "source" and "drain" are used interchangeably. It is possible to use it.

[0030] In this specification, patterning refers to a process using photolithography. However, the patterning is not limited to the photolithography process. A process other than the photolithography process can also be used. The mask is to be removed after the etching process.

[0031] (Embodiment 1) In this embodiment, a driving method and a driving circuit for a touch sensor or a touch panel according to one embodiment of the present invention will be described. A configuration example and a configuration example of a semiconductor device of one embodiment of the present invention will be described with reference to the drawings. do.

[0032] [Example of sensor detection method] FIG. 1(A) is a block diagram showing the configuration of a mutual capacitance type touch sensor. 1(A) shows a pulse voltage output circuit 601 and a current detection circuit 602. As an example, the electrode 621 to which the pulse voltage is applied is connected to six wires X1-X6, and the current The electrode 622 for detecting the change in the voltage is shown as six wires Y1-Y6. The number of electrodes is not limited to this. Alternatively, a capacitance is formed by arranging the electrodes 621 and 622 close to each other. The electrodes 621 and 622 are interchangeable in function. Good too.

[0033] As an example, the pulse voltage output circuit 601 applies a pulse voltage to the wirings X1-X6 in order. This is a circuit for applying a pulse voltage to the X1-X6 wiring. An electric field is generated between the electrodes 621 and 622 that form the electrode 3. Then, a pulse voltage is applied to A current flows through the capacitor 603. The electric field generated between these electrodes is generated by the touch of a finger or pen. In other words, the capacitance value of the capacitor 603 changes depending on the touch of a finger or a pen. In this way, the capacitance value changes when a finger or pen is touched. By utilizing this, the proximity or contact of a detection object can be detected.

[0034] The current detection circuit 602 detects the current in the wiring Y1-Y6 due to a change in the capacitance value of the capacitor 603. This is a circuit for detecting changes in flow. The Y1-Y6 wiring detects the proximity of a detected object or If there is no contact, the detected current value does not change, but if the object to be detected approaches or touches the sensor, When the capacitance value decreases, the change in the current value is detected. The total flow rate may be detected. In that case, an integrating circuit or the like may be used for detection. Alternatively, the peak value of the current may be detected. In that case, the current is converted into a voltage and the voltage value is The peak value of may be detected.

[0035] Next, FIG. 1B shows the input and output of the mutual capacitance type touch sensor shown in FIG. The timing chart of the waveform is shown in Fig. 1(B). In addition, in Fig. 1(B), when no object is detected (non-touch The two cases shown are Y1- For the wire Y6, the waveform is a voltage value corresponding to the detected current value. The display panel is also performing a display operation. It is desirable to synchronize the timing of the touch sensor detection operation with the timing of the touch sensor detection operation. Note that Fig. 1B shows an example in which the operation is not synchronized with the display operation.

[0036] A pulse voltage is applied to the wires X1-X6 in sequence, and the The waveform in the Y6 wiring changes. When there is no proximity or contact of the object to be detected, X1-X6 The waveforms of Y1-Y6 change uniformly according to the change in the voltage of the wiring. Or, at the point of contact, the current value decreases, and the corresponding voltage waveform also changes. do.

[0037] In this way, by detecting the change in capacitance, the proximity or contact of the object to be detected can be detected. In addition, when a detected object such as a finger or pen comes into contact with a touch sensor or a touch panel, Even if the device is not connected to the Internet and is in close proximity, a signal may still be detected.

[0038] The pulse voltage output circuit 601 and the current detection circuit 602 are, for example, integrated circuits (ICs). The IC is preferably formed in a semiconductor device. It is preferable that the terminal is mounted on a substrate inside the housing of an electronic device. When using a bent panel, parasitic capacitance increases at the bent parts, increasing the effect of noise. Therefore, it is recommended to use ICs that use a driving method that is less susceptible to noise. For example, a driving method that increases the signal-to-noise ratio (S / N ratio) is applied. It is preferable to use an IC having such a configuration.

[0039] In addition, in FIG. 1A, a package in which only a capacitor 603 is provided at the intersection of wiring as a touch sensor is used. The configuration of a sub-matrix type touch sensor has been shown, but the active element having a transistor and a capacitor is Alternatively, a touch sensor of an active matrix type may be used.

[0040] [Example of in-cell touch panel configuration] Here, a substrate on which a display element, a transistor, etc. are provided (hereinafter, also referred to as an element substrate) Next, an example in which at least one of the electrodes constituting the touch sensor is arranged will be described.

[0041] In the following, we will discuss a touch panel (a so-called Here, a configuration example of a display element (in-cell type) provided in a pixel is described. However, one embodiment of the present invention is not limited to this, and various Such a display element can be applied.

[0042] FIG. 2A shows a part of a pixel circuit provided in a display unit of a touch panel illustrated in this configuration example. FIG.

[0043] Each pixel includes at least a transistor 63 and a liquid crystal element 64. In addition, the transistor 63 may have a storage capacitor. A wiring 62 is electrically connected to either the source or the drain.

[0044] The pixel circuit includes a plurality of wirings (for example, wiring 72_1 and wiring 72_2) extending in the X direction. , a plurality of wirings (for example, wiring 71_1, wiring 71_2) extending in the Y direction, The wirings 71_1 are arranged to cross each other. A capacitance is formed between the wirings. The wiring 71_2 is formed at the same time as one electrode of the liquid crystal element 64 by processing the same conductive film. The wiring 72 is provided on a substrate facing the element substrate (hereinafter, also referred to as a facing substrate). The wiring 72 may be provided on the element substrate.

[0045] As an example, among the pixels provided in the pixel circuit, some adjacent pixels , one electrode of the liquid crystal element 64 provided in each block is electrically connected to each other. Here, a plurality of linear blocks (for example, blocks In FIG. 2A, a block 65_1 and a block 65_2 are formed. Although only one block is shown, these blocks are actually arranged repeatedly in the X direction.

[0046] With this configuration, the electrodes constituting the touch sensor and the liquid crystal of the pixel circuit The wiring 71_1 and the wiring 71_2 can also serve as one electrode of the element. 2 serves as one electrode of the liquid crystal element and also serves as an electrode constituting a touch sensor. The line 72_1 and the wiring 72_2 function as electrodes that constitute a touch sensor. Therefore, the configuration of the touch panel can be simplified. In FIG. 2(A), a plurality of The wiring (for example, the wiring 71_1 and the wiring 71_2) is connected to one electrode of the liquid crystal element and the touch sensor. However, one embodiment of the present invention is not limited to this. For example, A plurality of wirings (for example, wiring 72_1 and wiring 72_2) extending in the X direction are arranged to face one of the liquid crystal elements. The electrodes may also serve as electrodes constituting the touch sensor. is shown in FIG. 2(B).

[0047] As shown in FIG. 3, a plurality of wirings ( For example, a configuration including wirings 66_1 to 66_4 may be used. A plurality of linear blocks extending in the Y direction (for example, block 65_1, block 65 These blocks 65 are repeatedly arranged in the X direction. A plurality of linear blocks extending in the X direction are arranged across a plurality of linear blocks extending in the X direction. Blocks (e.g., blocks 67_1 to 67_4) are formed. The blocks 67 are repeatedly arranged in the Y direction. The manufacturing process of the touch panel can be simplified by processing the same conductive film and forming them at the same time.

[0048] In addition, in FIG. 2(A), (B) and FIG. 3, an example in which a liquid crystal element is used as a display element is shown. However, one embodiment of the present invention is not limited thereto. An example of this case is shown in Figures 4(A) and (B).

[0049] FIG. 5A shows a plurality of wirings 72 extending in the X direction and a plurality of wirings 71 extending in the Y direction. It is an equivalent circuit diagram showing the connection configuration of the touch sensor. Each of the wirings 71 extending in the Y direction is connected to an input voltage (or , selected voltage) or common potential (or ground potential, or reference potential) In addition, each of the wirings 72 extending in the X direction is connected to a ground potential (or a reference potential). Alternatively, the wiring 72 can be electrically connected to the detection circuit. In addition, the wiring 71 and the wiring 72 can be interchanged. may be connected.

[0050] The operation of the above-mentioned touch panel will be described below with reference to FIGS.

[0051] As an example, one frame period is divided into a writing period and a detection period. The write period is a period in which image data is written to the pixels, and the wiring 72 (gate line, or On the other hand, the detection period is the period during which the touch sensor senses the pixel. This is a period in which the above-mentioned operation is performed, during which the wirings 71 extending in the Y direction are selected in sequence and an input voltage is input.

[0052] FIG. 5B is an equivalent circuit diagram during the writing period. A common potential is input to both the wiring 72 extending in the Y direction and the wiring 71 extending in the Y direction.

[0053] FIG. 5C is an equivalent circuit diagram at a certain point in the detection period. An input voltage is input to each of the wirings 71 extending in the X direction. The selected one of these is connected to the detection circuit, and the other ones are input with a common potential. .

[0054] The driving method shown here can be used not only with the in-cell method but also with other touch panels. can be applied.

[0055] In this way, the image writing period and the period for sensing by the touch sensor are separated. For example, it is preferable to perform sensing during a blanking period of a display. This prevents the touch sensor sensitivity from decreasing due to noise when writing to pixels. It is possible.

[0056] [About the touch panel system] In the following, several methods that can be applied to the touch panel according to one embodiment of the present invention will be described. do.

[0057] In this specification, the touch panel has a function of displaying (outputting) images on a display surface. A touch sensor that detects when a finger, stylus, or other object touches or approaches the display surface. Therefore, the touch panel is one type of input / output device. do.

[0058] In the present specification, the substrate of the touch panel is provided with, for example, an FPC (Flexible Printed Circuit). rinted Circuit) or TCP (Tape Carrier Pack Connectors such as COG (Chip On Gauge) are attached to the board. The touch panel module is a device that uses the touch panel glass method to mount an IC (integrated circuit). It may be called a touch panel, display module, or simply a touch panel.

[0059] A capacitive touch sensor that can be applied to one aspect of the present invention includes a pair of conductive films. A capacitance is formed between the pair of conductive films. When the object to be detected touches or is close to the pair of conductive films, The capacitance between the pair of conductive films changes when the films come into contact with each other, and this is used for detection. It is possible.

[0060] The capacitive touch panel includes a surface capacitive touch panel and a projected capacitive touch panel. Capacitive methods include self-capacitance and mutual capacitance, mainly depending on the driving method. The mutual capacitance method is preferable because it allows simultaneous multi-point detection.

[0061] In addition, a liquid crystal element (vertical electric field type) can be used as a display element in the touch panel of one embodiment of the present invention. type, or in-plane electric field type), MEMS (Micro Electro Mechanical Al Systems, optical elements, organic EL (Electro Luminescence) scene elements and light emitting diodes (LEDs) Various display elements such as light-emitting elements such as those shown in FIG.

[0062] Here, the touch panel is a transparent display using a liquid crystal element that uses a horizontal electric field method. It is preferable to apply a transmission type liquid crystal display device.

[0063] The touch panel according to one embodiment of the present invention has a touch sensor on one or both of a pair of substrates. By having a pair of electrodes (also called conductive films or wirings) that constitute the display panel, The touch sensor is integrated into the display panel, which reduces the thickness of the touch panel. This makes it possible to realize a lightweight touch panel.

[0064] FIG. 6(A) is a schematic cross-sectional view illustrating a mode of a touch panel 10 according to an embodiment of the present invention. do.

[0065] The touch panel 10 includes a substrate 11, a substrate 12, an FPC 13, a conductive film 14, a liquid crystal element 20, It has a colored film 31, a conductive film 41, and the like.

[0066] The liquid crystal element 20 is composed of a conductive film 21, a conductive film 22, and liquid crystal 23. The FFS (Fringe Field Switching) mode is suitable for the crystal element 20. The liquid crystal element is formed on the conductive film 21 via the insulating film 24. A conductive film 22 is disposed. The conductive film 22 has, for example, a comb-tooth-shaped upper surface or a slip-shaped upper surface. The conductive film 21 and the conductive film 22 have a top surface shape (also referred to as a planar shape) on which a conductive film is provided. One of them functions as a common electrode and the other functions as a pixel electrode. In the case where a light emitting element or the like is used, for example, the conductive film 22 has a comb-like upper surface shape, Alternatively, the upper surface does not have a slit.

[0067] The touch sensor is formed by a conductive film 41 provided on the substrate 12 side and a pair of electrodes of the liquid crystal element 20. The capacitance formed between the conductive film 21 functioning as one of the two can be used for detection. With this configuration, one electrode of the liquid crystal element 20 is connected to a pair of electrodes of the touch sensor. This allows the process to be simplified and the yield to be improved. The conductive film 41 is formed on the display surface of the substrate 12. The conductive film 41 is provided on the substrate 12 side. The conductive film 21 is attached to the substrate 11 via the conductive film 14. It is electrically connected to the FPC13 attached to the board.

[0068] The touch panel 10 shown in FIG. 6B does not include the conductive film 41 and the FPC 43. The conductive film 21a and the conductive film 21b functioning as a common electrode of the liquid crystal element 20 are The electrodes also function as a pair of electrodes of the ch sensor. The process can be further simplified compared to the configuration in which the conductive film 21a is formed by the conductive film 14. The conductive film 21b is electrically connected to the FPC 13 via a conductive film (not shown). Electrically connect to C13.

[0069] 6A and 6B show the lower electrode of the pair of electrodes constituting the liquid crystal element 20. In the illustrated example, the electrodes (conductive films 21, 21a, 21b) are common electrodes, but the present invention is not limited to this. 6A and 6B, a pair of electrodes constituting the liquid crystal element 20 6(C) and (D) show examples in which the electrode (conductive film 22) located in the upper layer is a common electrode. As shown in.

[0070] This concludes the explanation of the touch panel method.

[0071] [Configuration example 1] A more specific example of the configuration of the touch panel will be described below.

[0072] FIG. 7(A) is a perspective schematic diagram of a touch panel 310 according to an embodiment of the present invention. 7B) and (C) are schematic perspective views of FIG. 7A in which FIG. 7B is a perspective view of the opposing substrate side. 7(A) is a schematic perspective view of the element substrate side, and FIG. 7(B) is a schematic perspective view of the element substrate side. Only essential components are shown.

[0073] The touch panel 310 has a substrate 102 and a substrate 372 disposed opposite each other.

[0074] On the substrate 102, a display unit 381, a driving circuit 382, ​​wiring 386, a driving circuit 384, etc. are provided. In addition, the display portion 381 is provided with an oxide semiconductor film 111. The substrate 102 is provided with an FPC 373 that is electrically connected to the wiring 386. In addition, in Fig. 7(A) and (C), IC374 is provided on FPC373. An example is shown.

[0075] In addition, on the surface of the substrate 372 opposite to the surface facing the substrate 102, a plurality of conductive films 334 and a plurality of A conductive film 335, a plurality of conductive films 341, and the like are formed (see FIG. 7B). 1 is electrically connected to one of the plurality of conductive films 334. The substrate 372 has a plurality of conductive films An FPC 375 is provided which is electrically connected to 341 .

[0076] The conductive film 335 is disposed between the two conductive films 334. A difference in transmittance occurs between an area where the conductive film 334 is provided and an area where the conductive film 334 is not provided. In addition, the conductive film 335 is preferably electrically floating. In this way, the conductive film 334 and the oxide semiconductor film 111 are not exposed to the conductive film 335. The change in potential of one electrode can be efficiently transmitted to the other electrode, improving detection sensitivity. Note that the conductive film 335 does not have to be provided if it is not necessary.

[0077] The display portion 381 has at least a plurality of pixels (see FIG. 7C). Each pixel may include a transistor and a display element. Representative examples of the display element include light-emitting elements such as organic EL elements and liquid crystal elements. In this configuration example, a liquid crystal element is used as the display element.

[0078] The driving circuit 382 is, for example, a circuit that functions as a scanning line driving circuit, a signal line driving circuit, etc. There can be.

[0079] The wiring 386 has a function of supplying signals and power to the display portion 381 and the driver circuit 382 . The signal and power are input to the outside via FPC373 or from IC374 to wiring 386. will be done.

[0080] The driver circuit 384 has a function of sequentially selecting the oxide semiconductor films 111. The touch sensor is driven by sequentially selecting the conductive film 334 instead of the semiconductor film 111. In this case, the driving circuit 384 switches between a fixed potential and a signal used for sensing to oxidize the The semiconductor film 111 is supplied with a current by the IC 374 or an external device. In the case where a signal for driving the driver circuit 384 is provided, the driver circuit 384 may not be provided.

[0081] In addition, in FIG. 7(A) to (C), a COF (Chip On Film) is formed on the FPC 373. The figure shows an example in which IC374 is mounted in accordance with the method m). For example, an IC that functions as a scanning line driver circuit or a signal line driver circuit is applied. In addition, the touch panel 310 can be a circuit that functions as a scanning line driving circuit and a signal line driving circuit. In some cases, a circuit that functions as a scanning line driver circuit or a signal line driver circuit is provided externally, When inputting a signal to drive the display unit 381 via the FPC 373, the IC The IC 374 may be omitted. Alternatively, the semiconductor device may be directly mounted on the substrate 102 by a method such as a glass mounting method.

[0082] At this time, the IC 374 may have a function of driving a touch sensor, or Alternatively, an IC for driving the touch sensor may be provided. It may be mounted on a substrate 102 .

[0083] The touch sensor is formed by a conductive film 334 provided on a substrate 372 and an oxide film provided on a substrate 102. The conductive film 334 is formed between the oxide semiconductor film 111 and the conductive film 334. The formed capacitance can be used to detect the proximity or contact of a detection object.

[0084] [Cross-sectional configuration example 1] Hereinafter, an example of a cross-sectional configuration of a touch panel according to one embodiment of the present invention will be described with reference to the drawings. Reveal.

[0085] 8 is a schematic cross-sectional view of a touch panel 310. In FIG. 8, the FPC in FIG. The area including 373 and 375, the area including the driving circuit 382, ​​and the area including the display unit 381 The cross sections of each are shown.

[0086] The substrate 102 and the substrate 372 are bonded together by a sealant 151. A liquid crystal 353 is sealed in the area surrounded by the plate 102, the substrate 372, and the sealant 151. There are.

[0087] The touch panel 310 shown in FIG. 8 includes an oxide semiconductor film 110 in a display portion 381. The semiconductor device has a transistor 150 including a pair of electrodes and a capacitor 160 including an insulating film between the pair of electrodes. In the capacitor 160, one of a pair of electrodes is the oxide semiconductor film 111. The other electrode is a conductive film 120 .

[0088] The transistor 150 includes a gate electrode 104 on a substrate 102 and a gate insulating film on the gate electrode 104. The insulating film 108 functions as a gate insulating film, and the gate electrode 104 overlaps the insulating film 108. The oxide semiconductor film 110 at the position where the source electrode 112a and the drain electrode 112b are formed is shown in FIG. In other words, the transistor 150 has an oxide semiconductor film 1 10, and an insulating film 110 that functions as a gate insulating film provided in contact with the oxide semiconductor film 110. The insulating film 108 is provided in contact with the insulating film 108 and overlaps with the oxide semiconductor film 110. The gate electrode 104 is electrically connected to the oxide semiconductor film 110. a and drain electrode 112b.

[0089] In addition, on the transistor 150, more specifically, the oxide semiconductor film 110, the source electrode 11 Insulating films 114, 116, 118, and 119 are formed on the drain electrode 112a and the drain electrode 112b. The insulating films 114, 116, and 118 function as protective insulating films for the transistor 150. The insulating film 119 functions as a planarization film. An opening reaching the drain electrode 112b is formed in the first and second electrodes 118 and 119. The conductive film 120 is formed on the insulating film 119 as shown in FIG. Note that the insulating film 119 does not necessarily have to be provided.

[0090] The capacitor 160 is provided over the insulating film 116. The capacitor 160 is The oxide semiconductor film 111 functions as one electrode, and the dielectric film 112 on the oxide semiconductor film 111 The insulating films 118 and 119 function as a semiconductor film, and the oxide semiconductor film is formed by interposing the insulating films 118 and 119. A conductive film 1 having a function as the other electrode of a pair of electrodes located at a position overlapping the body film 111. That is, the conductive film 120 functions as a pixel electrode and an electrode of a capacitor element. Note that the thickness of the oxide semiconductor film 111 is set to be smaller than the resistance in the thickness direction of the film. It is preferable that the thickness is such that the rate of the photoresist is not biased. m or less, and more preferably 50 nm or more and 70 nm or less.

[0091] The touch panel 310 shown in FIG. 8 has a touch sensor in the display unit 381. The touch sensor has a pair of electrodes, which are provided over the oxide semiconductor film 111 and the substrate 372. The transistor 150, the capacitor 160, and the touch sensor 140 are connected to the conductive film 334. The transistor 150 and the touch sensor can be collectively called a semiconductor device. The auxiliary electrode may be formed of an oxide semiconductor film. For example, a conductive film may be provided in contact with the gate electrode 104 or the source electrode 111. 2a, a conductive layer is formed at a position overlapping the light-shielding film 332 using the same material as the drain electrode 112b. By providing the auxiliary electrode so as to overlap the light-shielding film 332, the aperture ratio of the pixel is maintained. This makes it possible to suppress delays in signal transmission due to detection by the touch sensor while maintaining the same quality.

