Semiconductor Device

Abstract

To provide a semiconductor device with an oxide semiconductor film.SOLUTION: A semiconductor device 100 consists of a transistor Tr1 and a transistor Tr2. The transistor Tr1 has: a first gate electrode 104; a first insulating film 106 on the first gate electrode; a first oxide semiconductor film 108 on the first insulating film; a first source electrode 112a and a first drain electrode 112b on the first oxide semiconductor film; a second insulating film 114, 116 on the first oxide semiconductor film, the first source electrode, and the first drain electrode; and a second gate electrode 122c on the second insulating film. The transistor Tr2 has: a first drain electrode; the second insulating film on the first drain electrode; a second oxide semiconductor film 128 on the second insulating film; a second source electrode 122a and a second drain electrode 122b on the second oxide semiconductor film; a third insulating film 124, 126 on the second oxide semiconductor film, the second source electrode, and the second drain electrode; and a third gate electrode 130 on the third insulating film. The first and second oxide semiconductor films have regions overlapped with each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One embodiment of the present invention is a semiconductor device including an oxide semiconductor film and a display device including the semiconductor device. Regarding the device.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect of the present invention relates to a product, a method, or a manufacturing method. process, machine, manufacture, or composition of matter In particular, one embodiment of the present invention relates to a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, The present invention relates to a device, 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. Optical devices, power generation devices (including thin-film solar cells, organic thin-film solar cells, etc.), and electronic devices The device may include a semiconductor device. [Background technology]

[0004] A transistor (field effect transistor) is made using a semiconductor thin film formed on a substrate with an insulating surface. The technology that makes up the field-effect transistor (FET) or thin-film transistor (TFT) is attracting attention. The transistor is used in integrated circuits (ICs) and image display devices (display devices). It is widely used in electronic devices. Silicon is a semiconductor thin film that can be used in transistors. Semiconductor materials such as silicon are widely known, but oxide semiconductors are also attracting attention. It is being watched.

[0005] For example, Patent Document 1 discloses a first transistor using an oxide semiconductor film and a second transistor using an oxide semiconductor film. By stacking a second transistor using a dielectric film, multiple memory cells can be stacked. There is disclosed a technology for reducing the cell area by using a multilayer structure.

[0006] In addition, Patent Document 2 discloses a pixel section having a plurality of pixels arranged two-dimensionally, The display device includes a driving circuit section for driving the display, and the first layer includes the driving circuit section, and the second layer includes the pixel section. By stacking, the space required for arranging the driver circuit unit in the peripheral area of ​​the pixel unit is reduced. The technology is disclosed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-138191 A [Patent Document 2] JP 2015-194577 A Summary of the Invention [Problem to be solved by the invention]

[0008] As shown in Patent Documents 1 and 2, by stacking multiple transistors, On the other hand, stacking multiple transistors reduces the area required for placement. This increases the number of wafers or the number of steps.

[0009] In view of the above problems, one embodiment of the present invention is a semiconductor device including a plurality of stacked transistors. One of the objectives is to provide a semiconductor device with a small increase in the number of masks or steps. Alternatively, in one embodiment of the present invention, a plurality of transistors each including an oxide semiconductor film are stacked. To provide a semiconductor device with a small increase in the number of masks or steps. Another object of one embodiment of the present invention is to provide a novel semiconductor device. This is one of the topics.

[0010] The above description of the problem does not preclude the existence of other problems. The embodiment does not necessarily have to solve all of these problems. Problems other than those mentioned above may be solved by the specification. The above problems are obvious from the description of the specification, etc., and problems other than those mentioned above cannot be extracted from the description of the specification, etc. It is possible to issue it. [Means for solving the problem]

[0011] One embodiment of the present invention is a semiconductor device including a first transistor and a second transistor. The first transistor includes a first gate electrode and a first gate electrode. an insulating film, a first oxide semiconductor film on the first insulating film, and a first a source electrode, a first drain electrode on the first oxide semiconductor film, and a first oxide semiconductor film a second insulating film on the first source electrode and the first drain electrode; The first transistor has a first drain electrode and a second gate electrode. A second insulating film on the doped electrode, a second oxide semiconductor film on the second insulating film, and a second oxide a second source electrode on the semiconductor film; a second drain electrode on the second oxide semiconductor film; a third insulating film on the second oxide semiconductor film, the second source electrode, and the second drain electrode; a third gate electrode on the third insulating film; and The semiconductor film is a semiconductor device having overlapping regions.

[0012] Another embodiment of the present invention is a semiconductor device including a first transistor and a second transistor. The first transistor has a first gate electrode and a second gate electrode a first insulating film on the first oxide semiconductor film; and a first oxide semiconductor film on the first insulating film. a first source electrode on the first oxide semiconductor film; a first drain electrode on the first oxide semiconductor film; a second insulating film on the semiconductor film, the first source electrode, and the first drain electrode; a second gate electrode on the insulating film, and the second transistor has a third gate electrode on the first insulating film. a second insulating film on the third gate electrode; and a transistor formed on the second insulating film. a second oxide semiconductor film having a channel region, a source region, and a drain region; a third insulating film in contact with the region; a fourth gate electrode in contact with the third insulating film; and a source region; A fourth insulating film electrically connected to the drain region and the fourth gate electrode and a fourth insulating film electrically connected to the source region. a second source electrode electrically connected to the drain region; and a second drain electrode electrically connected to the drain region. The first oxide semiconductor film and the second oxide semiconductor film have an overlapping region. It is a semiconductor device.

[0013] In the above embodiment, the first gate electrode and the second gate electrode are a first insulating film and and a second insulating film connected to the first oxide semiconductor film through an opening formed in the first insulating film. It is preferable to have a region located outside the end portion.

[0014] In the above embodiment, either the first oxide semiconductor film or the second oxide semiconductor film One or both of the elements have In, Zn, and M (wherein M is Al, Ga, Y, or Sn). It is preferable to do so.

[0015] In the above embodiment, the atomic ratio of In, M, and Zn is In:M:Zn=4: 2:3, and when In is 4, M is 1.5 to 2.5 and Zn is 2 or less. It is preferable that the top 4 or lower.

[0016] In the above embodiment, either the first oxide semiconductor film or the second oxide semiconductor film It is preferable that one or both of them have a crystalline portion, and the crystalline portion has a c-axis orientation.

[0017] Another embodiment of the present invention is a semiconductor device having a first transistor and a second transistor. A semiconductor device, comprising: a first transistor including a first oxide semiconductor film and a first oxide semiconductor A first insulating film on the conductive film and a region overlapping the first oxide semiconductor film with the first insulating film therebetween. a first conductive film having a region, a second insulating film on the first oxide semiconductor film, and a second insulating film on the first conductive film. a second conductive film on the first oxide semiconductor film; and a third conductive film on the first oxide semiconductor film. a third insulating film over the first oxide semiconductor film, the second conductive film, and the third conductive film; The first oxide semiconductor film has a channel region in contact with the first insulating film and a second insulating film. The second transistor has a source region in contact with the insulating film and a drain region in contact with the second insulating film. The transistor includes a third conductive film, a third insulating film on the third conductive film, and a second insulating film on the third insulating film. a fourth conductive film over the second oxide semiconductor film; and a fifth conductive film on the first oxide semiconductor film. The semiconductor device has overlapping regions.

[0018] Another embodiment of the present invention is a semiconductor device having a first transistor and a second transistor. A semiconductor device, comprising: a first transistor including a first oxide semiconductor film and a first oxide semiconductor A first insulating film on the conductive film and a region overlapping the first oxide semiconductor film with the first insulating film therebetween. a first conductive film having a region, a second insulating film on the first oxide semiconductor film, and a second insulating film on the first conductive film. a second conductive film on the first oxide semiconductor film; and a third conductive film on the first oxide semiconductor film. a third insulating film over the first oxide semiconductor film, the second conductive film, and the third conductive film; The first oxide semiconductor film has a channel region in contact with the first insulating film and a second insulating film. The second transistor has a source region in contact with the insulating film and a drain region in contact with the second insulating film. The transistor includes a third conductive film, a third insulating film on the third conductive film, and a second insulating film on the third insulating film. a fourth conductive film over the second oxide semiconductor film; a fifth conductive film over the second oxide semiconductor film, a fourth conductive film over the fifth conductive film, a first insulating film and a second insulating film, the first insulating film and the second oxide semiconductor film being overlapped with each other with a fourth insulating film interposed therebetween; The first oxide semiconductor film and the second oxide semiconductor film are overlapped with each other. The semiconductor device has a region.

[0019] Another embodiment of the present invention is a semiconductor device having a first transistor and a second transistor. A semiconductor device, comprising: a first transistor including a first oxide semiconductor film and a first oxide semiconductor A first insulating film on the conductive film and a region overlapping the first oxide semiconductor film with the first insulating film therebetween. a first conductive film having a region, a second insulating film on the first oxide semiconductor film, and a second insulating film on the first conductive film. a second conductive film on the first oxide semiconductor film; and a third conductive film on the first oxide semiconductor film. a third insulating film over the first oxide semiconductor film, the second conductive film, and the third conductive film; The first oxide semiconductor film has a channel region in contact with the first insulating film and a second insulating film. The second transistor has a source region in contact with the insulating film and a drain region in contact with the second insulating film. The transistor includes a third conductive film, a third insulating film on the third conductive film, and a second insulating film on the third insulating film. a fourth conductive film over the second oxide semiconductor film; a fifth conductive film on the first oxide semiconductor film, a fourth insulating film on the second oxide semiconductor film, and a fourth insulating film sandwiched therebetween. a sixth conductive film having a region overlapping with the second oxide semiconductor film; a fifth insulating film over the second oxide semiconductor film and a sixth conductive film; A channel region in contact with the insulating film, a source region in contact with the fifth insulating film, and a second insulating film in contact with the fifth insulating film. and a drain region corresponding to the first oxide semiconductor film and the second oxide semiconductor film. The semiconductor device has overlapping regions.

[0020] In each of the above structures, one of the first oxide semiconductor film and the second oxide semiconductor film Or both have In, M (wherein M is Al, Ga, Y, or Sn), and Zn. preferable.

[0021] In each of the above structures, the atomic ratio of In, M, and Zn is In:M:Zn=4. :2:3, and when In is 4, M is 1.5 to 2.5, and Zn is 2 It is preferable that the number is 4 or less.

[0022] In each of the above structures, any one of the first oxide semiconductor film and the second oxide semiconductor film It is preferable that one or both of them have a crystalline portion, and the crystalline portion has a c-axis orientation.

[0023] Another embodiment of the present invention is a semiconductor device comprising: The display device has an organic compound. It is preferable that the polymer compound is included.

[0024] Another embodiment of the present invention is a display module including the above display device and a touch sensor. Another aspect of the present invention is a semiconductor device according to any one of the above aspects. An electronic device having the above display device or the above display module, and an operation key or a battery. It is a vessel. Effect of the Invention

[0025] According to one embodiment of the present invention, in a semiconductor device in which a plurality of transistors are stacked, It is possible to provide a semiconductor device with a small increase in the number of processes or steps. According to an embodiment, in a semiconductor device in which a plurality of transistors each having an oxide semiconductor film are stacked, It is possible to provide a semiconductor device with a small increase in the number of masks or steps. According to one embodiment of the present invention, a novel semiconductor device can be provided.

[0026] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. The above will become apparent from the description in the specification, drawings, claims, etc. It is possible to extract other effects from the descriptions in the claims, etc. [Brief description of the drawings]

[0027] [Figure 1] 1A and 1B are diagrams illustrating a top view and a cross section of a semiconductor device. [Diagram 2] 1A to 1C are diagrams illustrating a circuit of a semiconductor device. [Diagram 3] 1A to 1C are cross-sectional views of a semiconductor device. [Figure 4] 1A to 1C are cross-sectional views of a semiconductor device. [Diagram 5] 1A to 1C are cross-sectional views of a semiconductor device. [Figure 6] 1A to 1C are cross-sectional views of a semiconductor device. [Figure 7] FIG. 1 is a diagram illustrating energy bands. [Figure 8] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 9] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 10] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 11] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 12] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 13] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 14] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 15] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 16] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 17] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 18] 1A and 1B are diagrams illustrating a top view and a cross section of a semiconductor device. [Figure 19] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 20] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 21] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 22] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 23] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 24] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 25] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 26] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 27] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 28] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 29] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 30] 1A and 1B are diagrams illustrating a top view and a cross section of a semiconductor device. [Diagram 31] 1A to 1C are diagrams illustrating a circuit of a semiconductor device. [Diagram 32] 1A to 1C are cross-sectional views of a semiconductor device. [Diagram 33] 1A to 1C are cross-sectional views of a semiconductor device. [Diagram 34] 1A to 1C are cross-sectional views of a semiconductor device. [Diagram 35] FIG. 1 is a diagram illustrating energy bands. [Diagram 36] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 37] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 38] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 39] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 40] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 41] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 42] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 43] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 44] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Diagram 45] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 46] 1A and 1B are diagrams illustrating a top view and a cross section of a semiconductor device. [Figure 47] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 48] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 49] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 50] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 51] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 52] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 53] 1A and 1B are a top view and a cross-sectional view illustrating a method for manufacturing a semiconductor device. [Figure 54] FIG. [Figure 55] 1A to 1C are schematic cross-sectional views illustrating a method for producing an EL layer. [Figure 56] FIG. 2 is a conceptual diagram illustrating a droplet ejection device. [Figure 57] 1A and 1B are diagrams illustrating the range of atomic ratios of oxide semiconductors. [Figure 58] A diagram explaining the InMZnO4 crystal. [Figure 59] 1A and 1B are diagrams illustrating energy bands of a transistor in which an oxide semiconductor is used for a channel region. [Figure 60] 1A and 1B are diagrams illustrating structural analyses of a CAAC-OS and a single crystal oxide semiconductor by XRD, and diagrams showing selected-area electron diffraction patterns of a CAAC-OS. [Figure 61] Cross-sectional TEM image of CAAC-OS, as well as planar TEM image and corresponding image analysis images. [Figure 62]Electron diffraction pattern and cross-sectional TEM image of nc-OS. [Figure 63] Cross-sectional TEM image of a-like OS. [Figure 64] FIG. 1 shows the change in the crystal part of an In-Ga-Zn oxide due to electron irradiation. [Figure 65] FIG. 1 is a top view illustrating one embodiment of a display device. [Figure 66] FIG. 1 is a cross-sectional view showing one embodiment of a display device. [Figure 67] FIG. 1 is a cross-sectional view showing one embodiment of a display device. [Figure 68] FIG. 1 is a block diagram illustrating a display device. [Figure 69] FIG. 2 is a diagram illustrating a display module. [Figure 70] 1A to 1C are diagrams illustrating electronic devices. [Figure 71] 1A to 1C are diagrams illustrating electronic devices. [Figure 72] FIG. 1 is a perspective view illustrating a display device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments will be described with reference to the drawings. The present invention may be embodied in various different forms without departing from its spirit and scope. It will be readily understood by those skilled in the art that various modifications and changes may be made to the embodiments and details of the present invention. However, the present invention should not be construed as being limited to the description of the following embodiments.

[0029] Also, in the drawings, the size, layer thickness, or area are exaggerated for clarity. Therefore, the scale is not necessarily limited to that shown in the drawings. The drawings are merely schematic illustrations and are not limited to the shapes or values ​​shown in the drawings.

[0030] In addition, the ordinal numbers "first," "second," and "third" used in this specification refer to the components of the It should be noted that this is added to avoid confusion and is not intended to limit the numbers.

[0031] In addition, in this specification, the words "above" and "below" indicating the position of the components are used. The positional relationship is used for convenience in describing the drawings. The relationship changes depending on the direction in which each component is depicted. The above words and phrases are not limited to those used above, but can be rephrased appropriately depending on the situation.

[0032] In this specification, a transistor includes a gate, a drain, and a source. The drain terminal is a diode that has at least three terminals. Between the drain region or drain electrode and the source (source terminal, source region or source electrode) A current flows through the drain, the channel region, and the source. In this specification and the like, the channel region refers to a region through which a current mainly flows. The flow area.

[0033] In addition, the functions of the source and drain may differ depending on whether transistors of different polarities are used or the circuit In operation, when the direction of the current changes, the positions may be reversed. In the specification, the terms source and drain may be used interchangeably. do.

[0034] In addition, in this specification, "electrically connected" means "something that has some kind of electrical effect." This includes cases where the device is connected via a "device having some electrical function." "of" is not subject to any particular restrictions as long as it enables the transmission and reception of electrical signals between connected objects. For example, "something that has an electrical effect" includes electrodes, wiring, and transistors. These devices have various functions such as switching elements, resistor elements, inductors, capacitors, etc. This includes elements such as:

[0035] In addition, in this specification, "parallel" means that two straight lines are at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Perpendicular" means that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, this also includes cases where the angle is between 85° and 95°.

[0036] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the term "conductive layer" can be changed to the term "conductive film." For example, the term "insulating film" may be changed to "insulating layer." It may be possible to change the term to:

[0037] In this specification and the like, unless otherwise specified, the off-state current refers to the current that occurs when a transistor is off. This refers to the drain current when the device is in a non-conducting state (also called a cut-off state). Unless otherwise specified, for n-channel transistors, V is the voltage between the gate and source When gs is lower than the threshold voltage Vth, the gate and This refers to a state in which the voltage Vgs between the n-channel transistors is higher than the threshold voltage Vth. The off-state current of a transistor is the voltage between the gate and source, Vgs, that is, the threshold voltage, Vt It may refer to the drain current when it is lower than h.

[0038] The off-state current of a transistor may depend on Vgs. The off-state current is I or less if there exists a Vgs value at which the off-state current of the transistor is I or less. The off-state current of a transistor is the current that flows through it in the off-state at a given Vgs. , an off-state at Vgs within a given range or a sufficiently reduced off-current is obtained. In some cases, it may refer to the off-state current at Vgs.

[0039] As an example, when the threshold voltage Vth is 0.5V and Vgs is 0.5V, The current is 1×10 -9 A, and the drain current at Vgs of 0.1 V is 1×10 -1 3 A, and the drain current at Vgs -0.5 V is 1×10 -19 A and Vg The drain current at s = -0.8 V is 1 × 10 -22 A n-channel transistor The drain current of the transistor is as follows when Vgs is -0.5V: , or 1×10 when Vgs is in the range of -0.5V to -0.8V -19 A or below Therefore, the off-state current of the transistor is 1×10 -19 There are cases where it is said to be A or lower. The drain current of the transistor is 1×10 -22 A or less Vgs exists. Therefore, the off-state current of the transistor is 1×10 -22 It may be said that it is below A.

[0040] In this specification, the off-state current of a transistor having a channel width W is expressed as It is sometimes expressed as the current value that flows per watt. Also, for a given channel width (for example, 1 μm), In the latter case, the unit of the off-state current is current / length. It may be expressed in units with an element (e.g., A / μm).

[0041] The off-state current of a transistor may depend on temperature. Unless otherwise specified, the operating temperature is room temperature, 60°C, 85°C, 95°C, or 125°C. Or, the reliability of a semiconductor device including the transistor may be guaranteed. The temperature at which the transistor is certified, or the temperature at which a semiconductor device or the like that contains the transistor is used (e.g. For example, the off-state current at any one of temperatures from 5° C. to 35° C. The off-state current of the transistor is I or less at room temperature, 60°C, 85°C, 95°C, 125°C, The temperature at which the reliability of a semiconductor device including the transistor is guaranteed, or The temperature at which the semiconductor device containing the transistor is used (for example, any one of 5°C to 35°C) (temperature), there exists a value of Vgs at which the off-state current of the transistor is equal to or less than I. There are cases where it is pointed out.

[0042] The off-state current of a transistor may depend on the voltage Vds between the drain and source In this specification, unless otherwise specified, the off-state current is measured when Vds is 0.1 V, 0.8 V, 1V, 1.2V, 1.8V, 2.5V, 3V, 3.3V, 10V, 12V, 16V, and In some cases, it indicates the off-state current at 20 V. In other cases, it indicates the off-state current at 20 V. Vds that guarantees the reliability of semiconductor devices, or semiconductor devices including the transistor The term may also refer to the off-state current at Vds used in the transistor off-state. The current is equal to or less than I when Vds is 0.1V, 0.8V, 1V, 1.2V, 1.8V, 2.5V, 3V, 3.3V, 10V, 12V, 16V, 20V, transistors included Vds that guarantees the reliability of the semiconductor device in which the transistor is used, or Vds used in semiconductor devices, etc., where the off-state current of the transistor is I or less This may refer to the existence of a gs value.

[0043] In the above description of the off-state current, the drain may be read as the source. The current may also refer to the current through the source when the transistor is in the off state.

[0044] In this specification and the like, the term "leak current" may be used to mean the same thing as the "off current." In this specification, the off-state current refers to, for example, the current flowing when a transistor is in an off state. , may refer to the current flowing between the source and drain.

[0045] In this specification, the threshold voltage of a transistor is the threshold voltage of a transistor. This refers to the gate voltage (Vg) when a gate is formed. Specifically, it refers to the threshold voltage of a transistor. Voltage is plotted on the horizontal axis as gate voltage (Vg) and on the vertical axis as the square root of drain current (Id). The line obtained by extrapolating the tangent line with the maximum slope in the simulated curve (Vg-√Id characteristics) is , the gate voltage (Vg Alternatively, the threshold voltage of a transistor can be expressed as the channel length L and the The channel width is W, and the value of Id[A]×L[μm] / W[μm] is 1×10 -9 [A] Sometimes it refers to the gate voltage (Vg) applied to the device.

[0046] 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." In some cases, the term "insulator" in the specification can be replaced with "semiconductor." In some cases, the term "insulator" in this specification can be rephrased as "semi-insulator." .

[0047] 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.

[0048] In this specification, the term "impurities in a semiconductor" refers to anything other than the main component that constitutes the semiconductor film. For example, an element with a concentration of less than 0.1 atomic percent is an impurity. This causes the formation of DOS (Density of States) in the semiconductor and the In some cases, the rear mobility and crystallinity of the semiconductor may decrease. In the case of an oxide semiconductor, impurities that change the characteristics of the semiconductor include, for example, Group 1 There are elements, group 2 elements, group 14 elements, group 15 elements, transition metals other than the main components, etc. Hydrogen (also found in water), lithium, sodium, silicon, boron, phosphorus, carbon, In the case of oxide semiconductors, oxygen vacancies can occur due to the inclusion of impurities such as hydrogen. In addition, when the semiconductor contains silicon, the properties of the semiconductor may be changed. Examples of impurities include oxygen, Group 1 elements excluding hydrogen, Group 2 elements, Group 13 elements, Group 15 elements, etc.

[0049] (Embodiment 1) In this embodiment, a semiconductor device and a manufacturing method of the semiconductor device according to one embodiment of the present invention will be described. The following description will be given with reference to FIGS.

[0050] <1-1. Configuration example 1 of semiconductor device> FIG. 1A is a top view of a semiconductor device 100 according to one embodiment of the present invention, and FIG. 1(A) is a cross-sectional view taken along the dashed line A1-A2 in FIG. B) is a cross section in the channel length (L) direction of transistor Tr1 and a cross section in the channel length (L) direction of transistor Tr2. Includes a cross section in the channel length (L) direction.

[0051] In addition, in FIG. 1A, in order to avoid complication, the components of the semiconductor device 100 are shown. Some of the elements (such as the insulating film that functions as the gate insulating film) and some of the reference numerals of the components are omitted. In the top view of the semiconductor device, the same reference numerals are used in the following drawings. ), some of the components and some of the reference numerals of the components may be omitted in the illustration.

[0052] The semiconductor device 100 shown in FIGS. 1A and 1B includes a transistor Tr1 and a transistor T The transistor Tr2 at least partially overlaps with the transistor r1. Both transistor Tr1 and transistor Tr2 are bottom-gate transistors. .

[0053] A region where the transistor Tr1 and the transistor Tr2 at least partially overlap each other is defined as By providing the transistor, the layout area can be reduced.

[0054] The transistor Tr1 is a transistor including a conductive film 104 on a substrate 102 and a conductive film 104 on the substrate 102. the insulating film 106 on the oxide semiconductor film 108; The conductive film 112a on the oxide semiconductor film 108, the conductive film 112b on the oxide semiconductor film 108, and the conductive film 112c on the oxide semiconductor film 108 are 08, the insulating film 114 on the conductive film 112a and the conductive film 112b, and the insulating film 114 The insulating film 116 and the conductive film 122c on the insulating film 116 are provided.

[0055] The transistor Tr2 includes a conductive film 112b and an insulating film 114 on the conductive film 112b. , an insulating film 116 on the insulating film 114, an oxide semiconductor film 128 on the insulating film 116, and an oxide The conductive film 122a over the semiconductor film 128, the conductive film 122b over the oxide semiconductor film 128, and the oxide semiconductor film 122b are an insulating film 124 on the nitride semiconductor film 128, the conductive film 122a, and the conductive film 122b; The insulating film 126 is formed on the insulating film 124, and the conductive film 130 is formed on the insulating film 126. The insulating film 124 and the conductive film 122a are connected to the insulating film 124 through an opening 182 formed in the insulating film 126. To be continued.

[0056] As shown in FIGS. 1A and 1B, the oxide semiconductor film 108 and the oxide semiconductor film 12 8 have an overlapping area. As shown in FIG. 1(A) and (B), A channel region formed in the oxide semiconductor film 108 of the transistor Tr1 and an oxide semiconductor film 109 of the transistor Tr2 are It is preferable that the channel region formed in the semiconductor film 128 does not overlap with the channel region formed in the semiconductor film 126 .

[0057] The channel region of the transistor Tr1 and the channel region of the transistor Tr2 are mutually In the case of overlap, when one of the transistors is operating, it affects the other. In order to avoid this effect, A structure that increases the distance between transistors Tr1 and Tr2, or a conductive film However, in the case of the former configuration, the semiconductor device becomes thick. Therefore, for example, when the semiconductor device 100 is formed on a flexible substrate, bending property is an issue. In the latter case, the number of steps for forming the conductive film increases, and As in the case of the configuration of (1), the semiconductor device becomes thicker, which may cause problems.

[0058] On the other hand, in the semiconductor device 100 according to one embodiment of the present invention, the transistor Tr1 and the The transistors Tr1 and Tr2 are disposed so as to overlap each other, and the channel regions of the transistors are provided so as not to overlap each other. In addition, by arranging a part of the oxide semiconductor film in which the channel region is formed to overlap, This makes it possible to advantageously reduce the layout area of ​​the resistors.

[0059] The oxide semiconductor film 108 and the oxide semiconductor film 128 each contain In and M (M For example, the oxide semiconductor film 108 and the oxide semiconductor film 128, the atomic ratio of In is larger than the atomic ratio of M. However, the semiconductor device of one embodiment of the present invention is not limited thereto, A structure having a region in which the atomic ratio of In is smaller than the atomic ratio of M, or a region in which the atomic ratio of In is smaller than the atomic ratio of M may have the same atomic ratio as M.

[0060] The oxide semiconductor film 108 and the oxide semiconductor film 128 have the same composition or different compositions. The oxide semiconductor film 108 and the oxide semiconductor film 128 preferably have substantially the same composition. By making the same, it is possible to reduce the manufacturing cost. The semiconductor device is not limited to this. The composition of the two materials may be different.

[0061] The oxide semiconductor film 108 and the oxide semiconductor film 128 have an atomic ratio of In that is higher than the atomic ratio of M. By having a larger area, the field effect transfer of the transistors Tr1 and Tr2 Specifically, the transistors Tr1 and Tr2 can be Either or both have a field effect mobility of 10 cm 2 / Vs, more preferably is the field effect transfer of either or both of the transistors Tr1 and Tr2. Degree is 30cm 2 / Vs can be exceeded.

[0062] For example, the above-mentioned high field effect mobility transistor is By using this in the gate driver that generates the MOS transistors, a display device with a narrow frame width (also called a narrow frame) can be provided. In addition, the above-mentioned transistor having high field effect mobility can be effectively used in a display device. A source driver (especially a system having a source driver) that supplies signals from a signal line to the By using it as a demultiplexer connected to the output terminal of a soft register, It is possible to provide a display device having a small number of wirings. The transistor having a high resistance is used as a selection transistor and a driving transistor of a pixel circuit of a display device. To provide a display device with high display quality by using either one or both of the two sensors. can be done.

[0063] The semiconductor device 100 shown in FIGS. 1A and 1B is preferably used in a pixel circuit of a display device. By using the arrangement shown in FIG. 1(A)(B), the pixel density of the display device can be increased. For example, if the pixel density of a display device is 1000 ppi (pixel per inch), or the pixel density of the display device exceeds 2000 ppi. Even in this case, the aperture ratio of the pixel can be increased by using the arrangement shown in Fig. 1(A)(B). Note that ppi is a unit that represents the number of pixels per inch.

[0064] <1-2. Pixel circuits of display devices> Here, when the semiconductor device 100 shown in FIG. 1(A)(B) is applied to a pixel circuit of a display device, An example of this case will be described with reference to FIG.

[0065] FIG. 2 is a circuit diagram showing an example in which the semiconductor device 100 is applied to a pixel circuit of a display device. This is a road map.

[0066] The semiconductor device 100 shown in FIG. 2 includes a transistor Tr1, a transistor Tr2, and a capacitor. The semiconductor device 100 includes an element Cs1 and a light-emitting element 160. In the example shown, the semiconductor device 100 has two adjacent pixels (or sub-pixels) in the column direction. The capacitance element Cs1 functions as one of the capacitance elements shown in FIG. Although not shown, for example, the conductive film 112b of the transistor Tr1 and the conductive film 112b of the transistor Tr The capacitance can be formed by using a parasitic capacitance between the conductive film 122b and the second conductive film 122b.