[0092] Note that the oxide semiconductor film 110 functions as a channel region of the transistor 150. The oxide semiconductor film 111 functions as one of a pair of electrodes of the capacitor 160. Therefore, the resistivity of the oxide semiconductor film 111 is lower than that of the oxide semiconductor film 110. The oxide semiconductor films 110 and 111 preferably contain the same metal element. The oxide semiconductor film 110 and the oxide semiconductor film 111 contain the same metal element. This allows for common use of manufacturing equipment (e.g., deposition equipment, processing equipment, etc.), Manufacturing costs can be reduced.

[0093] In addition, the capacitor 160 has a light-transmitting property. The semiconductor film 111, the conductive film 120, and the insulating films 118 and 119 are each transparent. In this way, the capacitor element 160 is made of a material that transmits light. It is possible to form the transistor in a large area in a region other than the region where the transistor is formed. Therefore, it is possible to provide a touch panel with an increased aperture ratio and an increased capacitance value. As a result, a touch panel with excellent display quality can be obtained.

[0094] Note that the insulating film 118 provided over the transistor 150 and used for the capacitor 160 An insulating film containing at least hydrogen is used as the insulating film for the transistor 150. The insulating film 107 and the insulating films 114 and 116 provided on the transistor 150 include: An insulating film containing at least oxygen is used. 60, and an insulating film used on the transistor 150 and the capacitor element 160. By using the insulating film having the above structure, the oxide semiconductor film of the transistor 150 can be The resistivity of the oxide semiconductor film 110 and the oxide semiconductor film 111 included in the capacitor 160 can be controlled. do.

[0095] In addition, an insulating film used in the capacitor 160, the transistor 150, and the capacitor 160 The insulating film used thereon can be configured as follows to improve the flatness of the conductive film 120. Specifically, the insulating films 114 and 116 are provided over the oxide semiconductor film 110. The insulating film 118 is formed by sandwiching the oxide semiconductor film 111 between the insulating film 116 and the insulating film 118. By providing the insulating film 114 over the oxide semiconductor film 111 so as to overlap with the oxide semiconductor film 111, The resistivity of the oxide semiconductor film 111 is controlled without providing an opening in the insulating films 114 and 116 at the position With such a configuration, the alignment of the liquid crystal formed on the conductive film 120 can be improved. can be made good.

[0096] In FIG. 8, the oxide semiconductor film 111 and the oxide semiconductor film 112 are formed and etched at the same time. The oxide semiconductor film 111a is formed at the same time so as to have a region overlapping with the oxide semiconductor film 110. The oxide semiconductor film 111a serves as a second gate electrode of the transistor 150. At this time, the gate insulating film for the second gate electrode is an insulating film. In other words, the transistor 150 has an oxide semiconductor film 110 and an oxide semiconductor film 116. Insulating films 114 and 116 are provided on the source electrode 112a and the drain electrode 112b. An oxide semiconductor film is provided over the insulating films 114 and 116 at a position overlapping with the oxide semiconductor film 110. and a conductive film 111a.

[0097] The oxide semiconductor film 111a is formed and etched simultaneously with the oxide semiconductor film 111. By forming them simultaneously, the number of process steps can be reduced. One aspect of the embodiment of the present invention is not limited thereto. The oxide semiconductor film 111a may be formed in a process different from that of the conductive film 111. Alternatively, the oxide semiconductor film 111a may be connected to a gate electrode 104. 104 and is supplied with a signal or potential different from that of the gate electrode 104. Good too.

[0098] In the transistor 150, the oxide semiconductor film 110 is used as a channel region. Therefore, the resistivity of the oxide semiconductor film 111 is higher than that of the oxide semiconductor film 111. Since the oxide semiconductor film 1 functions as an electrode, the oxide semiconductor film 1 has a lower resistivity than the oxide semiconductor film 110. A method for controlling the resistivity of the compound semiconductor film 110 and the oxide semiconductor film 111 will be described later.

[0099] The touch panel 310 includes a transistor 301, a transistor 150, and a The connection portion 306, the conductive film 317, the conductive film 120 constituting the liquid crystal element 308, and the oxide semiconductor The film 111 and the like.

[0100] FIG. 8 shows a cross section of two pixels as an example of the display unit 381. For example, the pixels are By selecting one of the pixels that exhibit red, green, or blue, For example, in the display unit 381 shown in FIG. R is a transistor 150, a capacitance element 160, a liquid crystal element 308, and a colored film 331R. The pixel 388G also includes a transistor (not shown), a capacitor element 160, and a liquid crystal It has an element 308 and a colored film 331G.

[0101] FIG. 8 shows an example in which a transistor 301 is provided as the driving circuit 382. is doing.

[0102] In FIG. 8, as an example of the transistor 301 and the transistor 150, a channel is formed. This shows an example in which a semiconductor layer is sandwiched between two gate electrodes. The transistor can have a higher field effect mobility than other transistors, It is possible to increase the on-current. As a result, it is possible to fabricate circuits capable of high-speed operation. Furthermore, it is possible to reduce the area occupied by the circuit section. By applying this transistor, the display panel or touch panel can be made larger or have higher resolution. Even if the number of wirings increases when This makes it possible to suppress display unevenness.

[0103] Note that the transistor 301 in the driver circuit 382 and the transistor in the display unit 381 The transistors 150 may have the same structure. The transistors may all be of the same structure, or may be of different structures. In addition, the transistors in the display unit 381 may all have the same structure. Alternatively, transistors having different structures may be used in combination.

[0104] FIG. 8 shows a liquid crystal element 308 with FFS (Fringe Field Switching) The liquid crystal element 308 is a conductive liquid crystal element. The conductive film 120, the liquid crystal 353, and the oxide semiconductor film 111 are included. The orientation of the liquid crystal 353 can be controlled by the electric field generated between the liquid crystal 353 and the body membrane 111 .

[0105] The conductive film 120 has a comb-like upper surface shape or an upper surface shape with slits (planar shape The oxide semiconductor film 111 is overlapped with the conductive film 120. In addition, in a region overlapping with the colored film 331R and the like, the conductive film 12 is formed on the oxide semiconductor film 111. There are parts where no 0s are placed.

[0106] In FIG. 8, the conductive film 120 functions as a pixel electrode, and the oxide semiconductor film 111 functions as a common electrode. In addition, the conductive layer 110 is provided in the upper layer and has a comb-like or slit-like upper surface. The conductive film 120 is used as a common electrode, and the oxide semiconductor film 111 provided below is used as a pixel electrode. In the touch panel 310 shown in FIG. 9, the oxide semiconductor film 111 may be used. It is electrically connected to the drain electrode 112b of the transistor 150. The touch sensor of the touch panel 310 has a conductive film 334 and a conductive film 120 as a pair of electrodes. It is composed of:

[0107] A connection portion 306 is provided in a region near the edge of the substrate 102. In this case, the conductive film 317 is electrically connected to the FPC 373 via a connection layer 319 . In FIG. 8, a part of the conductive film 317 and a conductive film formed by processing the same conductive film as the conductive film 120 are 3 shows an example in which the connection portion 306 is formed by laminating a film.

[0108] The surface of the substrate 372 facing the substrate 102 is provided with colored films 331R and 331G, a light-shielding film 332, and an insulating film. A conductive film 355 is provided on the surface of the substrate 372 opposite to the substrate 102. 34, a conductive film 335, a conductive film 341, etc. are provided.

[0109] The conductive film 334 and the conductive film 341 are electrically connected to each other. The conductive film 334 and the conductive film 341 are insulated from each other. It is preferable that the film 335 is formed at the same time by processing the same conductive film. The conductive film 341 may be integrated with the display unit 381. The portion corresponds to a conductive film 334 that functions as one electrode of the touch sensor, and the other This portion may also be referred to as a conductive film 341.

[0110] Here, the arrangement of the electrodes constituting the touch sensor will be described. 10 is a top view of a pair of touch sensor electrodes of a touch panel 310. The dashed dotted line Z1-Z2 corresponds to the display unit 381 shown in FIG.

[0111] The conductive film 334, which is one electrode of the touch sensor, is provided extending in the Y direction. The oxide semiconductor film 111, which is the other electrode of the touch sensor, extends in the X direction. The conductive film 335 has an area where it intersects with the conductive film 334. However, due to differences in function, the conductive film 334 is shown with different hatching. By electrically floating the conductive film 335, the conductive A change in potential of one of the conductive film 334 and the oxide semiconductor film 111 can be efficiently transmitted to the other. This makes it possible to increase the detection sensitivity of the touch sensor.

[0112] The colored films 331R and 331G and the light-shielding film 332 are provided on the substrate 102 side of the substrate 372. Also, an insulating film 355 is provided to cover the colored film 331R and the light-shielding film 332 (see FIG. 8). It is being done.

[0113] The insulating film 355 prevents impurities contained in the colored film 331R, the light-shielding film 332, etc. from penetrating into the liquid crystal 353. It functions as an overcoat to prevent diffusion.

[0114] The spacer 316 is provided on the insulating film 119 and adjusts the distance between the substrate 102 and the substrate 372. In FIG. 8, the spacer 316 and the structure on the substrate 372 side (for example, the insulating film 3 55, etc.) are in contact with each other, but they do not have to be in contact. Although an example in which the spacer 316 is provided on the substrate 102 side has been shown, it may be provided on the substrate 372 side. For example, it may be disposed between two adjacent pixels. Granular spacers may be used. For the granular spacers, materials such as silica may be used. However, it is preferable to use a material having elasticity such as organic resin or rubber. When the spacer is moved, the granular spacer may become crushed in the vertical direction.

[0115] In addition, in the conductive film 120, the insulating film 119, the insulating film 355, etc., the surface in contact with the liquid crystal 353 An alignment film for controlling the alignment of the liquid crystal 353 may be provided on the liquid crystal layer 353 .

[0116] At least the portions of the conductive film 334 and the conductive film 335 that overlap the colored film 331R and the like are transparent. It is preferable to use a material having optical properties.

[0117] In addition, when the touch panel 310 includes a transmissive liquid crystal display device, for example, a polarizing The two polarizing plates are arranged so as to sandwich the display unit 381 from above and below. The light from the backlight is incident through a polarizing plate. The orientation of the liquid crystal 353 is controlled by applying a voltage between the polarizing plate 111. The intensity of the light emitted from the backlight can be controlled. In the case of a colored film, light outside a specific wavelength range is absorbed, and the emitted light is, for example, red or blue. , or green light.

[0118] In addition to the polarizing plate, for example, a circular polarizing plate can be used. For example, a linear polarizing plate and a quarter-wave retardation plate can be laminated. This makes it possible to reduce viewing angle dependence.

[0119] In this example, an element to which the FFS mode is applied is used as the liquid crystal element 308. Liquid crystal elements that use various modes can be used, not limited to VA (Ve (Twisted Nematic) mode, TN (Twisted Nematic) mode, IPS (In Plane Switching) mode, ASM (Axial ly Symmetric aligned Micro-cell) mode, OCB( Optically Compensated Birefringence (Optical Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFL C (AntiFerroelectric Liquid Crystal) mode etc. An applied liquid crystal element can be used.

[0120] In addition, the touch panel 310 is provided with a normally black type liquid crystal display device, for example, a vertical alignment ( A transmissive liquid crystal display device using a vertical alignment (VA) mode may be used. The MVA (Multi-Domain Vertical Alignment) mode mode, PVA (Patterned Vertical Alignment) mode, A SV (Advanced Super View) mode, etc. can be used.

[0121] The liquid crystal element is an element that controls the transmission or non-transmission of light by the optical modulation action of liquid crystal. The optical modulation of liquid crystals is caused by the electric field applied to the liquid crystal (horizontal electric field, vertical electric field The liquid crystal used in the liquid crystal element is , Thermotropic Liquid Crystal, Low Molecular Weight Liquid Crystal, Polymer Liquid Crystal, Polymer Dispersed Liquid Crystal (PDLC:Po lymer Dispersed Liquid Crystal), Ferroelectric Liquid Crystal, Antiferroelectric Liquid Crystal Ferroelectric liquid crystals can be used. These liquid crystal materials can be cholesteric or These phases include nematic phase, smectic phase, cubic phase, chiral nematic phase, isotropic phase, etc.

[0122] As the liquid crystal material, either a positive type liquid crystal or a negative type liquid crystal may be used. It is only necessary to use an optimum liquid crystal material depending on the mode and design to be applied.

[0123] In addition, when the in-plane switching method is adopted, 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 a cholesteric liquid crystal is increased, the cholesteric The blue phase appears just before the transition from the black phase to the isotropic phase. In order to improve the temperature range, a liquid crystal composition containing a chiral agent of several weight percent or more is used. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent is used in the liquid crystal layer. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent has a short wavelength and is optically isotropic. The composition does not require alignment treatment and has low viewing angle dependency. Also, no alignment film is required. This eliminates the need for rubbing, preventing electrostatic damage caused by rubbing. This can prevent the liquid crystal display device from being damaged or broken during the manufacturing process.

[0124] In this configuration example, the touch panel 310 includes a conductive film 334 and an oxide semiconductor film 111. The capacitance formed on the oxide semiconductor layer can be used to detect touch operations. The conductive film 111 is connected to one of a pair of electrodes of the liquid crystal element 308 and one of a pair of electrodes of the touch sensor. It serves both purposes.

[0125] Here, the conductive film 120 and / or the conductive film 334 is a conductive material that transmits visible light. It is preferable to use a conductive material containing, for example, a metal oxide. For example, among the light-transmitting conductive materials described later, metal oxides can be used.

[0126] Alternatively, the conductive film 120 and / or the conductive film 334 may be formed in the same layer as other conductive films or semiconductor layers. It is preferable to use a metal oxide containing a metal element. When an oxide semiconductor is used for the semiconductor layer of a transistor, the conductive material containing the metal element is It is preferred to apply a conductive oxide.

[0127] In addition, a fixed potential is applied to the conductive film 334, thereby blocking electromagnetic noise from the outside. For example, when sensing is not performed, the conductive film 334 is covered with the liquid crystal 35. A constant potential that does not affect the switching of 3 can be supplied. For example, the ground potential, the common potential, or Alternatively, any constant potential can be used. 11 may be at the same potential.

[0128] In addition, by applying an appropriate potential to the conductive film 334, the conductive film 120 and the oxide semiconductor film The thickness direction component of the electric field (electric field line) generated between the electrode 111 is reduced. It is possible to more effectively orient the electric field in a direction approximately perpendicular to the thickness (horizontal direction). This suppresses alignment defects of the liquid crystal 353 and prevents problems such as light leakage. It is possible to do so.

[0129] It should be noted that if a finger or a stylus is placed on the conductive film 334, the conductive film 335 and the substrate 372, A substrate may be provided for direct contact with the detection object. In this case, it is preferable to provide a polarizing plate or a circular polarizing plate between the substrate and the protective layer. It is preferable to provide a protective layer (such as a ceramic coat). Inorganic insulating materials such as aluminum, yttrium oxide, and yttria-stabilized zirconia (YSZ) The substrate may be made of reinforced glass. The surface is physically or chemically treated by ion exchange or air cooling. It is possible to use a material in which a compressive stress is applied to the

[0130] [About each component] Each of the above components will be described below.

[0131] {substrate} The substrate of the touch panel can be made of a material having a flat surface. The substrate on the side from which the light is extracted is made of a material that transmits the light. For example, glass or quartz is used. Materials such as ceramic, sapphire, and organic resin can be used. Single crystal semiconductor substrates made of silicon carbide, polycrystalline semiconductor substrates, silicon germanium, etc. It is also possible to apply compound semiconductor substrates, SOI substrates, etc., and semiconductors can be formed on these substrates. A substrate provided with a semiconductor element may be used as the substrate.

[0132] In addition, when using a glass substrate as the substrate, the sixth generation (1500 mm × 1850 mm ), 7th generation (1870mm x 2200mm), 8th generation (2200mm x 2400mm ), 9th generation (2400mm x 2800mm), 10th generation (2950mm x 3400m By using a large-area substrate such as a GaN-based LCD, a large-sized display device can be manufactured. A flexible substrate is used as the plate, and transistors, capacitors, etc. are formed directly on the flexible substrate. This is also fine.

[0133] By using a thin substrate, the touch panel can be made lighter and thinner. Furthermore, by using a substrate having a thickness sufficient to provide flexibility, a flexible touch panel can be obtained. This can be achieved.

[0134] Examples of glass include non-alkali glass, barium borosilicate glass, and aluminophore glass. Usable materials include silicate glass.

[0135] Examples of materials having flexibility and transparency to visible light include materials having flexibility. Thickness of glass, polyethylene terephthalate (PET), polyethylene naphthalate Polyester resins such as (PEN), polyacrylonitrile resins, polyimide resins, methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PE S) Resin, polyamide resin, cycloolefin resin, polystyrene resin, polyamide imide resin, polyvinyl chloride resin, polytetrafluoroethylene (PTFE) resin, etc. In particular, it is preferable to use a material with a low thermal expansion coefficient, such as polyamide-imide. Resin, polyimide resin, PET, etc. can be suitably used. Uses substrates impregnated with resin or substrates with inorganic fillers mixed into organic resin to reduce the coefficient of thermal expansion Since the substrate using such a material is light in weight, The touch panel can also be made lighter.

[0136] In addition, the substrate on the side from which light is not extracted does not need to have light-transmitting properties. In addition to the above substrates, metal substrates using metal or alloy materials, ceramic substrates, or semiconductor substrates are also available. Metallic and alloy materials have high thermal conductivity, and the entire sealing substrate can be heated. Since the heat can be easily conducted, local temperature rise of the touch panel can be suppressed, which is preferable. In order to obtain flexibility and bendability, the thickness of the metal substrate should be between 10 μm and 200 μm. is preferable, and the thickness is more preferably 20 μm or more and 50 μm or less.

[0137] The material constituting the metal substrate is not particularly limited, but examples thereof include aluminum, copper, and nickel. Nickel, an aluminum alloy, a stainless steel alloy, or the like can be suitably used. Cut.

[0138] In addition, the surface of a conductive substrate can be oxidized or an insulating film can be formed on the surface to provide an insulating film. A substrate that has been subjected to a treatment may be used. For example, a coating method such as a spin coating method or a dip method may be used. The insulating film may be formed by using an electrodeposition method, a vapor deposition method, a sputtering method, or the like. In addition to leaving it in an atmosphere or heating it, an oxide film is formed on the surface of the substrate by anodizing or other methods. It may be possible to do so.

[0139] As the flexible substrate, a layer using the above-mentioned material is used to protect the surface of the touch panel from scratches, etc. Hard coat layers (e.g., silicon nitride layers) that protect the material from the pressure and layers made of materials that can disperse pressure The laminate may be formed by laminating a layer (e.g., an aramid resin layer) or the like. In order to prevent the deterioration of the life of the display element due to the above-mentioned problems, silicon nitride film and silicon oxynitride film are used. and permeable films containing nitrogen and silicon such as aluminum nitride films. It may have an insulating film with low water resistance.

[0140] The substrate may be formed by laminating a plurality of layers. In particular, the substrate may have a glass layer. This improves the barrier properties against water and oxygen, making it possible to create a highly reliable touch panel. do.

[0141] For example, a substrate having a glass layer, an adhesive layer, and an organic resin layer laminated thereon from the side closest to the display element is used. The thickness of the glass layer is preferably 20 μm or more and 200 μm or less. The thickness of the glass layer is 25 μm or more and 100 μm or less. It is possible to simultaneously achieve high barrier properties and flexibility. The thickness of the organic resin layer is 10 μm. The thickness of such an organic resin is set to be 200 μm or more, and preferably 20 μm or more and 50 μm or less. By providing this layer, it is possible to suppress breakage and cracks in the glass layer and improve the mechanical strength. By applying such a composite material of glass material and organic resin to a substrate, This makes it possible to produce a highly reliable and flexible touch panel.

[0142] {Transistor} The transistor includes a conductive film serving as a gate electrode, a semiconductor layer, and a a conductive film that functions as a drain electrode, and a conductive film that functions as a gate insulating film The above describes the case where a bottom-gate transistor is used. There are.

[0143] Note that there is no particular limitation on the structure of a transistor included in a touch panel of one embodiment of the present invention. For example, the transistor may be a staggered type transistor or an inverted staggered type transistor. In addition, the transistor structure may be either a top gate type or a bottom gate type. stomach.

[0144] The crystallinity of the semiconductor material used in the transistor is not particularly limited. A semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a partially crystalline region) If a semiconductor having crystallinity is used, the This is preferable because it is possible to suppress deterioration of the resistor characteristics.

[0145] In addition, the semiconductor material used in the transistor is, for example, a Group 14 element, a compound semiconductor, or the like. A conductor or an oxide semiconductor can be used for the semiconductor layer. A conductor, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used.

[0146] In particular, an oxide semiconductor can be used as a semiconductor in which a channel of a transistor is formed. It is particularly preferable to use an oxide semiconductor having a larger band gap than silicon. A semiconductor material with a wider band gap and lower carrier density than silicon is preferable. The use of such a compound is preferable because it can reduce the current in the off state of the transistor.

[0147] For example, the oxide semiconductor may contain at least indium (In) or zinc (Zn It is preferable that the oxide contains In-M-Zn (wherein M is Al, Ti, or G). a, Y, Zr, La, Ce, Sn, or Hf).

[0148] In particular, the semiconductor layer has a plurality of crystal parts, and the crystal parts have a c-axis aligned with a surface on which the semiconductor layer is formed. or oriented approximately perpendicular to the upper surface of the semiconductor layer and having no grain boundary between adjacent crystal portions. It is preferable to use an oxide semiconductor film having no insulating properties.

[0149] Such an oxide semiconductor does not have crystal grain boundaries, so that when the display panel is curved, The occurrence of cracks in the oxide semiconductor film due to stress is suppressed. Such oxide semiconductors are suitable for use in touch panels that are flexible and can be curved. It can be used.

[0150] In addition, by using such an oxide semiconductor as the semiconductor layer, the fluctuation of the electrical characteristics is suppressed. This makes it possible to realize a highly reliable transistor.

[0151] In addition, due to its low off-state current, the charge stored in the capacitance through the transistor can be released for a long period of time. By applying such a transistor to a pixel, It is also possible to stop the driving circuit while maintaining the grayscale of the image displayed in the display area. As a result, a display device with extremely reduced power consumption can be realized.

[0152] <Oxide Semiconductor Film> The oxide semiconductor film 110 and the oxide semiconductor film 111 contain at least indium (In), Zinc (Zn) and M (Al, Ti, Ga, Y, Zr, La, Ce, Sn, or Hf, etc.) It is preferable that the oxide film contains In-M-Zn oxide. In order to reduce the variation in the electrical characteristics of transistors using semiconductors, It is preferred that the heat exchanger includes a heat exchanger.

[0153] The stabilizer includes the metals listed above under M, such as gallium (Ga), sulphuric acid (SA), and gallium (Ga). Sn, Hf, Al, or Zr Other stabilizers include the lanthanide lanthanum (La). , Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium ( Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), lutetium (Lu), etc.

[0154] The oxide semiconductor films 110 and 111 may be formed of, for example, For example, In-Ga-Zn oxide, In-Al-Zn oxide, In-Sn-Zn oxide , In-Hf-Zn oxide, In-La-Zn oxide, In-Ce-Zn oxide, In-Pr-Zn oxide, In-Nd-Zn oxide, In-Sm-Zn oxide, I n-Eu-Zn oxide, In-Gd-Zn oxide, In-Tb-Zn oxide, In -Dy-Zn oxide, In-Ho-Zn oxide, In-Er-Zn oxide, In- Tm-Zn oxide, In-Yb-Zn oxide, In-Lu-Zn ​​oxide, In-S n-Ga-Zn oxide, In-Hf-Ga-Zn oxide, In-Al-Ga-Zn oxide Oxides, In-Sn-Al-Zn oxides, In-Sn-Hf-Zn oxides, In-H f-Al-Zn based oxides can be used.

[0155] In this case, the In-Ga-Zn oxide is an oxide having In, Ga, and Zn as main components. The ratio of In, Ga, and Zn does not matter. Metal elements other than n may be present.

[0156] The oxide semiconductor film 110 and the oxide semiconductor film 111 are formed using the same oxide among the above oxides. The oxide semiconductor film 110 and the oxide semiconductor film 111 may be formed by the same By using metal elements, the manufacturing cost can be reduced. For example, By using a metal oxide target, the manufacturing cost can be reduced. By using a metal oxide target having the above metal composition, the oxide semiconductor film 110 and the oxide The etching gas or the etching solution used for processing the compound semiconductor film 111 is shared. However, the oxide semiconductor film 110 and the oxide semiconductor film 111 may be made of the same metal. Even if the elements are the same, the composition may be different. For example, During the manufacturing process, metal elements in the film may be released, resulting in a different metal composition.

[0157] When the oxide semiconductor film 110 is an In-M-Zn oxide, the atomic ratio of In to M is When the sum of In and M is 100 atomic %, In is preferably 25 atomic %. % or more, M is less than 75 atomic %, and more preferably In is 34 atomic % or less. mic% and M less than 66 atomic%.

[0158] The oxide semiconductor film 110 has an energy gap of 2 eV or more, preferably 2.5 eV or more. In this way, the oxide semiconductor having a wide energy gap is By using a conductor, the off-state current of a transistor can be reduced.

[0159] The thickness of the oxide semiconductor film 110 is 3 nm to 200 nm, preferably 3 nm to 100 nm. 00 nm or less, and more preferably 3 nm or more and 50 nm or less.

[0160] The oxide semiconductor film 110 is an In-M-Zn oxide (wherein M is Al, Ga, Y, Zr, La, or C e, or Nd), the sputtering method used to deposit In-M-Zn oxide The atomic ratio of the metal elements in the target preferably satisfies In≧M and Zn≧M. The atomic ratio of metal elements in such a sputtering target is In:M:Zn=1:1. :1, In:M:Zn=1:1:1.2, In:M:Zn=3:1:2, In:M:Zn In:M:Zn=1:3:4, In:M:Zn=1:3:6, etc. The atomic ratio of the conductive film 110 is included in the above sputtering target as an error. This includes a variation of ±40% in the atomic ratio of the metallic elements.

[0161] As the oxide semiconductor film 110, an oxide semiconductor film with low carrier density is used. For example, The oxide semiconductor film 110 has a carrier density of 1×10 17 pieces / cm 3 Below, preferably 1 ×10 15 pieces / cm 3 Less than 1×10, more preferably 13 pieces / cm 3 The following is more preferred: 1×10 11 pieces / cm 3 The following oxide semiconductor film is used.

[0162] In addition, the semiconductor characteristics and electrical characteristics (field effect) of the required transistors are not limited to these. It is sufficient to use a material with an appropriate composition according to the required properties (e.g., the resultant mobility, threshold voltage, etc.). In order to obtain semiconductor characteristics of a transistor, the carrier density and impurity of the oxide semiconductor film 110 are The concentration of metals, defect density, atomic ratio of metal elements to oxygen, interatomic distance, density, etc. are appropriately adjusted. It is preferable.

[0163] The oxide semiconductor film 110 contains silicon or carbon, which is one of the Group 14 elements. As a result, oxygen vacancies increase in the oxide semiconductor film 110, causing the oxide semiconductor film 110 to become n-type. The concentrations of silicon and carbon in the nitride semiconductor film 110 (secondary ion mass spectrometry (SIMS) Concentration obtained by Secondary Ion Mass Spectrometry degrees), 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / c m 3 The following applies.

[0164] In addition, in the oxide semiconductor film 110, an alkali metal or alkali metal oxide obtained by SIMS is The concentration of alkaline earth metals is increased by 1×10 18 atoms / cm 3Less than or equal to 2 x 10 1 6 atoms / cm 3 Alkali metals and alkaline earth metals are oxide semiconductors. When the electrons combine with each other, carriers may be generated, increasing the off-state current of the transistor. For this reason, the alkali metal or alkaline earth metal of the oxide semiconductor film 110 may be It is preferable to reduce the concentration.

[0165] In addition, when the oxide semiconductor film 110 contains nitrogen, electrons that serve as carriers are generated, and The carrier density increases and it becomes easier to make the material n-type. Therefore, the transistor having the oxide semiconductor film tends to be normally on. In this case, it is preferable that the nitrogen content is reduced as much as possible. For example, The nitrogen concentration is 5×10 18 atoms / cm 3 It is preferable to do the following:

[0166] The oxide semiconductor film 110 may have a non-single crystal structure, for example. For example, CAAC-OS (C Axis Aligned-Crystalline Oxide Semiconductor), polycrystalline structure, microcrystalline structure (described later), Among non-single crystal structures, the amorphous structure has the highest defect level density, C AAC-OS has the lowest defect state density.

[0167] The oxide semiconductor film 110 may have an amorphous structure. For example, the atomic arrangement is disordered and has no crystalline components. Or, an oxide with an amorphous structure The film, for example, has a completely amorphous structure and does not have any crystalline portions.

[0168] Note that the oxide semiconductor film 110 may have an amorphous structure, a microcrystalline structure, a polycrystalline structure, or a A mixed film having two or more of the following regions may be used: a region of a CAAC-OS structure, a region of a single crystal structure, and a region of a crystalline structure. The mixed film may have, for example, an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, and the like. The layer structure is composed of two or more regions of either a CAAC-OS region or a single crystal structure region. There may be cases where this occurs.

[0169] Note that silicon may be used as a semiconductor in which a channel of a transistor is formed. Although amorphous silicon may be used as the capacitor, it is particularly preferable to use silicon having crystallinity. For example, microcrystalline silicon, polycrystalline silicon, single crystal silicon, etc. are used. In particular, polycrystalline silicon can be formed at a lower temperature than single crystal silicon. Moreover, it has higher field effect mobility and higher reliability than amorphous silicon. By applying such a polycrystalline semiconductor to a pixel, the aperture ratio of the pixel can be improved. Even when pixels are extremely densely packed, the gate driver and source driver circuits are located in the same area as the pixels. It is possible to form the components on a substrate, which reduces the number of components that make up an electronic device. .

[0170] {Conductive film} In addition to the gate, source, and drain of the transistor, the various wiring that makes up the touch panel Materials that can be used for conductive films such as wires and electrodes include aluminum, titanium, Chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, The material is a single-layer or multi-layer structure made of metal such as tungsten or an alloy that contains this metal as its main component. For example, a single layer structure of aluminum film containing silicon, aluminum on titanium film, A two-layer structure in which an aluminum film is laminated on a tungsten film; a two-layer structure in which an aluminum film is laminated on a tungsten film; - Two-layer structure with copper film laminated on magnesium-aluminum alloy film, copper film laminated on titanium film Two-layer structure with copper film laminated on tungsten film, two-layer structure with titanium film or titanium nitride film laminated on tungsten film A titanium film and an aluminum film or a copper film are laminated on the titanium film or the titanium nitride film. A three-layer structure is formed by forming a titanium film or titanium nitride film on the top of the molybdenum film or The molybdenum nitride film is laminated with an aluminum film on the molybdenum film or the molybdenum nitride film. A molybdenum film or a copper film is laminated on the copper film, and a molybdenum film or a molybdenum nitride film is further formed on the copper film. Transparent conductive materials containing indium oxide, tin oxide, or zinc oxide are also used. In addition, when copper containing manganese is used, the shape can be easily controlled by etching. This is preferable because it increases the

[0171] In addition, examples of conductive materials having light-transmitting properties include indium oxide and indium tin oxide (I TO: Indium Tin Oxide, Indium Zinc Oxide, Zinc Oxide, Gallium Conductive oxides such as zinc oxide doped with ruthenium or graphene can be used. are gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, Metallic materials such as cobalt, copper, palladium, or titanium, and alloy materials containing such metallic materials Alternatively, a nitride of the metal material (for example, titanium nitride) can be used. In addition, when a metal material or an alloy material (or a nitride thereof) is used, a light-transmitting In addition, a laminated film of the above materials may be used as the conductive film. For example, a laminated film of an alloy of silver and magnesium and indium tin oxide is used. This is preferable because it is possible to increase the electrical conductivity.

[0172] Alternatively, the conductive film is preferably made of an oxide semiconductor similar to that of the semiconductor layer. When the conductive film is formed, the conductive film exhibits a lower electrical resistance than a region in which a channel of the semiconductor layer is formed. , is preferably formed.

[0173] For example, such a conductive film can be used for the oxide semiconductor films 111 and 111a. Alternatively, the present invention can be applied to other conductive films having light-transmitting properties.

[0174] {Method for controlling resistivity of oxide semiconductor} An oxide semiconductor film that can be used for the oxide semiconductor film 110 and the oxide semiconductor films 111 and 111a The resistance of semiconductor films varies depending on the oxygen vacancies and / or the concentration of impurities such as hydrogen and water in the film. The oxide semiconductor film 110 and the oxide The semiconductor films 111 and 111a are subjected to a treatment that increases oxygen vacancies and / or impurity concentrations, or By selecting a treatment that reduces the elemental deficiency and / or impurity concentration, each oxide The resistivity of the semiconductor film can be controlled.

[0175] Specifically, the oxide semiconductor films 111 and 111a functioning as electrodes of the capacitor 160 are The oxide semiconductor film to be used is subjected to a plasma treatment to increase oxygen vacancies in the oxide semiconductor film. and / or by increasing impurities such as hydrogen and water in the oxide semiconductor film. In this way, an oxide semiconductor film having high carrier density and low resistivity can be obtained. An insulating film containing hydrogen is formed in contact with the semiconductor film, and the insulating film containing hydrogen, for example, insulating film 11 By diffusing hydrogen from 8 into the oxide semiconductor film, the carrier density is increased and the resistivity is reduced. The oxide semiconductor films 111 and 111a can be formed as oxide semiconductor films having low thermal conductivity. Thus, before the step of increasing oxygen vacancies in the film or diffusing hydrogen, the film is treated as a semiconductor. After this step, it functions as a conductor.

[0176] Note that when the plasma treatment is performed to increase oxygen vacancies in the oxide semiconductor film, If the thickness is too small, the increase in oxygen vacancies in the film may be uneven. When hydrogen is diffused into a semiconductor film, if the film thickness is large, impurities such as hydrogen and water in the film may be diffused. As a result, the resistivity of the oxide semiconductor film near the bottom surface may increase more than that of the oxide semiconductor film. The resistivity of the upper surface may be higher than that of the upper surface. Even if the resistivity of the oxide semiconductor film is sufficiently low, the oxide semiconductor film is not easily damaged by wiring from the bottom side. When the oxide semiconductor film is electrically connected to a conductive film such as a conductive film, the contact resistance between the oxide semiconductor film and the conductive film increases. On the other hand, the oxide semiconductor film has a large thickness so that it can function as a conductive film. For the above reasons, the thicknesses of the oxide semiconductor films 111 and 111a need to be It is preferable that the thickness is such that the resistivity is not biased in the direction. The thickness is preferably from 50 nm to 70 nm, and more preferably from 50 nm to 70 nm. More preferred.

[0177] On the other hand, the oxide semiconductor film 110 functioning as a channel region of the transistor 150 is an insulating By providing the insulating films 107, 114, and 116, the insulating films 106 and 118 containing hydrogen are formed. At least one of the insulating films 107, 114, and 116 contains oxygen. In other words, an insulating film capable of releasing oxygen is used to form an oxide semiconductor film. Oxygen can be supplied to the oxide semiconductor film 110. Alternatively, oxygen vacancies at the interface are filled, resulting in an oxide semiconductor film with high resistivity. Examples of the insulating film that can be used include a silicon oxide film and a silicon oxynitride film. can be used.

[0178] In order to obtain an oxide semiconductor film with low resistivity, an ion implantation method, an ion doping method, etc. Using techniques such as plasma immersion ion implantation, hydrogen, boron, and lithium are implanted. Nitrogen or nitrogen may be implanted into the oxide semiconductor film.

[0179] In order to obtain an oxide semiconductor film with low resistivity, the oxide semiconductor film is subjected to plasma treatment. For example, the plasma treatment may be performed using a rare gas (He, Ne, A Plasma using gas containing one or more of the following: r, Kr, Xe), hydrogen, and nitrogen. More specifically, plasma treatment in an Ar atmosphere and a mixture of Ar and hydrogen are used. Plasma treatment in a mixed gas atmosphere, plasma treatment in an ammonia atmosphere, and plasma treatment in an Ar and ammonia atmosphere. Plasma treatment in a mixed gas atmosphere of nitric acid or in a nitrogen atmosphere. Some examples include:

[0180] By the above plasma treatment, the oxide semiconductor film is formed into a lattice from which oxygen has been desorbed (or This creates oxygen vacancies in the area (the area separated from the surface). These oxygen vacancies may be a cause of carrier generation. In addition, in the vicinity of the oxide semiconductor film, more specifically, in the lower side or the upper side of the oxide semiconductor film, When hydrogen is supplied from the insulating film adjacent to the side, the oxygen vacancies are combined with the hydrogen, forming a carrier In some cases, electrons that are rearranged may be generated.

[0181] On the other hand, an oxide semiconductor film in which oxygen vacancies are filled and the hydrogen concentration is reduced is highly purified and intrinsic. Alternatively, it can be said that the oxide semiconductor film is substantially highly purified and intrinsic. The carrier density of the oxide semiconductor film is 8×10 11 pieces / cm 3 Less than 1 x 10 1 1 / cm 3 less than 1×10 10 pieces / cm 3 It means that the purity is less than 100%. A highly pure or substantially highly pure intrinsic oxide semiconductor film has a small carrier generation source. In addition, the carrier density can be reduced. Since some oxide semiconductor films have a low density of defect states, the density of trap states can be reduced. Cut.

[0182] In addition, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a significantly low off-state current. Very small, with a channel width of 1×10 6 Even if the device has a channel length of 10 μm, When the voltage between the source electrode and the drain electrode (drain voltage) is in the range of 1V to 10V, The current is below the measurement limit of the semiconductor parameter analyzer, i.e., 1×10 -13 A and below Therefore, the above-mentioned high purity intrinsic or substantially high purity intrinsic The oxide semiconductor film 110 is used as a channel region of a transistor. The transistor 150 has small fluctuations in electrical characteristics and is highly reliable.

[0183] The insulating film 118 may be, for example, an insulating film containing hydrogen, in other words, capable of releasing hydrogen. By using an insulating film capable of absorbing hydrogen, typically a silicon nitride film, the oxide semiconductor film 111 can be The insulating film capable of releasing hydrogen is one having a hydrogen concentration of 1000 or less. Degree is 1×10 22 atoms / cm 3 It is preferable that the insulating film is an oxide film. By forming the insulating film 111 in contact with the semiconductor films 111 and 111a, In this manner, hydrogen can be effectively contained in the oxide semiconductor film 110 and the oxide By changing the configuration of the insulating film in contact with the semiconductor film 111, 111a, the oxide semiconductor film The insulating film 106 can be made of the same material as the insulating film 118. By using silicon nitride as the insulating film 106, The released oxygen is supplied to the gate electrode 104, and oxidation of the gate electrode 104 can be suppressed.

[0184] Hydrogen contained in the oxide semiconductor film reacts with oxygen that is bonded to metal atoms to form water. In this case, oxygen vacancies are formed in the lattice from which oxygen has been desorbed (or in the portion from which oxygen has been desorbed). When hydrogen enters the electron carrier, it can generate electrons. When it bonds with oxygen, which bonds with a metal atom, it may generate electrons, which act as carriers. Therefore, the oxide semiconductor film 111 provided in contact with the insulating film containing hydrogen is The oxide semiconductor film has a higher carrier density than the oxide semiconductor film 110.

[0185] The oxide semiconductor film 110 in which the channel region of the transistor 150 is formed is Specifically, in the oxide semiconductor film 110, S The hydrogen concentration obtained by IMS is 2×10 20 atoms / cm 3 Less than or equal to 5, preferably ×10 19 atoms / cm 3 Less than or equal to 1×10 19 atoms / cm 3 Below Bottom, 5×10 18 atoms / cm 3 Less than 1 x 10 18 atoms / cm 3 Less than or equal to 5×10 17 atoms / cm 3 Less than 1×10, more preferably 16 atoms / cm 3 The following applies.

[0186] On the other hand, the oxide semiconductor film 111 functioning as an electrode of the capacitor 160 and the transistor The oxide semiconductor film 111a functioning as the second gate electrode of the oxide semiconductor film 150 is 10 and has a higher hydrogen concentration and / or an amount of oxygen vacancies and a lower resistivity. The hydrogen concentration in the oxide semiconductor films 111 and 111a is 8×10 19 atoms / cm 3 More than 1×10 20 atoms / cm 3 More preferably, 5×10 20 atoms / cm 3 In addition, compared with the oxide semiconductor film 110, The hydrogen concentration in the films 111 and 111a is at least twice as high, and preferably at least 10 times as high. The resistivity of the oxide semiconductor films 111 and 111a is 1×1 of the resistivity of the oxide semiconductor film 110. 0 -8 more than 1x10-1 It is preferable that the ratio is less than 1×10 -3 Ωcm More than 1×10 4 Ωcm, and more preferably a resistivity of 1×10 -3 Ωcm or more 1×1 0 -1 It is preferable that the resistivity is less than Ωcm.

[0187] Insulating film The insulating films 106 and 107 functioning as the gate insulating film of the transistor 150 are Plasma CVD (CVD: Chemical Vapor Deposition) method, By sputtering or the like, a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, Silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film, dioxide film ZrO2 film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film The insulating film may include at least one of a cerium oxide film and a neodymium oxide film. It is possible to form the insulating films 106 and 107 in a laminated structure, but to form a single insulating film selected from the above-mentioned materials. A layer insulating film may be used.

[0188] The insulating film 106 functions as a blocking film that suppresses oxygen permeation. For example, , excess oxygen is supplied to the insulating films 107, 114, and 116 and / or the oxide semiconductor film 110. In this case, the insulating film 106 can suppress the permeation of oxygen.

[0189] Note that the oxide semiconductor film 110 which functions as a channel region of the transistor 150 The insulating film 107 is preferably an oxide insulating film, and has an oxide content in excess of the stoichiometric composition. It is more preferable that the insulating film 1 has a region containing oxygen (an oxygen excess region). The insulating film 107 is capable of releasing oxygen. In order to provide the insulating film 107, for example, the insulating film 107 may be formed in an oxygen atmosphere. Oxygen may be introduced into the insulating film 107 to form an oxygen excess region. These include ion implantation, ion doping, plasma immersion ion implantation, and plasma Zuma processing or the like can be used.

[0190] Furthermore, when hafnium oxide is used for the insulating films 106 and 107, the following effects are obtained. Hafnium oxide has a higher dielectric constant than silicon oxide and silicon oxynitride. Therefore, compared to the case where silicon oxide is used, the thickness of the insulating films 106 and 107 can be made larger. Therefore, the leakage current due to the tunnel current can be reduced. Furthermore, it is possible to realize a transistor with a small capacitance. Hafnium oxide has a higher dielectric constant than hafnium oxide having an amorphous structure. To make a transistor with a small off-state current, hafnium oxide with a crystalline structure is used. Examples of the crystal structure include monoclinic and cubic systems. However, one aspect of the present invention is not limited to these.