[0067] In the circuit diagram shown in FIG. 2, a data line DL _Y-1, a data line DL_Y for writing a data signal to an adjacent pixel, and a light emitting element and an anode line ANODE_X-1 that supplies a potential to the adjacent light-emitting element. An anode line ANODE_X and a scan line GL_X that supplies a scan signal to the pixel are shown. There are.

[0068] One of the source electrode and the drain electrode of the transistor Tr1 is connected to the data line DL_Y-1. Furthermore, the first gate electrode and the second gate electrode of the transistor Tr1 are electrically connected to each other. The electrode is electrically connected to the scanning line GL_X. The transistor Tr1 is in an on state or When the transistor is in the OFF state, it has a function of controlling the writing of data of a data signal.

[0069] One of the pair of electrodes of the capacitance element Cs1 is connected to the source electrode and drain electrode of the transistor Tr1. The other of the pair of electrodes of the capacitance element Cs1 is electrically connected to the transistor. The second gate electrode (also called a backgate electrode) of transistor Tr2 is electrically connected to the second gate electrode (also called a backgate electrode) of transistor Tr3. The capacitive element Cs1 functions as a storage capacitor that stores written data.

[0070] One of the source electrode and the drain electrode of the transistor Tr2 is connected to the anode line ANODE_ Electrically connected to X-1.

[0071] One of the pair of electrodes of the light emitting element 160 is the source electrode and the drain electrode of the transistor Tr2. The other electrode is electrically connected to the cathode wire CATHODE. One of the pair of electrodes of the light emitting element 160 is connected to the other of the pair of electrodes of the capacitance element Cs1. are electrically connected.

[0072] When the semiconductor device 100 having the above configuration is applied to a pixel of a display device, This is an example of the case.

[0073] <1-3. Configuration of semiconductor device> The semiconductor device 100 shown in FIGS. 1(A) and 1(B) will be described again. When the semiconductor device 100 is applied to a pixel of a display device, for example, The length (L) and channel width (W), or the line width of the wiring and electrodes connected to the transistor, For example, the transistors Tr1 and Tr2 can be made relatively large. As shown in Figure 1(A)(B), compared to the case where the transistors are arranged on the same plane, By arranging the transistor Tr1 and the transistor Tr2 to overlap at least partially, the line width, etc. Since the size can be increased, it is possible to reduce the variation in processing dimensions.

[0074] In addition, the transistor Tr1 and the transistor Tr2 each have a conductive film or an insulating film. One or both can be used in common, reducing the number of masks or steps. It is possible.

[0075] For example, in the transistor Tr1, the conductive film 104 functions as a first gate electrode. The conductive film 112a functions as a source electrode, and the conductive film 112b functions as a drain electrode. The conductive film 122c functions as a second gate electrode. In this case, the insulating film 106 functions as a first gate insulating film, and the insulating films 114 and 116 function as a second gate insulating film. In the transistor Tr2, the conductive film 112b functions as a gate insulating film. 1, the conductive film 122a functions as a source electrode, and the conductive film 122 b functions as a drain electrode, and the conductive film 130 functions as a second gate electrode. In the transistor Tr2, the insulating films 114 and 116 function as a first gate insulating film. The insulating films 124 and 126 function as a second gate insulating film.

[0076] In this specification and the like, the insulating film 106 is referred to as a first insulating film, and the insulating films 114 and 116 are referred to as a second insulating film. The second insulating film and the insulating films 124 and 126 may be referred to as a third insulating film. .

[0077] Moreover, an insulating film 134 is provided on the conductive film 130, and an insulating film 136 is provided on the insulating film 134. In addition, an opening 184 reaching the conductive film 130 is provided in the insulating films 134 and 136. A conductive film 138 is provided over the insulating film 136. It is connected to the conductive film 130 through the opening 184 .

[0078] Moreover, an insulating film 140, an EL layer 142, and a conductive film 144 are provided on the conductive film 138. The insulating film 140 covers a part of the side edge of the conductive film 138 and prevents the conductive film 138 from being electrically conductive between adjacent pixels. The EL layer 142 has a function of emitting light. The conductive film 138, the EL layer 142, and the conductive film 144 constitute a light-emitting element 160. The conductive film 138 functions as one electrode of the light-emitting element 160, and the conductive film 144 , which functions as the other electrode of the light emitting element 160 .

[0079] As described above, a semiconductor device according to one embodiment of the present invention has a stacked structure including a plurality of transistors. The area required for installing the transistor is reduced. In addition, the insulating film and By using either one or both of the conductive films in common, the number of masks or the number of processes can be reduced. It can be reduced.

[0080] <1-4. Gate electrode configuration> As shown in FIGS. 1A and 1B, the transistors Tr1 and Tr2 are , each of which has two gate electrodes.

[0081] Here, the effect of the structure having two gate electrodes will be described with reference to FIGS. 1(A) and 1(B) and FIG. This will be used to explain.

[0082] FIG. 3 corresponds to a cross-sectional view taken along the dashed line B1-B2 in FIG. 1(A). 3 also includes a cross section of the transistor Tr1 in the channel width (W) direction.

[0083] As shown in FIG. 3, the conductive film 122c functioning as the second gate electrode is formed in an opening 181. The first gate electrode 104 is electrically connected to the conductive film 104 through the first gate electrode 104. The conductive film 104 and the conductive film 122c are applied with the same potential. The oxide semiconductor film 108 is located so as to face the conductive film 104 and the conductive film 122c. The conductive film 104 and the conductive film 122 are sandwiched between two conductive films functioning as gate electrodes. The length of c in the channel width direction is longer than the length of the oxide semiconductor film 108 in the channel width direction. The oxide semiconductor film 108 is longer than the insulating film 106, 114, and 116. It is covered by the film 104 and the conductive film 122c.

[0084] In other words, the conductive film 104 and the conductive film 122c are provided on the insulating films 106, 114, and 116. The oxide semiconductor film 108 is connected to the opening 181 formed in the opening 181 and is formed on the outer side of the side edge of the oxide semiconductor film 108. It has an area located at

[0085] With this structure, the oxide semiconductor film 108 included in the transistor Tr1 The transistor can be electrically surrounded by the electric field of the conductive film 104 and the conductive film 122c. As in the case of the transistor Tr1, the electric field of the first gate electrode and the second gate electrode causes the channel The device structure of the transistor that electrically surrounds the oxide semiconductor film in which the region is formed is called Sur This can be called a rounded channel (S-channel) structure.

[0086] Since the transistor Tr1 has an S-channel structure, the first gate electrode The conductive film 104 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 Tr1 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 Tr1. The conductive film 104 functions as a first gate electrode and the conductive film 105 functions as a second gate electrode. Since the conductive film 122c is arranged to surround the conductive film 122c, the mechanical strength can be increased.

[0087] In the above description, the first gate electrode and the second gate electrode are connected to each other. The configuration is illustrated, but is not limited to this. For example, the transistor T The conductive film 130 functioning as the second gate electrode is disposed at the source of the transistor Tr2 as shown by r2. The conductive film 122a functions as a source electrode or a drain electrode. This is also fine.

[0088] <1-5. Components of Semiconductor Device> Next, components included in the semiconductor device of this embodiment will be described in detail.

[0089] [substrate] There is no particular restriction on the material of the substrate 102, but it should be strong enough to withstand the subsequent heat treatment. For example, glass substrates, ceramic substrates, quartz substrates, and sa A fire substrate or the like may be used as the substrate 102. Also, a material such as silicon or silicon carbide may be used. Single crystal semiconductor substrates, polycrystalline semiconductor substrates, compound semiconductors such as silicon germanium, etc. It is also possible to use a substrate, an SOI substrate, or the like, on which a semiconductor element is provided. The substrate 102 may be a glass substrate. If you have 6th generation (1500mm x 1850mm), 7th generation (1870mm x 220 0mm), 8th generation (2200mm x 2400mm), 9th generation (2400mm x 280 By using large-area substrates such as 10th generation (2950mm x 3400mm), Larger display devices can be manufactured.

[0090] In addition, a flexible substrate is used as the substrate 102, and the semiconductor device 100 is directly formed on the flexible substrate. Alternatively, a release layer may be provided between the substrate 102 and the semiconductor device 100. The release layer is used to separate the semiconductor device from the substrate 102 after a part or whole of the semiconductor device is completed thereon. The semiconductor device 100 can be transferred to another substrate. It can be transferred to weaker or more flexible substrates.

[0091] [Conductive film] Conductive film 104, conductive film 112a, conductive film 112b, conductive film 122a, conductive film 122b, The conductive film 122c, the conductive film 130, the conductive film 138, and the conductive film 144 are each made of chromium (C r), copper (Cu), aluminum (Al), gold (Au), silver (Ag), zinc (Zn), molybdenum (Mo), Libden (Mo), Tantalum (Ta), Titanium (Ti), Tungsten (W), Manganese Metal elements selected from the group consisting of Mn, nickel (Ni), iron (Fe), and cobalt (Co), or an alloy containing the above-mentioned metal elements or an alloy combining the above-mentioned metal elements. Each of them can be formed by

[0092] In addition, the conductive film 104, the conductive film 112a, the conductive film 112b, the conductive film 122a, and the conductive film 12 2b, the conductive film 122c, the conductive film 130, the conductive film 138, and the conductive film 144 are made of indium. oxides containing tungsten and tin, oxides containing tungsten and indium, oxides containing tungsten and Oxides containing indium and zinc, oxides containing titanium and indium, oxides containing titanium and in Oxides containing indium and tin, oxides containing indium and zinc, oxides containing silicon and indium oxides containing tin and indium, gallium and zinc, etc. A conductive material can also be applied.

[0093] In particular, the conductive film 130 can be preferably made of the oxide conductor described above. The oxide conductor will be described. In this specification, the oxide conductor is referred to as OC (Oxid The oxide conductor may be, for example, an oxide semiconductor. When oxygen vacancies are formed in a conductor and hydrogen is added to the oxygen vacancies, a donor level is formed near the conduction band. As a result, the oxide semiconductor becomes conductive and becomes a conductor. An oxide semiconductor can be called an oxide conductor. The large gap between the oxides allows them to transmit visible light. The oxide conductor is an oxide semiconductor having a donor level in the vicinity of the band. The effect of absorption due to levels is small, and the transparent property to visible light is comparable to that of oxide semiconductors. .

[0094] In addition, the conductive film 104, the conductive film 112a, the conductive film 112b, the conductive film 122a, and the conductive film 12 2b, the conductive film 122c, the conductive film 130, the conductive film 138, and the conductive film 144 are made of Cu-X Even if alloy films (X is Mn, Ni, Cr, Fe, Co, Mo, Ta, or Ti) are applied, By using a Cu-X alloy film, it can be processed by wet etching process. This makes it possible to reduce manufacturing costs.

[0095] In particular, the conductive film 104, the conductive film 112a, the conductive film 112b, the conductive film 122a, and the conductive film 12 2b and the conductive film 122c, the above-mentioned Cu-X alloy film is preferably used. As the Cu-X alloy film, a Cu-Mn alloy film is particularly preferable.

[0096] In addition, the conductive film 104, the conductive film 112a, the conductive film 112b, the conductive film 122a, and the conductive film 12 One or more of the above-mentioned metal elements may be used in the conductive film 122c. The material is selected from aluminum, copper, titanium, tungsten, tantalum, and molybdenum. It is preferable that the present invention has one or more of the above.

[0097] In addition, the conductive film 104, the conductive film 112a, the conductive film 112b, the conductive film 122a, and the conductive film 12 One or more of the conductive films 122b and 122c may contain nitrogen and tantalum. It is preferable to use a tantalum nitride film. The tantalum nitride film is conductive and has a copper-containing property. The tantalum nitride film also has high barrier properties against hydrogen. Since hydrogen is released little from the metal film or the oxide semiconductor film in contact with the oxide semiconductor film 108, It is most suitable for use as the metal film adjacent to film 108 .

[0098] [Insulating film] Insulating film 106, insulating film 114, insulating film 116, insulating film 124, insulating film 126, insulating film 1 34, the insulating film 136, and the insulating film 140 may be a silicon oxide film or a silicon oxynitride film. , silicon oxynitride film, silicon nitride film, aluminum oxide film, hafnium oxide film, oxide Yttrium film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film An insulating layer containing one or more of aluminium oxide film, lanthanum oxide film, cerium oxide film and neodymium oxide film. , respectively.

[0099] The insulating film 106 also functions as a blocking film that suppresses oxygen permeation. For example, the insulating film 114, the insulating film 116, the oxide semiconductor film 108, the oxide semiconductor film 128, When either or both of the insulating film 124 and the insulating film 126 have an excess oxygen region In this case, the insulating film 106 can suppress oxygen permeation.

[0100] Note that when the oxide semiconductor film 108 or the oxide semiconductor film 128 is in contact with the The insulating film to be used is preferably an oxide insulating film, and the insulating film has a stoichiometric composition. It is more preferable to have a region containing oxygen (excess oxygen region). The oxide insulating film having an elemental region is an insulating film capable of releasing oxygen.

[0101] Note that the oxide insulating film having the above-described excess oxygen region can be formed, for example, in an oxygen atmosphere. Form an insulating film, heat-treat the formed insulating film in an oxygen atmosphere, or The method of adding oxygen to the insulating film after the film formation is as follows. A plasma treatment is preferable.

[0102] In addition, an insulating film that functions as a gate insulating film of the transistor Tr1 and the transistor Tr2 The insulating film that functions as a gate insulating film may be made of hafnium oxide. When nium is used, the following effects are obtained.

[0103] 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 film can be made larger, so that the tunnel This reduces the leakage current caused by the current. Furthermore, hafnium oxide, which has a crystalline structure, can be used to realize an amorphous structure. It has a higher relative dielectric constant than hafnium oxide, which has a low off-current. To form a transistor, it is preferable to use hafnium oxide having a crystalline structure. Examples of the crystal structure include monoclinic and cubic. The types are not limited to these.

[0104] In addition, an insulating film that functions as a gate insulating film of the transistor Tr1 and the transistor Tr2 The insulating film that functions as a gate insulating film may be made of silicon nitride. When silicon nitride is used, the following effects are obtained: Silicon nitride has a low dielectric constant compared to silicon oxide. Since the dielectric constant is high and the thickness required to obtain the same capacitance as silicon oxide is large, Therefore, the insulation resistance of the transistor Tr1 and the transistor Tr2 can be increased. By suppressing the voltage drop and improving the withstand voltage, the transistor Tr1 and the transistor This can suppress electrostatic damage to Tr2.

[0105] The insulating films 114, 116, 124, and 126 are each formed of the oxide semiconductor film 108 or an oxide It has a function of supplying oxygen to one or both of the semiconductor films 128. The insulating films 114, 116, 124, and 126 contain oxygen. The insulating film 114 is an insulating film that can transmit oxygen. The insulating film 116 also functions as a film for reducing damage to the oxide semiconductor film 108 when the insulating film 116 is formed. The insulating film 124 is formed to prevent damage to the oxide semiconductor film 128 when the insulating film 126 is formed later. It also functions as an image-relieving membrane.

[0106] The insulating films 114 and 124 have a thickness of 5 nm to 150 nm, preferably 5 nm. Silicon oxide, silicon oxynitride, etc. having a thickness of 50 nm or more and less can be used.

[0107] In addition, it is preferable that the insulating films 114 and 124 have a small number of defects. Typically, the insulating films 114 and 124 have an ESR The measurement revealed that the signal at g = 2.001 originated from the dangling bond of silicon. Pin density is 3x10 17 spins / cm 3 This is because the insulating film If the density of defects in the insulating film 114 and 124 is high, oxygen will be bonded to the defects, and the insulating film 11 The amount of oxygen permeable through 4 is reduced.

[0108] The insulating films 114 and 124 are oxide insulating films having a low density of states caused by nitrogen oxides. The density of states caused by the nitrogen oxide can be reduced by using an oxide semiconductor. The energy of the upper end of the valence band of the oxide semiconductor film (Ev_os) and the lower end of the conduction band of the oxide semiconductor film The oxide insulating film may be formed between the gate electrode and the gate electrode. Silicon oxynitride film that releases less oxide or nitroxide An aluminum oxide film or the like can be used.

[0109] In addition, the silicon oxynitride film, which emits a small amount of nitrogen oxide, was analyzed by thermal desorption spectrometry (TD S), it is a membrane that releases more ammonia than nitrogen oxides, and is typically The amount of ammonia released is 1×10 18 cm -3 5×10 or more 19 cm -3 The following is the case. The amount of ammonia released is as follows: The total amount of ammonia in the range of 50°C to 550°C or 50°C to 550°C is also included. The output amount is the total amount converted into ammonia molecules in TDS.

[0110] Nitrogen oxides (NO x , x is more than 0 and not more than 2, preferably 1 or more and not more than 2), typically NO 2 Alternatively, NO forms a level in the insulating films 114, 124, etc. Located within the energy gap of the semiconductor films 108 and 128. Therefore, the nitrogen oxides The interface between the insulating film 114 and the oxide semiconductor film 108 or the interface between the insulating film 124 and the oxide semiconductor film When the electrons diffuse to the interface of the insulating film 114 and the insulating film 128, the level traps electrons on the insulating film 114 and the insulating film 124 side. As a result, the trapped electrons may flow through the insulating film 114 and the oxide semiconductor film 1 08 or near the interface between the insulating film 124 and the oxide semiconductor film 128. , the threshold voltage of the transistor is shifted in the positive direction.

[0111] Nitrogen oxide reacts with ammonia and oxygen during heat treatment. The nitrogen oxide contained in the insulating films 116 and 126 is removed by the heat treatment. By reacting with ammonia, the nitrogen oxides contained in the insulating films 114 and 124 are reduced. Therefore, the interface between the insulating film 114 and the oxide semiconductor film 108 or the interface between the insulating film 124 and the oxide semiconductor film 108 may be Therefore, electrons are less likely to be trapped at the interface of the compound semiconductor film 128.

[0112] By using the oxide insulating film as the insulating films 114 and 124, the width of the transistors can be reduced. It is possible to reduce the shift in the low voltage and to reduce the variation in the electrical characteristics of the transistor. It is possible.

[0113] Heat treatment in the manufacturing process of a transistor is typically performed at a temperature of 300° C. or higher and lower than 350° C. By the heat treatment, the insulating films 114 and 124 have a spectrum obtained by measuring the ESR at 100K or less. The first signal has a g value between 2.037 and 2.039 in the spectrum, and the g value is 2.00 The second signal has a g value between 1 and 2.003, and the third signal has a g value between 1.964 and 1.966. The split width of the first signal and the second signal is: The split width of the second and third signals is The g value is about 5 mT. The first signal, g A second signal with a g value between 2.001 and 2.003, and a second signal with a g value between 1.964 and 1.9 The sum of the spin densities of the third signals that are 66 or less is 1 × 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.

[0114] In the ESR spectrum below 100K, the g value is 2.037 or more and 2.039 or less. The first signal below, the second signal with a g-value between 2.001 and 2.003, and the g-value The sum of the spin densities of the third signal, which is greater than or equal to 1.964 and less than or equal to 1.966, is the nitrogen oxide Monster (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) It corresponds to the total density of the pins. Representative examples of nitrogen oxides include nitrogen monoxide, nitrogen dioxide, etc. That is, the first signal has a g value of 2.037 to 2.039, and the second signal has a g value of 2.00 A second signal between 1 and 2.003 and a g value between 1.964 and 1.966. The smaller the total spin density of the third signal, the more the nitrogen oxide in the oxide insulating film is. It can be said that the content of the substance is low.

[0115] The nitrogen concentration of the oxide insulating film measured by SIMS is 6×10 20 atoms / cm 3 The following is the result.

[0116] 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.

[0117] The insulating films 116 and 126 are made of oxides containing more oxygen than the oxygen required for the stoichiometric composition. The insulating film is formed using an oxide insulating film that contains more oxygen than the oxygen required for the stoichiometric composition. The membrane releases some of the oxygen when heated. The oxide insulating film containing oxygen has an oxygen release rate of 1.0×10 19 cm -3 More than 3, preferably 3 .0×10 20 cm -3 The amount of oxygen released is calculated based on the heating temperature in TDS. The total amount of the treatment temperature is in the range of 50°C to 650°C or 50°C to 550°C. The amount of oxygen released above is the total amount converted into oxygen molecules in TDS.

[0118] The insulating films 116 and 126 have a thickness of 30 nm to 500 nm, preferably 50 Silicon oxide, silicon oxynitride, etc. having a thickness of 400 nm or more can be used.

[0119] In addition, it is preferable that the insulating films 116 and 126 have a small number of defects. Typically, the insulating films 116 and 126 have an ESR The measurement revealed that the signal at g = 2.001 originated from the dangling bond of silicon. Pin density is 1.5 x 10 18 spins / cm 3Less than or even 1×10 18 spins / cm 3 It is preferable that:

[0120] The insulating films 114 and 116, and the insulating films 124 and 126 are made of the same material. Since the insulating film can be used, the interface between the insulating film 114 and the insulating film 116 and the insulating film In some cases, the interface between the insulating film 124 and the insulating film 126 cannot be clearly seen. In terms of the configuration, the interface between the insulating film 114 and the insulating film 116 and the interface between the insulating film 124 and the insulating film 12 The interface with 6 is shown by a dashed line.

[0121] The insulating film 134 functions as a protective insulating film for the transistors Tr1 and Tr2. Possesses the ability.

[0122] The insulating film 134 contains either hydrogen or nitrogen, or both. The insulating film 34 contains nitrogen and silicon. The insulating film 134 contains oxygen, hydrogen, water, and alkali. The insulating film 134 has a function of blocking metals, alkaline earth metals, etc. As a result, oxygen is diffused from the oxide semiconductor film 108 and the oxide semiconductor film 128 to the outside, and the insulating film 126 is prevented from being broken down. The oxygen contained in the coatings 114, 116, 124, and 126 diffuses to the outside, and the oxide It is possible to prevent hydrogen, water, and the like from entering the semiconductor films 108 and 128 .

[0123] The insulating film 134 may be, for example, a nitride insulating film. Examples include silicon nitride, silicon nitride oxide, aluminum nitride, and aluminum nitride oxide. etc.

[0124] [Oxide semiconductor film] The oxide semiconductor film 108 and the oxide semiconductor film 128 are formed using the above-described materials. There can be.

[0125] When the oxide semiconductor film 108 and the oxide semiconductor film 128 are an In-M-Zn oxide, In -The number of atoms of the metal element in the sputtering target used to deposit the M-Zn oxide film The ratio of In to M is preferably satisfied. The atomic ratio of elements is In:M:Zn=2:1:3, In:M:Zn=3:1:2, In :M:Zn=4:2:4.1 etc.

[0126] In addition, when the oxide semiconductor film 108 and the oxide semiconductor film 128 are an In-M-Zn oxide, The metal elements of the sputtering target used to form the In-M-Zn oxide film The atomic ratio may be a composition that satisfies In≦M. The atomic ratio of group elements is In:M:Zn=1:1:1, In:M:Zn=1:1:1. 2, In:M:Zn=1:3:2, In:M:Zn=1:3:4, In:M:Zn=1: 3:6, etc.

[0127] The oxide semiconductor film 108 and the oxide semiconductor film 128 are each made of In-M-Zn oxide. In the case of In-Zn oxides, the sputtering target is a polycrystalline In-M-Zn oxide. It is preferable to use a target containing polycrystalline In-M-Zn oxide. This makes it easier to form the oxide semiconductor film 108 and the oxide semiconductor film 128 having crystallinity. Note that the atomic ratio of the oxide semiconductor film 108 and the oxide semiconductor film 128 to be formed is The positive and negative atomic ratios of the metal elements contained in the sputtering target are For example, the oxide semiconductor film 108 and the oxide semiconductor film 128 have a 40% variation. The atomic ratio of In:Ga:Zn=4:2:4.1 is used as the sputtering target. In this case, the atomic ratio of the oxide semiconductor film 108 and the oxide semiconductor film 128 to be formed is In: In some cases, the Ga:Zn ratio is approximately 4:2:3.

[0128] The oxide semiconductor film 108 and the oxide semiconductor film 128 each have an energy gap of 2e 5 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more. By using an oxide semiconductor with a wide energy gap, The off-current of the starter Tr2 can be reduced.

[0129] The oxide semiconductor film 108 and the oxide semiconductor film 128 each have a thickness of 3 nm or more. 200 nm or less, preferably 3 nm or more and 100 nm or less, and more preferably 3 nm or more and 5 0 nm or less.

[0130] In addition, hydrogen contained in the oxide semiconductor film 108 and the oxide semiconductor film 128 reacts with metal atoms. The bonded oxygen reacts with the water to form water, and the lattice from which the oxygen is removed (or the part from which the oxygen is removed) When hydrogen enters the oxygen vacancy, electrons, which act as carriers, are generated. In addition, some of the hydrogen may bond with oxygen that bonds with metal atoms, forming a carrier. Therefore, a transistor using an oxide semiconductor film containing hydrogen may generate electrons. The transistor tends to be normally on. It is preferable that the amount of hydrogen in the nitride semiconductor film 128 be reduced as much as possible.

[0131] Specifically, the oxide semiconductor film 108 and the oxide semiconductor film 128 were analyzed by SIMS. The hydrogen concentration obtained by 20 atoms / cm 3 Hereinafter, preferably 5×10 19 atoms / cm 3 Less than or equal to 1×10 19 atoms / cm 3 Below, 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than or equal to 5×10 17 atoms / cm 3 Below, more preferably 1×1 0 16 atoms / cm 3 The following applies.

[0132] In addition, in the oxide semiconductor film 108 and the oxide semiconductor film 128, one of Group 14 elements When the oxide semiconductor film 108 and the oxide semiconductor film 12 contain silicon or carbon, As a result, oxygen vacancies increase in the oxide semiconductor film 108 and the oxide semiconductor film 109, which become n-type. The silicon concentrations in the oxide semiconductor film 128 obtained by SIMS analysis were ×10 18 atoms / cm 3 Less than or equal to 2×10 17 atoms / cm 3 Below and do. In addition, the oxide semiconductor film 108 and the oxide semiconductor film 128 were analyzed by SIMS. The carbon concentration is 2×10 18 atoms / cm 3 Less than or equal to 2×10 1 7 atoms / cm 3 The following applies.

[0133] In addition, the oxide semiconductor film 108 and the oxide semiconductor film 128 were analyzed by SIMS. The resulting alkali metal or alkaline earth metal concentration is 1×10 18 atom s / cm 3 Less than or equal to 2×10 16 atoms / cm 3 Below: Alkali metals When the alkaline earth metal and the oxide semiconductor are bonded, they may generate carriers. The off-state current of the transistor may be increased. In addition, the concentration of an alkali metal or an alkaline earth metal in the oxide semiconductor film 128 can be reduced. preferable.

[0134] In addition, each of the oxide semiconductor film 108 and the oxide semiconductor film 128 may have a non-single crystal structure. The non-single crystal structure is, for example, CAAC-OS (C Axis Alignment-type crystalline structure) which will be described later. d Crystalline Oxide Semiconductor), polycrystalline structure , microcrystalline, or amorphous structures. In non-single crystal structures, the amorphous structure is the most defect-free. The defect state density is high in CAAC-OS, while the defect state density is the lowest in CAAC-OS.

[0135] The above-mentioned various films such as the conductive film, the insulating film, and the oxide semiconductor film may be formed by sputtering. Plasma Enhanced Chemical Vapor Deposition (PECVD) Chemical Vapor Deposition) method, thermal CVD (Chemical It can be formed by the thermal vapor deposition method. As a VD method, MOCVD (Metal Organic Chemical Vapor Deposition) Deposition) method or ALD (Atomic Layer Deposition) method ition method, etc.

[0136] Thermal CVD is a film formation method that does not use plasma, so defects can occur due to plasma damage. This has the advantage that no additional steps are required.

[0137] In the thermal CVD method, the source gas and the oxidizing agent are fed into the chamber at the same time, and the chamber is filled with air. The reaction is carried out near or on the substrate under high or low pressure, and the material is deposited on the substrate to form a film. may be carried out.

[0138] In addition, in the ALD method, the pressure inside the chamber is set at atmospheric pressure or reduced pressure, and the source gas for the reaction is The film may be formed using the same.

[0139] Thermal CVD methods such as MOCVD and ALD can be used to form the conductive film, insulating film, and oxide film of the above-mentioned embodiment. It is possible to form various films such as semiconductor films. For example, an In-Ga-ZnO film can be formed. In some cases, trimethylindium, trimethylgallium, and dimethylzinc are used. The chemical formula for trimethylindium is In(CH 3 ) 3 In addition, trimethyl gas The chemical formula for lithium is Ga(CH 3 ) 3 The chemical formula for dimethylzinc is Zn(C H 3 ) 2 In addition, the combination is not limited to these, and instead of trimethylgallium, Triethylgallium (chemical formula Ga(C 2 H 5 ) 3 ) can also be used, and dimethyl zinc Instead, diethylzinc (chemical formula Zn(C 2 H 5 )2 ) can also be used.

[0140] For example, when forming a hafnium oxide film using a film forming apparatus that uses ALD, the solvent and liquids containing hafnium precursor compounds (hafnium alkoxides, tetrakisdimethyl The raw material gas is made by vaporizing hafnium amide (such as TDMAH) and acid. Ozone (O 3 Two types of gases are used: tetrakisdimethylamide The chemical formula for Hf is Hf[N(CH 3 ) 2 ] 4 In addition, other material liquids include tetrahydrofuran. Examples include rakis(ethylmethylamido)hafnium.