[0191] In this embodiment, a silicon nitride film is formed as the insulating film 106, and the insulating film 107 is The silicon oxide film is formed as a result of the above. The silicon nitride film has a lower dielectric constant than the silicon oxide film. The film thickness required to obtain the same capacitance as a silicon oxide film is large, so it is suitable for transistors. The insulating film 108 that functions as the gate insulating film of the transistor 150 includes a silicon nitride film. This makes it possible to physically thicken the insulating film. By suppressing the voltage drop and improving the dielectric strength, electrostatic damage to the transistor 150 is suppressed. It is possible.

[0192] <Protective insulating film> The insulating films 114, 116, and 118 function as protective insulating films for the transistor 150. is a silicon oxide film, a silicon oxynitride film, etc., which is formed by plasma CVD method, sputtering method, etc. film, silicon oxynitride film, silicon nitride film, aluminum oxide film, hafnium oxide film, oxide Yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film An insulating film containing one or more of a sodium film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film. can be used, respectively.

[0193] In addition, the oxide semiconductor film 110 which functions as a channel region of the transistor 150 The insulating film 114 is preferably an oxide insulating film that can release oxygen. In other words, an insulating film capable of releasing oxygen is used. The insulating film 114 has a region containing excess oxygen (oxygen excess region). In order to provide an oxygen excess region in the insulating film 114, for example, the insulating film 114 may be formed in an oxygen atmosphere. Alternatively, oxygen may be introduced into the insulating film 114 after it is formed to form an oxygen excess region. The methods of introducing elements include ion implantation, ion doping, plasma immersion ion implantation, and The implantation method, plasma treatment, etc. can be used.

[0194] By using an insulating film capable of releasing oxygen as the insulating film 114, Oxygen is transferred to the oxide semiconductor film 110 which functions as a channel region of the transistor 150. It is possible to reduce the amount of oxygen vacancies in the semiconductor film 110. For example, The surface temperature of the film measured by TDS analysis is 100°C to 700°C. or less, or the amount of oxygen molecules released in the range of 100°C to 500°C is 1.0 x 1 0 18 molecule / cm 3 By using the insulating film as described above, the oxide semiconductor film 110 can be prevented from being easily damaged. The amount of elemental deficiency can be reduced.

[0195] In addition, it is preferable that the insulating film 114 has a small amount of defects. Typically, the insulating film 114 has a small amount of defects as determined by ESR measurement. The spin density of the signal at g=2.001 originating from the silicon dangling bond is 3×10 17 spins / cm 3 This is because the insulating film 114 is preferably If the density of defects is high, oxygen is bound to the defects, and the oxygen in the insulating film 114 is reduced. In addition, the insulating film 114 and the oxide semiconductor film 110 are It is preferable that the amount of defects at the interface between the oxide and the metal oxide layer is small. The spin of the signal that appears when the g value due to defects in the semiconductor film 110 is 1.89 or more and 1.96 or less Density is 1×10 17 spins / cm 3 It is preferably below the lower limit of detection. stomach.

[0196] In the insulating film 114, all of the oxygen that has entered the insulating film 114 from the outside is Alternatively, some of the oxygen that has entered the insulating film 114 from the outside may move to the outside of the insulating film 114. In some cases, oxygen may remain in the insulating film 114. In addition, oxygen may enter the insulating film 114 from the outside, and When oxygen contained in the insulating film 114 moves to the outside of the insulating film 114, In some cases, oxygen transfer may occur due to the insulating film 114 being made of an oxide that can transmit oxygen. When the oxide insulating film is formed, oxygen desorbed from the insulating film 116 provided on the insulating film 114 can be transferred to the oxide semiconductor film 110 through the insulating film 114.

[0197] The insulating film 114 is formed using an oxide insulating film having a low density of states caused by nitrogen oxides. Note that the density of states due to the nitrogen oxides can be determined by the valence The energy of the top of the electron band (E V_OS ) and the conduction band minimum energy of the oxide semiconductor film (E C_OS ) may be formed between the oxide insulating film. Silicon oxynitride film with low nitrogen oxide emission or aluminum oxynitride film with low nitrogen oxide emission A thin film or the like can be used.

[0198] In addition, the silicon oxynitride film, which emits a small amount of nitrogen oxide, was found to have a low nitrogen oxide emission rate in the TDS analysis. This is a film that releases more ammonia than oxide, and typically releases ammonia molecules. Output is 1×10 18 molecule / cm 3 5×10 or more 19 molecule / cm 3 The following is the case. The amount of monia released is determined when the surface temperature of the membrane is 50°C or higher and 650°C or lower, preferably 50°C or higher and 55°C or lower. This is the amount released by heating at 0℃ or below.

[0199] Nitrogen oxides (NO x , x is greater than 0 and less than or equal to 2, preferably greater than or equal to 1 and less than or equal to 2), typically NO or NO forms a level in the insulating film 114 or the like. The oxides of nitrogen are located within the energy gap of the insulating film 114 and the When the oxide semiconductor film 110 and the insulating film 114 are diffused to the interface, the level of the oxide semiconductor film 110 is absorbed by the electrons on the insulating film 114 side. As a result, the trapped electrons may penetrate into the insulating film 114 and the oxide semiconductor. Since it remains near the interface with the conductor film 110, it shifts the threshold voltage of the transistor in the positive direction. This causes them to do so.

[0200] Nitrogen oxide reacts with ammonia and oxygen during heat treatment. The nitrogen oxide contained in the insulating film 116 reacts with ammonia contained in the insulating film 116 during the heat treatment. Therefore, the amount of nitrogen oxide contained in the insulating film 114 is reduced. Electrons are less likely to be trapped at the interface between the oxide semiconductor film 110 and the oxide semiconductor film 110.

[0201] By using the oxide insulating film as the insulating film 114, the threshold voltage of the transistor It is possible to reduce the shift in the electrical characteristics of the transistor. can.

[0202] Heat treatment in the manufacturing process of a transistor is typically performed at a temperature of less than 400° C. or less than 375° C. The insulating film 114 is heated for 10 min (preferably, 340° C. or more and 360° C. or less). In the spectrum obtained by ESR measurement below 0 K, the g value is 2.037 or more and 2.03 a first signal with a g value of 0.9 or less, a second signal with a g value of 0.25 or more and 0.3 or less, and A third signal with a g value between 1.964 and 1.966 is observed. The split width of the null and the second signal, and the split width of the second signal and the third signal The split width is about 5 mT in the X-band ESR measurement. The g value is 2.037. The first signal has a g value of 2.039 or more, and the second signal has a g value of 2.001 or more, and The sum of the spin densities of the third signal with g values ​​between 1.964 and 1.966 The total is 1 x 10 18 spins / cm 3 is less than 1×10 17 spins / cm 3 More than 1×10 18 spins / cm 3 is less than.

[0203] In addition, the g value in the ESR spectrum below 100K is 2.037 to 2.039. The first signal has a g value of 2.001 to 2.003, and the second signal has a g value of 1 The third signal, between .964 and 1.966, is nitrogen oxide (NO x , x is greater than 0 Representative examples of nitrogen oxides are: Examples include nitrogen monoxide and nitrogen dioxide. That is, the g value is between 2.037 and 2.039. a first signal having a g value of 2.001 to 2.003, and a second signal having a g value of The lower the sum of the spin densities of the third signals between 1.964 and 1.966, the more acidic the signal is. This means that the nitride insulating film contains a small amount of nitrogen oxide.

[0204] The nitrogen concentration of the oxide insulating film measured by SIMS is 6×10 20 atoms / cm 3 The following is the result.

[0205] The substrate temperature is between 220℃ and 350℃, and PEC using silane and nitrous oxide is used. By forming the oxide insulating film by the VD method, a dense and hard film can be obtained. It can be formed.

[0206] The insulating film 116 formed in contact with the insulating film 114 is an oxygen-containing film having a stoichiometric composition. The oxide insulating film is formed using an oxide insulating film containing more oxygen than the stoichiometric composition. When the oxide insulating film contains more oxygen than the stoichiometric composition, part of the oxygen is released by heating. The oxide insulating film containing more oxygen than the oxygen that satisfies the composition of the oxide insulating film is converted into oxygen atoms by TDS analysis. The calculated oxygen release rate is 1.0 x 10 19 atoms / cm 3 More than 3.0x, preferably 10 20 atoms / cm 3 The oxide insulating film is as described above. The surface temperature of the film is in the range of 100°C to 700°C or 100°C to 500°C. The range is preferably 100-200 mm.

[0207] In addition, it is preferable that the insulating film 116 has a small amount of defects. The spin density of the signal at g=2.001 originating from the silicon dangling bond is 1.5×10 18 spins / cm 3 Less than or even 1×10 18 spins / cm 3 Below Note that the insulating film 116 is preferably made of an oxide semiconductor material as compared with the insulating film 114. Since it is separated from the film 110 , it may have a higher defect density than the insulating film 114 .

[0208] The thickness of the insulating film 114 is 5 nm to 150 nm, preferably 5 nm to 50 nm. The thickness of the insulating film 116 can be set to 10 nm or less and preferably 30 nm or less. The thickness can be set to 30 nm or more and 500 nm or less, preferably 150 nm or more and 400 nm or less. Cut.

[0209] In addition, the insulating films 114 and 116 can be made of the same material, so that the insulating films In some cases, the interface between the film 114 and the insulating film 116 cannot be clearly seen. In this embodiment, the interface between the insulating film 114 and the insulating film 116 is shown by a dashed line. In the embodiment, the two-layer structure of the insulating film 114 and the insulating film 116 has been described. For example, the insulating film 114 may have a single layer structure, the insulating film 116 may have a single layer structure, or the insulating film 116 may have a three-layer structure. A laminated structure of more than one layer may also be used.

[0210] The insulating film 118 that functions as the dielectric film of the capacitance element 160 is a nitride insulating film. In particular, a silicon nitride film has a higher relative dielectric constant than a silicon oxide film, and is therefore preferable. Since the thickness required to obtain the same capacitance as that of a silicon oxide film is large, the conductor The insulating film 118 that functions as a dielectric film contains a silicon nitride film, so that the insulating film can be physically Therefore, the decrease in the dielectric strength of the capacitance element 160 can be suppressed, and The dielectric strength can be improved to suppress electrostatic breakdown of the capacitance element 160. The film 118 reduces the resistivity of the oxide semiconductor film 111 that functions as an electrode of the capacitor 160. It also has the function of

[0211] The insulating film 118 also blocks oxygen, hydrogen, water, alkali metals, alkaline earth metals, and the like. By providing the insulating film 118, the insulating film 118 can prevent the formation of a dielectric film from the oxide semiconductor film 110. The diffusion of oxygen to the outside, the diffusion of oxygen contained in the insulating films 114 and 116 to the outside, and the diffusion of oxygen from the outside Therefore, it is possible to prevent hydrogen, water, and the like from entering the oxide semiconductor film 110. A nitride insulating film having a blocking effect against silicon, water, alkali metals, alkaline earth metals, etc. Instead, an oxide insulating film having a blocking effect against oxygen, hydrogen, water, and the like may be provided. As an oxide insulating film having a blocking effect against oxygen, hydrogen, water, and the like, aluminum oxide is used. , aluminum oxide, gallium oxide, gallium oxide, yttrium oxide, nitric oxide Examples of such oxides include yttrium nitride, hafnium oxide, and hafnium oxynitride.

[0212] Examples of insulating materials that can be used for flattening films, overcoats, spacers, etc. include In addition to resins such as acrylic and epoxy resins and resins with siloxane bonds, silicon oxide, acid Inorganic insulating materials such as silicon nitride, silicon oxynitride, silicon nitride, and aluminum oxide Fees can be used.

[0213] {adhesive layer} The adhesive layer is made of a hardening resin such as a thermosetting resin, a photocurable resin, or a two-liquid mixed hardening resin. For example, acrylic resin, polyurethane, epoxy resin, or silicone can be used. A resin having a hydroxyl bond can be used.

[0214] {Connection Layer} The connection layer is made of anisotropic conductive film (ACF). conductive film) and anisotropic conductive paste (ACP) Conductive Paste) can be used.

[0215] {Colored film} Materials that can be used for the colored film include metal materials, resin materials, pigments, and dyes. Examples of such materials include resin materials.

[0216] The above is a description of each component.

[0217] [Cross-sectional configuration example 2] FIG. 11 shows an example of a cross-sectional configuration of a touch panel that is partially different from the above example. Note that we will omit the explanation of the parts that overlap with the above and will only explain the differences. .

[0218] FIG. 11 shows a substrate 372 on the display surface side thereof, on which conductive films 334, 335, 341 and an FPC 375 are provided. The oxide semiconductor film 111 functioning as a common electrode of the liquid crystal element 308 is not provided. However, it also functions as a pair of electrodes of the touch sensor. A semiconductor film 111b and a conductive film 104a extending in a direction perpendicular to the oxide semiconductor film 111b. and an oxide semiconductor film 111c electrically connected to the first electrode 111b function as a pair of electrodes of a touch sensor. With this configuration, the process can be further simplified compared to the configuration shown in FIG. Note that the oxide semiconductor film 111c is provided over the insulating films 108, 114, and 116. The conductive film 104a is electrically connected to the conductive film 104a through the opening 333. It is formed at the same time as the gate electrode 104 using the same material.

[0219] Here, the arrangement of the electrodes constituting the touch sensor will be described. 1 is a top view schematic diagram of a pair of touch sensor electrodes included in the touch panel 310 shown in FIG. 11. The dashed dotted line Z3-Z4 shown in FIG. 2(A) corresponds to the display unit 381 shown in FIG.

[0220] The oxide semiconductor film 111b, which is one electrode of the touch sensor, is provided to extend in the Y direction. The oxide semiconductor film 111c which is the other electrode of the touch sensor has an opening 333. The conductive film 104a is electrically connected to the conductive film 104a via an oxide film. It has a region intersecting with the semiconductor film 111b.

[0221] In addition, as a conductive film extending in one direction, the source electrode 112a is used instead of the conductive film 104a. In addition, a conductive film 112 formed at the same time using the same material as the drain electrode 112b is applied. In FIG. 12B, the oxide semiconductor film 111 1 shows an example in which the conductive film 112 extends in the Y direction and the oxide semiconductor film 114 extends in the X direction. The conductive film 112 is connected to the insulating film 118 through an opening 336 provided in the insulating film 118 (not shown). and electrically connected to the

[0222] [Other configuration examples] Note that one embodiment of the present invention is not limited to the above-described exemplary configurations and may have various configurations. .

[0223] <Peripheral circuits> The peripheral circuits may be configured not to be integrally formed. The circuit for driving the pixel and the circuit for driving the pixel can be formed separately. These functions may be realized by one circuit.

[0224] In addition, either the conductive film in the X direction or the conductive film (electrode) in the Y direction of the touch sensor A driver circuit for selecting the conductive film can also be formed integrally with the TFT.

[0225] The circuit that drives the touch sensor is the gate driver side that drives the pixels, or the source driver side. It may be located on either side of the driver.

[0226] In addition, it is electrically connected to the conductive film (electrode) in the X direction or the conductive film (electrode) in the Y direction of the touch sensor. Of the two circuits, it is preferable to use an IC as the circuit having the detection function. In this case, it is preferable that the conductive film is controlled by the IC via an FPC.

[0227] <Conductive film (electrode) material of touch sensor> A pair of conductive films constituting the touch sensor is connected to a common electrode and a pixel electrode constituting a liquid crystal element. It is preferable to use the same material as that of the

[0228] Alternatively, it may be made of a metal film processed into a mesh shape (also called metal mesh). .

[0229] At least one of the conductive film in the X direction or the conductive film in the Y direction (electrode) of the touch sensor The resistance can be reduced by providing a metal film directly below or above the In the case of a laminated structure of a conductive film containing a metal oxide and a conductive film containing a metal, It is preferable to form the insulating film by a patterning technique using a mask, since this simplifies the process. .

[0230] <Wiring that connects the conductive film (electrodes) of the touch sensor> At the intersection of the X-direction conductive film and the Y-direction conductive film of the touch sensor, When a bridge structure is realized using the conductive film, for example, the conductive film is used as a gate electrode of a transistor. The conductive film in the X direction is routed horizontally across the entire pixel in parallel with the gate line. Alternatively, the conductive film is formed on the same surface as the source and drain electrodes of the transistor. The conductive film in the Y direction is parallel to the source line and is routed vertically across the entire pixel. A contact portion is formed in the pixel. Alternatively, the conductive film is used as a conductive film that functions as a common electrode. The same conductive film as the pixel electrode or a conductive film on the same surface as the pixel electrode may be used. good.

[0231] (Conductive film (electrode) of touch sensor and conductive film (electrode) of liquid crystal element) The conductive film (electrode) with slits arranged on the top is used as a pixel electrode, and the A conductive film (electrode) provided across multiple pixels is called a common electrode (also called a common electrode). ) can be used.

[0232] Alternatively, a conductive film ( The upper electrode is used as a common electrode, and the lower conductive film (electrode) is used as a pixel electrode. It is possible.

[0233] The conductive film in the X direction of the touch sensor is called a conductive film that functions as a pixel electrode or a common electrode. The insulating film may also function as a conductive film.

[0234] Alternatively, the conductive film in the Y direction of the touch sensor may be a conductive film that functions as a pixel electrode or The conductive film may also function as a monitor electrode.

[0235] In addition, the conductive film in the X direction of the touch sensor is a conductive film to which a pulse voltage is applied or a current is detected. In this case, the conductive film in the Y direction of the touch sensor may be Just do the other one.

[0236] In addition, the conductive film functioning as a common electrode is provided across a plurality of pixels. Alternatively, for example, a common gate electrode formed of a conductive film on the same surface as the gate electrode of a transistor may be used. In this case, the conductive layer functions as a common electrode. The membrane may have an island shape.

[0237] <Opposite substrate> A substrate (also called an opposing substrate) is provided opposite a substrate on which a transistor or the like is provided. When a conductive film is provided in the X direction or Y direction of the touch sensor, the It is preferable to place a light-shielding film on the side of the light-shielding film.

[0238] In addition, when one electrode of a liquid crystal element such as a TN mode or MVA mode is formed on the opposing substrate, In the portion overlapping with the conductive film of the touch sensor provided on the opposing substrate, a slit is provided in the electrode. It is preferable to provide such a function.

[0239] In addition, in FFS mode, IPS mode, etc., a pair of electrodes is connected to a transistor, etc. Even when the liquid crystal display device is formed on a substrate that is opposite to the liquid crystal display device, a conductive film that controls the alignment of the liquid crystal is provided on the opposite substrate. In this case, the conductive film may have a groove at the portion overlapping the conductive film of the touch sensor. It is preferable to provide a slot.

[0240] <Driving method> As a method for driving the touch sensor, for example, one horizontal period (one gate selection) for driving the pixel is In this case, a method of sensing (scanning) the corresponding row during the gap between the pixel selection periods can be used. Alternatively, one frame period can be divided into two, with all pixels written in the first half and sensing in the second half. You may also search for

[0241] [Method of manufacturing transistors, capacitors, etc.] Next, the transistor 150, the capacitor element 160, and the and forming a pair of electrodes (the oxide semiconductor film 111 and the conductive film 120) that constitute the liquid crystal element 308. An example of the manufacturing method will be described with reference to FIGS.

[0242] First, the gate electrode 104 is formed on the substrate 102. Then, the substrate 102 and the gate An insulating film 108 including insulating films 106 and 107 is formed on the electrode 104 (see FIG. 25(A)). ).

[0243] The substrate 102, the gate electrode 104, and the insulating films 106 and 107 are the same as those described above. The substrate 1 can be formed by selecting the material from the materials listed above. A glass substrate is used as the gate electrode 102, and a tungsten conductive film is used as the gate electrode 104. A silicon nitride film capable of releasing hydrogen is used as the insulating film 106. The insulating film 107 is a silicon oxynitride film capable of releasing oxygen.

[0244] The gate electrode 104 is formed by depositing a conductive film on the substrate 102 so that a desired region of the conductive film remains. The pattern can be formed as shown in FIG. 1 and then etching away unnecessary areas.

[0245] Next, an oxide semiconductor film 110 is formed on the insulating film 108 at a position overlapping with the gate electrode 104. (See FIG. 25(B)).

[0246] The oxide semiconductor film 110 can be formed by selecting from the materials listed above. In this embodiment, the oxide semiconductor film 110 is made of In-Ga-Zn The oxide film (In:Ga:Zn=1:1:1.2 [atomic ratio] metal oxide target was used. For use.) is used.

[0247] The oxide semiconductor film 110 is formed by depositing an oxide semiconductor film over the insulating film 108 and then The semiconductor film is patterned so that the desired areas remain, and then the unwanted areas are etched away. This can be formed.

[0248] After the oxide semiconductor film 110 is formed, heat treatment is preferably performed. 650°C or less, preferably 300°C to 500°C, more preferably 350°C to 45°C At temperatures below 0°C, in an inert gas atmosphere, or an atmosphere containing 10 ppm or more of oxidizing gas, or The heat treatment may be performed in a reduced pressure atmosphere. After that, an oxidizing gas is added at a concentration of 10 ppm or more in order to compensate for oxygen released from the oxide semiconductor film 110. The heat treatment may be performed in an atmosphere containing oxidized silicon. Impurities such as hydrogen and water can be removed from at least one of the semiconductor films 110. Note that the heat treatment may be performed before the oxide semiconductor film 110 is processed into an island shape.