[0141] For example, when forming an aluminum oxide film using an ALD deposition system, A liquid containing a catalyst and an aluminum precursor compound (e.g., trimethylaluminum (TMA)) is added. Vaporized raw gas and H as oxidant 2 Two types of gases are used: trimethyl The chemical formula for aluminum is Al(CH 3 ) 3 In addition, other material liquids include Tris( Dimethylamido)aluminum, triisobutylaluminum, aluminum tris(2 ,2,6,6-tetramethyl-3,5-heptanedionate).

[0142] For example, when forming a silicon oxide film using a deposition system that uses ALD, Chlorodisilane is adsorbed onto the surface to be coated, removing the chlorine contained in the adsorbed matter, and the oxidizing gas (O 2 , nitrous oxide) radicals are supplied to react with the adsorbate.

[0143] For example, when forming a tungsten film using a deposition system that uses ALD, the WF 6 Gas and B 2 H 6 gas to form an initial tungsten film, and then WF 6 Gas and H 2 A tungsten film is formed using the gas B 2 H 6 Instead of gas, SiH 4 Gas It may be used.

[0144] For example, an oxide semiconductor film, such as In-Ga-ZnO, can be formed by a film formation apparatus using ALD. When forming a film, In(CH 3 ) 3 Gas and O 3 An In-O layer is formed using gas. , then Ga(CH 3 ) 3 Gas and O 3 A GaO layer is formed using the gas, and then Z n(CH 3 ) 2 Gas and O 3 The ZnO layer is formed using the gas. The example is not limited to this. In addition, by mixing these gases, In-Ga-O layers and In-Zn-O layers can be obtained. Alternatively, a mixed compound layer such as a Ga-Zn-O layer may be formed. 3 Gas replaced with Ar H obtained by bubbling with an inert gas such as 2 O gas may be used, but it should be O gas that does not contain H. 3 It is preferable to use In(CH 3 ) 3 Instead of gas, In(C 2 H 5 ) 3 Gas may also be used. 3 ) 3 Instead of gas, Ga(C 2 H5 ) 3 gas Also, Zn(CH 3 ) 2 A gas may also be used.

[0145] <1-6. Configuration example 2 of semiconductor device> Next, regarding a modified example of the semiconductor device 100 shown in FIG. 1(A)(B), This will be explained with reference to FIG.

[0146] FIG. 4(A) is a cross-sectional view of a modified example of the semiconductor device 100 shown in FIG. 1(B). 1B.) is a cross-sectional view of a modified example of the semiconductor device 100 shown in FIG. 1B. FIG. 1 is a cross-sectional view of a modified example of the semiconductor device 100 shown in FIG.

[0147] FIG. 4A shows a second gate electrode of a transistor Tr1 included in the semiconductor device 100. In this configuration, the conductive film 122c that functions as a conductive film is not provided.

[0148] FIG. 4B shows a second gate electrode of the transistor Tr2 of the semiconductor device 100. In this configuration, the conductive film 130 that functions as a conductive film and the insulating film 134 on the conductive film 130 are not provided. In FIG. 4B, an opening 182 is provided in the insulating film 124 and the insulating film 126, and Instead of the insulating film 134 and the opening 184 provided in the insulating film 136, the insulating film 124, the insulating The insulating film 126 and the insulating film 136 are provided with an opening 183. Having only one opening is preferable because it reduces the number of manufacturing steps.

[0149] FIG. 5 shows a semiconductor device 100 having a second gate electrode functioning as a second gate electrode of a transistor Tr1. and a conductive film 122c that functions as the second gate electrode of the transistor Tr2. 30, and the insulating film 134 on the conductive film 130 is not provided. Similarly, an opening 183 is provided in the insulating film 124, the insulating film 126, and the insulating film 136. It is a completion.

[0150] <1-7. Configuration example 3 of semiconductor device> Next, a modified example of the semiconductor device 100 shown in FIG. 1(A)(B) will be described with reference to FIG. 6(A)(B). This will be explained with reference to FIG.

[0151] Here, a stacked structure of oxide semiconductor films is described.

[0152] 6A and 6B show the channel length (L ) Cross-sectional view.

[0153] FIG. 6A shows an oxide semiconductor film 108 included in the transistor Tr1. 108a, an oxide semiconductor film 108b on the oxide semiconductor film 108a, and an oxide semiconductor film 1 and an oxide semiconductor film 108c over the oxide semiconductor film 108b. It has a three-layer laminated structure.

[0154] FIG. 6B shows the oxide semiconductor film 108 of the transistor Tr1. and an oxide semiconductor film 108c over the oxide semiconductor film 108b. That is, the oxide semiconductor film has a stacked structure of two layers.

[0155] 1 is a diagram showing an example of a band structure of the oxide semiconductor film 108 and an insulating film in contact with the oxide semiconductor film 108. Shown in Figures 7(A) and (B).

[0156] FIG. 7A illustrates the insulating film 106, the oxide semiconductor films 108a, 108b, and 108c, and the insulating film 108. FIG. 7B is an example of a band structure in the thickness direction of a laminated structure having an insulating film 114. a stacked structure including an insulating film 106, oxide semiconductor films 108b and 108c, and an insulating film 114. The band structure is shown in FIG. 1 in the thickness direction of the structure. The conduction band of the insulating film 106, the oxide semiconductor films 108a, 108b, and 108c, and the insulating film 114 The lowest energy level (Ec) is shown.

[0157] FIG. 7A shows a case where a silicon oxide film is used as the insulating film 106 and the insulating film 114. The oxide semiconductor film 108a is made of a metal having an atomic ratio of In:Ga:Zn=1:3:2. The oxide semiconductor film 108b is formed using an oxide semiconductor film formed using a metal oxide target. The atomic ratio of the metal elements is In:Ga:Zn=4:2:4.1. The oxide semiconductor film 108c is formed using an oxide semiconductor film formed using The oxide formed using a metal oxide target with a molecular ratio of In:Ga:Zn=1:3:2 FIG. 1 is a band diagram of a structure using a compound semiconductor film.

[0158] FIG. 7B shows a case where a silicon oxide film is used as the insulating film 106 and the insulating film 114. The oxide semiconductor film 108b has an atomic ratio of metal elements of In:Ga:Zn=4:2:4.1. The oxide semiconductor film 10 is formed by using the oxide semiconductor film formed by using the metal oxide target. 8c: A metal oxide target with an atomic ratio of metal elements of In:Ga:Zn=1:3:2 FIG. 1 is a band diagram of a configuration using a metal oxide film formed using

[0159] As shown in FIGS. 7A and 7B, in the oxide semiconductor films 108a, 108b, and 108c, 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 At the interface between the semiconductor film 108a and the oxide semiconductor film 108b or at the interface between the oxide semiconductor film 108b and the oxide semiconductor film 108c, At the interface with the oxide semiconductor film 108c, defect states such as trap centers and recombination centers are generated. Assume that there are no impurities that would form

[0160] In order to form a continuous junction in the oxide semiconductor films 108a, 108b, and 108c, 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.

[0161] With the structure shown in FIGS. 7A and 7B, the oxide semiconductor film 108b serves as a well. In the transistor using the above-mentioned stacked structure, the channel region is formed of the oxide semiconductor film 10 It can be seen that it is formed in 8b.

[0162] Note that by providing the oxide semiconductor films 108a and 108c, the trap states can be reduced by It can be located away from the semiconductor film 108b.

[0163] In addition, the trap states are below the conduction band of the oxide semiconductor film 108b functioning as a channel region. The energy level of the edge (Ec) can be farther from the vacuum level, and electrons can be trapped in the trap level. When electrons accumulate in the trap level, negative 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 108b. 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.

[0164] In addition, the oxide semiconductor films 108a and 108c have a conduction band lower than that of the oxide semiconductor film 108b. The energy level of the edge of the oxide semiconductor film 108b is close to the vacuum level, and typically, and the energy levels of the conduction band minimums of the oxide semiconductor films 108a and 108c. 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 108a and 108c and the The difference between the electron affinity of the organic film 108b and the electron affinity of the organic film 108c is 0.15 eV or more, or 0.5 eV or more, and eV or less, or 1 eV or less.

[0165] With such a structure, the oxide semiconductor film 108b serves as a main path for current. The oxide semiconductor films 108a and 108c function as a channel region. The oxide semiconductor film 108b is formed by using an oxide semiconductor material having one or more metal elements. Since the oxide semiconductor film 108a is an oxide semiconductor film, the interface between the oxide semiconductor film 108a and the oxide semiconductor film 108b and Alternatively, interface scattering occurs at the interface between the oxide semiconductor film 108b and the oxide semiconductor film 108c. Therefore, the movement of carriers is not hindered at the interface, and the transistor The field effect mobility of the

[0166] In addition, the oxide semiconductor films 108a and 108c function as part of a channel region. In order to prevent this, a material having a sufficiently low electrical conductivity is used. 108a and 108c are the electron affinities (the difference between the vacuum level and the energy level at the bottom of the conduction band) is smaller than that of the oxide semiconductor film 108b, and the energy level of the conduction band minimum is Use a material that has a difference (band offset) with the conduction band minimum energy level of 108b In addition, the occurrence of a difference in threshold voltage depending on the magnitude of the drain voltage is suppressed. In order to suppress this, the energy levels of the conduction band minimums of the oxide semiconductor films 108a and 108c must be A material having an energy level closer to a vacuum level than the conduction band minimum of the oxide semiconductor film 108b is used. For example, it is preferable that the energy level of the conduction band minimum of the oxide semiconductor film 108b is The difference between the energy levels of the conduction band minimums of the nitride semiconductor films 108a and 108c is 0.2 eV or less. It is preferable to set the value to 0.5 eV or more.

[0167] In addition, the oxide semiconductor films 108a and 108c do not contain a spinel crystal structure. It is preferable that the oxide semiconductor films 108a and 108c have a spinel crystal structure. In the case where the spinel type crystal structure is included, the conductive film 112a, 11 In some cases, the constituent elements of the oxide semiconductor film 2b may diffuse into the oxide semiconductor film 108b. When the conductive films 108a and 108c are made of CAAC-OS, which will be described later, the conductive films 112a and 11 This is preferable because it enhances the blocking properties of the constituent elements of 2b, for example, copper element.

[0168] The thicknesses of the oxide semiconductor films 108a and 108c are determined by the composition of the conductive films 112a and 112b. The insulating film has a thickness that is greater than or equal to a thickness that can prevent the insulating film from diffusing into the oxide semiconductor film 108b. The thickness of the oxide semiconductor film 108b is set to be less than the thickness at which oxygen supply from the film 114 to the oxide semiconductor film 108b is suppressed. For example, When the oxide semiconductor films 108a and 108c have a thickness of 10 nm or more, the conductive films 112a and This can prevent the constituent elements of the oxide semiconductor film 112b from diffusing into the oxide semiconductor film 108b. In addition, when the thickness of the oxide semiconductor films 108a and 108c is set to 100 nm or less, the insulating film 114 Therefore, oxygen can be effectively supplied to the oxide semiconductor film 108b.

[0169] The oxide semiconductor films 108a and 108c are made of In-M-Zn oxide (M is Al, Ga, Y, or When M is an In or Sn, the oxide semiconductor film 10 can be formed by having M in a higher atomic ratio than In. The energy gap of 8a and 108c can be increased and the electron affinity can be reduced. The difference in electron affinity between the compound semiconductor film 108b and the compound semiconductor film 108c can be controlled by the composition of M. In addition, since M is a metal element with strong bonding power with oxygen, these elements are called I By having an atomic ratio higher than n, oxygen deficiency is less likely to occur.

[0170] When the oxide semiconductor films 108a and 108c are made of In-M-Zn oxide, Zn and The atomic ratio of In and M excluding O is preferably 50 atomic % In. less than 50 atomic %, M is more than 50 atomic %, and more preferably In is 25 atomic % In addition, the oxide semiconductor films 108a and 108c are A gallium oxide film may be used as the insulating film.

[0171] In addition, when the oxide semiconductor films 108a, 108b, and 108c are made of In-M-Zn oxide, , compared with the oxide semiconductor film 108b, M contained in the oxide semiconductor films 108a and 108c The atomic ratio of the above atoms is typically larger than that of the above atoms contained in the oxide semiconductor film 108b. The atomic ratio is 1.5 times or more, preferably 2 times or more, and more preferably 3 times or more. .

[0172] In addition, when the oxide semiconductor films 108a, 108b, and 108c are made of In-M-Zn oxide, The oxide semiconductor film 108b is In:M:Zn=x 1 :y 1 :z 1 [Atomic ratio], oxide half The conductor films 108a and 108c are In:M:Zn=x 2 :y 2 :z 2 [Atomic ratio], y 2 / x 2 y 1 / x 1 preferably greater than y 2 / x 2 y 1 / x 1 than 1. More preferably, y 2 / x 2 y 1 / x 1 More than twice as large as Preferably, y 2 / x 2 y 1 / x 1 is more than three or four times larger than In the oxide semiconductor film 108b, y 1 x 1 In this case, the oxide semiconductor film 108b This is preferable because it can provide stable electrical characteristics to a transistor using y 1 x 1 When the field-effect mobility of the transistor including the oxide semiconductor film 108b is three times or more Because y 1 x 1 It is preferable that the amount of the ion exchange resin is less than three times as large as that of the ion exchange resin.

[0173] When the oxide semiconductor film 108b is an In-M-Zn oxide, the oxide semiconductor film 108b is formed. The atomic ratio of the metal elements in the target used for film formation is In:M:Zn=x 1 : y 1 :z 1 So, 、 x 1 / y 1 is between 1 / 3 and 6, or between 1 and 6. , z 1 / y 1 is preferably 1 / 3 or more and 6 or less, and more preferably 1 or more and 6 or less. , z 1 / y 1 When the ratio of the cation concentration to the cation concentration is 1 to 6, the oxide semiconductor film 108b can be formed using the CAA The atomic ratio of the target metal elements is typically I n:M:Zn=4:2:4.1, In:M:Zn=1:1:1.2, In:M:Zn=3 :1:2 etc.

[0174] In addition, when the oxide semiconductor films 108a and 108c are made of an In-M-Zn oxide, In the target used for forming the solid films 108a and 108c, the number of atoms of the metal element is The ratio is In:M:Zn=x 2 :y 2 :z 2 So, 、 x 2 / y 2 <x 1 / y 1 Where z 2 / y 2 is preferably 1 / 3 or more and 6 or less, and more preferably 1 or more and 6 or less. By increasing the atomic ratio of M to n, the oxide semiconductor films 108a and 108c It is possible to increase the energy gap and decrease the electron affinity, so y 2 / x 2 It is preferable that the atomic ratio of the metal elements in the target is 3 or more, or 4 or more. Examples are In:M:Zn=1:3:2, In:M:Zn=1:3:4, In:M:Z n=1:3:5, In:M:Zn=1:3:6, In:M:Zn=1:4:2, In:M :Zn=1:4:4, In:M:Zn=1:4:5, In:M:Zn=1:5:5 etc. do.

[0175] In addition, when the oxide semiconductor films 108a and 108c are made of an In-M oxide, M is divalent gold. By making the composition free of atomic elements (e.g., zinc), it has a spinel-type crystal structure. In addition, the oxide semiconductor films 108a and 108c can be formed without using the oxide semiconductor The films 108a and 108c may be, for example, In-Ga oxide films. As the In-Ga oxide film, for example, an In-Ga metal oxide target (In:Ga= 7:93) can be formed by sputtering. In order to form the solid films 108a and 108c by a sputtering method using DC discharge, When n:M=x:y [atomic number ratio], y / (x+y) is 0.96 or less, preferably It is recommended to set it to 0.95 or less, for example 0.93.

[0176] Note that the atomic ratios of the oxide semiconductor films 108a, 108b, and 108c are each determined with an error. The atomic ratios listed above may vary by ±40%.

[0177] In addition, in FIGS. 6A and 6B, the oxide semiconductor film 108 of the transistor Tr1 is a two-layer film. The above embodiment illustrates a stacked structure of three layers, the oxide semiconductor film 12 of the transistor Tr2, 8 may have a similar configuration.

[0178] In this way, the semiconductor device of the present invention can be characterized by the presence or absence of a second gate electrode, or the presence or absence of an oxide semiconductor. The laminated structure of the conductor film may be changed. Each of the above structures can be freely combined.

[0179] <1-8. Manufacturing method of semiconductor device> Next, a manufacturing method of the semiconductor device 100 according to one embodiment of the present invention will be described with reference to FIGS. He explains.

[0180] In addition, Figs. 8(A), 9(A), 10(A), 11(A), 12(A), and 13 14(A), 15(A), 16(A), and 17(A) are diagrams showing semiconductor devices. 8(B), 9(B), 10(B), and 11(C) are top views for explaining a method for manufacturing the semiconductor device 100. 11(B), Fig. 12(B), Fig. 13(B), Fig. 14(B), Fig. 15(B), Fig. 16(B) 17A and 17B are cross-sectional views illustrating a method for manufacturing the semiconductor device 100. FIG.

[0181] First, a conductive film is formed on the substrate 102, and the conductive film is then subjected to a lithography process and an etching process. Then, a conductive film 104 that functions as a first gate electrode is formed by carrying out a process. An insulating film 106 that functions as a first gate insulating film is formed on the conductive film 104 (FIG. 8(A)). (See (B)).

[0182] In this embodiment, a glass substrate is used as the substrate 102, which functions as the first gate electrode. A tungsten film having a thickness of 100 nm is formed by sputtering as the conductive film 104. The insulating film 106 is made of a silicon nitride film having a thickness of 400 nm and a silicon nitride film having a thickness of 50 nm. A silicon oxynitride film is formed by the PECVD method.

[0183] Note that the silicon nitride film used as the insulating film 106 has a stacked structure. The silicon nitride film is a first silicon nitride film, a second silicon nitride film, and a third silicon nitride film. An example of the three-layer laminate structure is as follows: It can be formed into.

[0184] The first silicon nitride film is formed by, for example, silane at a flow rate of 200 sccm, PE-CV was performed using nitrogen at a flow rate of 100 sccm and ammonia gas at a flow rate of 100 sccm as source gas. The pressure in the reaction chamber was controlled to 100 Pa, and a 27.12 MHz high-frequency If a power of 2000 W is supplied using a frequency power supply and the thickness is formed to be 50 nm, good.

[0185] For the second silicon nitride film, silane at a flow rate of 200 sccm, The nitrogen gas and the ammonia gas with a flow rate of 2000sccm were used as raw material gases in the PECVD equipment. The pressure in the reaction chamber was controlled to 100 Pa, and a 27.12 MHz high-frequency power supply was used. A power of 2000 W may be supplied using the above method to form a film having a thickness of 300 nm.

[0186] The third silicon nitride film was prepared by using silane at a flow rate of 200 sccm and 5000 sccm. The pressure in the reaction chamber was kept at 100 The thickness was measured by controlling the temperature to 50 Pa and supplying 2000 W of power using a 27.12 MHz high frequency power source. It is sufficient to form it so that the thickness is 50 nm.

[0187] The first silicon nitride film, the second silicon nitride film, and the third silicon nitride film The substrate temperature during formation can be 350° C. or less.

[0188] By forming the insulating film 106 in a three-layered structure of silicon nitride films, for example, the conductive film 10 When a conductive film containing copper (Cu) is used for 4, the following effects are achieved.

[0189] The first silicon nitride film can suppress the diffusion of copper (Cu) elements from the conductive film 104. The second silicon nitride film has the function of releasing hydrogen and functions as a gate insulating film. The third silicon nitride film can improve the breakdown voltage of the insulating film. Hydrogen release from the silicon nitride film is small, and hydrogen released from the second silicon nitride film is diffused. can be suppressed.

[0190] Next, the oxide semiconductor film 108 is formed over the insulating film 106 (see FIGS. 9A and 9B).

[0191] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 1. Note that a wet etching apparatus is used to form the oxide semiconductor film.

[0192] Next, a conductive film is formed over the insulating film 106 and the oxide semiconductor film 108. The insulating film 106 is then processed into the shape shown in FIG. , forming insulating films 114 and 116 over the oxide semiconductor film 108 and the conductive films 112a and 112b. (See Figures 10(A) and (B)).

[0193] In this embodiment, the conductive films 112a and 112b are made of tungsten films having a thickness of 50 nm. A 100 nm thick aluminum film and a 50 nm thick titanium film are stacked in this order. The layer film is formed by a sputtering method.

[0194] After the conductive films 112a and 112b are formed, the surface of the oxide semiconductor film 108 (back-cut The cleaning method may be, for example, cleaning with an etching solution such as phosphoric acid solution. As a result, the oxide semiconductor film 108 can be cleaned by washing with a cleaning agent. Impurities (for example, elements contained in the conductive films 112a and 112b) can be removed. However, this cleaning is not always necessary, and in some cases, cleaning may not be necessary. .

[0195] In addition, either one of the steps of forming the conductive films 112a and 112b and the above-mentioned cleaning step may be performed. In either case, the region of the oxide semiconductor film 108 that is exposed from the conductive films 112a and 112b is But it may become thinner.

[0196] In this embodiment, a silicon oxynitride film having a thickness of 20 nm is used as the insulating film 114. A silicon oxynitride film with a thickness of 200 nm was formed as 116 using the PECVD method. Complete.

[0197] 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 108. As a result, the amount of oxygen vacancies in the oxide semiconductor film 108 can be reduced. .

[0198] In this embodiment, the insulating film 114 is formed by heating the substrate 102 at a temperature of 220° C. The source gases were silane at a flow rate of 50 sccm and dinitrogen monoxide at a flow rate of 2000 sccm. The pressure in the treatment chamber was set to 20 Pa, and the high frequency power supplied to the parallel plate electrodes was set to 13.56 M. Hz, 100W (power density is 1.6×10 -2 W / cm 2 ) PECVD method A silicon oxynitride film is formed using this.

[0199] The insulating film 116 is formed by depositing a substrate in a vacuum-evacuated processing chamber of a PECVD apparatus. The temperature is kept at 180°C or higher and 350°C or lower, and the raw material gas is introduced into the treatment chamber to increase the pressure in the treatment chamber. is set to 100 Pa or more and 250 Pa or less, and more preferably set to 100 Pa or more and 200 Pa or less. 0.17 W / cm2 at the electrode installed in the treatment chamber 2 More than 0.5W / cm 2 Below are some more Preferably 0.25W / cm 2 More than 0.35W / cm 2 The following high frequency power supply conditions are met: In this way, a silicon oxide film or a silicon oxynitride film is formed.

[0200] The conditions for forming the insulating film 116 are as follows: high frequency power density in a reaction chamber with the above pressure; By supplying power, the efficiency of decomposing the source gas in the plasma increases, and the number of oxygen radicals increases. As the oxidation of the source gas progresses, the oxygen content in the insulating film 116 becomes lower than the stoichiometric composition. On the other hand, in the film formed at the above substrate temperature, the bonding strength between silicon and oxygen is Since the oxygen in the film is weak, some of the oxygen in the film is released by the heat treatment in the subsequent process. An oxide that contains more oxygen than satisfies the theoretical composition and loses some of the oxygen when heated. An insulating film can be formed.

[0201] In the step of forming the insulating film 116, the insulating film 114 serves as a protection film for the oxide semiconductor film 108. Therefore, the power density can be reduced while reducing damage to the oxide semiconductor film 108. The insulating film 116 can be formed using high radio frequency power.

[0202] In the deposition conditions for the insulating film 116, a deposition gas containing silicon is mixed with an oxidizing gas. By increasing the flow rate of the gas, it is possible to reduce the amount of defects in the insulating film 116. In the first place, ESR measurements revealed that the g value was 2.001, which is due to the dangling bonds of silicon. The spin density of the signal is 6×10 17 spins / cm 3 Less than 3 x 10 17 spins / cm 3 Less than or equal to 1.5×10 17 spins / cm 3 The following is a missing As a result, the signal strength of the transistor Tr1 is improved. It can increase reliability.

[0203] 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 108 is transferred to the oxide semiconductor film 108. This can reduce the amount of oxygen vacancies.

[0204] 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, preferably 10 ppb The reaction may be carried out under an atmosphere of air (see below) 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. Heat treatment is performed using an electric furnace, RTA (Rapid Thermal Anneal), etc. It is possible.

[0205] Next, the oxide semiconductor film 128 is formed over the insulating film 116 (see FIGS. 11A and 11B). .

[0206] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 1. The oxide semiconductor film 28 is formed using a wet etching apparatus.

[0207] Next, the conductive films 122a, 122b, and 122c are formed over the insulating film 116 and the oxide semiconductor film 128. 2c is formed, and then the insulating film 116, the oxide semiconductor film 128, and the conductive films 122a and 122b are formed. Insulating films 124 and 126 are formed on 22b and 122c (see FIGS. 12(A) and 12(B)).

[0208] The conductive films 122a, 122b, and 122c are the same as the conductive films 112a and 112b shown above. The insulating films 124 and 126 can be formed by the same method. The insulating films 114 and 116 can be formed in the same manner.

[0209] Next, an opening 182 is formed in a desired region of the insulating films 124 and 126, reaching the conductive film 122a. After that, a conductive film 130 is formed over the insulating film 126 and the conductive film 122a (FIG. 13). (See (A) and (B)).

[0210] The opening 182 is formed using a dry etching device or a wet etching device. The conductive film 130 is made of an oxide containing indium, tin, and silicon (I Target (In 2 O 3 :SnO 2 :SiO 2 =85:10:5[Weight %]) to form a 100 nm thick ITSO film, which is then processed into islands.

[0211] Next, an insulating film 126, an insulating film that will become an insulating film 134 on the conductive film 130, and an insulating film 136 are formed. Then, a laminated film is formed by applying a conductive film 130 to a desired region of the laminated film. An opening 184 is formed through the insulating film 184 (see FIGS. 14(A) and 14(B)).

[0212] The insulating film 134 is a silicon oxynitride film having a thickness of 200 nm, which is deposited by using the PECVD method. The insulating film 136 is formed of a photosensitive acrylic organic film having a thickness of 1.5 μm. A resin film is formed.

[0213] The opening 184 is formed using a dry etching device or a wet etching device. do.

[0214] Next, a conductive film is formed over the insulating film 136 and the conductive film 130, and the conductive film is processed into an island shape. In this way, a conductive film 138 is formed (see FIGS. 15A and 15B).

[0215] In this embodiment, the conductive film 138 is a 10 nm thick ITSO film and a 200 nm thick SiO2 film. A reflective metal film (here, a metal film having silver, palladium, and copper) with a thickness of 1 nm A laminated film with a 0 nm ITSO film is used. In addition, a wet etching process is used for processing the conductive film 138. An etching device is used.

[0216] Next, an island-shaped insulating film 140 is formed on the insulating film 136 and the conductive film 138 (FIG. 16(A) )(see B)).

[0217] The insulating film 140 is a photosensitive polyimide organic resin film having a thickness of 1.5 μm. .

[0218] Next, the EL layer 142 is formed on the conductive film 138, and then the insulating film 140 and the EL layer 14 2, a conductive film 144 is formed on the substrate 1 to form a light-emitting element 160 (FIGS. 17(A) and 17(B)). reference).

[0219] A method for forming the light emitting element 160 will be described in detail in the third embodiment.

[0220] Through the above steps, the semiconductor device 100 shown in FIGS. 1(A) and 1(B) can be formed.

[0221] Note that 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.

[0222] (Embodiment 2) In this embodiment, a semiconductor device and a manufacturing method of the semiconductor device according to one embodiment of the present invention will be described. The following description will be given with reference to FIGS.

[0223] <2-1. Configuration example 1 of semiconductor device> FIG. 18A is a top view of a semiconductor device 200 of one embodiment of the present invention, and FIG. 18(A) corresponds to a cross-sectional view taken along dashed line A1-A2 in FIG. FIG. 18B shows a cross section of the transistor Tr1 in the channel length (L) direction and The cross section of Tr2 in the channel length (L) direction is included.

[0224] The semiconductor device 100 shown in FIGS. 18A and 18B includes a transistor Tr1 and a transistor The transistor Tr1 and the transistor Tr2 are at least partially overlapped with each other. Transistor Tr1 is a bottom-gate transistor, and transistor Tr2 is a top-gate transistor. This is a transistor with a gate structure.

[0225] A region where the transistor Tr1 and the transistor Tr2 at least partially overlap each other is defined as By providing the transistor, the layout area can be reduced.

[0226] The transistor Tr1 is a transistor including a conductive film 104 on a substrate 102 and a conductive film 104 on the substrate 102. the insulating film 106 on the oxide semiconductor film 108; The conductive film 112a on the oxide semiconductor film 108, the conductive film 112b on the oxide semiconductor film 108, and the conductive film 112c on the oxide semiconductor film 108 are 08, the insulating film 114 on the conductive film 112a and the conductive film 112b, and the insulating film 114 A film 116, an insulating film 118 on the insulating film 116, an insulating film 119 on the insulating film 118, It has an insulating film 210a on the film 119 and a conductive film 212a on the insulating film 210a.

[0227] The transistor Tr2 includes a conductive film 112c and an insulating film 114 on the conductive film 112c. , an insulating film 116 on the insulating film 114, an insulating film 118 on the insulating film 116, and an insulating film 118 on the insulating film 118. the insulating film 119, the oxide semiconductor film 208 over the insulating film 119, the insulating film 210b, the conductive film 212b over the insulating film 210b, the oxide semiconductor film 208, and An insulating film 214 on the conductive film 212b, an insulating film 216 on the insulating film 214, and A conductive film 218a and an insulating film 21 and a conductive film 218b provided over the insulating film 6 and electrically connected to the oxide semiconductor film 208. do.