[0249] Note that a stable electric current is generated in the transistor 150 in which the oxide semiconductor film 110 is used as a channel region. In order to provide the above characteristics, impurities in the oxide semiconductor film 110 are reduced and the oxide semiconductor film 1 It is useful to have 10 be true or substantially true.

[0250] Next, a conductive film is formed over the insulating film 108 and the oxide semiconductor film 110. The insulating film is then patterned so that the desired area remains, and then the unnecessary area is etched away. A source electrode 112a and a drain electrode 112b are formed on the oxide semiconductor film 110. (See FIG. 25(C)).

[0251] The source electrode 112a and the drain electrode 112b are made of the above-listed materials. In this embodiment, the source electrode 112a and The drain electrode 112b is made of a tungsten film, an aluminum film, and a titanium film. A three-layer laminated structure is used.

[0252] After the source electrode 112a and the drain electrode 112b are formed, the oxide semiconductor film 1 The surface of the substrate 10 may be cleaned. For example, the cleaning method may be a cleaning method using a chemical solution such as phosphoric acid. By performing cleaning using a chemical solution such as phosphoric acid, the oxide semiconductor film 110 can be Impurities attached to the surface (for example, impurities contained in the source electrode 112a and the drain electrode 112b) However, this cleaning is not always necessary, and in some cases, In some cases, cleaning may not be necessary.

[0253] In addition, the process of forming the source electrode 112a and the drain electrode 112b and the cleaning process In one or both of the steps, the source electrode 112a of the oxide semiconductor film 110, And the area exposed from the drain electrode 112b may become thin.

[0254] Next, the insulating film 108, the oxide semiconductor film 110, the source electrode 112a, and the drain electrode The insulating films 114 and 116 are formed on the insulating film 112b. The pattern is then formed so that an unnecessary region remains, and then the unnecessary region is etched to form an opening 141. (See FIG. 25(D)).

[0255] After the insulating film 114 is formed, the insulating film 116 is successively formed without exposing it to the air. After the insulating film 114 is formed, it is preferable to adjust the flow rate, pressure, and temperature of the source gas without exposing the insulating film 114 to the air. By adjusting one or more of the frequency power and the substrate temperature, the insulating film 116 is continuously formed. The concentration of impurities derived from atmospheric components can be reduced at the interface between the insulating film 114 and the insulating film 116. At the same time, oxygen contained in the insulating films 114 and 116 is transferred to the oxide semiconductor film 110. As a result, the amount of oxygen vacancies in the oxide semiconductor film 110 can be reduced. .

[0256] In addition, in the process of forming the insulating film 116, the insulating film 114 serves as a protection film for the oxide semiconductor film 110. Therefore, the power density can be reduced while reducing damage to the oxide semiconductor film 110. The insulating film 116 can be formed using high radio frequency power.

[0257] The insulating films 114 and 116 can be formed by selecting from the materials listed above. In this embodiment, the insulating films 114 and 116 are made of a material that can release oxygen. A silicon oxynitride film capable of this is used.

[0258] After the insulating films 114 and 116 are formed, heat treatment (hereinafter referred to as first heat treatment) is performed. The first heat treatment is preferably performed to remove nitrogen oxide contained in the insulating films 114 and 116. Alternatively, the first heat treatment can reduce the amount of oxides in the insulating films 114 and 116. Part of the oxygen contained in the oxide semiconductor film 110 is transferred to the oxide semiconductor film 110. This can reduce the amount of oxygen vacancies.

[0259] The temperature of the first heat treatment is typically less than 400° C., preferably less than 375° C., and The first heat treatment is preferably performed at a temperature of 150° C. or higher and 350° C. or lower. Dry air (water content is 20 ppm or less, preferably 1 ppm or less, more preferably 10 The reaction may be carried out under an atmosphere of air (ppb or less) or a rare gas (argon, helium, etc.). It is preferable that the nitrogen, oxygen, ultra-dry air, or rare gas does not contain hydrogen, water, etc. The heat treatment may be performed in an electric furnace or RTA (Rapid Thermal Anneal). A device or the like can be used.

[0260] The opening 141 is formed so as to expose the drain electrode 112b. As a method for forming the opening, for example, a dry etching method can be used. The method for forming 41 is not limited to this, and may be a wet etching method or a dry etching method. The opening 14 may be formed by a combination of a chipping method and a wet etching method. In the case where the thickness of the drain electrode 112b is reduced by the etching process for forming the drain electrode 112b, There is a match.

[0261] Next, the oxide semiconductor films 111 and 111a are formed on the insulating film 116 so as to cover the openings 141. Then, an oxide semiconductor film is formed (see FIGS. 26A and 26B).

[0262] Note that FIG. 26A illustrates a state in a film formation apparatus when an oxide semiconductor film is formed over the insulating film 116. FIG. 26(A) is a schematic cross-sectional view of a portion of the film forming apparatus. A target 193 installed inside the sputtering device and a target 193 below the target 1 and 2. A plasma 194 formed at the surface is shown diagrammatically.

[0263] First, when forming an oxide semiconductor film, plasma is discharged in an atmosphere containing oxygen gas. At that time, oxygen is added to the insulating film 116 which is a surface on which the oxide semiconductor film is to be formed. In addition, when forming the oxide semiconductor film, in addition to oxygen gas, an inert gas (e.g., helium For example, argon gas and xenon gas may be mixed. It is preferable to use oxygen gas and argon gas, and to set the flow rate of oxygen gas higher than the flow rate of argon gas. By increasing the flow rate of oxygen gas, oxygen can be suitably added to the insulating film 116. For example, the oxide semiconductor film is formed under the following conditions: The ratio of is 50% or more and 100% or less, preferably 80% or more and 100% or less. .

[0264] In FIG. 26A, oxygen or excess oxygen added to the insulating film 116 is shown as a schematic diagram. is indicated by a dashed arrow.

[0265] The substrate temperature during the formation of the oxide semiconductor film is preferably from room temperature to 340° C. or from room temperature to 300°C, more preferably from 100°C to 250°C, and further preferably The temperature is generally 100° C. or higher and 200° C. or lower. On the other hand, the substrate 102 is a large glass substrate. In the case of using a substrate (for example, a sixth to tenth generation substrate), the substrate for forming the oxide semiconductor film is If the plate temperature is set to 150° C. or higher and lower than 340° C., the substrate 102 will deform (distort or warp). Therefore, when a large glass substrate is used, it is difficult to form an oxide semiconductor film. By keeping the substrate temperature during deposition at 100°C or higher but less than 150°C, deformation of the glass substrate is suppressed. It is possible.

[0266] The oxide semiconductor film can be formed using a material selected from the materials listed above. In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=1:3) is used. :6 [atomic ratio]) by a sputtering method to form an oxide semiconductor film.

[0267] Next, the oxide semiconductor is processed into a desired shape to form an island-shaped oxide semiconductor film 111. 111a is formed (see FIG. 26(C)).

[0268] The oxide semiconductor films 111 and 111a are formed by depositing an oxide semiconductor film over the insulating film 116 and then The semiconductor film is patterned so that the desired regions remain, and then the unnecessary regions are etched away. It can be formed by

[0269] Next, the insulating film 118 is formed over the insulating film 116 and the oxide semiconductor films 111 and 111a. (See FIG. 27(A)).

[0270] The insulating film 118 contains either hydrogen or nitrogen, or both. For example, a silicon nitride film is preferably used as the insulating film 118. For example, it can be formed by using a sputtering method or a PECVD method. When the insulating film 118 is formed by the PECVD method, the substrate temperature is set to less than 400° C., preferably less than 375° C. The temperature is preferably less than 180° C. and more preferably 350° C. or higher. In this case, it is preferable to set the substrate temperature in the above-mentioned range since a dense film can be formed. By setting the substrate temperature in the above range when forming the insulating film 118, the insulating films 114 and 1 Oxygen or excess oxygen in the oxide semiconductor film 16 can be moved to the oxide semiconductor film 110.

[0271] After the insulating film 118 is formed, a heat treatment similar to the first heat treatment described above (hereinafter, In this manner, the oxide semiconductor films 111 and 111a may be subjected to a second heat treatment. After oxygen is added to the insulating film 116 during the formation of the oxide semiconductor film, The heat treatment is preferably performed at a temperature of less than 375°C, more preferably at a temperature of 180°C to 350°C. By performing the treatment, oxygen or excess oxygen in the insulating film 116 is moved into the oxide semiconductor film 110. As a result, oxygen vacancies in the oxide semiconductor film 110 can be filled.

[0272] Here, oxygen moving into the oxide semiconductor film 110 will be described with reference to FIG. FIG. 28 shows the relationship between the substrate temperature (typically less than 375° C.) during the formation of the insulating film 118 and the temperature of the insulating film 118. The oxide semiconductor film 118 is then heated to a temperature of 375° C. or lower. 28 is a model diagram showing oxygen moving into the oxide semiconductor film 110. The dashed arrow indicates the oxygen (oxygen radical, oxygen atom, or oxygen molecule) moving into 0. 28 is a cross-sectional view of the transistor 150 and its surroundings after the insulating film 118 is formed.

[0273] The oxide semiconductor film 110 shown in FIG. 28 is a film in contact with the oxide semiconductor film 110 (here, Oxygen moves from the insulating films 107 and 114, thereby filling the oxygen vacancies. In particular, in the touch panel of one embodiment of the present invention, the oxide semiconductor film 110 is When oxygen gas is used to add oxygen to the insulating film 107 during sputtering deposition of the insulating film, The insulating film 107 has an excess oxygen region. In order to add oxygen to the insulating film 116 by using oxygen gas during sputtering of the insulating film, The insulating film 116 has an excess oxygen region. In the oxide semiconductor film 110, oxygen vacancies are suitably filled.

[0274] In addition, the insulating film 106 is provided below the insulating film 107, and the insulating films 114 and 11 An insulating film 118 is provided above the insulating films 106 and 118. By forming the insulating films 107, 114, and 116 from a thin material such as silicon nitride, Since the oxygen contained therein can be trapped on the oxide semiconductor film 110 side, the oxide semiconductor film 110 can be suitably oxidized. It is possible to move oxygen to the semiconductor film 110. Impurities from these, such as water, alkali metals, alkaline earth metals, etc., may enter the transistor 150. This also has the effect of preventing diffusion of the oxygen into the oxide semiconductor film 110 contained therein.

[0275] The insulating film 118 contains either hydrogen or nitrogen, or both. By forming the insulating film 118, the oxide semiconductor films 111 and 111a in contact with the insulating film 118 are The carrier density is increased by adding either hydrogen or nitrogen or both. Thus, it can function as an oxide conductive film.

[0276] As the resistivity of the oxide semiconductor films 111 and 111a decreases, The hatching of the oxide semiconductor films 111 and 111a shown in FIG. At this point, transistor 150 is fabricated.

[0277] The resistivity of the oxide semiconductor films 111 and 111a is at least higher than that of the oxide semiconductor film 110. Low, preferably 1×10 -3 Ωcm or more 1×10 4less than Ωcm, more preferably 1×10 -3 Ωcm or more 1×10 -1 It is preferable that the resistivity is less than Ωcm.

[0278] Next, an insulating film 119 is formed on the insulating film 118, and desired regions of the insulating films 118 and 119 are The pattern is then formed so that the remaining area is left behind, and the unnecessary area is then etched away to form the opening 142. (See FIG. 27(B)).

[0279] The insulating film 119 can be formed by selecting from the materials described above. In this embodiment, the insulating film 119 is made of an acrylic resin.

[0280] The opening 142 is formed so as to expose the drain electrode 112b. As a method for forming the opening, for example, a dry etching method can be used. The method for forming 42 is not limited to this, and may be a wet etching method or a dry etching method. The opening 14 may be formed by a combination of a chipping method and a wet etching method. In the case where the thickness of the drain electrode 112b is reduced by the etching process for forming the drain electrode 112b, There is a match.

[0281] In addition, the step of forming the opening 142 is performed without performing the step of forming the opening 141 described above. In this way, openings may be formed continuously in the insulating films 114, 116, 118, and 119. By adopting the above-mentioned process, it is possible to reduce the number of steps in manufacturing the touch panel of one embodiment of the present invention. Therefore, the manufacturing cost can be reduced.

[0282] Next, a conductive film is formed on the insulating film 119 so as to cover the opening 142. The conductive film 1 is patterned so that a certain area remains, and then the unnecessary area is etched away. 20 is formed (see FIG. 27(C)).

[0283] The conductive film 120 can be formed by selecting a material from the materials listed above. In this embodiment, the conductive film 120 is made of indium tin oxide.

[0284] In addition, the capacitor element 160 is fabricated in conjunction with the formation of the conductive film 120. The capacitor element 160 is The dielectric layer is sandwiched between a pair of electrodes, and one of the pair of electrodes is an oxide semiconductor film 1. The other of the pair of electrodes is a conductive film 120. In addition, the insulating films 118 and 119 are It functions as a dielectric layer for the capacitor 160 .

[0285] Through the above steps, the transistor 150 and the capacitor 152 of the touch panel 310 shown in FIG. A pair of electrodes constituting the capacitor element 160 and the liquid crystal element 308 can be fabricated.

[0286] Although the insulating film 119 is provided in FIG. 27C, the insulating film 119 is not provided. In this case, the insulating film 118 may be formed on the capacitor 160. It functions as a dielectric film. In addition, the transistor 150 does not have a gate electrode 104. The oxide semiconductor film 111a may function as the first gate electrode (see FIG. 29). FIG. 29(B) shows the gate electrode 104 and the insulating film 105 in comparison with FIG. 27(C). The difference is that the transistor 150 shown in FIG. It is a gate type transistor.

[0287] The structures, methods, etc. described in this embodiment may be different from the structures, methods, etc. described in other embodiments. They can be used in appropriate combination.

[0288] [Configuration example 2] In this configuration example, an organic EL element is used as the display element of the touch panel.

[0289] [Cross-sectional configuration example 1] Hereinafter, an example of a cross-sectional configuration of a touch panel according to one embodiment of the present invention will be described with reference to the drawings. Note that the explanation of the parts that overlap with the above will be omitted, and only the differences will be explained.

[0290] The touch panel 320 shown in FIG. 13 includes a light emitting element 280 in a display unit 381. The element 280 includes a conductive film 120, an EL layer 281, and a conductive film 282. The conductive film 120 is a reflective film. through the openings provided in the insulating films 114, 116, 118, and 119. The conductive film 282 is electrically connected to the drain electrode 112b of the transistor 150. The conductive film 282 is made of a material that transmits visible light. The conductive film 282 may also function as a semi-reflective film. By applying a voltage between the conductive film 120 and the conductive film 282, the light-emitting layer included in the EL layer 281 The light emitted by the light source 371 is extracted through a colored film (for example, the colored film 331R) provided on the substrate 372. The touch panel 320 shown in FIG. 13 is a so-called top emission type. The specific configuration of the light emitting device 280 will be described later in the fourth embodiment. State.

[0291] An insulating film 391 functioning as a partition wall is provided over the insulating film 119. The insulating film 391 includes The EL layer 281 is provided so as to overlap the ends of the conductive film 120 of two adjacent pixels. 20 and the insulating film 391. The conductive film 282 overlaps at least the conductive film 120. For example, the touch panel 320 shown in FIG. In the figure, the conductive film 282 is a conductive film 282 of two conductive films 120 of two pixels adjacent in one direction. The conductive film 282 has an opening 385 at a position overlapping the gap. For each block containing a certain number of pixels (e.g., 30 pixels, 60 pixels, etc.), An opening 385 may be provided at a position overlapping the gap between the two conductive films 120 of one pixel. stomach.

[0292] In addition, the oxide semiconductor film 111 is provided in a position overlapping with the opening 385 over the insulating film 116. The oxide semiconductor film 111 serves as a second gate electrode of the transistor 150. Since the oxide semiconductor film 111a and the oxide semiconductor film 112 can be formed simultaneously using the same material, It can be simplified.

[0293] The touch sensor of the touch panel 320 is formed by a conductive film 334 provided on a substrate 372 and , and the oxide semiconductor film 111 provided over the substrate 102. and the oxide semiconductor film 111 to detect the proximity or contact of an object to be detected. It can be detected.

[0294] Here, the arrangement of the electrodes constituting the touch sensor will be described. 14 is a top view schematic diagram of a pair of touch sensor electrodes included in the touch panel 320. The dashed dotted line Z5-Z6 corresponds to the display unit 381 shown in FIG.

[0295] The conductive film 334, which is one electrode of the touch sensor, is provided extending in the Y direction. The oxide semiconductor film 111, which is the other electrode of the touch sensor, extends in the X direction. The conductive film 334 extends in the X direction and intersects with the oxide semiconductor film 11. 1 may extend in the Y direction.

[0296] In addition, the touch panel 320 is formed by bonding the substrate 102 and the substrate 372 with a seal material 151. The area surrounded by the substrate 102, the substrate 372, and the sealant 151 is hollow. However, the region may be filled with a sealing material. Although the film 332 does not have an insulating film on it, it functions as the overcoat described above. An insulating film 355 may be provided.

[0297] In addition, in FIG. 13, a light emitting element 280 is configured in which an EL layer 281 is common to a plurality of pixels. However, an EL layer 281 may be provided for each pixel (see FIG. 15). In this case, the EL layer 281 has a light-emitting layer that emits light of a color corresponding to the emission color required for each pixel. In addition, a colored film (for example, colored films 331R, 331G, etc.) may be provided for each pixel. It is also possible to adopt a configuration in which no

[0298] [Cross-sectional configuration example 2] FIG. 16 shows an example of a cross-sectional configuration of a touch panel that is partially different from that shown in FIG. Note that we will omit the explanation of the parts that overlap with the above and will only explain the differences.

[0299] In FIG. 16, conductive films 334, 341 and an FPC 375 are not provided on the display surface side of a substrate 372. The second gate electrode of the transistor 150 is formed at the same time using the same material. The oxide semiconductor film 111 functions as a pair of electrodes of the touch sensor. , an oxide semiconductor film 111b (not shown) extending in one direction, and an oxide semiconductor film 111b The oxide semiconductor film 111c is electrically connected to the conductive film 104a extending in a direction perpendicular to the These function as a pair of electrodes of the touch sensor. The process can be further simplified as compared with the structure shown in FIG. The conductive film 104a and the conductive layer 104b are electrically connected to each other through the openings 333 provided in the insulating films 108, 114, and 116. The conductive film 104a is formed of the same material as the gate electrode 104. is formed.

[0300] Here, the arrangement of the electrodes constituting the touch sensor will be described. 17 is a top view of a pair of touch sensor electrodes included in the touch panel 320. The dashed dotted line Z7-Z8 corresponds to the display unit 381 shown in FIG.

[0301] The oxide semiconductor film 111b, which is one electrode of the touch sensor, is provided to extend in the Y direction. The oxide semiconductor film 111c which is the other electrode of the touch sensor has an opening 333. The conductive film 104a is electrically connected to the conductive film 104a via an oxide film. It has a region intersecting with the semiconductor film 111b.

[0302] The conductive film 282 functioning as one electrode of the light emitting element 280 is The touch panel 320 shown in FIG. The oxide semiconductor film 111, which is one of the electrodes of the capacitor, is provided to extend in the X direction. The gate electrode 282 extends in the Y direction and has a region intersecting with the oxide semiconductor film 111. FIG. 19 is a top view of a pair of touch sensor electrodes of the touch panel 320 shown in FIG. 19 corresponds to the display unit 381 shown in FIG. The conductive film 282 has an opening 385 extending in a direction perpendicular to the direction in which the oxide semiconductor film 111 extends. The opening 385 extends in the insulating direction and partly overlaps with the oxide semiconductor film 111 .

[0303] [Cross-sectional configuration example 3] FIG. 20 shows an example of a cross-sectional configuration of a touch panel that is partially different from the above example. Note that we will omit the explanation of the parts that overlap with the above and will only explain the differences. .

[0304] The touch panel 320 shown in FIG. 20 includes a light emitting element 280 in a display unit 381. The element 280 includes a conductive film 285, an EL layer 281, and a conductive film 286. The conductive film 285 is an insulating The drain of transistor 150 is connected through openings in films 114, 116, 118, and 119. The conductive film 285 is made of a material that transmits visible light. The conductive film 285 may also function as a semi-reflective film. It functions as a reflective film. By applying a voltage between the conductive film 285 and the conductive film 286, The light emitted by the light-emitting layer included in the EL layer 281 is reflected by a colored film (e.g., a colored film) provided on the substrate 102. The touch panel 320 shown in FIG. It is equipped with a so-called bottom emission type display device.

[0305] The light-shielding film 332 and the colored films 331R and 331G are provided on the insulating film 118. 2 is provided at a position overlapping the insulating film 391. The EL layer 281 and the conductive film 286 are provided at a position overlapping the conductive film 285. 5 in this order.

[0306] The conductive films 334, 341 and the FPC 375 are disposed on the display surface side of the substrate 102 (the side opposite to the substrate 372). The conductive film 334 and the oxide semiconductor film 111 are used as a pair of electrodes. The conductive film 334 is connected to the display surface of the substrate 102. By providing the conductive film 285 on the side of the pair of electrodes, it is possible to provide another conductive film (e.g., the conductive film 285, the conductive film 286, etc.) between the pair of electrodes. In addition, the oxide semiconductor film 111 transmits visible light. Therefore, the conductive film 285 is also provided at a position overlapping with the conductive film 285 which is a path of light emitted by the light emitting element 280. Therefore, the oxide semiconductor film 111 can be formed over a large area. The capacitance value of the touch sensor can be increased.