[0228] As shown in FIGS. 18A and 18B, the oxide semiconductor film 108 and the oxide semiconductor film 2 08 have an overlapping area.

[0229] The oxide semiconductor film 108 can have a structure similar to that described in Embodiment 1. The oxide semiconductor film 208 has a structure similar to that of the oxide semiconductor film 128 described in Embodiment 1. It can be said that:

[0230] Therefore, either or both of the transistors Tr1 and Tr2 Field effect mobility is 10 cm 2 / Vs, more preferably the transistors Tr1 and The field effect mobility of one or both of the transistors Tr2 is 30 cm 2 / Vs It will be possible to do so.

[0231] For example, the above-mentioned high field effect mobility transistor is By using this in the gate driver that generates the MOS transistors, a display device with a narrow frame width (also called a narrow frame) can be provided. In addition, the above-mentioned transistor having high field effect mobility can be effectively used in a display device. A source driver (especially a system having a source driver) that supplies signals from a signal line to the By using it as a demultiplexer connected to the output terminal of a soft register, It is possible to provide a display device having a small number of wirings. The transistor having a high resistance is used as a selection transistor and a driving transistor of a pixel circuit of a display device. To provide a display device with high display quality by using either one or both of the two sensors. can be done.

[0232] The semiconductor device 100 shown in FIGS. 18(A) and 18(B) is preferably used in a pixel circuit of a display device. By using the arrangement shown in FIG. 18(A) and (B), the pixel density of the display device can be improved. For example, the pixel density of a display device can exceed 1000 ppi. Even when the pixel density of the display device exceeds 2000 ppi, ) the aperture ratio of the pixel can be increased.

[0233] When the semiconductor device 100 shown in FIG. 18(A)(B) is applied to a pixel circuit of a display device, In this case, the pixel circuit may have the same configuration as that shown in FIG.

[0234] When the semiconductor device 100 shown in FIG. 18(A)(B) is applied to a pixel of a display device, For example, the channel length (L) and channel width (W) of a transistor For example, the width of the wiring and electrodes connected to the transistor can be made relatively large. In comparison with the case where transistors Tr1 and Tr2 are arranged on the same plane, As shown in (B), at least a part of the transistor Tr1 and the transistor Tr2 is By stacking the parts, it is possible to increase the line width, etc., thereby reducing the variation in processing dimensions. It is possible to reduce the

[0235] In addition, the transistor Tr1 and the transistor Tr2 each have a conductive film or an insulating film. One or both can be used in common, reducing the number of masks or steps. It is possible.

[0236] For example, in the transistor Tr1, the conductive film 104 functions as a first gate electrode. The conductive film 112a functions as a source electrode, and the conductive film 112b functions as a drain electrode. The conductive film 212a functions as a second gate electrode. In this case, the insulating film 106 functions as a first gate insulating film, and the insulating films 114, 116, and 118 , 119, 210a function as a second gate insulating film. In this case, the conductive film 112c functions as a first gate electrode, and the conductive film 218a functions as a source electrode. The conductive film 218b serves as a drain electrode, and the conductive film 212b serves as a second gate electrode. In the transistor Tr2, the insulating films 114, 116, The insulating film 210b functions as a second gate insulating film. It acts as a membrane.

[0237] In this specification and the like, the insulating film 210a is referred to as a fourth insulating film, and the insulating film 210b is referred to as a fifth insulating film. These insulating films may be referred to as the insulating films.

[0238] In addition, an insulating film 136 is provided on the insulating film 216 and the conductive films 218a and 218b. In addition, an opening 186 is provided in the insulating film 136, reaching the conductive film 218b. A conductive film 138 is provided on the insulating film 136. The conductive film 138 is formed in the opening 18. 6, it is connected to the conductive film 218b.

[0239] Moreover, an insulating film 140, an EL layer 142, and a conductive film 144 are provided on the conductive film 138. The conductive film 138, the EL layer 142, and the conductive film 144 constitute a light-emitting element 16. 0 is configured.

[0240] Thus, in one aspect of the present invention, a bottom-gate transistor and a top It is possible to use the transistor in combination with a transistor having a gate structure.

[0241] Although not shown in the drawings, the transistors Tr1 and Tr2 shown in FIGS. The transistor Tr2 may have the S-channel structure described in the first embodiment.

[0242] In addition, the transistor Tr1 and the transistor The semiconductor device 100 shown in the first embodiment has a transistor Tr1 and a transistor Tr2. It is possible to use it in combination with transistor Tr2.

[0243] As described above, a semiconductor device according to one embodiment of the present invention has a stacked structure including a plurality of transistors. The area required for installing the transistor is reduced. In addition, the insulating film and By using either one or both of the conductive films in common, the number of masks or the number of processes can be reduced. It can be reduced.

[0244] <2-2. Components of Semiconductor Device> Next, components included in the semiconductor device of this embodiment will be described in detail.

[0245] [Conductive film] The conductive films 212a, 212b, 218a, and 218b may be made of the conductive material described in the first embodiment. Films (conductive film 104, conductive film 112a, conductive film 112b, conductive film 122a, conductive film 122b , the conductive film 122c, the conductive film 130, the conductive film 138, and the conductive film 144) are used. In particular, when an oxide conductor (OC) is used for the conductive films 212a and 212b, This is preferable because oxygen can be added to the insulating films 210a and 210b.

[0246] [Insulating film] The insulating films 118, 119, 214, 216, 210a, and 210b are the same as those in the first embodiment. The insulating film according to the present invention (insulating film 106, insulating film 114, insulating film 116, insulating film 124, insulating film 1 26, the insulating film 134, the insulating film 136, and the insulating film 140) can be used.

[0247] In particular, when a silicon nitride film or a silicon nitride oxide film is used as the insulating film 118, This is preferable because it can suppress impurities from entering the transistor Tr1. Since the insulating film is in contact with the oxide semiconductor film 208, an oxide insulating film is preferable. In particular, a silicon oxide insulating film is preferable. A silicon oxide film or a silicon nitride film is preferable. The insulating film is preferably an oxide insulating film, and the region containing oxygen in excess of the stoichiometric composition It is more preferable that the insulating films 210a and 210b have an oxygen excess region. It is preferable to use a silicon nitride film or a silicon oxynitride film.

[0248] The insulating film 214 contains either hydrogen or nitrogen, or both. The insulating film 214 contains nitrogen and silicon. The insulating film 214 also contains oxygen, hydrogen, water, and ammonia. It has the function of blocking alkali metals, alkaline earth metals, etc. When the insulating film 214 is in contact with the insulating film 214, either hydrogen or nitrogen in the insulating film 214 is removed. At least one of them penetrates into the oxide semiconductor film 208, and the carrier density of the oxide semiconductor film 208 increases. Therefore, the oxide semiconductor film 208 and the insulating film 214 can be in contact with each other. A region in the oxide semiconductor film 208 functions as a source region or a drain region.

[0249] [Oxide semiconductor film] As the oxide semiconductor film 208, the oxide semiconductor film described in Embodiment 1 (the oxide semiconductor The materials of the oxide semiconductor film 108 and the oxide semiconductor film 128 can be used.

[0250] <2-3. Manufacturing method of semiconductor device> Next, a manufacturing method of the semiconductor device 200 according to one embodiment of the present invention will be described with reference to FIGS. I will explain this in more detail.

[0251] 19(A), 20(A), 21(A), 22(A), 23(A), 24(A), 25(A), 26(A), 27(A), 28(A), and 29( 19(A) is a top view illustrating a method for manufacturing a semiconductor device 200, and FIG. B), Fig. 21(B), Fig. 22(B), Fig. 23(B), Fig. 24(B), Fig. 25(B), Fig. 2 6(B), 27(B), 28(B), and 29(B) show the fabrication of the semiconductor device 200. 1A to 1C are cross-sectional views illustrating a method.

[0252] First, a conductive film is formed on the substrate 102, and the conductive film is then subjected to a lithography process and an etching process. Then, a conductive film 104 that functions as a first gate electrode is formed by carrying out a process. An insulating film 106 that functions as a first gate insulating film is formed on the conductive film 104 (FIG. 19(A)). )(see B)).

[0253] In this embodiment, a glass substrate is used as the substrate 102, which functions as the first gate electrode. A tungsten film having a thickness of 100 nm is formed by sputtering as the conductive film 104. The insulating film 106 is made of a silicon nitride film having a thickness of 400 nm and a silicon nitride film having a thickness of 50 nm. A silicon oxynitride film is formed by the PECVD method.

[0254] Next, the oxide semiconductor film 108 is formed over the insulating film 106 (see FIGS. 20A and 20B). .

[0255] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 1. Note that a wet etching apparatus is used to form the oxide semiconductor film.

[0256] Next, a conductive film is formed over the insulating film 106 and the oxide semiconductor film 108. By processing the insulating film into the shape shown in FIG. The insulating film 106, the oxide semiconductor film 108, and the conductive films 112a, 112b, and 112c are Films 114, 116, 118, and 119 are formed (see Figures 21(A) and (B)).

[0257] In this embodiment, the conductive films 112a, 112b, and 112c are made of 50 nm thick tin. A 100 nm thick titanium film was then stacked on top of a 100 nm thick aluminum film. The laminated film is formed by sputtering.

[0258] In this embodiment, a silicon oxynitride film having a thickness of 20 nm is used as the insulating film 114. The insulating film 116 is a silicon oxynitride film having a thickness of 200 nm, and the insulating film 118 is a silicon nitride film having a thickness of 1 A silicon nitride oxide film having a thickness of 50 nm is used as the insulating film 119. The films are each formed using a PECVD method.

[0259] After the insulating films 114, 116, 118, and 119 are formed, a first heat treatment is performed. By the first heat treatment, part of oxygen contained in the insulating films 114 and 116 is converted to oxygen. The oxygen vacancies in the oxide semiconductor film 108 are reduced by transferring the oxygen vacancies to the oxide semiconductor film 108. It is possible.

[0260] Next, the oxide semiconductor film 208 is formed over the insulating film 119 (see FIGS. 22A and 22B). .

[0261] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 2. Note that a wet etching apparatus is used to form the oxide semiconductor film.

[0262] Next, a stack of an insulating film and a conductive film is formed over the insulating film 119 and the oxide semiconductor film 208. Thereafter, the laminated film is processed into a desired shape to form island-shaped insulating films 210a, 210b, and 21c. 0b and island-shaped conductive films 212a and 212b are formed. Then, the insulating film 119 and the oxide Insulating films 214 and 216 are formed on the semiconductor film 208 and the conductive films 212a and 212b ( See Figures 23(A)(B).

[0263] In this embodiment, the insulating films 210a and 210b are made of silicon oxynitride having a thickness of 50 nm. The conductive films 212a and 212b are formed by using a PECVD apparatus. A 200-nm-thick oxide semiconductor film is formed by using a sputtering apparatus. The oxide semiconductor film has the same composition as that of the oxide semiconductor film 208. As the layer 14, a silicon nitride film having a thickness of 100 nm is formed using a PECVD apparatus. The insulating film 216 is a silicon oxynitride film having a thickness of 200 nm, which is deposited by a PECVD apparatus. It is formed using:

[0264] A part of the oxide semiconductor film 208 and the conductive films 212a and 212b are formed by an insulating film. By contacting with the insulating film 214, either or both of hydrogen and nitrogen in the insulating film 214 are added. This process results in an oxide conductor (OC).

[0265] The insulating films 210a and 210b are formed by etching using the conductive films 212a and 212b as masks. It is formed in a self-consistent manner.

[0266] Next, an opening 28 is formed in a desired region of the insulating films 214 and 216, reaching the oxide semiconductor film 208. 2a and 282b are formed (see Figures 24(A) and (B)).

[0267] The openings 282a and 282b are formed using a dry etching device or a wet etching device. A gadget is used.

[0268] Next, the insulating film 216 and the oxide semiconductor film 20 are formed so as to cover the openings 282a and 282b. 8, and the conductive film is processed into an island shape to form conductive films 218a and 218b. (See Figures 25(A) and (B)).

[0269] The conductive films 218a and 218b are a tungsten film having a thickness of 100 nm and a tungsten film having a thickness of 200 nm. A copper film having a thickness of 100 nm is formed by sputtering.

[0270] Next, the insulating film 136 is formed over the insulating film 216 and the conductive films 218a and 218b. Thereafter, a desired region of the insulating film 136 is processed to form an opening 186 reaching the conductive film 218b. (See Figures 26(A) and (B)).

[0271] In this embodiment, the insulating film 136 is a photosensitive acrylic organic film having a thickness of 1.5 μm. A resin film is formed.

[0272] Next, a conductive film is formed over the insulating film 136 and the conductive film 218b, and the conductive film is processed into an island shape. In this way, a conductive film 138 is formed (see FIGS. 27A and 27B).

[0273] In this embodiment, the conductive film 138 is a 10 nm thick ITSO film and a 200 nm thick SiO2 film. A reflective metal film (here, a metal film having silver, palladium, and copper) with a thickness of 1 nm A laminated film with a 0 nm ITSO film is used. In addition, a wet etching process is used for processing the conductive film 138. An etching device is used.

[0274] Next, an island-shaped insulating film 140 is formed on the insulating film 136 and the conductive film 138 (FIG. 28(A) )(see B)).

[0275] The insulating film 140 is a photosensitive polyimide organic resin film having a thickness of 1.5 μm. .

[0276] Next, the EL layer 142 is formed on the conductive film 138, and then the insulating film 140 and the EL layer 14 2, a conductive film 144 is formed on the substrate 1 to form a light-emitting element 160 (FIGS. 29(A) and 29(B)). reference).

[0277] A method for forming the light emitting element 160 will be described in detail in the third embodiment.

[0278] Through the above steps, the semiconductor device 200 shown in FIGS. 18(A) and 18(B) can be manufactured.

[0279] Note that 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.

[0280] (Embodiment 3) In this embodiment, a semiconductor device and a manufacturing method of the semiconductor device according to one embodiment of the present invention will be described. The following description will be given with reference to Figures 30 to 45.

[0281] <3-1. Configuration example 1 of semiconductor device> FIG. 30A is a top view of a semiconductor device 300 of one embodiment of the present invention, and FIG. , which corresponds to a cross-sectional view taken along the dashed line A1-A2 in FIG. FIG. 30B shows a cross section of the transistor Tr1 in the channel length (L) direction and The cross section of Tr2 in the channel length (L) direction is included.

[0282] In addition, in order to avoid complication, in FIG. 30(A), the configuration of the semiconductor device 300 is Some elements (such as the insulating film that functions as a gate insulating film) and some of the reference numerals of the components are omitted. In addition, in the top view of the semiconductor device, the same structure as in FIG. As in (A), some of the components and some of the reference numerals of the components may be omitted. do.

[0283] The semiconductor device 300 shown in FIGS. 30(A) and 30(B) includes a transistor Tr1 and a transistor The transistors Tr1 and Tr2 are at least partially connected to each other. The transistor Tr1 has a top gate structure. The transistor Tr2 is a transistor with a bottom gate structure.

[0284] A region where the transistor Tr1 and the transistor Tr2 at least partially overlap each other is defined as By providing the transistor, the layout area can be reduced.

[0285] The transistor Tr1 is formed by an insulating film 306 on a substrate 302 and an oxide semiconductor layer on the insulating film 306. A semiconductor film 308, an insulating film 310 on the oxide semiconductor film 308, and a conductive film 32 on the insulating film 310. 0, an insulating film 306, an oxide semiconductor film 308, and an insulating film 314 over a conductive film 320. The oxide semiconductor film 308 overlaps with the conductive film 320 and is in contact with the insulating film 310. A channel region 308i, a source region 308s in contact with the insulating film 314, and a and a drain region 308d.

[0286] The transistor Tr1 includes an insulating film 316 on the insulating film 314 and an insulating film 314 and an insulating film 316 on the insulating film 314. An oxide semiconductor is formed in the source region 308s through an opening 341a provided in the insulating film 316. A conductive film 312a electrically connected to the conductive film 308, an insulating film 314, and an insulating film 316 The oxide semiconductor film 30 is exposed to the drain region 308d through the opening 341b. 8, the insulating film 316, the conductive film 312a, and the conductive film and an insulating film 318 on 312b.

[0287] The transistor Tr2 includes a conductive film 312b and an insulating film 318 on the conductive film 312b. , an oxide semiconductor film 328 over the insulating film 318, and a conductive film 322a over the oxide semiconductor film 328. and the conductive film 322b over the oxide semiconductor film 328. a, an insulating film 324 on the conductive film 322b, an insulating film 326 on the insulating film 324, and an insulating film The conductive film 330 is formed on the insulating films 324 and 326. It is connected to the conductive film 322a through the opening 382 provided.

[0288] As shown in FIGS. 30A and 30B, the oxide semiconductor film 308 and the oxide semiconductor film 3 28 have an overlapping area. As shown in FIG. 30(A)(B), A channel region formed in the oxide semiconductor film 308 of the transistor Tr1 and a It is preferable that the channel region formed in the oxide semiconductor film 328 does not overlap with the oxide semiconductor film 326. .

[0289] The channel region of the transistor Tr1 and the channel region of the transistor Tr2 are mutually In the case of overlap, when one of the transistors is operating, it affects the other. In order to avoid this effect, A structure that increases the distance between transistors Tr1 and Tr2, or a conductive film However, in the case of the former configuration, the semiconductor device becomes thick. Therefore, for example, when the semiconductor device 300 is formed on a flexible substrate, bending property is an issue. In the latter case, the number of steps for forming the conductive film increases, and As in the case of the configuration of (1), the semiconductor device becomes thicker, which may cause problems.

[0290] On the other hand, in the semiconductor device 300 according to one embodiment of the present invention, the transistor Tr1 and the The transistors Tr1 and Tr2 are disposed so as to overlap each other, and the channel regions of the transistors are provided so as not to overlap each other. In addition, by arranging a part of the oxide semiconductor film in which the channel region is formed to overlap, This makes it possible to advantageously reduce the layout area of ​​the resistors.

[0291] The oxide semiconductor film 308 and the oxide semiconductor film 328 each contain In and M (M For example, the oxide semiconductor film 308 and the oxide semiconductor film 328, the atomic ratio of In is larger than the atomic ratio of M. However, the semiconductor device of one embodiment of the present invention is not limited thereto, A structure having a region in which the atomic ratio of In is smaller than the atomic ratio of M, or a region in which the atomic ratio of In is smaller than the atomic ratio of M may have the same atomic ratio as M.

[0292] The oxide semiconductor film 308 and the oxide semiconductor film 328 have the same composition or different compositions. The oxide semiconductor film 308 and the oxide semiconductor film 328 preferably have substantially the same composition. By making the same, it is possible to reduce the manufacturing cost. The semiconductor device is not limited to this. The composition of the two materials may be different.

[0293] The oxide semiconductor film 308 and the oxide semiconductor film 328 have an atomic ratio of In that is higher than the atomic ratio of M. By having a larger area, the field effect transfer of the transistors Tr1 and Tr2 Specifically, the transistors Tr1 and Tr2 can be Either or both have a field effect mobility of 10 cm 2 / Vs, more preferably is the field effect transfer of either or both of the transistors Tr1 and Tr2. Degree is 30cm 2 / Vs can be exceeded.

[0294] For example, the above-mentioned high field effect mobility transistor is By using this in the gate driver that generates the MOS transistors, a display device with a narrow frame width (also called a narrow frame) can be provided. In addition, the above-mentioned transistor having high field effect mobility can be effectively used in a display device. A source driver (especially a system having a source driver) that supplies signals from a signal line to the By using it as a demultiplexer connected to the output terminal of a soft register, It is possible to provide a display device having a small number of wirings. The transistor having a high resistance is used as a selection transistor and a driving transistor of a pixel circuit of a display device. To provide a display device with high display quality by using either one or both of the two sensors. can be done.

[0295] The semiconductor device 300 shown in FIGS. 30(A) and 30(B) is preferably used in a pixel circuit of a display device. By using the arrangement shown in FIG. 30(A)(B), the pixel density of the display device can be increased. For example, if the pixel density of a display device is 1000 ppi (pixel l per inch), or the pixel density of the display device exceeds 2000 ppi Even in this case, the aperture ratio of the pixel can be increased by using the arrangement shown in FIG. Note that ppi is a unit that represents the number of pixels per inch.

[0296] <3-2. Pixel circuits of display devices> Here, the semiconductor device 300 shown in FIG. 30(A)(B) is applied to a pixel circuit of a display device. An example of this case will be described with reference to FIG.

[0297] FIG. 31 shows an example in which the semiconductor device 300 is applied to a pixel circuit of a display device. FIG.

[0298] The semiconductor device 300 shown in FIG. 31 includes a transistor Tr1, a transistor Tr2, and a capacitor. The semiconductor device 310 includes a capacitor Cs1 and a light-emitting element 360. The semiconductor device 300 has a structure in which two pixels (or sub-pixels) are adjacent to each other in the column direction. As for the capacitance element Cs1, in FIG. Although not shown, for example, the conductive film 312b of the transistor Tr1 and the This can be formed by using a parasitic capacitance between the conductive film 322b of the transistor Tr2.

[0299] In the circuit diagram shown in FIG. 31, a data line D L_Y-1, a data line DL_Y for writing a data signal to an adjacent pixel, and a light-emitting element The anode line ANODE_X-1 supplies a potential to the adjacent light-emitting element. 1, an anode line ANODE_X for supplying a scanning signal to the pixel, and a scanning line GL_X for supplying a scanning signal to the pixel are shown. is.

[0300] One of the source electrode and the drain electrode of the transistor Tr1 is connected to the data line DL_Y-1. Furthermore, the first gate electrode and the second gate electrode of the transistor Tr1 are electrically connected to each other. The electrode is electrically connected to the scanning line GL_X. The transistor Tr1 receives the data signal. It has the function of controlling the writing of data.

[0301] One of the pair of electrodes of the capacitance element Cs1 is connected to the source electrode and drain electrode of the transistor Tr1. The other of the pair of electrodes of the capacitance element Cs1 is electrically connected to the transistor. The second gate electrode (also called a backgate electrode) of transistor Tr2 is electrically connected to the second gate electrode (also called a backgate electrode) of transistor Tr3. The capacitive element Cs1 functions as a storage capacitor that stores written data.

[0302] One of the source electrode and the drain electrode of the transistor Tr2 is connected to the anode line ANODE_ Electrically connected to X-1.

[0303] One of the pair of electrodes of the light emitting element 360 is the source electrode and the drain electrode of the transistor Tr2. The other electrode is electrically connected to the cathode wire CATHODE. One of the pair of electrodes of the light emitting element 360 is connected to the other of the pair of electrodes of the capacitance element Cs1. are electrically connected.

[0304] The semiconductor device 300 having the above configuration shown in FIGS. 30(A) and 30(B) is applied to a pixel of a display device. This is an example of the case.

[0305] <3-3. Configuration of semiconductor device> The semiconductor device 300 shown in Figures 30(A) and 30(B) will be described again. When the semiconductor device 300 shown in FIG. 1 is applied to a pixel of a display device, for example, The length (L) and width (W) of the channel, or the wiring and electrode lines connecting to the transistor For example, the width of the transistor Tr1 and the transistor T r1 and r2 are placed on the same plane, as shown in Figure 30(A) and (B). By arranging the transistor Tr1 and the transistor Tr2 so that they at least partially overlap each other, etc., it is possible to reduce the variation in processing dimensions.

[0306] In addition, the transistor Tr1 and the transistor Tr2 each have a conductive film or an insulating film. One or both can be used in common, reducing the number of masks or steps. It is possible.

[0307] For example, in the transistor Tr1, the conductive film 320 functions as a gate electrode and The film 312a functions as a source electrode, and the conductive film 312b functions as a drain electrode. In addition, in the transistor Tr1, the insulating film 310 functions as a gate insulating film. In the transistor Tr2, the conductive film 312b functions as a first gate electrode and The conductive film 322a functions as a source electrode, the conductive film 322b functions as a drain electrode, and The insulating film 330 functions as a second gate electrode. The insulating film 318 functions as a first gate insulating film, and the insulating films 324 and 326 function as second gate insulating films. It functions as a veneer.

[0308] In this specification and the like, the insulating film 310 is referred to as a first insulating film, and the insulating film 318 is referred to as a second insulating film. The insulating film and the insulating films 324 and 326 may be referred to as a third insulating film.

[0309] Further, an insulating film 334 and an insulating film 336 are provided on the conductive film 330. In addition, an opening 384 reaching the conductive film 330 is provided in the insulating films 334 and 336. A conductive film 338 is provided over the insulating film 336. It is connected to the conductive film 330 through the opening 384 .

[0310] Moreover, an insulating film 340, an EL layer 342, and a conductive film 344 are provided on the conductive film 338. The insulating film 340 covers a part of the side edge of the conductive film 338 and prevents the conductive film 338 from being electrically conductive between adjacent pixels. The EL layer 342 has a function of emitting light. The conductive film 338, the EL layer 342, and the conductive film 344 constitute a light-emitting element 360. The conductive film 338 functions as one electrode of the light-emitting element 360, and the conductive film 344 , which functions as the other electrode of the light emitting element 360 .

[0311] Thus, in one aspect of the present invention, a transistor having a top gate structure and a transistor having a bottom gate structure are It is possible to use the transistor in combination with a transistor having a gate structure.

[0312] As described above, a semiconductor device according to one embodiment of the present invention has a stacked structure including a plurality of transistors. The area required for installing the transistor is reduced. In addition, the insulating film and By using either one or both of the conductive films in common, the number of masks or the number of processes can be reduced. It can be reduced.

[0313] <3-4. Gate electrode configuration> As shown in FIG. 30(A) and (B), the transistor Tr2 has two gate electrodes. This is the configuration.

[0314] Here, the effect of the structure having two gate electrodes will be described with reference to FIGS. 30(A) and 30(B) and FIG. 2 will be used for the explanation.

[0315] FIG. 32 is a cross-sectional view taken along the dashed line B1-B2 in FIG. 30(A). 32 also includes a cross section of the transistor Tr2 in the channel width (W) direction.

[0316] As shown in FIG. 32, the oxide semiconductor film 328 is formed by bonding the conductive film 312b and the conductive film 330. It is sandwiched between two conductive films that function as gate electrodes and face each other. The lengths of the oxide semiconductor film 328 and the conductive film 330 in the channel width direction are The length of the oxide semiconductor film 328 is longer than the length in the channel width direction. 4, 326 are covered by the conductive film 312b and the conductive film 330.

[0317] In other words, the conductive film 312b and the conductive film 330 are formed on the oxide semiconductor film 328 from the side edges of the oxide semiconductor film 328. also has an area located on the outside.

[0318] With this structure, the oxide semiconductor film 328 included in the transistor Tr2 The transistor can be electrically surrounded by the electric field of the conductive film 312b and the conductive film 330. As in the case of the transistor Tr2, the electric field of the first gate electrode and the second gate electrode causes the channel The device structure of the transistor that electrically surrounds the oxide semiconductor film in which the region is formed is called Sur This can be called a rounded channel (S-channel) structure.

[0319] Since the transistor Tr2 has an S-channel structure, the first gate electrode The conductive film 312b functions as a gate insulating film, and the electric field for inducing the channel is effectively applied to the oxide semiconductor. Since the voltage can be applied to the conductive film 328, the current driving capability of the transistor Tr2 is improved. Therefore, it is possible to obtain high on-current characteristics. Therefore, it is possible to miniaturize the transistor Tr2. The conductive film 312b functions as a first gate electrode and the conductive film 312c functions as a second gate electrode. Since the semiconductor device has a structure surrounded by the conductive film 330, the mechanical strength can be increased.

[0320] The transistor Tr2 shown in FIG. 30B has a conductive layer functioning as a second gate electrode. The conductive film 330 functions as a source electrode or a drain electrode of the transistor Tr2. 322a, but is not limited thereto. For example, The first gate electrode and the second gate electrode may be connected to each other. By providing openings at 318, 324, and 326, a conductive layer that functions as a second gate electrode is formed. The film 330 is electrically connected to the conductive film 312b that functions as the first gate electrode in the opening. Therefore, the conductive film 312b and the conductive film 330 are applied with the same potential.

[0321] <3-5. Components of Semiconductor Device> Next, components included in the semiconductor device of this embodiment will be described in detail.

[0322] [substrate] There is no particular restriction on the material of the substrate 302, but it should be strong enough to withstand the subsequent heat treatment. For example, glass substrates, ceramic substrates, quartz substrates, and sa A fire substrate or the like may be used as the substrate 302. Also, a material such as silicon or silicon carbide may be used. Single crystal semiconductor substrates, polycrystalline semiconductor substrates, compound semiconductors such as silicon germanium, etc. It is also possible to use a substrate, an SOI substrate, or the like, on which a semiconductor element is provided. The substrate 302 may be a glass substrate. If you have 6th generation (1500mm x 1850mm), 7th generation (1870mm x 220 0mm), 8th generation (2200mm x 2400mm), 9th generation (2400mm x 280 By using large-area substrates such as 10th generation (2950mm x 3400mm), Larger display devices can be manufactured.

[0323] In addition, a flexible substrate is used as the substrate 302, and the semiconductor device 300 is directly formed on the flexible substrate. Alternatively, a release layer may be provided between the substrate 302 and the semiconductor device 300. The release layer is separated from the substrate 302 after a semiconductor device is partially or completely completed thereon. The semiconductor device 300 can be transferred to another substrate. It can be transferred to weaker or more flexible substrates.

[0324] [Conductive film] Conductive film 312a, conductive film 312b, conductive film 320, conductive film 322a, conductive film 322b, The conductive film 330, the conductive film 338, and the conductive film 344 may be made of chromium (Cr), copper (Cu), or the like. , Aluminum (Al), Gold (Au), Silver (Ag), Zinc (Zn), Molybdenum (Mo) , Tantalum (Ta), Titanium (Ti), Tungsten (W), Manganese (Mn), Nickel A metal element selected from nickel (Ni), iron (Fe), and cobalt (Co), or the above-mentioned metals. They are formed using alloys that contain the elements or alloys that combine the above-mentioned metal elements. It is possible.

[0325] In addition, the conductive film 312a, the conductive film 312b, the conductive film 320, the conductive film 322a, and the conductive film 32 2b, the conductive film 330, the conductive film 338, and the conductive film 344 contain indium and tin. Oxides, oxides having tungsten and indium, oxides having tungsten, indium and zinc and an oxide having titanium and indium; and an oxide having titanium, indium, and tin. oxide having indium and zinc; oxide having silicon, indium, and tin The oxide conductor, such as an oxide containing indium, gallium, and zinc, is applied. It is also possible.

[0326] In particular, the conductive film 320 and the conductive film 330 can be preferably made of the oxide conductor described above. Here, the oxide conductor will be described. The oxide conductor may be called OC (Oxide Conductor). For example, when oxygen vacancies are formed in an oxide semiconductor and hydrogen is added to the oxygen vacancies, As a result, the oxide semiconductor becomes conductive and becomes a conductor. An oxide semiconductor that has been made into a conductor can be called an oxide conductor. Conductors have a large energy gap and are therefore transparent to visible light. The material conductor is an oxide semiconductor having a donor level near the conduction band. Conductors are less affected by absorption due to donor levels, and exhibit the same level of absorption as oxide semiconductors for visible light. It has a light transmittance of .

[0327] In addition, the conductive film 312a, the conductive film 312b, the conductive film 322a, the conductive film 322b, and the conductive film 3 30, the conductive film 338, and the conductive film 344 are made of a Cu-X alloy film (X is Mn, Ni, Cr , Fe, Co, Mo, Ta, or Ti) may be applied. This allows for wet etching, which reduces manufacturing costs. It becomes.

[0328] In particular, the conductive film 312a, the conductive film 312b, the conductive film 322a, the conductive film 322b, and the conductive One or more of the films 330 may suitably be the Cu-X alloy film described above. As the Cu-X alloy film, a Cu-Mn alloy film is particularly preferable.

[0329] In addition, the conductive film 312a, the conductive film 312b, the conductive film 320, the conductive film 322a, and the conductive film 32 One or more of the above-mentioned metal elements may be used for the conductive film 330. Selected from aluminum, copper, titanium, tungsten, tantalum, and molybdenum It is preferable to have one or more of these.

[0330] In addition, the conductive film 312a, the conductive film 312b, the conductive film 320, the conductive film 322a, and the conductive film 32 2b and the conductive film 330 may be a so-called nitrogen-containing material, which contains nitrogen and tantalum. It is preferable to use a tantalum nitride film. The tantalum nitride film is conductive and can be easily etched with copper or other metals. The tantalum nitride film also has high barrier properties against hydrogen and oxygen. Since hydrogen is released little, the metal film or the oxide semiconductor film in contact with the oxide semiconductor film 308 It is most suitable for use as the metal film in the vicinity of 308.

[0331] [Insulating film] Insulating film 306, insulating film 314, insulating film 316, insulating film 318, insulating film 324, insulating film 3 26, the insulating film 334, the insulating film 336, and the insulating film 340 may be a silicon oxide film, an oxide Silicon nitride film, silicon oxynitride film, silicon nitride film, aluminum oxide film, haf oxide film tungsten oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film , magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film. Insulating layers including those mentioned above can be used.

[0332] The insulating film 306 also functions as a blocking film that suppresses oxygen permeation. For example, the insulating film 314, the insulating film 316, the oxide semiconductor film 308, the oxide semiconductor film 328, When either or both of the insulating film 324 and the insulating film 326 have an excess oxygen region In this case, the insulating film 306 can suppress oxygen permeation.

[0333] Note that when the oxide semiconductor film 308 or the oxide semiconductor film 328 is in contact with the The insulating film to be used is preferably an oxide insulating film, and the insulating film has a stoichiometric composition. It is more preferable to have a region containing oxygen (excess oxygen region). The oxide insulating film having an elemental region is an insulating film capable of releasing oxygen.

[0334] Note that the oxide insulating film having the above-described excess oxygen region can be formed, for example, in an oxygen atmosphere. Form an insulating film, heat-treat the formed insulating film in an oxygen atmosphere, or The method of adding oxygen to the insulating film after the film formation is as follows. A plasma treatment is preferable.

[0335] In addition, an insulating film that functions as a gate insulating film of the transistor Tr1 and the transistor Tr2 The insulating film that functions as a gate insulating film may be made of hafnium oxide. When nium is used, the following effects are obtained.

[0336] 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 film can be made larger, so that the tunnel This reduces the leakage current caused by the current. Furthermore, hafnium oxide, which has a crystalline structure, can be used to realize an amorphous structure. It has a higher relative dielectric constant than hafnium oxide, which has a low off-current. To form a transistor, it is preferable to use hafnium oxide having a crystalline structure. Examples of the crystal structure include monoclinic and cubic. The types are not limited to these.

[0337] In addition, an insulating film that functions as a gate insulating film of the transistor Tr1 and the transistor Tr2 The insulating film that functions as a gate insulating film may be made of silicon nitride. When silicon nitride is used, the following effects are obtained: Silicon nitride has a low dielectric constant compared to silicon oxide. Since the dielectric constant is high and the thickness required to obtain the same capacitance as silicon oxide is large, Therefore, the insulation resistance of the transistor Tr1 and the transistor Tr2 can be increased. By suppressing the voltage drop and improving the withstand voltage, the transistor Tr1 and the transistor This can suppress electrostatic damage to Tr2.

[0338] The insulating films 310, 316, 318, 324, and 326 are the oxide semiconductor film 308 or The oxide semiconductor film 328 has a function of supplying oxygen to one or both of the oxide semiconductor films 328. That is, the insulating films 310, 316, 318, 324, and 326 contain oxygen. Reference numerals 310 and 324 denote insulating films that are permeable to oxygen. The oxide semiconductor film 308 is formed by forming a conductive film 320. The insulating film 324 functions as an oxide semiconductor when the insulating film 326 is formed later. It also functions as a membrane for reducing damage to the body membrane 328.

[0339] The insulating films 310 and 324 have a thickness of 5 nm to 150 nm, preferably 5 nm. Silicon oxide, silicon oxynitride, etc. having a thickness of 50 nm or more and less can be used.

[0340] In addition, it is preferable that the insulating films 310 and 324 have a small number of defects. Typically, the insulating films 310 and 324 have an ESR The measurement revealed that the signal at g = 2.001 originated from the dangling bond of silicon. Pin density is 3x10 17 spins / cm 3 This is because the insulating film If the density of defects in 314 and 324 is high, oxygen will bond to the defects, and the insulating film 31 The amount of oxygen permeable through 4 is reduced.

[0341] The insulating films 310 and 324 are oxide insulating films having a low density of states caused by nitrogen oxides. The density of states caused by the nitrogen oxide can be reduced by using an oxide semiconductor. The energy of the upper end of the valence band of the oxide semiconductor film (Ev_os) and the lower end of the conduction band of the oxide semiconductor film The oxide insulating film may be formed between the gate electrode and the gate electrode. Silicon oxynitride film that releases less oxide or nitroxide An aluminum oxide film or the like can be used.

[0342] In addition, the silicon oxynitride film, which emits a small amount of nitrogen oxide, was analyzed by thermal desorption spectrometry (TD S), it is a membrane that releases more ammonia than nitrogen oxides, and is typically The amount of ammonia released is 1×10 18 cm -3 5×10 or more 19 cm -3 The following is the case. The amount of ammonia released is as follows: The total amount of ammonia in the range of 50°C to 550°C or 50°C to 550°C is also included. The output amount is the total amount converted into ammonia molecules in TDS.

[0343] Nitrogen oxides (NO x , x is more than 0 and not more than 2, preferably 1 or more and not more than 2), typically NO 2 Alternatively, NO forms a level in the insulating films 310, 324, etc. The level is an oxide Located within the energy gap of the semiconductor films 308 and 328. Therefore, the nitrogen oxides At the interface between the insulating film 310 and the oxide semiconductor film 308 or at the interface between the insulating film 324 and the oxide semiconductor film When the electrons diffuse to the interface of the insulating film 310 and 324, the level traps electrons on the insulating film 310 and 324 side. As a result, the trapped electrons may be transported through the insulating film 310 and the oxide semiconductor film 3 3 and 4, or in the vicinity of the interface between the insulating film 324 and the oxide semiconductor film 328. , the threshold voltage of the transistor is shifted in the positive direction.

[0344] Nitrogen oxide reacts with ammonia and oxygen during heat treatment. The nitrogen oxide contained in reacts with the ammonia contained in the insulating film 326 during the heat treatment. Therefore, the nitrogen oxide contained in the insulating film 324 is reduced. Electrons are less likely to be trapped at the interface between the oxide semiconductor film 326 and the oxide semiconductor film 328.

[0345] By using the oxide insulating film as the insulating films 310 and 324, the width of the transistor can be reduced. It is possible to reduce the shift in the low voltage and to reduce the variation in the electrical characteristics of the transistor. It is possible.

[0346] Heat treatment in the manufacturing process of a transistor is typically performed at a temperature of 300° C. or higher and lower than 350° C. By the heat treatment, the insulating films 310 and 324 have a spectrum obtained by measuring the ESR at 100K or less. The first signal has a g value between 2.037 and 2.039 in the spectrum, and the g value is 2.00 The second signal has a g value between 1 and 2.003, and the third signal has a g value between 1.964 and 1.966. The split width of the first signal and the second signal is: The split width of the second and third signals is The g value is about 5 mT. The first signal, g A second signal with a g value between 2.001 and 2.003, and a second signal with a g value between 1.964 and 1.9 The sum of the spin densities of the third signals that are 66 or less is 1 × 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.

[0347] In the ESR spectrum below 100K, the g value is 2.037 or more and 2.039 or less. The first signal below, the second signal with a g-value between 2.001 and 2.003, and the g-value The sum of the spin densities of the third signal, which is greater than or equal to 1.964 and less than or equal to 1.966, is the nitrogen oxide Monster (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) It corresponds to the total density of the pins. Representative examples of nitrogen oxides include nitrogen monoxide, nitrogen dioxide, etc. That is, the first signal has a g value of 2.037 to 2.039, and the second signal has a g value of 2.00 A second signal between 1 and 2.003 and a g value between 1.964 and 1.966. The smaller the total spin density of the third signal, the more the nitrogen oxide in the oxide insulating film is. It can be said that the content of the substance is low.

[0348] The nitrogen concentration of the oxide insulating film measured by SIMS is 6×10 20 atoms / cm 3The following is the result.

[0349] 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.

[0350] The insulating film 314 contains at least one of nitrogen and hydrogen. For example, a nitride insulating film can be used. Examples of the nitride insulating film include silicon nitride, It can be formed using silicon nitride oxide, aluminum nitride, aluminum nitride oxide, etc. The hydrogen concentration in the insulating film 314 is 1×10 22 atoms / cm 3 That's all. The insulating film 314 is preferably formed on the source region 308s of the oxide semiconductor film 308 and The insulating film 314 is in contact with the conductive film 320. Therefore, the source region 308s and the drain region 308d in contact with the insulating film 314 , and the hydrogen concentration in the conductive film 320 increases, and the source region 308s and the drain region 308 d and the carrier density of the conductive film 320 can be increased. The drain region 308d and the conductive film 320 are in contact with the insulating film 314. There may be regions in which the hydrogen concentration in the film is the same.

[0351] The insulating films 316, 318, and 326 contain more oxygen than is required for the stoichiometric composition. The oxide insulating film contains more oxygen than the stoichiometric composition. When the oxide insulating film is heated, some of the oxygen is released. Oxide insulating films that contain a lot of oxygen have a release rate of 1 .0×10 19 cm -3 More than 3.0×10 20 cm -3 That's all. The amount of oxygen released is as follows: the temperature of the heat treatment in TDS is 50°C or higher and 650°C or lower; The total amount of oxygen released is in the range of 50°C to 550°C. This is the total amount converted into oxygen molecules in

[0352] The insulating films 316, 318, and 326 preferably have a thickness of 30 nm or more and 500 nm or less. Silicon oxide, silicon oxynitride, etc., with a thickness of 50 nm to 400 nm, are generally used. can.

[0353] In addition, it is preferable that the insulating films 316, 318, and 326 have a small number of defects. , ESR measurements reveal that the g value is 2.001, which is due to the dangling bond of silicon. The signal spin density is 1.5×10 18 spins / cm 3 Less than or even 1×10 18 s pins / cm 3 It is preferable that:

[0354] In addition, the insulating film 324 and the insulating film 326 can be made of the same material. In some cases, the interface between the insulating film 324 and the insulating film 326 may not be clearly visible. In this embodiment, the interface between the insulating film 324 and the insulating film 326 is illustrated by a dashed line. .

[0355] The insulating film 334 functions as a protective insulating film for the transistors Tr1 and Tr2. Possesses the ability.

[0356] The insulating film 334 contains either hydrogen or nitrogen, or both. The insulating film 334 contains nitrogen and silicon. The insulating film 334 contains oxygen, hydrogen, water, and alkali. The insulating film 334 has a function of blocking metals, alkaline earth metals, etc. As a result, oxygen is diffused from the oxide semiconductor film 308 and the oxide semiconductor film 328 to the outside, and the insulating film 326 is prevented from being broken down. The oxygen contained in the coatings 310, 316, 324, and 326 diffuses to the outside, and the oxide It is possible to prevent hydrogen, water, and the like from entering the semiconductor films 308 and 328 .

[0357] The insulating film 334 may be, for example, a nitride insulating film. Examples include silicon nitride, silicon nitride oxide, aluminum nitride, and aluminum nitride oxide. etc.

[0358] [Oxide semiconductor film] The oxide semiconductor film 308 and the oxide semiconductor film 328 are formed using the above-described materials. There can be.

[0359] When the oxide semiconductor film 308 and the oxide semiconductor film 328 are an In-M-Zn oxide, In -The number of atoms of the metal element in the sputtering target used to deposit the M-Zn oxide film The ratio of In to M is preferably satisfied. The atomic ratio of elements is In:M:Zn=2:1:3, In:M:Zn=3:1:2, In :M:Zn=4:2:4.1 etc.

[0360] In addition, when the oxide semiconductor film 308 and the oxide semiconductor film 328 are an In-M-Zn oxide, The metal elements of the sputtering target used to form the In-M-Zn oxide film The atomic ratio may be a composition that satisfies In≦M. The atomic ratio of group elements is In:M:Zn=1:1:1, In:M:Zn=1:1:1. 2, In:M:Zn=1:3:2, In:M:Zn=1:3:4, In:M:Zn=1: 3:6, etc.

[0361] The oxide semiconductor film 308 and the oxide semiconductor film 328 are each made of In-M-Zn oxide. In the case of In-Zn oxides, the sputtering target is a polycrystalline In-M-Zn oxide. It is preferable to use a target containing polycrystalline In-M-Zn oxide. This makes it easier to form the oxide semiconductor film 308 and the oxide semiconductor film 328 having crystallinity. Note that the atomic ratio of the oxide semiconductor film 308 and the oxide semiconductor film 328 to be formed is The positive and negative atomic ratios of the metal elements contained in the sputtering target are For example, the oxide semiconductor film 308 and the oxide semiconductor film 328 have a 40% variation. The atomic ratio of In:Ga:Zn=4:2:4.1 is used as the sputtering target. In this case, the atomic ratio of the oxide semiconductor film 308 and the oxide semiconductor film 328 to be formed is In: In some cases, the Ga:Zn ratio is approximately 4:2:3.

[0362] The oxide semiconductor film 308 and the oxide semiconductor film 328 each have an energy gap of 2e 5 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more. By using an oxide semiconductor with a wide energy gap, The off-current of the starter Tr2 can be reduced.

[0363] The oxide semiconductor film 308 and the oxide semiconductor film 328 each have a thickness of 3 nm or more. 200 nm or less, preferably 3 nm or more and 100 nm or less, and more preferably 3 nm or more and 5 0 nm or less.

[0364] Hydrogen contained in the oxide semiconductor film 308 and the oxide semiconductor film 328 reacts with metal atoms. The bonded oxygen reacts with the water to form water, and the lattice from which the oxygen is removed (or the part from which the oxygen is removed) When hydrogen enters the oxygen vacancy, electrons, which act as carriers, are generated. In addition, some of the hydrogen may bond with oxygen that bonds with metal atoms, forming a carrier. Therefore, a transistor using an oxide semiconductor film containing hydrogen may generate electrons. The transistor tends to be normally on. It is preferable that the amount of hydrogen in the nitride semiconductor film 328 is reduced as much as possible.

[0365] Specifically, the oxide semiconductor film 308 and the oxide semiconductor film 328 were analyzed by SIMS. The hydrogen concentration obtained by 20 atoms / cm 3 Hereinafter, preferably 5×10 19 atoms / cm 3 Less than or equal to 1×10 19 atoms / cm 3 Below, 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than or equal to 5×10 17 atoms / cm 3 Below, more preferably 1×1 0 16 atoms / cm 3 The following applies.

[0366] In addition, in the oxide semiconductor film 308 and the oxide semiconductor film 328, one of Group 14 elements When silicon or carbon is contained, the oxide semiconductor film 308 and the oxide semiconductor film 32 As a result, oxygen vacancies increase in the oxide semiconductor film 308 and the oxide semiconductor film 309, which become n-type. The silicon concentrations in the oxide semiconductor film 328 obtained by SIMS analysis were ×10 18 atoms / cm 3 Less than or equal to 2×10 17 atoms / cm 3 Below and do. In addition, the oxide semiconductor films 308 and 328 were analyzed by SIMS. The carbon concentration is 2×10 18 atoms / cm 3 Less than or equal to 2×10 1 7 atoms / cm 3 The following applies.

[0367] In addition, the oxide semiconductor film 308 and the oxide semiconductor film 328 were analyzed by SIMS. The resulting alkali metal or alkaline earth metal concentration is 1×10 18 atom s / cm 3 Less than or equal to 2×10 16 atoms / cm 3 Below: Alkali metals When the alkaline earth metal and the oxide semiconductor are bonded, they may generate carriers. The off-state current of the transistor may be increased. In addition, the concentration of alkali metal or alkaline earth metal in the oxide semiconductor film 328 can be reduced. preferable.

[0368] In addition, each of the oxide semiconductor film 308 and the oxide semiconductor film 328 may have a non-single crystal structure. The non-single crystal structure is, for example, CAAC-OS (C Axis Alignment-type crystalline structure) which will be described later. d Crystalline Oxide Semiconductor), polycrystalline structure , microcrystalline, or amorphous structures. In non-single crystal structures, the amorphous structure is the most defect-free. The defect state density is high in CAAC-OS, while the defect state density is the lowest in CAAC-OS.

[0369] The above-mentioned various films such as the conductive film, the insulating film, and the oxide semiconductor film may be formed by sputtering. Plasma Enhanced Chemical Vapor Deposition (PECVD) Chemical Vapor Deposition) method, thermal CVD (Chemical It can be formed by the thermal vapor deposition method. As a VD method, MOCVD (Metal Organic Chemical Vapor Deposition) Deposition) method or ALD (Atomic Layer Deposition) method ition method, etc.

[0370] Thermal CVD is a film formation method that does not use plasma, so defects can occur due to plasma damage. This has the advantage that no additional steps are required.

[0371] In the thermal CVD method, the source gas and the oxidizing agent are fed into the chamber at the same time, and the chamber is filled with air. The reaction is carried out near or on the substrate under high or low pressure, and the material is deposited on the substrate to form a film. may be carried out.

[0372] In addition, in the ALD method, the pressure inside the chamber is set at atmospheric pressure or reduced pressure, and the source gas for the reaction is The film may be formed using the same.

[0373] Thermal CVD methods such as MOCVD and ALD can be used to form the conductive film, insulating film, and oxide film of the above-mentioned embodiment. It is possible to form various films such as semiconductor films. For example, an In-Ga-ZnO film can be formed. In some cases, trimethylindium, trimethylgallium, and dimethylzinc are used. The chemical formula for trimethylindium is In(CH 3 ) 3 In addition, trimethyl gas The chemical formula for lithium is Ga(CH 3 ) 3 The chemical formula for dimethylzinc is Zn(C H 3 ) 2 In addition, the combination is not limited to these, and instead of trimethylgallium, Triethylgallium (chemical formula Ga(C 2 H 5 ) 3 ) can also be used, and dimethyl zinc Instead, diethylzinc (chemical formula Zn(C 2 H 5 ) 2 ) can also be used.

[0374] For example, when forming a hafnium oxide film using a film forming apparatus that uses ALD, the solvent and liquids containing hafnium precursor compounds (hafnium alkoxides, tetrakisdimethyl The raw material gas is made by vaporizing hafnium amide (such as TDMAH) and acid. Ozone (O 3 Two types of gases are used: tetrakisdimethylamide The chemical formula for Hf is Hf[N(CH 3 ) 2 ] 4 In addition, other material liquids include tetrahydrofuran. Examples include rakis(ethylmethylamido)hafnium.

[0375] For example, when forming an aluminum oxide film using an ALD deposition system, A liquid containing a catalyst and an aluminum precursor compound (e.g., trimethylaluminum (TMA)) is added. Vaporized raw gas and H as oxidant 2 Two types of gases are used: trimethyl The chemical formula for aluminum is Al(CH 3 ) 3 In addition, other material liquids include Tris( Dimethylamido)aluminum, triisobutylaluminum, aluminum tris(2 ,2,6,6-tetramethyl-3,5-heptanedionate).

[0376] For example, when forming a silicon oxide film using a deposition system that uses ALD, Chlorodisilane is adsorbed onto the surface to be coated, removing the chlorine contained in the adsorbed matter, and the oxidizing gas (O 2 , nitrous oxide) radicals are supplied to react with the adsorbate.

[0377] For example, when forming a tungsten film using a deposition system that uses ALD, the WF 6 Gas and B 2 H 6 gas to form an initial tungsten film, and then WF 6 Gas and H 2 A tungsten film is formed using the gas B 2 H 6 Instead of gas, SiH 4 Gas It may be used.

[0378] For example, an oxide semiconductor film, such as In-Ga-ZnO, can be formed by a film formation apparatus using ALD. When forming a film, In(CH 3 ) 3 Gas and O 3 An In-O layer is formed using gas. , then Ga(CH 3 ) 3 Gas and O 3 A GaO layer is formed using the gas, and then Z n(CH 3 ) 2 Gas and O 3 The ZnO layer is formed using the gas. The present invention is not limited to this example. In addition, In-Ga-O layers and In-Zn-O layers can be formed by using these gases. Alternatively, a mixed compound layer such as a Ga-Zn-O layer may be formed. 3 Gas replaced with Ar H obtained by bubbling with an inert gas such as 2 O gas may be used, but it should be O gas that does not contain H. 3 It is preferable to use In(CH 3 ) 3 Instead of gas, In(C 2 H 5 ) 3 Gas may also be used. 3 ) 3 Instead of gas, Ga(C 2 H 5 ) 3 gas Also, Zn(CH 3 ) 2 A gas may also be used.

[0379] <3-6. Configuration example 2 of semiconductor device> Next, a modified example of the semiconductor device 300 shown in FIGS. 30(A) and 30(B) will be described with reference to FIG. explain.

[0380] FIG. 33 is a cross-sectional view of a modified example of the semiconductor device 300 shown in FIG.

[0381] FIG. 33 shows a semiconductor device 300 having a second gate electrode functioning as a second gate electrode of a transistor Tr2. In this configuration, the conductive film 330 that functions as a conductive film and the insulating film 334 on the conductive film 330 are not provided. In FIG. 33, an opening 382 is provided in the insulating film 324 and the insulating film 326, and the insulating film 33 Instead of the insulating film 324 and the opening 384 provided in the insulating film 336, the insulating film 324 and the insulating film 32 6, and an opening 383 is provided in the insulating film 336. This is preferable because it reduces the number of manufacturing steps.

[0382] <3-7. Configuration example 3 of semiconductor device> Next, a modified example of the semiconductor device 300 shown in FIG. 30(A)(B) will be described with reference to FIG. This will be explained using Figures 35(A) and (B).

[0383] Here, a stacked structure of oxide semiconductor films is described.

[0384] 34(A) and (B) show the channel length ( FIG. 11 is a cross-sectional view taken in the L direction.

[0385] FIG. 34A shows an oxide semiconductor film 328 of the transistor Tr2. the oxide semiconductor film 328a, the oxide semiconductor film 328b over the oxide semiconductor film 328a, and the oxide semiconductor film 328b and an oxide semiconductor film 328c over the oxide semiconductor film 328b. It has a three-layer laminated structure.

[0386] FIG. 34B shows an oxide semiconductor film 328 of the transistor Tr2. and an oxide semiconductor film 328c over the oxide semiconductor film 328b. That is, the oxide semiconductor film has a stacked structure of two layers.

[0387] 1 is a diagram showing an example of a band structure of the oxide semiconductor film 328 and an insulating film in contact with the oxide semiconductor film 328. Shown in Figures 35(A) and (B).

[0388] FIG. 35A illustrates the insulating film 318, the oxide semiconductor films 328a, 328b, and 328c, and This is an example of a band structure in the thickness direction of a laminated structure having an insulating film 324. ) is a multilayer structure including the insulating film 318, the oxide semiconductor films 328b and 328c, and the insulating film 324. 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 318, the oxide semiconductor films 328a, 328b, and 328c, and the insulating film 324 are The energy level (Ec) at the bottom of the conductive band is shown.

[0389] FIG. 35(A) shows a case where a silicon oxide film is used as the insulating film 318 and the insulating film 324. The oxide semiconductor film 328a has an atomic ratio of metal elements of In:Ga:Zn=1:3:2. The oxide semiconductor film 328 is formed using an oxide semiconductor film formed using a metal oxide target. b is a metal oxide target with an atomic ratio of metal elements of In:Ga:Zn=4:2:4.1. The oxide semiconductor film 328c is formed using an oxide semiconductor film formed using a metal element. The oxide formed using a metal oxide target with an atomic ratio of In:Ga:Zn=1:3:2 FIG. 1 is a band diagram of a structure using a compound semiconductor film.

[0390] FIG. 35B shows a case where a silicon oxide film is used as the insulating film 318 and the insulating film 324. The atomic ratio of metal elements in the oxide semiconductor film 328b is In:Ga:Zn=4:2:4. The oxide semiconductor film formed by using the metal oxide target of 1 is used to form the oxide semiconductor film 3. 28c is a metal oxide target with an atomic ratio of metal elements of In:Ga:Zn=1:3:2. FIG. 1 is a band diagram of a configuration using a metal oxide film formed using a tantalum oxide.

[0391] As shown in FIGS. 35A and 35B, in the oxide semiconductor films 328a, 328b, and 328c, 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 328a and the oxide semiconductor film 328b, or the oxide semiconductor film 328b At the interface between the oxide semiconductor film 328c and the oxide semiconductor film 328c, a defect state such as a trap center or a recombination center is generated. Assume that there are no impurities that would form a

[0392] In order to form a continuous junction in the oxide semiconductor films 328a, 328b, and 328c, 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.

[0393] With the structure shown in FIG. 35A and FIG. 35B, the oxide semiconductor film 328b serves as a well. In the transistor using the above stacked structure, the channel region is formed of the oxide semiconductor film 3 It can be seen that it is formed in 28b.

[0394] Note that by providing the oxide semiconductor films 328a and 328c, the trap states can be reduced by It can be located away from the semiconductor film 328b.

[0395] In addition, the trap states are below the conduction band of the oxide semiconductor film 328b functioning as a channel region. The energy level of the edge (Ec) can be farther from the vacuum level, and electrons can be trapped in the trap level. When electrons accumulate in the trap level, negative 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 328b. 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.

[0396] The oxide semiconductor films 328a and 328c have a conduction band lower than that of the oxide semiconductor film 328b. The energy level of the edge of the oxide semiconductor film 328b is close to the vacuum level. and the energy levels of the conduction band minimums of the oxide semiconductor films 328a and 328c. 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 328a and 328c and the The difference between the electron affinity of the organic film 328b and the electron affinity of the organic film 328c is 0.15 eV or more, or 0.5 eV or more, and eV or less, or 1 eV or less.

[0397] With such a structure, the oxide semiconductor film 328b serves as a main path for current. The oxide semiconductor films 328a and 328c function as a channel region. The oxide semiconductor film 328b is formed by using an oxide semiconductor material including at least one metal element. Since the oxide semiconductor film 328a is an oxide semiconductor film, the interface between the oxide semiconductor film 328a and the oxide semiconductor film 328b and Alternatively, interface scattering occurs at the interface between the oxide semiconductor film 328b and the oxide semiconductor film 328c. Therefore, the movement of carriers is not hindered at the interface, and the transistor The field effect mobility of the

[0398] In addition, the oxide semiconductor films 328a and 328c function as part of a channel region. In order to prevent this, a material having sufficiently low electrical conductivity is used. In 328c, the electron affinity (the difference between the vacuum level and the energy level at the bottom of the conduction band) is The energy level of the conduction band minimum is smaller than that of the oxide semiconductor film 328b. A material with a conduction band offset is used. In order to suppress the occurrence of a difference in threshold voltage depending on the magnitude of the drain voltage, The energy levels of the conduction band minimums of the oxide semiconductor films 328a and 328c are It is preferable to use a material whose energy level is closer to the vacuum level than the conduction band minimum energy level of b. For example, the energy level of the conduction band minimum of the oxide semiconductor film 328b is , 328c, the difference between the energy level of the conduction band minimum is 0.2 eV or more, preferably 0.5 It is preferable that the viscosity is 100 eV or more.