[0307] Here, the arrangement of the electrodes constituting the touch sensor will be described. 21 is a top view schematic diagram of a pair of touch sensor electrodes included in the touch panel 320. The dashed dotted line Z11-Z12 corresponds to the display unit 381 shown in FIG.

[0308] The conductive film 334, which is one electrode of the touch sensor, is provided extending in the Y direction. The oxide semiconductor film 111, which is the other electrode of the touch sensor, extends in the X direction. The conductive film 334 extends in the X direction and intersects with the oxide semiconductor film 11. 1 may extend in the Y direction.

[0309] In addition, in FIG. 20, the EL layer 281 is common to a plurality of pixels. However, an EL layer 281 may be provided for each pixel (see FIG. 22). In this case, the EL layer 281 has a light-emitting layer that emits light of a color corresponding to the emission color required for each pixel. In addition, a colored film (for example, colored films 331R, 331G, etc.) may be provided for each pixel. It is also possible to adopt a configuration in which no

[0310] [Cross-sectional configuration example 4] FIG. 23 shows an example of a cross-sectional configuration of a touch panel that is partially different from that shown in FIG. Note that we will omit the explanation of the parts that overlap with the above and will only explain the differences.

[0311] In FIG. 23, conductive films 334, 341 and an FPC 375 are not provided on the display surface side of the substrate 102. The second gate electrode of the transistor 150 is formed at the same time using the same material. The oxide semiconductor film 111 functions as a pair of electrodes of the touch sensor. , an oxide semiconductor film 111b extending in one direction and a direction perpendicular to the oxide semiconductor film 111b The conductive film 104a extending to the touch sensor 101 and the oxide semiconductor film 111c electrically connected thereto form a touch sensor. By using such a configuration, the structure shown in FIG. The oxide semiconductor film 111c can be formed on the insulating film 10. 8, 114, and 116 are electrically connected to the conductive film 104a through the openings 333 provided therein. The conductive film 104a is formed at the same time as the gate electrode 104 using the same material. The conductive film 104a is provided at a position overlapping the light-shielding film 332, so that the aperture ratio of the pixel is maintained. This is preferable because it is possible to configure a pair of electrodes of the touch sensor.

[0312] Here, the arrangement of the electrodes constituting the touch sensor will be described. 24 is a top view schematic diagram of a pair of touch sensor electrodes included in the touch panel 320. The dashed dotted line Z13-Z14 corresponds to the display unit 381 shown in FIG.

[0313] The oxide semiconductor film 111b, which is one electrode of the touch sensor, is provided to extend in the Y direction. The oxide semiconductor film 111c which is the other electrode of the touch sensor has an opening 333. The conductive film 104a is electrically connected to the conductive film 104a via an oxide film. It has a region intersecting with the semiconductor film 111b.

[0314] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0315] (Embodiment 2) In this embodiment, a semiconductor device according to one embodiment of the present invention is applied to a transistor and a capacitor of a liquid crystal display device. An example of a possible oxide semiconductor will be described below. The structure of an oxide semiconductor will be described below. Reveal.

[0316] In this specification, "parallel" means that two straight lines are arranged at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Parallel" refers to two lines that are arranged at an angle between -30° and 30°. Also, "perpendicular" means that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, it also includes the case where the angle is between 85° and 95°. This refers to a state in which two straight lines are arranged at an angle of 60° or more and 120° or less.

[0317] In this specification, when the crystal is a trigonal or rhombohedral crystal, it is represented as a hexagonal crystal system. vinegar.

[0318] Oxide semiconductors are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, CAAC-OS (C Axis Aligned Crystalline Oxide Semiconductor, polycrystalline oxide Semiconductor, nc-OS (nanocrystalline oxide semiconductor uctor), pseudo-amorphous oxide semiconductor (a-like OS: amorphous l Examples include amorphous oxide semiconductors, amorphous oxide semiconductors, etc.

[0319] From another point of view, the oxide semiconductor is classified into an amorphous oxide semiconductor and a crystalline oxide semiconductor. Crystalline oxide semiconductors are classified into single crystal oxide semiconductors, CAAC- These include OS, polycrystalline oxide semiconductor, and nc-OS.

[0320] The definition of an amorphous structure is generally that it is not fixed in a metastable state and is isotropic. It is known that the bond angle is flexible and the bond length is short. In other words, it is a structure that has discrete order but does not have long-range order.

[0321] On the other hand, in the case of an essentially stable oxide semiconductor, In addition, it cannot be called an oxide semiconductor because it is not isotropic. The oxide semiconductor, which is not amorphous (for example, has a periodic structure in a microscopic region), is transformed into a completely amorphous oxide. However, a-like OS is a semiconductor that can be used in a small area. Although it has a periodic structure, it has voids and is an unstable structure. In terms of physical properties, it can be said that the semiconductor is close to an amorphous oxide semiconductor.

[0322] <caac-os> First, let me explain about CAAC-OS.

[0323] CAAC-OS is an oxide that has multiple crystal parts (also called pellets) aligned along the c-axis. It is a type of semiconductor.

[0324] Transmission Electron Microscope (TEM) A combined analysis image (high resolution) of the bright-field image and diffraction pattern of CAAC-OS was obtained by using a microscope. When observing a high-resolution TEM image, multiple pellets can be confirmed. On the other hand, in high-resolution TEM images, the boundaries between pellets, i.e., grain boundaries, are clearly visible. Therefore, it is difficult to clearly confirm the presence of the CAAC-OS at the grain boundaries. It can be said that the decrease in electron mobility caused by the above phenomenon is unlikely to occur.

[0325] The following describes the CAAC-OS observed by TEM. 1 shows a high-resolution TEM image of a cross section of CAAC-OS observed from a direction approximately parallel to the sample surface. For high-resolution TEM imaging, spherical aberration correction is required. The spherical aberration corrector function was used. , specifically called a Cs-corrected high-resolution TEM image. Cs-corrected high-resolution TEM images are obtained, for example, This is performed using an atomic resolution analytical electron microscope such as the JEM-ARM200F manufactured by JEOL Ltd. It is possible.

[0326] An enlarged Cs-corrected high-resolution TEM image of region (1) in Figure 30(A) is shown in Figure 30(B). From Figure 30(B), it can be confirmed that the metal atoms are arranged in layers in the pellet. The arrangement of each metal atom layer is determined by the surface on which the CAAC-OS film is to be formed (also called the surface on which the film is to be formed). Or it reflects the unevenness of the top surface and is parallel to the surface on which the CAAC-OS is formed or the top surface.

[0327] As shown in FIG. 30(B), CAAC-OS has a characteristic atomic arrangement. ) shows the characteristic atomic arrangement with auxiliary lines. ) the size of a single pellet can be 1 nm or more, or 3 nm or more. It can be seen that the size of the gap caused by the inclination between the plate and the pellet is about 0.8 nm. Therefore, the pellets can also be called nanocrystals (nc). CAAC-OS is also used as a C-Axis Aligned Nanoclip The semiconductor may also be referred to as an oxide semiconductor having metal ions.

[0328] Here, based on the Cs-corrected high-resolution TEM image, the pellets of CAAC-OS on the substrate 5120 were The layout of the 5100 is shown diagrammatically as a stack of bricks or blocks. (See FIG. 30(D)). Between the pellets observed in FIG. 30(C), The portion where the inclination occurs corresponds to the area 5161 shown in FIG.

[0329] FIG. 31(A) shows the C 31(A) shows the s-corrected high-resolution TEM images of regions (1), (2) and (3) in FIG. ) are enlarged Cs-corrected high-resolution TEM images shown in Fig. 31(B), Fig. 31(C) and Fig. 31(D), respectively. As shown in Figure 31(D), Figure 31(B), Figure 31(C) and Figure 31(D) show that the pellet It can be seen that the metal atoms are arranged in a triangular, quadrangular or hexagonal shape. However, no regularity is observed in the arrangement of metal atoms among different pellets.

[0330] Next, C was analyzed by X-ray diffraction (XRD). We will explain AAC-OS. For example, CAAC-O with InGaZnO4 crystals When the structure of S is analyzed using the out-of-plane method, the result is as shown in Figure 32(A). As shown in the figure, a peak may appear at a diffraction angle (2θ) of around 31°. Since this is attributed to the (009) plane of the ZnO4 crystal, it is believed that the CAAC-OS crystal has a c-axis orientation. It can be seen that the crystal has a c-axis oriented in a direction substantially perpendicular to the surface on which the crystal is formed or to the upper surface.

[0331] In addition, in the out-of-plane structural analysis of CAAC-OS, 2θ is 31 In addition to the peaks around 2θ of 36°, a peak may also appear around 2θ of 36°. The peaks in the vicinity indicate that some of the CAAC-OS contains crystals that do not have the c-axis orientation. The more preferable CAAC-OS is a structure obtained by the out-of-plane method. The analysis shows a peak at 2θ around 31° and no peak at 2θ around 36°.

[0332] On the other hand, in-pla, X-rays are incident on CAAC-OS from a direction nearly perpendicular to the c-axis. When the structure is analyzed by the NE method, a peak appears at 2θ of about 56°. This peak is I It is attributed to the (110) plane of the crystal of nGaZnO4. In the case of CAAC-OS, 2θ is set to 5 The sample was fixed at approximately 6° and analyzed while rotating around the normal vector of the sample surface (φ axis). Even if a φ scan is performed, no clear peak appears as shown in FIG. On the other hand, in the case of a single crystal oxide semiconductor such as InGaZnO4, 2θ is fixed at around 56° and φ When scanned, it is assigned to a crystal plane equivalent to the (110) plane, as shown in Figure 32(C). Six peaks are observed. Therefore, from the structural analysis using XRD, CAAC-OS It can be seen that the orientation of the a-axis and the b-axis is irregular.

[0333] Next, we will explain the CAAC-OS analyzed by electron diffraction. For CAAC-OS with ZnO4 crystals, a probe diameter of 300 nm was used parallel to the sample surface. When an electron beam is incident on the sample, a diffraction pattern (selected area transmission electron diffraction) as shown in FIG. This diffraction pattern may appear due to the InGaZnO4 The spots due to the (009) plane of the crystal are included. Therefore, even by electron diffraction, The pellets contained in the CAAC-OS have a c-axis orientation, and the c-axis faces the surface to be formed or the upper surface. On the other hand, when the probe was applied perpendicular to the sample surface, The diffraction pattern when an electron beam with a diameter of 300 nm was incident is shown in FIG. 3(B), a ring-shaped diffraction pattern is confirmed. Therefore, electron diffraction also It can be seen that the a-axis and b-axis of the pellets contained in CAAC-OS do not have any orientation. In addition, the first ring in FIG. 33(B) is the (010) plane of the InGaZnO4 crystal. This is thought to be due to the (100) plane and the like. This is thought to be due to the (110) surface, etc.

[0334] As described above, the CAAC-OS is an oxide semiconductor with high crystallinity. Crystallinity can be reduced by the inclusion of impurities or the generation of defects, so the opposite view can be taken. Therefore, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies).

[0335] The impurities are elements other than the main components of the oxide semiconductor, such as hydrogen, carbon, silicon, and transition metals. For example, metal elements such as silicon have a higher acidity than metal elements that constitute oxide semiconductors. Elements with strong bonds to oxygen remove oxygen from the oxide semiconductor, which changes the atomic arrangement of the oxide semiconductor. In addition, heavy metals such as iron and nickel, argon, Carbon dioxide and other molecules have a large atomic radius (or molecular radius), so the atomic arrangement of oxide semiconductors This disrupts the structure and reduces the crystallinity.

[0336] When an oxide semiconductor has impurities or defects, its characteristics may change due to light, heat, etc. For example, impurities contained in oxide semiconductors can act as carrier traps or In addition, oxygen vacancies in oxide semiconductors can act as carrier traps and In some cases, the SiO 2 can become a carrier generation source by capturing hydrogen.

[0337] CAAC-OS, which has few impurities and oxygen vacancies, is an oxide semiconductor with low carrier density. There is. Specifically, 8×10 11 pieces / cm 3 Less than 1 x 10 11 / cm 3 less than , and more preferably 1×10 10 pieces / cm 3 Less than 1 x 10 -9 pieces / cm 3 The above Such an oxide semiconductor can be obtained by using a high-purity pure oxide semiconductor. CAAC-OS is a highly pure or substantially intrinsic oxide semiconductor with low impurity concentration. In other words, it can be said that the oxide semiconductor has stable characteristics.

[0338] <nc-os> Next, we will explain nc-OS.

[0339] In the high-resolution TEM image, the nc-OS is divided into two regions: one where the crystals can be confirmed, and the other where the clear The crystalline parts in nc-OS are In most cases, the size is between 1 nm and 10 nm, or between 1 nm and 3 nm. An oxide semiconductor having a crystal size of 10 nm or more and 100 nm or less is called a microcrystalline oxide. For example, in high-resolution TEM images, nc-OS shows grain boundaries. In some cases, the nanocrystals are not clearly visible in the pellets of CAAC-OS. Therefore, in the following, the crystalline part of nc-OS is referred to as the pellet. There is a chance to call.

[0340] nc-OS is a material that is used in microscopic regions (e.g., regions between 1 nm and 10 nm, especially regions between 1 nm and The atomic arrangement has periodicity in the region of 3 nm or less. There is no regularity in the crystal orientation between the layers. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, nc-OS may be classified as a-like OS or amorphous oxide semiconductor. For example, the nc-OS may be a pellet with a larger diameter than the pellet. When X-rays are used, the peaks that indicate the crystal planes are In addition, for nc-OS, the probe diameter is larger than the pellet (e.g., 50 When electron diffraction is performed using an electron beam of 1 nm or more, a halo-like diffraction pattern is produced. On the other hand, for nc-OS, pellets with sizes close to or smaller than the pellets were observed. When nanobeam electron diffraction is performed using an electron beam with a lobe diameter, spots are observed. When nanobeam electron diffraction was performed on nc-OS, high brightness regions were observed in a circular (ring-like) pattern. In addition, multiple spots may be observed within a ring-shaped area. There may be cases where this occurs.

[0341] In this way, the crystal orientation between the pellets (nanocrystals) is not regular, so nc -OS with RANC (Random Aligned nanocrystals) The oxide semiconductor or NANC (Non-Aligned Nanocrystal The semiconductor may also be referred to as an oxide semiconductor having a structure including a metal oxide layer.

[0342] The nc-OS is an oxide semiconductor with higher order than an amorphous oxide semiconductor. The nc-OS has a lower density of defect states than the a-like OS and amorphous oxide semiconductors. However, the crystal orientation of nc-OS is not regular among different pellets. Therefore, the nc-OS has a higher density of defect states than the CAAC-OS.

[0343] <a-like OS> The a-like OS is an oxide semiconductor that has a structure between the nc-OS and the amorphous oxide semiconductor. It is a semiconductor.

[0344] In a-like OS, pores may be observed in high-resolution TEM images. In the high-resolution TEM image, there are areas where crystals can be clearly seen, and areas where crystals can be seen. and areas where it is not possible to

[0345] Because of the porosity, the a-like OS has an unstable structure. e OS has an unstable structure compared with CAAC-OS and nc-OS. This shows the change in structure due to electron irradiation.

[0346] The samples to be irradiated with electrons were a-like OS (referred to as sample A), nc-OS (hereinafter referred to as sample B) and CAAC-OS (hereinafter referred to as sample C) are prepared. Both samples are In-Ga-Zn oxides.

[0347] First, high-resolution cross-sectional TEM images of each sample are obtained. It can be seen that all the materials have crystalline parts.

[0348] The determination of which part is regarded as one crystal part can be made as follows. For example, The unit cell of the InGaZnO4 crystal has three In-O layers and one Ga-Zn-O layer. It is known that the structure has a total of nine layers, six of which are layered in the c-axis direction. The spacing between these adjacent layers is approximately the same as the lattice spacing (also called the d value) of the (009) plane. The value is calculated to be 0.29 nm from crystal structure analysis. The areas where the spacing between the crystals is 0.28 nm to 0.30 nm are considered to be crystal parts of InGaZnO4. The lattice fringes correspond to the ab plane of the InGaZnO4 crystal.

[0349] Figure 34 shows an example of the average size of the crystal parts (22 to 45 places) of each sample. However, the length of the lattice fringes is the size of the crystal part. It can be seen that the crystalline part of the ke OS grows in size according to the cumulative dose of electron irradiation. Specifically, as shown by (1) in Figure 34, the initial TEM observation showed a size of about 1.2 nm. The crystal part (also called the initial nucleus), which was 4.2×10 8 e - / n m 2 On the other hand, in the nc-O For S and CAAC-OS, the cumulative electron dose from the start of electron irradiation was 4.2 × 10 8 e - / nm 2 It can be seen that there is no change in the size of the crystals within the range of As shown in (2) and (3) in Fig. 34, the nc-OS and The sizes of the crystal parts of the CAAC-OS and CAAC-OS are approximately 1.4 nm and 2.1 nm, respectively. It can be seen that.

[0350] Thus, in a-like OS, the growth of crystals can be observed by electron irradiation. On the other hand, in the case of nc-OS and CAAC-OS, the growth of the crystals due to electron irradiation is almost nonexistent. In other words, a-like OS is not seen as a nc-OS or CAAC-OS. It is clear that it has an unstable structure compared to the OS.

[0351] In addition, because of the porosity, a-like OS is more difficult to treat than nc-OS and CAAC-OS. Specifically, the density of the a-like OS is The density of the nc-OS and the CAA The density of C-OS is 92.3% or more but less than 100% of the density of a single crystal of the same composition. It is difficult to form a film of an oxide semiconductor having a crystal density of less than 78%.

[0352] For example, in an oxide semiconductor having an atomic ratio of In:Ga:Zn=1:1:1, The density of a single crystal InGaZnO4 having a rhombohedral crystal structure is 6.357 g / cm 3 becomes. Thus, for example, in an oxide semiconductor satisfying In:Ga:Zn = 1:1:1 [atomic ratio], the density of a-like OS is 5.0 g / cm or more and less than 5.9 g / cm 3 3 becomes. Also, for example, in an oxide semiconductor satisfying In:Ga:Zn = 1:1:1 [atomic ratio], the density of nc-OS and the density of CAAC-OS are 5.9 g / cm or more and less than 6.3 g / cm 3 3 becomes. 3

[0353] Note that there may be no single crystal of the same composition. In that case, by combining single crystals with different compositions in any ratio, the density corresponding to the single crystal in the desired composition can be estimated. The density corresponding to the single crystal of the desired composition may be estimated using a weighted average with respect to the ratio of combining single crystals with different compositions. However, it is preferable to estimate the density by combining as few types of single crystals as possible.

[0354] As described above, the oxide semiconductor has various structures, each having various characteristics. Note that the oxide semiconductor may be, for example, a laminated film having two or more of an amorphous oxide semiconductor, a-like OS, nc-OS, and CAAC-OS.

[0355] <Method for forming CAAC-OS> Hereinafter, an example of a method for forming CAAC-OS will be described. FIG. 35 is a schematic diagram of the inside of a film formation chamber. CAAC-OS can be formed by a sputtering method.

[0356] As shown in FIG. 35, the substrate 5220 and the target 5230 are disposed so as to face each other. There is a plasma 5240 between the substrate 5220 and the target 5230. A heating mechanism 5260 is provided below the substrate 5220. Although not shown, a target 5230 is bonded to the backing plate. A number of magnets are arranged opposite the magnet 5230. The sputtering method that uses magnetron sputtering to increase the deposition rate is called magnetron sputtering. can be.

[0357] The distance d between the substrate 5220 and the target 5230 (target-substrate distance (TS distance) The distance is 0.01 m or more and 1 m or less, preferably 0.02 m or more and 0.5 m or less. The deposition chamber is mostly filled with deposition gas (e.g., oxygen, argon, or oxygen 5 volumes). % or more), and the pressure is 0.01 Pa to 100 Pa, preferably The pressure is controlled to be 0.1 Pa or more and 10 Pa or less. By applying a voltage, a discharge starts and plasma 5240 is observed. A high-density plasma region is formed near the nozzle 5230 by the magnetic field. In the region, the deposition gas is ionized to generate ions 5201. The ions 5201 are For example, the oxygen cation (O + ) and argon cations (Ar + ) etc.

[0358] The target 5230 has a polycrystalline structure having a plurality of crystal grains, and As an example, FIG. 36 shows a target 5230 having an InMZn The crystal structure of O4 (wherein element M is, for example, Al, Ga, Y, or Sn) is shown in FIG. A) is the crystal structure of InMZnO4 when observed parallel to the b-axis. In ZnO4 crystals, the oxygen atoms have a negative charge, so that two adjacent M-Zn Therefore, the InMZnO4 crystal is composed of two adjacent M -The cleavage plane is between the Zn-O layers.

[0359] Ions 5201 generated in the high-density plasma region are attracted to the target 5230 by the electric field. The cleavage plane is then accelerated and collides with the target 5230. At this time, flat or planar particles are generated from the cleavage plane. A pellet 5200, which is a pellet-shaped sputtered particle, is peeled off (see FIG. 35). 200 is the portion sandwiched between the two cleavage planes shown in FIG. 36(A). When only 200 is extracted, its cross section looks like Figure 36(B) and its top surface looks like Figure 36(C). It can be seen that the pellet 5200 is formed by the impact of the ion 5201. This can cause distortion of the structure.