[0399] In addition, the oxide semiconductor films 328a and 328c do not contain a spinel crystal structure. It is preferable that the oxide semiconductor films 328a and 328c have a spinel crystal structure. When the spinel type crystal structure includes the conductive film 322a, 322b, the conductive film 322c is formed at the interface between the spinel type crystal structure and other regions. In some cases, a constituent element of the oxide semiconductor film 2b may diffuse into the oxide semiconductor film 328b. When the conductive films 328a and 328c are made of CAAC-OS, which will be described later, the conductive films 322a and 32 This is preferable because it enhances the blocking properties of the constituent elements of 2b, for example, copper element.

[0400] The thicknesses of the oxide semiconductor films 328a and 328c are determined by the composition of the conductive films 322a and 322b. The insulating film has a thickness that is greater than or equal to a thickness that can prevent the insulating film from diffusing into the oxide semiconductor film 328b. The thickness of the oxide semiconductor film 328b is set to be less than the thickness at which oxygen supply from the film 324 to the oxide semiconductor film 328b is suppressed. For example, When the thickness of the oxide semiconductor films 328a and 328c is 10 nm or more, the conductive films 322a and This can prevent the constituent elements of the oxide semiconductor film 322b from diffusing into the oxide semiconductor film 328b. In addition, when the thickness of the oxide semiconductor films 328a and 328c is 100 nm or less, the insulating film 324 Therefore, oxygen can be effectively supplied to the oxide semiconductor film 328b.

[0401] The oxide semiconductor films 328a and 328c are made of In-M-Zn oxide (M is Al, Ga, Y, or When M is an atomic ratio higher than In, the oxide semiconductor film 32 8a, 328c can increase the energy gap and decrease the electron affinity. The difference in electron affinity between the compound semiconductor film 328b and the compound semiconductor film 328c can be controlled by the composition of M. In addition, since M is a metal element with strong bonding power with oxygen, these elements are called I By having an atomic ratio higher than n, oxygen deficiency is less likely to occur.

[0402] When the oxide semiconductor films 328a and 328c are made of In-M-Zn oxide, Zn and The atomic ratio of In and M excluding O is preferably 50 atomic % In. less than 50 atomic %, M is more than 50 atomic %, and more preferably In is 25 atomic % In addition, the oxide semiconductor films 328a and 328c are A gallium oxide film may be used as the insulating film.

[0403] In addition, when the oxide semiconductor films 328a, 328b, and 328c are In-M-Zn oxide, , compared with the oxide semiconductor film 328b, M Typically, the atomic ratio of the above atoms contained in the oxide semiconductor film 328b is larger than that of the above atoms contained in the oxide semiconductor film 328c. The atomic ratio is 1.5 times or more, preferably 2 times or more, and more preferably 3 times or more. .

[0404] In addition, when the oxide semiconductor films 328a, 328b, and 328c are In-M-Zn oxide, The oxide semiconductor film 328b is In:M:Zn=x 1 :y 1 :z 1 [Atomic ratio], oxide half The conductor films 328a and 328c are In:M:Zn=x 2 :y 2 :z 2 [Atomic ratio], y 2 / x 2 y 1 / x 1 preferably greater than y 2 / x 2 y 1 / x 1 than 1. More preferably, y 2 / x 2 y 1 / x 1 More than twice as large as Preferably, y 2 / x 2 y 1 / x 1 is more than three or four times larger than In the oxide semiconductor film 328b, y 1 x 1 In this case, the oxide semiconductor film 328b This is preferable because it can provide stable electrical characteristics to a transistor using y 1 x 1 When the field-effect mobility of the transistor including the oxide semiconductor film 328b is three times or more Because y 1 x 1 It is preferable that the amount of the ion exchange resin is less than three times as large as that of the ion exchange resin.

[0405] When the oxide semiconductor film 328b is an In-M-Zn oxide, the oxide semiconductor film 328b is formed. The atomic ratio of the metal elements in the target used for film formation is In:M:Zn=x 1 : y 1 :z 1 So, 、 x 1 / y 1 is between 1 / 3 and 6, or between 1 and 6. , z 1 / y 1 is preferably 1 / 3 or more and 6 or less, and more preferably 1 or more and 6 or less. , z 1 / y 1 When the ratio of the cation concentration to the cation concentration is 1 to 6, the oxide semiconductor film 328b can be formed using the CAA The atomic ratio of the target metal elements is typically I n:M:Zn=4:2:4.1, In:M:Zn=1:1:1.2, In:M:Zn=3 :1:2 etc.

[0406] In addition, when the oxide semiconductor films 328a and 328c are made of In-M-Zn oxide, In the target used to form the solid films 328a and 328c, the number of atoms of the metal element is The ratio is In:M:Zn=x 2 :y 2 :z 2 So, 、 x 2 / y 2 <x 1 / y 1 Where z 2 / y 2 is preferably 1 / 3 or more and 6 or less, and more preferably 1 or more and 6 or less. By increasing the atomic ratio of M to n, the oxide semiconductor films 328a and 328c can be It is possible to increase the energy gap and decrease the electron affinity, so y 2 / x2 It is preferable that the atomic ratio of the metal elements in the target is 3 or more, or 4 or more. Examples are In:M:Zn=1:3:2, In:M:Zn=1:3:4, In:M:Z n=1:3:5, In:M:Zn=1:3:6, In:M:Zn=1:4:2, In:M :Zn=1:4:4, In:M:Zn=1:4:5, In:M:Zn=1:5:5 etc. do.

[0407] In addition, when the oxide semiconductor films 328a and 328c are an In-M oxide, M is a divalent metal. By making the composition free of atomic elements (e.g., zinc), it has a spinel-type crystal structure. In addition, the oxide semiconductor films 328a and 328c can be formed without using the oxide semiconductor The films 328a and 328c may be, for example, In-Ga oxide films. As the In-Ga oxide, for example, an In-Ga metal oxide target (In:Ga=7 The insulating film can be formed by a sputtering method using an oxide semiconductor. In order to form the films 328a and 328c by a sputtering method using DC discharge, When M=x:y [atomic ratio], y / (x+y) is 0.96 or less, preferably 0 It is best to set it to .95 or less, for example 0.93.

[0408] Note that the atomic ratios of the oxide semiconductor films 328a, 328b, and 328c are each determined with an error. The atomic ratios listed above may vary by ±40%.

[0409] In addition, in FIG. 34(A) and (B), the oxide semiconductor film 328 of the transistor Tr2 is a two-layer The transistor Tr1 has a stacked structure of three layers, but the oxide semiconductor film 3 A similar configuration may be used in 08 as well.

[0410] In this way, the semiconductor device of the present invention can be characterized by the presence or absence of a second gate electrode, or the presence or absence of an oxide semiconductor. The laminated structure of the conductor film may be changed. Each of the above structures can be freely combined.

[0411] <3-8. Manufacturing method of semiconductor device> Next, a manufacturing method of the semiconductor device 300 according to one embodiment of the present invention will be described with reference to FIGS. I will explain this in more detail.

[0412] In addition, Fig. 36(A), Fig. 37(A), Fig. 38(A), Fig. 39(A), Fig. 40(A), Fig. 41(A), 42(A), 43(A), 44(A), and 45(A) are semiconductor 36(B), 37(B), and 38(C) are top views for explaining a method for manufacturing the device 300. B), Fig. 39(B), Fig. 40(B), Fig. 41(B), Fig. 42(B), Fig. 43(B), Fig. 4 4(B) and 45(B) are cross-sectional views illustrating a method for manufacturing the semiconductor device 300. FIG.

[0413] First, an insulating film 306 is formed on a substrate 302, and an oxide semiconductor film is formed on the insulating film 306. After that, the oxide semiconductor film is processed into an island shape to form an oxide semiconductor film 308. (See Figures 36(A) and (B)).

[0414] In this embodiment, the substrate 302 can be a glass substrate.

[0415] The insulating film 306 can be formed by sputtering, CVD, vapor deposition, pulsed laser deposition ( The film can be formed by appropriately using a PLD method, a printing method, a coating method, or the like. In this case, a silicon nitride film having a thickness of 400 nm was deposited as the insulating film 306 using a PECVD apparatus. Then, a silicon oxynitride film having a thickness of 50 nm is formed.

[0416] After the insulating film 306 is formed, oxygen may be added to the insulating film 306. The oxygen added to 6 may be an oxygen radical, an oxygen atom, an oxygen atomic ion, or an oxygen molecular ion. The doping method includes ion doping, ion implantation, plasma treatment, etc. In addition, a film that suppresses oxygen desorption is formed on the insulating film, and then the insulating film is formed through the film. The film 306 may be doped with oxygen.

[0417] The above-mentioned oxygen desorption-suppressing film may be made of indium, zinc, gallium, tin, aluminum, or the like. Aluminum, chromium, tantalum, titanium, molybdenum, nickel, iron, cobalt, tungsten A metal element selected from the above, an alloy containing the above metal element, or a combination of the above metal elements. an alloy having the above-mentioned metal element, a metal nitride having the above-mentioned metal element, a metal oxide having the above-mentioned metal element, The insulating layer 11 is formed by using a conductive material such as a metal nitride oxide having the above-mentioned metal element. This can be done.

[0418] In addition, when oxygen is added in plasma treatment, the oxygen is excited by microwaves to produce high-density oxygen. By generating atomic plasma, the amount of oxygen added to the insulating film 306 can be increased. .

[0419] The oxide semiconductor film 308 can be formed by a sputtering method, a coating method, a pulsed laser deposition method, or the like. It can be formed by a laser ablation method, a thermal CVD method, etc. To process the conductive film 308, a mask is formed on the oxide semiconductor film by a lithography process. Then, part of the oxide semiconductor film is etched using the mask. Alternatively, the oxide semiconductor film 308 may be directly formed by using a printing method. .

[0420] When an oxide semiconductor film is formed by a sputtering method, a power source for generating plasma The device may be an RF power supply device, an AC power supply device, a DC power supply device, or the like. In the case of forming an oxide semiconductor film, a sputtering gas is a rare gas (typically, argon). ), oxygen, rare gas, and mixed gas of oxygen are used as appropriate. Note that the mixed gas of rare gas and oxygen In this case, it is preferable to increase the gas ratio of oxygen to the rare gas.

[0421] Note that when the oxide semiconductor film is formed by, for example, a sputtering method, Temperature: 150℃ to 750℃, 150℃ to 450℃, or 200℃ By forming the oxide semiconductor film at a temperature of 350° C. or less, the crystallinity can be improved. Therefore, it is preferable.

[0422] Note that in this embodiment, a sputtering apparatus is used to deposit the oxide semiconductor film 308. The sputtering target was In-Ga-Zn metal oxide (In:Ga:Zn = 4:2:4.1 [atomic ratio]) to form a 40-nm-thick oxide semiconductor film.

[0423] After the oxide semiconductor film 308 is formed, heat treatment is performed. The temperature of the heat treatment is typically 150° C. or higher. Less than the strain point, or 250°C to 450°C, or 300°C to 450°C .

[0424] Heat treatment is carried out using rare gases such as helium, neon, argon, xenon, krypton, or It can be carried out in an inert gas atmosphere containing nitrogen. Alternatively, it can be heated in an inert gas atmosphere. After that, heating may be performed in an oxygen atmosphere. Note that hydrogen, water, etc. may be added to the inert atmosphere and oxygen atmosphere. It is preferable that the treatment time does not include the above-mentioned. The treatment time may be from 3 minutes to 24 hours.

[0425] The heat treatment can be performed using an electric furnace, an RTA device, or the like. Therefore, heat treatment can be performed at a temperature above the distortion point of the substrate for a short period of time. The processing time can be reduced.

[0426] The oxide semiconductor film is formed while being heated, or the oxide semiconductor film is formed and then subjected to heat treatment. By performing the process, the hydrogen concentration in the oxide semiconductor film obtained by secondary ion mass spectrometry can be Degrees 5×10 19 atoms / cm 3 or less, or 1×10 19 atoms / cm 3 below , 5×10 18 atoms / cm 3 or less, or 1×10 18 atoms / cm 3 below, or 5×10 17 atoms / cm 3 or less, or 1×10 16 atoms / cm 3 Below It can be below.

[0427] Next, an insulating film and a conductive film are formed over the insulating film 306 and the oxide semiconductor film 308. The insulating film 310 and the conductive film 320 are formed by processing the insulating film 310 and the conductive film 320 (see FIGS. 37(A) and (B)). .

[0428] The insulating film 310 is a silicon oxide film or a silicon oxynitride film formed by a PECVD method. In this case, the source gas is a deposition gas containing silicon. It is preferable to use an oxidizing gas. Representative examples of deposition gases containing silicon include: Examples of oxidizing gases include oxygen, fluorine, and silane. These include nitrous oxide, nitrous oxide, and nitrogen dioxide.

[0429] In addition, the flow rate of the oxidizing gas is set to 20 times or more the flow rate of the deposition gas for the insulating film 310. The pressure in the treatment chamber should be less than 100 times, or between 40 and 80 times. By using the PECVD method with a pressure of 50 Pa or less, it is possible to fabricate an oxynitride silicon nitride film with a small amount of defects. A silicon film can be formed.

[0430] The insulating film 310 is formed on a substrate placed in a vacuum-evacuated processing chamber of a PECVD apparatus. The plate is kept at 280°C or more and 400°C or less, and raw material gas is introduced into the treatment chamber to The pressure is set to 20 Pa or more and 250 Pa or less, and more preferably, 100 Pa or more and 250 Pa or less. By supplying high frequency power to an electrode provided in the processing chamber, the insulating film 310 is formed. A dense silicon oxide film or silicon oxynitride film can be formed.

[0431] The insulating film 310 may be formed by using a plasma CVD method using microwaves. Microwaves refer to the frequency range from 300MHz to 300GHz. In this case, the electron temperature is low and the electron energy is small. The proportion of the ions used quickly is small, allowing more molecules to be dissociated and ionized. This allows for the excitation of high density plasma. The insulating film 310 can be formed with less defects due to less plasma damage to the film surface and deposits. This can be done.

[0432] The insulating film 310 can be formed by a CVD method using an organic silane gas. The organic silane gas is ethyl silicate (TEOS: chemical formula Si(OC 2 H 5 ) 4 ), Tetramethylsilane (TMS: Chemical formula Si(CH 3 ) 4 ), tetramethylcyclotetramethyl Octamethylcyclotetrasiloxane (TMCTS), Octamethylcyclotetrasiloxane (OMCTS), Hexa Methyldisilazane (HMDS), Triethoxysilane (SiH(OC 2 H 5 ) 3 ), Tori Dimethylaminosilane (SiH(N(CH 3 ) 2 ) 3 ) and other silicon-containing compounds. By using the CVD method with organic silane gas, it is possible to obtain insulating films with high coating properties. A membrane 310 may be formed.

[0433] In this embodiment, a PECVD apparatus is used to form the insulating film 310, and an oxide film having a thickness of 150 nm is formed. A silicon nitride film is formed.

[0434] The conductive film 320 is preferably made of an oxide conductor (OC). During formation, oxygen is added from the conductive film 320 into the insulating film 310 .

[0435] The conductive film 320 is formed by sputtering, and oxygen gas is included in the formation. It is preferable to form the conductive film 320 in an atmosphere containing oxygen gas. This allows oxygen to be suitably added to the insulating film 310.

[0436] Note that the conductive film 320 is formed using a material similar to that of the oxide semiconductor film 308 described above. It is possible.

[0437] In this embodiment, a sputtering device is used to form the conductive film 320. The ring target was In-Ga-Zn metal oxide (In:Ga:Zn=5:1:7[ A conductive film with a thickness of 20 nm is formed using a 1000 uF2O3 solution (atomic ratio).

[0438] In this embodiment, the conductive film 320 and the insulating film 310 are processed by dry etching. This is done using an etching method.

[0439] In addition, when processing the conductive film 320 and the insulating film 310, the conductive film 320 is not overlapped in the region. In some cases, the thickness of the oxide semiconductor film 308 becomes thin.

[0440] Next, an impurity element was added from above the insulating film 306, the oxide semiconductor film 308, and the conductive film 320. Addition is carried out.

[0441] The method of adding impurity elements includes ion doping, ion implantation, and plasma treatment. In the case of plasma processing, plasma is generated in a gas atmosphere containing the impurity element to be added. By generating and performing a plasma treatment, an impurity element can be added. The plasma generating device may be a dry etching device, an ashing device, a plasma A CVD apparatus, a high density plasma CVD apparatus, etc. can be used.

[0442] In addition, the source gas for the impurity element is B 2 H 6 , PH 3 , C.H. 4 , N 2 , N.H. 3 , Al H 3 , AlCl 3 , SiH 4 , Si 2 H 6 , F 2 , H.F., H. 2 and one or more rare gases Or, B diluted with rare gas can be used. 2 H 6 , PH 3 , N 2 , N.H. 3 , AlH 3 , AlCl 3 , F 2 , HF, and H 2 One or more of the following can be used: B 2 H 6 , PH 3 , N 2 , N.H. 3 , AlH 3 , AlCl 3 , F 2 , HF, and H 2 of By adding one or more impurity elements to the oxide semiconductor film 308 and the conductive film 320, A rare gas, hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, and / or chlorine oxide semi-conductor. The conductive film 308 and the conductive film 320 may be doped.

[0443] Or, after adding rare gas, B 2 H 6 , PH 3 , C.H. 4 , N 2 , N.H. 3 , AlH 3 , AlCl 3 , SiH 4 , Si 2 H6 , F 2 , HF, and H 2 At least one of the oxide semiconductor film 3 It may be added to the conductive film 320.

[0444] Or B 2 H 6 , PH 3 , C.H. 4 , N 2 , N.H. 3 , AlH 3 , AlCl 3 , SiH 4 , Si 2 H 6 , F 2 , HF, and H 2 After adding one or more of the following, a rare gas is added to the oxide semiconductor film 3 It may be added to the conductive film 320.

[0445] The addition of impurity elements can be controlled by appropriately setting implantation conditions such as acceleration voltage and dose amount. For example, when adding argon by ion implantation, the acceleration voltage is 10 kV or more and 100 kV or less. V or less, dose is 1×10 13 ions / cm 2 More than 1×10 16 ions / cm 2 Below For example, 1×10 14 ions / cm 2 In addition, ion implantation When phosphorus ions are added using the injection method, the acceleration voltage is 30 kV and the dose is 1×10 13 ion s / cm 2 5×10 or more 16 ions / cm 2 For example, 1×10 15 ions / cm 2 This can be done as follows.

[0446] In this embodiment, argon is doped as an impurity element by using a doping device. The oxide semiconductor film 308 and the conductive film 320 are doped with fluorine. In the above embodiment, argon is added as an impurity element. However, the present invention is not limited to this. For example, nitrogen may be added. This does not have to be done.

[0447] Next, an insulating film 314 is formed over the insulating film 306, the oxide semiconductor film 308, and the conductive film 320. Note that by forming the insulating film 314, the oxide semiconductor film 3 in contact with the insulating film 314 is The insulating film 314 is connected to the source region 308s and the drain region 308d. In other words, the oxide semiconductor film 308 in contact with the insulating film 310 This results in a channel region 308i. 38A, an oxide semiconductor film 308 having a drain region 308d is formed. (See (B)).

[0448] The insulating film 314 is formed by selecting a material that can be used for the insulating film 314. In this embodiment, the insulating film 314 is formed by a PECVD apparatus. A 00 nm thick silicon nitride film is formed.

[0449] By using a silicon nitride film as the insulating film 314, the conductive film 3 20, hydrogen and nitrogen in the silicon nitride film in the source region 308s and the drain region 308d Either one or both of the elements penetrates into the conductive film 320, the source region 308s, and the drain region 308s. The carrier density in the in-region 308d can be increased.

[0450] Next, an insulating film 316 is formed on the insulating film 314 .

[0451] The insulating film 316 is formed by selecting a material that can be used for the insulating film 316. In this embodiment, the insulating film 316 is formed by a PECVD apparatus. A 00 nm thick silicon oxynitride film is formed.

[0452] Next, a mask is formed by lithography at a desired position on the insulating film 316, and then the insulating film 316 and a part of the insulating film 314 are etched to form an opening that reaches the source region 308s. An opening 341a and an opening 341b reaching the drain region 308d are formed (FIG. 38). (See (A) and (B)).

[0453] The method for etching the insulating film 316 and the insulating film 314 is a wet etching method. and / or dry etching can be appropriately used. The insulating film 316 and the insulating film 314 are processed by dry etching.

[0454] Next, a conductive film is formed on the insulating film 316 so as to cover the openings 341a and 341b. A mask is formed at a desired position by a lithography process, and then a part of the conductive film is etched. In this way, conductive films 312a and 312b are formed (see FIGS. 38(A) and (B)).

[0455] The conductive films 312a and 312b can be formed by using In this embodiment, the conductive films 312a and 312b are formed by selecting the material. Then, a titanium film with a thickness of 50 nm and an aluminum film with a thickness of 400 nm were deposited using a sputtering device. A laminate film of a 100 nm thick tungsten film and a 100 nm thick titanium film is formed.

[0456] The conductive films 312a and 312b can be processed by wet etching and / or dry etching. In this embodiment, a dry etching method is used. The conductive film is processed using the conductive film to form conductive films 312a and 312b.

[0457] Through the above steps, the transistor Tr1 can be manufactured.

[0458] The films (insulating film, oxide semiconductor film, conductive film, etc.) constituting the transistor Tr1 are Sputtering, Chemical Vapor Deposition (CVD), Vacuum Evaporation, Pulsed Laser Deposition (PLD) ) method, ALD (atomic layer deposition) method, or coating method or printing method. The film can be formed by a sputtering method, a plasma chemical vapor deposition method, etc. The most typical method is the plasma-enhanced chemical vapor deposition (PECVD) method, but the thermal CVD method may also be used. One example is the OCVD (metal organic chemical vapor deposition) method.

[0459] In the thermal CVD method, the pressure in the chamber is set to atmospheric pressure or reduced pressure, and the source gas and the oxidizing agent are simultaneously The reaction is carried out in the chamber near or on the substrate, where it is deposited on the substrate to form a film. As described above, the thermal CVD method is a film formation method that does not generate plasma. This has the advantage that defects are not generated due to damage.

[0460] In addition, in the ALD method, the pressure inside the chamber is set at atmospheric pressure or reduced pressure, and the source gas for the reaction is The film is formed by repeatedly introducing the gas into the chamber and reacting it. A reactive gas (such as argon or nitrogen) may be introduced as a carrier gas. For example, two types of At least one type of source gas may be supplied to the chamber in sequence. In order to avoid this, after the reaction of the first raw material gas, an inert gas is introduced, and then the second raw material gas is introduced. Alternatively, instead of introducing an inert gas, the first source gas is discharged by evacuation. After that, the second source gas may be introduced. The first source gas is adsorbed and reacted with the surface of the substrate. The first layer is formed, and the second source gas introduced later is adsorbed and reacted with the first layer. The order of gas introduction is controlled to obtain a thin film of the desired thickness. By repeating the process several times up to 1000 nm, a thin film with excellent step coverage can be formed. The thickness can be adjusted by repeating the gas introduction, allowing precise adjustment of the film thickness. This makes it suitable for fabricating miniaturized FETs.

[0461] Thermal CVD methods such as MOCVD can be used to form the above-mentioned conductive films, insulating films, oxide semiconductor films, and metal It is possible to form films such as oxide films. For example, when forming an In-Ga-Zn-O film, Trimethylindium (In(CH 3 ) 3 ), trimethylgallium (Ga(CH 3 ) 3 ), and dimethylzinc (Zn(CH 3 ) 2 ). Limited to these combinations. Instead of trimethylgallium, triethylgallium (Ga(C 2 H 5 ) 3 ) Dimethyl zinc can also be used instead of diethyl zinc (Zn(C 2 H 5 ) 2 ) can also be used. can.

[0462] For example, when forming a hafnium oxide film using a film forming apparatus that uses ALD, the solvent and liquids containing hafnium precursors (hafnium alkoxides and tetrakisdimethylamide Hafnium (TDMAH, Hf[N(CH 3 ) 2 ] 4 ) and tetrakis(ethylmethylamine C) Hafnium amide (e.g. hafnium) is vaporized as a raw material gas, and ozone is used as an oxidizer. (O 3 ) two types of gas are used.

[0463] For example, when forming an aluminum oxide film using an ALD deposition system, A liquid containing a catalyst and an aluminum precursor (trimethylaluminum (TMA, Al(CH 3 ) 3 ) and H as an oxidizing agent. 2 Two types of gases are used: O and O. The materials used are tris(dimethylamido)aluminum, triisobutylaluminum, Aluminum tris(2,2,6,6-tetramethyl-3,5-heptanedionate) There are some.

[0464] For example, when forming a silicon oxide film using a deposition system that uses ALD, Chlorodisilane is adsorbed on the surface to be coated, and oxidizing gas (O 2 , nitrous oxide) radicals The adsorbate is reacted with the adsorbate.

[0465] For example, when forming a tungsten film using a deposition system that uses ALD, the WF 6 Gas and B 2 H 6 Gases are introduced sequentially to form an initial tungsten film, and then WF 6 Gas and H 2 A tungsten film is formed using the gas B 2 H 6Instead of gas, SiH 4 G A suction cup may also be used.

[0466] For example, an oxide semiconductor film, such as In-Ga-Zn- When forming an O film, In(CH 3 ) 3 Gas and O 3 Forming an In-O layer using gas , then Ga(CH 3 ) 3 Gas and O 3 A GaO layer is formed using the gas, and then Z n(CH 3 ) 2 Gas and O 3 The ZnO layer is formed using the gas. The present invention is not limited to this example. In addition, In-Ga-O layers and In-Zn-O layers can be formed by using these gases. Alternatively, a mixed compound layer such as a Ga-Zn-O layer may be formed. 3 Change to gas Ar H obtained by bubbling water with an inert gas such as 2 O gas may be used, but it must not contain H. I O 3 It is preferable to use a gas.

[0467] Next, an insulating film 318 is formed over the insulating film 316 and the conductive films 312a and 312b.

[0468] The insulating film 318 can be formed by sputtering, CVD, vapor deposition, pulsed laser deposition ( The film can be formed by appropriately using a PLD method, a printing method, a coating method, or the like. In this case, a silicon nitride film having a thickness of 400 nm was deposited as the insulating film 318 using a PECVD apparatus. Then, a silicon oxynitride film having a thickness of 50 nm is formed.

[0469] After the insulating film 318 is formed, oxygen may be added to the insulating film 318. The oxygen added to 8 may be an oxygen radical, an oxygen atom, an oxygen atomic ion, or an oxygen molecular ion. The doping method includes ion doping, ion implantation, plasma treatment, etc. In addition, a film that suppresses oxygen desorption is formed on the insulating film, and then the insulating film is formed through the film. The film 318 may be doped with oxygen.

[0470] The above-mentioned oxygen desorption-suppressing film may be made of indium, zinc, gallium, tin, aluminum, or the like. Aluminum, chromium, tantalum, titanium, molybdenum, nickel, iron, cobalt, tungsten A metal element selected from the above, an alloy containing the above metal element, or a combination of the above metal elements. an alloy having the above-mentioned metal element, a metal nitride having the above-mentioned metal element, a metal oxide having the above-mentioned metal element, The insulating layer 11 is formed by using a conductive material such as a metal nitride oxide having the above-mentioned metal element. This can be done.

[0471] In addition, when oxygen is added in plasma treatment, the oxygen is excited by microwaves to produce high-density oxygen. By generating atomic plasma, the amount of oxygen added to the insulating film 318 can be increased. .

[0472] The silicon nitride film used as the insulating film 318 has a stacked structure. The silicon nitride film is a first silicon nitride film, a second silicon nitride film, and a third silicon nitride film. An example of the three-layer laminate structure is as follows: It can be formed into.

[0473] The first silicon nitride film is formed by, for example, silane at a flow rate of 200 sccm, PE-CV was performed using nitrogen at a flow rate of 100 sccm and ammonia gas at a flow rate of 100 sccm as source gas. The pressure in the reaction chamber was controlled to 100 Pa, and a 27.12 MHz high-frequency If a power of 2000 W is supplied using a frequency power supply and the thickness is formed to be 50 nm, good.

[0474] For the second silicon nitride film, silane at a flow rate of 200 sccm, The nitrogen gas and the ammonia gas with a flow rate of 2000sccm were used as raw material gases in the PECVD equipment. The pressure in the reaction chamber was controlled to 100 Pa, and a 27.12 MHz high-frequency power supply was used. A power of 2000 W may be supplied using the above method to form a film having a thickness of 300 nm.

[0475] The third silicon nitride film was prepared by using silane at a flow rate of 200 sccm and 5000 sccm. The pressure in the reaction chamber was kept at 100 The thickness was measured by controlling the temperature to 50 Pa and supplying 2000 W of power using a 27.12 MHz high frequency power source. It is sufficient to form it so that the thickness is 50 nm.

[0476] The first silicon nitride film, the second silicon nitride film, and the third silicon nitride film The substrate temperature during formation can be 350° C. or less.

[0477] By forming the insulating film 318 in a three-layered structure of silicon nitride films, for example, the conductive film 31 When a conductive film containing copper (Cu) is used for 2a and 312b, the following effects are obtained.