[0360] The pellet 5200 is a flat or pellet-shaped pellet having a triangular, e.g., equilateral, plane. The pellet 5200 is a sputtered particle having a hexagonal, for example, a regular hexagonal plane. The sputtered particles are in the form of a plate or pellet. However, the shape of the pellet 5200 is not limited to a triangle or a hexagon, for example, it may be a shape made up of multiple triangles. For example, a quadrilateral (such as a rhombus) is made up of two triangles (such as an equilateral triangle). ) in some cases.

[0361] The thickness of the pellet 5200 is determined depending on the type of deposition gas. For example, 5200 has a thickness of 0.4 nm or more and 1 nm or less, preferably 0.6 nm or more and 0.8 nm or less. For example, the pellet 5200 has a width of 1 nm or more and 100 nm or less. The thickness is preferably 2 nm or more and 50 nm or less, and more preferably 3 nm or more and 30 nm or less. For example, The target 5230 having an In-M-Zn oxide is bombarded with ions 5201. As a result, a pellet 5 having three layers, an M-Zn-O layer, an In-O layer, and an M-Zn-O layer, was obtained. As the pellet 5200 is peeled off, particles are released from the target 5230. Particle 5203 is also ejected. Particle 5203 has an aggregate of one atom or several atoms. Therefore, the particle 5203 is called atomic particles. It is also possible.

[0362] As the pellet 5200 passes through the plasma 5240, the surface becomes negatively or positively charged. For example, the pellet 5200 may be in the plasma 5240. 2- negative charge from As a result, the oxygen atoms on the surface of the pellet 5200 may become negatively charged. In addition, when the pellet 5200 passes through the plasma 5240, the pellet 5200 may be mixed with the plasma 52 It may grow by combining with indium, element M, zinc, or oxygen in 40. .

[0363] The pellets 5200 and particles 5203 that have passed through the plasma 5240 are Some of the particles 5203 reach the surface because of their small mass. It may be discharged to the outside.

[0364] Next, the deposition of pellets 5200 and particles 5203 on the surface of the substrate 5220 is This will be explained with reference to FIG.

[0365] First, the first pellet 5200 is deposited on the substrate 5220. Since the pellets 52 are in the shape of a pellet, the flat side of the pellets 52 is deposited toward the surface of the substrate 5220. The charge on the surface of 00 on the substrate 5220 side is discharged through the substrate 5220.

[0366] Next, the second pellet 5200 reaches the substrate 5220. The surface of the pellet 5200 that is being held in the first position and the surface of the second pellet 5200 are charged. As a result, the second pellet 5200 is pushed into the pile already. Avoid placing the pellets 5200 on the substrate 5220, and place the flat side a little away from the surface of the substrate 5220. By repeating this process, countless pellets 52 are deposited on the surface of the substrate 5220. 00 is piled up to the thickness of one layer. Also, between the pellets 5200, Non-deposited areas are generated (see FIG. 37(A)).

[0367] Next, the particles 5203 that have received energy from the plasma reach the surface of the substrate 5220. The particles 5203 can accumulate in active areas such as the surface of the pellet 5200. Therefore, the particles 5203 move to the areas where the pellets 5200 are not deposited, and the pellets The particle 5203 adheres to the side of the nozzle 5200. The bond becomes more active, and the pellet 5200 is chemically bonded to the lateral growth portion 52. 02 (see Figure 37(B)).

[0368] Furthermore, the lateral growth portion 5202 grows in the lateral direction (also called lateral growth), The pellets 5200 are connected to each other (see FIG. 37(C)). Lateral growth 5202 is formed until it fills the undeposited area. Deposition mechanism of atomic layer deposition (ALD) method Similar to a rhythm.

[0369] Therefore, even if the pellets 5200 are piled up in different directions, Since the grains 5203 grow laterally and fill the gaps between the grains 5200, clear grain boundaries are formed. In addition, the particles 5203 smoothly connect the pellets 5200. Therefore, a crystal structure different from single crystal and polycrystal is formed. A crystal structure having distortion between the crystal regions (pellets 5200) is formed. Since the regions filling the gaps are distorted crystalline regions, it is not appropriate to refer to these regions as amorphous structures. It is considered that this is not the case.

[0370] Next, a new pellet 5200 is deposited with its flat side facing the surface (see FIG. 37(D)). ) Then, the particles 5203 accumulate to fill the unaccumulated areas of the pellet 5200. By stacking the particles 520, a lateral growth portion 5202 is formed (see FIG. 37(E)). 3 adheres to the side of the pellet 5200, and the lateral growth portion 5202 grows laterally. The pellets 5200 in the mth layer are connected together (see FIG. 37(F)). The deposition continues until a thin film structure having a laminate is formed.

[0371] The deposition of the pellets 5200 also changes depending on the surface temperature of the substrate 5220. For example, if the surface temperature of the substrate 5220 is high, the pellet 5200 may be heated to the surface of the substrate 5220. As a result, the pellets 5200 are connected to each other through the particles 5203. The proportion of bonds without any bonds increases, resulting in a CAAC-OS with higher orientation. The surface temperature of the substrate 5220 during the formation of the OS film is equal to or higher than room temperature and lower than 340° C., and preferably, is equal to or higher than room temperature. More preferably, the temperature is from 100° C. to 250° C. ℃ or more and 200 ℃ or less. Therefore, the substrate 5220 is a large-area substrate of the 8th generation or more. Even when using a CAAC-OS, warping due to the deposition of the CAAC-OS hardly occurs. I understand.

[0372] On the other hand, when the surface temperature of the substrate 5220 is low, the pellet 5200 is mixed with the surface of the substrate 5220. As a result, pellets 5200 do not pile up on each other. In the case of nc-OS, the pellet 5200 is negatively charged. Due to this, the pellets 5200 may accumulate at regular intervals. Although the orientation is low, the film has a slight regularity, which makes it easier to form a film than an amorphous oxide semiconductor. The result is a dense structure.

[0373] In addition, in CAAC-OS, the gaps between the pellets are extremely small, Large pellets of one type may be formed. The inside of one large pellet has a single crystal structure. For example, the size of the pellet is 10 nm to 200 nm, 15 It may be between 20 nm and 50 nm, or between 20 nm and 50 nm.

[0374] According to the above-described film formation model, it is believed that the pellets are deposited on the surface of the substrate. CAAC-OS can be deposited even on a substrate that does not have a crystalline structure. Therefore, the above-mentioned film formation model, which has a growth mechanism different from epitaxial growth, is highly valid. In addition, because of the above-mentioned deposition model, the CAAC-OS and nc-OS It can be seen that it is possible to form a uniform film even on a large glass substrate. For example, Even if the structure of the substrate surface (the surface on which the film is formed) is amorphous (e.g., amorphous silicon oxide), It is possible to form a film of CAAC-OS.

[0375] In addition, even if the surface of the substrate on which the coating is to be applied is uneven, the pellets will adhere to the shape of the uneven surface. It is clear that the arrangement is

[0376] In addition, from the above-mentioned deposition model, the following conditions are required to deposit a CAAC-OS film with high crystallinity: First, in order to lengthen the mean free path, we need to use a higher vacuum. Next, in order to reduce damage near the substrate, the plasma energy is Next, heat energy is applied to the surface to be formed, and the plasma damage is reduced each time a film is formed. It will heal.

[0377] In addition, the above-mentioned deposition model is an In-M-Zn oxide target with multiple crystal grains. In the case where the material has a polycrystalline structure of a complex oxide such as a crystalline material, and one of the crystal grains contains a cleavage plane, For example, a mixture having indium oxide, an oxide of element M, and zinc oxide. The present invention can also be applied to the case where an object target is used.

[0378] The target of the mixture does not have a cleavage plane, so when sputtered, atoms are ejected from the target. During film formation, a strong electric field region of plasma is formed near the target. Therefore, atomic particles detached from the target are connected by the action of the strong electric field region of the plasma. For example, first, atomic particles of indium join together and grow laterally, forming In Next, M-Zn-O layers are formed above and below it to complement it. Thus, even when a mixed target is used, pellets may be formed. Therefore, the above-mentioned deposition model can be applied even when a mixture target is used. It is possible.

[0379] However, if a strong electric field region of the plasma is not formed near the target, the target Only atomic particles detached from the substrate are deposited on the substrate surface. In some cases, atomic particles grow laterally. However, the orientation of the atomic particles is not uniform. However, the crystal orientation in the resulting thin film is not uniform. .

[0380] (Embodiment 3) In this embodiment, a transistor having a different structure from that described in Embodiment 1 is used. The configuration will be described with reference to FIGS.

[0381] <Transistor configuration example 1> FIG. 38(A) is a top view of a transistor 270, and FIG. 38(B) is a top view of the transistor 270. FIG. 38(C) corresponds to a cross-sectional view taken along the dashed line A1-A2 in FIG. This corresponds to a cross-sectional view taken along the dashed line B1-B2 in FIG. The A1-A2 direction is called the channel length direction, and the dashed line B1-B2 direction is called the channel width direction. There are cases.

[0382] The transistor 270 includes a conductive film 204 over a substrate 202, the conductive film 204 serving as a first gate electrode. an insulating film 206 on the substrate 202 and the conductive film 204; and an insulating film 207 on the insulating film 206. The oxide semiconductor film 208 over the insulating film 207 and the insulating film 208 electrically connected to the oxide semiconductor film 208 The conductive film 212 a serving as a source electrode and the oxide semiconductor film 208 are electrically connected to each other. The conductive film 212b serving as a drain electrode is connected to the oxide semiconductor film 208 and the conductive film 21 The insulating films 214 and 216 on the conductive film 212b and the oxide semiconductor film on the insulating film 216 An insulating film 218 is provided over the oxide semiconductor film 211b.

[0383] In the transistor 270, the insulating film 214 and the insulating film 216 The oxide semiconductor film 211a functions as a second gate insulating film of the oxide semiconductor film 270. Through an opening 252c provided in the insulating film 214 and the insulating film 216, the conductive film 212b and The oxide semiconductor film 211a is used, for example, as a pixel electrode for a display device. In the transistor 270, the oxide semiconductor film 211b has a second gate It functions as a gate electrode (also called a backgate electrode).

[0384] As shown in FIG. 38C, the oxide semiconductor film 211b is formed by insulating films 206 and 207. In the openings 252a and 252b provided in the insulating film 214 and the insulating film 216, the first The conductive film 220b is connected to the conductive film 204 which functions as a gate electrode. The same potential is applied to the semiconductor film 211b.

[0385] In this embodiment, the openings 252a and 252b are provided, and the oxide semiconductor film 2 Although the configuration in which 11b and the conductive film 204 are connected has been illustrated, the present invention is not limited to this. For example, Then, only one of the openings 252a and 252b is formed, and the oxide semiconductor A structure in which the conductive film 211b and the conductive film 204 are connected, or an opening 252a and an opening 252 Alternatively, the insulating film 204 may be omitted, and the oxide semiconductor film 211b and the conductive film 204 may not be connected to each other. In the case where the oxide semiconductor film 211b and the conductive film 204 are not connected to each other, Different potentials can be applied to the conductive film 211b and the conductive film 204, respectively.

[0386] As shown in FIG. 38B, the oxide semiconductor film 208 is used as a first gate electrode. The conductive film 204 functions as a second gate electrode, and the oxide semiconductor film 211b functions as a second gate electrode. They are positioned opposite each other and are sandwiched between two conductive films that function as gate electrodes. The length in the channel length direction of the oxide semiconductor film 211b functioning as the second gate electrode and The length in the channel width direction is determined by dividing the length in the channel length direction and the channel width of the oxide semiconductor film 208. The length of the oxide semiconductor film 208 is longer than the length in each direction. The gate electrode is covered with the oxide semiconductor film 211b via the film 216. The oxide semiconductor film 211b functioning as a gate electrode and the conductive film 204 functioning as a first gate electrode are , an opening 252a provided in the insulating films 206, 207, the insulating film 214, and the insulating film 216; Since the oxide semiconductor film 208 is connected at the insulating layer 252b, the side surface of the oxide semiconductor film 208 in the channel width direction is insulated. The oxide semiconductor film 2 functions as a second gate electrode via the insulating film 214 and the insulating film 216. It faces 11b.

[0387] In other words, in the channel width direction of the transistor 270, The conductive film 204 and the oxide semiconductor film 211b functioning as a second gate electrode are Insulating films 206 and 207 functioning as a first gate insulating film and a second gate insulating film The insulating film 214 and the insulating film 216 are connected through an opening provided therein, and the first The insulating films 206 and 207 functioning as the first gate insulating film and the second gate insulating film The oxide semiconductor film 208 is surrounded by the insulating film 214 and the insulating film 216. .

[0388] With such a structure, the oxide semiconductor film 208 included in the transistor 270 The conductive film 204 functions as a first gate electrode and the conductive film 205 functions as a second gate electrode. The transistor 270 can be electrically surrounded by the electric field of the oxide semiconductor film 211b. As described above, a channel region is formed by the electric field of the first gate electrode and the second gate electrode. The device structure of the transistor that electrically surrounds the oxide semiconductor film to be formed is This can be called a d channel (s-channel) structure.

[0389] Since the transistor 270 has an s-channel structure, the first gate electrode The conductive film 204 functions as a gate insulating film, and the electric field for inducing the channel is effectively applied to the oxide semiconductor. This allows the current drive capability of the transistor 270 to be improved. It is possible to obtain high on-current characteristics. It is also possible to increase the on-current. Therefore, it is possible to miniaturize the transistor 270. The conductive film 204 functions as a first gate electrode and the oxide film 205 functions as a second gate electrode. Since the transistor 270 has a structure surrounded by the nitride semiconductor film 211b, Strength can be increased.

[0390] <Transistor configuration example 2> Next, regarding a configuration example different from that of the transistor 270 shown in FIGS. The following description will be given with reference to Figures 39(A), (B), (C), and (D). Figures 39(A) and (B) are the same as Figure 38(B). 39(C)(D) are cross-sectional views of a modified example of the transistor 270 shown in FIG. 38(B)(C) is a cross-sectional view of a modified example of the transistor 270 shown in FIG.

[0391] The transistor 270A shown in FIG. 39(A)(B) is a transistor shown in FIG. The oxide semiconductor film 208 included in the transistor 270 has a three-layer structure. The oxide semiconductor film 208 included in the transistor 270A is an oxide semiconductor film 208a. , an oxide semiconductor film 208b, and an oxide semiconductor film 208c.

[0392] The transistor 270B shown in FIG. 39(C)(D) is the same as the transistor 270 shown in FIG. The oxide semiconductor film 208 included in the transistor 270 has a two-layer structure. The oxide semiconductor film 208 included in the transistor 270B is an oxide semiconductor film 208b. , and an oxide semiconductor film 208c.

[0393] The structures of the transistors 270, 270A, and 270B shown in this embodiment are the same as those of the embodiment. The structure of the transistor 150 described in 1 can be referred to. That is, the material of the substrate 202 and The manufacturing method can be referred to for the substrate 102. The material and manufacturing method of the conductive film 204 are the same as those of the gate electrode. The materials and manufacturing methods of the insulating film 206 and the insulating film 207 are respectively The insulating film 106 and the insulating film 107 can be referred to. The oxide semiconductor film 211a and the oxide semiconductor film 211b can be referred to. The material and formation method of the conductive film 212a and the conductive film 112b can be referred to the oxide semiconductor film 111. The material and manufacturing method of the conductive film 212b refer to the source electrode 112a and the drain electrode 112b. The materials and manufacturing methods of the insulating film 214, the insulating film 216, and the insulating film 218 are as follows: For example, the insulating films 114, 116, and 118 can be seen.

[0394] Here, the band structure of the oxide semiconductor film 208 and the insulating film in contact with the oxide semiconductor film 208 is The structure will be explained with reference to FIG.

[0395] FIG. 40A illustrates the insulating film 207, the oxide semiconductor films 208a, 208b, and 208c, and This is an example of a band structure in the thickness direction of a laminated structure having an insulating film 214. ) is a multilayer structure including the insulating film 207, the oxide semiconductor films 208b and 208c, and the insulating film 214. This is an example of a band structure in the thickness direction of a layer structure. Note that the band structure is shown in the figure for ease of understanding. Therefore, the insulating film 207, the oxide semiconductor films 208a, 208b, and 208c, and the insulating film 214 are The energy level (Ec) at the bottom of the conductive band is shown.

[0396] FIG. 40A shows a case where a silicon oxide film is used as the insulating films 207 and 214, and an oxide semiconductor film is used as the insulating films 207 and 214. The conductor film 208a is a metal oxide film having an atomic ratio of In:Ga:Zn=1:1:1.2. The oxide semiconductor film 208b was formed using an oxide semiconductor film formed using an oxide target. A metal oxide target with an atomic ratio of metal elements of In:Ga:Zn=4:2:4.1 was used. The oxide semiconductor film 208c is formed by using an oxide semiconductor film having an atomic number of a metal element. The oxide formed using a metal oxide target with a ratio of In:Ga:Zn=1:1:1.2 FIG. 1 is a band diagram of a structure using a compound semiconductor film.

[0397] FIG. 40B shows that silicon oxide films are used as the insulating films 207 and 214, and oxide semiconductor films are used as the insulating films 207 and 214. The conductor film 208b is a metal oxide film having an atomic ratio of metal elements of In:Ga:Zn=4:2:4.1. The oxide semiconductor film 208c was formed using an oxide semiconductor film formed using an oxide target. A metal oxide target with an atomic ratio of metal elements of In:Ga:Zn=1:1:1.2 was used. FIG. 13 is a band diagram of a structure using an oxide semiconductor film formed in accordance with the present invention.

[0398] As shown in FIGS. 40A and 40B, in the oxide semiconductor films 208a, 208b, and 208c, In other words, the energy level at the bottom of the conduction band changes smoothly. In order to have such a band structure, the oxide The interface between the oxide semiconductor film 208a and the oxide semiconductor film 208b, or the oxide semiconductor film 208b At the interface between the oxide semiconductor film 208c and the oxide semiconductor film 208c, defect quasi-states such as trap centers and recombination centers are generated. Assume that there are no impurities that would form positions.

[0399] In order to form a continuous junction in the oxide semiconductor films 208a, 208b, and 208c, Each film is deposited using a multi-chamber deposition system (sputtering system) equipped with a lock chamber. It is necessary to continuously stack the layers without exposing them to the air.

[0400] With the structure shown in FIG. 40A and FIG. 40B, the oxide semiconductor film 208b serves as a well. In the transistor using the above stacked structure, the channel region is formed of the oxide semiconductor film 2 It can be seen that it is formed in 08b.

[0401] Note that by providing the oxide semiconductor films 208a and 208c, the oxide semiconductor film 208 Therefore, trap states that may be formed in the oxide semiconductor film 208b can be made farther away from the oxide semiconductor film 208b.

[0402] In addition, the trap level is below the conduction band of the oxide semiconductor film 208b functioning as a channel region. The energy level (Ec) of the edge of the trap is farther from the vacuum level, making it easier for electrons to accumulate in the trap level. When electrons accumulate in the trap level, negative charges are fixed. This causes the threshold voltage of the transistor to shift in the positive direction. The trap level is lower than the energy level (Ec) of the conduction band minimum of the oxide semiconductor film 208b. It is preferable to configure the trap level so that the trap level is close to the empty level. This makes it difficult for electrons to accumulate, which makes it possible to increase the on-state current of the transistor. , the field effect mobility can be increased.

[0403] In addition, the oxide semiconductor films 208a and 208c have a conduction band lower than that of the oxide semiconductor film 208b. The energy level of the edge of the oxide semiconductor film 208b is close to the vacuum level. and the energy levels of the conduction band minimums of the oxide semiconductor films 208a and 208c. The difference between the two is 0.15 eV or more, or 0.5 eV or more and 2 eV or less, or 1 eV That is, the electron affinity of the oxide semiconductor films 208a and 208c and the The difference between the electron affinity of the solid film 208b and the electron affinity of the solid film 208c is 0.15 eV or more, or 0.5 eV or more, and eV or less, or 1 eV or less.

[0404] With such a structure, the oxide semiconductor film 208b serves as a main current path. That is, the oxide semiconductor film 208b functions as a channel region, and the oxide semiconductor film 2 The oxide semiconductor film 208a and 208c function as oxide insulating films. a and 208c are metal elements constituting the oxide semiconductor film 208b in which the channel region is formed. Since the oxide semiconductor film 208a is made of one or more of the oxide semiconductor films At the interface with the oxide semiconductor film 208b or at the interface between the oxide semiconductor film 208b and the oxide semiconductor film 208c At the interface, the interface scattering is unlikely to occur. Therefore, at the interface, the movement of carriers is Since the electrons are not inhibited, the field effect mobility of the transistor is increased.

[0405] In addition, the oxide semiconductor films 208a and 208c function as part of a channel region. To prevent this, a material with sufficiently low electrical conductivity is used. The films 208a and 208c are also called oxide insulating films based on their physical properties and / or functions. In addition, the oxide semiconductor films 208a and 208c have a high electron affinity (vacuum level and the energy level at the bottom of the conduction band) is smaller than that of the oxide semiconductor film 208b. The energy level of the conduction band minimum of the oxide semiconductor film 208b is different from that of the oxide semiconductor film 208c ( In addition, the material with the band offset is used. In order to prevent a difference in threshold voltage between the oxide semiconductor films 208a and 208b, The energy level of the conduction band minimum of the oxide semiconductor film 208c is lower than that of the oxide semiconductor film 208b. It is preferable to use a material having a vacuum level closer to the Gamma level. For example, The energy levels of the conduction band minimums of the oxide semiconductor films 208a and 208c are The difference between the energy level of the I wish.