[0478] The first silicon nitride film suppresses the diffusion of copper (Cu) elements from the conductive films 312a and 312b. The second silicon nitride film has a function of releasing hydrogen and acts as a gate insulator. The third silicon nitride film can improve the breakdown voltage of the insulating film that functions as a first insulating film. The hydrogen release from the third silicon nitride film is small, and the hydrogen release from the second silicon nitride film is small. This can suppress the diffusion of hydrogen.

[0479] Next, an oxide semiconductor film 328 is formed over the insulating film 318 (see FIGS. 39A and 39B). .

[0480] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 3. The oxide semiconductor film 28 is formed using a wet etching apparatus.

[0481] Next, a conductive film is formed over the insulating film 318 and the oxide semiconductor film 328. The insulating film 318 is then processed into the shape shown in FIG. , forming insulating films 324 and 326 over the oxide semiconductor film 328 and the conductive films 322a and 322b. (See Figures 40(A) and (B)).

[0482] In this embodiment, the conductive films 322a and 322b are made of a tungsten film having a thickness of 50 nm. A 100 nm thick aluminum film and a 50 nm thick titanium film are stacked in this order. The layer film is formed by a sputtering method.

[0483] After the conductive films 322a and 322b are formed, the surface of the oxide semiconductor film 328 (back-cut The cleaning method may be, for example, cleaning with an etching solution such as phosphoric acid solution. As a result, the oxide semiconductor film 328 is washed with a cleaning agent. Impurities (such as elements contained in the conductive films 322a and 322b) can be removed. However, this cleaning is not always necessary, and in some cases, cleaning may not be necessary. .

[0484] In addition, either one of the steps of forming the conductive films 322a and 322b and the above-mentioned cleaning step may be performed. In either case, a region of the oxide semiconductor film 328 that is exposed from the conductive films 322a and 322b is But it may become thinner.

[0485] In this embodiment, a silicon oxynitride film having a thickness of 20 nm is used as the insulating film 324. 326, a silicon oxynitride film with a thickness of 200 nm was formed using the PECVD method. Complete.

[0486] After the insulating film 324 is formed, the insulating film 326 is successively formed without exposing it to the air. After the insulating film 324 is formed, the flow rate, pressure, and temperature of the source gas are controlled without exposing the insulating film 324 to the atmosphere. By adjusting one or more of the frequency power and the substrate temperature, the insulating film 326 is continuously formed. The concentration of impurities derived from atmospheric components can be reduced at the interface between the insulating film 324 and the insulating film 326. At the same time, oxygen contained in the insulating films 324 and 326 can be transferred to the oxide semiconductor film 328. As a result, the amount of oxygen vacancies in the oxide semiconductor film 328 can be reduced. .

[0487] In this embodiment, the insulating film 324 is formed by heating the substrate 302 at a temperature of 220° C. The source gases were silane at a flow rate of 50 sccm and dinitrogen monoxide at a flow rate of 2000 sccm. The pressure in the treatment chamber was set to 20 Pa, and the high frequency power supplied to the parallel plate electrodes was set to 13.56 M. Hz, 100W (power density is 1.6×10 -2 W / cm 2 ) PECVD method A silicon oxynitride film is formed using this.

[0488] The insulating film 326 is formed by depositing a substrate in a vacuum-evacuated processing chamber of a PECVD apparatus. The temperature is kept at 180°C or higher and 350°C or lower, and the raw material gas is introduced into the treatment chamber to increase the pressure in the treatment chamber. is set to 100 Pa or more and 250 Pa or less, and more preferably set to 100 Pa or more and 200 Pa or less. 0.17 W / cm2 at the electrode installed in the treatment chamber 2 More than 0.5W / cm 2 Below are some more Preferably 0.25W / cm 2 More than 0.35W / cm 2 The following high frequency power supply conditions are met: In this way, a silicon oxide film or a silicon oxynitride film is formed.

[0489] The deposition conditions for the insulating film 326 are as follows: high frequency power density in a reaction chamber with the above pressure. By supplying power, the efficiency of decomposing the source gas in the plasma increases, and the number of oxygen radicals increases. As the oxidation of the source gas progresses, the oxygen content in the insulating film 326 becomes lower than the stoichiometric composition. On the other hand, in the film formed at the above substrate temperature, the bonding strength between silicon and oxygen is Since the oxygen in the film is weak, some of the oxygen in the film is released by the heat treatment in the subsequent process. An oxide that contains more oxygen than satisfies the theoretical composition and loses some of the oxygen when heated. An insulating film can be formed.

[0490] In the step of forming the insulating film 326, the insulating film 324 serves as a protection film for the oxide semiconductor film 328. Therefore, the power density can be reduced while reducing damage to the oxide semiconductor film 328. The insulating film 326 can be formed using high radio frequency power.

[0491] In addition, in the film formation conditions of the insulating film 326, a deposition gas containing silicon is mixed with an oxidizing gas. By increasing the flow rate of the gas, it is possible to reduce the amount of defects in the insulating film 326. In the first place, ESR measurements revealed that the g value was 2.001, which is due to the dangling bonds of silicon. The spin density of the signal is 6×10 17 spins / cm 3 Less than 3 x 10 17 spins / cm 3 Less than or equal to 1.5×10 17 spins / cm 3 The following is a missing As a result, the signal strength of the transistor Tr2 is improved. It can increase reliability.

[0492] After the insulating films 324 and 326 are formed, a heat treatment (hereinafter referred to as a first heat treatment) is performed. The first heat treatment is preferably performed to remove nitrogen oxide contained in the insulating films 324 and 326. Alternatively, the first heat treatment can reduce the amount of oxides in the insulating films 324 and 326. Part of the oxygen contained in the oxide semiconductor film 328 is transferred to the oxide semiconductor film 328. This can reduce the amount of oxygen vacancies.

[0493] 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, preferably 10 ppb The reaction may be carried out under an atmosphere of air (see below) 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. Heat treatment is performed using an electric furnace, RTA (Rapid Thermal Anneal), etc. It is possible.

[0494] Next, an opening 382 is formed in a desired region of the insulating films 324 and 326, reaching the conductive film 322a. After that, a conductive film 330 is formed over the insulating film 326 and the conductive film 322a (FIG. 41). (See (A) and (B)).

[0495] The opening 382 is formed using a dry etching device or a wet etching device. The conductive film 330 is made of an oxide containing indium, tin, and silicon (I Target (In 2 O 3 :SnO 2 :SiO 2 =85:10:5[Weight %]) to form a 100 nm thick ITSO film, which is then processed into islands.

[0496] Through the above steps, the transistor Tr2 can be fabricated.

[0497] Next, an insulating film 326, an insulating film that will become an insulating film 334 on the conductive film 330, and an insulating film 336 are formed. Then, a laminated film is formed by applying a conductive film 330 to a desired region of the laminated film. An opening 384 is formed through the hole (see FIGS. 42(A) and (B)).

[0498] The insulating film 334 is a silicon oxynitride film having a thickness of 200 nm, which is deposited by using the PECVD method. The insulating film 336 is formed of a photosensitive acrylic resin having a thickness of 1.5 μm. A film is formed.

[0499] The opening 384 is formed using a dry etching device or a wet etching device. do.

[0500] Next, a conductive film is formed over the insulating film 336 and the conductive film 330, and the conductive film is processed into an island shape. In this way, a conductive film 338 is formed (see FIGS. 43(A) and (B)).

[0501] In this embodiment, the conductive film 338 is a 10 nm thick ITSO film and a 200 nm thick SiO2 film. A reflective metal film (here, a metal film having silver, palladium, and copper) with a thickness of 1 nm A laminated film with a 0 nm ITSO film is used. In addition, a wet etching process is used for processing the conductive film 338. An etching device is used.

[0502] Next, an island-shaped insulating film 340 is formed on the insulating film 336 and the conductive film 338 (FIG. 44(A) )(see B)).

[0503] The insulating film 340 is a photosensitive polyimide resin film having a thickness of 1.5 μm.

[0504] Next, the EL layer 342 is formed on the conductive film 338, and then the insulating film 340 and the EL layer 34 2, a conductive film 344 is formed on the substrate 30 to form a light emitting element 360 (FIGS. 45(A) and (B)). reference).

[0505] A method for forming the light emitting element 360 will be described in detail in the fifth embodiment.

[0506] Through the above steps, the semiconductor device 300 shown in FIGS. 30(A) and 30(B) can be formed.

[0507] Note that 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.

[0508] (Embodiment 4) In this embodiment, a semiconductor device and a manufacturing method of the semiconductor device according to one embodiment of the present invention will be described. The following description will be given with reference to Figures 46 to 53.

[0509] <4-1. Configuration example 1 of semiconductor device> FIG. 46A is a top view of a semiconductor device 400 of one embodiment of the present invention, and FIG. 46(A) corresponds to a cross-sectional view taken along the dashed line A1-A2 in FIG. FIG. 46B shows a cross section of the transistor Tr1 in the channel length (L) direction and The cross section of Tr2 in the channel length (L) direction is included.

[0510] The semiconductor device 400 shown in FIGS. 46(A) and 46(B) includes a transistor Tr1 and a transistor The transistor Tr1 and the transistor Tr2 are at least partially overlapped with each other. Both transistors Tr1 and Tr2 are top-gate transistors. do.

[0511] A region where the transistor Tr1 and the transistor Tr2 at least partially overlap each other is defined as By providing the transistor, the layout area can be reduced.

[0512] The transistor Tr1 is formed by an insulating film 306 on a substrate 302 and an oxide semiconductor layer on the insulating film 306. A semiconductor film 308, an insulating film 310 on the oxide semiconductor film 308, and a conductive film 32 on the insulating film 310. 0, an insulating film 306, an oxide semiconductor film 308, and an insulating film 314 over a conductive film 320. In addition, similarly to Embodiment 3, the oxide semiconductor film 308 overlaps with the conductive film 320. A channel region 308i contacting the insulating film 310 and a source region 308i contacting the insulating film 314 s and a drain region 308d in contact with the insulating film 314.

[0513] The transistor Tr1 includes an insulating film 316 on the insulating film 314 and an insulating film 314 and an insulating film 316 on the insulating film 314. The insulating film 316 is electrically connected to the oxide semiconductor film 308 through an opening 341a. The conductive film 312a connected to the insulating film 314 and the opening 341b provided in the insulating film 316 are The conductive film 312b is electrically connected to the oxide semiconductor film 308 through an insulating film 316. , and an insulating film 318 over the conductive film 312a and the conductive film 312b.

[0514] The transistor Tr2 includes a conductive film 312b and an insulating film 318 on the conductive film 312b. , the oxide semiconductor film 408 over the insulating film 318, and the insulating film 410b over the oxide semiconductor film 408. the conductive film 412b over the insulating film 410b; The oxide semiconductor film 40 is formed of an insulating film 414 similar to the oxide semiconductor film 308. 8 is a channel region 408i that overlaps with the conductive film 412b and is in contact with the insulating film 410b; A source region 408s in contact with the insulating film 414 and a drain region 408 d and.

[0515] The transistor Tr2 is provided on the insulating film 414 and on the insulating film 416. The conductive film 418a is electrically connected to the oxide semiconductor film 408, and the insulating film 416 is and a conductive film 418b which is electrically connected to the oxide semiconductor film 408.

[0516] As shown in FIGS. 46(A) and 46(B), the oxide semiconductor film 308 and the oxide semiconductor film 4 08 have an overlapping area.

[0517] The oxide semiconductor film 308 can have a structure similar to that described in Embodiment 3. The oxide semiconductor film 408 has a structure similar to that of the oxide semiconductor film 328 described in Embodiment 3. It can be said that:

[0518] Therefore, either or both of the transistors Tr1 and Tr2 Field effect mobility is 10 cm 2 / Vs, more preferably the transistors Tr1 and The field effect mobility of one or both of the transistors Tr2 is 30 cm 2 / Vs It will be possible to do so.

[0519] For example, the above-mentioned high field effect mobility transistor is By using this in the gate driver that generates the MOS transistors, a display device with a narrow frame width (also called a narrow frame) can be provided. In addition, the above-mentioned transistor having high field effect mobility can be effectively used in a display device. A source driver (especially a system having a source driver) that supplies signals from a signal line to the By using it as a demultiplexer connected to the output terminal of a soft register, It is possible to provide a display device having a small number of wirings. The transistor having a high resistance is used as a selection transistor and a driving transistor of a pixel circuit of a display device. To provide a display device with high display quality by using either one or both of the two sensors. can be done.

[0520] The semiconductor device 400 shown in FIGS. 46(A) and 46(B) is preferably used in a pixel circuit of a display device. By using the arrangement shown in FIG. 46(A)(B), the pixel density of the display device can be improved. For example, the pixel density of a display device can exceed 1000 ppi. Even when the pixel density of the display device exceeds 2000 ppi, ) the aperture ratio of the pixel can be increased.

[0521] When the semiconductor device 400 shown in FIG. 46(A)(B) is applied to a pixel circuit of a display device, In this case, the pixel circuit may have a configuration similar to that shown in FIG.

[0522] When the semiconductor device 400 shown in FIG. 46(A)(B) is applied to a pixel of a display device, For example, the channel length (L) and channel width (W) of a transistor For example, the width of the wiring and electrodes connected to the transistor can be made relatively large. In comparison with the case where transistors Tr1 and Tr2 are arranged on the same plane, As shown in (B), at least a part of the transistor Tr1 and the transistor Tr2 is By stacking the parts, it is possible to increase the line width, etc., thereby reducing the variation in processing dimensions. It is possible to reduce the

[0523] In addition, the transistor Tr1 and the transistor Tr2 each have a conductive film or an insulating film. One or both can be used in common, reducing the number of masks or steps. It is possible.

[0524] For example, in the transistor Tr1, the conductive film 320 functions as a gate electrode and The film 312a functions as a source electrode, and the conductive film 312b functions as a drain electrode. In addition, in the transistor Tr1, the insulating film 310 functions as a gate insulating film. In the transistor Tr2, the conductive film 312b functions as a first gate electrode and The conductive film 418a functions as a source electrode, the conductive film 418b functions as a drain electrode, and The conductive film 412b functions as a second gate electrode. The insulating film 318 functions as a first gate insulating film, and the insulating film 410b functions as a second gate insulating film. It functions as:

[0525] In this specification and the like, the insulating film 410b may be referred to as a fourth insulating film.

[0526] In addition, an insulating film 336 is provided over the insulating film 416 and the conductive films 418a and 418b. In addition, an opening 386 is provided in the insulating film 336, reaching the conductive film 418b. A conductive film 338 is provided on the insulating film 336. The conductive film 338 is provided in the opening 38. 6, it is connected to the conductive film 418a.

[0527] Moreover, an insulating film 340, an EL layer 342, and a conductive film 344 are provided on the conductive film 338. The conductive film 338, the EL layer 342, and the conductive film 344 constitute a light-emitting element 36. 0 is configured.

[0528] Although not shown in the drawings, the transistors Tr1 and The transistor Tr2 may have the S-channel structure described in the third embodiment.

[0529] In addition, the transistor Tr1 and the transistor Tr2 of the semiconductor device 300 shown in the third embodiment. It is possible to use it in combination with transistor Tr2.

[0530] As described above, a semiconductor device according to one embodiment of the present invention has a stacked structure including a plurality of transistors. The area required for installing the transistor is reduced. In addition, the insulating film and By using either one or both of the conductive films in common, the number of masks or the number of processes can be reduced. It can be reduced.

[0531] <4-2. Components of Semiconductor Device> Next, components included in the semiconductor device of this embodiment will be described in detail.

[0532] [Conductive film] The conductive films 412b, 418a, and 418b may be the conductive films described in embodiment 3 (conductive films 312a, conductive film 312b, conductive film 322a, conductive film 322b, conductive film 320, conductive film 3 30, conductive film 338, and conductive film 344) can be used. When an oxide conductor (OC) is used for 12b, oxygen can be added to the insulating film 410b. This is preferable.

[0533] [Insulating film] The insulating films 414, 416, and 410b may be the insulating films described in the third embodiment (insulating film 30 6, insulating film 314, insulating film 316, insulating film 318, insulating film 324, insulating film 326, insulating film The materials for the insulating film 334, the insulating film 336, and the insulating film 340 can be used.

[0534] The insulating film 318 is preferably an oxide insulating film because it is in contact with the oxide semiconductor film 408. A silicon oxide film or a silicon oxynitride film is preferable. It is preferable that b is an oxide insulating film, and the oxide insulating film contains oxygen in excess of the stoichiometric composition. It is more preferable that the insulating film 410b has a region having an oxygen content (excess oxygen region). It is preferable to use a silicon nitride film or a silicon oxynitride film.

[0535] The insulating film 414 contains either hydrogen or nitrogen, or both. The insulating film 414 contains nitrogen and silicon. The insulating film 414 also contains oxygen, hydrogen, water, and ammonia. It has the function of blocking alkali metals, alkaline earth metals, etc. Oxide semiconductor film 4 When the insulating film 414 is in contact with the insulating film 414, either hydrogen or nitrogen in the insulating film 414 is removed. At least one of them penetrates into the oxide semiconductor film 408, and the carrier density of the oxide semiconductor film 408 increases. Therefore, the oxide semiconductor film 408 and the insulating film 414 can be in contact with each other. A region in the oxide semiconductor film 408 functions as a source region or a drain region.

[0536] [Oxide semiconductor film] As the oxide semiconductor film 408, the oxide semiconductor film (oxide semiconductor The materials of the oxide semiconductor film 308 and the oxide semiconductor film 328 can be used.

[0537] <4-3. Manufacturing method of semiconductor device> Next, a manufacturing method of the semiconductor device 400 according to one embodiment of the present invention will be described with reference to FIGS. I will explain this in more detail.

[0538] In addition, Fig. 47(A), Fig. 48(A), Fig. 49(A), Fig. 50(A), Fig. 51(A), Fig. 52(A) and 53(A) are top views illustrating a method for manufacturing the semiconductor device 400. ,Figure 47(B),Figure 48(B),Figure 49(B),Figure 50(B),Figure 51(B),Figure 52( 53B) and FIG. 53B are cross-sectional views illustrating a method for manufacturing the semiconductor device 400.

[0539] The transistor Tr1 is manufactured by the method described in the third embodiment. Therefore, the insulating film 306, the oxide semiconductor film 308, the insulating film 309, and the 10, conductive film 320, insulating film 314, insulating film 316, conductive film 312a, conductive film 312b, The method for forming the insulating film 318 can be seen in Embodiment 3 and FIGS. stomach.

[0540] Next, an insulating film 318 is formed over the insulating film 316, the conductive film 312a, and the conductive film 312b. The insulating film 318 can be formed in the same manner as in the third embodiment.

[0541] Next, the oxide semiconductor film 408 is formed over the insulating film 318 (see FIGS. 47A and 47B). .

[0542] In this embodiment, an In-Ga-Zn metal oxide target (In:Ga:Zn=4: 2:4.1 [atomic ratio]) to form an oxide semiconductor film by sputtering. The substrate temperature during the formation of the oxide semiconductor film was set to 170° C., and the deposition gas during the formation was set to 1000 nm. The flow rate of oxygen gas is 60 sccm and the flow rate of argon gas is 140 sccm. Thereafter, the oxide semiconductor film is processed into a desired shape to obtain an island-shaped oxide semiconductor film 4. Note that a wet etching apparatus is used to form the oxide semiconductor film.

[0543] Next, a stack of an insulating film and a conductive film is formed over the insulating film 318 and the oxide semiconductor film 408. Thereafter, the laminated film is processed into a desired shape to form island-shaped insulating film 410b and island A conductive film 412b having a rectangular shape is formed (see FIGS. 48(A) and (B)).

[0544] After that, the insulating film 414 is formed over the insulating film 318, the oxide semiconductor film 408, and the conductive film 412b. By forming the insulating film 414, the oxide film in contact with the insulating film 414 is formed. The semiconductor film 408 becomes a source region 408s and a drain region 408d. The oxide semiconductor film 408 that is not in contact with the insulating film 414, in other words, the oxide semiconductor film 408 that is in contact with the insulating film 410b, The conductive film 408 becomes a channel region 408i. The oxide semiconductor film 408 having a source region 408s and a drain region 408d is formed. (See Figures 49(A)(B)).

[0545] In this embodiment, the insulating film 410b is a silicon oxynitride film having a thickness of 50 nm. The conductive film 412b is formed by using a PECVD apparatus. The oxide semiconductor film is formed by using a sputtering apparatus. The insulating film 414 has the same composition as the oxide semiconductor film 408. A silicon nitride film having a thickness of 0.00 nm is formed using a PECVD apparatus. For this purpose, a silicon oxynitride film having a thickness of 200 nm is formed using a PECVD apparatus.

[0546] By using a silicon nitride film as the insulating film 414, the conductive film 4 12b, hydrogen and ions in the silicon nitride film are formed in the source region 408s and the drain region 408d. Either or both of the nitrogen atoms enter the conductive film 412b, the source region 408s, and The carrier density in the drain region 408d can be increased. A portion of the conductive film 408 and the conductive film 412b become an oxide conductor (OC).

[0547] The insulating film 410b is formed in a self-aligned manner using the conductive film 412b as a mask.

[0548] Next, an opening 48 reaching the oxide semiconductor film 408 is formed in a desired region of the insulating films 414 and 416. 2a, 482b are formed (see Figures 49(A) and (B)).

[0549] The openings 482a and 482b are formed using a dry etching device or a wet etching device. A gadget is used.

[0550] Next, the insulating film 416 and the oxide semiconductor film 40 are 8, and the conductive film is processed into an island shape to form conductive films 418a and 418b. (See Figures 49(A) and (B)).

[0551] The conductive films 418a and 418b are a tungsten film having a thickness of 100 nm and a tungsten film having a thickness of 200 nm. A copper film having a thickness of 100 nm is formed by sputtering.

[0552] Through the above steps, the transistor Tr2 can be fabricated.

[0553] Next, the insulating film 336 is formed over the insulating film 416 and the conductive films 418a and 418b. Thereafter, a desired region of the insulating film 336 is processed to form an opening 386 reaching the conductive film 418a. (See Figures 50(A) and (B)).

[0554] In this embodiment, the insulating film 336 is a photosensitive acrylic resin having a thickness of 1.5 μm. A film is formed.

[0555] Next, a conductive film is formed over the insulating film 336 and the conductive film 418a, and the conductive film is processed into an island shape. In this way, a conductive film 338 is formed (see FIGS. 51(A) and (B)).

[0556] In this embodiment, the conductive film 338 is a 10 nm thick ITSO film and a 200 nm thick SiO2 film. A reflective metal film (here, a metal film having silver, palladium, and copper) with a thickness of 1 nm A laminated film with a 0 nm ITSO film is used. In addition, a wet etching process is used for processing the conductive film 338. An etching device is used.

[0557] Next, an island-shaped insulating film 340 is formed on the insulating film 336 and the conductive film 338 (FIG. 52(A) )(see B)).

[0558] The insulating film 340 is a photosensitive polyimide resin film having a thickness of 1.5 μm.

[0559] Next, the EL layer 342 is formed on the conductive film 338, and then the insulating film 340 and the EL layer 34 2, a conductive film 344 is formed on the substrate 30 to form a light emitting element 360 (FIGS. 53(A) and (B)). reference).

[0560] A method for forming the light emitting element 360 will be described in detail in the fifth embodiment.

[0561] Through the above steps, the semiconductor device 400 shown in FIGS. 46(A) and 46(B) can be manufactured.

[0562] Note that 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.

[0563] (Embodiment 5) In this embodiment, a light-emitting element that can be used in a semiconductor device of one embodiment of the present invention will be described. This will be explained with reference to Figures 54 to 56.

[0564] <5-1. Example of the configuration of light-emitting element> First, a structure of a light-emitting element that can be used in a semiconductor device of one embodiment of the present invention will be described with reference to FIG. 54 is a schematic cross-sectional view of the light-emitting element 160.

[0565] The light-emitting element 160 may be made of either an inorganic compound or an organic compound, or both. The organic compound used in the light-emitting element 160 may be a low molecular weight compound or Polymer compounds are thermally stable and can be easily applied uniformly by coating methods, etc. This is preferable because it allows the formation of a thin film with excellent uniformity.

[0566] The light-emitting element 160 shown in FIG. 54 has a pair of electrodes (conductive films 138 and 144). The EL layer 142 is provided between the pair of electrodes. It has a layer 150.

[0567] In addition, the EL layer 142 shown in FIG. 54 includes a hole injection layer 151, a hole transport layer 152, and a light emitting layer 150. The organic electroluminescent device has functional layers such as an electron transport layer 152 , an electron transport layer 153 , and an electron injection layer 154 .

[0568] In this embodiment, of the pair of electrodes, the conductive film 138 serves as an anode, and the conductive Although the film 144 will be described as a cathode, the configuration of the light emitting element 160 is not limited to this. That is, the conductive film 138 is a cathode, the conductive film 144 is an anode, and the layers between the electrodes are stacked. That is, from the anode side, the hole injection layer 151 and the hole transport layer 15 2, the light-emitting layer 150, the electron transport layer 153, and the electron injection layer 154 are laminated in this order. That's good.

[0569] The configuration of the EL layer 142 is not limited to the configuration shown in FIG. 54. In addition to the light-emitting layer 150, Among the hole injection layer 151, the hole transport layer 152, the electron transport layer 153, and the electron injection layer 154, Alternatively, the EL layer 142 may have at least one selected from the following: or reducing the barrier for injection of electrons; improving the transportability of holes or electrons; It has the function of inhibiting the transport of fluorine or suppressing the quenching phenomenon caused by electrodes. The functional layers may each be a single layer or a plurality of layers. The layer may be laminated.

[0570] The light-emitting layer 150 can include low molecular weight compounds and high molecular weight compounds.

[0571] In this specification and the like, a polymer compound is a compound having a molecular weight distribution and an average molecular weight of 1 ×10 3 〜1×10 8 A low molecular weight compound is a polymer having an average molecular weight of 1×10 4 The compound is as follows:

[0572] A polymer compound is a compound in which one or more structural units are polymerized. In other words, the structural unit refers to a unit that a polymer compound has one or more of.

[0573] The polymer compounds include block copolymers, random copolymers, alternating copolymers, graph copolymers, and The copolymer may be either a copolymer or a copolymer of the above-mentioned structure, or may be in another form.

[0574] When the end group of the polymer compound has a polymerization active group, the light-emitting device has light-emitting properties or brightness. Therefore, the end groups of polymer compounds should be stable. The stable terminal group is preferably a group that is covalently bonded to the main chain. A group that is bonded to an aryl group or a heterocyclic group via a carbon-carbon bond is preferred.

[0575] When a low molecular weight compound is used in the light emitting layer 150, the low molecular weight compound that functions as a host material In addition, it is preferable that the light-emitting layer 150 contains a light-emitting low-molecular-weight compound as a guest material. In the present embodiment, the host material is present in a larger amount by weight than the guest material, and the guest material is The material is dispersed in the

[0576] As the guest material, a light-emitting organic compound may be used. For example, a substance capable of emitting fluorescence (hereinafter also referred to as a fluorescent compound) or a substance capable of emitting phosphorescence is used. A substance capable of emitting phosphorescence (hereinafter also referred to as a phosphorescent compound) can be used.

[0577] In the light-emitting element 160 according to one embodiment of the present invention, a pair of electrodes (conductive film 138 and conductive film 1 44) By applying a voltage between the cathode and the anode, electrons flow from the cathode and holes flow from the anode. The electrons and holes are then injected into the EL layer 142, causing a current to flow. The recombination of carriers (electrons and holes) forms an exciton. The ratio of singlet excitons to triplet excitons (hereafter referred to as exciton generation probability) is The statistical probability is 1:3. Therefore, in a light-emitting element using a fluorescent compound, The rate of singlet excitons that contribute to light emission is 25%, and the rate of triplet excitons that do not contribute to light emission is 1. On the other hand, in the case of a light-emitting element using a phosphorescent compound, Both singlet and triplet excitons can contribute to light emission. Light-emitting elements using phosphorescent compounds have higher luminous efficiency than light-emitting elements using fluorescent compounds. This is preferable.

[0578] An exciton is a pair of carriers (electrons and holes). Therefore, the material in which the excitons are generated is in an excited state.

[0579] When a polymer compound is used in the light-emitting layer 150, the polymer compound has a hole The structure has a structure that transports holes (hole transport properties) and a structure that transports electrons (electron transport properties). Alternatively, it is preferable that the π-electron-rich heteroaromatic skeleton or the aromatic heteroaromatic skeleton be It is preferable that the compound has at least one amine skeleton and a π-electron deficient heteroaromatic skeleton. These backbones are linked either directly or through other backbones.

[0580] In addition, the polymer compound has a skeleton having a hole transporting property and a skeleton having an electron transporting property. In this case, it is possible to easily control the carrier balance. The bonding region can be easily controlled. To achieve this, a structure having a hole transport property and The ratio of the skeleton having electron transport properties to the structure is preferably in the range of 1:9 to 9:1 (molar ratio). and the proportion of the skeleton having the electron transporting property is higher than the proportion of the skeleton having the hole transporting property. Even more preferred.

[0581] The polymer compound has a structure including a skeleton having hole transport properties and a structure having electron transport properties. In addition to the skeleton having a light-emitting property, the polymer compound may have a light-emitting skeleton. In this case, the ratio of the light-emitting skeleton to the total structural units of the polymer compound is preferably low. Specifically, the content is preferably 0.1 mol % or more and 10 mol % or less, and more preferably is 0.1 mol % or more and 5 mol % or less.