[0406] In addition, the oxide semiconductor films 208a and 208c do not contain a spinel crystal structure. It is preferable that the oxide semiconductor films 208a and 208c have a spinel crystal structure. When the spinel type crystal structure includes the conductive film 212a, 212b, the conductive film 212c is formed at the interface between the spinel type crystal structure and other regions. In some cases, the constituent elements of the oxide semiconductor film 208b may diffuse into the oxide semiconductor film 208b. When the conductive films 208a and 208c are made of CAAC-OS, the structure of the conductive films 212a and 212b is This is preferable because it enhances the blocking property of the component element, for example, copper element.

[0407] The thicknesses of the oxide semiconductor films 208a and 208c are determined by the composition of the conductive films 212a and 212b. The thickness of the insulating film is equal to or larger than the thickness at which the insulating film is prevented from diffusing into the oxide semiconductor film 208b. The thickness of the oxide semiconductor film 208b is set to be less than the thickness at which oxygen supply from the film 214 to the oxide semiconductor film 208b is suppressed. For example, When the thickness of the oxide semiconductor films 208a and 208c is 10 nm or more, the conductive film 212a This can prevent the constituent elements of the oxide semiconductor film 212b from diffusing into the oxide semiconductor film 208b. In addition, when the thickness of the oxide semiconductor films 208a and 208c is set to 100 nm or less, the insulating film 214 Therefore, oxygen can be effectively supplied to the oxide semiconductor film 208b.

[0408] In this embodiment, the oxide semiconductor films 208a and 208c are formed using a metal element. The atomic ratio of In:Ga:Zn was 1:1:1.2. However, the present invention is not limited to this structure. The compound semiconductor films 208a and 208c are made of In:Ga:Zn=1:1:1 [atomic ratio], In:Ga:Zn=1:3:2 [atomic ratio], In:Ga:Zn=1:3:4 [atomic ratio] ], or a metal oxide target with In:Ga:Zn=1:3:6 [atomic ratio] A formed oxide semiconductor film may be used.

[0409] Note that the oxide semiconductor films 208a and 208c were formed using a compound in which In:Ga:Zn=1:1:1 [original When a metal oxide target having a molecular weight ratio of 1:1 or less is used, the oxide semiconductor films 208a and 208c are In:Ga:Zn=1:β1(0<β1≦2):β2(0<β2≦3) In addition, the oxide semiconductor films 208a and 208c were formed of In:Ga:Zn=1:3:4 [prime When a metal oxide target having a molecular weight ratio of 1:1 or less is used, the oxide semiconductor films 208a and 208c are In:Ga:Zn=1:β3(1≦β3≦5):β4(2≦β4≦6) The oxide semiconductor films 208a and 208c were formed of In:Ga:Zn=1:3:6 [primary When a metal oxide target having a molecular weight ratio of 1:1 or less is used, the oxide semiconductor films 208a and 208c are In:Ga:Zn=1:β5(1≦β5≦5):β6(4≦β6≦8) .

[0410] In addition, the oxide semiconductor film 208 included in the transistor 270 and the transistor 270A In the drawing, the oxide semiconductor film 208c in the semiconductor device 270B is the conductive film 212a. In other words, a part of the oxide semiconductor film becomes concave. However, one embodiment of the present invention is not limited to this. The oxide semiconductor film in the region not overlapping with the conductive films 212a and 212b does not necessarily have to have a recess. An example of this case is shown in Figure 41 (A) and (B). 41A and 41B are cross-sectional views showing an example of the transistor 270B shown above. The oxide semiconductor film 208 does not have a recess.

[0411] As shown in FIG. 41C and FIG. 41D, the thickness of the oxide semiconductor film 208c is set to 100 nm by pre-oxidizing the oxide semiconductor film 208c. The oxide semiconductor film 208c and the insulating film 207 are formed thinner than the oxide semiconductor film 208b. In this case, the insulating film 219 may be formed over the oxide semiconductor film 208. The insulating film 219 is formed with openings so that the insulating film 219 c is in contact with the conductive film 212 a and the conductive film 212 b. It can be formed by the same material and method as the insulating film 214.

[0412] In addition, the transistor according to the present embodiment can be freely combined with each of the above structures. It is possible.

[0413] The structures and methods described in this embodiment mode may be appropriately combined with the structures and methods described in other embodiment modes. They can be used in combination.

[0414] (Embodiment 4) In this embodiment, a configuration example of a light emitting element that can be used for the light emitting element 280 will be described. Note that the EL layer 1320 shown in this embodiment is the same as the EL layer 2 shown in the other embodiments. This is equivalent to 81.

[0415] <Configuration of light-emitting element> The light-emitting element 1330 shown in FIG. 42A has a pair of electrodes (electrode 1318 and electrode 1322). In the following description of the present embodiment, For example, electrode 1318 is used as an anode and electrode 1322 is used as a cathode. do.

[0416] The EL layer 1320 may be formed to include at least a light-emitting layer. The functional layer other than the light-emitting layer may be a layered structure including a hole-injecting layer. high hole transporting material, high electron transporting material, high electron injecting material, A layer containing a polar substance (a substance having high electron and hole transporting properties) can be used. Specifically, functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer are appropriately combined. It can be used in combination.

[0417] The light-emitting element 1330 shown in FIG. 42(A) is provided between an electrode 1318 and an electrode 1322. The applied potential difference causes a current to flow, and holes and electrons recombine in the EL layer 1320, emitting light. In other words, the EL layer 1320 is configured to form a light emitting region.

[0418] In the present invention, light emitted from the light emitting element 1330 is incident on the electrode 1318 or the electrode 1322. Therefore, either the electrode 1318 or the electrode 1322 is made of a material having optical transparency.

[0419] In addition, the EL layer 1320 is formed by disposing an electrode 1318 as in the case of a light-emitting element 1331 shown in FIG. A plurality of layers may be laminated between the electrode 1322 and the electrode 1322. In the case of having the structure, the mth (m is a natural number equal to or greater than 1 and smaller than n) EL layer 132 Between the 0th and (m+1)th EL layers 1320, a charge generating layer 1320a is provided. It is preferable that the structure other than the electrodes 1318 and 1322 is the same as that of the EL layer of the above embodiment. This is equivalent to 281.

[0420] The charge generating layer 1320a may be formed using a composite material of an organic compound and a metal oxide. Examples of metal oxides include vanadium oxide, molybdenum oxide, and tungsten oxide. Examples of the organic compound include aromatic amine compounds, carbazole derivatives, Aromatic hydrocarbons, or oligomers, dendrimers, and polymers that have these as their basic skeletons As the organic compound, a compound having a hole transporting property can be used. The hole mobility of the organic compound is 10 -6 cm 2 It is preferable to apply a value of 0.1 V or more. However, other materials may be used as long as they have a higher hole transporting property than an electron transporting property. In addition, the materials used for the charge generation layer 1320a have the following characteristics: carrier injection property, carrier Due to its excellent transport properties, it is possible to realize low current and low voltage driving of the light emitting element 1331. In addition to the above composite materials, the above composite materials can also be made of alkali metals, alkaline earth metals, etc. , an alkali metal compound, an alkaline earth metal compound, or the like is added to the charge generating layer 1320 It may also be used for a.

[0421] The charge generating layer 1320a is made of a composite material of an organic compound and a metal oxide, and other materials. For example, a layer including a composite material of an organic compound and a metal oxide and a layer including an electrode may be formed. A layer containing a compound selected from among electron donating substances and a compound with high electron transport properties is combined. Alternatively, a layer containing a composite material of an organic compound and a metal oxide and a transparent conductive layer may be formed together. It may be formed in combination with a conductive film.

[0422] The light-emitting element 1331 having such a configuration has an energy distribution between adjacent EL layers 1320. It is easy to make a light-emitting element that is difficult to cause the migration of electrons and has both high luminous efficiency and a long life. It is also easy to obtain phosphorescence in one light-emitting layer and fluorescence in the other.

[0423] The charge generating layer 1320a is a layer that is generated when a voltage is applied between the electrodes 1318 and 1322. Then, holes are injected into one of the EL layers 1320 formed in contact with the charge generating layer 1320a. and has a function of injecting electrons into the other EL layer 1320.

[0424] The light-emitting element 1331 shown in FIG. 42B has a structure in which the type of light-emitting substance used in the EL layer 1320 is changed. By combining these, various luminescent colors can be obtained. By using multiple light-emitting materials, it is possible to obtain a broad spectrum of light and white light. It is also possible.

[0425] When white light is to be emitted using the light-emitting element 1331 shown in FIG. The combination may be any combination that includes red, blue, and green light and emits white light. For example, For example, an EL layer containing a blue fluorescent material as the luminescent material and a layer containing green and red phosphorescent materials as the luminescent material may be used. In addition, a red emitting EL layer and a green emitting EL layer may be used. It is also possible to have a structure having an EL layer that emits light and an EL layer that emits blue light. In the case of a device having an EL layer that emits light of a complementary color, white light can be obtained. In a stacked element with two L layers, the luminescent colors from these EL layers are in a complementary relationship. In this case, examples of complementary colors include blue and yellow, or blue-green and red. can be done.

[0426] In the above-mentioned stacked element configuration, a charge generating layer is disposed between stacked light emitting layers. By doing so, it is possible to obtain high-luminance light emission while keeping the current density low, and to realize a long-life element. It can be realized.

[0427] This embodiment can be implemented in appropriate combination with the configurations described in other embodiments. It is Noh.

[0428] (Embodiment 5) In this embodiment, a display module and an electronic device having a touch panel according to one embodiment of the present invention will be described. The container will be described with reference to FIGS.

[0429] The touch panel of one embodiment of the present invention can be used for the touch panel 8004, for example. do.

[0430] The display module 8000 shown in FIG. 43 includes an upper cover 8001 and a lower cover 8002. Between them, touch panel 8004 connected to FPC8003, A display panel 8006, a backlight 8007, a frame 8009, and a printed circuit board 801 0, has battery 8011.

[0431] The display device of one embodiment of the present invention can be used for the display panel 8006, for example.

[0432] The upper cover 8001 and the lower cover 8002 are connected to the touch panel 8004 and the display panel The shape and dimensions can be changed as appropriate to match the size of 8006.

[0433] The touch panel 8004 is a resistive or capacitive touch panel. The display panel 8006 can be used by overlapping it with the opposing substrate (sealing substrate). It is also possible to provide the display panel 8 with a touch panel function. It is also possible to provide an optical sensor in each pixel of the display panel 006 to make it into an optical touch panel.

[0434] The backlight 8007 includes a light source 8008 .

[0435] In FIG. 43, the light source 8008 is disposed above the backlight 8007. However, the present invention is not limited to this. For example, a light source 8008 is provided at the end of the backlight 8007. In addition, a light diffusing plate may be used. In the case of using a light emitting element such as a backlight 800, or in the case of a reflective panel, 7 may not be provided.

[0436] The frame 8009 protects the display panel 8006 and also supports the movement of the printed circuit board 8010. It also functions as an electromagnetic shield to block electromagnetic waves generated by the operation of the frame. The frame 8009 may also function as a heat sink.

[0437] The printed circuit board 8010 includes a power supply circuit, a signal circuit for outputting a video signal, and a clock signal. The power supply circuit is provided with a signal processing circuit. Alternatively, the power source may be a battery 8011 provided separately. , this can be omitted when using a commercial power source.

[0438] In addition, the display module 8000 includes components such as a polarizing plate, a retardation plate, and a prism sheet. It may be added.

[0439] 44(A) to (H) and 45 are diagrams showing electronic devices. These electronic devices are , a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, and an operation key 5005 (including a power switch or an operation switch), a connection terminal 5006, a sensor 500 7 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemistry Material, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, (including a function to measure odor or infrared rays), microphone 5008, etc. This can be done.

[0440] FIG. 44(A) shows a mobile computer, which includes, in addition to the above, a switch 5009. , an infrared port 5010, etc. FIG. 44(B) shows a mobile phone equipped with a recording medium. A portable image reproducing device (e.g., a DVD reproducing device) and, in addition to the above, the following devices are also included: The display unit 5002, the recording medium reading unit 5011, etc. The vision device may include, in addition to the above, a stand 5012 and the like. The television device can be operated using an operation switch provided in the housing 5000 or a separate remote control. The remote control unit 5013 has an operation key. This allows you to control the channel and volume, and manipulate the image displayed on the display unit 5001. In addition, the remote control operation device 5013 can be operated by the remote control operation device 5013. A display unit for displaying information output from the portable game device may be provided. In addition to the above, the device may also include a recording medium reading unit 5011. 44(E) is a digital camera with a television receiving function, and in addition to the above, 5014, a shutter button 5015, an image receiving unit 5016, etc. 4(F) is a portable gaming machine, which, in addition to the above, has a second display unit 5002, a recording medium reader / writer, FIG. 44(G) shows a portable television receiver. In addition to the above, a charger 5017 capable of transmitting and receiving signals may be included. FIG. 44(H) shows a wristwatch type information terminal, which, in addition to the above, includes a band 5018, a clasp, and The housing 5000, which also serves as a bezel, may have a clasp 5019, etc. The display unit 5001 has a non-rectangular display area. icon 5020, other icons 5021, etc. can be displayed. This is a digital signage. ) is a digital signage mounted on a cylindrical pillar.

[0441] The electronic devices shown in FIGS. 44(A) to 44(H) and 45 can have various functions. For example, functions to display various information (still images, videos, text images, etc.) on the display unit, Touch panel function, calendar, date or time display function, various software (Program-based) processing control function, wireless communication function, and various Functions for connecting to computer networks and transmitting various data using wireless communication functions or reception function, and reading and displaying programs or data recorded on a recording medium. Furthermore, the electronic device may have a function of displaying information on a display unit. In this case, one display section is used mainly to display image information, and another display section is used mainly to display text. A function to display information, or a function to display images that take parallax into account on multiple displays to create a three-dimensional effect. Furthermore, in electronic devices having an image receiving unit, The functions include taking still images, taking videos, and automatically or manually correcting the captured images. The camera has a function to correct the captured image, a function to save the captured image on a recording medium (external or built-in to the camera), The image displayed on the display unit can be displayed in the same manner as in FIG. ) and the functions that the electronic device shown in FIG. 45 can have are not limited to these, and various functions can be used. It is possible to have the ability.

[0442] The electronic device of the present embodiment is characterized in that it has a display unit for displaying some information. The touch panel of one embodiment of the present invention can be used for the display portion.

[0443] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. [Explanation of symbols]

[0444] 10 Touch Panel 11 Substrate 12 Substrate 13 FPC 14 Conductive film 20 Liquid crystal element 21 Conductive film 21a Conductive film 21b Conductive film 22 Conductive Film 23 Liquid crystal 24 Insulating film 31 Colored film 41 Conductive Film 43 FPC 61 Wiring 62 Wiring 63 Transistor 64 Liquid crystal element 65 blocks 65_1 Block 65_2 Block 66_1 Wiring 66_4 Wiring Block 67_1 67_4 Block 71 Wiring 71_1 Wiring 71_2 Wiring 72 Wiring 72_1 Wiring 72_2 Wiring 102 Substrate 104 Gate electrode 104a Conductive film 106 Insulating film 107 Insulating film 108 Insulating film 110 Oxide semiconductor film 111 Oxide semiconductor film 111a Oxide semiconductor film 111b Oxide semiconductor film 111c Oxide semiconductor film 112 Conductive film 112a Source electrode 112b Drain electrode 114 Insulating film 116 Insulating film 118 Insulating film 119 Insulating film 120 Conductive film 141 Aperture 142 Aperture 150 Transistors 151 Sealing material 160 Capacitive element 193 Target 194 Plasma 202 Substrate 204 Conductive Film 206 Insulating Film 207 Insulating Film 208 Oxide Semiconductor Film 208a Oxide semiconductor film 208b Oxide semiconductor film 208c Oxide semiconductor film 211a Oxide semiconductor film 211b Oxide semiconductor film 212a Conductive film 212b Conductive film 214 Insulating film 216 Insulating film 218 Insulating film 219 Insulating Film 220b Conductive film 252a opening 252b opening 252c opening 270 Transistors 270A Transistor 270B Transistor 280 Light-emitting element 281 EL layer 282 Conductive Film 285 Conductive Film 286 Conductive Film 301 Transistor 306 Connection 308 Liquid crystal element 310 Touch Panel 316 Spacer 317 Conductive Film 319 Connection Layer 320 Touch Panel 331G Colored film 331R colored film 332 Light-shielding film 333 Aperture 334 Conductive Film 335 Conductive Film 336 Aperture 341 Conductive Film 353 Liquid crystal 355 Insulating Film 372 Substrate 373 FPC 374 IC 375 FPC 381 Display section 382 Drive circuit 384 Drive circuit 385 Aperture 386 Wiring 388G pixels 388R pixels 391 Insulating Film 601 Pulse voltage output circuit 602 Current detection circuit 603 capacity 621 Electrode 622 Electrode 1318 Electrode 1320 EL layer 1320a Charge generating layer 1322 Electrode 1330 Light emitting element 1331 Light emitting element 5000 cabinet 5001 Display section 5002 Display section 5003 Speaker 5004 LED Lamp 5005 Operation key 5006 Connection terminal 5007 Sensor 5008 Microphone 5009 Switch 5010 Infrared port 5011 Recording medium reading unit 5012 Stand 5013 Remote control device 5014 Antenna 5015 Shutter button 5016 Image receiving unit 5017 charger 5018 Band 5019 Clasp 5020 Icon 5021 Icon 5100 pellets 5120 PCB 5161 area 5200 pellets 5201 AEON 5202 Lateral growth part 5203 particles 5220 PCB 5230 Target 5240 Plasma 5260 Heating mechanism 8000 Display Module 8001 Top cover 8002 Lower cover 8003 FPC 8004 Touch Panel 8005 FPC 8006 Display Panel 8007 Backlight 8008 light source 8009 Frame 8010 Printed Circuit Board 8011 Battery

Claims

1. A semiconductor device having a first electrode of a touch sensor, a second electrode of the touch sensor, and a wiring electrically connected to the first electrode, A gate electrode of a transistor; a gate insulating film provided in contact with the wiring and the gate electrode; a semiconductor film having a channel formation region of the transistor, the semiconductor film being provided in contact with the gate insulating film; a source electrode and a drain electrode electrically connected to the semiconductor film; a first insulating film provided on the semiconductor film, the source electrode, and the drain electrode; a first metal oxide film and a second metal oxide film provided on the first insulating film so as to be in contact with the first insulating film; a second insulating film provided on the first metal oxide film and the second metal oxide film; a pixel electrode provided on the second insulating film; having the first electrode includes the first metal oxide film, the second electrode includes the second metal oxide film; the first metal oxide film and the second metal oxide film comprise the same material; the wiring includes the same material as the gate electrode; In a plan view, the wiring is disposed to extend in a first direction, In a plan view, the second electrode is disposed to extend in a second direction intersecting the first direction.

2. a first substrate, a second substrate, a liquid crystal between the first substrate and the second substrate, and a spacer provided on a surface of the first substrate facing the second substrate; A semiconductor device having, on the first substrate, a first electrode of a touch sensor, a second electrode of the touch sensor, and wiring electrically connected to the first electrode, A gate electrode of a transistor; a gate insulating film provided in contact with the wiring and the gate electrode; a semiconductor film having a channel formation region of the transistor, the semiconductor film being provided in contact with the gate insulating film; a source electrode and a drain electrode electrically connected to the semiconductor film; a first insulating film provided on the semiconductor film, the source electrode, and the drain electrode; a first metal oxide film and a second metal oxide film provided on the first insulating film so as to be in contact with the first insulating film; a second insulating film provided on the first metal oxide film and the second metal oxide film; a pixel electrode provided on the second insulating film; having the first electrode includes the first metal oxide film, the second electrode includes the second metal oxide film; the first metal oxide film and the second metal oxide film comprise the same material; the wiring includes the same material as the gate electrode; In a plan view, the wiring is disposed to extend in a first direction, In a plan view, the second electrode is disposed to extend in a second direction intersecting the first direction.

3. a first substrate, a second substrate, a liquid crystal between the first substrate and the second substrate, and a spacer provided on a surface of the first substrate facing the second substrate; On the first substrate, A plurality of pixel circuits each having a transistor and a pixel electrode electrically connected to one of a source electrode or a drain electrode of the transistor; a plurality of first electrodes of the touch sensor; a plurality of second electrodes of the touch sensor; a wiring electrically connected to the first electrode, The transistor is a semiconductor device including a gate electrode, a semiconductor film having a channel formation region, and a source electrode and a drain electrode electrically connected to the semiconductor film, a first insulating film provided on the semiconductor film, the source electrode, and the drain electrode; a first metal oxide film and a second metal oxide film provided on the first insulating film so as to be in contact with the first insulating film; a second insulating film provided on the first metal oxide film and the second metal oxide film; the pixel electrode is provided on and in contact with the second insulating film, the first metal oxide film functions as the first electrode; the second metal oxide film functions as the second electrode; In a plan view, the wiring is disposed to extend in a first direction, In a plan view, the second electrode is disposed to extend in a second direction intersecting the first direction, The semiconductor device, wherein, in a plan view, the wiring is arranged to overlap a region between adjacent first electrodes in the second direction among the plurality of first electrodes.

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