[0582] The polymer compound used in the light emitting device 160 has a bond direction, a bond angle, and a bond In addition, each constituent unit may have a different substituent, and each constituent unit may have a different length. The structural units may have different skeletons between the two positions. Also, the polymerization method of each structural unit may be different. stomach.

[0583] The light-emitting layer 150 contains a polymer compound that functions as a host material and a low-luminescence The molecular compound may be used as a guest material. A light-emitting low molecular weight compound is dispersed as a guest material in the polymer compound, and the polymer compound is At least, it is present in a larger amount by weight than the luminescent low molecular weight compound. The content is preferably 0.1 wt% or more and 10 wt% or less in terms of weight ratio to the polymer compound. and more preferably, from 0.1 wt % to 5 wt %.

[0584] Next, components of a light-emitting element according to one embodiment of the present invention will be described in detail below.

[0585] [Light-emitting layer] Each of the materials that can be used for the light-emitting layer 150 is described below.

[0586] The polymer compound that can be used in the light-emitting layer 150 is not particularly limited, but may be a heteroaromatic It is preferable that the compound has at least one of an aromatic skeleton and an aromatic hydrocarbon skeleton. The skeletons are bonded to each other directly or via an arylene group or an alkylene group. The groups bonded via the above skeleton include arylene groups and alkylene groups. The present invention is not limited to the above-mentioned alkyl groups.

[0587] In addition, among the heteroaromatic skeletons possessed by polymer compounds, furan skeletons, thiophene skeletons, or Since the pyrrole skeleton is stable and reliable, any one of these skeletons is preferably used. It is preferable that the compound has one or more pyridine skeletons, diazine skeletons (pyrazine skeletons), etc. Preferred are diphenylamine skeletons, pyrimidine skeletons, pyridazine skeletons, and triazine skeletons. Azine skeletons and triazine skeletons are preferred because they are stable and reliable. , furan skeleton, benzofuran skeleton, dibenzofuran skeleton, benzodifuran skeleton, thiophene Thiophene skeleton, benzothiophene skeleton, dibenzothiophene skeleton, benzodithiophene skeleton, Enothiophene skeleton, dithienothiophene skeleton, dithienofuran skeleton, dithienoselenov Cyclopentadithiophene skeleton, cyclopentadithiophene skeleton, dithienosilole skeleton, thienopyrrole skeleton , dithienopyrrole skeleton, thienoindole skeleton, thienopyridine skeleton, thienopyrazine skeleton, thiazole skeleton, thiadiazole skeleton, benzothiazole skeleton, benzodithiazo oxazole skeleton, oxadiazole skeleton, benzoxazole skeleton, benzodiazole skeleton, Oxazole skeleton, selenophene skeleton, benzoselenophene skeleton, dibenzoselenophene skeleton, benzodiselenophene skeleton, selenoloselenophene skeleton, indacenothiophene skeleton Indacenodithiophene skeleton, indacenoselenophene skeleton, indacenodiselenophene skeleton Enene skeleton, pyrrole skeleton, indole skeleton, carbazole skeleton, indolocarbazole skeleton Bicarbazole skeleton, pyrrolopyrrole skeleton, acridan skeleton, acridone skeleton, phenanthroline skeleton Noxazine skeleton, phenothiazine skeleton, phenazine skeleton, phenazasiline skeleton, azepine The quinolinone skeleton, the julolidine skeleton, etc. can be used. Lysine skeleton, quinoxaline skeleton, quinazoline skeleton, phthalazine skeleton, cinnoline skeleton, proline skeleton Teridine skeleton, acridine skeleton, phenanthridine skeleton, phenanthroline skeleton, benzo Quinoline skeleton, benzoquinoxaline skeleton, benzoquinazoline skeleton, dibenzoquinoline skeleton , dibenzoquinoxaline skeleton, dibenzoquinazoline skeleton, imidazole skeleton, pyrazole skeleton, triazole skeleton, benzimidazole skeleton, imidazopyridine skeleton, purine skeleton A triazolopyrimidine skeleton, a triazolopyridine skeleton, an indazole skeleton, etc. can be used. This can be done.

[0588] Moreover, an aromatic hydrocarbon skeleton may be used in place of the heteroaromatic skeleton. Examples of the hydrogen hydride skeleton include a biphenyl skeleton, a naphthalene skeleton, an anthracene skeleton, and a chlo Ricenes, phenanthrene, triphenylene, fluorene, spirofluorene Examples of the skeleton include an indacene skeleton, an indacene skeleton, and a dibenzosilole skeleton.

[0589] In addition, aromatic amine structures can be used in polymer compounds, and in particular secondary amine structures. or a tertiary amine skeleton is preferred, and a triarylamine skeleton is particularly preferred. The aryl group of the amine skeleton is a substituted or unsubstituted aryl group having 6 to 13 carbon atoms forming a ring. The aryl group is preferably a phenyl group, a naphthyl group, a fluorenyl group, etc. For example, triphenylamine skeleton, phenylenediamine skeleton, naphthalenediamine skeleton, Examples include a benzoidine skeleton.

[0590] Other skeletons that can be used in polymer compounds include ketone skeletons and alkoxy skeletons. Examples include skeletons.

[0591] The aromatic amine skeleton, the heteroaromatic skeleton, and the aromatic hydrocarbon skeleton may be an aryl group. When the bond is formed via an arylene group or an alkylene group, the arylene group and the alkylene group are For example, a phenylene group, a biphenyldiyl group, a terphenyldiyl group, a naphthalenediyl group, diyl group, fluorenediyl group, anthracenediyl group, 9,10-dihydroanthracenediyl group, yl group, phenanthrenediyl group, pyrenediyl group, perylenediyl group, chrysenediyl group, alkoxyphenylene group, arylenevinylene group (phenylenevinylene group, etc.), vinyl In addition, ether bonds, thioether bonds, ester bonds, etc. Alternatively, they may be combined.

[0592] The aromatic amine skeleton, the heteroaromatic skeleton, and the aromatic hydrocarbon skeleton described above, or the above The arylene group and the alkylene group may each have a substituent. Examples of the alkyl group include an alkyl group, an alkoxy group, or an alkylthio group having 1 to 20 carbon atoms. a cycloalkyl group having 3 to 20 carbon atoms, or an unsubstituted or substituted cycloalkyl group having 6 to 18 carbon atoms; or an unsubstituted aryl group or aryloxy group, a heterocyclic compound having 4 to 14 carbon atoms The substituent may also be selected from alkyl groups having 1 to 20 carbon atoms. Specifically, the alkyl group includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and an isopropyl group. butyl, pentyl, hexyl, heptyl, octyl, decyl Examples of the aryl group include the aryl group, lauryl group, 2-ethylhexyl group, and 3-methylbutyl group. Specific examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, and an alkoxy group having 1 to 20 carbon atoms. oxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group aryloxy group, decyloxy group, lauryloxy group, 2-ethylhexyloxy group, 3-methyloxy group, Examples of the aryloxy group include a butyl-butoxy group and an isopropyloxy group. Specific examples of the alkylthio group having up to 20 carbon atoms include a methylthio group, an ethylthio group, a butylthio group, thio group, pentylthio group, hexylthio group, heptylthio group, octylthio group, decylthio group, Thio group, laurylthio group, 2-ethylhexylthio group, 3-methylbutylthio group, isoprene Further, a cycloalkyl group having 3 to 20 carbon atoms can be used. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, Cyclohexyl group, norbornyl group, noradamantyl group, adamantyl group, homoadamantyl group Also, examples of the alkyl group having 6 to 1 carbon atoms include a cycloalkyl group, a tricyclodecyl group, and a tricyclodecanyl group. Specific examples of the aryl group of 8 include substituted or unsubstituted phenyl, naphthyl, biphenyl, and the like. Examples include a phenyl group, a fluorenyl group, an anthracenyl group, and a pyrenyl group. Specific examples of the aryloxy group having 6 to 18 carbon atoms include substituted or unsubstituted aryloxy groups. Substituted alkoxyphenoxy groups, alkylphenoxy groups, naphthyloxy groups, anthracene groups Further, the aryloxy group having 4 to 10 carbon atoms and the pyrenyloxy group can be given as examples. Specific examples of the heterocyclic compound group of 14 include a substituted or unsubstituted thienyl group and a pyrrolyl group. In addition, the above-mentioned substituents may be bonded to each other to form a substituted or unsubstituted aryl group. An example of such a ring is, for example, a ring formed at the 9-position of the fluorene skeleton. When a compound has two phenyl groups as substituents, the phenyl groups are bonded to each other to form a compound having a structure similar to that of the compound of the present invention. In the case of no substitution, a spirofluorene skeleton is formed. It has advantages in terms of ease of synthesis and the cost of raw materials.

[0593] Examples of the polymer compound include poly[2-methoxy-5-(2-ethylhexyl Poly(2,5-phenylenevinylene) (abbreviation: MEH-PPV) Polyphenylenevinylene (PPV) derivatives such as dioctyl-1,4-phenylenevinylene Poly(9,9-di-n-octylfluorenyl-2,7-diyl) (abbreviation: PF8) , poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(benzoyl) zo[2,1,3]thiadiazole-4,8-diyl)] (abbreviation: F8BT), poly[(9 ,9-di-n-octylfluorenyl-2,7-diyl)-alt-(2,2'-bithio phen-5,5'-diyl)] (abbreviated as F8T2), poly[(9,9-dioctyl-2,7 -divinylenefluorenylene)-alt-(9,10-anthracene)], poly[(9, 9-Dihexylfluorene-2,7-diyl)-alt-(2,5-dimethyl-1,4- Polyfluorene derivatives such as poly(3-hexylthiophene-2,5-diphenylene) Polyalkylthiophene (PAT) derivatives such as polyphenylene (P3HT) In addition, these polymer compounds and poly(9-vinylcarbazole) derivatives are also included. Poly(2-vinylnaphthalene), poly[bis(4-phenyl)( 2,4,6-trimethylphenylamine (abbreviation: PTAA) and other polymer compounds. The light-emitting layer may be doped with a light-emitting low molecular weight compound.

[0594] The fluorescent compound that can be used in the light-emitting layer 150 is not particularly limited, but may be an anthracene compound. Helicene derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives Perylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxy For example, the following materials may be substituted: Preferably, a non-substituted material can be used. As the substituent, the above-mentioned substituents can be used. Moreover, an aliphatic hydrocarbon group is preferable, an alkyl group is more preferable, and an alkyl group is further more preferable. is a branched alkyl group.

[0595] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2 BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoro 1,6-Pyrene-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn) , N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H -fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMem FLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl )phenyl]-N,N'-bis(4-tert-butylphenyl)-pyrene-1,6-di Amine (abbreviation: 1,6tBu-FLPAPrn), N,N'-bis[4-(9-phenyl -9H-fluoren-9-yl)phenyl]-N,N'-diphenyl-3,8-dicyclo Hexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'- Bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstyrene Ben-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl )-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA ), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-an tolyl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4 -(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine ( Abbreviation: PCAPA), Perylene, 2,5,8,11-tetra(tert-butyl)perylene TBP, 4-(10-phenyl-9-anthryl)-4'-(9-phenyl -9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N ''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene ) Bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPA BPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-( 9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl- 1,4-Phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'', N'',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,1 0,15-Tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl (2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-an Tolyl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABP hA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl N-[9,10-bis(1, 1'-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1 ,4-Phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl) Phenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N- Phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenyl Nyl anthracene-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545 T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 2,8-di-t ert-Butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Nyltetracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl) 2-(2-(2-yl)-6,11-diphenyltetracene (abbreviation: BPT), -[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yl 2-(2-methyl-6-[(2-(2, 3,6,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl N,N,[4H-pyran-4-ylidene]propanedinitrile (abbreviation: DCM2) N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation :p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl) acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethylphenyl) Chil-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizine-9-yl DCJTI ), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3 ,6,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl ]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2 ,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4- 2-{2,6-bis[2-(8-phenylenediphenyl)propanedinitrile (abbreviation: BisDCM), -Methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5 H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene Propanedinitrile (abbreviation: BisDCJTM), 5,10,15,20-tetraphenyl Rubisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene Examples include, etc.

[0596] The luminescent skeleton that can be used in the polymer compound is not particularly limited, but may be an anthraquinone. Helicene, tetracene, chrysene, phenanthrene, pyrene, perylene, stilbene, acrylonitrile, From the skeleton of lysine, coumarin, phenoxazine, phenothiazine, etc., one or two It is preferable that the structural unit has a structure in which hydrogen has been removed from an aromatic ring. The above-mentioned substituents can be used. In addition, an aliphatic hydrocarbon group can be introduced as a substituent. It may be, preferably an alkyl group, more preferably a branched alkyl group.

[0597] The phosphorescent compounds include organometallic complexes of iridium, rhodium, or platinum, or Examples of iridium complexes include metal complexes, particularly organic iridium complexes, such as iridium orthometal complexes. The orthometalated ligands are 4H-triazole and 1H-triazole. Riazole ligands, imidazole ligands, pyridine ligands, pyrimidine ligands, pyrazine The metal complexes include porphyrin ligands and isoquinoline ligands. In addition, the following materials may be substituted or unsubstituted: The above-mentioned substituents can be used as the substituents. can be done.

[0598] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo {3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp) 3 ), tris(5-methyl-3,4-diphenyl-4H-1,2,4-trimethyl Riazolato)iridium(III) (abbreviation: Ir(Mptz) 3 ), Tris[4-(3- Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]i Iridium(III) (abbreviation: Ir(iPrptz-3b) 3 ), Tris[3-(5-biphenyl (phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]irid Ir(III) (abbreviation: Ir(iPr5btz) 3) Organometallic iridium complexes with tris[3-methyl-1-(2-methylphenyl)- 5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir( Mptz1-mp) 3 ), tris(1-methyl-5-phenyl-3-propyl-1H-1 ,2,4-Triazolate)iridium(III) (abbreviation: Ir(Prtz1-Me) 3 ) and fac-tris [1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole] Ir(iPrpmi) 3 ), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(II I) (Abbreviation: Ir(dmpimpt-Me) 3 ) Metal iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinato-N ,C 2’ ]Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr 6), Bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Iridescent ium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis( (trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) picol Ir(CF 3 ppy) 2 (pic)), bis[2-(4',6'-difluoro (O-phenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate( A phenylpyridine derivative having an electron-withdrawing group such as FIr(acac) is coordinated. Among the above, the organometallic iridium complexes with 4H-triazole skeletons are Organometallic iridium complexes having such properties are particularly preferred because they are highly reliable and have excellent luminous efficiency. .

[0599] In addition, examples of substances having a green or yellow emission peak include tris(4-methylphenyl) Ir(mppm) 3 ), Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm) 3 ), (acetylacetonato)bis(6-methyl-4-phenylpyridine Iridium(III) (abbreviation: Ir(mppm) 2 (acac)), (Acetyl ruacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium( III) (Abbreviation: Ir(tBuppm) 2 (acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation :Ir(nbppm) 2 (acac)), (acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm) 2 (acac)), (acetylacetonato)bis{4,6-dimethyl 2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl- κC}Iridium(III) (abbreviation: Ir(dmppm-dmp) 2 (acac)), ( Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Abbreviation: Ir(dppm) 2 Organometallic iridium with pyrimidine skeleton such as (acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine) G) Iridium(III) (abbreviation: Ir(mppr-Me) 2 (acac)), (Acetyl arylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinate)irid Ir(mppr-iPr) 2 Pyrazine bone such as (acac) Organometallic iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy) 3 ), Bis(2-phenylpyridinato-N ,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy) 2 (ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (Abbreviation: Ir(bzq) 2 (acac)), tris(benzo[h]quinolinato)iridium Ir(bzq) 3 ), tris(2-phenylquinolinato-N,C 2 ’ ) Iridium(III) (abbreviation: Ir(pq) 3 ), bis(2-phenylquinolinato- N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(pq) 2 (ac Organometallic iridium complexes with pyridine skeletons such as bis(2,4-difluorophenyl) and Venyl-1,3-oxazolato-N,C 2’) Iridium(III) acetylacetoner (abbreviation: Ir(dpo) 2 (acac)), bis{2-[4'-(perfluorophenyl (phenyl)pyridinato-N,C 2’}Iridium(III) acetylacetonate ( Abbreviation: Ir(p-PF-ph) 2 (acac)), bis(2-phenylbenzothiazol -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt) 2 (a In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenyl) Anthroline) terbium(III) (abbreviation: Tb(acac) 3 (Phen) Among the above, the organometallic iridium complexes having a pyrimidine skeleton are Dium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0600] Examples of substances having a yellow or red emission peak include diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II I) (Abbreviation: Ir(5mdppm) 2 (dibm)), bis[4,6-bis(3-methyl Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5mdppm) 2 (dpm)), bis[4,6-di(naphthalene-1-yl)pyrimidinyl] Nato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1npm) 2 ( Organometallic iridium complexes with pyrimidine skeletons such as (acetylacetamide) Iridium(III) r(tppr) 2 (acac)), bis(2,3,5-triphenylpyrazinate)(dipyridine) Valoylmethanato)iridium(III) (abbreviation: Ir(tppr) 2 (dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]i Iridium(III) (abbreviation: [Ir(Fdpq) 2 (acac)]) Organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C 2 ’ ) Iridium(III) (abbreviation: Ir(piq) 3 ), bis(1-phenylisoquinol) Nat-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq) 2 In addition to organometallic iridium complexes with pyridine skeletons such as (acac)), 2,3, 7,8,12,13,17,18-Octaethyl-21H,23H-porphyrin platinum ( II) (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3 -propanedionato)(monophenanthroline)europium(III)(abbreviation:Eu( DBM) 3 (Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoro Acetonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA) 3 Among the above, pyrimidine skeleton complexes such as rare earth metal complexes are also useful. Organometallic iridium complexes, which have excellent reliability and luminescence efficiency, are particularly In addition, organometallic iridium complexes having a pyrazine skeleton emit red light with good chromaticity. is obtained.

[0601] The phosphorescent compound may be a polymer compound, for example, iridium, rhodium, Organometallic complexes of cadmium or platinum, or polymers having metal complexes as structural units Compounds such as organometallic complexes of iridium, rhodium, or platinum are preferred. The structural unit is a structure in which one or two hydrogen atoms have been removed from a metal complex or a compound. It is preferable to do so.

[0602] The light-emitting organic compound contained in the light-emitting layer 150 is a compound that converts triplet excitation energy into light. As a substance capable of converting the triplet excitation energy into luminescence, In addition to phosphorescent compounds, thermally activated delayed fluorescence (TFA) compounds are also used. delayed fluorescence (TADF) bodies. The term "phosphorescent compound" may be replaced with "thermally activated delayed phosphor." In addition, a thermally activated delayed fluorescent substance is a substance that has a triplet excitation energy level and a singlet excitation energy level. The difference between the triplet excited state and the singlet excited state is small, and reverse intersystem crossing transfers energy from the triplet excited state to the singlet excited state. Therefore, it is possible to convert the triplet excited state into a small amount of thermal energy. Therefore, upconversion (reverse intersystem crossing) to a singlet excited state is possible. In addition, thermally activated delayed fluorescence can be efficiently obtained. The conditions for this are the energies of the triplet excited energy level and the singlet excited energy level. The difference is preferably greater than 0 eV and not greater than 0.2 eV, and more preferably greater than 0 eV and not greater than 0 The optical density is 0.1 eV or less.

[0603] As the thermally activated delayed phosphor, for example, the following substances can be used.

[0604] First, fullerene and its derivatives, acridine derivatives such as proflavine, and eosin are listed. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S n), platinum (Pt), indium (In), or palladium (Pd) Examples of the metal-containing porphyrin include protoporphyrin. Fluorine-tin fluoride complex (SnF 2 (Proto IX)), mesoporphyrin-fluoride Tin complex (SnF 2 (Meso IX)), hematoporphyrin-tin fluoride complex (Sn F 2 (Hemato IX), coproporphyrin tetramethyl ester-tin fluoride Complex (SnF 2 (Copro III-4Me)), Octaethylporphyrin-fluoride Tin complex (SnF 2 (OEP)), etioporphyrin-tin fluoride complex (SnF 2 (E tio I), octaethylporphyrin-platinum chloride complex (PtCl 2 OEP) etc. Can be obtained.

[0605] In addition, as a thermally activated delayed fluorescent material composed of one type of material, π-electron-rich heteroaromatic Heterocyclic compounds having a ring and a π-electron deficient heteroaromatic ring can also be used. , 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a ]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2 -{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazole -9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCC zPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6 -Diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl (phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl -1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9 H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), Bis[4-(9,9-dimethyl-acridan)phenyl]sulfone (abbreviation: DMAC-D PS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthra The heterocyclic compound has a π electron Electron-transporting and hole-transporting properties due to the presence of π-electron-deficient heteroaromatic rings In addition, the π-electron rich heteroaromatic ring and the π-electron deficient heteroaromatic ring are directly bonded to each other, and thus the π-electron rich heteroaromatic ring is preferably bonded to each other. The compound synthesized exhibits the donor property of π-electron-rich heteroaromatic rings and the acceptor property of π-electron-deficient heteroaromatic rings. The difference between the singlet and triplet excited energy levels is small. Therefore, it is particularly preferable.

[0606] In addition, materials that exhibit thermally activated delayed fluorescence include exciplexes (exciplexes, exciplexes, It involves the combination of two materials that form a composite (also called an exciplex or exciplex). The combination of two materials may be a combination of a hole transporting material and an electron transporting material. Specifically, in addition to zinc and aluminum metal complexes, oxadiazo derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, diazole derivatives, Benzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidinium azine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline Other examples include aromatic amines and carbazole derivatives. Can be obtained.

[0607] The light-emitting layer 150 contains a compound that functions as a host material and a light-emitting guest compound. In addition to the compound functioning as the material, other substances may be included. For example, the following hole transporting Substituted or unsubstituted materials of the electron transporting material and the electron transporting material can be used. As the substituent, the substituents already mentioned can be used.

[0608] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. ×10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. The compounds are made using aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. The hole transport material may be a polymer compound. Hole transporting skeletons of polymer compounds, π-electron rich heteroaromatic skeletons, aromatic amines It may be a polymer compound having a skeleton.

[0609] As examples of materials with high hole transport properties, aromatic amine compounds include N,N' -Di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDP PA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino ]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl) Amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-di Amine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl Examples include]-N-phenylamino]benzene (abbreviation: DPA3B).

[0610] Specific examples of carbazole derivatives include 3-[N-(4-diphenylamino phenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1 ), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9 -Phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl [N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation :PCzTPN2), 3-[N-(9-phenylcarbazol-3-yl)-N-phenyl 3,6-bis[N- (9-Phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazol PCzPCA2, 3-[N-(1-naphthyl)-N-(9-phenylcarbazone] carbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) etc. can be mentioned.

[0611] Another example of a carbazole derivative is 4,4'-di(N-carbazolyl)biphene. Nyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzoyl Zene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]- 9H-Carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl] nyl)-2,3,5,6-tetraphenylbenzene and the like can be used.

[0612] As the aromatic hydrocarbon, for example, 2-tert-butyl-9,10-di(2- naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10- Di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene DPPA, 2-tert-butyl-9,10-bis(4-phenylphenyl) phenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene Helical (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-Butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4- Methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9, 10-Bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1 -naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di( 1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene 9,9'-bianthryl, 10,10'-diphenyl-9,9'- Bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl , 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9' -Bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11- Tetra(tert-butyl)perylene, etc. In addition, pentacene, coro Years and years can also be used. In this way, 1×10 -6 cm 2 Hole mobility above / Vs It is more preferable to use an aromatic hydrocarbon having 14 to 42 carbon atoms.

[0613] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl. (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl ]anthracene (abbreviation: DPVPA), etc.

[0614] In addition, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenylphosphine) nylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl Amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis Polymer compounds such as Poly(phenyl)benzidine (abbreviation: Poly-TPD) can also be used. can.

[0615] As a material with high hole transport properties, for example, 4,4'-bis[N-(1-naphthyl )-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD) and N,N'-biphenyl S(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4 '-Diamine (abbreviation: TPD), 4,4',4''-tris(carbazol-9-yl) Triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphthalene 1'-TNATA, 4,4'-N-phenylamino]triphenylamine ,4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA ), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino] Triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'- Bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4- Phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: B PAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenyl mBPAFLP, N-(9,9-dimethyl-9H-fluorene-2- yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl- 9H-Fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H-fluorenyl) Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl N-phenylaminophenyl)spiro-9,9'-bifluorene (abbreviation: D PASF), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl) PCBA1BP, 4,4'-diphenyl-4''-(9-phenyl) (phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP ), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl) Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-( 9-Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNB) B) 4-phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine N,N'-bis(9-phenylcarbazol-3-yl)- N,N'-Diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N',N ''-Triphenyl-N,N',N''-tris(9-phenylcarbazol-3-yl) ) Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl)- N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carba PCBiF, N-(1,1'-biphenyl-4-yl)- N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl 9,9-Dimethyl-N- Phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluor PCBAF, N-phenyl-N-[4-(9-phenyl- 9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluorene-2-amine PCBASF, 2-[N-(9-phenylcarbazol-3-yl)-N- Phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bis [N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'- Bifluorene (abbreviation: DPA2SF), N-[4-(9H-carbazol-9-yl)fluorene N,N'-phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), Bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F) Also, 3-[4-(1-naphthyl)-phenyl]-9-phenyl can be used. -9H-Carbazole (abbreviation: PCPN), 3-[4-(9-phenanthryl)-phenyl PCPPn, 3,3'-bis(9- phenyl-9H-carbazole) (abbreviation: PCCP), 1,3-bis(N-carbazolyl )benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nylcarbazole (abbreviation: CzTP), 3,6-di(9H-carbazol-9-yl)- 9-Phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-di(9H-carbazole) 4-{3-[3-( 9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation Name: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl 1,3,5-tri(dibenzofuran) (abbreviation: DBF3P-II), Thiophen-4-yl)-benzene (abbreviation: DBT3P-II), 2,8-diphenyl- 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene DBTFLP-III, 4-[4-(9-phenyl-9H-fluorene-9 -yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDB TPTp-II) and other amine compounds, carbazole compounds, thiophene compounds, furan compounds Compounds, fluorene compounds, triphenylene compounds, phenanthrene compounds, etc. The substances mentioned here are mainly 1×10 -6 cm 2 / Vs or higher hole mobility However, other materials that have a higher hole transporting property than electron transporting property can be used. It may be used.

[0616] As the electron transport material, a material having a higher electron transporting property than a hole transporting property can be used. ×10 -6 cm 2 It is preferable that the material has an electron mobility of 1 / Vs or more. Nitrogen-containing heteroaromatic compounds are examples of materials that are easy to absorb (materials with electron transport properties). A π-electron deficient heteroaromatic compound or a metal complex can be used. Quinoline, benzoquinoline, oxazole, or thiazole ligands Metal complexes having the above-mentioned oxadiazole derivatives and triazole derivatives are also included. , phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, etc. The electron transporting material may be a polymer compound. Polymer compounds with electron-transporting skeletons and π-electron-deficient heteroaromatic skeletons It can be an object.

[0617] For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tri Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq 3 ), B BeBq 2 ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum ( III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation...

Claims

1. A first insulating film on a substrate; a first semiconductor film having a region in contact with an upper surface of the first insulating film and having a first channel formation region of a first transistor; a second insulating film on the first semiconductor film; a first conductive film provided on the second insulating film and functioning as a first gate electrode of the first transistor; a second conductive film having a region in contact with an upper surface of the first insulating film and functioning as a first gate electrode of a second transistor; a second semiconductor film provided on the second insulating film and having a second channel formation region of the second transistor; a third conductive film provided over the second semiconductor film and functioning as a second gate electrode of the second transistor; a third insulating film on the third conductive film; a fourth conductive film provided over the third insulating film and functioning as one of a second source electrode and a second drain electrode of the second transistor; a fifth conductive film provided on the third insulating film and functioning as the other of the second source electrode and the second drain electrode of the second transistor; a fourth insulating film on the fourth conductive film and the fifth conductive film; a light emitting element on the fourth insulating film, the fourth conductive film is electrically connected to the second semiconductor film through a first opening provided in the third insulating film; the fifth conductive film is electrically connected to the second semiconductor film through a second opening provided in the third insulating film; one of the fourth conductive film and the fifth conductive film is electrically connected to a first electrode of the light-emitting element; the second semiconductor film includes an oxide semiconductor; The second channel formation region does not overlap with the first channel formation region.

2. a first conductive film on a substrate; a first insulating film on the first conductive film; a first semiconductor film having a region in contact with an upper surface of the first insulating film and having a first channel formation region of a first transistor; a second conductive film having a region in contact with an upper surface of the first semiconductor film and functioning as a first source electrode and a first drain electrode of the first transistor; a second insulating film on the first semiconductor film; a third conductive film provided on the second insulating film and functioning as a first gate electrode of the first transistor; a fourth conductive film having a region in contact with an upper surface of the first insulating film and functioning as a first gate electrode of a second transistor; a second semiconductor film provided on the second insulating film and having a second channel formation region of the second transistor; a fifth conductive film provided over the second semiconductor film and functioning as a second gate electrode of the second transistor; a third insulating film on the fifth conductive film; a sixth conductive film provided over the third insulating film and functioning as one of a second source electrode and a second drain electrode of the second transistor; a fourth insulating film on the sixth conductive film; a light emitting element on the fourth insulating film, the sixth conductive film is electrically connected to the second semiconductor film through a first opening provided in the third insulating film; the sixth conductive film is electrically connected to a first electrode of the light emitting element; the composition of the second semiconductor film is different from the composition of the first semiconductor film; the second channel formation region does not overlap with the first channel formation region.

Images